View PDF

0163-769X/04/$20.00/0 Printed in U.S.A.

Endocrine Reviews 25(5):831– 866 Copyright © 2004 by The Endocrine Society doi: 10.1210/er.2003-0031

11␤-Hydroxysteroid Dehydrogenase Type 1: A TissueSpecific Regulator of Glucocorticoid Response JEREMY W. TOMLINSON, ELIZABETH A. WALKER, IWONA J. BUJALSKA, NICOLE DRAPER, GARETH G. LAVERY, MARK S. COOPER, MARTIN HEWISON, AND PAUL M. STEWART Endocrinology, Division of Medical Sciences, University of Birmingham, Queen Elizabeth Hospital, Edgbaston, Birmingham B15 2TH, United Kingdom 11␤-Hydroxysteroid dehydrogenase type 1 (11␤-HSD1) interconverts inactive cortisone and active cortisol. Although bidirectional, in vivo it is believed to function as a reductase generating active glucocorticoid at a prereceptor level, enhancing glucocorticoid receptor activation. In this review, we discuss both the genetic and enzymatic characterization of 11␤-HSD1, as well as describing its role in physiology and pathology in a tissue-specific manner. The molecular basis of cortisone reductase deficiency, the putative “11␤-HSD1 knockout state” in humans, has been defined and is caused by intronic mutations in HSD11B1 that decrease gene transcrip-

tion together with mutations in hexose-6-phosphate dehydrogenase, an endoluminal enzyme that provides reduced nicotinamide-adenine dinucleotide phosphate as cofactor to 11␤HSD1 to permit reductase activity. We speculate that hexose6-phosphate dehydrogenase activity and therefore reduced nicotinamide-adenine dinucleotide phosphate supply may be crucial in determining the directionality of 11␤-HSD1 activity. Therapeutic inhibition of 11␤-HSD1 reductase activity in patients with obesity and the metabolic syndrome, as well as in glaucoma and osteoporosis, remains an exciting prospect. (Endocrine Reviews 25: 831– 866, 2004)

I. Introduction II. Cortisol Metabolism and History of 11␤-HSD1 III. Short-Chain Dehydrogenases/Reductases (SDRs) and Enzymology of 11␤-HSD1 A. The SDR superfamily B. 11␤-HSD1 enzymology C. Substrate specificity and inhibitors of 11␤-HSD1 D. Selective inhibitors IV. Molecular Biology of 11␤-HSD1 A. Cloning of 11␤-HSD1 cDNAs B. Human HSD11B1 gene C. Recombinant models of 11␤-HSD1 V. Localization and Ontogeny of 11␤-HSD1 A. Localization B. Ontogeny and sexual dimorphic expression VI. Regulation of 11␤-HSD1 Expression VII. Role of 11␤-HSD1 in Normal Physiology and Pathophysiology in Peripheral Tissues A. Kidney, colon, and skin

B. Liver and adipose tissue C. Fetoplacental tissues D. Cardiovascular system E. Gonad F. Central nervous system and pituitary G. Bone H. Eye I. Malignant tissues J. Immune tissues K. Other tissues VIII. CRD A. Clinical features B. Molecular basis for CRD and directionality of 11␤-HSD1 IX. HSD11B1 Linkage and Association Studies A. Obesity B. Other diseases X. Conclusions

Abbreviations: allo-THF, ␣-Tetrahydrocortisol; BMI, body mass index; CBX, carbenoxolone; CDCA, chenodeoxycholic acid; C/EBP, CAAT/enhancer binding protein; CRD, cortisone reductase deficiency; ER, endoplasmic reticulum; GHD, GH deficiency; GR, glucocorticoid receptor; HPA, hypothalamo-pituitary-adrenal; H6PDH, hexose-6phosphate dehydrogenase; 11␤-HSD1, 11␤-hydroxysteroid dehydrogenase type 1; IOP, intraocular pressure; MR, mineralocorticoid receptor; NADP, nicotinamide-adenine dinucleotide phosphate; NADPH, reduced NADP; NNK, nitrosamine 4-methylnitrosamino-1-(3-pyridyl)-1butanone; NPE, nonpigmented epithelial cells; PCOS, polycystic ovary syndrome; PEPCK, phosphoenol pyruvate carboxykinase; SDR, shortchain dehydrogenases/reductases; SNP, single-nucleotide polymorphism; TB, tuberculosis; Th1 and Th2, T helper cell type 1 and 2; THE, tetrahydrocortisone; THF, tetrahydrocortisol; UFE, urinary free cortisone; UFF, urinary free cortisol; WHR, waist-to-hip ratio. Endocrine Reviews is published bimonthly by The Endocrine Society (http://www.endo-society.org), the foremost professional society serving the endocrine community.

I. Introduction

T

WO ISOZYMES OF 11␤-hydroxysteroid dehydrogenase (11␤-HSD1 and 11␤-HSD2) catalyze the interconversion of hormonally active cortisol and inactive cortisone. Although the type 1 or “liver” isozyme was the first to be characterized, it was the type 2 or “kidney” isozyme that gained most acclaim in the late 1980s to mid-1990s because of its link to an inherited monogenic form of hypertension, apparent mineralocorticoid excess. The physiology and pathophysiology of 11␤-HSD2 and its link to human hypertension have been covered in this Journal in an excellent review by White et al. (1). The last decade has seen an exponential increase in research focusing on 11␤-HSD1, principally because of its putative role in human obesity and insulin resistance, but also 831

832

Endocrine Reviews, October 2004, 25(5):831– 866

in other diseases in which glucocorticoids have historically been implicated (osteoporosis, glaucoma). These clinical studies have been underpinned by studies in vitro and the manipulation of enzyme expression in vivo using recombinant mouse models. Finally, the molecular basis for the putative human 11␤-HSD1 knockout— cortisone reductase deficiency (CRD)— has recently been described, an observation that also answers a long-standing conundrum relating to the enzymology of 11␤-HSD1.

II. Cortisol Metabolism and History of 11␤-HSD1

Functionally, adrenal corticosteroids have been divided into two distinct classes, glucocorticoids and mineralocorticoids. Glucocorticoids (cortisol, corticosterone) exert a diverse array of physiological roles including the regulation of carbohydrate and amino acid metabolism, maintenance of blood pressure, and modulation of the stress and inflammatory responses (2). In contrast, mineralocorticoids (aldosterone) principally stimulate epithelial sodium transport (3). Both classes of corticosteroid hormone exert their effects through binding to intracellular receptors [glucocorticoid and mineralocorticoid receptors (GR, MR)] with subsequent stimulation or repression of target gene transcription. Cortisol is the principal circulating glucocorticoid in man and is secreted under the control of the hypothalamo-pituitary-adrenal (HPA) axis. Aldosterone, which is secreted from the outer zona glomerulosa predominantly under the control of the renin-angiotensin system through angiotensin II, is the principal mineralocorticoid in man. Glucocorticoids are secreted in relatively high amounts [cortisol, 15 mg/d (4, 5), corticosterone, 2 mg/d (6)] and mineralocorticoids are secreted in low amounts [aldosterone, 150 ␮g/d (7)]. More than 90% of circulating cortisol is bound, predominantly to the ␣2-globulin, cortisol-binding globulin. Only the free fraction is biologically active; the excretion of this “free” cortisol through the kidneys is termed urinary free cortisol (UFF) and represents only 1% of the total cortisol secretion rate. The circulating half-life of cortisol varies between 70 and 120 min. The major steps for cortisol metabolism are: 1. The interconversion of the 11-hydroxyl (cortisol, Kendall’s compound F) to the 11-oxo group (cortisone, compound E) through the activity of 11␤-hydroxysteroid dehydrogenase (EC 1.1.1.146) (8, 9). The metabolism of cortisol and cortisone then follow similar pathways. 2. Reduction of the C4 –5 double bond to form dihydrocortisol (DHF) or DHE followed by hydroxylation of the 3-oxo group to form tetrahydrocortisol (THF) and tetrahydrocortisone (THE). The reduction of the C4 –5 double bond can be carried out by either 5␤-reductase or 5␣-reductase to yield, respectively, 5␤-THF (THF) or 5␣-THF (allo-THF) (10). In normal subjects, the 5␤-metabolites predominate (5␤-THF: 5␣-THF, 2:1). THF and THE are rapidly conjugated with glucuronic acid and excreted in the urine (11). 3. Additional reduction of the 20-oxo group by either 20␣or 20␤-HSD to yield ␣- and ␤-cortols and cortolones from cortisol and cortisone, respectively. Reduction of the C-20 position may also occur without A ring reduction giving rise to 20␣- and 20␤-hydroxycortisol (12).

Tomlinson et al. • 11␤-HSD1

4. Hydroxylation at C-6 to form 6␤-hydroxycortisol. 5. Cleavage of THF and THE to the C19 steroids 11hydroxy- or 11-oxo-androsterone or etiocholanolone. 6. Oxidation of the C-21 position or cortols and cortolones to form the extremely polar metabolites cortolic and cortolonic acids (13). Approximately 50% of secreted cortisol appears in the urine as THF, allo-THF, and THE; 25% as cortols/cortolones; 10% as C19 steroids; and 10% as cortolic/cortolonic acids. The remaining metabolites are free, unconjugated steroids (cortisol, cortisone, 6␤- and 20␣/20␤-metabolites of cortisol and cortisone) (14). Although some cortisone may be secreted by the adrenal (15), circulating cortisone concentrations are principally dependent upon “oxidative” 11␤-HSD2 and are approximately one fifth those of cortisol (⬃60 nmol/liter). However, because of the lower binding affinity to cortisol-binding globulin, free cortisone concentrations are similar to those of free cortisol (16, 17). The biological activity of any glucocorticoid relates, in part, to the presence of a hydroxyl group at position C-11 of the steroid structure. Cortisol and the principal glucocorticoid in rodents, corticosterone, are active steroids whereas cortisone and 11-dehydrocorticosterone, possessing a C-11 keto group, are inactive. Thus, any tissue expressing 11␤HSDs can regulate the exposure of that tissue to “active” glucocorticoid. In retrospect, the first appreciation of 11␤-HSD activity came through the discovery by Kendall (18) of cortisone and elucidation of its potent antiinflammatory activity in patients with rheumatoid arthritis. Unbeknownst to him at the time, he had discovered an “inactive” hormone; bioactivity was dependent upon 11␤-HSD activity in the liver, activating cortisol from cortisone. Subsequently, cortisol was characterized as the active ligand, and shortly thereafter the first description of tissues converting cortisol to cortisone was published. These early studies demonstrated significant amounts of 11␤-HSD activity in human placenta (19), kidney (20), and liver (21), although the “set point” of the enzyme varied, with oxidative activity (F to E) predominating in the placenta and kidney and reductive (E to F) in the liver. Isotopic studies (22) and clinical studies measuring F/E levels in patients with renal disease (23, 24) confirmed that the kidney was an important site for cortisol to cortisone conversion. Selective venous catheterization studies indicated significantly lower circulating F/E ratios in renal venous blood compared with peripheral values. In contrast, circulating F/E ratios were much higher in hepatic venous blood, confirming that the liver predominantly converts cortisone to cortisol (25). This is explained by the activity of two distinct isozymes of 11␤-HSD, a predominantly reductive nicotinamide-adenine dinucleotide phosphate reduced (NADPH)-dependent type 1 or “liver” isozyme and a NADdependent oxidative type 2 or “renal” isozyme. The contributions of these isozymes to global cortisolcortisone interconversion can be assessed clinically through gas chromatographic/mass spectrometry analysis of the principal urinary cortisol and cortisone metabolites. Thus, the ratio of UFF/urinary free cortisone (UFE) accurately reflects the activity of renal 11␤-HSD2. If this ratio is normal,



then the ratio of urinary tetrahydrocortisols (5␣-THF or alloTHF and 5␤-THF) to tetrahydrocortisone (THE) is a useful marker of 11␤-HSD1 activity (26). Other workers extend this ratio to include all cortisol and cortisone metabolites (Fm/Em ratio: THF, allo-THF, cortols, cortisol/THE, cortolones, and cortisone) (27–30). III. Short-Chain Dehydrogenases/Reductases (SDRs) and Enzymology of 11␤-HSD1 A. The SDR superfamily

11␤-HSD1 belongs to the SDR superfamily, a well-established enzyme family of oxidoreductases, distinct from zinccontaining alcohol dehydrogenases (31, 32), iron-containing dehydrogenases (32), aldoketo-reductases (33), and medium-chain dehydrogenases/reductases (34). Also known as short-chain alcohol dehydrogenases (35) or sec (secondary) alcohol dehydrogenases (36), members of this family were originally classified as having 250 –300 residues (classical family) with an N-terminal cofactor-binding domain and a centrally located active site, although some enzymes now have more than 400 residues (extended family) (37). These families are now distinguished further into three subfamilies (intermediate, divergent, and complex), based on patterns of charged residues within the cosubstrate-binding region (38). At present, around 3000 members of this family have been identified through the occurrence of several distinct sequence motifs highlighted in Table 1 (35, 37– 41). These primary structure features form essential parts of the nucleotide cofactor-binding region (Rossmann-fold) and the active site (37, 40). The nucleotide cofactor-binding region characterized by GXXXGXG confers specificity to NADPH and is highly conserved within the family (40), although the presence of dehydratase and epimerase reactions utilizing other cofactors within the family explains why many of the residues found in the motifs are not completely conserved within the entire family (37). The active site of these enzymes contains invariant tyrosine (Y) and lysine (K) residues, although adjacent serine (S) residues are also highly conserved, and this denotes the catalytic triad. An analysis of 116 active site motifs in SDR family members from the SWISS-PROT database showed that 48% contain the YZX(S/T)K motif, 30% contain the Y(S/T)X(S/T)K motif, and 14% contain the Y(S/T)XZK motif where X is any residue and Z denotes residues other than serine (S) or threonine (T) (42). This catalytic triad of residues has recently been extended to a tetrad as recent data have supported the concept that Asn111 is essential and TABLE 1. Sequence motifs identifying SDR superfamily members Region

Motif

Location

12–19 86 – 89 111 132–139 152–156 182–183

TGXXXGXG NNAG N GXXXXXXS YXXXK PG

Cofactor-binding site Cofactor-binding site Contacts to active site Part of active site Part of active site Proximity to cofactor

Sequence numbering taken from 3␣/20␤HSD from Streptomyces hydrogenans (40).

833

highly conserved in most SDR forms (41, 43). The regions likely to confer specificity are less well conserved, such as the potential substrate binding loop (between the ␤F strand and the ␣ G helix), and regions in the C-terminal segment (44, 45). The crystal structures of 27 members of the family have been reported, and their atomic coordinates have been deposited in the Protein Data Bank. All share a nearly superimposable protein-folding arrangement of ␣-helices and ␤-strands (␣ ⫺ ␤ ⫺ ␣ ⫺ ␤ ⫻ 2) to form a Rossmann fold for cofactor binding (46), although this similarity is not present in the substratebinding pocket (47). A comparison between the conformations of five SDR crystal structures (bacterial 3␣-, 20␤-HSD, human 17␤-HSD1, bacterial 7␣-HSD, mouse dihydropteridine reductase, and mouse lung carbonyl reductase) revealed that although there are only 11 fully conserved amino acid residues common to the five structures, the threedimensional conformation is highly conserved (48). The ␣-helix F interface of human 11␤-HSD1 has been modeled on the crystal structure of Streptomyces hydrogenans 20␤-HSD and has identified similar residues in type 1 that are important in the stabilization of the dimer of 20␤-HSD (49). B. 11␤-HSD1 enzymology

1. Kinetic analyses. From the pioneering studies of White and colleagues (50) and Monder and co-workers (51, 52) an 11␤HSD was purified from rat liver, and an antiserum was raised against the protein and used to clone a rat cDNA although the cDNA sequence was subsequently updated in 2002 (53). This enzyme is microsomal (54), and activity is nicotinamideadenine dinucleotide phosphate (NADP) dependent; in the cell-free system it behaved mainly as a dehydrogenase, and no reductase activity was detected in the purified preparation. Subsequently, this enzyme was named 11␤-HSD1. Homogeneous enzyme gave rectilinear Eadie plots and MichaelisMenten (Km) constants of 1.83 ⫾ 0.06 ␮m for corticosterone and 17.3 ⫾ 2.24 ␮m for cortisol. First-order rate constants were one order of magnitude higher for corticosterone than cortisol, but maximal velocities were similar (52). Subsequently, cDNAs and proteins were published for the human (55), mouse (56), squirrel monkey (57), sheep (58), rabbit (54), pig, cow, and guinea-pig (59, 60) 11␤-HSD1. Human liver 11␤-HSD1 was eventually purified in an active form and was postulated to exist as a dimer (61). The value of the Km determined for 11␤-HSD1 dehydrogenase activity is puzzling given that it is more than two orders of magnitude higher than the circulating level of free cortisol (1–100 nm). Maser et al. (61, 62) discovered an unusual kinetic mechanism of action of the human liver 11␤-HSD1. They determined that this isoform exhibits Michaelis-Menten kinetics with respect to cortisol but cooperative kinetics with cortisone. In this way, 11␤-HSD1 could operate at both nanomolar and micromolar substrate concentrations. However, using recombinant purified guinea pig and human proteins, no evidence for cooperative kinetics has been found (60). Mouse liver 11␤-HSD1 has been shown to accept nicotinamide-adenine dinucleotide (NAD) as well as NADP as cofactor (63, 64). Guinea pig liver 11␤-HSD1 has been shown to have equal affinity for cortisone and cortisol with apparent Km value in intact cells for both substrates being 3 ␮m (59) and the pu-

834



rified protein exhibiting a Km value for cortisone of 0.8 ␮m (60). A summary of the published kinetic analyses of 11␤HSD1 in differing species is given in Table 2. In original purification studies, 11␤-HSD1 in the liver was TABLE 2. Species- and tissue-specific apparent Km values for 11␤-HSD1 Species

Tissue

Apparent Km (␮ M )

Substrate

Ref.

F B F

108 52

0.3 2.3 0.1 0.06

E F B A

51

1.92 14.6 5.9 0.89

B A B A

51 171 287

Rat Rat

Liver Liver microsomes

Rat

Liver microsomes

Rat Rat Rat

Liver Hepatocytes Leydig cells

Mouse

Liver microsomes

0.56 0.34 0.22 0.18

B F A E

64

Mouse

Liver

1.7 0.7

B A

63

Pancreatic islets of Langerhans Squirrel monkey Liver

0.09

A

338

1.9 0.3

F B

57

Guinea pig Guinea pig

Liver microsomes Liver microsomes

1.2 3.0 3.0

E F E

370 59

Ovine

Liver microsomes

8.0 0.95

F E

109

Ovine Ovine

Liver Placenta

1.6 12.0 4.0

F F E

179 234

Human Human

Decidua Liver microsomes

2.0 2.5 9.5

F E F

152 371

Human

Liver microsomes

1.4 0.98

E F

93

Human Human

Hepatocytes Liver

E E F A B

171 61

Human Human

Bone Granulosa-lutein cells

4.2 0.49

F F

307 264

2.6

F

2.8

F

0.27

E

Mouse

Human

Omental preadipocytes

16.4 1.8 17.3

0.4 13.9 41.3 19.7 42.8

372

A, 11-Dehydrocorticosterone; B, corticosterone; E, cortisone; F, cortisol.

shown to be bidirectional, although, in contrast with its dehydrogenase activity, the reductase activity was unstable in vitro (52). A series of studies subsequently demonstrated that the enzyme acts as a reductase unless cells are disrupted (65, 66). Importantly, when intact cell systems, including primary cultures of hepatocytes (67), fibroblasts (68), adipose stromal cells (69, 70), lung (71), and cultured hippocampal cells (72), were studied, 11␤-HSD1 activity was reductive in nature. This is supported by kinetic analysis of the enzyme as in vitro this enzyme has a higher affinity for E (Km 0.3 ␮m) than F (Km 2.1 ␮m), suggesting that the enzyme acts predominantly as a reductase in vivo, thereby generating F (55, 73). However, in a few studies, 11␤-dehydrogenase activity has been reported in intact cell preparations, with the direction of 11␤HSD1 catalysis appearing to vary according to physiological or developmental status of a particular cell type. In Leydig cells, both 11␤-dehydrogenase and oxoreductase activities have been reported (74 –76). Freshly isolated cells display dehydrogenase activity that dramatically decreases after several days’ culture in vitro. However, others have found predominant 11␤-reduction (77). In human omental adipose stromal cells, 11␤-HSD1 switches from a dehydrogenase to a reductase when these cells differentiate into adipocytes (78). In neuronal cells, 11␤-HSD1 reductase and dehydrogenase activities have been reported (79, 80). These findings indicate a possible important role for 11␤-HSD1 dehydrogenase activity in normal physiology, with the relative contribution of the dehydrogenase and reductase activities being important in controlling the overall equilibrium of local glucocorticoid levels (81). In every case, however, when cells are disrupted or the enzyme purified, reductase activity is lost. This striking change in directionality between intact cells and homogenates seems to reflect the specific intracellular localization of 11␤-HSD1 within the lumen of the endoplasmic reticulum (ER), where neighboring enzymes may be powerful generators of the reduced cosubstrate NADP phosphate (NADPH). Indeed, studies using purified human enzyme have shown that the equilibrium constant for the E to F direction (defined as the concentration of products divided by concentration of reactants) is 0.03. Given that a figure of 1 would represent the exact equilibrium position, a value of 0.03 indicates a strong preference toward dehydrogenase (F to E) activity (82). Reductase activity can be regained from tissue homogenates and purified enzyme, upon inclusion of a NADPH regeneration system employing the cytosolic enzyme glucose-6-phosphate dehydrogenase (82, 83). This suggests that reductase activity predominates in intact cells due to a high level of NADPH present within the ER lumen. Recently, it has been shown that the enzyme hexose6-phosphate dehydrogenase (H6PDH) serves this crucial role in generating NADPH levels in the ER (84) (Fig. 1A) (see Section VIII.B). 2. Protein structure. 11␤-HSDs can be separated from most other members of the SDR family due to the presence of one or more amino-terminal transmembrane domains. Other members of the SDR family that possess this secondary structure characteristic include some 17␤-HSD isozymes and follicular variant translocation protein isozymes. There is a high



835

FIG. 1. A, Schematic representation of the interaction between 11␤-HSD1 and H6PDH, which provides NADPH as cofactor to permit reductase (cortisone to cortisol) activity. GT, Glucose-6-phosphate translocase; G6P, glucose-6-phosphate; 6PG, 6-phosphogluconolactonate. B, Three-dimensional structure and localization of 11␤-HSD1 within the lumen of the ER.

level of sequence homology between species (Fig. 2), particularly within the cofactor-binding region (GASKGIG) and the catalytic site (YSASK). The 11␤-HSD1 protein has a single hydrophobic N-terminal extension preceding the cofactorbinding domain, suggesting that this region anchors the protein in microsomes. The precise topology of 11␤-HSD1 was demonstrated using 11␤-HSD1 constructs with attached FLAG epitopes at the N- and C-terminal regions (85). The protein was shown to be intrinsic to the membrane of the ER, having a short five-amino acid region on the cytosolic side of the membrane, followed by a single transmembrane domain (Fig. 1B) and the majority of the enzyme residing in the lumen of the ER. Chimeric proteins, where the N-terminal regions from 11␤-HSD1 and 11␤-HSD2 were exchanged, led to inverted orientation within the ER. Both chimeric proteins were inactive (85). Within the single N-terminal transmembrane region, the charge distribution of two positively charged lysine residues on the cytoplasmic side and two negatively charged glutamate residues suggests these are

crucial residues in the orientation of 11␤-HSD1 in the ER membrane. Mutation analysis of Lys5 residue suggests that it is critical in the determination of 11␤-HSD1 topology and that its charge and specific side chain are both important (85). The importance of the transmembrane domain upon 11␤HSD1 activity has been studied, but with conflicting results. An N-terminally truncated variant of rat 11␤-HSD1 was expressed in COS cells and reported to be inactive (86, 87). However, this construct encoded a protein that had lost more than just the transmembrane helix, and may, therefore, have lost vital parts of the enzymatic domain. In addition, these expression studies were performed in COS and Chinese hamster ovary cells, where the truncated protein would have been targeted (because of the lack of signal sequence) to the cytosol and not the ER. The lumen of the ER promotes the formation of disulfide bonds, and studies have indicated that there are important intrachain disulfide bonds within the 11␤-HSD1 protein (54). Extraction of the enzyme from the cells by sonication or the addition of fusion proteins to

836



FIG. 2. Alignment of 11␤-HSD1 amino acid residues across species. The dark gray shading represents primary consensus sequence (identical amino acids), light gray shading indicates the secondary consensus sequences (groups amino acids with similar chemical structures), and white shading represents amino acids that vary by chemical structure across species. Boxed residues indicate the cofactor binding region (GxxxGxG) and the catalytic site (YxxxK). The large double arrow highlights the residues proposed to form the dimer interface. The small double arrows highlight putative N-linked glycosylation sites (alignment created using GeneDoc program, UK).


the C terminus (88) possibly disrupting the conformation of the protein structure to the detriment of enzyme activity (47) could also account for the reported requirement of the Nterminal region for activity. However, analysis of 11␤-HSD1 constructs expressed in Escherichia coli demonstrated enzyme activity from an N-terminus-deleted construct, with activity levels even higher than those observed for the full-length 11␤-HSD1 construct (82). The importance of glycosylation upon 11␤-HSD1 activity has been variously reported. Examination of the 11␤-HSD1 peptide sequence revealed the presence of two potential Nlinked glycosylation sites in the cloned rat enzyme (asparagine-X-serine, residues 158 –160 and 203–205) consistent with the original description of the purified rat hepatic 11␤HSD1 as a glycoprotein (52). Interestingly, studies in the vaccinia expression system showed that although partial inhibition of glycosylation decreased dehydrogenase activity by 50%, it did so without affecting reductase activity (83). The relative importance of the two glycosylation sites was further investigated in a mutagenesis study in Chinese hamster ovary cells. Modification of the first site decreased dehydrogenase and reductase activities to 75 and 50% of the wild type, whereas mutation of the second site caused an almost complete abolition of both activities (89). These findings show that in the rat, glycosylation of 11␤-HSD1 at N203 plays a major role, and at N158 a minor role in catalysis, and are consistent with the incomplete conservation of the corresponding residues between species. Conflicting studies on the human enzyme have also been reported. Within the human sequence, there are three putative glycosylation sites. The Asn-X-Ser sites are at positions 123–125, 162–164, and 207–209 of the protein. Human 11␤-HSD1 has been expressed in E. coli, where the biosynthesis of N-linked glycoproteins does not occur. This resulted in a recombinant protein that was completely devoid of enzyme activity (90). The same group also investigated the effects of deglycosylation on human 11␤-HSD1 purified from liver and recombinant protein produced by the yeast Pichia pastoris (91). Sitedirected mutagenesis of the three potential glycosylation sites yielded an inactive protein from yeast cells as assessed using metyrapone and metyrapol as the substrates. However, the enzyme purified from human liver, upon complete deglycosylation, remained fully active. In support of this finding, recent data conclusively show fully active nonglycosylated 11␤-HSD1 enzyme activity generated in E. coli, with kinetic properties for both dehydrogenase and reductase activities similar to those reported in mammalian systems (82). These data suggest that glycosylation is not required for correct protein folding or enzyme activity of the human 11␤-HSD1. Studies carried out on the rabbit enzyme, which, like the human homolog, contains three potential glycosylation sites, also suggest that glycosylation is not important for enzyme activity (54). Glycosylation of 11␤HSD1, however, may still play a role in preventing protein aggregation, in addition to stabilizing the overall structure within the ER. The sequence of the guinea pig 11␤-HSD1 predicts only one N-glycosylation site (59), but the functional significance of this has not been investigated.


837

C. Substrate specificity and inhibitors of 11␤-HSD1

Numerous studies have been directed toward understanding the effects of various steroid moieties upon 11␤-HSD1 activity because any factors that inhibit metabolism of the 11␤-hydroxyl group will increase glucocorticoid potency. Most studies appear to have been performed with tissue extracts containing 11␤-HSD1 (9). In essence, a substrate for 11␤-HSD1 possesses a flat A/B ring junction (5␣), with the 5␤ conformation disallowed; bulky groups on the ␣-surface inhibit binding, although the effect of ␣-halogens appears to be inductive rather than steric; an aromatic A ring is forbidden, and steroids with bulky groups at C-21 are not substrates. Data indicate the importance of the structural conformation of the A and B rings because modifications to these can confer specific inhibitory properties on some steroidal compounds (92). C ring deoxysteroids, such as chenodeoxycholic acid (CDCA), can also be inhibitors for 11␤-HSD1 (93). Many mammalian steroid dehydrogenases, including 11␤HSD1, have been implicated in the detoxification of molecules in addition to roles in steroid metabolism (94 –96). In addition to its important endocrinological involvement in glucocorticoid metabolism, 11␤-HSD1 mediates the phase I biotransformation of several carbonyl group-bearing foreign compounds, including xenobiotics (64), drugs (97, 98), insecticides (99, 100), and carcinogens (101, 102). The reductive metabolism of xenobiotic compounds such as metyrapone, p-nitroacetophenone, and p-nitrobenzaldehyde (64) allows the formation of a hydroxyl group rendering the toxic substrate more hydrophilic and more likely to be conjugated by glucuronidation or sulfation facilitating excretion (103). 11␤HSD1 exhibits other protective roles with the inactivation of carcinogen, nitrosamine 4-methylnitrosamino-1-(3-pyridyl)1-butanone (NNK), to its secondary metabolite, 4-methylnitrosamino-1-(3-pyridyl)-1-butanol (102), the metabolism of the antineoplastic agent, oracin, into its active metabolite, 11-dihydrooracin (97, 104), the conversion of the nonsteroidal antiinflammatory prodrug, 5,5-dimethyl-3-(3-fluorphenyl)4-(4-methysulfonyl)phenyl-2-(5H)-furanone-lactol, to its active lactone form (98), and the detoxification of antiinsect agents (azole analogs of metyrapone) (100). Inhibitors may have properties different from these. An exhaustive list of inhibitors has been compiled and includes steroids with C-21 and 2␣-methyl substituents (9). The most commonly used inhibitor for in vitro studies and of clinical relevance are the licorice derivatives, glycyrrhizic acid, its hydrolytic product glycyrrhetinic acid, and the hemisuccinate derivative carbenoxolone (CBX). Glycyrrhetinic acid is a potent inhibitor of 11␤-HSD1 (both competitive and inhibiting 11␤-HSD1 mRNA levels) (105, 106), and, in addition, inhibits 11␤-HSD2 with an inhibition constant (Ki) of 5–10 nm (73, 107). Far fewer steroids have been shown to be inhibitors of 11-oxidoreduction, and obligatory functional groups have not been assigned. Reduction at C-20 eliminates inhibitory activity, but the specific configuration of side chains is not critical as androgens are also potent inhibitors (108). Because the protein sequence of 11␤-HSD1 is not identical between species, subtle differences in protein conformation may lead to differences in substrate or inhibitor efficacy. Indeed, CBX

838



displays little inhibition of ovine 11␤-HSD1 (109), although it inhibits both oxoreductase and dehydrogenase activities in human liver microsomes (93). Clinical studies in subjects consuming glycyrrhetinic acid vs. CBX also suggest that CBX is an inhibitor of 11␤-HSD1 in vivo (110, 111). Prednisolone and prednisone are substrates for 11␤-HSD1 (112, 113). 9␣-Fluorinated steroids, such as dexamethasone, are metabolized by 11␤-HSD2 (114) but may also be regenerated by 11␤-HSD1 (115). The inhibitory effects of progesterone, glycyrrhetinic acid, and related compounds on 11␤HSD1 have been reported, and 5␣ - and 5␤-adrenocorticoids inhibit 11␤-HSD1. Bile acids are potent inhibitors with lithocholic acid exerting the strongest effect (116). In intact cells 11␣-hydroxyprogesterone is a more potent inhibitor of 11␤HSD1 than glycyrrhetinic acid or 11␤-hydroxyprogesterone (117, 118). D. Selective inhibitors

To date, there are few inhibitor compounds reported to be specific for 11␤-HSD1. As mentioned earlier, a variety of bile acids have inhibitory effects on 11␤-HSD1 with lithocholic acid and CDCA reported as the most potent. However, only CDCA has been shown to be selective for 11␤-HSD1 oxoreductase and dehydrogenase activities (93). The antidiabetic arylsulfonamidothiazole compounds have been shown to inhibit 11␤-HSD1 both in vivo and in vitro (119 –121). The diethylamide derivative was shown to inhibit human 11␤HSD1 with an IC50 of 52 nm, and an N-methylpiperazinamide form (BVT.2733: 3-chloro-2-methyl-N-{4-[2-(methyl-1-piperazinyl)-2-oxoethyl]-1,3-thiazol-2-yl} benzenesulfonamide) was shown to be specific for the mouse enzyme (IC50 of 96 nm). In the hyperglycemic mouse strain KKA(y), the compound BVT.2733 lowered hepatic phosphoenol pyruvate carboxykinase (PEPCK) and glucose-6-phosphatase mRNA, blood glucose, and serum insulin concentrations (121), raising the possibility that inhibition of 11␤-HSD1 might be used therapeutically to treat patients with insulin resistance (see Section VII.B.3). IV. Molecular Biology of 11␤-HSD1 A. Cloning of 11␤-HSD1 cDNAs

The first mammalian 11␤-HSD to be cloned was a cDNA from rat liver, isolated using an antiserum raised against the purified protein (50 –52, 122). Initial analysis indicated an 861-bp open reading frame encoding a protein of 288 amino acids. Later, a cDNA library derived from human testis was probed using the rat 11␤-HSD cDNA, and clones were isolated (55). The human cDNA of approximately 1.4 kb in length predicted an open reading frame of 876 bp and a protein of 292 amino acids, which was 77% identical at the amino acid level to the rat enzyme (Fig. 2). Subsequently, 11␤-HSD1 cDNAs have been cloned for a number of species including sheep (58), squirrel monkey (57), mouse (56), baboon (123), and guinea pig (59). Interestingly, and possibly unique among mammalian species, is the Australian koala, which appears to be devoid of 11␤-HSD1 activity in its liver. A study suggests that this may be due to the absence of a gene

encoding 11␤-HSD1 activity homologous to that of other known species (124). Alternate 11␤-HSD1 mRNA transcripts, as a result of differential promoter usage and alternate splicing mechanisms, have been demonstrated. In rat kidney, liver, and lung, a transcript initiated from an intron 1 promoter uses methionine 27 in exon 2 as a new start codon, maintaining the reading frame, and has been designated 11␤-HSD1B (86, 87). However, expression of the truncated enzyme did not produce a soluble protein in its native form in cells (87) but was found to be active once released from the ER membrane when overexpressed in yeast (125). However, the precise role of this truncated form is not clear. Additional studies have also revealed a third putative 11␤-HSD1 congener in the sheep arising as the result of the deletion of exon 5 (126). The reading frame is maintained from exon 4 into exon 6, with the loss of 48 amino acids, which includes the catalytic domain (126). Again, no functional significance has been attributed to this transcriptional variant. The three proteins are now referred to as 11␤-HSD1A, 11␤-HSD1B, and 11␤HSD1C, respectively. The message for 11␤-HSD1B is restricted to the kidney in the rat and parallels the developmental expression of 11␤-HSD1A mRNA (127). At present, there is no evidence that 11␤-HSD1C exhibits enzymatic activity toward glucocorticoids. However, the association of 11␤-HSD1A with carbonyl reductase activity in mouse liver suggests that it may act on substrates including xenobiotics (128, 129). Of note, an expressed sequence tag expressed in human pregnant uterus has been described that represents 11␤-HSD1C; however, the significance and validity of this finding remains unclear (130). B. Human HSD11B1 gene

Hybridization of the human 11␤-HSD1 cDNA to a humanhamster hybrid panel localized the single HSD11 gene to chromosome 1 (subsequently refined to chromosome 1q32.2– 41). Genomic clones of HSD11 were isolated from a chromosome 1-specific library, again using the cDNA as a probe (55). The human gene has been designated HSD11B1 and consists of six exons (182, 130, 111, 185, 143, and 617 bp, respectively) and five introns (776, 767, 120, 25,300, and 1,700 bp, respectively) (Fig. 3). Originally, the HSD11B1 gene was thought to be approximately 9 kb in size; however, the isolation and analysis of a PAC clone containing the entire human HSD11B1 gene revealed that intron 4 spans approximately 25 kb, expanding the gene size to 30 kb (131). Primer extension analysis using human liver RNA indicated that transcription initiates 93 bp upstream from the start of translation, yielding a 5⬘-untranslated region similar in length to that of rat 11␤-HSD1 mRNA. There is no TATA box in the 5⬘-flanking region, but there is a consensus CAAT box 76 bp upstream of the start of transcription (55). To date, there are few reports describing polymorphism in and around the HSD11B1 locus. A scan of the GenBank single-nucleotide polymorphism (SNP) database (db SNP at http://www.ncbi.nim.nih.gov/SNP/) reveals a number of documented sequence variations detected primarily through human genome-sequencing projects (and our unpublished



839

FIG. 3. Organization of the human 11␤-HSD1 gene. Open boxes indicate the 5⬘- and 3⬘-untranslated regions, gray shaded boxes indicate coding exons (1– 6), and intervening solid lines indicate introns (dashed line of intron 4 is 25 kb and is not to scale). The NADP⫹ cofactor-binding domain GASKGIG motif in exon 2 and catalytic domain motif YSASK in exon 5 are indicated.

observations). All but one polymorphism is located in noncoding regions of the gene; 31 SNPs are within intron 4, one SNP is located in the 3⬘-untranslated region, and seven SNPs are located within 2 kb of the mRNA transcript (three in 5⬘-regions of the gene and four in 3⬘-gene regions). An adenine insertion has been detected in intron 3. The coding region SNP is a synonymous C to T change in exon 5 that has no effect upon the encoded amino acid (Ser204Ser). Also, two polymorphic CA repeat microsatellites located at opposite ends of the 25-kb intron 4 of the HSD11B1 gene have been isolated (124). A deletion of 11 bp in intron 1 [position 441– 451 of GenBank accession no. M76661 (Exon 1)] was detected in one study. This polymorphism does not alter splicing and does not affect donor or acceptor splice sites (130). Analysis of the polymorphism showed that the 11 bases appear to belong to a tandem repeat consisting of two contiguous repetitions of the same 11 nucleotides, and thus could easily be deleted due to mispairing during replication. Recently, two further polymorphisms have been identified within intron 3 of HSD11B1 that are in complete linkage disequilibrium: an A insertion (83557), and 40 bp downstream a T to G substitution (83597). Functional analyses showed that these polymorphisms reduce transcriptional activity of HSD11B1 by 2.5-fold in luciferase reporter assays, suggesting that this region of the gene acts as an intronic enhancer of HSD11B1 expression (84). The rat 11␤-HSD1 promoter has been cloned from genomic DNA (132). An initial study utilizing this sequence demonstrated a single major promoter in the rat liver, but two further promoters are used in the kidney (132). Analysis of the promoter revealed the presence of a CCAAT sequence at ⫺73 to ⫺69 (transcription start site is ⫹1), and the lack of a TATA box. Several putative transcription factor-binding sites were identified including several glucocorticoid response element consensus half-sites, hepatocyte nuclear factor 1, hepatocyte nuclear factor 3, and CAAT/enhancer binding proteins (C/EBP) sites. Also a (CT)26 microsatellite is present at ⫺462 (133). Recent studies upon the rat 11␤-HSD1 promoter showed that it is predominantly regulated by the C/EBP family of transcription factors, mainly C/EBP␣. C/EBP␣ coordinately regulates a series of genes concerned with the metabolism of fuels (134), and C/EBP␣ is regulated by glucocorticoids in a tissue-specific manner (135). In liver, basal C/EBP␣ levels are high, ensuring high levels of 11␤-HSD1 transcription, and

hence high glucocorticoid levels (80). The 11␤-HSD1 promoter exhibits an unusually large number of these sites, having at least 10, with most genes containing two or three sites. Williams et al. (133) developed a series of reporter plasmids containing increasing sized promoter regions (from ⫺88 to ⫺3.5 kb/⫹49), transfected into HepG2 cells (human hepatoma cell line). These experiments identified a repressor element between ⫺812 and ⫺754. C/EBP␣ inducibility of the 11␤-HSD1 promoter was most prominent between ⫺579 and ⫺88. DNase 1 protection analysis identified 11 sites of nuclear protein interaction with the 11␤-HSD1 promoter, and 10 of these can be occupied by C/EBP-related proteins (133). Two of these regions, FP1 and FP2, span the transcription start site between ⫺88 and ⫹76. Mutation analysis of four footprinted sites proximal to the transcription start site FP1, FP2, FP3, and FP4 showed that they are required for full C/EBP␣ inducibility and basal transcription. Mutation of FP2 actually decreased basal transcription levels, suggesting that C/EBP may act here as an initiator (Inr)-binding protein. EMSA analysis confirmed that C/EBP␣ binds to at least two of the footprinted sites (133). Analysis of 11␤-HSD1 liver RNA expression in C/EBP␣ knockout mice confirmed these findings: 11␤-HSD1 was dramatically reduced in these mice compared with wild-type littermates (136). Similar analysis of the related transcription factor, C/EBP␤, showed it to be a weak activator of 11␤-HSD1 transcription, and C/EBP␤ knockout mice (137) show increased hepatic 11␤-HSD1 mRNA expression (133). The importance of C/EBP␣ in the regulation of 11␤-HSD1 transcription has been shown only for the rat promoter thus far, and it will be interesting to note whether this translates to the human promoter sequence and whether other transcription factors play a similarly important role. The analysis of the HSD11B1 gene in patients with CRD and the application of the polymorphisms in linkage and association studies are detailed in Sections VIII and IX. C. Recombinant models of 11␤-HSD1

To determine the role of 11␤-HSD1 in vivo, transgenic mice with a null HSD11B1 gene have been generated by the replacement of the genomic region containing exons 3 and 4 with a neomycin-resistance cassette via homologous recombination in mouse 129 embryonic stem cells (138). The resulting knockout

840



mice were fertile, had regular litter size with pups of normal birth weight, and postnatal development with normal morphological appearance. There was no deviation from Mendelian inheritance of alleles, and therefore no embryonic lethality associated with this knockout was assumed. No mRNA from 11␤-HSD1 homozygous mutant mice, and approximately 50% mRNA from heterozygous mice was detected by Northern analysis compared with wild type, confirming the true ablation of this gene. In homozygous mutant mice hepatic 11␤-HSD activity was less than 5% of wild type. Wild-type and knockout mice were adrenalectomized and implanted with 11-dehydrocorticosterone pellets. Wild-type mice readily converted 11dehydrocorticosterone to corticosterone, whereas corticosterone levels in knockout mice remained undetectable, demonstrating that 11␤-HSD1 is the only 11-oxoreductase (at least in the mouse) able to generate active glucocorticoid from inert 11-ketosteroids. 11␤-HSD ⫺/⫺ mice also displayed adrenal hyperplasia due to reduced negative feedback on the HPA axis causing increased ACTH-stimulated corticosterone secretion. The expression and activity of the 11␤-HSD2 enzyme appeared to be unaffected in this model, suggesting no compensatory mechanisms. An important experiment, which tested the hypothesis that increased 11␤-HSD1 activity within adipose tissue may be implicated in obesity and the metabolic syndrome, was the creation of transgenic mice overexpressing the enzyme (139). This was achieved through the fusion of 5.4 kb of the aP2 promoter/enhancer, which is an adipocyte-specific promoter, and a 1.6-kb fragment of rat 11␤-HSD1 cDNA, followed by an SV40 consensus polyadenylation signal. This construct was microinjected into the pronucleus of fertilized FVB mouse eggs. Successful targeting of transgene expression was determined by RNase protection assay using a probe able to differentiate between transgene-derived and endogenous 11␤-HSD1 mRNA from various adipose tissues and showed relative equivalence in expression in adipose tissue from sc, epididymal, mesenteric, and interscapular brown adipose tissue depots. The transgene was not expressed in nonadipose tissue such as brain and liver of transgenic mice. All mice studies were performed on inbred strains of male FVB mice in which transgene mRNA expression was increased 7-fold compared with endogenous mRNA. 11␤-HSD1 enzyme activity was increased almost 3-fold in adipose tissue, comparable to ob/ob mice or that seen in obese humans (140), demonstrating that the extent of transgenic amplification of 11␤-HSD1 activity is physiologically relevant. Transgenic mice under nonstressed conditions had similar serum corticosterone concentrations as controls, whereas concentrations in adipose tissue were elevated up to 30% higher compared with wild-type mice, reflecting local increased activation of glucocorticoid via 11␤-HSD1. The detailed phenotype of these animals is discussed in Section VII. However, to further define the role of 11␤-HSD1 upon homeostasis, it may be necessary to develop more refined recombinant mouse models. The use of Cre-LoxP technology in the generation of a conditional HSD11B1 allele, whereby particular gene promoters of Cre recombinase can ablate gene function in a spatial and temporal manner, would provide information on the relative contributions of specific

tissues such as liver and adipose to the global effects of 11␤-HSD1 enzyme activity on murine physiology. V. Localization and Ontogeny of 11␤-HSD1 A. Localization

A variety of studies have examined expression using different methodologies that include immunohistochemistry, Western blotting, PCR, and specific enzyme assays. Table 3 provides a comprehensive list of the tissue-specific distribution of 11␤-HSD1 in different species from which it can be seen that 11␤-HSD1 is expressed in many tissues throughout the body. Expression often occurs in what have traditionally been regarded as glucocorticoid target tissues. Highest levels of expression are seen in the liver, gonad, adipose tissue, and brain, and these are discussed in more detail in Section VII. B. Ontogeny and sexual dimorphic expression

In contrast to 11␤-HSD2, the ontogeny of 11␤-HSD1 is less well characterized, but it has been most extensively studied in rodents. In rat liver, 11␤-HSD1 activity can be detected during gestation (141). Dehydrogenase activity predominates and increases with advancing gestation into adult life (142, 143). The patterns of expression in the rat lung are similar to those seen in the liver, although levels of activity are lower (141, 142). Within the rat fetal brain, 11␤-HSD1 is undetectable until late gestation. Expression then begins to appear in the hippocampus, precerebellar area, and medulla. Subsequently, a more generalized increase in expression occurs, and at birth expression is highest in the thalamus, neocortex, hypothalamus, pituitary, periaqueductal gray area, spinal cord, and hippocampus (143). However, although expression has been detected using in situ hybridization, there is little detectable enzyme activity (143). In contrast, in primary cultures of rat fetal hippocampal neurons, significant amounts of 11␤HSD1 reductase activity can be detected (72). Within the postnatal rat cortex and hippocampus, 11␤-HSD1 activity decreases until postnatal d 10 and then increases. Conversely, in the cerebellum a peak of activity is reached by d 10 and then gradually falls until adult levels are achieved (d 15) (144). In the mouse, 11␤-HSD1 expression is undetectable but rises dramatically after birth until sexual maturity, after which it declines (145). Ontological expression has also been studied in sheep. In sheep liver 11␤-HSD1 expression is present by midgestation. Levels remain constant until immediately before birth when they increase more than 2-fold. Reductase activity always exceeds dehydrogenase activity (146). In the pars distalis of the sheep pituitary, 11␤-HSD1 expression can be detected by midgestation and, although levels do not change in late gestation, they increase dramatically after birth (147). Both reductase and dehydrogenase activities are present, although dehydrogenase activity predominates. However, in a further study, levels of activity in liver and pituitary were similar in tissues from late gestational fetuses and adults (148). In the pars intermedia, 11␤-HSD1 is only detectable at term, and



TABLE 3. Tissue- and species-specific expression of 11␤-HSD1 Tissue

11␤-HSD1

Ref.

Hepatobiliary system Liver (centripetal distribution) Pancreatic islets of Langerhans Rodent pancreatic acinar cells

⻫⻫⻫

Kidney Kidney cortex (rodent) Kidney medulla

x(⻫) ⻫

Gastrointestinal tract Sigmoid colon Rectal colon Surface epithelia and lamina propria

x x ⻫

167

Connective tissues Adipose tissue Skin fibroblasts Vascular smooth muscle Skeletal myoblasts

⻫⻫⻫⻫

69, 170 68 253, 374 225

Heart Rat cardiac myocytes Rat cardiac fibroblasts

⻫⻫

256

⻫⻫

307

⻫

236, 239, 375, 376

Bone Osteoblasts Osteoclasts Placenta Syncytiotrophoblast Chorion Decidua Uterus Gonad Testis Rodent Leydig cells Rodent vas deferens, seminal vesicle, penile urethra Oocyte Ovarian stroma Thecal cells Luteinized granulosa cells Nonluteinized granulosa cells

⻫⻫

170, 277, 373 277, 338

277, 373

⻫

237–239

⻫⻫⻫

55 77 278

⻫

170, 237, 264, 377

x x ⻫ x

Eye Trabecular meshwork Lens epithelium Nonpigmented ciliary epithelial cells Corneal epithelium Corneal endothelium

⻫/x ⻫/x ⻫⻫⻫

Adrenal Adrenal cortex Adrenal medulla (rodent)

⻫ x(⻫)

Central nervous system Cerebellum Rodent hippocampus, hypothalamus, brain stem, spinal cord

⻫⻫

373 79, 144

Pituitary Lactotrophs Folliculo-stellate cells Gonadotrophs Somatotrophs Corticotrophs

⻫⻫ x x x

144, 294

Lymphoid tissues Spleen Lymph nodes Peyer’s patch Thymus Macrophage

⻫⻫⻫⻫⻫

316 –319

841

levels do not change after birth (147). In the ovine placenta 11␤-HSD1 immunoreactivity is observed in the fetal trophoblast cells. Dehydrogenase activity exceeds reductase, and activity decreases in late gestation (149). Studies in humans are very limited. In fetal lung tissue homogenates, small amounts of dehydrogenase activity have been detected. In the neonatal and infant period, reductase activity is present although this is lost on progression through childhood (150). The significance of these results and, in particular, the source of dehydrogenase activity are uncertain, being published before the elucidation of the two 11␤-HSD isozymes. However, in primary cultures from explants of midgestation human fetal lung, both reductase and dehydrogenase activity are observed (151), suggesting the presence of 11␤-HSD1. In other tissues, however, 11␤-HSD1 could not be identified at least at midgestation (152). The activity of 11␤-HSD1 in childhood is not well characterized. Cortisone acetate therapy in neonates with congenital adrenal hyperplasia is ineffective up to 2 months of age, reflecting a lack of 11␤-HSD1 reductase (principally hepatic) activity (153). In children aged 4 or 5 yr, activity, as measured by urinary corticosteroid metabolites, is similar in boys and girls (154). In boys, activity remains relatively constant up to, and during, puberty. However, in girls activity decreases around the time of puberty (154), and it is possible that it is at this time point that the well-described sexually dimorphic pattern of activity is obtained. In most studies in both elderly normal individuals (155) and in GH-deficient, hypopituitary patients (28), 11␤-HSD1 activity is higher in men. In rats, although not in mice (56), a similar sexual dimorphic pattern is observed (156). The explanation for this difference in rats is believed to lie in patterns of GH secretion. Hypophysectomized male rats given a continuous GH infusion (as observed in female rats), suppress 11␤-HSD1 in the liver to levels observed in females (156, 157). The explanation in humans is not clear although it seems unlikely to involve regulation by estrogen as differences persist into the postmenopausal period (155). However, one additional study (158), although demonstrating sex differences in A-ring reductase activity, has failed to confirm this relationship.

170, 277, 333

VI. Regulation of 11␤-HSD1 Expression

326, 328, 373

⻫, Present; x, absent. Where both symbols appear together, there are conflicting reports in the literature.

It should be appreciated that most of the regulation studies performed particularly on rodent tissues before the characterization of the two principal 11␤-HSD isozymes in 1994/ 1995 (and some which have been performed since that time) have failed to dissect out specific effects on either 11␤-HSD1 or 11␤-HSD2. Table 4 summarizes the studies that have analyzed the regulation of 11␤-HSD1 and details the tissues and species studied. To summarize, glucocorticoids, C/EBP, peroxisome proliferator-activated receptor-␥ agonists, and some proinflammatory cytokines (TNF␣, IL-1␤) increase 11␤HSD1 expression, whereas GH (acting via IGF-I) and liver X receptor agonists inhibit expression. The effect of other factors, including sex steroids, insulin, and thyroid hormone, vary from tissue to tissue and between species (Table 4).

842



TABLE 4. Regulation of 11␤-HSD1 activity and/or expression 11␤-HSD1 activity and/or expression

Ref.

Rat glomerular mesangial cells Human preadipocytes Differentiating human sc adipocytes Human hepatocytes MG63 osteosarcoma cells Human osteoblasts Human aortic smooth muscle cells Human bronchial smooth muscle cells Differentiating human monocytes Human amnion fibroblasts (⫹ dexamethasone)

1 1 1 4 1 1 1 1 4 4 (1)

164 183, 184 185 183 309 309 374 374 328 378

IL-1

Human sc and omental preadipocytes Differentiating human sc adipocytes Human hepatocytes Rat glomerular mesangial cells Rat granulosa cells MG63 osteosarcoma cells Human aortic smooth muscle cells Human bronchial smooth muscle cells Differentiating human monocytes Human ovarian surface epithelial cells Human amnion fibroblasts (⫹dexamethasone)

1 1 4 1 1 1 1 1 4 1 4 (1)

183 185 183 164 265 309 374 374 328 266 378

IL-2 IL-4

Human granulosa-lutein cells Human granulosa-lutein cells (leukocyte depleted) Differentiating human monocytes

4 1 1

379 379 328

IL-5 IL-6

Human granulosa-lutein cells Human sc preadipocytes Human granulosa-lutein cells Differentiating human monocytes Human granulosa-lutein cells (leukocyte depleted) Human omental preadipocytes Human hepatocytes Mouse liver (in vivo, leptin-deficient mice) Mouse hepatocytes

1 1 1 1 1 1 4 1 1

379 183 379 328 379 183 183 204 204

4/(2) 4 4 4 4/2 2

183, 227 227 227 183 67, 228 156, 157 29, 226 380 183, 227 227 227 183 175 171 74

Regulatory factor

Cytokines TNF␣

IL-13 IFN␥ Leptin

Growth factors GH

IGF-I

EGF TGF␤ bFGF HGF Glucocorticoids Cortisol or corticosterone

Betamethasone Dexamethasone

Cell type/tissue

Human sc and omental preadipocytes 293T1 cells 3T3-L1 cells Human hepatocytes Rat hepatocytes Rat liver (in vivo) Hypopituitary patients Obese patients Human preadipocytes 293T1 cells 3T3-L1 cells Human hepatocytes 2S FAZA rat hepatoma cell line Rat and human hepatocytes Rat Leydig cells Rat hepatocytes Rat hepatocytes Rat hepatocytes Human omental and sc preadipocytes Fetal ovine pituitary (in vivo) Rat Leydig cells Human skeletal myoblasts Fetal ovine liver (in vivo) Rodent testis (in vivo) Rodent liver (in vivo) Baboon placenta (in vivo) Rat hepatocytes Rat liver (in vivo) Rat testis/rat Leydig cells Rat hippocampus (in vivo) Human skin fibroblasts 2S FAZA rat hepatoma cell line

2 2 2 4 2 4 1 Reductase 2 Dehydrogenase 4 4 4 1 (om ⬎ sc) 4 2 Dehydrogenase 1 1 1 4 4 1 2 2 Reductase 1 Dehydrogenase 1 1 1

171 171 171 69, 191 147 381 225 382 383 383 384 67, 228 198, 383 74, 383 144 68 175



843

TABLE 4. Continued 11␤-HSD1 activity and/or expression

Ref.

3T3-F442A and 3T3-L1 cells Human chorionic trophoblast Human amnion fibroblast

1 1 1

193 385 378

Insulin

Omental preadipocytes Rat hepatocytes (in vivo) 2S FAZA rat hepatoma cells Human skin fibroblasts 3T3-F442A and 3T3-L1 cells

4 2 2 2 2

70 228 175 68 193

Vitamin D3

Human monocytes THP-1 cells

1 1

328 328

Rat uterus (in vivo) Endometrial stromal cells Rat liver (in vivo) Rat testis (in vivo) Rat kidney (in vivo) Endometrial stromal cells Human hepatocytes Rat hepatocytes Rat testis (in vivo) Rat liver (in vivo) Rat testis (in vivo) Rat kidney (in vivo)

1 1 2 2 2 1 2 4 1 Dehydrogenase 4 2 Reductase 4

386 387 174, 383 383 388 387 171 171 383 174, 383 383 388

Rat Rat Rat Rat Rat Rat

granulosa cells granulosa cells Leydig cells uterus (in vivo) uterus (in vivo) granulosa cells

1 1 (After FSH) 2 Dehydrogenase 1 1 1

265 265 74 386 386 265

Rat pituitary (in vivo) Rat liver (in vivo) GH3 rat pituitary cells Human hepatocytes Rat hepatocytes Rat testis

2 2 4 4 1 1 Reductase

176 176, 383 176 171 171 383

2S FAZA rat hepatoma cells Rat granulosa cells Human skin fibroblasts Rat granulosa cells

2 Reductase 1 2 1

175 265 68 265

2 1

68 265

1 1 2 Reductase 1 Reductase 4 2 Reductase 2 4 4 2 1 Reductase 2 2 1 1 1 (sc fat) 2 (Visceral fat) 2 2 2 2 Reductase

133 133 185 389 390 185 391 392 392 179 185 195 195 183 393 394

Regulatory factor

Sex steroids Estradiol

Medroxyprogesterone acetate Progesterone Testosterone

Gonadotropins FSH LH PMSG hCG LHRH Thyroid hormones T3

PKA activators Forskolin 8-bromo-cAMP Dibutyryl-cAMP PKC activators Phorbol ester Others C/EBP␣ C/EBP␤ CRH ACTH

Cell type/tissue

Human skin fibroblasts Rat granulosa cells

15-Deoxy12,14-prostaglandin J2 Prostaglandin F2␣ COOH (nonthiazolidinedione PPAR␥ agonist)

HepG2 cells HepG2 cells Differentiated sc human adipocytes Guinea pig (in vivo) Rodent testis Differentiated sc human adipocytes Rat liver (in vivo) Human placental trophoblast Human placental trophoblast Sheep liver microsomes Differentiated sc human adipocytes 3T3-L1 adipocytes Epidydimal white fat (db/db mice) Human sc and omental preadipocytes Human chorionic trophoblast cells Rat (in vivo)

PPAR␣ Liver X receptor antagonists Protease inhibitors Clonidine

Mouse liver (in vivo) 3T3-L1 cells Human omental and sc preadipocytes Differentiated sc human adipocytes

Dehydroepiandrosterone Sodium nitroprusside Penicillamine Metyraponea Salbutamol Thiazolidinediones

395 196 227 185

IFN, Interferon; EGF, epidermal growth factor; bFGF, basic fibroblast growth factor; HGF, hepatocyte growth factor; PKA, protein kinase A; PKC, protein kinase C; PMSG, pregnant mare serum gonadotropin; PPAR, peroxisome proliferator-activated receptor; hCG, human chorionic gonadotropin; 1, increase; 2, decrease; 4, unchanged. a Metyrapone and its analogs are known to act as substrates for 11␤-HSD1 (100).

844


VII. Role of 11␤-HSD1 in Normal Physiology and Pathophysiology in Peripheral Tissues A. Kidney, colon, and skin

The first 11␤-HSD isozyme to be characterized in the kidney was 11␤-HSD1. In situ hybridization studies did report the presence of 11␤-HSD1 mRNA within rat distal nephron (159, 160), and immunoreactivity was observed only in renal proximal tubules in the cortex and to interstitial cells within the medulla; no immunoreactivity was observed over the aldosterone target cells, distal tubules, and collecting ducts (161–163). In contrast to the rodent, little, if any, 11␤-HSD1 is expressed in human or sheep kidney and, in humans, expression is confined to the renal medulla. This was one impetus to the cloning and characterization of the highaffinity, NAD-dependent 11␤-HSD2 isozyme (107) that, expressed in distal renal epithelial cells, serves to protect the MR from cortisol excess (1). 11␤-HSD1 is expressed in cultured rat glomerular mesangial cells where it is up-regulated by IL-1␤ and TNF␣ and may modulate the antiinflammatory effects of glucocorticoids at this site (164). Renal 11␤-HSD1 is down-regulated in a heritable model of polycystic kidney disease, the cpk mouse (165). The relevance of these observations to human renal physiology or pathophysiology is uncertain. 11␤-HSD activity was demonstrated in the human colon in the early 1980s (166); expression is confined to nonepithelial cells within the lamina propria of the rat colonic mucosa (167). The function of the 11␤-HSD1 enzyme at this site is unknown. A nuclear receptor with a high affinity for 11dehydrocorticosterone has been postulated to be present within the rat colon (168), and it is possible that 11␤-HSD activity may modulate ligand exposure to such a receptor. In the skin, 11␤-HSD1 is expressed in the epidermis, and whereas the directional activity of the enzyme at this site has not been established, the potency of topically applied hydrocortisone (as assessed by the skin vasoconstrictor assay) can be increased by glycyrrhetinic acid administration (169). In vitro, reductase activity predominates in human skin fibroblasts, and this is increased by glucocorticoids and inhibited by insulin (68). B. Liver and adipose tissue

1. Liver. 11␤-HSD1 is expressed in the rodent and human liver, and, in man, the activity of this enzyme confers biological potency upon orally administered cortisone. In the human liver, 11␤-HSD1 is localized centripetally with maximum expression around the central vein (170). Whereas the reductase activity of 11␤-HSD1 appears to be unstable in homogenates in vitro, primary cultures of rat and human hepatocytes indicate exclusive 11-oxoreductase activity (67, 171). In the intact perfused rat liver, activity is predominantly, although not exclusively, reductase. Interestingly, simultaneous perfusion with CBX fails to inhibit activity. However, 7 d of pretreatment with oral CBX decreased reductase activity significantly (172). In rats (157, 172–174), but not mice (56), 11␤-HSD1 expression is 18-fold higher in males compared with females (157), an observation that can be explained by the sexual


dimorphic pattern of GH secretion (156) (see Section V.B). Estrogens and insulin reduce 11␤-HSD1 expression in the rodent liver (174), but a series of growth factors including TGF␤, basic fibroblast growth factor, epidermal growth factor, and hepatocyte growth factor are without effect (171). In the rat 2S FAZA hepatoma cell line, reductase activity is also inhibited by insulin and IGF-I and stimulated by dexamethasone (175). The promoter region of the rat 11␤-HSD1 gene has been cloned and is positively regulated by C/EBP␣ (133) and, to a lesser extent, by C/EBP␤. T4 appears to regulate hepatic 11␤-HSD1 mRNA and activity levels (176), although varying effects have been reported in different tissues in rodents and man (171, 176, 177). In man, hyperthyroidism moves the set point of F to E conversion toward E, and studies suggest that this requires a functional thyroid hormone receptor rather than being due to a direct effect of thyroid hormone per se on 11␤-HSD1 (178). In sheep liver microsomes, metyrapone inhibits 11␤-HSD1 reductase activity (179), and this may provide a further explanation for its inhibitory effects on adrenal steroidogenesis. Chronic liver disease is associated with deranged cortisol metabolism. Urinary steroid profiles performed on patients with both alcoholic and nonalcoholic chronic liver disease indicate a marked increase in the THF⫹allo-THF/THE ratio, suggesting either a reduction in renal 11 ␤-HSD2 or an increase in hepatic 11 ␤-HSD1 oxoreductase activity (180). However, in rats with cirrhosis, both hepatic 11 ␤ -HSD1 and renal 11 ␤-HSD2 were reduced, and this could be explained by the inhibitory action of bile salts (181). 2. Adipose tissue. Significant expression of 11␤-HSD1, but not 11␤-HSD2, has been found in human adipose tissue (69, 182). Activity is predominantly reductase in nature and is induced by glucocorticoids and proinflammatory cytokines (183– 185). Activity and expression are significantly higher in omental compared with sc preadipocytes (69, 70). The enzyme is induced upon adipocyte differentiation in human adipose tissue cultures (stromal cells to adipocytes). In stromal cell cultures, this is more related to a “switch” in enzyme set point from dehydrogenase (stromal cells) to reductase (adipocytes) without any significant change in 11␤-HSD1 mRNA levels (78). This may be explained upon induction of H6PDH across differentiation (84) (see Section VIII). With the known effect of glucocorticoids on adipose tissue function and distribution, it has been postulated that the enhanced conversion of E to F within omental adipose tissue plays an important role in the pathogenesis of central obesity. Cortisol is essential for adipocyte differentiation (186), and the autocrine generation of cortisol through the action of 11␤-HSD1 is able to regulate this process. Both cortisol and cortisone promote differentiation. Inhibition of 11␤-HSD1 prevents cortisone-mediated adipocyte differentiation by blocking the activation of cortisone to cortisol (Fig. 4) (70). In addition, increasing reductase activity during adipocyte differentiation may ensure delivery of cortisol to permit continued differentiation (78). Mice overexpressing 11␤-HSD1 under the aP2 promoter have enhanced adipocyte differentiation (as measured by increased fat cell size) as a consequence of increased adipose tissue corticosteroid concentrations (139) (see Section VII.B.3.b. and Fig 5). In general, glucocorticoids



845

FIG. 4. In human adipose tissue, the autocrine/paracrine generation of cortisol through the activity of 11␤-HSD1 enhances adipocyte differentiation and inhibits preadipocyte proliferation.

inhibit cellular proliferation by inducing cell cycle arrest at the G1 phase (187, 188), and the prereceptor modulation of cortisol metabolism has a dramatic effect upon cell proliferation rate (189). In both rat and human preadipocytes, glucocorticoids exert an antiproliferative effect (190), and inhibition of 11␤-HSD1 was shown to ameliorate the antiproliferative action of cortisone (Fig. 4) (191). Additionally, in adipose stromal cells, 11␤-HSD1 has also been shown to regulate the glucocorticoid induction of aromatase activity (192). In the absence of a human transformed adipocyte cell line, murine 3T3-L1 and 3T3-F442A adipocyte cell lines have been studied. 11␤-HSD1-mediated reductase activity and expression were shown to increase with differentiation in 3T3-L1 and 3T3-F442A mouse cell lines, reaching maximum 6 – 8 d after confluence (193). Microarray data showed increased (5-fold or more) expression of 11␤-HSD1 in 3T3L1 cells during differentiation across a 7-d period (194). The expression of 11␤-HSD1 in 3T3-F442A cells has been shown to be regulated by dexamethasone and insulin in line with glycerol 3-phosphate dehydrogenase expression (193). Peroxisome proliferator-activated receptor-␥ agonists indirectly inhibit 11␤-HSD1 mRNA expression in 3T3-L1 cells (195). Similarly, agonists for liver X receptor-␣ and -␤, the nuclear oxysterol receptors involved in lipid metabolic regulation, decreased 11␤-HSD1 mRNA expression and activity (cortisone to cortisol), a process that requires ongoing protein synthesis (196). 3. Insulin sensitivity. The pathological effects of circulating cortisol excess are exemplified in patients with Cushing’s syndrome who may develop glucose intolerance, decreased insulin sensitivity, and reversible central obesity. Largely based on these observations, there is currently great interest in 11␤-HSD1 and its putative role in regulating insulin sensitivity. This can occur at the level of the liver (hepatic gluconeogenesis), adipose tissue (central obesity), or muscle. a. Hepatic gluconeogenesis. As discussed above, 11␤-HSD1 is highly expressed in both rodent and human hepatocytes; in intact hepatocytes (67) and in the perfused intact rat liver (172), activity is almost exclusively reductase. Glucocorticoids are potent regulators of many of the key enzymes

FIG. 5. A, Transgenic mice overexpressing 11␤-HSD1 under the adipocyte-specific aP2 promoter develop central obesity as a consequence of elevated adipose tissue corticosteroid concentrations. B, Increases in adipose tissue mass are greatest within the abdomen reflecting enhanced glucocorticoid receptor expression. WT, Wild type; TG, transgenic; Abd, abdominal; HF, high-fat diet; LF, low-fat diet. *, P ⬍ 0.05; †, P ⬍ 0.01. [Reproduced with permission of Dr. J. Flier and Dr. H. Masuzaki (139)].

involved in hepatic gluconeogenesis including PEPCK, the rate-limiting step in hepatic gluconeogenesis (197). Estradiol treatment to Wistar rats decreases PEPCK expression, an effect that is dependent upon reduced 11␤-HSD1 expression and the resulting decrease in hepatic corticosterone generation (173, 174, 198). The 11␤-HSD1 knockout mouse does not display fasting hypoglycemia in the basal state; however, when fed a high-fat diet, fasting glucose levels are significantly lower than wild-type controls (138). Furthermore, although at baseline, hepatic expression of glucose-6-phosphatase and PEPCK did not differ from controls, they lack the characteristic induction upon starvation (138). Recently,

846


highly selective inhibitors of 11␤-HSD1 have been developed, and in rodents administration for 7 d significantly decreases both hepatic glucose 6-phosphatase and PEPCK expression (119). In addition, in the fasting state as well as during oral glucose tolerance testing, glucose and insulin concentrations are decreased in mouse models of type 2 diabetes mellitus (121). These in vitro and rodent studies are highly suggestive of a modulatory role for 11␤-HSD1 in the control of hepatic gluconeogenesis. These observations are borne out in clinical studies. CBX treatment in healthy men decreases hepatic glucose production (199). In addition, during a hyperinsulinemic, hyperglucagonemic, normoglycemic clamp, glucose production rates decrease after treatment with CBX in patients with type 2 diabetes mellitus. However, this was principally due to reduced glycogenolysis with no effect on hepatic gluconeogenesis (200). Although there is considerable evidence that alterations in hepatic glucocorticoid concentrations can impact upon hepatic glucose flux, observational clinical studies in states of impaired glucose tolerance have, in almost all cases, demonstrated decreased hepatic 11␤-HSD1 reductase activity as measured by cortisol generation profiles after an oral dose of cortisone acetate (140, 201–203) and urinary F/E metabolite ratios (140, 203). Furthermore, leptin-deficient and leptinresistant models of obesity display decreased hepatic 11␤HSD1 expression (204). However, analysis of urinary corticosteroid metabolites has failed to show differences between patients with type 2 diabetes mellitus and healthy controls (205), although cortisol generation from oral cortisone appears to be impaired (201). It is plausible that decreased hepatic cortisol concentrations, resulting from decreased 11␤-HSD1 expression, represent a physiological compensatory mechanism to decrease fasting hyperglycemia and to improve insulin sensitivity. Transgenic mice overexpressing hepatic 11␤-HSD1 have been developed. These animals appear to have elevated insulin levels after a glucose load as well as dyslipidemia and hypertension, but more detailed data with respect to hepatic glucose flux in these animals are not yet available (206). b. Central obesity. The description of 11␤-HSD1 expression within adipose tissue and the suggestion that it may lead to central obesity—“Cushing’s disease of the omentum” (69)— have stimulated a critical appraisal of the role of 11␤-HSD1 in models of both rodent obesity and human obesity. i. 11␤-HSD1 and rodent models of obesity. Whereas there are clear differences between rodent and human obesity, these studies have enhanced our understanding of the role of tissue-specific cortisol metabolism in the pathogenesis of visceral obesity. In the obese Zucker rat, adipose tissuespecific 11␤-HSD1 expression is increased and hepatic expression is decreased (207). The mechanism for this dysregulation is not known. It is unlikely that insulin mediates this response, and insulin sensitizers, the thiazolidinediones, fail to correct this dysregulation in obese rats (208). Tissuespecific regulation by growth factors and cytokines may be important (183). These animals also have decreased 11␤HSD1 expression within hippocampal neurons, and this may be important in the abnormalities that are present in the HPA


axis in obesity (209). Recently, 11␤-HSD1 expression has been examined in other obesity-prone rodent models. Hepatic expression inversely correlates with markers of obesity in leptin-deficient and leptin-resistant models (204). In the leptin-deficient, but not the leptin-resistant, model this can be reversed by recombinant leptin therapy (204). Adipose tissue 11␤-HSD1 expression decreases with high-fat dietary feeding in other obesity-prone models (210). This down-regulation in liver and adipose tissue would appear to conflict with some of the human data described below. It is possible that this represents a compensatory mechanism in obesity to decrease tissue-specific corticosterone generation in an attempt to increase insulin sensitivity. The 11␤-HSD1 knockout mouse does not display a characteristic adipose tissue phenotype (138). It does, however, resist high-fat diet-induced obesity despite increasing food intake, and, in addition, insulin sensitivity is enhanced (211). The lack of phenotype may be explained by the fact that expression is lost at both an adipocyte and preadipocyte level. Within each cellular compartment, 11␤-HSD1 is likely to have distinct roles limiting proliferation in preadipocytes (191) and promoting differentiation and lipid accumulation in mature adipocytes (70). Evidence to support this comes from the development of the transgenic mouse overexpressing 11␤-HSD1 under the adipocyte-specific aP2 promoter (139). These mice develop a centrally obese phenotype as a consequence of elevated local glucocorticoid levels (Fig. 5). The predisposition for central obesity probably relates to the increased expression of GR in omental rather than sc fat. Importantly, however, because the transgene was targeted to already differentiating cells (aP2 is only expressed in adipocytes committed to differentiation) it will have had little effect on preadipocytes, and this is reflected in the fact that increases in adipose tissue mass were a consequence only of increased cell size and not number. In addition, these animals also develop hypertension with elevated circulating levels of angiotensinogen, angiotensin II, and aldosterone (212). This is an elegant model of visceral obesity and the metabolic syndrome, and its importance lies in demonstrating the impact of tissue-specific cortisol metabolism. However, increased adipose tissue corticosteroid levels have not been demonstrated in human obesity. ii. Human obesity. The role of cortisol metabolism and, in particular, 11␤-HSD1 in the pathogenesis of visceral obesity in man is an area of much scientific, clinical, and pharmaceutical interest. The global epidemic of obesity and its associated morbidity and mortality have hastened the need to determine its pathogenesis and to develop effective therapeutic strategies. The pathological effects of glucocorticoid excess are exemplified in patients with Cushing’s syndrome. Patients with visceral obesity and the metabolic syndrome share many of these features, although circulating cortisol levels in these patients are not elevated (213, 214). 11␤-HSD1 is highly expressed in human adipose tissue (69, 170, 214). In whole adipose tissue, levels of expression are similar between omental and sc depots (191). However, in preadipocytes, the fibroblast-like precursors of mature adipocytes, expression is higher in omental cells (69, 191, 215). Adipose tissue-specific expression of 11␤-HSD1 in human obesity


remains a controversial area. The parallels with Cushing’s syndrome have led to the hypothesis that adipose tissuespecific overexpression and therefore increased adipose tissue cortisol concentrations through enhanced reductase activity underpin the pathogenesis of visceral obesity. Until recently, few clinical studies had addressed this question. Global assessments of 11␤-HSD1 activity have been undertaken in several clinical studies and have used two principal methods. Generation of cortisol from an oral dose of cortisone acetate is believed to largely reflect hepatic 11␤HSD1 activity. In obese patients this activation is impaired (140, 202, 203). The urinary THF⫹allo-THF:THE ratio, in the setting of a normal UFF and UFE excretion, is also believed to reflect global 11␤-HSD1 activity (26). Results have been more variable in comparison with the cortisol generation profile. Some studies have described decreased ratios consistent with decreased 11␤-HSD1 reductase activity with increasing body mass index (BMI) in simple obesity (140, 203). Other studies have failed to show this relationship (213, 216 –218) and, indeed, positive correlations have also been described (202, 219, 220). The explanation for this discrepancy is not clear. However, in all cases cortisol generation after an oral dose of cortisone is clearly reduced in simple obesity. The sexual dimorphic expression of 11␤-HSD1 in the rodent has been discussed in Section V.B. As determined from a reduced THF⫹allo-THF/THE, but unchanged UFF/UFE ratio, human studies also suggest a reduction in 11␤-HSD1 oxoreductase activity in females compared with males (28, 155), and this may be explained on differing patterns of fat distribution. In adipose tissue, Weidenfeld et al. (221) obtained sc adipose tissue biopsies from lean and obese individuals and were unable to detect differences in 11␤-HSD1 dehydrogenase activity (the preferred direction when 11␤-HSD1 is disrupted from its normal cellular localization) in tissue homogenates. There were, however, only three patients in each group (221). Arteriovenous gradients of cortisol and cortisone across sc abdominal fat have also been used to assess 11␤-HSD1 activity, and cortisone clearance correlates with total body fat (222). More recently, several clinical studies have examined 11␤-HSD1 activity in sc abdominal adipose tissue from obese men and women including a population of obese Pima Indians (140, 202, 223). Dehydrogenase activity in adipose tissue homogenates in these studies significantly correlated with indices of obesity. In an additional study using in situ hybridization, mRNA expression in sc adipocytes (but not preadipocytes) was highest in the most obese patients (215). In our own studies, we were unable to detect differences in mRNA expression in whole adipose tissue between lean and obese individuals using real-time RT-PCR. Furthermore, in cultured preadipocytes, 11␤-HSD1 reductase activity decreased with increasing BMI (191). The apparent discrepancies in some of these clinical data may be due to the fact that all of these studies have had relatively small subject numbers and that they have all used different techniques and assays to determine 11␤-HSD1 activity. Whereas 11␤-HSD1 activity correlates well with mRNA expression in some of these studies, it does not correlate with adipose tissue cortisol concentrations (224). Therefore, the hypothesis that human obesity occurs as a consequence of


847

adipose tissue-specific overexpression of 11␤-HSD1 and hence increased tissue-specific cortisol concentrations is yet to be confirmed. Our inclination is the converse—that 11␤HSD1 expression in liver is already reduced in obesity and serves as an important protective mechanism to protect against the ongoing deleterious metabolic effects of obesity. c. Muscle. 11␤-HSD1 is also expressed in skeletal muscle (225). The role of tissue-specific cortisol metabolism within muscle and its impact upon insulin sensitivity have not been extensively studied. However, in a single study, levels of expression within human skeletal myoblasts correlated with measures of insulin resistance, BMI, and blood pressure (225). d. GH deficiency (GHD). Adult patients with endogenous GHD are known to have a series of metabolic defects including insulin resistance and obesity. Studies in hypopituitary patients commencing GH therapy show a reduction in the THF⫹allo-THF/THE ratio but no alteration in the UFF/ UFE ratio, indicative of a decrease in 11␤-HSD1 reductase activity (226). The same finding was confirmed in elderly GH-deficient subjects (29). In untreated GH-deficient hypopituitary subjects, urinary THF⫹allo-THF/THE ratios are increased by about 50% from baseline. The opposite is seen in untreated acromegalics (227). These clinical studies are endorsed by studies in vivo that also indicate reduction of hepatic 11␤-HSD1 expression in rats treated with GH (156, 228, 229). However, subsequent in vitro analyses revealed that GH has no direct effect upon 11␤-HSD1 activity, but that the GH effects are mediated via IGF-I; IGF-I inhibits 11␤HSD1 activity (175, 227). This is supported by the observation that pegvisomant, a GH antagonist that increases endogenous GH but effectively blocks GH signal transduction and lowers IGF-I levels, reverses the reduction in the THF⫹alloTHF/THE ratio seen in untreated acromegaly (30). GH therefore, acting via IGF-I, increases the metabolic clearance rate of cortisol by inhibiting 11␤-HSD1. Clinically, care should be taken to ensure adequate cortisol replacement in GHD patients commencing GH replacement therapy. Equally, there are many similarities between Cushing’s syndrome and GHD (central obesity, osteopenia, insulin resistance, premature cardiovascular mortality), and it is exciting to speculate that the phenotype of GHD may, in part, relate to its modulation of the tissue-specific actions of cortisol. C. Fetoplacental tissues

In contrast to adulthood where the ratio of circulating F/E is 7:1, the ratio in umbilical arterial and venous blood is approximately 1:1. This relative increase in cortisone levels reflects the intense and extensive expression of 11␤-HSD2 in the fetoplacental unit, notably the placental syncytiocytotrophoblast (152, 230, 231). 11␤-HSD1 is expressed at low levels in trophoblast tissue, although there is evidence for NADP-dependent dehydrogenase activity in human, baboon, and sheep trophoblast (232–234). 11␤-HSD1 gene expression in the ovine placenta decreases as term approaches (149). 11␤-HSD1 is more abundantly expressed in chorion and decidua (152, 235, 236). Human and rodent endometrium expresses both 11␤-HSD

848


isozymes (237–239). 11␤-HSD1 expression in the sheep endometrium is low in the estrous cycle but increases markedly in pregnancy (240). Decidualization of endometrial stromal cells is a fundamental process in implantation and invasion of the trophoblast. Estradiol and progesterone act, in a synergistic fashion, to induce 11␤-HSD1 expression in cultured endometrial stromal cells (241). Glucocorticoids are known to regulate decidual matrix-degrading proteases such as collagenase and plasminogen activator, and this induction of expression of 11␤-HSD1 with the decidualization process may be of importance in this regard. D. Cardiovascular system

Studies on patients with Cushing’s syndrome (242), and in subjects given hydrocortisone (243), indicate that glucocorticoids play an important role in determining vascular reactivity in man, probably by potentiating the vasopressor action of endogenous catecholamines. MRs have been identified in the rabbit aorta and rat mesenteric vasculature (244, 245). CBX and other 11␤-HSD inhibitors (including 11␤HSD1 antisense oligonucleotides), through inhibition of dehydrogenase activity, potentiate noradrenaline and angiotensin II-induced vasoconstriction (25, 246, 247), enhance vasoconstriction by reducing endothelium-dependent relaxation (248), and increase Na⫹/ H⫹ exchanger activity in vascular smooth muscle cells (249). However, in vivo, cortisol infusions in human studies have failed to produce any alteration in forearm vascular resistance with or without 11␤HSD1 inhibition (250). Furthermore, enhanced vasoconstrictor and impaired relaxation responses are observed in mice lacking 11␤-HSD2, but not 11␤-HSD1 knockout mice (251). To date, the evidence suggests that it is the 11␤-HSD1 isoform that is predominantly expressed in the vasculature, specifically in vascular smooth muscle and cultured rat aortic endothelial cells (25, 252, 253), and here oxoreductase activity predominates (254). Dehydrogenase activity is reduced in the mesentery of Dahl salt-sensitive hypertensive rats compared with the salt-resistant strain (255). Expression is also reported in interstitial fibroblasts within the endocardium (256). The expression of 11␤-HSD1 in these cells and in vascular smooth muscle cells has led to speculation that it might be involved in the pathogenesis of acute coronary vascular inflammation (257). Additional studies are clearly warranted. Aberrant expression of 11␤-HSD1 in other tissues may also result in a cardiovascular phenotype. Transgenic mice overexpressing 11␤-HSD1 develop hypertension as a consequence of increased circulating angiotensinogen (212). E. Gonad

1. Ovary. Appreciable levels of 11␤-HSD have been detected in the rodent and human ovary (170, 258, 259). Glucocorticoids are known to affect ovarian function in many ways, including inhibition of FSH-stimulated aromatase activity (260), stimulation of the production of plasminogen activator in granulosa cells (261, 262), and inhibition of LH-induced steroidogenesis from granulosa-lutein cells (263). In rodent and human ovaries, 11␤-HSD1 is expressed in the developing oocyte and luteinized theca cells, whereas 11␤-HSD2 is


found only in preovulatory, nonluteinized granulosa cells (170, 259, 264). Treatment of granulosa cells at the time of ovulation with gonadotropins, human chorionic gonadotropin, and IL-1␤ stimulates 11␤-HSD1 expression in a dosedependent fashion (265). IL-1␣ increased expression of 11␤HSD1 mRNA and oxoreductase activity in human ovarian epithelial cells 3-fold, which was blocked with an IL-1 receptor antagonist (266). The antiinflammatory role of glucocorticoids and its modulatory enzyme, 11␤-HSD, in the ovaries is reviewed by Hillier and Tetsuka (267). Although the concept of developmental expression of 11␤-HSD enzyme in the ovaries has been widely accepted (170, 259, 268, 269), there remains some debate as to the “directionality” of activity at this site. In bovine granulosa cells, 11␤-HSD1 mRNA expression inversely correlated with follicular fluid cortisol concentrations, suggesting dehydrogenase activity (270). In the human, predominant reductase activity (269) or predominant NADP-dependent dehydrogenase activity (264, 271) has been reported. The kinetics of the dehydrogenase reaction are not entirely in keeping with 11␤-HSD1, but additional isozymes have not been characterized (264). The expression of 11␤-HSD1 in cultured granulosa-lutein cells has been inversely correlated with pregnancy rates across in vitro fertilization cycles. Thus, in patients with detectable granulosa cell 11␤-HSD1-mediated dehydrogenase activity, pregnancy rates were zero, compared with a pregnancy rate of 76% in patients with no activity (272, 273). In a subsequent study that detected dehydrogenase and reductase activities in granulose-leutein cells shortly before ovulation, no such correlation was observed (274). However, a possible poor outcome in patients with detectable granulosa 11␤-HSD dehydrogenase activity, together with the expression of 11␤HSD1 in the oocyte itself, would indicate that high local concentrations of cortisol are required for oocyte maturation. In keeping with these data, high concentrations of cortisol have been shown to be present in follicular fluid during the LH surge (275). 2. Testis and male reproductive tract. High levels of 11␤-HSD1 were first described in the Leydig cells of the testis in 1965 (276) and subsequently confirmed by others (75, 122, 277). 11␤-HSD1 is not expressed in Sertoli cells but is present in the apical region of the principal epithelial cells of the caput epididymis, the epithelium of vas deferens, seminal vesicle, and penile urethra (278). Glucocorticoids decrease testosterone production in mouse Leydig cell cultures (279, 280), and inhibition of testicular 11␤-HSD dehydrogenase activity potentiates the inhibitory effect of corticosterone on testosterone secretion in rats (281). The endogenous activity of testicular 11␤-HSD may explain male hormone-dependent behavior in the rat (282); dehydrogenase activity is higher in dominant male rats compared with controls and subordinates (283). As with the ovary, there is ongoing debate as to the directionality of 11␤-HSD1 in the testis and the characterization of NADP-dependent dehydrogenase activity. Both dehydrogenase and reductase activities are reported. Leckie et al. (77) report almost exclusive reductase activity, but it is likely that reductase activity exceeds dehydrogenase activity in immature Leydig cells but dehydrogenase activity predominates in mature adult cells (284). Differences in studies


probably reflect the cell populations studied and culture media (285). Protein kinase C induced dehydrogenase and decreased reductase activity, whereas calcium-dependent signaling mechanisms had the opposite effect (286). However, studies have raised the possibility of a further putative 11␤-HSD isoform with high substrate affinity and NADPdependent dehydrogenase activity (287). Recently, in vitro and in vivo, glucocorticoid-induced apoptosis has been shown in Leydig cells mediated by FasL/Fas and caspase-3 pathways (288, 289). F. Central nervous system and pituitary

High levels of NADP-dependent 11␤-HSD dehydrogenase activity have been detected in the rat brain, including the cerebellum, pituitary, and hippocampus. In situ hybridization and immunohistochemistry confirm this to be the 11␤HSD1 isozyme (144, 290), and in one study, in cultured hippocampal neurons, the isozyme was shown to act predominantly as a reductase potentiating the neurotoxic effects of the inert glucocorticoid, 11-dehydrocorticosterone (72). Other studies (80, 291) have also supported the hypothesis that 11␤-HSD1 in the brain is acting primarily as a reductase. Despite elevated circulating corticosterone levels, 11␤-HSD1 knockout mice have decreased corticosterone levels within the hippocampus indicative of impaired glucocorticoid reactivation. It has been hypothesized that this is important in explaining their improved age-related learning impairments in comparison with controls (291). However, Jellinck et al. (79) reported both reductase and dehydrogenase activities from intact hippocampus from rats under near-normal physiological conditions. Intracerebral microinjection into one or both lobes of the hippocampus revealed interconversion of tritium-labeled 11-dehyrocorticosterone and corticosterone. Additionally, in the hypothalamus/pituitary, inhibition of 11␤-HSD with glycyrrhetinic acid was shown to modulate the negative glucocorticoid feedback mechanism by inhibiting corticotropin-releasing factor concentrations within hypophysial portal blood (292) and also altered cerebral glucose metabolism (293), all of which suggest functional dehydrogenase activity at these sites. Studies in the developing sheep pituitary support such observations (147). Similarly, in vitro in rat pituitary GH3 cells, inhibition of 11␤-HSD1 dehydrogenase activity by glycyrrhetinic acid potentiated the glucocorticoid-inhibitory effect on prolactin gene transcription (106). In the normal human pituitary, 11␤-HSD1 expression is confined to GH- and prolactin-secreting cells and folliculostellate cells. Expression was absent in gonadotrophs, thyrotrophs, and, importantly, corticotrophs, suggesting that in normal physiology it does not modulate HPA axis glucocorticoid-negative feedback, at least at an autocrine level (294). However, 11␤-HSD1 knockout mice do display abnormalities of the HPA axis. These animals have elevated corticosterone and ACTH levels, enhanced responses to stress, and insensitivity of HPA axis suppression with exogenous cortisol. Importantly, glucocorticoid-sensitive gene expression is not increased (295). The conclusion from these studies is that local active glucocorticoid regeneration in this rodent model is an important regulator of HPA axis function. Cortisol metabolism may have a role in pituitary tumor


849

tumorigenesis. 11␤-HSD1 mRNA and activity are reduced to approximately 30% of normal levels in pituitary tumors (see Section VII.I) (296). G. Bone

Glucocorticoids have profound, yet potentially opposing, effects on bone. In vitro they are required for the differentiation of osteoblasts but in excess can cause suppression of the mature osteoblast phenotype by reducing proliferation and inducing apoptosis (297, 298). Similarly, in vivo, glucocorticoids are anabolic at physiological concentrations, but in excess have an adverse effect on the skeleton, most clearly seen in glucocorticoid-induced osteoporosis. As a potential amplifier of glucocorticoid action in bone, 11␤-HSD isozyme expression has recently been examined in this tissue. The first description of a relationship between 11␤-HSD and bone came with the description of a rickets phenotype in a child with apparent mineralocorticoid expression (299). The bone problems appeared to be due to the metabolic alkalosis rather than any abnormality of intracellular glucocorticoid levels because this was reversible with spironolactone treatment. 11␤-HSD2 expression was next demonstrated in human fetal osteoblasts at midgestation using in situ hybridization and immunohistochemistry (300). 11␤HSD2 mRNA expression and enzyme activity were further demonstrated in a range of rat and human osteosarcoma cell lines (301, 302). Expression of this enzyme had important functional consequences, reducing expression of alkaline phosphatase in response to corticosterone treatment. [Indeed, based largely on these preliminary characterization data, transgenic mice have been created overexpressing 11␤HSD2 in osteoblasts via the Col1a1 promoter: studies confirm the important anabolic role of glucocorticoids in bone using this model (Ref. 303, and B. Kream, personal communication).] However, in contrast to its more restricted expression in adult life, it is now established that 11␤-HSD2 expression is widespread during fetal development. Additionally, expression of 11␤-HSD2 has been demonstrated in a range of cultured cell lines and is thought to be a manifestation of the malignant phenotype (304) (see Section VII.I). That 11␤-HSD1 rather than 11␤-HSD2 was the major glucocorticoid-modifying enzyme in bone was suggested by the observation that differentiation of rat and mouse calvarial osteoblasts could be induced by cortisone treatment (305). This effect was partially blocked by a nonselective 11␤-HSD1 inhibitor, CBX. Furthermore, in cultures of osteoblasts derived from adult female and male rat vertebrae, 11␤-HSD activity was detectable, but this activity was exclusively oxoreductase (306). Expression of 11␤-HSD1 has now been assessed directly in human bone and primary osteoblast cultures (301, 307, 308). Here, 11␤-HSD1 mRNA expression and enzyme activity were present, and bidirectional enzyme activity was apparent. No 11␤-HSD2 mRNA expression or enzyme activity was present in these cultures. A detailed characterization of 11␤HSD1 in adult bone demonstrated both dehydrogenase and reductase activities in chips of normal fresh bone, but kinetics of the reactions (bidirectionality and preference for a higher substrate concentrations) strongly supported the expression

850



of 11␤-HSD1 and not 11␤-HSD2 (307). In homogenates of human bone (in which endogenous cofactors are released) enzyme activity could be restored with NADP but not NAD, again indicating 11␤-HSD1 expression. Abundant 11␤-HSD1 mRNA expression by RT-PCR was also evident in fresh human bone obtained at orthopedic surgery. Immunohistochemistry and in situ hybridization using specific probes demonstrated expression of 11␤-HSD1 in osteoblasts and bone-lining cells, whereas expression in fibroblasts and adipocytes was low. 11␤-HSD2 expression under similar conditions was very low. Interestingly, 11␤-HSD1 expression was also seen in some (but not all) osteoclasts. Several additional studies have replicated the expression of 11␤-HSD1 in adult human primary osteoblasts in which the activity is primarily reductase. The in vitro regulation of this activity has been explored. The proinflammatory cytokines TNF␣ and IL-1 increase 11␤-HSD1 mRNA expression and enzyme activity in a dose-dependent manner in primary osteoblasts and MG-63 osteosarcoma cells (309). Cortisol and dexamethasone (100 nm) were also found to induce a 2-fold increase in 11␤-HSD1 activity and mRNA expression in primary human osteoblasts (308), but the cellular basis for this increase was not examined (310). More provocatively, 11␤HSD1 expression in primary cultures of osteoblasts obtained from orthopedic operations appeared to increase with the donor age with an approximate 3-fold difference between young and old donors (Fig. 6A) (308). The potential functional impact of 11␤-HSD1 expression has been assessed in vivo in a small number of clinical studies. Short-term (7 d) inhibition of 11␤-HSD activities with CBX in normal volunteers had no impact on bone formation markers but did result in a suppression of the bone resorption markers, pyridinoline and deoxypyridinoline (307). Whether these effects were due to direct inhibition of 11␤-HSD1 in osteoclasts (which mediate bone resorption) is unclear. The impact of selective inhibitors of 11␤-HSD1 activity is awaited with interest. It is possible that 11␤-HSD1 expression within osteoblasts could account for differences between individuals in the sensitivity of bone to therapeutic glucocorticoids in a clinical setting. In primary human osteoblasts the most widely used therapeutic glucocorticoids, prednisone and prednisolone, are metabolized by 11␤-HSD1 (Fig. 6B) with kinetics indistinguishable from those of the established endogenous glucocorticoids, cortisone and cortisol (308). The impact of 11␤-HSD activity on susceptibility to glucocorticoid-induced changes in biochemical markers of bone turnover has been assessed in normal volunteers taking a moderate dose of prednisolone orally (311). Systemic 11␤-HSD1 activity measured by the urinary THF⫹allo-THF/THE ratio before steroid treatment strongly predicted the extent of the fall in bone formation markers (osteocalcin and N-terminal propeptide of type I collagen) at 4 and 7 d (Fig. 6C). These relationships did not appear to be mediated by changes in systemic levels of glucocorticoids or total corticosteroid metabolite production. These data support the possibility that simple measures of 11␤-HSD1 activity may predict the development of bone-related adverse effects of systemic glucocorticoids during treatment. This hypothesis will need further exploration, especially given the potential changes in expression of 11␤-HSD1 that may occur during

inflammatory conditions that necessitate systemic glucocorticoid treatment. H. Eye

Topical and systemic glucocorticoids are used in a diverse range of conditions in clinical ophthalmology, and one of the most significant complications is corticosteroid-induced glaucoma. This condition is characterized by a significant increase in intraocular pressure (IOP), which, if untreated, can lead to visual field loss and blindness. Nearly one third of the normal population and virtually all patients with normal tension or primary open-angle glaucomas will develop raised IOP after topical steroid therapy (312). IOP is maintained by a balance between production and drainage of aqueous humor. The major site of aqueous production is from the nonpigmented epithelial cells (NPE) of the ciliary body, whereas drainage is predominantly through the cells of the trabecular meshwork. The eye represents an important target tissue for corticosteroids, expressing both the MR (313) and GR (314). Corticosteroids have long been implicated in the natural diurnal variation of IOP, and raised IOP may also occur in patients with Cushing’s syndrome (315). Several groups have used immunohistochemical and in situ hybridization analyses to assess the expression of 11␤-HSDs in a variety of human ocular tissues and have produced conflicting results. One study localized mRNA and protein for 11␤HSD2 in the NPE, with coexpression of MR (316). Because the NPE has morphological characteristics of epithelia engaged in salt and water transport, this, perhaps, was not surprising. However, Stokes et al. (317) and Rauz et al. (318) localized 11␤-HSD1 to this tissue type, suggesting that it is this isozyme that has an important role in aqueous humor production. Rauz and co-workers also demonstrated mRNA for GR, MR, and 11␤-HSD1 (but not 11␤-HSD2) in the human, ciliary epithelial cell line, ODM-2. Additionally, they noted that aqueous humor concentrations of “free” cortisol greatly exceeded those of cortisone (by gas chromatography/mass spectrometry analysis: cortisol-cortisone ratio, 14:1, compared with circulating F/E ratio of ⬃3:1). This would be consistent with local 11␤-HSD1 activity generating cortisol from cortisone. The functional significance of 11␤-HSD1 in the eye was then investigated by administering a nonspecific 11␤-HSD inhibitor, CBX, to healthy volunteers. After 7 d of CBX, IOP fell by 17.5%, in keeping with the hypothesis that inhibition of 11␤-HSD1 within the NPE reduces local cortisol generation, causing a fall in IOP. More recently, Rauz et al. (319) confirmed their earlier work by showing expression of 11␤-HSD1 within the NPE using in situ hybridization. They also found mRNA for 11␤-HSD1, but not type 2 in ciliary body tissue of patients undergoing surgical enucleation. Additionally, they showed that aqueous humor levels of cortisol were consistently higher than those of cortisone in both patients with primary open-angle glaucoma and controls, although levels were no different between these two groups. Finally, randomized, placebo-controlled studies of healthy controls and patients with ocular hypertension, revealed that systemic CBX for 4 d significantly lowered IOP by 10% (319). An important application of these findings could be in the therapeutic management of glaucoma, with topical prepa-



851

FIG. 6. A, 11␤-HSD1 reductase activity increases with donor age in cultured human osteoblasts. B, Oral administration of prednisone (inactive) or prednisolone (active) results in significant exposure of active glucocorticoid to human bone through the activity of 11␤-HSD1 in osteoblasts. C, 11␤-HSD1 activity as measured by urinary corticosteroid metabolites predicts the fall in bone formation (osteocalcin) caused by exogenous glucocorticoid administration.

rations of CBX or more selective 11␤-HSD1 inhibitors, effective in lowering IOP. However, a more critical analysis defining the role of 11␤-HSD in regulating epithelial sodium transport within the eye and its expression in glaucoma is now required. I. Malignant tissues

Although 11␤-HSD1 expression and activity have been described for a diverse array of tissues, the enzyme is notable for its absence in tumors and tumor-derived cell lines (296). For example, normal pituitary tissue shows strong expression of 11␤-HSD1, particularly in GH- and prolactin-secreting cells (294). Conversely, expression of the enzyme in pituitary adenomas is greatly diminished, with a concomitant

induction of 11␤-HSD2 expression (294, 296). In a similar fashion, bone biopsies and primary cultures of osteoblastic cells have clearly defined expression of 11␤-HSD1 (301, 309) whereas osteoblastic cell lines derived from osteosarcomas express only 11␤-HSD2 (301, 302). Other reports have described decreased expression of 11␤-HSD1 in squamous cell carcinomas of the head and neck compared with nonaffected mucosal tissues (320), whereas adrenal adenomas show strong induction of 11␤-HSD2 without a concomitant decrease in 11␤-HSD1 (321). Studies in vitro suggest that this switch in isozyme expression may manifest itself through opposing effects on cell proliferation and differentiation (189): 11␤-HSD1 acts to decrease cell proliferation by raising local levels of antiproliferative cortisol, and 11␤-HSD2 pro-

852



vides a proproliferative signal by deactivating cortisol. As yet, the precise mechanism by which expression of 11␤HSD1 is lost in neoplastic cells remains unclear, although key factors associated with the transcriptional regulation of 11␤HSD1 such as CEBPs are known to be dysregulated in some tumors (322). Another potential link between 11␤-HSD1 and cancer has developed from studies of purified, membranebound enzyme, which showed that 11␤-HSD1 is able to metabolize nanomolar concentrations of the tobacco-specific NNK, a known carcinogen. These studies have also raised important questions concerning the potential impact of 11␤HSD inhibitors on tumor development. In the case of NNK, 11␤-HSD inhibitors such as glycyrrhetinic acid might promote tumorigenesis by decreasing the potential of 11␤-HSD1 to metabolize nitrosamines. By contrast, glycyrrhetinic acid has also been shown to act as an antiproliferative agent in 11␤-HSD2-expressing cancer cell lines (323). In this case the putative mode of action is to moderate the inactivation of antiproliferative cortisol. J. Immune tissues

Immunomodulation represents an important facet of glucocorticoid physiology and inflammation therapy and is manifested by the regulation of cytokine production and immune cell function (324). In common with other target tissues, the ability of glucocorticoids to achieve these effects is likely to be dependent on the local regulation of glucocorticoid metabolism. This was recognized more than a quarter of a century ago by Dougherty et al. (325), who first described the metabolism of active glucocorticoids in spleen and lymph tissues from rats. Subsequent studies have described expression of protein for 11␤-HSD1 in rat spleen and lymph nodes, and the conversion of corticosterone to 11-dehydrocorticosterone in various immune tissues, notably spleen, lymph nodes, Peyer’s patch, and thymus (326). However, it should be emphasized that these studies were carried out using homogenates from lymphoid tissues and, as such, it is difficult to make firm conclusions about the relative importance of reductase vs. dehydrogenase activity at these sites. In the rat immune system, the principal source of 11␤-HSD1 activity appeared to be the stromal cells associated with the spleen, thymus, or lymph nodes. However, transcripts for 11␤-HSD1 have also been detected in human lymphocyte (327) and macrophage preparations (328). Importantly, in the latter study, Thieringer et al. demonstrated increased expression and reductase activity of 11␤-HSD1 during the differentiation of monocyte-derived macrophages. These data suggest a role for 11␤-HSD1 in macrophage-driven innate immune responses. However, induction of macrophage 11␤HSD1 may also be linked to acquired immune responses: 11␤-HSD1 activity is enhanced by the T helper cell type 2 (Th2) cytokines IL-4 and IL-1, with this effect being abrogated by interferon-␥, a Th1 cytokine (328). 11␤-HSD1, in turn, may influence the expression of Th1 and Th2 cytokines. At least in the rat, 11␤-HSD activity appears to be highest in tissues (spleen and peripheral and mesenteric lymph nodes) with a high proportion of Th1 T cells, and lower in tissues (Peyer’s patch, thymus) in which T cells produce predominantly Th2 cytokines. Furthermore,

inhibition of 11␤-HSD1 in lymphoid organs results in a shift from expression of Th1 cytokines (IL-2, interferon-␥) to Th2 cytokines (IL-4, IL-10) (329). The authors concluded that this reflected a glycyrrhetinic acid-induced decrease in glucocorticoid inactivation such that the increased concentration of glucocorticoids in lymphoid tissue stimulated a shift toward a Th2 phenotype, with a concomitant suppression of hypersensitivity responses. By contrast, other studies have reported depressed natural resistance to infection by Listeria monocytogenes after treatment with glycyrrhetinic acid (330). Thus, the initial conclusion that lymphoid 11␤-HSD1 acted to support Th1 responses via dehydrogenase inactivation of glucocorticoids may be somewhat simplistic, particularly as glucocorticoids are potent generators of regulatory T cells, which play a key role in immune tolerance (327). In view of the expression of 11␤-HSD1 in a wide variety of immune tissues, it is perhaps not surprising that pathophysiological dysregulation of immune 11␤-HSD activity has also been demonstrated. In rodent and humans, abnormal cortisol metabolism has been reported after infection with tuberculosis (TB): analysis of urinary corticosteroids reveals an increase in cortisol rather than cortisone metabolites (331). In addition, generation of cortisol from oral cortisone is higher in patients with active, rather than cured, pulmonary TB. Lastly, cortisol-cortisone ratios in bronchoalveolar lavage fluid (although not in serum) were increased in active TB groups compared with cured patients (332). It has therefore been hypothesized that enhanced cortisol generation may be responsible for the immunoparesis that is observed in pulmonary TB. K. Other tissues

The human and rodent adrenal expresses 11␤-HSD1 with highest expression seen in the zona reticularis at the corticomedullary junction (170, 333, 334). It is possible that the high expression of 11␤-HSD1 at the corticomedullary junction facilitates the high intraadrenal glucocorticoid concentrations required for medullary catecholamine biosynthesis. Aldosterone-secreting adrenal adenomas also express high levels of 11␤-HSD1, and it has been hypothesized that enhanced reductase activity and cortisol generation promote steroidogenic activity within these tumors (334). In the lung, Northern blot analyses and assays of reductase activity (71, 151, 335) suggest the presence of 11␤-HSD1. Expression is highest in interstitial fibroblasts but also in type II pneumocytes. Within the fetal rat lung, corticosteroids increased 11-oxoreductase activity, which in turn resulted in an increase in surfactant synthesis (71), a glucocorticoiddependent process (336) essential for normal lung maturation. In addition, inhibition of 11␤-HSD1 with glycyrrhetinic acid in pregnant rats significantly impaired lung maturation and decreased surfactant production in the fetus (335). Additional evidence to support a role for 11␤-HSD1 in lung maturation is found in studies in 11␤-HSD1 knockout mice. These animals have lower surfactant protein A concentrations, decreased surfactant production, and decreased amniotic fluid in comparison with wild-type animals (337). 11␤-HSD1 is expressed in both human and rodent islets of Langerhans as well as rodent acinar cells (338). Activation of



11-dehydrocorticosterone by 11␤-HSD1 in isolated rodent ␤-cells inhibited insulin release, an effect that was prevented by inhibition of 11␤-HSD1 with CBX. An autocrine-regulatory role in the control of insulin release has therefore been postulated (338). VIII. CRD A. Clinical features

CRD was first described in 1984. To date, 11 cases have been described, the majority of which are female. Detailed clinical and biochemical data for the published cases are presented in Table 5. Female patients have invariably presented in adolescence or early adulthood with features of hyperandrogenism (acne, hirsutism, oligomenorrhea, infertility). Obesity has been a feature of some cases. Males have presented with precocious puberty. Serum androgens (dehydroepiandrosterone sulfate, androstenedione, and testosterone) have been elevated in each case, but readily decline after dexamethasone administration. Patients display a defect in the conversion of cortisone to cortisol, suggesting inhibition of 11-oxoreductase activity and therefore, by im-

853

plication, inhibition of 11␤-HSD1. Indeed, CRD represents the putative “human 11␤-HSD1 knockout.” Studies indicate an increased excretion of total cortisol metabolites indicative of enhanced cortisol secretion rates, often to values reported in patients with Cushing’s syndrome. However, virtually all the urinary metabolites are excreted as 11-oxo-metabolites (THE, THA) with very low/undetectable levels of THF and allo-THF appearing in the urine. Typical THF⫹allo-THF/ THE ratios, therefore, of ⬍0.05 (normal adult range, 0.7–1.3) have been reported. (It is of interest that similar patterns of cortisol metabolism are observed in the normal neonatal period.) These data, together with an attenuated plasma cortisol response after oral cortisone acetate, suggest defective 11-oxoreductase activity (and thus 11␤-HSD1 activity). The defect in E to F conversion results in an increased metabolic clearance rate for cortisol; through the negative feedback mechanism, ACTH secretion is increased to maintain normal circulating cortisol concentrations, but at the expense of ACTH-mediated androgen excess. Dexamethasone suppresses endogenous ACTH and adrenal androgen levels, thereby explaining its therapeutic role in CRD. Although this biochemical evidence strongly implicated a defect in 11␤HSD1 as being causative in the syndrome of CRD, it is only

TABLE 5. Clinical and biochemical characteristics of all currently reported cases of CRD Age at presentation (yr)

Sex

28

F

Hirsutism

1 Test 1 DHEAS 1 Androst

17

F

Oligomenorrhea, hirsutism, acne, obesity

1 Test 1 DHEAS

18

F

Oligomenorrhea, hirsutism, acne

1 DHEAS

30

F

1 Test

27

F

Oligomenorrhea, hirsutism, infertility Oligomennorrhea, hirsutism

M

Clinical features

Excess body hair (sibling of above patient) Obesity, oligomenorrhea, hirsutism

37

F

4

F

55

F

44

F

Hirsutism

7

M

Precocious puberty

CAH diagnosed shortly after birth (21-hydroxylase deficiency). 17-OHP levels unresponsive to cortisone acetate. Androgenetic alopecia, mild hirsutes

Serum androgens

THF ⫹ allo-THF: THE ratio

Comments

Fall in androgens with dexamethasone treatment

396

0.039

Fall in androgens with dexamethasone treatment although developed cushingoid side effects

397

0.045

Sibling of above patient. Fall in androgens with dexamethasone treatment Fall in testosterone with dexamethasone treatment Normal menstrual cycle and suppression of elevated androgens with dexamethasone treatment

397

1 Test 1 DHEAS 1 Androst

Sibling of above patient 1 Test 1 DHEAS 1 Androst

0.03

2

1 1 1 1 1 1 1 1

Test DHEAS Androst Test Androst Test DHEAS Androst

Ref.

17-OHP levels suppressed completely with prednisolone indicative of an inability to activate cortisone acetate

0.05 0.04 0.04

398 348

348 348 84, 340

341

342 Fall in androgens with dexamethasone treatment Pubertal development halted with dexamethasone treatment

84, 344 84, 343

Test, Testosterone; DHEAS, dehydroepiandrosterone sulfate; CAH, congenital adrenal hyperplasia; 17-OHP, 17-hydroxyprogesterone; Androst, androstenedione; F, female; M, male; 1, increased; 2, decreased.

854



recently that the molecular basis for the disease has been defined. B. Molecular basis for CRD and directionality of 11␤-HSD1

The mode of inheritance of CRD is thought to be autosomally recessive, as two sets of sib-pairs have been identified without affected parents. Analysis of genomic DNA has been undertaken in a number of patients to try and determine a mutation within HSD11B1. Southern blot analysis of HSD11B1 from one CRD patient showed no gross deletions or rearrangements (339). In addition, further sequencing of the coding region of HSD11B1 within four CRD patients revealed no mutations (339 –342). Recently, we have reported an extensive genetic investigation of HSD11B1 in three CRD kindreds, each with a single affected case. The CRD cases, one of which is male, all exhibited characteristically low urinary THF⫹allo-THF/THE ratios of between 0.03 and 0.04 (reference range, 0.7–1.1) and have been described previously in the literature (340, 343, 344). We also reported the first analysis of 11␤-HSD1 mRNA levels and enzyme activity in tissue from a CRD subject. We failed to identify mutations in the six exons of HSD11B1 in affected cases. The same was true for 1.5 kb of the HSD11B1 promoter and introns 1, 2, and 5. However, in all three CRD cases, two polymorphisms in complete linkage disequilibrium within intron 3 of HSD11B1 were identified: an A insertion (83557) and, 40 bp downstream, a T to G substitution (83597). The allele frequency for the 83557A/83597T-G haplotype was 14% in control populations (84). Although the 11␤-HSD1 cDNA sequence was normal in case 1, adipose tissue mRNA levels were 28-fold lower when compared with an unaffected sister, and corresponding oxoreductase activity was absent (0% conversion of E to F vs. 14% in the unaffected sibling). In luciferase reporter assays, there was a 2.5-fold reduction in transcriptional activity in HSD11B1 constructs containing the intron 3 83557A/ 83597T-G mutation compared with wild type, suggesting that this region of the gene acts as an intronic enhancer of HSD11B1 expression. These data are in keeping with published precedents suggesting a silencer/enhancer role for intronic sequences in many genes including HSD11B2 (345). The impact of heterozygosity for the 83557A/83597T-G mutation upon cortisol metabolism is unknown, but the CRD phenotype cannot be explained by heterozygosity or homozygosity at this single locus because this was present in 25% and 3% of normals, respectively. As discussed in Section III.B, 11␤-HSD1 oxoreductase activity requires NADPH. The purified enzyme behaves as a NADP-dependent dehydrogenase (52), and the switch to oxoreductase activity upon tissue homogenization (83) suggests a close association between 11␤-HSD1 and a NADPH generation system. The glucose-6-phosphate dehydrogenase enzyme of the pentose phosphate pathway has been considered to be the major source of intracellular NADPH (346), but this is a cytosolic enzyme and the membrane-binding domain of 11␤-HSD1 directs the active site of the enzyme toward the ER lumen, away from the cytosol (54, 85, 347). Here H6PDH, an enzyme of previously uncertain significance but related to glucose-6-phosphate dehydrogenase,

can catalyze the first two steps of the pentose phosphate pathway and generate NADPH (349, 350). H6PDH is present in most tissues but is highly expressed in liver and adipose tissue, sites of 11␤-HSD1 oxoreductase activity (349, 351, 352). Sequencing of the H6PD gene, localized to chromosome 1p36.2 (353), revealed mutations within exon 5 in all three CRD cases. Case 1 was heterozygous for 620ins29bp621, an insert of 29 bp between residues 620 and 621 that results in the inclusion of three new amino acids and a stop codon, truncating the protein by 171 amino acids. Cases 2 and 3 were homozygous for R453Q, a nonconservative missense amino acid change. When H6PD mutant cDNAs were synthesized and expressed in hepatic WRL68 cells, the 620ins29bp621 mutant was devoid of H6PDH activity, and the R453Q mutant demonstrated residual activity that was consistently less than 50% of wild type. The impact of the R453Q mutation in the context of a normal HSD11B1 genotype is unknown. The allele frequency of R453Q in both Scottish and Indo-Asian controls is 21–22%, so that approximately 4% of the normal population is homozygous for this mutation. The combination of homozygosity for the H6PD R453Q and heterozygosity for the HSD11B1 intron 3 83557A/83597T-G mutations was not observed in our control subjects, and its presence in two of the three CRD patients is unlikely to be due to chance (P ⫽ 0.0008, Fisher’s exact test). Based on our normative allelic frequency data, we can predict a prevalence rate for CRD of approximately 0.1% for the mutations HSD11B1⫹/⫺ and R453Q H6PD⫺/⫺. Alternatively, interaction with an unidentified third locus, modifying penetrance, might be implicated. Thus, a combination of mutations in the HSD11B1 and H6PD genes interacts to cause CRD manifesting in a reduction in 11␤-HSD1 expression and impaired provision of NADPH to an enzyme that is critically dependent on reduced cofactor for oxoreductase activity (Fig. 1A). A digenic triallelic mode of inheritance is proposed, in which three distinct alleles, from two (or more) loci (HSD11B1 and H6PD) are necessary for trait manifestation. IX. HSD11B1 Linkage and Association Studies A. Obesity

Strong evidence for a genetic component to obesity is provided through studies of correlations in BMI and other adiposity measures between family members, adoptees and their biological relatives, and monozygotic and dizygotic twins. In fact, the genetic effect on visceral fat (adjusted for fat mass) has been calculated from twin studies to account for about 50% of the phenotypic variance (354). Monogenic forms of obesity due to mutations, notably in the genes encoding leptin, leptin receptor, MCR4, and proopiomelanocortin, have been described. However, the role of genetic factors in common obesity is likely to be polygenic, comprising an interaction between several susceptibility genes that individually have small effects (355). Indeed, more than 50 different loci have been linked to obesity through genome scan and linkage studies including loci on chromosome 1 (355).


The characterization of polymorphisms within the human HSD11B1 gene has enabled an evaluation of this locus as a susceptibility factor for obesity. Genotyping of a large normal population demonstrated a lack of association between the HSD11B1 gene and BMI, but a weak association was observed with waist-to-hip ratio (WHR) in women. Similarly, in a case-control association study evaluating a group of Danish obese subjects, no relationship between allelic variation at these microsatellite loci and BMI was observed (131). However, the link between glucocorticoids and adipose tissue biology primarily relates to adipose tissue distribution rather than absolute fat mass. Although urinary steroids were not analyzed in the Danish ADIGEN study, a borderline significant association was found between long alleles for a CA15 microsatellite marker and short alleles for an adjacent CA19 marker with a raised THF⫹allo-THF/THE ratio and WHR in the montoring of trends and determinants in cardiovascular disease (MONICA) population. These data are compatible with increased 11␤-HSD1 activity predisposing to central obesity. However, a relationship between this allele distribution and central fat distribution was not evident in the ADIGEN study. HSD11B1 genotypes were similar in lean and obese groups, and no relationship was seen with allele length at the two polymorphic loci and BMI or WHR in either group. The lack of association seen in this study may be explained, in part, by the relatively poor heterozygosity rates for the (CA)n microsatellite markers, and other markers may prove more fruitful in future studies. A study has screened the HSD11B1 gene-coding region and intron/exon boundaries for mutations in eight patients with abdominal obesity and four lean control subjects (130). No mutations were identified in the coding region; however, a polymorphism within an intron was identified: a deletion of 11 bp in intron 1 [position 441– 451 of GenBank accession no. M76661 (exon 1)] was detected in all subjects studied. This polymorphism does not alter splicing and does not affect donor or acceptor splice sites (130). In a separate study, the intron 3 adenine insertion was identified and associated with pediatric obesity in a mutation screen of the HSD11B1 locus (356). These data support our functional analyses of this mutation, as described in Section VIII.B., whereby the presence of the inserted A leads to a reduction in transcription and consequently a decrease in 11␤-HSD1 activity. A recent study identified five common haplotypes within the 55-kb region surrounding HSD11B1 from 96 chromosomes. Family trio samples (350) were reported with extremes of WHR. A SNP in the 5⬘-untranslated region of HSD11B1 was associated with WHR, the minor allele being associated with lower WHRs (357). Interestingly, the obesity gene map includes several studies that have implicated the chromosomal loci 1p36.2–1p36.3, the H6PDH chromosomal location, for association with obesity (355). B. Other diseases

Genetic analysis of HSD11B1 in CRD patients may provide an important candidate gene for future analysis in larger more heterogeneous polycystic ovary syndrome (PCOS) population studies. It is accepted that PCOS has a genetic


855

component, although most likely working in concert with environmental factors (358, 359). Epidemiological studies show that PCOS is a familial disorder with a sibling risk of 50 – 80% (360, 361). Twin studies have shown discordance for polycystic ovaries, suggesting that PCOS might have a complex inheritance pattern, and segregation analyses within families propose polygenic influences confounded by environmental factors (362). However, a single gene may have a predominant effect in a given family. With the reported partial defects in 11␤-HSD1 in patients with PCOS (363), it will be of interest to determine whether the HSD11B1 gene (and/or the H6PD gene) acts as important susceptibility loci in this regard. Primary open-angle glaucoma has a significant hereditary component (364, 365), and several genetic loci, many of which are located on chromosome 1q, have been linked to its pathogenesis (366). Mutations of the myocilin/trabecular meshwork-inducible glucocorticoid response account for most, but probably not all, of these cases, and other additional pathological factors may be implicated. Interestingly, HSD11B1 is localized to 1q32– 41. The recent identification of 11␤-HSD1 in human bone has raised the possibility that it may be implicated in the pathogenesis of age-related and glucocorticoid-induced osteoporosis. Several candidate genes have been identified as being important in the pathogenesis of osteoporosis (367), but to date there are no large genetic studies that have assessed the contribution of 11␤-HSD1. However, the cytogenetic localization of H6PD gene, 1p36, has been implicated for association with hip and femoral neck bone mineral density in several genome-wide scans (368, 369).

X. Conclusions

11␤-HSD isozymes serve an important function in cortisol metabolism and clearance. However, based on the important precedent of 11␤-HSD2 and the control of renal cortisol concentrations, a series of in vitro, in vivo, and clinical studies have now defined the pivotal role that 11␤-HSD1 plays in modulating glucocorticoid hormone action in many tissues. Interest has principally focused on the liver and adipose tissue and the regulation of hepatic gluconeogenesis and fat mass. As a consequence, 11␤-HSD1 has emerged as an exciting novel therapeutic target in the metabolic syndrome, and the results of trials employing selective 11␤-HSD1 inhibitors are anxiously awaited. The role of 11␤-HSD1 in other diseases including osteoporosis and glaucoma is under evaluation. Unlike its type 2 counterpart, 11␤-HSD1 is a bidirectional enzyme, and the elucidation of the molecular basis for the “human 11␤-HSD1 knockout” (i.e., CRD) has uncovered the crucial enzyme that conveys reductase activity upon 11␤HSD1 (i.e., H6PDH). In turn, this has opened up new avenues of research in terms of intracellular redox control and its impact upon cellular metabolism. More than 50 yr ago Hench, Kendall, and Reichstein shared the Nobel prize for their discovery of cortisone and description of its antiinflammatory properties in patients with rheumatoid arthritis, thereby establishing the endocrine

856


importance of 11␤-HSD1. Today 11␤-HSD1 is also established as an important “prereceptor” regulator of glucocorticoid action at an autocrine level. Targeted inhibition of the enzyme may reduce the action of cortisol in key tissues without resulting in the deleterious consequences of circulating cortisol excess or deficiency.

Acknowledgments Address all correspondence and requests for reprints to: Paul M. Stewart, M.D., FRCP FMedSci, Professor of Medicine, Division of Medical Sciences, University of Birmingham, Queen Elizabeth Hospital, Edgbaston, B15 2TH, United Kingdom. E-mail: [email protected]

References 1. White PC, Mune T, Agarwal AK 1997 11 ␤-Hydroxysteroid dehydrogenase and the syndrome of apparent mineralocorticoid excess. Endocr Rev 18:135–156 2. Munck A, Naray-Fejes-Toth A 1992 The ups and downs of glucocorticoid physiology. Permissive and suppressive effects revisited. Mol Cell Endocrinol 90:C1–C4 3. Marver D 1984 Evidence of corticosteroid action along the nephron. Am J Physiol 246:F111–F123 4. Cope CL, Black E 1958 The production rate of cortisol in man. Lancet 1:1020 –1024 5. Esteban NV, Loughlin T, Yergey AL, Zawadzki JK, Booth JD, Winterer JC, Loriaux DL 1991 Daily cortisol production rate in man determined by stable isotope dilution/mass spectrometry. J Clin Endocrinol Metab 72:39 – 45 6. Peterson RE, Pierce CE 1960 The metabolism of corticosterone in man. J Clin Invest 39:741–757 7. Jones KM, Lloyd-Jones R, Riondel A, Tait JF, Tait SAS, Bulbrook RD, Greenwood FC 1959 Aldosterone secretion and metabolism in normal men and women and in pregnancy. Acta Endocrinol (Copenh) 30:321–329 8. Monder C, Shackleton CHL 1984 11␤-Hydroxysteroid dehydrogenase: fact or fancy? Steroids 44:383– 415 9. Monder C, White PC 1993 11␤-Hydroxysteroid dehydrogenase. Vitam Horm 47:187–271 10. McGuire JS, Tomkins GS 1959 The multiplicity and specificity of ␦4-3-ketosteroid hydrogenases. Arch Biochem Biophys 82:476 – 481 11. Cope CL 1972 Metabolic breakdown. In: Cope CL, ed. Adrenal steroids and disease. London: Pitman Medical; 80 –104 12. Shackleton CHL 1993 Mass spectrometry in the diagnosis of steroid-related disorders and hypertension research. J Steroid Biochem Mol Biol 45:127–140 13. Monder C, Bradlow HL 1980 Cortoic acids: explorations at the frontier of corticosteroid metabolism. Recent Prog Horm Res 36: 345– 400 14. Fukushima DK, Bradlow HL, Hellman L, Zumoff B, Gallagher TF 1960 Metabolic transformation of hydrocortisone-4-C14 in normal men. J Biol Chem 235:2246 –2253 15. Tortorella C, Aragona F, Nussdorfer GG 1999 In vivo evidence that human adrenal glands possess 11 ␤-hydroxysteroid dehydrogenase activity. Life Sci 65:2823–2827 16. Meulenberg EP, Hofman JA 1990 The effect of pretreatment of saliva on steroid hormone concentrations. J Clin Chem Clin Biochem 28:923–928 17. Meulenberg PM, Hofman JA 1990 The effect of oral contraceptive use and pregnancy on the daily rhythm of cortisol and cortisone. Clin Chim Acta 190:211–221 18. Kendall EC 1971 Arthritis. In: Cortisone. New York: Charles Scribner’s Sons; 121–137 19. Osinski PA 1960 Steroid 11␤-ol dehydrogenase in human placenta. Nature 187:777

Tomlinson et al. • 11␤-HSD1 20. Jenkins JS 1966 The metabolism of cortisol by human extrahepatic tissues. J Endocrinol 34:51–56 21. Bush IE 1969 11␤-Hydroxysteroid dehydrogenase: contrast between studies in vivo and studies in vitro. Adv Biosci 3:23–39 22. Hellman L, Nakada F, Zumoff B, Fukushima D, Bradlow HL, Gallagher TF 1971 Renal capture and oxidation of cortisol in man. J Clin Endocrinol 33:52– 62 23. Srivastava LS, Werk EE, Thrasher K, Sholiton LJ, Kozera R, Nolten W, Knowles HC 1973 Plasma cortisone concentration as measured by radioimmunoassay. J Clin Endocrinol Metab 36: 937–943 24. Whitworth JA, Stewart PM, Burt D, Atherden SM, Edwards CRW 1989 The kidney is the major site of cortisone production in man. Clin Endocrinol (Oxf) 31:355–361 25. Walker BR, Connacher AA, Webb DJ, Edwards CR 1992 Glucocorticoids and blood pressure: a role for the cortisol/cortisone shuttle in the control of vascular tone in man. Clin Sci 83:171–178 26. Palermo M, Shackleton CH, Mantero F, Stewart PM 1996 Urinary free cortisone and the assessment of 11␤-hydroxysteroid dehydrogenase activity in man. Clin Endocrinol (Oxf) 45:605– 611 27. Weaver JU, Thaventhiran L, Noonan K, Burrin JM, Taylor NF, Norman MR, Monson JP 1994 The effect of growth hormone replacement on cortisol metabolism and glucocorticoid sensitivity in hypopituitary adults. Clin Endocrinol (Oxf) 41:639 – 648 28. Weaver JU, Taylor NF, Monson JP, Wood PJ, Kelly WF 1998 Sexual dimorphism in 11 beta hydroxysteroid dehydrogenase activity and its relation to fat distribution and insulin sensitivity; a study in hypopituitary subjects. Clin Endocrinol (Oxf) 49:13–20 29. Toogood AA, Taylor NF, Shalet SM, Monson JP 2000 Modulation of cortisol metabolism by low-dose growth hormone replacement in elderly hypopituitary patients. J Clin Endocrinol Metab 85:1727– 1730 30. Trainer PJ, Drake WM, Perry LA, Taylor NF, Besser GM, Monson JP 2001 Modulation of cortisol metabolism by the growth hormone receptor antagonist pegvisomant in patients with acromegaly. J Clin Endocrinol Metab 86:2989 –2992 31. Persson B, Hallborn J, Walfridsson M, Hahn-Hagerdal B, Keranen S, Penttila M, Jornvall H 1993 Dual relationships of xylitol and alcohol dehydrogenases in families of two protein types. FEBS Lett 324:9 –14 32. Walter KA, Bennett GN, Papoutsakis ET 1992 Molecular characterization of two Clostridium acetobutylicum ATCC 824 butanol dehydrogenase isozyme genes. J Bacteriol 174:7149 –7158 33. Bohren KM, Bullock B, Wermuth B, Gabbay KH 1989 The aldoketo reductase superfamily. cDNAs and deduced amino acid sequences of human aldehyde and aldose reductases. J Biol Chem 264:9547–9551 34. Nordling E, Jornvall H, Persson B 2002 Medium-chain dehydrogenases/reductases (MDR). Family characterizations including genome comparisons and active site modeling. Eur J Biochem 269: 4267– 4276 35. Persson B, Krook M, Jo¨rnvall H 1991 Characteristics of short-chain alcohol dehydrogenases and related enzymes. Eur J Biochem 200: 537–543 36. Baker ME 1996 Unusual evolution of 11␤- and 17␤-hydroxysteroid and retinol dehydrogenases. Bioessays 18:63–70 37. Jornvall H, Persson B, Krook M, Atrian S, Gonzalez-Duarte R, Jeffery J, Ghosh D 1995 Short-chain dehydrogenases/reductases (SDR). Biochemistry 34:6003– 6013 38. Persson B, Kallberg Y, Oppermann U, Jornvall H 2003 Coenzymebased functional assignments of short-chain dehydrogenases/ reductases (SDRs). Chem Biol Interact 143–144:271–278 39. Krozowski Z 1994 The short-chain alcohol dehydrogenase superfamily: variations on a common theme. J Steroid Biochem Mol Biol 51:125–130 40. Oppermann UC, Filling C, Jornvall H 2001 Forms and functions of human SDR enzymes. Chem Biol Interact 130 –132:699 –705 41. Oppermann U, Filling C, Hult M, Shafqat N, Wu X, Lindh M, Shafqat J, Nordling E, Kallberg Y, Persson B, Jornvall H 2003 Short-chain dehydrogenases/reductases (SDR): the 2002 update. Chem Biol Interact 143–144:247–253 42. Stewart PM, Krozowski ZS 1999 11␤-Hydroxysteroid dehydrogenase. Vitam Horm 57:249 –324

Tomlinson et al. • 11␤-HSD1 43. Filling C, Berndt KD, Benach J, Knapp S, Prozorovski T, Nordling E, Ladenstein R, Jornvall H, Oppermann U 2002 Critical residues for structure and catalysis in short-chain dehydrogenases/reductases. J Biol Chem 277:25677–25684 44. Tanabe T, Tanaka N, Uchikawa K, Kabashima T, Ito K, Nonaka T, Mitsui Y, Tsuru M, Yoshimoto T 1998 Roles of the Ser146, Tyr159, and Lys163 residues in the catalytic action of 7␣-hydroxysteroid dehydrogenase from Escherichia coli. J Biochem (Tokyo) 124:634 – 641 45. Tanaka N, Nonaka T, Tanabe T, Yoshimoto T, Tsuru D, Mitsui Y 1996 Crystal structures of the binary and ternary complexes of 7␣-hydroxysteroid dehydrogenase from Escherichia coli. Biochemistry 35:7715–7730 46. Grundy WN, Bailey TL, Elkan CP, Baker ME 1997 Hidden Markov model analysis of motifs in steroid dehydrogenases and their homologs. Biochem Biophys Res Commun 231:760 –766 47. Duax WL, Ghosh D, Pletnev V 2000 Steroid dehydrogenase structures, mechanism of action, and disease. Vitam Horm 58:121–148 48. Duax WL, Griffin JF, Ghosh D 1996 The fascinating complexities of steroid-binding enzymes. Curr Opin Struct Biol 6:813– 823 49. Tsigelny I, Baker ME 1995 Structures stabilizing the dimer interface on human 11 ␤-hydroxysteroid dehydrogenase types 1 and 2 and human 15-hydroxyprostaglandin dehydrogenase and their homologs. Biochem Biophys Res Commun 217:859 – 868 50. Agarwal AK, Monder C, Eckstein B, White PC 1989 Cloning and expression of rat cDNA encoding corticosteroid 11␤-dehydrogenase. J Biol Chem 264:18939 –18943 51. Monder C, Lakshmi V 1989 Evidence for kinetically distinct forms of corticosteroid 11␤-dehydrogenase in rat liver microsomes. J Steroid Biochem 32:77– 83 52. Lakshmi V, Monder C 1988 Purification and characterization of the corticosteroid 11␤-dehydrogenase component of the rat liver 11␤hydroxysteroid dehydrogenase complex. Endocrinology 123:2390 – 2398 53. Nobel CS, Dunas F, Abrahmsen LB 2002 Purification of full-length recombinant human and rat type 1 11␤-hydroxysteroid dehydrogenases with retained oxidoreductase activities. Protein Expr Purif 26:349 –356 54. Ozols J 1995 Lumenal orientation and post-translational modifications of the liver microsomal 11␤-hydroxysteroid dehydrogenase. J Biol Chem [Erratum (1995) 270:10360] 270:2305–2312 55. Tannin GM, Agarwal AK, Monder C, New MI, White PC 1991 The human gene for 11␤-hydroxysteroid dehydrogenase. Structure, tissue distribution, and chromosomal localization. J Biol Chem 266: 16653–16658 56. Rajan V, Chapman KE, Lyons V, Jamieson P, Mullins JJ, Edwards CR, Seckl JR 1995 Cloning, sequencing and tissue-distribution of mouse 11␤-hydroxysteroid dehydrogenase-1 cDNA. J Steroid Biochem Mol Biol 52:141–147 57. Moore CC, Mellon SH, Murai J, Siiteri PK, Miller WL 1993 Structure and function of the hepatic form of 11␤-hydroxysteroid dehydrogenase in the squirrel monkey, an animal model of glucocorticoid resistance. Endocrinology 133:368 –375 58. Yang K, Smith CL, Dales D, Hammond GL, Challis JR 1992 Cloning of an ovine 11␤-hydroxysteroid dehydrogenase complementary deoxyribonucleic acid: tissue and temporal distribution of its messenger ribonucleic acid during fetal and neonatal development. Endocrinology 131:2120 –2126 59. Pu X, Yang K 2000 Guinea pig 11␤-hydroxysteroid dehydrogenase type 1: primary structure and catalytic properties. Steroids 65: 148 –156 60. Shafqat N, Elleby B, Svensson S, Shafqat J, Jornvall H, Abrahmsen L, Oppermann U 2003 Comparative enzymology of 11␤-hydroxysteroid dehydrogenase type 1 from glucocorticoid resistant (Guinea pig) versus sensitive (human) species. J Biol Chem 278:2030 –2035 61. Maser E, Volker B, Friebertshauser J 2002 11 ␤-Hydroxysteroid dehydrogenase type 1 from human liver: dimerization and enzyme cooperativity support its postulated role as glucocorticoid reductase. Biochemistry 41:2459 –2465 62. Maser E, Friebertshauser J, Volker B 2003 Purification, characterization and NNK carbonyl reductase activities of 11␤-hydroxysteroid dehydrogenase type 1 from human liver: enzyme cooper-


63. 64. 65.

66.

67.

68.

69. 70. 71.

72.

73.

74.

75. 76. 77. 78.

79.

80. 81. 82.

857

ativity and significance in the detoxification of a tobacco-derived carcinogen. Chem Biol Interact 143–144:435– 448 Condon J, Ricketts ML, Whorwood CB, Stewart PM 1997 Ontogeny and sexual dimorphic expression of mouse type 2 11␤-hydroxysteroid dehydrogenase. Mol Cell Endocrinol 127:121–128 Maser E, Bannenberg G 1994 11␤-Hydroxysteroid dehydrogenase mediates reductive metabolism of xenobiotic carbonyl compounds. Biochem Pharmacol 47:1805–1812 Duperrex H, Kenouch S, Gaeggeler HP, Seckl JR, Edwards CR, Farman N, Rossier BC 1993 Rat liver 11␤-hydroxysteroid dehydrogenase complementary deoxyribonucleic acid encodes oxoreductase activity in a mineralocorticoid-responsive toad bladder cell line. Endocrinology 132:612– 619 Low SC, Chapman KE, Edwards CR, Seckl JR 1994 ’Liver-type’ 11␤-hydroxysteroid dehydrogenase cDNA encodes reductase but not dehydrogenase activity in intact mammalian COS-7 cells. J Mol Endocrinol 13:167–174 Jamieson PM, Chapman KE, Edwards CR, Seckl JR 1995 11␤Hydroxysteroid dehydrogenase is an exclusive 11␤-reductase in primary cultures of rat hepatocytes: effect of physicochemical and hormonal manipulations. Endocrinology 136:4754 – 4761 Hammami MM, Siiteri PK 1991 Regulation of 11␤-hydroxysteroid dehydrogenase activity in human skin fibroblasts: enzymatic modulation of glucocorticoid action. J Clin Endocrinol Metab 73: 326 –334 Bujalska IJ, Kumar S, Stewart PM 1997 Does central obesity reflect “Cushing’s disease of the omentum”? Lancet 349:1210 –1213 Bujalska IJ, Kumar S, Hewison M, Stewart PM 1999 Differentiation of adipose stromal cells: the roles of glucocorticoids and 11␤-hydroxysteroid dehydrogenase. Endocrinology 140:3188 –3196 Hundertmark S, Buhler H, Ragosch V, Dinkelborg L, Arabin B, Weitzel HK 1995 Correlation of surfactant phosphatidylcholine synthesis and 11␤-hydroxysteroid dehydrogenase in fetal lung. Endocrinology 136:2573–2578 Rajan V, Edwards CR, Seckl JR 1996 11␤-Hydroxysteroid dehydrogenase in cultured hippocampal cells reactivates inert 11dehydrocorticosterone, potentiating neurotoxicity. J Neurosci 16: 65–70 Stewart PM, Murry BA, Mason JI 1994 Human kidney 11 ␤hydroxysteroid dehydrogenase is a high affinity nicotinamide adenine dinucleotide-dependent enzyme and differs from the cloned type I isoform. J Clin Endocrinol Metab 79:480 – 484 Gao HB, Ge RS, Lakshmi V, Marandici A, Hardy MP 1997 Hormonal regulation of oxidative and reductive activities of 11␤hydroxysteroid dehydrogenase in rat Leydig cells. Endocrinology 138:156 –161 Phillips DM, Lakshmi V, Monder C 1989 Corticosteroid 11␤dehydrogenase in rat testis. Endocrinology 125:209 –216 Wang GM, Ge RS, Latif SA, Morris DJ, Hardy MP 2002 Expression of 11␤-hydroxylase in rat Leydig cells. Endocrinology 143:621– 626 Leckie CM, Welberg LA, Seckl JR 1998 11␤-Hydroxysteroid dehydrogenase is a predominant reductase in intact rat Leydig cells. J Endocrinol 159:233–238 Bujalska IJ, Walker EA, Hewison M, Stewart PM 2002 A switch in dehydrogenase to reductase activity of 11␤-hydroxysteroid dehydrogenase type 1 upon differentiation of human omental adipose stromal cells. J Clin Endocrinol Metab 87:1205–1210 Jellinck PH, Pavlides C, Sakai RR, McEwen BS 1999 11␤Hydroxysteroid dehydrogenase functions reversibly as an oxidoreductase in the rat hippocampus in vivo. J Steroid Biochem Mol Biol 71:139 –144 Seckl JR, Walker BR 2001 Minireview: 11␤-hydroxysteroid dehydrogenase type 1—a tissue-specific amplifier of glucocorticoid action. Endocrinology 142:1371–1376 Morris DJ, Brem AS, Ge R, Jellinck PH, Sakai RR, Hardy MP 2003 The functional roles of 11␤-HSD1: vascular tissue, testis and brain. Mol Cell Endocrinol 203:1–12 Walker EA, Clark AM, Hewison M, Ride JP, Stewart PM 2001 Functional expression, characterization, and purification of the catalytic domain of human 11-␤-hydroxysteroid dehydrogenase type 1. J Biol Chem 276:21343–21350

858


83. Agarwal AK, Tusie-Luna MT, Monder C, White PC 1990 Expression of 11␤-hydroxysteroid dehydrogenase using recombinant vaccinia virus. Mol Endocrinol 4:1827–1832 84. Draper N, Walker EA, Bujalska IJ, Tomlinson JW, Chalder SM, Arlt W, Lavery GG, Bedendo O, Ray DW, Laing I, Malunowicz E, White PC, Hewison M, Mason PJ, Connell JM, Shackleton CH, Stewart PM 2003 Mutations in the genes encoding 11␤-hydroxysteroid dehydrogenase type 1 and hexose-6-phosphate dehydrogenase interact to cause cortisone reductase deficiency. Nat Genet 34:434 – 439 85. Odermatt A, Arnold P, Stauffer A, Frey BM, Frey FJ 1999 The N-terminal anchor sequences of 11␤-hydroxysteroid dehydrogenases determine their orientation in the endoplasmic reticulum membrane. J Biol Chem 274:28762–28770 86. Obeid J, White PC 1992 Tyr-179 and Lys-183 are essential for enzymatic activity of 11␤-hydroxysteroid dehydrogenase. Biochem Biophys Res Commun 188:222–227 87. Mercer W, Obeyesekere V, Smith R, Krozowski Z 1993 Characterization of 11␤-HSD1B gene expression and enzymatic activity. Mol Cell Endocrinol 92:247–251 88. Blum A, Raum A, Martin H, Maser E 2001 Human 11␤-hydroxysteroid dehydrogenase 1/carbonyl reductase: additional domains for membrane attachment? Chem Biol Interact 130 –132:749 –759 89. Agarwal AK, Mune T, Monder C, White PC 1995 Mutations in putative glycosylation sites of rat 11␤-hydroxysteroid dehydrogenase affect enzymatic activity. Biochim Biophys Acta 1248:70 –74 90. Blum A, Martin HJ, Maser E 2000 Human 11␤-hydroxysteroid dehydrogenase type 1 is enzymatically active in its nonglycosylated form. Biochem Biophys Res Commun 276:428 – 434 91. Blum A, Martin HJ, Maser E 2000 Human 11␤-hydroxysteroid dehydrogenase 1/carbonyl reductase: recombinant expression in the yeast Pichia pastoris and Escherichia coli. Toxicology 144:113–120 92. Latif SA, Sheff MF, Ribeiro CE, Morris DJ 1997 Selective inhibition of sheep kidney 11␤-hydroxysteroid dehydrogenase isoform 2 activity by 5␣-reduced (but not 5␤) derivatives of adrenocorticosteroids. Steroids 62:230 –237 93. Diederich S, Grossmann C, Hanke B, Quinkler M, Herrmann M, Bahr V, Oelkers W 2000 In the search for specific inhibitors of human 11␤-hydroxysteroid-dehydrogenases (11␤-HSDs): chenodeoxycholic acid selectively inhibits 11␤-HSD-I. Eur J Endocrinol 142:200 –207 94. Sreerama L, Sladek NE 1994 Identification of the class-3 aldehyde dehydrogenases present in human MCF-7/0 breast adenocarcinoma cells and normal human breast tissue. Biochem Pharmacol 48:617– 620 95. Maser E, Oppermann UC 1997 Role of type-1 11␤-hydroxysteroid dehydrogenase in detoxification processes. Eur J Biochem 249: 365–369 96. Winzer K, Van Noorden CJ, Kohler A 2002 Sex-specific biotransformation and detoxification after xenobiotic exposure of primary cultured hepatocytes of European flounder (Platichthys flesus L.). Aquat Toxicol 59:17–33 97. Szotakova B, Skalova L, Wsol V, Kvasnieckova E 2000 Reduction of the potential anticancer drug oracin in the rat liver in-vitro. J Pharm Pharmacol 52:495–500 98. Hult M, Nobel CS, Abrahmsen L, Nicoll-Griffith DA, Jornvall H, Oppermann UC 2001 Novel enzymological profiles of human 11␤hydroxysteroid dehydrogenase type 1. Chem Biol Interact 130 – 132:805– 814 99. Oppermann UC, Maser E 2000 Molecular and structural aspects of xenobiotic carbonyl metabolizing enzymes. Role of reductases and dehydrogenases in xenobiotic phase I reactions. Toxicology 144: 71– 81 100. Bannenberg G, Martin HJ, Belai I, Maser E 2003 11␤-Hydroxysteroid dehydrogenase type 1: tissue-specific expression and reductive metabolism of some anti-insect agent azole analogues of metyrapone. Chem Biol Interact 143–144:449 – 457 101. Maser E 1998 11Beta-hydroxysteroid dehydrogenase responsible for carbonyl reduction of the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone in mouse lung microsomes. Cancer Res 58:2996 –3003

Tomlinson et al. • 11␤-HSD1 102. Finckh C, Atalla A, Nagel G, Stinner B, Maser E 2001 Expression and NNK reducing activities of carbonyl reductase and 11␤hydroxysteroid dehydrogenase type 1 in human lung. Chem Biol Interact 130 –132:761–773 103. Maser E 1995 Xenobiotic carbonyl reduction and physiological steroid oxidoreduction. The pluripotency of several hydroxysteroid dehydrogenases. Biochem Pharmacol 49:421– 440 104. Wsol V, Szotakova B, Skalova L, Maser E 2003 Stereochemical aspects of carbonyl reduction of the original anticancer drug oracin by mouse liver microsomes and purified 11␤-hydroxysteroid dehydrogenase type 1. Chem Biol Interact 143–144:459 – 468 105. Monder C, Stewart PM, Lakshmi V, Valentino R, Burt D, Edwards CRW 1989 Licorice inhibits corticosteroid 11␤-dehydrogenase of rat liver and kidney: in vivo and in vitro studies. Endocrinology 124:1046 –1053 106. Whorwood CB, Sheppard MC, Stewart PM 1993 Licorice inhibits 11␤-hydroxysteroid dehydrogenase messenger ribonucleic acid levels and potentiates glucocorticoid hormone action. Endocrinology 132:2287–2292 107. Albiston AL, Obeyesekere VR, Smith RE, Krozowski ZS 1994 Cloning and tissue distribution of the human 11␤-hydroxysteroid dehydrogenase type 2 enzyme. Mol Cell Endocrinol 105:R11–R17 108. Bush IE, Hunter SA, Meigs RA 1968 Metabolism of 11-oxygenated steroids. Metabolism in vitro by preparations of liver. Biochem J 107:239 –258 109. Yang K, Yu M 1994 Evidence for distinct isoforms of 11␤-hydroxysteroid dehydrogenase in the ovine liver and kidney. J Steroid Biochem Mol Biol 49:245–250 110. Stewart PM, Wallace AM, Valentino R, Burt D, Shackleton CHL, Edwards CRW 1987 Mineralocorticoid activity of liquorice: 11␤hydroxysteroid dehydrogenase deficiency comes of age. Lancet 2:821– 824 111. Stewart PM, Wallace AM, Atherden SM, Shearing C, Edwards CRW 1990 Mineralocorticoid activity of carbenoxolone: contrasting effects of carbenoxolone and liquorice on 11␤-hydroxysteroid dehydrogenase activity in man. Clin Sci 78:49 –54 112. Murphy BE 1981 Specificity of human 11␤-hydroxysteroid dehydrogenase. J Steroid Biochem 14:807– 809 113. Frey FJ 1987 Kinetics and dynamics of prednisolone. Endocr Rev 8:453– 473 114. Ferrari P, Smith RE, Funder JW, Krozowski ZS 1996 Substrate and inhibitor specificity of the cloned human 11␤-hydroxysteroid dehydrogenase type 2 isoform. Am J Physiol 270:E900 –E904 115. Diederich S, Eigendorff E, Burkhardt P, Quinkler M, BumkeVogt C, Rochel M, Seidelmann D, Esperling P, Oelkers W, Bahr V 2002 11␤-hydroxysteroid dehydrogenase types 1 and 2: an important pharmacokinetic determinant for the activity of synthetic mineralo- and glucocorticoids. J Clin Endocrinol Metab 87:5695– 5701 116. Buhler H, Perschel FH, Fitzner R, Hierholzer K 1994 Endogenous inhibitors of 11␤-OHSD: existence and possible significance. Steroids 59:131–135 117. Morita H, Zhou M, Foecking MF, Gomez-Sanchez EP, Cozza EN, Gomez-Sanchez CE 1996 11␤-Hydroxysteroid dehydrogenase type 2 complementary deoxyribonucleic acid stably transfected into Chinese hamster ovary cells: specific inhibition by 11 ␣hydroxyprogesterone. Endocrinology 137:2308 –2314 118. Souness GW, Morris DJ 1996 11␣- And 11 ␤-hydroxyprogesterone, potent inhibitors of 11␤-hydroxysteroid dehydrogenase, possess hypertensinogenic activity in the rat. Hypertension 27:421– 425 119. Alberts P, Engblom L, Edling N, Forsgren M, Klingstrom G, Larsson C, Ronquist-Nii Y, Ohman B, Abrahmsen L 2002 Selective inhibition of 11␤-hydroxysteroid dehydrogenase type 1 decreases blood glucose concentrations in hyperglycaemic mice. Diabetologia 45:1528 –1532 120. Barf T, Vallgarda J, Emond R, Haggstrom C, Kurz G, Nygren A, Larwood V, Mosialou E, Axelsson K, Olsson R, Engblom L, Edling N, Ronquist-Nii Y, Ohman B, Alberts P, Abrahmsen L 2002 Arylsulfonamidothiazoles as a new class of potential antidiabetic drugs. Discovery of potent and selective inhibitors of the 11␤-hydroxysteroid dehydrogenase type 1. J Med Chem 45:3813– 3815

Tomlinson et al. • 11␤-HSD1 121. Alberts P, Nilsson C, Selen G, Engblom LO, Edling NH, Norling S, Klingstrom G, Larsson C, Forsgren M, Ashkzari M, Nilsson CE, Fiedler M, Bergqvist E, Eva BB, Abrahmsen LB 2003 Selective inhibition of 11␤-hydroxysteroid dehydrogenase type 1 improves hepatic insulin sensitivity in hyperglycemic mice strains. Endocrinology 144:4755– 4762 122. Monder C, Lakshmi V 1990 Corticosteroid 11␤-dehydrogenase of rat tissues: immunological studies. Endocrinology 126:2435–2443 123. Davies WA, Luo H, Dong KW, Albrecht ED, Pepe GJ 1997 Cloning and expression of the 11␤-hydroxysteroid dehydrogenase type 1 gene in the baboon. Mol Cell Endocrinol 127:201–209 124. Kong S, McKinnon RA, Mojarrabi B, Stupans I 2002 Absence of type 1 11␤-hydroxysteroid dehydrogenase enzyme in koala liver. Comp Biochem Physiol C Toxicol Pharmacol 131:39 –50 125. Blum A, Raum A, Maser E 2003 Functional characterization of the human 11␤-hydroxysteroid dehydrogenase 1B (11␤-HSD 1B) variant. Biochemistry 42:4108 – 4117 126. Yang K, Yu M, Han VK 1995 Identification and tissue distribution of a novel variant of 11␤-hydroxysteroid dehydrogenase 1 transcript. J Steroid Biochem Mol Biol 55:247–253 127. Krozowski Z, Obeyesekere V, Smith R, Mercer W 1992 Tissuespecific expression of an 11␤-hydroxysteroid dehydrogenase with a truncated N-terminal domain. A potential mechanism for differential intracellular localization within mineralocorticoid target cells. J Biol Chem 267:2569 –2574 128. Maser E, Richter E, Friebertshauser J 1996 The identification of 11␤-hydroxysteroid dehydrogenase as carbonyl reductase of the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)1-butanone. Eur J Biochem 238:484 – 489 129. Oppermann UC, Netter KJ, Maser E 1995 Cloning and primary structure of murine 11␤-hydroxysteroid dehydrogenase/microsomal carbonyl reductase. Eur J Biochem 227:202–208 130. Caramelli E, Strippoli P, Di Giacomi T, Tietz C, Carinci P, Pasquali R 2001 Lack of mutations of type 1 11␤-hydroxysteroid dehydrogenase gene in patients with abdominal obesity. Endocr Res 27:47– 61 131. Draper N, Echwald SM, Lavery GG, Walker EA, Fraser R, Davies E, Sorensen TI, Astrup A, Adamski J, Hewison M, Connell JM, Pedersen O, Stewart PM 2002 Association studies between microsatellite markers within the gene encoding human 11␤-hydroxysteroid dehydrogenase type 1 and body mass index, waist to hip ratio, and glucocorticoid metabolism. J Clin Endocrinol Metab 87: 4984 – 4990 132. Moisan MP, Edwards CR, Seckl JR 1992 Differential promoter usage by the rat 11␤-hydroxysteroid dehydrogenase gene. Mol Endocrinol 6:1082–1087 133. Williams LJ, Lyons V, MacLeod I, Rajan V, Darlington GJ, Poli V, Seckl JR, Chapman KE 2000 C/EBP regulates hepatic transcription of 11beta -hydroxysteroid dehydrogenase type 1. A novel mechanism for cross-talk between the C/EBP and glucocorticoid signaling pathways. J Biol Chem 275:30232–30239 134. McKnight SL, Lane MD, Gluecksohn-Waelsch S 1989 Is CCAAT/ enhancer-binding protein a central regulator of energy metabolism? Genes Dev 3:2021–2024 135. Ramos RA, Nishio Y, Maiyar AC, Simon KE, Ridder CC, Ge Y, Firestone GL 1996 Glucocorticoid-stimulated CCAAT/enhancerbinding protein ␣ expression is required for steroid-induced G1 cell cycle arrest of minimal-deviation rat hepatoma cells. Mol Cell Biol 16:5288 –5301 136. Wang ND, Finegold MJ, Bradley A, Ou CN, Abdelsayed SV, Wilde MD, Taylor LR, Wilson DR, Darlington GJ 1995 Impaired energy homeostasis in C/EBP␣ knockout mice. Science 269:1108 – 1112 137. Screpanti I, Romani L, Musiani P, Modesti A, Fattori E, Lazzaro D, Sellitto C, Scarpa S, Bellavia D, Lattanzio G 1995 Lymphoproliferative disorder and imbalanced T-helper response in C/EBP␤-deficient mice. EMBO J 14:1932–1941 138. Kotelevtsev Y, Holmes MC, Burchell A, Houston PM, Schmoll D, Jamieson P, Best R, Brown R, Edwards CR, Seckl JR, Mullins JJ 1997 11␤-Hydroxysteroid dehydrogenase type 1 knockout mice show attenuated glucocorticoid-inducible responses and resist hyperglycemia on obesity or stress. Proc Natl Acad Sci USA 94:14924 – 14929


859

139. Masuzaki H, Paterson J, Shinyama H, Morton NM, Mullins JJ, Seckl JR, Flier JS 2001 A transgenic model of visceral obesity and the metabolic syndrome. Science 294:2166 –2170 140. Rask E, Olsson T, Soderberg S, Andrew R, Livingstone DE, Johnson O, Walker BR 2001 Tissue-specific dysregulation of cortisol metabolism in human obesity. J Clin Endocrinol Metab 86:1418 – 1421 141. Smith BT, Tanswell AK, Minshall D, Bogues WN, Vreeken E 1982 Influence of corticosteroids on glycogen content and steroid 11reductase activity in lung and liver of the fetal and newborn rat. Biol Neonate 42:201–207 142. Hundertmark S, Ragosch V, Schein B, Buhler H, Lorenz U, Fromm M, Weitzel HK 1994 Gestational age dependence of 11␤hydroxysteroid dehydrogenase and its relationship to the enzymes of phosphatidylcholine synthesis in lung and liver of fetal rat. Biochim Biophys Acta 1210:348 –354 143. Diaz R, Brown RW, Seckl JR 1998 Distinct ontogeny of glucocorticoid and mineralocorticoid receptor and 11␤-hydroxysteroid dehydrogenase types I and II mRNAs in the fetal rat brain suggest a complex control of glucocorticoid actions. J Neurosci 18:2570 –2580 144. Moisan MP, Seckl JR, Edwards CRW 1990 11␤-Hydroxysteroid dehydrogenase bioactivity and messenger RNA expression in rat forebrain: localization in hypothalamus, hippocampus, and cortex. Endocrinology 127:1450 –1455 145. Maser E, Friebertshauser J, Mangoura SA 1994 Ontogenic pattern of carbonyl reductase activity of 11␤-hydroxysteroid dehydrogenase in mouse liver and kidney. Xenobiotica 24:109 –117 146. Langlois DA, Matthews SG, Yu M, Yang K 1995 Differential expression of 11␤-hydroxysteroid dehydrogenase 1 and 2 in the developing ovine fetal liver and kidney. J Endocrinol 147:405– 411 147. Yang K, Matthews SG, Challis JR 1995 Developmental and glucocorticoid regulation of pituitary 11␤-hydroxysteroid dehydrogenase 1 gene expression in the ovine fetus and lamb. J Mol Endocrinol 14:109 –116 148. Kim EK, Wood CE, Keller-Wood M 1995 Characterization of 11␤hydroxysteroid dehydrogenase activity in fetal and adult ovine tissues. Reprod Fertil Dev 7:377–383 149. Yang K, Langlois DA, Campbell LE, Challis JR, Krkosek M, Yu M 1997 Cellular localization and developmental regulation of 11␤hydroxysteroid dehydrogenase type 1 (11␤-HSD1) gene expression in the ovine placenta. Placenta 18:503–509 150. Murphy BE 1978 Cortisol production and inactivation by the human lung during gestation and infancy. J Clin Endocrinol Metab 47:243–248 151. Abramovitz M, Branchaud CL, Murphy BE 1982 Cortisol-cortisone interconversion in human fetal lung: contrasting results using explant and monolayer cultures suggest that 11␤-hydroxysteroid dehydrogenase (EC 1.1.1.146) comprises two enzymes. J Clin Endocrinol Metab 54:563–568 152. Stewart PM, Rogerson FM, Mason JI 1995 Type 2 11 ␤-hydroxysteroid dehydrogenase messenger ribonucleic acid and activity in human placenta and fetal membranes: its relationship to birth weight and putative role in fetal adrenal steroidogenesis. J Clin Endocrinol Metab 80:885– 890 153. Jinno K, Sakura N, Nomura S, Fujitaka M, Ueda K, Kihara M 2001 Failure of cortisone acetate therapy in 21-hydroxylase deficiency in early infancy. Pediatr Int 43:478 – 482 154. Dimitriou T, Maser-Gluth C, Remer T 2003 Adrenocortical activity in healthy children is associated with fat mass. Am J Clin Nutr 77:731–736 155. Toogood AA, Taylor NF, Shalet SM, Monson JP 2000 Sexual dimorphism of cortisol metabolism is maintained in elderly subjects and is not oestrogen dependent. Clin Endocrinol (Oxf) 52: 61– 66 156. Low SC, Chapman KE, Edwards CR, Wells T, Robinson IC, Seckl JR 1994 Sexual dimorphism of hepatic 11␤-hydroxysteroid dehydrogenase in the rat: the role of growth hormone patterns. J Endocrinol 143:541–548 157. Albiston AL, Smith RE, Krozowski ZS 1995 Sex- and tissuespecific regulation of 11␤-hydroxysteroid dehydrogenase mRNA. Mol Cell Endocrinol 109:183–188

860


158. Finken MJ, Andrews RC, Andrew R, Walker BR 1999 Cortisol metabolism in healthy young adults: sexual dimorphism in activities of A-ring reductases, but not 11␤-hydroxysteroid dehydrogenases. J Clin Endocrinol Metab 84:3316 –3321 159. Stewart PM, Whorwood CB, Barber P, Gregory J, Monder C, Franklyn JA, Sheppard MC 1991 Localization of renal 11␤dehydrogenase by in situ hybridization: autocrine not paracrine protector of the mineralocorticoid receptor. Endocrinology 128: 2129 –2135 160. Yau JL, Van Haarst AD, Moisan MP, Fleming S, Edwards CR, Seckl JR 1991 11␤-Hydroxysteroid dehydrogenase mRNA expression in rat kidney. Am J Physiol 260:F764 –F767 161. Castello R, Schwarting R, Muller C, Hierholzer K 1989 Immunohistochemical localization of 11-hydroxysteroid dehydrogenase in rat kidney with monoclonal antibody. Ren Physiol Biochem 12: 320 –327 162. Edwards CRW, Stewart PM, Burt D, Brett L, McIntyre MA, Sutanto WS, DeKloet ER, Monder C 1988 Localisation of 11␤hydroxysteroid dehydrogenase-tissue specific protector of the mineralocorticoid receptor. Lancet 2:986 –989 163. Rundle SE, Funder JW, Lakshmi V, Monder C 1989 The intrarenal localization of mineralocorticoid receptors and 11␤-dehydrogenase: immunocytochemical studies. Endocrinology 125:1700 –1704 164. Escher G, Galli I, Vishwanath BS, Frey BM, Frey FJ 1997 Tumor necrosis factor ␣ and interleukin 1␤ enhance the cortisone/cortisol shuttle. J Exp Med 186:189 –198 165. Aziz N, Brown D, Lee WS, Naray-Fejes-Toth A 1996 Aberrant 11␤-hydroxysteroid dehydrogenase-1 activity in the cpk mouse: implications for regulation by the Ke 6 gene. Endocrinology 137: 5581–5588 166. Burton AF, Anderson FH 1983 Inactivation of corticosteroids in intestinal mucosa by 11␤-hydroxysteroid: NADP oxidoreductase (EC 1.1.1.146). Am J Gastroenterol 78:627– 631 167. Whorwood CB, Ricketts ML, Stewart PM 1994 Epithelial cell localization of type 2 11␤-hydroxysteroid dehydrogenase in rat and human colon. Endocrinology 135:2533–2541 168. Sheppard KE, Funder JW 1996 Specific nuclear localization of 11-dehydrocorticosterone in rat colon: evidence for a novel corticosteroid receptor. Endocrinology 137:3274 –3278 169. Teelucksingh S, Mackie AD, Burt D, McIntyre MA, Brett L, Edwards CR 1990 Potentiation of hydrocortisone activity in skin by glycyrrhetinic acid. Lancet 335:l060 –l063 170. Ricketts ML, Verhaeg JM, Bujalska I, Howie AJ, Rainey WE, Stewart PM 1998 Immunohistochemical localization of type 1 11␤hydroxysteroid dehydrogenase in human tissues. J Clin Endocrinol Metab 83:1325–1335 171. Ricketts ML, Shoesmith KJ, Hewison M, Strain A, Eggo MC, Stewart PM 1998 Regulation of 11␤-hydroxysteroid dehydrogenase type 1 in primary cultures of rat and human hepatocytes. J Endocrinol 156:159 –168 172. Jamieson PM, Walker BR, Chapman KE, Andrew R, Rossiter S, Seckl JR 2000 11␤-Hydroxysteroid dehydrogenase type 1 is a predominant 11␤-reductase in the intact perfused rat liver. J Endocrinol 165:685– 692 173. Lax ER, Ghraf R, Schriefers H 1978 The hormonal regulation of hepatic microsomal 11␤-hydroxysteroid dehydrogenase activity in the rat. Acta Endocrinol (Copenh) 89:352–358 174. Low SC, Assaad SN, Rajan V, Chapman KE, Edwards CR, Seckl JR 1993 Regulation of 11␤-hydroxysteroid dehydrogenase by sex steroids in vivo: further evidence for the existence of a second dehydrogenase in rat kidney. J Endocrinol 139:27–35 175. Voice MW, Seckl JR, Edwards CR, Chapman KE 1996 11␤Hydroxysteroid dehydrogenase type 1 expression in 2S FAZA hepatoma cells is hormonally regulated: a model system for the study of hepatic glucocorticoid metabolism. Biochem J 317:621– 625 176. Whorwood CB, Sheppard MC, Stewart PM 1993 Tissue specific effects of thyroid hormone on 11␤-hydroxysteroid dehydrogenase gene expression. J Steroid Biochem Mol Biol 46:539 –547 177. Zumoff B, Bradlow HL, Levin J, Fukushima DK 1983 Influence of thyroid function on the in vivo cortisol in equilibrium cortisone equilibrium in man. J Steroid Biochem 18:437– 440

Tomlinson et al. • 11␤-HSD1 178. Taniyama M, Honma K, Ban Y 1993 Urinary cortisol metabolites in the assessment of peripheral thyroid hormone action: application for diagnosis of resistance to thyroid hormone. Thyroid 3:229 –233 179. Sampath-Kumar R, Yu M, Khalil MW, Yang K 1997 Metyrapone is a competitive inhibitor of 11␤-hydroxysteroid dehydrogenase type 1 reductase. J Steroid Biochem Mol Biol 62:195–199 180. Stewart PM, Burra P, Shackleton CHL, Sheppard MC, Elias E 1993 11␤-Hydroxysteroid dehydrogenase deficiency and glucocorticoid status in patients with alcoholic and non-alcoholic chronic liver disease. J Clin Endocrinol Metab 76:748 –751 181. Escher G, Nawrocki A, Staub T, Vishwanath BS, Frey BM, Reichen J, Frey FJ 1998 Down-regulation of hepatic and renal 11␤-hydroxysteroid dehydrogenase in rats with liver cirrhosis. Gastroenterology 114:175–184 182. Quirk SJ, Slattery JA, Funder JW 1990 Epithelial and adipose cells isolated from mammary glands of pregnant and lactating rats differ in 11 ␤-hydroxysteroid dehydrogenase activity. J Steroid Biochem Mol Biol 37:529 –534 183. Tomlinson JW, Moore J, Cooper MS, Bujalska I, Shahmanesh M, Burt C, Strain A, Hewison M, Stewart PM 2001 Regulation of expression of 11␤-hydroxysteroid dehydrogenase type 1 in adipose tissue: tissue-specific induction by cytokines. Endocrinology 142: 1982–1989 184. Handoko K, Yang K, Strutt B, Khalil W, Killinger D 2000 Insulin attenuates the stimulatory effects of tumor necrosis factor ␣ on 11␤-hydroxysteroid dehydrogenase 1 in human adipose stromal cells. J Steroid Biochem Mol Biol 72:163–168 185. Friedberg M, Zoumakis E, Hiroi N, Bader T, Chrousos GP, Hochberg Z 2003 Modulation of 11␤-hydroxysteroid dehydrogenase type 1 in mature human subcutaneous adipocytes by hypothalamic messengers. J Clin Endocrinol Metab 88:385–393 186. Hauner H, Schmid P, Pfeiffer EF 1987 Glucocorticoids and insulin promote the differentiation of human adipocyte precursor cells into fat cells. J Clin Endocrinol Metab 64:832– 835 187. Rogatsky I, Trowbridge JM, Garabedian MJ 1997 Glucocorticoid receptor-mediated cell cycle arrest is achieved through distinct cell-specific transcriptional regulatory mechanisms. Mol Cell Biol 17:3181–3193 188. Sanchez I, Goya L, Vallerga AK, Firestone GL 1993 Glucocorticoids reversibly arrest rat hepatoma cell growth by inducing an early G1 block in cell cycle progression. Cell Growth Differ 4:215–225 189. Rabbitt EH, Lavery GG, Walker EA, Cooper MS, Stewart PM, Hewison M 2002 Prereceptor regulation of glucocorticoid action by 11␤-hydroxysteroid dehydrogenase: a novel determinant of cell proliferation. FASEB J 16:36 – 44 190. Gregoire F, Genart C, Hauser N, Remacle C 1991 Glucocorticoids induce a drastic inhibition of proliferation and stimulate differentiation of adult rat fat cell precursors. Exp Cell Res 196:270 –278 191. Tomlinson JW, Sinha B, Bujalska I, Hewison M, Stewart PM 2002 Expression of 11␤-hydroxysteroid dehydrogenase type 1 in adipose tissue is not increased in human obesity. J Clin Endocrinol Metab 87:5630 –5635 192. Yang K, Khalil MW, Strutt BJ, Killinger DW 1997 11 ␤-Hydroxysteroid dehydrogenase 1 activity and gene expression in human adipose stromal cells: effect on aromatase activity. J Steroid Biochem Mol Biol 60:247–253 193. Napolitano A, Voice MW, Edwards CR, Seckl JR, Chapman KE 1998 11␤-hydroxysteroid dehydrogenase 1 in adipocytes: expression is differentiation-dependent and hormonally regulated. J Steroid Biochem Mol Biol 64:251–260 194. Jessen BA, Stevens GJ 2002 Expression profiling during adipocyte differentiation of 3T3–L1 fibroblasts. Gene 299:95–100 195. Berger J, Tanen M, Elbrecht A, Hermanowski-Vosatka A, Moller DE, Wright SD, Thieringer R 2001 Peroxisome proliferatoractivated receptor-␥ ligands inhibit adipocyte 11␤-hydroxysteroid dehydrogenase type 1 expression and activity. J Biol Chem 276: 12629 –12635 196. Stulnig TM, Oppermann U, Steffensen KR, Schuster GU, Gustafsson JA 2002 Liver X receptors downregulate 11␤-hydroxysteroid dehydrogenase type 1 expression and activity. Diabetes 51:2426 –2433

Tomlinson et al. • 11␤-HSD1 197. Sasaki K, Cripe TP, Koch SR, Andreone TL, Petersen DD, Beale EG, Granner DK 1984 Multihormonal regulation of phosphoenolpyruvate carboxykinase gene transcription. The dominant role of insulin. J Biol Chem 259:15242–15251 198. Jamieson PM, Chapman KE, Seckl JR 1999 Tissue- and temporalspecific regulation of 11␤-hydroxysteroid dehydrogenase type 1 by glucocorticoids in vivo. J Steroid Biochem Mol Biol 68:245–250 199. Walker BR, Connacher AA, Lindsay RM, Webb DJ, Edwards CR 1995 Carbenoxolone increases hepatic insulin sensitivity in man: a novel role for 11-oxosteroid reductase in enhancing glucocorticoid receptor activation. J Clin Endocrinol Metab 80:3155–3159 200. Andrews RC, Rooyackers O, Walker BR 2003 Effects of the 11␤hydroxysteroid dehydrogenase inhibitor carbenoxolone on insulin sensitivity in men with type 2 diabetes. J Clin Endocrinol Metab 88:285–291 201. Andrews RC, Herlihy O, Livingstone DE, Andrew R, Walker BR 2002 Abnormal cortisol metabolism and tissue sensitivity to cortisol in patients with glucose intolerance. J Clin Endocrinol Metab 87: 5587–5593 202. Rask E, Walker BR, Soderberg S, Livingstone DE, Eliasson M, Johnson O, Andrew R, Olsson T 2002 Tissue-specific changes in peripheral cortisol metabolism in obese women: increased adipose 11␤-hydroxysteroid dehydrogenase type 1 activity. J Clin Endocrinol Metab 87:3330 –3336 203. Stewart PM, Boulton A, Kumar S, Clark PM, Shackleton CH 1999 Cortisol metabolism in human obesity: impaired cortisone3 cortisol conversion in subjects with central adiposity. J Clin Endocrinol Metab 84:1022–1027 204. Liu Y, Nakagawa Y, Wang Y, Li R, Li X, Ohzeki T, Friedman TC 2003 Leptin activation of corticosterone production in hepatocytes may contribute to the reversal of obesity and hyperglycemia in leptin-deficient ob/ob mice. Diabetes 52:1409 –1416 205. Kerstens MN, Riemens SC, Sluiter WJ, Pratt JJ, Wolthers BG, Dullaart RP 2000 Lack of relationship between 11␤-hydroxysteroid dehydrogenase setpoint and insulin sensitivity in the basal state and after 24 h of insulin infusion in healthy subjects and type 2 diabetic patients. Clin Endocrinol (Oxf) 52:403– 411 206. Paterson JM, Morton NM, Fievet C, Kenyon CJ, Holmes MC, Staels B, Seckl JR, Mullins JJ 2004 Metabolic syndrome without obesity: hepatic overexpression of 11␤-hydroxysteroid dehydrogenase type 1 in transgenic mice. Proc Natl Acad Sci USA 101: 7088 –7093 207. Livingstone DE, Jones GC, Smith K, Jamieson PM, Andrew R, Kenyon CJ, Walker BR 2000 Understanding the role of glucocorticoids in obesity: tissue-specific alterations of corticosterone metabolism in obese Zucker rats. Endocrinology 141:560 –563 208. Livingstone DE, Kenyon CJ, Walker BR 2000 Mechanisms of dysregulation of 11␤-hydroxysteroid dehydrogenase type 1 in obese Zucker rats. J Endocrinol 167:533–539 209. Mattsson C, Lai M, Noble J, McKinney E, Yau JL, Seckl JR, Walker BR 2003 Obese Zucker rats have reduced mineralocorticoid receptor and 11␤-hydroxysteroid dehydrogenase type 1 expression in hippocampus—implications for dysregulation of the hypothalamic-pituitary-adrenal axis in obesity. Endocrinology 144:2997– 3003 210. Morton NM, Ramage L, Seckl JR 2004 Down-regulation of adipose 11␤-hydroxysteroid dehydrogenase type 1 by high-fat feeding in mice: a potential adaptive mechanism counteracting metabolic disease. Endocrinology 145:2707–2712 211. Morton NM, Holmes MC, Fievet C, Staels B, Tailleux A, Mullins JJ, Seckl JR 2001 Improved lipid and lipoprotein profile, hepatic insulin sensitivity, and glucose tolerance in 11␤-hydroxysteroid dehydrogenase type 1 null mice. J Biol Chem 276:41293– 41300 212. Masuzaki H, Yamamoto H, Kenyon CJ, Elmquist JK, Morton NM, Paterson JM, Shinyama H, Sharp MG, Fleming S, Mullins JJ, Seckl JR, Flier JS 2003 Transgenic amplification of glucocorticoid action in adipose tissue causes high blood pressure in mice. J Clin Invest 112:83–90 213. Fraser R, Ingram MC, Anderson NH, Morrison C, Davies E, Connell JM 1999 Cortisol effects on body mass, blood pressure, and cholesterol in the general population. Hypertension 33:1364 –1368


861

214. Marin P, Darin N, Amemiya T, Andersson B, Jern S, Bjorntorp P 1992 Cortisol secretion in relation to body fat distribution in obese premenopausal women. Metabolism 41:882– 886 215. Paulmyer-Lacroix O, Boullu S, Oliver C, Alessi MC, Grino M 2002 Expression of the mRNA coding for 11␤-hydroxysteroid dehydrogenase type 1 in adipose tissue from obese patients: an in situ hybridization study. J Clin Endocrinol Metab 87:2701–2705 216. Csabi GY, Juricskay S, Molnar D 2000 Urinary cortisol to cortisone metabolites in hypertensive obese children. J Endocrinol Invest 23:435– 439 217. Reynolds RM, Walker BR, Syddall HE, Andrew R, Wood PJ, Whorwood CB, Phillips DI 2001 Altered control of cortisol secretion in adult men with low birth weight and cardiovascular risk factors. J Clin Endocrinol Metab 86:245–250 218. Andrew R, Gale CR, Walker BR, Seckl JR, Martyn CN 2002 Glucocorticoid metabolism and the metabolic syndrome: associations in an elderly cohort. Exp Clin Endocrinol Diabetes 110:284 –290 219. Andrew R, Phillips DI, Walker BR 1998 Obesity and gender influence cortisol secretion and metabolism in man. J Clin Endocrinol Metab 83:1806 –1809 220. Tiosano D, Eisentein I, Militianu D, Chrousos GP, Hochberg Z 2003 11␤-Hydroxysteroid dehydrogenase activity in hypothalamic obesity. J Clin Endocrinol Metab 88:379 –384 221. Weidenfeld J, Siegel RA, Levy J, Chowers I 1982 In vitro metabolism of cortisol by human abdominal adipose tissue. J Steroid Biochem 17:357–360 222. Katz JR, Mohamed-Ali V, Wood PJ, Yudkin JS, Coppack SW 1999 An in vivo study of the cortisol-cortisone shuttle in subcutaneous abdominal adipose tissue. Clin Endocrinol (Oxf) 50:63– 68 223. Lindsay RS, Wake DJ, Nair S, Bunt J, Livingstone DE, Permana PA, Tataranni PA, Walker BR 2003 Subcutaneous adipose 11␤hydroxysteroid dehydrogenase type 1 activity and messenger ribonucleic acid levels are associated with adiposity and insulinemia in Pima Indians and Caucasians. J Clin Endocrinol Metab 88:2738 – 2744 224. Wake DJ, Rask E, Livingstone DE, Soderberg S, Olsson T, Walker BR 2003 Local and systemic impact of transcriptional up-regulation of 11␤-hydroxysteroid dehydrogenase type 1 in adipose tissue in human obesity. J Clin Endocrinol Metab 88:3983–3988 225. Whorwood CB, Donovan SJ, Flanagan D, Phillips DI, Byrne CD 2002 Increased glucocorticoid receptor expression in human skeletal muscle cells may contribute to the pathogenesis of the metabolic syndrome. Diabetes 51:1066 –1075 226. Gelding SV, Taylor NF, Wood PJ, Noonan K, Weaver JU, Wood DF, Monson JP 1998 The effect of growth hormone replacement therapy on cortisol-cortisone interconversion in hypopituitary adults: evidence for growth hormone modulation of extrarenal 11␤-hydroxysteroid dehydrogenase activity. Clin Endocrinol (Oxf) 48:153–162 227. Moore JS, Monson JP, Kaltsas G, Putignano P, Wood PJ, Sheppard MC, Besser GM, Taylor NF, Stewart PM 1999 Modulation of 11␤-hydroxysteroid dehydrogenase isozymes by growth hormone and insulin-like growth factor: in vivo and in vitro studies. J Clin Endocrinol Metab 84:4172– 4177 228. Liu YJ, Nakagawa Y, Nasuda K, Saegusa H, Igarashi Y 1996 Effect of growth hormone, insulin and dexamethasone on 11␤-hydroxysteroid dehydrogenase activity on a primary culture of rat hepatocytes. Life Sci 59:227–234 229. Liu YJ, Nakagawa Y, Toya K, Ozeki T 1997 Sex-specific effects of growth hormone on hepatic 11␤-hydroxysteroid dehydrogenase activity and gene expression in hypothyroid rats. Life Sci 61:325–334 230. Brown RW, Chapman KE, Edwards CRW, Seckl JR 1993 Human placental 11␤-hydroxysteroid dehydrogenase: evidence for and partial purification of a distinct NAD-dependent isoform. Endocrinology 132:2614 –2621 231. Krozowski Z, Maguire JA, Stein-Oakley AN, Dowling J, Smith RE, Andrews RK 1995 Immunohistochemical localization of the 11␤-hydroxysteroid dehydrogenase type II enzyme in human kidney and placenta. J Clin Endocrinol Metab 80:2203–2209

862


232. Lakshmi V, Nath N, Muneyyirci-Delale O 1993 Characterisation of 11␤-hydroxysteroid dehydrogenase of human placenta: evidence for the existence of two species of 11␤-hydroxysteroid dehydrogenase. J Steroid Biochem Mol Biol 45:391–397 233. Pepe GJ, Waddell BJ, Burch MG, Albrecht ED 1996 Interconversion of cortisol and cortisone in the baboon placenta at midgestation: expression of 11␤-hydroxysteroid dehydrogenase type 1 messenger RNA. J Steroid Biochem Mol Biol 58:403– 410 234. Yang K 1995 Co-expression of two distinct isoforms of 11␤hydroxysteroid dehydrogenase in the ovine placenta. J Steroid Biochem Mol Biol 52:337–343 235. Lopez BA, Craft IL 1981 Corticosteroid metabolism in vitro by human placenta, fetal membranes and decidua in early and late gestation. Placenta 2:279 –285 236. Sun K, Yang K, Challis JR 1997 Differential expression of 11␤hydroxysteroid dehydrogenase types 1 and 2 in human placenta and fetal membranes. J Clin Endocrinol Metab 82:300 –305 237. Smith MP, Keay SD, Hall L, Harlow CR, Jenkins JM 1997 The detection and confirmation of 11␤-hydroxysteroid dehydrogenase type 1 transcripts in human luteinized granulosa cells using RTPCR and plasmid pUC18. Mol Hum Reprod 3:651– 654 238. Burton PJ, Krozowski ZS, Waddell BJ 1998 Immunolocalization of 11␤-hydroxysteroid dehydrogenase types 1 and 2 in rat uterus: variation across the estrous cycle and regulation by estrogen and progesterone. Endocrinology 139:376 –382 239. Thompson A, Han VK, Yang K 2002 Spatial and temporal patterns of expression of 11␤-hydroxysteroid dehydrogenase types 1 and 2 messenger RNA and glucocorticoid receptor protein in the murine placenta and uterus during late pregnancy. Biol Reprod 67:1708 – 1718 240. Yang K, Fraser M, Yu M, Krkosek M, Challis JR, Lamming GE, Campbell LE, Darnel A 1996 Pattern of 11␤-hydroxysteroid dehydrogenase type 1 messenger ribonucleic acid expression in the ovine uterus during the estrous cycle and pregnancy. Biol Reprod 55:1231–1236 241. Arcuri F, Monder C, Lockwood CJ, Schatz F 1996 Expression of 11␤-hydroxysteroid dehydrogenase during decidualization of human endometrial stromal cells. Endocrinology 137:595– 600 242. Saruta T, Suzuki H, Handa M, Igarashi Y, Kondo K, Senba S 1986 Multiple factors contribute to the pathogenesis of hypertension in Cushing’s syndrome. J Clin Endocrinol Metab 62:275–279 243. Whitworth JA, Kelly JJ, Brown MA, Williamson PM, Lawson JA 1997 Glucocorticoids and hypertension in man. Clin Exp Hypertens 19:871– 884 244. Kornel L, Prancan AV, Kanamarlapudi N, Hynes J, Kuzianik E 1995 Study on the mechanisms of glucocorticoid-induced hypertension: glucocorticoids increase transmembrane Ca2⫹ influx in vascular smooth muscle in vivo. Endocr Res 21:203–210 245. Funder JW, Pearce PT, Smith R, Campbell J 1989 Vascular type I aldosterone binding sites are physiological mineralocorticoid receptors. Endocrinology 125:2224 –2226 246. Brem AS, Bina RB, Hill N, Alia C, Morris DJ 1997 Effects of licorice derivatives on vascular smooth muscle function. Life Sci 60:207–214 247. Souness GW, Brem AS, Morris DJ 2002 11␤-Hydroxysteroid dehydrogenase antisense affects vascular contractile response and glucocorticoid metabolism. Steroids 67:195–201 248. Ullian ME, Hazen-Martin DJ, Walsh LG, Davda RK, Egan BM 1996 Carbenoxolone damages endothelium and enhances vasoconstrictor action in aortic rings. Hypertension 27:1346 –1352 249. Alzamora R, Michea L, Marusic ET 2000 Role of 11␤-hydroxysteroid dehydrogenase in nongenomic aldosterone effects in human arteries. Hypertension 35:1099 –1104 250. van Uum SH, Hermus AR, Sweep CG, Walker BR, Ross HA, de Leeuw PW, Lenders JW 2002 Short-term cortisol infusion in the brachial artery, with and without inhibiting 11␤-hydroxysteroid dehydrogenase, does not alter forearm vascular resistance in normotensive and hypertensive subjects. Eur J Clin Invest 32:874 – 881 251. Hadoke PW, Christy C, Kotelevtsev YV, Williams BC, Kenyon CJ, Seckl JR, Mullins JJ, Walker BR 2001 Endothelial cell dysfunction in mice after transgenic knockout of type 2, but not type 1, 11␤hydroxysteroid dehydrogenase. Circulation 104:2832–2837

Tomlinson et al. • 11␤-HSD1 252. Brem AS, Bina RB, King TC, Morris DJ 1998 Localization of 2 11␤-OH steroid dehydrogenase isoforms in aortic endothelial cells. Hypertension 31:459 – 462 253. Walker BR, Yau JL, Brett LP, Seckl JR, Monder C, Williams BC, Edwards CR 1991 11␤-Hydroxysteroid dehydrogenase in vascular smooth muscle and heart: implications for cardiovascular responses to glucocorticoids. Endocrinology 129:3305–3312 254. Brem AS, Bina RB, King T, Morris DJ 1995 Bidirectional activity of 11␤-hydroxysteroid dehydrogenase in vascular smooth muscle cells. Steroids 60:406 – 410 255. Takeda Y, Miyamori I, Yoneda T, Hatakeyama H, Iki K, Takeda R 1994 Decreased activity of 11␤-hydroxysteroid dehydrogenase in mesenteric arteries of Dahl salt-sensitive rats. Life Sci 54:1343–1349 256. Sheppard KE, Autelitano DJ 2002 11␤-Hydroxysteroid dehydrogenase 1 transforms 11-dehydrocorticosterone into transcriptionally active glucocorticoid in neonatal rat heart. Endocrinology 143: 198 –204 257. Young MJ, Moussa L, Dilley R, Funder JW 2003 Early inflammatory responses in experimental cardiac hypertrophy and fibrosis: effects of 11␤-hydroxysteroid dehydrogenase inactivation. Endocrinology 144:1121–1125 258. Benediktsson R, Yau JL, Low S, Brett LP, Cooke BE, Edwards CR, Seckl JR 1992 11␤-Hydroxysteroid dehydrogenase in the rat ovary: high expression in the oocyte. J Endocrinol 135:53–58 259. Tetsuka M, Thomas FJ, Thomas MJ, Anderson RA, Mason JI, Hillier SG 1997 Differential expression of messenger ribonucleic acids encoding 11␤-hydroxysteroid dehydrogenase types 1 and 2 in human granulosa cells. J Clin Endocrinol Metab 82:2006 –2009 260. Hsueh AJ, Erickson GF 1978 Glucocorticoid inhibition of FSHinduced estrogen production in cultured rat granulosa cells. Steroids 32:639 – 648 261. Harlow CR, Coombs RJ, Hodges JK, Jenkins N 1987 Modulation of plasminogen activation by glucocorticoid hormones in the rat granulosa cell. J Endocrinol 114:207–212 262. Wang C, Leung A 1989 Glucocorticoids stimulate plasminogen activator production by rat granulosa cells. Endocrinology 124: 1595–1601 263. Michael AE, Pester LA, Curtis P, Shaw RW, Edwards CRW, Cooke BA 1993 Direct inhibition of ovarian steroidogenesis by cortisol and the modulatory role of 11␤-hydroxysteroid dehydrogenase. Clin Endocrinol (Oxf) 38:641– 644 264. Michael AE, Evagelatou M, Norgate DP, Clarke RJ, Antoniw JW, Stedman BA, Brennan A, Welsby R, Bujalska I, Stewart PM, Cooke BA 1997 Isoforms of 11␤-hydroxysteroid dehydrogenase in human granulosa-lutein cells. Mol Cell Endocrinol 132:43–52 265. Tetsuka M, Haines LC, Milne M, Simpson GE, Hillier SG 1999 Regulation of 11␤-hydroxysteroid dehydrogenase type 1 gene expression by LH and interleukin-1␤ in cultured rat granulosa cells. J Endocrinol 163:417– 423 266. Yong PY, Harlow C, Thong KJ, Hillier SG 2002 Regulation of 11␤-hydroxysteroid dehydrogenase type 1 gene expression in human ovarian surface epithelial cells by interleukin-1. Hum Reprod 17:2300 –2306 267. Hillier SG, Tetsuka M 1998 An anti-inflammatory role for glucocorticoids in the ovaries? J Reprod Immunol 39:21–27 268. Smith MP, Mathur RS, Keay SD, Hall L, Hull MG, Jenkins JM 2000 Periovulatory human oocytes, cumulus cells, and ovarian leukocytes express type 1 but not type 2 11␤-hydroxysteroid dehydrogenase RNA. Fertil Steril 73:825– 830 269. Yong PY, Thong KJ, Andrew R, Walker BR, Hillier SG 2000 Development-related increase in cortisol biosynthesis by human granulosa cells. J Clin Endocrinol Metab 85:4728 – 4733 270. Tetsuka M, Yamamoto S, Hayashida N, Hayashi KG, Hayashi M, Acosta TJ, Miyamoto A 2003 Expression of 11␤-hydroxysteroid dehydrogenases in bovine follicle and corpus luteum. J Endocrinol 177:445– 452 271. Thurston LM, Norgate DP, Jonas KC, Chandras C, Kloosterboer HJ, Cooke BA, Michael AE 2002 Ovarian modulators of 11␤hydroxysteroid dehydrogenase (11␤HSD) activity in follicular fluid from gonadotrophin-stimulated assisted conception cycles. Reproduction 124:801– 812

Tomlinson et al. • 11␤-HSD1 272. Michael AE, Gregory L, Walker SM, Antoniw JW, Shaw RW, Edwards CR, Cooke BA 1993 Ovarian 11␤-hydroxysteroid dehydrogenase: potential predictor of conception by in-vitro fertilisation and embryo transfer. Lancet 342:711–712 273. Michael AE, Collins TD, Norgate DP, Gregory L, Wood PJ, Cooke BA 1999 Relationship between ovarian cortisol:cortisone ratios and the clinical outcome of in vitro fertilization and embryo transfer (IVF-ET). Clin Endocrinol (Oxf) 51:535–540 274. Thomas FJ, Thomas MJ, Tetsuka M, Mason JI, Hillier SG 1998 Corticosteroid metabolism in human granulosa-lutein cells. Clin Endocrinol (Oxf) 48:509 –513 275. Harlow CR, Jenkins JM, Winston RM 1997 Increased follicular fluid total and free cortisol levels during the luteinizing hormone surge. Fertil Steril 68:48 –53 276. Baillie AH, Ferguson MM, Calman KC, Hart DM 1965 Histochemical demonstration of 11-␤-hydroxysteroid dehydrogenase. J Endocrinol 33:119 –125 277. Brereton PS, van Driel RR, Suhaimi F, Koyama K, Dilley R, Krozowski Z 2001 Light and electron microscopy localization of the 11␤-hydroxysteroid dehydrogenase type I enzyme in the rat. Endocrinology 142:1644 –1651 278. Waddell BJ, Hisheh S, Krozowski ZS, Burton PJ 2003 Localization of 11␤-hydroxysteroid dehydrogenase types 1 and 2 in the male reproductive tract. Endocrinology 144:3101–3106 279. Hales DB, Payne AH 1989 Glucocorticoid-mediated repression of P450scc mRNA and de novo synthesis in cultured Leydig cells. Endocrinology 124:2099 –2104 280. Payne AH, Sha LL 1991 Multiple mechanisms for regulation of 3␤-hydroxysteroid dehydrogenase/␦ 5—␦4-isomerase, 17 ␣hydroxylase/C17–20 lyase cytochrome P450, and cholesterol sidechain cleavage cytochrome P450 messenger ribonucleic acid levels in primary cultures of mouse Leydig cells. Endocrinology 129: 1429 –1435 281. Monder C, Miroff Y, Marandici A, Hardy M 1994 11␤-Hydroxysteroid dehydrogenase alleviates glucocorticoid-mediated inhibition of steroidogenesis in rat Leydig cells. Endocrinology 134:1199 – 1204 282. Monder C, Sakai RR, Miroff Y, Blanchard DC, Blanchard RJ 1994 Reciprocal changes in plasma corticosterone and testosterone in stressed male rats maintained in a visible burrow system: evidence for a mediating role of testicular 11␤-hydroxysteroid dehydrogenase. Endocrinology 134:1193–1198 283. Hardy MP, Sottas CM, Ge R, McKittrick CR, Tamashiro KL, McEwen BS, Haider SG, Markham CM, Blanchard RJ, Blanchard DC, Sakai RR 2002 Trends of reproductive hormones in male rats during psychosocial stress: role of glucocorticoid metabolism in behavioral dominance. Biol Reprod 67:1750 –1755 284. Ge RS, Hardy DO, Catterall JF, Hardy MP 1997 Developmental changes in glucocorticoid receptor and 11␤-hydroxysteroid dehydrogenase oxidative and reductive activities in rat Leydig cells. Endocrinology 138:5089 –5095 285. Ferguson SE, Pallikaros Z, Michael AE, Cooke BA 1999 The effects of different culture media, glucose, pyridine nucleotides and adenosine on the activity of 11␤-hydroxysteroid dehydrogenase in rat Leydig cells. Mol Cell Endocrinol 158:37– 44 286. Ge RS, Hardy MP 2002 Protein kinase C increases 11␤-hydroxysteroid dehydrogenase oxidation and inhibits reduction in rat Leydig cells. J Androl 23:135–143 287. Ge RS, Gao HB, Nacharaju VL, Gunsalus GL, Hardy MP 1997 Identification of a kinetically distinct activity of 11␤-hydroxysteroid dehydrogenase in rat Leydig cells. Endocrinology 138:2435– 2442 288. Gao HB, Tong MH, Hu YQ, Guo QS, Ge R, Hardy MP 2002 Glucocorticoid induces apoptosis in rat Leydig cells. Endocrinology 143:130 –138 289. Gao HB, Tong MH, Hu YQ, You HY, Guo QS, Ge RS, Hardy MP 2003 Mechanisms of glucocorticoid-induced Leydig cell apoptosis. Mol Cell Endocrinol 199:153–163 290. Lakshmi V, Sakai RR, McEwen BS, Monder C 1991 Regional distribution of 11␤-hydroxysteroid dehydrogenase in rat brain. Endocrinology 128:1741–1748 291. Yau JL, Noble J, Kenyon CJ, Hibberd C, Kotelevtsev Y, Mullins JJ, Seckl JR 2001 Lack of tissue glucocorticoid reactivation in 11␤-


292.

293. 294.

295.

296.

297. 298. 299.

300.

301.

302.

303.

304. 305. 306. 307. 308.

309.

863

hydroxysteroid dehydrogenase type 1 knockout mice ameliorates age-related learning impairments. Proc Natl Acad Sci USA 98: 4716 – 4721 Seckl JR, Dow RC, Low SC, Edwards CR, Fink G 1993 The 11␤hydroxysteroid dehydrogenase inhibitor glycyrrhetinic acid affects corticosteroid feedback regulation of hypothalamic corticotrophinreleasing peptides in rats. J Endocrinol 136:471– 477 Seckl JR, Fink G 1991 Use of in situ hybridization to investigate the regulation of hippocampal corticosteroid receptors by monoamines. J Steroid Biochem Mol Biol 40:685– 688 Korbonits M, Bujalska I, Shimojo M, Nobes J, Jordan S, Grossman AB, Stewart PM 2001 Expression of 11␤-hydroxysteroid dehydrogenase isoenzymes in the human pituitary: induction of the type 2 enzyme in corticotropinomas and other pituitary tumors. J Clin Endocrinol Metab 86:2728 –2733 Harris HJ, Kotelevtsev Y, Mullins JJ, Seckl JR, Holmes MC 2001 Intracellular regeneration of glucocorticoids by 11␤-hydroxysteroid dehydrogenase (11␤-HSD)-1 plays a key role in regulation of the hypothalamic-pituitary-adrenal axis: analysis of 11␤-HSD1-deficient mice. Endocrinology 142:114 –120 Rabbitt EH, Ayuk J, Boelaert K, Sheppard MC, Hewison M, Stewart PM, Gittoes NJ 2003 Abnormal expression of 11␤-hydroxysteroid dehydrogenase type 2 in human pituitary adenomas: a prereceptor determinant of pituitary cell proliferation. Oncogene 22:1663–1667 Cooper MS, Hewison M, Stewart PM 1999 Glucocorticoid activity, inactivity and the osteoblast. J Endocrinol 163:159 –164 Manolagas SC, Kousteni S, Jilka RL 2002 Sex steroids and bone. Recent Prog Horm Res 57:385– 409 Batista MC, Mendonca BB, Kater CE, Arnhold IJ, Rocha A, Nicolau W, Bloise W 1986 Spironolactone-reversible rickets associated with 11 ␤-hydroxysteroid dehydrogenase deficiency syndrome. J Pediatr 109:989 –993 Condon J, Gosden C, Gardener D, Nickson P, Hewison M, Howie AJ, Stewart PM 1998 Expression of type 2 11␤-hydroxysteroid dehydrogenase and corticosteroid hormone receptors in early human fetal life. J Clin Endocrinol Metab 83:4490 – 4497 Bland R, Worker CA, Noble BS, Eyre LJ, Bujalska IJ, Sheppard MC, Stewart PM, Hewison M 1999 Characterization of 11␤hydroxysteroid dehydrogenase activity and corticosteroid receptor expression in human osteosarcoma cell lines. J Endocrinol 161:455– 464 Eyre LJ, Rabbitt EH, Bland R, Hughes SV, Cooper MS, Sheppard MC, Stewart PM, Hewison M 2001 Expression of 11␤-hydroxysteroid dehydrogenase in rat osteoblastic cells: pre-receptor regulation of glucocorticoid responses in bone. J Cell Biochem 81:453– 462 Woitge H, Harrison J, Ivkosic A, Krozowski Z, Kream B 2001 Cloning and in vitro characterization of ␣ 1(I)-collagen 11␤hydroxysteroid dehydrogenase type 2 transgenes as models for osteoblast-selective inactivation of natural glucocorticoids. Endocrinology 142:1341–1348 Rabbitt EH, Gittoes NJ, Stewart PM, Hewison M 2003 11␤Hydroxysteroid dehydrogenases, cell proliferation and malignancy. J Steroid Biochem Mol Biol 85:415– 421 Bellows CG, Ciaccia A, Heersche JN 1998 Osteoprogenitor cells in cell populations derived from mouse and rat calvaria differ in their response to corticosterone, cortisol, and cortisone. Bone 23:119 –125 Ishida Y, Killinger DW, Khalil MW, Yang K, Strutt B, Heersche JN 2002 Expression of steroid-converting enzymes in osteoblasts derived from rat vertebrae. Osteoporos Int 13:235–240 Cooper MS, Walker EA, Bland R, Fraser WD, Hewison M, Stewart PM 2000 Expression and functional consequences of 11␤-hydroxysteroid dehydrogenase activity in human bone. Bone 27:375–381 Cooper MS, Rabbitt EH, Goddard PE, Bartlett WA, Hewison M, Stewart PM 2002 Osteoblastic 11␤-hydroxysteroid dehydrogenase type 1 activity increases with age and glucocorticoid exposure. J Bone Miner Res 17:979 –986 Cooper MS, Bujalska I, Rabbitt E, Walker EA, Bland R, Sheppard MC, Hewison M, Stewart PM 2001 Modulation of 11␤-hydroxysteroid dehydrogenase isozymes by proinflammatory cytokines in osteoblasts: an autocrine switch from glucocorticoid inactivation to activation. J Bone Miner Res 16:1037–1044

864


310. Canalis E, Delany AM 2002 11␤-Hydroxysteroid dehydrogenase, an amplifier of glucocorticoid action in osteoblasts. J Bone Miner Res 17:987–990 311. Cooper MS, Blumsohn A, Goddard PE, Bartlett WA, Shackleton CH, Eastell R, Hewison M, Stewart PM 2003 11␤-Hydroxysteroid dehydrogenase type 1 activity predicts the effects of glucocorticoids on bone. J Clin Endocrinol Metab 88:3874 –3877 312. Armaly MF 1967 Dexamethasone ocular hypertension and eosinopenia, and glucose tolerance test. Arch Ophthalmol 78:193–197 313. Mirshahi M, Mirshahi S, Golestaneh N, Nicolas C, Mishal Z, Lounes KC, Hecquet C, Dagonet F, Pouliquen Y, Agarwal MK 2001 Mineralocorticoid hormone signaling regulates the ’epithelial sodium channel’ in fibroblasts from human cornea. Ophthalmic Res 33:7–19 314. Weinreb RN, Bloom E, Baxter JD, Alvarado J, Lan N, O’Donnell J, Polansky JR 1981 Detection of glucocorticoid receptors in cultured human trabecular cells. Invest Ophthalmol Vis Sci 21:403– 407 315. Starka L, Obenberger J 1976 Steroids and intraocular pressure. J Steroid Biochem 7:979 –983 316. Suzuki T, Sasano H, Kaneko C, Ogawa S, Darnel AD, Krozowski ZS 2001 Immunohistochemical distribution of 11␤-hydroxysteroid dehydrogenase in human eye. Mol Cell Endocrinol 173:121–125 317. Stokes J, Noble J, Brett L, Phillips C, Seckl JR, O’Brien C, Andrew R 2000 Distribution of glucocorticoid and mineralocorticoid receptors and 11␤-hydroxysteroid dehydrogenases in human and rat ocular tissues. Invest Ophthalmol Vis Sci 41:1629 –1638 318. Rauz S, Walker EA, Shackleton CH, Hewison M, Murray PI, Stewart PM 2001 Expression and putative role of 11␤-hydroxysteroid dehydrogenase isozymes within the human eye. Invest Ophthalmol Vis Sci 42:2037–2042 319. Rauz S, Cheung CM, Wood PJ, Coca-Prados M, Walker EA, Murray PI, Stewart PM 2003 Inhibition of 11␤-hydroxysteroid dehydrogenase type 1 lowers intraocular pressure in patients with ocular hypertension. QJM 96:481– 490 320. Gronau S, Koenig GD, Jerg M, Riechelmann H 2002 11␤Hydroxysteroid dehydrogenase 1 expression in squamous cell carcinomas of the head and neck. Clin Otolaryngol 27:453– 457 321. Mune T, Morita H, Suzuki T, Takahashi Y, Isomura Y, Tanahashi T, Daido H, Yamakita N, Deguchi T, Sasano H, Yasuda K, White PC 2002 Role of local 11␤-hydroxysteroid dehydrogenase type 2 (HSD11B2) expression in determining the phenotype of adrenal adenomas. Endocr Res 28:751–752 322. Wall L, Destroismaisons N, Delvoye N, Guy LG 1996 CAAT/ enhancer-binding proteins are involved in ␤-globin gene expression and are differentially expressed in murine erythroleukemia and K562 cells. J Biol Chem 271:16477–16484 323. Koyama K, Myles K, Smith R, Krozowski Z 2001 Expression of the 11␤-hydroxysteroid dehydrogenase type II enzyme in breast tumors and modulation of activity and cell growth in PMC42 cells. J Steroid Biochem Mol Biol 76:153–159 324. Sapolsky RM, Romero LM, Munck AU 2000 How do glucocorticoids influence stress responses? Integrating permissive, suppressive, stimulatory, and preparative actions. Endocr Rev 21:55– 89 325. Dougherty TF, Berliner ML, Berliner DL 1960 11 ␤-Hydroxy dehydrogenase system activity in thymi of mice following prolonged cortisol treatment. Endocrinology 66:550 –558 326. Hennebold JD, Ryu SY, Mu HH, Galbraith A, Daynes RA 1996 11␤-Hydroxysteroid dehydrogenase modulation of glucocorticoid activities in lymphoid organs. Am J Physiol 270:R1296 –R1306 327. Zhou Z, Shackleton CH, Pahwa S, White PC, Speiser PW 1998 Prominent sex steroid metabolism in human lymphocytes. Mol Cell Endocrinol 138:61– 69 328. Thieringer R, Le Grand CB, Carbin L, Cai TQ, Wong B, Wright SD, Hermanowski-Vosatka A 2001 11␤-Hydroxysteroid dehydrogenase type 1 is induced in human monocytes upon differentiation to macrophages. J Immunol 167:30 –35 329. Marandici A, Monder C 1993 Inhibition by glycyrrhetinic acid of rat tissue 11␤-hydroxysteroid dehydrogenase in vivo. Steroids 58: 153–156 330. Hennebold JD, Mu HH, Poynter ME, Chen XP, Daynes RA 1997 Active catabolism of glucocorticoids by 11␤-hydroxysteroid dehydrogenase in vivo is a necessary requirement for natural resistance to infection with Listeria monocytogenes. Int Immunol 9:105–115

Tomlinson et al. • 11␤-HSD1 331. Rook GA, Hernandez-Pando R 1997 Pathogenetic role, in human and murine tuberculosis, of changes in the peripheral metabolism of glucocorticoids and antiglucocorticoids. Psychoneuroendocrinology 22(Suppl 1):S109 –S113 332. Baker RW, Walker BR, Shaw RJ, Honour JW, Jessop DS, Lightman SL, Zumla A, Rook GA 2000 Increased cortisol: cortisone ratio in acute pulmonary tuberculosis. Am J Respir Crit Care Med 162:1641–1647 333. Shimojo M, Whorwood CB, Stewart PM 1996 11 ␤-Hydroxysteroid dehydrogenase in the rat adrenal. J Mol Endocrinol 17:121–130 334. Albertin G, Tortorella C, Malendowicz LK, Aragona F, Neri G, Nussdorfer GG 2002 Human adrenal cortex and aldosterone secreting adenomas express both 11␤-hydroxysteroid dehydrogenase type 1 and type 2 genes. Int J Mol Med 9:495– 498 335. Hundertmark S, Dill A, Buhler H, Stevens P, Looman K, Ragosch V, Seckl JR, Lipka C 2002 11␤-Hydroxysteroid dehydrogenase type 1: a new regulator of fetal lung maturation. Horm Metab Res 34:537–544 336. Cole TJ, Blendy JA, Monaghan AP, Krieglstein K, Schmid W, Aguzzi A, Fantuzzi G, Hummler E, Unsicker K, Schutz G 1995 Targeted disruption of the glucocorticoid receptor gene blocks adrenergic chromaffin cell development and severely retards lung maturation. Genes Dev 9:1608 –1621 337. Hundertmark S, Dill A, Ebert A, Zimmermann B, Kotelevtsev YV, Mullins JJ, Seckl JR 2002 Foetal lung maturation in 11␤-hydroxysteroid dehydrogenase type 1 knockout mice. Horm Metab Res 34:545–549 338. Davani B, Khan A, Hult M, Martensson E, Okret S, Efendic S, Jornvall H, Oppermann UC 2000 Type 1 11␤-hydroxysteroid dehydrogenase mediates glucocorticoid activation and insulin release in pancreatic islets. J Biol Chem 275:34841–34844 339. Nikkila H, Tannin GM, New MI, Taylor NF, Kalaitzoglou G, Monder C, White PC 1993 Defects in the HSD11 gene encoding 11␤-hydroxysteroid dehydrogenase are not found in patients with apparent mineralocorticoid excess or 11-oxoreductase deficiency. J Clin Endocrinol Metab 77:687– 691 340. Jamieson A, Wallace AM, Andrew R, Nunez BS, Walker BR, Fraser R, White PC, Connell JM 1999 Apparent cortisone reductase deficiency: a functional defect in 11␤-hydroxysteroid dehydrogenase type 1. J Clin Endocrinol Metab 84:3570 –3574 341. Nordenstrom A, Marcus C, Axelson M, Wedell A, Ritzen EM 1999 Failure of cortisone acetate treatment in congenital adrenal hyperplasia because of defective 11␤-hydroxysteroid dehydrogenase reductase activity. J Clin Endocrinol Metab 84:1210 –1213 342. Biason-Lauber A, Suter SL, Shackleton CH, Zachmann M 2000 Apparent cortisone reductase deficiency: a rare cause of hyperandrogenemia and hypercortisolism. Horm Res 53:260 –266 343. Malunowicz EM, Romer TE, Urban M, Bossowski A 2003 11␤Hydroxysteroid dehydrogenase type 1 deficiency (’apparent cortisone reductase deficiency’) in a 6-year-old boy. Horm Res 59: 205–210 344. Laing I, Adams JE, Wood PJ, Taylor NF, Ray DW, Cortisone reductase deficiency (11␤-hydroxysteroid dehydrogenase type 1) deficiency presenting with features of late onset congenital adrenal hyperplasia. Proc 21st Joint Meeting of the British Endocrine Societies, Harrogate, UK, 2002, p 264 (Abstract) 345. Agarwal AK 2001 Transcriptional influence of two poly purinepyrimidine tracts located in the HSD11B2 (11␤-hydroxysteroid dehydrogenase type 2) gene. Endocr Res 27:1–9 346. Kletzien RF, Harris PK, Foellmi LA 1994 Glucose-6-phosphate dehydrogenase: a “housekeeping” enzyme subject to tissuespecific regulation by hormones, nutrients, and oxidant stress. FASEB J 8:174 –181 347. Mziaut H, Korza G, Hand AR, Gerard C, Ozols J 1999 Targeting proteins to the lumen of endoplasmic reticulum using N-terminal domains of 11␤-hydroxysteroid dehydrogenase and the 50-kDa esterase. J Biol Chem 274:14122–14129 348. Taylor NF, Pollock A, Dornan TL 1990 Corticosteroid 11reductase deficiency: steroid studies in a further family. J Clin Invest 13:P238

Tomlinson et al. • 11␤-HSD1 349. Kimura K, Endou H, Sudo J, Sakai F 1979 Glucose dehydrogenase (hexose 6-phosphate dehydrogenase) and the microsomal electron transport system. Evidence supporting their possible functional relationship. J Biochem (Tokyo) 85:319 –326 350. Stegeman JJ, Klotz AV 1979 A possible role for microsomal hexose6-phosphate dehydrogenase in microsomal electron transport and mixed-function oxygenase activity. Biochem Biophys Res Commun 87:410 – 415 351. Oka K, Takahashi T, Hori SH 1981 Differential effects of the NADPH/NADP⫹ ratio on the activities of hexose-6-phosphate dehydrogenase and glucose-6-phosphate dehydrogenase. Biochim Biophys Acta 662:318 –325 352. Kulkarni AP, Hodgson E 1982 Mouse liver microsomal hexose-6phosphate dehydrogenase. NADPH generation and utilization in monooxygenation reactions. Biochem Pharmacol 31:1131–1137 353. Mason PJ, Stevens D, Diez A, Knight SW, Scopes DA, Vulliamy TJ 1999 Human hexose-6-phosphate dehydrogenase (glucose 1dehydrogenase) encoded at 1p36: coding sequence and expression. Blood Cells Mol Dis 25:30 –37 354. Fabsitz RR, Carmelli D, Hewitt JK 1992 Evidence for independent genetic influences on obesity in middle age. Int J Obes Relat Metab Disord 16:657– 666 355. Rankinen T, Perusse L, Weisnagel SJ, Snyder EE, Chagnon YC, Bouchard C 2002 The human obesity gene map: the 2001 update. Obes Res 10:196 –243 356. Gelernter-Yaniv L, Feng N, Sebring NG, Hochberg Z, Yanovski JA 2003 Associations between a polymorphism in the 11␤ hydroxysteroid dehydrogenase type I gene and body composition. Int J Obes Relat Metab Disord 27:983–986 357. Burtt PB, Singer K, Schaffner SF, Daly MJ, Altschuler D, Flier JS, Groop L, Hirschhorn JN, Haplotype-based association studies of HSD11B1 and abdominal obesity. Program of the 86th annual meeting of The Endocrine Society, Philadelphia, PA, 2003, p 117 (Abstract) 358. Hutton C, Clark F 1984 Polycystic ovarian syndrome in identical twins. Postgrad Med J 60:64 – 65 359. McDonough PG, Mahesh VB, Ellegood JO 1972 Steroid, folliclestimulating hormone, and luteinizing hormone profiles in identical twins with polycystic ovaries. Am J Obstet Gynecol 113:1072–1078 360. Legro RS, Driscoll D, Strauss III JF, Fox J, Dunaif A 1998 Evidence for a genetic basis for hyperandrogenemia in polycystic ovary syndrome. Proc Natl Acad Sci USA 95:14956 –14960 361. Givens JR 1988 Familial polycystic ovarian disease. Endocrinol Metab Clin North Am 17:771–783 362. Franks S, Gharani N, McCarthy M 1999 Genetic abnormalities in polycystic ovary syndrome. Ann Endocrinol (Paris) 60:131–133 363. Rodin A, Thakkar H, Taylor N, Clayton R 1994 Hyperandrogenism in polycystic ovary syndrome: evidence of dysregulation of 11␤-hydroxysteroid dehydrogenase. N Engl J Med 330:460 – 465 364. Lichter PR 1994 Genetic clues to glaucoma’s secrets. The L Edward Jackson Memorial Lecture. Part 2. Am J Ophthalmol 117:706 –727 365. Beckman L, Frohlander N 1990 Heterozygosity effects in studies of genetic markers and disease. Hum Hered 40:322–329 366. Budde WM 2000 Heredity in primary open-angle glaucoma. Curr Opin Ophthalmol 11:101–106 367. Ralston SH 2002 Genetic control of susceptibility to osteoporosis. J Clin Endocrinol Metab 87:2460 –2466 368. Devoto M, Shimoya K, Caminis J, Ott J, Tenenhouse A, Whyte MP, Sereda L, Hall S, Considine E, Williams CJ, Tromp G, Kuivaniemi H, Ala-Kokko L, Prockop DJ, Spotila LD 1998 First-stage autosomal genome screen in extended pedigrees suggests genes predisposing to low bone mineral density on chromosomes 1p, 2p and 4q. Eur J Hum Genet 6:151–157 369. Devoto M, Specchia C, Li HH, Caminis J, Tenenhouse A, Rodriguez H, Spotila LD 2001 Variance component linkage analysis indicates a QTL for femoral neck bone mineral density on chromosome 1p36. Hum Mol Genet 10:2447–2452 370. Quinkler M, Kosmale B, Bahr V, Oelkers W, Diederich S 1997 Evidence for isoforms of 11␤-hydroxysteroid dehydrogenase in the liver and kidney of the guinea pig. J Endocrinol 153:291–298 371. Hult M, Jornvall H, Oppermann UC 1998 Selective inhibition of human type 1 11␤-hydroxysteroid dehydrogenase by synthetic steroids and xenobiotics. FEBS Lett 441:25–28


865

372. Bujalska IJ 2000 Glucocorticoids, 11␤-hydroxysteroid dehydrogenase and obesity, PhD thesis, University of Birmingham, UK; 158 –159 373. Whorwood CB, Mason JI, Ricketts ML, Howie AJ, Stewart PM 1995 Detection of human 11␤-hydroxysteroid dehydrogenase isoforms using reverse-transcriptase-polymerase chain reaction and localization of the type 2 isoform to renal collecting ducts. Mol Cell Endocrinol 110:R7–R12 374. Cai TQ, Wong B, Mundt SS, Thieringer R, Wright SD, Hermanowski-Vosatka A 2001 Induction of 11␤-hydroxysteroid dehydrogenase type 1 but not -2 in human aortic smooth muscle cells by inflammatory stimuli. J Steroid Biochem Mol Biol 77: 117–122 375. Driver PM, Kilby MD, Bujalska I, Walker EA, Hewison M, Stewart PM 2001 Expression of 11␤-hydroxysteroid dehydrogenase isozymes and corticosteroid hormone receptors in primary cultures of human trophoblast and placental bed biopsies. Mol Hum Reprod 7:357–363 376. Pepe GJ, Burch MG, Albrecht ED 1999 Expression of the 11␤hydroxysteroid dehydrogenase types 1 and 2 proteins in human and baboon placental syncytiotrophoblast. Placenta 20:575–582 377. Thurston LM, Chin E, Jonas KC, Bujalska IJ, Stewart PM, Abayasekara DR, Michael AE 2003 Expression of 11␤-hydroxysteroid dehydrogenase (11␤HSD) proteins in luteinizing human granulosa-lutein cells. J Endocrinol 178:127–135 378. Sun K, Myatt L 2003 Enhancement of glucocorticoid-induced 11␤-hydroxysteroid dehydrogenase type 1 expression by proinflammatory cytokines in cultured human amnion fibroblasts. Endocrinology 144:5568 –5577 379. Evagelatou M, Peterson SL, Cooke BA 1997 Leukocytes modulate 11␤-hydroxysteroid dehydrogenase (11␤-HSD) activity in human granulosa-lutein cell cultures. Mol Cell Endocrinol 133:81– 88 380. Tomlinson JW, Crabtree N, Clark PM, Holder G, Toogood AA, Shackleton CH, Stewart PM 2003 Low-dose growth hormone inhibits 11␤-hydroxysteroid dehydrogenase type 1 but has no effect upon fat mass in patients with simple obesity. J Clin Endocrinol Metab 88:2113–2118 381. Sankar BR, Maran RR, Sudha S, Govindarajulu P, Balasubramanian K 2000 Chronic corticosterone treatment impairs Leydig cell 11␤hydroxysteroid dehydrogenase activity and LH-stimulated testosterone production. Horm Metab Res 32:142–146 382. Gupta S, Alfaidy N, Holloway AC, Whittle WL, Lye SJ, Gibb W, Challis JR 2003 Effects of cortisol and oestradiol on hepatic 11␤hydroxysteroid dehydrogenase type 1 and glucocorticoid receptor proteins in late-gestation sheep fetus. J Endocrinol 176:175–184 383. Nwe KH, Hamid A, Morat PB, Khalid BA 2000 Differential regulation of the oxidative 11␤-hydroxysteroid dehydrogenase activity in testis and liver. Steroids 65:40 – 45 384. Ma XH, Wu WX, Nathanielsz PW 2003 Gestation-related and betamethasone-induced changes in 11␤-hydroxysteroid dehydrogenase types 1 and 2 in the baboon placenta. Am J Obstet Gynecol 188:13–21 385. Sun K, He P, Yang K 2002 Intracrine induction of 11␤-hydroxysteroid dehydrogenase type 1 expression by glucocorticoid potentiates prostaglandin production in the human chorionic trophoblast. Biol Reprod 67:1450 –1455 386. Ho CK, Tetsuka M, Hillier SG 1999 Regulation of 11␤-hydroxysteroid dehydrogenase isoforms and glucocorticoid receptor gene expression in the rat uterus. J Endocrinol 163:425– 431 387. Arcuri F, Battistini S, Hausknecht V, Cintorino M, Lockwood CJ, Schatz F 1997 Human endometrial decidual cell-associated 11 ␤-hydroxysteroid dehydrogenase expression: its potential role in implantation. Early Pregnancy 3:259 –264 388. Gomez-Sanchez EP, Ganjam V, Chen YJ, Liu Y, Zhou MY, Toroslu C, Romero DG, Hughson MD, de Rodriguez A, GomezSanchez CE 2003 Regulation of 11␤-hydroxysteroid dehydrogenase enzymes in the rat kidney by estradiol. Am J Physiol Endocrinol Metab 285:E272–E279 389. Quinkler M, Troeger H, Eigendorff E, Maser-Gluth C, Stiglic A, Oelkers W, Bahr V, Diederich S 2003 Enhanced 11␤-hydroxysteroid dehydrogenase type 1 activity in stress adaptation in the guinea pig. J Endocrinol 176:185–192 390. Nwe KH, Norhazlina AW, Hamid A, Morat PB, Khalid BA 2000

866

391.

392.

393.

394.


Endocrine Reviews, October 2004, 25(5):831– 866 In vivo effects of stress, ACTH and corticosterone on testicular 11␤-hydroxysteroid dehydrogenase oxidative activity in rats and the possible mechanism of actions. Exp Clin Endocrinol Diabetes 108:369 –377 Gu S, Ripp SL, Prough RA, Geoghegan TE 2003 Dehydroepiandrosterone affects the expression of multiple genes in rat liver including 11 ␤-hydroxysteroid dehydrogenase type 1: a cDNA array analysis. Mol Pharmacol 63:722–731 Sun K, Yang K, Challis JR 1997 Differential regulation of 11␤hydroxysteroid dehydrogenase type 1 and 2 by nitric oxide in cultured human placental trophoblast and chorionic cell preparation. Endocrinology 138:4912– 4920 Alfaidy N, Xiong ZG, Myatt L, Lye SJ, MacDonald JF, Challis JR 2001 Prostaglandin F2␣ potentiates cortisol production by stimulating 11␤-hydroxysteroid dehydrogenase 1: a novel feedback loop that may contribute to human labor. J Clin Endocrinol Metab 86: 5585–5592 Laplante M, Sell H, MacNaul KL, Richard D, Berger JP, Deshaies Y 2003 PPAR-␥ activation mediates adipose depot-specific effects

395.

396.

397.

398.

on gene expression and lipoprotein lipase activity: mechanisms for modulation of postprandial lipemia and differential adipose accretion. Diabetes 52:291–299 Hermanowski-Vosatka A, Gerhold D, Mundt SS, Loving VA, Lu M, Chen Y, Elbrecht A, Wu M, Doebber T, Kelly L, Milot D, Guo Q, Wang PR, Ippolito M, Chao YS, Wright SD, Thieringer R 2000 PPAR␣ agonists reduce 11␤-hydroxysteroid dehydrogenase type 1 in the liver. Biochem Biophys Res Commun 279:330 –336 Taylor NF, Bartlett WA, Dawson DJ 1984 Cortisone reductase deficiency: evidence for a new inborn error in metabolism of adrenal steroids. J Endocrinol 102(Suppl):89 Phillipov G, Palermo M, Shackleton CH 1996 Apparent cortisone reductase deficiency: a unique form of hypercortisolism. J Clin Endocrinol Metab 81:3855–3860 Savage MW Barton RN, Doman TL, Horan MA, Robins AK, Taylor N 1991 Increased metabolic clearance of cortisol in corticosteroid 11-reductase deficiency. J Endocrinol 129(Suppl):219 (Abstract)

Erratum In the article titled “Biological, Physiological, Pathophysiological, and Pharmacological Aspects of Ghrelin” by A. F. Van der Lely, M. Tschop, M. L. Heiman, and E. Ghigo (Endocrine Reviews 25:426 – 457, 2004), some elements of Fig. 3 were derived from Fig. 7 in the following article: Cowley MA et al. 2003 The distribution and mechanism of action of ghrelin in the CNS demonstrates a novel hypothalamic circuit regulating energy homeostasis. Neuron 37:649 – 661. This article is citation 137 in the bibliography of the Endocrine Reviews article and should have been included in the list of references given at the end of the figure legend. Endocrine Reviews is published bimonthly by The Endocrine Society (http://www.endo-society.org), the foremost professional society serving the endocrine community.