Mar 26, 2015 - Department of Surgery, Daejeon St. Mary's Hospital, College of Medicine, ...... Kilroy GE, Foster SJ, Wu X, Ruiz J, Sherwood S, Heifetz A, et al.
Lee et al. Stem Cell Research & Therapy (2015) 6:75 DOI 10.1186/s13287-015-0072-7
RESEARCH
Open Access
Lipopolysaccharide preconditioning of adipose-derived stem cells improves liver-regenerating activity of the secretome Sang Chul Lee, Hye Jin Jeong, Sang Kuon Lee and Say-June Kim*
Abstract Introduction: Growing recognition of paracrine mechanisms in stem cell plasticity has resulted in considerable interest in stem cell-derived secretome. The aim of this study was to investigate the effects of lipopolysaccharide (LPS) preconditioning on the composition and hepatic regenerative activity of adipose-derived stem cell (ASC) secretome. Methods: Conditioned medium (CM) and LPS-CM were obtained after culturing human ASCs without or with low-dose LPS (0.5 ng/mL) for 24 hours. Untreated and thioacetamide-treated mouse AML12 hepatocytes were incubated for 24 hours with the control medium, LPS (0.5 ng/mL), CM, and LPS-CM and then cell viabilities were compared. CM and LPS-CM were also intravenously administered to partially hepatectomized mice, and their effects on liver regeneration were assessed by using liver weight measurements, immunohistochemistry, and Western blotting. Results: In the in vitro experiments, LPS preconditioning of ASCs enhanced the mRNA expression levels of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), hepatocyte growth factor, and vascular endothelial growth factor, which evoke inflammatory response or liver regeneration. LPS-CM significantly promoted thioacetamidedamaged AML12 cell viability compared with CM-incubated cells and the control cells (77%, 69%, and 65% P
