Feb 19, 2018 - Methods: We analyzed in mouse embryonic fibroblasts (MEFs) the effects ... BMP9, and we inhibited ALK1 receptor with dorsomorphin-1 and.
Nephrology Dialysis Transplantation 30 (Supplement 3): iii70–iii79, 2015 doi:10.1093/ndt/gfv166.18
CELL SIGNALLING. CELL BIOLOGY. HORMONES FP030
BMP9 INDUCES A FIBROTIC PHENOTYPE THROUGH ALK1 AND ALK5 RECEPTORS
Jose M Muñoz-Felix1,2, Nuria Peretta-Tejedor1,2, Cristina Cuesta1,2, Isabel Fuentes-Calvo1,2, Nelida Eleno1,2, Jose M. Lopez-Novoa1,2 and Carlos Martinez-Salgado1,2,3 1 Universidad de Salamanca, Department of Physiology and Pharmacology, Salamanca, Spain, 2Biomedical Research Institute of Salamanca, Cardiovascular and Renal Research, Salamanca, Spain, 3Instituto de Estudios de Ciencias de la Salud de Castilla y Leon (IECSCYL), Unidad de Investigación, Hospital Universitario de Salamanca, Salamanca, Spain Introduction and Aims: Synthesis of extracellular matrix (ECM) proteins by myofibroblasts in the tubular interstitium is one of the most important processes in the development of renal fibrosis. Several cytokines have been described as profibrotic due to effect inducing ECM protein synthesis, such as transforming growth factor beta 1
(TGF-β1) and connective tissue growth factor (CTGF). Bone morphogenetic proteins (BMP) are members of the TGF-β superfamily which play important roles in development and differentiation. BMP9 is a potent ligand of the ALK1 receptor in endothelial cells. Signalling throughout ALK1 regulates ECM protein synthesis in several cell types such as fibroblasts, hepatocytes or chondrocytes. The aim of the present study is to assess the effect of BMP9 on ECM protein production by fibroblasts. Methods: We analyzed in mouse embryonic fibroblasts (MEFs) the effects induce on ECM protein synthesis and the intracellular pathways involved. We stimulated MEFs with 20 ng/ml BMP9, and we inhibited ALK1 receptor with dorsomorphin-1 and ALK5 receptor with SB431542. Results: BMP9 treatment increased collagen I, fibronectin and CTGF expression. Stimulation with BMP9 leaded to phosphorylation of Smad1/5/8 (through the ALK1 receptor) and Smad2/3 (through the ALK5 receptor). Inhibition of any of these receptors blocked BMP9-induced increase in ECM protein synthesis. Inhibition of ALK5 with SB431542 leads to a lower activation of Smad2/3 but not Smad1/5/8 pathway, whereas the inhibition with dorsomorphin-1 induces a lower activation of both pathways. Moreover, ALK1 knockdown with siRNA decreases the activation of both intracellular pathways. Conclusions: This study shows for the first time that BMP9 acts on cultured fibroblasts as a profibrotic factor, and that this effect is mediated by signalling throughout both ALK1and ALK5 receptors.
© The Author 2015. Published by Oxford University Press on behalf of ERA-EDTA. All rights reserved.
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