PURPOSE: Bone morphogenic protein-7 (BMP-7) is a member of the transforming growth factor beta (TGFbeta) superfamily involved in organogenesis. Recent work suggests that BMP-7 can reverse the fibrotic effects of TGFbeta but the underlying mechanism is unknown. We sought to determine BMP-7 signaling and its modulation of TGFbeta induced fibrotic outcomes in adult human proximal tubule epithelial cells (PTECs). METHODS: The effect of BMP-7 on phospho-p38 was assessed by Western blotting, p38 ELISA and Bio-plex phospho-protein assay. Secreted fibronectin (Fn) was measured by ELISA. RESULTS: BMP-7 had a concentration-dependent effect on intracellular signaling activating Smad 1/5/8 at higher concentrations and p38 mitogen activated protein (MAP) kinase at lower concentrations in both primary and transformed PTECs; BMP-7 caused phosphorylation of p38 at 2.5 ng/ml and Smads at 200 ng/ml. Similarly, nuclear accumulation of phospho-p38 and Smad were observed at these respective concentrations. These results suggested an inverse relationship between activation of Smads and p38 MAP kinase in this context. Consistent, with this BMP7 at 200 ng/ml reduced TGFbeta-induced p38 MAP activation and the p38-dependent TGFbeta-induced Fn secretion by PTECs. CONCLUSION: We have shown novel p38/Smad signaling along a BMP-7 gradient and demonstrated BMP-7 regulation of TGFbeta MAP kinase signaling and fibrotic outcomes.
PURPOSE:Bone morphogenic protein-7 (BMP-7) is a member of the transforming growth factor beta (TGFbeta) superfamily involved in organogenesis. Recent work suggests that BMP-7 can reverse the fibrotic effects of TGFbeta but the underlying mechanism is unknown. We sought to determine BMP-7 signaling and its modulation of TGFbeta induced fibrotic outcomes in adult human proximal tubule epithelial cells (PTECs). METHODS: The effect of BMP-7 on phospho-p38 was assessed by Western blotting, p38 ELISA and Bio-plex phospho-protein assay. Secreted fibronectin (Fn) was measured by ELISA. RESULTS:BMP-7 had a concentration-dependent effect on intracellular signaling activating Smad 1/5/8 at higher concentrations and p38 mitogen activated protein (MAP) kinase at lower concentrations in both primary and transformed PTECs; BMP-7 caused phosphorylation of p38 at 2.5 ng/ml and Smads at 200 ng/ml. Similarly, nuclear accumulation of phospho-p38 and Smad were observed at these respective concentrations. These results suggested an inverse relationship between activation of Smads and p38 MAP kinase in this context. Consistent, with this BMP7 at 200 ng/ml reduced TGFbeta-induced p38 MAP activation and the p38-dependent TGFbeta-induced Fn secretion by PTECs. CONCLUSION: We have shown novel p38/Smad signaling along a BMP-7 gradient and demonstrated BMP-7 regulation of TGFbeta MAP kinase signaling and fibrotic outcomes.
Authors: K Yamaguchi; K Shirakabe; H Shibuya; K Irie; I Oishi; N Ueno; T Taniguchi; E Nishida; K Matsumoto Journal: Science Date: 1995-12-22 Impact factor: 47.728
Authors: S Vukicevic; V Basic; D Rogic; N Basic; M S Shih; A Shepard; D Jin; B Dattatreyamurty; W Jones; H Dorai; S Ryan; D Griffiths; J Maliakal; M Jelic; M Pastorcic; A Stavljenic; T K Sampath Journal: J Clin Invest Date: 1998-07-01 Impact factor: 14.808
Authors: Caroline N Jones; Nazgul Tuleuova; Ji Youn Lee; Erlan Ramanculov; A Hari Reddi; Mark A Zern; Alexander Revzin Journal: Biomaterials Date: 2010-05-21 Impact factor: 12.479