TGF-b Prevents Phosphate-Induced Osteogenesis through Inhibition of BMP and Wnt/b-Catenin Pathways
Background: Transforming growth factor-b (TGF-b) is a key cytokine during differentiation of mesenchymal stem cells (MSC) into vascular smooth muscle cells (VSMC). High phosphate induces a phenotypic transformation of vascular smooth muscle cells (VSMC) into osteogenic-like cells. This study was aim...
| Autores: | , , , |
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| Tipo de documento: | artigo |
| Data de publicação: | 2014 |
| País: | España |
| Recursos: | Universidad de Huelva (UHU) |
| Repositório: | Arias Montano. Repositorio Institucional de la Universidad de Huelva |
| Idioma: | inglês |
| OAI Identifier: | oai:ariasmontano.uhu.es:10272/18561 |
| Acesso em linha: | http://hdl.handle.net/10272/18561 |
| Access Level: | Acceso aberto |
| Palavra-chave: | TGF-b Phosphate-Induced Osteogenesis Inhibition of BMP Wnt/b-Catenin |
| Resumo: | Background: Transforming growth factor-b (TGF-b) is a key cytokine during differentiation of mesenchymal stem cells (MSC) into vascular smooth muscle cells (VSMC). High phosphate induces a phenotypic transformation of vascular smooth muscle cells (VSMC) into osteogenic-like cells. This study was aimed to evaluate signaling pathways involved during VSMC differentiation of MSC in presence or not of high phosphate. Results: Our results showed that TGF-b induced nuclear translocation of Smad3 as well as the expression of vascular smooth muscle markers, such as smooth muscle alpha actin, SM22a, myocardin, and smooth muscle-myosin heavy chain. The addition of high phosphate to MSC promoted nuclear translocation of Smad1/5/8 and the activation of canonical Wnt/bcatenin in addition to an increase in BMP-2 expression, calcium deposition and alkaline phosphatase activity. The administration of TGF-b to MSC treated with high phosphate abolished all these effects by inhibiting canonical Wnt, BMP and TGF-b pathways. A similar outcome was observed in high phosphate-treated cells after the inhibition of canonical Wnt signaling with Dkk-1. Conversely, addition of both Wnt/b-catenin activators CHIR98014 and lithium chloride enhanced the effect of high phosphate on BMP-2, calcium deposition and alkaline phosphatase activity. Conclusions: Full VSMC differentiation induced by TGF-b may not be achieved when extracellular phosphate levels are high. Moreover, TGF-b prevents high phosphate-induced osteogenesis by decreasing the nuclear translocation of Smad 1/5/8 and avoiding the activation of Wnt/b-catenin pathway. |
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