First Author | Jin EJ | Year | 2006 |
Journal | Mol Cells | Volume | 22 |
Issue | 3 | Pages | 353-9 |
PubMed ID | 17202865 | Mgi Jnum | J:196353 |
Mgi Id | MGI:5487758 | Citation | Jin EJ, et al. (2006) BMP-2-enhanced chondrogenesis involves p38 MAPK-mediated down-regulation of Wnt-7a pathway. Mol Cells 22(3):353-9 |
abstractText | The bone morphogenetic protein (BMP) family has been implicated in control of cartilage development. Here, we demonstrate that BMP-2 promotes chondrogenesis by activating p38 mitogen-activated protein kinase (MAPK), which in turn downregulates Wnt-7a/b-catenin signaling responsible for proteasomal degradation of Sox9. Exposure of mesenchymal cells to BMP-2 resulted in upregulation of Sox9 protein and a concomitant decrease in the level of b-catenin protein and Wnt-7a signaling. In agreement with this, the interaction of Sox9 with b-catenin was inhibited in the presence of BMP-2. Inhibition of the p38 MAPK pathway using a dominant negative mutant led to sustained Wnt-7a signaling and decreased Sox9 expression, with consequent inhibition of precartilage condensation and chondrogenic differentiation. Moreover, overexpression of b-catenin caused degradation of Sox9 via the ubiquitin/26S proteasome pathway. Our results collectively indicate that the increase in Sox9 protein resulting from downregulation of b-catenin/Wnt-7a signaling is mediated by p38 MAPK during BMP-2 induced chondrogenesis in chick wing bud mesenchymal cells. |