Bone Abstracts

Although EGF has been known to inhibit osteoblast differentiation, its molecular mechanism has not been clearly elucidated. Smurf1 acts as a negative regulator of BMP signaling by inducing ubiquitination and proteasomal degradation of BMP type I receptor and R-Smads. In this study, we investigated the effect of EGF on the expression of Smurf1 and the role of Smurf1 in EGF-induced inhibition of BMP2-induced osteogenesis. EGF increased Smurf1 expression which was blocked by trea...

Smurf1 is an E3 ubiquitin ligase for Smad1/5, Runx2 and MEKK2 and plays a role as a negative regulator for osteoblast differentiation and bone formation. However, the role of Smurf1 in odontoblast differentiation has not been elucidated. Previously, we reported that histone deacetylase inhibitors (HDACi) enhance odontoblast differentiation through the upregulation of Nfic expression. In this study, we investigated the regulatory effect of HDACi on Smurf1 expression and the rol...

BMPs and canonical Wnts are the representative developmental signals that enhance osteoblast differentiation and bone formation. Previously, we demonstrated that EGF inhibits BMP2-induced osteoblast differentiation through the induction of Smurf1 expression. However, the regulatory role of EGF in Wnt/β-catenin-induced osteoblast differentiation has not been elucidated. In this study, we investigated the effect of EGF on Wnt/β-catenin signaling-induced osteoblast diff...

Distal-less homeobox 5 (Dlx5) is a transcription factor that enhances osteogenic differentiation of mesenchymal stem cells via upregulating the expression of Runx2 and other osteoblast phenotypic genes. We have previously demonstrated that Dlx5 also downregulates adipogenic differentiation of mesenchymal stem cells and that insulin decreases expression levels of Dlx5 via increasing expression levels of miR-124, a microRNA targeting 3′UTR of Dlx5. However, the mechanism o...

Mesenchymal cells alter and retain their phenotype during skeletal development through activation or suppression of signaling pathways. For example, we have shown that Wnt3a only stimulates osteoblast differentiation in cells with intrinsic osteogenic potential (e.g., MC3T3-E1 pre-osteoblasts) and not in fat cell precursors or fibroblasts (respectively, 3T3-L1 pre-adipocytes or NIH3T3 fibroblasts). Wnt3a promotes osteogenesis in part by stimulating autocrine production of the ...