Biochemical and Biophysical Research Communications, Vol.403, No.1, 7-12, 2010
Protein kinase C beta II and delta/theta play critical roles in bone morphogenic protein-4-stimulated osteoblastic differentiation of MC3T3-E1 cells
Bone morphogenic protein-4 (BMP-4), one of TGF-beta superfamily, is involved in bone and cartilage development, specifically tooth and bone fracture repair. In the present study, the role of protein kinase C (PKC) was investigated in BMP-4-induced differentiation of osteoblast-like MC3T3-E1 cells. PKC inhibitor UCN-01 significantly attenuated the synthesis of osteocalcin, a marker of mature osteoblast phenotype, in a dose-dependent manner as well as blocked osteroblastic differentiation and mineralization in BMP-4-treated MC3T3-E1 cells. Also, UCN-01 suppressed vascular endothelial growth factor (VEGF) production in BMP-4-treated MC3T3-E1 cells. In addition, UCN-01 remarkably suppressed BMP-4-activated PKC beta II and PKC delta/theta of PKC family proteins by Western blotting. Consistently, 2-dimensional electrophoresis (2-DE) immunoblotting revealed that UCN-01 inhibited the BMP-4-induced activation of PKC subfamilies in MC3T3-E1 cells. Taken together, our findings suggest that PKC beta II and PKC delta/theta mediate BMP-4-induced osteoblastic differentiation. (C) 2010 Elsevier Inc. All rights reserved.