[Recent advances in researches on bone formation--role of BMP in bone formation]

Recent advances in action of bone morphogenetic protein (BMP), a member of TGF-beta superfamily, in the differentiation process of mesenchymal cells such as osteoblasts, chondrocytes, bone marrow stromal cells and muscle cells have been reviewed. BMPs induce osteoblast differentiation of various types of cells including undifferentiated mesenchymal cells, bone marrow stromal cells and preosteoblasts. BMPs not only inhibit myogenic differentiation but also convert differentiation pathway of some myogenic cells into an osteoblast lineage. The regulatory mechanism of BMP action discovered in the process of early embryogenesis is also reviewed; noggin, chordin and follistatin inhibit BMP action by specifically binding to BMPs.