[Bone and calcium update; bone research update. Regulatory mechanisms in osteoblast differentiation].
ABSTRACT Differentiation process of osteoblasts, which play a central role in bone formation, is harmoniously controlled by several cytokines and hormones. Particularly, Bone Morphogenetic Protein (BMP) , Indian Hedgehog (Ihh) , and Wnt family proteins are important cytokines for osteoblast differentiation. Understandings of molecular mechanisms by which these cytokines stimulate osteoblast differentiation have been extensively investigated. BMP/Smad signaling, canonical Wnt pathway, non-canonical Wnt pathway and Ihh/Gli signaling play critical role in osteoblast differentiation. Furthermore, biochemical and genetic studies have demonstrated important roles of Runt related transcription factor 2 (Runx2) , Osterix, Activating transcription factor 4 (ATF4) , Msh homeobox 2 (Msx2) and Oasis for osteoblast differentiation. Thus, these milestone studies have dramatically progressed in our understanding of the cellular and molecular mechanisms of osteoblast differentiation for 20 years.