Japan Society for the Promotion of Science:Grants-in-Aid for Scientific Research
Date (from‐to) : 2015/04 -2018/03
Author : Otsuka Takanobu
Heat shock proteins (HSPs) are induced by a variety of physiological and environmental stresses, such as heat. As molecular chaperones, HSPs facilitate the refolding of unfolded proteins. However, the details behind the HSP-mediated effects on osteoblasts remain to be clarified. In the present study, in order to investigate the exact mechanism of HSPs in osteoblasts, we explored the molecular targets of HSP27 and HSP22 using osteoblast-like MC3T3-E1 cells. Our results strongly suggest that HSP27 functions as a negative regulator in the PDGF-BB-stimulated migration of osteoblasts, and the suppressive effect is amplified by the phosphorylation state of HSP27. HSP22 functions as a negative regulator in the TGF-β-stimulated migration of osteoblasts via suppression of the Smad-dependent pathway. In addition, HSP22 interacts with mTOR and regulates TNF-α-induced IL-6 synthesis in osteoblasts.