Epigenetic Regulation Of Runx2 Transcription And Osteoblast Differentiation By Nicotinamide Phosphoribosyltransferase

Objective: In this article,by observe Epigenetic regulation of Runx2 transcription and osteoblast differentiation by Nampt.Methods : evaluated by ALP staining,ALP activity and osteoblast-mediated mineralization,which are biomarkers for osteoblasts.Results: We found the lower osteogenesis in bone marrow stromal cells differentiation isolated from Namp+/-mice than those from Nampt+/+ mice.The similar results were observed in differentiated Nampt-deficient C3H/10T1/2,and MC3T3-E1 cells.Further studies showed that Nampt promotes osteoblastic differentiation through increase both of function and expression of Runx2 as tested by luciferase activity assay and RT-PCR.Our data also demonstrated that Nampt regulates Runx2 partially through epigenetic modification by elevation of H3-Lys9 acetylation.Conclusions: Our study firstly showed the critical role of Nampt in osteoblastic differentiation in mice and in preosteoblasts,which may lead to the development of novel aging-related osteoporosis therapies.