Abstract
BACKGROUND The essence of osteoporosis is mainly the imbalance of bone formation and absorption. Previous studies indicated that SIRT1 is closely related to bone metabolism and bone mass as a regulator of bone mass. The literature reports that microRNAs are significant regulators of osteoblast proliferation and differentiation. MATERIAL AND METHODS In this study, SIRT1 protein and mRNA levels were examined by Western blot and RT-PCR. Osteogenic proliferation was examined by CCK8 assay and osteogenic markers, including ALP, OCN, and RUNX2, were examined by ELISA. The target of miR-132-3p was identified by luciferase reporter assay. RESULTS LPS downregulated the SIRT1 protein level and ß-glycerophosphate upregulated the SIRT1 protein level. The results demonstrated that SIRT1 overexpression promoted the proliferation and differentiation in MC3T3-E1 cells, and SIRT1 interference had the opposite effect. Luciferase reporter assay revealed that miR-132-3p inhibited the reporter gene activity of SIRT1. LPS upregulated the mRNA level of miR-132-3p, and ß-glycerophosphate downregulated the mRNA level of miR-132-3p. CONCLUSIONS miR-132-3p is a pivotal regulator in osteogenic proliferation and differentiation by targeting SIRT1.