MiR-23b-3p functions as a positive factor for osteoporosis progression by targeting CCND1 in MC3T3-E1 cells.

MiRNAs have gained tremendous attention as studies have shown that miRNAs play important roles in osteoporosis (OP) progression. This study attempted to explore whether miR-23b-3p is involved in the pathogenesis of OP. We detected the miR-23b-3p and Cyclin D1 (CCND1) expressional patterns in the bone of patients with or without OP relying on the GEO database. β-Glycerophosphate disodium salt and L-ascorbic acid were utilized to stimulate differentiation of MC3T3-E1 cells. Cell proliferative, apoptotic abilities, and cell cycle distribution were determined by CCK-8 and flow cytometry experiments. TargetScan and dual-luciferase reporter analysis were employed to predict and verify the targets of miR-23b-3p. Western blot was implemented to detect the expression of CCND1, apoptosis-related proteins, and cell osteogenesis-related proteins. ALP activity of MC3T3-E1 cells was measured using ALP kit. MiR-23b-3p was increased in OP specimens. Gain-/loss-of-function analysis indicated that the miR-23b-3p inhibited proliferation and differentiation and promoted apoptosis of MC3T3-E1 cells. The levels of Bax and cleaved caspase-3 were increased while those of Bcl-2 were decreased. ALP activity was reduced, and the levels of ALP, Runx2, Osterix, and OPN were declined in MC3T3-E1 cells relative to control. Further analyses demonstrated that CCND1 was a putative target gene of miR-23b-3p. Moreover, knockdown of CCND1 could reverse the impacts of miR-23b-3p inhibitor in MC3T3-E1 cells. MiR-23b-3p functioned as an O-positive factor through regulating cell cycle, proliferation, apoptosis, and differentiation via targeting CCND1.