Effect of microrna-132-3p overexpression onproliferation and osteogenic differentiation of mc3t3-e1 cells / 中国组织工程研究

ABSTRACT

BACKGROUND: Mechanical stress can influence the proliferation and differentiation of MC3T3-E1 cells and trigger differential expression of miR-132-3p. However, further research is warranted concerning whether tensile stress can influence the proliferation and differentiation of osteoblasts by regulating miR-132-3p. OBJECTIVE: To determine the expression of osteogenic differentiation markers and miR-132-3p in MC3T3-E1 cells under 12% cyclic stretch and to explore the effect of miR-132-3p on cell proliferation and differentiation. METHODS: MC3T3-E1 cells were loaded with 0% and 12% tensile stress, and alkaline phosphatase activity, osteocalcin mRNA and miR-132-3p expression levels were detected. MC3T3-E1 cells were transiently transfected with miR-132-3p mimics and a negative control transfection group was set up. The expression of alkaline phosphatase, osteocalcin and Runx2 mRNA in transfected cells were detected by qRT-PCR, and the effect of miR-132-3p on cell proliferation were detected by cell counting kit-8 assay. RESULTS AND CONCLUSION: The alkaline phosphatase activity and osteocalcin mRNA expression were down-regulated in MC3T3-E1 cells under 12% stretch stress (P < 0.01), and the expression of miR-132-3p was significantly increased (P < 0.05). QRT-PCR results showed the expression levels of osteogenic differentiation markers alkaline phosphatase activity, osteocalcin, and Runx2 mRNA in miR-132-3p mimics group were significantly decreased after intracellular transfection of miR-132-3p (P < 0.05). Compared with the negative control transfection group, the cell proliferation in the miR-132-3p mimic group was decreased at 24, 48, and 72 hours after transfection (P < 0.001), and the most obvious reduction was observed after 48-hour transfection. These findings indicate that 12% cyclic tensile stress can negatively regulate the proliferation and differentiation ability of MC3T3-E1 cells by overexpressing miR-132-3p.