miR-532-3p inhibits osteogenic differentiation in MC3T3-E1 cells by downregulating ETS1

Background: Many studies had identified that MicroRNAs (miRNAs) could affect bone metabolism by regulating the expression of various proteins. This study explored the effect and mechanism of miR-532-3p on osteogenic differentiation. Methods: We analyzed the content of miR-532-3p in osteoporosis patients, osteoporosis rats, and osteogenic induced MC3T3-E1 cells. MiR-532-3p mimic or inhibitor utilized to alter intracellular miR-532-3p content. MTT method executed to detect the effect of miR-532-3p on osteoblast proliferation. Real-time qPCR, Western blot, alkaline phosphatase staining, and alizarin red staining utilized to ascertain the influence of miR-532-3p on osteogenic differentiation. Then, databases and a dual-luciferase reporter gene assay used to verify the target of miR-532-3p. Furthermore, the lentiviral vector was utilized to overexpress interesting target gene expression and checked whether the target gene was involved in the regulation of osteogenic differentiation by miR-532-3p. Results: MiR-532-3p expression boosted in low bone mineral density (BMD) patients and rats. In MC3T3-E1 cells, miR-532-3p expression gradually decreased as osteogenic induction matures. MiR-532-3p mimic negatively regulated succinate dehydrogenase (SDH) activity, alkaline phosphatase (ALP) activity, mineralization ability, the osteogenic-associated gene (Col1A1, Runx2, ALP, OPN, and OCN) and E-26 transformation specific-1 (ETS1) expression of MC3T3-E1 cells. Things are the opposite of the miR-532-3p inhibitor. ETS1 identified as the miR-532-3p target gene, and miR-532-3p could inhibit its expression. Besides, improved ETS1 expression could rescue the suppressive effect of miR-532-3p mimic on osteogenic differentiation. Conclusion: miR-532-3p can suppress osteogenic differentiation by downregulating ETS1 expression. (C) 2020 Elsevier Inc. All rights reserved.