MicroRNA-215 promotes proliferation and differentiation of osteoblasts by regulation of c-fos

Background: Exploration of the molecular mechanisms governing osteoblast proliferation and differentiation is very important for improving the treatment of osteoporosis. MicroRNAs (miRNAs) have been shown to act as a regulator during osteoblastic differentiation. In this study, we examined the role of miR-215 in the proliferation and differentiation of MC3T3-E1 cells. Methods: The murine pre-osteoblast cell line MC3T3-E1 was used in the experiment. After transfected with miR-215 mimic, miR-215 inhibitor, or negative control, the expressions of miR-215, Runx2, Ocn, c-fos, MAPK, and JAK/STAT were assessed using qRT-PCR. Cell viability and migration were analyzed by Cell Counting Kit-8 assay and the level of expressions of Runx2, Ocn, c-fos, MAPK, and JAK/STAT were detected by western blotting. Results: MiR-215 expression was significantly upregulated during osteoblastic differentiation. Overexpression of miR-215 significantly promoted viability, migration, and differentiation of MC3T3-E1 cells, whereas silencing of miR-215 inhibited these processes. Furthermore, it was found that overexpression of miR-215 significantly upregulated the expression of c-fos, MAPK, and JAK/STAT proteins, while silencing of c-fos reversed these effects. These findings together indicate that miR-215 promotes proliferation and differentiation of osteoblasts by upregulating the expression of c-fos. Conclusion: Our findings imply that miR-215 promotes osteoblastic differentiation of MC3T3-E1 cells by regulating c-fos expression, and thus represent a novel and potential therapeutic target for treatment of osteoporosis.