[Effect of miR-705 on osteogenic differentiation of mouse embryo osteoblast precursor cells MC3T3-E1]

Objective: To investigate the effect of miR-705 on osteogenic differentiation of mouse embryo osteoblast precursor (MC3T3-E1) cells. Methods: miR-705 mimics, inhibitors and negative control were transfected into MC3T3-E1 cells. Alkaline phosphates (ALP) staining were performed and quantified after 7 days of osteogenic medium induction. The mRNA and protein expression levels of runt-related transcription factor 2 (Runx2) and osteocalcin (OCN) were detected by real-time RT-PCR and Western blot after 14 days of osteogenic induction. Alizarin red staining was performed and quantified in MC3T3-E1 cells after 21 days of osteogenic induction. Results: After 7 days of osteogenic induction, ALP staining showed that overexpression of miR-705 significantly reduced ALP activity, whereas knockdown of miR-705 increased ALP activity (all P<0.05). Consistently, after 14 days of osteogenic induction, mRNA and protein expressions of Runx2 and OCN were suppressed by overexpression of miR-705, whereas they were promoted by knockdown of miR-705 (all P<0.05). After 21 days of osteogenic induction, alizarin red staining showed that overexpression of miR-705 significantly reduced the formation of mineralized node, the opposite results were found in miR-705 knockdown group (all P<0.05). Conclusion: miR-705 can inhibit the osteogenic differentiation of MC3T3-E1 cells.