MicroRNA-1-3p enhances osteoblast differentiation of MC3T3-E1 cells by interacting with hypoxia-inducible factor 1 α inhibitor (HIF1AN).

Studies have proved that miRNAs participate in the regulation of osteoblast differentiation (OD), and abnormal expression of miRNAs is related with various states of OD. In this study, we investigated the role of miRNA-1-3p in OD using MC3T3-E1 cells. BMP2 is used to induce OD of MC3T3-E1 cells. MiRNA-1-3p mimics or miRNA-1-3p inhibitor was transfected to MC3T3-E1 cells with BMP2. The expression levels of miRNA-1-3p were determined by qRT-PCR. The expression of Runx2, OSX, OPN, and OCN was detected by Western blotting. ALP assay was performed to measure alkaline phosphatase activity. Calcium nodules were evaluated by alizarin red staining. Over-expression of hypoxia-inducible factor 1-alpha inhibitor (HIF1AN) was performed and miRNA-1-3p rescue experiments were carried out. Over-expression of miRNA-1-3p promoted osteogenic differentiations and calcifications, as demonstrated by increased ALP, calcification and osteogenic markers. Knock-down of miRNA-1-3p generated the opposite results. HIF1AN was identified to be directly targeted by miRNA-1-3p. Over-expression of HIF1AN suppressed OD and calcifications, and miRNA-1-3p reversed the effect. Our results demonstrated that miRNA-1-3p could enhance OD of MC3T3-E1 cells through interacting with HIF1AN, which might be employed as therapeutic applications for bone formation and regeneration.