MicroRNA-214 inhibits the osteogenic differentiation of human osteoblasts through the direct regulation of baculoviral IAP repeat-containing 7

Osteoblasts and osteoclasts coordinate to monitor the dynamic osteogenic balance between bone formation and bone resorption. Hence, an investigation of the regulatory mechanisms underlying osteogenic osteoblast differentiation will provide more methods for bone repair and bone regeneration. In the present study, human osteoblast hFOB 1.19 cells were cultured. MicroRNA-214 (miR-214) expression significantly down-regulated during the osteogenic differentiation of hFOB 1.19 cells. In addition, miR-214 overexpression by miR-214 precursor transfection markedly inhibited the expression of alkaline phosphatase (ALP), collagen type I alpha 1 (col1 alpha 1) and runt-related transcription factor 2 (Runx2), which concomitantly decreased ALP activity and the number of mineralized nodules but promoted the expression of signal transducer and activator of transcription 1 (STAT1), an osteogenesis blocker. We next found that miR-214 inhibited the expression of baculoviral IAP repeat-containing 7 (BIRC7), a member of the inhibitor of apoptosis proteins family. However, BIRC7 overexpression, which was induced by plasmid transfection, notably reversed the inhibitory effects of miR-214, indicating a potential BIRC7-dependent osteogenic differentiation manner mediated by miR-214. Taken together, our results demonstrate for the first time that miR-214 suppresses osteogenesis by targeting BIRC7, providing a possible therapeutic target for bone degenerative diseases.