MiR-146a regulates osteogenic differentiation and proliferation of bone marrow stromal cells in traumatic femoral head necrosis.

OBJECTIVE: To investigate the regulatory mechanism of micro ribonucleic acid (miR)-146a in osteogenic differentiation and proliferation of bone marrow stromal cells (BMSCs) in traumatic femoral head necrosis. PATIENTS AND METHODS: Femoral neck fracture patients undergoing surgery were divided into necrosis group and non-necrosis group. The expression level of miR-146a in BMSCs isolated from these patients was detected via quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The clinical correlation of miR-146a with BMSCs in traumatic femoral head necrosis was explored. The regulatory effects of miR-146a on osteogenic differentiation and proliferation of BMSCs in traumatic femoral head necrosis were detected. Moreover, the cell proliferation was analyzed via cell counting kit-8 (CCK-8) assay. The deposition of calcium on the cell surface was detected via alizarin red staining to evaluate the osteogenic differentiation. The messenger RNA (mRNA) expressions of osteogenesis-specific genes, alkaline phosphatase (ALP), and osteocalcin (Ocn) in BMSCs undergoing osteogenic differentiation were detected via qRT-PCR. RESULTS: Expression level of miR-146a in BMSCs of necrosis group was significantly lower than that in non-necrosis group, and the difference was statistically significant (p<0.01). CCK-8 assay revealed that the proliferation of BMSCs was significantly enhanced in miR-146a-mimic group compared with that in miR-NC group, while it significantly declined in miR-146a-inhibitor group compared with that in miR-NC group. The results of alizarin red staining showed that the deposition of calcium obviously increased in miR-146a-mimic group compared with that in miR-NC group, indicating that the osteogenic differentiation ability is significantly enhanced, while it markedly decreased in miR-146a-inhibitor group compared with that in miR-NC group. The detection of osteogenesis-specific genes via qRT-PCR manifested that the mRNA expressions of ALP and Ocn remarkably increased in miR-146a-mimic group compared with those in miR-NC group, and there were statistically significant differences (p<0.05). The mRNA expressions of ALP and Ocn remarkably decreased in miR-146a-inhibitor group compared with those in miR-NC group, and there were statistically significant differences (p<0.05), suggesting the inhibited osteogenic differentiation ability. CONCLUSIONS: We showed that miR-146a regulates the osteogenic differentiation and proliferation of BMSCs in traumatic femoral head necrosis.