Long noncoding RNA MIRG induces osteoclastogenesis and bone resorption in osteoporosis through negative regulation of miR-1897.

OBJECTIVE: To investigate the expression of long noncoding RNA (LncRNA) MIRG and its potential functions in regulating osteoclastogenesis and bone resorption function through modulating miR-1897 in bone marrow macrophages (BMMs). MATERIALS AND METHODS: qRT-PCR was performed to detect the expressions of MIRG and its co-expression mRNA NFATc1 at different stages during osteoclastogenesis. The CCK-8 assay was performed to evaluate cell proliferation and differentiation. The correlation between miR-1897 and MIRG was detected by statistical analysis. Bioinformatics and luciferase assay were performed to explore the interaction and binding site of MIRG and miR-1897. We also cloned the mice NFATc1 3'-UTR into the luciferase reporter vector and constructed miR-1897 binding mutants to validate the inhibited regulation of miR-1897 to the expression of NFATc1. RESULTS: Results showed that expressions of MIRG and NFATc1 were upregulated during osteoclastogenesis. qRT-PCR and CCK-8 assay showed that MIRG expression is associated with osteoclastogenesis and bone resorption. The bioinformatics prediction and luciferase assay suggested that by interacting with miR-1897, MIRG acts as a molecular sponge for the miR-1897 target NFATc1, to partly modulate the inhibitory effect of miR-1897 on NFATc1. CONCLUSIONS: We found that lncRNA-MIRG was upregulated in osteoclasts, which could promote osteoclastogenesis and bone resorption function as a molecular sponge by modulating the inhibitory effect of miR-1897 on NFATc1.