LINC00472 promotes osteogenic differentiation and alleviates osteoporosis by sponging miR-300 to upregulate the expression of FGFR2.

OBJECTIVE: To investigate the expression of LINC00472 in osteoporotic issues of patients, ovariectomized (OVX) mice and mice bone marrow mesenchymal stem cells (BMSCs), its effect on osteogenic differentiation of BMSCs and its mechanism. PATIENTS AND METHODS: The expression of LINC00472 and miR-300 in osteoporosis patients (n=55), ovariectomized (OVX) mice (n=10) and mice BMSCs (n=3) was detected by RT-qPCR and the correlation between the expression of miR-300 and LINC00472 was analyzed. After transferring sh-LINC00472 and overexpression LINC00472 plasmids into mice BMSCs, the expression of ALP, Bglap, OPN, Runx2 was detected by RT-qPCR and Western blot, which were related with osteogenic differentiation. In addition, Luciferase activity was used to detect whether miR-300 combined with LINC00472 and FGFR2 in mice BMSCs directly. Finally, Western blot (WB) was used to detect the change of FGFR2 protein expression by miR-300 inhibitor and sh-LINC00472. RESULTS: We found there was a negative correlation between the expression of miR-300 and LINC00472 in osteoporosis patients, bone tissues of OVX mice and mice BMSCs. The expression of LINC00472 in mice BMSCs was gradually increased with osteogenic differentiation. Transferring overexpression plasmid of LINC00472 into BMSCs, the expression of ALP, Bglap, OPN, Runx2 was increased both in mRNA and protein levels. Transferring sh-LINC00472 to BMSCs, the results were the opposite. Luciferase results showed that miR-300 could directly bind to LINC00472 and FGFR2 in mice BMSCs. What's more, RT-qPCR and WB results showed that transferring sh-LINC00472 could decrease the expression of FGFR2 mRNA and protein, while miR-300 inhibitor could recover this tendency. CONCLUSIONS: According to these results, this study revealed the previously neglected LINC00472/miR-300/FGFR2 regulatory axis for the regulation of osteogenic differentiation in osteoporosis, which may be a potential target for the treatment of osteoporosis.