lncRNA MALAT1 promotes osteogenic differentiation through the miR-217/AKT3 axis: A possible strategy to alleviate osteoporosis

Background Accumulating evidence demonstrates that long non-coding RNAs (lncRNAs) are associated with the development of osteoporosis. The present study aimed to investigate the effect of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on osteogenic differentiation in osteoporosis. Methods MALAT1 levels were detected by a real-time polymerase chain reaction (RT-qPCR). Moreover, the levels of osteogenic differentiation-related factors (Bmp4, Col1a1 and Spp1) were measured by a RT-qPCR and western blotting. Alkaline phosphatase (ALP) activity was detected using an ALP staining assay. Results MALAT1 levels were downregulated in hindlimb unloading mice and simulated in microgravity (MG) treated MC3T3-E1 cells. Moreover, MG treatment induced the downregulation of the expression of ALP, BMP4, Col1a1 and Spp1, whereas overexpression of MALAT1 abolished the downregulation. MG also inhibited ALP activity, whereas MALAT1 reversed the effect. Furthermore, miR-217 was identified as a target of MALAT1, and AKT3 was verified as a target of miR-217. Overexpression of miR-217 rescued the promotion of osteogenic differentiation induced by MALAT1 in MG treated cells. Knockdown of AKT3 abolished the facilitation of osteogenic differentiation induced by downregulation of miR-217. Conclusions MALAT1 promotes osteogenic differentiation through regulating miR-217/AKT3 axis, suggesting that MALAT1 is a potential target with respect to alleviating osteoporosis.