FTO inhibited miR-487a-3p biosynthesis via N6-methyladenosine-dependent pathway to promote WNT5A-mediated osteogenic differentiation of adipose-derived stem cells.

miR-487a-3p shows the potential of modulating adipose-derived stem cells (ADSCs) differentiation. This study aimed to investigate the mechanism of miR-487a-3p on the osteogenic differentiation of ADSCs. In this work, ADSCs were induced to differentiate into osteoblasts. miR-487a-3p were regulated by miRNA mimics or inhibitors in ADSCs. Wnt family member 5A (WNT5A) siRNA was used to reverse miR-487a-3p inhibitor-induced effects on WNT5A expression in ADSCs. Fat mass and obesity-associated protein (FTO) in ADSCs were altered by shRNAs or overexpression vectors. Calcium nodule, ALP activity, and biomarkers of osteogenic differentiation (OD) were investigated. Rats received ovariectomy (OVX) to construct osteoporosis (OP) model, followed by ADSCs transplantation. Histopathological changes, bone histomorphometry, and detection of OD biomarkers were performed. We found that osteogenesis induced a decrease in miR-487a-3p expression and an increase in FTO expression. miR-487a-3p upregulation inhibited the OD of ADSCs, including decreases in calcium nodule formation, ALP activity, and OD biomarkers. miR-487a-3p downregulation showed the opposite role in OD. miR-487a-3p negatively regulated WNT5A in ADSCs. WNT5A silence reversed the effect of miR-487a-3p downregulation on OD. FTO silence caused the increase in m6A of pri-miR-487a. FTO overexpression inhibited DGCR8 recruitment in pri-miR-487a, and reversed the effect of miR-487a-3p upregulation in OD. ADSCs transplantation improved OP symptom in rats, including improvement of femur tissue, increase in percent bone volume and trabecular number, and upregulation in OD biomarkers. miR-487a-3p downregulation enhanced the therapeutic role of ADSC in rats with OP. Collectively, FTO regulated pri-miR-487a maturation via m6A-dependent pathway, which altered the WNT5A-mediated osteogenesis of ADSCs.