FTO-mediated m6A demethylation of pri-miR-3591 alleviates osteoarthritis progression

Abstract

Objectives

Increasing evidence have demonstrated the N6-methyladenosine (m ⁶A) plays critical roles in osteoarthritis (OA) progression, but the role of m ⁶A in OA has not been completely illuminated. Herein, we investigated the function and underlying mechanism of m ⁶A demethylase fat mass and obesity-associated protein ( FTO) in OA progression.

Materials and methods

The FTO expression was detected in mice OA cartilage tissues and lipopolysaccharide (LPS)-stimulated chondrocytes. Gain-of-function assays was used to evaluate the role of FTO in OA cartilage injury in vitro and in vivo. The miRNA-sequencing, RNA-binding protein immunoprecipitation (RIP), luciferase reporter assay, and in vitro pri-miRNA processing assays were conducted to confirm that FTO modulated the pri-miR-3591 process in an m6A-dependent manner and then the binding sites of miR-3591-5p with PRKAA2.

Results

FTO was outstandingly downregulated in LPS-stimulated chondrocytes and OA cartilage tissues. FTO overexpression enhanced the proliferation, suppressed apoptosis, and decreased degradation of extracellular matrix in LPS-induced chondrocytes, whereas FTO knockdown contributed to the opposite effects. In vivo animal experiments showed that FTO overexpression markedly alleviated OA mice cartilage injury. Mechanically, FTO-mediated m6A demethylation of pri-miR-3591 leaded to a maturation block of miR-3591-5p, which relieved the inhibitory effect of miR-3591-5p on PRKAA2 and then promoted the increase of PRKAA2, thereby alleviating OA cartilage damage.

Conclusions

Our results attested that FTO alleviated the OA cartilage damage by mediating FTO/ miR-3591-5p/ PRKAA2 axis, which provided fresh insights into the therapeutic strategies for OA.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-023-03035-5.