Fig. 1

Downregulation of FTO in OA and LPS-stimulated chondrocytes. A RT-qPCR results attested that the mRNA expression of FTO was significantly downregulated in the cartilage tissues of OA mice. B Pearson correlation coefficient analysis certified that the mRNA expression of FTO was markedly negatively related with the total m⁶A levels in cartilage tissue of OA mice (R =  − 0.89). C After the chondrocytes were dealt with different concentration gradients of LPS, the mRNA and protein expression of FTO was evaluated by RT-qPCR and western blotting. D After the chondrocytes were dealt with different concentration gradients of LPS, the relative m⁶A levels were detected by the m⁶A RNA methylation assay kit. E RT-qPCR and western blot were applied to confirm the overexpression of FTO in LPS-treated chondrocytes. F The m⁶A levels were detected using m.⁶A RNA methylation assay kit in different groups. Sham, mice without DMM; model, DMM surgery-induced OA mice; LPS, lipopolysaccharide; FTO, FTO overexpression adenovirus; mock, negative control corresponding to FTO overexpression adenovirus; n = 3 ~ 6, **p < 0.01, ***p < 0.001