T-2 toxin induces degradation of chondrocytes extracellular matrix through the methyltransferase-like 3/m6A/Csf1 axis.

T-2 toxin can induce the development of cartilage diseases. N6-methyladenosine (m6A) modification mediated by methyltransferase-like 3 (METTL3) is involved in the occurrence and progression of bone-related diseases. However, the mechanism of action of METTL3 in T-2 toxin-caused cartilage injury has not been fully revealed. It is unclear whether METTL3 regulates cartilage injury by modulating its downstream target macrophage colony-stimulating factor (Csf1). Here, we aimed to investigate the mechanism by which the T-2 toxin induces cartilage damage. We performed histological staining, western blotting, immunohistochemistry, immunofluorescence, RNA-seq, MeRIP-seq, and qRT-PCR. T-2 toxin was found to down- and upregulate METTL3 and Csf1 expression levels in the articular cartilage tissue of mice, respectively. According to the in vitro experiments, the knockdown of METTL3 exacerbates the extracellular matrix (ECM) degradation associated with the HT-2 toxin (the deacetylated form of the T-2 toxin). Based on bioinformatics analysis and related experiments, we found that Csf1 interacts with METTL3 through m6A modification, serving as a METTL3 target to promote the degradation of the cartilage extracellular matrix of chondrocytes. Summarily, gene regulation of the METTL3/m6A/Csf1 axis in the extracellular matrix of chondrocytes can promote the development of T-2 toxin-induced cartilage damage, providing a reference for the effective treatment of cartilage-related diseases. These findings reveal the regulatory mechanism of METTL3/m6A/Csf1 axis as a potential therapeutic target for the treatment of cartilage-associated diseases.