Mettl3 promotes oxLDL-mediated inflammation through activating STAT1 signaling

Atherosclerosis (AS) is the main cause of cerebrovascular diseases, and macrophages act important roles during the AS pathological process through regulating inflammation. Modification of the novel N(6)-methyladenine (m6A) RNA is reported to be associated with AS, but its role in AS is largely unknown. The aim of this study was to investigate the role and mechanism of m6A modification in inflammation triggered by oxidized low-density lipoprotein (oxLDL) in macrophages during AS.

RAW264.7 macrophage cells were stimulated with 40 μg/ml ox-LDL, Dot blot, Immunoprecipitation, western blot, Rip and chip experiments were used in our study.

We found oxLDL stimulation significantly promoted m6A modification level of mRNA in macrophages and knockdown of Methyltransferase-Like Protein 3 (Mettl3) inhibited oxLDL-induced m6A modification and inflammatory response. Mettl3 promoted oxLDL-induced inflammatory response in macrophages through regulating m6A modification of Signal transducer and activator of transcription 1 (STAT1) mRNA, thereby affecting STAT1 expression and activation. Moreover, oxLDL stimulation enhanced the interaction between Mettl3 and STAT1 protein, promoting STAT1 transcriptional regulation of inflammatory factor expression in macrophages eventually.

These results indicate that Mettl3 promotes oxLDL-triggered inflammation through interacting with STAT1 protein and mRNA in RAW264.7 macrophages, suggesting that Mettl3 may be as a potential target for the clinical treatment of AS.