METTL16 silencing attenuates atherosclerosis by suppressing NF-κB-mediated VSMC senescence and inflammation

Aim This study aims to investigate whether METTL16, an m 6 A methyltransferase, regulates atherosclerosis via VSMC senescence, inflammation, and NF-κB signaling. Methods ApoE −/− mice received tail-vein injection of lentivirus encoding METTL16-targeting shRNA to establish a METTL16 knockdown (KD) model. Atherosclerotic lesions were evaluated by Oil Red O and H&E staining, and serum lipid profiles were measured biochemically. Aortic METTL16 knockdown and tissue specificity were verified by Western blot, qPCR, and multi-tissue qPCR. For in vitro mechanistic studies, human aortic smooth muscle cells (CP-H081) were treated with ox-LDL with or without METTL16 siRNA; cellular senescence, inflammatory cytokine expression, NF-κB pathway activation, and the NF-κB activator TNF-α was used for pathway verification. Results METTL16 knockdown significantly reduced aortic plaque, luminal obstruction, and serum TC, TG, and LDL-C levels. Mechanistically, METTL16 silencing suppressed VSMC senescence and inflammatory responses, accompanied by reduced p65 phosphorylation without affecting total p65 protein levels. In vivo tissue analysis confirmed METTL16 downregulation in aortic tissues and isolated medial layers, while liver tissue showed no significant changes, supporting VSMC-targeted effect. TNF-α stimulation partially reversed METTL16 knockdown-mediated suppression of p-p65 and inflammatory cytokines, confirming NF-κB involvement. Conclusion METTL16 promotes atherosclerosis, at least in part, through NF-κB-mediated VSMC senescence and inflammation, with its effects associated with m6A methyltransferase activity. These findings suggest that selective inhibition of METTL16 may represent a novel therapeutic strategy for atherosclerosis.