METTL3-mediated m⁶A Methylation Modification Promotes the Endothelial Cell Pyroptosis in Kawasaki Disease

Kawasaki disease (KD) is classified as an acute febrile illness characterized primarily by systemic vasculitis. While the involvement of N6-methyladenosine (m⁶A) modification in various cardiovascular conditions has been established, its specific role in KD remains unexplored. This study aims to investigate the potential influence of m⁶A modification in KD and to elucidate the mechanisms involved. Clinically, 18 KD patients and 15 healthy volunteers were recruited. Reverse transcription-quantitative polymerase chain reactio (RT-qPCR) was performed to assess the expression of m⁶A-related enzymes. Lactate dehydrogenase (LDH) release, interleukin (IL)-1β and IL-18 concentrations were analyzed by commercial kits. Hoechst 33,342/PI staining was performed for cell death detection. Pyroptosis-related protein levels were detected by Western blot. RNA immunoprecipitation (RIP) and dual-luciferase reporter assays were performed to assess the interaction between methyltransferase-like protein 3 (METTL3) and Nod-like receptor (NLR) family CARD domain-containing protein 4 (NLRC4). Finally, a KD mouse model was induced by Candida albicans cell wall extracts. Results showed that serum from KD patients exhibited higher METTL3 expression. Additionally, KD serum-treated THP1 cells induced pyroptosis of human umbilical vein endothelial cells (HUVECs). Mechanistically, METTL3 promoted the stability of NLRC4 mRNA via m⁶A methylation. Furthermore, NLRC4 overexpression promoted pyroptosis in KD-treated HUVECs. Finally, METTL3 inhibition attenuated coronary arteritis and pyroptosis in a KD mouse model. In summary, this study concluded that METTL3-mediated m⁶A methylation modification promoted the endothelial cell pyroptosis in KD, which might provide a reference for the pathogenesis of KD.