METTL3‐mediated m6A modification enhances lncRNA H19 stability to promote endothelial cell inflammation and pyroptosis to aggravate atherosclerosis

Abstract This study explored the impact of N 6 ‐methyladenosine (m6A) modification on the regulation of long noncoding RNA (lncRNA) and atherosclerosis progression. An atherosclerosis cell model was established by treating human aortic endothelial cells (HAECs) with oxidized low‐density lipoprotein. Additionally, an atherosclerotic animal model was developed using ApoE −/− C57BL/6 male mice fed a high‐fat diet. Both models were employed to assess the expression changes of proteins associated with m6A modification. First, the effect of m6A modification writer protein methyltransferase‐like 3 (METTL3) knockdown on changes in the level of pyroptosis in HAECs was investigated, and bioinformatic analysis confirmed that lncRNA H19 (H19) was the potential target of m6A modification. RNA‐binding protein immunoprecipitation assays were subsequently performed to explore the interaction between H19 and the m6A writer protein METTL3, as well as the reader protein recombinant insulin‐like growth factor 2 mRNA‐binding protein 2 (IGF2BP2). Finally, the effect of H19 expression on pyroptosis levels in HAECs was evaluated. In the aortas of atherosclerosis mice, overall m6A levels were significantly elevated compared with controls ( p < .05), with METTL3 and METTL14 mRNA and protein levels notably increased ( p < .05). Similarly, ox‐LDL‐treated HAECs showed a significant rise in m6A levels, along with increased METTL3 and METTL14 expression ( p < .05). METTL3 knockdown in HAECs led to decreased pyroptosis, as evidenced by reduced lactate dehydrogenase release and lower levels of IL‐1β, IL‐18, and IL‐6 ( p < .05). Overexpression of H19 reversed these effects, indicating METTL3's role in promoting atherosclerosis by stabilizing H19 through m6A modification. H19 was the primary target lncRNA molecule of METTL3‐mediated m6A modification in the pathogenesis of atherosclerosis. METTL3‐mediated m6A modification regulated H19 expression, thereby aggravating atherosclerosis by activating pyroptosis.