ZC3H13-Mediated m 6 A Modification of TRIM16 Suppresses EndMT and Atherosclerosis by Destabilizing Ang2 and Inhibiting the TLR4/NLRP3 Pathway

The RNA methyltransferase zinc finger CCCH-type containing protein 13 (ZC3H13) is downregulated in atherosclerosis (AS), but its functional mechanism remains unclear. Endothelial-mesenchymal transition (EndMT) is a core pathological driver of endothelial dysfunction in AS. This study aimed to investigate the biological function and molecular mechanism of ZC3H13 in regulating EndMT during AS progression. We found that ZC3H13 expression was reduced in aortic tissues of AS mice and in oxidized low‑density lipoprotein (ox‑LDL)-treated human umbilical vein endothelial cells (HUVECs). In ox-LDL-stimulated HUVECs, overexpression of ZC3H13 markedly upregulated endothelial markers (CD31, VE-cadherin), downregulated mesenchymal markers (α-SMA, vimentin), suppressed cell migration, and restored angiogenesis. Conversely, ZC3H13 silencing induced HUVECs EndMT, enhanced migration and impaired angiogenesis. Mechanistically, ZC3H13 elevated tripartite motif-containing protein 16 (TRIM16) mRNA stability by modulating its N6-methyladenosine (m6A) modification. TRIM16 knockdown abolished the protective effects of ZC3H13 overexpression against ox-LDL-induced EndMT and endothelial dysfunction. Furthermore, TRIM16 interacts with angiopoietin-2 (Ang2) and promotes its K48- and K63-linked ubiquitination, thereby inhibiting TLR4/NLRP3 activation and consequently suppressing EndMT. In vivo, lentivirus-mediated ZC3H13 overexpression attenuated atherosclerotic plaque formation and inhibited EndMT. In conclusion, ZC3H13 alleviates AS by suppressing EndMT via the TRIM16/Ang2/TLR4/NLRP3 pathway, highlighting ZC3H13 as a potential therapeutic target for AS.