Exenatide ameliorates hydrogen peroxide-induced pancreatic β-cell apoptosis through regulation of METTL3-mediated m⁶A methylation.

Exenatide, a glucagon-like peptide-1 (GLP-1) receptor agonist, is a commonly used hypoglycemic agent in clinical practice; it inhibits reactive oxygen species-induced pancreatic β-cell apoptosis. N-methyladenosine (mA) is produced by the methylation of RNA N6 residues and has recently been shown to play a crucial role in the regulation of islet β-cell growth and development. However, the involvement of mA methylation in the β-cell protective effects of exenatide has not been clarified. In this study, the mA-methylated RNA content and methyltransferase-like 3 (METTL3) expression levels in NIT-1 cells and primary mouse islets were found to significantly decrease following treatment with hydrogen peroxide (HO). Treatment with exenatide induced an increase in mA content and METTL3 expression in the HO-treated NIT-1 cells and islets. Moreover, METTL3 silencing resulted in NIT-1 cell apoptosis under normal culture conditions. METTL3 upregulation significantly ameliorated HO-induced apoptosis in NIT-1 cells and primary islets. Furthermore, the anti-apoptotic effects of exenatide were obviously reversed by METTL3 knockdown. In conclusion, these findings suggest that exenatide elicits its anti-apoptotic effects in pancreatic β-cells by promoting mA methylation through the upregulation METTL3 expression.