ALKBH5 Downregulation Links Glucose-Induced m⁶A Remodeling to Impaired Basal Insulin Secretion in Pancreatic β Cells

Immunochemistry analysis further confirmed a reduction in ALKBH5 protein levels, reinforcing its role in glucose-induced m⁶A methylation changes. Functionally, β-cells cultured in high glucose for 24 hours displayed impaired basal insulin secretion, which was rescued by Alkbh5 overexpression, indicating a direct link between m⁶A dynamics and β-cell secretory function. To assess whether these epitranscriptomic changes were driven by reactive oxygen species (ROS), we compared glucose-treated cells with those exposed to glucose oxidase (generates extracellular H₂O₂) or menadione (generates intracellular superoxide).

The distinct expression patterns of m⁶A regulators in each condition suggest that glucose-induced changes occur independently of ROS signaling. Collectively, our findings reveal a glucose-dependent, ROS-independent modulation of β-cell m⁶A methylation, mediated in part by ALKBH5 downregulation. This regulatory axis may contribute to β-cell dysfunction under hyperglycemic stress, offering new insights into the epitranscriptomic mechanisms underpinning glucose homeostasis and diabetes pathogenesis.