SLC30A8 (ZnT8) at the crossroads of epigenetics and microRNA regulation in type 2 diabetes and nephropathy

Figure 1 MiRNA-mediated suppression of PDX-1 disrupts slc30a8/znt8 regulation and insulin granule zinc homeostasis under hyperglycemic conditions schematic representation of the molecular interplay between hyperglycemia-induced microRNAs and PDX-1–ZnT8 signaling in pancreatic β-cells. Under hyperglycemic conditions, upregulation of specific microRNAs (e.g., miR-375, miR-765) leads to translational repression of PDX-1 mRNA in the cytoplasm, resulting in reduced nuclear PDX-1 levels. Attenuated PDX-1 binding to Enhancer A, a regulatory element associated with the SLC30A8 locus compromises transcriptional regulation of ZnT8. Dysregulated ZnT8 expression alters zinc transport into insulin granules, affecting zinc-stabilized insulin hexamer formation and contributing to β-cell dysfunction. This pathway highlights miRNA-driven epigenetic control as a critical mechanism linking chronic hyperglycemia to impaired insulin storage and secretion in diabetes.