miRNA in the Progression of Diabetic Kidney Disease: New Insight.

Diabetic kidney disease (DKD) is a major microvascular complication of diabetes and a leading cause of end-stage renal disease worldwide. Despite advances in metabolic and blood pressure control, the prevalence of DKD continues to rise, creating a significant clinical and socioeconomic burden. Recent studies have revealed that non-coding RNAs, particularly microRNAs (miRNAs), play an important role in the development and progression of DKD. Distinct patterns of miRNA dysregulation have been identified in specific renal cell types, including podocytes, mesangial cells, tubular epithelial cells, endothelial cells, fibroblasts, and macrophages. These alterations drive characteristic cellular injuries such as podocyte loss, mesangial matrix expansion, tubular epithelial-mesenchymal transition, endothelial dysfunction, and interstitial fibrosis. Certain miRNAs, such as miR-21, miR-192, and miR-214, reinforce profibrotic TGF-β/Smad signaling, whereas protective groups, including the miR-29 and miR-30 families, maintain epithelial stability and restrict matrix deposition. Beyond their regulatory roles, circulating and urinary miRNAs have emerged as stable, non-invasive biomarkers that reflect renal injury and disease progression. This review summarizes recent progress in elucidating cell-specific miRNA networks in DKD and highlights their potential as diagnostic indicators and therapeutic targets for precision management of diabetic kidney disease.