Mitochondrial Dysfunction Across Renal Compartments in Diabetic Kidney Disease

Diabetic kidney disease (DKD) remains a leading cause of chronic kidney disease and kidney failure despite considerable therapeutic progress. Mitochondrial dysfunction has emerged as a central mechanism linking diabetic metabolic stress to progressive renal injury, yet it is often described as a generalized, whole-kidney abnormality. This view is incomplete because renal compartments differ in metabolic demand, substrate preference, oxygen exposure, mitochondrial density, and repair capacity. Therefore, diabetes is unlikely to induce a uniform mitochondrial defect across the kidney. Here, we introduce a compartment- and stage-specific framework that integrates evidence from proximal tubules, distal nephron segments, glomerular endothelial cells, podocytes, mesangial cells, immune cells, and interstitial compartments. Using this framework, we define how mitochondrial metabolism, dynamics, quality control, redox signaling, mtDNA stress, and inflammatory pathways contribute to DKD progression across distinct renal cell types. We highlight which mitochondrial programs are most clearly implicated in specific renal compartments, where evidence remains limited, and how understudied cell types may contribute to disease progression. This cell- and stage-specific framework provides a basis for interpreting mitochondrial dysfunction by renal compartment and biological context rather than as a single kidney-wide process. Moving beyond bulk mitochondrial measurements toward spatial, functional, and cell-specific mitochondrial phenotyping may clarify whether mitochondrial responses are adaptive, injurious, or reversible and support therapeutic strategies directed toward the relevant mitochondrial programs in the appropriate compartment and at the appropriate disease stage. Article Highlights Mitochondrial dysfunction in diabetic kidney disease is compartment and stage specific, reflecting differences in renal cell metabolism, function, and injury response. This article introduces a framework for interpreting mitochondrial dysfunction across renal cell types and disease stages. Proximal tubular stress progresses from increased transport demand to mitochondrial injury and impaired quality control. Distal nephron, immune, and interstitial mitochondrial mechanisms remain incompletely defined. In glomerular endothelial cells and podocytes, mitochondria primarily regulate stress and injury signaling. Cell-specific mitochondrial phenotyping may reveal reversible pathways and guide more precise therapeutic strategies in diabetic kidney disease.