Integrated Multi-Omics and Experimental Validation Reveal Dysregulation of the OXPHOS-NADPH-GSH Axis in Renal Fibrosis

Chronic renal failure (CRF) is a growing global health burden, with renal fibrosis representing its key pathological feature. However, the metabolic mechanisms linking mitochondrial dysfunction to redox imbalance during fibrogenesis remain incompletely understood. In this study, we investigated the relationship between mitochondrial Oxidative Phosphorylation (OXPHOS) disruption and alterations in cellular redox metabolism during CRF progression. Integrated proteomic and metabolomic analyses revealed remodeling of mitochondrial respiratory chain components together with reduced expression of NADPH-generating Enzymes, including ME1, ME2, and IDH1. These changes were accompanied by decreased NADPH availability, imbalance of the glutathione redox system (GSH/GSSG), and suppression of NRF2-dependent antioxidant defenses, including HO-1 and GPX4. These alterations were associated with increased oxidative stress and extracellular matrix accumulation in fibrotic kidneys. In vitro experiments further showed that N-acetylcysteine (NAC) partially restored redox homeostasis, improved mitochondrial function, and attenuated TGF-β1-induced profibrotic responses in renal fibroblasts. In addition, the mitochondria-targeted antioxidant Mito-TEMPO reduced mitochondrial ROS accumulation and alleviated fibroblast activation. Collectively, these findings suggest that coordinated disruption of mitochondrial OXPHOS, NADPH metabolism, and glutathione-dependent antioxidant defense is associated with redox imbalance during renal fibrosis. Targeting mitochondrial redox metabolism may therefore represent a potential strategy for mitigating fibrotic progression in CRF.