N-Acetylcysteine Mitigates Renal Fibrosis by Modulating Inflammasome and Gluconeogenic Pathways Under Cardiometabolic Stress

Cardio-renal metabolic (CRM) syndrome, characterized by insulin resistance and dyslipidemia, disrupts renal insulin signaling, enhances oxidative stress, and activates inflammasome pathways, ultimately promoting renal fibrosis and kidney dysfunction. Aberrant renal gluconeogenesis has emerged as a critical contributor to tubular injury under cardiometabolic stress; however, its mechanistic linkage to inflammatory and fibrotic remodeling remains incompletely defined. In this study, ApoE−/− mice subjected to streptozotocin administration and a high-fat diet developed pronounced cardiometabolic dysfunction, accompanied by elevated blood urea nitrogen, creatinine, uric acid, and glycated hemoglobin levels, as well as severe renal histopathological alterations. N-Acetylcysteine (NAC) supplementation significantly improved metabolic abnormalities and attenuated tubular dilation, glomerular hypertrophy, and mesangial expansion. Mechanistically, NAC suppressed renal gluconeogenesis by downregulating glucose-6-phosphatase and phosphoenolpyruvate carboxykinase expression and mitigated epithelial–mesenchymal transition by restoring E-cadherin and reducing vimentin expression, thereby limiting fibrotic remodeling. Consistent with in vivo findings, NAC reduced reactive oxygen species production, restored PI3K/Akt-dependent insulin signaling, and inhibited inflammasome activation in NRK-52E renal tubular cells exposed to high glucose and oleic acid, resulting in attenuation of inflammatory signaling and gluconeogenic activity. Collectively, these results demonstrate that NAC mitigates cardiometabolic stress-induced renal injury by modulating inflammasome activation and gluconeogenic reprogramming, highlighting its potential as a mechanistic modulator of renal fibrosis under CRM conditions.