Enhanced TRPC3 Transcription Through AT1R/PKA/CREB Signaling Contributes to Mitochondrial Dysfunction in Renal Tubular Epithelial Cells in D-galactose-induced Accelerated Aging Mice

Aging-associated renal dysfunction promotes the pathogenesis of chronic kidney disease. Mitochondrial dysfunction in renal tubular epithelial cells is a hallmark of senescence and leads to accelerated progression of renal disorders. Dysregulated calcium profiles in mitochondria contribute to aging-associated disorders, but the detailed mechanism of this process is not clear. In this study, modulation of the sirtuin 1/angiotensin II type 1 receptor (Sirt1/AT1R) pathway partially attenuated renal glomerular sclerosis, tubular atrophy, and interstitial fibrosis in D-galactose (D-gal)-induced accelerated aging mice. Moreover, modulation of the Sirt1/AT1R pathway improved mitochondrial dysfunction induced by D-gal treatment. Transient receptor potential channel, subtype C, member 3 (TRPC3) upregulation mediated dysregulated cellular and mitochondrial calcium homeostasis during aging. Furthermore, knockdown or knockout (KO) of Trpc3 in mice ameliorated D-gal-induced mitochondrial reactive oxygen species production, membrane potential deterioration, and energy metabolism disorder. Mechanistically, activation of the AT1R/PKA pathway promoted CREB phosphorylation and nucleation of CRE2 binding to the Trpc3 promoter (-1659 to -1648 bp) to enhance transcription. Trpc3 KO significantly improved the renal disorder and cell senescence in D-gal-induced mice. Taken together, these results indicate that TRPC3 upregulation mediates age-related renal disorder and is associated with mitochondrial calcium overload and dysfunction. TRPC3 is a promising therapeutic target for aging-associated renal disorders.