Diabetic nephropathy (DN) is one of the most common and serious complications of diabetes mellitus, and glomerular sclerosis and renal tubular interstitial fibrosis are the main pathological features. Current evidence indicates that the Notch pathway can mediate the impairment of renal tubular function and induce angiogenesis and renal interstitial fibrosis. This study was conducted to explore the potential signaling pathway through which Notch regulates oxidative damage and apoptosis in renal tubular epithelial cells induced by high glucose. mRNA and protein expression levels were assessed using real-time PCR and Western blot, respectively. The protein expression levels of Jaggedl, Notchl, pro-caspase-3, Drpl, and PGC-1α were increased by high glucose, but N-[N-(3,5-difluorohenacetyl)-l-alanyl]-S-phenylglycine tert-butyl ester (DAPT; an inhibitor of the Notch signaling pathway) reversed these effects. Furthermore, DAPT reduced the mRNA expression of Jaggedl, Notchl, MnSOD2, Drpl, and PGC-1α in renal tubular epithelial cells induced by high glucose. In conclusion, the Notch signaling pathway may regulate oxidative damage and apoptosis in renal tubular epithelial cells induced by high glucose by regulating mitochondrial dynein and biogenesis genes, which can accelerate renal interstitial fibrosis in DN. The Notch signaling pathway might be a potential therapeutic target for DN, and DAPT might become a potential drug for the treatment of DN.
Keywords: Diabetic nephropathy (DN); Notch pathway; high glucose; human renal tubular epithelial cells (HK-2 cells); mitochondrial oxidative damage and apoptosis.