Celastrol antagonizes high glucose-evoked podocyte injury, inflammation and insulin resistance by restoring the HO-1-mediated autophagy pathway

• Published in: Molecular immunology 2018-12, Vol.104, p.61-68
• Main Authors: Zhan, Xiaojiang, Yan, Caixia, Chen, Yanbing, Wei, Xin, Xiao, Jun, Deng, Lijuan, Yang, Yuting, Qiu, Panlin, Chen, Qinkai
• Format: Article
• Language: English
• Subjects: Animals; Autophagy; Autophagy - drug effects; Autophagy - immunology; Celastrol; Cytokines - immunology; Diabetic Nephropathies - immunology; Diabetic Nephropathies - pathology; Diabetic nephropathy; Gene Expression Regulation, Enzymologic - drug effects; Gene Expression Regulation, Enzymologic - immunology; Glucose - adverse effects; Glucose - pharmacology; Heme Oxygenase-1 - immunology; Inflammation; Inflammation - chemically induced; Inflammation - immunology; Inflammation - pathology; Insulin resistance; Insulin Resistance - immunology; Membrane Proteins - immunology; Mice; Podocyte injury; Podocytes - immunology; Podocytes - pathology; Signal Transduction - drug effects; Signal Transduction - immunology; Triterpenes - pharmacology
• ISSN: 0161-5890; 1872-9142
• DOI: 10.1016/j.molimm.2018.10.021

•Celastrol alleviates HG-induced oxidative stress damage and podocyte depletion.•Celastrol overturns HG-evoked inflammatory response and insulin resistance.•Treatment with celastrol restores HG-impaired autophagy pathway.•Celastrol restores HG-induced podovyte dysfunction by activating HO-autophagy pathway. Diabetic nephropathy (DN) contributes to end-stage renal disease and kidney dysfunction with a proverbial feature of podocyte injury. Inflammation and insulin resistance is recently implicated in the pathogenesis of diabetic kidney injury. Celastrol exerts critical roles in inflammatory diseases and injury progression. However, its function and mechanism in DN remains elusive. Here, celastrol dose-dependently restored podocyte viability under high glucose (HG) conditions, but with little cytotoxicity in podocyte. Preconditioning with celastrol counteracted HG-evoked cell apoptosis, LDH release, ROS production and podocyte depletion. Additionally, HG-elevated high transcripts and secretions of pro-inflammatory cytokines were reversed following celastrol treatment, including IL-1β, TNF-α, IL-6. Simultaneously, the inhibitory effects of HG on insulin-triggered glucose uptake and nephrin expression were overturned after celastrol exposure. Intriguingly, celastrol restored HG-induced deficiency of autophagy pathway. Nevertheless, blocking the autophagy signaling by its antagonist 3-MA muted celastrol-protected against HG-evoked cell injury, inflammation and insulin resistance. Importantly, celastrol enhanced heme oxygenase-1 (HO-1) expression in HG-stimulated podocytes. Notably, HO-1 cessation depressed autophagy pathway activation and subsequently blunted beneficial effects of celastrol on HG-exposed podocytes. These finding suggest that celastrol may protect against HG-induced podocyte injury, inflammation and insulin resistance by restoring HO-1-mediated autophagy pathway, implying a promising therapeutic strategy against DN.