title: Effects of ROS-relative NF-κB signaling on high glucose-induced TLR4 and MCP-1 expression in podocyte injury.
abstract: High glucose (HG) induced inflammation is central to progression in diabetic nephropathy (DN). Recent studies have suggested that nuclear factor-kappa B (NF-κB) signaling activation is associated with DN, and podocyte damage may be involved in orchestrating these effects. Therefore, the aim of this study was to investigate the effects of NF-κB signaling on podocytes under HG conditions. The effects of HG and NF-κB signaling on podocytes were assessed by CCK-8 assay, cellular NF-κB translocation assay, measurement of reactive oxygen species (ROS) and Western blot analysis. We found that HG reduced cell viability, activated NF-κB signaling and up-regulated toll-like receptor 4 (TLR4) and monocyte chemoattractant protein-1 (MCP-1). In these cells, NF-κB inhibition with ammonium pyrrolidinethiocarbamate (PDTC) resulted in effectively constraining TLR4 and MCP-1 up-regulation, indicating that protective effects associated with the inhibition of NF-κB were linked to TLR4 and MCP-1 down-regulation in podocytes. Furthermore, HG significantly increased the production of intracellular ROS. Pretreatment with N-acetyl-l-cysteine (NAC) significantly inhibited intracellular ROS generation and increased cell viability, accompanied by a significant NF-κB inhibition and suppression of TLR4 and inflammatory cytokine MCP-1 expression. Collectively, our novel data suggest that HG induces the over-experssion of TLR-4 and MCP-1 through a NF-κB-dependent signaling. NF-κB-mediated increased inflammation is possibly via ROS and contributes to the cell injury. These results may provide potential therapeutic target for diabetic nephropathy in the future.
authors.affiliation: College of Medicine, State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Tumor Microenvironment and Neuro-vascular Regulation, Nankai University, Tianjin 300071, China.
authors.forename: Miaomiao
authors.initials: M
authors.lastname: Wei
authors.affiliation: College of Medicine, State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Tumor Microenvironment and Neuro-vascular Regulation, Nankai University, Tianjin 300071, China.
authors.forename: Zhigui
authors.initials: Z
authors.lastname: Li
authors.affiliation: College of Medicine, State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Tumor Microenvironment and Neuro-vascular Regulation, Nankai University, Tianjin 300071, China.
authors.forename: Lu
authors.initials: L
authors.lastname: Xiao
authors.affiliation: College of Medicine, State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Tumor Microenvironment and Neuro-vascular Regulation, Nankai University, Tianjin 300071, China. Electronic address: zhuoyang@nankai.edu.cn.
authors.forename: Zhuo
authors.initials: Z
authors.lastname: Yang
mesh_terms: D000111:Acetylcysteine / Q000494:pharmacology; D000818:Animals; D002461:Cell Line, Transformed; D018932:Chemokine CCL2 / Q000235:genetics / Q000276:immunology*; D005786:Gene Expression Regulation; D005947:Glucose / Q000633:toxicity*; D007249:Inflammation; D051379:Mice; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000235:genetics / Q000276:immunology*; D050199:Podocytes / Q000187:drug effects* / Q000276:immunology / Q000473:pathology; D011759:Pyrrolidines / Q000494:pharmacology; D017382:Reactive Oxygen Species / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D015398:Signal Transduction; D013859:Thiocarbamates / Q000494:pharmacology; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000276:immunology*
chemical_list: C491768:Ccl2 protein, mouse; D018932:Chemokine CCL2; D016328:NF-kappa B; D011759:Pyrrolidines; D017382:Reactive Oxygen Species; D013859:Thiocarbamates; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; C020972:pyrrolidine dithiocarbamic acid; D005947:Glucose; D000111:Acetylcysteine
keywords: Monocyte chemoattractant protein-1; Nuclear factor-kappa B; Podocytes; Toll-like receptor-4