title: Downregulation of connective tissue growth factor by LPS/IFN-γ-induced nitric oxide is reversed by aristolochic acid treatment in glomerular mesangial cells via STAT-1α and NF-κB signaling.
abstract: Aristolochic acid (AA) is a common cause of Chinese herb nephropathy. The mechanisms involved in the pathogenesis of AA nephropathy (AAN) are intricate. One well-documented effect of AA in the kidney is its pro-fibrotic activity. Nitric oxide (NO), a messenger gas generated from l-arginine, is the product of nitric oxide synthase (NOS). NO is involved in renal hemodynamics and exerts cytoprotective effects against renal injury. In the present study, the role of NO in AAN was investigated in MES-13 cells, a glomerular mesangial cell line. NO endogenously generated by the induction of inducible nitric oxide synthase (iNOS) with lipopolysaccharide (LPS)/interferon-γ (IFN-γ) significantly downregulated connective tissue growth factor (CTGF) protein expression in MES-13 cells. AA significantly suppressed LPS/IFN-γ-induced NO production and reversed CTGF expression that was downregulated by LPS/IFN-γ. AA decreased iNOS gene and protein expressions in a concentration-dependent manner. AA caused declines in LPS/IFN-γ-induced signal transducer and activator of transcription-1α (STAT-1α) phosphorylation and interferon response factor-1 (IRF-1) mRNA expression. Furthermore, AA attenuated IκB phosphorylation and reduced NF-κB translocation to the nuclear fraction. Taken together, our data indicate that AA reversed the CTGF expression inhibited by LPS/IFN-γ treatment via suppression of NO and iNOS expressions in MES-13 cells through inhibition of the JAK/STAT-1α and NF-κB signaling pathways. NO potentially exerts antifibrotic activity by down regulation of CTGF in MES-13 cells and inhibition of the iNOS gene by AA might partially account for the fibrotic effects of AA in nephropathy.
authors.affiliation: Department of Internal Medicine, China Medical University and Beigang Hospital, 123, Sinde Road, Beigang Township, Yunlin County 65152, Taiwan, ROC; Institute of Molecular Biology, National Chung Cheng University, 168 University Road, Minhsiung Township, Chiayi County 62102, Taiwan, ROC.
authors.forename: Kuen-Daw
authors.initials: KD
authors.lastname: Tsai
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Chia-Yi Christian Hospital, Chiayi, Taiwan, ROC.
authors.forename: Wei
authors.initials: W
authors.lastname: Chen
authors.affiliation: Department of Biomedical Sciences, Chung Shan Medical University, No. 110, Jianguo North Road, Section 1, Taichung 40203, Taiwan, ROC; Department of Medical Research, Chung Shan Medical University Hospital, No. 110, Jianguo North Road, Section 1, Taichung 40203, Taiwan, ROC.
authors.forename: Sue-Hong
authors.initials: SH
authors.lastname: Wang
authors.affiliation: Department of Biomedical Sciences, Chung Shan Medical University, No. 110, Jianguo North Road, Section 1, Taichung 40203, Taiwan, ROC; Department of Medical Research, Chung Shan Medical University Hospital, No. 110, Jianguo North Road, Section 1, Taichung 40203, Taiwan, ROC.
authors.forename: Yu-Wei
authors.initials: YW
authors.lastname: Hsiao
authors.affiliation: Department of Biomedical Sciences, Chung Shan Medical University, No. 110, Jianguo North Road, Section 1, Taichung 40203, Taiwan, ROC; Department of Medical Research, Chung Shan Medical University Hospital, No. 110, Jianguo North Road, Section 1, Taichung 40203, Taiwan, ROC.
authors.forename: Jhih-Ying
authors.initials: JY
authors.lastname: Chi
authors.affiliation: Department of Biomedical Sciences, Chung Shan Medical University, No. 110, Jianguo North Road, Section 1, Taichung 40203, Taiwan, ROC; Department of Medical Research, Chung Shan Medical University Hospital, No. 110, Jianguo North Road, Section 1, Taichung 40203, Taiwan, ROC.
authors.forename: Hsing-Yu
authors.initials: HY
authors.lastname: Wu
authors.affiliation: Institute of Microbiology and Immunology, Chung Shan Medical University, No. 110, Jianguo North Road, Section 1, Taichung 40203, Taiwan, ROC.
authors.forename: Yi-Ju
authors.initials: YJ
authors.lastname: Lee
authors.affiliation: Department of Internal Medicine, China Medical University and Beigang Hospital, 123, Sinde Road, Beigang Township, Yunlin County 65152, Taiwan, ROC.
authors.forename: Ho-Yiu
authors.initials: HY
authors.lastname: Wong
authors.affiliation: Institute of Molecular Biology, National Chung Cheng University, 168 University Road, Minhsiung Township, Chiayi County 62102, Taiwan, ROC.
authors.forename: Min-Jen
authors.initials: MJ
authors.lastname: Tseng
authors.affiliation: Department of Biomedical Sciences, Chung Shan Medical University, No. 110, Jianguo North Road, Section 1, Taichung 40203, Taiwan, ROC; Department of Medical Research, Chung Shan Medical University Hospital, No. 110, Jianguo North Road, Section 1, Taichung 40203, Taiwan, ROC. Electronic address: thlin@csmu.edu.tw.
authors.forename: Ting-Hui
authors.initials: TH
authors.lastname: Lin
mesh_terms: D034341:Aristolochic Acids / Q000494:pharmacology*; D002273:Carcinogens / Q000494:pharmacology; D002460:Cell Line; D055513:Connective Tissue Growth Factor / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation / Q000187:drug effects*; D005920:Glomerular Mesangium / Q000166:cytology / Q000187:drug effects; D006801:Humans; D050856:Interferon Regulatory Factor-1 / Q000378:metabolism; D007371:Interferon-gamma / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology*; D016328:NF-kappa B / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D052247:Nitric Oxide Synthase Type II / Q000235:genetics / Q000378:metabolism; D050794:STAT1 Transcription Factor / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D034341:Aristolochic Acids; D002273:Carcinogens; D050856:Interferon Regulatory Factor-1; D008070:Lipopolysaccharides; D016328:NF-kappa B; D050794:STAT1 Transcription Factor; C494079:STAT1 protein, human; D055513:Connective Tissue Growth Factor; D009569:Nitric Oxide; D007371:Interferon-gamma; C000228:aristolochic acid I; C496319:NOS2 protein, human; D052247:Nitric Oxide Synthase Type II
keywords: Aristolochic acid; Connective tissue growth factor; Glomerular mesangial cells; NF-κB; Nitric oxide; STAT-1α