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

• Published in: Chemico-biological interactions 2014-03, Vol.210, p.86-95
• Main Authors: Tsai, Kuen-daw, Chen, Wei, Wang, Sue-Hong, Hsiao, Yu-Wei, Chi, Jhih-Ying, Wu, Hsing-Yu, Lee, Yi-Ju, Wong, Ho-Yiu, Tseng, Min-Jen, Lin, Ting-Hui
• Format: Article
• Language: English
• Subjects: Aristolochic acid; Aristolochic Acids - pharmacology; Carcinogens - pharmacology; Cell Line; Connective tissue growth factor; Connective Tissue Growth Factor - genetics; Connective Tissue Growth Factor - metabolism; Dose-Response Relationship, Drug; Down-Regulation - drug effects; Glomerular mesangial cells; Glomerular Mesangium - cytology; Glomerular Mesangium - drug effects; Humans; Interferon Regulatory Factor-1 - metabolism; Interferon-gamma - pharmacology; Lipopolysaccharides - pharmacology; NF-kappa B - metabolism; NF-κB; Nitric oxide; Nitric Oxide - metabolism; Nitric Oxide Synthase Type II - genetics; Nitric Oxide Synthase Type II - metabolism; Signal Transduction - drug effects; STAT-1α; STAT1 Transcription Factor - metabolism
• ISSN: 0009-2797; 1872-7786
• DOI: 10.1016/j.cbi.2013.12.017

•LPS/IFN-γ-induced NO downregulates CTGF protein expression in MES-13 cells.•AA significantly suppressed LPS/IFN-γ-induced NO production in MES-13 cells.•AA significantly reversed CTGF expression that was downregulated by LPS/IFN-γ.•AA decreased STAT-1α phosphorylation and IRF-1 mRNA expression in MES-13 cells.•AA attenuated IKB phosphorylation and reduced NF-κB activation in MES-13 cells. 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.