title: Andrographolide suppresses high glucose-induced fibronectin expression in mesangial cells via inhibiting the AP-1 pathway.
abstract: Mesangial cells (MCs) proliferation and accumulation of glomerular matrix proteins such as fibronectin (FN) are the early features of diabetic nephropathy, with MCs known to upregulate matrix protein synthesis in response to high glucose. Recently, it has been found that andrographolide has renoprotective effects on diabetic nephropathy. However, the molecular mechanism underlying these effects remains unclear. Cell viability and proliferation was evaluated by MTT. FN expression was examined by immunofluorescence and immunoblotting. Activator protein-1 (AP-1) activation was assessed by immunoblotting, luciferase reporter and electrophoretic mobility shift assays. Andrographolide significantly decreased high glucose-induced cell proliferation and FN expression in MCs. Exposure of MCs to high glucose markedly stimulated the expression of phosphorylated c-jun, whereas the stimulation was inhibited by andrographolide. Plasmid pAP-1-Luc luciferase reporter assay showed that andrographolide blocked high glucose-induced AP-1 transcriptional activity. EMSA assay demonstrated that increased AP-1 binding to an AP-1 binding site at -1,029 in the FN gene promoter upon high glucose stimulation, and the binding were disrupted by andrographolide treatment. These data indicate that andrographolide suppresses high glucose-induced FN expression by inhibiting AP-1-mediated pathway.
authors.affiliation: Vascular Biology Research Institute, Guangdong Pharmaceutical University, Guangzhou, 510006, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Lan
authors.forename: Teng
authors.initials: T
authors.lastname: Wu
authors.forename: Hongju
authors.initials: H
authors.lastname: Gou
authors.forename: Qianqian
authors.initials: Q
authors.lastname: Zhang
authors.forename: Jiangchao
authors.initials: J
authors.lastname: Li
authors.forename: Cuiling
authors.initials: C
authors.lastname: Qi
authors.forename: Xiaodong
authors.initials: X
authors.lastname: He
authors.forename: Pingxiang
authors.initials: P
authors.lastname: Wu
authors.forename: Lijing
authors.initials: L
authors.lastname: Wang
mesh_terms: D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects; D004224:Diterpenes / Q000494:pharmacology*; D024202:Electrophoretic Mobility Shift Assay; D005353:Fibronectins / Q000235:genetics / Q000378:metabolism*; D005947:Glucose / Q000494:pharmacology*; D015151:Immunoblotting; D050527:Mesangial Cells / Q000187:drug effects / Q000378:metabolism*; D000073718:Pancreatitis-Associated Proteins; D051381:Rats; D017207:Rats, Sprague-Dawley; D015398:Signal Transduction / Q000187:drug effects; D018808:Transcription Factor AP-1 / Q000378:metabolism*
chemical_list: D004224:Diterpenes; D005353:Fibronectins; D000073718:Pancreatitis-Associated Proteins; C000612141:REG3A protein, human; D018808:Transcription Factor AP-1; C030419:andrographolide; D005947:Glucose
keywords: ANDROGRAPHOLIDE; AP-1; DIABETIC NEPHROPATHY; HIGH GLUCOSE; MESANGIAL CELLS