title: Insulin-like growth factor binding protein-related protein 1 (IGFBPrP1) contributes to liver inflammation and fibrosis via activation of the ERK1/2 pathway.
abstract: OBJECTIVE
  Previously, we suggested that IGFBPrP1 played a major role in hepatic stellate cell (HSC) activation, yet the molecular mechanism of IGFBPrP1 in hepatic fibrosis is unclear. The ERK pathway is involved in activation of HSCs. This study investigated the involvement of the ERK1/2 pathway in IGFBPrP1-induced liver inflammation and fibrosis.
  
  
  METHODS
  An adenoviral vector encoding IGFBPrP1 (AdIGFBPrP1) was constructed. Rats received AdIGFBPrP1 or CAd (vector control) via their tail vein injection. One hour prior to adenoviral injections, rats were intraperitoneally administrated with 10 mg/kg U0126 (a specific MEK/ERK1/2 inhibitor) or DMSO (vehicle control). At weeks 2 or 4 post-gene transduction, serum samples were obtained and the levels of liver enzymes and hydroxyproline were determined. Liver tissue were histologically evaluated for inflammation and fibrosis. The expression of α-SMA and ECM were evaluated by qRT-PCR and western blotting.
  
  
  RESULTS
  After transduction, IGFBPrP1 expression significantly increased in livers and transduced cells. MEK/ERK1/2 inhibition administration of AdIGFBPrP1-treated rats and cells significantly blocked AdIGFBPrP1-induced activation of ERK1/2. U0126 significantly down-regulated the number of F4/80-positive cells and CD3-positive cells (markers of liver inflammation), the expression of α-SMA and the concentration of ECM components in vivo. In addition, α-SMA and TGF-β1 levels in AdIGFBPrP1 HSCs were markedly inhibited by a MEK/ERK1/2 inhibitor, indicating that HSC activation was inhibited.
  
  
  CONCLUSIONS
  These findings suggest that IGFBPrP1 acts as an initiator of liver fibrosis by inducing inflammation, HSC activation and ECM deposition through the ERK1/2 pathway.
authors: Department of Gastroenterology and Hepatology, The First Clinical Hospital of Shanxi Medical University, Mailbox 427, 85 Jiefang South Road, Taiyuan, 030001, Shanxi Province, China.
authors: Yarong
authors: Y
authors: Guo
authors: Yun
authors: Y
authors: Zhang
authors: Qianqian
authors: Q
authors: Zhang
authors: Xiaohong
authors: X
authors: Guo
authors: Haiyan
authors: H
authors: Zhang
authors: Guoping
authors: G
authors: Zheng
authors: Lixin
authors: L
authors: Liu
mesh_terms: D000199:Actins / Q000235:genetics / Q000378:metabolism; D000818:Animals; D002070:Butadienes / Q000494:pharmacology; D017252:CD3 Complex / Q000032:analysis; D002478:Cells, Cultured; D004791:Enzyme Inhibitors / Q000494:pharmacology; D016326:Extracellular Matrix Proteins / Q000235:genetics / Q000378:metabolism; D005822:Genetic Vectors; D055166:Hepatic Stellate Cells; D006505:Hepatitis / Q000378:metabolism* / Q000473:pathology; D018969:Insulin-Like Growth Factor Binding Proteins / Q000235:genetics / Q000378:metabolism*; D007728:Kupffer Cells; D008099:Liver / Q000737:chemistry; D008103:Liver Cirrhosis / Q000378:metabolism* / Q000473:pathology; D018655:Lymphocyte Count; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008297:Male; D009570:Nitriles / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013601:T-Lymphocytes / Q000737:chemistry; D014161:Transduction, Genetic; D053773:Transforming Growth Factor beta1 / Q000187:drug effects / Q000378:metabolism
chemical_list: D000199:Actins; D002070:Butadienes; D017252:CD3 Complex; D004791:Enzyme Inhibitors; D016326:Extracellular Matrix Proteins; D018969:Insulin-Like Growth Factor Binding Proteins; D009570:Nitriles; D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1; C113580:U 0126; C102529:insulin-like growth factor binding protein-related protein 1; C498862:Acta2 protein, rat