title: Cloning and expression of retinoic acid-induced gene-I and its effect on hepatitis C virus replication.
abstract: OBJECTIVE
  To explore the influence of the retinoic acid indicible gene-I (RIG-I) on hepatitis C virus (HCV) replication and the molecular mechanism of action of RIG-I.
  
  
  METHODS
  We constructed an RIG-I expression vector and co-transfected it into Huh-7 cells along with HCV-replicon RNA. We assayed HCV replication and NS5A protein synthesis via real-time polymerase chain reaction (RT-PCR) and western blotting. Also, we performed an enzyme-linked immunosorbent assay (ELISA) to measure the level of interferon (IFN)-alpha/-beta secretion. Additionally, we examined, via western blotting, the phosphorylation state of p38, Erk1/2, and nuclear factor (NF)-kappaB p65.
  
  
  RESULTS
  Overexpression of RIG-1 in Huh-7 cells co-transfected with an HCV-replicon RNA significantly inhibited HCV replication and NS5A protein synthesis. Co-transfected cells had increased production of IFN-alpha/-beta production and had higher levels of phosphorylated p38, Erk1/2, and NF-kappaB p65.
  
  
  CONCLUSIONS
  RIG-I significantly inhibits HCV replication and NS5A protein synthesis by inducing type I IFN production. The underlying molecular mechanism for this effect appears to be mediated by increased phosphorylation of NF-kappaB p65, p38-mitogen-activated protein kinases (MAPK), and Erk1/2.
authors.forename: Yuedi
authors.initials: Y
authors.lastname: Shen
authors.forename: Yun
authors.initials: Y
authors.lastname: Qian
authors.forename: Ling
authors.initials: L
authors.lastname: Shen
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Wu
authors.forename: Chenhuai
authors.initials: C
authors.lastname: Xu
authors.forename: Xiangming
authors.initials: X
authors.lastname: Tong
mesh_terms: D045744:Cell Line, Tumor; D003001:Cloning, Molecular; D005786:Gene Expression Regulation; D005822:Genetic Vectors; D016174:Hepacivirus / Q000235:genetics* / Q000378:metabolism; D022781:Hepatocytes / Q000378:metabolism* / Q000821:virology; D054884:Host-Pathogen Interactions; D006801:Humans; D007370:Interferon Type I / Q000096:biosynthesis* / Q000235:genetics; D019950:Mitogen-Activated Protein Kinase 1 / Q000235:genetics / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000235:genetics / Q000378:metabolism; D010766:Phosphorylation; D018168:Receptors, Retinoic Acid / Q000235:genetics* / Q000378:metabolism; D012093:Replicon; D015398:Signal Transduction; D051996:Transcription Factor RelA / Q000235:genetics / Q000378:metabolism; D014162:Transfection; D017361:Viral Nonstructural Proteins / Q000235:genetics* / Q000378:metabolism; D014779:Virus Replication / Q000235:genetics*; D048051:p38 Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism; D012324:RNA-Dependent RNA Polymerase
chemical_list: D007370:Interferon Type I; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D018168:Receptors, Retinoic Acid; D051996:Transcription Factor RelA; D017361:Viral Nonstructural Proteins; D048051:p38 Mitogen-Activated Protein Kinases; C437968:PLAAT4 protein, human; C535150:MAPK1 protein, human; C087036:NS-5 protein, hepatitis C virus; D012324:RNA-Dependent RNA Polymerase