title: MiR-122 decreases HCV entry into hepatocytes through binding to the 3' UTR of OCLN mRNA.
abstract: OBJECTIVE
  Analysis in silico suggests that occludin (OCLN), a key receptor for HCV, is a candidate target of miR-122; the most abundant hepatic micro RNA. We aimed to determine if miR-122 can decrease HCV entry through binding to the 3' UTR of OCLN mRNA.
  
  
  METHODS
  Huh7.5 cells were cotransfected with luciferase construct containing 3' UTR of OCLN (pLuc-OCLN) and with selected miRNAs (0-50 nM) and luciferase activity was measured. Huh7.5 cells were also infected by viral particles containing lenti-miR122 genome or control virus. After 48 h, the cells were infected with HCV pseudo-particles (HCVpp) and VSV pseudo-particles (VSVpp). After 72 h of infection, luciferase activity was measured and HCVpp activity was normalized to VSVpp activity.
  
  
  RESULTS
  miR-122 binds to the 3'-UTR of OCLN and down-regulates its expression; cotransfection of miR-122 mimic with pLuc-OCLN resulted in a significant decrease in luciferase activity [by 55% (P < 0.01)], while a non-specific miRNA and a mutant miR-122 did not have any effect. miR-122 mimic significantly down-regulated [by 80% (P < 0.01)] OCLN protein in Huh7.5 cells. Accordingly, patients with chronic hepatitis C and higher levels of hepatic miR-122 have lower hepatic expression of OCLN. Immuno-fluorescence imaging showed a decrease in colocalization of OCLN and CLDN following miR-122 over-expression in HCV infected cells. Huh7.5 cells transiently expressing Lenti-miR122 system showed 42% (P < 0.01) decrease in HCV entry.
  
  
  CONCLUSIONS
  This study uncovers a novel antiviral effect of miR-122 on human liver cells and shows that over-expression of miR-122 can decrease HCV entry into hepatocytes through down-regulation of OCLN.
authors.affiliation: The Liver-Biliary-Pancreatic Center, Carolinas Medical Center, Charlotte, NC, USA; Department of Biology, University of North Carolina at Charlotte, Charlotte, NC, USA.
authors.forename: Hossein
authors.initials: H
authors.lastname: Sendi
authors.forename: Marjan
authors.initials: M
authors.lastname: Mehrab-Mohseni
authors.forename: David M
authors.initials: DM
authors.lastname: Foureau
authors.forename: Sriparna
authors.initials: S
authors.lastname: Ghosh
authors.forename: Tracy L
authors.initials: TL
authors.lastname: Walling
authors.forename: Nury
authors.initials: N
authors.lastname: Steuerwald
authors.forename: Philippe J
authors.initials: PJ
authors.lastname: Zamor
authors.forename: Keith J
authors.initials: KJ
authors.lastname: Kaplan
authors.forename: Carl
authors.initials: C
authors.lastname: Jacobs
authors.forename: William A
authors.initials: WA
authors.lastname: Ahrens
authors.forename: Mark W
authors.initials: MW
authors.lastname: Russo
authors.forename: Mark G
authors.initials: MG
authors.lastname: Clemens
authors.forename: Laura W
authors.initials: LW
authors.lastname: Schrum
authors.forename: Herbert L
authors.initials: HL
authors.lastname: Bonkovsky
mesh_terms: D020413:3' Untranslated Regions; D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D057167:Claudins / Q000378:metabolism; D003198:Computer Simulation; D030541:Databases, Genetic; D015536:Down-Regulation; D016174:Hepacivirus / Q000472:pathogenicity*; D019698:Hepatitis C, Chronic / Q000235:genetics / Q000378:metabolism; D022781:Hepatocytes / Q000378:metabolism* / Q000821:virology*; D054884:Host-Pathogen Interactions; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D062793:Occludin / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D015854:Up-Regulation; D053586:Virus Internalization
chemical_list: D020413:3' Untranslated Regions; D057167:Claudins; C531907:MIRN122 microRNA, human; D035683:MicroRNAs; C568985:OCLN protein, human; D062793:Occludin; D012333:RNA, Messenger
keywords: hepatitis; hepatitis C; liver; micro RNA; occludin