title: Augmentation of DHCR24 expression by hepatitis C virus infection facilitates viral replication in hepatocytes.
abstract: OBJECTIVE
  We characterized the role of 24-dehydrocholesterol reductase (DHCR24) in hepatitis C virus infection (HCV). DHCR24 is a cholesterol biosynthetic enzyme and cholesterol is a major component of lipid rafts, which is reported to play an important role in HCV replication. Therefore, we examined the potential of DHCR24 as a target for novel HCV therapeutic agents.
  
  
  METHODS
  We examined DHCR24 expression in human hepatocytes in both the livers of HCV-infected patients and those of chimeric mice with human hepatocytes. We targeted DHCR24 with siRNA and U18666A which is an inhibitor of both DHCR24 and cholesterol synthesis. We measured the level of HCV replication in these HCV replicon cell lines and HCV infected cells. U18666A was administrated into chimeric mice with humanized liver, and anti-viral effects were assessed.
  
  
  RESULTS
  Expression of DHCR24 was induced by HCV infection in human hepatocytes in vitro, and in human hepatocytes of chimeric mouse liver. Silencing of DHCR24 by siRNA decreased HCV replication in replicon cell lines and HCV JFH-1 strain-infected cells. Treatment with U18666A suppressed HCV replication in the replicon cell lines. Moreover, to evaluate the anti-viral effect of U18666A in vivo, we administrated U18666A with or without pegylated interferon to chimeric mice and observed an inhibitory effect of U18666A on HCV infection and a synergistic effect with interferon.
  
  
  CONCLUSIONS
  DHCR24 is an essential host factor which augmented its expression by HCV infection, and plays a significant role in HCV replication. DHCR24 may serve as a novel anti-HCV drug target.
authors.affiliation: Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Takano
authors.affiliation: Department of Experimental Phylaxiology, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto, Kumamoto 860-8556, Japan. Electronic address: kkohara@kumamoto-u.ac.jp.
authors.forename: Kyoko
authors.initials: K
authors.lastname: Tsukiyama-Kohara
authors.affiliation: Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Hayashi
authors.affiliation: Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Hirata
authors.affiliation: Department of Experimental Phylaxiology, Faculty of Medical and Pharmaceutical Sciences, Kumamoto University, 1-1-1 Honjo, Kumamoto, Kumamoto 860-8556, Japan.
authors.forename: Masaaki
authors.initials: M
authors.lastname: Satoh
authors.affiliation: Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Tokunaga
authors.affiliation: Phoenix Bio Co., Ltd., Study Service Department, 3-4-1 Kagamiyama, Higashi-Hiroshima 739-0046, Japan.
authors.forename: Chise
authors.initials: C
authors.lastname: Tateno
authors.affiliation: Department of Pathology, Tokyo Metropolitan Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8677, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Hayashi
authors.affiliation: Department of Pathology, Tokyo Metropolitan Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8677, Japan.
authors.forename: Tsunekazu
authors.initials: T
authors.lastname: Hishima
authors.affiliation: Department of Pathology, Tokyo Metropolitan Komagome Hospital, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113-8677, Japan.
authors.forename: Nobuaki
authors.initials: N
authors.lastname: Funata
authors.affiliation: Kamakura Research Laboratories, Chugai Pharmaceutical Co., Ltd., Kajiwara 200, Kamakura-City, Kanagawa 247-8530, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sudoh
authors.affiliation: Department of Microbiology and Cell Biology, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kamikitazawa, Setagaya-ku, Tokyo 156-8506, Japan.
authors.forename: Michinori
authors.initials: M
authors.lastname: Kohara
mesh_terms: D000736:Androstenes / Q000494:pharmacology / Q000627:therapeutic use; D000818:Animals; D002784:Cholesterol / Q000378:metabolism; D056945:Hep G2 Cells; D016174:Hepacivirus / Q000502:physiology*; D006526:Hepatitis C / Q000188:drug therapy / Q000378:metabolism / Q000821:virology*; D006801:Humans; D016898:Interferon-alpha / Q000627:therapeutic use; D051379:Mice; D008807:Mice, Inbred BALB C; D009419:Nerve Tissue Proteins / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D044925:Oxidoreductases Acting on CH-CH Group Donors / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology; D011092:Polyethylene Glycols / Q000627:therapeutic use; D034741:RNA, Small Interfering / Q000494:pharmacology; D011994:Recombinant Proteins / Q000627:therapeutic use; D015854:Up-Regulation; D014779:Virus Replication / Q000502:physiology*
chemical_list: D000736:Androstenes; D016898:Interferon-alpha; D009419:Nerve Tissue Proteins; D034741:RNA, Small Interfering; D011994:Recombinant Proteins; C006261:3-beta-(2-(diethylamino)ethoxy)androst-5-en-17-one; D011092:Polyethylene Glycols; D002784:Cholesterol; D044925:Oxidoreductases Acting on CH-CH Group Donors; C499055:DHCR24 protein, human; C100416:peginterferon alfa-2a