Expression of uncoupling protein-2 in biliary epithelial cells in primary biliary cirrhosis

Authors

  • Eitaro Taniguchi,

    1. Second Department of Medicine and Kurume University Research Center for Innovative Cancer Therapy, Kurume University School of Medicine, Japan,
    Search for more papers by this author
  • Masaru Harada,

    1. Second Department of Medicine and Kurume University Research Center for Innovative Cancer Therapy, Kurume University School of Medicine, Japan,
    Search for more papers by this author
  • Takumi Kawaguchi,

    1. Second Department of Medicine and Kurume University Research Center for Innovative Cancer Therapy, Kurume University School of Medicine, Japan,
    Search for more papers by this author
  • Hironori Koga,

    1. Second Department of Medicine and Kurume University Research Center for Innovative Cancer Therapy, Kurume University School of Medicine, Japan,
    Search for more papers by this author
  • Hiroto Kumemura,

    1. Second Department of Medicine and Kurume University Research Center for Innovative Cancer Therapy, Kurume University School of Medicine, Japan,
    Search for more papers by this author
  • Shinichiro Hanada,

    1. Second Department of Medicine and Kurume University Research Center for Innovative Cancer Therapy, Kurume University School of Medicine, Japan,
    Search for more papers by this author
  • Shoichiro Shishido,

    1. Second Department of Medicine and Kurume University Research Center for Innovative Cancer Therapy, Kurume University School of Medicine, Japan,
    Search for more papers by this author
  • Shinji Baba,

    1. Second Department of Medicine and Kurume University Research Center for Innovative Cancer Therapy, Kurume University School of Medicine, Japan,
    Search for more papers by this author
  • Ryukichi Kumashiro,

    1. Second Department of Medicine and Kurume University Research Center for Innovative Cancer Therapy, Kurume University School of Medicine, Japan,
    Search for more papers by this author
  • Takato Ueno,

    1. Second Department of Medicine and Kurume University Research Center for Innovative Cancer Therapy, Kurume University School of Medicine, Japan,
    Search for more papers by this author
  • Shotaro Sakisaka,

    1. Third Department of Medicine, Fukuoka University School of Medicine, Japan
    Search for more papers by this author
  • Michio Sata

    1. Second Department of Medicine and Kurume University Research Center for Innovative Cancer Therapy, Kurume University School of Medicine, Japan,
    Search for more papers by this author

Eitaro Taniguchi, Second Department of Medicine, Kurume University School of Medicine, 67 Asahi-machi, Kurume 830-0011, Japan. Tel: + 81 942 31 7561.
Fax: + 81 942 34 2623.
e-mail: eitaro@med.kurume-u.ac.jp

Abstract

Abstract:Background/Aims: Uncoupling proteins are thought to protect cells from oxidative stresses. Because uncoupling protein-2 is expressed in liver and reactive oxygen species are involved in pathogenesis of various liver diseases, this protein may protect liver cells from disease-associated oxidative stress. However, uncoupling protein-2 expression in human liver has not been examined. Methods: We investigated hepatic uncoupling protein-2 distribution in various liver diseases including primary biliary cirrhosis, autoimmune hepatitis, chronic viral hepatitis, and histologically normal liver by immunohistochemistry.Results: Uncoupling protein-2 was expressed in some hepatocytes, however, the degree of hepatocytic uncoupling protein-2 expression did not differ significantly among liver diseases and normal liver. Uncoupling protein-2 was abundant in biliary epithelial cells in primary biliary cirrhosis but not in other liver specimens. Enhanced uncoupling protein-2 expression in biliary epithelial cells was specific for primary biliary cirrhosis and did not result simply from cholestasis. The percentage of uncoupling protein-2 positive bile ducts in primary biliary cirrhosis patients treated with ursodeoxycholic acid was significantly lower than in untreated patients.Conclusions: These results suggest that uncoupling protein-2 is involved in the pathogenesis of primary biliary cirrhosis.

Ancillary