title: Expression of uncoupling protein-2 in biliary epithelial cells in primary biliary cirrhosis.
abstract: OBJECTIVE
  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.
authors.affiliation: Second Department of Medicine and Kurume University Research Center for Innovative Cancer Therapy, Kurume University School of Medicine, Japan. eitaro@med.kurume-u.ac.jp
authors.forename: Eitaro
authors.initials: E
authors.lastname: Taniguchi
authors.forename: Masaru
authors.initials: M
authors.lastname: Harada
authors.forename: Takumi
authors.initials: T
authors.lastname: Kawaguchi
authors.forename: Hironori
authors.initials: H
authors.lastname: Koga
authors.forename: Hiroto
authors.initials: H
authors.lastname: Kumemura
authors.forename: Shinichiro
authors.initials: S
authors.lastname: Hanada
authors.forename: Shoichiro
authors.initials: S
authors.lastname: Shishido
authors.forename: Shinji
authors.initials: S
authors.lastname: Baba
authors.forename: Ryukichi
authors.initials: R
authors.lastname: Kumashiro
authors.forename: Takato
authors.initials: T
authors.lastname: Ueno
authors.forename: Shotaro
authors.initials: S
authors.lastname: Sakisaka
authors.forename: Michio
authors.initials: M
authors.lastname: Sata
mesh_terms: D001652:Bile Ducts / Q000378:metabolism / Q000473:pathology; D004848:Epithelium / Q000378:metabolism / Q000473:pathology; D019693:Hepatitis, Autoimmune / Q000378:metabolism / Q000473:pathology; D006525:Hepatitis, Viral, Human / Q000378:metabolism / Q000473:pathology; D022781:Hepatocytes / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D007473:Ion Channels; D008099:Liver / Q000378:metabolism / Q000473:pathology; D008105:Liver Cirrhosis, Biliary / Q000378:metabolism* / Q000473:pathology; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; D014176:Protein Biosynthesis; D014475:Uncoupling Agents; D000071246:Uncoupling Protein 2
chemical_list: D007473:Ion Channels; D026901:Membrane Transport Proteins; D024101:Mitochondrial Proteins; C000604389:UCP2 protein, human; D014475:Uncoupling Agents; D000071246:Uncoupling Protein 2