Article Text

other Versions

PDF
Alteration of energy metabolism in the pathogenesis of bile duct lesions in primary biliary cirrhosis
  1. Kenichi Harada1,
  2. Yuko Kakuda1,
  3. Yasunori Sato1,
  4. Hiroko Ikeda2,
  5. Shinji Shimoda3,
  6. Yasuhiko Yamamoto4,
  7. Hiroshi Inoue5,
  8. Hajime Ohta6,
  9. Satomi Kasashima7,
  10. Atsuhiro Kawashima7,
  11. Yasuni Nakanuma1
  1. 1Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Ishikawa, Japan
  2. 2Division of Pathology, Kanazawa University Hospital, Kanazawa, Ishikawa, Japan
  3. 3Department of Medicine and Biosystemic Science, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
  4. 4Department of Biochemistry and Molecular Vascular Biology, Kanazawa University Graduate School of Medical Science, Kanazawa, Ishikawa, Japan
  5. 5Department of Physiology and Metabolism, Brain/Liver Interface Medicine Research Center, Kanazawa University, Kanazawa, Ishikawa, Japan
  6. 6Department of Gastroenterology, National Hospital Organization, Kanazawa Medical Center, Kanazawa, Ishikawa, Japan
  7. 7Department of Pathology, National Hospital Organization, Kanazawa Medical Center, Kanazawa, Ishikawa, Japan
  1. Correspondence to Dr Kenichi Harada, Department of Human Pathology, Kanazawa University Graduate School of Medicine, Kanazawa, Ishikawa 920-8640, Japan; kenichih{at}med.kanazawa-u.ac.jp

Abstract

Aim Primary biliary cirrhosis (PBC) is characterised by antimitochondrial antibody against the pyruvate dehydrogenase complex (PDC) and chronic non-suppurative destructive cholangitis (CNSDC). Pyruvate oxidation to acetyl-CoA by PDC is a key step in the glycolytic system. Oestrogen-related receptor-α (ERRα) is functionally activated by inducible coactivators such as peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) and Bcl-3. Moreover, the PGC-1α–ERRα axis interrupts glycolytic metabolism through the upregulation of pyruvate dehydrogenase kinase, isozyme 4 (PDK4), which functionally inhibits PDC-E1α and stimulates fatty acid oxidation. In this study, we investigated the PGC-1α–ERRα axis to clarify PDC dysfunction in CNSDC of PBC.

Methods The expression of PGC-1α, Bcl-3, ERRα, PDK4 and PDC-E1α was examined by immunohistochemistry in liver sections from patients with PBC and controls. The expression of these molecules, the activity of mitochondrial dehydrogenase and PDC, and their alterations by starvation, a treatment used to induce PGC-1α expression, were examined in cultured human biliary epithelial cells (BECs).

Results The nuclear expression of PGC-1α, Bcl-3 and ERRα was exclusively observed in CNSDC of PBC. Moreover, the expression of PDK4 and PDC-E1α was enhanced in CNSDC of PBC. In cultured BECs, the amplification of Bcl-3 and PDK4 mRNAs by reverse-transcription-PCR and mitochondrial dehydrogenase activity were markedly increased but PDC activity was decreased according to the upregulation of PGC-1α.

Conclusions In CNSDC of PBC, the activation of the ERRα–PGC-1α axis was exclusively observed, suggesting the interference of PDC-related glycolytic function and the induction of the fatty acid degradation system. The switching of the cellular energy system is possibly associated with the pathogenesis of CNSDC in PBC.

  • BILIARY
  • LIVER DISEASE
  • AUTO-IMMUNE BILIARY DISEASE

Statistics from Altmetric.com

Request permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.