Impaired autophagy promotes bile acid-induced hepatic injury and accumulation of ubiquitinated proteins
- Department of Cell Biology, Myunggok Medical Research Institute, Konyang University College of Medicine, Daejeon 35365, South (Korea, Republic of)
- Department of Anatomy, Konyang University College of Medicine, Daejeon 35365, South (Korea, Republic of)
- Department of Stem Cell and Regenerative Biotechnology, Humanized Pig Research Center (SRC), Konkuk University, Seoul 05029, South (Korea, Republic of)
Highlights: • CDCA, CA and bile duct ligation caused defective autophagic clearance. • CDCA suppressed Beclin-1 expression, which exhibits a higher cytotoxicity than CA. • Pharmacological or genetic inhibition of autophagy enhanced bile acid-induced cell death. • Reduced Beclin-1 expression may lead to higher cytotoxicity of CDCA. Chronic exposure to hydrophobic bile acids such as chenodeoxycholic acid (CDCA) and cholic acid (CA) in the liver during cholestasis causes hepatotoxicity and inflammatory response. However, the detailed mechanisms regarding the role of autophagy in cholestatic hepatotoxicity remain largely unknown. Here we determined autophagic clearance in livers of bile duct-ligated mice, in which bile acids accumulate, and in human hepatoma HepG2 cells treated with CDCA and CA. The accumulation of bile acids caused defective autophagic clearance, shown by the accumulation of insoluble p62 and ubiquitinated proteins and cell death accompanied by caspase-3 processing. Hepatocytes exposed to bile acids also showed the accumulation of autophagosomes via suppressed autophagy flux. Treatment of CDCA markedly suppressed Beclin-1 expression, which exhibits a higher cytotoxicity than CA. Moreover, pharmacological or genetic inhibition of autophagy enhanced bile acid-induced cell death. Finally, in vivo, bile duct ligation led to aberrant accumulation of p62 and ubiquitinated proteins in the liver. Our data demonstrate that inhibited autophagy is an essential component of liver injury during cholestasis.
- OSTI ID:
- 23134415
- Journal Information:
- Biochemical and Biophysical Research Communications, Journal Name: Biochemical and Biophysical Research Communications Journal Issue: 1 Vol. 495; ISSN BBRCA9; ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
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