Biochem Biophys Res Commun. 2007;361(1):156-61.
Bile acid-induced TGR5-dependent c-Jun-N terminal kinase activation leads to enhanced caspase 8 activation in hepatocytes.
제1저자 양종인 · 교신저자 윤정환
소속 (1)
- Department of Internal Medicine and Liver Research Institute, Seoul National University College of Medicine, Seoul 110-744, Republic of Korea.
Abstract
TGR5 is a novel G protein-coupled cell-surface bile acid receptor. In cholestasis, bile acids induce hepatocyte apoptosis by primarily activating death receptor-mediated signaling. We examined if bile acid-induced TGR5 activation is participating in bile acid-induced hepatocyte apoptosis. TGR5 expression and its responsiveness to bile acid were confirmed in human hepatocytes. TGR5 inhibition attenuated bile acid-induced caspase 8 activation, which resulted from reduced bile acid-induced caspase 8 recruited to a death-inducing signaling complex (DISC). Bile acid-induced c-Jun-N terminal kinase (JNK) activation was dependent on bile acid activation of TGR5. JNK formed complexes with caspase 8, which were reduced following bile acid treatment, but this reduction was prevented when TGR5 or JNK was inhibited. In conclusion, bile acids activate TGR5, which leads to JNK activation and reduced complex formation of JNK with caspase 8, thus facilitating caspase 8 recruitment to DISC. These observations suggest therapeutic applications for TGR5 signaling blockage in cholestasis.
그 밖의 정보
- 출판 형태
- Journal Article, Research Support, Non-U.S. Gov't
- 저널
- Biochemical and biophysical research communications · ISSN 0006-291X
- 전자 출판
- 2007-07-19
- MeSH
- Apoptosis · Bile Acids and Salts / pharmacology · Caspase 8 / metabolism · Cell Line, Tumor · Death Domain Receptor Signaling Adaptor Proteins / metabolism · Enzyme Activation · Hepatocytes / cytology / drug effects / enzymology · Humans · JNK Mitogen-Activated Protein Kinases / metabolism · Receptors, G-Protein-Coupled / metabolism
- Substances
- Bile Acids and Salts · Death Domain Receptor Signaling Adaptor Proteins · GPBAR1 protein, human · Receptors, G-Protein-Coupled · JNK Mitogen-Activated Protein Kinases · Caspase 8