Expression and function of the atypical cadherin FAT1 in chronic liver disease
- Department of Internal Medicine I, University Hospital Regensburg, Regensburg (Germany)
- Grosshadern Tissue Bank and Center for Liver Cell Research, Department of Surgery, Ludwig-Maximilians-University Munich (Germany)
- Institute of Pathology, University of Regensburg, Regensburg (Germany)
Highlights: Black-Right-Pointing-Pointer The expression of the atypical cadherin FAT1 is increased in chronic liver disease. Black-Right-Pointing-Pointer FAT1 expression goes up during the activation of hepatic stellate cells (HSCs). Black-Right-Pointing-Pointer Activated HSCs are the cellular source of enhanced FAT1 expression in diseased livers. Black-Right-Pointing-Pointer FAT1 enhanced NFkB activity and resistance to apoptosis in activated HSCs. Black-Right-Pointing-Pointer FAT1 is a new therapeutic target for prevention and treatment of hepatic fibrosis. -- Abstract: Hepatic fibrosis can be considered as wound healing process in response to hepatocellular injury. Activation of hepatic stellate cells (HSCs) is a key event of hepatic fibrosis since activated HSCs are the cellular source of enhanced extracellular matrix deposition, and reversion of liver fibrosis is accompanied by clearance of activated HSCs by apoptosis. The atypical cadherin FAT1 has been shown to regulate diverse biological functions as cell proliferation and planar cell polarity, and also to affect wound healing. Here, we found increased FAT1 expression in different murine models of chronic liver injury and in cirrhotic livers of patients with different liver disease. Also in hepatic tissue of patients with non-alcoholic steatohepatitis FAT1 expression was significantly enhanced and correlated with collagen alpha I(1) expression. Immunohistochemistry revealed no significant differences in staining intensity between hepatocytes in normal and cirrhotic liver tissue but myofibroblast like cells in fibrotic septa of cirrhotic livers showed a prominent immunosignal. Furthermore, FAT1 mRNA and protein expression markedly increased during in vitro activation of primary human and murine HSCs. Together, these data indicated activated HSCs as cellular source of enhanced FAT1 expression in diseased livers. To gain insight into the functional role of FAT1 in activated HSCs we suppressed FAT1 in these cells by siRNA. We newly found that FAT1 suppression in activated HSCs caused a downregulation of NF{kappa}B activity. This transcription factor is critical for apoptosis resistance of HSCs, and consequently, we detected a higher apoptosis rate in FAT1 suppressed HSCs compared to control cells. Our findings suggest FAT1 as new therapeutic target for the prevention and treatment of hepatic fibrosis in chronic liver disease.
- OSTI ID:
- 22210264
- Journal Information:
- Biochemical and Biophysical Research Communications, Vol. 426, Issue 3; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0006-291X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Fibroblast growth factor 7 inhibits cholesterol 7{alpha}-hydroxylase gene expression in hepatocytes
Nicotine induces fibrogenic changes in human liver via nicotinic acetylcholine receptors expressed on hepatic stellate cells