Wordprocessing

Tumor necrosis factor α sensitizes primary murine hepatocytes to Fas/CD95-induced apoptosis in a Bim- and Bid-dependent manner

Abstract:

Fas/CD95 is a critical mediator of cell death in many chronic and acute liver diseases and induces apoptosis in primary hepatocytes in vitro. In contrast, the proinflammatory cytokine tumor necrosis factor α (TNFα) fails to provoke cell death in isolated hepatocytes but has been implicated in hepatocyte apoptosis during liver diseases associated with chronic inflammation. Here we report that TNFα sensitizes primary murine hepatocytes cultured on collagen to Fas ligand (FasL)-induced apoptosis. This synergism is time-dependent and is specifically mediated by TNFα. Fas itself is essential for the sensitization, but neither Fas up-regulation nor endogenous FasL is responsible for this effect. Although FasL is shown to induce Bid-independent apoptosis in hepatocytes cultured on collagen, the sensitizing effect of TNFα is clearly dependent on Bid. Moreover, both c-Jun N-terminal kinase activation and Bim, another B cell lymphoma 2 homology domain 3 (BH3)-only protein, are crucial mediators of TNFα-induced apoptosis sensitization. Bim and Bid activate the mitochondrial amplification loop and induce cytochrome c release, a hallmark of type II apoptosis. The mechanism of TNFα-induced sensitization is supported by a mathematical model that correctly reproduces the biological findings. Finally, our results are physiologically relevant because TNFα also induces sensitivity to agonistic anti-Fas-induced liver damage. CONCLUSION: Our data suggest that TNFα can cooperate with FasL to induce hepatocyte apoptosis by activating the BH3-only proteins Bim and Bid.

20872776

Projects: A2.2: Regulation of pro-apoptotic and anti-apoptotic responses in hepato...

Hepatology
Hepatology 53(1): 282-92
24th Sep 2010

Kathrin Schmich, Rebekka Schlatter, Nadia Corazza, Karine Sá Ferreira, Michael Ederer, Thomas Brunner, Christoph Borner, Irmgard Merfort

help Authors

[Karine Ferreira] [Michael Ederer] [Christoph Borner] [Irmgard Merfort]

help Attributions

None

help Scales


Cell and Intercellular
Views: 2047
  • Created: 16th Jul 2012 at 16:53
  • Last updated: 24th Oct 2013 at 16:19

Related items

Ajax-loader-large

Log in / Register

Need an account?
Sign up

Forgotten password?

Front Page

Virtual Liver Network

(v.0.22.0)

Related Projects and friends


Imprint Taverna workflow workbench myExperiment JWS Online ISATAB myGrid Sabio-RK BioPortal Semantic SBML

Powered by:

Ror-logo-32

Icons:
Silk icons 1.3
Crystal Clear icons