These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


PUBMED FOR HANDHELDS

Search MEDLINE/PubMed


  • Title: Lethal hepatic apoptosis mediated by tumor necrosis factor receptor, unlike Fas-mediated apoptosis, requires hepatocyte sensitization in mice.
    Author: Nagaki M, Sugiyama A, Osawa Y, Naiki T, Nakashima S, Nozawa Y, Moriwaki H.
    Journal: J Hepatol; 1999 Dec; 31(6):997-1005. PubMed ID: 10604572.
    Abstract:
    BACKGROUND/AIMS: Tumor necrosis factor a (TNF-alpha) and Fas ligand are apoptotic cell-death mediators that act by binding to their responsive receptors. The aims of this study were to assess the differences between liver cell deaths induced by TNF-alpha and anti-Fas antibody, and to investigate the mechanism by which GalN sensitizes the hepatocyte to injury by TNF-alpha. METHODS: TNF-alpha or anti-Fas antibody was injected into BALB/c mice sensitized or unsensitized by D-galactosamine (GalN). Liver injury was assessed biochemically and histologically. The expressions of TNF receptor (TNFR)1 and TNFR2 mRNA in the liver were determined by Northern blot analysis. Nuclear factor-kappaB (NF-kappaB) DNA binding activity was determined by gel shift assay. RESULTS: In GalN-sensitized mice, hepatocyte apoptosis and liver failure were observed after TNF-alpha injection, but neither occurred in unsensitized mice. Microscopically, GalN preceding TNF-alpha caused massive hemorrhagic liver damage with fragmented hepatocyte nuclei resembling effects of anti-Fas antibody, but GalN largely failed to sensitize to injury by this antibody. TNFR1 mRNA expression in the liver was upregulated within 3 h after GalN administration, and anti-TNFR1 antibody protected GalN-sensitized mice from hepatotoxic effects of TNF-alpha. GalN treatment failed to affect TNF-alpha-induced NF-kappaB activation. CONCLUSIONS: Unlike Fas-related apoptosis, TNFR-mediated apoptosis requires hepatocyte sensitization involving TNFR1 upregulation.
    [Abstract] [Full Text] [Related] [New Search]