ICE-protease inhibitors block murine liver injury and apoptosis caused by CD95 or by TNF-alpha.
The two apoptosis receptors of mammalian cells, i.e. the 55 kDa TNF receptor (TNF-R1) and CD95 (Fas/APO1) are activated independently of each other, however, their signaling involves a variety of ICE-related proteases [I]. We used a cell-permeable inhibitor of ICE-like protease activity to examine in vivo whether post-receptor signaling of TNF and CD95 are fully independent processes. Mice pretreated with the inhibitor, Z-VAD-fluoromethylketone (FMK) were dose-dependently protected from liver injury caused by CD95 activation as determined by plasma alanine aminotransferase and also from hepatocyte apoptosis assessed by DNA fragmentation (ID50 = 0.1 mg/kg). A dose of 10 mg/kg protected mice also from liver injury induced by TNF-alpha. Similar results were found when apoptosis was initiated via TNF-alpha or via CD95 in primary murine hepatocytes (IC50 = 1.5 nM) or in various human cell lines. In addition to prevention, an arrest of cell death by Z-VAD-FMK was demonstrated in vivo and in vitro after stimulation of apoptosis receptors. These findings show in vitro and in vivo in mammals that CD95 and the TNF-alpha receptor share a distal proteolytic apoptosis signal.
Künstle
G
G
Department of Biochemical Pharmacology, Faculty of Biology, University of Konstanz, Germany.
Leist
M
M
Uhlig
S
S
Revesz
L
L
Feifel
R
R
MacKenzie
A
A
Wendel
A
A
D000410:Alanine Transaminase / Q000097:blood; D000590:Amino Acid Chloromethyl Ketones / Q000494:pharmacology / Q000627:therapeutic use*; D000818:Animals; D015703:Antigens, CD / Q000187:drug effects / Q000502:physiology; D017209:Apoptosis / Q000187:drug effects*; D006528:Carcinoma, Hepatocellular / Q000473:pathology; D020170:Caspase 1; D002478:Cells, Cultured; D056486:Chemical and Drug Induced Liver Injury / Q000503:physiopathology / Q000517:prevention & control*; D003546:Cysteine Endopeptidases / Q000502:physiology*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D053938:DNA Fragmentation; D006367:HeLa Cells / Q000187:drug effects; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism; D015459:Leukemia-Lymphoma, Adult T-Cell / Q000473:pathology; D008070:Lipopolysaccharides; D008099:Liver / Q000166:cytology / Q000187:drug effects*; D008113:Liver Neoplasms / Q000473:pathology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018124:Receptors, Tumor Necrosis Factor / Q000187:drug effects / Q000502:physiology; D047888:Receptors, Tumor Necrosis Factor, Type I; D014407:Tumor Cells, Cultured; D014409:Tumor Necrosis Factor-alpha / Q000633:toxicity*; D019014:fas Receptor / Q000502:physiology*
D000590:Amino Acid Chloromethyl Ketones; D015703:Antigens, CD; D015853:Cysteine Proteinase Inhibitors; D007375:Interleukin-1; D008070:Lipopolysaccharides; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D014409:Tumor Necrosis Factor-alpha; C096713:benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone; D019014:fas Receptor; D000410:Alanine Transaminase; D003546:Cysteine Endopeptidases; D020170:Caspase 1