Concanavalin A hepatotoxicity in mice: tumor necrosis factor-mediated organ failure independent of caspase-3-like protease activation

Hepatology. 1999 Nov;30(5):1241-51. doi: 10.1002/hep.510300517.

Abstract

Several models of tumor necrosis factor (TNF)/TNF-receptor 1 (TNF-R1)-dependent liver injury in mice were investigated with respect to caspase-3-like protease activation representing a pivotal mechanism of apoptotic cell death. Injection of TNF or T-cell-activating agents (i.e., agonistic anti-CD3 antibody or staphylococcal enterotoxin B [SEB]) into galactosamine (GalN)-sensitized mice caused TNF/TNF-R1-dependent liver injury. Intravenous concanavalin A (Con A) alone induced TNF-mediated hepatotoxicity dependent on both TNF-R1 and TNF-R2. Hepatic caspase-3-like proteases were activated in GalN/TNF, GalN/anti-CD3, or GalN/SEB-treated mice, but not in Con A-treated mice. Consistently, the broad-spectrum caspase inhibitor, benzoyloxycarbonyl-val-ala-asp-fluoromethylketone (zVADfmk), prevented TNF-mediated hepatotoxicity in all GalN-dependent models, but failed to protect against Con A. Under transcriptional arrest, however, Con A induced TNF-R1-dependent, but not TNF-R2-dependent, activation of caspase-3-like proteases, and zVADfmk prevented animals from Con A-mediated liver injury under this condition. Histological analysis revealed distinct differences between Con A- and GalN/Con A-induced liver injury regarding apoptotic morphology of hepatocytes. We conclude that impaired transcription induces a switch of Con A hepatotoxicity toward a caspase-3-like protease-dependent pathway. The observation that the functional state of the transcriptional machinery decides whether TNF-driven hepatocyte apoptosis involves activation of caspase-3-like proteases or alternative signaling pathways in vivo might be of relevance for the immunopathology of the liver.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Chloromethyl Ketones / pharmacology
  • Animals
  • Antibodies / pharmacology
  • Antigens, CD / physiology
  • Apoptosis / drug effects
  • CD3 Complex / physiology
  • Caspase 3
  • Caspases / metabolism*
  • Concanavalin A / toxicity*
  • Cysteine Proteinase Inhibitors / pharmacology
  • Enterotoxins / toxicity
  • Enzyme Activation
  • Galactosamine / toxicity
  • Lipid Metabolism
  • Liver / drug effects
  • Liver / enzymology
  • Liver / pathology*
  • Male
  • Mice
  • Mice, Inbred BALB C
  • Receptors, Tumor Necrosis Factor / physiology
  • Receptors, Tumor Necrosis Factor, Type I
  • Receptors, Tumor Necrosis Factor, Type II
  • Specific Pathogen-Free Organisms
  • Staphylococcus aureus
  • Tumor Necrosis Factor-alpha / physiology*

Substances

  • Amino Acid Chloromethyl Ketones
  • Antibodies
  • Antigens, CD
  • CD3 Complex
  • Cysteine Proteinase Inhibitors
  • Enterotoxins
  • Receptors, Tumor Necrosis Factor
  • Receptors, Tumor Necrosis Factor, Type I
  • Receptors, Tumor Necrosis Factor, Type II
  • Tumor Necrosis Factor-alpha
  • benzyloxycarbonylvalyl-alanyl-aspartyl fluoromethyl ketone
  • Concanavalin A
  • enterotoxin B, staphylococcal
  • Galactosamine
  • Casp3 protein, mouse
  • Caspase 3
  • Caspases