title: Role of p55 tumor necrosis factor receptor 1 in acetaminophen-induced antioxidant defense.
abstract: Tumor necrosis factor (TNF)-alpha is a macrophage-derived proinflammatory cytokine implicated in hepatotoxicity. In the present studies, p55 TNF receptor 1 (TNFR1) -/- mice were used to assess the role of TNF-alpha in acetaminophen-induced antioxidant defense. Treatment of wild-type (WT) mice with acetaminophen (300 mg/kg) resulted in centrilobular hepatic necrosis and increased serum alanine transaminases. This was correlated with a rapid depletion of hepatic glutathione (GSH). Whereas in WT mice GSH levels returned to control after 6-12 h, in TNFR1-/- mice recovery was delayed for 48 h. Delayed induction of heme oxygenase-1 and reduced expression of CuZn superoxide dismutase were also observed in TNFR1-/- compared with WT mice. This was associated with exaggerated hepatotoxicity. In WT mice, acetaminophen caused a time-dependent increase in activator protein-1 nuclear binding activity and in c-Jun expression. This response was significantly attenuated in TNFR1-/- mice. Constitutive NF-kappaB binding activity was detectable in livers of both WT and TNFR1-/- mice. A transient decrease in this activity was observed 3 h after acetaminophen in WT mice, followed by an increase that was maximal after 6-12 h. In contrast, in TNFR1-/- mice, acetaminophen-induced decreases in NF-kappaB activity were prolonged and did not return to control levels for 24 h. These data indicate that TNF-alpha signaling through TNFR1 plays an important role in regulating the expression of antioxidants in this model. Reduced generation of antioxidants may contribute to the increased sensitivity of TNFR1-/- mice to acetaminophen.
authors.affiliation: Dept. of Pharmacology and Toxicology, Rutgers Univ., 170 Frelinghuysen Rd., Piscataway, NJ 08854-8020, USA.
authors.forename: Hawjyh
authors.initials: H
authors.lastname: Chiu
authors.forename: Carol R
authors.initials: CR
authors.lastname: Gardner
authors.forename: Donna M
authors.initials: DM
authors.lastname: Dambach
authors.forename: Jennie A
authors.initials: JA
authors.lastname: Brittingham
authors.forename: Stephen K
authors.initials: SK
authors.lastname: Durham
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Laskin
authors.forename: Debra L
authors.initials: DL
authors.lastname: Laskin
mesh_terms: D000082:Acetaminophen / Q000494:pharmacology* / Q000506:poisoning; D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D015703:Antigens, CD / Q000502:physiology*; D000975:Antioxidants / Q000378:metabolism*; D004790:Enzyme Induction / Q000187:drug effects; D005978:Glutathione / Q000037:antagonists & inhibitors / Q000378:metabolism; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism; D051547:Heme Oxygenase-1; D008099:Liver / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D008297:Male; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D016328:NF-kappa B / Q000378:metabolism; D009336:Necrosis; D018124:Receptors, Tumor Necrosis Factor / Q000502:physiology*; D047888:Receptors, Tumor Necrosis Factor, Type I; D013482:Superoxide Dismutase / Q000037:antagonists & inhibitors; D018808:Transcription Factor AP-1 / Q000378:metabolism
chemical_list: D015703:Antigens, CD; D000975:Antioxidants; D008565:Membrane Proteins; D016328:NF-kappa B; D018124:Receptors, Tumor Necrosis Factor; D047888:Receptors, Tumor Necrosis Factor, Type I; D018808:Transcription Factor AP-1; D000082:Acetaminophen; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1; C496542:Hmox1 protein, mouse; D013482:Superoxide Dismutase; D000410:Alanine Transaminase; D005978:Glutathione