NF-kappaB stimulates inducible nitric oxide synthase to protect mouse hepatocytes from TNF-alpha- and Fas-mediated apoptosis

Gastroenterology. 2001 Apr;120(5):1251-62. doi: 10.1053/gast.2001.23239.


Background and aims: Hepatocyte apoptosis is induced by tumor necrosis factor alpha (TNF-alpha) and Fas ligand. Although nuclear factor-kappaB (NF-kappaB) activation protects hepatocytes from TNF-alpha-mediated apoptosis, the NF-kappaB responsive genes that protect hepatocytes are unknown. Our aim was to study the role of NF-kappaB activation and inducible nitric oxide synthases (iNOSs) in TNF-alpha- and Fas-mediated apoptosis in hepatocytes.

Methods: Primary cultures of hepatocytes from wild-type and iNOS knockout mice were treated with TNF-alpha, the Fas agonistic antibody Jo2, a nitric oxide (NO) donor (S-nitroso-N-acetylpenicillamine), an NO inhibitor (N(G)-methyl-L-arginine acetate), and/or adenovirus-expressing NF-kappaB inhibitors.

Results: The IkappaB superrepressor and a dominant-negative form of IkappaB kinase beta (IKKbeta) inhibited NF-kappaB binding activity by TNF-alpha or Jo2 and sensitized hepatocytes to TNF-alpha- and Jo2-mediated apoptosis. TNF-alpha and Jo2 induced iNOS messenger RNA and protein levels through the induction of NF-kappaB. S-nitroso-N-acetylpenicillamine inhibited Bid cleavage, the mitochondrial permeability transition, cytochrome c release, and caspase-8 and -3 activity, and reduced TNF-alpha- and Fas-mediated death in hepatocytes expressing IkappaB superrepressor. N(G)-methyl-L-arginine acetate partially sensitized hepatocytes to TNF-alpha- and Fas-mediated cell killing. TNF-alpha alone or Jo2 alone induced moderate cell death in hepatocytes from iNOS(-)/(-) mice.

Conclusions: NO protects hepatocytes from TNF-alpha- and Fas-mediated apoptosis. Endogenous iNOS, which is activated by NF-kappaB via IKKbeta, provides partial protection from apoptosis.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Antibodies / pharmacology
  • Apoptosis / drug effects
  • Apoptosis / physiology*
  • BH3 Interacting Domain Death Agonist Protein
  • Carrier Proteins / metabolism
  • Caspase 3
  • Caspase 8
  • Caspase 9
  • Caspases / metabolism
  • Cells, Cultured
  • Cytochrome c Group / metabolism
  • Gene Expression Regulation, Enzymologic / drug effects
  • Gene Expression Regulation, Enzymologic / physiology
  • Hepatocytes / cytology
  • Hepatocytes / enzymology*
  • I-kappa B Proteins / genetics
  • I-kappa B Proteins / metabolism
  • Male
  • Mice
  • Mice, Inbred C57BL
  • Mitochondria / enzymology
  • Mutagenesis / physiology
  • NF-kappa B / metabolism*
  • Nitric Oxide / metabolism
  • Nitric Oxide Donors / pharmacology
  • Nitric Oxide Synthase / genetics
  • Nitric Oxide Synthase / metabolism*
  • Nitric Oxide Synthase Type II
  • Penicillamine / analogs & derivatives*
  • Penicillamine / pharmacology
  • Signal Transduction / physiology
  • Tumor Necrosis Factor-alpha / immunology
  • Tumor Necrosis Factor-alpha / pharmacology*
  • fas Receptor / immunology
  • fas Receptor / pharmacology*


  • Antibodies
  • BH3 Interacting Domain Death Agonist Protein
  • Bid protein, mouse
  • Carrier Proteins
  • Cytochrome c Group
  • I-kappa B Proteins
  • NF-kappa B
  • Nitric Oxide Donors
  • S-nitro-N-acetylpenicillamine
  • Tumor Necrosis Factor-alpha
  • fas Receptor
  • Nitric Oxide
  • Nitric Oxide Synthase
  • Nitric Oxide Synthase Type II
  • Nos2 protein, mouse
  • Casp3 protein, mouse
  • Casp8 protein, mouse
  • Casp9 protein, mouse
  • Caspase 3
  • Caspase 8
  • Caspase 9
  • Caspases
  • Penicillamine