Cytokine regulation of human intestinal primary epithelial cell susceptibility to Fas-mediated apoptosis

Am J Physiol Gastrointest Liver Physiol. 2002 Jan;282(1):G92-G104. doi: 10.1152/ajpgi.2002.282.1.G92.

Abstract

The regulatory mechanisms of nontransformed intestinal epithelial cell apoptosis have not been thoroughly investigated. We determined the susceptibility and mechanism of Fas-mediated apoptosis in nontransformed human intestinal epithelial cells (HIPEC) in the presence and absence of inflammatory cytokines. Despite ample expression of Fas, HIPEC were relatively insensitive to Fas-mediated apoptosis in that agonist anti-Fas antibody (CH11) induced a <25% increase in HIPEC apoptosis. Pretreatment of HIPEC with interferon (IFN)-gamma, but not tumor necrosis factor-alpha or granulocyte-macrophage colony-stimulating factor, significantly increased CH11-induced apoptosis of these cells without increasing Fas expression. Increased apoptosis correlated with increased caspase 3 activation but not expression of procaspase 3. Also, there was a significant delay in the onset of Fas-mediated apoptosis in HIPEC, which correlated with the generation of an activated caspase 3 p22/20 subunit. HIPEC required both initiator caspases 8 and 9 activity but expressed significantly less of the zymogen form of these caspases than did control cells. IFN-gamma-mediated sensitization of HIPEC occurred upstream of caspase 9 activation and correlated with a small increase in procaspase 8 expression (<1-fold increase) and a significant increase in expression of an intermediate form (p35) of caspase 4 (3.3-fold increase).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing*
  • Antibodies, Monoclonal / pharmacology
  • Antineoplastic Agents / pharmacology*
  • Apoptosis / drug effects
  • Apoptosis / physiology*
  • CASP8 and FADD-Like Apoptosis Regulating Protein
  • Carrier Proteins / metabolism
  • Caspase 1 / metabolism
  • Caspase 3
  • Caspase 8
  • Caspase 9
  • Caspases / metabolism
  • Caspases, Initiator
  • Cysteine Proteinase Inhibitors / pharmacology
  • Enzyme Precursors / metabolism
  • Fas-Associated Death Domain Protein
  • HT29 Cells
  • Humans
  • Inhibitor of Apoptosis Proteins
  • Interferon-gamma / pharmacology*
  • Intestinal Mucosa / cytology*
  • Intestinal Mucosa / metabolism
  • Intracellular Signaling Peptides and Proteins*
  • Jurkat Cells
  • Proteins / metabolism
  • Proto-Oncogene Proteins c-bcl-2 / metabolism
  • Tumor Necrosis Factor-alpha / pharmacology
  • fas Receptor / immunology
  • fas Receptor / metabolism*

Substances

  • Adaptor Proteins, Signal Transducing
  • Antibodies, Monoclonal
  • Antineoplastic Agents
  • CASP8 and FADD-Like Apoptosis Regulating Protein
  • CFLAR protein, human
  • Carrier Proteins
  • Cysteine Proteinase Inhibitors
  • Enzyme Precursors
  • FADD protein, human
  • Fas-Associated Death Domain Protein
  • Inhibitor of Apoptosis Proteins
  • Intracellular Signaling Peptides and Proteins
  • Proteins
  • Proto-Oncogene Proteins c-bcl-2
  • Tumor Necrosis Factor-alpha
  • fas Receptor
  • Interferon-gamma
  • CASP3 protein, human
  • CASP4 protein, human
  • CASP8 protein, human
  • CASP9 protein, human
  • Caspase 3
  • Caspase 8
  • Caspase 9
  • Caspases
  • Caspases, Initiator
  • Caspase 1