Abstract
COS cells are resistant to cell death induced either by interleukin-1beta-converting enzyme (*ICE) and ICE homolog (ICH-1L) overexpression or by serum deprivation. COS cells deprived of serum undergo apoptosis after transfection with an ICE expression construct, but not an ICH-1L construct. ICE-mediated apoptosis of COS cells in serum-free medium is suppressed by insulin-like growth factor (IGF)-1 and insulin. Viability of Rat-1 cell line (Rat-1/ICE) expressing low levels of ICE-LacZ fusion protein is lower than those of cell lines expressing either both Bcl-2 and ICE or mutant ICEGly-->Ser during serum deprivation. Enzymatic activation and processing of ICE are observed in cells induced to die by serum deprivation, which are suppressed by IGF-1. IGF-1 or insulin suppresses ICE-mediated cell death without affecting the expression levels of Bcl-2, Bcl-x, or Bax. Taken together, these results indicate that ICE is activated by growth factor deprivation, and IGF-1 is able to suppress ICE-mediated cell death through a mechanism independent of the expression of Bcl-2, Bcl-x, or Bax.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Amino Acid Sequence
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Animals
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Antibodies
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Base Sequence
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Caspase 1
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Cell Death / drug effects
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Cell Death / physiology*
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Cell Line
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Cell Survival / drug effects
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Chlorocebus aethiops
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Culture Media, Serum-Free
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Cysteine Endopeptidases / biosynthesis
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Cysteine Endopeptidases / drug effects
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Cysteine Endopeptidases / metabolism*
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DNA Primers
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Growth Substances / pharmacology
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Immunoblotting
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Insulin / pharmacology
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Insulin-Like Growth Factor I / pharmacology*
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Kinetics
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Molecular Sequence Data
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Peptide Fragments / chemistry
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Peptide Fragments / immunology
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Point Mutation
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Polymerase Chain Reaction
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Rabbits
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Rats
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Recombinant Fusion Proteins / antagonists & inhibitors
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Recombinant Fusion Proteins / biosynthesis
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Recombinant Fusion Proteins / metabolism
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Transfection
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beta-Galactosidase / biosynthesis
Substances
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Antibodies
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Culture Media, Serum-Free
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DNA Primers
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Growth Substances
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Insulin
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Peptide Fragments
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Recombinant Fusion Proteins
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Insulin-Like Growth Factor I
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beta-Galactosidase
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Cysteine Endopeptidases
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Caspase 1