Abstract
The presenilin/gamma-secretase protease cleaves many type-I membrane proteins, including the amyloid beta-protein (Abeta) precursor (APP). Previous studies have shown that apoptosis induces alterations in Abeta production in a caspase-dependent manner. Here, we report that staurosporine (STS)-induced apoptosis induces caspase-8 and/or-2-dependent gamma-secretase activation. Blocking of caspase activity with caspase-8 inhibitor z-IETD-fmk, and caspase-2 inhibitor z-VDVAD-fmk reduced Abeta production by STS in H4 cells expressing the Swedish mutant of APP (HSW) or APP-C99 (H4-C99). There was no inhibitory effect of other caspases (-1, -3, -5, -6, -9) on Abeta production by STS. This finding was further supported by evidence that siRNA transfection, depleting caspase-2 or -8 levels, lowered Abeta production in HSW and H4-C99 cells without affecting expression of APP or gamma-secretase complex. In addition, Abeta production by STS was decreased by JNK inhibitors, SP600125. These results suggest that caspase-2 and/or -8 is involved in presenilin/gamma-secretase activation and Abeta production in apoptosis.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Amyloid Precursor Protein Secretases / metabolism*
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Amyloid beta-Protein Precursor / genetics
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Amyloid beta-Protein Precursor / metabolism*
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Anthracenes / pharmacology
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Apoptosis / drug effects
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Apoptosis / physiology*
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Caspase 2 / genetics
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Caspase 2 / metabolism*
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Caspase 8 / genetics
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Caspase 8 / metabolism*
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Caspase Inhibitors
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Caspases / metabolism
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Cell Line, Tumor
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Cysteine Endopeptidases / genetics
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Cysteine Endopeptidases / metabolism*
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Cysteine Proteinase Inhibitors / pharmacology
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Enzyme Inhibitors / pharmacology
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Enzyme Inhibitors / toxicity
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Humans
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JNK Mitogen-Activated Protein Kinases / antagonists & inhibitors
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JNK Mitogen-Activated Protein Kinases / metabolism
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Mutation
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Oligopeptides / pharmacology
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Presenilin-1 / metabolism*
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Protease Nexins
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RNA, Small Interfering
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Receptors, Cell Surface / genetics
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Receptors, Cell Surface / metabolism*
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Staurosporine / toxicity
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Transfection
Substances
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APP protein, human
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Amyloid beta-Protein Precursor
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Anthracenes
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Caspase Inhibitors
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Cysteine Proteinase Inhibitors
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Enzyme Inhibitors
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Oligopeptides
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PSEN1 protein, human
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Presenilin-1
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Protease Nexins
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RNA, Small Interfering
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Receptors, Cell Surface
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benzoylcarbonyl-valyl-aspartyl-valyl-alanyl-aspartyl-fluoromethyl ketone
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benzyloxycarbonyl-isoleucyl-glutamyl-threonyl-aspartic acid fluoromethyl ketone
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pyrazolanthrone
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JNK Mitogen-Activated Protein Kinases
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Amyloid Precursor Protein Secretases
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CASP2 protein, human
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CASP8 protein, human
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Caspase 2
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Caspase 8
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Caspases
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Cysteine Endopeptidases
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Staurosporine