Adenovirus‐Mediated Gene Transfer of Inhibitors of Apoptosis Proteins Delays Apoptosis in Cerebellar Granule Neurons
: The inhibitor of apoptosis (IAP) family of anti‐apoptotic genes, originally discovered in baculovirus, exists in animals ranging from insects to humans. Here, we investigated the ability of IAPs to suppress cell death in both a neuronal model of apoptosis and excitotoxicity. Cerebellar granule neu...
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Published in | Journal of neurochemistry Vol. 72; no. 1; pp. 292 - 301 |
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Main Authors | , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
Oxford UK
Blackwell Science Ltd
01.01.1999
Blackwell |
Subjects | |
Online Access | Get full text |
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Summary: | : The inhibitor of apoptosis (IAP) family of anti‐apoptotic
genes, originally discovered in baculovirus, exists in animals ranging from
insects to humans. Here, we investigated the ability of IAPs to suppress cell
death in both a neuronal model of apoptosis and excitotoxicity. Cerebellar
granule neurons undergo apoptosis when switched from 25 to 5 mM
potassium, and excitotoxic cell death in response to glutamate. We examined
the endogenous expression of four members of the IAP family, X
chromosome‐linked IAP (XIAP), rat IAP1 (RIAP1), RIAP2, and neuronal apoptosis
inhibitory protein (NAIP), by semiquantitative reverse PCR and immunoblot
analysis in cultured cerebellar granule neurons. Cerebellar granule neurons
express significant levels of RIAP2 mRNA and protein, but expression of RIAP1,
NAIP, and XIAP was not detected. RIAP2 mRNA content and protein levels did not
change when cells were switched from 25 to 5 mM potassium. To
determine whether ectopic expression of IAP influenced neuronal survival after
potassium withdrawal or glutamate exposure, we used recombinant adenoviral
vectors to target XIAP, human IAP1 (HIAP1), HIAP2, and NAIP into cerebellar
granule neurons. We demonstrate that forced expression of IAPs efficiently
blocked potassium withdrawal‐induced
N‐acetly‐Asp‐Glu‐Val‐Asp‐specific caspase activity and reduced DNA
fragmentation. However, neurons were only protected from apoptosis up to 24 h
after potassium withdrawal, not at later time points suggesting that IAPS
delay but do not block apoptosis in cerebellar granule neurons. In contrast,
treatment with 100 μM or 1 mM glutamate did not induce caspase activity and adenoviral‐mediated expression of IAPs had no influence on subsequent excitotoxic cell death. |
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Bibliography: | acetyl‐Asp‐Glu‐Val‐Asp‐amino‐4‐methylcoumarin ; HIAP, human inhibitor of apoptosis protein ; IAP, inhibitor of apoptosis protein ; MK‐801, dizocilpine ; MOI, multiplicity of infection ; NAIP, neuronal apoptosis inhibitory protein ; nt, nucleotides ; PBS, phosphate‐buffered saline ; RIAP, rat IAP ; SDS, sodium dodecyl sulfate ; SMA, spinal muscular atrophy ; TNF, tumor necrosis factor ; TUNEL, terminal transferase‐mediated dUTP‐biotin DNA nick end‐labeling ; XIAP, X chromosome‐linked IAP ; zVAD‐fmk, benzyloxycarbonyl‐Val‐Ala‐Asp‐fluoromethyl ketone. AdV, adenoviral vector system ; AdV‐LacZ, adenoviral construct encoding LacZ ; DEVD‐amc N Abbreviations used ObjectType-Article-2 SourceType-Scholarly Journals-1 ObjectType-Feature-1 content type line 23 |
ISSN: | 0022-3042 1471-4159 |
DOI: | 10.1046/j.1471-4159.1999.0720292.x |