Human Bcl-2 protects against AMPA receptor-mediated apoptosis

Cheung, NS; Beart, PM; Pascoe, CJ; John, CA; Bernard, O

Author(s): Cheung, NS; Beart, PM; Pascoe, CJ; John, CA; Bernard, O;
Details: Publication Year 2000-04,Volume 74,Issue #4,Page 1613-1620
Journal Title: JOURNAL OF NEUROCHEMISTRY
Publication Type: Journal Article
Abstract: Dysfunctions of the (S)-alpha-amino-3-hydroxy-5-methylisoxazole-4-propionate (AMPA) subtype of ionotropic receptor for the brain's major excitatory neurotransmitter, L-glutamate, occur in various neurological conditions. We have previously demonstrated that AMPA receptor-mediated excitotoxicity occurs by apoptosis and here examined the influence of the expression of cell death repressor gene Bcl-2 on this excitotoxic insult. Using neuronal cortical cultures prepared from transgenic mice expressing the human Bcl-2 gene, the influence of Bcl-2 on AMPA receptor-mediated neuronal death was compared with that seen with staurosporine and H2O2. At day 6 cultures were exposed to AMPA (0.1-100 mu M), and cellular injury was analyzed 48 h after insult using phase-contrast microscopy, a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide viability assay, and DNA staining with 4,6-diamidino-2-phenylindole and Sytox Green. AMPA produced a concentration-dependent increase in cell death that was significantly attenuated by human Bcl-2. AMPA (3 mu M) increased the number of apoptotic nuclei to 60% of control in wild-type cultures, and human Bcl-2 significantly decreased the number of apoptotic nuclei to 30% of AMPA-treated cultures. Human Bcl-2 only provided significant neuroprotection against neuronal injury induced by tow concentrations of staurosporine (1-10 nM) and H2O2 (0.1-30 mu M) and where neuronal death was by apoptosis, but not against H2O2-induced necrosis. Our findings indicate that overexpression of Bcl-2 in primary cultured neurons protects in an insult-dependent manner against AMPA receptor-mediated apoptosis, whereas protection was not seen against more traumatic insults. This study provides new insights into the molecular therapeutics of neurodegenerative conditions.
Publisher: LIPPINCOTT WILLIAMS & WILKINS
Keywords: PROGRAMMED CELL-DEATH; INDUCED NEURONAL APOPTOSIS; PROTOONCOGENE BCL-2; HIPPOCAMPAL-NEURONS; GLUTAMATE RECEPTORS; CORTICAL-NEURONS; KAINIC ACID; NEUROTOXICITY; SCHIZOPHRENIA; ACTIVATION
Publisher's Version: https://doi.org/10.1046/j.1471-4159.2000.0741613.x
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Creation Date: 2000-04-01 12:00:00