Abstract
Increasing data suggest that the amyloid β-peptide (Aβ), which accumulates in the brains of Alzheimer's victims, plays a role in promoting neuronal degeneration. Cell culture studies have shown that Aβ can be neurotoxic and recent findings suggest that the mechanism involves destabilization of cellular calcium homeostasis. We now report that cytochalasin D, a compound that depolymerizes actin microfilaments selectively, protects cultured rat hippocampal neurons against Aβ neurotoxicity. Cytochalasin D was effective at concentrations that depolymerized actin (10-100 nM). The elevation of [Ca2+]i induced by Aβ, and the enhancement of [Ca2+]i responses to glutamate in neurons exposed to Aβ, were markedly attenuated in neurons pretreated with cytochalasin D. The protective effect of cytochalasin D appeared to result from a specific effect on actin filaments and reduction in calcium influx, because cytochalasin E, another actin filament-disrupting agent, also protected neurons against Aβ toxicity; the microtubule-disrupting agent colchicine was ineffective; cytochalasin D did not protect neurons against the toxicity of hydrogen peroxide. These findings suggest that actin filaments play a role in modulating [Ca2+]i responses to neurotoxic insults and that depolymerization of actin can protect neurons against insults relevant to the pathogenesis of Alzheimer's disease.
Original language | English (US) |
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Pages (from-to) | 1061-1068 |
Number of pages | 8 |
Journal | Journal of Neurochemistry |
Volume | 65 |
Issue number | 3 |
State | Published - Sep 1995 |
Externally published | Yes |
Keywords
- Actin microfilaments
- Alzheimer's disease
- Amyloid
- Calcium
- Cytochalasin
- Glutamate
- Neurotoxicity
- Phalloidin
ASJC Scopus subject areas
- Biochemistry
- Cellular and Molecular Neuroscience