1. Isoflurane-Induced Caspase-3 Activation Is Dependent on Cytosolic Calcium and Can Be Attenuated by Memantine.
- Author
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Guohua Zhang, Yuanlin Dong, Bin Zhang, Ichinose, Fumito, Xu Wu, Culley, Deborah J., Crosby, Gregory, Tanzi, Rudolph E., and Zhongcong Xie
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ISOFLURANE , *ANESTHETICS , *APOPTOSIS , *ALZHEIMER'S disease , *CALCIUM - Abstract
Increasing evidence indicates that caspase activation and apoptosis are associated with a variety of neurodegenerative disorders, including Alzheimer's disease. We reported that anesthetic isoflurane can induce apoptosis, alter processing of the amyloid precursor protein (APP), and increase amyloid-β protein (Aβ) generation. However, the mechanism by which isoflurane induces apoptosis is primarily unknown. We therefore set out to assess effects of extracellular calcium concentration on isoflurane-induced caspase-3 activation in H4 human neuroglioma cells stably transfected to express human full-length APP (H4-APP cells). In addition, we tested effects of RNA interference (RNAi) silencing of IP3 receptor, NMDA receptor, and endoplasmic reticulum (ER) calcium pump, sacro-/ER calcium ATPase (SERCA1). Finally, we examined the effects of the NMDA receptor partial antagonist, memantine, inH4-APP cells and brain tissue of naive mice. EDTA (10 mM), BAPTA (10 µM), and RNAi silencing of IP3 receptor, NMDA receptor, or SERCA1 attenuated capase-3 activation. Memantine (4 µM) inhibited isoflurane-induced elevations in cytosolic calcium levels and attenuated isoflurane-induced caspase-3 activation, apoptosis, and cell viability. Memantine (20 mg/kg, i.p.) reduced isoflurane-induced caspase-3 activation in brain tissue of naive mice. These results suggest that disruption of calcium homeostasis underlies isoflurane-induced caspase activation and apoptosis. We also show for the first time that the NMDA receptor partial antagonist, memantine, can prevent isoflurane-induced caspase-3 activation and apoptosis in vivo and in vitro. These findings, indicating that isoflurane-induced caspase activation and apoptosis are dependent on cytosolic calcium levels, should facilitate the provision of safer anesthesia care, especially for Alzheimer's disease and elderly patients. [ABSTRACT FROM AUTHOR]
- Published
- 2008
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