Isoflurane preconditions hippocampal neurons against oxygen-glucose deprivation -: Role of intracellular Ca2+ and mitogen-activated protein kinase signaling
Isoflurane preconditions hippocampal neurons against oxygen-glucose deprivation -: Role of intracellular Ca2+ and mitogen-activated protein kinase signaling
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DOI：
10.1097/00000542-200509000-00016
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发表时间：
2005-09-01
期刊：
影响因子：
8.8
通讯作者：
Fahlman, CS
中科院分区：
文献类型：
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作者：
Bickler, PE;Zhan, XH;Fahlman, CS
背景：异氟烷预处理神经元以提高完整动物模型和体外制剂对随后缺血的耐受性。这种保护的机制在很大程度上仍未定义。由于异氟烷会增加细胞内 Ca2+ 浓度，并且 Ca2+ 参与许多与预处理相关的过程，因此作者假设异氟烷通过涉及 Ca2+ 结合蛋白钙调蛋白和丝裂原激活蛋白激酶-ERK 途径的 Ca2+ 依赖性过程来预处理神经元。 方法：作者使用了一种预处理模型，其中将大鼠海马的器官型培养物暴露于 0.5-1.5% 异氟烷，持续一段时间。缺氧-葡萄糖剥夺缺血样损伤前 24 小时的 2 小时期间。 48 年后评估 CA1、CA3 和齿状神经元的存活率，以及细胞内 Ca2+ 浓度的间隔测量（CA1 神经元中的 fura-2 荧光显微镜）、丝裂原激活蛋白激酶 p42/44 以及存活相关蛋白 Akt 和 GSK-3 beta（原位免疫染色和蛋白质印迹）。结果：用 0.5-1.5% 异氟烷预处理可减少 CA1 中的神经元死亡氧-葡萄糖剥夺后海马切片培养物的 CA3 和 CA3 区域。预处理期与基础细胞内 Ca2+ 浓度增加 7-15% 相关，这涉及内质网中肌醇三磷酸敏感储备的 Ca2+ 释放，以及丝裂原激活蛋白激酶 p42/44 和生存相关蛋白 Akt 和 GSK-3 beta 的瞬时磷酸化。丝裂原激活的细胞外激酶抑制剂 U0126 和卡米达唑可消除预处理保护，前者可在预处理过程中阻止 p44 的磷酸化，后者可拮抗 Ca2+ 结合钙调蛋白的作用。结论：临床浓度的异氟烷通过明显涉及内质网释放 Ca2+、细胞内 Ca2+ 瞬时增加的机制来预处理海马切片培养物中的神经元。浓度、Ca2+ 结合蛋白钙调蛋白和丝裂原激活蛋白激酶 p42/44 的磷酸化。
Background: Isoflurane preconditions neurons to improve tolerance of subsequent ischemia in both intact animal models and in in vitro preparations. The mechanisms for this protection remain largely undefined. Because isoflurane increases intracellular Ca2+ concentrations and Ca2+ is involved in many processes related to preconditioning, the authors hypothesized that isoflurane preconditions neurons via Ca2+-dependent processes involving the Ca2+-binding protein calmodulin and the mitogen-activated protein kinase-ERK pathway.Methods: The authors used a preconditioning model in which organotypic cultures of rat hippocampus were exposed to 0.5-1.5% isoflurane for a 2-h period 24 h before an ischemia-like injury of oxygen-glucose deprivation. Survival of CA1, CA3, and dentate neurons was assessed 48 later, along with interval measurements of intracellular Ca2+ concentration (fura-2 fluorescence microscopy in CA1 neurons), mitogen-activated protein kinase p42/44, and the survival associated proteins Akt and GSK-3 beta (in situ immunostaining and Western blots).Results: Preconditioning with 0.5-1.5% isoflurane decreased neuron death in CA1 and CA3 regions of hippocampal slice cultures after oxygen-glucose deprivation. The preconditioning period was associated with an increase in basal intracellular Ca2+ concentration of 7-15%, which involved Ca2+ release from inositol triphosphate-sensitive stores in the endoplasmic reticulum, and transient phosphorylation of mitogen-activated protein kinase p42/44 and the survival-associated proteins Akt and GSK-3 beta. Preconditioning protection was eliminated by the mitogen-activated extracellular kinase inhibitor U0126, which prevented phosphorylation of p44 during preconditioning, and by calmidazolium, which antagonizes the effects of Ca2+-bound calmodulin.Conclusions: Isoflurane, at clinical concentrations, preconditions neurons in hippocampal slice cultures by mechanisms that apparently involve release of Ca2+ from the endoplasmic reticulum, transient increases in intracellular Ca2+ concentration, the Ca2+ binding protein calmodulin, and phosphorylation of the mitogen-activated protein kinase p42/44.