摘要
目的 探讨缺氧损伤后神经元膜表面谷氨酸AMPA受体亚单位 (GluRs)含量、受体结构组成、功能的变化及其在Ca2 + 超载和延迟性细胞死亡中的作用。方法 建立神经元缺氧损伤模型 ,采用PI染色、双重免疫荧光标记和细胞比色分析技术定量观察神经元死亡和膜表面GluRs含量变化 ,采用Fura 2法测定胞内Ca2 + 含量 ,以膜片钳技术检测微兴奋性突触后电流 (mEPSCs)的变化。结果 伤后胞内Ca2 + 含量和神经元死亡数量明显高于对照组 ;膜表面GluR2含量及含GluR2的突触数目显著减少 (P <0 .0 5 ) ,而GluR3含量较对照组则显著升高 (P <0 0 5 ) ;缺乏GluR2的AMPA受体通道对Ca2 + 有很高的通透性。结论 缺氧可致神经元膜表面AMPA受体的结构组成发生变化 ,缺乏GluR2的受体通道数目增加 ,介导了Ca2 + 的快速内流 ,引起神经元的延迟性死亡。
Objective To explore the changes of the subunits content, constitution and function of glutamate receptor subunits on neuron membrane induced by anoxia, and furthermore to elucidate the contribution of these changes to the delayed neuron death. Methods The neuron death was quantitated with PI staining. The number of GluRs on the neuron membrane was quantitatively measured by colorimetric assay and double immunofluorescence labeling on neuron anoxic model. The intracellular Ca 2+ content was determined by Fura-2 method. The miniature excitatory postsynaptic currents (mEPSCs) were recorded with the patch clamp. Results The intracellular Ca 2+ content and the number of delayed death neuron were marked higher than those in the control group after anoxic injury (P<0.05). The total surface GluR2 and the number of synapse with GluR2 decreased significantly (P<0.05), but surface GluR3 increased significantly as compared with that in the control group. GluR2-lacking AMPA receptors appeared high permeability to Ca 2+. Conclusion Anoxia can induce changes in the constitution of AMPA receptors on neuron membrane. The increase of the number of surface GluR2-lacking AMPA receptors can activate Ca 2+ influx, resulting in delayed neuron death.
出处
《第三军医大学学报》
CAS
CSCD
北大核心
2004年第23期2139-2142,共4页
Journal of Third Military Medical University
基金
重庆市科技计划项目 ( 810 7)~~
