NA/CA EXCHANGE, BRAIN AGING, ALZHEIMER'S DISEASE

在RFA NS/AG-91-03项下要求提供资金， 正常人类衰老和阿尔茨海默病中的神经元细胞死亡。 的 与衰老和人类神经退行性疾病相关的认知能力下降 疾病（例如阿尔茨海默病、帕金森病和亨廷顿病 疾病）最肯定是由神经元功能障碍，最终细胞 死亡和突触丢失（1）。但是，神经系统疾病的原因是什么呢？ 堕落和死亡 “大脑老化的钙假说”（2） 提出细胞机制的变化， 细胞内游离钙浓度（[Cai]） 神经元有助于导致神经元 功能障碍和退化。 一个类似的假设也被 提出解释神经退行性过程发生在 阿尔茨海默病（AD）。 “AD的钙假说”提出， Cai体内平衡的丧失是神经元死亡的最终共同途径。 退化 不幸的是，人们对 人类衰老和AD对神经元Ca 2+稳态过程的影响。 这 一项提案描述了神经元血浆特性的重点研究 衰老大鼠脑细胞膜Na+/Ca ~（2+）逆向转运 人中枢神经系统（CNS）和AD。 具体目标是 研究内容如下： 1.确定衰老的动物模型，正常人衰老的效果 和AD对神经元的几个重要的分子和动力学性质的影响 质膜Na+/Ca 2+逆向转运。 a. Ca 2+激活Ca 2+转运Km和Vmax B.质膜对Ca ~（2+）的被动渗透性 C.存在K+敏感和不敏感形式的证据 大鼠脑和人中枢神经系统Na ~+/Ca ~（2+）交换体 D.亲脂性肽（包括β A41 -40，β A425 -35， 和P物质类似物）对Na+/Ca 2+交换剂的作用 e.通过SDS PAGE和蛋白质印迹分析测定分子量 使用针对狗的肽序列产生的单克隆抗体（MAB）， 心脏交换器 F.交换器的蜂窝位置由 使用相同MAB的免疫细胞化学 2.分析AD发病年龄与项目的关系 1.上文a-e。 3.使用有充分证据的家族性AD的组织， 对Ca 2+激活Ca 2+转运的Km和Vmax的影响和蛋白质印迹 分析.

Funding is requested under RFA NS/AG-91-03 to study the mechanisms of neuronal cell death in normal human aging and Alzheimer's disease. The cognitive decline associated with aging and the human neurodegenerative diseases (e.g. Alzheimer's disease, Parkinson's disease and Huntington's disease) is most certainly caused by neuronal dysfunction, eventual cell death, and loss of synapses (1). But, what are the causes of neural degeneration and death? The "calcium hypothesis of brain aging" (2) proposes that changes in the cellular mechanisms that act to modulate the concentration of free intracellular calcium ([Cai]) within the neuron contribute to the causative factors leading to neuronal dysfunction and degeneration. A similar hypothesis has also been proposed to explain the neurodegenerative processes occurring in Alzheimer's disease (AD). The "calcium hypothesis of AD" proposes that a loss of Cai homeostasis is the final common pathway to neuronal degeneration. Unfortunately, very little is known about the effects of human aging and AD on neuronal Ca2+ homeostatic processes. This proposal describes a focused study of the properties of neuronal plasma membrane Na+/Ca2+ countertransport in the aging rat brain, the aging human central nervous system (CNS) and in AD. The specific aims of this study are as follows: 1. Determine the effect of an animal model of aging, normal human aging and AD on several important molecular and kinetic properties of neuronal plasma membrane Na+/Ca2+ countertransport. a. the Km and Vmax for Ca2+ activation of Ca2+ transport b. the passive permeability of the plasma membrane to Ca2+ c. evidence for the presence of K+ sensitive and insensitive forms of the Na+/Ca2+ exchanger in rat brain and the human central nervous (CNS) d. the effect of lipophilic peptides (including betaA41-40, betaA425-35, and substance P analogs) on the Na+/Ca2+ exchanger e. molecular weight determination by SDS PAGE and western blot analysis using monoclonal antibodies (MAB) raised to peptide sequences of the dog heart exchanger f. the cellular location of the exchanger depicted by immunocytochemistry using the same MAB 2. Analyze the relationship between age of onset of AD and items 1.a-e above. 3. Using tissues from well documented familial AD, determine the effect on Km and Vmax for Ca2+ activation of Ca2+ transport and western blot analysis.