EXCITATORY AA RECEPTORS' IN ALZHEIMER'S AND OTHER NEURODEGENERATIVE DISORDERS

阿尔茨海默病和其他神经退行性疾病中的兴奋性 AA 受体

• 批准号: 5200318
• 负责人: J W KUSIAK
• 金额: --
• 依托单位: NATIONAL INSTITUTE ON AGING
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/5200318
• 关键词: Alzheimer's disease; DNA binding protein; NMDA receptors; aging; biological signal transduction; cyclic AMP; cyclic AMP receptors; excitatory aminoacid; fibroblast growth factor; gene induction /repression; genetic promoter element; genetic regulation; glutamate receptor; glutamates; molecular cloning; molecular pathology; neural degeneration; neurotoxins; neurotrophic factors; phosphorylation; protein isoforms; receptor expression; reporter genes; tissue /cell culture; transcription factor

Excitatory amino acids (EAAs) and their receptors play many important physiological roles in the central nervous system. They are involved in brain development, neural plasticity, and memory acquisition. In addition there is much circumstantial evidence suggesting a role for EAAs and their receptors in neurodegenerative disorders of aging, including Alzheimer's Disease. The receptors for EAAs exist in different functional forms due to the presence of multiple subunits and isoforms and their differential distribution in the brain. We propose the hypothesis that abnormal regulation of expression of EAA receptors or their persistent overactivity may be responsible for the neuropathology seen in these disorders. We previously cloned the promoter of the NMDAR1 gene and observed that a proximal region is sufficient to confer neuronal specific expression. We now show that both Sp1 and GSG motifs are required for basal activity suggesting control over NMDA receptor expression by immediate early genes. An Sp1-like and several other transcription factors cooperatively interact to control this activity. We show that CREB protein induces reporter gene activity. Various trophic factors also induce expression of a reporter gene including NGF and FGF. Interestingly, TPA stimulates expression greater than 5-fold suggesting a role for PKC in regulating NMDAR1 expression. A combination of cAMP and NGF treatment increases expression 7-fold suggesting phosphorylation events are also critical in regulating gene activity. The regulation of NMDAR1 gene expression appears to be complex and tightly controlled. We also cloned promoter regions for NMDAR2-A,B, and C genes and are currently characterizing them. Transgenic technology, utilizing lacZ promoter constructs will be used to confirm the neuronal specificity and regulation of this promoter. A neuronal cell culture model is being developed to examine receptor gene expression and signal transduction cascades involved in glutamate mediated cell death.

兴奋性氨基酸（EAA）及其受体发挥了许多重要的 中枢神经系统的生理作用。他们参与了 大脑发育，神经可塑性和记忆的获取。此外 有很多间接证据表明EAA和 他们在衰老的神经退行性疾病中的受体，包括 阿尔茨海默氏病。 EAA的受体存在于不同的功能 由于存在多个亚基和同工型及其形式 大脑中的差分分布。我们提出了以下假设 EAA受体表达或其持久性的表达异常调节 过度活动可能是导致这些神经病理学的原因 疾病。我们以前克隆了NMDAR1基因的启动子和 观察到近端区域足以赋予神经元特异性 表达。现在，我们证明SP1和GSG图案都是必需的 基础活性表明控制NMDA受体表达 直接的早期基因。类似SP1的和其他几个转录 因素合作相互作用以控制这一活动。我们表明 CREB蛋白诱导报告基因活性。各种营养因素 诱导包括NGF和FGF在内的报告基因的表达。 有趣的是，TPA刺激表达大于5倍 PKC在调节NMDAR1表达中的作用。阵营和 NGF处理增加了表达7倍，表明磷酸化 事件对于调节基因活性也至关重要。调节 NMDAR1基因表达似乎很复杂且受到严格控制。我们 还克隆的NMDAR2-A，B和C基因的启动子区域，并且是 目前在表征它们。转基因技术，利用LACZ 启动子构建体将用于确认神经元特异性和 该启动子的调节。神经元细胞培养模型正在 开发用于检查受体基因表达和信号转导 参与谷氨酸介导的细胞死亡的级联反应。