Structure/function of Nerve Growth Factor/Neurotrophins

与神经生长因子（NGF）相关的神经营养因子家族与两种类型的受体相互作用， Trk酪氨酸激酶受体和常见的神经营养因子受体p75 NTR，以支持神经元 反应性外周神经元（感觉，交感）和中枢神经元（胆碱能， 多巴胺能的）和提供神经变性疾病中神经元存活的信号。这项建议是 目的在于进一步开发神经营养因子突变体（“突变蛋白”）， 的特异性一个主要的假设是，受体和/或信号选择性神经营养因子 突变体在某些疾病中将是比野生型神经营养因子更有效的治疗试剂。的 受体选择性神经营养素'突变蛋白'正处于在神经退行性疾病的动物模型中进行测试的阶段。 疾病该提案的具体目的是：（i）利用受体选择性神经营养素突变蛋白 异二聚体来测试特异性受体活化模型。新的神经营养素异源二聚体将是 其特征在于确定对每种受体的结合亲和力，主要的细胞反应（存活， 细胞凋亡或分化）和关键信号传导途径中的酶，（ii）表征信号传导 p53/capase-3依赖性和非依赖性介导的细胞凋亡途径 机制等将筛选神经营养因子突变蛋白，以区分p53依赖性 p53温度敏感性PC 12细胞的非依赖性通路。几种神经元细胞系和 还将用选择的突变蛋白研究原代培养物。(iii)为了测试信号的治疗潜力- 通过鼻内吸入递送至啮齿动物的中枢神经系统的选择性神经营养素突变蛋白。 将使用正常小鼠、p53缺失小鼠、p75 NTR缺失小鼠、正常大鼠和老年大鼠。信号通路， 包括TrkA磷酸化、MAP激酶和DNA片段化 在处理的大鼠和小鼠大脑中的化学和生物化学。 选择性刺激神经营养因子的治疗试剂的合理设计 信号通路可能导致阿尔茨海默病，帕金森病和相关疾病的新疗法 神经系统疾病-反应选择性NGF突变体可能最终比野生型更有效 神经生长因子治疗神经退行性疾病。

The family of neurotrophins, related to nerve growth factor (NGF), interact with two types of receptors, the Trk tyrosine kinase receptor and the common neurotrophin receptor p75NTR, to support neuronal development in responsive peripheral neurons (sensory, sympathetic) and central neurons (cholinergic, dopaminergic) and to provide signals for survival of neurons in neurodegenerative disorders. This proposal is aimed at further development of neurotrophin mutants ('muteins') designed to produce preferential receptor specificity. A major hypothesis being addressed is that receptor- and/or signal- selective neurotrophin mutants would be more effective therapeutic reagents in certain disorders than wild type neurotrophins. The receptor-selective neurotrophin 'muteins' are at a stage to be tested in animal models of neurodegenerative diseases. The Specific Aims of the proposal are: (i) To utilize receptor-selective neurotrophin mutein heterodimers to test specific receptor activation models. Novel neurotrophin heterodimers will be characterized to determine the binding affinity to each receptor, the main cellular responses (survival, apoptosis, or differentiation) and enzymes in key signaling pathways, (ii) To characterize the signaling pathway to apoptosis through p53 tumor suppressor protein/capase-3 -dependent and -independent mechanisms. Neurotrophin muteins will be screened for those that discriminate between p53 -dependent and -independent pathways with p53 temperature sensitive PC12 cells. Several neuronal cell lines and primary cultures will also be studied with select muteins. (iii) To test the therapeutic potential of signal- selective neurotrophin muteins by intranasal inhalation delivery to the central nervous system of rodents. Normal mice, p53 null mice, p75NTR null mice, normal rats, and aged rats will be used. Signaling pathways, including TrkA phosphorylation, MAP kinase, and DNA fragmentation, will be compared immunohistochemically and biochemically in the treated rat and mice brains. The rational design of therapeutic reagents derived from neurotrophins that selectively stimulate signaling pathways may lead to novel treatments for Alzheimer's Disease, Parkinson's Disease, and related neurological disorders - response-selective NGFmutants mayultimately be more effective than wild type NGF in treating neurodegenerative diseases.