NEUROTROPHIC FACTOR DEPRIVATION AND NEURONAL CELL DEATH

描述：这项工作的总体目标是了解分子 哺乳动物神经元经历凋亡性死亡的途径。 整体 假设神经元凋亡的途径是由 多个因果联系的步骤，这些步骤的性质 取决于最初的死因 主要焦点将关注 营养因子剥夺诱发的细胞凋亡。 两种额外的方法 为了比较的目的，将考虑诱发细胞凋亡， DNA损伤剂和通过消耗DNA损伤剂诱导氧化应激 超氧化物歧化酶1. 将在大鼠PC 12培养物中进行研究 细胞和交感神经元。 拟议的具体目标集中在两个方面 凋亡途径的组成部分。 假设将被检验， 细胞凋亡启动营养因子剥夺和DNA损伤（而不是 氧化应激）需要激活特定的细胞周期蛋白依赖性激酶， 增强Rb蛋白的磷酸化和E2F转录的激活 因素 第二个目标是关注caspase成员的作用 半胱氨酸脱氢酶家族作为神经元凋亡的执行者。 实验将确定死亡所需的半胱天冬酶在每一个 三个实验性的apopotic范式，确定了半胱天冬酶 在细胞凋亡的刺激下被激活，并揭示了相对的 半胱天冬酶彼此之间以及与半胱天冬酶中的其他元件之间的位置 凋亡途径 将评估神经元凋亡的假设 由不同的原因引起的是由不同的caspase家族成员介导的。

DESCRIPTION: The overall goal of this work is to understand the molecular pathways by which mammalian neurons undergo apoptotic death. The overall hypotheses are that the pathways of neuronal apoptotoic death are composed of multiple, causally-linked steps and that the nature of these steps depends on the initiating causes of death. The major focus will concern apoptosis evoked by trophic factor deprivation. Two additional means of evoking apoptosis will be considered for purposes of comparison, exposure to DNA damaging agents and induction of oxidative stress by depletion of superoxide dismutase 1. Studies will be performed in cultures of rat PC12 cells and sympathetic neurons. The proposed specific aims focus on two components of the apoptotic pathway. The hypothesis will be tested that apoptosis initiated by trophic factor deprivation and DNA damage (and not oxidative stress) requires activation of specific cyclin-dependent kinases, enhanced phosphorylation of Rb protein and activation of E2F transcription factors. The second aim focuses on the roles of members of the caspase family of cysteine aspartases as executors of neuronal apopototic death. Experiments will identify the caspases required for death in each of the three experimental apopotic paradigms, determine the means by which caspases are activated in response to apoptotic stimuli, and uncover the relative positions of the caspases to one another and to other elements in the apoptotic pathway. The hypothesis will be evaluated that neuronal apoptosis evoked by different causes is mediated by distinct caspase family members.