C-JUN AND AMYLOID-INDUCED APOPTOSIS

C-JUN 和淀粉样蛋白诱导的细胞凋亡

• 批准号: 2750954
• 负责人: Steven Estus
• 金额: $ 17.01万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-09-01 至 2000-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2750954
• 关键词: amyloid proteins; apoptosis; free radicals; gene induction /repression; laboratory rat; microinjections; neural degeneration; neurons; neuropharmacology; neurotrophic factors; neutralizing antibody; oncoproteins; oxidative stress; tissue /cell culture

DESCRIPTION: Apoptosis is emerging as a type of cell death with characteristic morphology that contributes to neuronal loss during normal development and in pathologic situations, including Alzheimer disease (AD), Huntington disease, stroke and seizure. Despite increasing interest in the process, few details concerning the molecular mechanisms of neuronal apoptosis are known. We previously identified a temporal cascade of gene induction in sympathetic neurons undergoing apoptosis because of nerve growth factor (NGF) deprivation and showed that the protein product of one induced gene, c-Jun, was necessary for death. In cortical neurons, apoptosis induced by AD amyloid b-protein (Ab) treatment is accompanied by a genetic cascade that is strikingly similar to that identified previously, including a robust c-jun induction. Since (i) c-jun mRNA is induced during neuronal apoptosis initiated by either Ab-treatment or NGF deprivation, (ii) this c-jun mRNA appears to form functional c-Jun protein in both model systems, as discerned by the subsequent activation of "downstream" genes, and (iii) c-Jun is necessary for apoptosis after NGF deprivation, our current working hypothesis is that events which lead up to, modulate, and include the induction of c-jun are necessary for Ab-induced neuronal death. In pursuit of this hypothesis, we propose to (i) compare and contrast patterns of gene expression in neurons undergoing apoptosis as a result of Ab -treatment of NGF-deprivation; (ii) define the role of c-Jun in Ab -induced neuronal apoptosis by using microinjected, neutralizing antibodies and ectopic expression of a dominant negative form of c-Jun; (iii) elucidate the mechanism(s) leading to c-jun induction in Ab-treated neurons, with particular emphasis on the role of oxidative stress; (iv) explore a possible mechanism of c-Jun action by analyzing Ab -treated neurons for markers of cell cycle re-entry, including patterns of c-Jun heterodimer formation; (v) compare the patterns of neuronal apoptosis and "apoptotic" gene expression in AD and control brain tissue to discern whether this genetic cascade may contribute to neuronal loss in vivo. These studies will evaluate the hypotheses that Ab -induced neuronal death is critically dependent on altered gene expression, that oxidative stress is central to these genetic events, and that this genetic cascade may contribute to neuronal loss in vivo in AD. Hence, this work will further our long-term goals of elucidating the mechanisms underlying neuronal death, and, ultimately, identifying pharmacologic means to prevent this death.

描述：细胞凋亡是一种细胞死亡类型， 特征形态，有助于正常过程中的神经元损失 发展和病理情况，包括阿尔茨海默病（AD）， 亨廷顿舞蹈病，中风和癫痫。 尽管人们越来越关注 过程中，关于神经元的分子机制的细节很少 细胞凋亡是已知的。 我们以前发现了一个时间级联的基因 诱导交感神经元发生凋亡， 生长因子（NGF）的剥夺，并表明，蛋白质产物的一个 诱导基因c-Jun是死亡所必需的。 在皮层神经元中， 由AD淀粉样蛋白b-蛋白（Ab）处理诱导的细胞凋亡伴随着 与先前发现的惊人相似的遗传级联， 包括强有力的c-jun诱导。 由于（i）c-jun mRNA在 由Ab处理或NGF剥夺引发的神经元凋亡，（ii） 该c-jun mRNA似乎在两种模型中形成功能性c-Jun蛋白 系统，如通过随后的“下游”基因的激活所辨别的， 和（iii）c-Jun是NGF剥夺后细胞凋亡所必需的，我们 目前的工作假设是，导致、调节和 包括c-jun的诱导是Ab诱导的神经元死亡所必需的。 在追求这一假设，我们建议（一）比较和对比 基因表达的模式在神经元进行凋亡的结果， Ab -NGF剥夺的治疗;（ii）定义c-Jun在Ab中的作用 - 通过使用显微注射的中和抗体诱导神经元凋亡 和c-Jun的显性阴性形式的异位表达;（iii）阐明 导致Ab处理的神经元中c-jun诱导的机制， 特别强调氧化应激的作用;（四）探索可能的 通过分析Ab处理的神经元的c-Jun作用的标志物， 细胞周期再进入，包括c-Jun异二聚体形成的模式;（v） 比较神经元凋亡和“凋亡”基因表达的模式 在AD和控制脑组织中，以辨别这种遗传级联是否可以 导致体内神经元损失。 这些研究将评估Ab诱导神经元死亡的假设， 严重依赖于基因表达的改变，氧化应激是 这些遗传事件的核心，这种遗传级联可能 导致AD中的体内神经元损失。 因此，这项工作将进一步 我们的长期目标是阐明神经元死亡的机制， 并最终确定预防这种死亡的药理学方法。