C JUN, C FOS AND NEURONAL PROGRAMMED CELL DEATH

C JUN、C FOS 和神经元程序性细胞死亡

• 批准号: 2891999
• 负责人: Steven Estus
• 金额: $ 12.46万
• 依托单位: UNIVERSITY OF KENTUCKY
• 依托单位国家: 美国
• 财政年份: 1995
• 资助国家: 美国
• 起止时间: 1995-08-01 至 2001-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2891999
• 关键词: antisense nucleic acid; apoptosis; binding proteins; cAMP response element binding protein; complementary DNA; embryo /fetus tissue /cell culture; gene induction /repression; genetic promoter element; immunofluorescence technique; laboratory rat; neurogenetics; neuropharmacology; neurotrophic factors; oligonucleotides; oncoproteins; oxidative stress; peptidylprolyl isomerase; phosphoproteins; polymerase chain reaction; protein protein interaction; protooncogene; sympathetic nervous system; transfection /expression vector; western blottings

Programmed cell death (PCD) is a well-recognized developmental phenomenon that occurs by a process of apoptosis. Recent evidence strongly suggests that PCD also contributes to pathological conditions. Several lines of evidence have indicated that PCD results from the expression of a specific genetic program leading to proteins that kill the cell. We have identified several genes whose expression in increased in sympathetic neurons undergoing PCD in response to deprivation of the neurotrophic factor, NGF, and many genes whose expression is decreased. We have presented evidence that c-Jun, a transcription factor encoded by the one of the induced genes, is required for neuronal PCD. We have also presented evidence that implicate the Fos family as being necessary for apoptosis; in NGF-deprived neurons, certain Fos family members, i.e., c-fos and fos B, are induced, while other, potentially inhibitory family members, i.e., fra-1 and fra-2, are repressed. These results led us to theorize that neuronal PCD depends upon both the activation of certain genes, i.e., c-jun, and the repression of other genes, i.e., fra-1 and fra-2. Since (i) the induction f c-jun is the earliest detectable genetic event, (ii) c-Jun interacts with each Fos family member, and (iii) c-Jun has been implicated specifically as necessary for death, our current working hypothesis is that events that induce c-jun, modulate the activity of c-Jun, and that emanate from the actions of c-Jun, constitute critical portions of a biochemical and genetic cascade that results in neuronal death. We propose a focused attack aimed at evaluating this hypothesis. We shall further define the roles of the jun and Fos family members in neuronal death by using several molecular genetic approaches. We shall analyze athe expression of these genes at athe protein level to investigate possible post-transcriptional regulation. We shall examine the protein:protein interactions among the Jun and Fos family members to identify directly athe proteins that interact with c-Jun. We shall evaluate whether agents that protect neurons from NGF deprivation, i.e., cAMP analogs and potassium depolarization, do so by activating CREB-2, a transcription factor that these agents activate and that modulates c-Jun. We shall determine the biochemical changes during apoptosis that depend on c-Jun, to identify 'downstream" mechanisms of c-Jun action. We shall identify the molecular and cellular mechanisms leading to the activation of c-jun; this investigation will lead "upstream" in the temporal cascade of events by evaluating the roles of oxidative stress and c-Jun phosphorylation. These studies will provide considerable insight into the role of the Jun and Fos family members in neuronal PCD and athe overall mechanism of neuronal PCD. Given the increasing evidence for a role of neuronal PCD in pathological conditions of the nervous system, i.e., stroke, neurotoxicity, and neurodegenerative disease, these insights may lead to strategies to intervene pharmacologically to prevent or retard death in these conditions.

程序性细胞死亡（PCD）是一种公认​​的发育现象 这是通过细胞凋亡过程发生的。 最近的证据强烈表明 PCD 也会导致病理状况。 几行 有证据表明 PCD 是由特定的表达引起的 导致杀死细胞的蛋白质的遗传程序。 我们已经确定 交感神经元中表达增加的几个基因 因神经营养因子 NGF 的剥夺而接受 PCD， 以及许多表达降低的基因。 我们已经出示了证据 c-Jun，一种由诱导基因之一编码的转录因子， 是神经元 PCD 所必需的。 我们还提供了证据表明 暗示 Fos 家族对于细胞凋亡是必需的；在 NGF 剥夺的情况下 神经元，某些 Fos 家族成员，即 c-fos 和 fos B，被诱导， 而其他潜在的抑制性家族成员，即 fra-1 和 fra-2， 受到压制。 这些结果使我们推测神经元 PCD 取决于 某些基因（即 c-jun）的激活和抑制 其他基因，即 fra-1 和 fra-2。 由于 (i) 归纳 f c-jun 是 最早可检测到的遗传事件，(ii) c-Jun 与每个 Fos 相互作用 家庭成员，以及 (iii) c-Jun 被明确牵连为 死亡所必需的，我们目前的工作假设是，事件 诱导 c-Jun，调节 c-Jun 的活性，并从 c-Jun 的作用构成了生化和遗传的关键部分 级联反应导致神经元死亡。 我们建议集中攻击 在评估这个假设时。 我们将进一步明确jun和Fos家族成员的角色。 通过使用几种分子遗传学方法来实现神经元死亡。 我们将 在蛋白质水平分析这些基因的表达以进行研究 可能的转录后调控。 我们将检查 蛋白质：Jun 和 Fos 家族成员之间的蛋白质相互作用 直接鉴定与 c-Jun 相互作用的蛋白质。 我们将 评估是否可以保护神经元免受 NGF 剥夺的影响，即 cAMP 类似物和钾去极化，通过激活 CREB-2 来实现，CREB-2 这些药物激活并调节 c-Jun 的转录因子。 我们将确定细胞凋亡过程中的生化变化，这些变化取决于 c-Jun，确定 c-Jun 行动的“下游”机制。我们将 确定导致激活的分子和细胞机制 c-君；这项调查将在时间级联中引导“上游” 通过评估氧化应激和 c-Jun 的作用来评估事件 磷酸化。 这些研究将为了解军的作用提供相当多的见解。 和 Fos 家族成员在神经元 PCD 中的作用及其总体机制 神经元PCD。 鉴于越来越多的证据表明神经元 PCD 在 神经系统的病理状况，即中风、神经毒性、 和神经退行性疾病，这些见解可能会导致制定策略 在这些情况下进行药理学干预以预防或延缓死亡。