MECHANISMS OF NEURONAL APOPTOSIS

神经元凋亡机制

• 批准号: 2685778
• 负责人: HERBERT M. GELLER
• 金额: $ 19.92万
• 依托单位: UNIV OF MED/DENT NJ-R W JOHNSON MED SCH
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-04-20 至 2001-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2685778
• 关键词: DNA damage; animal genetic material tag; apoptosis; camptothecin; chemical structure function; cyclin dependent kinase; cyclins; enzyme activity; gene induction /repression; gene targeting; genetically modified animals; guanine nucleotide binding protein; ionizing radiation; laboratory mouse; laboratory rat; neural degeneration; neurons; neuroprotectants; neurotoxicology; neurotoxins; radiation genetics; regulatory gene; tissue /cell culture; tumor suppressor proteins

This research to investigate the underlying molecular mechanisms that trigger neuronal apoptosis after DNA damage. While apoptosis is a cardinal feature of programmed cell death during neural development , it has been increasingly recognized that neurons also undergo apoptosis in response to injury. DNA damage produces apoptotic death in cultured mammalian central nervous system (CNS) neurons. Cell death is inhibited by two drugs which inhibit cyclin-dependent kinases. These drugs also protect neurons against apoptotic cell death after trophic factor withdrawal. This suggest that apoptosis in neurons due to both toxic injury and lack of trophic support required enzymes that normally control the cell cycle. Investigating this hypothesis is the major focus of this application. The first two specific aims will determine the role of immediate early genes and cycle-related proteins in apoptosis of cultured rat CNS neurons after DNA damage by irradiation or treatment with camptothecin. We will first determine the changes in immediate early genes (IEGs) and cell cycle-related proteins (cyclin- dependent kinases, Cdks) following DNA damage. We will then determine whether apoptosis is reduced by microinjection of antibodies directed against the IEGs that are increased following DNA damage or by injection of inhibitors or dominant negative mutants the Cdks and also by treatment with antisense oligonucleotides against the cyclins and Cdks that are increased following DNA damage. We will also evaluate the role of the p53 protein in neuronal apoptosis by utilizing neurons from p53 knockout mice. We will also utilize a series of Cdk-inhibitor drugs to determine a structure/activity relationship between Cdk inhibitory activity and reduction of neuronal apoptosis due to DNA damage and also for their ability to produce apoptosis in dividing PC12 cells. Finally, since campotothecin toxicity is reduced by inhibition of transcription, we will evaluate whether inhibition of transcription reduces toxicity of campothecin by reducing 1)DNA damage by camptothecin or 2) the apoptotic process itself or both. These studies should provide significant information about the underlying mechanisms that trigger apoptosis after DNA damage. Moreover, drugs that simultaneously kill dividing cells and protect neurons against toxicity from cancer chemotherapeutic agents or radiation may be exceedingly useful in therapy of brain cancers, in which survivors normally suffer a significant intellectual impairment.

这项研究旨在调查潜在的分子机制 DNA损伤后引发神经细胞凋亡。 虽然细胞凋亡是 神经发育过程中程序性细胞死亡的主要特征 人们越来越认识到神经元也会发生细胞凋亡 对伤害的反应。 DNA损伤导致培养细胞凋亡 哺乳动物中枢神经系统（CNS）神经元。 细胞死亡被抑制 通过两种抑制细胞周期蛋白依赖性激酶的药物。 这些药物还 保护神经元免受营养因子后的细胞凋亡 撤回。 这表明神经元细胞凋亡是由于两种毒性 损伤和缺乏营养支持需要正常情况下的酶 控制细胞周期。 研究这个假设是主要的 本应用的重点。 前两个具体目标将决定 立即早期基因和周期相关蛋白的作用 辐射或 DNA 损伤后培养的大鼠 CNS 神经元的凋亡 用喜树碱治疗。 我们首先要确定变化 立即早期基因（IEG）和细胞周期相关蛋白（细胞周期蛋白） DNA 损伤后的依赖性激酶 (Cdks)。 然后我们将确定 显微注射抗体是否会减少细胞凋亡 对抗 DNA 损伤或注射后增加的 IEG 抑制剂或显性失活突变体的 Cdks 以及 使用针对细胞周期蛋白和 Cdks 的反义寡核苷酸进行治疗 DNA 损伤后会增加。 我们还将评估该角色 利用来自 p53 的神经元研究 p53 蛋白在神经元凋亡中的作用 基因敲除小鼠。 我们还将利用一系列Cdk抑制剂药物来 确定 Cdk 抑制之间的结构/活性关系 由于 DNA 损伤而导致的神经元凋亡的活性和减少，以及 表彰其在分裂的 PC12 细胞中产生细胞凋亡的能力。 最后， 由于喜树碱的毒性通过抑制转录而降低， 我们将评估转录抑制是否会降低毒性 喜树碱通过减少 1) 喜树碱造成的 DNA 损伤或 2) 细胞凋亡 处理本身或两者。 这些研究应该提供重要的 有关触发细胞凋亡的潜在机制的信息 DNA损伤。 此外，同时杀死分裂细胞和 保护神经元免受癌症化疗药物的毒性或 放射线在治疗脑癌方面可能非常有用， 幸存者通常会遭受严重的智力障碍。