MECHANISMS OF NEURONAL APOPTOSIS

神经元凋亡机制

• 批准号: 2892254
• 负责人: HERBERT M. GELLER
• 金额: $ 20.52万
• 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/2892254
• 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; p53 gene /protein; 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.

这项研究旨在研究潜在的分子机制， DNA损伤后引发神经元凋亡。 而凋亡是一种 神经发育过程中程序性细胞死亡的主要特征， 越来越多的人认识到，神经元也会发生凋亡， 对伤害的反应。 DNA损伤导致细胞凋亡 哺乳动物中枢神经系统（CNS）神经元。 细胞死亡受到抑制 两种抑制细胞周期蛋白依赖性激酶的药物。 这些药物也 保护神经元免受营养因子诱导的细胞凋亡 戒断 这表明，神经细胞凋亡，由于这两种毒性 损伤和缺乏营养支持需要酶， 控制细胞周期。 调查这个假设是主要的 这个应用程序的重点。 前两个具体目标将决定 即早基因和细胞周期相关蛋白在 放射性损伤或放射性损伤对培养大鼠中枢神经细胞DNA损伤后细胞凋亡的影响 喜树碱治疗。 我们将首先确定 立即早期基因（IEG）和细胞周期相关蛋白（cyclin- 依赖性激酶（Cdks）。 然后我们将决定 细胞凋亡是否通过显微注射针对 针对DNA损伤或注射后增加的IEG 的抑制剂或显性负突变体的Cdks， 用针对细胞周期蛋白和Cdks的反义寡核苷酸处理 在DNA损伤后会增加 我们还将评估 p53蛋白在神经元凋亡中的作用 敲除小鼠 我们还将利用一系列Cdk抑制剂药物， 确定Cdk抑制剂之间的结构/活性关系 活性和减少由于DNA损伤引起的神经元凋亡， 因为它们在分裂的PC 12细胞中产生凋亡的能力。 最后， 由于喜树碱毒性通过抑制转录而降低， 我们将评估转录抑制是否降低了 喜树碱通过减少1）喜树碱引起的DNA损伤或2）细胞凋亡， 过程本身或两者。 这些研究将提供重要的 关于引发细胞凋亡的潜在机制的信息， DNA损伤。 此外，药物，同时杀死分裂细胞， 保护神经元免受癌症化疗剂的毒性，或 放射治疗在脑癌的治疗中可能非常有用， 幸存者通常会遭受严重的智力障碍。