DNA Damage/Repair and Cell Death

DNA 损伤/修复和细胞死亡

• 批准号: 7012331
• 负责人: LEE J MARTIN
• 金额: $ 29.51万
• 依托单位: JOHNS HOPKINS UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-04-01 至 2010-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7012331
• 关键词: DNA damage; DNA repair; apoptosis; biological signal transduction; cell age; cell death; cerebral cortex; cysteine endopeptidases; developmental neurobiology; embryo /fetus tissue /cell culture; fluorescent in situ hybridization; gene expression; laboratory mouse; mitogen activated protein kinase; neural degeneration; p53 gene /protein

DESCRIPTION (provided by applicant): Neuronal cell death induced by DNA damage has been implicated in the pathogenesis of many acute and chronic neurological disorders in humans, and DNA damage-induced cell death is a fundamental principle driving therapy for many types of cancer. The major goal of the experiments in this grant proposal is to determine if DNA damage is a cause or consequence of neurodegeneration. Cultured embryonic mouse cortical neurons will be used as a model to study cause-effect links between specific types of DNA lesions and cell death and the mechanisms of DNA damage-induced apoptosis in young and mature neurons. In Specific Aim 1 we will identify lethal levels of DNA damage in neurons and the relationships between DNA damage level, DNA lesion type, and cell death pattern (apoptosis, necrosis, or hybrid) and will test the hypothesis that toxicity of DNA damaging agents on neurons is maturation-related. We will study if DNA damage occurs preferentially at specific sites within the neuronal genome using comet-FISH analysis. We will identify the major DNA repair and DNA degradation pathways in cortical neurons and will determine whether DNA repair is different in neurons at different stages of maturation. We will test the hypothesis that the dependence of DNA damage-triggered death on caspases and MARK signaling differs in neurons of different maturational states. In Specific Aim 2, we will evaluate upstream mechanisms that link DNA damage to downstream apoptosis mechanisms in cortical neurons. We will test the hypothesis that DNA damage-induced apoptosis in young and mature neurons is mediated by the ATM-p53 or cAbl-p53 signaling networks. In Specific Aim 3, we will determine if enforced expression of DNA repair enzymes that function in base excision repair can be neuroprotective. These experiments will provide important information on the toxicity of DNA damage in neurons, the specific types of DNA damage that can occur in neurons, the effects of DNA damage on neurons of different ages, and the molecular mechanisms that transduce DNA damage signals to apoptotic pathways in neurons. This work is relevant to human disease because it will contribute to the understanding of the pathobiology of DNA damage-induced neurodegeneration and to the identification of possible molecular targets for reducing the toxic and neurologic side-effects of cancer therapy.

描述（由申请人提供）：DNA损伤诱导的神经元细胞死亡与人类许多急性和慢性神经系统疾病的发病机制有关，DNA损伤诱导的细胞死亡是驱动许多类型癌症治疗的基本原理。这项研究的主要目的是确定DNA损伤是否是神经退行性变的原因或后果。培养的胚胎小鼠皮层神经元将被用作模型，以研究特定类型的DNA损伤和细胞死亡之间的因果关系，以及年轻和成熟神经元中DNA损伤诱导的细胞凋亡的机制。在特定目标1中，我们将确定神经元中DNA损伤的致死水平以及DNA损伤水平、DNA损伤类型和细胞死亡模式（凋亡、坏死或杂交）之间的关系，并将检验DNA损伤剂对神经元的毒性与成熟相关的假设。我们将使用彗星FISH分析研究DNA损伤是否优先发生在神经元基因组内的特定位点。我们将确定皮质神经元中主要的DNA修复和DNA降解途径，并确定DNA修复在不同成熟阶段的神经元中是否不同。我们将检验这一假设，即DNA损伤引发的死亡依赖于半胱天冬酶和MARK信号在不同成熟状态的神经元中存在差异。在具体目标2中，我们将评估在皮层神经元中将DNA损伤与下游凋亡机制联系起来的上游机制。我们将测试的假设，即DNA损伤诱导的凋亡在年轻和成熟的神经元是由ATM-p53或cDNA-p53信号网络介导的。在具体目标3中，我们将确定在碱基切除修复中起作用的DNA修复酶的强制表达是否可以具有神经保护作用。这些实验将提供重要的信息，在神经元中的DNA损伤的毒性，DNA损伤的具体类型，可以发生在神经元中，DNA损伤对不同年龄的神经元的影响，和DNA损伤信号的分子机制，在神经元中的凋亡途径。这项工作与人类疾病有关，因为它将有助于理解DNA损伤诱导的神经变性的病理生物学，并确定可能的分子靶点，以减少癌症治疗的毒性和神经副作用。