Inducible DNA Repair in Cerebral Ischemia

脑缺血中的诱导性 DNA 修复

• 批准号: 6531073
• 负责人: Jun Chen
• 金额: $ 29.81万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-06-16 至 2006-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6531073
• 关键词: DNA damage; DNA directed DNA polymerase; DNA repair; PC12 cells; apoptosis; cell type; cerebral artery; cerebral ischemia /hypoxia; enzyme activity; gene expression; histology; laboratory rat; neurons; neuroprotectants; phosphoester ligase; proliferating cell nuclear antigen; tissue /cell culture; transfection /expression vector; western blottings

DESCRIPTION (provided by applicant): Endogenous oxidative damage to nuclear DNA is an early event in ischemic brain injury that may trigger neuronal cell death. DNA base-excision-repair (BER), consisting of the short-patch and long-patch repair pathways, is the predominant repair mechanism of endogenous oxidative DNA damage in the brain. BER is an inducible mechanism; induced BER activity in ischemic brain has been associated with rapid repair of DNA damage and cell survival. Thus, we hypothesize that the inducible BER activity constitutes an endogenous mechanism of neuroprotection that determines, at least in part, the outcome of ischemic brain injury. Exciting and relevant preliminary data supporting this hypothesis have now been obtained. These include the finding that increased expression of BER enzymes and induced cellular BER activity via endogenous (ischemic preconditioning) or ekogenous (vector-mediated gene transfection) mechanisms enable neurons to be tolerant to subsequent ischemic injury and related insults. The overall objective of this application for competing renewal is to further explore the neuroprotective role of inducible BER activity in ischernic brain and in cell culture model of neuronal ischemia, and to elucidate the mechanism by which this important cellular mechanism is activated. The specific aims of this project are to: 1. Study the mechanism and functional role of inducible DNA base-excision-repair activity in a rat model of ischemic tolerance. 2. Study the mechanism and functional role of inducible DNA base-excision-repair activity in cell culture models of neuronal ischemia and tolerance. 3. Determine if inducible DNA base-excision-repair activity is neuroprotective by altering BER gene expression in vivo using adeno-associated virus expression vectors. Endogenous adaptive responses, such as tolerance, are evolutionarily highly conserved, and may reveal particularly relevant protective neurobiological mechanisms. Therefore, understanding the role of inducible BER activity in the mechanism underlying tolerance may yield novel insights into the mechanism by which the brain's endogenous protective capacity functions. Studies in both in vivo and in vitro models are proposed. The in vivo animal model of cerebral ischernia minics many aspects of pathophysiological changes in the brain after clinical ischemia. The in vitro models will complement the in vivo studies by allowing for precise mechanistic studies to be performed.

描述（由申请人提供）：核 DNA 的内源性氧化损伤 是缺血性脑损伤的早期事件，可能触发神经元细胞 死亡。 DNA 碱基切除修复 (BER)，由短补丁和 长补丁修复途径是内源性修复的主要机制 大脑中的DNA氧化损伤。 BER 是一种诱导机制；诱导误码率 缺血性脑部的活动与 DNA 损伤的快速修复有关 和细胞存活。因此，我们假设可诱导的 BER 活性 构成神经保护的内源性机制，决定 至少部分是缺血性脑损伤的结果。令人兴奋且相关 现已获得支持这一假设的初步数据。这些 包括发现 BER 酶的表达增加并诱导 通过内源性（缺血预处理）或外源性的细胞 BER 活性 （载体介导的基因转染）机制使神经元能够耐受 随后的缺血性损伤和相关的损伤。 此竞争性更新申请的总体目标是进一步 探索诱导 BER 活性在缺血脑中的神经保护作用 并在神经元缺血的细胞培养模型中，阐明其机制 通过它激活这一重要的细胞机制。 该项目的具体目标是： 1. 研究诱导型DNA的作用机制和功能作用 缺血耐受大鼠模型中的碱基切除修复活性。 2. 研究诱导型DNA的作用机制和功能作用 神经元缺血和细胞培养模型中的碱基切除修复活性 宽容。 3. 确定诱导性 DNA 碱基切除修复活性是否具有神经保护作用 通过使用腺相关病毒表达改变体内 BER 基因表达 向量。 内源性适应性反应，例如耐受性，在进化上是高度 保守的，并且可能揭示特别相关的保护性神经生物学 机制。因此，了解诱导 BER 活动在 耐受性背后的机制可能会通过以下方式对该机制产生新的见解： 大脑的内源性保护能力发挥作用。 提出了体内和体外模型的研究。活体动物 脑缺血模型多方面的病理生理变化 临床缺血后的大脑中。体外模型将补充 通过允许进行精确的机制研究来进行体内研究。