Inducible DNA Repair in Cerebral Ischemia

描述（由申请方提供）：对核DNA的内源性氧化损伤 是缺血性脑损伤早期事件，其可触发神经元细胞 死亡DNA碱基切除修复（BER），由短补丁和 长斑修复途径，是内源性损伤的主要修复机制。 大脑中的DNA氧化损伤BER是一种诱导机制;诱导BER 缺血脑中的活性与DNA损伤的快速修复有关 和细胞存活。因此，我们假设诱导BER活性 构成了一种内源性的神经保护机制， 至少部分是缺血性脑损伤的结果。令人兴奋和相关 现已获得支持这一假设的初步数据。这些 包括BER酶表达增加和诱导 通过内源性（缺血预处理）或外源性（缺血预处理）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损伤。 本次竞争性续期申请的总体目标是进一步 探讨诱导型BER活性在脑缺血中的神经保护作用 在神经元缺血的细胞培养模型中， 这一重要的细胞机制被激活。 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 在大鼠缺血耐受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 在神经元缺血的细胞培养模型中的碱基切除修复活性， 宽容 3.确定诱导型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BER基因在体内的表达， 向量。 内源性适应性反应，如耐受性，在进化上是高度相关的。 保守，并可能揭示特别相关的保护性神经生物学 机制等因此，了解诱导型BER活性在细胞凋亡中的作用， 耐受性的潜在机制可能会产生新的见解， 大脑的内源性保护功能。 提出了在体内和体外模型中的研究。体内动物 脑缺血模型可观察到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理研究来进行体内研究。

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.