OXIDATIVE STRESS AND NEURODEGENERATION

描述(摘自申请者的摘要)：热休克蛋白90结合的苯醌 阿萨霉素、格尔达那霉素对Ht22细胞和未成熟原代大鼠的保护作用 谷氨酸诱导的皮层神经元氧化毒性。 此外，初步结果表明，在复苏过程中给予GA 改善大鼠全脑缺血后的神经转归 窒息心脏骤停。GA与HSP90结合破坏多种细胞内 信号通路和导致Hsp70的诱导，Raf-1的缺失 原癌基因和Raf-1、ERK-1下游靶点的激活减少 和ERK-2。GA对ERK活性的下调作用可能是 它的神经保护活性的一个重要组成部分，因为它抑制了 ERK激活的激酶(即MEK-1)也能保护心肌细胞免受氧化毒性。 Ht22细胞和原代培养的大鼠皮质神经元。我们假设 操纵Hsp90功能可能是一种有用的策略，以影响各种 体内触发神经细胞死亡的信号转导通路。这个 神经保护相关分子机制的鉴定 与Hsp90功能相关的药理学操作是主要的 此应用程序的目标。在具体目标1中，我们将确定 HSP90调控谷氨酸氧化毒性的信号转导途径 Ht22小鼠海马区细胞系，并回答以下问题。会吗？ 热休克蛋白70的诱导参与热休克蛋白90结合药物的保护作用 试管婴儿？持续的ERK激活对于 谷氨酸对Ht22细胞的氧化毒性？谷氨酸诱导的 氧化毒性影响MAPK家族的其他成员(即JNK/SAPK和 P38MAPK)？在具体目标2中，我们将确定Hsp90调节的影响 谷氨酸诱导未成熟原代细胞氧化毒性的信号转导途径 大鼠皮层神经细胞培养。GA和U1026是否可防止 原代培养未成熟大鼠皮质神经元细胞的氧化毒性？什么 生化事件与Hsp90结合的神经保护作用有关 未成熟的原代大鼠皮质神经元培养中的药物？最后在特定的目标中 3我们将确定Hsp90结合药物是否在治疗后有效 全脑缺血大鼠模型中的神经保护剂。Hsp90结合药物 改善窒息心脏骤停或中期心脏骤停后的神经预后 大脑动脉闭塞？Hsp90结合药物在体内能诱导Hsp70吗？做 热休克蛋白90结合药物影响体内MAPK激活？

Description (From the applicant's abstract): The Hsp90-binding benzoquinoid ansamycin, geldanamycin (GA) protects Ht22 cells and immature primary rat cortical neuron cultures from glutamate induced oxidative toxicity. Furthermore, preliminary results suggest that GA given during resuscitation improves neurological outcome in rats subjected to global ischemia induced by asphyxial cardiac arrest. GA binding to HSP90 disrupts various intracellular signaling pathways and leads to induction of Hsp70, depletion of the Raf-1 protooconcogene, and reduced activation of downstream targets of Raf-1, ERK-1 and ERK-2. The downregulation of ERK activation caused by GA treatment might be an important component of its neuroprotective activity since inhibition of an ERK activating kinases (i.e. MEK-1) also protects against oxidative toxicity in Ht22 cells and primary rat cortical neuron cultures. We hypothesize that manipulation of Hsp90 function may be a useful strategy to impact various signal transduction pathways in vivo that trigger neuronal cell death. The identification of the molecular mechanisms involved in neuroprotection associated with pharmacological manipulation of Hsp90 function is the major goal of this application. In specific aim 1 we will determine the impact of Hsp90 regulated signaling pathway on glutamate-induced oxidative toxicity in the Ht22 mouse hippocampal cell line and address the following questions. Does Hsp70 induction contribute to the protective effects of Hsp90 binding drugs in vitro? Is persistent ERK activation necessary and sufficient for glutamate-induced oxidative toxicity in Ht22 cells? Does glutamate-induced oxidative toxicity affect other members of the MAPK family (i.e. JNK/SAPK and P38MAPK)? In specific aim 2 we will determine the impact of Hsp90-regulated signaling pathways on glutamate-induced oxidative toxicity in immature primary rat cortical neuron cell cultures. Are GA and U1026 protective against oxidative toxicity in immature primary rat cortical neuron cell cultures? What biochemical events are associated with neuroprotective effects of Hsp90-binding drugs in immature primary rat cortical neuron cultures? Finally in Specific Aim 3 we will determine whether Hsp90 binding drugs are effective post-treatment neuroprotective agents in rat models of global ischemia. Do Hsp90-binding drugs improve neurological outcome following asphyxial cardiac arrest or middle cerebral artery occlusion? Do Hsp90-binding drugs induce Hsp70 in vivo? Do Hsp90-binding drugs affect MAPK activation in vivo?