OXIDATIVE STRESS AND NEURODEGENERATION

描述（来自申请人的摘要）：Hsp 90结合型苯醌 安莎霉素、格尔德霉素（GA）对原代未成熟大鼠及Ht 22细胞的保护作用 皮层神经元培养物谷氨酸诱导的氧化毒性。 此外，初步结果表明，在复苏期间给予GA 改善大鼠的神经学结果， 窒息性心脏骤停GA与HSP 90的结合破坏了细胞内的各种 信号传导途径，并导致Hsp 70的诱导，Raf-1的消耗， 原癌基因，并减少Raf-1，ERK-1下游靶点的激活 ERK-2 GA处理引起的ERK激活的下调可能是 它的神经保护活性的一个重要组成部分，因为抑制一个 ERK激活激酶（即MEK-1）也可保护细胞免受氧化毒性。 ht 22细胞和原代大鼠皮层神经元培养物。我们假设 操纵Hsp 90功能可能是一种有用的策略， 体内信号转导途径引发神经元细胞死亡。的 识别神经保护的分子机制 与Hsp 90功能的药理学操作相关的主要是 这个应用程序的目标。在具体目标1中，我们将确定 热休克蛋白90调控谷氨酸诱导的氧化毒性的信号通路 Ht 22小鼠海马细胞系，并解决以下问题。并 Hsp 70诱导有助于Hsp 90结合药物的保护作用， 试管？持续的ERK激活是否是 谷氨酸诱导的Ht 22细胞氧化毒性？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Hsp 90调节的 谷氨酸诱导的未成熟原代小鼠氧化毒性的信号通路 大鼠皮层神经元细胞培养物。GA和U1026是否能防止 未成熟原代大鼠皮层神经元细胞培养物的氧化毒性？什么 生物化学事件与Hsp 90结合的神经保护作用相关 药物在未成熟的原代大鼠皮层神经元培养中的作用最后，具体目标 3我们将确定Hsp 90结合药物是否有效的治疗后 在大鼠全脑缺血模型中的神经保护剂。Hsp 90结合药物 改善窒息性心脏骤停或中度 脑动脉闭塞Hsp 90结合药物在体内诱导Hsp 70吗？做 Hsp 90结合药物影响体内MAPK活化？

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?