Stress Proteins in Brain Cell Injury

脑细胞损伤中的应激蛋白

基本信息

批准号：
9270635
负责人：
Rona G Giffard
金额：
$ 34.44万
依托单位：
STANFORD UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-09-01 至 2018-05-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9270635
关键词：
Aftercare Animals Apoptosis Apoptotic Astrocytes BCL-2 Protein BCL2 gene Behavioral Brain Brain Injuries Calcium Cause of Death Cell Death Cell Survival Cells Cerebral Ischemia Clinical Clinical Trials Complex Endoplasmic Reticulum Explosion Family Family member Female Follow-Up Studies GRP75 GRP78 gene Goals Grant Heat shock proteins Heat-Shock Proteins 70 Homeostasis Infusion procedures Injection of therapeutic agent Injury Inner mitochondrial membrane Ischemia Ischemic Brain Injury MCL1 gene Measures Membrane Membrane Potentials Messenger RNA MicroRNAs Mitochondria Molecular Chaperones Mus Necrosis Neuroglia Neurologic Neurons Outcome Oxygen Consumption Pathway interactions Patients Protein Family Proteins RNA Interference Recovery Regulation Reporting Research Role Site Stress Stroke Testing Translating United States Work behavioral outcome brain cell cell injury cytochrome c disability effective therapy human disease improved in vivo inhibitor/antagonist male mitochondrial membrane neuronal survival new therapeutic target novel overexpression public health relevance stress protein thrombolysis uptake

项目摘要

DESCRIPTION (provided by applicant): Stroke is one of the leading causes of death worldwide and a major cause of long-term disability. Although many clinical trials have targeted stroke patients, only thrombolysis has so far emerged as an effective treatment. Nonetheless, new therapeutic targets have emerged. Calcium dysregulation has long been implicated in brain injury in the setting of stroke. Our prior work on this grant, as well as work from others, has shown that the heat shock protein 70 kDa (HSP70) family of chaperones or stress proteins, even if expressed after ischemia, can protect the brain. The regulation of apoptosis by the BCL2 family of proteins is another important determinant of ischemic outcome. These pathways converge to control cellular calcium homeostasis and both apoptotic and necrotic cell death. The endoplasmic reticulum (ER) and mitochondria interact at specific sites called the mitochondrial associated ER membrane (MAM) to regulate cellular calcium homeostasis and cell death. MAM is a critical site of stress/chaperone protein and BCL2 family interaction, and is central to determining the outcome from cerebral ischemia. We recently found that overexpressing GRP78, an ER chaperone and HSP70 family member, preserves mitochondrial function, reduces mitochondrial Ca2+ overload, and improves brain cell survival after stress. We also found that GRP78 translocates to the mitochondrial inner membrane after stress in astrocytes, CNS glial cells that are known to be integral to neuronal survival. In Aim 1 of this proposal we will investigate the role of translocated GRP78 in mitochondrial function by comparing wild type and mitochondrially targeted GRP78. The discovery of posttranscriptional gene silencing by miRNAs has led to an explosion of new hypotheses in human disease. Studies of miRNAs in cerebral ischemia are recent, and most have focused on profiling changes in miRNAs. We recently reported that reducing or blocking miR-181, a brain-enriched miRNA, protects the brain from stroke in the initial post-injury period. Aim 2 is a translational aim and ill follow up these studies to determine the effects of altering miR-181 on long term behavioral outcome from stroke, test post-treatment, and determine whether miR-181 is also effective in female animals. We recently demonstrated that miR-181 can target both GRP78 and anti-apoptotic BCL2 family members BCL2 and MCL1. Therefore, the role of miR-181 in ER-mitochondrial calcium transfer in MAM will be studied. Using computational miRNA target prediction we identified miR-200 as potentially targeting GRP75, a mitochondrial chaperone, and BCL2. Aim 3 of this proposal will focus on the mechanism of protection by reducing miR-181 levels investigating in detail effects on ER and mitochondrial Ca2+, and mitochondrial function. Overall this proposal exams a novel hypothesis: that miRNAs act as master regulators of chaperones and BCL2 family members influencing Ca2+ homeostasis, mitochondria-ER crosstalk, and outcome after cerebral ischemia.

描述（由申请人提供）：中风是全球死亡的主要原因之一，也是长期残疾的主要原因。尽管许多临床试验针对中风患者，但迄今为止，仅作为一种有效治疗而出现了溶栓。但是，出现了新的治疗靶标。在中风的环境中，钙失调长期与脑损伤有关。我们先前在这笔赠款方面的工作以及其他工作的工作表明，即使在缺血后表达，热休克蛋白70 kDa（HSP70）家族也可以保护大脑。 BCL2蛋白质家族对凋亡的调节是缺血结果的另一个重要决定因素。这些途径融合以控制细胞钙稳态以及凋亡和坏死细胞死亡。内质网（ER）和线粒体在称为线粒体相关的ER膜（MAM）的特定部位相互作用，以调节细胞钙稳态和细胞死亡。 MAM是应力/伴侣蛋白和BCL2家族相互作用的关键部位，并且是确定脑缺血结果的核心。我们最近发现，ER伴侣和HSP70家族成员过度表达GRP78可保留线粒体功能，减少线粒体Ca2+过载，并改善压力后的脑细胞存活。我们还发现，在星形胶质细胞中应激后，GRP78易位到线粒体内膜，CNS神经胶质细胞已知与神经元存活不可或缺。在该提案的目标1中，我们将通过比较野生型和线粒体靶向的GRP78来研究易位的GRP78在线粒体功能中的作用。 miRNA的转录后基因沉默发现导致人类疾病的新假设爆炸。脑缺血中的miRNA研究是最近的，大多数都集中在miRNA中的分析变化上。我们最近报告说，富含脑部富含脑部的miRNA的miR-181在最初的伤害后时期可保护大脑免受中风的影响。 AIM 2是一个翻译目标，不跟进这些研究，以确定改变miR-181对中风，测试后测试后的长期行为结果的影响，并确定miR-181是否在雌性动物中也有效。我们最近证明，miR-181可以针对GRP78和抗凋亡BCL2家族成员Bcl2和Mcl1。因此，将研究miR-181在MAM中的ER-线粒体钙转移中的作用。使用计算miRNA靶标预测，我们将miR-200鉴定为潜在的靶向GRP75，线粒体伴侣和BCL2。该提案的目标3将通过降低对ER和线粒体Ca2+以及线粒体功能的详细研究的miR-181水平来介绍保护机制。总的来说，该提案考试是一个新的假设：miRNA充当影响CA2+稳态，线粒体-ER串扰和大脑缺血后结果的伴侣和BCL2家庭成员的主要调节剂。