Anesthetics and Stress Proteins in Brain Cell Injury

描述(由申请人提供)： 中风是这个国家的第三大死因。此外，围手术期神经功能障碍是心脏和神经外科最可怕的并发症之一。这项工作的目标是开发新的治疗方法，以降低中风的发病率和死亡率。大量文献表明，过表达保护性蛋白热休克蛋白70(Hsp70)可减少缺血性脑损伤。已知HSP70具有许多不同的功能，但其中有多少对神经保护有贡献尚不清楚。这一建议试图更好地确定Hsp70在1)阻断蛋白质聚集，2)改善线粒体功能，以及3)调节伴随缺血性脑损伤的星形胶质细胞激活中的作用机制。蛋白质聚集可能会导致中风损伤，就像许多慢性神经退行性疾病一样。已知HSP70可抑制蛋白质聚集。AIM 1将使用分子建模来预测Hsp70中防止聚集的最小亚域。该亚结构域的表达将被用来检验它将在体外减少星形胶质细胞的缺血性损伤和在体内减少中风损伤的预测。目的2将测试热休克蛋白70在应激状态下保护星形胶质细胞线粒体功能的能力。线粒体为细胞提供能量，产生自由基，是细胞死亡的中心调节器。将评估线粒体膜电位、自由基生成和呼吸作用。在AIM 3中，将在体外和体内研究星形胶质细胞的激活。星形胶质细胞对于正常的大脑功能是必不可少的。它们维持严格控制的细胞外环境，提供抗氧化剂和营养支持，并参与缺血引起的炎症反应。Hsp70抑制星形胶质细胞炎症激活的能力将被确定。将研究核因子kB激活的调节和随后的炎症级联反应，包括细胞因子的释放。这些研究将确定新的治疗策略，并为开发用于神经保护的Hsp70模拟物奠定基础。

DESCRIPTION (provided by applicant): Stroke is the third leading cause of death in this country. Furthermore, perioperative neurologic dysfunction is one of the most feared complications of cardiac and neurosurgery. The goal of this work is to develop novel therapies to reduce the morbidity and mortality of stroke. A large body of literature demonstrates that overexpression of the protective protein heat shock protein 70 (Hsp70) reduces ischemic brain injury. Hsp70 is known to have many distinct functions, how many contribute to neuroprotection is unknown. This proposal seeks to better define the mechanisms of action of Hsp70 in 1) blocking protein aggregation, 2) improving mitochondrial function, and 3) modulating the astrocyte activation that accompanies ischemic brain injury. Protein aggregation likely contributes to stroke injury as it does to many chronic neurological degenerative diseases. Hsp70 is known to inhibit protein aggregation. Aim 1 will use molecular modeling to predict the minimum subdomain within Hsp70 that prevents aggregation. Expression of this subdomain will be used to test the prediction that it will reduce ischemia-like injury of astrocytes in vitro and reduce stroke damage in vivo. Aim 2 will test the ability of Hsp70 to preserve mitochondrial function in stressed astrocytes. Mitochondria provide energy for the cell, produce free radicals, and are central regulators of cell death. Mitochondrial membrane potential, free radical generation, and respiration will be assessed. In aim 3 astrocyte activation will be studied in vitro and in vivo. Astrocytes are essential for normal brain function. They maintain a tightly controlled extracellular environment, provide antioxidant and trophic support, and participate in the inflammatory response provoked by ischemia. The ability of Hsp70 to inhibit astrocyte inflammatory activation will be determined. Modulation of nuclear factor kB activation and the ensuing inflammatory cascade including cytokine release will be studied. These studies will identify new therapeutic strategies and lay the foundation for the development of Hsp70 mimetics for neuroprotection.