Cell-Specific Targets and Functions of Caspase-9 in Cerebral Ischemia

描述（由申请人提供）：当大脑的一部分血液供应中断，剥夺脑组织的氧气和葡萄糖，通常导致细胞死亡时，就会发生中风。美国fda批准的唯一治疗缺血性中风（占所有病例的87%）的药物是组织型纤溶酶原激活剂（tPA），它可以溶解凝块，允许缺血组织再灌注。然而，再灌注会加剧对血脑屏障的损害，并促使脑内异常积聚液体，称为水肿。脑水肿是由小血管的血管完整性丧失引起的，是中风后三天内死亡的主要原因。更好地了解缺血性水肿发展的分子机制是优化治疗的必要条件。特洛伊实验室已经证明，活性caspase-9在脑水肿和神经元损伤的形成中起着关键作用。用一种新的、细胞渗透的caspase-9抑制剂可逆抑制caspase-9，可提供长达三周的神经保护，并消除小鼠水肿。这项工作提出了缺血性水肿发展的新机制，并将利用体外和体内方法确定caspase-9在水肿形成中的作用。目的1旨在阐明caspase-9的水肿相关底物，以确定这一具有医学意义的机制的机制细节。Aim 2旨在通过小鼠caspase-9的细胞特异性缺失，解剖内皮细胞和神经元在中风期间caspase-9激活的细胞特异性贡献，以确定该机制的位置和中风发病机制的进展顺序。这种水肿特异性机制可能广泛适用于其他中枢神经系统疾病的水肿，如外伤性脑损伤和黄斑水肿，以及中枢神经系统外的肺水肿和血管性水肿。这种caspase-9抑制剂的鼻内疗效为开发这种治疗方法干预人类中风提供了潜力。哥伦比亚大学为开展这项研究提供了一个特殊的科学环境，拥有高素质的教师、同事和资源。该培训项目将提供研讨会、助学金课程、指导机会，并与哥伦比亚大学和其他大学的多个研究小组进行互动。

DESCRIPTION (provided by applicant): A stroke occurs when the blood supply to a portion of the brain is disrupted, depriving brain tissue of oxygen and glucose, and commonly causing cell death. The sole US FDA-approved treatment for ischemic stroke (87 % of all cases), tissue-type plasminogen activator (tPA), dissolves the clot, allowing for reperfusion of the ischemic tissue. However, reperfusion can exacerbate damage to the blood-brain barrier and prompt an abnormal accumulation of fluid in the brain, called edema. Cerebral edema is caused by a loss of vascular integrity of small blood vessels, and is the primary cause of mortality within the firs three days following a stroke. A better understanding of the molecular mechanisms underlying the development of ischemic-induced edema is required for optimal therapeutic treatment. The Troy laboratory has shown that active caspase-9 plays a critical role in the formation of cerebral edema and in neuronal injury. Reversibly inhibiting caspase-9 with a novel, cell-permeant caspase-9 inhibitor provides neuroprotection out to three weeks and abolishes edema in mice. This work proposes a novel mechanism for the development of ischemic induced edema and will utilize in vitro and in vivo approaches to determine caspase-9's role in edema formation. Aim 1 aspires to elucidate the edema-related substrates of caspase-9 to determine the mechanistic details of this medically significant mechanism. Aim 2 seeks to dissect the cell-specific contributions of caspase-9 activation during stroke in endothelial cells and neurons using cell-specific deletion of caspase-9 in mice to identify the location of this mechanism and the order of progression of stroke pathogenesis. This edema-specific mechanism may be broadly applicable to edema in other central nervous system disorders, such as traumatic brain injury and macular edema, and outside the central nervous system in pulmonary edema and angioedema. The intranasal efficacy of this caspase-9 inhibitor affords the potential for developing this therapy a an intervention in human stroke. Columbia University provides an exceptional scientific environment to carry out this research, with high caliber faculty, colleagues, and resources. The training program will provide exposure to seminars, classes in grantsmanship, mentoring opportunities, and interactions with multiple research groups at Columbia and at other universities.