Cerebroprotection via viral-mediated gene delivery of angiotensin AT2 receptors

描述(由申请人提供)： 中风是美国第三大致死原因，也是导致长期严重残疾的主要原因。了解卒中的机制和开发新的治疗策略是至关重要的，也是这项研究的长期目标。许多实验证据表明，血管紧张素II 2型受体(AT2R)在中风中的有益作用在血管紧张素II 1型受体(AT1R)阻滞剂(ARB)的存在下得到增强，ARB是有效的抗中风药物。因此，我们提出了一个普遍的假设，即在大脑皮层和纹状体区域的神经元过度表达AT2R将在缺血性卒中中提供保护。此外，我们假设AT2R过度表达和ARB给药相结合将提供比单独使用更多的脑保护。具体地说，我们假设病毒介导的AT2R基因的传递以及随之而来的AT2R在皮质和纹状体区域的神经元过度表达将减少由实验诱导的中风引起的梗塞面积和神经功能缺陷。我们进一步假设，病毒介导的AT2R shRNA的传递以及随之而来的AT2R表达的减少将加剧神经功能障碍并增加梗塞面积。这项提议的目标是通过基因转移、分子、细胞和体内实验相结合的方法来检验这些假设。这项研究的数据不仅有助于巩固AT2R在卒中中的脑保护作用，而且有助于确定AT2R在CMS中的过度表达是否可以产生有益的作用。其具体目的是：(1)研究病毒介导的AT2R在大鼠大脑皮层和纹状体的过度表达和下调。(2)确定病毒介导的AT2R神经元过度表达是否具有脑保护作用，并改善ARB的脑保护作用。(3)确定病毒介导的神经元AT2R减少是否加重了缺血性卒中所致的神经损伤，并降低了ARB的脑保护作用。综上所述，这里提出的实验不仅将使我们能够巩固AT2R在中风中的脑保护作用，而且还将使我们能够确定AT2R在中枢神经系统中的过度表达是否可以单独或与ARB一起提供有益的作用。 公共卫生相关性：这些研究与公共健康相关，因为它们将有助于了解中风发生后大脑中发生的事情，并可能确定有助于减少中风症状的新的治疗靶点。这显然与美国国立神经疾病和中风研究所的使命有关。

DESCRIPTION (provided by applicant): Stroke is the third leading cause of death in the United States and a major cause of serious, long-term disability. Understanding the mechanisms that underlie stroke and the development of new therapeutic strategies is of key importance and is the long-term objective of this study. Much experimental evidence points to a beneficial action of angiotensin II type 2 receptors (AT2R) in stroke that is enhanced in the presence of Ang II type 1 receptor (AT1R) blockers (ARBs), drugs that are effective anti-stroke agents. Thus, we have developed the general hypothesis that neuronal over expression of AT2R in the cerebral cortical and striatal regions will provide protection during ischemic stroke. In addition, we hypothesize that the combination of AT2R over expression and ARB administration will provide additional cerebroprotection than either alone. Specifically, we hypothesize that viral-mediated delivery of the AT2R gene and consequent neuronal over expression of AT2R within the cortical and striatal regions will reduce the infarct size and neurological deficits resulting from experimentally induced stroke. We further hypothesize that viral mediated delivery of an AT2R shRNA and consequent reduction in AT2R expression will exacerbate the neurological deficits and increase infarct size. The goal of this proposal is to test these hypotheses, using a combination of gene transfer, molecular, cellular and in vivo experimental approaches. The data from this study will not only help to solidify a cerebroprotective role of AT2R in stroke, but will help to determine whether the over expression of AT2R in the CMS can elicit a beneficial action. The specific aims are: (1) Characterize viral-mediated over expression and reduction of AT2R in rat cerebral cortical and striatal regions. (2)Determine whether viral-mediated neuronal over expression of AT2R elicits cerebroprotection during ischemic stroke and improves the cerebroprotective action of ARBs. (3)Determine whether viralmediated reduction of neuronal AT2R potentiates the neural damage elicited by ischemic stroke and reduces the cerebroprotective action of ARBs. In summary, the experiments proposed here will not only allow us to solidify a cerebroprotective role of AT2R in stroke, but will also allow us to determine whether over expression of AT2R in the CNS can provide a beneficial action alone or in in combination with ARBs. PUBLIC HEALTH RELEVANCE: These studies are relevant to public health as they will help to understand what happens in the brain after a stroke occurs, and may identify a new therapeutic target that would be helpful in reducing stroke symptoms. This is clearly relevant to the mission of the National Institutes of Neurological Disorders and Stroke.