Functional deficits in neurovascular coupling in Alzheimer's disease

项目总结 阿尔茨海默病(AD)是美国主要的公共卫生负担，死亡人数继续增加。 急剧增加。在AD患者脑血流量(CBF)显著减少的同时，血管病理生理学 还没有完全被描述出来。我们已经确定了两种神经血管偶联(NVC)机制，它们在 CBF的调节：电信号(由K+介导)，快速(毫秒时间尺度)并作用于 长距离和钙信号(由GqPCR激动剂介导)，这是缓慢的(秒)，并在局部作用。还没有 这些NVC机制在AD中是如何改变的还不完全清楚。因此，长期目标是 这项建议的目的是使用家族性AD小鼠模型(5xFAD)来确定NVC的功能缺陷 阿尔茨海默病的机制，并设计治疗策略，以恢复这些损害。初步数据显示， 5xFAD小鼠由于Kir2.1通道功能受损而导致电信号减少，并通过 补充膜磷脂；PIP2-Kir2.1通道功能的基本成分。因此， 我有一个新的假设，阿尔茨海默病患者功能性充血缺陷是血管PIP2耗竭的结果， 它削弱了血液流动的电和钙信号控制。因此，我将确定分子 PIP2丢失扰乱这些过程的机制，并评估PIP2补充 恢复脑血流量控制，进而改善5xFAD小鼠的认知功能。我将通过执行以下命令来验证这一假设 具体目的如下：1)阐明阿尔茨海默病电信号缺陷的相关机制，2) 评估AD病理对脑内皮细胞钙活性的影响，以及3)确定PIP2的作用 AD时NVC的恢复。为了实现这些具体目标，我将结合体内和体外的尖端技术 行为测试的实验方法。总的来说，这项提案将确定血管功能 以AD和PIP2为基础的治疗干预对脑血流量的恢复以及认知功能的缺陷 广告。这项建议与美国国立卫生研究院预防和有效治疗阿尔茨海默氏症的使命声明之一一致 到2025年将会出现疾病。 目前的这项提议将有助于Amreen Mughal博士从 博士后研究员转为独立研究员。除了她在血管生物学方面的强大背景外，Amreen 将在最先进的图像分析和行为测试方面开发新技能。马克·T·纳尔逊博士，专家 在离子通道、钙信号和血管生物学方面，将指导Amreen的科学发展和转变 在颁奖期间走向独立。为了加强候选人的培训，该计划还招募了一名 职业顾问团队，包括Anne Joutel博士、Sayamwong Hammack博士和Severin Schnebeli博士。这个 在NIH独立之路奖(K99/R00)的支持下，富有成效的研究环境将 允许候选人开发自己的研究利基市场，并成功过渡为独立研究 调查员。

PROJECT SUMMARY Alzheimer’s disease (AD) is a major public health burden in the United states with a death toll that continues to increase steeply. While cerebral blood flow (CBF) is substantially reduced in AD, the vascular pathophysiology is not yet entirely characterized. We have identified two neurovascular coupling (NVC) mechanisms essential in regulation of CBF: electrical signaling (mediated by K+), which is rapid (millisecond time scale) and acts over long distances, and Ca2+ signaling (mediated by GqPCR agonists), which is slow (seconds) and acts locally. Yet how- these NVC mechanisms are altered in AD is incompletely understood. Therefore, the long-term objective of this proposal is to use a familial mouse model of AD (5xFAD) to determine functional deficit in NVC mechanisms in AD and design therapeutic strategies to restore these impairments. Preliminary data show that electrical signaling is reduced in 5xFAD mice due to impaired Kir2.1 channel function and restored by supplementation of membrane phospholipid; PIP2—an essential component for Kir2.1 channel function. Hence, I have a novel hypothesis that deficit in functional hyperemia in AD is the result of vascular PIP2 depletion, which cripples electrical and Ca2+ signaling control of blood flow. Accordingly, I will determine the molecular mechanisms through which loss of PIP2 disrupts these processes and evaluate whether PIP2 supplementation restores CBF control and in turn, improve cognitive function in 5xFAD mice. I will test this hypothesis by executing the following specific aims: 1) Elucidate mechanisms associated with defective electrical signaling in AD, 2) Evaluate the impact of AD pathology on brain endothelial Ca2+ activity, and 3) Determine the effect of PIP2 restoration on NVC in AD. To execute these specific aims, I will combine of cutting edge in vivo and ex vivo experimental approaches with behavioral testing. Collectively, this proposal will identify vascular functional deficits in AD and PIP2 based therapeutic intervention for restoration of CBF and in turn, cognitive function in AD. This proposal aligns with one of the NIH mission statements to prevent and effectively treat Alzheimer's disease by 2025. This current proposal will contribute Dr. Amreen Mughal’s career development as she transitions from a postdoctoral fellow to an independent researcher. Adding to her strong background in vascular biology, Amreen will develop new skills in the state-of-the-art image analysis and behavioral testing. Dr. Mark T. Nelson, an expert in ion channels, Ca2+ signaling, and vascular biology, will mentor Amreen’s scientific development and transition to independence during this award. To enhance the Candidate’s training, the program additionally enlists a career advisory team, including Drs. Anne Joutel, Sayamwong Hammack, and Severin Schneebeli. The productive research environment with the backing of the NIH Pathway to Independence Award (K99/R00) will allow the Candidate to develop her own research niche and successfully transition as an independent research investigator.