Supplemental Proposal for HL142888: Role of vascular and non-vascular TRPV1 channels in AD/ARD

家长奖摘要：家长奖中概述的研究重点是 研究 TRPV1 离子通道激活增加脑血流量 (CBF) 的机制 并在促进脑灌注不足的情况下维持大脑健康。我们的工作表明这 CBF 调节的新途径在血压急剧下降期间可能至关重要，例如， 失血性休克期间。重要的是，通过与该项目的合作者 David Julius 教授合作，我们 已成功产生 floxed-TRPV1 小鼠品系。这一突破使我们能够生产 条件性平滑肌特异性 TRPV1 敲除 (SM-TRPV1-KO) 小鼠以及感觉神经元特异性 TRPV1 缺陷动物。这些新型小鼠品系正在体内和离体组合使用 CBF 和神经血管耦合的测量、大脑健康的免疫组织化学评估和 认知功能的行为测试。 补充文件与 AD/ADRD 的相关性：本补充文件 (NOT-AG-20-034) 的目的是 扩展这些研究并确定 TRPV1 通道是否能提供针对缺陷的保护性益处 CBF 和神经血管耦合发生在与 AD/ADRD 相关的认知衰退和痴呆之前。 具体目标 1：阐明 TRPV1 通道对导致 CBF 缺乏的影响 血管性认知障碍伴痴呆（VCID）和阿尔茨海默病（AD）。目标是 该目的是剖析血管和非血管 TRPV1 通道对因素的有益影响 导致 CBF 减少，而 CBF 减少先于与 VCID 相关的认知能力下降。使用我们新开发的 组织特异性 TRPV1 缺陷小鼠喂食 VCID 诱导的高胆固醇饮食和转基因 (5XFAD) AD 模型小鼠，我们将对导致局部和小鼠缺陷的机制进行多层次的检查 全球 CBF 监管。具体来说，我们将测试以下假设： 平滑肌 TRPV1 的激活 全身脉管系统中的通道可防止 CBF 整体下降。具体目标 2：阐明 TRPV1 通道对改善行为缺陷和结构性脑损伤的影响 VCID和AD模型小鼠。在这里，我们将使用一系列行为测试来阐明 TRPV1 的好处 维持 VCID 和 AD 模型小鼠认知功能的通道活性。行为测试将是 随后对大脑白质和灰质进行全面检查，并检查 脉管系统的结构完整性。该提案将为 TRPV1 通道提供前所未有的分辨率 对 CBF 调节和大脑健康的影响。确定 ASM TRPV1 在促进 CBF 过程中的关键作用 有潜力提供大量新信息，对 AD/ADRD 患者个人和我们的患者大有裨益 整个社会。

SUMMARY OF THE PARENT AWARD: The studies outlined in the parent award are focused on investigating the mechanisms by which the activation of TRPV1 ion channels increase cerebral blood flow (CBF) and maintain brain health during conditions promoting cerebral hypoperfusion. Our work indicates that this novel pathway of CBF regulation may be critical during acute drops in blood pressure that occur, for example, during hemorrhagic shock. Importantly, working with our collaborator on this project, Prof. David Julius, we have succeeded in the generation of a floxed-TRPV1 mouse strain. This breakthrough has enabled us to produce conditional smooth muscle-specific TRPV1-knockout (SM-TRPV1-KO) mice, as well as sensory neuron-specific TRPV1-deficient animals. These novel mouse strains are being used in combination with in vivo and ex vivo measurements of CBF and neurovascular coupling, immunohistochemical assessment of brain health and behavioral tests of cognitive function. RELEVANCE OF SUPPLEMENT TO AD/ADRD: The purpose of this Supplement (NOT-AG-20-034) is to extend these studies and determine whether TRPV1 channels provide a protective benefit against deficits in CBF and neurovascular coupling that precede cognitive decline and dementia associated with AD/ADRD. Specific Aim 1: To elucidate the impact of TRPV1 channels on CBF deficits contributing to vascular cognitive impairment with dementia (VCID) and Alzheimer's Disease (AD). The goal of this aim is to dissect the beneficial effects of vascular and non-vascular TRPV1 channels against factors contributing to decreases in CBF, which precede cognitive decline associated VCID. Using our newly developed tissue-specific TRPV1 deficient mice fed a VCID-inducing high cholesterol diet and transgenic (5XFAD) AD model mice, we will undertake a multi-level examination of mechanisms contributing to deficits in local and global CBF regulation. Specifically, we will test the following hypothesis: Activation of smooth muscle TRPV1 channels in the systemic vasculature protect against global declines in CBF. Specific Aim 2: To elucidate the impact of TRPV1 channels to ameliorate behavioral deficits and structural brain damage in VCID and AD model mice. Here, using a battery of behavioral tests we will elucidate the benefit of TRPV1 channel activity in preserving cognitive function in VCID and AD model mice. The behavioral tests will be followed by a comprehensive examination of brain white matter and grey matter, as well an examination of the structural integrity of the vasculature. This proposal will provide unprecedented resolution of TRPV1 channel impact on CBF regulation and brain health. Identifying a key role for ASM TRPV1 in promoting CBF during has the potential to provide a wealth of new information of great benefit to individual AD/ADRD patients and our society at large.