TRP channels as fundamental sensors of the cerebral microcirculation

项目概要 大脑内血液的最佳流动是通过两个过程来确保的：（1）自动调节，内在的集合 不断调节微循环以维持面部血液恒定流动的机制 灌注压的变化，以及（2）神经血管耦合，脑血管系统的整体 使局部血流与身体代谢活跃区域的需求紧密匹配的生理过程 大脑。这些独特的反应对于大脑健康和功能是必要的，但仍然不完全 明白了。此外，微血管控制的丧失与常见的与年龄相关的脑血管疾病有关。 病理学，包括中风、脑小血管疾病 (cSVD) 和血管性认知障碍 痴呆症（VCID）。该提案的总体目标是通过提供 更好地了解大脑不断变化的物理、环境、内分泌、旁分泌环境， 脑微血管在细胞水平上感知代谢和神经化学刺激，以及如何感知 这些信号经过处理以确保体内平衡和适应性。我们的主要机械焦点 研究的是瞬时受体电位（TRP）家族的离子通道——多种类型的多模态传感器 所有细胞中都存在物理和化学刺激。在过去的10年里，我们的研究团队发现， 脑血管平滑肌细胞中的TRPM4（TRP melastatin 4）和TRPML1（TRP mucolipin 1）通道 对于肌原性张力（一种基本的自动调节机制）的发展很重要，并且具有 证明 TRPA1（TRP 锚蛋白 1）和 TRPV3（TRP 香草酸 3）通道在 脑动脉和小动脉的内皮。继续这个主题并使用先进的生物医学 成像方法和下一代遗传小鼠模型，我们将把中心概念编织在一起 由我们的独立项目建立，旨在全面概述 TRP 通道作为蜂窝 大脑微血管中的传感器。拟议研究的例子包括将定义 使用超分辨率研究健康和疾病中 TRP 通道信号网络的纳米级结构 显微镜，阐明 TRPML1 通道如何在平滑肌细胞中进行内源性调节，以防止 肌源性血管收缩期间的血管过度收缩，并检验 TRPA1 通道的假设 脑毛细血管内皮细胞充当活性氧的探测器，促进神经血管耦合。 我们将进行基础科学研究，旨在阐明基本的监管机制 研究旨在了解 TRP 通道控制的过程如何出错并有助于 衰老过程中大脑中健康的小血管转变为疾病状态。为了进一步实现这一目标，我们 与以下机构合作开发和表征与年龄相关的 CSVD 和 VCID 的新遗传模型 加州大学旧金山分校的研究人员，并提议利用这一独特的资源来探索包括参与在内的主题 TRPM4、TRPML1 和 TRPA1 通道在年龄相关 cSVD 和 VCID 期间脑血管功能障碍中的作用。

PROJECT SUMMARY Optimal flow of blood within the brain is ensured by two processes: (1) autoregulation, a collection of intrinsic mechanisms that continuously adjust the microcirculation to maintain a constant flow of blood in the face of changes in perfusion pressure, and (2) neurovascular coupling, an ensemble of cerebral vasculature physiological processes that tightly match local blood flow to the needs of metabolically active regions of the brain. These distinctive responses are necessary for brain health and function but remain incompletely understood. Further, loss of microvascular control is associated with common age-related cerebrovascular pathologies, including stroke, cerebral small vessel diseases (cSVDs), and vascular cognitive impairment and dementia (VCID). The overarching goal of this proposal is to address this critical knowledge gap by providing a better understand of how the brain’s ever-changing milieu of physical, environmental, endocrine, paracrine, metabolic, and neurochemical stimuli are sensed by the cerebral microvasculature at the cellular level, and how these signals are processed to ensure homeostasis and adaptability. The primary mechanistic focus of our research is ion channels of the transient receptor potential (TRP) family—polymodal sensors of many types of physical and chemical stimuli present in all cells. Over the past 10 years, our research team has discovered that TRPM4 (TRP melastatin 4) and TRPML1 (TRP mucolipin 1) channels in cerebral vascular smooth muscle cells are important for the development of myogenic tone, a fundamental autoregulatory mechanism, and has demonstrated critical sensory roles for TRPA1 (TRP ankyrin 1) and TRPV3 (TRP vanilloid 3) channels on the endothelium of cerebral arteries and arterioles. Continuing with this theme and using advanced biomedical imaging approaches and next-generation genetic mouse models, we will weave together the central concepts established by our independent projects to develop a comprehensive overview of TRP channels as cellular sensors in the cerebral microvasculature. Examples of proposed studies include investigations that will define the nanoscale architecture of TRP channel signaling networks in health and disease using superresolution microscopy, elucidate how TRPML1 channels are endogenously regulated in smooth muscle cells to prevent vascular hypercontractility during myogenic vasoconstriction, and test the hypothesis that TRPA1 channels on brain capillary endothelial cells act as detectors of reactive oxygen species to promote neurovascular coupling. We will layer basic science investigations intended to elucidate fundamental regulatory mechanisms with research designed to understand how processes controlled by TRP channels go wrong and contribute to the transformation of healthy small vessels in the brain to a disease state during aging. To further this goal, we are developing and characterizing new genetic models of age-related cSVDs and VCID in collaboration with investigators at UCSF, and propose to use this unique resource to explore themes that include the involvement of TRPM4, TRPML1, and TRPA1 channels in cerebral vascular dysfunction during age-related cSVDs and VCID.