Neurohumoral regulation of PVAT

项目概要-项目II 心血管疾病是全球死亡的主要原因，包括多种疾病， 动脉粥样硬化、高血压、中风和心力衰竭。血与人之间有直接的正相关关系 血压和心血管疾病的风险，但导致血压异常的因素 对疾病的调控还不完全了解。血管周围脂肪组织（PVAT）最近出现 作为血管张力和血压的关键调节器。PVAT包围大部分血管， 释放抗收缩因子抗收缩介质的产生是由交感神经系统驱动的。 神经递质去甲肾上腺素（NE），但驱动这种作用的NE的来源仍然未知。的 本提案的总体目标是了解PVAT中介导神经传递的机制， 健康和疾病。驱动脂肪细胞活性的潜在机制包括局部产生介质， 非神经元细胞、神经支配或循环神经递质。这项提案考验了中央 假设由脂肪细胞摄取和释放NE介导的自分泌信号是主要的 PVAT脂肪细胞活性的调节因子，而神经支配和循环因子起次要作用。此外，本发明还 我们认为PVAT脂肪细胞的突触前功能在产生血管紧张素Ⅱ的条件下发生改变， 疾病将在研究男性肠系膜和主动脉PVAT的两个特定目的中检验这一假设 和雌性动物在健康和疾病期间。实验将利用有针对性的遗传追踪和组织 清除以确定神经和脂肪细胞之间的物理相互作用，遗传编码的钙 研究脂肪细胞活化的指标，测试脂肪细胞活化的功能相关性的化学遗传学， 荧光假神经递质，以研究脂肪细胞中NE摄取和释放的动力学，以及RNA 测序以了解疾病期间特定机制和途径是如何调节的。具体目标 1将检验NE对PVAT脂肪细胞的刺激涉及自分泌信号介导 而不是直接的神经支配或循环神经递质。这方面的实验包括 遗传报告细胞系的解剖学研究，用遗传编码指示剂的钙成像， 血管张力功能测定中的化学遗传学和荧光假神经递质的测量 摄取和释放。具体目标2将检验PVAT脂肪细胞的突触前功能是 在产生血管疾病的条件下受损。本研究将采用高脂饮食模型， 功能障碍，并将研究候选机制与RNA测序。对脂肪细胞神经递质的影响 摄取，释放和反应将使用荧光假神经递质和遗传学研究。 编码的钙指标。这项研究的结果将确定新的机制，调节功能 的PVAT。对驱动抗收缩因子释放的机制的新见解将促进 开发用于常见疾病如高血压中的血管功能障碍的疗法。

Project Summary – Project II Cardiovascular disease is the leading cause of death worldwide and encompasses multiple disorders including atherosclerosis, hypertension, stroke, and heart failure. There is a direct positive relationship between blood pressure and cardiovascular disease risk in humans, but the factors that contribute to abnormal blood pressure regulation in disease are incompletely understood. Perivascular adipose tissue (PVAT) has recently emerged as a key regulator of vascular tone and blood pressure. PVAT surrounds the majority of blood vessels and releases anticontractile factors. The production of anticontractile mediators is driven by the sympathetic neurotransmitter norepinephrine (NE), but the source of NE that drives this effect remains unknown. The overall goal of this proposal is to understand the mechanisms that mediate neurotransmission in PVAT in health and disease. Potential mechanisms that drive adipocyte activity include local production of mediators by non-neuronal cells, neural innervation, or circulating neurotransmitters. This proposal tests the central hypothesis that autocrine signaling mediated by the uptake and release of NE by adipocytes is the primary regulator of PVAT adipocyte activity, while neural innervation and circulating factors play minor roles. Further, we propose that the presynaptic functions of PVAT adipocytes are altered in conditions that produce vascular disease. This hypothesis will be tested in two specific aims that will study mesenteric and aortic PVAT in male and female animals during health and disease. Experiments will utilize targeted genetic tracing and tissue clearing to identify physical interactions between nerves and adipocytes, genetically encoded calcium indicators to study adipocyte activation, chemogenetics to test the functional relevance of adipocyte activation, fluorescent false neurotransmitters to study the dynamics of NE uptake and release in adipocytes, and RNA sequencing to understand how specific mechanisms and pathways are regulated during disease. Specific Aim 1 will test the hypothesis that the stimulation of PVAT adipocytes by NE involves autocrine signaling mediated by adipocytes rather direct neural innervation or circulating neurotransmitters. Experiments in this aim include anatomical studies in genetic reporter lines, calcium imaging with genetically encoded indicators, chemogenetics in functional assays of vascular tone, and measures of fluorescent false neurotransmitter uptake and release. Specific Aim 2 will test the hypothesis that presynaptic functions of PVAT adipocytes are impaired in conditions that produce vascular disease. This aim will use the high fat diet model of vascular dysfunction and will study candidate mechanisms with RNA sequencing. Effects on adipocyte neurotransmitter uptake, release, and responsiveness will be studied using fluorescent false neurotransmitters and genetically encoded calcium indicators. The results of this study will identify novel mechanisms that regulate the functions of PVAT. New insight into mechanisms that drive the release of anticontractile factors will facilitate the development of therapies for vascular dysfunction in common disorders, such as hypertension.