Aging and neurovascular regulation of endothelial cell calcium signals, in vivo

体内内皮细胞钙信号的衰老和神经血管调节

• 批准号: 8521849
• 负责人: Erika Mary Boerman
• 金额: $ 5.22万
• 依托单位: UNIVERSITY OF MISSOURI-COLUMBIA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-12-01 至 2015-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8521849
• 关键词: Address; Affect; Aging; Agonist; Arteries; Attenuated; Blood; Blood Vessels; Blood flow; Calcitonin Gene-Related Peptide; Calcium Signaling; Caliber; Capsaicin; Cardiac Output; Cardiovascular Diseases; Cell Communication; Cells; Chemicals; Communication; Complement; Confocal Microscopy; Coupling; Data; Dyes; Elderly; Endothelial Cells; Endothelium; Event; Exercise; Foundations; Frequencies; Functional disorder; Goals; Guanethidine; Housing; Image; In Vitro; Intervention; Lead; Light; Link; Masks; Mediating; Mesenteric Arteries; Metabolic; Modeling; Morphologic artifacts; Mus; Muscle Contraction; Nature; Nerve; Neuroeffector Junction; Phenylephrine; Physiological; Play; Population; Preparation; Proteins; Quality of life; Regulation; Reporting; Research; Research Project Grants; Resistance; Rest; Role; Sensory; Signal Transduction; Site; Smooth Muscle Myocytes; Solid; Speed; Splanchnic Circulation; Structure; Techniques; Testing; Time; Tissues; Training; Transgenic Mice; Transgenic Organisms; Vasomotor; Work; afferent nerve; age related; animal breeding; arteriole; base; career; constriction; density; desensitization; experience; feeding; improved; in vivo; inhibitor/antagonist; insight; intercellular communication; juvenile animal; neurotransmission; neurotransmitter release; novel; novel therapeutics; public health relevance; research study; response; sex; vasoconstriction

DESCRIPTION (provided by applicant): Intercellular communication between sympathetic and sensory perivascular nerves (PVNs), smooth muscle cells (SMCs) and endothelial cells (ECs) is essential to the regulation of vasomotor tone and the ability to mobilize blood to body tissues in accord with metabolic demand. Critical to this regulation are myoendothelial junctions (MEJs), which exist at holes (fenestrae) in the internal elastic lamina (IEL) and allow communication of electrical and chemical signals between ECs and SMCs. By releasing neurotransmitters that activate SMCs, PVNs play an important role in the initiating cell-cell communication through MEJs. Advancing age is linked to endothelial dysfunction and impaired exercise capacity, but the underlying changes in signaling mechanisms are still unclear. The majority of studies on intercellular communication do not incorporate the role of PVN, instead focusing on EC-to-SMC communication (e.g., endothelium-dependent hyperpolarization) and how signals originating in ECs affect SMC Ca2+. Therefore, the purpose of this proposal is to characterize EC Ca2+ signals arising from PVN activation of SMCs. In Young (3-4 month) and Old (24-26 month) mice, this project is focused on how stimulation of sympathetic and sensory nerves affects local EC Ca2+ signaling via MEJs. My preliminary studies show aging to be associated with a decrease in the ability of sensory nerves to inhibit sympathetic vasoconstriction along with desensitization of ¿1-adrenoreceptors. In light of reports linking adrenoreceptor activation to global EC Ca2+ signaling, my data led to the overall hypothesis that local EC Ca2+ signals arising from PVN activation of SMC are altered with aging. To investigate these functional relationships in vivo, I have developed a novel intravital preparation to study mesenteric arteries (MA) in anesthetized transgenic GCaMP2. These animals are bred in house and express an EC-specific Ca2+ indicator (GCaMP2), enabling high speed confocal imaging of local EC Ca2+ in vivo without the need for external dyes or concern for their potential artifacts. Using this model to stimulate PVNs before and during selective inhibition of sensory or sympathetic neurotransmission will address the following Specific Aims: (1) Determine how PVN activation modulates EC Ca2+ signals during blood flow control; and (2) Determine the impact of aging on EC Ca2+ signals and vasomotor function in vivo. Completion of the proposed studies will provide valuable new insight with respect to the role of EC Ca2+ signaling during blood flow control in the young and aging vasculature that may serve as the basis for novel therapeutic strategies for treating age-related endothelial dysfunction.

描述（由申请人提供）：交感和感觉血管周围神经（PVN）、平滑肌细胞（SMC）和内皮细胞（EC）之间的细胞间通讯对于血管紧张素的调节和雅阁代谢需求将血液动员到身体组织的能力至关重要。这种调节的关键是肌内皮连接（MEJ），其存在于内弹性膜（IEL）中的孔（窗孔）处，并允许EC和SMC之间的电信号和化学信号的通信。PVN通过释放激活SMC的神经递质，在通过MEJ启动细胞间通讯中发挥重要作用。年龄增长与内皮功能障碍和运动能力受损有关，但信号机制的潜在变化仍不清楚。大多数关于细胞间通讯的研究都没有纳入PVN的作用，而是集中在EC与SMC的通讯上（例如，内皮依赖性超极化）以及起源于EC的信号如何影响SMC Ca 2+。因此，本提案的目的是表征SMC的PVN激活所产生的EC Ca 2+信号。在年轻（3-4个月）和老年（24-26个月）小鼠中，该项目的重点是交感神经和感觉神经的刺激如何通过MEJ影响局部EC Ca 2+信号传导。我的初步研究表明，衰老与感觉神经抑制交感血管收缩的能力下降以及沿着1-肾上腺素受体脱敏有关。鉴于肾上腺素受体激活全球EC Ca 2+信号的报告，我的数据导致的整体假设，局部EC Ca 2+信号所产生的PVN激活SMC的改变与老化。为了在体内研究这些功能关系，我开发了一种新的活体制备来研究肠系膜动脉 (MA)在麻醉的转基因GCaMP 2中。这些动物在室内饲养并表达EC特异性Ca 2+指示剂（GCaMP 2），从而能够在体内对局部EC Ca 2+进行高速共聚焦成像，而无需外部染料或担心其潜在伪影。使用该模型在选择性抑制感觉或交感神经传递之前和期间刺激PVN将解决以下特定目的：（1）确定PVN激活如何在血流控制期间调节EC Ca 2+信号;和（2）确定衰老对EC Ca 2+信号和体内血管功能的影响。完成拟议的研究将提供有价值的新见解EC Ca 2+信号传导的作用，在年轻和老龄化血管系统的血流控制，可作为治疗年龄相关的内皮功能障碍的新的治疗策略的基础。