Calcium wave propagation along microvascular endothelial tubes

钙波沿微血管内皮管传播

• 批准号: 8510936
• 负责人: Matthew John Socha
• 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: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2013-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8510936
• 关键词: ATP phosphohydrolase; Abbreviations; Abdominal Muscles; Acetylcholine; Address; Affect; Agonist; Arteries; Atherosclerosis; Behavior; Blood Vessels; Blood flow; Calcium Oscillations; Caliber; Cell membrane; Cells; Characteristics; Coupled; Development; Diabetes Mellitus; Digestion; Disease; Dyes; Endoplasmic Reticulum; Endothelial Cells; Endothelium; Endothelium-Dependent Relaxing Factors; Event; Exercise; Fatigue; Gap Junctions; Goals; Gold; Hypertension; Individual; Inositol; Ischemia; Knowledge; Laboratories; Lead; Length; Metabolic; Microcirculation; Microdissection; Modeling; Mus; Nature; Nitric Oxide; Nutrient; Oxygen; Perfusion; Physiological; Preparation; Process; Production; Receptor Activation; Regulation; Relaxation; Reperfusion Therapy; Research; Research Project Grants; Resistance; Role; Signal Pathway; Signal Transduction; Site; Skeletal Muscle; Smooth Muscle Myocytes; Solutions; Source; Stimulus; Testing; Tissues; Travel; Tube; Vascular Diseases; Vascular Endothelial Cell; Vasodilation; Work; arteriole; base; extracellular; feeding; improved; insight; intercellular communication; novel; novel strategies; novel therapeutic intervention; pressure; prevent; receptor; research study; response; tripolyphosphate

DESCRIPTION (provided by applicant): The long-term research goals of our laboratory center on defining signaling events in the microcirculation that underlie the control of oxygen and nutrient delivery to tissue with an emphasis on skeletal muscle during exercise. My working hypothesis is that the local control of blood flow reflects the coordination of activity among endothelial cells (ECs) and smooth muscle cell (SMCs) of arterioles and feed arteries (FA) that comprise microvascular resistance networks. When delivered to a discrete site on an arteriole or FA, acetylcholine (ACh; the "gold standard" endothelium-dependent vasodilator) initiates a Ca+2 wave that travels from EC to EC for hundreds of microns along the intima to promote relaxation of surrounding SMCs by releasing nitric oxide. However little is known of how calcium waves are initiated or propagated in the microcirculation. To directly address this question, I have developed the intact "endothelial tube" preparation from mouse abdominal muscle feed arteries as a unique model to study the nature of Ca+2 waves independent from the influence of blood flow, transmural pressure, or surrounding SMCs and tissue. Intact microvascular endothelial tubes (diameter, 50-80 5m; length, 1-2 mm) are isolated using microdissection of FA followed by partial enzymatic digestion and gentle trituration. Preliminary studies with dye transfer confirm that ECs throughout the tube are well-coupled through gap junctions and generate robust Ca+2 waves in response to ACh that can propagate more than 500 5m along the tube. My research is focused on understanding how these Ca+2 waves are initiated and how they actually propagate from EC to EC. AIM 1 will identify the source(s) of Ca+2 for wave initiation and propagation by preferentially inhibiting internal release of Ca+2 from the endoplasmic reticulum (ER) and/or its influx across the plasma membrane. AIM 2 will investigate how partial depletion or overloading of intracellular Ca+2 stores affects the initiation and propagation of Ca+2 waves. Resolving the role(s) of intra- and extracellular Ca+2 sources in producing waves will provide new insight concerning how these signaling pathways may contribute to the local regulation of blood flow. In turn, this knowledge will lead to a better understanding of how intrinsic Ca+2 signaling pathways may be altered during such conditions as atherosclerosis, diabetes, hypertension, and ischemia. My overall goal is to apply the findings of this research to the development of novel strategies for treating vascular disease in which tissue perfusion is impaired.

描述（由申请人提供）：我们实验室的长期研究目标集中在定义微循环中的信号事件上，微循环是运动期间控制氧气和营养输送到组织的基础，重点是骨骼肌。我的工作假设是，血流的局部控制反映了组成微血管阻力网络的小动脉和供血动脉的内皮细胞（EC）和平滑肌细胞（SMC）之间的活动协调。当乙酰胆碱（ACh;“金标准”内皮依赖性血管扩张剂）被递送至小动脉或FA上的离散位点时，其启动Ca+2波，该Ca+2波沿着内膜从EC行进至EC达数百微米，以通过释放一氧化氮促进周围SMC的松弛。然而，很少有人知道钙波是如何启动或传播的微循环。为了直接解决这个问题，我已经开发了完整的“内皮管”制备小鼠腹部肌肉供血动脉作为一个独特的模型来研究Ca+2波的性质独立于血流，跨壁压，或周围的SMC和组织的影响。完整的微血管内皮管（直径，50-80 5 m;长度，1-2 mm）分离使用显微解剖FA，然后部分酶消化和温和的研磨。染料转移的初步研究证实，整个管的EC通过缝隙连接良好耦合，并产生强大的Ca+2波响应ACh，可以传播超过500 5米沿着管。我的研究重点是了解这些Ca+2波是如何启动的，以及它们如何从EC传播到EC。AIM 1将通过优先抑制Ca +2从内质网（ER）的内部释放和/或其穿过质膜的流入来识别波启动和传播的Ca+2来源。目的2将研究细胞内Ca+2库的部分耗竭或超载如何影响Ca+2波的起始和传播。解决内和细胞外Ca+2源在产生波中的作用将提供关于这些信号传导途径如何有助于血流局部调节的新见解。反过来，这些知识将导致更好地理解内在Ca+2信号通路如何在动脉粥样硬化，糖尿病，高血压和缺血等条件下改变。我的总体目标是将这项研究的发现应用于治疗组织灌注受损的血管疾病的新策略的开发。