Calcium wave propagation along microvascular endothelial tubes

钙波沿微血管内皮管传播

• 批准号: 8203129
• 负责人: Matthew John Socha
• 金额: $ 4.84万
• 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/8203129
• 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. PUBLIC HEALTH RELEVANCE: Relevance Blood flow throughout the body is compromised in many diseased states. Healthy endothelial cells promote flow by relaxing blood vessels but are disturbed in diseased states in ways that are not well understood. Research to be performed in this application will provide important new insight into key regulatory processes that endothelial cells use to relax blood vessels. This information will further our understanding how disease disrupts these essential processes and thereby identify new therapeutic approaches for treating vascular disease to improve blood flow throughout the body.

描述（由申请人提供）：我们实验室中心的长期研究目标是确定微循环中的信号事件，这些信号事件是控制组织中氧气和营养物质输送的基础，重点是运动过程中的骨骼肌。我的工作假设是，血流的局部控制反映了构成微血管阻力网络的小动脉和饲料动脉（FA）的内皮细胞（ECs）和平滑肌细胞（SMCs）之间活动的协调。当乙酰胆碱（乙酰胆碱，“金标准”内皮依赖性血管扩张剂）被输送到小动脉或FA上的一个离散位点时，它会启动一个Ca+2波，沿着内膜从EC到EC传播数百微米，通过释放一氧化氮来促进周围SMCs的松弛。然而，钙波是如何在微循环中产生或传播的，我们所知甚少。为了直接解决这个问题，我开发了来自小鼠腹肌喂养动脉的完整“内皮管”制备，作为一种独特的模型来研究不受血流、跨壁压力或周围SMCs和组织影响的Ca+2波的性质。完整的微血管内皮管（直径50-80 5m，长度1-2 mm）采用FA显微解剖，然后进行部分酶解和温和滋养分离。染料转移的初步研究证实，整个管中的ECs通过间隙连接良好耦合，并产生强大的Ca+2波，以响应ACh，可沿管传播超过500 5m。我的研究重点是了解这些Ca+2波是如何产生的，以及它们是如何从EC传播到EC的。AIM 1将通过优先抑制Ca+2从内质网（ER）的内部释放和/或其穿过质膜的内流来识别Ca+2的波起始和传播源。AIM 2将研究细胞内Ca+2储存的部分耗尽或过载如何影响Ca+2波的产生和传播。解决细胞内和细胞外Ca+2源在产生波中的作用将为这些信号通路如何促进局部血流调节提供新的见解。反过来，这一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、高血压和缺血等情况下改变。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发展。