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）：我们实验室的长期研究目标是定义微循环中的信号事件，这些信号事件是控制氧气和营养物质输送到组织的基础，重点是运动期间的骨骼肌。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供给动脉（FA）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”内皮依赖性血管舒张剂）递送至小动脉或 FA 上的离散部位时，会引发 Ca+2 波，该波沿内膜从 EC 传播到 EC 数百微米，以促进周围血管松弛。 SMC 通过释放一氧化氮。然而，人们对钙波如何在微循环中引发或传播知之甚少。为了直接解决这个问题，我开发了来自小鼠腹部肌肉供给动脉的完整“内皮管”制剂，作为一种独特的模型来研究 Ca+2 波的性质，不受血流、跨壁压力或周围 SMC 的影响，并且组织。使用 FA 显微解剖分离完整的微血管内皮管（直径，50-80 5m；长度，1-2 mm），然后进行部分酶消化和温和研磨。染料转移的初步研究证实，整个管内的 EC 通过间隙连接良好耦合，并响应 ACh 产生强大的 Ca+2 波，可沿管传播超过 500 5m。我的研究重点是了解这些 Ca+2 波是如何启动的以及它们实际上如何从 EC 传播到 EC。 AIM 1 将通过优先抑制 Ca+2 从内质网 (ER) 内部释放和/或其跨质膜流入来识别波启动和传播的 Ca+2 来源。 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 波的启动和传播。解决细胞内和细胞外 Ca+2 源在产生波中的作用将为了解这些信号传导途径如何促进血流的局部调节提供新的见解。反过来，这些知识将有助于更好地理解内在的 Ca+2 信号通路在动脉粥样硬化、糖尿病、高血压和缺血等情况下如何改变。我的总体目标是将这项研究的结果应用于开发治疗组织灌注受损的血管疾病的新策略。 公共卫生相关性： 相关性 在许多疾病状态下，全身的血流都会受到损害。健康的内皮细胞通过放松血管来促进血流，但在疾病状态下会以一种尚不清楚的方式受到干扰。该应用中将进行的研究将为内皮细胞用于放松血管的关键调节过程提供重要的新见解。这些信息将进一步我们了解疾病如何破坏这些基本过程，从而确定治疗血管疾病的新治疗方法，以改善全身的血液流动。