Flow-induced coronary vasospasm in diabetic patients

糖尿病患者血流诱发的冠状血管痉挛

• 批准号: 8478180
• 负责人: Zsolt Bagi
• 金额: $ 35.34万
• 依托单位: AUGUSTA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-08-15 至 2015-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8478180
• 关键词: Acetylcholine; Affect; Age; Animal Model; Arachidonic Acids; Arginine; Arteries; Blocking Antibodies; Blood Platelets; Blood Vessels; Blood flow; CD31 Antigens; Caliber; Cardiac Surgery procedures; Cell Adhesion Molecules; Cell membrane; Cells; Comorbidity; Complication; Control Groups; Coronary; Coronary Artery Vasospasm; Coronary Vessels; Coronary artery; Coupled; Cyclooxygenase Inhibitors; Cytosolic Phospholipase A2; Data; Dependence; Dilatation - action; Disease; Distal; Endothelial Cells; Endothelium; Ensure; Enzyme Inhibitor Drugs; Enzyme Inhibitors; Exhibits; Fluorescence; Fluorescence Resonance Energy Transfer; Fluorescent Dyes; Fura-2; Gender; Grant; Heart; High Prevalence; Human; Image; Immunohistochemistry; In Situ; Indomethacin; Inflammatory; Intercellular Junctions; Intervention; Label; Laser Scanning Confocal Microscopy; Lasers; Lead; Lesion; Life; Measures; Mediating; Mediator of activation protein; Metabolism; Microcirculatory Bed; Microdissection; Monomeric GTP-Binding Proteins; Myography; Nature; Nitric Oxide; Nitric Oxide Synthase; Non-Insulin-Dependent Diabetes Mellitus; Patients; Perfusion; Pharmaceutical Preparations; Phospholipase A2; Preventive; Process; Production; Prostaglandins; Prostaglandins I; Proteins; Protocols documentation; Research Support; Resistance; Rho-associated kinase; Role; Sarcoplasmic Reticulum; Signal Pathway; Signal Transduction; Spatial Distribution; Surface; Techniques; Testing; Therapeutic; Therapeutic Embolization; Therapeutic Intervention; Thromboxane A2; Time; Tissues; Transfection; Translating; Tyrosine Phosphorylation; Up-Regulation; Vasodilation; Vasodilator Agents; Vasospasm; Video Microscopy; Western Blotting; antibody inhibitor; arginase; arteriole; auricular appendage; cellular imaging; clinical practice; connexin 37; constriction; cyclooxygenase 1; cyclooxygenase 2; diabetic; diabetic patient; feeding; immunoglobulin receptor; inhibitor/antagonist; mouse model; novel; occludin; percutaneous coronary intervention; pressure; prevent; public health relevance; ratiometric; receptor; research study; response; sensor; spatiotemporal; vasoconstriction

DESCRIPTION (provided by applicant): Patients with type 2 diabetes mellitus (T2-DM) have higher prevalence of no-reflow phenomenon - a poorly understood and unpredictable complication of percutaneous coronary intervention (PCI) in which diminished blood flow to distal microvascular beds persists despite the successful treatment of the occlusive lesion of the epicardial coronary artery. Current therapeutic interventions to prevent no reflow are ineffective. Preliminary observations related to this application led to my main hypothesis that small coronary arteries of diabetic patients exhibit a paradoxical constriction to sudden increases in flow, an alteration, which contributes to no reflow. I propose that RhoA-dependent co-localization of arginase I and eNOS leads to reduced NO synthesis and diminished NO-mediated dilatation in response to flow in T2-DM. I also hypothesize that stimulation of platelet endothelium cell adhesion molecule -1 (Pecam-1, known as primary flow sensor in endothelium) with increases in intraluminal flow elevates endothelial [Ca2+]i, which via inducing phospholipase A2 and arachidonic acid release leads to enhanced production of thromboxane A2 in coronary vessels of T2-DM patients. To test these hypotheses, I aim to isolate small coronary vessels from the (discarded) atrial appendages of patients with T2-DM undergoing cardiac surgery. Using small vessel pressure myography and videomicroscopy, diameter changes of the isolated, coronary arteriole (< 100 5m) exposed to sudden increase in intraluminal flow will be measured in the presence of inhibitors of specific signaling pathways. To investigate (co)localization of eNOS and arginase I as well as to detect spatial distribution and interaction of Pecam-1 laser scanning confocal microscopy and fluorescence resonance energy transfer approaches will be used in isolated, pressurized coronary arteries and coronary endothelial cells in culture. Moreover, flow-induced changes in endothelial [Ca2+]i will be measured with Fura-2 fluorescence in intact, pressurized coronary arterioles to reveal spatial differences of [Ca2+]i elevations at subcellular level. Should the results obtained in the course of the project support my hypothesis this will be the first description of Pecam-1-coupled constrictor prostanoid production in human coronary arteries. Results will also provide a novel mechanism by which spatial distribution of Pecam-1 determines the nature of vasoactive mediators released to increase in flow in T2-DM. Data obtained in this project will also help to develop novel avenues for effective therapeutic strategies, such as the use of prostanoid inhibitors at the time of PCI, to prevent no reflow in patients with T2-DM.

描述（由申请人提供）：2 型糖尿病 (T2-DM) 患者的无复流现象发生率较高，这是一种人们知之甚少且不可预测的经皮冠状动脉介入治疗 (PCI) 并发症，尽管成功治疗了心外膜冠状动脉的闭塞病变，但远端微血管床的血流持续减少。目前防止无复流的治疗干预措施是无效的。与此应用相关的初步观察得出了我的主要假设，即糖尿病患者的小冠状动脉对流量突然增加表现出矛盾的收缩，这种改变导致无回流。我认为精氨酸酶 I 和 eNOS 的 RhoA 依赖性共定位会导致 NO 合成减少，并减少 T2-DM 中响应血流的 NO 介导的扩张。我还假设，刺激血小板内皮细胞粘附分子 -1（Pecam-1，称为内皮细胞初级流量传感器）会增加腔内流量，从而升高内皮 [Ca2+]i，通过诱导磷脂酶 A2 和花生四烯酸释放，导致 T2-DM 患者冠状动脉中血栓素 A2 的产生增加。为了检验这些假设，我的目标是从接受心脏手术的 T2-DM 患者（废弃的）心耳中分离出小冠状血管。使用小血管压力肌动描记术和视频显微镜，在特定信号通路抑制剂存在的情况下，测量暴露于腔内流量突然增加的孤立冠状动脉（<100±5m）的直径变化。为了研究 eNOS 和精氨酸酶 I 的（共）定位以及检测 Pecam-1 激光扫描共聚焦显微镜和荧光共振能量转移方法的空间分布和相互作用，将在分离的加压冠状动脉和培养的冠状内皮细胞中使用。此外，将使用完整加压冠状动脉中的 Fura-2 荧光测量血流诱导的内皮 [Ca2+]i 变化，以揭示亚细胞水平上 [Ca2+]i 升高的空间差异。如果项目过程中获得的结果支持我的假设，这将是对人类冠状动脉中 Pecam-1 偶联的缩窄前列腺素生成的首次描述。研究结果还将提供一种新的机制，通过该机制，Pecam-1 的空间分布决定了 T2-DM 中为增加血流而释放的血管活性介质的性质。该项目获得的数据还将有助于开发有效治疗策略的新途径，例如在 PCI 时使用前列腺素抑制剂，以防止 T2-DM 患者出现无复流。