Microparticles and vascular dysfunction in diabetes

糖尿病中的微粒和血管功能障碍

• 批准号: 8315416
• 负责人: Christian Jensen Stork
• 金额: $ 4.92万
• 依托单位: WEST VIRGINIA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-04-03 至 2015-04-02
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8315416
• 关键词: Adhesions; Animal Model; Animals; Antibodies; Binding; Biological Assay; Blood; Blood Platelets; Blood Vessels; Blood coagulation; Brain; Cannulations; Cardiovascular Diseases; Cell Adhesion Molecules; Cells; Coagulants; Coagulation Process; Confocal Microscopy; Development; Diabetes Mellitus; Diabetic Angiopathies; Disease; Disease Progression; Fibrin; Flow Cytometry; Functional disorder; Goals; Health; Hemostatic Agents; Hyperglycemia; Image; In Vitro; Inflammation; Inflammation Mediators; Inflammatory; Investigation; Label; Learning; Leukocytes; Measurement; Measures; Mediating; Membrane; Methodology; Microvascular Permeability; Parents; Pathogenesis; Pathology; Perfusion; Permeability; Phosphatidylserines; Plasma; Population; Postdoctoral Fellow; Prevention strategy; Production; Proteins; Prothrombin; Rattus; Reactive Oxygen Species; Reporting; Research; Research Personnel; Role; Science; Scientist; Severity of illness; Signal Transduction; Source; Streptozocin; Techniques; Testing; Thrombin; Thromboplastin; Thrombus; Training; Vesicle; Work; annexin A5; antibody conjugate; base; career; cell injury; cell type; diabetic; diabetic patient; diabetic rat; experience; in vivo; in vivo Model; innovation; knowledge of results; novel; response; therapeutic development

DESCRIPTION (provided by applicant): The proposed research aims to provide training experiences for a promising postdoctoral fellow to become an independent scientist in a health-related field through collaborative efforts between the trainee and sponsor. To gain a better understanding of disease associated microvascular dysfunction, we have recently used the streptozotocin-induced diabetic rat model to examine hyperglycemia-induced changes in microvessel permeability. Although diabetes-associated vascular complications have been studied extensively, quantitative measurements of microvessel permeability in diabetic animals have not yet been done and the factors that contribute to the microvascular dysfunction under diabetic conditions remain unclear. Our permeability measurements in diabetic rat microvessels showed significantly increased baseline permeability and a markedly augmented permeability response to inflammatory mediators. In the plasma of these diabetic rats, we found significantly increased levels of circulating microparticles (MPs) when compared to normal rats. Following the perfusion of MPs isolated from diabetic rat plasma into intact microvessels, we observed increases in leukocyte adhesion on the microvessel walls as well as thrombus formation. Based on the novel preliminary findings we hypothesize that the increased MPs under diabetic conditions are not simply the result of vascular dysfunction, but that MPs actively mediate pro-inflammatory and pro-coagulant signaling and thus potentiate vascular dysfunction under diabetic disease conditions. This hypothesis will be tested by three specific aims. Aim 1 is to identify sources of the increased MPs in diabetic rats and investigate the mechanisms by which MP levels increase under diabetic conditions. Aim 2 is to investigate mechanisms by which MPs interact with microvessel walls, mediating leukocyte adhesion and increases in microvascular permeability. Aim 3 is to investigate the effect of MPs on promoting the coagulation that results in thrombus formation in intact microvessels. The innovative aspect of this proposal is that we will combine flow cytometry analysis of MPs with confocal imaging and quantitative measurement of permeability in individually perfused intact microvessels. This proposed study will provide the most direct in vivo evidence for the effects of microparticles on the development of vascular complications and contribute to a better understanding of the pathogenesis of vascular dysfunction associated with diabetes. The results and knowledge gained from this study will benefit the development of therapeutic and preventive strategies for diabetic vascular dysfunctions. The completion of these proposed studies will broaden the applicant's scientific perspective and experimental methodologies while enhancing the applicant's potential to become an independent researcher in the field of biomedical sciences. PUBLIC HEALTH RELEVANCE: Our recent research conducted on diabetic animals found that the levels of circulating plasma microparticles, small membrane-bound vesicles, were significantly increased in diabetic rats compared to normal rats. The proposed research aims to identify the mechanisms of increased levels of microparticles under diabetic conditions and investigate whether increased numbers of circulating microparticles further promote the development of diabetic vascular complications. The results and knowledge gained from this study may significantly benefit the development of therapeutic and preventive strategies for diabetic vascular pathogenesis.

描述（由申请人提供）：拟议的研究旨在通过学员和赞助商之间的合作努力为有前途的博士后研究员提供培训经验，以成为健康相关领域的独立科学家。为了更好地了解疾病相关的微血管功能障碍，我们最近使用了链蛋白酶诱导的糖尿病大鼠模型来检查高血糖诱导的微血管通透性的变化。尽管已经对与糖尿病相关的血管并发症进行了广泛的研究，但尚未完成糖尿病动物微血管通透性的定量测量，并且在糖尿病状况下导致微血管功能障碍的因素尚不清楚。我们在糖尿病大鼠微血管中的渗透率测量显示出基线渗透性的显着增加，并且对炎症介质的渗透性反应显着增加。在这些糖尿病大鼠的血浆中，与正常大鼠相比，我们发现循环微粒（MP）的水平显着增加。从糖尿病大鼠血浆中分离成完整微血管中的MPS之后，我们观察到微血管壁上的白细胞粘附以及血栓形成的增加。基于新的初步发现，我们假设在糖尿病性疾病下增加的MPS不仅是血管功能障碍的结果，而且MPS会在糖尿病疾病条件下积极介导促炎和促凝信号传导，从而有助于血管功能障碍。该假设将通过三个特定目标检验。目的1是鉴定糖尿病大鼠中MPS增加的来源，并研究在糖尿病疾病下MP水平升高的机制。 AIM 2是研究MPS与微血管壁相互作用的机制，介导白细胞粘附并增加微血管通透性。 AIM 3是研究MPS对促进凝血的影响，从而导致完整微血管中的血栓形成。该提案的创新方面是，我们将将MPS的流式细胞仪分析与共聚焦成像和对个体灌注完整微血管中渗透性的定量测量相结合。这项拟议的研究将为微粒对血管并发症发展的影响提供最直接的体内证据，并有助于更好地理解与糖尿病相关的血管功能障碍的发病机理。从这项研究中获得的结果和知识将使糖尿病血管功能障碍的治疗和预防策略的发展有益。这些提出的研究的完成将扩大申请人的科学观点和实验方法，同时增强了申请人成为生物医学科学领域的独立研究人员的潜力。 公共卫生相关性：我们最近对糖尿病动物进行的研究发现，与正常大鼠相比，糖尿病大鼠的循环血浆微粒（小膜结合囊泡）的水平显着增加。拟议的研究旨在确定在糖尿病条件下微粒升高的机制，并研究循环微粒数量增加是否进一步促进了糖尿病血管并发症的发展。从这项研究中获得的结果和知识可能会显着有益于糖尿病血管发病机理的治疗和预防策略的发展。