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受训者和申办者之间的合作努力，为有前途的博士后研究员提供培训经验，使其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，我们最近使用链脲佐菌素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。虽然糖尿病相关的血管并发症已被广泛研究，但糖尿病动物微血管通透性的定量测量尚未完成，导致糖尿病条件下微血管功能障碍的因素仍不清楚。我们在糖尿病大鼠微血管中的渗透性测量显示基线渗透性显著增加，并且对炎症介质的渗透性反应显著增强。在这些糖尿病大鼠的血浆中，我们发现与正常大鼠相比，循环微粒（MP）的水平显着增加。将从糖尿病大鼠血浆中分离的MP灌注到完整的微血管中后，我们观察到微血管壁上白细胞粘附增加以及血栓形成。基于新的初步发现，我们假设在糖尿病条件下增加的MP不仅仅是血管功能障碍的结果，而是MP主动介导促炎和促凝血信号传导，从而增强糖尿病疾病条件下的血管功能障碍。这一假设将通过三个具体目标进行检验。目的1是确定糖尿病大鼠MP升高的来源，并探讨糖尿病条件下MP水平升高的机制。目的2是研究MP与微血管壁相互作用，介导白细胞粘附和微血管通透性增加的机制。目的3：研究MP对完整微血管内血栓形成的促凝作用。该建议的创新之处在于，我们将结合联合收割机流式细胞术分析的MP与共聚焦成像和定量测量的渗透性在单独灌注完整的微血管。这项拟议的研究将为微粒对血管并发症的发展的影响提供最直接的体内证据，并有助于更好地了解与糖尿病相关的血管功能障碍的发病机制。本研究的结果和知识将有助于糖尿病血管功能障碍的治疗和预防策略的发展。完成这些拟议的研究将拓宽申请人的科学视角和实验方法，同时提高申请人成为生物医学科学领域独立研究人员的潜力。 公共卫生关系：我们最近对糖尿病动物进行的研究发现，与正常大鼠相比，糖尿病大鼠循环血浆微粒（小膜结合囊泡）的水平显著增加。该研究旨在确定糖尿病条件下微粒水平增加的机制，并研究循环微粒数量的增加是否进一步促进糖尿病血管并发症的发展。本研究的结果和知识可能对糖尿病血管发病机制的治疗和预防策略的发展具有重要意义。