Tissue Factor, Flow, and Platelet Adhesion/Aggregation on Activated Endothelium

活化内皮上的组织因子、血流和血小板粘附/聚集

• 批准号: 7813875
• 负责人: Eric Franklin Grabowski
• 金额: $ 39.83万
• 依托单位: MASSACHUSETTS GENERAL HOSPITAL
• 依托单位国家: 美国
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-04-15 至 2012-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7813875
• 关键词: Adhesions; Adhesives; Affect; Antibodies; Antiphospholipid Antibodies; Apoptosis; Appearance; Arteries; Attention; Bacterial Toxins; Beds; Binding; Blood; Blood Platelets; Blood Vessels; Blood flow; Cell Adhesion Molecules; Cell membrane; Cell secretion; Cell surface; Cells; Cessation of life; Childhood; Cleaved cell; Coagulation Process; Collagen; Coma; Coronary artery; Culture Media; Deposition; Disease; Down-Regulation; Endothelial Cells; Endothelium; Enhancers; Ensure; Epidemic; Epithelial Cells; Escherichia coli; Escherichia coli EHEC; Factor VIIa; Fibrin; Fibrinogen; Fostering; Glass; Glycosylphosphatidylinositols; Hemolytic-Uremic Syndrome; Hour; Human; Image; Impairment; Incubated; Inflammatory; Integrin beta3; Integrins; Intercellular adhesion molecule 1; Interruption; Intestines; Kidney; Kidney Failure; Lead; Leukocytes; Link; Measurement; Mediating; Membrane; Messenger RNA; Modeling; Necrosis; Organ; P-Selectin; Pathway interactions; Peptide Hydrolases; Phenotype; Phosphatidylserines; Phospholipids; Play; Process; Production; Proteins; Recombinants; Relative (related person); Reporting; Resolution; Role; Route; Seizures; Selectins; Shiga Toxin; Shiga-Like Toxin I; Site; Slide; Stress; Surface; System; TFPI; TNF gene; Testing; Therapeutic; Therapeutic Intervention; Thick; Thrombin; Thromboplastin; Thrombosis; Thrombus; Tissues; Toxin; United States; Up-Regulation; Vascular Endothelium; Video Microscopy; Vitronectin Receptors; Whole Blood; Work; arteriole; cell injury; cytokine; digital; exposed human population; foodborne; granulocyte; in vitro Model; in vivo; inhibitor/antagonist; mRNA Stability; monolayer; oxidized low density lipoprotein; public health relevance; receptor; research study; shear stress; von Willebrand Factor

DESCRIPTION (provided by applicant): In vivo, platelet adhesion/aggregation on activated endothelium may proceed via upregulation of endothelial cell (EC) molecules adhesive for platelets, especially 1v23 (the vitronectin receptor), ICAM-1, P-selectin, and ultra large von Willebrand factor (vWF) strings, accompanied and followed by tissue factor (TF)-driven mural platelet thrombosis in arteries or arterioles. The necessary EC activation may arise via several routes, including oxidized low density lipoproteins, bacterial toxins, and/or cytokines. The present work will test the hypothesis and paradigm that upregulation of these adhesion molecules permits the initiation of platelet adhesion/aggregation on endothelium, a process which is then amplified by both EC-associated TF and blood- borne TF. Blood-borne TF exists in the form of microparticles derived from leukocytes, platelets, and ECs. Upregulation of the EC-associated type of TF may take place by a variety of mechanisms, studied here: a) increases in TF mRNA stability and/or decreases in TFPI mRNA stability, b) enhancement of phosphatidylserine on the EC membrane outer leaflet, and c) reduction in the regulatory ability of EC-associated TFPI. We further hypothesize that mural platelet thrombi, in turn, slow blood flow sufficiently to allow activated endothelium to assume an even more procoagulant phenotype. A prime example of this paradigm is the epidemic childhood hemolytic uremic syndrome (HUS), in which food-borne, Shiga toxin (STX)-producing E. coli lead to a systemic inflammatory and prothrombotic state, with complications which can include renal failure, seizures, coma, and death. In an in vitro model of HUS we have demonstrated that STX significantly augments functional TF on monolayers of human glomerular ECs (HGECs), and markedly enhances platelet strings (associated with ultra large vWF strings) and small aggregate formation on these monolayers. Specific Aim 1 is to determine the mechanism(s) of TF augmentation observed with exposure of activated HGECs to STX. Specific Aim 2 is to demonstrate that STX augments platelet adhesion/aggregation in flowing blood on activated HGECs via upregulation of the above adhesion molecules, but also via upregulation of the TF pathway. These studies should elucidate the potential of therapeutic interventions in HUS directed at blocking adhesion molecules and blocking EC surface and/or blood-borne TF. PUBLIC HEALTH RELEVANCE: We will test the hypothesis that the presence of certain molecules on vascular endothelium (the blood vessel wall) which are adhesive for blood platelets are what initiates platelet thrombus formation on the inflamed blood vessel wall. This thrombus formation is then amplified by the clotting activity known as tissue factor, expressed on the surface of this same inflamed endothelium. A prime application of this hypothesis, we believe, is the epidemic childhood hemolytic uremic syndrome (HUS), in which food- borne toxin-producing E. coli leads to a disease state with complications including kidney failure, seizures, coma, and death. Our studies promise to clarify the potential of treatments for HUS directed at blocking the above adhesive molecules and vessel wall tissue factor.

DESCRIPTION (provided by applicant): In vivo, platelet adhesion/aggregation on activated endothelium may proceed via upregulation of endothelial cell (EC) molecules adhesive for platelets, especially 1v23 (the vitronectin receptor), ICAM-1, P-selectin, and ultra large von Willebrand factor (vWF) strings, accompanied and followed by tissue factor (TF)-driven mural动脉或动脉中的血小板血栓形成。必要的EC激活可能通过多种途径（包括氧化的低密度脂蛋白，细菌毒素和/或细胞因子）出现。目前的工作将检验假设和范式，即这些粘附分子的上调允许在内皮上启动血小板粘附/聚集，然后通过EC相关的TF和血液传播的TF对此进行扩增。血源性TF的形式存在于源自白细胞，血小板和EC的微粒。可以通过多种机制进行与EC相关类型的TF的上调，在此研究：a）TF mRNA稳定性的增加和/或TFPI mRNA稳定性的降低，b）EC膜外部叶片上磷脂酰丝氨酸的增强，以及C）在EC-Meculative of Ec-Membrane Outsy上的降低EC-EC-EC-EC-EC-EC-CASSIPATION CASSIPATION cASSIPATIENT TFPI。我们进一步假设壁画血小板又足够缓慢的血液流动，以使活化的内皮假设更具凝聚力的表型。该范式的一个主要例子是流行病儿童溶血性尿毒症综合征（HUS），其中食物传播，志贺毒素（STX）产生的大肠杆菌会导致系统性炎症和促血栓形成状态，并发症，并发症，并发症可能包括肾功能衰竭，癫痫发作，昏迷和死亡。在HUS的体外模型中，我们已经证明，STX显着增强了人肾小球EC（HGEC）单层的功能性TF，并明显增强了血小板（与超大的VWF字符串）和对这些单层的小聚集体形成。具体目的1是确定随着激活的HGEC暴露于STX观察到的TF增强的机制。具体目的2是证明STX通过上述上述粘附分子的上调而在活化HGEC上流动血液粘附/聚集，但也通过上调TF途径。这些研究应阐明用于阻断粘附分子并阻止EC表面和/或血传递TF的HUS的治疗干预措施的潜力。公共卫生相关性：我们将检验以下假设：血小板上具有粘合的血管内皮（血管壁）上某些分子的存在是启动发炎的血管壁上血小板血栓形成的原因。然后，通过称为组织因子的凝血活性在同一发炎的内皮表面表达的凝血活性来扩增该血栓形成。我们认为，这种假设的主要应用是流行病儿童溶血性尿毒症综合征（HUS），其中食物传播的毒素产生大肠杆菌导致疾病状态，并发症，包括肾衰竭，癫痫发作，昏迷和死亡。我们的研究有望阐明旨在阻止上述粘合分子和血管壁组织因子的HUS治疗的潜力。