The Vascular Effects of Clopidogrel Metabolites

氯吡格雷代谢物的血管作用

• 批准号: 10292921
• 负责人: Dawn Kuszynski
• 金额: $ 4.6万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-08-16 至 2022-08-15
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10292921
• 关键词: Adverse effects; Affect; Agonist; Antiplatelet Drugs; Arteries; Aspirin; Astrocytoma; Binding; Biological Assay; Bleeding time procedure; Blood - brain barrier anatomy; Blood Vessels; Blood flow; Cells; Cerebral hemisphere hemorrhage; Cerebrovascular Circulation; Cerebrovascular system; Cytochrome P450; Data; Development; Dose; Endothelium; Enzymes; Event; Generations; Genetic Polymorphism; Glutathione; Goals; Hemorrhage; Homeostasis; Impairment; In Vitro; Knowledge; Lead; Mediating; Methods; Modeling; Mus; Myography; New Zealand; Oryctolagus cuniculus; Parents; Pathway interactions; Patients; Pharmaceutical Preparations; Platelet Activation; Platelet aggregation; Prodrugs; Purinoceptor; Reaction; Receptor Signaling; Regulation; Reporting; Reverse Transcriptase Polymerase Chain Reaction; Risk; Signal Pathway; Signal Transduction; Smooth Muscle; Sulfhydryl Compounds; System; Techniques; Testing; Thrombosis; Vasodilation; arteriole; blood-brain barrier permeabilization; capillary bed; cerebral artery; cerebral microbleeds; clopidogrel; constriction; improved; in vivo; loss of function; middle cerebral artery; parenchymal arterioles; pressure; receptor; release of sequestered calcium ion into cytoplasm; response; side effect; temporal measurement; vasoconstriction

Project Summary: Dual antiplatelet therapy using low-dose aspirin with a purinergic receptor 2Y12 (P2Y12) antagonist is the most common preventative method for arterial thrombosis. Antiplatelet agents, such as clopidogrel, cause an increased risk of cerebral microbleeds and intracerebral hemorrhage. Of patients who have taken clopidogrel for at least one year, 31% have cerebral microbleeds and 47% of those patients also develop intracerebral hemorrhage. Clopidogrel inhibits ADP-induced platelet aggregation, but this effect does not correlate with the increase in adverse bleeding. This suggests adverse effects of clopidogrel are not mediated by the active metabolite and that the parent compound or one of the many inactive metabolites might be responsible. A more complete understanding of the cellular pathways affected by clopidogrel and its metabolites are required in order to decrease this risk. Clopidogrel is converted into the active metabolite by cytochrome P450 enzymes (CYP450's). Only approximately 5% of clopidogrel is activated and loss of function polymorphisms in CYP450's reduce this further. DT678 is a conjugate of the clopidogrel active metabolite that is converted into the active form through a non-enzymatic thiol exchange reaction with glutathione. We have previously reported that DT678 has a reduced bleeding risk compared to clopidogrel in a rabbit model. My preliminary data revealed that spontaneous myogenic tone (MT) and ADP-induced vasodilation are inhibited in clopidogrel-treated, but not DT678-treated middle cerebral arteries (MCA's). My central hypothesis is that clopidogrel modulates P2Y1, P2Y2, P2Y4, P2Y6, P2Y11 and/or P2Y14 signaling in the vasculature, and this impairs vascular function which results in the increased bleeding side effects without causing a correlated decrease in platelet aggregation. In order to test my central hypothesis, I will pursue the following three specific aims: 1. Identify the receptor signaling pathways modulated by clopidogrel and DT678. My working hypothesis is that clopidogrel inhibits P2Y1, P2Y2, P2Y4, P2Y6, P2Y11 and/or P2Y14 as well as P2Y12 in stably transfected cells. Additionally, I hypothesize that DT-678 only inhibits the P2Y12 receptor without having effects on other purinergic receptors. 2. Determine the effect of specific purinergic agonists in the middle cerebral artery from clopidogrel- and DT678-treated rabbits. My working hypothesis is that clopidogrel metabolites interact with P2Y1, P2Y2, P2Y4, P2Y6, P2Y11 and/or P2Y14 in the MCA to impair MT generation and dilation. 3. Evaluate the effects of clopidogrel and DT678 in the parenchymal arterioles of P2Y12-/- mice. My working hypothesis that clopidogrel modulates P2Y1, P2Y2, P2Y4, P2Y6, P2Y11 and/or P2Y14 in the vasculature to inhibit myogenic tone, constriction and dilation in P2Y12-/- mice. The information obtained from this project will allow for development of new antiplatelet therapies that have improved efficacy with a decreased risk of intracerebral hemorrhage.

项目摘要： 使用低剂量阿司匹林与嘌呤能受体2Y12（P2Y12）拮抗剂的双抗血小板治疗是最多的 通用动脉血栓形成方法。抗血小板剂，例如氯吡格雷，导致 大脑微血管和脑出血的风险增加。服用氯吡格雷的患者 至少一年，有31％的脑微孔物，其中47％的患者也会出现脑内脑部 出血。氯吡格雷抑制ADP诱导的血小板聚集，但这种作用与 增加不良出血。这表明氯吡格雷的不良影响不是由活性介导的 代谢产物和母体化合物或许多非活性代谢产物之一可能是负责的。更多 需要完全了解受氯吡格雷影响及其代谢物影响的细胞途径。 降低这种风险。通过细胞色素P450酶转化为活性代谢产物 （CYP450）。仅激活氯吡格雷的约5％，CYP450的功能多态性丧失 进一步减少。 DT678是氯吡格雷活性代谢产物的共轭物，转化为活性 通过与谷胱甘肽的非酶硫醇交换反应形成。我们以前已经报道了DT678 与兔模型中的氯吡格雷相比，出血风险降低。我的初步数据表明 在氯吡格雷治疗中抑制自发的肌吻合（MT）和ADP诱导的血管舒张 DT678处理的中大脑动脉（MCA）。我的中心假设是氯吡格雷调节P2Y1， P2Y2，P2Y4，P2Y6，P2Y11和/或P2Y14脉管系统中的信号传导，此损害血管功能 这导致出血副作用的增加而不会导致血小板相关减少 聚合。为了检验我的中心假设，我将追求以下三个具体目标：1。 由氯吡格雷和DT678调节的受体信号通路。我的工作假设是 氯吡格雷在稳定转染的细胞中抑制P2Y1，P2Y2，P2Y4，P2Y6，P2Y6，P2Y11和/或P2Y14以及P2Y12。 另外，我假设DT-678仅抑制P2Y12受体，而没有对其他嘌呤能影响 受体。 2。确定特定的嘌呤能激动剂在中部动脉中的影响 氯吡格雷和DT678处理的兔子。我的工作假设是氯吡格雷代谢物与 MCA中的P2Y1，P2Y2，P2Y4，P2Y6，P2Y6和/或P2Y14，以损害MT的生成和扩张。 3。评估 氯吡格雷和DT678在P2Y12 - / - 小鼠的实质动脉中的影响。我的工作假设 该氯吡格雷调节P2Y1，P2Y2，P2Y4，P2Y6，P2Y11和/或P2Y14在脉管系统中抑制肌原性 p2Y12 - / - 小鼠中的音调，收缩和扩张。从该项目获得的信息将允许 开发新的抗血小板疗法，并降低了脑内风险的疗效 出血。