Ectonucleotidases in Atherothrombosis and Stroke

激活的血小板释放的ADP招募附近的血小板，导致爆炸 血栓性坏死灶的增生。激活的血小板或受损细胞释放的三磷酸腺苷促进 发炎。细胞外核苷酸的配位磷酸化水解酶 胞外核苷酸酶CD39的作用(核苷酸二磷酸水解酶1，转化ATP-&GT； ADP-GT；AMP)和CD73(51个核苷酸酶，转化AMP-&GT；腺苷)，是一种重要的内皮细胞 限制血管界面血栓形成和炎症的动态平衡机制。 CD39基因缺失的小鼠表现出潜在的血栓前表型，结果比对照组更差 局灶性脑缺血的发生。这些小鼠可以被重组的可溶性CD39拯救， 它保留了apyrase的活性，而不会增加脑出血。此外， 高胆固醇血症ApoE/CD39双基因敲除小鼠表现出过度的动脉粥样硬化， 与血小板和炎症细胞募集到正在形成的斑块中的作用相一致。 这些数据表明，胞外核苷酸酶可以预防动脉粥样硬化血栓形成事件，并且 与中风的发病机制有关。实验将阐明CD39和CD39的作用机制 CD73具有动脉粥样硬化保护作用，其重点在于其抑制血小板活化和炎症的能力。 使用CD39或CD73基因缺失的野生型小鼠作为对照或高胆固醇血症小鼠 背景。实验将测试ECTs是否能改善缺血性中风的预后 在易发生动脉粥样硬化的脑血管环境中，使用solCD39(和/或纯化的CD73)作为 单一疗法或作为小剂量溶栓疗法的辅助疗法。这里的首要目标是 描绘出保护血管免受动脉粥样硬化血栓形成的内源性级联反应，并确定 是否可以通过治疗手段来改善缺血性中风的预后。 与公共健康相关：这个项目将探索存在于细胞衬里的两种蛋白质是如何 血管，降解循环物质，否则会促进凝血， 炎症和动脉粥样硬化。利用这些蛋白质的活性可能会导致一种新的 预防血栓形成和动脉粥样硬化的方法，从而导致一种全新的 也许对中风的治疗更安全。

ADP released from activated platelets recruits nearby platelets, resulting in explosive accretion of a thrombotic nidus. ATP, released from activated platelets or injured cells, promotes inflammation. The coordinated phosphohydrolysis of extracellular nucleotides, by the sequential actions of the ectonucleotidases CD39 (nucleotide diphosphohydrolase 1, converts ATP-> ADP->AMP) and CD73 (51 nucleotidase, converts AMP->adenosine), is an important endothelial homeostatic mechanism which limits thrombosis and inflammation at the blood-vessel interface. CD39 gene null mice exhibit a latent prothrombotic phenotype and worse outcomes than controls in the setting of focal cerebral ischemia. These mice can be rescued by recombinant soluble CD39, which retains apyrase activity, without increasing intracerebral hemorrhage. Furthermore, hypercholesterolemic ApoE/CD39 double knockout mice exhibit exaggerated atherogenesis, consistent with a role for platelet and inflammatory cell recruitment into the developing plaque. These data suggest that ectonucleotidases protect against atherothrombotic events and are relevant to the pathoaenesis of stroke. Experiments will elucidate mechanisms by which CD39 and CD73 are atheroprotective, focusing on their ability to suppress platelet activation and inflammatory cascades, using wild-type, cd39- or cd73-gene null mice in control or hypercholesterolemic backgrounds. Experiments will test whether ectonucleotidases improve ischemic stroke outcomes in an atherosclerosis-prone cerebrovascular milieu, using solCD39 (and/or purified CD73) as monotherapy or as an adjunct to low dose thrombolytic therapy. The overarching goal here is to delineate an endogenous cascade which protects vessels against atherothrombosis, and determine whether it may be therapeutically harnessed to ameliorate ischemic stroke outcomes. Relevance to Public Health: This project will explore how two proteins, which exist on cells lining blood vessels, degrade circulating substances which would otherwise promote clotting, inflammation, and atherosclerosis. Harnessing the activity of these proteins might lead to a new way of preventing clot formation and atherosclerosis, and thereby lead to a completely new and perhaps safer treatment for stroke.