趋化因子Fractalkine在心房纤颤相关血栓的作用机制研究

Our previous cohort study showed that chemokine Fractalkine(FKN) predicted independently the risk for thromboembolism in patients with atrial fibrillation (AF). Based on them, the present study aims to explore the mechanism of FKN-regulated endothelial and platelet activation, identify the cell signal pathway, and then observe the effect of interruptting FKN-receptor pathway on prothrombotic state in cell level, animal model and AF patients, with molecular biology, cytometric bead array （CBA）and multi-analyte enzyme-linked immunosorbent assay (ELISA). Co-culture human umbilical arterial / venous endothelial cell (HUAC/HUVC) and platelet, observe FKN and its receptor expression in activated HUAC/HUVC and platelet, and clarify the role of FKN-CX3CR1、FKN-GPIb pathway on endothelial and platelet activation, as well as FKN-related signal pathway; Building the goat model with AF, assess the prothrombotic state with echo, and evaluate the influence of FKN-CX3CR1、FKN-GPIb pathway on prothrombotic state; Further, explore the impact of blocking FKN-CX3CR1、FKN-GPIb pathway on endothelial and platelet activation in AF patients and AF patients with ischemic stroke/thromboembolism. The critical role of FKN on prothrombotic state in AF patients will be evaluated in this study and provide the newest evidence of revised Virchow's trid on AF-related thromboembolism mechanism.

我们前期研究显示趋化因子Fractalkine(FKN)独立预测房颤血栓风险。拟使用细胞培养，分子生物学，蛋白芯片及多通道酶联免疫吸附等技术，在细胞水平、动物模型及房颤患者，明确FKN-CX3CR1及 FKN-GPIb通路在内皮及血小板活化等房颤血栓前状态中的作用，确定其相关的细胞信号传导机制，观察干预FKN-CX3CR1及 FKN-GPIb通路对前血栓状态的影响。检测炎症刺激人脐动脉、脐静脉内皮细胞FKN及受体的表达、FKN相关内皮/血小板活化的细胞信号通路；建立山羊房颤模型，超声评价前血栓状态，观察阻断FKN-CX3CR1、FKN-GPIb 对房颤前血栓形成的影响；进而，在房颤患者及房颤脑卒中/血栓患者，评价FKN-CX3CR1、FKN-GPIb 及相关信号传导通路阻断对内皮/血小板活化的影响。以期明确FKN在房颤相关血栓前状态及血栓形成中的作用机制。

房颤前血栓状态（prothrombotic state）为房颤血栓形成的关键。修正Virchow's 三角（Virchow's triad）是房颤前血栓状态的基础。在修正的Virchow's 三角中，炎症机制介导的内皮功能失调，凝血因子及血小板活化，可能促发凝血瀑布，是房颤前血栓形成的关键。本研究检测27种炎症趋化因子生物标记物获得的优化实验条件参数，明确验证趋化因子与 血样内皮、血小板活化的关系；继而在6148房颤血栓高危人群队列中，检测了1016例房颤患者趋化因子Fractalkine等水平表达，明确Fractalkine在房颤相关血栓前状态及血栓形成中的作用机制。显示房颤炎症激活Fractalkine，作用于内皮，血小板，内皮及血小板活化，Fractalkine 表达进一步增加，促使血小板-单核细胞/白细胞聚集，内皮功能损害，血小板与内皮粘附增加，内皮前凝血组织因子激活，凝血瀑布活化，确定Fractalkine在相关的房颤血栓前状态及血栓形成中的作用及在房颤相关风险中的诊断价值。