血管性血友病因子裂解酶ADAMTS13在血栓形成中的调控机制研究

Von Willebrand factor (VWF) is the "bridge" for the adherence of endothelial cells (ECs) with other cells or molecules; and its adherence capability is closely associated with its multimeric sizes, which can be regulated by the specific enzyme VWF-cleaving protease, ADAMTS13. Recently, by using flow chamber combined with immunofluorescence microscopy, we found that the newly released ultra-large VWF (UL-VWF) from activated ECs was rapidly cleaved by ADAMTS13 under the physiological shear stress. Nevertheless, UL-VWF release results in more ADAMTS13 production and secretion from ECs. Based on these results, we will investigate (1) the molecular mechanism of UL-VWF cleavage by ADAMTS13 under physiological flow state and the role of ECs derived ADAMTS13 in this process. (2) To observe the regulation of UL-VWF multimeric sizes by ADAMTS13 in thrombosis model triggered by EC injury with contrast-enhanced ultrasound molecular imaging, and to compare the UL-VWF cleavage by ECs derived ADAMTS13 with hepatic cell derived ADAMTS13. (3) To understand the effect of signal transduction pathway regulating the VWF release on the secretion of ADAMTS13 in ECs. Therefore, we will further characterize the molecular mechanism of UL-VWF/ADAMTS13 axis in the process of thrombosis to map diagnostic and therapeutic targets for thrombotic disorders.

血管性血友病因子（VWF）是血栓形成中的主要介质，其黏附功能与分子量大小密切相关，这由VWF裂解酶ADAMTS13来调节。但是血栓形成中该酶的调控机制并不清楚。申请者最近发现，ADAMTS13降解内皮释放的超大分子量VWF（UL-VWF）涉及P-选择素的参与；凝血酶刺激的UL-VWF释放伴随内皮细胞ADAMTS13表达的增高，而组胺活化后该酶表达并不增高。提示与VWF相关的分子和信号通路可能影响ADAMTS13的作用。本课题将⑴在流体状态下探讨ADAMTS13降解UL-VWF的分子调控机制和内皮源性裂解酶在其中的作用；⑵在血栓模型中利用对比增强超声分子成像技术观察血栓形成中影响UL-VWF降解的因素，揭示内皮源性ADAMTS13的作用；⑶了解调控UL-VWF释放的信号通路对内皮细胞ADAMTS13分泌的影响。上述研究有助于明确ADAMTS13的分子调控，也为血栓性疾病的诊断治疗提供新靶点.

血栓栓塞性疾病是临床常见的病理综合症，严重威胁人类的生命健康。因此，深入研究血栓形成和抗栓的分子机制及其关键的影响因素，对于寻找诊断、监控和靶向抗血栓、溶栓干预治疗的新方法具有重要意义。血管性血友病因子(VWF)是血栓形成中的主要介质，其黏附功能与分子量大小密切相关，这由VWF裂解酶ADAMTS13来调节。但是血栓形成中该酶的调控机制并不清楚。申请者发现，ADAMTS13降解内皮释放的超大分子量VWF(UL-VWF)涉及P-选择素的参与凝血酶刺激的UL-VWF释放伴随内皮细胞ADAMTS13表达的增高，而组胺活化后该酶表达并不增高。提示与VWF相关的分子和信号通路可能影响ADAMTS13的作用。本课题在流体状态下探讨ADAMTS13降解UL-VWF的分子调控机制和内皮源性裂解酶在其中的作用；并在血栓模型中利用对比增强超声分子成像技术观察血栓形成中影响UL-VWF降解的因素，揭示内皮源性ADAMTS13的作用；另外，了解调控 UL-VWF释放的信号通路对内皮细胞ADAMTS13分泌的影响。上述工作有助于阐明血栓形成起始阶段的分子机制及其主要影响因素，为我们在后续工作中设计预防血栓的策略和治疗血栓的靶向干预奠定坚实的基础，具有较好的应用前景。