Exocytosis and Vascular Inflammation

描述（由申请人提供）： 内皮细胞在血管炎症和血栓形成的启动中发挥着关键作用。在血管损伤或炎性激动剂的刺激下，内皮细胞表达调节白细胞运输和血小板活化的介质。内皮激活的动力学包括由先前合成的因子的快速释放介导的早期阶段和由新蛋白质的合成介导的后期阶段。内皮细胞的早期炎症反应包括胞吐韦伯-帕拉德小体、内皮细胞颗粒（含有yon Willebrand因子（vWF）和P-选择素）。韦伯-帕拉德小体的胞吐作用释放调节血小板粘附和聚集的vWF，并将P-选择素易位至内皮表面，在内皮表面调节白细胞滚动。因此，内皮细胞胞吐在介导血管炎症和血栓形成中起重要作用。 内皮细胞胞吐作用的调节部分被理解。胞吐作用是囊泡运输的一种形式，其中颗粒与细胞质膜融合，将其内容物释放到细胞外空间并将跨膜蛋白转运到细胞表面。几个蛋白质家族调节胞吐作用，包括N-乙基马来酰亚胺敏感因子（NSF）、可溶性NSF附着蛋白受体（SNARE）、rab GTP酶和Munc。我们最近发现，NSF在调节韦伯-帕拉德体的胞吐作用中起着关键作用。我们还发现一氧化氮（NO）通过靶向NSF抑制胞吐作用。 我们的观察部分解释了NO如何抑制血管炎症和血栓形成。 本研究的主要目的是探讨内皮细胞胞吐作用调控血管炎症的分子机制。该应用重点关注NSF对内皮细胞胞吐作用的调节。 我们计划继续研究自由基如何调节NSF。接下来，我们计划研究特定的酶如何还原氧化的NSF。最后，我们计划开发一类新的药物，通过靶向内皮细胞胞吐作用来减少血管炎症。

DESCRIPTION (provided by applicant): Endothelial cells play a critical role in the initiation of vascular inflammation and thrombosis. Stimulated by vascular injury or inflammatory agonists, endothelial cells express mediators that regulate leukocyte trafficking and platelet activation. The kinetics of endothelial activation include an early phase mediated by the rapid release of previously synthesized factors, and a later phase mediated by the synthesis of new proteins. The early inflammatory response of endothelial cells includes the exocytosis of Weibel-Palade bodies, endothelial granules that contain yon Willebrand Factor (vWF) and P-selectin. Exocytosis of Weibel-Palade bodies releases vWF which regulates platelet adhesion and aggregation, and translocates P-selectin to the endothelial surface where it regulates leukocyte rolling. Thus endothelial exocytosis plays an important role in mediating vascular inflammation and thrombosis. The regulation of endothelial exocytosis is partially understood. Exocytosis is a form of vesicle trafficking in which the granule fuses with the cellular plasma membrane, releasing its contents into the extracellular space and translocating transmembrane proteins to the surface of the cell. Several families of proteins regulate exocytosis, including N-ethylmaleimide sensitive factor (NSF), soluble NSF attachment protein receptors (SNAREs), rab GTPases, and Munc. We recently showed that NSF plays a critical role in the regulation of exocytosis of Weibel-Palade bodies. We also discovered that nitric oxide (NO) inhibits exocytosis by targeting NSF. Our observations explain in part how NO inhibits vascular inflammation and thrombosis. The over-all goal of our studies is to explore the molecular mechanisms by which endothelial exocytosis regulates vascular inflammation. This application focuses on NSF regulation of endothelial cell exocytosis. We plan to continue our studies of how radicals regulates NSF. Next we plan to study how specific enzymes reduce oxidized NSF. Finally, we plan to develop a novel class of drugs that decrease vascular inflammation by targeting endothelial cell exocytosis.