Biophysical Aspects of Leukocyte Transmigration through the Vascular Endothelium

描述（由申请人提供）：心血管疾病（CVD）是世界上主要的死亡原因。一种类型的CVD，动脉粥样硬化，通常发生在血流紊乱的区域，并且其发作导致动脉硬化和升高的斑块的产生，这增加了完全动脉阻塞的机会。如果大脑的血液供应由于这种阻塞而停止，就会发生中风。与动脉硬化的机械效应相关的生物物理方面以及它们与免疫功能的关系将在拟议的研究计划中同时进行研究。该提议的主要假设是免疫细胞的跨内皮迁移（TEM）机制受到内皮细胞（EC）层的组织和硬度的影响。提出了三个具体的目标来调查这一假设。第一个目的是设计和表征血管内皮的体外模型。形态学，蛋白质表达，刚度，牵引力，F-肌动蛋白分布，和局灶性粘连的EC将检查作为潜在的刚度和剪切应力是不同的。第二个目的是研究白细胞迁移沿着EC单层作为一个功能的基础刚度和剪切应力。白细胞沿EC层的沿着迁移将使用几个参数来量化，例如速度、随机运动系数和转向角的分布，并且由EC施加的牵引力也将被量化为通过EC的力传递的变化的量度。第三个目的是通过EC研究白细胞TEM作为基础刚度和剪切力的函数。白细胞TEM对EC机械传递的影响将通过检查EC的牵引力、F-肌动蛋白分布和粘着斑来研究。随着拟议的研究计划的完成，我们将更充分地了解EC在细胞TEM中作为力传递器的作用，以及这一过程如何在硬化的动脉粥样硬化组织中改变。中风是一种心血管和神经系统疾病，通常是由于通往大脑的动脉阻塞和硬化而发生的。该提案调查硬化的动脉粥样硬化组织如何影响免疫细胞迁移到患病动脉中，以及在此过程中力如何通过血管内皮传递。最终，我们的目标是找到更好的方法来预测中风的发作，以便治疗成为可能。

DESCRIPTION (provided by applicant): Cardiovascular disease (CVD) is the leading cause of death in the world. One type of CVD, atherosclerosis, typically occurs in regions of disturbed blood flow, and its onset results in the stiffening of arteries and the creation of raised plaques which increase the chance of complete artery blockage. If blood supply to the brain is stopped as a result of this blockage, stroke occurs. The biophysical aspects associated with the mechanical effects of artery stiffening and how they relate to immune function will be investigated simultaneously in the proposed research plan. The main hypothesis of this proposal is that the mechanisms of transendothelial migration (TEM) by immune cells are affected by the organization and stiffness of the endothelial cell (EC) layer. Three specific aims are proposed to investigate this hypothesis. The first aim is to design and characterize an in vitro model of the vascular endothelium. The morphology, protein expression, stiffness, traction forces, F-actin distribution, and focal adhesions of the ECs will be examined as the underlying stiffness and shear stress are varied. The second aim is to investigate leukocyte migration along the EC monolayer as a function of underlying stiffness and shear stress. Leukocyte migration along the EC layer will be quantified using several parameters such as speed, random motility coefficient, and distribution of turning angles, and the traction forces exerted by the ECs will also be quantified as a measure of changes in force transmission through the ECs. The third aim is to investigate leukocyte TEM through ECs as a function of underlying stiffness and shear stress. The effects of leukocyte TEM on EC mechanotransmission will be investigated by examining the traction forces, F-actin distribution, and focal adhesions of the ECs. With the completion of the proposed research plan, we will more fully understand the role the ECs play as force transmitters during cellular TEM, and how this process might be altered in stiffened, atherosclerotic tissue. Stroke is a type of cardiovascular and neurological disease which often occurs due to blockage and stiffening of the arteries leading to the brain. This proposal investigates how stiffened, atherosclerotic tissue might affect immune cell migration into the diseased arteries, and how forces are transmitted through the vascular endothelium during this process. Ultimately, our goal is to find better ways to predict onset of a stroke before it occurs, so that treatment may be possible.