Biophysical Aspects of Leukocyte Transmigration through the Vascular Endothelium

描述（由申请人提供）：心血管疾病（CVD）是世界上导致死亡的主要原因。一种类型的心血管疾病，动脉粥样硬化，通常发生在血流紊乱的区域，它的发作导致动脉硬化和产生凸起的斑块，这增加了动脉完全阻塞的机会。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及其与免疫功能的关系将在拟议的研究计划中同时进行研究。本研究的主要假设是免疫细胞跨内皮迁移（TEM）的机制受到内皮细胞（EC）层的组织和刚度的影响。提出了三个具体目的来调查这一假设。第一个目的是设计和表征血管内皮的体外模型。形态学、蛋白表达、刚度、牵引力、f -肌动蛋白分布和ECs的局灶粘连将随着潜在刚度和剪切应力的变化而变化。第二个目的是研究白细胞沿EC单层迁移作为底层刚度和剪切应力的函数。白细胞沿着EC层的迁移将被量化，使用几个参数，如速度、随机运动系数和转角分布，EC施加的牵引力也将被量化，作为通过EC的力传递变化的测量。第三个目的是通过ECs研究白细胞透射电镜作为底层刚度和剪切应力的函数。白细胞透射电镜对EC机械传递的影响将通过检查EC的牵引力、f -肌动蛋白分布和局灶粘连来研究。随着该研究计划的完成，我们将更充分地了解ec在细胞透射电镜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发生改变。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。本研究旨在探讨硬化的动脉粥样硬化组织如何影响免疫细胞向病变动脉的迁移，以及在此过程中作用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，在中风发生之前预测它的发作，从而使治疗成为可能。

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.