Cellular Mechanics and Microvascular Interactions

我们在这个项目中的目标是了解粘合剂的特定物理特性 界面具有粘附性和随后细胞行为。特别是，我们的调查集中在 细胞膜的微观形貌、受体的分布和移动性以及粘附的变化 分子亲和力，以及这些属性如何作为趋化因子刺激和键的结果而改变 中性粒细胞和内皮细胞之间的形成。将单细胞微机械操作成 与具有明确粘附分子呈递的人造基质接触， 控制与粘合剂相互作用有关的化学和机械力的能力。这 方法，结合新实施的荧光成像方法，使我们能够确定 细胞力学、表面化学和膜形态学在形成 粘合剂触点。根据对这些因素的基本贡献的了解， 上一阶段，我们将扩大我们的调查，以确定如何物理和化学特性， 细胞表面和下层基质的作用影响粘附行为和细胞粘附的变化。 迁移具体地说，我们将确定如何接触表面提出固定的IL 8和 粘附受体（主要是ICAM-1）诱导表面形貌的变化，并通过关键信号传导 中间体（例如，钙、RAP-1和钙依赖性鸟嘌呤核苷酸交换因子CalDAG GEF 1）对整联蛋白活化和粘附的影响。我们还将测量趋化因子刺激对 粘附配体的分布、迁移和活化状态以及膜细胞骨架的稳定性 接口.最后，我们将确定细胞表面微地形的变化，在接口与其 底物增强趋触信号，以及这些趋触信号的分布和浓度 信号导致细胞扩散和定向细胞爬行。这些研究将使我们更清楚地了解 中性粒细胞在内皮细胞上粘附和迁移的机制及其调节，从而导致 对健康和疾病中的炎症反应有更清晰和更详细的了解。

Our goal in this project is to understand the role that specific physical characteristics of the adhesive interface have on adhesion and subsequent cell behavior. In particular, our investigation focuses on the microtopography of the cell membrane, the distribution and mobility of receptors, and changes in adhesion molecule affinity, as well as how these attributes change as a result of chemokine stimulus and bond formation between neutrophils and the endothelium. Micromechanical manipulation of single cells into contact with artificial substrates with well-defined adhesion molecule presentation provides unparalleled ability to control both the chemistry and the mechanical forces in relation to adhesive interactions. This approach, combined with newly implemented fluorescence imaging methods, enables us to determine the specific role that cellular mechanics, surface chemistry, and membrane topography play in the formation of adhesive contacts. Building on knowledge of the fundamental contributions of these factors obtained In the previous period, we will extend our investigations to determine how the physical and chemical characteristics of the cell surface and the underiying substrate work to effect changes in adhesive behavior and cell migration. Specifically, we will determine how contact with surfaces presenting immobilized IL8 and adhesion receptors (principally ICAM-1) induces changes in surface topography, and leads via key signaling intermediates (e.g., calcium, RAP-1 and the calcium-dependent guanine nucleotide exchange factor CalDAG GEFl) to integrin activation and adhesion. We will also measure the effects of chemokine stimulus on the distribution, mobility and activation state of adhesive ligands and the stability of the membrane cytoskeletal interface. Finally, we will determine how changes in cell surface microtopgraphy at the interface with its substrate enhance haptotactic signals, and how the distribution and concentration of those haptotactic signals lead to cell spreading and directed cell crawling. These studies will result in a clearer understanding of the mechanisms of neutrophil adhesion and migration on endothelium and its regulation, and thus result in a clearer and more detailed understanding of the inflammatory response in health and disease.