PECAM-INDEPENDENT TRANSENDOTHELIAL MIGRATION

PECAM 独立的跨内皮迁移

• 批准号: 6088605
• 负责人: William A Muller
• 金额: $ 39.26万
• 依托单位: WEILL MEDICAL COLL OF CORNELL UNIV
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-01 至 2004-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6088605
• 关键词: CD antigens; acute disease /disorder; cell membrane; cell migration; complementary DNA; gene targeting; genetically modified animals; human tissue; inflammation; integrins; laboratory mouse; laboratory rat; leukocyte activation /transformation; leukocyte adhesion molecules; ligands; molecular cloning; molecular pathology; monoclonal antibody; monocyte; platelets; protein structure function; vascular cell adhesion molecule; vascular endothelium

DESCRIPTION (Verbatim from Investigator's Abstract): The inflammatory response is a double-edged sword. Mobilization of leukocytes to a focus of inflammation is critical for the rapid resolution of infections and restoration of tissue damage resulting from a variety of injuries. On the other hand, most human pathology results from inflammation that is misdirected or prolonged with the result that host tissues are damaged as a result. Therefore, much attention has been directed toward understanding the molecular basis of inflammation in the hope of being better able to regulate it. Previous studies have demonstrated a crucial role for platelet/endothelial cell adhesion molecule-2 (PECAM) in transendothelial migration (TEM), the step in which leukocytes (WBC) enter inflamed tissues by squeezing between the tightly apposed endothelial cells (EC) lining the blood vessels. However, even under the most favorable circumstances, blocking PECAM function only blocks 80-90% of leukocyte influx. The residual 10-20% of WBC that are not blocked may represent a clinically significant population under chronic conditions. Furthermore, there may be inflammatory stimuli, vascular beds, or WBC types for which PECAM does not play a major role in TEM. The aims of this proposal are to identify molecules responsible for PECAM-independent (PECAM alternative) mechanisms of TEM. We have developed an in vitro assay that can distinguish a block in adhesion of WBC tot he apical surface of EC from a block in TEM. Using this assay, we have identified two candidate molecules. In aim 1 we will further characterize and clone HEC2, a novel membrane proteins on EBC and EC junctions that are involved in TEM. In aim 2, we will further characterize a leukocyte beta2 integrin that plays a unique role in TEM that is independent of its role in adhesion and dependent on blockade of PECAM. In aim 3, we will test predictions made in vitro in two murine models of acute inflammation in which we can distinguish a block in adhesion from a block in transmigration. We have generated mice that are genetically deficient in PECAM and mice in which PECAM does not function. These mice will be critical to evaluate PECAM-independent TEM.

描述（逐字摘自研究者摘要）：炎症反应 是一把双刃剑白细胞向炎症病灶的动员 对于快速解决感染和组织修复至关重要 各种伤害造成的损害。另一方面，大多数人 病理学是由炎症引起的， 结果导致宿主组织受损。因此，许多注意力 一直致力于了解炎症的分子基础， 希望能够更好地调节它。以前的研究表明， 血小板/内皮细胞粘附分子-2（PECAM）在 跨内皮迁移（TEM），即白细胞（WBC）进入 通过紧密贴壁的内皮细胞之间的挤压， (EC)衬在血管上然而，即使在最有利的情况下， 在这种情况下，阻断PECAM功能仅阻断80-90%的白细胞流入。 残留的10-20%未被阻断的WBC可能代表临床上 在慢性疾病中的重要人群。此外，可能有 PECAM不起作用的炎症刺激、血管床或WBC类型 在TEM中扮演重要角色。这项提案的目的是确定分子 负责TEM的PECAM独立（PECAM替代）机制。我们 已经开发了一种体外试验，可以区分粘连的阻滞， 透射电镜下可见白细胞从EC块的顶面脱落。使用该分析，我们有 确定了两个候选分子在目标1中，我们将进一步描述和 克隆HEC 2，一种新的EBC和EC连接处的膜蛋白， 在TEM中。在目标2中，我们将进一步表征白细胞β 2整联蛋白， 在TEM中发挥着独特的作用，独立于其在粘附中的作用， 依赖于PECAM的阻断。在目标3中，我们将测试 在两种急性炎症的小鼠模型中，我们可以区分 从轮回中的阻碍到粘附中的阻碍。我们培育出的老鼠 在PECAM和PECAM不起作用的小鼠中存在遗传缺陷。 这些小鼠对于评价PECAM非依赖性TEM至关重要。