Integrin activation during neutrophil adhesion and vascular inflammation

中性粒细胞粘附和血管炎症期间的整合素激活

• 批准号: 10822018
• 负责人: Lai Wen
• 金额: $ 21.3万
• 依托单位: UNIVERSITY OF NEVADA RENO
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-01-01 至 2024-03-04
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10822018
• 关键词: Actin-Binding Protein; Actins; Adaptor Signaling Protein; Adhesions; Affinity; Bacterial Infections; Binding; Blood Circulation; Cardiovascular system; Cell membrane; Centers of Research Excellence; Cytoskeleton; Detection; Disease; Host Defense; Human; Image; Inflammation; Inflammatory; Injury; Integrin Binding; Integrins; Molecular; Molecular Conformation; Mus; Mycoses; Nevada; PH Domain; Play; Process; Reperfusion Injury; Reporter; Reporting; Research; Role; Signal Transduction; Site; Talin; Tertiary Protein Structure; Testing; Transmembrane Domain; chemokine; driving force; innovation; insight; ischemic injury; necrotic tissue; neutrophil; recruit; vascular inflammation

Neutrophils, which are essential for host defense against bacterial and fungal infections, induce inflammation following tissue necrosis or ischemic injury. If not properly resolved, neutrophilic inflammation is the driving force behind a plethora of human inflammatory diseases. Neutrophils arrive at the site of injury from the bloodstream by first rolling and then arresting. Arrest is triggered by chemokines that induce the high-affinity conformation of ..2 integrins. Two FERM domain proteins, kindlin-3 and talin-1, are required for neutrophil arrest. It is well known that talin-1, an adaptor protein that binds the actin cytoskeleton, activates integrins by binding and altering the topology of the .. transmembrane domain. We recently reported that kindlin-3 is recruited to the plasma membrane through its pleckstrin homology domain prior to neutrophil arrest. However, the mechanism underlying neutrophil spreading and the role of kindlin-3 in this process are poorly understood. Moreover, how kindlin-3 cooperates with talin-1 to activate integrins and whether kindlin-3 also functions as an adaptor protein by directly binding to actin are completely unknown. Our overarching hypothesis is that, during neutrophil spreading, both kindlin-3 and talin-1 are simultaneously recruited to the plasma membrane, where kindlin-3 organizes high-affinity integrin activation. To test this hypothesis, we generated reporter mouse lines for simultaneous detection of ..2 integrin activation and imaging of kindlin-3 and talin-1 in mouse neutrophils. In Aim 1, we will test the hypothesis that kindlin-3 organizes a ring of clustered high-affinity ..2 integrins during neutrophil spreading under flow conditions; in Aim 2, we will test the hypothesis that kindlin-3 regulates integrin activation by directly binding to the actin cytoskeleton; and in Aim 3, we will determine the role of ..2 integrin activation in ischemia-reperfusion injury (IRI). The proposed research is conceptually innovative and highly significant because it will resolve the enigma of how kindlin-3 organizes high-affinity integrin activation and define the role it plays in IRI-induced inflammation. Successful completion of this proposal will establish molecular mechanisms of integrin activation and provide mechanistic insight into neutrophil spreading and vascular inflammation.

中性粒细胞对于宿主防御细菌和真菌感染至关重要，可诱导 组织坏死或缺血性损伤后的炎症。如果没有正确解决，中性粒细胞 炎症是多种人类炎症性疾病的驱动力。中性粒细胞到达 首先滚动然后停止，以防止血液流向受伤部位。逮捕是由趋化因子触发的 诱导 ..2 整合素的高亲和力构象。两个 FERM 结构域蛋白 kindlin-3 和 talin-1 是中性粒细胞停滞所必需的。众所周知，talin-1 是一种接头蛋白，可结合 肌动蛋白细胞骨架，通过结合和改变跨膜的拓扑结构来激活整合素 领域。我们最近报道 kindlin-3 通过其 pleckstrin 被招募到质膜上 中性粒细胞停滞前的同源域。然而，中性粒细胞扩散的机制和 kindlin-3 在此过程中的作用人们知之甚少。而且kindlin-3如何与talin-1配合 激活整合素以及 kindlin-3 是否也通过直接结合肌动蛋白而充当衔接蛋白 完全未知。我们的总体假设是，在中性粒细胞扩散过程中，kindlin-3 和talin-1同时被招募到质膜，其中kindlin-3组织高亲和力 整合素激活。为了检验这一假设，我们生成了用于同时检测的报告小鼠系 ..2 小鼠中性粒细胞中 kindlin-3 和 talin-1 的整合素激活和成像。在目标 1 中，我们将测试 假设 kindlin-3 在中性粒细胞扩散过程中组织一簇聚集的高亲和力 ..2 整合素环 在流动条件下；在目标 2 中，我们将通过以下方式检验 kindlin-3 调节整合素激活的假设： 直接结合肌动蛋白细胞骨架；在目标 3 中，我们将确定 ..2 整合素激活的作用 在缺血再灌注损伤（IRI）中。所提出的研究在概念上具有创新性且高度 意义重大，因为它将解决 kindlin-3 如何组织高亲和力整合素激活的谜团 并定义它在 IRI 诱导的炎症中所起的作用。本提案的顺利完成将 建立整合素激活的分子机制并提供中性粒细胞的机制见解 扩散和血管炎症。