PMN-Endothelial Cross-Talk via TRPM2 and Lung Vascular Injury

项目1的中心目标是确定新型氧化敏感瞬时受体电位美拉他芬（TRPM）2的特性，它是肺内皮细胞（ECs）中Ca（2+）可渗透通道，它如何调节Ca（2+）信号，以及它在中性粒细胞依赖性肺血管通透性增加和炎症损伤机制中的作用。我们的方法将是确定中性粒细胞- ec相互作用在激活TRPM2通道中的重要作用，然后确定其激活机制，最后确定TRPM2激活如何导致肺内皮通透性增加和PMNs在粘附连接水平上的转运。目的1将验证PMN通过β -整合素/ICAM-1结合与肺内皮相互作用，通过激活ECs中的TRPM2通道增加肺血管通透性的假设。目标#2将定义TRPM2短剪接变体TRPM2- s的作用。在调节肺内皮细胞中trpm2介导的Ca2+进入以及内皮细胞的超通透性和PMN转运机制中的作用。目的3将确定nf - kappab依赖性ICAM-1表达在ECs中放大TRPM2活性的作用，从而介导pmn依赖性肺炎症损伤。拟议的研究将使用分子，基因。与pmn共培养EC单层细胞的生理途径

The central objective of Project 1 is to define the properties of the novel, oxidant-sensitive transient receptor potenfial melastafin (TRPM)2, a Ca(2+)-permeable channel in lung endothelial cells (ECs), how it regulates Ca(2+) signaling, and its role in the mechanism of neutrophil-dependent increases in lung vascular permeability and infiammatory injury. Our approach will be to identify the essenfial role of neutrophil-EC interactions in activafing the TRPM2 channel, then its mechanism of activation, and finally define how TRPM2 activation leads to increased lung endothelial permeability and transmigration of PMNs at the level of adherens juncfions. Aim #1 will test the hypothesis that PMN interaction with the lung endothelium via beta2-integrin/ICAM-1 binding increases lung vascular permeability through the activation of TRPM2 channels in ECs. Aim #2 will define the role of the short splice variant of TRPM2, TRPM2-S. in regulafing TRPM2-mediated Ca2+ entry in lung ECs and in the mechanism of endothelial hyper-permeability and PMN transmigration. Aim #3 will determine the role of NF-kappaB-dependent ICAM-1 expression in amplifying TRPM2 acfivity in ECs and thereby in mediating PMN-dependent lung infiammatory injury. The proposed studies will use molecular, genefic. and physiological approaches in EC monolayers co-cultured with PMNs and mouse lung models (including the recentiy developed TRPM2(-/-) mice). These data will provide new insights into the mechanisms of acute lung injury and specifically theTRPM2-activated pathways that mediate lung injury. Furthermore, we believe that it will be possible, with a new understanding of this transcellular cross-talk, to block inappropriate neutrophil-EC interacfions and PMN-mediated lung injury by interfering with TRPM2-activated signaling pathways.