Novel Roles for ADAM15 in Acute Lung Injury

描述（由申请人提供）：ADAM15是ADAM家族（具有崩解素和金属蛋白酶结构域的蛋白酶）的成员。它由炎症细胞表达，但对其在肺中的作用知之甚少。我们在小鼠急性肺损伤模型中对ADAM15-/-小鼠的研究表明，ADAM15促进PMN在肺中的积累，促进肺泡毛细血管屏障的损伤。ADAM15延缓肺PMN凋亡，减少巨噬细胞对凋亡靶点的摄取。ADAM15储存在PMN中，当细胞被激活时迅速转运到PMN表面。ADAM15降解肺细胞外基质蛋白。我们将研究ADAM15增加ALI期间肺PMN负荷的机制，以及ADAM15在PMN中的细胞生物学和酶生化。我们建议实现以下具体目标：研究ADAM15促进肺PMN存活的机制：目的1A：我们将验证我们的假设，即ADAM15通过释放调节细胞凋亡的TNF受体家族成员来延缓PMN凋亡，从而增加肺PMN负担。目的1B：我们将验证我们的假设，ADAM15也通过抑制肺巨噬细胞对凋亡的PMN的摄取来增加肺PMN负荷。具体目标2。探讨ADAM15在PMN中的细胞生物学特性。目标2。我们将验证我们的假设，即ADAM15作为预形成的蛋白酶储存在PMN细胞质储存位点，并在PMN被激活去颗粒时迅速转运到细胞表面。我们将在PMN中确定ADAM15的存储位置。目标2 b。我们将验证我们的假设，即ADAM15随后通过网格蛋白依赖机制从活化的PMN表面内化。具体目标3。我们将验证我们的假设，即PMN表面表达的ADAM15是一种timresistant蛋白酶，它可以切割基质和非基质蛋白，从而促进肺部炎症和损伤。我们希望我们的研究能够为ADAM 15在ALI期间促进中性粒细胞肺炎症和肺损伤的机制提供新的见解，并且从长远来看，这将有助于设计新的治疗策略。

DESCRIPTION (provided by applicant): ADAM15 is a member of the ADAM family (proteinases with a disintegrin and a metalloproteinase domain). It is expressed by inflammatory cells, but little is known about its roles in the lung. Our studies of ADAM15-/- mice in a murine model of acute lung injury show that ADAM15 promotes PMN accumulation in the lung, and promotes alveolar capillary barrier injury. ADAM15 delays PMN apoptosis in the lung, and reduces macrophage uptake of apoptotic targets in vitro. ADAM15 is stored in PMN, and rapidly translocates to the PMN surface when cells are activated. ADAM15 degrades a lung extracellular matrix protein. We will investigate the mechanisms by which ADAM15 increases the lung PMN burden during ALI, and the cell biology and enzyme biochemistry of ADAM15 in PMN. We propose to pursue the following Specific Aims: Specific Aim 1. Investigate the mechanism by which ADAM15 promotes PMN survival in the lung: Aim 1A: We will test our hypothesis that ADAM15 increases the lung PMN burden by delaying PMN apoptosis by shedding of TNF receptor family members that regulate apoptosis. Aim 1B: We will test our hypothesis that ADAM15 also increases the lung PMN burden by inhibiting uptake of apoptotic PMN by lung macrophages. Specific Aim 2. Investigate the cell biology of ADAM15 in PMN. Aim 2A. We will test our hypothesis that ADAM15 is stored as a preformed proteinase within PMN cytoplasmic storage sites, and rapidly translocates to the cell surface when PMN are activated to degranulate. We will identify the storage sites for ADAM15 in PMN. Aim 2B. We will test our hypothesis that ADAM15 is subsequently internalized from the surface of activated PMN by a clathrin-dependent mechanism. Specific Aim 3. We will test our hypothesis that ADAM15 expressed on the surface of PMN is a TIMPresistant proteinase that cleaves matrix and non-matrix proteins to promote lung inflammation and injury. We hope that our studies will provide novel insights into the mechanisms by which ADAM 15 promotes neutrophilic lung inflammation and lung injury during ALI, and that in the long term, this will facilitate the design of new treatment strategies for ALI in man.