Disintegrin Metalloprotease and Endothelial Permeability

性状（由申请人提供）：ADAM 15是一种具有去整合素金属蛋白酶特征的跨膜糖蛋白，具有脱落受体分子和调节细胞-细胞/基质粘附的能力。增加的ADAM15表达与转移性癌症、动脉粥样硬化和炎性肠病的发展相关。我们最近的工作已经确定了一个新的功能，这种分子作为一个促炎因子能够增加血管内皮细胞的通透性。进一步的研究表明，在细菌感染或脓毒症刺激期间，ADAM15在肺中上调，导致中性粒细胞浸润和肺水肿。ADAM 15介导的屏障损伤的组织特异性作用和潜在机制尚未得到表征。该项目的总体目标是了解炎症中ADAM 15表达和功能的分子控制。提出了两个具体的目标：1）描述脓毒症中ADAM 15活性的功能和调节途径，以及2）阐明ADAM 15诱导高通透性的分子机制。待检验的中心假设是脓毒症诱导ADAM 15在转录和翻译后水平上调。ADAM 15通过其胞质结构域激活Src信号转导增加内皮细胞-细胞连接通透性，而解整合素调节局灶性粘连和/或连接结构的金属蛋白酶脱落作为替代途径。这一新概念将通过一系列补充研究进行验证，这些研究将使用动物模型进行体内生理分析和培养细胞中的体外分子测定相结合。创新的实验模型和分子工具将被构建和测试。从拟议的工作中获得的数据不仅将建立蛋白酶分子生物学的新理论，而且还将为脓毒症和急性炎症的病理生理学提供新的机制见解。此外，该研究对识别和开发有效治疗炎症性疾病的新治疗靶点具有潜在影响。

DESCRIPTION (provided by applicant): ADAM15 is a transmembrane glycoprotein characteristic of disintegrin metalloprotease with the ability to shed receptor molecules and regulate cell-cell/matrix adhesions. Increased ADAM15 expression is associated with the development of metastatic cancer, atherosclerosis, and inflammatory bowl disease. Our recent work has identified a novel function of this molecule as a pro-inflammatory factor capable of increasing vascular endothelial permeability. Further studies suggest that ADAM15 is upregulated in the lungs during bacterial infection or septic stimulation, contributing to neutrophil infiltration and pulmonary edema. The tissue-specific effect and underlying mechanisms of ADAM15-mediated barrier injury have not been characterized. The overall goal of this project is to understand the molecular control of ADAM15 expression and function in inflammation. Two specific aims are proposed: 1) to characterize the functions and regulatory pathways of ADAM15 activity in sepsis, and 2) to elucidate the molecular mechanisms by which ADAM15 induces hyperpermeability. The central hypothesis to be tested is that sepsis induces ADAM15 upregulation at the transcriptional and posttranslational levels. ADAM15 increases endothelial cell-cell junction permeability by activating Src signal transduction via its cytoplasmic domain, whereas disintegrin regulation of focal adhesions and/or metalloprotease shedding of junctional structures serve as alternative pathways. This novel concept will be validated through a series of complementary studies that integrate in vivo physiological analyses using animal models and in vitro molecular assays in cultured cells. Innovative experimental models and molecular tools will be constructed and tested. Data derived from the proposed work will not only establish a novel theory in protease molecular biology, but also provide new mechanistic insights into the pathophysiology of sepsis and acute inflammation. In addition, the study has potential impact on the identification and development of novel therapeutic targets for effective treatment of inflammatory disease.