Cadherin Regulation of Epithelial Barriers

钙粘蛋白对上皮屏障的调节

• 批准号: 8706916
• 负责人: BARRY M. GUMBINER
• 金额: $ 39.5万
• 依托单位: UNIVERSITY OF VIRGINIA
• 依托单位国家: 美国
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8706916
• 关键词: Actomyosin; Acute; Adhesions; Adhesives; Affinity; Allergens; Animal Model; Antibodies; Binding; Binding Sites; Biophysics; Cadherins; Calcium Binding; Cell Culture Techniques; Cell Line; Cell surface; Cells; Collaborations; Complex; Cytoskeleton; Dendritic Cells; Disease; Dissociation; E-Cadherin; Endothelium; Enzymes; Epithelial; Epithelium; Epitopes; Event; Goals; Illinois; Immune; Inflammation; Inflammation Mediators; Inflammatory; Intercellular Junctions; Intestines; Kinetics; Laboratories; Left; Lung; Lung Inflammation; Maintenance; Measurement; Microbe; Microtubules; Modeling; Molecular; Molecular Conformation; Monoclonal Antibodies; Mutation; N-terminal; Organ; Permeability; Phosphorylation; Physiological; Physiological Processes; Play; Process; Property; Proteins; Regulation; Role; Site; Structure; Surface; System; Therapeutic; Tissues; base; extracellular; in vivo; insight; migration; neutrophil; novel; novel strategies; public health relevance; response; seal

DESCRIPTION (provided by applicant): Epithelia form dynamic barriers between tissue compartments and modulate their permeability properties during physiological and pathophysiological processes. Inappropriate maintenance or control of epithelial paracellular barriers contributes to many disease processes, especially inflammation. Cadherins are particularly important for the regulation of paracellular permeability in epithelia as well as endothelia, and the cadherin-catenin system has been directly implicated in inflammatory disease. New findings from my laboratory provide important new insights into the mechanisms of E-cadherin regulation in epithelia as well as novel approaches to manipulate cadherin activity experimentally. We discovered a mechanism that controls cadherin conformation and adhesive activity at the cell surface independent of any changes in levels of expression or amounts of associated catenins. This included the discovery of E-cadherin activating monoclonal antibodies (mAbs) and a role for p120-catenin phosphorylation and microtubules in the control of E-cadherin activity state. I hypothesize that regulation of the adhesive homophilic bond itself is a key event in cell junction regulation, allowing the catenin-associated cytoskeleton to pull the junctions apart once the adhesive bond is broken, and that this mechanism plays a role in barrier regulation in both epithelia and endothelia during inflammatory processes. The overall goals of this proposal are to determine the roles of cadherin cell surface regulation in the contro of epithelial barrier function and to understand in greater depth the mechanisms by which cadherins are regulated at the cell surface. The specific aims are: A. Investigate the role of E-cadherin activity state in the regulation of the epithelial barrier during inflammatory processes i cell culture and animal models. Regulation by soluble inflammatory mediators, control of neutrophil transmigration, and regulation of the interactions of dendritic cells with epithelium wil be investigated. The role of E-cadherin regulation in vivo will be assessed in an animal model of lung inflammation. B. Determine the mechanisms regulating cadherin adhesive binding activity at the cell surface. Analysis of the structure of epitopes recognized by activity associated mAbs, the biophysical changes in the properties of the homophilic adhesive bond, and the role of cadherin oligomerization, clustering, and localization in adhesion sites, all will provide insights into how the extracellular adhesive domain is regulated. C. Investigate cytoplasmic mechanisms of E-cadherin activation and cell surface regulation. Determining the enzymes that control p120-catenin phosphorylation, the role of microtubules in controlling E-cadherin activity and p120-catenin phosphorylation, and the effectors through which p120-catenin phosphorylation controls adhesion activity, will provide insights into the molecular mechanisms underlying adhesion regulation. Findings from these studies may allow us to develop cadherin- based approaches, or even therapeutics, to manipulate barrier function during inflammation and related disease processes.

描述（由申请人提供）：上皮在组织室之间形成动态障碍，并在生理和病理生理过程中调节其渗透率。不当维持或控制上皮细胞屏障会导致许多疾病过程，尤其是炎症。钙粘着蛋白对于调节上皮和内皮的细胞细胞渗透性尤为重要，而钙粘蛋白 - 钙蛋白系统已直接与炎症性疾病有关。我实验室的新发现提供了对上皮e-钙粘蛋白调节机制的重要新见解，以及实验操纵钙粘蛋白活性的新方法。我们发现了一种机制，该机制可以控制钙粘着蛋白的构象和粘合活性，而与相关链氨酸蛋白原蛋白酶的表达水平或量的任何变化无关。这包括发现E-钙粘蛋白激活单克隆抗体（mAb），以及P120-catenin磷酸化和微管在控制E-钙粘蛋白活性态中的作用。我假设对粘合剂均电键本身的调控是细胞连接调节中的关键事件，使链球菌相关的细胞骨架一旦破裂后，与链球菌相关的细胞骨架分开，并且这种机制在两个上皮中的障碍物调节中都起着作用和炎症过程中的内皮。该提案的总体目标是确定钙粘蛋白细胞表面调节在上皮屏障功能的控制中的作用，并在更深入地理解钙粘蛋白在细胞表面调节的机制。具体目的是：A。研究E-钙粘蛋白活性状态在炎症过程I细胞培养和动物模型期间的调节中的作用。可以研究可溶性炎症介体的调节，中性粒细胞转移的控制以及树突状细胞与上皮细胞相互作用的调节。 E-钙粘蛋白调节体内的作用将在肺部炎症的动物模型中评估。 B.确定调节细胞表面上钙粘着蛋白粘附活性的机制。分析与活动相关的单元识别的表位的结构，均质粘合键特性的生物物理变化以及钙粘蛋白低聚，聚类和粘附部位的定位的作用，所有这些都将提供见解 如何调节细胞外粘合剂结构域。 C.研究E-钙粘蛋白激活和细胞表面调节的细胞质机制。确定控制p120-catenin磷酸化的酶，微管在控制E-钙粘蛋白活性和p120-catenin磷酸化中的作用，以及p120-catenin磷酸化的效应子，将控制粘附活性，可为分子机制提供洞察力。这些研究的发现可能使我们能够开发基于钙粘蛋白的方法，甚至是治疗剂，以操纵炎症和相关疾病过程中的屏障功能。