Tetraspanin-enriched microdomains and endothelial barrier function

富含四跨膜蛋白的微区和内皮屏障功能

• 批准号: 9238927
• 负责人: XIN A ZHANG
• 金额: $ 37.44万
• 依托单位: UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
• 依托单位国家: 美国
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-12-15 至 2020-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9238927
• 关键词: 1-Phosphatidylinositol 4-Kinase; Actins; Adhesions; Adhesiveness; Animal Model; Basal Cell; Basement membrane; Blood Vessels; C-terminal; Cardiovascular Diseases; Cell Adhesion; Cell Adhesion Molecules; Cell Communication; Cell membrane; Cell physiology; Cell surface; Cell-Cell Adhesion; Cell-Matrix Junction; Cells; Cyclic AMP; Cysteine; Cytoplasmic Tail; Cytoskeleton; Cytosol; Deposition; Development; Disease; Endothelial Cells; Endothelium; Equilibrium; Extravasation; Filopodia; Fostering; Generations; Goals; Gray unit of radiation dose; Growth Factor Receptors; Guanosine Triphosphate Phosphohydrolases; Human; In Vitro; Infection; Inflammation; Integrin Binding; Integrins; Intracellular Signaling Proteins; Knockout Mice; Laminin; Lead; Link; Membrane; Membrane Microdomains; Molecular; Monomeric GTP-Binding Proteins; Mus; Pathogenesis; Pathology; Permeability; Play; Prevention; Proteins; Role; Signal Transduction; Signaling Protein; Sorting - Cell Movement; Stress Fibers; Structure; Surface; Transmembrane Domain; Vascular Diseases; Vascular Permeabilities; base; biophysical properties; cell motility; disulfide bond; extracellular; in vivo; insight; member; nanoscale; novel; prevent; receptor; rho; therapeutic development; vascular abnormality

Cell-cell and cell-matrix adhesions play essential roles in endothelial barrier function. Various tetraspanins are expressed in endothelium, form tetraspanin-enriched microdomains with cell adhesion proteins such as integrins, and regulate endothelial cell adhesion and vascular permeability. Our early study revealed that tetraspanins are required for maintaining proper endothelial adhesiveness, endothelial barrier, and vascular permeability. We have demonstrated that, to sustain vascular stability, tetraspanin-enriched microdomains tune the balance of Rac1 and RhoA small GTPase activities or the balance of cortical actin meshwork and stress fibers to sustain endothelial cell-cell and cell matrix adhesions. But the in-depth mechanisms by which tetraspanins regulate endothelial barrier function still remain elusive. We will use tetraspanin CD151 as example in this study to elucidate the mechanisms by which tetraspanin-enriched microdomains regulate endothelial barrier function and vascular permeability. The overarching hypotheses of this project include that, at the cellular level, CD151 promotes endothelial barrier function by primarily increasing endothelial cell-matrix interactions, which subsequently elevates endothelial cell-cell adhesion. Meanwhile, CD151 can also directly reinforce endothelial cell-cell interaction. At the molecular level, CD151 reinforces cell adhesions by enhancing the functional accessibility and nanoscale organization of cell adhesion proteins at endothelial cell surface. Specifically, we will first unravel the mechanism by which CD151 reinforces endothelial cell- matrix adhesion. We will assess both in vitro and in vivo mechanistic roles of CD151 in integrin activation and accessibility at the basal surface of endothelial cells. Secondly, we will reveal the mechanism by which CD151 reinforces endothelial cell-cell adhesion. We will assess both in vitro and in vivo mechanistic roles of CD151 in maintaining structural and functional integrity of endothelial cell-cell contacts, which directly prevents endothelial hyper-permeability. Finally, we will delineate the signaling mechanisms by which CD151 reinforces endothelial barrier and reduces vascular hyper-permeability. Hence, the general goal of this project is to understand how CD151 sustains the endothelium barrier function by assessing both in vitro and in vivo mechanistic roles of CD151 in stabilizing the structural and functional interactions of endothelium with the underlying basement membrane and in maintaining the structural and functional integrity of endothelial cell-cell contacts and junctions. From these studies, we will understand why and how tetraspanin-enriched microdomains are important for endothelial barrier function, establish a novel paradigm between vascular permeability and membrane organization of cell adhesion molecules, and delineate the signaling axis that governs the fine balance of small GTPases in endothelium. From the in-depth mechanistic study, we will develop an integrated understanding of the unique features of tetraspanin-enriched microdomains, which will ultimately lead to the development of therapeutic mean against vascular diseases.

细胞-细胞和细胞-基质粘附在内皮屏障功能中起重要作用。各种 四跨膜蛋白在内皮中表达，与细胞形成四跨膜蛋白富集微区 粘附蛋白如整合素，并调节内皮细胞粘附和血管内皮细胞粘附。 磁导率我们的早期研究表明，四跨膜蛋白是维持正常的 内皮细胞粘附、内皮屏障和血管通透性。我们已经证明 为了维持血管稳定性，富含四跨膜蛋白的微区调节Rac 1的平衡， 和RhoA小GT3活性或皮质肌动蛋白网络和应力纤维的平衡， 维持内皮细胞-细胞和细胞基质粘附。但是， 四跨膜蛋白调节内皮屏障功能仍然是未知。 本研究以四跨膜蛋白CD 151为例，探讨其在细胞内表达的机制。 富含四跨膜蛋白的微区调节内皮屏障功能和血管通透性。 该项目的主要假设包括，在细胞水平，CD 151促进 内皮屏障功能主要通过增加内皮细胞-基质相互作用， 随后提高内皮细胞-细胞粘附。同时，CD 151也可以直接 增强内皮细胞-细胞相互作用。在分子水平上，CD 151增强细胞粘附 通过增强细胞粘附蛋白的功能可及性和纳米级组织， 内皮细胞表面 具体来说，我们将首先阐明CD 151增强内皮细胞的机制， 基体附着力我们将评估CD 151在整合素中的体外和体内机制作用， 活化和可接近性在内皮细胞的基底表面。其次，我们将揭示 CD 151增强内皮细胞-细胞粘附的机制。我们将在体外评估 以及CD 151在维持细胞结构和功能完整性中的体内机制作用。 内皮细胞-细胞接触，其直接防止内皮细胞高渗透性。最后我们 将描述CD 151增强内皮屏障的信号传导机制， 降低血管通透性过高。 因此，本项目的总体目标是了解CD 151如何维持内皮细胞 通过评估CD 151在稳定细胞中的体外和体内机制作用， 内皮与基底膜的结构和功能相互作用， 维持内皮细胞-细胞接触和连接的结构和功能完整性。 从这些研究中，我们将了解为什么以及如何富含四跨膜蛋白的微域是 对于内皮屏障功能重要，建立了血管 细胞粘附分子的通透性和膜组织，并描绘信号转导 调节内皮细胞中小GTP酶精细平衡的轴。从深入 机械研究，我们将开发的独特功能的综合理解， 富含四跨膜蛋白的微区，这将最终导致治疗的发展， 意味着可以预防血管疾病。