权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Role of AJC in umbrella cell function and dysfunction

AJC 在伞细胞功能和功能障碍中的作用

基本信息

批准号：
10655616
负责人：
Gerard L Apodaca
金额：
$ 63.61万
依托单位：
UNIVERSITY OF PITTSBURGH AT PITTSBURGH
依托单位国家：
美国
项目类别：
财政年份：
2021
资助国家：
美国
起止时间：
2021-09-06 至 2026-06-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10655616
关键词：
3-Dimensional Actins Actomyosin Acute Adherens Junction Adhesions Affect Animal Model Apical Benign Prostatic Hypertrophy Binding Biology Bladder Bladder Dysfunction Cell Line Cell physiology Cell-Cell Adhesion Cells Complex Contracts Coupled Cystitis Cytoskeleton Data Desmosomes Devices Electron Microscopy Endocytosis Endothelial Cells Enterocytes Environment Epithelium Event Exocytosis Functional disorder Gene Expression Global Change Image Image Analysis Integral Membrane Protein Interstitial Cystitis Length Lower urinary tract Mechanics Membrane Membrane Proteins Microscopy Myosin Type II Obstruction Organ of Corti Pathologic Pathology Pathway interactions Patients Polymers Process Proliferating Proteins Regulation Renal tubule structure Reporting Role Sarcomeres Signal Pathway Site Spinal cord injury Stomach Stretching Structure Testing Tight Junctions Time Tissues Urine Urologic Diseases Urothelial Cell Urothelium Variant confocal imaging experimental study force sensor genetic regulatory protein insight intravesical live cell imaging mechanotransduction non-muscle myosin novel pneumocyte polymerization preservation pressure response sensor trafficking ultra high resolution

项目摘要

Abstract: A critical component of the umbrella cell barrier is the apical junctional complex (AJC), a multipartite, belt-like structure comprised of the tight junction, the adherens junction, desmosomes, and an associated cytoskeleton. Functions of the AJC include regulation of paracellular flux, cell-cell adhesion, and mechanotransduction. Despite evidence that the umbrella cell AJC is integral to urothelial function and disrupted in several lower urinary tract disorders, we have limited understanding of key aspects of umbrella cell AJC biology and pathobiology including: (i) how the AJC maintains its continuity in the face of cyclical bladder filling and voiding; (ii) how the AJC is organized to undergo these transitions and the function of the cytoskeleton in these events; and (iii) how the umbrella cell AJC senses tension and whether pathologically high intravesical pressures stimulate AJC-associated mechanotransduction pathways. Our preliminary studies include the novel findings that during bladder filling the AJC perimeter expands dramatically, a process that depends on changes in the actin cytoskeleton and vesicular traffic, likely directed toward the AJC. In contrast, the AJC contracts soon after bladder voiding, events driven by the non-muscle myosin II-triggered contraction of the actin cytoskeleton, RhoA, as well as endocytosis. Based on available data, we hypothesize that critical functions of the umbrella cell AJC are to maintain urothelial barrier function by undergoing dynamic expansion and contraction and to serve as a site of mechanotransduction under normal and pathological conditions. To test this global hypothesis, we propose the following experiments. In Aim 1, we will use a newly developed biaxial stretching device, coupled with live-cell image analysis, to determine if increased strain triggers exocytosis of junction-associated proteins directed toward the AJC, and if release of strain stimulates their endocytosis. We will also assess if blocking AJC expansion perturbs urothelial barrier function. In Aim 2, we will focus on deciphering the function and organization of the umbrella cell AJC-associated cytoskeleton. We will use super-resolution confocal imaging, as well as electron microscopy to reconstruct the umbrella cell AJC in 3D. In addition, we will determine if formins drive actin polymerization in response to filling. In Aim 3, we will use tension sensors to determine if transmembrane proteins associated with the umbrella cell AJC sense force, and assess whether junction-associated signaling pathways are activated in response to partial bladder outlet obstruction (PBOO). Upon completion of these studies we will have new insights into how umbrella cell AJC dynamics contribute to urothelial barrier function, the organization of the AJC and the function of its associated cytoskeleton, and important new information about how the AJC senses and responds to perturbations in its mechanical milieu, including in response to PBOO.

摘要/ Abstract摘要：保护伞细胞屏障的一个关键组成部分是AJC