Role of Membrane Trafficking in Epithelial Homeostasis

膜运输在上皮稳态中的作用

• 批准号: 10543529
• 负责人: HEIKE FOLSCH
• 金额: $ 35.48万
• 依托单位: NORTHWESTERN UNIVERSITY AT CHICAGO
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-01-01 至 2025-11-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10543529
• 关键词: Amino Acids; Apical; Area; Biochemical; Biochemistry; Biological; Biological Assay; Cell Adhesion Molecules; Cell Polarity; Cell membrane; Cell physiology; Cells; Chronic; Clathrin Adaptors; Complement; Complex; Crohn' s disease; Development; Disease; Disseminated Malignant Neoplasm; Elements; Endocytosis; Endosomes; Epithelial Cells; Epithelium; Exocytosis; Focal Adhesions; Growth; Growth Hormone Receptor; Health; Homeostasis; Human; Human body; Imaging Techniques; Inflammation; Integrins; Kidney Diseases; Laboratories; Lipids; Maintenance; Malignant Neoplasms; Mass Spectrum Analysis; Mediating; Membrane; Microscopy; Molecular; Monomeric GTP-Binding Proteins; Nature; Nutrient; Organ; Organizational Change; Phosphotransferases; Play; Polycystic Kidney Diseases; Post-Translational Protein Processing; Process; Proteins; Receptor Signaling; Recycling; Reporting; Research; Role; Sorting; Speed; Surface; TLR3 gene; Testing; Tissues; Vesicle; Waste Products; Work; apical membrane; autosome; basolateral membrane; cell motility; experimental study; human disease; hypercholesterolemia; innovation; insight; intestinal epithelium; migration; monolayer; novel; novel strategies; phosphoinositide-3,4,5-triphosphate; photoactivation; prevent; receptor; recruit; trafficking; trans-Golgi Network; uptake; wound; wound healing

Epithelial cells play critical roles in many organs and are responsible for elemental processes such as nutrient uptake and waste product secretion. To fulfill these functions, they polarize their plasma membrane into apical and basolateral domains. To maintain tissue homeostasis, epithelial cells must continuously sort newly synthesized and internalized surface receptors to the correct target domain. And after tissue damage, epithelial cells must correctly migrate into the wound and re-colonize the wound area. Loss of polarity is associated with numerous diseases including metastatic cancer, polycystic kidney disease, and Crohn’s disease. How epithelial cell polarity is regulated is thus an important cell biological question with profound implications for human health. Our work identified the epithelial cell-specific clathrin adaptor complex AP-1B as crucial for polarized recycling of cargos to the basolateral domain. Cargos that depend on AP-1B for basolateral localization include important signaling receptors such as epidermal growth hormone receptor whose missorting to the apical domain has been implicated in cancer and polycystic kidney disease, and toll-like receptor 3 whose missorting results in chronic inflammation. A major unresolved question in the field is how AP-1B uniquely functions in epithelial cells, and why its close cousin AP-1A mostly fails to substitute. Our previous work suggested that AP-1B changes the organization of recycling endosomes (REs) to accommodate AP-1B’s function in basolateral sorting. Only AP- 1B but not AP-1A localizes in REs where it triggers the formation of a lipid domain enriched in PI(3,4,5)P3, and facilitates the recruitment of accessory factors including a vesicle-tethering complex (the exocyst) and a lipid kinase (PIPKIg-90). We recently showed that AP-1B expression reduced the speed of collective cell migration after monolayer wounding, a novel function independent of basolateral sorting. We will test the central hypothesis that AP-1B plays dual roles in establishment and maintenance of epithelial monolayers by 1) directing cargos to the basolateral membrane by generating a sorting platform in REs at steady-state and 2) during cell migration by modulating the availability of focal adhesion molecules at the plasma membrane. We will test this hypothesis in our proposed experiments by using state-of-the-art imaging techniques including live TIRF microscopy in combination with photoactivation and unbiased screens including BioID and mass spectrometry to complement innovative cell biological and biochemistry approaches to: 1. Determine how AP-1B generates a basolateral sorting platform, and 2. Determine how AP-1B controls cell migration. Our studies will define new mechanisms governing the organization of polarized epithelial cells at steady-state and during cell migration.

上皮细胞在许多器官中起关键作用，并负责元素过程，例如养分 吸收和废物产品分泌。为了实现这些功能，它们将其质膜偏振 和基底外侧域。为了维持组织稳态，上皮细胞必须继续新排序 合成和内部化的表面受体与正确的目标域。在组织损伤后，上皮 细胞必须正确迁移到伤口并重新殖民地伤口区域。极性丧失与 许多疾病，包括转移性癌症，多囊性肾脏病和克罗恩病。多么上皮 因此，调节细胞极性是一个重要的细胞生物学问题，对人类健康产生了深远的影响。 我们的工作确定上皮细胞特异性网状蛋白适配器复合物AP-1B对于极化回收至关重要 赤道到底型域。依赖于AP-1B进行大量本地化的符号包括重要的 信号传导受体，例如表皮生长马酮受体，其顶端域的缺失已是 在癌症和多囊性肾脏疾病中实施，以及类似收费的受体3，其缺失导致慢性 炎。该领域的一个主要未解决的问题是AP-1B在上皮细胞中的唯一功能以及 为什么它的表弟AP-1A主要无法替代。我们以前的工作表明AP-1B改变了 回收内体（RES）的组织可容纳AP-1B在基底外侧分类中的功能。只有ap- 1B但不可AP-1A定位于RES中，它触发了富含Pi（3,4,5）P3的脂质结构域的形成，并且 促进招募辅助因子，包括囊泡螺旋络合物（外囊）和脂质 激酶（Pipkig-90）。我们最近表明，AP-1B表达降低了集体细胞迁移的速度 单层绕组后，一种新型的功能与基底外侧分类无关。我们将检验中心假设 AP-1B在1）将Cargos引导到上皮单层中扮演双重角色 基底外侧膜通过在稳态的RES中生成一个分选平台，在细胞迁移期间2） 通过调节质膜上粘着粘着分子的可用性。我们将检验这个假设 在我们提出的实验中，使用最先进的成像技术，包括实时TIRF显微镜 结合光活化和公正的屏幕，包括生物学和质谱仪，完成 创新的细胞生物学和生物化学方法：1。确定AP-1B如何生成副腔 排序平台和2。确定AP-1B如何控制细胞迁移。我们的研究将定义新机制 管理稳态和细胞迁移期间极化上皮细胞的组织。