The role of extrusion in controlling epithelial homeostasis

挤压在控制上皮稳态中的作用

基本信息

批准号：
8515474
负责人：
Jody Snow Rosenblatt
金额：
$ 30.93万
依托单位：
UNIVERSITY OF UTAH
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-08-01 至 2016-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8515474
关键词：
Actins Actomyosin Address Adherent Culture Adult Anoikis Apoptosis Apoptotic Asthma Binding Biological Assay Biological Models Biomedical Engineering Calcium Channel Carcinoma Cell Count Cell Culture Techniques Cell Death Cell Proliferation Cell division Cell membrane Cells Cessation of life Colon Commit Crowding Death Rate Dependency Devices Disease Dominant-Negative Mutation Drug usage Epidermis Epithelial Epithelial Cells Epithelium Equilibrium Fishes G Protein-Coupled Receptor Genes Heart Heart Neoplasms Homeostasis Human body Image Integrins Investigation Life Link Lipids Mediating Methods Modeling Molecular Myosin ATPase Organ Organism PTK2 gene Pathway interactions Pharmaceutical Preparations Positioning Attribute Predisposition Process Production Proliferating Proteins Research Role Shapes Signal Transduction Site Skin Solid Neoplasm Sphingosine-1-Phosphate Receptor Stimulus Stress Stretching Survival Rate System Test Result Testing Tissues Zebrafish abstracting base cell behavior in vivo in vivo Model inhibitor/antagonist innovation interdisciplinary approach knock-down migration monolayer mutant novel prevent response rho small hairpin RNA sphingosine 1-phosphate

项目摘要

DESCRIPTION (provided by applicant): The role of extrusion in controlling epithelial homeostasis Project Summary/Abstract Epithelia provide a protective barrier for the organs they encase; yet cells comprising this barrier are constantly renewed via cell death (apoptosis) and division. Surprisingly little is known about what triggers cells to naturally divide or die or how he number of cells dying and dividing are balanced during homeostasis. However, maintaining this balance is critical for maintaining barrier function and preventing diseases: if the death rate is higher, barrier function diseases such as asthma may result and if the division rate is higher, solid tumors will result. Through our investigations of how cells maintain a barrier when they die, we believe we have discovered a novel mechanism for how epithelia maintain homeostatic cell numbers, which we further investigate in this proposal. We previously discovered that when a cell dies within an epithelium, it signals its neighboring cells to form a contractile actomyosin rng to extrude it out. To do so, the dying cell emits the lipid Sphingosine 1-Phosphate (S1P), which activates extrusion by signaling the S1P receptor 2 (S1P2) in neighboring cells. More recently, we have found that in adult colon tissue and in developing zebrafish epidermis, epithelial cells appear to extrude prior to dying at sites of high cell crowding. Live cells also extrude in respons to experimental overcrowding using a chamber we devised. While both homeostatic and overcrowding-induced extrusion use the same S1P-S1P2 pathway we defined for apoptotic cell extrusion, the live cell extrusion pathway is activated by the stretch-activated channel Piezo 1. Importantly, we found that disrupting either stretch-activated signaling or the S1P-S1P2 pathway leads to cellular masses in both cell culture and developing zebrafish. Thus, we propose a model where the underlying tissue provides a space limit on epithelia so that any cell divisions and/or migrations cause overcrowding strain, which induces live cells to extrude. Extruding cells then die due to lack of survival signaling while promoting surrounding to survive and proliferate. We will test this hypothesis in Aims 1 and 2 by 1) investigating if extrusion promotes cell death in a cell culture model and 2) testing if cell masses in S1P2 zebrafish mutants result from lack of cell extrusion, increased proliferation, or both. To define what activates extrusion, we will 3) determine how Piezo 1 stretch-activated channels and calcium currents mediate S1P to trigger extrusion and 4) identify cell- cell or cell-matrix proteins critical for determining which cells extrude in response to uniform epithelial crowding forces. The proposed research is innovative because it investigates a novel mechanism for how epithelial cells maintain homeostatic cell numbers and uses multidisciplinary approaches, which include a zebrafish epidermal model we have developed to study epithelia and a cell overcrowding device we have developed with a bioengineer. The proposal is medically significant because misregulation of epithelial homeostasis is likely at the heart of most solid tumor formation and barrier function diseases.

描述（由申请人提供）：挤出在控制上皮稳态项目摘要/摘要上皮中的作用为它们所包含的器官提供了保护性障碍；然而，包含该障碍的细胞通过细胞死亡（凋亡）和分裂不断更新。令人惊讶的是，关于触发细胞自然分裂或死亡的知识知之甚少，或者在体内稳态期间，死亡和分裂的细胞数量如何平衡。但是，保持这种平衡对于维持障碍功能和预防疾病至关重要：如果死亡率较高，则可能导致屏障功能疾病，例如哮喘，如果分裂率较高，则会导致实体瘤。通过我们对细胞死亡时如何保持屏障的调查，我们相信我们已经发现了一种新型的机制，用于上皮稳态细胞数量，我们在该提案中进一步研究了这一机制。我们先前发现，当一个细胞死在上皮中时，它标志着其相邻的细胞形成收缩的肌动蛋白RNG以将其挤出。为此，垂死的细胞发射了1-磷酸盐（S1P）的脂质鞘氨醇，该脂质通过在邻近细胞中发出S1P受体2（S1P2）来激活挤出。最近，我们发现在成年结肠组织和发展斑马鱼表皮中，上皮细胞在高细胞拥挤的部位死亡之前似乎挤出了。活细胞还使用我们设计的腔室挤出了对实验过度拥挤的响应。虽然我们定义了用于凋亡细胞挤出的相同S1P-S1P2途径的稳态和拥挤诱导的挤压途径，但通过拉伸激活的通道压电1激活了活细胞挤出途径。因此，我们提出了一个模型，其中基础组织对上皮提供了空间限制，以使任何细胞分裂和/或迁移会导致过度拥挤的菌株，从而诱导活细胞挤出。然后挤出细胞由于缺乏存活信号传导而死亡，同时促进周围的生存和增殖。我们将在目标1和2 x 1）中检验这一假设细胞挤出，增殖增加或两者兼而有之。为了定义什么激活挤出，我们将3）确定压电1伸展激活的通道和钙电流如何介导S1P触发挤出，4）识别细胞细胞或细胞 - 矩阵蛋白，对于确定哪些细胞对响应均匀上皮上皮人群的响应至关重要。拟议的研究具有创新性，因为它研究了上皮细胞如何保持体内稳态细胞数量并使用多学科方法的新机制，其中包括我们开发的斑马鱼表皮模型来研究上皮细胞和我们使用生物工具开发的细胞拥挤设备。该提案具有医学意义，因为上皮稳态的不正调可能是大多数实体瘤形成和屏障功能疾病的核心。