The Role of Extrusion in Controlling Epithelial Homeostasis

挤压在控制上皮稳态中的作用

• 批准号: 8572960
• 负责人: Jody Snow Rosenblatt
• 金额: $ 7.95万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 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/8572960
• 关键词: Antimitotic Agents; Aphidicolin; Apoptosis; Area; Asthma; Binding; Biomedical Engineering; Candidate Disease Gene; Carcinoma; Cell Count; Cell Cycle; Cell Cycle Progression; Cell Death; Cell Proliferation; Cell division; Cells; Cessation of life; Crowding; Death Rate; Development; Devices; Disease; Epithelial; Epithelial Cells; Epithelium; Equilibrium; Event; G0 Phase; G2 Phase; Gadolinium; Grant; Growth; Heart; Homeostasis; Hour; Kinetics; Lead; Link; Literature; Mechanics; Mediator of activation protein; Membrane; Methods; Microtubules; Mitosis; Modeling; Molecular; Morphogenesis; Organ; Pathway interactions; Phosphorylation; Population; Process; Production; Proliferating; Proteins; Proteomics; Reporter; Research; Role; S Phase; Semaphorin-3A; Signal Transduction; Solid Neoplasm; Staging; Stretching; Testing; Translating; Two-Dimensional Gel Electrophoresis; Well in self; Wound Healing; Zebrafish; aurora kinase; base; cell growth; gadolinium oxide; gel electrophoresis; in vivo; inhibitor/antagonist; innovation; interdisciplinary approach; migration; monolayer; mutant; novel; parent grant; prevent; public health relevance; research study; response; tool; tumor; wound

DESCRIPTION (provided by applicant): The role of cell stretch for inducing proliferation in epithelia provide a protective barrier for the organs they encase; yet cells comprising this barrie are constantly renewed via cell death (apoptosis) and division. Surprisingly little is known about what triggers cells to naturally divide or die or how the number of cells dying and dividing are balanced during homeostasis. If the death rate becomes higher, barrier function diseases such as asthma may result and if the division rate is higher, solid tumors may result. Previously, we found that epithelia match cell death with cell division mechanically through crowding. Epithelial crowding forces from cells accumulating through division and migration act to shove cells out, through a process I discovered termed cell extrusion. Blocking any step of the crowding-induced extrusion pathway that we defined leads to epidermal masses in zebrafish, confirming its critical role for controlling epithelial cell turnover in vivo. While the parent grant investigated how too many cells, manifested by cell crowding, can lead to extrusion-dependent cell death, here, we examine how too few cells within an epithelium, manifested by cell stretching, can lead to production of more cells by cell division. Cell stretching during developmental morphogenesis or wound healing cells frequently occurs prior to a wave of proliferation. We recently found that stretching contact-inhibited epithelial monolayers leads to rapid cell proliferation (within one hour), independently of wound or developmental signals. Because mitosis occurs so rapidly, we predict that these cells initiate division from the G2 phase of the cell cycle, despite starting frm a state usually associated with quiescence. Gadolinium addition block mitosis following stretch, suggesting that stretch-activated channels translate stretch into mitosis. To understand how stretch translates into mitogenic signaling, we will test the following in this revision grant: 1) est from which point(s) in the cell cycle cells initiate proliferation following stretch and 2) identif signals that translate cell stretch into proliferation by testing candidates from the literature an a proteomic screen. Once we identify how stretch activates cells to proliferate, we will test if this same signaling regulates division during normal homeostasis. If so, cell growth could similarly cause stretching of the membrane to trigger mitosis and reveal the elusive link between cell growth and division. Having developed many tools in our parent grant, we feel we are well poised to make rapid strides in identifying this fundamental pathway for regulating cell division. The proposed research is innovative because it examines a novel mechanism for how epithelial cells maintain homeostatic cell numbers, which may also reveal how cells link growth with division. It also uses multidisciplinary approaches, including a zebrafish epidermal model we developed to study epithelia and a cell stretch device we 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）：细胞伸展诱导上皮细胞增殖的作用为其包裹的器官提供了保护屏障;然而，构成该巴里屏障的细胞通过细胞死亡（凋亡）和分裂不断更新。令人惊讶的是，关于是什么触发细胞自然分裂或死亡，或者在体内平衡过程中死亡和分裂的细胞数量如何平衡，人们知之甚少。如果死亡率变得更高，则可能导致屏障功能疾病如哮喘，如果分裂率更高，则可能导致实体瘤。以前，我们发现上皮细胞通过拥挤机械地匹配细胞死亡和细胞分裂。上皮细胞通过分裂和迁移聚集而产生的拥挤力，通过我发现的称为细胞挤出的过程，将细胞挤出。阻断我们定义的拥挤诱导的挤出途径的任何一步都会导致斑马鱼的表皮肿块，证实了其在体内控制上皮细胞更新的关键作用。虽然父母格兰特研究了太多的细胞，表现为细胞拥挤，可以导致挤压依赖性细胞死亡，在这里，我们研究了上皮细胞内的细胞太少，表现为细胞拉伸，可以导致细胞分裂产生更多的细胞。在发育形态发生或伤口愈合过程中的细胞拉伸经常发生在增殖波之前。我们最近发现，拉伸接触抑制上皮单层导致快速细胞增殖（一小时内），独立于伤口或发育信号。由于有丝分裂发生得如此之快，我们预测这些细胞从细胞周期的G2期开始分裂，尽管从通常与静止相关联的状态开始。钆的加入阻断了拉伸后的有丝分裂，这表明拉伸激活的通道将拉伸转化为有丝分裂。为了了解拉伸如何转化为促有丝分裂信号，我们将在本修订资助中测试以下内容：1）测试细胞周期中细胞在拉伸后启动增殖的时间点，2）通过测试来自文献的候选蛋白质组学筛选来鉴定将细胞拉伸转化为增殖的信号。一旦我们确定了拉伸是如何激活细胞增殖的，我们将测试这一点。 在正常的体内平衡中，相同的信号调节分裂。如果是这样的话，细胞生长可能同样会导致膜的拉伸，从而引发有丝分裂，并揭示细胞生长和分裂之间难以捉摸的联系。在我们的母基金中开发了许多工具之后，我们觉得我们已经准备好在确定调节细胞分裂的基本途径方面取得快速进展。这项研究具有创新性，因为它研究了上皮细胞如何维持稳态细胞数量的新机制，这也可能揭示细胞如何将生长与分裂联系起来。它还使用多学科方法，包括我们开发的用于研究上皮细胞的斑马鱼表皮模型和我们与生物工程师开发的细胞拉伸装置。该提议具有医学意义，因为上皮稳态的失调可能是大多数实体瘤形成和屏障功能疾病的核心。