Branching Morphogenesis of Urinary Epithelia: from Genes to Cellular Behaviors

泌尿上皮细胞的分支形态发生：从基因到细胞行为

• 批准号: 8296331
• 负责人: FRANKLIN D COSTANTINI
• 金额: $ 48.71万
• 依托单位: COLUMBIA UNIVERSITY HEALTH SCIENCES
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-09-01 至 2014-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8296331
• 关键词: 3-Dimensional; Address; Adhesions; Affect; Apoptosis; Artificial Organs; Behavior; Biological Assay; CXCL12 gene; CXCR4 gene; Candidate Disease Gene; Cell Count; Cell Separation; Cells; Chemotactic Factors; Clinical; Complex; Congenital Abnormality; Defect; Development; Duct (organ) structure; Ductal Epithelium; Epithelial; Epithelial Cells; Epithelium; Etiology; Event; GDNF gene; Genes; Genetic; Genitourinary system; Growth; Health; Image; Imaging technology; Individual; Instruction; Kidney; Kidney Diseases; Knock-out; Knockout Mice; Label; Lead; Liver; Location; Mediating; Metanephric Diverticulum; Methods; Mitosis; Modeling; Morphogenesis; Movement; Mutation; Nephrons; Obstruction; Organ; Organ Culture Techniques; Organism; Organogenesis; Pattern; Positioning Attribute; Primordium; Process; Pseudostratified Epithelium; Receptor Protein-Tyrosine Kinases; Receptor Signaling; Relative (related person); Renal Hypertension; Research; Role; Shapes; Signal Transduction; Signaling Pathway Gene; Site; Stem cells; Structure; Structure of mesonephric duct; System; Testing; Time; Translating; Ureter; Urinary system; Work; base; behavior influence; blood filter; cell behavior; cell motility; cell type; chemokine; chemokine receptor; genetic manipulation; in vivo; malformation; migration; mouse model; nephrogenesis; prevent; progenitor; repaired; research study; response; time use; transcription factor; urinary; urologic

DESCRIPTION (provided by applicant): The formation of a single ureteric bud (UB) at the proper location on the Wolffian duct (WD) is important to make a functional ureter, while complex patterns of UB branching morphogenesis are required for normal renal organogenesis. While many genes involved in these events have been identified, the genetic instructions must be translated into specific cellular responses (for example, mitosis, apoptosis, migration, adhesion) in order to shape and organize a complex 3-D structure like the urinary epithelium. While very little is known about the specific cellular behaviors that underlie epithelial morphogenesis in higher organisms, or how they are controlled, advances in genetic manipulation and imaging technologies now make it feasible to address such questions using mouse models. This project will focus on the cellular events that are regulated by the secreted factor GDNF, which signals through the Ret receptor tyrosine kinase. Ret signaling is needed to make a normal ureter and kidney, but how it influences the behavior of WD and UB epithelial cells in vivo remains to be defined. Ret-expressing cells at the tips of the branching UB are the main progenitors of the collecting duct system epithelium during kidney development, and they arise from a specific region of the Wolffian duct, the "primary tip domain". Recent findings reveal that the primary tip domain is itself generated via Ret-dependent cell movements within the Wolffian duct. This raises several important questions: How are these cell movements controlled, and what is the role of GDNF/Ret signaling in Wolffian duct cell motility and guidance? What other genes and signaling pathways downstream of Ret are involved? Do similar cell movements underlie the growth and branching of the ureteric bud tip epithelium during kidney development? How else may Ret signaling affect the behavior of the epithelial progenitor cells at the UB tips? To address these questions, several methods will be used to genetically modify small numbers of WD or UB cells, and then to examine the effects of these alterations on cell behaviors in organ cultures, using time-lapse imaging, or in vivo. The proposed research should advance the field not only by extending to the cellular level our understanding of the role of GDNF/Ret signaling, but also by providing a paradigm for studying how other signaling systems affect the behavior of urinary epithelial cells during organogenesis. The information gained should also advance our understanding of the etiology of congenital urological and renal malformations, and may suggest new strategies to prevent or treat them. PUBLIC HEALTH RELEVANCE: Understanding how the urinary system achieves its normal size and shape has important clinical implications, as defects can lead to obstruction, impaired function or even absence of the ureters and kidneys. The development of the urinary system affects the number of nephrons (blood-filtering units) that form in the kidney, which may influence the progression of renal diseases and hypertension. An understanding of the genes and cellular events that underlie ureter and kidney development may eventually permit treatments for congenital malformations, repair of damaged organs, or growth of artificial organs.

描述（由申请人提供）：在沃尔夫（Wolffian）管道（WD）上适当位置的单个输尿管芽（UB）形成对于制作功能性输尿管很重要，而UB分支形态发生的复杂模式对于正常的肾脏器官需要。尽管已经确定了这些事件中涉及的许多基因，但必须将遗传指示转化为特定的细胞反应（例如有丝分裂，凋亡，迁移，粘附），以形成和组织复杂的3-D结构，例如尿皮细胞。尽管对高等生物体上皮形态发生的特定细胞行为知之甚少，或者是如何控制它们的方式，但遗传操纵和成像技术的进步现在使使用鼠标模型解决此类问题是可行的。 该项目将集中于由分泌因子GDNF调节的细胞事件，该事件通过RET受体酪氨酸激酶发出信号。需要进行RET信号传导以制造正常的输尿管和肾脏，但是它如何影响体内WD和UB上皮细胞的行为。分支UB尖端的表达细胞是肾脏发育过程中收集管系统上皮的主要祖细胞，它们源自沃尔夫管道的特定区域，沃尔夫管（“主要的尖端结构域”。最近的发现表明，主要的尖端结构域本身是通过沃尔夫管道内的RET依赖性细胞运动产生的。这提出了几个重要的问题：这些细胞运动如何控制，GDNF/ret信号在沃尔夫管细胞运动和指导中的作用是什么？ RET下游涉及哪些其他基因和信号通路？类似的细胞运动是否是肾发育过程中输尿管芽尖上皮的生长和分支的基础？ RET信号如何影响UB尖端上上皮祖细胞的行为？为了解决这些问题，将使用几种方法来修改少量的WD或UB细胞，然后使用延时成像或体内检查这些改变对器官培养物中细胞行为的影响。拟议的研究不仅应通过扩展到细胞水平来推进该领域，因此我们对GDNF/RET信号传导的作用的理解，而且还通过提供用于研究其他信号系统如何影响器官中尿中皮细胞行为的范式。获得的信息还应提高我们对先天性泌尿外科和肾脏畸形的病因的理解，并可能提出预防或治疗它们的新策略。公共卫生相关性：了解尿液系统如何实现其正常的大小和形状具有重要的临床意义，因为缺陷会导致阻塞，功能受损甚至没有输尿管和肾脏。尿液系统的发展会影响肾脏中形成的肾单位数（过滤单位）的数量，这可能会影响肾脏疾病和高血压的进展。对输尿管和肾脏发育构成的基因和细胞事件的理解最终可能允许治疗先天性畸形，修复受损的器官或人工器官的生长。