Vangl2 function in mammalian convergent extension

Vangl2 在哺乳动物会聚延伸中的功能

基本信息

批准号：
9247221
负责人：
Ann E Sutherland
金额：
$ 32.79万
依托单位：
UNIVERSITY OF VIRGINIA
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-04-01 至 2021-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9247221
关键词：
Abdomen Address Adherens Junction Adhesions Adhesives Adult Affect Alleles Apical Behavior Birth CELSR1 gene Cadherins Cell Polarity Cells Cellular Morphology Characteristics Chordata Complex Confocal Microscopy Congenital Abnormality Core Protein Craniorachischises Defect Development Drosophila genus Dsh protein E-Cadherin Elements Embryo Embryonic Development Epithelial Epithelial Cells Epithelium Exhibits Eye Failure Fetus Fishes Frequencies Future Genes Genetic Genetic Models Hair Head Heterozygote Human Human Development Image Infant Infant Mortality Lead Medical Membrane Proteins Mesoderm Modeling Mus Mutant Strains Mice Mutation N-Cadherin Neural Tube Closure Neural Tube Defects Neural tube Neurons Paraxial Mesoderm Pathway interactions Phenotype Process Proteins Publishing Rana Regulation Resolution Role Set protein Shapes Signal Pathway Signal Transduction Skeleton Spinal Cord Surface Syndrome Tail Testing Time Tissue membrane Tissues Variant Vertebrates Wing Work base cell behavior constriction convergent extension disability experimental study fly hindbrain insight intercalation loss of function mortality mutant neurodevelopment paralogous gene planar cell polarity polarized cell public health relevance relating to nervous system rib bone structure spine bone structure

项目摘要

DESCRIPTION (provided by applicant): Elongation of the body in the head-to-rump axis is a fundamental aspect of vertebrate embryogenesis whose failure is associated with neural tube defects and embryonic mortality in fish, frogs, mice, and humans. In humans, neural-tube defects affect 1 to 2 infants per 1000 births and lead in the worst cases to early infant mortality and in less severe cases to lifelong medical treatment and disability. Elongation occurs by a process in which cells of the future spinal cord and associated mesoderm actively move (intercalate) between one another to form narrower, longer tissues (called "convergence and extension' or CE), which elongates the embryonic body. In vertebrates, this "mediolateral" cell intercalation is dependent on the non-canonical Wnt planar cell polarity (Wnt/PCP) pathway, which consists of a core set of proteins thought to polarize cells within the plane of the tissue: the membrane proteins Celsr, Frizzled (Frz), and Van Gogh-like (Vangl), and the intracellular proteins Dishevelled (Dvl) and Prickle (Pk). Mice carrying mutations in the genes Celsr1, Frz3/6, Vangl2 and Dvl1/2 as well as Ptk7 and Scrib, two genes not directly associated with Wnt/PCP, exhibit a characteristic phenotype of a short, wide body axis, an open neural tube, and lethality at birth. One model of genetic regulation of cell intercalation focuses on polarized remodeling of junctions at the apical surfaces of epithelial cells and the other on polarized "crawling" of non-epithelial cells. Use of high resolution, multi-plane time-lapse confocal microscopy to simultaneously image both apical junctional and the basolateral surfaces of the neural epithelium of normal mouse embryos as compared to Vangl2 and Ptk7 mutants, showed that apical cell boundary rearrangement and polarized basolateral protrusive activity must act cooperatively for mediolateral intercalation and CE to occur. Neural cells lacking Ptk7 fail to planarly polarize both apical and basolateral cell behaviors and they intercalate vigorously but randomly. Surprisingly, polarity of both basal protrusive activity and apical boundary rearrangement is maintained in the Vangl2 mutant, and instead the frequency of apical neighbor exchange is significantly diminished. These unexpected observations, and other, published variations in phenotypes of Wnt/PCP mutant genes across the chordates, suggest that Wnt/PCP function has diversified across species and tissues. The proposed experiments explore this possibility by determining how Vangl and the related protein Scrib regulate neural cell behavior. First, because the loss of Vangl2 does not affect planar polarity of cell behavior, we will test whether the paralog Vangl1 can compensate to generate polarity in the absence of Vangl2, or whether polarity is regulated instead by a complex of Vangl2 and Scrib. Second, because Vangl2 specifically affects apical junctional rearrangement, we will test whether it affects the dynamics of cadherin-based adhesion in neural cell intercalation. The results will provide broader and deeper insights into the cellular behaviors regulated by the Wnt/PCP pathway during neural development, and how they coordinate elongation and closure of the neural tube.

描述（由申请人提供）：身体从头到臀轴的伸长是脊椎动物胚胎发生的一个基本方面，其失败与鱼、青蛙、小鼠和人类的神经管缺陷和胚胎死亡率有关。每 1000 名新生儿中就有 1 至 2 名婴儿患有神经管缺陷，最严重的情况下会导致婴儿早期死亡在不太严重的情况下，会导致终生医疗和残疾。伸长是通过未来脊髓和相关中胚层的细胞在彼此之间主动移动（插入）以形成更窄、更长的组织（称为“收敛和延伸”或）的过程而发生的。 CE），它延长了脊椎动物的胚胎体，这种“内侧”细胞嵌入依赖于非典型的 Wnt 平面细胞极性（Wnt/PCP）途径。由一组核心蛋白质组成，这些蛋白质被认为可以在组织平面内极化细胞：膜蛋白 Celsr、Frizzled (Frz) 和 Van Gogh-like (Vangl)，以及细胞内蛋白质 Disheveled (Dvl) 和 Prickle (Pk)携带 Celsr1、Frz3/6、Vangl2 和 Dvl1/2 基因以及 Ptk7 和 Scrib 突变的小鼠，这两个基因与Wnt/PCP 表现出短而宽的体轴、开放的神经管和出生时致死性的特征表型，一种细胞嵌入的遗传调控模型侧重于上皮细胞顶端表面连接的极化重塑，另一种模型则侧重于上皮细胞顶端表面连接的极化重塑。使用高分辨率、多平面延时共聚焦显微镜对神经的顶端连接和基底外侧表面进行同步成像。与 Vangl2 和 Ptk7 突变体相比，正常小鼠胚胎的上皮细胞显示，顶端细胞边界重排和极化的基底外侧突出活动必须协同作用才能发生中外侧嵌入，并且缺乏 Ptk7 的神经细胞无法平面极化顶端和基底外侧细胞的行为。令人惊讶的是，它们的插入有力但随机，基部的极性既是突出的活动又是顶端的。 Vangl2 突变体中维持了边界重排，相反，顶端邻居交换的频率显着降低。这些意外的观察结果以及其他已发表的脊索动物中 Wnt/PCP 突变基因表型的变化表明，Wnt/PCP 功能已经多样化。拟议的实验通过确定 Vangl 和相关蛋白 Scrib 如何调节神经细胞行为来探索这种可能性。首先，由于 Vangl2 的丢失不会影响细胞行为的平面极性，因此我们将进行测试。旁系同源物 Vangl1 是否可以在没有 Vangl2 的情况下补偿产生极性，或者极性是否由 Vangl2 和 Scrib 的复合物调节。其次，因为 Vangl2 专门影响顶端连接重排，我们将测试它是否影响钙粘蛋白的动态。研究结果将为神经发育过程中 Wnt/PCP 通路调节的细胞行为以及它们如何协调提供更广泛和更深入的见解。神经管的伸长和闭合。