Investigating a role for Wnt-associated planar polarity in collective migration of human intestinal epithelium

抽象的。肠上皮（IE）衬在肠的整个内表面，处理所有的 身体的营养和液体吸收，同时作为一个屏障，有毒的管腔 内容物和病原体。为了对抗人类肠上皮细胞（hIEC）的损伤， 在体内平衡过程中积累，绒毛上的细胞（初级吸收表面）不断地 更换肠腺中的专用肠干细胞（hISCs）持续增殖， 稳定的祖细胞流，集体迁移到绒毛在一个最 成年人体内细胞集体迁移的广泛例子。IEC受伤或丧失后， 附近的IEC会进行快速的集体迁移，称为恢复，以快速修复损坏。 由集体迁移驱动的恢复是保护屏障的基本细胞过程 对抗管腔内容物。尽管集体细胞迁移对肠道功能的重要性， 关于hIEC如何协调这一过程知之甚少。WNT相关的平面电池极性 （WPCP）途径，特别是细胞表面蛋白VANGL 2，已经越来越多地被研究。 作为协调集体细胞迁移的主要参与者，但研究表明， 由于研究WPCP的生理相关模型系统的主要缺陷， 更高的生物。从我的初步数据观察表明：1）零星 VANGL 2的过表达足以强烈损害集体迁移，2）VANGL 2是 在划痕试验中在上皮伤口的前缘上调，和3）蛋白梯度 VANGL 2在体内沿着隐窝-绒毛轴存在。综合这些观察，我得出了 假设IE利用WPCP途径来协调集体细胞迁移。 我将用两个目标来检验这个假设。目标1将确立妇女初级保健方案在以下方面的机制作用： Aim 2将确定其在伤口愈合中的作用。这两个目标将使用 WPCP途径扰动的新的诱导型遗传模型，以产生原始数据。这 将用于训练WPCP极性的计算反应扩散模型，以破译如何 局部WPCP反馈可以如此强烈地影响大组织区域的集体迁移。这 这项研究将填补关键的技术和知识差距，产生新的文化模式， 人类细胞，揭示了hIE如何控制集体迁移的新机制， 建立新的计算模型研究集体迁移和WPCP。我的发现将 随着VANGL 2和WPCP配体越来越多地参与多种健康 包括发育缺陷、神经和肾脏疾病、骨骼肌和 胆管再生、癌症转移和慢性结肠炎。

Abstract. The intestinal epithelium (IE) lines the entire inner surface of the intestine, handling all of the body’s nutrient and fluid uptake while simultaneously serving as a barrier to toxic luminal contents and pathogens. To combat the damage human intestinal epithelial cells (hIECs) accumulate during homeostasis, cells on the villi (primary absorptive surfaces) are constantly replaced. Dedicated intestinal stem cells (hISCs) in crypts proliferate continuously to generate a steady stream of progenitor cells that collectively migrate towards the villi in one of the most expansive examples of collective cell migration in the adult body. Following IEC injury or loss, nearby IECs undergo a rapid collective migration called restitution to quickly repair the damage. Restitution driven by collective migration is an essential cellular process to preserve the barrier against luminal contents. Despite the importance of collective cell migration to intestinal function, little is known about how hIECs coordinate this process. The WNT-associatedPlanar Cell Polarity (WPCP) pathway, and in particular the cell surface protein VANGL2, has been increasingly implicated as a major player in the coordination of collective cell migration, but research is hampered due to a major deficit of physiologically relevant model systems for studying WPCP in higher organisms. Observations from my preliminary data indicate that: 1) sporadic overexpression of VANGL2 is sufficient to strongly impair collective migration, 2) VANGL2 is upregulated at the leading edge of an epithelial wound in scratchassays, and 3) a protein gradient of VANGL2 exists along the in vivo crypt-villus axis. Together these observations led me to hypothesize that the IE utilizes the WPCP pathway to coordinate collective cell migration. I will test this hypothesis using two aims. Aim 1 will establish a mechanistic role for WPCP in homeostatic migration, while Aim 2 will establish its role in wound healing. Both aims will use novel inducible genetic models of WPCP pathway perturbations to generate primary data. This will be used to train a computational reaction-diffusion model of WPCP polarity to decipher how local WPCP feedback can so strongly impact collective migration of large tissue regions. This study will fill critical technical and knowledge gaps by generating new culture models with primary human cells, uncovering novel mechanisms of how the hIE controls collective migration, and building novel computational models for studying collective migration and WPCP. My findings will be significant as VANGL2 and WPCP ligands are increasingly implicated in diverse health conditions including developmental defects, neurological and kidney disease, skeletal muscle and biliary duct regeneration, cancer metastasis, and chronic colitis.