The genetic control of epithelial cell migration and wound healing physiology

细胞迁移，即细胞从A点到达B点的能力，是身体发育、生长和维持的基础。最明显的例子是在伤口和划痕愈合过程中，皮肤最上层的上皮细胞不得不移动来覆盖伤口。他们是怎么做到的？我们打算通过研究细胞在眼睛角膜表面的迁移来找出答案(这是成年人定期长距离细胞迁移的最令人印象深刻的例子之一)。只有几种方法可以指示细胞移动。它们可以沿着化学痕迹，或者沿着它们爬过的表面的凹槽摸索前进。它们可以被细胞从后面物理地推开，繁殖并推开以腾出空间，或者它们可以感觉到并沿着流经身体组织的内源性电流的方向移动。我们想找出哪些因素是最重要的，以及细胞迁移问题如何导致疾病。我们打算使用一种突变的小鼠，尽管它基本上是健康的，但它的眼睛问题与角膜表面上皮细胞无法正常迁移有关。我们已经证明，这些小鼠的角膜伤口愈合也存在异常。细胞迁移的潜在驱动力之一，内源电场，在我们的突变小鼠中严重异常。我们将确定我们的突变小鼠的角膜细胞是否能‘看到’电场，如果是的话，突变小鼠的电场问题是否会导致细胞迁移的问题。使用药物和化学物质，我们可以改善突变小鼠的细胞迁移，我们将证明这是否由电场的改善所介导。我们将展示磁场的强度和方向是否与细胞迁移的强度和方向相关。我们还将确定角膜上皮细胞是否通过感知与它们爬行的组织中的物理线索(非常小的凹槽或化学标志)的接触来引导，以及这些线索本身是否可以将细胞推向正确的方向。我们将比较正常细胞和突变细胞在有凹槽的石英表面(它们只得到物理指导)和真实角膜组织上的运动，在真实角膜组织上，它们可能得到化学和物理指导。我们将研究细胞内负责指导正常细胞方向和运动的分子。我们将展示角膜外部的细胞分裂是否从物理上将细胞从角膜边缘推到中间，以及这是否在我们的突变小鼠中最直接地出现问题，这项工作将与遭受与创伤相关的角膜表面异常的患者相关，包括遭受与我们的小鼠相同的基因缺陷的患者，以及与放射治疗相关的长期角膜溃疡患者。之前的工作已经带来了新的方法来尝试改善背部或颈部脊髓损伤后的愈合，这个项目将开始为加速皮肤愈合的方法带来新的理解。具有普遍意义的是，这些数据将对科学和医学环境中的伤口愈合和上皮迁移研究具有广泛的相关性。我们将首次提供一种基因测试，让细胞有机会忽略电场，看看他们是否会这样做。因此，该项目解决了一些基本问题，即我们的身体是如何工作的，以及如何可能在受伤或疾病后加速伤口愈合。

Cell migration, the ability of a cell to get from point A to point B, is fundamental to development, growth and maintenance of the body. The most obvious example is during healing of cuts and scratches, when the epithelial cells, the top layer of the skin, have to move over to cover the wound. How do they do it? We intend to find out by studying the migration of cells across the surface of the cornea of the eye (one of the most impressive examples of regular long-distance cell migration in adults). There are only a few ways of directing a cell to move. They can follow chemical trails, or feel their way along grooves in the surface they are crawling over. They can be physically pushed by cells from behind multiplying and shoving them over to make room, or they can sense and move in the direction of endogenous electrical currents flowing through body tissues. We want to find out which factors are most important, and how problems with cell migration can lead to disease. We intend to use a mutant strain of mouse which, although it is basically healthy, exhibits eye problems associated with a failure of epithelial cells to migrate normally over the corneal surface. We have shown that there are also abnormalities with corneal wound healing in these mice. One of the potential drivers of cell migration, endogenous electric fields, are severely abnormal in our mutant mice. We will determine whether corneal cells from our mutant mice can 'see' electric fields and, if so, whether the problems with electric fields in the mutant cause the problems with cell migration. Using drugs and chemicals, we can improve cell migration in our mutant mice, and we will show whether this is mediated by improvement in electric fields. We will show whether the strength and direction of the field correlates with the strength and direction of cell migration. We will also determine whether corneal epithelial cells are steered by sensing contact with physical cues (very small grooves or chemical signposts) in the tissues they are crawling across, and whether these by themselves can push cells in the right direction. We will compare normal and mutant cells moving on grooved quartz surfaces (where they get only physical guidance) and on real corneal tissues, where they may get both chemical and physical guidance. We will investigate the molecules within the cell that are responsible for directing normal cell orientation and movement. We will show whether cell division at the outside of the cornea physically pushes cells from the edge of the cornea to the middle, and whether this goes wrong in our mutant mice Most immediately, the work will be relevant to people who suffer from corneal surface abnormalities associated with wounding, including patients who suffer the same genetic defects as our mice and patieints with long-term corneal ulceration associated with, for example, radiotherapy. Previous work has lead to new ways to try to improve healing after injuries to the spinal cord in the back or the neck, and this project will start to bring new understandings to ways of accelerating healing in the skin. Of general significance, the data will be of wide relevance to wound healing and epithelial migration studies in scientific and medical settings. For the first time, we will provide a genetic test where we give cells the opportunity to ignore electric fields, and see whether they will do so. As such, the project gets at fundamental questions about how our bodies work and how it might be possible to accelerate wound healing after injury or disease.