Determinants of Lens Fiber Cell Structure

项目总结/摘要 透镜的主要功能是把光线聚焦在视网膜上，使我们能够看见东西。此功能依赖于 透镜的透明度，这种透明度取决于其主要的精确组织。 构成细胞类型为透镜纤维细胞。我们的目标是了解是什么决定了正确的细胞 在透镜内赋予其透明度的组织。当透镜纤维细胞分化时，它们伸长， 它们之间直接相互作用，形成高度有序的组织细胞组织， 赋予组织的整体结构及其透明度。任何对这个组织的破坏都会导致 不透明晶状体（即白内障）是世界范围内最常见的致盲原因。我们最近 发现了两种决定透镜结构的蛋白质：Dlg-1和Scrib 1。此外，我们确定 Dlg-1对小鼠的平面细胞极性（PCP）至关重要。PCP指的是细胞间的协调 使得它们在对正常形态发生至关重要的特定方向上移动、定向和/或增殖。 相关组织。另一种核心PCP蛋白Vangl 2与决定透镜形状有关。这里 我们提供的证据表明，Scrib以及新发现的PCP蛋白Dlg-1和公认的 PCP蛋白、Vangl 2决定整体透镜结构。他们通过确定透镜的整体形状来实现这一点 纤维细胞和细胞：在透镜的赤道区域内的透镜纤维细胞之间的细胞接触。不清楚的是 这是否是由于这些蛋白质对透镜结构的PCP依赖性或PCP非依赖性作用。的 这个探索性的R21补助金申请的主要目标是区分这两种可能性。我们将 使用在其他无脊椎动物中得到充分验证的遗传方法来解决这个问题， 详细的机制研究，包括使用最先进的高分辨率STED显微镜来解决 核心PCP蛋白与决定透镜形状的其他因素之间的相互作用。两 R21提案的目的是：1）确定平面单元极性是否是确定透镜的关键 结构和2）定义平面细胞极性因子和细胞之间的相互作用：细胞粘附因子， 确定透镜结构。这些研究的完成将提供重要和新颖的见解， 实现和保持透镜透明度所需的机制，这是NEI的研究重点， 对NEI更好地预防和治疗白内障的总体目标的影响。

PROJECT SUMMARY/ABSTRACT The primary function of the lens is to focus light on the retina so as to allow us to see. This function relies on the transparency of the lens, and this transparency depends on the precise organization of its primary constituent cell type, the lens fiber cells. Our goal is to understand what determines the correct cellular organization within the lens that confers its transparency. As lens fiber cells differentiate, they elongate and make direct interactions between themselves to create a highly ordered, tissue-wide cellular organization that confers the overall architecture of the tissue and its transparency. Any disruption of this organization leads to opaque lenses (i.e. cataracts) that are the most common cause of blindness world-wide. We recently discovered two proteins that dictate lens architecture: they are Dlg-1 and Scrib1. Furthermore, we determined that Dlg-1 is critical for conferring planar cell polarity (PCP) in mice. PCP refers to the coordination of cells such that they move, orient, and/or proliferate in a particular direction critical for the normal morphogenesis of the relevant tissue. Another core PCP protein, Vangl2, has been implicated in determining lens shape. Here we provide evidence that Scrib as well as the newly identified PCP protein, Dlg-1, and the well-established PCP protein, Vangl2 determine overall lens architecture. They do so by determining the overall shape of lens fiber cells, and the cell:cell contacts between lens fiber cells within the equatorial region of the lens. Unclear is whether this is due to PCP-dependent or PCP-independent effects of these proteins on lens architecture. The primary goal of this exploratory R21 grant application is to distinguish between these two possibilities. We will approach this using genetic approaches that have been well-validated in other invertebrates as well as more detailed mechanistic studies including the use of state-of-the-art high resolution STED microscopy to resolve the interactions between core PCP proteins and other factors involved in determining lens shape. The two aims of this R21 proposal are to 1) Determine whether planar cell polarity is key to determining lens architecture and 2) Define the interplay between planar cell polarity factors and cell:cell adhesion factors in determining lens architecture. Completion of these studies will provide important and novel insights into the mechanisms required to achieve and maintain lens transparency, a research priority of the NEI, and have an impact on the overarching NEI goal of better preventing and treating cataracts.