Role of Extracellular Matrix in Retinal Development and Disease

描述（由申请人提供）：Muller细胞（MCs）在视网膜稳态中起关键作用。它们是极化的，顶端隔室面向视网膜下间隙，基底表面粘附于内限制膜（ILM）。任何一个隔室的破坏都会导致MCs的激活和导致视力丧失的病理生物学后果。层粘连蛋白组织基底膜（BM），如ILM，作为细胞粘附、极性和增殖的附着位点。我们制造了两个层粘连蛋白基因Lamb2和Lamc3无突变的小鼠，发现这些分子对于视网膜的正常发育是必需的。Lamb2/c3空洞的缺陷包括：ILM畸形；MC瓦解;光感受器发育不全;以及内视网膜的进行性病变。我们的长期目标是了解层粘连蛋白对MC组织的发展和稳定的分子贡献，特别是因为它与功能结构有关。我们的直接目标是评估MC-层粘连蛋白相互作用对以下方面至关重要的组织假设：1)建立MC极性；2)维持MC亚细胞组织和3)稳定视网膜的结构完整性。在目的1中，我们将研究层粘连蛋白介导的巨噬细胞支架的分子机制。我们将回答以下三个问题。首先，我们将讨论：MC底端足的粘附复合物的分子组织是什么？接下来，我们将确定：离子通道亚细胞定位和功能对层粘连蛋白的依赖性是什么？最后，我们将探讨：层粘连蛋白调控MC增殖的机制是什么？在目标2中，我们将检验一个推论假设，即层粘连蛋白底物的粘附丧失会破坏内视网膜的正常结构/功能关系。我们的数据表明，Lamb2/c3缺失的动物在IPL中有选择性中断。我们将回答以下问题。首先，我们会问：在IPL中树突发生的层粘连蛋白依赖是什么？接下来，我们将讨论：Lamb2/Lamc3缺失中进行性视网膜神经节细胞损失的机制是什么？这些实验及其揭示的分子机制将有助于我们对胶质瘤的病理生理学的理解；增生性玻璃体视网膜病变和先天性眼部疾病，包括Walker-Warburg， Bardet-Biedl， Pierson综合征。

DESCRIPTION (provided by applicant): The Muller cells (MCs) have a key role in retinal homeostasis. They are polarized with an apical compartment facing the subretinal space, and a basal surface adhering to the inner limiting membrane (ILM). Disruption of either compartment leads to activation of MCs and pathobiological consequences leading to vision loss. Laminins organize basement membranes (BM), such as the ILM serving as attachment sites for cell adhesion, polarity and proliferation. We produced mice with null mutations in two laminin genes, Lamb2 and Lamc3, and found that these molecules are necessary for normal retinal development. The defects in the Lamb2/c3 nulls include: ILM malformation; MC disorganization; photoreceptor dysgenesis; and progressive pathology in the inner retina. Our long-range goal is to understand the molecular contributions of laminin to the development and stability of MC organization, in particular, as it relates to the functional architecture. Our immediate goal is to assess the organizing hypothesis that MC-laminin interactions are critical for: 1) establishing MC polarity; 2) maintaining MC sub cellular organization and 3) stabilizing the structural integrity of the retina. In Aim 1, we will examine the molecular mechanisms underlying laminin- mediated scaffolding in the MC. We will answer the following three questions. First, we will address: What Is The Molecular Organization Of The Adhesion Complex Of The MC Basal Endfoot? Next, we will determine: What Is The Laminin Dependence Of Ion Channel Sub cellular Localization And Function? Finally, we will investigate: What Is The Mechanism Of Laminin Regulation Of MC Proliferation? In Aim 2, we will examine the corollary hypothesis that the loss of adhesion to laminin substrates disrupts the normal structure/function relationships in the inner retina. Our data show that the Lamb2/c3 null animals have selective disruptions in the IPL. We will answer the following questions. First, we will ask: What Is The Laminin Dependence Of Dendritogenesis In The IPL? Next, we will address: What Are The Mechanisms Of Progressive Retinal Ganglion Cell Loss in Lamb2/Lamc3 nulls? These experiments and the molecular mechanisms they reveal will contribute to our understanding of the pathophysiology of gliosis; proliferative vitreoretinopathy and congenital ocular disorders including Walker-Warburg, Bardet-Biedl, Pierson Syndrome. PUBLIC HEALTH RELEVANCE: Congenital birth defects affect millions of Americans and people world-wide. These diseases include muscular dystrophy, brain and eye disorders leading to mental retardation and blindness. This project investigates the cause of several of these diseases and the results will lead to new diagnostics and therapeutics.