The influence of capsule composition on lens biology

描述（由申请人提供）：透镜囊是一层增厚的基底膜，从最早发育阶段直至死亡，完全包围透镜。众所周知，透镜囊对于透镜发育和功能至关重要，并且透镜囊病变可威胁视力。透镜囊的既定功能是充当透镜与眼环境之间的可选择滤光器，然而，关于此滤光器的性质相对知之甚少。在先前的赠款周期，我们开发了一个强大的荧光恢复后，光漂白（FRAP）协议，可以评估分子进入透镜囊的能力，并定量确定其扩散系数。在本申请的第一个目的中，我们提出使用FRAP来阐明正常透镜囊膜过滤器的分子性质。还已知细胞外基质（ECM）蛋白基因的突变导致白内障。第二个目的是测试胶原IV的改变激活未折叠蛋白反应导致白内障的假设。透镜囊的另一个既定功能是接合透镜细胞上的ECM受体，为细胞提供结构锚并诱导对透镜细胞表型至关重要的细胞信号传导级联。整联蛋白是存在于透镜细胞上的一类主要ECM受体，并且β 1整联蛋白是由透镜表达的主要β-整联蛋白亚基。在之前的研究周期中，我们创建了所有透镜细胞或仅透镜纤维中缺乏<$1整合素的小鼠，以测试<$1整合素对透镜细胞/透镜囊通讯很重要的假设。所得到的动物的表型是相当不同的，我们现在提出在具体的目标三，以阐明的功能，1-整联蛋白在体内透镜通过分析在这些动物中看到的分子异常。公共卫生相关性：透镜囊对于正常眼透镜的功能是重要的，尽管关于影响透镜囊的疾病如何导致透镜异常知之甚少。此外，在白内障手术切除后，透镜囊通常保留在眼睛中，以支撑植入的人工置换透镜并用作眼睛前部和后部之间的屏障，尽管所产生的异常透镜细胞/囊相互作用通常导致继发性白内障。完全了解透镜细胞和囊膜之间的通讯对于开发预防继发性白内障的治疗方法至关重要。

DESCRIPTION (provided by applicant): The lens capsule is a thickened basement membrane that completely surrounds the lens from its earliest developmental stages until death. It is well established that the lens capsule is crucial for lens development and function and lens capsule pathologies can threaten vision. An established function of the lens capsule is to serve as a selectable filter between the lens and the ocular environment, however, relatively little is known about the properties of this filter. During the prior grant cycle, we developed a robust fluorescence recovery after photobleaching (FRAP) protocol which can evaluate both the ability of molecules to enter the lens capsule and quantitatively determine their diffusion coefficient. In the first aim of this application, we propose to use FRAP to elucidate the molecular properties of the normal lens capsule filter. It is also known that mutations in extracellular matrix (ECM) protein genes result in cataract. The second aim tests the hypothesis that alterations in collagen IV activate the unfolded protein response leading to cataract. Another established function of the lens capsule is to engage ECM receptors on lens cells, providing both a structural anchor for the cell and inducing cell signaling cascades crucial for lens cell phenotype. Integrins are a major class of ECM receptors present on lens cells and ¿1 integrin is the major b-integrin subunit expressed by the lens. In the prior grant cycle, we created mice lacking ¿1 integrin in either all lens cells or just lens fibers to test the hypothesis that ¿1-integrin is important for lens cell/lens capsule communication. The phenotypes of the resulting animals are quite distinct and we now propose in specific aim three to elucidate the function of ¿1-integrin in the in vivo lens by analyzing the molecular abnormalities seen in these animals. Public Health Relevance: The lens capsule is important for the function of the normal ocular lens, although little is known about how diseases affecting the lens capsule result in lens abnormalities. Further, the lens capsule is usually retained in the eye after the surgical removal of cataracts to both support the implanted artificial replacement lens and to serve as a barrier, between the anterior and posterior portions of the eye, although the resulting abnormal lens cell/capsule interactions often result in secondary cataract. A complete understanding of the communication between lens cells and the capsule are crucial to develop treatments to prevent secondary cataract.