Exploring the relationship of water flow across the RPE and mutant-MYO7A/Usher 1B

项目摘要 视网膜色素上皮（retinal pigment epithelium，RPE）具有活跃的转运机制和上皮连接 调节着从细胞顶端到基底面的水流。任何一种缺陷 RPE功能的这些方面可促进疾病，如囊样黄斑水肿（CME）， 以及随后的视力损害。Usher综合征1B型（USH1B），由以下原因引起： MYO7A突变，包括相对高的CME发病率。然而， USH1B中的CME尚不清楚。在这里，我们建议探讨MYO7A是必要的建议， 正常的液体流过视网膜色素上皮使用RPE培养物，从诱导的 多能干细胞（iPSC），来自USH1B患者，我们将测试这一建议， 研究MYO7A功能的丧失是否会导致相关蛋白质的定位缺陷 在RPE连接复合体中或在跨膜离子和水流中。此外，我们将使用 这些iPSC-RPE培养物用于测试目前使用的CME药物的疗效， 增加穿过RPE的水流。这些研究可能会提供新的见解， MYO7A的视网膜功能，以及USH1B中视力受损的更好理解， 尤其是CME造成的。

Project Summary The retinal pigment epithelium (RPE) has active transport mechanisms and epithelial junctions that regulate water flow from the apical to the basal surface of the cell. Defects in either of these aspects of RPE function may promote disorders, such as cystoid macular edema (CME), and subsequent visual impairment. Usher Syndrome type 1B (USH1B), which is caused by mutations in MYO7A, includes a relatively high incidence of CME. However, the mechanism of CME in USH1B is unclear. Here, we propose to explore the suggestion that MYO7A is required for normal fluid flow across the RPE. Using RPE cultures, differentiated from induced pluripotent stem cells (iPSCs), derived from USH1B patients, we will test this suggestion and investigate whether loss of MYO7A function results in defective localization of proteins involved in the RPE junctional complex or in transmembrane ion and water flow. Further, we will use these iPSC-RPE cultures to test the efficacy of currently-used medications for CME in increasing water flow across the RPE. These studies will potentially provide novel insight into the retinal function of MYO7A, and a better understanding of impaired vision in USH1B, particularly that resulting from CME.