Approaches to enhance lysosomal function in RPE cells

项目摘要 氯喹视网膜病变是一个日益严重的健康问题，因为这种药物越来越多地用于治疗狼疮和 类风湿关节炎。患者出现中心视力丧失，视网膜色素上皮异常， 还有牛眼黄斑病变。目前除了停止服用氯喹之外，没有其他治疗方法；这限制了 其他疾病的长期治疗，以及氯喹在着色组织中的滞留使 甚至在治疗停止后仍在进行性视力丧失。而已知的靶向是RPE溶酶体和 虽然这会损害它们的降解活性，但目前尚不清楚这是如何导致视力丧失的，以及如何治疗。 最近，溶酶体被发现在细胞内和细胞外信号转导中发挥关键作用。 随着溶酶体的功能从降解延伸到钙信号和废物的胞吐， 传递物和炎症信号。这项提议将决定这些新发现的溶酶体 氯喹视网膜病变患者的功能受到干扰。氯喹处理对溶酶体的影响 在我们的氯喹视网膜病变体外模型中，首先将检测钙信号和胞吐作用，然后 在我们新开发的氯喹视网膜病变小鼠体内模型中得到证实。然后，该提案将 确定近年来开发的治疗方法是否能增强溶酶体的pH和钙调节 预防氯喹所致的病理改变。溶酶体功能的恢复将是 使用体外和体内模型测定。最后，这些治疗措施的能力，以防止损失 将测定氯喹视网膜病变小鼠的视力和光感受器。该项目的成果 将促进我们对RPE信号在健康和疾病中的机械性理解，同时潜在地帮助 回答一个真正的健康需求。

Project Summary Chloroquine retinopathy is a growing health problem with the increased use of the drug to treat lupus and rheumatoid arthritis. Patients present with a loss of central vision, retinal pigmented epithelium abnormalities, and bull’s eye maculopathy. There is currently no treatment other than to stop giving chloroquine; this limits the long-term treatment of the other diseases, and the retention of chloroquine in pigmented tissues enables progressing loss of vision even after treatment has stopped. While is known to target RPE lysosomes and impair their degradative activity, it remains unclear how this leads to vision loss and how this can be treated. Recently, lysosomes have been identified as playing a critical role in intracellular and extracellular signaling, with lysosomal function extending beyond degradation to calcium signaling and the exocytosis of waste, transmitters and inflammatory signals. This proposal will determine whether these newly identified lysosomal functions are perturbed in chloroquine retinopathy. The ability of chloroquine treatment to alter lysosomal calcium signaling and exocytosis will be assayed first in our in vitro model of chloroquine retinopathy, then confirmed in our newly developed in vivo murine model of chloroquine retinopathy. The proposal will then determine whether treatments developed in recent years to enhance lysosomal pH and calcium regulation prevent the pathological changes induced by chloroquine. The restoration of lysosomal function will be determined using both in vitro and in vivo models. Finally, the ability of these treatments to prevent the loss of vision and photoreceptors in the chloroquine retinopathy mouse will be determined. The results of the project will advance our mechanistic understanding of RPE signaling in health and disease while potentially helping answer a real health need.