Neural Stability after Retinal Detachment

项目摘要/摘要 视网膜脱离修复后的视力恢复通常令人失望，超过一半的患者接受了治疗 报告视力低于正常的患者。视网膜神经元经历了戏剧性的结构可塑性 剥离包括杆状轴突的回缩，锥体末端的圆整，以及两极和两极发芽 水平单元格。在动物模型中，其中一些变化发生在视网膜损伤后的几个小时内。一直以来 提示这种突触重塑导致视力恢复不良。在视网膜细胞培养中， RhoA-Rho激酶(ROCK)信号通路的激活是杆状轴突形成的主要原因 撤回。因此，这项应用测试了RhoA拮抗剂和RhoA受体拮抗剂联合治疗的假设 视网膜手术可显著改善视网膜脱离修复后的视力结果 或者降低突触的可塑性。这一假设将在成年猪身上进行验证，因为成年猪的眼睛与人类相似 眼睛，集中在以下具体目的：1)测试是否有抑制活性的RhoA拮抗剂 RhoA、RhoA或它们的底物将防止因分离而引起的结构性突触变化 包括视杆轴突回缩、视杆-双极突触溶解、视锥终末形态改变以及 双极细胞萌发。对胶质细胞反应性的影响也将被检测；2)以确定 RhoA相关药物可以在脱离后应用，这是一种更具治疗相关性的情况，如果是这样的话， 损伤后多长时间；以及3)确定视网膜脱离是否真的用RhoA相关药物治疗 有助于再附着手术后视觉结构和功能的恢复。形态将通过以下方式评估 免疫组织化学、图像分析及激光共聚焦扫描和电子显微镜观察。级别 Rho信号的活性和时间进程将通过多种生化分析来确定 成分包括RhoA激活和肌球蛋白轻链磷酸化。术后视网膜功能 再附着将通过视网膜电图仪进行评估。将进行测试的一些药物(CT-04和 法舒地尔)已经被批准用于人类。我们希望确定大致的剂量和 如果RhoA拮抗剂被证明是外科手术的有用辅助药物，将在患者身上测试应用模式 重新连接。

Project Summary/Abstract Visual recovery after repair of a retinal detachment is often disappointing with more than half of treated patients reporting below normal visual acuity. Retinal neurons undergo dramatic structural plasticity after detachment including retraction of rod axons, rounding of cone terminals, and sprouting by bipolar and horizontal cells. Some of these changes occur within hours after retinal injury in animal models. It has been suggested that this synaptic remodeling contributes to poor visual recovery. In retinal cell cultures, activation of the RhoA-Rho kinase (ROCK) signaling cascade is primarily responsible for rod axon retraction. Thus, this application tests the hypothesis that a combined therapy of RhoA-antagonists and retinal surgery may significantly improve the visual outcome after repair of a detached retina by preventing or reducing synaptic plasticity. This hypothesis will be tested on adult pigs, whose eyes are similar to human eyes, focusing on the following specific aims: 1) To test whether RhoA antagonists which inhibit the activity of RhoA, ROCK, or their substrates will prevent the structural synaptic changes caused by detachment including rod axon retraction, rod-bipolar synaptic dissolution, cone terminal morphological change, and bipolar cell sprouting. The effect on glial cell reactivity will also be examined; 2) To determine whether RhoA-related drugs can be applied after a detachment, a more therapeutically relevant scenario, and if so, how long after the injury; and 3) To determine if detached retinas treated with RhoA-related drugs indeed help visual structural and functional recovery after reattachment surgery. Morphology will be assessed by immunohistochemistry, image analysis and confocal laser scanning and electron microscopy. Levels of activity and the time-course of Rho signaling will be determined by biochemical assays for multiple components including RhoA activation and myosin light chain phosphorylation. Retinal function after reattachment will be assessed by electroretinograms. Some of the drugs that will be tested (Ct-04 and fasudil) have already been approved for human use. We hope to establish the approximate dosage and mode of application to be tested in patients, if RhoA antagonists prove to be a useful adjunct to surgical reattachment.