Inflammation and Degeneration of Optic Nerve in EAE

视神经损伤导致的视力下降是患者最常见的症状之一 多发性硬化症（MS）MS相关的视神经损伤是由于自身反应性T细胞的流入， 其他免疫细胞炎症过程被认为有助于脱髓鞘，轴突变性， 以及少突胶质细胞和视网膜神经节细胞（RGC）的损失。了解视神经病变的病理生理学 EAE中的神经变性对开发恢复视觉功能的药剂具有潜在的治疗意义。 证明在OP-1中钙蛋白酶（一种钙（Ca 2+）依赖性蛋白酶）的活性和表达增加， 在刘易斯大鼠中，使用MS动物模型（实验性过敏性脑脊髓炎（EAE））的抽动神经具有免疫抑制作用。 钙蛋白酶在EAE视神经损害中起一定作用。因为炎症和机械的精确时间- 视神经中细胞和轴突损伤的机理尚未完全了解， 以及导致轴突和细胞损伤的分子事件，可以改善和恢复功能。我们假造- 确定钙蛋白酶介导自身反应性T细胞活化和免疫细胞浸润到CNS中的大小 将由于炎症导致轴突和少突胶质细胞损伤而导致视觉功能丧失 在EAE视神经中，随后RGC损失可能发生在临床症状之前， 疾病由此推论，在激发后的不同时间点抑制钙蛋白酶 将通过预防周围和视神经的炎症来恢复视觉功能，并改善 视神经损伤后的神经退化率已经开始。数据表明Ca 2+内流， EAE视神经中钙蛋白酶表达、轴突损伤、细胞死亡和视网膜损伤增加， 在疾病发作之前影响几个参数。钙蛋白酶抑制剂治疗减少免疫细胞 浸润、钙蛋白酶表达、细胞死亡和视网膜损伤，导致视觉反应改善 与未治疗的EAE动物相比。体外干扰素（IFN？）诱导神经胶质细胞中钙蛋白酶激活， MBP特异性T细胞上清液降解MBP。以下具体目标是为了测试这些 假设：（1）确定炎症反应的时间，Ca 2+内流，Ca 2+依赖性事件，细胞 EAE视神经中的轴突/髓鞘变性，并检查与EAE视神经死亡相关的RGC状态。 激发后EAE动物的视觉功能障碍;（2）研究用钙蛋白酶抑制剂治疗是否 将通过改变免疫臂（T细胞活化，免疫细胞浸润到视觉中）来恢复视觉功能。 神经）和/或神经变性臂（细胞死亡，轴突损伤）的影响 检查钙蛋白酶抑制剂在保留和保护RGC功能中的作用 在体外，当经受促炎细胞因子或与来自活化的MBP的上清液孵育时， 特异性T细胞了解视神经损伤的过程和时间将进一步发展 治疗策略，以最好地恢复MS中视神经变性引起的损伤。

Impaired vision due to optic nerve damage is one of the most common presenting symptoms of patients with multiple sclerosis (MS). MS-associated optic nerve damage is due to an influx of auto-reactive T cells and other immune cells. The inflammatory process is thought to contribute to demyelination, axonal degeneration, and loss of oligodendrocytes and retinal ganglion cells (RGCs). Understanding the pathophysiology of optic nerve degeneration in EAE has potential therapeutic implications to develop agents that restore visual function. Demonstration of increased activity and expression of calpain, a calcium (Ca2+)-dependent protease, in op- tic nerve using an animal model of MS, experimental allergic encephalomyelitis (EAE), in Lewis rats has im- plied a role for calpain in optic nerve damage in EAE. Since the precise timing of inflammation and mecha- nisms of cell and axon damage in optic nerve are not fully understood, the potential to prevent inflammation and molecular events that lead to axonal and cell damage, may improve and restore function. We hypothe- size that calpain-mediated activation of auto-reactive T cells and immune cell infiltration into the CNS will result in loss of visual function due to inflammation leading to axon and oligodendrocyte damage in EAE optic nerve with subsequent loss of RGCs which may occur prior to clinical symptoms of disease. A corollary hypothesis is that inhibiting calpain at different time-points following challenge will restore visual function by preventing inflammation in the periphery and in optic nerve, and amelio- rate neurodegeneration after damage to the optic nerve have begun. Data indicate that Ca2+ influx, calpain expression, axonal damage, cell death, and retinal damage are increased in EAE optic nerve with several parameters affected before disease onset. Treatment with calpain inhibitors reduced immune cell infiltration, calpain expression, cells death, and retinal damage, resulting in improved visual responses compared to untreated EAE animals. In vitro interferon (IFN¿) induced calpain activation in glial cells and MBP-specific T cell supernatant degraded MBP. The following specific aims have been designed to test these hypotheses: (1) determine the timing of inflammatory responses, Ca2+ influx, Ca2+-dependent events, cell death, and axonal/myelin degeneration in EAE optic nerve and examine the status of RGCs in correlation with visual dysfunction in EAE animals following challenge; (2) investigate whether treatment with calpain inhibitors will restore visual function by altering the immune arm (T cell activation, immune cell infiltration into optic nerve) and/or the neurodegenerative arm (cell death, axonal damage) in acute EAE, as compared to vehicle treated animals; and (3) examine the effects of calpain inhibitors in preserving and protecting function of RGCs in vitro when subjected to pro-inflammatory cytokines or incubated with supernatant from activated MBP- specific T cells. Understanding the process and timing of optic nerve damage will further the development of treatment of strategies to best restore the impairment caused by optic nerve degeneration in MS.