The John Curtin School of Medical Research, The Australian National University, Canberra, Australia.
ANU Medical School, The Australian National University, Canberra, Australia.
PLoS One. 2018 Mar 13;13(3):e0193740. doi: 10.1371/journal.pone.0193740. eCollection 2018.
The complement system is highly implicated in both the prevalence and progression of Age-Related Macular Degeneration (AMD). Complement system inhibitors therefore have potential therapeutic value in managing excessive activation of the complement pathways in retinal degenerations. The vaccinia virus complement control protein (VCP) has been shown to be effective as a complement inhibitor in neuroinflammatory models including traumatic brain injury and spinal cord injury. We aimed to investigate the potential of VCP as a therapeutic molecule for retinal degenerations. In this study, we investigated the effect, localisation and delivery of VCP to the rodent retina. Complement inhibition activity of VCP was tested using a hemolytic assay. Photoreceptor cell death, inflammation and retinal stress were assayed to determine if any retinal toxicity was induced by an intravitreal injection of VCP. The effect of VCP was investigated in a model of photo-oxidative retinal degeneration. Localisation of VCP after injection was determined using a fluorescein-tagged form of VCP, as well as immunohistochemistry. Finally, a copolymer resin (Elvax) was trialled for the slow-release delivery of VCP to the retina. We found that a dose equivalent to 20μg VCP when intravitreally injected into the rat eye did not cause any photoreceptor cell death or immune cell recruitment, but led to an increase in GFAP. In photo-oxidative damaged retinas, there were no differences in photoreceptor loss, retinal stress (Gfap) and inflammation (Ccl2 and C3) between VCP and saline-injected groups; however, Jun expression was reduced in VCP-treated retinas. After VCP was injected into the eye, it was taken up in all layers of the retina but was cleared within 1-3 hours of delivery. This study indicates that a method to sustain the delivery of VCP to the retina is necessary to further investigate the effect of VCP as a complement inhibitor for retinal degenerations.
补体系统在年龄相关性黄斑变性（AMD）的发生和进展中都有高度的牵连。因此，补体系统抑制剂在管理视网膜变性中补体途径的过度激活方面具有潜在的治疗价值。牛痘病毒补体控制蛋白（VCP）已被证明在包括创伤性脑损伤和脊髓损伤在内的神经炎症模型中作为补体抑制剂是有效的。我们旨在研究 VCP 作为治疗视网膜变性的潜在治疗分子。在这项研究中，我们研究了 VCP 对啮齿动物视网膜的作用、定位和传递。使用溶血测定法测试 VCP 的补体抑制活性。通过检测光感受器细胞死亡、炎症和视网膜应激来确定玻璃体腔注射 VCP 是否会引起任何视网膜毒性。在光氧化性视网膜变性模型中研究了 VCP 的作用。通过注射后的荧光素标记形式的 VCP 以及免疫组织化学来确定 VCP 的定位。最后，试用一种共聚物树脂（Elvax）将 VCP 缓慢释放到视网膜中。我们发现，当将相当于 20μg 的 VCP 玻璃体腔注射到大鼠眼中时，不会引起任何光感受器细胞死亡或免疫细胞募集，但会导致 GFAP 增加。在光氧化损伤的视网膜中，VCP 和盐水注射组之间在光感受器丧失、视网膜应激（Gfap）和炎症（Ccl2 和 C3）方面没有差异；然而，VCP 处理的视网膜中 Jun 表达减少。将 VCP 注入眼睛后，它被视网膜的所有层吸收，但在 1-3 小时的输送后被清除。这项研究表明，需要一种持续将 VCP 输送到视网膜的方法，以进一步研究 VCP 作为视网膜变性的补体抑制剂的效果。
