Research Unit Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany.
J Proteomics. 2012 Jul 19;75(14):4545-54. doi: 10.1016/j.jprot.2012.04.052. Epub 2012 May 23.
Equine recurrent uveitis is a severe and frequent blinding disease in horses which presents with auto-reactive invading T-cells, resulting in the destruction of the inner eye. Infiltration of inflammatory cells into the retina and vitreous is driven by currently unknown guidance cues, however surgical removal of the vitreous (vitrectomy) has proven therapeutically successful. Therefore, proteomic analyses of vitrectomy samples are likely to result in detection of proteins contributing to disease pathogenesis. Vitreous from healthy and ERU diseased horses were directly compared by quantitative mass spectrometry based on label-free quantification of peak intensities across samples. We found a significant upregulation of complement and coagulation cascades and downregulation of negative paracrine regulators of canonical Wnt signalling including the Wnt signalling inhibitors DKK3 and SFRP2. Based on immunohistochemistry, both proteins are expressed in equine retina and suggest localisation to retinal Müller glial cells (RMG), which may be the source cells for these proteins. Furthermore, retinal expression levels and patterns of DKK3 change in response to ERU. Since many other regulated proteins identified here are associated with RMG cells, these cells qualify as the prime responders to autoimmune triggers.
马的复发性眼葡萄膜炎是一种严重且常见的致盲性疾病，其特征为自身反应性浸润 T 细胞，导致眼内组织破坏。目前尚不清楚炎症细胞浸润视网膜和玻璃体的机制，但玻璃体切除术（vitrectomy）已被证明具有治疗效果。因此，对玻璃体切除术样本进行蛋白质组学分析可能会发现与疾病发病机制相关的蛋白质。通过基于无标记定量的峰强度对样品进行定量质谱分析，直接比较了健康马和 ERU 病马的玻璃体。我们发现补体和凝血级联反应显著上调，经典 Wnt 信号的负旁分泌调节因子（包括 Wnt 信号抑制剂 DKK3 和 SFRP2）下调。基于免疫组织化学，这两种蛋白质均在马视网膜中表达，并提示其定位于视网膜 Müller 胶质细胞（RMG），这可能是这些蛋白质的来源细胞。此外，DKK3 的视网膜表达水平和模式在 ERU 中发生变化。由于这里鉴定的许多其他受调控的蛋白质与 RMG 细胞相关，因此这些细胞是对自身免疫触发的主要反应细胞。
