Tezel Gülgün, Yang Xiangjun, Luo Cheng, Kain Angela D, Powell David W, Kuehn Markus H, Kaplan Henry J
Department of Ophthalmology and Visual Sciences, University of Louisville School of Medicine, Louisville, Kentucky, USA.
Invest Ophthalmol Vis Sci. 2010 Oct;51(10):5071-82. doi: 10.1167/iovs.10-5289. Epub 2010 May 19.
As part of ongoing studies on proteomic alterations during glaucomatous neurodegeneration, this study focused on the complement system.
Human retinal protein samples obtained from donor eyes with (n = 10) or without (n = 10) glaucoma were analyzed by a quantitative proteomic approach using mass spectrometry. Cellular localization of protein expression for different complement components and regulators were also determined by immunohistochemical analysis of an additional group of human donor eyes with glaucoma (n = 34) compared with age-matched control eyes without glaucoma (n = 20). In addition, to determine the regulation of complement factor H (CFH) by oxidative stress, in vitro experiments were performed using rat retinal cell cultures incubated in the presence and absence of an oxidant treatment.
Proteomic analysis detected the expression and differential regulation of several complement components in glaucomatous samples, which included proteins involved in the classical and the lectin pathways of complement activation. In addition, several complement regulatory proteins were detected in the human retinal proteome, and glaucomatous samples exhibited a trend toward downregulation of CFH expression. In vitro experiments revealed that oxidative stress, which was also prominently detectable in the glaucomatous human retinas, downregulated CFH expression in retinal cells.
These findings expand the current knowledge of complement activation by presenting new evidence in human glaucoma and support that despite important roles in tissue cleaning and healing, a potential deficiency in intrinsic regulation of complement activation, as is evident in the presence of oxidative stress, may lead to uncontrolled complement attack with neurodestructive consequences.
作为青光眼性神经变性过程中蛋白质组学改变的持续研究的一部分，本研究聚焦于补体系统。
使用质谱定量蛋白质组学方法分析从患有青光眼（n = 10）或未患青光眼（n = 10）的供体眼中获得的人视网膜蛋白质样品。还通过免疫组织化学分析另一组患有青光眼的人供体眼（n = 34）与年龄匹配的未患青光眼的对照眼（n = 20），确定不同补体成分和调节因子的蛋白质表达的细胞定位。此外，为了确定氧化应激对补体因子H（CFH）的调节作用，使用在有或没有氧化剂处理的情况下孵育的大鼠视网膜细胞培养物进行体外实验。
蛋白质组学分析检测到青光眼样品中几种补体成分的表达和差异调节，其中包括参与补体激活经典途径和凝集素途径的蛋白质。此外，在人视网膜蛋白质组中检测到几种补体调节蛋白，青光眼样品显示出CFH表达下调的趋势。体外实验表明，在青光眼患者的视网膜中也明显可检测到的氧化应激下调了视网膜细胞中CFH的表达。
这些发现通过在人类青光眼中提供新证据扩展了目前对补体激活的认识，并支持尽管补体在组织清洁和愈合中起重要作用，但如氧化应激存在时所显示的那样，补体激活内在调节的潜在缺陷可能导致不受控制的补体攻击并产生神经破坏性后果。
