Uhl Patrizia B, Amann Barbara, Hauck Stefanie M, Deeg Cornelia A
Institute for Animal Physiology, Department of Veterinary Sciences, Ludwig-Maximilians-University, Veterinärstraße 13, D-80539 Munich, Germany.
Research Unit for Protein Science, Helmholtz Zentrum München, German Research Center for Environmental Health GmbH, Ingolstädter Landstr. 1, D-85764 Neuherberg, Germany.
Int J Mol Sci. 2015 Jan 26;16(2):2678-92. doi: 10.3390/ijms16022678.
Retinal pigment epithelium (RPE) builds the outer blood-retinal barrier of the eye. Since one typical feature of the autoimmune disease, equine recurrent uveitis (ERU), is the breakdown of this barrier, we recently performed comparative analysis of healthy and uveitic RPE. We identified for the first time peripherin 2, which is responsible for visual perception and retina development, to be localized in RPE. The purpose of this study was therefore to validate our findings by characterizing the expression patterns of peripherin 2 in RPE and retina. We also investigated whether peripherin 2 expression changes in ERU and if it is expressed by the RPE itself. Via immunohistochemistry, significant downregulation of peripherin 2 in uveitic RPE compared to the control was detectable, but there was no difference in healthy and uveitic retina. A further interesting finding was the clear distinction between peripherin 2 and the phagocytosis marker, rhodopsin, in healthy RPE. In conclusion, changes in the expression pattern of peripherin 2 selectively affect RPE, but not retina, in ERU. Moreover, peripherin 2 is clearly detectable in healthy RPE due to both phagocytosis and the expression by the RPE cells themselves. Our novel findings are very promising for better understanding the molecular mechanisms taking place on RPE in uveitis.
视网膜色素上皮（RPE）构成了眼睛的外血视网膜屏障。由于自身免疫性疾病马反复性葡萄膜炎（ERU）的一个典型特征是这种屏障的破坏，我们最近对健康和葡萄膜炎性RPE进行了比较分析。我们首次确定了负责视觉感知和视网膜发育的外周蛋白2定位于RPE中。因此，本研究的目的是通过表征外周蛋白2在RPE和视网膜中的表达模式来验证我们的发现。我们还研究了外周蛋白2在ERU中的表达是否发生变化以及它是否由RPE自身表达。通过免疫组织化学，与对照组相比，葡萄膜炎性RPE中外周蛋白2有明显下调，但健康和葡萄膜炎性视网膜之间没有差异。另一个有趣的发现是在健康RPE中外周蛋白2与吞噬作用标志物视紫红质之间有明显区别。总之，在外周蛋白2的表达模式变化在ERU中选择性地影响RPE，而不是视网膜。此外，由于吞噬作用以及RPE细胞自身的表达，在外周健康RPE中可清楚检测到外周蛋白2。我们的新发现对于更好地理解葡萄膜炎中RPE上发生的分子机制非常有前景。
