Gao Mei-Ling, Wu Kun-Chao, Deng Wen-Li, Lei Xin-Lan, Xiang Lue, Zhou Gao-Hui, Feng Chun-Yun, Cheng Xue-Wen, Zhang Chang-Jun, Gu Feng, Wu Rong-Han, Jin Zi-Bing
Lab for Stem Cell & Retinal Regeneration, Institute of Stem Cell Research, Division of Ophthalmic Genetics, The Eye Hospital, Wenzhou Medical University, Wenzhou, China.
Gu Laboratory, The Eye Hospital, Wenzhou Medical University, Wenzhou, China.
Invest Ophthalmol Vis Sci. 2017 Feb 1;58(2):801-811. doi: 10.1167/iovs.16-20692.
Accumulating evidence has demonstrated that excessive immunoreaction plays a prominent role in the pathogenesis of dry AMD. Toll-like receptor 3 (TLR3) can be activated by double-stranded (ds)RNA in retinal pigment epithelia and trigger an innate immunity-mediated inflammatory response. However, its role in photoreceptor cells, the effectors of AMD geographic atrophy, remains unclear.
The expression of TLR3 was examined in mouse retina and in a murine photoreceptor cell line (661W). Retinal structure, function, and cell death in the polyinosine-polycytidylic acid (poly I:C)-treated retina were investigated by optical coherence tomography, electroretinography (ERG), and immunostaining. Cytokine and chemokine expression as well as cell death were measured in poly I:C-exposed 661W cells and explant retinas. By comparing the RNA sequencing (seq) data of 661W cells and murine retina, we comprehensively investigated the contribution of photoreceptor in poly I:C-induced retinal immune response.
Toll-like receptor 3 was highly expressed in the inner segment of the photoreceptor and in 661W cells. We found poly I:C induced significant retinal structural damages and impairment of ERG responses. Focal ERG demonstrated that injected and parainjected zones were functionally damaged by poly I:C. In addition, poly I:C acted on cultured photoreceptor cells directly and evoked an inflammatory response that exhibited similarities with the immune response in mouse retina. Moreover, TLR3 activation initiated cell death in murine photoreceptor cells in vivo and in vitro. Additionally, poly I:C initiated immune response in explant retinas.
We deciphered the TLR3-mediated inflammatory response in photoreceptor cells. Our findings suggested TLR3-mediated inflammatory response in photoreceptor cells may play an important role in dry AMD, offering new insights of potential treatments targeting photoreceptor immunity.
越来越多的证据表明，过度的免疫反应在干性年龄相关性黄斑变性（dry AMD）的发病机制中起重要作用。Toll样受体3（TLR3）可被视网膜色素上皮中的双链（ds）RNA激活，并引发先天性免疫介导的炎症反应。然而，其在AMD地图状萎缩的效应细胞——光感受器细胞中的作用仍不清楚。
检测TLR3在小鼠视网膜和小鼠光感受器细胞系（661W）中的表达。通过光学相干断层扫描、视网膜电图（ERG）和免疫染色研究聚肌苷酸-聚胞苷酸（poly I:C）处理的视网膜中的视网膜结构、功能和细胞死亡情况。检测poly I:C处理的661W细胞和视网膜外植体中的细胞因子和趋化因子表达以及细胞死亡情况。通过比较661W细胞和小鼠视网膜的RNA测序（seq）数据，我们全面研究了光感受器在poly I:C诱导的视网膜免疫反应中的作用。
Toll样受体3在光感受器的内段和661W细胞中高表达。我们发现poly I:C诱导了显著的视网膜结构损伤和ERG反应受损。局灶性ERG显示，注射区和旁注射区因poly I:C而功能受损。此外，poly I:C直接作用于培养的光感受器细胞，引发炎症反应，该反应与小鼠视网膜中的免疫反应相似。此外，TLR3激活在体内和体外均可引发小鼠光感受器细胞死亡。此外，poly I:C可引发视网膜外植体中的免疫反应。
我们解析了光感受器细胞中TLR3介导的炎症反应。我们的研究结果表明，光感受器细胞中TLR3介导的炎症反应可能在干性AMD中起重要作用，为针对光感受器免疫的潜在治疗提供了新的见解。
