Eye Center, Medical Center, Faculty of Medicine, University of Freiburg, Baden-Wuerttemberg, Germany.
Institute of Anatomy, University of Leipzig, Leipzig, Saxony, Germany.
Invest Ophthalmol Vis Sci. 2022 Mar 2;63(3):9. doi: 10.1167/iovs.63.3.9.
Hyalocytes are the tissue-resident innate immune cell population of the vitreous body with important functions in health and vitreoretinal disease. The purpose of this study is to gain new insights into the biology and function of human hyalocytes in comparison to other innate immune cells.
The present study applies fluorescence-activated cell sorting and RNA sequencing to compare the transcriptional profiles of human hyalocytes, retinal microglia (rMG) and classical, intermediate, and non-classical monocytes isolated from the same patients. Immunohistochemistry was applied for morphological characterization of human hyalocytes.
Pairwise analysis indicates distinct differences between hyalocytes and monocytes, whereas a high degree of similarity to rMG is apparent, with comparable expression levels of established microglia markers, such as TREM2, P2RY12, and TMEM119. Among the top expressed genes in hyalocytes, SPP1, CD74, and C3, were significantly upregulated when compared with monocytes. Despite the high level of similarity of hyalocytes and rMG, ten highly expressed genes in hyalocytes compared to microglia were identified, among them FOS, DUSP1, and EGR2.
This study reveals a high degree of similarity between hyalocytes and retinal microglia. Nevertheless, hyalocytes exhibit some expression differences that may adapt them to the specific needs of the vitreous and provide the basis for deciphering the multiple roles of this fascinating cell population in health and vitreoretinal diseases.
玻璃体细胞是玻璃体组织驻留的先天免疫细胞群，在眼部健康和视网膜疾病中具有重要功能。本研究的目的是深入了解人类玻璃体细胞与其他先天免疫细胞的生物学和功能。
本研究应用荧光激活细胞分选和 RNA 测序，比较从同一患者分离的人玻璃体细胞、视网膜小胶质细胞（rMG）以及经典、中间和非经典单核细胞的转录谱。免疫组织化学用于人玻璃体细胞的形态学特征分析。
两两比较分析表明玻璃体细胞与单核细胞之间存在明显差异，而与 rMG 之间具有高度相似性，表现为类似的成熟小胶质细胞标志物，如 TREM2、P2RY12 和 TMEM119 的表达水平。在玻璃体细胞中表达最高的基因中，与单核细胞相比，SPP1、CD74 和 C3 显著上调。尽管玻璃体细胞与 rMG 具有高度相似性，但与小胶质细胞相比，在玻璃体细胞中鉴定出 10 个高表达基因，其中包括 FOS、DUSP1 和 EGR2。
本研究揭示了玻璃体细胞与视网膜小胶质细胞之间具有高度相似性。然而，玻璃体细胞表现出一些表达差异，可能使其适应玻璃体的特殊需求，并为阐明该迷人细胞群在眼部健康和视网膜疾病中的多种作用提供基础。
