Astronauts exhibit an assortment of clinical abnormalities in their eyes during long-duration spaceflight. The purpose of this study was to determine whether spaceflight induces epigenomic and transcriptomic reprogramming in the retina or alters the epigenetic clock. The mice were flown for 37 days in animal enclosure modules on the International Space Station; ground-based control animals were maintained under similar housing conditions. Mouse retinas were isolated and both DNA methylome and transcriptome were determined by deep sequencing. We found that a large number of genes were differentially methylated with spaceflight, whereas there were fewer differentially expressed genes at the transcriptome level. Several biological pathways involved in retinal diseases such as macular degeneration were significantly altered. Our results indicated that spaceflight decelerated the retinal epigenetic clock. This study demonstrates that spaceflight impacts the retina at the epigenomic and transcriptomic levels, and such changes could be involved in the etiology of eye-related disorders among astronauts.

中文翻译：

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太空飞行使表观遗传时钟减速，该表观时钟是由小鼠视网膜中DNA甲基化组和转录组的整体改变所精心组织的

在长时间的太空飞行中，宇航员的眼睛表现出各种临床异常。这项研究的目的是确定航天是否在视网膜中诱导表观基因组和转录组重编程或改变表观遗传时钟。将这些小鼠在国际空间站的动物围护舱中飞行37天；以地面为基础的对照动物饲养在相似的住房条件下。分离小鼠视网膜，并通过深度测序确定DNA甲基化组和转录组。我们发现，大量基因通过航天被甲基化，而在转录组水平上差异表达的基因较少。视网膜疾病（如黄斑变性）中涉及的几种生物途径均发生了显着改变。我们的结果表明，太空飞行使视网膜表观遗传时钟减速。这项研究表明，太空飞行会在表观基因组和转录组水平上影响视网膜，并且这种变化可能与宇航员中与眼有关的疾病的病因有关。