Illinois Eye and Ear Infirmary, Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA.
Illinois Eye and Ear Infirmary, Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, USA.
Ocul Surf. 2022 Jan;23:49-59. doi: 10.1016/j.jtos.2021.11.006. Epub 2021 Nov 19.
Commensal microbiome secretes various metabolites that can exert important effects on the host immunity and inflammation and can alter cellular functions. However, little is known regarding the effect of microbiome on corneal immunity and genetic expression. The purpose of this study is to describe the effect of diet-induced gut dysbiosis on corneal immunity and corneal gene expression after wounding.
This study is approved by the Animal Care and Use of the University of Illinois. Six-week-old female C57BL6 mice were fed on a normal chow diet (ND), isocaloric low-fat control diet (LFD), or a 21% milk high-fat diet (HFD) for six weeks. 2 mm corneal epithelial debridement was performed (n = 10). Fecal samples from mice were used for microbial diversity analysis (n > 3). Immunofluorescence staining of corneal wholemount tissue post-debridement was used to visualize immune cell distribution. RNA Seq was performed on tissue samples from corneas following debridement.
Mice fed differing diets had significant alterations in gut microbial diversities. After corneal debridement, HFD mice experienced delayed wound healing in comparison to LFD mice and ND mice groups. However, fecal transplantation led to normalization of wound closure rates. Increased γδTCR staining was observed in the LFD group, and decreased LY6G was observed in HFD group (p < 0.05). Gene Ontology terms of differentially expressed genes included response to external stimulus, cell proliferation, migration, adhesion, defense response and leukocyte migration. Top over-represented pathways included ECM-receptor interaction, Cytokine-cytokine receptor interaction, Focal adhesion and Leukocyte trans-endothelial migration.
Gut microbial dysbiosis alters corneal immune cell distribution, corneal response to injury, and genes related to epithelial function and corneal immunity.
共生微生物群体会分泌各种代谢产物，这些代谢产物对宿主的免疫和炎症有重要影响，并能改变细胞功能。然而，对于微生物组对角膜免疫和基因表达的影响知之甚少。本研究旨在描述饮食诱导的肠道菌群失调对创伤后角膜免疫和角膜基因表达的影响。
本研究得到了伊利诺伊大学动物护理和使用委员会的批准。将 6 周龄雌性 C57BL6 小鼠分别喂食正常日粮（ND）、等热量低脂对照饮食（LFD）或 21%牛奶高脂肪饮食（HFD）6 周。对 2mm 角膜上皮进行清创（n=10）。对小鼠粪便样本进行微生物多样性分析（n>3）。清创后对角膜全层组织的免疫荧光染色用于观察免疫细胞的分布。对清创后角膜组织样本进行 RNA Seq 分析。
不同饮食喂养的小鼠肠道微生物多样性发生显著变化。与 LFD 组和 ND 组相比，HFD 组小鼠角膜清创后愈合延迟。然而，粪便移植可使伤口愈合率正常化。LFD 组观察到 γδTCR 染色增加，HFD 组观察到 LY6G 减少（p<0.05）。差异表达基因的基因本体术语包括对外界刺激的反应、细胞增殖、迁移、黏附、防御反应和白细胞迁移。过表达途径包括 ECM-受体相互作用、细胞因子-细胞因子受体相互作用、焦点黏附和白细胞经内皮迁移。
肠道微生物失调改变了角膜免疫细胞的分布、角膜对损伤的反应以及与上皮功能和角膜免疫相关的基因。
