γ射线全身照射小鼠肠组织损伤效应及对肠道微生物的影响研究OACSTPCD

Objective To investigate the effects of 0.5 Gy 60Co γ-ray irradiation on intestinal tissue injury and intestinal microflora in mice.Methods C57BL/6N mice were irradiated with 0.5 Gy 60Co γ-ray at 1 d,3 d,7 d and 14 d after irradiation.Jejunum tissues were fixed and frozen,and feces were frozen.Hematoxylin-eosin staining was used to observe the pathological injury to jejunum after irradiation,ki67 immunohistochemical staining was adopted to detect the proliferation of jejunum crypt cells,and TdT-mediated dUTP nick end labeling was employed to detect the apoptosis of jejunum crypt cells.The expressions of TNF-α,IL-1β,IL-6 and IL-10 cytokines in small intestines were detected via radioimmunoassay.The changes of intestinal flora in mice after irradiation were analyzed by metagenomic sequencing,and LEfSe analysis and ROC analysis were used to screen the bacteria with significant differences.Results After 0.5 Gy 60Co γ-ray irradiation,the proliferative cells of the jejunal crypt were significantly decreased at 1 d after irradiation(P＜0.05),while the apoptotic cells were significantly increased at 1 and 3 d after irradiation(P＜0.01).The expression of TNF-α at 7 and 14 d after irradiation,that of IL-1 β at 1,3,7 and 14 d after irradiation and that of IL-6 at 3,7 and 14 d after irradiation were significantly increased(P＜0.05),while the expression of IL-10 at 7 and 14 d after irradiation was significantly decreased(P＜0.05).After 0.5 Gy 60Co γ-ray irradiation,intestinal flora composition changed significantly at phylum,genus and species levels,and Lactobacillus murinus,Lactobacillus johnsonii,Alistipes-unclassified,Mucispirillum schaedleri underwent the most significant changes and had higher LDA scores.Conclusion The whole body irradiation of 0.5 Gy 60Co γ-ray can cause intestinal tissue damage and change the composition of intestinal flora in mice.