基于宏基因组学技术的炎症性肠病小鼠的运动干预研究

Intervention Study of Exercise on Mice with Inflammatory Bowel Disease Based on Metagenomic Technique

目的:基于宏基因组学测序技术,建立小鼠炎症性肠病(inflammatory bowel disease,IBD)模型,探索运动对炎症性肠病小鼠的干预效果,分析适度运动对肠道微生物群落特征的影响。方法:22只无特异病原体(specific pathogen free,SPF)级雄性C57BL/6小鼠(4~6周龄)随机分为4组,5%的葡聚糖硫酸钠(dextran sulphate sodium,DSS)诱导IBD造模。6周阶梯递增负荷的适度跑台运动后,以小鼠结肠的疾病活动性指数、肠道病理组织学、宿主免疫反应的表达和宏基因组学分析肠道微生物群落的特征性作为运动干预效果的指标体系。结果:1)H.E.染色显示,DSS给药扭曲了小鼠结肠腺体的形态,导致炎症细胞大量募集到粘膜下层。运动干预后,小鼠结肠上皮细胞的紧密连接得以部分恢复,疾病活动评分和组织学损伤评分显著降低。2)IBD造模与运动干预可引起小鼠肠道菌群的物种多样性和优势群落菌属的丰度变化,其中厚壁菌门(Phylum Firmicutes)、放线菌门(Phylum Actinobacteria)和疣微杆菌门(Phylum Verrucomicrobia)显著增加,但拟杆菌门(Phylum Bacteroidetes)具有特征性减少和运动逆转的趋势,可作为干预IBD肠道菌群的靶向干预群落。3)运动后在健康小鼠中,运动组血清IL-10、TNF-α、MPO的表达量均显著高于安静组;在炎症性肠病小鼠中,运动组IL-1β和IL-10的表达量均显著高于安静组。结论:1)适度跑台运动对小鼠炎性肠病引起的结肠上皮损伤具有良好的修复和转归作用;2)运动可引起炎性肠病的肠道微生物种属的多样性变化和优势群落的特征变化,具有特征性优势群落可作为炎性肠道疾病治疗靶向干预群落;3)适度运动可有效抑制炎症反应,其干预炎症肠病的机制可能与运动激活肠道的固有免疫相关。

Objective: Based on metagenomic sequencing technology, this study established IBD mice model, and explored the intervention effect of exercise on inflammatory bowel disease mice, and analyzed the effects of moderate exercise on intestinal microflora characteristics, thus provided a new idea for exercise in intervening chronic diseases for the prevention and treatment of inflammatory bowel disease. Methods: Twenty-two specific pathogen free(SPF) male C57BL/6 mice(4~6 weeks old) were randomly divided into 4 groups, and IBD mice models were induced by oral administration of 5% dextran sulphate sodium(DSS). After 6-week medium-low-intensity treadmill exercise,the effect of exercise intervention were evaluated by disease activity index(DAI), intestinal histopathology, host immunoreaction and characteristic changes of intestinal microflora that were measured by Metagenomic technology. Results: 1) H.E.showed that DSS distorted the morphology of colonic glands in mice, leading to the mass recruitment of inflammatory cells into the submucosa. After exercise intervention, the tight junctions of colonic epithelial cells were partially restored, and the disease activity score and histological injury score were significantly reduced. 2) IBD model and exercise intervention caused changes in species diversity and abundance of dominant community bacteria genus in intestinal flora of mice,among which Phylum Firmicutes,Phylum Actinobacteria and Phylum Verrucom icrobia significantly increased, but Phylum Bacteroidetes has characteristic decrease. Movement reversibility Bacteroidetes could be used as a targeted intervention community for IBD. 3) In healthy mice,serum Interleukin-10(IL-10),Tum or necrosis factor-α(TNF-α) and Myeloperoxidase(MPO) in exercise group were significantly higher than quiet group;in IBD mice,Interleukin-1β(IL-1β)and IL-10 were significantly higher in exercise group. Conclusions: 1) Moderate treadmill exercise has a good repair effect on colonic epithelial damage in IBD mice;2) exercise can change the diversity of intestinal microflora and characteristic dominant communities in IBD mice. A community with characteristic advantages can be used as a targeted intervention community for the treatment of IBD;3) moderate exercise can effectively inhibit the inflammatory response,and its mechanism of intervention in IBD may be related to the innate immunity of exercise-activated intestinal tract.