牙龈卟啉单胞菌对小鼠肠道炎症的影响研究

Effect of Porphyromonas gingivalis on intestinal inflammation in mice

目的:研究牙龈卟啉单胞菌(Porphyromonas gingivalis,P.g)对小鼠肠道炎症的诱导作用及机制探究。方法:将12只BALB/C小鼠随机均分为2组,P.g组灌饲0.2 mL OD_(600)=0.5的P.g菌液,对照组灌饲等量无菌BHI液体培养基。每只小鼠每日灌饲1次,起始和每次灌饲1周时小鼠称重,7周后采用颈椎脱臼法处死小鼠,采取小肠组织并收取粪便。粪便进行16S rRNA测序分析肠道菌群多样性;小肠组织行HE染色分析肠道炎症进展。免疫组化分析炎症因子IL-17的表达及铁死亡指标(ACSL4,SLC7A11,GPX4)的水平变化。结果:对照组和P.g灌饲组小鼠体重第7周时存在差异(P<0.05)。HE染色显示P.g组小鼠小肠黏膜下炎症细胞浸润增加,绒毛间质轻微水肿,提示肠道炎症浸润。免疫组化结果显示,P.g灌饲组小鼠小肠组织IL-17明显升高。小肠组织中ACSL4水平显著增高,SLC7A11和GPX4水平降低,小鼠小肠组织在P.g作用下发生了铁死亡。16S rRNA结果显示P.g组与对照组间肠道菌群差异明显(P<0.05)。结论:P.g可诱导肠道菌群紊乱进而诱导小肠炎症,并促使小鼠小肠组织发生铁死亡。

Objective:To study the inducing effect of Porphyromonas gingivalis(P.g)on intestinal inflammation in mice and explore its mechanism.Methods:Twelve BALB/C mice were randomly divided into two groups, P.g group was fed with 0.2 mL of P.g bacteria solution with OD_(600)=0.5,while control group was fed with the same amount of sterile BHI liquid medium.Each mouse was fed once a day, and each mouse in each group was weighed at the beginning and at the end of each week of feeding.After 7 weeks, the mice were sacrificed by cervical dislocation, and the small intestine tissues were collected and feces were collected.Intestinal microbiota diversity was analyzed by 16 S rRNA sequencing.HE staining was performed to analyze the progression of intestinal inflammation.The expression of inflammatory cytokines IL-17 and the levels of iron death indicators(ACSL4,SLC7 A11,GPX4)were analyzed by immunohistochemistry.Results:The difference was significant in body weight between the two groups at the 7 th week(P<0.05).HE staining showed increased infiltration of inflammatory cells in the small intestinal mucosa of mice in P.g group and slight edema in the villous interstitium, suggesting intestinal inflammatory infiltration.The results of immunohistochemistry showed that IL-17 was significantly increased in the small intestine of mice in P.g group.The levels of ACSL4 were significantly increased and the levels of SLC7 A11 and GPX4 were decreased in the small intestine, indicating that iron death occurred in the small intestine of mice under the action of P.g.16 S rRNA results showed significant differences in intestinal flora between P.g group and control group(P<0.05).Conclusion:P.g can induce intestinal microbiota disorder and small intestinal inflammation, and promote iron death in small intestinal tissue of mice.