米诺环素对海湾战争综合征模型大鼠海马神经炎症水平及肠道菌群影响

Effects of minocycline on the level of hippocampal neuroinflammation and intestinal flora in the Gulf War syndrome model rats

目的探讨米诺环素对海湾战争综合征(GWS)模型大鼠海马神经炎症水平及肠道菌群的影响。方法选取健康成年雄性SD大鼠30只为研究对象。将大鼠随机分成对照组、GWS模型组、米诺环素组3组,每组各10只。采用16s DNA测序法检测肠道菌群的变化;采用聚合酶链式反应(PCR)、免疫印迹分析检测脑内Toll样受体4(TLR4)、核因子-κB(NF-κB)表达水平;用酶联免疫吸附法(ELISA)检测脑内白细胞介素(IL)-10、IL-17表达水平。结果GWS模型组ACE指数、Shannon指数均显著高于对照组与米诺环素组,差异有统计学意义(P<0.05)。Beta多样性分析结果显示,对照组与GWS模型组菌群之间的相似度较低,而对照组与米诺环素组菌群之间的相似度较高。在纲水平上,GWS模型组中杆菌、丹毒丝菌纲、δ变形杆菌纲所占比例显著低于对照组,拟杆菌纲、丙型变形杆菌纲、螺旋体属和柔膜菌纲比例显著高于对照组,差异有统计学意义(P<0.05)。在科水平上,GWS模型组瘤胃球菌科、琥珀酸弧菌科、毛螺菌科、普雷沃氏菌科和桑科的比例显著高于对照组,乳杆菌科、消化链球菌科和韦荣球菌科比例显著低于对照组,差异具有统计学意义(P<0.05)。PCR及蛋白免疫印迹法结果显示,GWS模型组大鼠海马中TLR4、NF-κB p65的蛋白与mRNA水平均显著高于对照组及米诺环素组,差异有统计学意义(P<0.05)。ELISA结果显示,GWS模型组大鼠海马中IL-17的表达水平显著高于对照组及米诺环素组,IL-10的水平显著低于对照组及米诺环素组,差异有统计学意义(P<0.05)。结论米诺环素处理可以抑制GWS模型大鼠海马的神经炎症水平,其作用机制可能与米诺环素处理改变肠道菌群相关。

Objective To investigate the effects of minocycline on the level of hippocampal neuroinflammation and intestinal flora in Gulf War syndrome(GWS)model rats.Methods Thirty healthy adult male SD rats were selected for the study.The rats were randomly divided into three groups:the control group,the GWS model group and the minocycline hydrochloride group,with 10 rats in each group.The changes of intestinal flora were detected by 16 s DNA sequencing.Toll-like receptors 4(TLR4)and nuclear factor-kappa B(NF-κB)expression levels were detected by polymerase chain reaction(PCR)and Western blot analysis.The expression levels of interleukin(IL)-10 and IL-17 in the brain were detected by enzyme linked immunosorbent assay(ELISA).Results The ACE index and Shannon index of the GWS model group were significantly higher than those of the control group and the minocycline group,with statistically significant differences(P<0.05).The results of Beta diversity analysis showed that the similarity between the control group and the GWS model group was low,while the similarity between the control group and the minocycline group was high.At the level of class,the proportion of Bacillus,erysipelothrix andδproteobacterium in GWS model group was significantly lower than that in control group,and the proportion of bacteroides,δproteobacterium C,spirochetes and pachymycetes was significantly higher than that in control group(P<0.05).At the family level,the ratios of ruminococcaceae,Vibriovibriaceae,Trichoderma,Prevobacteriaceae and Sancomaceae in the GWS model group were significantly higher than those in the control group,and the ratios of Lactobacillaceae,digestive Streptococcaceae and Veronaceae were significantly lower than those in the control group(P<0.05).PCR and Western blot results showed that the protein and mRNA levels in TLR4 and NF-κB p65 of the hippocampus of GWS model group were significantly higher than those in the control group and minocycline groups(P<0.05).ELISA results showed that the expression level of IL-17 in the hippocampus of GWS model group was significantly higher than that of the control group and minocycline group,and the level of IL-10 was significantly lower than that of the control group and minocycline group(P<0.05).Conclusion Minocycline treatment can inhibit the level of neuroinflammation in the hippocampus of GWS model rats,and its mechanism may be related to the change of intestinal flora by the treatment of minocycline.