高脂食物对动脉硬化合并类风湿关节炎小鼠肠道菌群的影响

Effects of high fat diet on the intestinal microbiota of mice with atherosclerosis combined with rheumatoid arthritis

目的分析高脂食物对动脉硬化合并类风湿关节炎小鼠肠道微生物的影响,了解动脉硬化合并类风湿关节炎小鼠肠道微生物的变化。方法 8周龄ApoE^(-/-)小鼠饲喂高脂食物和普通食物至17周龄来诱发动脉硬化症状,再通过给17周龄ApoE^(-/-)小鼠腹腔注射抗6-磷酸葡萄糖异构酶(glucose-6-phosphate isomerase,GPI)抗体呈阳性的K/BxN血清,从而诱导其产生类风湿关节炎症状。通过Illumina HiSeq平台对各组小鼠粪便进行16S rDNA V4区测序,分析动脉硬化合并类风湿关节炎小鼠肠道微生物的变化。结果 ApoE^(-/-)小鼠饲喂高脂食物后,其血清低密度脂蛋白胆固醇(LDL-C)浓度和血清总胆固醇(TC)浓度均显著升高,主动脉内膜斑块面积比喂普通食物的ApoE^(-/-)小鼠显著增加,表明ApoE^(-/-)小鼠饲喂高脂食物后引起更显著的动脉硬化症状。再通过腹腔注射抗GPI抗体呈阳性的K/BxN血清,各组ApoE^(-/-)小鼠均出现关节肿胀,饲喂高脂食物的ApoE^(-/-)小鼠其踝关节宽度和临床评分(clinical score)低于饲喂普通食物组小鼠。OTU数、Shannon指数和Simpson指数显示高脂食物和K/BxN血清处理组ApoE^(-/-)小鼠肠道菌群多样性降低,Firmicutes/Bacteroidetes值升高,t-test分析显示在属水平上,Prevotellaceae_UCG-001显著降低,Ruminiclostridium_6显著升高。t-test分析和Firmicutes/Bacteroidetes比值显示ApoE^(-/-)小鼠肠道菌群结构紊乱。结论高脂食物使ApoE^(-/-)小鼠的肠道菌群组成和结构发生改变,导致ApoE^(-/-)小鼠的动脉硬化症状加重,类风湿关节炎症状减轻。提示肠道微生物组成和结构的改变,可能与动脉硬化合并类风湿关节炎发病机制相关。

Objective To explore the effects of high fat diet on the intestinal microbiota in mice with atherosclerosis and rheumatoid arthritis(RA).Methods ApoE knockout(ApoE-/-)mice were fed with high fat diet and control(ordinary)diet from 8 to 17 weeks of age to induce symptoms of atherosclerosis.The K/BxN serum which anti-GPI(glucose-6-phosphate isomerase)antibody was positive was then injected to ApoE-/-mice intra-peritoneally from 17 to 26 weeks of age,in order to induce the symptoms of rheumatoid arthritis.The intestinal microbiota of mice were analyzed by the Illumina HiSeq platform targeting the V4 region of the 16 S rDNA.Results Compared to ApoE-/-mice which were treated with control diet and K/BxN serum,the levels of low density lipoprotein cholesterol(LDL-C)and total cholesterol(TC)in serum were significantly elevated,and the atherosclerotic plaque areas of aorta were significantly increased in ApoE-/-mice which were treated with high fat diet and K/BxN serum.The high fat diet induced more serious symptoms of atherosclerosis than control diet in ApoE-/-mice.After intra-peritoneal injection with K/BxN serum,the ankles of all mice were swelling.However,the ankle width and the clinical score were lower in high fat diet and K/BxN serum treated mice than control diet and K/BxN serum treated mice.Compared to control diet and K/BxN serum treated mice,the OTUs number,Shannon index and Simpson′s index showed that the community diversity of intestinal microbiota in high fat diet and K/BxN serum treated mice were decreased;t-test analysis showed that PrevotellaceaeUCG-001 were significantly decreased and Ruminiclostridium6 were significantly increased at the genus level.Firmicutes/Bacteroidetes ratio was increased in ApoE-/-mice treated with high fat diet and K/BxN serum.There was a dysbiosis of intestinal microbiota in ApoE-/-mice which were fed with high fat diet and K/BxN serum.Conclusion The composition and structure of intestinal microbiota of high fat diet and K/BxN serum treated mice were changed,resulting to aggravation of atherosclerosis symptoms and alleviation of rheumatoid arthritis symptoms.The changes of the composition and structure of intestinal microbiota may be related to the pathogenesis of atherosclerosis combined with rheumatoid arthritis.