细粒棘球蚴感染小鼠血清的代谢组学分析

Metabolomics analysis of serum in mice infected with Echinococcus granulosus

目的检测分析感染细粒棘球蚴的囊型包虫病(cystic echinococcosis,CE)小鼠与健康小鼠血清代谢产物的差异性,从代谢组学层面为CE的早期诊断和发病机制研究提供依据。方法门静脉注射感染细粒棘球绦虫原头蚴,建立CE小鼠模型。用液相色谱质谱联用技术(1iquid chromatography-mass spectrometry,LC-MS)分别对CE小鼠和对照组小鼠血清进行检测,采用无监督的主成分分析(principal component analysis,PCA)、偏最小二乘判别分析(partial least squares-discriminant analysis,PLS-DA)、正交偏最小二乘法判别分析(orthogonal partial least squares discriminant analysis,OPLS-DA)及学生t检验筛选差异代谢物,并对其进行层次聚类和代谢通路富集分析。结果PLS-DA和OPLS-DA分析两组血清共获得198个显著差异代谢产物,显著上调的代谢产物有88个,显著下调的代谢产物有110个。与对照组比较,CE组小鼠血清中辅酶Q8、磷脂酸、肾上腺素、胆碱、5-氨基颉草酸、L-异亮氨酸、L-缬氨酸、肌酸和γ-氨基丁酸等含量增多,L-精氨酸、D-甘油酸、胆碱磷酸、谷胱甘肽、前列腺素、花生四烯酸和溶血磷脂酰胆碱等代谢物含量均显著减少(均P<0.01)。胆碱(AUC=1,P<0.01)、肌酸(AUC=0.97,P<0.01)、L-缬氨酸(AUC=0.902,P<0.01)、溶血磷脂酰胆碱(AUC=0.899,P<0.01)与花生四烯酸(AUC=0.838,P<0.01)代谢物的受试者工作特征曲线(receiver operating characteristic,ROC)下面积均大于0.75,被选为具有诊断价值的候选生物标志物。差异代谢产物富集精氨酸和脯氨酸代谢、脂肪代谢调节、醛固酮的合成与分泌代谢途径。结论小鼠感染细粒棘球蚴早期血清中存在差异代谢产物,其与氨基酸代谢、脂肪代谢途径密切相关,但将血清中的差异代谢产物作为CE早期感染诊断的生物标志物仍需进一步筛选与验证。

Objective To investigate the differences in serum metabolites between cystic echinococcosis(CE)mice infected with Echinococcus granulosus(Eg)and healthy mice,which provided a basis for the early diagnosis and pathogenesis of CE.Methods The CE mice model was established by portal vein injection of protoscoleces.Serum samples from CE mice and healthy mice were detected by 1iquid chromatography-mass spectrometry(LC-MS).Unsupervised principal component analyses(PCA),partial least squares-discriminant analysis(PLS-DA),orthogonal partial least squares discriminant analysis(OPLS-DA)and student's t test were used to screen out the differential metabolites,and hierarchical clustering and metabolic pathway enrichment analysis were performed.Results 198 serum metabolites between two groups were obtained by PLS-DA and OPLS-DA analysis,88 metabolites were significantly up-regulated and 110 metabolites were significantly down-regulated.Compared with the control group,the contents of coenzyme Q8,phospholipid acid,epinephrine,choline,5-amino-antagonic oxalic acid,L-isoleucine,L-valine,creatine andγ-aminobutyric acid in serum of CE mice were increased.The contents of L-arginine,D-glyceric acid,cholinophosphate,glutathione,prostaglandin,arachidonic acid and lysophosphatidylcholine were decreased,and the difference was statistically significant(P<0.01).The area under receiver operating characteristic(ROC)curve of choline(AUC=1,P<0.01),creatine(AUC=0.97,P<0.01),L-valine(AUC=0.902,P<0.01),lysophosphatidylcholine(AUC=0.899,P<0.01)and arachidonic acid(AUC=0.838,P<0.01)was greater than 0.75,and they were selected as candidate biomarkers with diagnostic performance.Differential metabolites enriched arginine and proline metabolism,lipid metabolism regulation,aldosterone synthesis and secretion metabolic pathways.Conclusion Metabolomics provides a reference for the diagnosis and screening of CE with high sensitivity and specificity.The serum differential metabolites during the early host infection of Eg are closely related to amino acid metabolism and lipid metabolism pathway.The valuable serum biomarkers of early CE infection still need to be further verified and studied.