基于UPLC-Q-TOF MS代谢组学技术筛选表征奶牛产后异食癖的候选生物标识物

Selection of candidate biomarkers featuring pica in postpartum cows based on UPLC-Q-TOF MS metabolomics

旨在筛选表征奶牛产后异食沙土的生物标志物。本试验共采集29份产后15~22 d血浆样品,根据奶牛产后有无异食沙土现象,结合血钙浓度进行分组,其中13头产后有异食现象的奶牛血浆样品为试验组,16头健康奶牛血浆样品为对照组,采用超高效液相色谱-四极杆-飞行时间质谱(UPLC-Q-TOF MS)代谢组学技术探讨2组血浆代谢轮廓和代谢物的变化趋势。主成分分析(PCA)和正交偏最小二乘法-判别分析(OPLS-DA)结果显示,试验组代谢轮廓较对照组发生明显变化,正、负离子下共筛选出28种差异代谢物,其中21种代谢物水平显著降低(P<0.05),7种代谢物水平显著升高(P<0.05);ROC曲线进一步考察这些差异代谢物对分类的识别能力,结果显示仅有11种代谢物对2组血浆具有显著的区分能力。综上表明,乙酰肉碱、DL-苯丙氨酸、2-八烯酸、辛酸、癸酸、D-泛醇、NG,NG-二甲基-L-精氨酸(ADMA)、雄烯二酮、脯氨酸-酪氨酸、异亮氨酸-丝氨酸、精氨酸-缬氨酸可作为表征奶牛产后是否有异食现象的潜在生物标志物,为研究奶牛产后异食沙土的预防提供新的方法和思路。

To select biomarkers featuring pica in postpartum cows,29 of postpartum 15-22 days were tested,including 13 cows with postpartum pica phenomenon and 16 healthy cows according to the phenomenon of picnic sand and the blood calcium concentration.UPLC-Q-TOF MS metabolomics was used to study change in metabolic profile and metabolites of plasma.Principal component(PCA)and orthogonal partial least squares-discriminant analysis(OPLS-DA)analysis revealed that,compared to the control group,plasma metabolic profiles obviously altered,a total of twenty-eight different metabolites were screened under positive and negative ions,twenty-one metabolites significantly decreased,and seven metabolites significantly increased in test group.These metabolites were further analyzed by ROC curve to observe their discriminating ability to classification.As a result,only eleven metabolites including acetylcarnitine,DL-phenylalanine,2-octenoic acid,caprylic acid,capric acid,dexpanthenol,NG,NG-dimethyl-L-arginine(ADMA),androstendione,Pro-Tyr,Ile-Ser and Arg-Val had an obviously separating capacity for the two groups of plasma.In conclusion,acetylcarnitine,DL-phenylalanine,2-octenoic acid,caprylic acid,capric acid,dexpanthenol,NG,NG-dimethyl-L-arginine(ADMA),and rostendione,Pro-Tyr,Ile-Ser and Arg-Val in plasma could be better potential biomarkers to evaluate postpartum cows pica.The study provided a new methods and ideas for the prevention of postpartum picnic sand in dairy cows.