基于气相色谱-质谱的大鼠溃疡性结肠炎模型结肠组织代谢组学特征

Metabolomic features of the colon tissue in ulcerative colitis rat model based on gas chromatography- mass spectrometry

目的寻找溃疡性结肠炎(UC)大鼠结肠黏膜组织中UC相关的特异性标志物。方法将16只健康大鼠分为UC模型组(12只)和正常对照组(4只),用2,4,6-三硝基苯磺酸(TNBS)建立UC大鼠模型,正常对照组大鼠正常喂养。UC模型组分别在造模后5、10、15 d各取4只大鼠与正常对照组病变部位的黏膜组织进行GC-MS检测,并采用主成分分析法、偏最小二乘-线性判别分析法、化学计量学方法进行分析,最后采用t检验并结合OPLS-DA模型第一主成分的VIP值(VIP>1)来寻找差异性表达代谢物。结果与正常对照组相比,UC模型组结肠组织的代谢谱有明显改变,共找到9种差异代谢产物(P<0.05),分别是尿苷、腺嘌呤、胞嘧啶、甘氨酸、乳酸、牛磺酸、苏氨酸、甘露糖、β-丙氨酸。结论 UC大鼠和正常大鼠结肠组织间存在差异代谢组分,9种差异代谢物在临床上可作为UC早期诊疗的生物学标志物。

Objective To compare the colonic mucosa tissue of the ulcerative colitis rat model group with the normal control group using gas chromatography（ GC）- mass spectrometry（ MS） coupling techniques,and to identify the UC-specific markers from the colonic mucosa tissue of rats. Methods The 16 healthy rats were randomly divided into the UC model group（ 12 rats） and normal control group（ 4 rats）. The UC rat model was established using TNBS,while rats in the control group were treated with normal diets. Colonic mucosa of both groups was collected and underwent GC- MS detection. In the model group,4 samples were collected on the 5th,10 th,15th day,respectively. Principal component analysis（ PCA）,partial least squares- linear discriminant analysis（ PLS- LDA） and chemometric methods were used in the comparative analysis and finally,t test（ P〈0. 05） combined with the VIP（ Variable Importance in the Projection） value of the first principal component in OPLS- DA model（ VIP 〉1） was used to find differentially expressed metabolites. Results Compared with the normal control group,the metabolic spectrum of colon tissue in the UC model group changed significantly. The t test results revealed a total of 9 metabolites with statistically significant differences. Conclusion The metabolic components in colon tissue are different between UC rats and normal rats. 9 metabolites can be regarded as biomarkers in early diagnose and treatment of UC.