咪喹莫特治疗后溃疡性结肠炎小鼠结肠组织的差异表达蛋白及其功能

Differentially expressed proteins and their functions in colonic tissues of mice with ulcerative colitis after imiquimod therapy

目的分析咪喹莫特治疗后溃疡性结肠炎(UC)小鼠结肠组织的差异表达蛋白及其功能。方法将30只C57BL/6小鼠随机分为正常组、模型组、咪喹莫特组,各10只。正常组常规饲养,模型组和咪喹莫特组建立UC小鼠模型。咪喹莫特组给予咪喹莫特灌胃,模型组与正常组给予等体积磷酸缓冲盐溶液灌胃。干预7 d后,提取小鼠结肠组织蛋白,采用同位素标记相对和绝对定量技术结合质谱定量蛋白质组学方法分析和鉴定3组差异表达蛋白,运用生物信息学分析差异表达蛋白的功能。结果模型组/正常组、咪喹莫特组/正常组、咪喹莫特组/模型组分别存在317个、253个和209个差异表达蛋白。模型组和正常组相比上调而咪喹莫特组与模型组相比下调的蛋白有62个,模型组与正常组相比下调而咪喹莫特组与模型组相比上调的蛋白有48个。这些差异表达蛋白主要分布在细胞器、细胞及胞外区,分子功能以结合功能、催化功能及酶调节活性为主,主要参与细胞进程、生物调节及代谢过程。结论 S100钙结合蛋白A8、黏蛋白2、角蛋白等有可能成为咪喹莫特治疗UC的重要分子靶点。

Objective To analyze differentially expressed proteins and their functions in colonic tissues of mice with ulcerative colitis( UC) after imiquimod therapy. Methods Thirty C57 BL/6 mice were randomly divided into normal group,model group and imiquimod group,with 10 mice in each group. The normal group was given conventional diet,and a mouse model of UC was established in the model group and imiquimod group. The imiquimod group was given imiquimod by gavage,the model group and the normal group were given isometric phosphate buffered saline by gavage. Seven days after intervention,the proteins in colon tissues of the mice were extracted,differentially expressed proteins were analyzed and identified among the three groups using isobaric tags for relative and absolute quantification combined with mass spectrometry quantitative proteomics,then bioinformatics was used to analyze the function of differentially expressed proteins. Results There were 317,253 and 209 differentially expressed proteins in the model group/normal group,imiquimod group/normal group and imiquimod group/model group,respectively. Sixty-two proteins were up-regulated in the model group compared with those in the normal group but were down-regulated in the imiquimod group compared with those in the model group,48 proteins were down-regulated in the model group compared with those in the normal group but were up-regulated in the imiquimod group compared with those in the model group. These differentially expressed proteins were mainly distributed in organelles,cells and extracellular regions,obtaining major molecular functions of binding function,catalytic function and enzymatic regulation activity,and were mainly involved in cellular process,biological regulation process,and metabolic process. Conclusion S100 calcium binding protein A8,mucin 2,and keratin might be the important molecular targets for treating UC by imiquimod.