腹泻型肠易激综合征患者结肠黏膜组织异常表达蛋白质的筛选与鉴定

目的 筛选及鉴定腹泻型肠易激综合征(D-IBS)患者与正常人结肠黏膜组织中的差异表达蛋白.方法 D-IBS患者及健康志愿者各4例,分别为D-IBS组和正常对照组.通过结肠镜取回盲部及乙状结肠黏膜进行活检,用含0.1% PMSF的冰盐水将标本洗净后立即置于液氮中保存.提取蛋白质,采用双向凝胶电泳法筛选差异表达蛋白,并采用质谱法对变化最明显的蛋白点进行鉴定.结果 利用双向凝胶电泳技术成功得到人结肠黏膜组织的蛋白质组图谱.正常对照组图谱平均得到蛋白点336个,组内图像平均匹配率92%,D-IBS组图谱平均得到蛋白点426个,组内图像平均匹配率95%.D-IBS组与正常对照组之间进行平均胶图谱的比较,两组间匹配率为74%.Volume值变化大于2倍以上的点共24个,其中21个点表达上调,3个点表达下调.表达上调最明显的2个蛋白点经鉴定分别为免疫球蛋白J链(Ig-j)和热休克蛋白27(HSP27),表达下调最明显的2个蛋白点则分别为血红蛋白β亚基和果糖二磷酸醛缩酶A.结论 采用双向凝胶电泳法可以成功得到人结肠黏膜组织蛋白质组表达图谱,D-IBS患者与正常人结肠黏膜组织蛋白质表达存在差异,已经鉴定出来的4个蛋白可能在D-IBS的发病机制中起一定作用.

Screening and identification of anomously expressed proteins in colon mucosa in diarrhea-predominant irritable bowel syndrome

Objective To screen and identify the anomously expressed proteins at protein level in colon mucosa of diarrhea-predominant irritable bowel syndrome(D-IBS)patients and healthy individuals.Methods Four D-IBS patients and four healthy individuals were included in the study.Biopsies of mucosa at the ileocecal junction and sigmoid colon were performed via colonoscopy.The specimens were cleaned with ice cold saline which contained 0.1% PMSF,and were snap frozen in liquid nitrogen.The two-dimensional gel electrophoresis(2-DE)was used to screen the anomously expressed proteins,and the two proteins which presented the greatest changes in each group were identified by mass spectrometry method.Results Proteomics maps of human colon mucosa were obtained successfully with 2-DE.Average protein spots were 336 in normal control group,and the matching rate among them was 92%,while in D-IBS group,the average protein spots were 426,and the matching rate was 95%.The average matching rate between the test group and the control group was 74%.It was found that the volume value of 24 proteins spots changed more than two folds.The protein expression was found to decrease in 3 spots and increase in 21 spots.Four proteins were chosen for analysis with mass spectrometry analysis.The two up-regulated proteins were identified as Immunoglobulin J chain and heat shock protein 27,while the other two down-regulated proteins were identified as hemoglobin beta subunit and fructose-bisphosphate aldolase A.Conclusion With 2-DE,proteomics maps of human colon mucosa have been obtained successfully.The proteome expressions of colon mucosa in D-IBS patients are remarkably different from that of the healthy individuals.The four identified proteins may play a certain role in the pathogenesis of D-IBS.