Screening and identification of anomously expressed proteins in colon mucosa in diarrhea-predominant irritable bowel syndrome / 解放军医学杂志

ABSTRACT

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.