P027. Proteomics analysis of serum and tissue proteins in patients with intestinal Behçet's disease by MALDI-TOF/TOF mass spectrometry
H.J. Lee, S.J. Park, S.P. Hong, T.I. Kim, W.H. Kim, J.H. Cheon, Institute of Gastroenterology, Yonsei University College of Medicine, Department of Internal Medicine, Seoul, Korea, Republic of
Although intestinal Behçet's disease (BD) has an unpredictable disease course with exacerbations and remission like inflammatory bowel disease (IBD), data concerning diagnosis, treatment, and prognosis are yet to be determined and the pathogenesis of intestinal BD are poorly understood. Therefore, we aimed to investigate the differentially expressed proteins both in serum and tissue from patients with intestinal BD and search for biomarkers associated with disease pathogenesis using proteomics analysis.
Serum samples from 15 intestinal BD, systemic BD, and normal control were pooled and tissues were obtained from surgical specimens of intestinal BD patients who underwent surgery due to disease exacerbation. Two-dimensional electrophoresis (2-DE) technology was performed to characterize the total proteins of serum and tissues from intestinal BD patients. Candidate protein spots were identified using matrix-assisted lase desorption/ionization tandem time-of-flight mass spectrometry (MALDI-TOF/TOF-MS) and bioinformatics analysis. Enzyme-linked immunosorbent assay (ELISA) was applied to validate the results of 2-DE and MS.
Proteomic profiles of serum pooled samples were compared, and approximately 400 protein spots were observed in intestinal BD patients. Mass spectrometric analysis identified that expression levels of 3 of the protein spots in intestinal BD were significantly higher than those in the normal control and systemic BD, including serum amyloid A, apolipoprotein A-IV, and fibrin. ELISA revealed that serum amyloid A was overexpressed in intestinal BD (median 12.17 ng/ml, range 6.15–58.34) but not in systemic BD (median 10.57 ng/ml, range 5.67–38.67). The 2-DE protein expression profile of 575 protein spots from the intestinal BD tissues also shows a definite difference from that of the normal controls. Seven individual protein spots were identified, of which 4 proteins were up-regulated including heat shock protein 27, transgelin, manganese superoxide dismutase, and calprotectin, and 3 were down-regulated including heat shock protein 60, selenium binding protein, and galectin-3.
A distinct proteomic profile of serum and tissue in intestinal BD patients was found that 7 up-regulated and 3 down-regulated proteins were identified. Our data might be helpful for understanding the pathogenesis of intestinal BD and providing potential biomarkers for the early diagnosis and treatment of intestinal BD.