Comparative analysis of inflamed and non-inflamed colon biopsies reveals strong proteomic inflammation profile in patients with ulcerative colitis
1 Department of Food Science, Aarhus University, Tjele 8830, Denmark
2 Medical Department, Viborg Regional Hospital, Viborg 8800, Denmark
3 Medical Department, SHS Aabenraa, Aabenraa 6200, Denmark
4 Institute of Regional Health Services Research, South Danish University, Odense 5000, Denmark
5 Pathological Department, Viborg Regional Hospital, Viborg 8800, Denmark
6 National Food Institute, Technical University of Denmark, 2800 Kgs Lyngby, Denmark
7 Department of Animal Science, Aarhus University, Tjele 8830, Denmark
BMC Gastroenterology 2012, 12:76 doi:10.1186/1471-230X-12-76Published: 24 June 2012
Accurate diagnostic and monitoring tools for ulcerative colitis (UC) are missing. Our aim was to describe the proteomic profile of UC and search for markers associated with disease exacerbation. Therefore, we aimed to characterize specific proteins associated with inflamed colon mucosa from patients with acute UC using mass spectrometry-based proteomic analysis.
Biopsies were sampled from rectum, sigmoid colon and left colonic flexure from twenty patients with active proctosigmoiditis and from four healthy controls for proteomics and histology. Proteomic profiles of whole colonic biopsies were characterized using 2D-gel electrophoresis, and peptide mass fingerprinting using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was applied for identification of differently expressed protein spots.
A total of 597 spots were annotated by image analysis and 222 of these had a statistically different protein level between inflamed and non-inflamed tissue in the patient group. Principal component analysis clearly grouped non-inflamed samples separately from the inflamed samples indicating that the proteomic signature of colon mucosa with acute UC is strong. Totally, 43 individual protein spots were identified, including proteins involved in energy metabolism (triosephosphate isomerase, glycerol-3-phosphate-dehydrogenase, alpha enolase and L-lactate dehydrogenase B-chain) and in oxidative stress (superoxide dismutase, thioredoxins and selenium binding protein).
A distinct proteomic profile of inflamed tissue in UC patients was found. Specific proteins involved in energy metabolism and oxidative stress were identified as potential candidate markers for UC.