Table 2

Members of the colon core mucus proteome and their abundance differences between patient groups

Protein nameGeneSuggested role in the mucus layerDifferentially regulated (P value)
UCA versus CTRL*UCR versus CTRL*Rank†
Anterior gradient protein 2 AGR2 Required for mucin biosynthesisn.s. (n.s.)n.s. (n.s.)30
Chromogranin A CHGA Secreted by enteroendocrine cells↓0.032 (0.006)n.s. (n.s.)196
CLCA1 CLCA1 Major component in mucus↓0.011 (0.004)n.s. (n.s.)18
Cathepsin D CTSD Secreted cysteine proteasen.s. (n.s.)n.s. (n.s.)530
Cathepsin S CTSS Secreted cysteine proteasen.s. (n.s.)n.s. (n.s.)734
Cathepsin Z CTSZ Secreted cysteine protease↓0.006 (n.s.)‡n.s. (n.s.)349
Decorin DCN Proteoglycan, part of extracellular matrixn.s. (n.s.)n.s. (n.s.)211
DMBT1 DMBT1 Aggregates both G+/− bacterian.s. (n.s.)n.s. (n.s.)277
Eosinophil peroxidase EPX Eosinophil granule protein↑0.006 (0.007)n.s. (n.s.)505
Protein FAM3D FAM3D Chemotaxisn.s. (n.s.)n.s. (n.s.)695
IgGFc-binding protein FCGBP Structural mucus protein↓<0.001 (<0.001)‡n.s. (n.s.)19
Cell surface A33 antigen GPA33 Affects intestinal permeability↓0.019 (0.015)n.s. (n.s.)296
IgA IGHA1 IgAn.s. (n.s.)n.s. (n.s.)24
IgJ IGJ Dimerisation of IgAn.s. (n.s.)n.s. (n.s.)61
IgM IGHM IgMn.s. (0.042) ↑n.s. (n.s.)203
Intelectin-1 ITLN1 Found in mucus granulesn.s. (n.s.)n.s. (n.s.)387
Kallikrein-1 KLK1 Serine protease found in mucus granulesn.s. (n.s.)‡↑n.s. (n.s.)586
Galectin-3 LGALS3 Lectin-binding galactosen.s. (n.s.)n.s. (n.s.)60
Galectin-3-binding protein LGALS3BP Galectin-3-binding proteinn.s. (0.010) ↓n.s. (n.s.)747
Lumican LUM Proteoglycan, part of extracellular matrixn.s. (n.s.)n.s. (n.s.)143
Meprin alpha MEP1A Metalloproteasen.s. (n.s.)n.s. (n.s.)917
Mucin-2 MUC2 Intestinal mucin↓<0.001 (<0.001)‡n.s. (n.s.)13
Mucin-4 MUC4 Transmembrane mucinn.s. (n.s.)n.s. (n.s.)755
Mucin-5B MUC5B Gel-forming mucinn.s. (n.s.)n.s. (n.s.)367
Mucin-12 MUC12 Transmembrane mucinn.s. (n.s.)n.s. (n.s.)363
Mucin-13 MUC13 Transmembrane mucinn.s. (n.s.)n.s. (0.010)↑561
Polymeric Ig receptor PIGR Transports IgAn.s. (n.s.)n.s. (n.s.)76
Eosinophil cationic protein RNASE3 Eosinophil granule protein↑0.010 (n.s.)‡↑0.003 (0.010)490
Zymogen granule protein 16 ZG16 Aggregates G+ bacteria↓0.001 (0.002)n.s. (n.s.)262
  • *Arrows denote a decrease/increase of proteins in UCA or UCR versus CTRL, the numbers denote p values. P values outside the bracket refer to the clinical stratification of patients with UC based on a synthesis of clinical Mayo score, endoscopy Mayo score and histology. Values inside the brackets refer to patients who were active/in remission based on sigmoid histology (Sandborn scale, cut-off for inflammation ≥2), and exclude patients who were clinically active but did not have inflammation of the sigmoid colon (n=18). Comparisons were performed by the Mann-Whitney U test.

  • †Abundance rank in the total identified proteome.

  • ‡Significantly altered in patients with UC with clinical activity without local active inflammation in the sigmoid colon (Sandborn scale ≤1), as compared with the control group.

  • CTRL, controls; n.s., not significant; UCA, active UC; UCR, UC in remission.