Members of the colon core mucus proteome and their abundance differences between patient groups
| Protein name | Gene | Suggested role in the mucus layer | Differentially regulated (P value) | ||
| UCA versus CTRL* | UCR versus CTRL* | Rank† | |||
| Anterior gradient protein 2 | AGR2 | Required for mucin biosynthesis | n.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 protease | n.s. (n.s.) | n.s. (n.s.) | 530 |
| Cathepsin S | CTSS | Secreted cysteine protease | n.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 matrix | n.s. (n.s.) | n.s. (n.s.) | 211 |
| DMBT1 | DMBT1 | Aggregates both G+/− bacteria | n.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 | Chemotaxis | n.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 | IgA | n.s. (n.s.) | n.s. (n.s.) | 24 |
| IgJ | IGJ | Dimerisation of IgA | n.s. (n.s.) | n.s. (n.s.) | 61 |
| IgM | IGHM | IgM | n.s. (0.042) ↑ | n.s. (n.s.) | 203 |
| Intelectin-1 | ITLN1 | Found in mucus granules | n.s. (n.s.) | n.s. (n.s.) | 387 |
| Kallikrein-1 | KLK1 | Serine protease found in mucus granules | n.s. (n.s.)‡↑ | n.s. (n.s.) | 586 |
| Galectin-3 | LGALS3 | Lectin-binding galactose | n.s. (n.s.) | n.s. (n.s.) | 60 |
| Galectin-3-binding protein | LGALS3BP | Galectin-3-binding protein | n.s. (0.010) ↓ | n.s. (n.s.) | 747 |
| Lumican | LUM | Proteoglycan, part of extracellular matrix | n.s. (n.s.) | n.s. (n.s.) | 143 |
| Meprin alpha | MEP1A | Metalloprotease | n.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 mucin | n.s. (n.s.) | n.s. (n.s.) | 755 |
| Mucin-5B | MUC5B | Gel-forming mucin | n.s. (n.s.) | n.s. (n.s.) | 367 |
| Mucin-12 | MUC12 | Transmembrane mucin | n.s. (n.s.) | n.s. (n.s.) | 363 |
| Mucin-13 | MUC13 | Transmembrane mucin | n.s. (n.s.) | n.s. (0.010)↑ | 561 |
| Polymeric Ig receptor | PIGR | Transports IgA | n.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.