Table 2.
Summary of the purpose for articles included for analysis and key findings.
| First Author, Reference | Purpose of Study | MUC Gene Investigated | Measuring MUC Expression | Key Findings |
|---|---|---|---|---|
| Weiss, [32] | To investigate effect of inflammation on expression of mucin genes at cellular level | MUC2, MUC3 | In-situ hybridisation with RNA probes | MUC2 and MUC3 expression in colonic mucosa is independent of inflammation |
| Tytgat, [33] | To study regulation of MUC2 expression in patients with UC compared with controls | MUC2 | MUC2 precursor quantified by SDS-PAGE, total MUC2 by dot blot, in-situ hybridisation with RNA probes to quantify MUC2 mRNA | Inefficient translation of MUC2 mRNA may lead to the reduction in MUC2 synthesis observed in active UC |
| Hinoda, [34] | To determine if MUC2 protein expression is altered in UC | MUC2 | MUC2 protein detected by Immunohistochemistry | Decreased MUC2 protein production and expression in active UC is associated with undifferentiated goblet cells |
| Van Klinken, [35] | To determine whether there are alterations in MU2 sulphation and secretion in active UC | MUC2 | Analysis and quantification of total MUC2 using SDS-PAGE and dot blotting | Absolute amount of MUC2 secreted is decreased and mucins are under-sulphated in active UC |
| Hanski, [36] | To study alterations in MUC2 expression in UC patient colonic tissue | MUC2 | MUC2 protein detected by immunohistochemistry and MUC2 mRNA detected using in-situ hybridisation | Increase in MUC2 protein detection in UC samples may be related to reduction in post transcriptional modification |
| Shaoul, [37] | To investigate alterations in expression and distribution of MUC2, MUC5AC, trefoil factor 1 (TFF1) in UC | MUC2, MUC5AC | PAS/Alcian blue immunohistochemistry | Immature (poorly glycos-ylated) MUC2 is expressed in UC colonic mucosa depleted of goblet cells |
| Longman, [38] | To investigate alterations in the expression of mucin genes and trefoil peptide genes in UC | MUC1-6 | Immunohistochemistry and in-situ hybridisation | MUC1 expression upregulation is associated with severe UC and there is a reduction of MUC2 expression in UC |
| Moehle, [39] | To characterize changes in mucin expression and identify allelic variants of MUC genes in UC | MUC1-20 | Affymetrix DNA-microarray analysis and RT-PCR | MUC12 mRNA expression is downregulated in UC and is independent of inflammation |
| Gersemann, [46] | To understand the mechanisms involved with goblet cell differentiation and mucin production in IBD | MUC1, MUC2, MUC4 | RT-PCR | Impairments in goblet cell differentiation factor induction in UC correlates with a reduction in mucin synthesis. |
| Furr, [40] | To determine whether MUC1 expression is altered in IBD | MUC1 | Immunochemistry using anti-MUC1 anti-bodies | Overexpression and hypoglycosylation of MUC1 observed in a subset of UC patients |
| Senapati, [47] | To determine the subcellular localization of MUC17 in colonic mucosa and to determine whether MUC17 expression is altered in IBD and neoplastic diseases. | MUC17 | Immunohistochemistry using anti-MUC17 polyclonal antibody | MUC17 expression is reduced in colonic mucosa of UC patients |
| Larsson, [41] | To determine whether MUC2 glycosylation is related to degree of mucosal inflammation in UC | MUC2 | SDS-PAGE used to identify and quantify MUC2 | Alterations in MUC2 glycosylation are associated with inflammation |
| Kini, [42] | To determine whether alterations occur in colonic stem cells during the pathogenesis of UC and to determine the impact of such changes on goblet cell development and proteins synthesized by goblet cells | MUC2 | H&E, Alcian blue and PAS immunohistochemistry staining to detect MUC2 protein | A reduction in MUC2 protein within the lower colonic crypt precedes inflammation. |
| Yamamoto-Furusho, [43] | To determine if MUC12, MUC16, MUC20 expression changes in UC | MUC12, MUC16, MUC20 | MUC gene expression measured using RT-PCR and MUC protein expression measured using immunohistochemistry | MUC16, MUC20 expression increase in UC and increase in MUC20 was associated with remission of UC |
| Alipour, [44] | To assess whether mucosal barrier defects are prerequisites to UC | MUC2 | Fluorescence in-situ hybridisation (FISH) and immunofluorescence | Reduction in mucin-containing goblet cells and mucin production in UC patients compared to controls |
| van der Post, [45] | To investigate compositional alterations that occur at the adherent mucus layer in UC | MUC2 | Absolute quantification of MUC2 using Skyline (V.3.6.0.1) following mass spectrometry | Reduction of MUC2 in active UC associated with exhaustion of secretory response of goblet cells to microbes |
Periodic acid–Schiff/Alcian blue (PAS/Alcian blue), Haematoxylin and eosin (H&E), Sodium Dodecyl Sulphate-Polyacrylamide Gel Electrophoresis (SDS-PAGE), Real Time Polymerase Chain Reaction (RT-PCR).