Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2013 Aug;173(2):332-42.
doi: 10.1111/cei.12119.

Bcl-3 deficiency protects against dextran-sodium sulphate-induced colitis in the mouse

C O'Carroll  1 , G Moloney, G Hurley, S Melgar, E Brint, K Nally, R J Nibbs, F Shanahan, R J Carmody
Affiliations

Bcl-3 deficiency protects against dextran-sodium sulphate-induced colitis in the mouse

C O'Carroll et al. Clin Exp Immunol. 2013 Aug.

Abstract

Bcl-3 is a member of the IκB family of proteins and is an essential negative regulator of Toll-like receptor-induced responses. Recently, a single nucleotide polymorphism associated with reduced Bcl-3 gene expression has been identified as a potential risk factor for Crohn's disease. Here we report that in contrast to the predictions of single nucleotide polymorphism (SNP) analysis, patients with Crohn's disease and ulcerative colitis demonstrate elevated Bcl-3 mRNA expression relative to healthy individuals. To explore further the potential role of Bcl-3 in inflammatory bowel disease (IBD), we used the dextran-sodium sulphate (DSS)-induced model of colitis in Bcl-3(-/-) mice. We found that Bcl-3(-/-) mice were less sensitive to DSS-induced colitis compared to wild-type controls and demonstrated no significant weight loss following treatment. Histological analysis revealed similar levels of oedema and leucocyte infiltration between DSS-treated wild-type and Bcl-3(-/-) mice, but showed that Bcl-3(-/-) mice retained colonic tissue architecture which was absent in wild-type mice following DSS treatment. Analysis of the expression of the proinflammatory cytokines interleukin (IL)-1β, tumour necrosis factor (TNF)-α and IL-6 revealed no significant differences between DSS-treated Bcl-3(-/-) and wild-type mice. Analysis of intestinal epithelial cell proliferation revealed enhanced proliferation in Bcl-3(-/-) mice, which correlated with preserved tissue architecture. Our results reveal that Bcl-3 has an important role in regulating intestinal epithelial cell proliferation and sensitivity to DSS-induced colitis which is distinct from its role as a negative regulator of inflammation.

Keywords: animal models/studies - mice/rats; epithelial cells; gut immunology/disease; inflammatory bowel disease; proliferation.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Bcl-3 expression in inflammatory bowel disease (IBD). (a) Bcl-3 mRNA levels in Crohn's disease (CD, n = 21) and ulcerative colitis (UC, n = 21) tissue samples relative to normal (N, n = 6) controls (P < 0·05 *). (b) Bcl-3 mRNA levels in colon tissue of untreated and dextran-sodium sulphate (DSS)-treated wild-type mice. Mice were treated with 2% DSS for 6 days followed by 2 days on normal drinking water before tissue was harvested. Data are expressed as means ± standard error of the mean. Statistical significance was determined using Mann–Whitney t-tests.
Fig. 2
Fig. 2
Bcl3−/− mice develop milder dextran-sodium sulphate (DSS)-induced colitis. (a) Weight loss (% change) was measured over time with differences between wild-type 2% DSS and wild-type healthy controls found to be statistically significant from days 6–8 (**P < 0·01; ***P < 0·001; ***P < 0·001), respectively. Differences in weight loss between wild-type 2% DSS and Bcl-3−/− healthy controls were found to be significant at day 8 (***P < 0·001). (b) Differences in disease activity index (DAI) scores were observed starting from days 5–8 in both wild-type and Bcl-3−/− DSS groups relative to both healthy controls (***P < 0·001). Differences in weight loss and DAI score were calculated over time by two-way analysis of variance (anova) with Bonferroni's post-hoc test. (c–d) Differences in colon length and distal colon weight between in both wild-type and Bcl-3−/− mice relative to healthy controls were found to be statistically significant (P < 0·05). Data are expressed as mean ± standard error of the mean. Statistical significance was determined using Mann–Whitney t-tests (n = 7/group).
Fig. 3
Fig. 3
Reduced histological damage in Bcl-3−/− mice following dextran-sodium sulphate (DSS)-induced colitis. (a) Representative haematoxylin and eosin (H&E) of untreated (control) and DSS-treated wild-type and Bcl-3−/− mice. Histological sections were scored for cellular infiltration (b), extent of injury (c), epithelium and crypt damage (d). DSS-induced cellular infiltration, extent of injury and epithelium and crypt damage scores were increased in wild-type and Bcl-3−/− mice relative to untreated controls (P < 0·05). DSS-treated wild-type mice showed greater crypt and epithelium damage relative to DSS-treated and Bcl-3−/− mice (P < 0·01). Data are representative of greater than seven fields of view per tissue section at ×20 (n = 7 per group).
Fig. 4
Fig. 4
Normal inflammatory cytokine expression in mucosal tissue of dextran-sodium sulphate (DSS)-treated Bcl-3−/− mice. Distal colon tissues were analysed for changes immune gene expression relative to the housekeeping gene 18 s rRNA. (a) Increased proinflammatory gene expression was found in the DSS group of wild-type and Bcl-3−/− mice relative to untreated control groups (*P < 0·05). No statistical significance in gene expression changes was observed between wild-type and Bcl-3−/− mice. (b) Increased interleukin (IL)-17A and IL-22 gene expression in DSS-treated wild-type and Bcl-3−/− mice relative to untreated controls. Data are represented as relative mRNA expression as determined by the 2-ΔΔCT method. Statistical significance was calculated using Mann–Whitney t-tests (*P < 0·05). Data are expressed as mean ± standard error of the mean (n = 7).
Fig. 5
Fig. 5
Analysis of inflammatory infiltration during colitis in Bcl-3−/− mice. (a) Immunofluorescent staining of 6 μm distal colon section at ×40 for macrophages (F/480), dentritic cells (CD11c), T cells (CD3) and neutrophils (Ly6G). (b) Quantification of F4/80, CD3, Ly6G- and CD11c-positive cellular populations was performed on seven fields of view per section. Data are representative of scoring of all sections per treatment group; n = 7.
Fig. 6
Fig. 6
Analysis of cell death during colitis in Bcl-3−/− mice. (a) Terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labelling (TUNEL)-stained distal colon 6 μm section. Arrows indicate TUNEL-positive cells. Quantification of TUNEL-positive cells was performed on seven fields of view per tissue section at ×20 (n = 7 per group). (b) Western blotting for inactive (32 KDa) and active (17 KDa) caspase-3 in distal colon tissue of control and dextran-sodium sulphate (DSS)-treated wild-type and Bcl-3−/− mice. (c) Quantitative polymerase chain reaction (qPCR) analysis of p53 up-regulated modulator of apoptosis (PUMA), Bcl-XL, cellular inhibitor of apoptosis protein 1/2 (cIAP1/2) and phorbol-12-myristate-13-acetate-induced (NOXA) mRNA in distal colon tissue of control and DSS-treated wild-type and Bcl-3−/− mice.
Fig. 7
Fig. 7
Elevated cellular proliferation in dextran-sodium sulphate (DSS)-treated Bcl-3−/− mice. (a) Ki67 immunofluorescence staining of 6 μm distal colon sections. Data are representative of greater than seven fields of view per tissue section at ×20 (n = 7 per group). Inset, magnified section of Ki67-positive cells indicated by arrowhead. (b) Quantification of Ki67-positive cells was performed on seven fields of view per tissue section at ×20 (n = 7 per group).
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

See all "Cited by" articles

References

    1. Ghosh S, Hayden MS. New regulators of NF-[kappa]B in inflammation. Nat Rev Immunol. 2008;8:837–848. - PubMed
    1. Hayden MS, Ghosh S. Shared principles in NF-κB signaling. Cell. 2008;132:344–362. - PubMed
    1. Schreiber S, Nikolaus S, Hampe J. Activation of nuclear factor κB in inflammatory bowel disease. Gut. 1998;42:477–484. - PMC - PubMed
    1. Wullaert A, Bonnet MC, Pasparakis M. NF-[kappa]B in the regulation of epithelial homeostasis and inflammation. Cell Res. 2011;21:146–158. - PMC - PubMed
    1. Karrasch T, Kim J-S, Muhlbauer M, Magness ST, Jobin C. Gnotobiotic IL-10−/−; NF-κBEGFP mice reveal the critical role of TLR/NF-κB signaling in commensal bacteria-induced colitis. J Immunol. 2007;178:6522–6532. - PubMed

Publication types

MeSH terms