Gastroenterology

Gastroenterology

Volume 129, Issue 3, September 2005, Pages 969-984
Gastroenterology

Basic–alimentary tract
Interleukin-22, a Member of the IL-10 Subfamily, Induces Inflammatory Responses in Colonic Subepithelial Myofibroblasts

https://doi.org/10.1053/j.gastro.2005.06.071Get rights and content

Background & Aims: Interleukin (IL)-22, a member of the IL-10 subfamily, is a recently identified T-cell-derived cytokine. We investigated IL-22 expression in the inflamed mucosa of patients with inflammatory bowel disease (IBD) and analyzed its biologic activities in human colonic subepithelial myofibroblasts (SEMFs). Methods: Mucosal IL-22 expression was evaluated by immunohistochemical procedures. The effects of IL-22 on colonic SEMFs were investigated by cDNA microarrays, Northern blots, enzyme-linked immunosorbent assay, and electrophoretic gel mobility shift assays (EMSAs). Results: IL-22 was not detectable in normal colonic mucosa. In IBD mucosa, IL-22 expression was detectable in CD4-positive T cells. IL-22-positive cells were increased in ulcerative colitis and even more so in Crohn’s disease. IL-22 receptor expression colocalized with a marker of SEMFs. IL-22 did not modulate SEMF proliferation and collagen synthesis. cDNA microarray analyses demonstrated that, in colonic SEMFs, IL-22 increased the messenger RNA (mRNA) expression of inflammatory cytokines (IL-6, IL-8, IL-11, and leukemia inhibitory factor [LIF]), chemokines, and matrix metalloproteinases. IL-22 induced an activation of nuclear factor (NF)-κB and activating protein (AP)-1 within 1 hour, and a blockade of NF-κB and AP-1 activation markedly reduced IL-22 induction of IL-6, IL-8, IL-11, and LIF mRNA. MAP-kinase inhibitors (PD98059, U0216, and SB202190) significantly reduced IL-22 induction of cytokine secretion. The combination of either IL-17 plus IL-22 or IL-19 plus IL-22 additively up-regulated cytokine secretion. Conclusions: IL-22 derived from activated T cells acts on SEMFs to elicit expression of proinflammatory cytokines and matrix-degrading molecules indicating proinflammatory/remodeling roles in IBD.

Section snippets

Reagents

Recombinant human IL-19, IL-20, and IL-22 were obtained from PeproTech (Rocky Hill, NJ), and IL-24 was purchased from R&D Systems (Minneapolis, MN). All other reagents were purchased from Sigma Chemical Co. (St Louis, MO). Inhibitors of p42/44 MAP kinases (PD98059 and U0216), an inhibitor for p38 MAPK (SB203580), and a JAK2 inhibitor (AG490) were purchased from Cell Signaling Technology (Beverly, MA).

Antibodies

The following primary antibodies were used in this study: goat anti-human IL-22 antibodies

IL-22 Expression in IBD Mucosa

To evaluate the expression of IL-22 protein in mucosa, samples were stained with anti-IL-22 antibodies. As shown in Figure 1A-a, there were no IL-22 positive cells in normal colonic mucosa samples. In contrast, IL-22-expressing cells increased in inflamed regions of active UC and CD patients (Figure 1A-b and A-c). In active UC patients, IL-22-positive cells were located mainly within the lamina propria, but, in active CD patients, these cells were scattered throughout the submucosa.

To confirm

Discussion

IL-22 is a newly identified cytokine, which belongs to the IL-10 subfamily.5, 6, 7, 8, 9, 10, 11, 12, 13, 14 IL-22 is an α-helical protein, whose amino acid sequence is approximately 22% identical to IL-10.5 IL-10 is regarded as an anti-inflammatory and immunosuppressive cytokine on the basis of its inhibitory effects on the production of IL-1, TNF-α, IL-6, and IL-8 by monocytes,5 and this is considered to be the molecular basis for spontaneous colitis developed in IL-10 knockout mice.41 On the

References (47)

  • M.H. Xie et al.

    Interleukin (IL)-22, a novel human cytokine that signals through the interferon receptor-related proteins CRF2-4 and IL-22R

    J Biol Chem

    (2000)
  • P. Chomczynski et al.

    Single-step method of RNA isolation by acid guanidinium thiocyanate-phenol-chloroform extraction

    Anal Biochem

    (1987)
  • A. Andoh et al.

    Cytokine regulation of chemokine (IL-8, MCP-1, and RANTES) gene expression in human pancreatic periacinar myofibroblasts

    Gastroenterology

    (2000)
  • A. Andoh et al.

    Extracellular signal-regulated kinases 1 and 2 participate in interleukin-17 plus tumor necrosis factor-α-induced stabilization of interleukin-6 mRNA in human pancreatic myofibroblasts

    Biochim Biophys Acta

    (2002)
  • D.R. Alessi et al.

    PD098059 is a specific inhibitor of the activation of mitogen-activated protein kinase kinase in vitro and in vivo

    J Biol Chem

    (1995)
  • M.F. Favata et al.

    Identification of a novel inhibitor of mitogen-activated protein kinase kinase

    J Biol Chem

    (1998)
  • A. Cuenda et al.

    SB203580 is a specific inhibitor of a MAP kinase homologue, which is stimulated by cellular stresses and interleukin-1

    FEBS Lett

    (1995)
  • R. Kuhn et al.

    Interleukin-10-deficient mice develop chronic enterocolitis

    Cell

    (1993)
  • X. Li et al.

    IKKα, IKKβ, and NEMO/IKKγ are each required for the NF-κB-mediated inflammatory response program

    J Biol Chem

    (2002)
  • D. McKinley et al.

    Genomic sequence and chromosomal location of human interleukin-11 gene (IL11)

    Genomics

    (1992)
  • M. Yeh et al.

    Oxidized phospholipids increase interleukin 8 (IL-8) synthesis by pathway

    J Biol Chem

    (2004)
  • M. D’Isanto et al.

    Prolactin modulates IL-8 production induced by porins or LPS through different signaling mechanisms

    Immunobiology

    (2004)
  • D.K. Podolsky

    Inflammatory bowel disease

    N Engl J Med

    (2002)
  • Cited by (413)

    View all citing articles on Scopus
    View full text