Colonic subepithelial myofibroblasts may play a role in the inflammatory responses and in extracellular matrix (ECM) metabolism. In this study, we investigated the effects of interleukin (IL)-1beta and tumor necrosis factor (TNF)-alpha on chemokine (IL-8 and monocyte chemoattractant protein (MCP)-1) and ECM turnover (proliferation of subepithelial myofibroblasts, and secretion of ECM and matrix metalloproteinases (MMPs)) in colonic subepithelial myofibroblasts.
Human colonic subepithelial myofibroblasts were isolated using the method described by Mahida et al. Chemokine and MMP expressions were determined by ELISA and Northern blotting. Nuclear factor (NF)-kappaB and NF-IL6 DNA binding activities were evaluated by electrophoretic gel mobility shift assays (EMSA).
IL-1beta and TNF-alpha did not affect the proliferation of subepithelial myofibroblasts, but stimulated the secretion of types I and IV collagens weakly. Unstimulated subepithelial myofibroblasts secreted a large amount of MMP-2, but a small amount of IL-8, MCP-1 and MMP-1. IL-1beta and TNF-alpha both induced a dose- and time-dependent increase in IL-8, MCP-1 and MMP-1 secretion, and weakly stimulated MMP-2 secretion. IL-1beta and TNF-alpha both rapidly evoked NF-kappaB DNA-binding activity. The inhibition of NF-kappaB activation markedly blocked both IL-1beta- and TNF-alpha-induced IL-8 and MCP-1 mRNA expression, but did not affect MMP-1 mRNA expression.
These observations indicate that chemokine secretion and ECM metabolism are collectively regulated by the proinflammatory cytokines, IL-1beta and TNF-alpha, in colonic subepithelial myofibroblasts. Thus, colonic subepithelial myofibroblasts may play an important role in the pathophysiology of inflammation in the colon.
"Myofibroblasts isolated from strictured gut tissue of patients with CD overexpress collagen and transforming growth factor (TGF)-β1, produce excessive amounts of tissue inhibitor of metalloproteinases (TIMP)-1, and display reduced migratory ability compared with myofibroblasts isolated from non-strictured intestinal areas in CD . Although intestinal myofibroblasts are the target of a number of pro-inflammatory cytokines, including IL-1β and tumor necrosis factor (TNF)-α , no information is available on expression of the IL-17A and IL-17E receptors (IL-17RC and IL-17RB respectively), or on the effect of IL-17A and IL-17E on the release of pro-fibrogenic mediators by these cells. "
[Show abstract][Hide abstract] ABSTRACT: Interleukin (IL)-17A and IL-17E (also known as IL-25) have been implicated in fibrosis in various tissues. However, the role of these cytokines in the development of intestinal strictures in Crohn's disease (CD) has not been explored. We investigated the levels ofIL-17A and IL-17E and their receptors in CD strictured and non-strictured gut, and the effects of IL-17A and IL-17E on CD myofibroblasts..
IL-17A was significantly overexpressed in strictured compared with non-strictured CD tissues, whereas no significant difference was found in the expression of IL-17E or IL-17A and IL-17E receptors (IL-17RC and IL-17RB, respectively) in strictured and non-strictured CD areas. Strictured CD explants released significantly higher amounts of IL-17A than non-strictured explants, whereas no difference was found as for IL-17E, IL-6, or tumor necrosis factor-alpha production. IL-17A, but not IL-17E, significantly inhibited myofibroblast migration, and also significantly upregulated matrix metalloproteinase (MMP)-3, MMP-12, tissue inhibitor of metalloproteinase-1 and collagen production by myofibroblasts from strictured CD tissues.
Our results suggest that IL-17A, but not IL-17E, is pro-fibrotic in CD. Further studies are needed to clarify whether the therapeutic blockade of IL-17A through the anti-IL-17A monoclonal antibody secukinumab is able to counteract the fibrogenic process in CD.
"MMPs have been shown to regulate leukocyte migration to sites of infection, but in excessive amounts may contribute to tissue destruction and fibrosis , , . A number of MMPs, such as MMP-1 (interstitial collagenase), MMP-9 (gelatinase B) and MMP-12 (macrophage metalloelastase), are secreted by monocytes and macrophages , and further upregulated by cytokines, TNF-α and IL-1β , , which degrade fibrillar collagens , , . The interstitial collagenases are therefore key initiators of ECM degradation, and comprises of the fibroblast-type collagenase/MMP-1 derived from fibroblasts , , and monocyte/macrophages , . "
[Show abstract][Hide abstract] ABSTRACT: Bronchiectasis is characterized by an irreversible dilatation of bronchi and is associated with lung fibrosis. MMP-1 polymorphism may alter its transcriptional activity, and differentially modulate bronchial destruction and lung fibrosis.
To investigate the association of MMP-1 polymorphisms with disease severity in non-cystic fibrosis (CF) bronchiectasis patients, 51 normal subjects and 113 patients with bronchiectasis were studied. The associations between MMP-1 polymorphisms, lung function, and disease severity evaluated by high resolution computed tomography (HRCT) were analyzed.
The frequency of MMP-1(-1607G) allele was significantly higher in patients with bronchiectasis than normal subjects (70.8% vs 45.1%, p<0.01). Forced expiratory volume in 1 second (FEV1) was decreased in bronchiectasis patients with 1G/1G (1.2±0.1 L, n = 14) and 1G/2G (1.3±0.1 L, n = 66) genotypes compared to the 2G/2G genotype (1.7±0.1 L, n = 33, p<0.01). Six minute walking distance was decreased in bronchiectasis patients with 1G/1G and 1G/2G compared to that of 2G/2G genotype. Disease severity evaluated by HRCT score significantly increased in bronchiectasis patients with 1G/1G and 1G/2G genotypes compared to that of 2G/2G genotype. Bronchiectasis patients with at least one MMP-1 (-1607G) allele showed increased tendency for hospitalization. Serum levels of pro-MMP-1, active MMP-1 and TGF-β1 were significantly increased in patients with bronchiectasis with 1G/1G and 1G/2G genotype compared with 2G/2G genotype or normal subjects. Under IL-1β stimulation, peripheral blood monocytes from subjects with 1G/2G or 1G/1G genotype secreted higher levels of TGF-β1compared to subjects with 2G/2G genotype.
This is the first report to address the influence of MMP-1 polymorphisms on lung function and airway destruction in non-CF bronchiectasis patients. Bronchiectasis patients with MMP-1(-1607G) polymorphism may be more vulnerable to permanent lung fibrosis or airway destruction due to the enhanced MMP-1 and TGF-β1 activity. Upregulated MMP-1 activity results in proteolytic destruction of matrix, and leads to subsequent fibrosis.
PLoS ONE 06/2013; 8(6):e66265. DOI:10.1371/journal.pone.0066265 · 3.23 Impact Factor
"Intestinal fibroblasts and ISEMFs are the predominant source of MMP-2 in gut [34–36], and an increase in the number of myofibroblasts in the intestine of CD patients occurs . These cells, secreting ECM and MMPs, are involved in changes of tissue architecture in this pathology. "
[Show abstract][Hide abstract] ABSTRACT: Purpose
Intestinal subepithelial myofibroblasts (ISEMFs)1 are the predominant source of matrix metalloproteinase-2 (MMP-2) in gut, and a decrease in glutathione/oxidized glutathione (GSH/GSSG) ratio, intracellular redox state index, occurs in the ISEMFs of patients with Crohn’s disease (CD). The aim of this study is to demonstrate a relationship between MMP-2 secretion and activation and changes of GSH/GSSG ratio in ISEMFs stimulated or not with tumor necrosis factor alpha (TNFα).
ISEMFs were isolated from ill and healthy colon mucosa of patients with active CD. Buthionine sulfoximine, GSH synthesis inhibitor, and N-acetylcysteine (NAC), precursor of GSH synthesis, were used to modulate GSH/GSSG ratio. GSH and GSSG were measured by HPLC and MMP-2 by ELISA Kit.
In cells, stimulated or not with TNFα, a significant increase in MMP-2 secretion and activation, related to increased oxidative stress, due to low GSH/GSSG ratio, was detected. NAC treatment, increasing this ratio, reduced MMP-2 secretion and exhibited a direct effect on the secreted MMP-2 activity. In NAC-treated and TNFα-stimulated ISEMFs of CD patients’ MMP-2 activity were restored to physiological value. The involvement of c-Jun N-terminal kinase pathway on redox regulation of MMP-2 secretion has been demonstrated.
For the first time, in CD patient ISEMFs, a redox regulation of MMP-2 secretion and activation related to GSH/GSSG ratio and inflammatory state have been demonstrated. This study suggests that compounds able to maintain GSH/GSSG ratio to physiological values can be useful to restore normal MMP-2 levels reducing in CD patient intestine the dysfunction of epithelial barrier.
International Journal of Colorectal Disease 12/2012; 28(7). DOI:10.1007/s00384-012-1632-2 · 2.45 Impact Factor
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