transforming-growth-factor-beta and Colonic-Diseases

Inflammatory bowel disease (IBD), a progressive and unpredictable colorectal inflammatory disease, is a global health problem. Currently, therapeutic strategies for the management of the disease are limited. Results from our previous studies indicated that probiotic Lactobacillus plantarum exhibits therapeutic effects against IBD, and through screening, we obtained an active 61-amino-acid long protein, L. plantarum membrane protein 1 (LpMP-1). Based on druggability-guided strategies, the search for LpMPs with lower molecular weights and better bioactivities contributes to the development of new anti-inflammatory agents to overcome the limitations of existing therapies against IBD. We used amino-acid-truncation strategies to obtain modified LpMPs (LpMP-2 - LpMP-9) using LpMP-1 as the parent template. Furthermore, we systematically evaluated the anti-colitis pharmacodynamics of these LpMPs in terms of symptomatology, histopathology, and cytokine levels in DSS-induced ulcerative colitis mice. Their possible targets of action against IBD was investigated under an iTRAQ-based pharmacoproteomic system and a docking-guided receptor-ligand relationship frame. We found a new active protein, LpMP-8, which had a lower molecular weight than LpMP-1. LpMP-8 was found to exhibit anti-colitis activity following oral administration in vivo (50 μg/kg) by improving symptoms of colitis, colonic ulcerations, and cytokine disorders. TLRs and TGF-β were found to be involved in the action of LpMP-8 against colitis; LpMP-8 was to compete with TLR4-MD2-bound LPS and reverse TGF-β and Smad2/7 disorders. Our probiotic-derived LpMP-8 was shown to elicit oral anti-colitis activity, and its significant efficacy is probably associated with TLR4 and TGF-β.

Topics: Animals; Anti-Inflammatory Agents; Colitis; Colonic Diseases; Cytokines; Dextran Sulfate; Inflammatory Bowel Diseases; Lactobacillus plantarum; Membrane Proteins; Mice; Toll-Like Receptor 4; Transforming Growth Factor beta

Intestinal fibrosis induced by chronic and recurrent colitis, which is exacerbated by bowel stenosis, stricture, and obstruction, is challenging to treat. Toll-like receptor 4 (TLR4) stimulates innate and acquired immunity in response to specific microbial components, but the role of TLR4 in intestinal fibrosis is largely unknown. We investigated its role in intestinal fibrosis using not only a murine fibrosis model but also human myofibroblasts and intestinal epithelial cells. Colon fibrosis was induced in TLR4-deficient (TLR4

Topics: Animals; Cell Line; Collagen; Colonic Diseases; Cytokines; Dextran Sulfate; Disease Models, Animal; Epithelial-Mesenchymal Transition; Fibrosis; Gene Expression Regulation; HCT116 Cells; Humans; Interleukin-12 Subunit p40; Macrophages, Peritoneal; Mice; Signal Transduction; Toll-Like Receptor 4; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha

Fibrosis represents a major complication of several chronic diseases, including inflammatory bowel disease (IBD). Treatment of IBD remains a clinical challenge despite several recent therapeutic advances. Melanin-concentrating hormone (MCH) is a hypothalamic neuropeptide shown to regulate appetite and energy balance. However, accumulating evidence suggests that MCH has additional biological effects, including modulation of inflammation. In the present study, we examined the efficacy of an MCH-blocking antibody in treating established, dextran sodium sulfate-induced experimental colitis. Histological and molecular analysis of mouse tissues revealed that mice receiving anti-MCH had accelerated mucosal restitution and lower colonic expression of several proinflammatory cytokines, as well as fibrogenic genes, including COL1A1. In parallel, they spared collagen deposits seen in the untreated mice, suggesting attenuated fibrosis. These findings raised the possibility of perhaps direct effects of MCH on myofibroblasts. Indeed, in biopsies from patients with IBD, we demonstrate expression of the MCH receptor MCHR1 in α-smooth muscle actin(+) subepithelial cells. CCD-18Co cells, a primary human colonic myofibroblast cell line, were also positive for MCHR1. In these cells, MCH acted as a profibrotic modulator by potentiating the effects of IGF-1 and TGF-β on proliferation and collagen production. Thus, by virtue of combined anti-inflammatory and anti-fibrotic effects, blocking MCH might represent a compelling approach for treating IBD.

Topics: Actins; Animals; Biomarkers; Cell Line; Cell Proliferation; Colitis; Collagen; Colonic Diseases; Fibrosis; Hypothalamic Hormones; Insulin-Like Growth Factor I; Male; Melanins; Mice; Myofibroblasts; Pituitary Hormones; Real-Time Polymerase Chain Reaction; Receptors, Somatostatin; Transforming Growth Factor beta; Up-Regulation; Wound Healing

Schistosomiasis mansoni is a major helminthic disease of the tropics characterised by chronic hepatic and intestinal granulomatous inflammation and fibrosis. The fibrotic response is regulated by the amount of collagen deposited in the tissues and the degradation of that collagen by matrix metalloproteinases (MMP). In the murine model of the disease, although hepatic granuloma formation and the ensuing fibrosis have been thoroughly examined, there is a dearth of information on the intestinal fibrotic process. The expression of fibrosis-related genes in the colons of chronically infected mice has therefore been investigated. Compared with that seen in uninfected mice, the expression of the genes coding for collagen of types I, III and IV was upregulated. Similarly, the messages for MMP-2, MMP-3 and MMP-8 were elevated, indicating the potential for collagen degradation. The genes for two tissue inhibitors of metalloproteinases (TIMP), TIMP-1 and TIMP-4, were, however, expressed at higher levels than those coding for the MMP. As a corollary, expression of the genes coding for three fibrogenic cytokines, transforming growth factor-beta, tumour necrosis factor and interleukin-4, was elevated. These data indicate that an imbalance in MMP:TIMP expression and enhanced levels of the messages for fibrogenic cytokines underlie the mechanism(s) of the colonic fibrosis seen in mice chronically infected with Schistosoma mansoni.

Topics: Animals; Chronic Disease; Collagen; Colon; Colonic Diseases; Cytokines; Disease Models, Animal; Female; Fibrosis; Genes, Helminth; Granuloma; Ileum; Interleukin-4; Matrix Metalloproteinases; Mice; Mice, Inbred CBA; Schistosomiasis mansoni; Tissue Inhibitor of Metalloproteinases; Transforming Growth Factor beta; Tumor Necrosis Factor-alpha; Up-Regulation

Ulceration is a common feature of inflammatory bowel diseases, where subepithelial cell growth is frequently necessary for resolution. In order to further understand the role of colonic fibroblasts in this process, we have used an in vitro model of wound repair to study the response of human colonic fibroblasts to several growth factors expressed in colonic tissues.. Proliferation was determined by [(3)H]thymidine incorporation into DNA in subconfluent fibroblast cultures. In vitro wound repair was determined in confluent fibroblast monolayers after mechanical denudation. The presence of growth factors secreted by fibroblasts was studied in conditioned medium by heparin affinity chromatography and immunodetection with specific antibodies.. Serum and platelet-derived growth factor (PDGF-BB) induced a dramatic increase in both colonic fibroblast proliferation and closure of wounded cell monolayers. Epidermal growth factor (EGF) stimulated both fibroblast activities, but the effect was less potent. However, colonic fibroblasts did not respond to transforming growth factor-beta(1). Conditioned medium stimulated fibroblast proliferation and wound repair activity, which was reverted by the addition of suramin. Furthermore, a PDGF-like factor was isolated from colonic fibroblast-conditioned medium.. EGF and PDGF-BB promote human colonic fibroblast-dependent wound repair activities. Human colonic fibroblasts may exert an autocrine regulation via the production of growth factors.

Topics: Cell Division; Cells, Cultured; Colon; Colonic Diseases; Culture Media, Conditioned; Epidermal Growth Factor; Fibroblasts; Humans; Platelet-Derived Growth Factor; Transforming Growth Factor beta; Ulcer; Wound Healing

A T helper cell type 1-mediated colitis develops in severe combined immunodeficient mice after transfer of CD45RB(high) CD4(+) T cells and can be prevented by cotransfer of the CD45RB(low) subset. The immune-suppressive activities of the CD45RB(low) T cell population can be reversed in vivo by administration of an anti-transforming growth factor beta antibody. Here we show that interleukin (IL)-10 is an essential mediator of the regulatory functions of the CD45RB(low) population. This population isolated from IL-10-deficient (IL-10(-/-)) mice was unable to protect from colitis and when transferred alone to immune-deficient recipients induced colitis. Treatment with an anti-murine IL-10 receptor monoclonal antibody abrogated inhibition of colitis mediated by wild-type (WT) CD45RB(low) CD4(+) cells, suggesting that IL-10 was necessary for the effector function of the regulatory T cell population. Inhibition of colitis by WT regulatory T cells was not dependent on IL-10 production by progeny of the CD45RB(high) CD4(+) cells, as CD45RB(low) CD4(+) cells from WT mice were able to inhibit colitis induced by IL-10(-/-) CD45RB(high) CD4(+) cells. These findings provide the first clear evidence that IL-10 plays a nonredundant role in the functioning of regulatory T cells that control inflammatory responses towards intestinal antigens.

Topics: Animals; Antibodies, Monoclonal; CD4-Positive T-Lymphocytes; Colon; Colonic Diseases; DNA-Binding Proteins; Immunity, Mucosal; Inflammation; Interferon-gamma; Interleukin-10; Intestinal Mucosa; Mice; Mice, Inbred BALB C; Mice, Knockout; Mice, SCID; Spleen; Th1 Cells; Transforming Growth Factor beta

Polyunsaturated phosphatidylcholine stimulates collagen breakdown in experimental models of liver cirrhosis. Bowel strictures are characterized by excess deposition of collagen in the intestinal wall. The aim of this study was to investigate the effect of polyunsaturated phosphatidylcholine in the prevention of bowel strictures.. Colitis was induced by trinitrobenzenesulfonic acid. On day 21, the presence of strictures was assessed in control rats, rats with colitis, and phosphatidylcholine-fed (100 mg/day) rats with colitis. Furthermore, serum transforming growth factor beta1, collagen deposition, and collagenase activity in colonic tissue were measured in all groups.. None of the control rats but 12 of 16 rats with colitis developed colonic strictures. In contrast, only 2 of 15 phosphatidylcholine-fed rats with colitis showed strictures. Collagen content was much higher in rats with colitis than in phosphatidylcholine-fed rats with colitis and control rats. Phosphatidylcholine-fed rats showed significantly higher collagenase activity in colonic tissue than rats with colitis and control rats. In an ancillary study, free linoleic acid-fed rats showed no differences when compared with rats with colitis. Stimulation of transforming growth factor beta1 was similar in all rats with colitis.. Oral supplementation with polyunsaturated phosphatidylcholine prevents the accumulation of collagen in inflamed intestinal tissue and the formation of strictures. This effect is associated with an enhanced collagen catabolism.

Topics: Analysis of Variance; Animals; Chronic Disease; Colitis; Collagen; Collagenases; Colon; Colonic Diseases; Constriction, Pathologic; Dietary Fats, Unsaturated; Disease Models, Animal; Intestinal Obstruction; Male; Phosphatidylcholines; Rats; Rats, Sprague-Dawley; Transforming Growth Factor beta; Trinitrobenzenesulfonic Acid