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The development of more effective, better tolerated drug treatments for progressive pulmonary fibrosis (of which idiopathic pulmonary fibrosis is the most common and severe form) is a research priority. The peroxisome proliferator-activated receptor gamma (PPAR-γ) is a key regulator of inflammation and fibrosis and therefore represents a potential therapeutic target. However, the use of synthetic PPAR-γ agonists may be limited by their potentially severe adverse effects. In a mouse model of bleomycin (BLM)-induced pulmonary fibrosis, we have demonstrated that the non-racemic selective PPAR-γ modulator GED-0507 is able to reduce body weight loss, ameliorate clinical and histological features of pulmonary fibrosis, and increase survival rate without any safety concerns. Here, we focused on the biomolecular effects of GED-0507 on various inflammatory/fibrotic pathways. We demonstrated that preventive and therapeutic administration of GED-0507 reduced the BLM-induced mRNA expression of several markers of fibrosis, including transforming growth factor (TGF)-β, alpha-smooth muscle actin, collagen and fibronectin as well as epithelial-to-mesenchymal transition (EMT) and expression of mucin 5B. The beneficial effect of GED-0507 on pulmonary fibrosis was confirmed in vitro by its ability to control TGFβ-induced myofibroblast activation in the A549 human alveolar epithelial cell line, the MRC-5 lung fibroblast line, and primary human lung fibroblasts. Compared with the US Food and Drug Administration-approved antifibrotic drugs pirfenidone and nintedanib, GED-0507 displayed greater antifibrotic activity by controlling alveolar epithelial cell dysfunction, EMT, and extracellular matrix remodeling. In conclusion, GED-0507 demonstrated potent antifibrotic properties and might be a promising drug candidate for the treatment of pulmonary fibrosis.

BACKGROUND Post-operative recurrence (POR) after ileocecal resection (ICR) affects most of Crohn’s disease (CD) patients within 3-5 years after surgery. Current immunomodulatory treatments have not proven efficiency in preventing POR, except for anti-TNFα biologic agents. AIM To evaluate the efficacy of the Janus Kinase inhibitor Tofacitinib to prevent POR after ICR in HLA-B27 transgenic rat model (TgB27) operated on an ICR. METHODS Thirty-three rats (strain F344, 29 TgB27, 4 control non Tg (nTg) rats) were operated on an ICR at the 12th week of life and were sacrificed at the 18th week of life. Tofacitinib (15 mg/kg, n=17) or placebo (n=16) were daily administered by oral gavage two weeks before surgery (10th week of life) until sacrifice. Anastomotic recurrence was blindly analyzed using macroscopic (from 0 to 4) and histologic (from 0 to 6) scores. Luminal microbiome was analyzed by shotgun metagenomic sequencing (Hiseq Illumina) in 9/33 rats before (week 9) and after Tofacitinib treatment or placebo (week 12), as well as 6 weeks following surgery (week 18). STAT3 phosphorylation was quantified in ileal samples by western blotting. Data were expressed by median with IQR. Comparisons were performed using not parametric two tailed Mann-Whitney analysis for unmatched data and Wilcoxon matched-pairs test for matched data. Two tailed χ2 test was used for contingency analysis. Spearman rank correlation was used for microbiota analysis. RESULTS 8/14 TgB27 rats receiving placebo (57%) showed signs of POR (macroscopic score ≥ 2) which were significantly prevented in 2/15 TgB27 rats (13%) treated with Tofacitinib (p= 0.013). nTg animals did not show macroscopic signs of POR. Macroscopic lesions were located 2 cm around the anastomosis in the TgB27 placebo group and consisted in ulcerations with a score of 2 (1-2.25). 11/15 TgB27 rats (73%) treated with Tofacitinib did not show macroscopic lesions and their score were significantly improved (0 (0-1), p= 0,0006). Histologic scores were significantly higher in TgB27 placebo group vs TgB27 Tofacitinib-treated rats (3 (2-4) vs 2 (1-3), p=0.036). Tofacitinib did not impact on alpha diversity and the relative abundance of bacterial taxa either before and after surgery. In contrast, surgery led to a significant 47% decrease of alpha diversity (p=0.0008) and loss of specific taxa in both TgB27 and nTg animals. No correlation was found between individual lesion scores and alpha diversity indexes. Ileal pSTAT3/STAT3 ratios were decreased by 80% in TgB27 rats treated with Tofacitinib (n=4) compared to placebo group (n=4) (0.3 ± 0,16 vs 1.58 ± 0,3, p=0,028). CONCLUSION We develop a reliable model of ICR in TgB27 rats mimicking the POR of CD. Tofacitinib prevents the macroscopic and histologic POR after ICR, without major modifications of the microbioma. ACKNOWLEDGMENTS Charity Foundation DigestScience and Pfizer SAS.

BACKGROUND Intestinal fibrosis is mainly associated with Crohn's disease and is defined as a progressive and excessive deposition of extracellular matrix components. No specific antifibrotic therapies are available. In this study, we evaluate the antifibrotic effect of a novel 5-ASA analog able to activate the peroxisome proliferator-activated receptor γ, named GED-0507-34 Levo. METHODS Colonic fibrosis was induced in 110 C57BL/6 mice by 3 cycles of 2.5% (wt/vol) dextran sulfate sodium administration for 6 weeks. The preventive effects of oral daily GED (30 mg · kg(-1) · d(-1)) administration were evaluated using a macroscopic and histological score and also through biological endpoints. Expression of main markers of myofibroblasts activation was determined in transforming growth factor (TGF-β)-stimulated intestinal fibroblasts and epithelial cells. RESULTS GED improved macroscopic and microscopic intestinal lesions in dextran sulfate sodium-treated animals and reduced the profibrotic gene expression of Acta2, COL1a1, and Fn1 by 1.48-folds (P < 0.05), 1.93-folds (P < 0.005), and 1.03-fold (P < 0.05), respectively. It reduced protein levels of main markers of fibrosis (α-SMA and Collagen I-II) and the main TGF-β/Smad pathway components. GED also decreased the interleukin-13 and connective tissue growth factor expression by 1.89-folds (P < 0.05) and 2.2-folds (P < 0.005), respectively. GED inhibited TGF-β-induced activation of both fibroblast and intestinal epithelial cell lines, by regulating mRNA expression of α-SMA and fibronectin, and restoring the TGF-β-induced loss of intestinal epithelial cell markers. GED treatment also reduced the TGF-β and ACTA1 expression in primary human intestinal fibroblasts from ulcerative colitis patients. CONCLUSIONS GED ameliorates intestinal fibrosis in dextran sulfate sodium-induced chronic colitis in mice and regulates major profibrotic cellular and molecular mechanisms.

Infection of mice with Citrobacter rodentium serves as a model to study human intestinal infections. C. rodentium infection leads to increased production of inflammatory cytokines, immune cell infiltration and damage to the gut barrier. We used this model of colitis to evaluate the therapeutic properties of OM-X®, an extract prepared by fermentation of vegetables, seaweeds, fruits and mushrooms. Administration of OM-X® to C. rodentium-infected mice reduced damage to the intestinal epithelium, lowered inflammation scores, increased IL-10 expression and maintained FoxP3 gene expression. OM-X® also partially prevented bacterial translocation, increased expression of tight junction genes and increased proliferation of epithelial cells. PCR analysis of stool samples showed that OM-X® significantly reduced the populations of bacteria harboring buk gene (mostly Clostridium species). It is suggested that alterations of microbiota composition, following OM-X® consumption, contribute to protection against infection and epithelial damage, and lead to an increased expression of anti-inflammatory cytokines.

Epidemiological evidences suggested that 5-aminosalicylic acid (5-ASA) therapy may prevent the development of colorectal cancer in inflammatory bowel disease patients. Our aim is to investigate whether peroxisome proliferator-activated receptor-γ (PPARγ) mediates the antineoplastic effects of 5-ASA. HT-29 and Caco-2 cells were treated by 5-ASA, rosiglitazone (PPARγ ligand) or etoposide (anticarcinogenic drug). Epithelial cell growth, proliferation and apoptosis were assessed by cell count, Ki-67 staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay, respectively. The antineoplastic effect of 5-ASA was evaluated in a xenograft tumor model in SCID mice and in azoxymethane (AOM)-induced colon carcinogenesis in A/JOlaHsd mice. The role of PPARγ was examined by administration of PPARγ antagonist, GW9662 and in PPAR knockdown cells. Compared with untreated cells, treatment of HT-29 cells by 5-ASA inhibited significantly cell growth and cell proliferation (respectively, 60% and 63%) and induced apoptosis in 75% of cells. These effects were abolished by co-treatment with GW9662 and blunted in PPAR knockdown cells. Contrarily to etoposide, similar inhibitory effects of GW9662 were obtained in HT-29 cells treated with rosiglitazone. In the xenograft model, GW9662 abolished the therapeutic effect of 5-ASA, which decreased tumor weight and volume by 80% in SCID mice compared with untreated mice. In A/JOlaHsd mice, 5-ASA suppressed colon carcinogenesis by decreasing the number of aberrant crypt foci (75%) and aberrant crypts (22%) induced by AOM treatment with an absence of 5-ASA response after GW9662 administration. In conclusion, 5-ASA exerts potent antineoplastic effects that are mediated through PPARγ. These data provide new rational for designing more effective and safe antineoplastic PPARγ ligands with topical effects.

Objective Mesenteric fat hyperplasia is a hallmark of Crohn’s disease (CD), and C reactive protein (CRP) is correlated with disease activity. The authors investigated whether mesenteric adipocytes may be a source of CRP in CD and whether inflammatory and bacterial triggers may stimulate its production by adipocytes. Design CRP expression in the mesenteric and subcutaneous fats of patients with CD and the correlation between CRP plasma concentrations and mesenteric messenger RNA (mRNA) levels were assessed. The impact of inflammatory and bacterial challenges on CRP synthesis was tested using an adipocyte cell line. Bacterial translocation to mesenteric fat was studied in experimental models of colitis and ileitis and in patients with CD. Results CRP expression was increased in the mesenteric fat of patients with CD, with mRNA levels being 80640 (p

The glucagon-like peptide 2 (GLP-2) is an intestinotrophic hormone with growth promoting and anti-inflammatory actions. However, the full biological functions of GLP-2 and the localization of its receptor (GLP-2R) remain controversial. Among cell lines tested, the expression of GLP-2R transcript was detected in human colonic myofibroblasts (CCD-18Co) and in primary culture of rat enteric nervous system but not in intestinal epithelial cell lines, lymphocytes, monocytes, or endothelial cells. Surprisingly, GLP-2R was expressed in murine (GLUTag), but not human (NCI-H716) enteroendocrine cells. The screening of GLP-2R mRNA in mice organs revealed an increasing gradient of GLP-2R toward the distal gut. An unexpected expression was detected in the mesenteric fat, mesenteric lymph nodes, bladder, spleen, and liver, particularly in hepatocytes. In two mice models of trinitrobenzene sulfonic acid (TNBS)- and dextran sulfate sodium (DSS)-induced colitis, the colonic expression of GLP-2R mRNA was decreased by 60% compared with control mice. Also, GLP-2R mRNA was significantly downregulated in intestinal tissues of inflammatory bowel disease patients. Therapeutically, GLP-2 showed a weak restorative effect on intestinal inflammation during TNBS-induced colitis as assessed by macroscopic score and inflammatory markers. Finally, GLP-2 treatment accelerated mouse liver regeneration following partial hepatectomy as assessed by histological and molecular analyses. In conclusion, the limited therapeutic effect of GLP-2 on colonic inflammation dampens its utility in the management of severe inflammatory intestinal disorders. However, the role of GLP-2 in liver regeneration is a novelty that might introduce GLP-2 into the management of liver diseases and emphasizes on the importance of elucidating other extraintestinal functions of GLP-2.

International audience; Abdominal pain is common in the general population and, in patients with irritable bowel syndrome, is attributed to visceral hypersensitivity. We found that oral administration of specific Lactobacillus strains induced the expression of mu-opioid and cannabinoid receptors in intestinal epithelial cells, and mediated analgesic functions in the gut-similar to the effects of morphine. These results suggest that the microbiology of the intestinal tract influences our visceral perception, and suggest new approaches for the treament of abdominal pain and irritable bowel syndrome.

Background and aims: Ulcerative colitis (UC) is chronic relapsing-remitting disease. Whereas it has been well characterized how various drug induce remission, the mechanisms involved in relapse are not known. We have previously shown that the epithelial expression of SOCS3, a negative regulator of cytokine signaling, was persistently upregulated in both active and inactive UC. Since the expression of SOCS3 during inactive disease may make the epithelial cells more vulnerable to various insults, we investigated whether this expression during remission was associated with the time till relapse. Materials and methods: 41 chronic UC patients in clinical remission underwent a first surveillance colonoscopy between 20012004, and were followed up till 2010. Biopsies from the first surveillance colonoscopy after remission were stained for SOCS3 protein expression and scored according to percentage of positive epithelial cells. Only biopsies from patients with clinical remission and without signs of histological inflammation were included. Clinical data, endoscopy and histology reviews were collected from patient charts. Results: 23 Patients (57.0%) of the 41 chronic UC patients developed histological relapse, and 19 patients (46.3%) had endoscopic relapse of colitis during the course of surveillance. SOCS3 protein expression in colon biopsies of inactive UC patients had a negative correlation with the time till histological (p