MicroRNAs Classify Different Disease Behavior Phenotypes of Crohn's Disease and May Have Prognostic Utility.

BACKGROUND: There is a dire need for reliable prognostic markers that can guide effective therapeutic intervention in Crohn's disease (CD). We examined whether different phenotypes in CD can be classified based on colonic microRNA (miRNA) expression and whether miRNAs have prognostic utility for CD. METHODS: High-throughput sequencing of small and total RNA isolated from colon tissue from patients with CD and controls without Inflammatory Bowel Disease (non-IBD) was performed. To identify miRNAs associated with specific phenotypes of CD, patients were stratified according to disease behavior (nonstricturing, nonpenetrating; stricturing; penetrating), and miRNA profiles in each subset were compared with those of the non-IBD group. Validation assays were performed using quantitative reverse transcription polymerase chain reaction. These miRNAs were further evaluated by quantitative reverse transcriptase polymerase chain reaction on formalin-fixed, paraffin-embedded tissue (index biopsies) of patients with nonpenetrating CD at the time of diagnosis that either retained the nonpenetrating phenotype or progressed to penetrating/fistulizing CD. RESULTS: We found a suite of miRNAs, including miR-31-5p, miR-215, miR-223-3p, miR-196b-5p, and miR-203 that stratify patients with CD according to disease behavior independent of the effect of inflammation. Furthermore, we also demonstrated that expression levels of miR-215 in index biopsies of patients with CD might predict the likelihood of progression to penetrating/fistulizing CD. Finally, using a novel statistical simulation approach applied to colonic RNA-sequencing data for patients with CD and non-IBD controls, we identified miR-31-5p and miR-203 as candidate master regulators of gene expression profiles associated with CD. CONCLUSIONS: miRNAs may serve as clinically useful prognostic markers guiding initial therapy and identifying patients who would benefit most from effective intervention.

Enterococcus faecalis Gelatinase Mediates Intestinal Permeability via Protease-Activated Receptor 2.

Microbial protease-mediated disruption of the intestinal epithelium is a potential mechanism whereby a dysbiotic enteric microbiota can lead to disease. This mechanism was investigated using the colitogenic, protease-secreting enteric microbe Enterococcus faecalis. Caco-2 and T-84 epithelial cell monolayers and the mouse colonic epithelium were exposed to concentrated conditioned media (CCM) from E. faecalis V583 and E. faecalis lacking the gelatinase gene (gelE). The flux of fluorescein isothiocyanate (FITC)-labeled dextran across monolayers or the mouse epithelium following exposure to CCM from parental or mutant E. faecalis strains indicated paracellular permeability. A protease-activated receptor 2 (PAR2) antagonist and PAR2-deficient (PAR2(-/-)) mice were used to investigate the role of this receptor in E. faecalis-induced permeability. Gelatinase (GelE) purified from E. faecalis V583 was used to confirm the ability of this protease to induce epithelial cell permeability and activate PAR2. The protease-mediated permeability of colonic epithelia from wild-type (WT) and PAR2(-/-) mice by fecal supernatants from ulcerative colitis patients was assessed. Secreted E. faecalis proteins induced permeability in epithelial cell monolayers, which was reduced in the absence of gelE or by blocking PAR2 activity. Secreted E. faecalis proteins induced permeability in the colonic epithelia of WT mice that was absent in tissues from PAR2(-/-) mice. Purified GelE confirmed the ability of this protease to induce epithelial cell permeability via PAR2 activation. Fecal supernatants from ulcerative colitis patients induced permeability in the colonic epithelia of WT mice that was reduced in tissues from PAR2(-/-) mice. Our investigations demonstrate that GelE from E. faecalis can regulate enteric epithelial permeability via PAR2.

Ciprofloxacin for the prevention of postoperative recurrence in patients with Crohn's disease: a randomized, double-blind, placebo-controlled pilot study.

BACKGROUND: The commensal bacterial flora plays a critical role in the postoperative recurrence of Crohn's disease (CD). We conducted a randomized, double-blind, placebo-controlled 6-month pilot trial of ciprofloxacin for the prevention of endoscopic recurrence in patients with CD who underwent surgery. METHODS: Thirty-three patients with CD, who had undergone surgery with ileocolonic anastomosis within the previous 2 weeks, were randomized to treatment with ciprofloxacin (500 mg twice daily) or placebo tablets for 6 months. Endpoints were endoscopic recurrence at 6 months and safety and tolerability of long-term ciprofloxacin therapy. RESULTS: Thirty-three patients were randomized; 14 patients discontinued the study early. Significant endoscopic recurrence was observed in 3 of 9 patients (33%) in the ciprofloxacin group and 5 of 10 patients (50%) in the placebo group at 6 months after surgery (P < 0.578). The intention-to-treat analysis demonstrated endoscopic recurrence in 11 of 17 patients (65%) in the ciprofloxacin group and 11 of 16 patients (69%) in the placebo group at month 6 (P < 0.805). Thirty-six adverse events occurred in 19 of 33 patients (58%). Possible drug-associated adverse events occurred significantly more often in the ciprofloxacin group (P < 0.043), leading to study drug discontinuation in 24% (4 of 17) and 6% of patients (1 of 16) in the ciprofloxacin and placebo groups, respectively (P < 0.166). CONCLUSIONS: In this pilot study, ciprofloxacin was not more effective than placebo for the prevention of postoperative recurrence in patients with CD. Long-term ciprofloxacin therapy is limited by drug-associated side effects. Future studies in postoperative prevention of CD should evaluate antibiotic approaches with a more favorable safety profile.

Impact of a probiotic Enterococcus faecalis in a gnotobiotic mouse model of experimental colitis.

SCOPE: IL-10-deficient (IL-10(-/-) ) mice are susceptible to the development of chronic intestinal inflammation in response to the colonization with commensal Enterococcus faecalis isolates. The aim of this study was to characterize the impact of a probiotic E. faecalis strain in germ-free, wild-type (WT), and disease-susceptible IL-10(-/-) mice. METHODS AND RESULTS: The probiotic E. faecalis and the colitogenic control strain OG1RF induced IL-6 and IFN-γ inducible protein-10 secretion in the murine intestinal epithelial cell line Mode K. Epithelial cell activation involved nuclear factor κ B, p38 and extracellular signal-regulated kinase 1/2-dependent pathways. Mouse embryonic fibroblasts from WT and toll-like receptor-2-deficient (TLR-2(-/-) ) mice confirmed that both E. faecalis strains trigger pro-inflammatory responses via the pattern recognition receptor TLR-2. Monoassociation of germ-free IL-10(-/-) mice with the probiotic E. faecalis strain revealed pro-inflammatory epithelial cell activation and colonic tissue pathology. The non-pathogenic nature of E. faecalis was confirmed in monoassociated WT mice. 2-DE and MALDI-TOF MS identified the ER stress chaperone Hspa5 (glucose-regulated protein 78) and 3-mercaptopyruvate sulfurtransferase as key targets in the epithelium from IL-10(-/-) and TLR-2(-/-) mice. CONCLUSION: This study shows the potential of probiotic bacteria to initiate pro-inflammatory responses in the disease-susceptible but not the normal host.