Barrett’s oesophagus is associated with abdominal obesity. Adiponectin is a peptide that is secreted from adipocytes and circulates in three multimeric forms: low molecular weight (LMW), middle molecular weight (MMW), and high molecular weight (HMW). The anti-inflammatory effects of adiponectin are specific to individual multimers, with LMW being most anti-inflammatory. We postulated that circulating levels of adiponectin and its multimers would be associated with the risk of Barrett’s oesophagus.

Cross-sectional study.

Outpatient clinic in North Carolina, USA.

Cases of Barrett’s oesophagus and controls undergoing upper endoscopy for gastro-oesophageal reflux disease (GORD).

Adjusted odds ratios of plasma adiponectin levels and its multimers for Barrett’s oesophagus.

There were 112 cases of Barrett’s oesophagus and 199 GORD controls. Total adiponectin was not associated with Barrett’s oesophagus (3^rd tertile vs 1^st tertile adjusted odds ratio (aOR) = 0.88; 95% confidence interval (CI) = 0.44 to 1.78). High levels of LMW adiponectin were associated with a decreased risk of Barrett’s oesophagus (3^rd tertile vs 1^st tertile aOR = 0.33; 95% CI, 0.16 to 0.69), and a high LMW/total ratio appeared particularly inversely associated with Barrett’s oesophagus (3^rd tertile vs 1^st tertile aOR = 0.27; 95% CI, 0.13 to 0.58).

High levels of LMW adiponectin are associated with a decreased risk of Barrett’s oesophagus among patients with GORD. Further human studies are required to confirm these findings, and in vitro studies are needed to understand if there is a mechanism whereby adiponectin may affect Barrett’s metaplasia.

Recent advances in endoscopy have revealed that non-steroidal anti-inflammatory drugs (NSAIDs) often cause ulcers in the human small intestine. However, the mechanism of intestinal ulcer formation is still unclear.

The role of dietary fibre (DF), intestinal motility and leukotrienes (LTs) in the formation of small intestinal ulcers induced by indomethacin (IND) was investigated in cats.

Several types of diets containing DF at various percentages were given to animals twice daily during the experiment. IND was administered orally once daily after the morning meal for 3 days, and the area of mucosal lesions in the intestine was measured. Gastrointestinal motility was measured using a telemetry system in conscious cats implanted with force transducers.

In cats fed regular dry food containing 2.8% DF, IND (3 mg/kg, p.o.) significantly increased the motility of the lower half of the small intestine and produced many severe lesions; the total lesion area was 7.7 (SEM 2.0) cm² (n = 5). The lesions were markedly decreased with the low-DF diet (0.4%) and increased with the high-DF diet (7.2%). The lesion area was 0.1 (SEM 0.1) cm² (p<0.05) and 18.2 (SEM 4.1) cm² (p<0.05), respectively. Supplementation with insoluble DF (6% cellulose), but not soluble DF (pectin), in the low-DF diet increased the lesion area significantly. The hypermotility and lesion formation in the small intestine induced by IND were significantly (p<0.05) inhibited by AA-861 (a 5-lipoxygenase inhibitor), pranlukast (a LT receptor antagonist) or atropine.

Insoluble DF, intestinal hypermotility, leukotrienes and cholinergic pathways are implicated in the pathogenesis of small intestinal ulcers induced by NSAIDs.

Coeliac disease is a common small intestinal inflammatory disorder that results from a breach of intestinal tolerance to dietary gluten proteins, driven by gluten-reactive effector T cells. We aimed to assess the pathogenic role of gluten-reactive T cells and to generate a model of gluten-induced enteropathy.

CD4+CD25– T cell fractions were adoptively transferred into lymphopenic mice, leading to "baseline" small intestinal inflammation.

Rag1–/– recipients of gliadin-presensitised CD4+CD45RBlowCD25– T cells, but not CD4+CD45RBhigh naive T cells, gained less weight and suffered from more severe duodenitis when challenged with oral gluten than recipients on gluten-free diet, or recipients of control (ovalbumin)-presensitised T cells. This was accompanied by deterioration of mucosal histological features characteristic of coeliac disease, and increased Th1/Th17 cell polarisation in the duodenum and the periphery. Interestingly, reintroduction of a gluten-free diet led to weight gain, improvement of histological duodenitis, and a decrease in duodenal interferon and interleukin 17 transcripts. Moreover, B cell-competent nude recipients of gliadin-presensitised CD4+CD45RBlowCD25– T cells produced high levels of serum anti-gliadin immunoglobulin A (IgA) and IgG1/IgG2c only when challenged with oral gluten.

CD4+ T cell immunity to gluten leads to a breach of oral gluten tolerance and small intestinal pathology in lymphopenic mice, similar to human coeliac disease. This model will be useful for the study of coeliac disease pathogenesis, and also for testing novel non-dietary therapies for coeliac disease.

Dietary linoleic acid, an n-6 polyunsaturated fatty acid, is metabolised to arachidonic acid, a component of colonocyte membranes. Metabolites of arachidonic acid have pro-inflammatory properties and are increased in the mucosa of patients with ulcerative colitis. The aim of this investigation was to conduct the first prospective cohort study investigating if a high dietary intake of linoleic acid increases the risk of developing incident ulcerative colitis.

Dietary data from food frequency questionnaires were available for 203 193 men and women aged 30–74 years, resident in the UK, Sweden, Denmark, Germany or Italy and participating in a prospective cohort study, the European Prospective Investigation into Cancer and Nutrition (EPIC). These participants were followed up for the diagnosis of ulcerative colitis. Each case was matched with four controls and the risk of disease calculated by quartile of intake of linoleic acid adjusted for gender, age, smoking, total energy intake and centre.

A total of 126 participants developed ulcerative colitis (47% women) after a median follow-up of 4.0 years (range, 1.7–11.3 years). The highest quartile of intake of linoleic acid was associated with an increased risk of ulcerative colitis (odds ratio (OR) = 2.49, 95% confidence interval (CI) = 1.23 to 5.07, p = 0.01) with a significant trend across quartiles (OR = 1.32 per quartile increase, 95% CI = 1.04 to 1.66, p = 0.02 for trend).

The data support a role for dietary linoleic acid in the aetiology of ulcerative colitis. An estimated 30% of cases could be attributed to having dietary intakes higher than the lowest quartile of linoleic acid intake.

Infliximab is an effective treatment for ulcerative colitis with over 60% of patients responding to treatment and up to 30% reaching remission. The mechanism of resistance to anti-tumour necrosis factor (anti-TNF) is unknown. This study used colonic mucosal gene expression to provide a predictive response signature for infliximab treatment in ulcerative colitis.

Two cohorts of patients who received their first treatment with infliximab for refractory ulcerative colitis were studied. Response to infliximab was defined as endoscopic and histological healing. Total RNA from pre-treatment colonic mucosal biopsies was analysed with Affymetrix Human Genome U133 Plus 2.0 Arrays. Quantitative RT-PCR was used to confirm microarray data.

For predicting response to infliximab treatment, pre-treatment colonic mucosal expression profiles were compared for responders and non-responders. Comparative analysis identified 179 differentially expressed probe sets in cohort A and 361 in cohort B with an overlap of 74 probe sets, representing 53 known genes, between both analyses. Comparative analysis of both cohorts combined, yielded 212 differentially expressed probe sets. The top five differentially expressed genes in a combined analysis of both cohorts were osteoprotegerin, stanniocalcin-1, prostaglandin-endoperoxide synthase 2, interleukin 13 receptor alpha 2 and interleukin 11. All proteins encoded by these genes are involved in the adaptive immune response. These markers separated responders from non-responders with 95% sensitivity and 85% specificity.

Gene array studies of ulcerative colitis mucosal biopsies identified predictive panels of genes for (non-)response to infliximab. Further study of the pathways involved should allow a better understanding of the mechanisms of resistance to infliximab therapy in ulcerative colitis.

ClinicalTrials.gov number, NCT00639821.

The aetiopathogenesis of Crohn’s disease, an inflammatory bowel disease (IBD), is not yet fully understood. Autoimmune mechanisms are thought to play a role in the development of Crohn’s disease, but the target antigens and the underlying pathways have not been sufficiently identified.

Based on data from immunoblotting and matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) mass spectrometry, the major antigenic target of pancreatic autoantibodies (PABs), which are specific for Crohn’s disease, was identified. Specificity of autoantibody reactivity was confirmed by enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence (IIF) using purified rat and human recombinant GP2 synthesised in transiently transfected mammalian HEK 293 cells. Real-time polymerase chain reaction (rt-PCR) and IIF were used to detect mRNA and antigen localisation in human colon biopsies.

The major zymogen granule membrane glycoprotein 2 (GP2) was identified as the autoantigen of PABs in Crohn’s disease. PAB-positive sera from patients with Crohn’s disease (n = 42) displayed significantly higher IgG reactivity to rat GP2 in ELISA than either PAB-negative sera (n = 31), or sera from patients with ulcerative colitis (n = 49), or sera from blood donors (n = 69) (p<0.0001, respectively). Twenty-eight (66%) and 18 (43%) of 42 PAB-positive sera demonstrated IgG and IgA reactivity to human recombinant GP2 in IIF, respectively. Patients with PAB-negative Crohn’s disease (n = 31) were not reactive. GP2 mRNA transcription was significantly higher in colon biopsies from patients with Crohn’s disease (n = 4) compared to patients with ulcerative colitis (n = 4) (p = 0.0286). Immunochemical staining confirmed GP2 expression in human colon biopsies from patients with Crohn’s disease.

Anti-GP2 autoantibodies constitute novel Crohn’s disease-specific markers, the quantification of which could significantly improve the serological diagnosis of IBD. The expression of GP2 in human enterocytes suggests an important role for anti-GP2 response in the pathogenesis of Crohn’s disease.

Interleukin 17 (IL17) is now known to be involved in a number of chronic inflammatory disorders. However, the mechanisms regulating its production in inflammatory bowel disease (IBD) are still unclear.

Endoscopic biopsies or surgical specimens were taken from inflamed and uninflamed colonic mucosa of 72 patients with IBD (38 with Crohn’s disease and 34 with ulcerative colitis), and normal colon of 38 control subjects. IL17 and interferon (IFN) were detected by ELISA in the supernatants of biopsies cultured ex vivo, and anti-CD3/CD28-stimulated lamina propria mononuclear cells (LPMCs) incubated with IL12, IL23, IL1β plus IL6, transforming growth factor β1 (TGFβ1), or anti-IL21 neutralising antibody. Intracellular flow cytometry was performed to analyse mucosal Th17 and Th1/Th17 cells.

IL17 production by organ culture biopsies was higher in IBD inflamed mucosa than IBD uninflamed mucosa and controls, and was equivalent in amount to IFN. Anti-CD3/CD28-stimulated IBD LPMCs produced higher IL17 amounts compared to controls. The percentages of Th17 and Th1/Th17 cells were increased in patients with IBD. IL23 and IL1β plus IL6 had no effect on IBD LPMC production of IL17; however, IL12 markedly increased IFN production and decreased IL17 production. TGFβ1 dose-dependently decreased IFN, but had no significant inhibitory effect on IL17 production. Blocking IL21 significantly downregulated IL17 production.

Our findings support a role for IL12, TGFβ and IL21 in modulating IL17/IFN production in IBD. The abundant IL17 in inflamed IBD mucosa may help explain the relative lack of efficacy of anti-IFN antibodies in clinical trials of Crohn’s disease.

The molecular mechanisms underlying the promotion of colorectal carcinogenesis by a high-fat diet (HFD) remain unclear. We investigated the role of the insulin-signal pathway and the c-Jun N-terminal kinase (JNK) pathway, which reportedly play crucial roles in insulin resistance, during colorectal carcinogenesis in the presence of hyperinsulinaemia induced by a HFD.

Azoxymethane-induced aberrant crypt foci formation and cell proliferation in the colonic epithelium were compared between mice fed a normal diet (ND) and mice fed a HFD. A western blot analysis was performed to elucidate the mechanism affecting colorectal carcinogenesis by a HFD.

The number of aberrant crypt foci and the colonic epithelial cell proliferative activity were significantly higher in the HFD group than in the ND group. While the plasma insulin level was significantly higher in the HFD group than in the ND group, a western blot analysis revealed the inactivation of Akt, which is located downstream of the insulin receptor, in the colonic epithelia of the HFD group. On the other hand, JNK activity was significantly higher in the HFD group than in the ND group. A JNK specific inhibitor significantly suppressed the increase in epithelial cell proliferation only under a HFD, but not under a ND.

Colonic cell proliferation was promoted via the JNK pathway in the presence of a HFD but not in the presence of a ND. This novel mechanism may explain the involvement of the JNK pathway in the effect of dietary fat intake on colon carcinogenesis.

Hepatitis C virus (HCV) infection is a major cause of chronic liver disease and is associated with significant morbidity and mortality. Since there is evidence for an interaction of NS5A with c-Raf we studied whether the c-Raf inhibitor sorafenib affects HCV replication.

HCV replicating HuH7.5 cells were treated with sorafenib and examined for HCV RNA titres by northern blotting or real time polymerase chain reaction (PCR), for core, NS3 and NS5A expression by immunostaining, and for replication by luciferase reporter assays.

Here we demonstrate that in cells replicating infectious HCV particles, NS5A recruits c-Raf to the replicon complex resulting in the activation of c-Raf. Therefore, we studied the effect of inhibition of c-Raf on HCV replication using the anti-tumour drug sorafenib that is known to inhibit c-Raf with high specificity. Sorafenib efficiently blocks HCV replication and viral gene expression. In addition, in HCV-replicating cells sorafenib decreased the hyperphosphorylated form of NS5A and resulted in the formation of additional hypophosphorylated forms. Further, sorafenib caused a rapid dissociation of lipid droplets. We provide evidence that the antiviral effect of sorafenib indeed is caused by inhibition of c-Raf. By contrast, inhibition of targets downstream of c-Raf or inhibition of tyrosine kinases by sunitinib did not affect HCV replication.

Our data demonstrate that the well-characterised anti-tumour drug sorafenib efficiently blocks HCV replication in vitro. This novel effect of sorafenib should be further explored as an antiviral strategy for patients with chronic HCV infection.

The factors that influence liver fibrosis progression in patients co-infected with human immunodeficiency virus/hepatitis C virus (HIV/HCV) are not completely understood. It is not known if insulin resistance (IR), a condition that promotes liver fibrosis in HCV mono-infected individuals, is one of these factors.

To evaluate the association between IR and liver stiffness (LS).

Multicentre cross-sectional study.

330 patients co-infected with HIV/HCV.

LS was assessed by transient elastography, which has shown a high accuracy to predict significant fibrosis in patients co-infected with HIV/HCV. The outcome variable of the study was LS. Patients with LS>=9 kPa were considered as having significant fibrosis. IR was calculated using the HOMA method.

LS was >=9 kPa in 150 (45%) patients. HOMA correlated with LS (Spearman’s rho correlation coefficient, 0.37; p<0.0001). The median (Q1–Q3) HOMA in patients with LS>=9 kPa was 3.30 (2.17–5.16) while it was 2.09 (1.37–3.22) in patients with LS <9 kPa (p<0.0001). Ninety-six (39%) individuals with a HOMA <4 and 54 (63%) with a HOMA >=4 showed LS>=9 kPa (p<0.0001). Analyses after excluding patients with cirrhosis yielded similar results. After multivariate analyses, age >=40 years (adjusted odds ratio (AOR), 1.85; 95% confidence interval (CI), 1.03 to 3.29; p = 0.03), CD4 cell count <200 cells/ml (AOR, 3.45; 95% CI, 1.67 to 7.11; p = 0.001), hepatitis B virus co-infection (AOR, 9.25; 95% CI, 2.42 to 35.31; p = 0.001), and HOMA >=4 (AOR, 5.33; 95% CI, 2.70 to 10.49; p<0.0001) were the independent predictors of LS>=9 kPa.

IR is associated with LS in patients co-infected with HIV/HCV.

Hepatitis C virus (HCV) genotype 4 (HCV-4) is increasing in prevalence in Western countries. However, little is known about the severity of the disease and response to treatment. The aim of this study was to assess the predictors (logistic regression) of severe fibrosis (METAVIR score F3–F4), and sustained virological response (SVR) to peginterferon and ribavirin in 226 consecutive HCV-4 patients (Egyptians 40%, Europeans 35% and Africans 24%).

Insulin resistance was assessed using the homeostasis model (HOMA-IR). Serum HCV-RNA level (bDNA) and subtypes of HCV (LiPA) were determined for all patients.

Insulin resistance (HOMA-IR >3) was present in 105 patients (46%), and was associated with: age >45 years (OR, 2.614; 95% CI, 1.316 to 5.194), body mass index (BMI) >25 kg/m² (OR, 2.105; 95% CI, 1.048 to 4.229), serum HCV-RNA >800 000 IU/ml (OR, 3.143; 95% CI, 1.503 to 6.574), severe fibrosis (OR, 2.657; 95% CI, 1.214 to 5.818), and steatosis >30% (OR, 2.488; 95% CI, 1.105 to 5.602). Severe fibrosis was present in 67 patients (29%) and was associated with Egyptian origin (OR, 5.872; 95% CI, 2.747 to 12.553), excessive alcohol intake (OR, 5.311; 95% CI, 1.287 to 21.924), and HOMA-IR >3 (OR, 3.864; 95% CI, 1.859 to 8.034). 108 patients received a 48 week course of peginterferon plus ribavirin. SVR (undetectable serum HCV-RNA (TMA) 24 weeks after treatment stopping) was achieved in 59 patients (55%) and was associated with Egyptian origin (OR, 13.119; 95% CI, 3.089 to 55.706), HOMA-IR <2 (OR, 5.314; 95% CI, 1.953 to 14.459), and non-severe fibrosis (OR, 8.059; 95% CI, 2.512 to 25.855).

Insulin resistance and geographical origin are major predictors of liver fibrosis and response to peginterferon and ribavirin in HCV-4 patients. Insulin resistance is frequently encountered in these patients, and correlated independently with serum HCV-RNA.

The transcription factor nuclear factor kappa B (NF-B) has risen as a promising target for anti-inflammatory therapeutics. In the liver, however, NF-B inhibition mediates both damaging and protective effects. The outcome is deemed to depend on the liver cell type addressed. Recent gene knock-out studies focused on the role of NF-B in hepatocytes, whereas the role of NF-B in Kupffer cells has not yet been investigated in vivo. Here we present a novel approach, which may be suitable for clinical application, to selectively target NF-B in Kupffer cells and analyse the effects in experimental models of liver injury.

NF-B inhibiting decoy oligodeoxynucleotides were loaded upon gelatin nanoparticles (D-NPs) and their in vivo distribution was determined by confocal microscopy. Liver damage, NF-B activity, cytokine levels and apoptotic protein expression were evaluated after lipopolysaccharide (LPS), d-galactosamine (GalN)/LPS, or concanavalin A (ConA) challenge and partial warm ischaemia and subsequent reperfusion, respectively.

D-NPs were selectively taken up by Kupffer cells and inhibited NF-B activation. Inhibition of NF-B in Kupffer cells improved survival and reduced liver injury after GalN/LPS as well as after ConA challenge. While anti-apoptotic protein expression in liver tissue was not reduced, pro-apoptotic players such as cJun N-terminal kinase (JNK) were inhibited. In contrast, selective inhibition of NF-B augmented reperfusion injury.

NF-B inhibiting decoy oligodeoxynucleotide-loaded gelatin nanoparticles is a novel tool to selectively inhibit NF-B activation in Kupffer cells in vivo. Thus, liver injury can be reduced in experimental fulminant hepatitis, but increased at ischaemia–reperfusion.