Soluble adhesion molecules in inflammatory bowel disease

Adsorption of Soluble Immunoglobulin-Type Adhesion Molecules to Cellulose Acetate Beads

Circulating levels of soluble intercellular adhesion molecule-1 (sICAM-1) and vascular adhesion molecule-1 (sVCAM-1) are elevated in patients with inflammatory bowel disease. Cellulose acetate (CA) beads are used as carriers for granulocyte and monocyte (GM) adsorptive apheresis (GMA). We investigated the effect of CA beads on sICAM-1 and sVCAM-1 plasma concentrations in vitro. Because GM adsorption to CA beads increased with a rise in the incubation temperature in our previous study, peripheral blood was incubated with and without CA beads at 5, 25, 37, or 43 °C and plasma sICAM-1 and sVCAM-1 was measured. The sICAM-1 and sVCAM-1 concentrations in samples incubated with CA beads were significantly lower than those without CA beads at all four temperatures. However, no significant differences were observed both sICAM-1 and sVCAM-1 plasma levels at the four different temperatures after incubation with CA beads. These results suggest that independent of incubation temperature, sICAM-1 and sVCAM-1 are likely to adsorb CA beads. These molecules may be a new index for predicting the therapeutic effects of GMA.

Endothelial dysfunction in inflammatory bowel diseases: Pathogenesis, assessment and implications

Endothelial dysfunction is considered one of the etiological factors of inflammatory bowel disease (IBD). An inflammatory process leads to functional and structural changes in the vascular endothelium. An increase of leukocyte adhesiveness and leukocyte diapedesis, as well as an increased vascular smooth muscle tone and procoagulant activity is observed. Structural changes of the vascular endothelium comprise as well capillary and venule remodeling and proliferation of endothelial cells. Hypoxia in the inflammatory area stimulates angiogenesis by up-regulation of vascular endothelial growth factor, fibroblast growth factor and tumor necrosis factor-α. Inflammatory mediators also alter the lymphatic vessel function and impair lymph flow, exacerbating tissue edema and accumulation of dead cells and bacteria. The endothelial dysfunction might be diagnosed by the use of two main methods: physical and biochemical. Physical methods are based on the assessment of large arteries vasodilatation in response to an increased flow and receptors stimulation. Flow-mediated vasodilatation (FMD) is the method that is the most widely used; however, it is less sensitive in detecting early changes of the endothelium function. Most of the studies demonstrated a decrease of FMD in IBD patients but no changes in the carotic intima-media thickness. Biochemical methods of detecting the endothelial dysfunction are based on the assessment of the synthesis of compounds produced both by the normal and damaged endothelium. The endothelial dysfunction is considered an initial step in the pathogenesis of atherosclerosis in the general population. In IBD patients, the risk of cardiovascular diseases is controversial. Large, prospective studies are needed to establish the role of particular medications or dietary elements in the endothelial dysfunction as well to determine the real risk of cardiovascular diseases.

Inflammatory bowel "Cardiac" disease: Point prevalence of atrial fibrillation in inflammatory bowel disease population

BACKGROUND/AIM

Proinflammatory markers such as interleukin (IL)-6 have been closely associated with atrial fibrillation (AF). These markers are characteristically elevated in chronic inflammatory bowel disease (IBD) and positively correlate with disease activity. Although IBD and AF have similar pathogenesis, there have been very limited studies looking at their association. The aim of this study is to determine the prevalence of AF in patients with IBD.

PATIENTS AND METHODS

Medical records of patients with biopsy proven IBD (n = 203, both in and outpatient) were retrospectively reviewed. One hundred and forty-one IBD patients with documentary evidence of electrocardiograms (ECG's) were included. The "Anticoagulation and Risk Factors in Atrial Fibrillation (ATRIA)" study, a large cross-sectional study (n = 1.89 million) done to evaluate the prevalence of AF among the US population, was our control population. All ECGs available till December 2010 for each IBD patient were reviewed carefully for evidence of AF. We studied the prevalence of AF among IBD population and compared it to that of control (ATRIA) population.

RESULTS

The prevalence of AF was significantly higher among IBD patients compared with the ATRIA study patients (11.3% vs 0.9%, P < 0.0001). Additionally, the IBD patient population were much younger compared with the controls (64.4 ± 10.7 vs 71.2 ± 12.2, P = 0.02).

CONCLUSION

AF has an overall higher prevalence across all age groups in IBD compared with the subjects of ATRIA study, which could be due to the chronic inflammatory state of IBD. Further studies are needed to study the association in detail.

The role of glycosylation in IBD

A number of genetic and immunological studies give impetus for investigating the role of glycosylation in IBD. Experimental mouse models have helped to delineate the role of glycosylation in intestinal mucins and to explore the putative pathogenic role of glycosylation in colitis. These experiments have been extended to human studies investigating the glycosylation patterns of intestinal mucins as well as levels of glycans of serum glycoproteins and expression of glycan receptors. These early human studies have generated interesting hypotheses regarding the pathogenic role of glycans in IBD, but have generally been restricted to fairly small underpowered studies. Decreased glycosylation has been observed in the intestinal mucus of patients with IBD, suggesting that a defective inner mucus layer might lead to increased bacterial contact with the epithelium, potentially triggering inflammation. In sera, decreased galactosylation of IgG has been suggested as a diagnostic marker for IBD. Advances in glycoprofiling technology make it technically feasible and affordable to perform high-throughput glycan pattern analyses and to build on previous work investigating a much wider range of glycan parameters in large numbers of patients.

Exploring the interplay of barrier function and leukocyte recruitment in intestinal inflammation by targeting fucosyltransferase VII and trefoil factor 3

Intestinal mucosal integrity is dependent on epithelial function and a regulated immune response to injury. Fucosyltransferase VII (Fuc-TVII) is an essential enzyme required for the expression of the functional ligand for E- and P-selectin. Trefoil factor 3 (TFF3) is involved in both protecting the intestinal epithelium against injury as well as aiding in wound repair following injury. The aim of the present study was to assess the interplay between barrier function and leukocyte recruitment in intestinal inflammation. More specifically, we aimed to examine how targeted disruption of Fuc-TVII either in wild-type or TFF3(-/-) mice would alter their susceptibility to colonic injury. TFF3 and Fuc-TVII double-knockout mice (TFF3/Fuc-TVII(-/-) mice) were generated by mating TFF3(-/-) and Fuc-TVII(-/-) mice. Colitis was induced by administration of dextran sodium sulfate (DSS) (2.5% wt/vol) in the drinking water. Changes in baseline body weight, diarrhea, and fecal blood were assessed daily. Upon euthanasia, extents of colonic inflammation were assessed macroscopically, microscopically, and through quantification of myeloperoxidase (MPO) activity. Colonic lymphocyte subpopulations were assessed at 6 days after administration of DSS by flow cytometry and immunohistochemistry. No baseline intestinal inflammation was found in TFF3/Fuc-TVII(-/-), TFF3(-/-), Fuc-TVII(-/-), or wild-type mice. Loss of Fuc-TVII resulted in a reduction in disease severity whereas TFF3(-/-) mice were markedly more susceptible to DSS-induced colitis. Remarkably, the loss of Fuc-TVII in TFF3(-/-) mice markedly decreased the severity of DSS-induced colitis as evidenced by reduced weight loss, diarrhea, decreased colonic MPO levels and improved survival. Furthermore, the loss of TFF3 resulted in increased severity of spontaneous colitis in IL-2/beta-microglobulin-deficient mice. These studies highlight the importance of the interplay between factors involved in the innate immune response, mucosal barrier function, and genes involved in regulating leukocyte recruitment and other aspects of the immune response.

Influence of apple polyphenols on inflammatory gene expression

Apples (Malus spp., Rosaceae) and products thereof contain high amounts of polyphenols which show diverse biological activities and may contribute to beneficial health effects, like protecting the intestine against inflammation initiated by chronic inflammatory bowel diseases (IBD). IBD are characterized by an excessive release of several proinflammatory cytokines and chemokines by different cell types which results consequently in an increased inflammatory response. In the present study we investigated the preventive effectiveness of polyphenolic juice extracts and single major constituents on inflammatory gene expression in immunorelevant human cell lines (DLD-1, T84, MonoMac6, Jurkat) induced with specific stimuli. Besides the influence on proinflammatory gene expression, the effect on NF-kappaB-, IP-10-, IL-8-promoter-, STAT1-dependent signal transduction, and the relative protein levels of multiple released cytokines and chemokines were studied. DNA microarray analysis of several genes known to be strongly regulated during gastrointestinal inflammation, combined with quantitative real-time PCR (qRT-PCR) revealed that the apple juice extract AE04 (100-200 microg/mL) significantly inhibited the expression of NF-kappaB regulated proinflammatory genes (TNF-alpha, IL-1beta, CXCL9, CXCL10), inflammatory relevant enzymes (COX-2, CYP3A4), and transcription factors (STAT1, IRF1) in LPS/IFN-gamma stimulated MonoMac6 cells without significant effects on the expression of house-keeping genes. A screening of some major compounds of AE04 revealed that the flavan-3-ol dimer procyanidin B(2 )is mainly responsible for the anti-inflammatory activity of AE04. Furthermore, the dihydrochalcone aglycone phloretin and the dimeric flavan-3-ol procyanidin B(1 )significantly inhibited proinflammatory gene expression and repressed NF-kappaB-, IP-10-, IL-8-promoter-, and STAT1-dependent signal transduction in a dose-dependent manner. The influence on proinflammatory gene expression by the applied polyphenols thereby strongly correlated with the increased protein levels investigated by human cytokine array studies. In summary, we evaluated selected compounds responsible for the anti-inflammatory activity of AE04. In particular, procyanidin B(1), procyanidin B(2), and phloretin revealed anti-inflammatory activities in vitro and therefore may serve as transcription-based inhibitors of proinflammatory gene expression.

Inflammatory bowel disease and coronary artery disease

Chronic inflammation with the presence of excess serum acute-phase proteins, cytokines and cell adhesion molecules is increasingly being implicated in atherosclerosis. The association between inflammatory bowel disease (IBD) and coronary artery disease (CAD) is unstudied. This is a preliminary, thesis-generating cross-sectional study aimed at evaluating the presence of traditional atherosclerotic risk factors in patients with IBD and CAD compared with the control population. The medical records of 42 consecutive IBD patients with CAD from 1999 to 2005 (27 men) were reviewed for the Framingham risk factors. The Framingham risk score (FRS) is calculated based on age, sex, hypertension, diabetes and hyperlipidemia. FRS of patients with IBD and CAD was compared with the FRS of 137 age- and sex-matched (102 men) consecutive patients with CAD (controls). When the Framingham risk score adjusted for group and gender with age as a covariate, the adjusted total FRS score was higher in patients with CAD alone (10.0 [3.75]) as compared to those with; IBD and CAD: (8.1 [3.47]; p = 0.001). FRS is lower in cases (patients with IBD and CAD) when compared with the controls (CAD alone).

Does the urinary excretion of alpha1-microglobulin and albumin predict clinical disease activity in ulcerative colitis?

INTRODUCTION

There remains some difficulty in determining disease activity during the development of inflammatory bowel disease (IBD). The excretion levels of some inflammatory response molecules increase as a result of the onset of this disease. We studied urinary alfa-1-microglobulin (alpha1-MG) and albumin levels in patients with active and inactive ulcerative colitis (UC) and investigated whether we could use these parameters as an activity index.

METHODS

The study was carried out at Gazi University Faculty of Medicine, Nephrology and Gastroenterology Departments, between December 2003 and March 2006. In total, 35 patients (male/female: 16/19, mean age: 38.3+/-2.4 years) and 13 healthy controls (male/female: 6/7, mean age: 35.8+/-2.8 years) were enrolled in the study. Nineteen patients had symptoms of active disease and the remaining 16 patients had inactive disease.

RESULTS

There was a significant difference in serum C-reactive protein (CRP), urinary albumin excretion, and alpha1-MG excretion levels between patients and controls. Patients with active disease had significantly higher serum CRP and alpha1-MG levels than those with inactive disease and controls. Patients with active disease had higher microalbuminuria levels than inactive patients, but this difference was not statistically significant. Urinary albumin and alpha1-MG excretion did not correlate with serum CRP levels.

CONCLUSION

The present study suggests that, as with CRP, urinary levels of albumin and alpha1-MG increase during the active period of UC. During the inactive period, concentrations of these parameters are comparable to controls. The measurement of alpha1-MG and/or microalbuminuria could provide information on disease severity and response to treatment.

Serum biomarkers in a mouse model of bacterial-induced inflammatory bowel disease

BACKGROUND

The diagnosis and classification of inflammatory bowel disease (IBD) require both clinical and histopathologic data. Serum biomarkers would be of considerable benefit to noninvasively monitor the progression of disease, assess effectiveness of therapies, and assist in understanding disease pathogenesis. Currently, there are limited noninvasive biomarkers for monitoring disease progression in animal IBD models, which are used extensively to develop new therapies and to understand IBD pathogenesis.

METHODS

Serum biomarkers of early and late IBD were identified using multianalyte profiling in mdr1a(-/-) mice with IBD triggered by infection with Helicobacter bilis. The correlation of changes in these biomarkers with histopathology scores and clinical signs in the presence and in the absence of antibiotic treatment was determined.

RESULTS

Serum levels of interleukin (IL)-11, IL-17, 10-kDa interferon-gamma-inducible protein (IP-10), lymphotactin, monocyte chemoattractant protein (MCP)-1, and vascular cell adhesion molecule (VCAM)-1 were elevated early in IBD. In late, more severe IBD, serum levels of IL-11, IP-10, haptoglobin, matrix metalloproteinase-9, macrophage inflammatory protein (MIP)-1gamma, fibrinogen, immunoglobulin A, MIP-3 beta (beta), VCAM-1, apolipoprotein (Apo) A1, and IL-18 were elevated. All late serum biomarkers except Apo A1 correlated with histopathology scores. Antibiotic treatment improved clinical signs of IBD and decreased mean serum values of many of the biomarkers. For all biomarkers, the individual pathology scores correlated significantly with individual serum analyte levels after treatment.

CONCLUSIONS

Serum analyte measurement is a useful, noninvasive method for monitoring disease in a mouse model of bacterial-induced IBD.

Review article: biological activity markers in inflammatory bowel disease

BACKGROUND

Traditionally, inflammatory bowel disease activity is assessed by clinical activity indices that measure clinical symptoms and endoscopic indices that measure endoscopic inflammation. Biological markers are a non-invasive way of objectively measuring inflammation and can play an adjunctive or primary role in the assessment of disease activity.

AIM

To review the data on biological markers for assessment of disease activity and prediction of relapse in inflammatory bowel disease.

METHODS

To collect relevant articles, a PubMed search was performed from 1980 to 2006 using following search terms in combination: inflammatory bowel disease, biomarkers, inflammation, disease activity, relapse, acute phase reactants cytokines, interleukins, adhesion molecules, integrins, calprotectin and lactoferrin.

RESULTS

Biological activity markers can be classified into serological, faecal and miscellaneous categories. Acute phase reactants levels correlate with disease activity and some can be used to help predict relapse. Cytokines and adhesion molecules are elevated in active disease inconsistently. Faecal markers are useful in assessment of disease activity and relapse.

CONCLUSIONS

Acute phase reactants and faecal markers are useful to assess the disease activity in clinical practice. More data are required on cytokines and adhesion molecules. C-reactive protein, erythrocyte sedimentation rate, interleukins and faecal markers may be useful in predicting a relapse.

Role of cell adhesion molecules in leukocyte recruitment in the liver and gut

This article reviews the evidence that adhesion molecules are critical in leukocyte recirculation and pathogenesis of diseases affecting the closely related tissues of the liver and gut, which offer novel opportunities for treatment.