Inflammatory bowel disease: progress and current concepts of etiopathogenesis

An overview on the cellular mechanisms of anthocyanins in maintaining intestinal integrity and function

Structural and functional changes of the intestinal barrier, as a consequence of a number of (epi)genetic and environmental causes, have a main role in penetrations of pathogens and toxic agents, and lead to the development of inflammation-related pathological conditions, not only at the level of the GI tract but also in other extra-digestive tissues and organs. Anthocyanins (ACNs), a subclass of polyphenols belonging to the flavonoid group, are well known for their health-promoting properties and are widely distributed in the human diet. There is large evidence about the correlation between the human intake of ACN-rich products and a reduction of intestinal inflammation and dysfunction. Our review describes the more recent advances in the knowledge of cellular and molecular mechanisms through which ACNs can modulate the main mechanisms involved in intestinal dysfunction and inflammation, in particular the inhibition of the NF-κB, JNK, MAPK, STAT3, and TLR4 proinflammatory pathways, the upregulation of the Nrf2 transcription factor and the expression of tight junction proteins and mucins.

Cinnamic Acid Ameliorates Acetic Acid-induced Inflammatory Response through Inhibition of TLR-4 in Colitis Rat Model

BACKGROUND

Cinnamic acid, an active compound in cinnamon spp., has anti-inflammatory and antioxidant characteristics and is favorable in managing inflammatory bowel diseases.

OBJECTIVES

Evaluate cinnamic acid's effects on colitis in rats.

METHODS

To induce colitis in experimental rats, excluding the sham group, a 4% intrarectal solution of acetic acid was administered. The rats were then given oral doses of cinnamic acid at 30, 45, and 90 mg/kg for two days. The animals were assessed for macroscopic and microscopic changes, and the levels of inflammatory mediators such as tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and myeloperoxidase (MPO) were measured using Eliza kits. Additionally, real-time PCR was performed to examine the gene level of toll-like receptor 4 (TLR-4) in the colon.

RESULTS

Effective reduction of inflammation in acetic acid-induced colitis was achieved through Cinnamic acid administration at doses of 45 and 90 mg/kg. The decrease was achieved by inhibiting the activities of TNF-α, IL-6, and MPO while downregulating the expression of TLR-4. It is important to note that macroscopic and microscopic evaluations were significant in determining the effectiveness of cinnamic acid in reducing inflammation.

CONCLUSION

Downregulation of inflammatory cytokines and TLR-4 expression may contribute to cinnamic acid's anti-inflammatory effect.

Potential Application of Intestinal Organoids in Intestinal Diseases

To accurately reveal the scenario and mecahnism of gastrointestinal diseases, the establishment of in vitro models of intestinal diseases and drug screening platforms have become the focus of attention. Over the past few decades, animal models and immortalized cell lines have provided valuable but limited insights into gastrointestinal research. In recent years, the development of intestinal organoid culture system has revolutionized in vitro studies of intestinal diseases. Intestinal organoids are derived from self-renewal and self-organization intestinal stem cells (ISCs), which can replicate the genetic characteristics, functions, and structures of the original tissues. Consequently, they provide new stragety for studying various intestinal diseases in vitro. In the review, we will discuss the culture techniques of intestinal organoids and describe the use of intestinal organoids as research tools for intestinal diseases. The role of intestinal epithelial cells (IECs) played in the pathogenesis of inflammatory bowel diseases (IBD) and the treatment of intestinal epithelial dysfunction will be highlighted. Besides, we review the current knowledge on using intestinal organoids as models to study the pathogenesis of IBD caused by epithelial dysfunction and to develop new therapeutic approaches. Finally, we shed light on the current challenges of using intestinal organoids as in vitro models.

Inactivation of Group 1B Phospholipase A2 Enhances Disease Recovery and Reduces Experimental Colitis in Mice

Phospholipase A2 (PLA2) enzymes influence inflammatory bowel disease in both positive and negative manners depending on the type of PLA2 that is expressed. This study explored the influence of the abundantly expressed Group 1B PLA2 (PLA2G1B) on ulcerative colitis. Wild-type C57BL/6J mice and Pla2g1b-/- mice were treated with dextran sulfate sodium (DSS) for 5 days to induce epithelial injury, followed by another 5 days without DSS for recovery. The Pla2g1b-/- mice displayed significantly less body weight loss, colitis pathology, and disease activity indexes compared to the wild-type mice. The differences in colitis were not due to differences in the colonic lysophospholipid levels, but higher numbers of stem and progenitor cells were found in the intestines of Pla2g1b-/- mice compared to the wild-type mice. The DSS-treated Pla2g1b-/- mice also showed higher expressions of genes that are responsible for epithelial repair and lower expressions of proinflammatory cytokine genes in the colon, as well as reduced inflammatory cytokine levels in the plasma. In vitro experiments revealed the PLA2G1B stimulation of inflammatory cytokine expression by myeloid cells. PLA2G1B inactivation protects against DSS-induced colitis in mice by increasing the intestinal stem cell reservoir for epithelial repair and reducing myeloid cell inflammation in the diseased colon. Thus, PLA2G1B may be a target for colitis management.

Integrative bioinformatics analysis to identify the effects of circadian rhythm on Crohn’s disease

Background: Crohn’s disease (CD) is a multifactorial inflammatory bowel disease characterized by complex aberrant autoimmune disorders. Currently, the involvement of the circadian rhythm in the pathogenesis of CD is unknown.

Methods: Bulk and single-cell RNA-seq data and associated clinical data from patients with CD were downloaded from the Gene Expression Omnibus (GEO). Single-sample gene set enrichment analysis was performed to calculate the enrichment score (ES) of circadian rhythm-related genes. Differential expression analysis was used to identify differentially expressed genes. Functional enrichment analysis was used to explore potential disease mechanisms. CIBERSORT was used to estimate immune cell abundance. Single-cell RNA-seq data were analyzed using the R package “Seurat.”

Results: The ES of circadian rhythm-related genes was lower in the CD tissue than in the normal tissue. Ubiquitin-specific protease 2 (USP2), a circadian rhythm-related gene, was identified as a potential modulator of CD pathogenesis. USP2 expression was reduced in CD and was associated with disease severity. Moreover, the analysis of bulk RNA-seq and single-cell RNA-seq data showed that monocyte and neutrophil abundance was elevated in CD and was negatively correlated with USP2 expression. It should be noted that USP2 expression in acinar cells was negatively correlated with monocyte and neutrophil abundance. Functional enrichment analysis revealed several canonical pathways to be enriched in CD, including the interleukin-17 signaling pathway, tumor necrosis factor signaling pathway, cytokine–cytokine receptor interaction, toll-like receptor signaling pathway, and nod-like receptor signaling pathway.

Conclusion: Aberrant expression of circadian rhythm-related genes is correlated with CD pathogenesis. USP2 might be related to crosstalk among the different cell types in CD. These findings provide insights into future chronotherapy for CD.

Motivational disposition towards psychological characteristics of israeli children with inflammatory bowel diseases: A case-control study

BACKGROUND

Psychological stress is a general and non-specific factor associated with many health conditions, including Inflammatory Bowel Diseases (IBD). It is related not only to external stressors but also to internal characteristics which enhance patients' vulnerability to stress.

PURPOSE

To identify specific psychological characteristics of pediatric IBD related to stress.

DESIGN AND METHODS

A case-control-cohort study that compared the psychological characteristics of 49 patients and 56 comparisons. The psychological characteristics were defined by four belief types - beliefs about self, general beliefs, beliefs about norms, and goals - which refer to a set of specific themes.

RESULTS

The belief types differentiated between the two groups, and the patients were characterized by six themes: like routines, strive to get others' love, caring about the body and the health, doing things only at their own pace, expressing negative emotion without regulations, and feeling over-identification with others. Patients' likelihood of being characterized by the themes is 2.18 to 2.90 times higher than the comparisons.

CONCLUSION

Children with IBD are characterized by a set of specific psychological characteristics. These characteristics were discussed mainly concerning generating chronic stress (e.g., over-identification with others) and interpersonal conflicts (e.g., doing things only at their own pace) among the patients.

IMPLICATIONS FOR PRACTICE

It is suggested to healthcare workers to be aware of the specific psychological characteristics of children with IBD, and sensitive to these characteristics during interactions with them. Besides, the characteristics may pave the way for developing a targeted psychological intervention that corresponds specifically to the patients' needs.

Fat of the Gut: Epithelial Phospholipids in Inflammatory Bowel Diseases

Inflammatory bowel diseases (IBD) comprise a distinct set of clinical symptoms resulting from chronic inflammation within the gastrointestinal (GI) tract. Despite the significant progress in understanding the etiology and development of treatment strategies, IBD remain incurable for thousands of patients. Metabolic deregulation is indicative of IBD, including substantial shifts in lipid metabolism. Recent data showed that changes in some phospholipids are very common in IBD patients. For instance, phosphatidylcholine (PC)/phosphatidylethanolamine (PE) and lysophosphatidylcholine (LPC)/PC ratios are associated with the severity of the inflammatory process. Composition of phospholipids also changes upon IBD towards an increase in arachidonic acid and a decrease in linoleic and a-linolenic acid levels. Moreover, an increase in certain phospholipid metabolites, such as lysophosphatidylcholine, sphingosine-1-phosphate and ceramide, can result in enhanced intestinal inflammation, malignancy, apoptosis or necroptosis. Because some phospholipids are associated with pathogenesis of IBD, they may provide a basis for new strategies to treat IBD. Current attempts are aimed at controlling phospholipid and fatty acid levels through the diet or via pharmacological manipulation of lipid metabolism.

The Role of Carrageenan in Inflammatory Bowel Diseases and Allergic Reactions: Where Do We Stand?

Carrageenan (CGN) is a high molecular weight polysaccharide extracted from red seaweeds, composed of D-galactose residues linked in β-1,4 and α-1,3 galactose-galactose bond, widely used as a food additive in processed foods for its properties as a thickener, gelling agent, emulsifier, and stabilizer. In recent years, with the spread of the Western diet (WD), its consumption has increased. Nonetheless, there is a debate on its safety. CGN is extensively used as an inflammatory and adjuvant agent in vitro and in animal experimental models for the investigation of immune processes or to assess the activity of anti-inflammatory drugs. CGN can activate the innate immune pathways of inflammation, alter the gut microbiota composition and the thickness of the mucus barrier. Clinical evidence suggests that CGN is involved in the pathogenesis and clinical management of inflammatory bowel diseases (IBD), indeed food-exclusion diets can be an effective therapy for disease remission. Moreover, specific IgE to the oligosaccharide α-Gal has been associated with allergic reactions commonly referred to as the "α-Gal syndrome". This review aims to discuss the role of carrageenan in inflammatory bowel diseases and allergic reactions following the current evidence. Furthermore, as no definitive data are available on the safety and the effects of CGN, we suggest gaps to be filled and advise to limit the human exposure to CGN by reducing the consumption of ultra-processed foods.

Characterization of terminal-ileal and colonic Crohn's disease in treatment-naïve paediatric patients based on transcriptomic profile using logistic regression

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic and idiopathic inflammatory disorder of the gastrointestinal tract and comprises ulcerative colitis (UC) and Crohn's disease (CD). Crohn's disease can affect any part of the gastrointestinal tract, but mainly the terminal ileum and colon. In the present study, we aimed to characterize terminal-ileal CD (ICD) and colonic CD (CCD) at the molecular level, which might enable a more optimized approach for the clinical care and scientific research of CD.

METHODS

We analyzed differentially expressed genes in samples from 23 treatment-naïve paediatric patients with CD and 25 non-IBD controls, and compared the data with previously published RNA-Seq data using multi-statistical tests and confidence intervals. We implemented functional profiling and proposed statistical methods for feature selection using a logistic regression model to identify genes that are highly associated in ICD or CCD. We also validated our final candidate genes in independent paediatric and adult cohorts.

RESULTS

We identified 550 genes specifically expressed in patients with CD compared with those in healthy controls (p < 0.05). Among these DEGs, 240 from patients with CCD were mainly involved in mitochondrial dysfunction, whereas 310 from patients with ICD were enriched in the ileum functions such as digestion, absorption, and metabolism. To choose the most effective gene set, we selected the most powerful genes (p-value ≤ 0.05, accuracy ≥ 0.8, and AUC ≥ 0.8) using logistic regression. Consequently, 33 genes were identified as useful for discriminating CD location; the accuracy and AUC were 0.86 and 0.83, respectively. We then validated the 33 genes with data from another independent paediatric cohort (accuracy = 0.93, AUC = 0.92) and adult cohort (accuracy = 0.88, AUC = 0.72).

CONCLUSIONS

In summary, we identified DEGs that are specifically expressed in CCD and ICD compared with those in healthy controls and patients with UC. Based on the feature selection analysis, 33 genes were identified as useful for discriminating CCD and ICD with high accuracy and AUC, for not only paediatric patients but also independent cohorts. We propose that our approach and the final gene set are useful for the molecular classification of patients with CD, and it could be beneficial in treatments based on disease location.

Mesalazine Activates Adenosine Monophosphate-activated Protein Kinase: Implication in the Anti-inflammatory Activity of this Anti-colitic Drug

OBJECTIVE

Mesalazine, 5-aminosalicylic acid (5-ASA), is an anti-inflammatory drug that is most widely used for the treatment of Inflammatory Bowel Disease (IBD). Despite extensive clinical use, the exact pharmacological mechanism underlying the anti-colitic effects of 5-ASA has not yet been elucidated. A potential molecular mechanism underlying 5-ASA-mediated anti-colitic activity was investigated.

METHODS

An anti-inflammatory pharmacology of 5-ASA was scrutinized in human colon carcinoma cells and murine macrophages and in a TNBS-induced rat colitis model.

RESULTS

5-ASA induced phosphorylation of adenosine monophosphate-activated protein kinase (AMPK) and its substrate acetyl-CoA carboxylase in cells. 5-ASA activation of AMPK occurred regardless of the presence of the pro-inflammatory mediators, Tumor Necrosis Factor Alpha (TNF-α) and lipopolysaccharide. 5-ASA inhibits TNF-α-dependent Nuclear Factor-Kappa B (NF-κB) activation, which was dampened by AMPK inhibition. Oral gavage of sulfasalazine (a colon-specific prodrug of 5- ASA) or rectal administration of 5-ASA ameliorated 2,4,6-trinitrobenzene sulfonic acid (TNBS)- induced rat colitis and activated AMPK in the inflamed colonic tissues while markedly diminishing the levels of NF-κB-regulated pro-inflammatory mediators cyclooxygenase-2, inducible nitric oxide synthase, and cytokine-induced neutrophil chemoattractant-3, elevated by the induction of inflammation. Rectal co-administration of 5-ASA and an AMPK inhibitor undermined 5-ASA-mediated activation of AMPK and its anti-colitic effects.

CONCLUSION

These findings suggest that the activation of AMPK is involved in 5-ASA-mediated anticolitic effects at least partly via interference with pro-inflammatory NF-κB signaling.

ILC2 Proliferated by IL-33 Stimulation Alleviates Acute Colitis in Rag1-/- Mouse through Promoting M2 Macrophage Polarization

This study was to identify functions of ILC2, a newly found innate lymphoid cell which mainly locates in mucosa organs like lungs and intestines, in IBD. We injected rIL-33 protein to C57/BL6 mouse to explore how IL-33 induces ILC2 proliferation. The results showed that ILC2 reached a proliferation peak at day 5 and expressed multiple surface markers like CD127, C-kit, CD69, CD44, ST2, CD27, DR3, MHCII, and CD90.2. ILC2 also expressed high quantity of IL-13 and IL-5 and few IL-17A which indicates a potentially immunological function in IBD development. Afterwards, we transferred sort purified ILC2 to Rag1^−/− mouse given DSS to induce acute colitis in order to explore the innate function of ILC2. Data showed that ILC2 alleviates DSS-induced acute innate colitis by repairing epithelial barrier and restore body weight. Furthermore, we found that ILC2 can cause macrophages polarizing to M2 macrophages in the gut. Therefore, we concluded that ILC2 played a therapeutic role in mouse acute colitis.

Evaluation of Physiological Parameters of Intestinal Sulfate-Reducing Bacteria Isolated from Patients Suffering from IBD and Healthy People

BACKGROUND

Inflammatory bowel diseases (IBDs) are multifactorial illnesses of the intestine, to which microorganisms are contributing. Among the contributing microorganisms, sulfate-reducing bacteria (SRB) are suggested to be involved in the process of bowel inflammation due to the production of hydrogen sulfide (H2S) by dissimilatory sulfate reduction. The aims of our research were to physiologically examine SRB in fecal samples of patients with IBD and a control group, their identification, the study of the process of dissimilatory sulfate reduction (sulfate consumption and H2S production) and biomass accumulation. Determination of biogenic elements of the SRB and evaluation of obtained parameters by using statistical methods were also included in the research. The material for the research consisted of 14 fecal samples, which was obtained from patients and control subjects.

METHODS

Microscopic techniques, microbiological, biochemical, biophysical methods and statistical analysis were included.

RESULTS

Colonies of SRB were isolated from all the fecal samples, and subsequently, 35 strains were obtained. Vibrio-shaped cells stained Gram-negative were dominant in all purified studied strains. All strains had a high percentage of similarity by the 16S rRNA gene with deposited sequences in GenBank of Desulfovibrio vulgaris. Cluster analysis of sulfate reduction parameters allowed the grouping of SRB strains. Significant (p < 0.05) differences were not observed between healthy individuals and patients with IBD with regard to sulfate reduction parameters (sulfate consumption, H2S and biomass accumulation). Moreover, we found that manganese and iron contents in the cell extracts are higher among healthy individuals in comparison to unhealthy individuals that have an intestinal bowel disease, especially ulcerative colitis.

CONCLUSIONS

The observations obtained from studying SRB emphasize differences in the intestinal microbial processes of healthy and unhealthy people.

Can diffusion weighted imaging be used as an alternative to contrast-enhanced imaging on magnetic resonance enterography for the assessment of active inflammation in Crohn disease?

The present study aimed to investigate the potential use of T2-weighted sequences with diffusion weighted imaging (DWI) in magnetic resonance (MR) enterography instead of conventional contrast-enhanced MR imaging (MRI) sequences for the evaluation of active inflammation in Crohn disease.Two-hundred thirteen intestinal segments of 43 patients, who underwent colonoscopy within 2 weeks before or after MR enterography were evaluated in this retrospective study. DWI sequences, T2-weighted sequences, and contrast-enhanced T1-weighted sequences were acquired in the MR enterography scan after cleaning of the bowel and using an oral contrast agent. First, the intestinal segments that had active inflammation in MR enterography were qualitatively evaluated in T2-weighted and contrast-enhanced T1-weighted sequences and then MR activity index (MRAI 1) and MRAI 2 were formed with and without contrast-enhanced sequences in 2 separate sessions.The correlation coefficient between contrast enhanced and DWI MR enterography scores (MRAI 1 and MRAI 2) of intestinal inflammation was 0.97 for all segments. In addition, separate correlation coefficients were calculated for terminal ileum, right colon, transverse colon, left colon, and rectum, and there was a strong correlation between the MRAI 1 and MRAI 2 scores of each segment (r = 0.86-0.97, P < .001). On the other hand, MR enterography had 88.7% sensitivity, 97.9% specificity, 95.5% positive predictive value, 94.6% negative predictive value, and 94.8% accuracy for detection of active inflammation in all intestinal segments in Crohn disease.DWI and T2-weighted sequences acquired with cleaning of the bowel can be used instead of contrast-enhanced MRI sequences for the evaluation of active inflammation in Crohn disease.

Anti-tumor necrosis factor α therapy associates to type 17 helper T lymphocytes immunological shift and significant microbial changes in dextran sodium sulphate colitis

BACKGROUND

Anti-tumor necrosis factor α (TNFα) represents the best therapeutic option to induce mucosal healing and clinical remission in patients with moderate-severe ulcerative colitis. On the other side gut microbiota plays a crucial role in pathogenesis of ulcerative colitis but few information exists on how microbiota changes following anti-TNFα therapy and on microbiota role in mucosal healing.

AIM

To elucidate whether gut microbiota and immune system changes appear following anti TNFα therapy during dextran sulfate sodium (DSS) colitis.

METHODS

Eighty C57BL/6 mice were divided into four groups: “No DSS”, “No DSS + anti-TNFα”, “DSS” and “DSS + anti-TNFα”. “DSS” and “DSS + anti-TNFα” were treated for 5 d with 3% DSS. At day 3, mice whithin “No DSS+anti-TNFα” and “DSS+anti-TNFα” group received 5 mg/kg of an anti-TNFα agent. Forty mice were sacrificed at day 5, forty at day 12, after one week of recovery post DSS. The severity of colitis was assessed by a clinical score (Disease Activity Index), colon length and histology. Bacteria such as Bacteroides, Clostridiaceae, Enterococcaceae and Fecalibacterium prausnitzii (F. prausnitzii) were evaluated by quantitative PCR. Type 1 helper T lymphocytes (Th1), type 17 helper T lymphocytes (Th17) and CD4⁺ regulatory T lymphocytes (Treg) distributions in the mesenteric lymph node (MLN) were studied by flow cytometry.

RESULTS

Bacteria associated with a healthy state (i.e., such as Bacteroides, Clostridiaceae and F. prausnitzii) decreased during colitis and increased in course of anti-TNFα treatment. Conversely, microorganisms belonging to Enterococcaceae genera, which are linked to inflammatory processes, showed an opposite trend. Furthermore, in colitic mice treated with anti-TNFα microbial changes were associated with an initial increase (day 5 of the colitis) in Treg cells and a consequent decrease (day 12 post DSS) in Th1 and Th17 frequency cells. Healthy mice treated with anti-TNFα showed the same histological, microbial and immune features of untreated colitic mice. “No DSS + anti-TNFα” group showed a lymphomononuclear infiltrate both at 5^th and 12^th d at hematoxylin and eosin staining, an increase of in Th1 and Th17 frequency at day 12, an increase of Enterococcaceae at day 5, a decrease of Bacteroides and Clostridiaceae at day 12.

CONCLUSION

Anti-TNFα treatment in experimental model of colitis improves disease activity but it is associated to an increase in Th17 pathway together with gut microbiota alteration.

Crohn’s disease of esophagus, stomach and duodenum

Crohn’s disease with involvement of the esophagus, stomach and duodenum has a prevalence of 0.5% to 4% in symptomatic adult patients, but some studies have shown that these results may be underestimated, since upper gastrointestinal endoscopy is not performed routinely in the initial evaluation of the disease in adult patients, as it is in the pediatric population. In general, involvement of the upper gastrointestinal tract in Crohn’s disease occurs concomitantly with involvement of the lower gastrointestinal tract. The diagnosis depends on clinical, endoscopic, histological and radiological evaluation. The presence of aphthoid ulcers, longitudinal ulcers, bamboo-joint-like appearance, stenoses and fistulas are endoscopic findings suggestive of the disease, and it is important to exclude the presence of Helicobacter pylori infection. The primary histological findings, which facilitate the diagnosis, are the presence of a chronic inflammatory process with a predominance of lymphoplasmacytic cells and active focal gastritis. The presence of epithelioid granuloma, although less frequent, is highly suggestive of the disease in the absence of chronic granulomatous disease. Treatment should include the use of proton pump inhibitors associated with corticosteroids, immunomodulators and biological therapy according to the severity of the disease.

Efficacy of Pyrus elaeagnifolia subsp. elaeagnifolia in acetic acid–induced colitis model

In Turkish folk medicine, the fruits of Pyrus elaeagnifolia subsp. elaeagnifolia have been used to treat diarrhea and detoxify poisonous snake bites by enlarging the wound. The aim of the study was to confirm the ethnopharmacological usage of the plant using in vivo and in vitro models. Experimental colitis was performed under anesthesia by intrarectal administration of acetic acid in rats, and the extracts were administered orally. The colonic malondialdehyde (MDA), tumor necrosis factor (TNF-α), interleukin-6 (IL-6), and nitrite levels, in addition to the myeloperoxidase (MPO) and caspase-3 activities, were measured to determine the effects of the plant extracts. The methanol (MeOH) extract revealed a significant decrease in MPO and caspase-3 levels. The MeOH extract was found to have the highest total tannin content. It was also found to have significant antioxidant (p ˂ 0.01) and anti-inflammatory activities (p ˂ 0.05) in acetic acid induced colitis rat model . According to our results, the present study exhibited a decrease in MDA, nitrite, IL-6, and TNF-α levels in the colon tissue and blood in the MeOH extract treated group. The findings of this study can help in treating various disorders, such as Clostridium difficile infection, irritable bowel syndrome, and inflammatory bowel diseases.

Ileal pouch of ulcerative colitis and familial adenomatous polyposis patients exhibit modulation of autophagy markers

Total retocolectomy with ileal pouch-anal anastomosis (IPAA) is the surgery of choice for patients with ulcerative colitis (UC) that are refractory to clinical treatment. Pouchitis is one of the most common complications after this procedure. Defects in autophagy have been reported in inflammatory bowel diseases. However, there are no studies on the IP. Therefore, we studied markers for autophagy in the IP mucosa of UC and FAP patients comparing them to controls with a normal distal ileum. Sixteen patients with IP in "J" shape, asymptomatic and with endoscopically normal IP were evaluated. The control group consisted of eight patients with normal colonoscopy. There was a significant decrease in the transcriptional levels of ATG5, MAP1LC3A and BAX in the FAP group. There was also a decrease in the protein level of Beclin-1 in the UC and FAP compared to the control group. Although the LC3II levels by immunoblot were higher in the UC group, LC3/p62 co-localization were lower in the immunofluorescence analysis in the UC and FAP compared to the control group. Corroborating these results, there was an increase of p62 by immunoblot in the UC group. These findings indicated a modulation of macroautophagy markers in the IP, which may explain the mucosa inflammation predisposition.

A randomized trial of the effects of the no-carrageenan diet on ulcerative colitis disease activity

BACKGROUND: Carrageenan is a very common food additive in Western diets, but predictably causes inflammation in thousands of cell-based and animal experiments.

OBJECTIVE: To assess the impact of carrageenan exposure on the interval to relapse in patients with ulcerative colitis in remission.

METHODS: A randomized, double-blind, placebo-controlled, multicenter, clinical trial was conducted to assess if patients with ulcerative colitis in remission would have a longer interval to relapse if they followed a diet with no carrageenan. All participants were instructed in the no-carrageenan diet and were randomized to either placebo capsules or carrageenan-containing capsules. The carrageenan in the capsules was less than the average daily carrageenan intake from the diet. Relapse was defined as an increase of two or more points on the Simple Clinical Colitis Activity Index (SCCAI) and intensification of treatment for ulcerative colitis. Participants were followed by telephone calls every two weeks until relapse or one year of participation. The occurrence of relapse and inflammatory biomarkers were compared between the two groups.

RESULTS: Twelve patients completed study questionnaires. Three patients who received carrageenan-containing capsules relapsed, and none of the patients who received placebo-containing capsules relapsed (p = 0.046, log-rank test). Laboratory tests showed increases in Interleukin-6 (p = 0.02, paired t-test, two-tailed) and fecal calprotectin (p = 0.06; paired t-test, two-tailed) between the beginning and the end of study participation in the carrageenan-exposed group, but not in the placebo-group.

CONCLUSION: Carrageenan intake contributed to earlier relapse in patients with ulcerative colitis in remission. Restriction of dietary carrageenan may benefit patients with ulcerative colitis.

IL-21/IL-21R signaling suppresses intestinal inflammation induced by DSS through regulation of Th responses in lamina propria in mice

Serum level of IL-21 is increased in patients with inflammatory bowel diseases (IBD), suggesting that IL-21/IL-21 receptor (IL-21R) signaling may be involved in the pathogenesis of IBD. However, the role of IL-21/IL-21 receptor signaling plays in the pathogenesis of IBD is not very clear. In this study, using IL-21R.KO mice, we tested the role of IL-21/IL-21R signaling in the regulation of T helper cell responses during intestinal inflammation. Here we found that IL-21R.KO mice were more susceptible to DSS-induced colitis as compared with C57BL/6 mice. The spontaneous inflammatory cytokines released by macrophages in LP of colon were significantly increased, and Th2, Th17 and Treg responses were down-regulated markedly. However, Th1 responses were significantly up-regulated in IL-21R.KO mice. Meanwhile, the population of CD8(+)CD44(+)IFN-γ(+) T cells was markedly elevated in LP of inflammatory intestine of IL-21RKO mice. In vivo, after disease onset, DSS-induced intestinal inflammation was ameliorated in C57BL/6 mice treated with rIL-21. Our results demonstrate that IL-21/IL-21R signaling contributes to protection against DSS-induced acute colitis through suppression of Th1 and activation of Th2, Th17 and Treg responses in mice. Therefore, therapeutic manipulation of IL-21/IL-21R activity may allow improved immunotherapy for IBD and other inflammatory diseases associated with Th cell responses.

Direct effect of infliximab on intestinal mucosa sustains mucosal healing: exploring new mechanisms of action

BACKGROUND

Infliximab is effective in inflammatory bowel disease through several mechanisms, possibly acting at the mucosal level.

AIM

To assess the role of infliximab on intestinal mucosa and whether it contributes to mucosal healing.

METHODS

Human colonic mucosal biopsies were incubated with or without infliximab. Cultured biopsies were evaluated for histological staining, CD68, CD3, E-cadherin and phospho-extracellular signal-regulated kinases (ERK) expression, and apoptosis. A scratch assay and MTT assay were performed with Caco2 cells in the presence of infliximab and/or tumour necrosis factor (TNF)-α or treated with supernatants obtained from human peripheral blood mononuclear cells or human intestinal fibroblasts treated with TNF-α and infliximab alone or in association.

RESULTS

Infliximab-treated biopsies displayed a better histological appearance, reduced inflammation with an increase of E-cadherin, phospho-ERK and apoptosis. Supernatants showed lower TNF-α, IL-17, IL-6 and IL-8 concentration, with an increase in fibroblast-growth-factor. Motility at scratch assay and proliferation at MTT assay of Caco2 cells displayed differential modulation by TNF-α and infliximab, directly or through supernatants of human intestinal fibroblasts and human peripheral blood mononuclear cells exposed to them.

CONCLUSION

Infliximab contributes to the mucosal healing process by acting directly at an intestinal mucosal level; infliximab indirectly affects epithelial cell migration and proliferation by acting on both fibroblasts and leukocytes.

Curriculum based clinical review: small bowel imaging in Crohn's disease

The multidisciplinary management of patients with small bowel Crohn's disease is complex with an increasing reliance on imaging to guide management. The use of barium fluoroscopy is in decline with a shift towards the cross-sectional modalities. This article provides an overview of the various techniques used to image the small bowel, and highlights the clinical scenarios where imaging tests are most useful.

Enteric glia: A new player in inflammatory bowel diseases

In addition to the well-known involvement of macrophages and neutrophils, other cell types have been recently reported to substantially contribute to the onset and progression of inflammatory bowel diseases (IBD). Enteric glial cells (EGC) are the equivalent cell type of astrocyte in the central nervous system (CNS) and share with them many neurotrophic and neuro-immunomodulatory properties. This short review highlights the role of EGC in IBD, describing the role played by these cells in the maintenance of gut homeostasis, and their modulation of enteric neuronal activities. In pathological conditions, EGC have been reported to trigger and support bowel inflammation through the specific over-secretion of S100B protein, a pivotal neurotrophic factor able to induce chronic inflammatory changes in gut mucosa. New pharmacological tools that may improve the current therapeutic strategies for inflammatory bowel diseases (IBD), lowering side effects (i.e. corticosteroids) and costs (i.e. anti-TNFα monoclonal antibodies) represent a very important challenge for gastroenterologists and pharmacologists. Novel drugs capable to modulate enteric glia reactivity, limiting the pro-inflammatory release of S100B, may thus represent a significant innovation in the field of pharmacological interventions for inflammatory bowel diseases.

The natural compound celastrol inhibits necroptosis and alleviates ulcerative colitis in mice

Ulcerative colitis (UC) is a chronic intestinal inflammatory disease. Necroptosis plays an important role in the pathogenesis of UC. Celastrol, a triterpene from the root bark of the Chinese medicinal plant Tripterygium wilfordii, has been reported to have anti-oxidant and anti-inflammatory activities in colitis. It is not known, however, how celastrol exerts its beneficial effects. The aim of this study is to investigate the effects and possible mechanism of celastrol in UC. Colitis was induced in mice by administration of 5% dextran sulfate sodium (DSS) in drinking water for 4days. Celastrol was administered intraperitoneally (1mg/kg) for 7days after colitis was induced. Our results showed that celastrol treatment ameliorated the severity of colitis, decreased the level of interleukin (IL)-1β, IL-6 and myeloperoxidase (MPO) and upregulated the level of E-cadherin in colitis mice. Moreover, the TUNEL staining and cleaved caspase-3 immunohistochemistry staining proved decreased necrotic cell death after celastrol treatment. On the mechanism, decreased level of necroptosis factors RIP3 and MLKL, and increased level of active caspase-8 were detected after celastrol treatment. Taken together, our results demonstrated that celastrol exerted beneficial effects in colitis treatment via suppressing the RIP3/MLKL necroptosis pathway.

IL-33 Aggravates DSS-Induced Acute Colitis in Mouse Colon Lamina Propria by Enhancing Th2 Cell Responses

Interleukin- (IL-) 33, a member of the IL-1 cytokine family, is an important modulator of the immune system associated with several immune-mediated diseases. IL-33 was expressed in high level on epithelial cells of intestinal tract. It suggested that IL-33 plays a potential role in inflammatory bowel diseases (IBD). We investigated the role of interleukin- (IL-) 33 in dextran sulphate sodium- (DSS-) induced acute colitis in mice using recombinant mouse IL-33 protein (rIL-33). We found that DSS-induced acute colitis was aggravated by rIL-33 treatment. rIL-33-treated DSS mice showed markedly reduced levels of interferon- (IFN-)γ and IL-17A in their colon lamina propria lymphocytes (LPL), but the levels of Th2 cytokines, such as IL-5 and IL-13, in these cells were significantly increased, compared to DSS mice treated with PBS. Our results suggested that IL-33 stimulated CD4⁺T cells and caused the cell to adopt a Th2-type response but at the same time suppressed Th17 and Th1 cell responses. Therefore, IL-33 may be involved in pathogenesis of DSS-induced acute colitis by promoting Th2 cell response in intestinal mucosa of mice. Modulation of IL-33/ST2 signaling by monoclonal antibody (mAb) could be a novel biological therapy in DSS-induced acute colitis.

Colonic delivery of celecoxib is a potential pharmaceutical strategy for repositioning the selective COX-2 inhibitor as an anti-colitic agent

Celecoxib is a selective cyclooxygenase-2 inhibitor applied to the treatment of arthritis. Repositioning the anti-inflammatory drug as an anti-inflammatory bowel disease drug has obstacles such as controversial anti-colitic efficacy and potential side effects. We examined whether colonic delivery of celecoxib could circumvent the therapeutic limitations. N-succinylglutam-1-yl celecoxib (SG1C), a colon-specific prodrug of celecoxib), was administered orally to rats with colitis and the anti-inflammatory activity and pharmacologic mechanisms were investigated. SG1C alleviated the colonic injury and lowered myeloperoxidase activity in the inflamed colonic tissues much more effectively than conventional celecoxib. While suppressing expression of pro-inflammatory nuclear factor kappaB gene products including cyclooxygenase-2, SG1C elevated an anti-inflammatory nuclear factor-erythroid 2 p45 (NF-E2)-related factor 2 (Nrf2) and its target gene product heme oxygenase (HO)-1 in the inflamed colon. In contrast, no significant molecular effects were observed with conventional celecoxib. Unlike conventional celecoxib, SG1C did not lower the serum level of 6-keto-PGF1α, an inverse indicator of cardiovascular adverse effects. Collectively, colonic delivery of celecoxib, likely improving therapeutic and toxicological properties of celecoxib, may be a feasible pharmaceutical strategy to therapeutically switch celecoxib to an anti-colitic drug.

Pediatric patients with inflammatory bowel disease exhibit increased serum levels of proinflammatory cytokines and chemokines, but decreased circulating levels of macrophage inhibitory protein-1β, interleukin-2 and interleukin-17

Inflammatory bowel disease (IBD) is a chronic and progressive inflammatory condition of the gastrointestinal tract. Although the causative events that lead to the onset of IBD are yet to be fully elucidated, deregulation of immune and inflammatory mechanisms are hypothesized to significantly contribute to this disorder. Since the onset of IBD is often during infancy, in the present study, the serum values of a large panel of cytokines and chemokines in pediatric patients (<18 years; n=26) were compared with age-matched controls (n=37). While elevations in the serum level of several proinflammatory and immune regulating cytokines were confirmed, such as interleukin (IL)-1β, IL-5, IL-7, interferon (IFN)-γ-inducible protein-10, IL-16, cutaneous T-cell-attracting chemokine, leukemia inhibitory factor, monokine induced by γ-IFN, IFN-α2 and IFN-γ, notably decreased levels of IL-2, IL-17 and macrophage inhibitory protein-1β were also observed. Therefore, while a number of proinflammatory cytokines exhibit increased levels in IBD patients, pediatric IBD patients may also exhibit certain aspects of a reduced immunological response.

The correlation between tenascin-C expression, and formation of intestinal stricture

OBJECTIVE:

A strong correlation exists between tenascin-C induction, and acute inflammation. Generally increased tenascin-C concentrations are correlated with various inflammatory, and infectious diseases. In patients with diagnosis of Inflammatory Bowel Disease (IBD) presence of tenascin-C in colonic mucosa demonstrates tissue repair, and its mucosal concentrations are correlated with local disease activity Therefore plasma levels of tenascin-C have been demonstrated to be a helpful indicator of the activity of inflammatory bowel diseases. In this study, firstly in the literature, we aimed to display the correlation between tenascin-C expression, and formation of intestinal stricture.

METHODS:

A total of 43 patients (male, n=19; 44.2%; and female, n=24, 55.8%) aged between 19, and 63 years, with clinically, endoscopically, radiologically, and histopathologically confirmed definitive diagnosis of Crohn’s disease who were examined, diagnosed, and treated in the Gastroenterology Clinic of Haydarpasa Numune Training and Research Hospital between January 2011, and April 2012 were investigated. Serum tenascin-C levels were measured using commercial sandwich enzyme-linked immunosorbent assay Human Tenascin-C Purified Protein kit (Chemicon, Millipore(R), USA). Study groups were categorized based on the type of the disease as inflammatory (n=17; 39.5%), obstructive (27.2%), and fistule formation (n=10; 23.3%) Crohn’s disease. For statistical analysis SPSS (Statistical Package for Social Sciences) Statistics 15 program was used.

RESULTS:

Median tenascin- C value in the obstructive group (6.57 ng/mL; range, 4.26-21.87 ng/mL) was statistically significantly higher than that detected in the inflammatory (1.74 ng/mL; range,1.29-3.16 ng/mL), and fistulizing (1.44 ng/mL; range, 0.74-2.47 ng/mL) groups (p=0.002).

CONCLUSION:

Intestinal fibroblasts have an important role in the stricture formation process in CD. Transforming growth factor (TGF)-b1 cytokine is in the center of this process. A strong correlation exists between tenascin-C induction, and acute inflammation. As a known fact, serum tenascin-C levels can be used in the determination of activity of IBD. Starting from this point, serum tenascin-C levels can be useful in the categorization of the Crohn’s disease without the need for invasive methods. In the future, studies with larger patient series investigating use of serum tenascin-C in the prediction of stricturing Crohn’s disease should be conducted.

Comparison between clinical and radiological evaluation before and after medical therapy in patients with Crohn's disease: new prospective roles of CT enterography

PURPOSE

In recent years, CT enterography (CTE) has emerged as an important methodology to study patients with Crohn's disease (CD). The aim of this study was to evaluate the correlation between clinical response to therapy and CTE findings in CD patients.

MATERIALS AND METHODS

Forty-five patients with proven CD underwent CTE before and after medical therapy. In CTE we evaluated bowel thickness, longitudinal extension of parietal thickening, presence of target signs and extraintestinal signs. The clinical response to therapy was judged based on clinical global assessment and classified as improved, worsened or stable disease. Radiological judgement was compared to clinical judgement. The Cohen kappa test, t test or Anova analysis and χ (2) test were used for comparisons.

RESULTS

Among 45 enrolled patients, 21 (47 %) improved clinically, five (11 %) worsened, 19 (42 %) remained stable. Clinical improvement was significantly correlated to reduced intestinal thickness, reduced longitudinal extension of the disease, increased diameter of pathological bowel and reduced target signs (p < 0.05). Worsening conditions were significantly correlated to increased longitudinal extent, increased parietal thickness and reduced lumen diameter (p < 0.05). CT judgement was in agreement with physician's clinical assessment in 34 patients (76 %), showing improved disease in 16/21 patients (76 %), stable disease in 14/19 patients (74 %) and worsening in 4/5 patients (80 %). No agreement was observed in 11 (24 %) patients.

CONCLUSIONS

CT enterography provide specific and measurable parameters in evaluating the response to therapy in CD patients.

Effect of professional follow-up care in patients with Crohn's disease receiving home enteral nutrition

AIM: To assess the effect of 3 mo of professional follow-up care in patients with Crohn's disease (CD) receiving home enteral nutrition.

METHODS: Fifty-two patients with CD in remission who were hospitalized from April 2013 to March 2014 at Shanghai Tenth People's Hospital, given enteral nutrient solution after discharge and received professional follow-up guidance for 3 mo were included in a study group. Sixty-one patients with CD in remission who were hospitalized from January 2012 to December 2012 at the same hospital, given the same enteral nutrient solution after discharge, but did not receive the professional follow-up guidance were included in a control group. The improvement of clinical symptoms and changes in nutritional and blood indexes were compared between the two groups.

RESULTS: Body mass index, upper arm circumference, triceps skinfold thickness, potassium, sodium, calcium, albumin, and hemoglobin differed significantly among different time points after discharge in the study group (P < 0.01). After 3 mo of home enteral nutrition, nutritional and blood indexes were statistically significant between the two groups (P < 0.01).

CONCLUSION: Professional follow-up care has a significant effect on the restoration of nutritional and blood indexes and can improve therapeutic effects and patients' quality of life.

Optimal b value of diffusion-weighted imaging on a 3.0T magnetic resonance scanner in Crohn’s disease

AIM: To determine the optimal b value of diffusion-weighted imaging for detecting active inflammation in Crohn’s disease.

METHODS: Thirty-one patients clinically diagnosed with active Crohn’s disease were referred for magnetic resonance examination. All patients were scanned on a 3.0T magnetic resonance scanner using the same protocol involving four different b values (800, 1500, 2000 and 2500 s/mm²). The diagnostic effect of diffusion-weighted imaging was evaluated and compared with endoscopic findings. The diffusion-weighted image quality of four b value groups was evaluated and apparent diffusion coefficient was measured for both normal and inflammatory intestinal segments.

RESULTS: The contrast-to-noise ratio and signal-to-noise ratio were not satisfied when b value 2000 or 2500 s/mm² was adopted (36.52 ± 14.95 vs 34.78 ± 24.83, P > 0.05; 53.58 ± 23.45 vs 47.58 ± 29.67, P > 0.05). The qualitative image quality was not enough to meet diagnostic requirement. No matter which b value was chosen, the apparent diffusion coefficient of inflammatory intestinal segments was significantly lower than that of normal intestinal segments (1.38 ± 0.28 vs 2.00 ± 0.38, P < 0.01; 1.09 ± 0.20 vs 1.50 ± 0.28, P < 0.01; 0.95 ± 0.19 vs 1.34 ± 0.28, P < 0.01; 0.88 ± 0.14 vs 1.20 ± 0.21, P < 0.01). The lesion detection rate (90.32%), diagnostic sensitivity (81.18%) and specificity (95.10%) would be appropriate when b value 1500 s/mm² was adopted.

CONCLUSION: High b value is suitable for intestinal DW examination on a high field MR scanner.

The genetic predisposition and the interplay of host genetics and gut microbiome in Crohn disease

Extensive genetic studies have identified more than 140 loci predisposing to Crohn disease (CD). Several major CD susceptibility genes have been shown to impair biological function with regard to immune response to recognizing and clearance of bacterial infection. Recent human microbiome studies suggest that the gut microbiome composition is differentiated in carriers of many risk variants of major CD susceptibility genes. This interplay between host genetics and its associated gut microbiome may play an essential role in the pathogenesis of CD. The ongoing microbiome research is aimed to investigate the detailed host genetics-microbiome interacting mechanism.

Association of MYO9B gene polymorphisms with inflammatory bowel disease in Chinese Han population

AIM: To explore the association of MYO9B gene polymorphisms with clinical phenotypes and intestinal permeability of individuals with inflammatory bowel disease (IBD) in China.

METHODS: A total of 442 IBD patients and 402 healthy volunteers were genotyped for two single nucleotides (rs962917 and rs1545620) using the ligase detection reaction and polymerase chain reaction. Allelic and genotype frequency analyses were performed for the two groups. Intestinal permeability was evaluated using lactulose (L) and mannitol (M) excretion. The association of MYO9B gene polymorphisms with intestinal permeability between the normal and high intestinal permeability groups was analyzed.

RESULTS: Overall, there was no significant difference in the genotypic and allelic frequencies of MYO9B between IBD patients and controls. Although no association was found with ulcerative colitis in the comparison between the subgroups, the frequencies of rs962917 and rs1545620 were different in the Crohn’s disease (CD) subgroup with ileocolitis (CC vs CT and TT, P = 0.014; and AA vs AC and CC, P = 0.022, respectively). rs1545620 variants appear to be the genetic susceptibility factor for perianal disease in CD patients (AA vs AC CC, P = 0.029). In addition, the L/M ratio was significantly higher in IBD patients than in controls (0.065 ± 0.013 vs 0.020 ± 0.002, P = 0.02), but no association was found between the MYO9B gene and the L/M ratio in IBD patients.

CONCLUSION: MYO9B gene polymorphisms may influence the sub-phenotypic expression of CD in China. No association between these MYO9B polymorphisms and intestinal permeability in IBD patients was found.

T300A GENETIC POLYMORPHISM: a susceptibility factor for Crohn’s disease?

ContextCrohn’s disease is characterized by a chronic and debilitating inflammatory disorder of the gastrointestinal tract. Several factors may contribute to its development. From extensive studies of the human genome, the polymorphism T300A of the gene ATG16L1 (autophagy-related 16-like 1) has been related to increased risk of developing this disease.ObjectivesAnalyze the role of polymorphism T300A (rs2241880) in patients with Crohn’s disease.Methods238 samples from (control group) and 106 samples from patients with Crohn’s disease recruited at five Southern Brazilian reference centers were evaluated. The genotyping consisted of the amplification via Polymerase Chain Reaction of the genomic segment encompassing T300A, followed by Restriction Fragment Length Polymorphism analysis. The amplicons and fragments were separated by agarose gel electrophoresis and confirmed under ultraviolet light.ResultsThe genotype AG was more prevalent among patients and controls (50% vs 44.8%), followed by genotypes AA (26.4% vs 35.1%) and GG (23.6% vs 20.1%). The frequency of the allele G of the polymorphism T300A was higher in the group of patients with Crohn’s disease (48.6%) than in controls (42.4%), although not reaching statistical significance.ConclusionsIt was not possible to confirm the increased susceptibility on development of Crohn’s disease conferred by polymorphism T300A.

Anti-inflammatory effect of Helichrysum oligocephalum DC extract on acetic acid - Induced acute colitis in rats

Background:

Helichrysum oligocephalum DC. from Asteraceae family is an endemic plant growing wild in Iran. This study was carried out to investigate the effect of H. oligocephalum hydroalcoholic extract (HOHE) on ulcerative colitis (UC) induced by acetic acid (AA) in rats.

Materials and Methods:

Rats were grouped (n = 6) and fasted for 24 h before colitis induction. Treatments were started 2 h before the induction of colitis and continued for two consecutive days with different doses of HOHE (100, 200, and 400 mg/kg) orally (p.o.) and intraperitoneally (i.p.). The colon tissue was removed and tissue damages were scored after macroscopic and histopathologic assessments.

Results:

Among the examined doses of HOHE, 100 mg/kg was the most effective dose that reduced the extent of UC lesions and resulted in significant alleviation. Weight/length ratio as an index of tissue inflammation and extravasation was also diminished in the treatment group administered HOHE at a dose of 100 mg/kg, and the results showed correlation with macroscopic and histopathologic evaluations. These data suggest that HOHE (100 mg/kg) administered either p.o. or i.p. was effective in diminishing inflammation and ulcer indices in this murine model of acute colitis in a non–dose-related manner.

Conclusions:

H. oligocephalum could be considered as a suitable anticolitis alternative; however, further studies are needed to support this hypothesis for clinical setting.

Interleukin-33 and inflammatory bowel diseases: lessons from human studies

Interleukin- (IL-) 33 is a widely expressed cytokine present in different cell types, such as epithelial, mesenchymal, and inflammatory cells, supporting a predominant role in innate immunity. IL-33 can function as a proinflammatory cytokine inducing Th2 type of immune response being involved with the defense against parasitic infections of the gastrointestinal tract. In addition, it has been proposed that IL-33 can act as a signaling molecule alerting the immune system of danger or tissue damage. Recently, in the intestinal mucosa, overexpression of IL-33 has been reported in samples from patients with inflammatory bowel diseases (IBD). This review highlights the available data regarding IL-33 in human IBD and discusses emerging roles for IL-33 as a key modulator of intestinal inflammation.

Vitamin D and Crohn's disease in the adult patient: a review

Crohn's disease (CD) is characterized as a chronic immune-mediated inflammatory disorder of the gastrointestinal tract. Current consensus surrounding the cause of the disease suggests a complex interplay between genetic susceptibility, the intestinal microbiome and environmental factors, leading to the aberrant Th1 and Th17 immune cell mediated response. Vitamin D deficiency is common in CD patients, and long-standing deficiency has been associated with reduced bone mineral density (BMD). Accumulating evidence now suggests that in addition to maintaining skeletal integrity, vitamin D also plays an integral role in regulating the general immune response, a function employed via its genomic actions on the vitamin D receptor (VDR). The VDR is expressed in all immune cells and both directly and indirectly targeted by the bioactive form of vitamin D, 1,25-Dihydroxyvitamin D (1,25[OH]2D). Impaired regulation or deficiency of the vitamin has been linked to the promotion of self-reactive T cell development, loss of immune tolerance to self-structures, and experimental colitis in animal models, whereas the subsequent administration of the vitamin in these models resulted in the improvement of immune-mediated symptoms. In addition, low vitamin D has been associated with disease activity in CD patients, and supplementation appears to be beneficial in improving clinical scores and reducing inflammation. Therefore, the primary aims of this article were to review the molecular evidence supporting the immunoregulatory roles of vitamin D and its supplementation in the CD patient, based on existing literature. The physiological processes, accepted serum concentration values, and its well-recognized role in bone health were also summarized.

Smoking does influence disease behaviour and impacts the need for therapy in Crohn's disease in the biologic era

BACKGROUND

Recently, the notion that smoking may adversely affect Crohn's disease (CD) outcomes has been challenged by the suggestion that the widespread use of immunosuppressants and anti-TNF drugs might offset the adverse effects of tobacco.

AIM

To reassess the influence of tobacco smoking on disease phenotype and complications on a time-dependent analysis, taking into account the different therapeutic interventions.

METHODS

We designed a retrospective cohort study of 3224 patients with Crohn's disease. The data were collected from the Spanish national inflammatory bowel disease registry (ENEIDA), including information regarding demographics, clinical characteristics, disease complications, therapeutic interventions and smoking status. Patients were classified as nonsmokers, smokers and former smokers, according to their present and past smoking habits.

RESULTS

In the univariate analysis, smokers had more strictures (22.6% vs. 19.3%, P < 0.05) and less colonic involvement (7.2% vs. 10.9%, P < 0.05), and were more frequently under treatment with steroids (91.6% vs. 85.8%, P < 0.05), immunosuppressants (73.5% vs. 63.6% P < 0.05) or anti-TNF drugs (31.4% vs. 25.1%, P < 0.05) than nonsmokers. In the time-dependent multivariate analysis, smokers were found to have a significantly decreased survival free of stricturing disease (HR: 1.5, CI 95% 1.18-1.90) or perianal complications (HR: 1.50, CI 95% 1.01-1.46), and had a higher risk for requiring thiopurine therapy (HR: 1.20, CI 95% 1.05-1.30).

CONCLUSION

These results suggest that, despite the widespread use of immunosuppressants and anti-TNF drugs, smokers with Crohn's disease still have a more severe disease course, with increased therapeutic requirements when compared with nonsmokers.

Relationship between neutrophil gelatinase-associated lipocalin (NGAL) levels and inflammatory bowel disease type and activity

BACKGROUND AND AIM

Neutrophil gelatinase associated lipocalin (NGAL) is a recently identified molecule, which is bacteriostatic, has tissue destructive effects and is pro-inflammatory with chemoattractant molecule binding properties. Our aim was to investigate the relationship between serum NGAL levels and the type and level of disease activity of IBD.

METHODS

A total of 92 patients [43 with Crohn's disease (CD) and 49 with ulcerative colitis (UC)], and 30 age- and sex-matched healthy controls (HC) were included in this study. Serum NGAL levels were measured using ELISA.

RESULTS

Serum NGAL levels were elevated in the IBD group [median 171, range (57-312) ng/mL] compared to the HC group [107 (45-234) ng/mL] (p<0.0001) and were elevated in UC patients [188 (74-312) ng/mL] compared to CD patients [168 (57-279) ng/mL] (p=0.006). When NGAL levels were further analysed based on localization of the CD and UC, the levels in ulcerative pancolitis [233 (144-312) ng/mL] were significantly higher (p=0.004) than the left-sided colitis [156 (103-309) ng/mL]. Similarly, NGAL levels were significantly higher in colonic CD [207 (125-249) ng/mL] than ileal CD [114 (78-210) ng/mL], and also in ileocolonic CD [198 (57-279) ng/mL] than ileal CD (p=0.033). When CD and UC groups were further categorized as active and inactive according to clinical and endoscopic activity indices, serum NGAL concentrations did not differ between inquiescent versus active stages. When a cut-off level of 129 ng/mL was used to distinguish IBD from HC, a sensitivity of 76.1% and a specificity of 60.9% was reached.

CONCLUSIONS

The serum NGAL levels in the IBD group was significantly higher than the HC group. Serum NGAL levels were higher in more extensive colonic involvement.

Enhanced blood lymphocytes apoptosis in children with inflammatory bowel disease

The aim of this work was to measure peripheral lymphocyte apoptosis during IBD flare and remission. Subjects and Methods. Flow-cytometric assessment of apoptosis of peripheral blood lymphocytes (PBL) was assessed in 30 children with IBD (16 with ulcerative colitis and 14 with Crohn's disease) compared to 22, age and sex matched, healthy children. This was carried out during a flare, whether in newly diagnosed or relapsing patients, and after achievement of remission. Clinical findings, complete blood count, liver transaminases, and kidney functions were assessed. Results. Early apoptotic and late apoptotic/necrotic lymphocytes were significantly higher during IBD flare compared to controls (P ≤ 0.01 and <0.01, resp., in ulcerative colitis and P ≤ 0.01 and <0.01, resp., in Crohn's disease patients). Remission values were significantly decreased but did not come back to the control levels. Early apoptotic values were significantly related to joint involvement in IBD patients (P < 0.0001). Conclusions. We can speculate a systemic nature of IBD as evident by enhanced peripheral lymphocyte apoptosis. This is related, to a great extent, to the disease process as it is more deranged in flare than in remission. Relation of this derangement to extraintestinal manifestations needs a special attention.

Establishment of a novel extracorporeal bowel model to study luminal approaches to treat inflammatory bowel disease

We have established an extracorporeal bowel model system for the analysis of early events in inflammatory bowel disease (IBD) and therapeutic applications. This model consists of an intestinal segment that is cannulated and perfused in situ, allowing the investigation of cellular responses of apical mucosa cells on luminal applied substances. Short-term treatment with iodoacetamide mimicked experimental intestinal inflammation in IBD, as indicated by histological alterations such as hemorrhage, hyperemia and loss of regular crypt architecture, as well as enhanced expression of cytokines (e.g. IL-6, IL-10 and MCP-1) compared with control segments perfused with media. Perfusion of therapeutic agents (e.g. dexamethasone or Mutaflor) in the small intestine segment significantly reduced the features of early inflammation that are induced by iodoacetamide. Moreover, similar data were obtained for Resormin(®), a montmorillonite-illite mixed-layer mineral (smectite), indicating that smectites might be a newly identified therapeutic option for IBD. In summary, this model could provide novel insights into epithelial injury as well as genesis of IBD and, therefore, be useful in testing the therapeutic potential of compounds for IBD therapy.

Erythrocytes-mediated delivery of dexamethasone 21-phosphate in steroid-dependent ulcerative colitis: a randomized, double-blind Sham-controlled study

BACKGROUND

Efficacy of erythrocyte-mediated delivery of dexamethasone 21-phosphate in patients with steroid-dependent ulcerative colitis.

METHODS

Thirty-seven patients with steroid-dependent ulcerative colitis were randomized to infusions of dexamethasone 21-phosphate encapsulated into autologous erythrocytes (n = 19) or to sham infusions (n = 18). Each infusion was given monthly for 6 months. The primary endpoint was the proportion of patients able to discontinue oral corticosteroids during treatment while maintaining clinical remission or stable disease. Secondary endpoint was the proportion of patients with disappearance of steroid-related adverse events.

RESULTS

At each infusion, a mean of 9.8 ± 4.6 mg dexamethasone 21-phosphate was administered at each infusion, which allowed steady-state plasma levels of 8 ng/mL for the following 28 days. Thirteen patients in the dexamethasone 21-phosphate group and 4 sham-treated patients attained the primary outcome of the study, i.e., maintaining a stable condition despite oral steroids withdrawal (P = 0.008). In the remaining patients (6 and 15 in the 2 experimental groups, respectively), the treatment was prematurely withdrawn because of clinical deterioration while tapering oral steroids. At endoscopy, mucosal healing was ascertained in 4 patients and 1 patient of the 2 experimental groups, respectively (P = 0.339). At inclusion, 14 and 13 patients in the 2 experimental groups complained of steroid-related adverse events; at end of the treatment, events were still present in 5 and 13 patients, respectively (P = 0.008).

CONCLUSIONS

In patients with steroid-dependent ulcerative colitis, 6-month therapy with low dose of dexamethasone 21-phosphate allowed the withdrawal of oral steroids and the reversal of steroid-related adverse events in most patients while maintaining clinical remission (ClinicalTrials.gov number, NCT01171807).

Gut microbiota imbalance and chaperoning system malfunction are central to ulcerative colitis pathogenesis and can be counteracted with specifically designed probiotics: a working hypothesis

In this work, we propose that for further studies of the physiopathology and treatment for inflammatory bowel diseases, an integral view of the conditions, including the triad of microbiota-heat shock proteins (HSPs)-probiotics, ought to be considered. Microbiota is the complex microbial flora that resides in the gut, affecting not only gut functions but also the health status of the whole body. Alteration in the microbiota's composition has been implicated in a variety of pathological conditions (e.g., ulcerative colitis, UC), involving both gut and extra-intestinal tissues and organs. Some of these pathologies are also associated with an altered expression of HSPs (chaperones) and this is the reason why they may be considered chaperonopathies. Probiotics, which are live microorganisms able to restore the correct, healthy equilibrium of microbiota composition, can ameliorate symptoms in patients suffering from UC and modulate expression levels of HSPs. However, currently probiotic therapy follows ex-adiuvantibus criteria, i.e., treatments with beneficial effects but whose mechanism of action is unknown, which should be changed so the probiotics needed in each case are predetermined on the basis of the patient's microbiota. Consequently, efforts are necessary to develop diagnostic tools for elucidating levels and distribution of HSPs and the microbiota composition (microbiota fingerprint) of each subject and, thus, guide specific probiotic therapy, tailored to meet the needs of the patient. Microbiota fingerprinting ought to include molecular biology techniques for sequencing highly conserved DNA, e.g., genes encoding 16S RNA, for species identification and, in addition, quantification of each relevant microbe.

Natural products as a source of anti-inflammatory agents associated with inflammatory bowel disease

Accumulating epidemiological and clinical study indicates that inflammation is a significant risk factor to develop various human diseases such as inflammatory bowel disease (IBD), chronic asthma, rheumatoid arthritis, multiple sclerosis, and psoriasis. Suppressing inflammation is therefore important to control or prevent various diseases. Among them, IBD is one of the major problems affecting people worldwide. IBD affects at least one in a thousand persons in many Western countries. Various natural products have been shown to safely suppress pro-inflammatory pathway and control IBD. In vivo and/or in vitro studies indicate that anti-IBD effects of natural products occur by inhibition of the expression of pro-inflammatory cytokines (for example, tumor necrosis factor-α (TNF-α), intercellular adhesion molecule expression and pro-inflammatory mediators (such as inducible nitric oxide synthase (iNOS) and cyclooxygenase 2 (COX2), master transcription factors (such as nuclear factor-κB (NF-κB)), reactive oxygen species (ROS) and by improving the antioxidant activity. In this review, we summarize recent research focused on IBD and the effects that natural products have on IBD factors.

Pre- and posttherapy assessment of intestinal soluble mediators in IBD: where we stand and future perspectives

Inflammatory bowel disease (IBD) is a chronic inflammatory condition characterized by an abnormal immune response against food or bacterial antigens in genetically predisposed individuals. Several factors of innate and adaptive immune system take part in the inflammatory process, probably actively contributing in endoscopic and histological healing at molecular level. Although it is difficult to discriminate whether they are primary factors in determining these events or they are secondarily involved, it would be interesting to have a clear map of those factors in order to have a restricted number of potentially "good candidates" for mucosal healing. The present review will present a class of these factors and their modulation in course of therapy, starting from pathogenic studies involving several treatments associated with good clinical outcomes. This approach is meant to help in the difficult task of identifying "good candidates" for healing signatures, which could also be possible new therapeutic targets for clinical management of IBD patients.

High smoking cessation rate in Crohn's disease patients after physician advice--the TABACROHN Study

INTRODUCTION

Tobacco smoking has a significant impact on the development of Crohn's disease (CD) and its clinical course, making smoking cessation one of the main goals in CD therapeutic strategy.

AIMS

To evaluate the effectiveness of an advice-based smoking cessation strategy among CD patients.

METHODS

We have performed a prospective multicenter study which enrolled 408 CD smokers. At inclusion all patients were instructed about the risks of smoking and subsequently followed every 3 months. Each center used additional smoking cessation strategies based on available resources. Urinary cotinine and exhaled carbon monoxide levels were evaluated in a subgroup of patients.

RESULTS

Median study follow up was 18 months. 31% of the patients achieved complete smoking cessation and 23% were smoking-free at the end of their follow up with 8% of smoking relapse. Most patients not achieving smoking cessation did not change their smoking habit with only 5% presenting a decrease in tobacco load. 63% of patients willing to quit smoking received help from another specialist, most frequently the pulmonologist (47%). Surprisingly, most patients (88%) tried to quit smoking with no pharmacological therapy and bupropion, varenicline and nicotine replacement treatment were used in few patients. Urinary cotinine and exhaled CO levels tested in a subgroup of patients proved to have a good correlation with the self-reported smoking habit. No predictors of successful smoking cessation were identified.

CONCLUSION

Our results underline that an anti-tobacco strategy mostly based on CD patients's education and counseling is feasible and effective in helping patients reach complete abstinence.