Genes and environment: how will our concepts on the pathophysiology of IBD develop in the future?

Epidemiologic profile of inflammatory bowel disease in Eastern Mediterranean Region (EMRO) countries: a systematic review and meta-analysis

BACKGROUND

Inflammatory bowel disease (IBD) consists of two main types: Crohn's disease (CD) and ulcerative colitis (UC). The epidemiology of IBD patients has not been comprehensively studied in EMRO countries; therefore, we conducted this meta-analysis to study the epidemiology of this disease in these countries.

METHODS

We searched four international databases, namely Scopus, Web of Knowledge (ISI), Medline/PubMed, and ProQuest, from inception up to the end of May 2023. The Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guideline was used to carry out this systematic review and meta-analysis investigation. Using the Joanna Briggs Institute (JBI) Critical Appraisal Checklist, the quality of the selected papers was assessed.

RESULTS

Based on the results of this study, the incidence of UC in EMRO countries was 2.65 per 100,000 (95% CI: 1.39-3.90), and the incidence of CD was 1.16 per 100,000 (95% CI: 0.73-1.59). The most commonly involved intestinal segment in CD was the terminal ileum (44.7%, 95% CI: 34.7-55.2), followed by the ileum (29.8%, 95% CI: 22.2-38.6), and colon (18.7%, 95% CI: 10.8-30.4). However, in UC patients, extensive colitis was the most common finding (32.3%, 95% CI: 26.4-38.8), followed by proctosigmoiditis (27.9%, 95% CI: 21.1-35.8), left-sided colitis (27.4%, 95% CI: 22.7-32.7), and proctitis (22.6%, 95% CI: 17.5-28.5).

CONCLUSION

As a result, we were able to establish the traits of IBD patients in EMRO nations. UC patients had a higher incidence than CD patients. The most common regions of involvement in CD and UC patients, respectively, were the colon and pancolitis. Compared to UC patients, CD patients had a higher history of appendectomy.

A systematic review and meta-analysis of extra-intestinal manifestation of inflammatory bowel disease in the Eastern Mediterranean Region (EMRO) countries

Background

Inflammatory bowel disease which is subgrouped mainly to ulcerative colitis and Crohn's disease is thought to be a multi-organ disease. Most organs can be involved in the disease course in addition to gastrointestinal tract involvement. In this systematic review we aimed to assess the prevalence of these manifestations in Eastern Mediterranean Regional Office (EMRO) countries.

Method

The present systematic review and meta-analysis study was performed according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guideline. Joanna Briggs Institute (JBI) Critical Appraisal Checklist was admired for the quality evaluation of the included studies. For determining the heterogeneity, we used Cochran test and I2 statistics.

Result

Finally, 12 studies were included in our study. Based on the results of our study the prevalence of arthritis in ulcerative colitis and Crohn's disease patients was 7.1% (95% CI: 2.6-18.2%) and 13.5% (95% CI: 2.6-47.3%), respectively. Prevalence of arthralgia in ulcerative colitis patients was 18.4% (95% CI: 14.3-23.3%). skin involvement prevalence was 9.9% (95% CI 4.7-19.6%) in inflammatory bowel disease (IBD) patients. ocular involvement prevalence was 7.2% (95% CI 17-25.8%) in IBD patients. PSC prevalence in ulcerative colitis and Crohn's disease patients was 3.5% (95% CI: 1.7-7.3%) and 2.7% (95% CI: 1.3-5.5%), respectively.

Conclusion

Based on the results of this study arthralgia and arthritis were the most common extra-intestinal manifestation of IBD followed by dermatologic and ocular involvements. This extra-intestinal manifestation can challenge the patients' management and identifying their pattern is important during the disease course.

Inflammatory Bowel Disease and Breastfeeding: A Narrative Review

Inflammatory bowel disease (IBD) frequently affects women of childbearing age who may consider breastfeeding. Although breastfeeding has numerous benefits, there remain concerns regarding the safety of breastfeeding among women with IBD. Breastfeeding is important in developing the immune system of infants and has been shown to protect against the development of IBD. The risk of developing an increase in disease activity postpartum is the same regardless of breastfeeding status. Most IBD medications are also considered safe in breastfeeding and have no major risks to infants. Despite this, breastfeeding rates remain low among women with IBD, mostly due to concerns about the safety of IBD therapy with breastfeeding. Many women self-discontinue their IBD medications to breastfeed, and there is often uncertainty among health professionals to make recommendations about therapy. Dedicated IBD clinics can greatly support mothers during pregnancy and breastfeeding periods to enhance their knowledge, optimize their medication adherence, and improve their postpartum outcomes. This review aims to provide the most recent evidence-based literature regarding the safety of breastfeeding in women with IBD and the current recommendations about medical therapies with breastfeeding.

Despite Recovery from Necrotizing Enterocolitis Infants Retain a Hyperinflammatory Response to Injury

Background

Necrotizing enterocolitis (NEC) is the leading gastrointestinal cause of death of premature neonates. NEC is associated with prematurity, a hyperinflammatory response, and dysregulation of intestinal barrier function. We hypothesize that patients with NEC will have, and continue to have after recovery, an increased hyperinflammatory intestinal response compared to those patients without NEC.

Methods

Neonates with NEC, those that have recovered from NEC, and those without NEC undergoing intestinal resections had specimens collected and snap frozen or generated into enteroids. The enteroids were treated with 100ug/mL lipopolysaccharide (LPS) and subjected to 24 hr of hypoxia together, then compared with untreated controls. Expression of Tumor Necrosis Factor (TNF-α) and interleukin 8 (IL-8) were evaluated via RT-qPCR and ELISA to measure inflammatory response. ANOVA determined statistical significance (p<0.05).

Results

There was no difference in inflammatory markers in recovered NEC tissue compared to non-NEC tissue on RTqPCR (p=0.701 TNF-α and 0.861 IL-8). However, recovered NEC enteroids demonstrate elevated levels of inflammatory markers after treatment compared to non-NEC enteroids after treatment on RTqPCR (p=0.0485 TNF-α, p=0.0057 IL-8) and ELISA (p=0.0354 TNF-α, p=0.0011 IL-8). Recovered NEC enteroids that underwent treatment demonstrated increased inflammatory markers compared to recovered NEC enteroids without treatment on RTqPCR (p=0.0045 TNF-α, p=0.0002 IL-8) and ELISA (p=0.034 TNF-α, p=0.0002 IL-8) suggesting a heightened inflammatory response to a second hit.

Conclusion

Intestinal tissue resected from neonates with NEC has an elevated hyperinflammatory response compared to neonates recovered from NEC and neonates without NEC. Enteroids generated from patients that have recovered from NEC have a heightened inflammatory response in response to NEC inducing stimuli compared to controls. This tendency towards an increased hyperinflammatory state may be correlated with an infant's proclivity to develop NEC and demonstrates the significance of a second hit on this tissue creating a heightened inflammatory response. This could be correlated with the impact and trajectory of an illness post recovery from NEC.

The effect of selenium supplementation on disease activity and immune-inflammatory biomarkers in patients with mild-to-moderate ulcerative colitis: a randomized, double-blind, placebo-controlled clinical trial

PURPOSE

Selenium (Se) supplementation may help reduce inflammation and disease activity in ulcerative colitis (UC) patients. We investigated the therapeutic effects of Se administration in cases with mild-to-moderate active UC.

METHODS

A multicenter, double-blind, randomized clinical trial (RCT) was conducted on 100 cases with active mild-to-moderate UC. The patients were randomly allocated to be given an oral selenomethionine capsule (200 mcg/day, n = 50) or a placebo capsule (n = 50) for 10 weeks. The primary outcome was defined as disease activity via the Simple Clinical Colitis Activity Index (SCCAI), and secondary outcomes were measured at the end of the study.

RESULTS

After 10 weeks, the SCCAI score's mean was reduced in the Se group (P < 0.001). At the end of the intervention, clinical improvement (decline of 3 ≥ score from baseline score) was observed in 19 patients (38%) of the Se group and 3 patients (6%) of the placebo group. The patients with clinical remission (defined as SCCAI ≤ 2) were assigned in the Se group (P = 0.014). The Se group's quality of life and Se serum levels were enhanced at the end of the study (P < 0/001). In the Se group, the mean concentration of interleukin-17 decreased (P < 0/001). However, the levels of interleukin-10 showed no considerable change between the two groups in the 10th week (P = 0.23).

CONCLUSION

Se supplementation as add-on therapy with medical management induced remission and improved the quality of life in patients with active mild-to-moderate UC.

TRIAL REGISTRATION NUMBER AND DATE OF REGISTRATION

IRCT20091114002709N51; 2020-04-13.

Incidence of Inflammatory Bowel Disease in Urban China: A Nationwide Population-based Study

BACKGROUND & AIMS

Limited studies have evaluated the burden of inflammatory bowel disease (IBD) in China. We aimed to estimate the incidence of IBD including ulcerative colitis (UC) and Crohn's disease (CD) in urban China.

METHODS

The national urban incidence in 2016 was calculated based on urban basic medical insurance from 2012 to 2016 in China by using a 4-year washout period. The incidence in Yinzhou District estimated from the Yinzhou electronic health care record database was used to test the accuracy of the results from insurance data.

RESULTS

A total of 95,555 patients with IBD were identified. The incidence in 2016 was 10.04 (95% confidence interval, 6.95-13.71) per 100,000 person-years. The incidence rates of both UC and CD were higher among males than among females. There was a sharp increase in UC incidence before the age of 30 years and stabilization in later years (50-79 years old), whereas CD incidence peaked at 30 to 34 years old and experienced decline subsequently. The incidence of UC was much greater than that of CD, with a UC-to-CD incidence ratio of 12.61. The results from the Yinzhou database confirmed these results.

CONCLUSIONS

This study is the first to draw a portrait of the distribution of IBD in urban China. The difference in IBD incidence between urban China and other countries suggests an association between the IBD burden and industrialization process. The accelerating urbanization and industrialization process in China, a country with a population of 1.4 billion people, will likely increase the burden of IBD.

Prophylactic Coloprotective Effect of Urtica dioica Leaves against Dextran Sulfate Sodium (DSS)-Induced Ulcerative Colitis in Rats

Background and Objectives: Urtica dioica, a source of bioactive functional compounds, provides nutritional and gastrointestinal therapeutic benefits. This study attempted to investigate the prophylactic coloprotective action of an aqueous extract of Urtica dioica (AEUD) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). Materials and Methods: Phenolic compounds, total sugar, and mineral levels were determined in AEUD. Then, AEUD at different doses (50, 100, and 200 mg/kg, BW, p.o.) and mesalazine (MESA) as a standard treatment (100 mg/kg, BW, p.o.) were given orally for 21 days. Acute colitis was induced by administering drinking water with 5% (w/v) DSS for 7 days. Body weight variation, fecal occult blood, and stool consistency were determined daily. The severity of colitis was graded according to colon length, disease activity index (DAI), histological evaluations, and biochemical alterations. Rats orally administered DSS regularly developed clinical and macroscopic signs of colitis. Results: Due to its richness in phenolic and flavonoid compounds (247.65 ± 2.69 mg EAG/g MS and 34.08 ± 0.53 mg EQt/g MS, respectively), AEUD markedly ameliorated DAI, ulcer scores, colon length shortening, colonic histopathological changes, and hematological and biochemical modifications. Taken together, AEUD treatment notably (p < 0.01) suppressed DSS-induced UC by reducing oxidative stress via lowering MDA/H2O2 production and stimulating the effect of enzyme antioxidants as well as attenuating inflammation by decreasing CRP levels by 79.5% between the DSS and DSS + AEUD-50 groups compared to the MESA group (75.6%). Conclusions: AEUD was sufficient to exert a coloprotective effect that might be influenced by its bioactive compounds' anti-inflammatory and antioxidant capabilities.

Effect of ethyl gallate and propyl gallate on dextran sulfate sodium (DSS)-induced ulcerative colitis in C57BL/6 J mice: preventive and protective

OBJECTIVE AND DESIGN

Inflammatory bowel disease (IBD) is an idiopathic inflammatory condition of the digestive system marked by oxidative stress, leukocyte infiltration, and elevation of inflammatory mediators. In this study, we demonstrate the protective effect of ethyl gallate (EG), a phytochemical, and propyl gallate (PG), an anti-oxidant, given through normal drinking water (DW) and copper water (CW) in various combinations, which had a positive effect on the amelioration of DSS-induced ulcerative colitis in C57BL/6 J mice.

MATERIALS AND METHODS

We successfully determined the levels of proinflammatory cytokines and anti-oxidant enzymes by ELISA, tracked oxidative/nitrosative stress (RO/NS) by in vivo imaging (IVIS) using L-012 chemiluminescent probe, disease activity index (DAI), and histopathological and morphometric analysis of colon in DSS-induced colitis in a model.

RESULTS

The results revealed that oral administration of ethyl gallate and propyl gallate at a dose of 50 mg/kg considerably reduced the severity of colitis and improved both macroscopic and microscopic clinical symptoms. The level of proinflammatory cytokines (TNF-α, IL-6, IL-1β, and IFN-γ) in colonic tissue was considerably reduced in the DSS + EG-treated and DSS + PG-treated groups, compared to the DSS alone-treated group. IVIS imaging of animals from the DSS + EG and DSS + PG-treated groups showed a highly significant decrease in RO/NS species relative to the DSS control group, with the exception of the DSS + PG/CW and DSS + EG + PG/CW-treated groups. We also observed lower levels of myeloperoxidase (MPO), nitric oxide (NO), and lipid peroxidation (LPO), and restored levels of GST and superoxide dismutase (SOD) in DSS + EG-DW/CW, DSS + PG/DW, and DSS + EG + PG/DW groups compared to DSS alone-treated group. In addition, we showed that the EG, PG, and EG + PG treatment significantly reduced the DAI score, and counteracted the body weight loss and colon shortening in mice compared to DSS alone-treated group. In this 21-day study, mice were treated daily with test substances and were challenged to DSS from day-8 to 14.

CONCLUSION

Our study highlights the protective effect of ethyl gallate and propyl gallate in various combinations which, in pre-clinical animals, serve as an anti-inflammatory drug against the severe form of colitis, indicating its potential for the treatment of IBD in humans. In addition, propyl gallate was investigated for the first time in this study for its anti-colitogenic effect with normal drinking water and reduced effect with copper water.

Urokinase-type plasminogen activator blockade ameliorates experimental colitis in mice

Although several angiogenesis-related factors are reportedly involved in the pathogenesis of ulcerative colitis (UC), the mechanisms by which they contribute to disease are unclear. We first examined the expression of angiogenesis-related factors in inflamed colorectal tissue of UC patients using antibody array, and identified the 5 factors with highest expression, which included matrix metalloproteinase-8, urokinase-type plasminogen activator (uPA), angiostatin/plasminogen, hepatocyte growth factor and endoglin. Subsequent real-time PCR experiments using additional colorectal tissues revealed that uPA mRNA levels were significantly higher in inflamed tissues than in non-inflamed tissues, and significantly correlated with the severity of UC. Mirror section immunohistochemistry revealed that uPA was expressed in the neutrophils of inflamed colorectal tissues. We administered dextran sulfate sodium (DSS) in drinking water to uPA knockout (uPA^-/-) mice, and found that the disease activity index in uPA^-/- mice was marginally lower and the histological score in uPA^-/- mice was significantly lower than those in wild-type mice, suggesting the importance of uPA in colitis. When an uPA-selective inhibitor, UK122, was administered to DSS-treated C57BL6J mice, the disease activity index and histological score in those mice were significantly lower compared with control mice. Multiple cytokine/chemokine assay using colorectal tissues from uPA^-/- and UK122-treated mice revealed significantly lowered level of RANTES. In conclusion, uPA was highly expressed in neutrophils of the inflamed mucosa of UC patients, and the expression level correlated with the severity of UC. Genetic uPA deletion or pharmacological uPA blockade significantly ameliorated colitis in mice, concomitant with downregulation of RANTES.

Inflammatory Bowel Diseases and Gut Microbiota

Inflammatory bowel disease (IBD) is an inflammatory disease of the gastrointestinal tract, the incidence of which has rapidly increased worldwide, especially in developing and Western countries. Recent research has suggested that genetic factors, the environment, microbiota, and immune responses are involved in the pathogenesis; however, the underlying causes of IBD are unclear. Recently, gut microbiota dysbiosis, especially a decrease in the abundance and diversity of specific genera, has been suggested as a trigger for IBD-initiating events. Improving the gut microbiota and identifying the specific bacterial species in IBD are essential for understanding the pathogenesis and treatment of IBD and autoimmune diseases. Here, we review the different aspects of the role played by gut microbiota in the pathogenesis of IBD and provide a theoretical basis for modulating gut microbiota through probiotics, fecal microbiota transplantation, and microbial metabolites.

The Current State of Care for Black and Hispanic Inflammatory Bowel Disease Patients

Research on the care of inflammatory bowel disease (IBD) patients has been primarily in populations of European ancestry. However, the incidence of IBD, which comprises Crohn's disease and ulcerative colitis, is increasing in different populations around the world. In this comprehensive review, we examine the epidemiology, clinical presentations, disease phenotypes, treatment outcomes, social determinants of health, and genetic and environmental factors in the pathogenesis of IBD in Black and Hispanic patients in the United States. To improve health equity of underserved minorities with IBD, we identified the following priority areas: access to care, accurate assessment of treatment outcomes, incorporation of Black and Hispanic patients in therapeutic clinical trials, and investigation of environmental factors that lead to the increase in disease incidence.

Canine chronic enteropathy—Current state-of-the-art and emerging concepts

Over the last decade, chronic inflammatory enteropathies (CIE) in dogs have received great attention in the basic and clinical research arena. The 2010 ACVIM Consensus Statement, including guidelines for the diagnostic criteria for canine and feline CIE, was an important milestone to a more standardized approach to patients suspected of a CIE diagnosis. Great strides have been made since understanding the pathogenesis and classification of CIE in dogs, and novel diagnostic and treatment options have evolved. New concepts in the microbiome-host-interaction, metabolic pathways, crosstalk within the mucosal immune system, and extension to the gut-brain axis have emerged. Novel diagnostics have been developed, the clinical utility of which remains to be critically evaluated in the next coming years. New directions are also expected to lead to a larger spectrum of treatment options tailored to the individual patient. This review offers insights into emerging concepts and future directions proposed for further CIE research in dogs for the next decade to come.

Retroviral glycoprotein-mediated immune suppression via the potassium channel KCa3.1 - A new strategy for amelioration of inflammatory bowel diseases

Peptides derived from retroviral envelope proteins have been shown to possess a wide range of immunosuppressive and anti-inflammatory activities. We have previously reported identification of such a peptide derived from the envelope protein coded by a human endogenous retrovirus (HERV). In this study, we identified that in vitro the peptide inhibits the K_Ca3.1 potassium channel, a potential target for therapy of immune diseases. We describe in vitro ENV59-GP3 effects with respect to potency of inhibition on K_Ca3.1 channels and calcium influx. Furthermore, we asses in vivo the effect of blocking K_Ca3.1 with ENV59-GP3 peptide or K_Ca3.1-blocker NS6180 on protection against DSS-induced acute colitis. ENV59-GP3 peptide treatment showed reduction of the disease score in the DSS-induced acute colitis mice model, which was comparable to effects of the K_Ca3.1 channel blocker NS6180. Analysis of cytokine production from DSS-mice model treated animals revealed equipotent inhibitory effects of the ENV59-GP3 and NS6180 compounds on the production of IL-6, TNF-α, IL-1β. These findings altogether suggest that ENV59-GP3 functions as a K_Ca3.1 channel inhibitor and underline the implications of using virus derived channel blockers for treatment of autoimmune diseases. Additionally, they open the possibilities whether K_Ca3.1 inhibition is efficacious in patients with inflammatory bowel diseases.

Interleukin 10 and interleukin 10 receptor in paediatric inflammatory bowel disease: from bench to bedside lesson

Background

The differences between adults and children in inflammatory bowel disease (IBD) phenotype, severity, complications, co-morbidities, and response to the therapy resulted in the extraction of paediatric IBD. It has been revealed that the substantial role in the development of IBD in children under 6 years of age plays a single genetic mutation (monogenic IBD). On the other hand, in older children and adolescents IBD is usually associated with number of interactions between susceptibility loci (polygenic IBD).

Main body

Until now there have been described about 60 monogenic defects which affect the variety of immune mechanisms in IBD pathogenesis including epithelial barrier, function of neutrophil granulocytes and phagocytes, T- and B-cell selection and activation, immune inhibitory mechanisms, or apoptosis. Il-10 is an anti-inflammatory cytokine which modulates innate and adaptive immunity affecting expression of pro-inflammatory molecules and function of the variety of immune cells. Patients with identified defects in Il-10 pathway manifest with life-threating colitis with perianal lesions which occurs within first months of life. Allogenic hematopoietic stem cell transplantation is curative therapy in children with Il-10 signalling defects.

Conclusion

Clinical awareness of Il-10 signalling defects enables early recognition and prompt management of the disease.

FAM3D is essential for colon homeostasis and host defense against inflammation associated carcinogenesis

The physiological homeostasis of gut mucosal barrier is maintained by both genetic and environmental factors and its impairment leads to pathogenesis such as inflammatory bowel disease. A cytokine like molecule, FAM3D (mouse Fam3D), is highly expressed in mouse gastrointestinal tract. Here, we demonstrate that deficiency in Fam3D is associated with impaired integrity of colonic mucosa, increased epithelial hyper-proliferation, reduced anti-microbial peptide production and increased sensitivity to chemically induced colitis associated with high incidence of cancer. Pretreatment of Fam3D^−/− mice with antibiotics significantly reduces the severity of chemically induced colitis and wild type (WT) mice co-housed with Fam3D^−/− mice phenocopy Fam3D-deficiency showing increased sensitivity to colitis and skewed composition of fecal microbiota. An initial equilibrium of microbiota in cohoused WT and Fam3D^−/− mice is followed by an increasing divergence of the bacterial composition after separation. These results demonstrate the essential role of Fam3D in colon homeostasis, protection against inflammation associated cancer and normal microbiota composition.

The cytokine like protein FAM3D (Fam3D in mice) is highly expressed in the digestive tract with unknown role in colon pathophysiology. Here, by using gene deficient mice, the authors show that Fam3D is critically involved in colon homeostasis, host defense against colitis-associated carcinogenesis, and the balance of microbiota.

Prescription Opioids induce Gut Dysbiosis and Exacerbate Colitis in a Murine Model of Inflammatory Bowel Disease

BACKGROUND AND AIMS

Opioids are the most prescribed analgesics for pain in inflammatory bowel diseases [IBD]; however, the consequences of opioid use on IBD severity are not well defined. This is the first study investigating consequences of hydromorphone in both dextran sodium sulphate [DSS]-induced colitis and spontaneous colitis (IL-10 knockout [IL-10-/-]) mouse models of IBD.

METHODS

To determine the consequences of opioids on IBD pathogenesis, wild-type [WT] mice were treated with clinically relevant doses of hydromorphone and colitis was induced via 3% DSS in drinking water for 5 days. In parallel we also determined the consequences of opioids in a spontaneous colitis model.

RESULTS

Hydromorphone and DSS independently induced barrier dysfunction, bacterial translocation, disruption of tight junction organisation and increased intestinal and systemic inflammation, which were exacerbated in mice receiving hydromorphone in combination with DSS. Hydromorphone + DSS-treated mice exhibited significant microbial dysbiosis. Predictive metagenomic analysis of the gut microbiota revealed high abundance in the bacterial communities associated with virulence, antibiotic resistance, toxin production, and inflammatory properties. Hydromorphone modulates tight junction organisation in a myosin light chain kinase [MLCK]-dependent manner. Treatment with MLCK inhibitor ML-7 ameliorates the detrimental effects of hydromorphone on DSS-induced colitis and thus decreases severity of IBD. Similarly, we demonstrated that hydromorphone treatment in IL-10-/- mice resulted in accelerated clinical manifestations of colitis compared with control mice.

CONCLUSIONS

Opioids used for pain management in IBD accelerate IBD progression by dysregulation of the gut microbiota, leading to expansion of pathogenic bacteria, translocation of bacteria, immune deregulation and sustained inflammation.

Inhibitory effect of Bifidobacterium bifidum ATCC 29521 on colitis and its mechanism

Probiotics are known to be beneficial in preventing different diseases in model animals, including inflammatory bowel disease. However, there are few studies on probiotics related to miRNA regulation and disease status. In this article, the beneficial role and mechanisms of the probiotic strain Bifidobacterium bifidum ATCC 29521 have been studied in ulcerative colitis using dextran sodium sulphate (DSS) model. Male C57JBL/6 mice were randomly divided into three groups (n=7): Normal group, dextran sulphate sodium (DSS) group, and Bifido group gavage with Bifidobacterium bifidum ATCC 29521 (2×10⁸ CFU/day). Our strain restored the DSS-caused damage by regulating the expression of immune markers and tight junction proteins (TJP) in the colon; briefly by up-regulating ROS-scavenging enzymes (SOD1, SOD2, CAT, and GPX2), anti-inflammatory cytokines (IL-10, PPARγ, IL-6), TJP's (ZO-1, MUC-2, Claudin-3, and E Cadherin-1) and downregulating inflammatory genes (TNF-α, IL-1β) in Bifido group mice. Inflammatory markers appeared to be regulated by NF-κB nuclear P65 subunit, and its translocation was inhibited in Bifido group mice colon. In addition, the expression of inflammatory genes and colonic TJP were also associated with the restoration of miRNAs (miR-150, miR-155, miR-223) in B. bifidum ATCC 29521 treated Bifido group. The dysbiosis executed by DSS was restored in the Bifido group, demonstrating that B. bifidum ATCC 29521 possessed a probiotic role in our DSS colitis mouse model. B. bifidum ATCC 29521 exhibited its probiotic role through its anti-inflammatory role by modulating miRNA-associated TJP and NF-κB regulation and by partially restoring dysbiosis.

Serratane triterpenoids isolated from Lycopodium clavatum by bioactivity-guided fractionation attenuate the production of inflammatory mediators

Lycopodium clavatum has been used in traditional medicine for the treatment of kidney disorders, rheumatic arthritis, cystitis, and gastritis. We isolated a new serratane triterpenoid (2), and five known triterpenoids (1, 3-6) from the ethyl acetate fraction of L. clavatum by bioactivity-guided fractionation based on their suppression of inflammatory cytokines. Two different cell lines, RAW 264.7 and HT-29 were used to determine the anti-inflammatory activity of the isolated compounds. Among them, compounds 1, 2, 4, and 5 significantly inhibited the production of lipopolysaccharide (LPS)-induced NO in macrophages. Compounds 1, 2, 4, and 5 reduced inducible nitric oxide (iNOS) expression in RAW 264.7 cells and compounds 1 and 6 downregulated COX-2, which correlated with the reduced expression of PGE2. Compounds 1, 2, 4, and 5 downregulated pro-inflammatory cytokines, such as interleukin-1β (IL-1β) in macrophages, and additionally suppressed the levels of IL-8 in HT-29 cells. To determine the signaling pathways involved in the suppression of NO production by these compounds, we investigated ERK1/2 and nuclear factor-kappa B (NF-κB) expression by western blot analysis. We observed that these compounds downregulated the expression of LPS-induced NF-κB and pERK 1/2 in RAW 264.7 cells. Our results demonstrate that serratane triterpenoids isolated from L. clavatum may be used as potential candidates for treating inflammatory bowel disease (IBD) due to their anti-inflammatory effects.

Protective effect of galangin against dextran sulfate sodium (DSS)-induced ulcerative colitis in Balb/c mice

OBJECTIVE AND DESIGN

Inflammatory bowel disease (IBD) is known to cause chronic inflammation in the digestive tract by the immune malfunction. Herein, we demonstrate the protective effect of galangin (GAL), a phytochemical, on LPS-induced inflammation in cultured mouse macrophages (RAW 264.7) and the treatment of DSS-induced ulcerative colitis in Balb/c mice. However, the anti-inflammatory effect of GAL in DSS-exposed experimental colitis has not been investigated.

MATERIALS AND METHODS

We determined the levels of proinflammatory cytokines by ELISA, biochemical analysis using standard protocols and protein expression level of NF-κB signaling pathway and activation of Nrf2 gene pathway were analyzed by western blot analysis in colitis-induced mice.

RESULTS

Our in vitro studies showed that LPS-stimulated RAW 264.7 cells treated with GAL reduced the levels of nitrites, IL-6, and TNF-α in a concentration-dependent manner. The results demonstrated that oral administration of GAL at 20 mg/kg (lower dose) and 40 mg/kg (higher dose) significantly reduced the severity of colitis and mitigated the clinical signs of both macroscopic and microscopic of the disease. The levels of proinflammatory cytokines (TNF-α and IL-6) in colonic tissue and serum were reduced significantly and in GAL + DSS-treated group relative to DSS alone treated group.  Increased levels of anti-inflammatory cytokine (IL-10) was detected in colon tissues in GAL + DSS-treated groups relative to DSS alone treated group. We also observed decreased levels of myeloperoxidase (MPO), nitrites and TBARS with increased SOD in colonic tissue of GAL + DSS group. Besides, GAL + DSS-treated animals significantly suppressed protein expressions of p-NF-κB and p-Ikk-βα, COX-2, iNOS, Nrf2 and increased HO-1 levels in colon tissues by inhibiting inflammation and oxidative stress.

CONCLUSION

Our study highlights the protective effect of galangin as an anti-inflammatory agent against the severe form of colitis in pre-clinical models suggesting its potency for the treatment of IBD in humans.

High-Salt Diet Induces IL-17-Dependent Gut Inflammation and Exacerbates Colitis in Mice

Excess intake of sodium is often associated with high risk for cardiovascular disease. More recently, some studies on the effects of high-salt diets (HSDs) have also demonstrated that they are able to activate Th17 cells and increase severity of autoimmune diseases. The purpose of the present study was to evaluate the effects of a diet supplemented with NaCl in the colonic mucosa at steady state and during inflammation. We showed that consumption of HSD by mice triggered a gut inflammatory reaction associated with IL-23 production, recruitment of neutrophils, and increased frequency of the IL-17-producing type 3 innate lymphoid cells (ILC3) in the colon. Moreover, gut inflammation was not observed in IL-17–/– mice but it was present, although at lower grade, in RAG^−/− mice suggesting that the inflammatory effects of HSD was dependent on IL-17 but only partially on Th17 cells. Expression of SGK1, a kinase involved in sodium homeostasis, increased 90 min after ingestion of 50% NaCl solution and decreased 3 weeks after HSD consumption. Colitis induced by oral administration of either dextran sodium sulfate or 2,4,6-trinitrobenzenesulfonic acid was exacerbated by HSD consumption and this effect was associated with increased frequencies of RORγt⁺ CD4⁺ T cells and neutrophils in the colon. Therefore, our results demonstrated that consumption of HSD per se triggered a histologically detectable inflammation in the colon and also exacerbated chemically induced models of colitis in mice by a mechanism dependent on IL-17 production most likely by both ILC3 and Th17 cells.

Current smoking improves ulcerative colitis patients' disease behaviour in the northwest of China

Introduction

The incidence of ulcerative colitis has increased tremendously over the past few decades, and caused much more attention in China. Several studies have revealed that both environmental and genetic factors play crucial roles in the formation and development of this disease. Among the environmental factors, the smoking condition is highly significant. Although current smoking has been associated with a protective effect on both the development and progression of ulcerative colitis (UC), the clinical characteristics of UC patients with current smoking in China is still unclear.

Aim

To clarify the relationship between current smoking and the UC in the northwest of China, patients diagnosed with ulcerative colitis in the General Hospital of Ningxia Medical University from 2003.03 to 2012.09 were assessed.

Material and methods

Data were collected about clinical features, cigarette smoking conditions, disease location, and therapeutic requirements. A total of 421 patients were included in this study, at diagnosis, 341 (81%) patients were non-smokers, and the current smokers amounted to 80 (19%).

Results

As for disease location, there were no differences between the current smokers and non-smokers regarding proctitis and extensive colitis, but the current smokers had less left-sided colitis than non-smokers (p = 0.049). Based on the Modified Mayo score, heavier smokers had lower scores than other smokers and non-smokers. For the therapeutic requirements, current smokers needed fewer corticosteroids than non-smokers (p = 0.048).

Conclusions

We found that current smoking is closely associated with a protective factor for UC.

Visceral Inflammation and Immune Activation Stress the Brain

Stress refers to a dynamic process in which the homeostasis of an organism is challenged, the outcome depending on the type, severity, and duration of stressors involved, the stress responses triggered, and the stress resilience of the organism. Importantly, the relationship between stress and the immune system is bidirectional, as not only stressors have an impact on immune function, but alterations in immune function themselves can elicit stress responses. Such bidirectional interactions have been prominently identified to occur in the gastrointestinal tract in which there is a close cross-talk between the gut microbiota and the local immune system, governed by the permeability of the intestinal mucosa. External stressors disturb the homeostasis between microbiota and gut, these disturbances being signaled to the brain via multiple communication pathways constituting the gut-brain axis, ultimately eliciting stress responses and perturbations of brain function. In view of these relationships, the present article sets out to highlight some of the interactions between peripheral immune activation, especially in the visceral system, and brain function, behavior, and stress coping. These issues are exemplified by the way through which the intestinal microbiota as well as microbe-associated molecular patterns including lipopolysaccharide communicate with the immune system and brain, and the mechanisms whereby overt inflammation in the GI tract impacts on emotional-affective behavior, pain sensitivity, and stress coping. The interactions between the peripheral immune system and the brain take place along the gut-brain axis, the major communication pathways of which comprise microbial metabolites, gut hormones, immune mediators, and sensory neurons. Through these signaling systems, several transmitter and neuropeptide systems within the brain are altered under conditions of peripheral immune stress, enabling adaptive processes related to stress coping and resilience to take place. These aspects of the impact of immune stress on molecular and behavioral processes in the brain have a bearing on several disturbances of mental health and highlight novel opportunities of therapeutic intervention.

Differential intestinal anti-inflammatory effects of Lactobacillus fermentum and Lactobacillus salivarius in DSS mouse colitis: impact on microRNAs expression and microbiota composition

SCOPE

To compare the intestinal anti-inflammatory effects of two probiotics Lactobacillus fermentum and Lactobacillus salivarius in mouse colitis, focusing on their impact on selected miRNAs and microbiota composition.

METHODS AND RESULTS

Male C57BL/6J mice were randomly assigned to four groups (n = 10): non-colitic, DSS colitic and two colitic groups treated with probiotics (5 × 10⁸ CFU/mouse/day). Both probiotics ameliorated macroscopic colonic damage. They improved the colonic expression of markers involved in the immune response, and the expression of miR-155 and miR-223. L. fermentum also restored miR-150 and miR-143 expression, also linked to the preservation of the intestinal barrier function. Besides, these beneficial effects were associated with the amelioration of the microbiota dysbiosis and a recovery of the SCFAs- and lactic acid-producing bacterial populations, although only L. fermentum improved Chao richness, Pielou evenness and Shannon diversity. Moreover, L. fermentum also restored the Treg cell population in MLNs and the Th1/Th2 cytokine balance.

CONCLUSION

Both probiotics exerted intestinal anti-inflammatory effects in DSS-mouse colitis, maybe due to their ability to restore the intestinal microbiota homeostasis and modulate the immune response. L. fermentum showed a greater beneficial effect compared to L. salivarius, which makes it more interesting for future studies.

Genetic Diversity and Virulence Determinants of Escherichia coli Strains Isolated from Patients with Crohn's Disease in Spain and Chile

Adherent-invasive Escherichia coli (AIEC) strains are genetically variable and virulence factors for AIEC are non-specific. FimH is the most studied pathogenicity-related protein, and there have been few studies on other proteins, such as Serine Protease Autotransporters of Enterobacteriacea (SPATEs). The goal of this study is to characterize E. coli strains isolated from patients with Crohn's disease (CD) in Chile and Spain, and identify genetic differences between strains associated with virulence markers and clonality. We characterized virulence factors and genetic variability by pulse field electrophoresis (PFGE) in 50 E. coli strains isolated from Chilean and Spanish patients with CD, and also determined which of these strains presented an AIEC phenotype. Twenty-six E. coli strains from control patients were also included. PFGE patterns were heterogeneous and we also observed a highly diverse profile of virulence genes among all E. coli strains obtained from patients with CD, including those strains defined as AIEC. Two iron transporter genes chuA, and irp2, were detected in various combinations in 68–84% of CD strains. We found that the most significant individual E. coli genetic marker associated with CD E. coli strains was chuA. In addition, patho-adaptative fimH mutations were absent in some of the highly adherent and invasive strains. The fimH adhesin, the iron transporter irp2, and Class-2 SPATEs did not show a significant association with CD strains. The V27A fimH mutation was detected in the most CD strains. This study highlights the genetic variability of E. coli CD strains from two distinct geographic origins, most of them affiliated with the B2 or D E. coli phylogroups and also reveals that nearly 40% of Chilean and Spanish CD patients are colonized with E.coli with a characteristic AIEC phenotype.

Altered sympathovagal balance and pain hypersensitivity in TNBS-induced colitis

INTRODUCTION

Pain hypersensitivity, abnormal motility and autonomic dysfunction contribute to functional symptoms of inflammatory bowel disease (IBD).

MATERIAL AND METHODS

The aim of this study was to assess: nociceptive thresholds for mechanical allodynia (MA) and thermal hyperalgesia (TH), intestinal motility (distal colonic transit and emptying), and cardiac autonomic neuropathy (indices of heart rate variability - HRV) in male Wistar rats with experimental trinitrobenzene sulfonic acid (TNBS) induced colitis. To identify a potential vagal contribution the bilateral subdiaphragmatic vagotomy (SDV) was performed.

RESULTS

Experimental colitis resulted in a significant decrease in pain threshold (MA 23.60 ±2.12, p < 0.001, TH 8.51 ±1.49, p < 0.001), reduced expulsion time (6.2 ±3.5, p < 0,01) and increase in the sympathetic autonomic activity (LFnu 32.54 ±21.16, p < 0.03). The animals with diminished vagal integrity presented with reduced gastrointestinal motility (39.8 ±25.1, p < 0.01) and a decrease in the parasympathetic high-frequency domain of HRV (HFnu 55.37 ±22.80, p < 0.002). The vagotomized rats with colitis showed the strongest nociceptive response (MA 22.46 ±3.02, p < 0.004; TH 7.99 ±1.12, p < 0.003) as well as significant changes in sympatho-vagal balance on HRV testing (LFnu 28.25 ±14.66, p < 0.04; HFnu 71.34 ±14.55, p < 0.04).

CONCLUSIONS

The relationship between the cardiovascular and gastrointestinal system is modulated by neural, hormonal and inflammatory factors. This leads to dysregulation of the brain-gut interactions in the course of IBD. Sensitization and visceral-somatic convergence trigger pain hypersensitivity and autonomic sympathovagal imbalance. While integral vagal innervation impacts analgesic mechanisms via modulation of the immune response, SDV raises sympathetic activity and induces excessive hyperalgesia.

Recent Trends in Pharmacological Activity of Alkaloids in Animal Colitis: Potential Use for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic and disrupted inflammation of the gastrointestinal tract. IBD have two main conditions, Crohn's disease and ulcerative colitis, and have been extensively investigated in recent years. Antibiotics derived from salicylates, steroids, immunosuppressors, and anti-TNF therapy are part of the therapeutic arsenal for IBD. However, very often patients stop responding to treatments over the time. In this context, searching for alternative agents is crucial for IBD clinical management. Natural products derived from medicinal plants are an interesting therapeutic alternative, since several studies have proven effective treatments in animal models of intestinal inflammation. Several naturally occurring compounds are potent antioxidants, both as free radical scavengers and as modulators of antioxidant enzymes expression and activity. A number of natural compounds have also been proved to inhibit the release of proinflammatory cytokines, decreasing the activation of nuclear factor κB (NF-κB), which is important to the inflammatory response in IBD. The alkaloids are substances of a very diverse class of plant secondary metabolites; an extensive list of biological activities has been attributed to alkaloids, such as being anticholinergic, antitumor, diuretic, antiviral, antihypertensive, antiulcer, analgesic, and anti-inflammatory. In the present work, studies on the pharmacological activity of alkaloids in experimental models of IBD were reviewed.

The role of gut microbiota in health and disease: In vitro modeling of host-microbe interactions at the aerobe-anaerobe interphase of the human gut

The microbiota of the gut has many crucial functions in human health. Dysbiosis of the microbiota has been correlated to a large and still increasing number of diseases. Recent studies have mostly focused on analyzing the associations between disease and an aberrant microbiota composition. Functional studies using (in vitro) gut models are required to investigate the precise interactions that occur between specific bacteria (or bacterial mixtures) and gut epithelial cells. As most gut bacteria are obligate or facultative anaerobes, studying their effect on oxygen-requiring human gut epithelial cells is technically challenging. Still, several (anaerobic) bacterial-epithelial co-culture systems have recently been developed that mimic host-microbe interactions occurring in the human gut, including 1) the Transwell "apical anaerobic model of the intestinal epithelial barrier", 2) the Host-Microbiota Interaction (HMI) module, 3) the "Human oxygen-Bacteria anaerobic" (HoxBan) system, 4) the human gut-on-a-chip and 5) the HuMiX model. This review discusses the role of gut microbiota in health and disease and gives an overview of the characteristics and applications of these novel host-microbe co-culture systems.

Is Whole Exome Sequencing Clinically Practical in the Management of Pediatric Crohn's Disease?

Background/Aims

The aim of this study was to identify the profile of rare variants associated with Crohn’s disease (CD) using whole exome sequencing (WES) analysis of Korean children with CD and to evaluate whether genetic profiles could provide information during medical decision making.

Methods

DNA samples from 18 control individuals and 22 patients with infantile, very-early and early onset CD of severe phenotype were used for WES. Genes were filtered using panels of inflammatory bowel disease (IBD)-associated genes and genes of primary immunodeficiency (PID) and monogenic IBD.

Results

Eighty-one IBD-associated variants and 35 variants in PID genes were revealed by WES. The most frequently occurring variants were carried by nine (41%) and four (18.2%) CD probands and were ATG16L2 (rs11235604) and IL17REL (rs142430606), respectively. Twenty-four IBD-associated variants and 10 PID variants were predicted to be deleterious and were identified in the heterozygous state. However, their functions were unknown with the exception of a novel p.Q111X variant in XIAP (X chromosome) of a male proband.

Conclusions

The presence of many rare variants of unknown significance limits the clinical applicability of WES for individual CD patients. However, WES in children may be beneficial for distinguishing CD secondary to PID.

Dysbiosis of gut microbiota induced the disorder of helper T cells in influenza virus-infected mice

It is widely understood that commensal microbiota contributes to the maintenance of intestinal homeostasis through dynamic interactions with a body's immunity. And the immune regulation is important for the influenza vaccine's effectiveness after body injection, however, the mechanism between commensal microbiota and vaccine's effectiveness remains unknown. The impact that individual bacteria species have on the balance of the systemic immune system beyond the local intestinal mucosal tissues also remains less clear, and the related mechanism is still unknown. In this study, through the administration of various antibiotics, we examined the balance of helper T cell subsets in mice after inoculating them with the influenza virus and then, attempted to imitate the clinical practice in which patients are always prescribed with an antibiotic treatment in flu season. The data indicates that the mice in each group present differential immune responses in terms of the makeup of helper T cell subsets, although the Th17 cell activity seems to not be involved in the systemic immune modulation in the mice that are susceptible to the intervention of antibiotic. Th1, Th2, and anti-inflammatory regulatory T cells have been implicated in the contribution to the systemic immune response influenced by the antibiotic-induced dysbiosis. Thus we believe that the normal intestinal flora could maintain the immune balance and inhibit the inflammatory responses, which may be useful for clinical application to take intestinal flora into consideration when influenza vaccination was used.

Environment and Genes: What Is the Interaction?

Inflammatory bowel disease (IBD) results from a continuum of complex interactions between a quartet of host-derived and external elements that involve various aspects of the intestinal microbiota, the immune system that is centered around the intestinal epithelial cell barrier, the genetic composition of the host and specific environmental factors. Recent studies into the complexity of these arrangements increasingly support the syndromic nature of this disorder and involve a wide range of interacting biologic pathways that affect innate immunity, adaptive immunity, endoplasmic reticulum stress and autophagy as well as metabolic pathways associated with cellular homeostasis. It is further likely that all of the aforementioned host factors including the microbiota, which is as much a part of ourselves as is any organ system, are under the influence of yet-to-be-understood environmental factors that predispose to and precipitate IBD. Notwithstanding the importance of genetic predisposition, these environmental influences are no doubt central to disease pathogenesis in light of the rapid emergence of IBD throughout the world and assumption of disease in migrating populations from low to high risk environments. It can thus be anticipated that environmental factors that modify the risk for development of IBD have the common attribute of affecting the relationship between the commensal microbiota and the immune system in a manner that intersects with the functionally relevant immuno-genetic pathways, and potentially modifies them through epigenetic effects, in a manner that are uniquely operative within a particular syndromic context of IBD and occur sequentially and in a reiterative fashion, perhaps beginning in early life.

Molecular Alterations of Colorectal Cancer with Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an important etiologic factor in the development of colorectal cancer (CRC). The risk of CRC begins to increase 8 or 10 years after the diagnosis of IBD. This type of cancer is called colitis-associated CRC (CA-CRC). The molecular pathogenesis of inflammatory epithelium might play a critical role in the development of CA-CRC. Genetic alterations detected in CA-CRC such as genetic mutations, microsatellite instability, and DNA hypermethylation are also recognized in sporadic CRC; however, there are differences in the timing and frequency of molecular events between CA-CRC and sporadic CRC. Interaction between gene-environmental factors, including inflammation, lifestyle, psychological stress, and prior appendectomy, might be associated with the etiopathology of IBD. The mucosal inflammatory mediators, such as oxidant stress, free radicals, and chemokines, may cause the genetic alterations. Understanding the molecular mechanisms of CA-CRC might be important to develop clinical efficacies for patients with IBD. This review discusses the molecular characteristics of CA-CRC, especially ulcerative colitis-associated CRC, including clinical features, signaling pathways, and interactions between genetic alterations and environment involved in inflammatory carcinogenesis.

Vaccination and Risk for Developing Inflammatory Bowel Disease: A Meta-Analysis of Case-Control and Cohort Studies

BACKGROUND & AIMS

Environmental factors may play a key role in the pathogenesis of inflammatory bowel disease (IBD). Whether vaccination is associated causally with IBD is controversial. We performed a meta-analysis of case-control and cohort studies on the association between vaccination and the risk for IBD.

METHODS

Studies and abstracts investigating the relationship between vaccination and subsequent risk for developing IBD were reviewed. Childhood or adult immunizations with any vaccine type, at any dose, and with any vaccine schedule were used as inclusion criteria.

RESULTS

Eleven studies were included in the systematic review and meta-analysis: 8 case-control studies and 3 cohort studies. Studied vaccines were bacille Calmette-Guérin), vaccines against diphtheria, tetanus, smallpox, poliomyelitis, pertussis, H1N1, measles, rubella, mumps, and the combined measles, mumps, and rubella vaccine. Only a few details about vaccine type or route of administration were found in studies. Overall, there was no association between childhood immunization and risk for developing IBD: bacille Calmette-Guérin, relative risk (RR) of 1.04 (95% confidence interval [CI], 0.78-1.38), diphtheria, RR of 1.24 (95% CI, 0.80-1.94), tetanus, RR of 1.27 (95% CI, 0.77-2.08), smallpox, RR of 1.08 (95% CI, 0.70-1.67), poliomyelitis, RR of 1.79 (95% CI, 0.88-3.66), an measles containing vaccines, RR of 1.33 (95% CI, 0.31-5.80) in cohort studies, and RR of 0.85 (95% CI, 0.60-1.20) in case-control studies. Subgroup analysis for Crohn's disease (CD) and ulcerative colitis (UC) found an association between the poliomyelitis vaccine and risk for developing CD (RR, 2.28; 95% CI, 1.12-4.63) or UC (RR, 3.48; 95% CI, 1.2-9.71). The RR of developing IBD after H1N1 vaccination was 1.13 (95% CI, 0.97-1.32).

CONCLUSIONS

Results of this meta-analysis show no evidence supporting an association between childhood immunization or H1N1 vaccination in adults and risk of developing IBD. The association between the poliomyelitis vaccine and the risk for CD or UC should be analyzed with caution because of study heterogeneity.

Inverse expression of prostaglandin E2-related enzymes highlights differences between diverticulitis and inflammatory bowel disease

BACKGROUND

Prostaglandin E2 (PGE2) is the dominant prostaglandin in the colon and is associated with colonic inflammation. PGE2 levels are regulated not only by cyclooxygenases (COX-1 and COX-2) but also by 15-hydroxyprostaglandin dehydrogenase (15-PGDH), the major PGE2-degrading enzyme. Information about the involvement of 15-PGDH in colonic inflammation is sparse.

AIM

We thus aimed to determine the gene expression and immunoreactivity (IR) of COX-1, COX-2, and 15-PGDH in colonic mucosa from patients with diverse inflammatory disorders: ulcerative colitis (UC), Crohn's disease (CD), and acute diverticular disease (DD).

METHODS

RNA from human colonic mucosa was extracted and assessed for gene expression by real-time PCR. Intact colon sections were processed for immunohistochemistry with immunostaining of the mucosal areas quantified using ImageJ.

RESULTS

In colonic mucosa of both UC and CD, COX-2 mRNA and COX-2-IR were significantly increased, whereas 15-PGDH mRNA and 15-PGDH-IR were significantly reduced. In macroscopically undamaged acute DD mucosa, the opposite findings were seen: for both gene expression and immunoreactivity, there was a significant downregulation of COX-2 and upregulation of 15-PGDH. COX-1 mRNA and COX-1-IR remained unchanged in all diseases.

CONCLUSIONS

Our study for the first time demonstrated differential expression of the PGE2-related enzymes COX-2 and 15-PGDH in colonic mucosa from UC, CD, and acute DD. The reduction of 15-PGDH in IBD provides an additional mechanism for PGE2 increase in IBD. With respect to DD, alterations of PGE2-related enzymes suggest that a low PGE2 level may precede the onset of inflammation, thus providing new insight into the pathogenesis of DD.

Myeloid-derived suppressor cells in inflammatory bowel disease

Immature myeloid cells, also known as myeloid-derived suppressor cells (MDSCs), include neutrophilic and monocytic myeloid cells, and are found in inflammatory loci and secondary lymphoid organs in mice with intestinal inflammation, inflammatory bowel disease (IBD) patients, and tumor tissues. However, the roles of MDSCs in IBD are not yet well understood, and there are controversies regarding their immunosuppressive functions in IBD. In addition, recent studies have suggested that endoplasmic reticulum (ER) stress in intestinal epithelial cells, especially in Paneth cells, is closely associated with the induction of IBD. However, the ER stress in MDSCs accumulated in the inflamed tissues of IBD patients is not yet fully understood. In the current review, we discuss the presence of accumulated MDSCs in the intestines of IBD patients, and further speculate on their physiological roles in the inflammatory condition with interleukin 17-producing cells, including Th17 cells. In particular, we will discuss the divergent functions of MDSCs in ER stressed intestinal environments, including their pro-inflammatory or immunosuppressive roles, based on the consideration of unfolded protein responses initiated in intestinal epithelial cells by ER stress.

Gut microbiome, gut function, and probiotics: Implications for health

New insights from a rapidly developing field of research have ushered in a new era of understanding of the complexity of host-microbe interactions within the human body. The paradigm shift from culturing to metagenomics has provided an insight into the complex diversity of the microbial species that we harbor, revealing the fact that we are in fact more microbes than human cells. The largest consortium of these microbes resides in the gut and is called the gut microbiota. This new science has expanded the ability to document shifts in microbial populations to an unparalleled degree. It is now understood that signals from the microbiota provide trophic, nutritional, metabolic, and protective effects for the development and maintenance of the host digestive, immune, and neuroendocrine system. Evidence linking changes in the gut microbiota to gastrointestinal and extraintestinal disorders like irritable bowel syndrome, inflammatory bowel disease, obesity, diabetes, and celiac disease have begun to emerge recently. Probiotics act through diverse mechanisms positively affecting the composition and/or function of the commensal microbiota and alter host immunological responses. Well-controlled intervention trials, systematic reviews, and meta-analysis provide convincing evidence for the benefit of probiotics in prevention and treatment of gastrointestinal as well as extraintestinal disorders.

The genetics of Crohn's disease and ulcerative colitis--status quo and beyond

The two major subtypes of inflammatory bowel disease (IBD), ulcerative colitis (UC, MIM#191390) and Crohn's disease (CD, MIM#266600), are chronic relapsing-remitting inflammatory disorders affecting primarily the gastrointestinal tract. Prevalence rates in North America and Europe range from 21 to 246 per 100,000 for UC and 8 to 214 per 100,000 for CD. Although CD and UC share some clinical and pathological features, they can be distinguished by localization, endoscopic appearance, histology and behavior, which suggest differences in the underlying pathophysiology. The importance of genetic risk factors in disease etiology is high and has been documented more clearly for CD than for UC (relative sibling risks λ(s): 15-35 for CD, 6-9 for UC). The most recent and largest genetic association study for IBD, which employed genome-wide association data for over 75,000 patients and controls, established the association of 163 susceptibility loci with IBD. Although the disease variance explained by the 163 loci only amounts to 13.6% for CD and 7.5% for UC, the identified loci and the candidate genes within yielded valuable insights into the pathogenesis of IBD and the relevant disease pathways. We here review the current research on the genetics of IBD and provide insights into on current efforts as well as suggest topics for future research.

Mucosal healing in the era of biologic agents in treatment of inflammatory bowel disease

Mucosal healing has been a central issue in inflammatory bowel disease (IBD) for the last years, and has been proposed to be included as the new treatment goal in IBD. The molecular understanding of both the disruption and the healing of the intestinal epithelial cell lining and the mucosal barrier in IBD is complex and only partly understood. There is no general agreement on how to define healed mucosa, but there is a general acceptance that clinicians should use endoscopy and imaging technique in their assessments. Mucosal healing is an old concept that has been actualized in the present era of the highly effective biological agents. Randomized clinical studies with mucosal healing as end-point parameters have been reported, and early mucosal healing has been associated with low complication rates. We are waiting for documentation of whether treatment to healed mucosa can change the natural course of IBD. The concept of immunological remission has recently been introduced and can be the new treatment goal and one of several criteria for discontinuation of biological treatment in IBD. In conclusion, mucosal healing is a fairly novel concept and goal for biological treatment of IBD. There is a need for a standardization of its assessment and validation of the prognostic value.

Clinical value of serum eosinophilic cationic protein assessment in children with inflammatory bowel disease

INTRODUCTION

Eosinophils contribute to the pathogenesis of inflammatory bowel disease (IBD) in the intestine. Eosinophilic cationic protein (ECP) is one of the most important eosinophilic specific mediators released during activation. The aim of the study was to evaluate the clinical value of serum ECP determination in children with active and inactive IBD and its correlation with disease activity.

MATERIAL AND METHODS

There were 125 children with IBD (63 with Crohn's disease - CD, 44 with ulcerative colitis - UC, 18 indeterminate colitis - IC) enrolled in the study. Among them 83 children were in the active phase of the disease, while the remaining 42 were in remission. The control group consisted of 56 healthy children. The ECP was assessed three times in children with active IBD, at baseline and after 2 and 6 weeks of treatment and once in children with inactive IBD and controls using fluoroenzymeimmunoassays.

RESULTS

We found elevated ECP at baseline in the total active IBD group when compared to the inactive IBD and control groups, decreasing during treatment. Serum ECP was also elevated in the active UC and CD groups when compared to the inactive UC and CD groups, and correlated with clinical UC and CD activity (R = 0.57 and R = 0.52, p < 0.05, respectively) and duration of the clinical manifestation in UC (R = 0.62, p < 0.05) but not with the disease location in the gastrointestinal tract, or endoscopic and histopathological activity.

CONCLUSIONS

Evaluation of serum ECP in children with IBD may be useful in disease activity assessment at onset and during the treatment.

Understanding host-adherent-invasive Escherichia coli interaction in Crohn's disease: opening up new therapeutic strategies

A trillion of microorganisms colonize the mammalian intestine. Most of them have coevolved with the host in a symbiotic relationship and some of them have developed strategies to promote their replication in the presence of competing microbiota. Recent evidence suggests that perturbation of the microbial community favors the emergence of opportunistic pathogens, in particular adherent-invasive Escherichia coli (AIEC) that can increase incidence and severity of gut inflammation in the context of Crohn's disease (CD). This review will report the importance of AIEC as triggers of intestinal inflammation, focusing on their impact on epithelial barrier function and stimulation of mucosal inflammation. Beyond manipulation of immune response, restoration of gut microbiota as a new treatment option for CD patients will be discussed.

Inflammatory bowel disease in pediatric and adolescent patients: A biomolecular and histopathological review

Crohn’s disease (CD) and ulcerative colitis (UC) are the two main forms of inflammatory bowel disease (IBD) with both overlapping and distinct clinical, pathological and biomolecular features. It has been suggested that pediatric IBD is a distinct disease entity, with probably different disease subtypes.The aim of this study is to review and summarize the evolution of the current concept of pediatric IBD. The results of this review reinforce the idea that pediatric CD and UC may be further classified in various clinicopathologic entities. For clinicians and pathologists convenience, practical algorithms for the distinction of the various subphenotypes of pediatric IBD are also provided.

Aluminum enhances inflammation and decreases mucosal healing in experimental colitis in mice

The increasing incidence of inflammatory bowel diseases (IBDs) in developing countries has highlighted the critical role of environmental pollutants as causative factors in their pathophysiology. Despite its ubiquity and immune toxicity, the impact of aluminum in the gut is not known. This study aimed to evaluate the effects of environmentally relevant intoxication with aluminum in murine models of colitis and to explore the underlying mechanisms. Oral administration of aluminum worsened intestinal inflammation in mice with 2,4,6-trinitrobenzene sulfonic acid- and dextran sodium sulfate-induced colitis and chronic colitis in interleukin 10-negative (IL10(-/-)) mice. Aluminum increased the intensity and duration of macroscopic and histologic inflammation, colonic myeloperoxidase activity, inflammatory cytokines expression, and decreased the epithelial cell renewal compared with control animals. Under basal conditions, aluminum impaired intestinal barrier function. In vitro, aluminum induced granuloma formation and synergized with lipopolysaccharide to stimulate inflammatory cytokines expression by epithelial cells. Deleterious effects of aluminum on intestinal inflammation and mucosal repair strongly suggest that aluminum might be an environmental IBD risk factor.

Fecal microbial composition of ulcerative colitis and Crohn's disease patients in remission and subsequent exacerbation

Background

Limited studies have examined the intestinal microbiota composition in relation to changes in disease course of IBD over time. We aimed to study prospectively the fecal microbiota in IBD patients developing an exacerbation during follow-up.

Design

Fecal samples from 10 Crohn’s disease (CD) and 9 ulcerative colitis (UC) patients during remission and subsequent exacerbation were included. Active disease was determined by colonoscopy and/or fecal calprotectine levels. Exclusion criteria were pregnancy, antibiotic use, enema use and/or medication changes between consecutive samples. The microbial composition was assessed by 16S rDNA pyrosequencing.

Results

After quality control, 6,194–11,030 sequences per sample were available for analysis. Patient-specific shifts in bacterial composition and diversity were observed during exacerbation compared to remission, but overarching shifts within UC or CD were not observed. Changes in the bacterial community composition between remission and exacerbation as assessed by Bray-Curtis dissimilarity, were significantly larger in CD versus UC patients (0.59 vs. 0.42, respectively; p = 0.025). Thiopurine use was found to be a significant cause of clustering as shown by Principal Coordinate Analysis and was associated with decreases in bacterial richness (Choa1 501.2 vs. 847.6 in non-users; p<0.001) and diversity (Shannon index: 5.13 vs. 6.78, respectively; p<0.01).

Conclusion

Shifts in microbial composition in IBD patients with changing disease activity over time seem to be patient-specific, and are more pronounced in CD than in UC patients. Furthermore, thiopurine use was found to be associated with the microbial composition and diversity, and should be considered when studying the intestinal microbiota in relation to disease course.

NFIL3-deficient mice develop microbiota-dependent, IL-12/23-driven spontaneous colitis

NFIL3 is a transcription factor that regulates multiple immunologic functions. In myeloid cells, NFIL3 is IL-10 inducible and has a key role as a repressor of IL-12p40 transcription. NFIL3 is a susceptibility gene for the human inflammatory bowel diseases. In this article, we describe spontaneous colitis in Nfil3(-/-) mice. Mice lacking both Nfil3 and Il10 had severe early-onset colitis, suggesting that NFIL3 and IL-10 independently regulate mucosal homeostasis. Lymphocytes were necessary for colitis, because Nfil3/Rag1 double-knockout mice were protected from disease. However, Nfil3/Rag1 double-knockout mice adoptively transferred with wild-type CD4(+) T cells developed severe colitis compared with Rag1(-/-) recipients, suggesting that colitis was linked to defects in innate immune cells. Colitis was abrogated in Nfil3/Il12b double-deficient mice, identifying Il12b dysregulation as a central pathogenic event. Finally, germ-free Nfil3(-/-) mice do not develop colonic inflammation. Thus, NFIL3 is a microbiota-dependent, IL-10-independent regulator of mucosal homeostasis via IL-12p40.

Inflammatory bowel disease: mechanisms, redox considerations, and therapeutic targets

Oxidative stress is thought to play a key role in the development of intestinal damage in inflammatory bowel disease (IBD), because of its primary involvement in intestinal cells' aberrant immune and inflammatory responses to dietary antigens and to the commensal bacteria. During the active disease phase, activated leukocytes generate not only a wide spectrum of pro-inflammatory cytokines, but also excess oxidative reactions, which markedly alter the redox equilibrium within the gut mucosa, and maintain inflammation by inducing redox-sensitive signaling pathways and transcription factors. Moreover, several inflammatory molecules generate further oxidation products, leading to a self-sustaining and auto-amplifying vicious circle, which eventually impairs the gut barrier. The current treatment of IBD consists of long-term conventional anti-inflammatory therapy and often leads to drug refractoriness or intolerance, limiting patients' quality of life. Immune modulators or anti-tumor necrosis factor α antibodies have recently been used, but all carry the risk of significant side effects and a poor treatment response. Recent developments in molecular medicine point to the possibility of treating the oxidative stress associated with IBD, by designing a proper supplementation of specific lipids to induce local production of anti-inflammatory derivatives, as well as by developing biological therapies that target selective molecules (i.e., nuclear factor-κB, NADPH oxidase, prohibitins, or inflammasomes) involved in redox signaling. The clinical significance of oxidative stress in IBD is now becoming clear, and may soon lead to important new therapeutic options to lessen intestinal damage in this disease.

Recent advances in inflammatory bowel disease: mucosal immune cells in intestinal inflammation

The intestine and its immune system have evolved to meet the extraordinary task of maintaining tolerance to the largest, most complex and diverse microbial commensal habitat, while meticulously attacking and containing even minute numbers of occasionally incoming pathogens. While our understanding is still far from complete, recent studies have provided exciting novel insights into the complex interplay of the many distinct intestinal immune cell types as well as the discovery of entirely new cell subsets. These studies have also revealed how proper development and function of the intestinal immune system is dependent on its specific microbiota, which appears to have evolutionarily co-evolved. Here we review key immune cells that maintain intestinal homeostasis and, conversely, describe how altered function and imbalances may lead to inflammatory bowel disease (IBD). We highlight the latest developments within this field, covering the major players in IBD including intestinal epithelial cells, macrophages, dendritic cells, adaptive immune cells, and the newly discovered innate lymphoid cells, which appear of characteristic importance for immune function at mucosal surfaces. We set these mucosal immune pathways in the functional context of IBD risk genes where such insight is available. Moreover, we frame our discussion of fundamental biological pathways that have been elucidated in model systems in the context of results from clinical trials in IBD that targeted key mediators secreted by these cells, as an attempt of 'functional' appraisal of these pathways in human disease.

Evolving concepts: how diet and the intestinal microbiome act as modulators of breast malignancy

The intestinal microbiome plays an important role in human physiology. Next-generation sequencing technologies, knockout and gnotobiotic mouse models, fecal transplant data and epidemiologic studies have accelerated our understanding of microbiome abnormalities seen in immune diseases and malignancies. Dysbiosis is the disturbed microbiome ecology secondary to external pressures such as host diseases, medications, diet and genetic conditions often leading to abnormalities of the host immune system. Specifically dysbiosis has been shown to lower circulating lymphocytes, and increase neutrophil to lymphocyte ratio, a finding which has been associated with a decreased survival in women with breast cancers. Dysbiosis also plays a role in the recycling of estrogens via the entero-hepatic circulation, increasing estrogenic potency in the host, which is another leading cause of breast malignancy. Non-modifiable factors such as age and genetic mutations disrupt the microbiome, but modifiable factors such as diet may also lead to profound disruptions as well. A better understanding of dietary factors and how they disrupt the microbiome may lead to beneficial nutritional interventions for breast cancer patients.