Immunopathology of inflammatory bowel disease

Specific T-Cell Subsets Can Predict the Efficacy of Anti-TNF Treatment in Inflammatory Bowel Diseases

The effect of TNF-blockers on T-lymphocyte subsets is largely unknown in inflammatory bowel diseases (IBDs). The aim of the present study was to analyze the prevalence of T-cell subtypes and their correlation to therapeutic response. Sixty-eight patients with Crohn’s disease (CD), 46 with ulcerative colitis (UC) were enrolled. (1) The clinical course was followed after the initiation of TNF-blockers (prospective study). (2) The immunophenotype was also compared between long-term anti-TNF treated-responders and non-responders (cross-sectional study). The results were compared with those of therapy-naïve patients with active disease and those in remission with non-biological immunosuppressive therapy, and with healthy controls. Fourteen subtypes of peripheral blood T cells were measured with flow cytometry. The prevalence of Th2 and Th17 cells, of HLA-DR- and CD69-positive CD4 and CD8 cells, was higher, whereas the percentage of CD45RA-positive CD4 and CD8 cells was lower in both IBDs than in controls. CD8CD69 cell frequency was lower in remission, and decreased during anti-TNF therapy in CD responders. CD8CD45RO memory cells had higher prevalence in UC non-responders than in those starting anti-TNF. CD4CD45RO percentage < 49.05 at the initiation of TNF-blockers was predictive of a subsequent therapeutic response in CD, and Th2 and Th17 prevalence correlated with the duration of remission on TNF-blockers in UC. This study provided a detailed description of the T-cell composition in IBDs. CD8CD69 prevalence may be an activity marker in CD, and CD4CD45RO, Th2 and Th17 levels could be predictive for a therapeutic response to anti-TNF.

Increased frequency of regulatory T cells in pediatric inflammatory bowel disease at diagnosis: a compensative role?

BACKGROUND

Regulatory T cells (Tregs) play a critical role in maintaining immune homeostasis. We investigated two main types of Tregs, the CD4+FOXP3+ and IL-10+ Tr1, in pediatric subjects with inflammatory bowel disease (IBD) both at diagnosis and after the clinical remission.

METHODS

Peripheral blood Tregs were analyzed in 16 children with Crohn's disease (CD), 19 with ulcerative colitis (UC), and 14 healthy controls (HC). Two cocktails of fluoresceinated antibodies were used to discriminate between CD4+FOXP3+ and Tr1.

RESULTS

We observed in both CD and UC groups a higher frequency of Tr1 at diagnosis compared to controls, which decreased at follow-up compared to diagnosis, in particular in UC. Similarly, in UC patients the percentage of CD4+FOXP3+ Tregs markedly decreased at follow-up compared to the same patients at diagnosis and compared to HC. The expression of CTLA-4 in CD4+FOXP3+ Tregs increased in both groups at clinical remission.

CONCLUSION

This study shows that IBD children present at diagnosis an increased frequency of circulating Tregs, probably as a compensative reaction to tissue inflammation. During the clinical remission, the Treg frequency diminishes, and concomitantly, their activation status increases. Notwithstanding, the high Treg density at diagnosis is not sufficient to counteract the inflammation in the childhood IBD.

First-in-human, randomized dose-escalation study of the safety, tolerability, pharmacokinetics, pharmacodynamics and immunogenicity of PF-06480605 in healthy subjects

AIMS

Human genetic, tissue expression, proteomics, transcriptomics and nonclinical studies implicate tumour necrosis factor α-like ligand 1A (TL1A) as a novel target in inflammatory bowel disease (IBD). PF-06480605, a fully human immunoglobulin G1 monoclonal antibody, targets TL1A. This first-in-human, Phase 1, dose-escalation study assessed safety, tolerability, pharmacokinetics, pharmacodynamics and immunogenicity of intravenous (IV) and subcutaneous (SC) PF-06480605 in healthy subjects (NCT01989143).

METHODS

Ninety-two subjects were randomized to single ascending doses (SAD), PF-06480605 1 mg, 3 mg, 10 mg, 30 mg, 100 mg, 300 mg, 600 mg or 800 mg IV, or multiple ascending doses (MAD), PF-06480605 3 × 500 mg IV, or 3 × 30 mg, 3 × 100 mg, or 3 × 300 mg SC every 2 weeks for three doses, or placebo. Safety, tolerability, pharmacokinetics, immunogenicity profiles and total TL1A, anti-drug antibody (ADA) and neutralizing antibody (NAb) levels were assessed at pre-determined times.

RESULTS

PF-06480605 SAD up to 800 mg IV and MAD up to 300 mg ×3 SC and 500 mg ×3 IV were well tolerated. Overall, there were 45 and 44 treatment-emergent adverse events in SAD and MAD cohorts, respectively, and no deaths or serious adverse events. PF-06480605 exposure generally increased dose-dependently. ADA and NAb levels did not impact safety, pharmacokinetics, or pharmacodynamics at higher doses. Target engagement was demonstrated through dose-dependent differences in serum total soluble TL1A concentrations for PF-06480605 vs placebo cohorts.

CONCLUSIONS

PF-06480605 was generally well tolerated, and binding of soluble TL1A was maintained throughout the dose interval, supporting further study of PF-06480605 in patients with IBD and other inflammatory conditions.

A new target for the treatment of inflammatory bowel disease: Interleukin-37

Interleukin (IL)-37 belongs to the IL-1 cytokine family. It has anti-inflammatory effects on numerous autoimmune diseases such as asthma, psoriasis, inflammatory bowel disease (IBD), systemic lupus erythematosus (SLE), multiple sclerosis (MS) and rheumatoid arthritis (RA). Mechanistically, IL-37 plays an anti-inflammatory role by regulating the expression of inflammatory factors in two ways: binding extracellular receptors IL-18R or transferring into the nucleus with Smad3. IBD is a kind of idiopathic intestinal inflammatory disease with unknown etiology and pathogenesis. Recent researches had proved that IL-37 is negatively involved in the pathogenesis and development of IBD. Among various inflammatory diseases, IL-37 has been shown to regulate inflammatory development by acting on various immune cells such as neutrophils, macrophages (Mϕ), dendritic cells (DCs), T cells and intestinal epithelial cells. This review summarizes the biological role of IL-37, and its immunoregulatory effects on the immune cells, especially anti-inflammatory function in both human and experimental models of IBD.

On-Treatment Decrease of Serum Interleukin-6 as a Predictor of Clinical Response to Biologic Therapy in Patients with Inflammatory Bowel Diseases

In patients with inflammatory bowel diseases (IBD) undergoing biologic therapy, biomarkers of treatment response are still scarce. This study aimed to evaluate whether serum zonulin, a biomarker of intestinal permeability; soluble CD163 (sCD163), a macrophage activation marker; and a panel of serum cytokines could predict the response to biologic treatment in patients with IBD. For this purpose, we prospectively enrolled 101 patients with IBD and 19 patients with irritable bowel syndrome (IBS) as a control group; 60 out of 101 patients underwent treatment with biologics. Zonulin, sCD163, and cytokines were measured at the baseline in all patients and after 10 weeks of treatment in the 60 patients who underwent biologic therapy. We observed that zonulin levels were higher in IBD patients with active disease compared to those in remission (p = 0.035), and that sCD163 values were higher in patients with IBD compared to those with IBS (p = 0.042), but no association with therapy response was observed for either biomarker. Conversely, interleukin (IL)-6, IL-8, IL-10, and tumor necrosis factor-alpha showed a significant reduction from baseline to week 10 of treatment, particularly in responder patients. By multivariate logistic regression analysis corrected for disease (Crohn’s disease or ulcerative colitis), type of biologic drug (Infliximab, Adalimumab, Vedolizumab, or Ustekinumab) and disease activity, the reduction in IL-6 values was associated with a clinical response at 12 months of biological therapy (odds ratio (OR) = 4.75, 95% confidence interval (CI) 1.25–18.02, p = 0.022). In conclusion, the measurement of serum IL-6 in biologics-treated IBD patients may allow for the prediction of response to treatment at 12 months of therapy and thus may help with tailoring personalized treatment strategies.

The Prophylactic Use of Bovine Colostrum in a Murine Model of TNBS-Induced Colitis

Simple Summary

Colostrum is the first milk secreted by the mammary glands, and it is very rich in bioactive components. Recently, the importance of bovine colostrum (BC) as a nutraceutical product has been emerging with regards to gastrointestinal diseases. One of the most widespread gastrointestinal disorders is the inflammatory bowel disease (IBD), a multifactorial chronic condition that has a powerful impact on the social life of millions of people. Because current therapy protocols neither ensure complete recovery from IBD nor are free of secondary side effects, the present study assessed the impact of a short-term prophylactic oral administration of BC in a murine model of TNBS-induced colitis. BC administration was both well tolerated and did not induce any pathological symptoms. It considerably modulated the response to inflammation through modifications of the TLR4 and cytokines gene expression profiles as well as that of the intestinal microbiota. Although further studies are needed to develop a precise therapeutic protocol of BC administration, it seems to have the potential to be used as a natural supplement in the treatment of IBD.

Abstract

This study investigated the effects of a short-term administration of bovine colostrum (BC) in a TNBS model of induced colitis. Colitis was induced by TNBS treatment after seven days of BC (BC group, n = 12) or saline (control group, n = 12) administration in mice. Clinical signs, histopathological characteristics, expression levels of Toll-like receptor 4 (TLR4), pro- and anti-inflammatory cytokines, and microbial composition were assessed. BC was well tolerated and did not induce any histological damage or clinical symptoms. After TNBS treatment, the BC group showed a reduction in body weight (BW) loss compared to Control (p < 0.05). Moreover, expression levels of TLR4 (p < 0.01), Interleukin-1β (IL-1β; p < 0.001), Interleukin-8 (IL-8; p < 0.001), and Interleukin-10 (IL-10; p < 0.001) were lower in mice administered with BC. Finally, Escherichia coli were higher (p < 0.05), while Enterococci (p < 0.001), Lactobacillus spp. (p < 0.001), and Bifidobacterium spp. (p < 0.05) were lower in Control than BC group. This study confirms that pre-treatment with BC modulates the expression of genes and the count of microbes involved in the etiopathogenesis of colitis.

Unexpected effect of probiotics by Lactococcus lactis subsp. lactis against colitis induced by dextran sulfate sodium in mice

Ulcerative colitis (UC) is a representative intestinal chronic inflammatory disease whose incidence is rapidly increasing worldwide. It was previously shown that some specific probiotics help to guard against UC. In this study, we analyzed the effect of Lactococcus lactis subsp. lactis JCM5805 (L. lactis), which has been put to practical use as a probiotic, on the pathogenesis of UC using a dextran sulfate sodium-induced colitis mouse model. Survival rate, length, and histopathological parameters of the colon were elucidated. Further, the concentrations of inflammatory cytokines in serum were measured. As a result, the oral administration of high-dose L. lactis showed significant decreases in survival rate and colon length. Histopathological analysis showed that a bleeding appearance was observed in the L. lactis group, and the histology scores in the L. lactis group were significantly higher than those in the normal saline group. Furthermore, the levels of interferon gamma, tumor necrosis factor alpha, and interleukin-6 were significantly elevated in the L. lactis group. These results support that high-dose administration of L. lactis deteriorates intestinal inflammation and suggest that the careful selection of probiotics strains and administration dose is important for improving colitis including UC.

Proteomic insights on the metabolism in inflammatory bowel disease

Inflammatory bowel diseases (IBD) are chronic and relapsing inflammatory conditions of the gut that include Crohn's disease and ulcerative colitis. The pathogenesis of IBD is not completely unraveled, IBD are multi-factorial diseases with reported alterations in the gut microbiota, activation of different immune cell types, changes in the vascular endothelium, and alterations in the tight junctions’ structure of the colonic epithelial cells. Proteomics represents a useful tool to enhance our biological understanding and to discover biomarkers in blood and intestinal specimens. It is expected to provide reproducible and quantitative data that can support clinical assessments and help clinicians in the diagnosis and treatment of IBD. Sometimes a differential diagnosis of Crohn's disease and ulcerative colitis and the prediction of treatment response can be deducted by finding meaningful biomarkers. Although some non-invasive biomarkers have been described, none can be considered as the “gold standard” for IBD diagnosis, disease activity and therapy outcome. For these reason new studies have proposed an “IBD signature”, which consists in a panel of biomarkers used to assess IBD. The above described approach characterizes “omics” and in this review we will focus on proteomics.

Measuring Vitamin D Status in Chronic Inflammatory Disorders: How does Chronic Inflammation Affect the Reliability of Vitamin D Metabolites in Patients with IBD?

Evidence gained from recent studies has generated increasing interest in the role of vitamin D in extraskeletal functions such as inflammation and immunoregulation. Although vitamin D deficiency has been implicated in the pathophysiology of inflammatory diseases including inflammatory bowel disease (IBD), evidence as to whether vitamin D supplementation may cure or prevent chronic disease is inconsistent. Since 25OH-vitamin D (25OHD) has been suggested to be an acute-phase protein, its utility as a vitamin D status marker is therefore questionable. In this study, possible interactions of vitamin D and inflammation were studied in 188 patients with IBD, with high-sensitivity C-reactive protein (hsCRP) levels ≥ 5 mg/dL and/or fecal calprotectin ≥ 250 µg/g defined as biochemical evidence of inflammatory activity. Levels of 25OHD and vitamin D-binding protein (VDBP) were determined by ELISA, and 1,25-dihydroxyvitamin D (1,25OHD) and dihydroxycholecalciferol (24,25OHD) by LC-MS/MS. Free and bioavailable vitamin D levels were calculated with the validated formula of Bikle. Serum 1,25OH2D and vitamin D binding protein (VDBP) levels were shown to differ between the inflammatory and noninflammatory groups: patients with inflammatory disease activity had significantly higher serum concentrations of 1,25OH2D (35.0 (16.4-67.3) vs. 18.5 (1.2-51.0) pg/mL, p < 0.001) and VDBP (351.2 (252.2-530.6) vs. 330.8 (183.5-560.3) mg/dL, p < 0.05) than patients without active inflammation. Serum 24,25OH2D levels were negatively correlated with erythrocyte sedimentation rate (ESR) (-0.155, p = 0.049) while concentrations of serum 1,25OH2D correlated positively with hsCRP (0.157, p = 0.036). Correlations with serum VDBP levels were found for ESR (0.150, p = 0.049), transferrin (0.160, p = 0.037) and hsCRP (0.261, p < 0.001). Levels of serum free and bioavailable 25OHD showed a negative correlation with ESR (-0.165, p = 0.031, -0.205, p < 0.001, respectively) and hsCRP (-0.164, p = 0.032, -0.208, p < 0.001 respectively), and a moderate negative correlation with fecal calprotectin (-0.377, p = 0.028, -0.409, p < 0.016, respectively). Serum total 25OHD concentration was the only vitamin D parameter found to have no specific correlation with any of the inflammatory markers. According to these results, the traditional parameter, total 25OHD, still appears to be the best marker of vitamin D status in patients with inflammatory bowel disease regardless of the presence of inflammation.

Microproteomics and Immunohistochemistry Reveal Differences in Aldo-Keto Reductase Family 1 Member C3 in Tissue Specimens of Ulcerative Colitis and Crohn's Disease

PURPOSE

Differential diagnosis of ulcerative colitis (UC) and Crohn's disease (CD) is of utmost importance for the decision making of respective therapeutic treatment strategies but in about 10-15% of cases, a clinical and histopathological assessment does not lead to a definite diagnosis. The aim of the study is to characterize proteomic differences between UC and CD.

EXPERIMENTAL DESIGN

Microproteomics is performed on formalin-fixed paraffin-embedded colonic tissue specimens from 9 UC and 9 CD patients. Protein validation is performed using immunohistochemistry (IHC) (n_UC =51, n_CD =62, n_CTRL =10) followed by digital analysis.

RESULTS

Microproteomic analyses reveal eight proteins with higher abundance in CD compared to UC including proteins related to neutrophil activity and damage-associated molecular patterns. Moreover, one protein, Aldo-keto reductase family 1 member C3 (AKR1C3), is present in eight out of nine CD and absent in all UC samples. Digital IHC analysis reveal a higher percentage and an increased expression intensity of AKR1C3-positive epithelial cells in CD compared to UC and in controls compared to inflammatory bowel disease (IBD).

CONCLUSION AND CLINICAL RELEVANCE

Overall, the results suggest that microproteomics is an adequate tool to highlight protein patterns in IBD. IHC and digital pathology might support future differential diagnosis of UC and CD.

The Methyl-CpG-Binding Protein Mbd2 Regulates Susceptibility to Experimental Colitis via Control of CD11c+ Cells and Colonic Epithelium

Methyl-CpG-binding domain-2 (Mbd2) acts as an epigenetic regulator of gene expression, by linking DNA methylation to repressive chromatin structure. Although Mbd2 is widely expressed in gastrointestinal immune cells and is implicated in regulating intestinal cancer, anti-helminth responses and colonic inflammation, the Mbd2-expressing cell types that control these responses are incompletely defined. Indeed, epigenetic control of gene expression in cells that regulate intestinal immunity is generally poorly understood, even though such mechanisms may explain the inability of standard genetic approaches to pinpoint the causes of conditions like inflammatory bowel disease. In this study we demonstrate a vital role for Mbd2 in regulating murine colonic inflammation. Mbd2^−/− mice displayed dramatically worse pathology than wild type controls during dextran sulfate sodium (DSS) induced colitis, with increased inflammatory (IL-1β⁺) monocytes. Profiling of mRNA from innate immune and epithelial cell (EC) populations suggested that Mbd2 suppresses inflammation and pathology via control of innate-epithelial cell crosstalk and T cell recruitment. Consequently, restriction of Mbd2 deficiency to CD11c⁺ dendritic cells and macrophages, or to ECs, resulted in increased DSS colitis severity. Our identification of this dual role for Mbd2 in regulating the inflammatory capacity of both CD11c⁺ cells and ECs highlights how epigenetic control mechanisms may limit intestinal inflammatory responses.

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.

Indole-3-carbinol prevents colitis and associated microbial dysbiosis in an IL-22-dependent manner

Colitis, an inflammatory bowel disease, is caused by a variety of factors, but luminal microbiota are thought to play crucial roles in disease development and progression. Indole is produced by gut microbiota and is believed to protect the colon from inflammatory damage. In the current study, we investigated whether indole-3-carbinol (I3C), a naturally occurring plant product found in numerous cruciferous vegetables, can prevent colitis-associated microbial dysbiosis and attempted to identify the mechanisms. Treatment with I3C led to repressed colonic inflammation and prevention of microbial dysbiosis caused by colitis, increasing a subset of gram-positive bacteria known to produce butyrate. I3C was shown to increase production of butyrate, and when mice with colitis were treated with butyrate, there was reduced colonic inflammation accompanied by suppression of Th17 and induction of Tregs, protection of the mucus layer, and upregulation in Pparg expression. Additionally, IL-22 was increased only after I3C but not butyrate administration, and neutralization of IL-22 prevented the beneficial effects of I3C against colitis, as well as blocked I3C-mediated dysbiosis and butyrate induction. This study suggests that I3C attenuates colitis primarily through induction of IL-22, which leads to modulation of gut microbiota that promote antiinflammatory butyrate.

[Kirenol relieves dextran sulfate sodium-induced ulcerative colitis in mice by inhibiting inflammatory cytokines and inducing CD4+ T lymphocyte apoptosis]

OBJECTIVE

To investigate whether kirenol, the major pharmacologically active compound of the Chinese medicinal herb Herba Siegesbeckiae, can protect mice from dextran sulfate sodium (DSS)-induced ulcerative colitis (UC).

METHODS

C57BL/6 mice with or without kirenol pretreatment were treated with DSS in drinking water for 7 days to induce UC. The symptoms of UC including weight loss, diarrhea and bloody stool were observed daily and graded using the disease activity index (DAI). Colon injury of the mice was assessed by measuring the length of the colon and HE staining of the colon tissue. The levels of inflammatory cytokines produced by the mesenteric lymph nodes (MLNs) lymphocytes were measured using enzyme-linked immunosorbent assay; the apoptosis of the lymphocytes and CD4⁺ T cells was analyzed using flow cytometry.

RESULTS

The mice receiving pretreatment with kirenol showed obviously ameliorated symptoms of UC and milder pathological changes in the colon as compared with the control mice. Kirenol treatment significantly down-regulated the secretion of IFN-γ, IL-17A, IL-6 and TNF-α by the MLNs lymphocytes and increased the apoptosis of lymphocytes, especially CD4⁺ T cells in the DSS-treated mice.

CONCLUSIONS

Kirenol can protect against T cell-mediated colon injury in DSS-treated mice possibly by suppressing the secretion of inflammatory mediators and inducing apoptosis of the inflammatory lymphocytes.

FSGHF3 and peptides, prepared from fish skin gelatin, exert a protective effect on DSS-induced colitis via the Nrf2 pathway

Inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), is a chronic inflammatory disease affecting the colon, and its incidence is rising worldwide.

Neutralization of IL-1α ameliorates Crohn's disease-like ileitis by functional alterations of the gut microbiome

Crohn's disease and ulcerative colitis are chronic and progressive inflammatory bowel diseases (IBDs) that are attributed to dysregulated interactions between the gut microbiome and the intestinal mucosa-associated immune system. There are limited studies investigating the role of either IL-1α or IL-1β in mouse models of colitis, and no clinical trials blocking either IL-1 have yet to be performed. In the present study, we show that neutralization of IL-1α by a specific monoclonal antibody against murine IL-1α was highly effective in reducing inflammation and damage in SAMP mice, mice that spontaneously develop a Crohn's-like ileitis. Anti-mouse IL-1α significantly ameliorated the established, chronic ileitis and also protected mice from developing acute DSS-induced colitis. Both were associated with taxonomic divergence of the fecal gut microbiome, which was treatment-specific and not dependent on inflammation. Anti-IL-1α administration led to a decreased ratio of Proteobacteria to Bacteroidetes, decreased presence of Helicobacter species, and elevated representation of Mucispirillum schaedleri and Lactobacillus salivarius. Such modification in flora was functionally linked to the antiinflammatory effects of IL-1α neutralization, as blockade of IL-1α was not effective in germfree SAMP mice. Furthermore, preemptive dexamethasone treatment of DSS-challenged SAMP mice led to changes in flora composition without preventing the development of colitis. Thus, neutralization of IL-1α changes specific bacterial species of the intestinal microbiome, which is linked to its antiinflammatory effects. These functional findings may be of significant value for patients with IBD, who may benefit from targeted IL-1α-based therapies.

Mechanisms Underlying Bone Loss Associated with Gut Inflammation

Patients with gastrointestinal diseases frequently suffer from skeletal abnormality, characterized by reduced bone mineral density, increased fracture risk, and/or joint inflammation. This pathological process is characterized by altered immune cell activity and elevated inflammatory cytokines in the bone marrow microenvironment due to disrupted gut immune response. Gastrointestinal disease is recognized as an immune malfunction driven by multiple factors, including cytokines and signaling molecules. However, the mechanism by which intestinal inflammation magnified by gut-residing actors stimulates bone loss remains to be elucidated. In this article, we discuss the main risk factors potentially contributing to intestinal disease-associated bone loss, and summarize current animal models, illustrating gut-bone axis to bridge the gap between intestinal inflammation and skeletal disease.

Toxoplasma ROP16I/III ameliorated inflammatory bowel diseases via inducing M2 phenotype of macrophages

BACKGROUND

Inflammatory bowel disease (IBD) is characterized by chronic and non-specific inflammation of the intestinal mucosa and mainly includes ulcerative colitis and Crohn's disease.

AIM

To explore the beneficial effect of ToxoROP16_I/III-induced M2 phynotype macrophages in homeostasis of IBDs through downregulation of M1 inflammatory cells.

METHODS

RAW264.7 macrophages stimulated by lipopolysaccharide (LPS) (M1 cells) were co-cultured with Caco-2 cells as an inflammatory model of IBD in vitro. The expression of ToxoROP16_I/III was observed in RAW264.7 macrophages that were transfected with pEGFP-rop16_I/III. The phenotypes of M2 and M1 macrophage cells were assessed by quantitative real-time reverse transcriptase polymerase chain reaction and the expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, transforming growth factor (TGF)-β1, IL-10, inducible nitric oxide synthase (iNOS), and arginase-1 (Arg-1) was detected. The expression of iNOS, Arg-1, signal transducer and activator of transcription 3 (Stat3), p-Stat3, Stat6, p-Stat6, programmed death ligand-2 (PD-L2), caspase-3, -8, and -9 was analyzed by Western blotting, and Griess assays were performed to detect nitric oxide (NO). TNF-α, IL-1β, IL-6, TGF-β1, and IL-10 expression in the supernatants was detected by enzyme-linked immunosorbent assay, and Caco-2 cell apoptosis was determined by flow cytometry after mixing M1 cells with M2 cells in a Caco-2 cell co-culture system.

RESULTS

M1 cells exhibited significantly increased production of iNOS, NO, TNF-α, IL-1β, and IL-6, while ToxoROP16_I/III induced macrophage bias to M2 cells in vitro, showing increased expression of Arg-1, IL-10 and TGF-β1 and elevated production of p-Stat3 and p-Stat6. The mixed M1 and M2 cell culture induced by ToxoROP16_I/III exhibited decreased production of NO and iNOS and upregulated expression of Arg-1 and PD-L2. Accordingly, Caco-2 cells became apoptotic, and apoptosis-associated proteins such as caspase-3, -8 and -9 were dampened during co-culture of M1 and M2 cells. Flow cytometry analysis showed that co-culture of M1 cells with Caco-2 cells facilitated the apoptosis of Caco-2 cells, but co-culture of M1 and M2 cells alleviated Caco-2 cell apoptosis.

CONCLUSION

ToxoROP16_I/III-induced M2 macrophages inhibited apoptosis of Caco-2 cells caused by M1 macrophages. This finding may help gain a better understanding of the underlying mechanism and represent a promising therapeutic strategy for IBDs.

Healthy Eating Index-2015 as a predictor of ulcerative colitis risk in a case-control cohort

OBJECTIVE

There is compelling clinical evidence implicating certain dietary components in the development and clinical course of progression in ulcerative colitis (UC). This study aimed to assess whether any association exists between ulcerative colitis and scores on a healthy eating index.

METHODS

In this case-control study patients with UC were recruited and assessed together with healthy controls. The participants completed a validated 168-item food frequency questionnaire, the results of which were subsequently used to generate individual healthy eating index (HEI-2015) scores.

RESULTS

Altogether 58 patients with UC and 123 healthy controls were recruited. After controlling for confounding factors, participants who were in the highest quartile of the HEI-2015 had a 66% lower odds ratio (OR) of UC than the lowest quartile (OR = 0.34, 95% confidence interval 0.12-0.96).

CONCLUSION

HEI-2015 was associated with UC in this cohort. Further elucidation of the role of key dietary elements is now warranted.

Intestinal barrier damage involved in intestinal microflora changes in fluoride-induced mice

Intestinal microflora play an important role in maintaining the homeostasis of the intestinal microenvironment, but fluoride-induced changes in intestinal mechanical barrier and intestinal microflora have not been well studied. Given this paucity of information, this study aims to determine the effects of high fluoride level on intestinal mechanical barrier and intestinal microflora in the cecum of mice. Seventy-two female 21-day-old Kunming mice were randomly assigned to three groups and raised for 70 days. Changes in intestinal pathomorphology and intestinal epithelial cell proliferation were observed by haematoxylin and eosin-staining and Brdu measurement, respectively. The distribution of goblet cells, glycoproteins and mast cells was analysed through Alcian blue and periodic acid-Schiff (AB-PAS) staining, Periodic Acid-Schiff (PAS) staining, and toluidine blue staining. Results showed that excessive fluoride damaged the structure of the cecal tissues, inhibited epithelial cell proliferation and decreased the relative distribution of goblet cells, glycoproteins and mast cells that are involved in defense responses. Intestinal microflora sequencing analysis revealed that the composition of the diversity and composition of intestinal microflora was altered by excessive fluoride based on 16S rRNA amplicon sequencing. The relative abundance of Firmicutes (P = 0.03174), Bacteroidetes (P = 0.04462), Actinobacteria (P = 0.01085) and Spirochacteria (P = 0.04084) was significantly changed in the fluoride group as compared with the control group. In conclusion, excessive fluoride intake induced intestinal barrier damage, leading to changes in cecal composition, epithelium secretion and intestinal microflora.

Inflammatory bowel diseases: interrelationships between dietary vitamin D, exposure to UV radiation and the fecal microbiome

Introduction: Environmental factors and an altered fecal microbiome are believed to be central to the pathogenesis of inflammatory bowel diseases (IBD). Vitamin D and ultraviolet radiation (UVR) are environmental factors that are associated by several pathways, including changes to the gastrointestinal microbiome, with the development and course of IBD.Area covered: This review explores the interaction of vitamin D, and UVR, with the intestinal innate and adaptive immune systems, and how they may influence the gut microbiome and the subsequent development, and progression, of IBD.Expert opinion: Vitamin D and UVR both regulate innate and adaptive immunity through a combination of common and independent mechanisms, with the overall effect being the promotion of immune tolerance. Vitamin D, and to a lesser extent UVR, can modify the gastrointestinal microbiome either directly, or through immune-mediated mechanisms and this may explain the effect on intestinal inflammation in animal models of IBD and some clinical studies. Thus, both vitamin D and UVR exposure can be considered potential 'master regulators' of gastrointestinal immunity, fine-tuning the complex interaction between genetics, host immunity and the gut microbiome. Further research and increased understanding of environment-host interactions is essential to achieving the ultimate goal of preventing and curing IBD.

Echinochrome A Reduces Colitis in Mice and Induces In Vitro Generation of Regulatory Immune Cells

Echinochrome A (Ech A), a natural pigment extracted from sea urchins, is the active ingredient of a marine-derived pharmaceutical called ‘histochrome’. Since it exhibits several biological activities including anti-oxidative and anti-inflammatory effects, it has been applied to the management of cardiac injury and ocular degenerative disorders in Russia and its protective role has been studied for other pathologic conditions. In the present study, we sought to investigate the therapeutic potential of Ech A for inflammatory bowel disease (IBD) using a murine model of experimental colitis. We found that intravenous injection of Ech A significantly prevented body weight loss and subsequent lethality in colitis-induced mice. Interestingly, T cell proliferation was significantly inhibited upon Ech A treatment in vitro. During the helper T (Th) cell differentiation process, Ech A stimulated the generation regulatory T (Treg) cells that modulate the inflammatory response and immune homeostasis. Moreover, Ech A treatment suppressed the in vitro activation of pro-inflammatory M1 type macrophages, while inducing the production of M2 type macrophages that promote the resolution of inflammation and initiate tissue repair. Based on these results, we suggest that Ech A could provide a beneficial impact on IBD by correcting the imbalance in the intestinal immune system.

Microbiota: a novel regulator of pain

Among the various regulators of the nervous system, the gut microbiota has been recently described to have the potential to modulate neuronal cells activation. While bacteria-derived products can induce aversive responses and influence pain perception, recent work suggests that "abnormal" microbiota is associated with neurological diseases such as Alzheimer's, Parkinson's disease or autism spectrum disorder (ASD). Here we review how the gut microbiota modulates afferent sensory neurons function and pain, highlighting the role of the microbiota/gut/brain axis in the control of behaviors and neurological diseases. We outline the changes in gut microbiota, known as dysbiosis, and their influence on painful gastrointestinal disorders. Furthermore, both direct host/microbiota interaction that implicates activation of "pain-sensing" neurons by metabolites, or indirect communication via immune activation is discussed. Finally, treatment options targeting the gut microbiota, including pre- or probiotics, will be proposed. Further studies on microbiota/nervous system interaction should lead to the identification of novel microbial ligands and host receptor-targeted drugs, which could ultimately improve chronic pain management and well-being.

Increased abundance of proteobacteria in aggressive Crohn's disease seven years after diagnosis

Intestinal dysbiosis in inflammatory bowel disease (IBD) patients depend on disease activity. We aimed to characterize the microbiota after 7 years of follow-up in an unselected cohort of IBD patients according to disease activity and disease severity. Fifty eight Crohn’s disease (CD) and 82 ulcerative colitis (UC) patients were included. Disease activity was assessed by the Harvey-Bradshaw Index for CD and Simple Clinical Colitis Activity Index for UC. Microbiota diversity was assessed by 16S rDNA MiSeq sequencing. In UC patients with active disease and in CD patients with aggressive disease the richness (number of OTUs, p = 0.018 and p = 0.013, respectively) and diversity (Shannons index, p = 0.017 and p = 0.023, respectively) were significantly decreased. In the active UC group there was a significant decrease in abundance of the phylum Firmicutes (p = 0.018). The same was found in CD patients with aggressive disease (p = 0.05) while the abundance of Proteobacteria phylum showed a significant increase (p = 0.03) in CD patients. We found a change in the microbial abundance in UC patients with active disease and in CD patients with aggressive disease. These results suggest that dysbiosis of the gut in IBD patients is not only related to current activity but also to the course of the disease.

Effect of Tripterygium wilfordii Polycoride on the NOXs-ROS-NLRP3 Inflammasome Signaling Pathway in Mice with Ulcerative Colitis

Objective

To explore the effect of Tripterygium wilfordii polycoride (TWP) on the NADPH oxidases (NOXs)-reactive oxygen species (ROS)-NOD-like receptor protein 3 (NLRP3) inflammasome signaling pathway and the possibility of using TWP to treat ulcerative colitis (UC).

Methods

BALB/c mice were randomly divided into five groups: model control, low TWP, middle TWP, high TWP, and normal control groups. A UC model was established with dextran sulfate sodium. The determination of ROS was carried out by using the fluorescent probe DCFH-DA, and NOXs activity was detected based on the NADPH consumption rate. The mRNA expression levels of NLRP3, ASC, and caspase-1 in the colon tissues and neutrophils were assessed via real-time PCR.

Results

The colon tissues were abnormal with different degrees in TWP groups with disease activity index and histopathological scores lower than those in the model group. In TWP groups, ROS generation, NOXs activity, and the mRNA expression levels of NLRP3, ASC, and caspase-1 in the colon tissues and colon-isolated neutrophils were remarkably lower than those in the model control group (P < 0.05) and higher than those in the normal group (P < 0.05). The results of pairwise comparison for the efficacy of TWP administration showed that the above indexes were statistically significant with the lowest expression in the high TWP group (P < 0.05) and the highest expression in the low TWP group (P < 0.05).

Conclusion

TWP demonstrated anti-inflammatory effects on UC by decreasing the expression of proinflammatory factors in the NOXs-ROS-NLRP3 signaling pathway.

Omega-3 Polyunsaturated Fatty Acids and Their Bioactive Metabolites in Gastrointestinal Malignancies Related to Unresolved Inflammation. A Review

Chronic inflammation takes part in the pathogenesis of some malignancies of the gastrointestinal tract including colorectal (CRC), gastric, and esophageal cancers. The use of ω3 polyunsaturated fatty acid (ω3-PUFA) supplements for chemoprevention or adjuvant therapy of gastrointestinal cancers is being investigated in recent years. Most evidence has been reported in CRC, although their protective role has also been reported for Helicobacter pylori-induced gastric cancer or Barrett’s esophagus-derived adenocarcinoma. Studies based on ω3-PUFA supplementation in animal models of familial adenomatous polyposis (FAP) and CRC revealed positive effects on cancer prevention, reducing the number and size of tumors, down-regulating arachidonic acid-derived eicosanoids, upregulating anti-oxidant enzymes, and reducing lipid peroxidation, whereas contradictory results have been found in induced colitis and colitis-associated cancer. Beneficial effects have also been found in FAP and ulcerative colitis patients. Of special interest is their positive effect as adjuvants on radio- and chemo-sensitivity, specificity, and prevention of treatment complications. Some controversial results obtained in CRC might be justified by different dietary sources, extraction and preparation procedures of ω3-PUFAs, difficulties on filling out food questionnaires, daily dose and type of PUFAs, adenoma subtype, location of CRC, sex differences, and genetic factors. Studies using animal models of inflammatory bowel disease have confirmed that exogenous administration of active metabolites derived from PUFAs called pro-resolving mediators like lipoxin A4, arachidonic acid-derived, resolvins derived from eicosapentaenoic (EPA), docosahexaenoic (DHA), and docosapentaenoic (DPA) acids as well as maresin 1 and protectins DHA- and DPA-derived improve disease and inflammatory outcomes without causing immunosuppression or other side effects.

Novel functions of inactive rhomboid proteins in immunity and disease

iRhoms are related to a family of intramembrane serine proteinases called rhomboids but lack proteolytic activity. In mammals, there are two iRhoms, iRhom1 and iRhom2, which have similar domain structures and overlapping specificities as well as distinctive functions. These catalytically inactive rhomboids are essential regulators for the maturation and trafficking of the disintegrin metalloprotease ADAM17 from the endoplasmic reticulum to the cell surface, and are required for the cleavage and release of a variety of membrane-associated proteins, including the IL-6 receptor, l-selectin, TNF, and EGFR ligands. iRhom2-dependent regulation of ADAM17 function has been recently implicated in the development and progression of several autoimmune diseases including rheumatoid arthritis, lupus nephritis, as well as hemophilic arthropathy. In this review, we discuss our current understanding of iRhom biology, their implications in autoimmune pathologies, and their potential as therapeutic targets.

Neutrophil/lymphocyte ratio and lymphocyte/monocyte ratio in ulcerative colitis as non-invasive biomarkers of disease activity and severity

Background

Apart from endoscopic interventions, readily attainable cost-effective biomarkers for ulcerative colitis (UC) assessment are required. For this purpose, we evaluated differential leucocytic ratio, mainly neutrophil–lymphocyte ratio (NLR) and lymphocyte-monocyte ratio (LMR) as simple available indicators of disease activity in patients with ulcerative colitis.

Methods

Study conducted on 80 UC patients who were classified into two groups of 40 each according to Mayo score and colonoscopic findings. Group 1 (active UC) and group 2 (inactive UC). Another 40 group-matched healthy participants were enrolled. White blood cell count, NLR, LMR, C-reactive protein, and Erythrocyte sedimentation rate were measured and recorded.

Results

Significant elevation of NLR was observed in active UC group compared to inactive UC and controls (2.63 ± 0.43, 1.64 ± 0.25, 1.44 ± 0.19 respectively; p < 0.0001). The optimal NLR cut-off value for active UC was > 1.91, with a sensitivity and a specificity of 90% and 90% respectively. The mean LMRs of active UC was significantly lower compared with inactive UC patients and controls (2.25 ± 0.51, 3.58 ± 0.76, 3.64 ± 0.49 respectively; p < 0.0001). The cut-off value of LMR for determining the disease activity was ≤ 2.88 with a sensitivity of 90% and a specificity of 90%. NLR, LMR, and CRP were found to be significant independent markers for discriminating disease activity (p = 0.000). Besides, NLR was significantly higher in patients with pancolitis and positively correlated with endoscopically severe disease.

Conclusion

NLRs and LMRs are simple non-invasive affordable independent markers of disease activity in UC.

I_MDS: an inflammatory bowel disease molecular activity score to classify patients with differing disease-driving pathways and therapeutic response to anti-TNF treatment

Crohn’s disease and ulcerative colitis are driven by both common and distinct underlying mechanisms of pathobiology. Both diseases, exhibit heterogeneity underscored by the variable clinical responses to therapeutic interventions.

We aimed to identify disease-driving pathways and classify individuals into subpopulations that differ in their pathobiology and response to treatment.

We applied hierarchical clustering of enrichment scores derived from gene set variation analysis of signatures representative of various immunological processes and activated cell types, to a colonic biopsy dataset that included healthy volunteers, Crohn’s disease and ulcerative colitis patients. Patient stratification at baseline or after anti-TNF treatment in clinical responders and non-responders was queried. Signatures with significantly different enrichment scores were identified using a general linear model. Comparisons to healthy controls were made at baseline in all participants and then separately in responders and non-responders. Fifty-nine percent of the signatures were commonly enriched in both conditions at baseline, supporting the notion of a disease continuum within ulcerative colitis and Crohn’s disease. Signatures included T cells, macrophages, neutrophil activation and poly:IC signatures, representing acute inflammation and a complex mix of potential disease-driving biology. Collectively, identification of significantly enriched signatures allowed establishment of an inflammatory bowel disease molecular activity score which uses biopsy transcriptomics as a surrogate marker to accurately track disease severity. This score separated diseased from healthy samples, enabled discrimination of clinical responders and non-responders at baseline with 100% specificity and 78.8% sensitivity, and was validated in an independent data set that showed comparable classification. Comparing responders and non-responders separately at baseline to controls, 43% and 70% of signatures were enriched, respectively, suggesting greater molecular dysregulation in TNF non-responders at baseline. This methodological approach could facilitate better targeted design of clinical studies to test therapeutics, concentrating on patient subsets sharing similar underlying pathobiology, therefore increasing the likelihood of clinical response.

Patients exhibiting similar phenotypical characteristics, diagnosed with the same disease, exhibit variable response to therapeutics. This is a major health care issue, due to the increased patient suffering and the socioeconomical burden that occurs. Crohn’s disease and ulcerative colitis constitute good examples of inflammatory conditions, with sufferers responding differentially to existent therapeutics. Here, we identified disease-driving pathways and classified individuals into subpopulations that differ in their pathobiology and response to treatment. We utilized gene set variation analysis and transcriptomic data from inflammatory bowel disease sufferers to stratify patients at baseline or after anti-TNF treatment in clinical responders and non-responders. We explored gene signatures obtained from the literature, relevant to immune processes, which were significantly enriched in disease compared to healthy controls, as well as before and after treatment. Using these signatures, we established an inflammatory bowel disease molecular activity score, which allowed us to separate clinical responders and non-responders at baseline with high specificity and sensitivity. We validated the proposed approach in an independent data set, demonstrating comparable classification. This methodological approach may lead to better targeted design of clinical studies, allowing the selection of patient sharing similar underlying pathobiology, thus increasing the likelihood of clinical response to treatment.

ADP-ribosylation signalling and human disease

ADP-ribosylation (ADPr) is a reversible post-translational modification of proteins, which controls major cellular and biological processes, including DNA damage repair, cell proliferation and differentiation, metabolism, stress and immune responses. In order to maintain the cellular homeostasis, diverse ADP-ribosyl transferases and hydrolases are involved in the fine-tuning of ADPr systems. The control of ADPr network is vital, and dysregulation of enzymes involved in the regulation of ADPr signalling has been linked to a number of inherited and acquired human diseases, such as several neurological disorders and in cancer. Conversely, the therapeutic manipulation of ADPr has been shown to ameliorate several disorders in both human and animal models. These include cardiovascular, inflammatory, autoimmune and neurological disorders. Herein, we summarize the recent findings in the field of ADPr, which support the impact of this modification in human pathophysiology and highlight the curative potential of targeting ADPr for translational and molecular medicine.

Therapeutic effects of a single injection of human umbilical mesenchymal stem cells on acute and chronic colitis in mice

Multiple injections of bone marrow mesenchymal stem cells (BMMSCs) have been used for treatment of chronic colitis in mice. We aimed to report the therapeutic effects of a single injection of human umbilical cord mesenchymal stem cells (hUCMSCs) on acute and chronic colitis. Male C57BL/6JNarl mice were divided into control, phosphate-buffered saline (PBS), and hUCMSCs treated groups, respectively. Acute and chronic colitis were induced in the mice (except controls) using 3% dextran sulfate sodium (DSS). The mice in the hUCMSCs group underwent a single injection of hUCMSCs. The disease activity index (DAI), colon length, histology, colon inflammation score, in vivo stem cells images, and blood cytokine levels were recorded. The DAI was significantly higher in the hUCMSCs group than in the control group and lower than in the PBS group on all days. The colon length was significantly longer and the colon inflammation score was significantly lower in the hUCMSCs group than in the PBS group on days 8 and 25. IL17A, Gro-α, MIP-1α, MIP-2, and eotaxin were significantly lower in the hUCMSCs group than in the PBS group on days 8 and 25. Single-injection hUCMSCs improved DSS–induced acute colitis and decreased progression of acute colitis to chronic colitis.

Influence of Preoperative Oropharyngeal Microflora on the Occurrence of Postoperative Pneumonia and Survival in Patients Undergoing Esophagectomy for Esophageal Cancer

OBJECTIVE

The aim of this study was to clarify the correlation between oropharyngeal microflora and postoperative complications as well as long-term survival after esophagectomy.

BACKGROUND

Although the oral cavity is known to be a potential reservoir for pathogens, the influence of abnormal oropharyngeal microflora on the outcomes of patients undergoing esophagectomy remains unknown.

METHODS

This study included 675 patients who underwent esophagectomy between 2007 and 2014. Saliva samples from the oropharynx were collected 2 days before the operation. There were 442 patients with indigenous flora (Ind group) and 233 with allopatric flora. Among the patients with allopatric flora, 140 had antibiotic-sensitive microbes only (Allo-S group) while 93 had different types of antibiotic-resistant microbes (Allo-R group). We investigated the correlation between the types of oropharyngeal microflora and the incidence of postoperative complications as well as long-term outcomes.

RESULTS

Sixteen microbes could be cultivated from the saliva samples. The incidence of postoperative pneumonia in the Allo-S and Allo-R groups was significantly higher than in the Ind group (P < 0.001). In addition, acute respiratory distress syndrome was more often observed in the Allo-R group than in the other groups (P = 0.002). A significantly higher rate of antibiotic use and longer hospital stays were observed in the Allo-R group compared with the Ind group. Multivariate logistic regression analysis revealed that the presence of allopatric antibiotic-resistant microbes in the oropharynx was an independent risk factor for postoperative pneumonia (odds ratio, 3.93; 95% confidence interval, 2.41-6.42). The overall survival was significantly poorer in the Allo-R group than in the other groups.

CONCLUSIONS

Preoperative oropharyngeal culture is a simple and low-cost method that can predict both the occurrence of postoperative pneumonia and poor prognosis after esophagectomy.

The anti-inflammatory activity of peptides from simulated gastrointestinal digestion of preserved egg white in DSS-induced mouse colitis

Peptides DEDTQAMPFR (DR-10), MLGATSL (ML-7), SLSFASR (SR-7), and MSYSAGF (MF-7) derived from simulated gastrointestinal digestion of preserved egg white (SGD-PEW) exerted anti-inflammatory effects on Caco-2 cells. Here, we aimed to evaluate the anti-inflammatory effects of these peptides derived from SGD-PEW in a mouse model of dextran sodium sulfate (DSS)-induced colitis. The results showed that DR-10, ML-7, SR-7 and MF-7 significantly ameliorated the clinical symptoms of DSS-induced mice colitis, such as weight loss, disease activity index (DAI), colon shortening, spleen hypertrophy and histological scores. Treatment with DR-10, ML-7, SR-7 and MF-7 also significantly inhibited the local secretion of pro-inflammatory cytokines TNF-α and IL-6 and markedly decreased the gene expression of pro-inflammatory cytokines, including TNF-α, IL-6, IL-17, IL-1β, IFN-γ and MCP-1, in DSS-induced mice colitis. Overall, MF-7 showed the best effect of alleviating DSS-induced colitis among the four peptides. These results suggested that MF-7, DR-10, ML-7 and SR-7 may be a potential promising candidate for the treatment of inflammatory bowel disease (IBD).

Redefining the Practical Utility of Blood Transcriptome Biomarkers in Inflammatory Bowel Diseases

BACKGROUND AND AIMS

The study investigates the practical utility of whole-blood gene expression profiling to diagnose inflammatory bowel diseases [IBDs].

METHODS

The discovery cohorts included 102 and 51 paediatric IBD patients and controls, and 95 and 46 adult IBD patients and controls, respectively. The replication cohorts included 447 and 76 paediatric IBD patients and controls, and 271 and 108 adult IBD patients and controls, respectively. In the discovery phase, RNA samples extracted from whole peripheral blood were analysed using RNA-Seq, and the predictive values of selected biomarkers were validated using quantitative polymerase chain reaction [qPCR].

RESULTS

In all, 15 differentially expressed transcripts [adjusted p ≤0.05] were selected from the discovery sequencing datasets. The receiver operating characteristic curves and area under the curve [ROC-AUC] in replication analyses showed high discriminative power [AUC range, 0.91-0.98] for 11 mRNAs in paediatric patients with active IBD. By contrast, the AUC-ROC values ranged from 0.63 to 0.75 in comparison among inactive paediatric IBDs and active/inactive adult IBDs, indicating a lack of discriminative power. The best multi-mRNA diagnostic classifier showed moderate discriminative power [AUC = 0.81] for paediatric inactive IBD, but was not able to discriminate active or inactive adult IBD patients from controls. The AUC-ROC values did not confirm an ability of the mRNAs abundances to discriminate between active ulcerative colitis and active Crohn's disease in paediatric or adult populations.

CONCLUSIONS

This study identifies and validates blood transcriptional biomarkers that could be used in clinical settings as diagnostic predictors of IBD clinical activity in paediatric, but not adult, IBD patients.

Elemental Diet Regulates Intestinal Permeability and Antibody Production in Indomethacin-Induced Intestinal Injury Rats

Crohn's disease is a type of inflammatory bowel disease of unknown etiology. Administration of indomethacin (Indo) to rats induces acute mucosal lesions similar to those observed in Crohn's disease patients, but the damage can be prevented by feeding the animals an elemental diet (ED). In this study, we examined changes in intestinal macroscopic appearance, permeability, and immunoglobulin production after administration of Indo to male Sprague-Dawley rats fed normal lab chow or an ED. Intestinal damage was induced by subcutaneous injection of Indo on two successive days. Mucosal permeability, as measured by urinary excretion of phenolsulfonphthalein, peaked on day 2 after Indo injection, whereas the most severe intestinal damage, as scored by macroscopic inflammatory changes, was observed on day 3. Flow cytometric analysis of mesenteric lymph node cells revealed that the proportion of CD45RA⁺ cells was increased after Indo treatment. Furthermore, in vitro-cultured mesenteric lymph node and spleen lymphocytes from Indo-treated rats produced higher levels of IgA and IgG than did cells from vehicle-treated rats. In contrast, IgG and albumin concentrations in plasma were significantly decreased by Indo administration. Notably, none of the Indo-induced changes was observed in ED-fed rats. These findings suggest that an ED may prevent the appearance of Indo-induced mucosal lesions, at least in part, by modulating intestinal permeability and antibody production.

The Multifactorial Etiopathogeneses Interplay of Inflammatory Bowel Disease: An Overview

The gastrointestinal system where inflammatory bowel disease occurs is central to the immune system where the innate and the adaptive/acquired immune systems are balanced in interactions with gut microbes under homeostasis conditions. This article overviews the high-throughput research screening on multifactorial interplay between genetic risk factors, the intestinal microbiota, urbanization, modernization, Westernization, the environmental influences and immune responses in the etiopathogenesis of inflammatory bowel disease in humans. Inflammatory bowel disease is an expensive multifactorial debilitating disease that affects thousands new people annually worldwide with no known etiology or cure. The conservative therapeutics focus on the established pathology where the immune dysfunction and gut injury have already happened but do not preclude or delay the progression. Inflammatory bowel disease is evolving globally and has become a global emergence disease. It is largely known to be a disease in industrial-urbanized societies attributed to modernization and Westernized lifestyle associated with environmental factors to genetically susceptible individuals with determined failure to process certain commensal antigens. In the developing nations, increasing incidence and prevalence of inflammatory bowel disease (IBD) has been associated with rapid urbanization, modernization and Westernization of the population. In summary, there are identified multiple associations to host exposures potentiating the landscape risk hazards of inflammatory bowel disease trigger, that include: Western life-style and diet, host genetics, altered innate and/or acquired/adaptive host immune responses, early-life microbiota exposure, change in microbiome symbiotic relationship (dysbiosis/dysbacteriosis), pollution, changing hygiene status, socioeconomic status and several other environmental factors have long-standing effects/influence tolerance. The ongoing multipronged robotic studies on gut microbiota composition disparate patterns between the rural vs. urban locations may help elucidate and better understand the contribution of microbiome disciplines/ecology and evolutionary biology in potentially protecting against the development of inflammatory bowel disease.

Cellular and Molecular Therapeutic Targets in Inflammatory Bowel Disease-Focusing on Intestinal Barrier Function

The human gut relies on several cellular and molecular mechanisms to allow for an intact and dynamical intestinal barrier. Normally, only small amounts of luminal content pass the mucosa, however, if the control is broken it can lead to enhanced passage, which might damage the mucosa, leading to pathological conditions, such as inflammatory bowel disease (IBD). It is well established that genetic, environmental, and immunological factors all contribute in the pathogenesis of IBD, and a disturbed intestinal barrier function has become a hallmark of the disease. Genetical studies support the involvement of intestinal barrier as several susceptibility genes for IBD encode proteins with key functions in gut barrier and homeostasis. IBD patients are associated with loss in bacterial diversity and shifts in the microbiota, with a possible link to local inflammation. Furthermore, alterations of immune cells and several neuro-immune signaling pathways in the lamina propria have been demonstrated. An inappropriate immune activation might lead to mucosal inflammation, with elevated secretion of pro-inflammatory cytokines that can affect the epithelium and promote a leakier barrier. This review will focus on the main cells and molecular mechanisms in IBD and how these can be targeted in order to improve intestinal barrier function and reduce inflammation.

Application of Proteomics to Inflammatory Bowel Disease Research: Current Status and Future Perspectives

Inflammatory bowel disease (IBD) is a chronic relapsing/remitting inflammatory illness of the gastrointestinal tract of unknown aetiology. Despite recent advances in decoding the pathophysiology of IBD, many questions regarding disease pathogenesis remain. Genome-wide association studies (GWAS) and knockout mouse models have significantly advanced our understanding of genetic susceptibility loci and inflammatory pathways involved in IBD pathogenesis. Despite their important contribution to a better delineation of the disease process in IBD, these genetic findings have had little clinical impact to date. This is because the presence of a given gene mutation does not automatically correspond to changes in its expression or final metabolic or structural effect(s). Furthermore, the existence of these gene susceptibility loci in the normal population suggests other driving prerequisites for the disease manifestation. Proteins can be considered the main functional units as almost all intracellular physiological functions as well as intercellular interactions are dependent on them. Proteomics provides methods for the large-scale study of the proteins encoded by the genome of an organism or a cell, to directly investigate the proteins and pathways involved. Understanding the proteome composition and alterations yields insights into IBD pathogenesis as well as identifying potential biomarkers of disease activity, mucosal healing, and cancer progression. This review describes the state of the art in the field with respect to the study of IBD and the potential for translation from biomarker discovery to clinical application.

The role of serum calprotectin as a novel biomarker in inflammatory bowel diseases: a review study

As the incidence of inflammatory bowel diseases (IBD) increases in the newly industrialized countries, the health and financial burden of disease also increase. These changes make the role of IBD biomarkers further crucial. Serum calprotectin, as a novel blood-based biomarker of IBD, has been investigated in several investigations. Yet, there is no consensus regarding its clinical utility. We searched the electronic database, including PubMed, EMBASE, Scopus, and Web of Science up to the end of 2018 to find how serum calprotectin associates with the disease characteristics in IBD. The search terms included: inflammatory bowel diseases, IBD, Crohn Diseases (CD), Ulcerative Colitis (UC), calprotectin, serum, and blood. Based on our review, a biomarker role has been suggested for serum calprotectin in IBD, as significant associations were found between serum calprotectin and disease burden, prognosis, and relapse. A complementary role to fecal calprotectin has also been suggested for serum calprotectin. On the other hand, considering a significant correlation between serum calprotectin and serum CRP, but not fecal calprotectin, serum calprotectin could be more representative of systemic inflammation than an intestinal inflammation. Consequently, further researches are needed to unwrap the potential of serum calprotectin as a blood-based biomarker in IBD.

The Role of the CXCL12/CXCR4/ACKR3 Axis in Autoimmune Diseases

Chemokine receptors are members of the G protein-coupled receptor superfamily. These receptors are intimately involved in cell movement, and thus play a critical role in several physiological and pathological situations that require the precise regulation of cell positioning. CXCR4 is one of the most studied chemokine receptors and is involved in many functions beyond leukocyte recruitment. During embryogenesis, it plays essential roles in vascular development, hematopoiesis, cardiogenesis, and nervous system organization. It has been also implicated in tumor progression and autoimmune diseases and, together with CD4, is one of the co-receptors used by the HIV-1 virus to infect immune cells. In contrast to other chemokine receptors that are characterized by ligand promiscuity, CXCR4 has a unique ligand-stromal cell-derived factor-1 (SDF1, CXCL12). However, this ligand also binds ACKR3, an atypical chemokine receptor that modulates CXCR4 functions and is overexpressed in multiple cancer types. The CXCL12/CXCR4/ACKR3 axis constitutes a potential therapeutic target for a wide variety of inflammatory diseases, not only by interfering with cell migration but also by modulating immune responses. Thus far, only one antagonist directed against the ligand-binding site of CXCR4, AMD3100, has demonstrated clinical relevance. Here, we review the role of this ligand and its receptors in different autoimmune diseases.

Treatment with P28GST, a schistosome-derived enzyme, after acute colitis induction in mice: Decrease of intestinal inflammation associated with a down regulation of Th1/Th17 responses

Background

P28GST, a 28Kd glutathione S-transferase enzymatic protein derived from a schistosome helminth prevents experimental colitis when administered subcutaneously in the presence of adjuvant by decreasing pro-inflammatory Th1/Th17 response. Given the antioxidant properties of P28GST, we evaluated its anti-inflammatory potential when administered locally after colitis induction in the absence of adjuvant.

Methods

Colitis was induced in BALB/c mice by rectal administration of TNBS, followed by two intraperitoneal injections of P28GST at day 1 and day 2. Mice were sacrificed 48h after TNBS administration and evaluated for macroscopic and histological scores, myeloperoxidase (MPO) quantification and cytokine messenger RNA expression in the colonic tissues.

Results

Both clinical and histological scores significantly decreased in mice treated with P28GST at 5 or 50μg/kg when compared to vehicle- treated mice. A significant reduction of MPO was detected in colonic tissues from P28GST–treated mice, similarly to mice treated with methylprednisolone as the reference treatment. Pro-inflammatory cytokines TNF, IL-1β, and IL-6, mRNA as well as serum levels were down-regulated in mice colonic tissues treated with P28GST at 5 or 50μg/kg. In addition, a significant decrease of mRNA expression levels of T-bet, and ROR-γ, respective markers of Th1 and Th17 cells was observed. Whereas no significant effect was detected on Gata3 mRNA, a marker of Th2 cells, the Arg/iNOS mRNA levels significantly increased in P28GST-treated mice, suggesting the induction of M2 macrophages.

Conclusions

These findings provide evidence that P28GST injected locally after colitis induction induces a potent decrease of colitis inflammation in mice, associated to downregulation of Th1/Th17 response, and induction of anti-inflammatory alternatively activated macrophages.