Interleukin 8: cells of origin in inflammatory bowel disease

Mucus-coated, magnetically-propelled fecal surrogate to mimic fecal shear forces on colonic epithelium

The relationship between the mechanical forces associated with bowel movement and colonic mucosal physiology is understudied. This is partly due to the limited availability of physiologically relevant fecal models that can exert these mechanical stimuli in in vitro colon models in a simple-to-implement manner. In this report, we created a mucus-coated fecal surrogate that was magnetically propelled to produce a controllable sweeping mechanical stimulation on primary intestinal epithelial cell monolayers. The mucus layer was derived from purified porcine stomach mucins, which were first modified with reactive vinyl sulfone (VS) groups followed by reaction with a thiol crosslinker (PEG-4SH) via a Michael addition click reaction. Formation of mucus hydrogel network was achieved at the optimal mixing ratio at 2.5 % w/v mucin-VS and 0.5 % w/v PEG-4SH. The artificial mucus layer possessed similar properties as the native mucus in terms of its storage modulus (66 Pa) and barrier function (resistance to penetration by 1-μm microbeads). This soft, but mechanically resilient mucus layer was covalently linked to a stiff fecal hydrogel surrogate (based on agarose and magnetic particles, with a storage modulus of 4600 Pa). The covalent bonding between the mucus and agarose ensured its stability in the subsequent fecal sliding movement when tested at travel distances as long as 203 m. The mucus layer served as a lubricant and protected epithelial cells from the moving fecal surrogate over a 1 h time without cell damage. To demonstrate its utility, this mucus-coated fecal surrogate was used to mechanically stimulate a fully differentiated, in vitro primary colon epithelium, and the physiological stimulated response of mucin-2 (MUC2), interleukin-8 (IL-8) and serotonin (5HT) secretion was quantified. Compared with a static control, mechanical stimulation caused a significant increase in MUC2 secretion into luminal compartment (6.4 × ), a small but significant increase in IL-8 secretion (2.5 × and 3.5 × , at both luminal and basal compartments, respectively), and no detectable alteration in 5HT secretion. This mucus-coated fecal surrogate is expected to be useful in in vitro colon organ-on-chips and microphysiological systems to facilitate the investigation of feces-induced mechanical stimulation on intestinal physiology and pathology.

An in vitro model to study immune activation, epithelial disruption and stromal remodelling in inflammatory bowel disease and fistulising Crohn's disease

At present, preclinical models of inflammatory bowel disease (IBD) are insufficient, limiting translation between research and new therapeutics. This is especially true for fistulising Crohn's disease (CD), as the severe lack of relevant models hinders research progression. To address this, we present in vitro human IBD mucosal models that recapitulate multiple pathological hallmarks of IBD simultaneously in one model system - immune cell infiltration, stromal remodelling and epithelial disruption. Stimulation of models induces epithelial aberrations common in IBD tissue including altered morphology, microvilli abnormalities, claudin gene expression changes and increased permeability. Inflammatory biomarkers are also significantly increased including cytokines and chemokines integral to IBD pathogenesis. Evidence of extracellular matrix remodelling, including upregulated matrix-metalloproteinases and altered basement membrane components, suggests the models simulate pathological stromal remodelling events that closely resemble fistulising CD. Importantly, MMP-9 is the most abundant MMP and mimics the unique localisation observed in IBD tissue. The inflamed models were subsequently used to elucidate the involvement of TNF-α and IFN- γ in intestinal stromal remodelling, in which TNF-α but not IFN- γ induced MMP upregulation, specifically of MMP-3 and MMP-9. Collectively, our results demonstrate the potential of the IBD models for use in preclinical research in IBD, particularly for fistulising CD.

Gene expression profile of HCT-8 cells following single or co-infections with Cryptosporidium parvum and bovine coronavirus

Among the causative agents of neonatal diarrhoea in calves, two of the most prevalent are bovine coronavirus (BCoV) and the intracellular parasite Cryptosporidium parvum. Although several studies indicate that co-infections are associated with greater symptom severity, the host-pathogen interplay remains unresolved. Here, our main objective was to investigate the modulation of the transcriptome of HCT-8 cells during single and co-infections with BCoV and C. parvum. For this, HCT-8 cells were inoculated with (1) BCoV alone, (2) C. parvum alone, (3) BCoV and C. parvum simultaneously. After 24 and 72 h, cells were harvested and analyzed using high-throughput RNA sequencing. Following differential expression analysis, over 6000 differentially expressed genes (DEGs) were identified in virus-infected and co-exposed cells at 72 hpi, whereas only 52 DEGs were found in C. parvum-infected cells at the same time point. Pathway (KEGG) and gene ontology (GO) analysis showed that DEGs in the virus-infected and co-exposed cells were mostly associated with immune pathways (such as NF-κB, TNF-α or, IL-17), apoptosis and regulation of transcription, with a more limited effect exerted by C. parvum. Although the modulation observed in the co-infection was apparently dominated by the virus, over 800 DEGs were uniquely expressed in co-exposed cells at 72 hpi. Our findings provide insights on possible biomarkers associated with co-infection, which could be further explored using in vivo models.

Golden thistle (Scolymus hispanicus L.) hydromethanolic extracts ameliorated glucose absorption and inflammatory markers in vitro

Golden thistle (GT, Scolymus hispanicus L.) is an edible plant native to the Mediterranean. Several activities have been reported for the GT, as it is used for traditional medicinal purposes in some cultures. In this study, we aimed to investigate the effects of GT crude extract on phenolic bioavailability, antidiabetic, and anti-inflammatory activities by using colonic epithelium (CaCo-2) and murine macrophage (RAW 264.7) cell lines. The CaCo-2 cells were grown on the bicameral membrane system for intestinal bioavailability and glucose efflux. Lipopolysaccharide (LPS, 0.5 μg/mL) was used to induce systemic inflammation on RAW 264.7. The inflammatory medium of RAW 264.7 cells was given to Caco-2 cells to mimic colonic inflammation. Our results showed that 5-o-caffeoylquinic acid had an apparent permeability of (1.82 ± 0.07) × 10-6 cm/s after 6 h. The extract lowered the glucose efflux by 39.4%-42.6%, in addition to the reductions in relative GLUT2 mRNA expressions by 49%-66% in pre- and co-treatments (p < .05). Decreases in systemic inflammation markers of nitric oxide, tumor necrosis factor-alpha, and interleukin-6 (IL-6) were also detected in 30%-45% range after pre-treatments with the GT extract (p < .05). Lastly, colonic inflammation markers of IL-6 and IL-8 were reduced by 8.7%-19.5% as a result of GT pre-treatments (p < .05). Thus, an in vitro investigation of GT extract revealed promising results on antidiabetic and anti-inflammatory activities.

Interleukin-8 is superior to CRP for the prediction of severe complications in a prospective cohort of patients undergoing major liver resection

INTRODUCTION

Early detection of severe complications may reduce morbidity and mortality in patients undergoing hepatic resection. Therefore, we prospectively evaluated a panel of inflammatory blood markers for their value in predicting postoperative complications in patients undergoing liver surgery.

METHODS

A total of 139 patients undergoing liver resections (45 wedge resections, 49 minor resections, and 45 major resections) were prospectively enrolled between August 2017 and December 2018. Leukocytes, CRP, neutrophil-lymphocyte ratio (NLR), thrombocyte-lymphocyte ratio (TLR), bilirubin, INR, and interleukin-6 and -8 (IL-6 and IL-8) were measured in blood drawn preoperatively and on postoperative days 1, 4, and 7. IL-6 and IL-8 were measured using standardized immunoassays approved for in vitro diagnostic use in Germany. ROC curve analysis was used to determine predictive values for the occurrence of severe postoperative complications (CDC ≥ 3).

RESULTS

For wedge and minor resections, leukocyte counts at day 7 (AUC 0.80 and 0.82, respectively), IL-6 at day 7 (AUC 0.74 and 0.73, respectively), and CRP change (∆CRP) at day 7 (AUC 0.72 and 0.71, respectively) were significant predictors of severe postoperative complications. IL-8 failed in patients undergoing wedge resections, but was a significant predictor of severe complications after minor resections on day 7 (AUC 0.79), had the best predictive value in all patients on days 1, 4, and 7 (AUC 0.72, 0.72, and 0.80, respectively), and was the only marker with a significant predictive value in patients undergoing major liver resections (AUC on day 1: 0.70, day 4: 0.86, and day 7: 0.92). No other marker, especially not CRP, was predictive of severe complications after major liver surgery.

CONCLUSION

IL-8 is superior to CRP in predicting severe complications in patients undergoing major hepatic resection and should be evaluated as a biomarker for patients undergoing major liver surgery. This is the first paper demonstrating a feasible implementation of IL-8 analysis in a clinical setting.

Unlocking the potential of targeting histone-modifying enzymes for treating IBD and CRC

Dysregulation of histone modifications has been implicated in the pathogenesis of both inflammatory bowel disease (IBD) and colorectal cancer (CRC). These diseases are characterized by chronic inflammation, and alterations in histone modifications have been linked to their development and progression. Furthermore, the gut microbiota plays a crucial role in regulating immune responses and maintaining gut homeostasis, and it has been shown to exert effects on histone modifications and gene expression in host cells. Recent advances in our understanding of the roles of histone-modifying enzymes and their associated chromatin modifications in IBD and CRC have provided new insights into potential therapeutic interventions. In particular, inhibitors of histone-modifying enzymes have been explored in clinical trials as a possible therapeutic approach for these diseases. This review aims to explore these potential therapeutic interventions and analyze previous and ongoing clinical trials that examined the use of histone-modifying enzyme inhibitors for the treatment of IBD and CRC. This paper will contribute to the current body of knowledge by exploring the latest advances in the field and discussing the limitations of existing approaches. By providing a comprehensive analysis of the potential benefits of targeting histone-modifying enzymes for the treatment of IBD and CRC, this review will help to inform future research in this area and highlight the significance of understanding the functions of histone-modifying enzymes and their associated chromatin modifications in gastrointestinal disorders for the development of potential therapeutic interventions.

Myeloid lineage cells evince distinct steady-state level of certain gene groups in dependence on hereditary angioedema severity

Hereditary angioedema (HAE) is a rare genetic disorder with variable expressivity even in carriers of the same underlying genetic defect, suggesting other genetic and epigenetic factors participate in modifying HAE severity. Recent knowledge indicates the role of immune cells in several aspects of HAE pathogenesis, which makes monocytes and macrophages candidates to mediate these effects. Here we combined a search for HAE phenotype modifying gene variants with the characterization of selected genes' mRNA levels in monocyte and macrophages in a symptom-free period. While no such gene variant was found to be associated with a more severe or milder disease, patients revealed a higher number of dysregulated genes and their expression profile was significantly altered, which was typically manifested by changes in individual gene expression or by strengthened or weakened relations in mutually co-expressed gene groups, depending on HAE severity. SERPING1 showed decreased expression in HAE-C1INH patients, but this effect was significant only in patients carrying mutations supposedly activating nonsense-mediated decay. Pro-inflammatory CXC chemokine superfamily members CXCL8, 10 and 11 were downregulated, while other genes such as FCGR1A, or long non-coding RNA NEAT1 were upregulated in patients. Co-expression within some gene groups (such as an NF-kappaB function related group) was strengthened in patients with a severe and/or mild course compared to controls. All these findings show that transcript levels in myeloid cells achieve different activation or depression levels in HAE-C1INH patients than in healthy controls and/or based on disease severity and could participate in determining the HAE phenotype.

Iridoid derivatives from Vitex rotundifolia L. f. with their anti-inflammatory activity

Three undescribed iridoid glucosides and nine known compounds were isolated from Vitex rotundifolia L. f. Their structural elucidation was performed based on their spectroscopic data or acid hydrolysis followed by HPLC analysis and comparison of their NMR data with those reported in the literature. These iridoids were then evaluated for inflammatory effects through inhibition on NO production level in LPS-stimulated RAW264.7 cells. The active compounds, rotundifoliin C, isonishindacin A, agnuside, and eurostoside, were further investigated for their anti-inflammatory mechanisms of action on expression levels of iNOS and COX-2 proteins. In addition, V. rotundifolia fractions also significantly inhibited LPS-induced IL-8 production, with IC₅₀ values ranging from 9.81 to 54.31 μg/mL. Rotundifoliin A, agnuside, VR-I (10-O-vanilloyl aucubin), and eurostoside showed inhibition rates of 55.5%, 94.6%, 55.6%, and 81.9% on IL-8 production at concentrations of 100 μM, respectively, compared to those of control without sample addition. The therapeutic properties of the plant might give rise to develop the functional products to treat inflammatory diseases.

Assessment of Anti-inflammatory Efficacy of Acupuncture in Patients with Inflammatory Bowel Disease: A Systematic Review and Meta-analysis

BACKGROUND

Inflammation has a significant role in the onset and progression of inflammatory bowel disease (IBD). Increasing attention has been paid to the use of acupuncture in IBD patients; however, its regulatory effects on inflammatory factors in IBD still require validation. Here, we systematically evaluated the effects of acupuncture on inflammatory factors in IBD patients.

METHODS

Eight electronic databases were searched for studies that met the inclusion criteria. After evaluating the quality of the studies selected by two reviewers, the meta-analysis was performed to assess the efficacy of acupuncture in IBD patients and the impact on inflammatory factors (TNF-α, IL-1, IL-8 and IL-10).

RESULTS

Four randomized controlled trials with a total of 228 patients satisfied the inclusion criteria. Acupuncture has a positive therapeutic impact on IBD (MD = 1.22, 95% CI [1.07, 1.39], P =0.003). Moreover, it regulates the levels of TNF-α (MD =-60.58, 95% CI [-100.30, -20.89], P =0.003), IL-8 (MD =-56.40, 95% CI [-60.02, -52.14], P<0.00001) and IL-10 (MD =35.96, 95% CI [11.02, 60.91], P =0.005) in IBD patients. However, the P value of meta-analysis in IL-1 great than 0.05.(MD =-27.90, 95% CI [-97.82, 42.02], P =0.11).

CONCLUSION

Acupuncture has a positive therapeutic impact on IBD and can effectively regulate inflammatory factors in IBD patients. TNF-α, IL-8 and IL-10 are more appropriate inflammatory indicators for clinically evaluating the anti-inflammatory response in the blood of IBD patients by acupuncture.

Psychosocial and behavioral factors affecting inflammation among pregnant African American women

African American women are reported to have greater inflammation compared with women from other racial groups. Higher inflammation during pregnancy has been associated with increased risk of adverse perinatal outcomes. We hypothesized that maternal inflammation is related to depressive symptoms and social and behavioral risk factors among pregnant African American women. Pregnant African American women (n ​= ​187) were recruited at prenatal clinics in the Midwest. Women completed questionnaires and had blood drawn at a prenatal visit. Plasma levels of cytokines (interferon gamma [IFN]-γ, interleukin [IL]-6, IL-8, IL-10, tumor necrosis factor [TNF]-α) and C-reactive protein (CRP) were measured by multiplex assays. Women had a mean age of 26.58±5.42 years and a mean gestational age at data collection of 16.35±5.95 weeks. Twenty-six percent of women had Center for Epidemiological Studies-Depression (CES-D) scores ≥23 (scores that have been correlated with clinical diagnosis of depression), 15.5% smoked cigarettes, 16.6% used marijuana, and 5.3% reported experiencing intimate partner violence (IPV). Higher CES-D scores were correlated with higher plasma CRP levels (r ​= ​0.16, p ​= ​0.046). Women who reported any experiences of IPV during pregnancy had higher levels of IL-8 (p ​= ​0.018) and lower levels of IFN-γ (p ​= ​0.012) compared with women who did not report IPV. Cigarette smoking during pregnancy was associated with lower levels of the anti-inflammatory cytokine IL-10 (p ​= ​0.003). These findings suggest that depressive symptoms, IPV, and cigarette smoking during pregnancy relate to select inflammatory markers in pregnant African American women. The relationships of inflammation with these factors should be further investigated to better understand the mechanisms which influence maternal and fetal health outcomes.

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Depressive symptoms are related to higher levels of CRP in pregnant African American Women.

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Intimate partner violence in pregnancy is related to higher interleukin 8 levels.

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Smoking during pregnancy is associated with lower interleukin 10 levels.

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Inflammation is related to depressive symptoms, intimate partner violence and smoking in pregnant African American women.

Effect of chronic and acute enterotoxigenic E. coli challenge on growth performance, intestinal inflammation, microbiome, and metabolome of weaned piglets

Post-weaning enteropathies in swine caused by pathogenic E. coli, such as post-weaning diarrhea (PWD) or edema disease (ED), remain a significant problem for the swine industry. Reduction in the use of antibiotics over concerns of antibiotic resistance and public health concerns, necessitate the evaluation of effective antibiotic alternatives to prevent significant loss of livestock and/or reductions in swine growth performance. For this purpose, an appropriate piglet model of pathogenic E. coli enteropathy is required. In this study, we attempted to induce clinical signs of post-weaning disease in a piglet model using a one-time acute or lower daily chronic dose of a pathogenic E. coli strain containing genes for both heat stable and labile toxins, as well as Shiga toxin. The induced disease state was monitored by determining fecal shedding and colonization of the challenge strain, animal growth performance, cytokine levels, fecal calprotectin, histology, fecal metabolomics, and fecal microbiome shifts. The most informative analyses were colonization and shedding of the pathogen, serum cytokines, metabolomics, and targeted metagenomics to determine dysbiosis. Histopathological changes of the gastrointestinal (GI) tract and tight junction leakage as measured by fecal calprotectin concentrations were not observed. Chronic dosing was similar to the acute regimen suggesting that a high dose of pathogen, as used in many studies, may not be necessary. The piglet disease model presented here can be used to evaluate alternative PWD treatment options.

Soy diet induces intestinal inflammation in adult Zebrafish: Role of OTX and P53 family

Inflammatory bowel diseases (IBDs) are a group of inflammatory conditions of the colon and small intestine, including Crohn's disease and ulcerative colitis. Since Danio rerio is a promising animal model to study gut function, we developed a soy-dependent model of intestinal inflammation in adult zebrafish. The soya bean meal diet was given for 4 weeks and induced an inflammatory process, as demonstrated by morphological changes together with an increased percentage of neutrophils infiltrating the intestinal wall, which developed between the second and fourth week of treatment. Pro-inflammatory genes such as interleukin-1beta, interleukin-8 and tumour necrosis factor alpha were upregulated in the second week and anti-inflammatory genes such as transforming growth factor beta and interleukin-10. Interestingly, an additional expression peak was found for interleukin-8 at the fourth week. Neuronal genes, OTX1 and OTX2, were significantly upregulated in the first two  weeks, compatible with the development of the changes in the gut wall. As for the genes of the p53 family such as p53, DNp63 and p73, a statistically significant increase was observed after two weeks of treatment compared with controls. Interestingly, DNp63 and p73 were shown an additional peak after four weeks. Our data demonstrate that soya bean meal diet negatively influences intestinal morphology and immunological function in adult zebrafish showing the features of acute inflammation. Data observed at the fourth week of treatment may suggest initiation of chronic inflammation. Adult zebrafish may represent a promising model to better understand the mechanisms of food-dependent intestinal inflammation.

Therapeutic Potential of Metabolites from Lactobacillus rhamnosus and Mare’s Milk in the Treatment of Dysbiosis

Ulcerative colitis is an inflammatory bowel disease that forms ulcerations in the mucous membrane of the colon and rectum, in which gut microbiota plays a pivotal role in its pathogenesis. Agents modulating microbial dysbiosis caused by colitis can help in the remission of this disease. The current study describes the potential therapeutic effects of active metabolites from Lactobacillus rhamnosus and mare's milk which have potential therapeutic values on the intestinal microbiota and proinflammatory cytokines. The analysis of the V1-V3 16S rDNA site revealed significant changes in the intestinal microbiome composition before and after treatment in the treated group compared to the positive control group that was treated with 5-aminosalicylic acid (5-ASA). So the effect of the study product on dextran sulfate sodium-induced dysbiosis was shown to be more potent than the positive control, 5-ASA. The level of proinflammatory cytokines also decreased under the influence of a biological product.

Morning Cortisol and Circulating Inflammatory Cytokine Levels: A Mendelian Randomisation Study

Cortisol exerts a broad anti-inflammatory effect on the immune system. Inflammatory cytokines contribute to the molecular signalling pathways implicated in various autoimmune and inflammatory conditions. However, the mechanisms by which cortisol modulates such signalling pathways remain uncertain. Leveraging summary-level data from the CORtisol NETwork (CORNET, n = 25,314) and FINRISK (n = 8293) genome-wide association studies, we used two-sample Mendelian randomisation to investigate the causal effect of genetically proxied morning cortisol levels on 42 circulating cytokines. We found that increased genetically proxied morning cortisol levels were associated with reduced levels of IL-8 and increased levels of MIF. These results provide mechanistic insight into the immunomodulatory effects of endogenous cortisol and the therapeutic effects of exogenous corticosteroids. Clinically, our findings underline the therapeutic importance of steroids in inflammatory conditions where IL-8 and MIF play a central pathophysiological role in the onset and progression of disease.

Zinc is a key regulator of gastrointestinal development, microbiota composition and inflammation with relevance for autism spectrum disorders

Gastrointestinal (GI) problems and microbiota alterations have been frequently reported in autism spectrum disorders (ASD). In addition, abnormal perinatal trace metal levels have been found in ASD. Accordingly, mice exposed to prenatal zinc deficiency display features of ASD-like behavior. Here, we model GI development using 3D intestinal organoids grown under zinc-restricted conditions. We found significant morphological alterations. Using proteomic approaches, we identified biological processes affected by zinc deficiency that regulate barrier permeability and pro-inflammatory pathways. We confirmed our results in vivo through proteomics studies and investigating GI development in zinc-deficient mice. These show altered GI physiology and pro-inflammatory signaling, resulting in chronic systemic and neuroinflammation, and gut microbiota composition similar to that reported in human ASD cases. Thus, low zinc status during development is sufficient to compromise intestinal barrier integrity and activate pro-inflammatory signaling, resulting in changes in microbiota composition that may aggravate inflammation, altogether mimicking the co-morbidities frequently observed in ASD.

Ingested Engineered Nanomaterials Affect the Expression of Mucin Genes-An In Vitro-In Vivo Comparison

The increasing use of engineered nanomaterials (ENM) in food has fueled the development of intestinal in vitro models for toxicity testing. However, ENM effects on intestinal mucus have barely been addressed, although its crucial role for intestinal health is evident. We investigated the effects of ENM on mucin expression and aimed to evaluate the suitability of four in vitro models of increasing complexity compared to a mouse model exposed through feed pellets. We assessed the gene expression of the mucins MUC1, MUC2, MUC5AC, MUC13 and MUC20 and the chemokine interleukin-8 in pre-confluent and confluent HT29-MTX-E12 cells, in stable and inflamed triple cultures of Caco-2, HT29-MTX-E12 and THP-1 cells, and in the ileum of mice following exposure to TiO₂, Ag, CeO₂ or SiO₂. All ENM had shared and specific effects. CeO₂ downregulated MUC1 in confluent E12 cells and in mice. Ag induced downregulation of Muc2 in mice. Overall, the in vivo data were consistent with the findings in the stable triple cultures and the confluent HT29-MTX-E12 cells but not in pre-confluent cells, indicating the higher relevance of advanced models for hazard assessment. The effects on MUC1 and MUC2 suggest that specific ENM may lead to an elevated susceptibility towards intestinal infections and inflammations.

Soybean Meal-Dependent Intestinal Inflammation Induces Different Patterns of Bone-Loss in Adult Zebrafish Scale

Inflammatory bowel disease have been linked to several health issues, including high risk of low bone mineral density. Danio rerio (zebrafish) is a good model to verify the effects of intestinal inflammation, since its gastrointestinal and immune systems are closely related to that of mammalians. Zebrafish is also a powerful model to study bone metabolism using the scale as the read-out model. Food strongly impacts zebrafish gut physiology, and it is well known that soybean meal induces intestinal inflammation. Adult zebrafish fed with defatted soybean meal (SBM) exhibited an intestinal inflammation evidenced by morphological alterations, inflammatory infiltrate, and increased mRNA expression of inflammatory cytokines (IL-1β, IL-6, IL-8, IL-10, TGFβ, TNF-α). The peak of acute intestinal inflammation, spanning between week 2 and 3, correlates with a transitory osteoporosis-like phenotype in the scale border. Later, a chronic inflammatory condition, associated with persistent IL-8 expression, correlates with the progression of resorption lacunae in the scale center. Both types of resorption lacunae were associated with intense osteoclastic tartrate-resistant acid phosphatase (TRAP) activity. After 3 weeks of SBM treatment, osteoclast activity decreased in the scale border but not in the center. At the same time, alkaline phosphatase (ALP) is activated in the border to repair the bone matrix. This model can contribute to elucidate in vivo the molecular mechanisms that links intestinal inflammation and bone metabolism in IBD.

Knockout-Induced Pluripotent Stem Cells for Disease and Therapy Modeling of IL-10-Associated Primary Immunodeficiencies

Samples from patients with rare diseases, such as primary immunodeficiencies, are often limited, which hampers careful analysis of the pathomechanisms involved in immune cell dysregulation. To overcome this issue, induced pluripotent stem cells (iPSCs) represent an almost inexhaustible cell source and thus provide an excellent opportunity to generate disease models for rare diseases and to validate new therapeutic approaches. To obtain a better understanding of primary immunodeficiencies associated with the interleukin (IL)-10 signaling pathway, for example, very-early-onset inflammatory bowel disease (VEO-IBD), we generated genetic knockouts (KOs) of IL-10RA (IL-10 receptor α-chain) and IL-10RB (IL-10 receptor β-chain) as well as the downstream targets of the IL-10-receptor (IL-10R) signal transducers and activators of transcription (STAT)1 and STAT3 via an sgRNA (single-guide RNA)-CRISPR-Cas9-expressing lentiviral system. IL-10 signaling-associated KO models and a VEO-IBD patient-derived iPSC clone were differentiated into macrophages for disease models. IL-10R- or STAT3-deficient disease models showed no IL-10-induced BCL3 or SOCS3 expression, whereas lipopolysaccharide (LPS) stimulation induced IL-10R independently of BCL3 and SOCS3 expression. Cytokine secretion profiles from iPSC-derived macrophage disease models showed that IL-10 was involved in many inflammatory cytokine secretions, which indicated formation of both anti- and proinflammatory macrophage phenotypes. Macrophage-secreted cytokines were separated into IL-10R- and STAT3-dependent (IL-6, TNF-α), or into IL-10R-, STAT1-, and STAT3-dependent cytokines (CCL2, CXCL10). Importantly, lentiviral correction restored IL-10-mediated regulation of LPS-induced cytokine secretion in corrected IL-10RB, STAT1, and VEO-IBD patient-derived disease models. Furthermore, treatment of IL-10RB-deficient macrophages with anti-inflammatory small molecules (SB202190, filgotinib) reduced proinflammatory cytokine secretion patterns. Taken together, the described iPSC KO models gave new insights into the pathomechanisms of immune cell dysregulation and served as model systems to test potential therapeutic approaches, including lentiviral gene therapy and targeted small-molecule treatment.

Increased Severity of Ulcerative Colitis in the Terminal Phase of the Metabolic Syndrome

Ulcerative colitis is chronic immune-mediated disorder that affects primarily colonic mucosa. The metabolic syndrome has increasing global prevalence with a significant impact on biology of chronic diseases, such as ulcerative colitis. Today it is known that the metabolic syndrome attenuates severity of ulcerative colitis. Still, there is no evidence that different stages of metabolic syndrome alter the course of the ulcerative colitis. The aim of this study was to dissect out how progression of the metabolic syndrome impacted the biology of ulcerative colitis and severity of clinical presentation. Seventy-two patients (41 men and 31 women, 22-81 years old) were enrolled in this observational cross-sectional study. Concentrations of pro- and anti-inflammatory cytokines in serum and feces samples were measured and phenotype of colon infiltrating cells was analyzed. Patients in the terminal phase of the metabolic syndrome have clinically and pathohistologically more severe form of ulcerative colitis, which is followed by decreased concentrations of systemic galectin-1, increased values of systemic pro-inflammatory mediators and increased influx of lymphocytes in affected colon tissue. Our data suggest that reduced concentrations of galectin-1 and predomination of the pro-inflammatory mediators in patients with terminal stage of the metabolic syndrome enhance local chronic inflammatory response and subsequent tissue damage, and together point on important role of galectin-1 in immune response in ulcerative colitis patients with the metabolic syndrome.

Increased Monocyte Inflammatory Responses to Oxidized LDL Are Associated with Insulin Resistance in HIV-Infected Individuals on Suppressive Antiretroviral Therapy

Despite long term antiretroviral therapy (ART), insulin resistance (IR) is common among people living with HIV/AIDS (PLWHA) exposing this population to a greater risk of cardiometabolic complications when compared to their uninfected counterparts. We previously identified an expansion in monocyte subpopulations in blood that were linked to the degree of IR in persons with HIV on stable ART. In this study, we directly assessed monocyte inflammatory functional properties from PLWHA on ART (n = 33) and HIV-uninfected controls (n = 14) of similar age, gender, and cardiovascular disease risk and determined the relationship with IR (homeostatic model assessment-insulin resistance (HOMA-IR)), calculated from fasting blood glucose and insulin measurements. Peripheral blood mononuclear cells were stimulated with oxidized low-density lipoproteins (oxLDL) and polyfunctional monocyte cytokine responses (IL-1β, IL-6, IL-8, or TNF-α) were determined by flow cytometry. Higher monocyte IL-1β and IL-8 responses to oxLDL were associated with higher IR in PLWHA but not in the control group. We observed that higher basal monocyte cytokine responses were associated with both duration since HIV diagnosis and ART initiation. In the management of IR in chronic HIV, strategies lowering monocyte IL-1β and IL-8 responses should be considered in addition to ART in order to limit adverse cardio-metabolic outcomes.

Translational research into the effects of cigarette smoke on inflammatory mediators and epithelial TRPV1 in Crohn's disease

Crohn's disease is a pathological condition of the gastro-intestinal tract, causing severe transmural inflammation in the ileum and/or colon. Cigarette smoking is one of the best known environmental risk factors for the development of Crohn's disease. Nevertheless, very little is known about the effect of prolonged cigarette smoke exposure on inflammatory modulators in the gut. We examined the effect of cigarette smoke on cytokine profiles in the healthy and inflamed gut of human subjects and in the trinitrobenzene sulphonic acid mouse model, which mimics distal Crohn-like colitis. In addition, the effect of cigarette smoke on epithelial expression of transient receptor potential channels and their concurrent increase with cigarette smoke-augmented cytokine production was investigated. Active smoking was associated with increased IL-8 transcription in ileum of controls (p < 0,001; n = 18-20/group). In the ileum, TRPV1 mRNA levels were decreased in never smoking Crohn's disease patients compared to healthy subjects (p <0,001; n = 20/group). In the colon, TRPV1 mRNA levels were decreased (p = 0,046) in smoking healthy controls (n = 20/group). Likewise, healthy mice chronically exposed to cigarette smoke (n = 10/group) showed elevated ileal Cxcl2 (p = 0,0075) and colonic Kc mRNA levels (p = 0,0186), whereas TRPV1 mRNA and protein levels were elevated in the ileum (p = 0,0315). Although cigarette smoke exposure prior to trinitrobenzene sulphonic acid administration did not alter disease activity, increased pro-inflammatory cytokine production was observed in the distal colon (Kc: p = 0,0273; Cxcl2: p = 0,104; Il1-β: p = 0,0796), in parallel with the increase of Trpv1 mRNA (p < 0,001). We infer that CS affects pro-inflammatory cytokine expression in healthy and inflamed gut, and that the simultaneous modulation of TRPV1 may point to a potential involvement of TRPV1 in cigarette smoke-induced production of inflammatory mediators.

Enhancing responsiveness of human jejunal enteroids to host and microbial stimuli

KEY POINTS

Enteroids are a physiologically relevant model to examine the human intestine and its functions. Previously, the measurable cytokine response of human intestinal enteroids has been limited following exposure to host or microbial pro-inflammatory stimuli. Modifications to enteroid culture conditions facilitated robust human cytokine responses to pro-inflammatory stimuli. This new human enteroid culture methodology refines the ability to study microbiome:human intestinal epithelium interactions in the laboratory.

ABSTRACT

The intestinal epithelium is the primary interface between the host, the gut microbiome and its external environment. Since the intestinal epithelium contributes to innate immunity as a first line of defence, understanding how the epithelium responds to microbial and host stimuli is an important consideration in promoting homeostasis. Human intestinal enteroids (HIEs) are primary epithelial cell cultures that can provide insights into the biology of the intestinal epithelium and innate immune responses. One potential limitation of using HIEs for innate immune studies is the relative lack of responsiveness to factors that stimulate epithelial cytokine production. We report technical refinements, including removal of extracellular antioxidants, to facilitate enhanced cytokine responses in HIEs. Using this new method, we demonstrate that HIEs have distinct cytokine profiles in response to pro-inflammatory stimuli derived from host and microbial sources. Overall, we found that host-derived cytokines tumour necrosis factor and interleukin-1α stimulated reactive oxygen species and a large repertoire of cytokines. In contrast, microbial lipopolysaccharide, lipoteichoic acid and flagellin stimulated a limited number of cytokines and histamine did not stimulate the release of any cytokines. Importantly, HIE-secreted cytokines were functionally active, as denoted by the ability of human blood-derived neutrophil to migrate towards HIE supernatant containing interleukin-8. These findings establish that the immune responsiveness of HIEs depends on medium composition and stimuli. By refining the experimental culture medium and creating an environment conducive to epithelial cytokine responses by human enteroids, HIEs can facilitate exploration of many experimental questions pertaining to the role of the intestinal epithelium in innate immunity.

Research Note: Correlation analysis of interleukin-6, interleukin-8, and C-C motif chemokine ligand 2 gene expression in chicken spleen and cecal tissues after Eimeria tenella infection in vivo

IL-6, IL-8, and C-C motif chemokine ligand 2 (CCLi2) are important factors in inflammatory and immune responses. To investigate their relationships in the spleen and cecum and between coccidiosis-infected and uninfected states, we performed quantitative real-time PCR to compare the relative expression difference of IL-6, IL-8, and CCLi2 in the same tissues between the infection and control groups. In addition, the correlations of the relative expression levels of these 3 genes were determined in the same and different tissues within the same group. The results showed that the expression levels of IL-6, IL-8, and CCLi2 in the spleen and cecum of the infected group were all higher than those of the uninfected group (P < 0.05). The correlation coefficients among the IL-6, IL-8, and CCLi2 expression levels in the spleen or cecum were all positive in both the infection and control groups. In the spleen tissues, CCLi2 expression was strongly correlated with IL-6 and IL-8 in the uninfected group (P < 0.01), and the correlation coefficients reached 0.853 (R² = 0.728) and 0.996 (R² = 0.992), respectively. The expression of CCLi2 was also strongly correlated with IL-8 (R reached 0.890, R² = 0.792) in the infected group. In the cecal tissues, the expression levels of the 3 genes were all extremely significantly correlated in the uninfected group (P < 0.01), and the correlation coefficients ranged from 0.498 to 0.765, indicating moderate correlations. The expression of IL-6 was extremely significantly positively correlated with IL-8 and CCLi2 in the infected group (P < 0.01), with moderate correlations (R ranged from 0.469–0.639). In addition, the expression levels of the 3 genes were not significantly correlated (P > 0.05) between the spleen and cecum tissues in either the infection group or the control group. These results indicate that IL-6, IL-8, and CCLi2 were correlated and play an important role in coccidiosis infection of Jinghai yellow chicken. Our data also provide a basis for further exploring the role of these 3 genes in genetic breeding for coccidiosis resistance.

Exploratory investigation of the anti-inflammatory effects of RNase A-treated Enterococcus faecalis strain EC-12

We previously reported that the major component of Enterococcus faecalis strain EC-12 (EC-12) inducing production of Interleukin (IL)-12 in mouse/human immune cells was its own RNA. This study aimed to investigate if RNase A-treated EC-12 could also produce IL-10 and to evaluate the possible effects of IL-10 produced by RNase A-treated EC-12. Three experiments were conducted: (1) Assessment of the effect of RNase A-treated EC-12 on transcriptome profiles and biological pathways in human peripheral blood mononuclear cells; (2) Determination of cytokine concentration in its culture supernatants; and (3) Supplementation of RNase A-treated EC-12 (RN) to mice with dextran sodium sulfate-induced colitis. Treatment of EC-12 with RNase A inhibited inflammatory response including the potency to induce IL-12 production, while it did not affect IL-10 production (Experiment 1 and 2). Colitis symptoms were milder in RN than in PBS-supplemented controls (Experiment 3). RNase A-treated EC-12 likely became an anti-inflammatory agent primarily inducing IL-10 production.

A Direct Effect of Sex Hormones on Epithelial Barrier Function in Inflammatory Bowel Disease Models

BACKGROUND

Pregnancy is often described as an immune-tolerant state, and a disease modulatory role for pregnancy on inflammatory bowel disease (IBD) has been suggested. The direct effect of estrogen and progesterone on the intestinal epithelial barrier is underexplored. We investigated the direct consequences of these pregnancy hormones on barrier cells and their function.

METHODS

We used IBD patient-derived inflammatory organoid models and 2D cell lines models. Epithelial barrier function was analyzed by measuring transepithelial electrical resistance; wound closure was determined by scratch assay; and cell viability was measured by MTT assays. Pro-inflammatory cytokine production was determined by enzyme-linked immunosorbent assays. Molecular modulation of endoplasmic reticulum (ER) stress induced by tunicamycin was studied by western blot analysis of the ER stress markers GRP78, CHOP and p-IRE1.

RESULTS

Progesterone and estrogen improved wound healing and epithelial barrier function in intestinal epithelial cells via upregulation of tight junction proteins. Furthermore, these sex hormones significantly reduced ER-stress and reduce pro-inflammatory cytokine production in intestinal epithelial models.

CONCLUSION

Our study shows that estrogen and progesterone alleviate ER stress, decrease pro-inflammatory cytokine production, stimulate wound healing, and increase barrier function of epithelial cells. Combined, these data suggest that pregnancy hormones can have beneficial effects on disease activity by positively modulating the intestinal epithelial lining.

The Inflammatory Response to Enterotoxigenic E. coli and Probiotic E. faecium in a Coculture Model of Porcine Intestinal Epithelial and Dendritic Cells

The gut epithelium constitutes an interface between the intestinal contents and the underlying gut-associated lymphoid tissue (GALT) including dendritic cells (DC). Interactions of intestinal epithelial cells (IEC) and resident DC are characterized by bidirectional crosstalk mediated by various factors, such as transforming growth factor-β (TGF-β) and thymic stromal lymphopoietin (TSLP). In the present study, we aimed (1) to model the interplay of both cell types in a porcine in vitro coculture consisting of IEC (cell line IPEC-J2) and monocyte-derived DC (MoDC) and (2) to assess whether immune responses to bacteria are altered because of the interplay between IPEC-J2 cells and MoDC. With regard to the latter, we focused on the inflammasome pathway. Here, we propose caspase-13 as a promising candidate for the noncanonical inflammasome activation in pigs. We conducted challenge experiments with enterotoxigenic Escherichia coli (ETEC) and probiotic Enterococcus faecium (E. faecium) NCIMB 10415. As potential mediators of IEC/DC interactions, TGF-β and TSLP were selected for analyses. Cocultured MoDC showed attenuated ETEC-induced inflammasome-related and proinflammatory interleukin (IL)-8 reactions compared with MoDC monocultures. Caspase-13 was more strongly expressed in IPEC-J2 cells cocultured with MoDC and upon ETEC incubation. We found that IPEC-J2 cells and MoDC were capable of releasing TSLP. The latter cells secreted greater amounts of TSLP when cocultured with IPEC-J2 cells. TGF-β was not modulated under the present experimental conditions in either cell types. We conclude that, in the presence of IPEC-J2 cells, porcine MoDC exhibited a more tolerogenic phenotype, which might be partially regulated by autocrine TSLP production. Noncanonical inflammasome signaling appeared to be modulated in IPEC-J2 cells. Our results indicate that the reciprocal interplay of the intestinal epithelium and GALT is essential for promoting balanced immune responses.

Immune response and inflammatory pathway of ulcerative colitis

Ulcerative colitis (UC) is an idiopathic relapsing inflammatory disease. Although the etiology of UC remains unclear, it could be characterized by inflammation of the intestinal mucosa, starting from the rectum and potentially involving the entire colon. The immune response and inflammatory pathway of UC have shown that tissue damage is driven by dynamic and complexes of cells and cytokines. Various types of cells, including antigen-presenting cells (dendritic cells and macrophages), T helper cells, regulatory T cells, and natural killer T cells, play a crucial role in UC pathogenesis by regulation, suppression, and maintenance of inflammation. Moreover, cytokine networks become an important part due to their signaling function, which is indispensable for cell communication. Pro-inflammatory cytokines [tumor necrosis factor-α, interleukin (IL)-1, IL-6, IL-9, IL-13, and IL-33] play significant roles in upregulation, while anti-inflammatory cytokines (transforming growth factor-β, IL-10, and IL-37) play significant roles in downregulation of disease progression. The pathogenesis of UC consists of immuno-inflammatory pathways related to the multiple components of the intestine, including the epithelial barrier, commensal microflora, antigen recognition, dysregulation of immunological responses, leukocyte recruitment, and genetic factors. The understanding of immuno-inflammatory pathways of UC might lead to the development of a specific therapy and/or a novel treatment that could be more efficient.

Therapeutic effects of kefir grain Lactobacillus-derived extracellular vesicles in mice with 2,4,6-trinitrobenzene sulfonic acid-induced inflammatory bowel disease

Kefir is a fermented product from yeast and lactic acid bacteria, and has been associated with various health benefits including relieving inflammatory bowel disease. Recently, it has been shown that gram-positive bacteria produce extracellular vesicles (EV). The EV could be appearing as potentially important mediators of cell to cell interaction. In this study, we explored the role of kefir grain Lactobacillus-derived EV in modulating inflammation responses via alleviating the production of inflammatory cytokines in tumor necrosis factor-α (TNF-α)-induced inflammation in Caco-2 cells and the 2,4,6-trinitrobenzene sulfonic acid-induced inflammatory bowel disease mouse model. Kefir-derived Lactobacillus EV were isolated by ultracentrifugation of the culture medium of 3 different kefir-derived strains (i.e., Lactobacillus kefir, Lactobacillus kefiranofaciens, and Lactobacillus kefirgranum). Nanoparticle tracking analysis showed that the size of isolated kefir-derived Lactobacillus EV was within 80 to 400 nm, and kefir-derived Lactobacillus EV uptake into recipient Caco-2 cells was confirmed by fluorescence labeling. Treatment of each kefir-derived Lactobacillus EV onto TNF-α-stimulated Caco-2 cells significantly reduced the level of both mRNA expression and secretion of IL-8, and Western blot analysis revealed that such an effect was related to inhibition of TNF-α signaling mediated by reducing the phosphorylation of p65, a subunit of NF-kB. Subsequent administration of kefir-derived Lactobacillus EV into inflammatory bowel disease-induced mice significantly alleviated the body weight loss and rectal bleeding, and enhanced stool consistency. Histological examination showed that kefir-derived Lactobacillus EV substantially reduced the infiltration of transmural leukocytes and loss of goblet cells within the colon, and the serum level of myeloperoxidase was significantly lower in the EV-treated group than control group. Our study demonstrates that kefir-derived Lactobacillus EV can be potentially used for developing innovative strategies for alleviating inflammatory bowel disease.

Subclinical Inflammation in Heart Failure: A Neutrophil Perspective

Although it is widely recognized that inflammation plays a critical role in the development and pathology of heart failure (HF), very little is known about the involvement of one of the most abundant immune cells in the blood, a primary immune response cell: the neutrophil. This review summarizes the current literature on the role of subclinical inflammation, with a focus on the neutrophil in the pathophysiology of the HF syndrome. Some emerging therapeutic strategies are also discussed.

Portulaca oleracea extracts and their active compounds ameliorate inflammatory bowel diseases in vitro and in vivo by modulating TNF-α, IL-6 and IL-1β signalling

Portulaca oleracea L. (P. oleracea) is an herb that is widely used in traditional medicine to treat various diseases. However, its effects on inflammatory diseases, such as inflammatory bowel disease (IBD), are not yet well characterized. Here, we investigated the impact of the ethyl acetate (EtOAc) and ethanol (EtOH) extracts of P. oleracea on lipopolysaccharide (LPS)-induced inflammatory responses and phosphorylation of ERK, JNK, and p38 expression in RAW264.7 macrophages. In addition, the inhibitory effects of these extracts and fractions on 3% dextran sulphate sodium (DSS)-induced ulcerative colitis were examined using an ICR mouse model. DSS-induced colitis, including body weight loss, reduced colon length, and histological colon injury, was significantly ameliorated in mice fed the P. oleracea extracts (200 and 500mg/kg). In particular, P. oleracea extracts also inhibited pro-inflammatory cytokine (TNF-α, IL-6, and 1L-1β) production in mice with DSS-induced colitis; the P. oleracea extracts displayed higher and/or similar inhibitory activity to sulfasalazine at high concentrations. Furthermore, the chemical structures of active compounds separated from the EtOAc extract of P. oleracea were elucidated using nuclear magnetic resonance (NMR) spectroscopy (see Figure in supplementary materials), resulting in the identification of three known compounds. Among these active compounds, cis-N-feruloyl-3'-methoxytyramine (2) exhibited the strongest effects on preventing DSS-induced IBD in animal models. Thus, extract of P. oleracea and their active compounds represents a new therapeutic approach for patients with inflammatory bowel diseases.

Salicylate-based phytopharmaceuticals induce adaptive cytokine and chemokine network responses in human fibroblast cultures

BACKGROUND

Cytokines and chemokines (CC) play a central role in immunoregulatory and inflammatory processes. Neutralising antibodies for single proinflammatory cytokines have developed into a powerful, though expensive and not always curative therapeutic strategy for severe diseases. Considering the redundancy of CC functions, network (N) rather than single target approaches are essential. Phytopharmaceuticals, common adjuvant therapies, are known modulators of a broad spectrum of CCs, but as complex mixtures with multiple targets they have not been systematically investigated. We investigated the effect of clinically established salicylate-based phytopharmaceuticals alone or in combination on CCNs under non-inflammatory and inflammatory conditions, using fibroblasts being a major source of cytokines in connective tissue diseases.

METHODS

Synchronised human skin fibroblasts (HSKF) were treated for 6 h with standardised fluid plant extracts (E) of Populus tremula L. [end concentration: 0.06%, 0.1%], Solidago virgaurea L. [0.02%, 0.1%], Fraxinus excelsior L. [0.02%, 0.1%], an established combination of the three extracts-STW1 [0.05, 0.1%] and acetyl salicylic acid (ASA) [30 µg/ml], individually or in the presence of lipopolysaccharides (LPS) [10 µg/ml]. Cell lysates were profiled for 23 cytokines. Supernatants were investigated for IL-6 and IL-8 release (ELISA). Total RNA was isolated for gene-expression profiling.

RESULTS

Under non-inflammatory conditions P. tremula E and ASA increased cellular proteins (P) IL-8 and IL-10; S. virgaurea E modulated IL-1α, IL-10, IL-15 and Groα (P). F. excelsior decreased IL-1α and IL-15 (P). The combination of the three extracts (STW1) modulated IL-1α, IL-3 and TNF-ß (P). LPS stimulation increased cellular IL-8, Groα, MCP-1 and RANTES (P) and increased the secretion of IL-6 and IL-8 into the medium. Under these inflammatory conditions F. excelsior reduced GMCSF, GCSF and RANTES. STW1 reduced IL-1α, IL-8, Groα, and MCP-1(P). Secretion of IL-8 and IL-6 was reduced by STW1 and ASA. Gene expression profiles supported non-additive CCN profiles.

CONCLUSION

Salicylate based phytopharmaceuticals provoke cellular pro-and anti-inflammatory CCN responses under non-stress conditions, which adapt to anti-inflammatory responses after LPS-stimulation. CCN-profiles of the single extracts are not additives in combination. A simultaneous activation of cellular pro- and anti-inflammatory cytokines might heighten the immunological reactivity status of a cell.

Distinct and common expression of receptors for inflammatory mediators in vagal nodose versus jugular capsaicin-sensitive/TRPV1-positive neurons detected by low input RNA sequencing

Capsaicin-sensitive sensory C-fibers derived from vagal ganglia innervate the visceral organs, and respond to inflammatory mediators and noxious stimuli. These neurons play an important role in maintenance of visceral homeostasis, and contribute to the symptoms of visceral inflammatory diseases. Vagal sensory neurons are located in two ganglia, the jugular ganglia (derived from the neural crest), and the nodose ganglia (from the epibranchial placodes). The functional difference, especially in response to immune mediators, between jugular and nodose neurons is not fully understood. In this study, we microscopically isolated murine nodose and jugular capsaicin-sensitive / Trpv1-expressing C-fiber neurons and performed transcriptome profiling using ultra-low input RNA sequencing. RNAseq detected genes with significantly differential expression in jugular and nodose neurons, which were mostly involved in neural functions. Transcriptional regulators, including Cited1, Hoxb5 and Prdm12 showed distinct expression patterns in the two C-fiber neuronal populations. Common and specific expression of immune receptor proteins was characterized in each neuronal type. The expression of immune receptors that have received little or no attention from vagal sensory biologists is highlighted including receptors for certain chemokines (CXCLs), interleukins (IL-4) and interferons (IFNα, IFNγ). Stimulation of immune receptors with their cognate ligands led to activation of the C-fibers in isolated functional assays.

Characterization and protective effect of Polygonatum sibiricum polysaccharide against cyclophosphamide-induced immunosuppression in Balb/c mice

In this study, the polysaccharide from Polygonatum sibiricum (PSP) was evaluated for the immunomodulatory activity by the cyclophosphamide (Cy)-induced immunosuppressed-model in vivo. The PSP has been analyzed in order to identify a variety of chemical properties such as monosaccharide compositions and structural confirmation. The results show that the main components of PSP were galactose and rhamnose. The PSP could significantly stimulate neutral red phagocytosis of RAW264.7 macrophages. Compared with the cyclophosphamide group, PSP accelerated recovery of spleen and thymus indexes, and enhanced T cell and B cell proliferation responses as well as peritoneal macrophage phagocytosis. In addition, PSP treatment restored the levels of IL-2, TNF-α, IL-8 and IL-10 in the serum of the Cy-treated mice in a dose-dependent manner. Therefore, PSP played an important role in the protection against immunosuppression in the Cy-treated mice and could be used as a potential immunostimulant agent.

Predicting the functional consequences of non-synonymous single nucleotide polymorphisms in IL8 gene

Here we report an in-silico approach for identification, characterization and validation of deleterious non-synonymous SNPs (nsSNPs) in the interleukin-8 gene using three steps. In first step, sequence homology-based genetic analysis of a set of 50 coding SNPs associated with 41 rsIDs using SIFT (Sorting Intolerant from Tolerant) and PROVEAN (Protein Variation Effect Analyzer) identified 23 nsSNPs to be putatively damaging/deleterious in at least one of the two tools used. Subsequently, structure-homology based PolyPhen-2 (Polymorphism Phenotyping) analysis predicted 9 of 23 nsSNPs (K4T, E31A, E31K, S41Y, I55N, P59L, P59S, L70P and V88D) to be damaging. According to the conditional hypothesis for the study, only nsSNPs that score damaging/deleterious prediction in both sequence and structural homology-based approach will be considered as 'high-confidence' nsSNPs. In step 2, based on conservation of amino acid residues, stability analysis, structural superimposition, RSMD and docking analysis, the possible structural-functional relationship was ascertained for high-confidence nsSNPs. Finally, in a separate analysis (step 3), the IL-8 deregulation has also appeared to be an important prognostic marker for detection of patients with gastric and lung cancer. This study, for the first time, provided in-depth insights on the effects of amino acid substitutions on IL-8 protein structure, function and disease association.

Increased Epithelial Gap Density in the Noninflamed Duodenum of Children With Inflammatory Bowel Diseases

OBJECTIVES

Inflammatory bowel diseases (IBD) present commonly in childhood, with unknown etiology, but an important role for the epithelial lining is suggested. Epithelial cell extrusion, measured by counting gaps between epithelial cells, is higher in adult patients with Crohn disease (CD) than in controls. Our objectives were to compare epithelial gaps in the duodenum of IBD and non-IBD pediatric patients, to study the correlation between epithelial gaps, inflammation, and disease activity, and identify potential mechanisms.

METHODS

Epithelial gap density of the duodenum was evaluated using probe-based confocal laser endomicroscopy in 26 pediatric patients with IBD (16 CD, 10 ulcerative colitis [UC]) and 17 non-IBD controls during endoscopy. Epithelial gaps were correlated with serum inflammatory markers, disease activity indices, and intraepithelial lymphocytes. A panel of 10 inflammatory cytokines and expression of TNFAIP3 (A20; inhibits NF-κβ-induced inflammation) were analyzed in duodenal and ileal biopsies.

RESULTS

Confocal imaging showed significantly higher epithelial gap density in patients with IBD, including UC. Interleukin (IL)-2 and IL-8 were higher in duodenal but not ileal biopsies of patients with UC. No significant correlation was present between C-reactive protein, erythrocyte sedimentation rate, disease activity indices, and epithelial gaps in patients with UC. In patients with CD, C-reactive protein positively correlated with epithelial gaps. A20 expression in the duodenum was unchanged among non-IBD and IBD cases.

CONCLUSIONS

Duodenal epithelial gaps are increased in pediatric patients with IBD (including UC) but are unrelated to inflammation. This suggests that altered epithelial barrier is an important systemic feature of pediatric IBD and is not only secondary to inflammation.

Inflammatory regulatory T cells in the microenvironments of ulcerative colitis and colon carcinoma

Foxp3(+)CD4(+) regulatory T (Treg) cells are thought to express negligible levels of effector cytokines, and inhibit immune responses and inflammation. Here, we have identified a population of IL-8(+)Foxp3(+)CD4(+) T cells in human peripheral blood, which is selectively increased in the microenvironments of ulcerative colitis and colon carcinoma. Phenotypically, this population is minimally overlapping with IL-17(+)Foxp3(+)CD4(+) T cells, and is different from IL-8(-)Foxp3(+)CD4(+) T cells in the same microenvironment. 40-60% of IL-8(+)Foxp3(+)CD4(+) T cells exhibit naive phenotype and express CD127, whereas IL-8(-)Foxp3(+)CD4(+) cells are basically memory T cells and express minimal CD127. The levels of CXCR5 expression are higher in IL-8(+)Foxp3(+) cells than in IL-8(-)Foxp3(+) cells. IL-2 and TGFβ induce IL-8(+)Foxp3(+) T cells. Exogenous Foxp3 expression promotes IL-8(+)Foxp3(+) T cells and inhibits effector cytokine IFNγ and IL-2 expression. Furthermore, Foxp3 binds to IL-8 proximal promoter and increases its activity. Functionally, IL-8(+)Foxp3(+) T cells inhibit T cell proliferation and effector cytokine production, but stimulate inflammatory cytokine production in the colon tissues, and promote neutrophil trafficking through IL-8. Thus, IL-8(+)Foxp3(+) cells may be an "inflammatory" Treg subset, and possess inflammatory and immunosuppressive dual biological activities. Given their dual roles and localization, these cells may be in a unique position to support tumor initiation and development in human chronic inflammatory environment.

Ursodeoxycholic acid inhibits TNFα-induced IL-8 release from monocytes

Monocytes are critical to the pathogenesis of inflammatory bowel disease (IBD) as they infiltrate the mucosa and release cytokines that drive the inflammatory response. Ursodeoxycholic acid (UDCA), a naturally occurring bile acid with anti-inflammatory actions, has been proposed as a potential new therapy for IBD. However, its effects on monocyte function are not yet known. Primary monocytes from healthy volunteers or cultured U937 monocytes were treated with either the proinflammatory cytokine, TNFα (5 ng/ml) or the bacterial endotoxin, lipopolysaccharide (LPS; 1 μg/ml) for 24 h, in the absence or presence of UDCA (25-100 μM). IL-8 release into the supernatant was measured by ELISA. mRNA levels were quantified by qPCR and changes in cell signaling proteins were determined by Western blotting. Toxicity was assessed by measuring lactate dehydrogenase (LDH) release. UDCA treatment significantly attenuated TNFα-, but not LPS-driven, release of IL-8 from both primary and cultured monocytes. UDCA inhibition of TNFα-driven responses was associated with reduced IL-8 mRNA expression. Both TNFα and LPS stimulated NFκB activation in monocytes, while IL-8 release in response to both cytokines was attenuated by an NFκB inhibitor, BMS-345541. Interestingly, UDCA inhibited TNFα-, but not LPS-stimulated, NFκB activation. Finally, TNFα, but not LPS, induced phosphorylation of TNF receptor associated factor (TRAF2), while UDCA cotreatment attenuated this response. We conclude that UDCA specifically inhibits TNFα-induced IL-8 release from monocytes by inhibiting TRAF2 activation. Since such actions would serve to dampen mucosal immune responses in vivo, our data support the therapeutic potential of UDCA for IBD.

Allyl methyl disulfide inhibits IL-8 and IP-10 secretion in intestinal epithelial cells via the NF-кB signaling pathway

Garlic and its active constituents have shown versatile medicinal activities in the prevention and treatment of various disorders. Allyl methyl disulfide (AMDS) was identified as one of the major bioactive components in an effective inhalation fork remedy using fresh garlic paste in our previous study. In this work, we investigated the immunological properties of AMDS to elucidate the underlying mechanisms of the fork inhalation treatment using fresh garlic. The inhibition effect of AMDS on TNF-α-induced IL-8 and IP-10 production in intestinal epithelial cell lines HT-29 and Caco-2 was first evaluated. Pretreatment of the cells with AMDS attenuated IL-8 and IP-10 secretion induced by TNF-α in a dose-dependent manner in the non-cytotoxic concentration range of 20 to 150 μM. Mechanistic studies revealed that AMDS suppressed the accumulation of IL-8 mRNA and inhibited IкBα degradation and NF-кB p65 translocation into the nucleus at both the transcriptional and translational levels, suggesting that the attenuation effort of AMDS on cytokine IL-8 secretion might at least be partially related to the NF-κB signaling pathway. These results suggest that AMDS may be a promising phytochemical agent in the treatment of immunological disorders, such as ulcerative colitis, Crohn's disease, intestinal inflammatory diseases and others. In addition, the mechanistic study data indicated that immune modulation could be one of the therapeutic mechanisms of the effective fork treatment containing AMDS as one of the major components.

CXCL8 histone H3 acetylation is dysfunctional in airway smooth muscle in asthma: regulation by BET

Asthma is characterized by airway inflammation and remodeling and CXCL8 is a CXC chemokine that drives steroid-resistant neutrophilic airway inflammation. We have shown that airway smooth muscle (ASM) cells isolated from asthmatic individuals secrete more CXCL8 than cells from nonasthmatic individuals. Here we investigated chromatin modifications at the CXCL8 promoter in ASM cells from nonasthmatic and asthmatic donors to further understand how CXCL8 is dysregulated in asthma. ASM cells from asthmatic donors had increased histone H3 acetylation, specifically histone H3K18 acetylation, and increased binding of histone acetyltransferase p300 compared with nonasthmatic donors but no differences in CXCL8 DNA methylation. The acetylation reader proteins Brd3 and Brd4 were bound to the CXCL8 promoter and Brd inhibitors inhibited CXCL8 secretion from ASM cells by disrupting Brd4 and RNA polymerase II binding to the CXCL8 promoter. Our results show a novel dysregulation of CXCL8 transcriptional regulation in asthma characterized by a promoter complex that is abnormal in ASM cells isolated from asthmatic donors and can be modulated by Brd inhibitors. Brd inhibitors may provide a new therapeutic strategy for steroid-resistant inflammation.

Phytochemical composition and anti-inflammatory activity of extracts from the whole-meal flour of Italian durum wheat cultivars

In this study, the quali-quantitative composition of hydrophilic (phenolic acids) and lipophilic (isoprenoids) extracts from whole-meal flour of five elite Italian durum wheat cultivars was determined. Significant differences in the content of bioactive compounds were observed among the wheat extracts, in particular concerning the content of bound phenolic acids, lutein and β-tocotrienols. The cultivars Duilio and Svevo showed the highest amount of phenolic acids and isoprenoids, respectively. Extracts were evaluated for their anti-inflammatory activity on HT-29 human colon cells by measuring the levels of interleukin 8 (IL-8) and transforming growth factor β1 (TGF-β1). Durum wheat extracts significantly inhibited the secretion of the pro-inflammatory IL-8 mediator at 66 µg/mL of phenolic acids and at 0.2 µg/mL of isoprenoids. Conversely, the secretion of the anti-inflammatory mediator TGF-β1 was not modified by neither hydrophilic nor lipophilic extracts. These results provide further insight into the potential of durum wheat on human health suggesting the significance of varieties with elevated contents of bioactive components.

Anti-inflammatory effects of Lactococcus lactis NCDO 2118 during the remission period of chemically induced colitis

Background

Many probiotic bacteria have been described as promising tools for the treatment and prevention of inflammatory bowel diseases (IBDs). Most of these bacteria are lactic acid bacteria, which are part of the healthy human microbiota. However, little is known about the effects of transient bacteria present in normal diets, including Lactococcus lactis.

Methods

In the present study, we analysed the immunomodulatory effects of three L. lactis strains in vitro using intestinal epithelial cells. L. lactis NCDO 2118 was administered for 4 days to C57BL/6 mice during the remission period of colitis induced by dextran sodium sulphate (DSS).

Results

Only one strain, L. lactis NCDO 2118, was able to reduce IL-1β-induced IL-8 secretion in Caco-2 cells, suggesting a potential anti-inflammatory effect. Oral treatment using L. lactis NCDO 2118 resulted in a milder form of recurrent colitis than that observed in control diseased mice. This protective effect was not attributable to changes in secretory IgA (sIgA); however, NCDO 2118 administration was associated with an early increase in IL-6 production and sustained IL-10 production in colonic tissue. Mice fed L. lactis NCDO 2118 had an increased number of regulatory CD4⁺ T cells (Tregs) bearing surface TGF-β in its latent form (Latency-associated peptide-LAP) in the mesenteric lymph nodes and spleen.

Conclusions

Here, we identified a new probiotic strain with a potential role in the treatment of IBD, and we elucidated some of the mechanisms underlying its anti-inflammatory effect.

Purine-metabolizing ectoenzymes control IL-8 production in human colon HT-29 cells

Interleukin-8 (IL-8) plays key roles in both chronic inflammatory diseases and tumor modulation. We previously observed that IL-8 secretion and function can be modulated by nucleotide (P2) receptors. Here we investigated whether IL-8 release by intestinal epithelial HT-29 cells, a cancer cell line, is modulated by extracellular nucleotide metabolism. We first identified that HT-29 cells regulated adenosine and adenine nucleotide concentration at their surface by the expression of the ectoenzymes NTPDase2, ecto-5′-nucleotidase, and adenylate kinase. The expression of the ectoenzymes was evaluated by RT-PCR, qPCR, and immunoblotting, and their activity was analyzed by RP-HPLC of the products and by detection of P_i produced from the hydrolysis of ATP, ADP, and AMP. In response to poly (I:C), with or without ATP and/or ADP, HT-29 cells released IL-8 and this secretion was modulated by the presence of NTPDase2 and adenylate kinase. Taken together, these results demonstrate the presence of 3 ectoenzymes at the surface of HT-29 cells that control nucleotide levels and adenosine production (NTPDase2, ecto-5′-nucleotidase and adenylate kinase) and that P2 receptor-mediated signaling controls IL-8 release in HT-29 cells which is modulated by the presence of NTPDase2 and adenylate kinase.

Chronic inflammation and cytokines in the tumor microenvironment

Acute inflammation is a response to an alteration induced by a pathogen or a physical or chemical insult, which functions to eliminate the source of the damage and restore homeostasis to the affected tissue. However, chronic inflammation triggers cellular events that can promote malignant transformation of cells and carcinogenesis. Several inflammatory mediators, such as TNF-α, IL-6, TGF-β, and IL-10, have been shown to participate in both the initiation and progression of cancer. In this review, we explore the role of these cytokines in important events of carcinogenesis, such as their capacity to generate reactive oxygen and nitrogen species, their potential mutagenic effect, and their involvement in mechanisms for epithelial mesenchymal transition, angiogenesis, and metastasis. Finally, we will provide an in-depth analysis of the participation of these cytokines in two types of cancer attributable to chronic inflammatory disease: colitis-associated colorectal cancer and cholangiocarcinoma.

Collection of in vivo transmigrated neutrophils from human skin

A wealth of knowledge on the life and death of human neutrophils has been obtained by the in vitro study of isolated cells derived from peripheral blood. However, neutrophils are of main importance, physiologically as well as pathologically, after they have left circulation and transmigrated to extravascular tissues. The journey from blood to tissue is complex and eventful, and tissue neutrophils are in many aspects distinct from the cells left in circulation. Here we describe how to obtain human tissue neutrophils in a controlled experimental setting from aseptic skin lesions created by the application of negative pressure. One protocol enables the direct analysis of the blister content, infiltrating leukocytes as well as exudate fluid, and is a simple method to follow multiple parameters of aseptic inflammation in vivo. Also described is the skin chamber technique, a method based on denuded skin blisters which are subsequently covered by collection chambers filled with autologous serum. Although slightly more artificial as compared to analysis of the blister content directly, the cellular yield of this skin chamber method is sufficient to perform a large number of functional analyses of in vivo transmigrated cells.

Markedly increased expression of interleukin-8 in the colorectal mucosa of inflammatory colorectal polyps in miniature dachshunds

Inflammatory colorectal polyps (ICRPs) in miniature dachshunds were recently recognized as a major cause of large bowel diarrhea in this dog breed in Japan. ICRPs are characterized by the formation of multiple small polyps and/or space-occupying large polyps in the colorectal area and are thought to be a novel form of inflammatory bowel disease (IBD). To explore key mediators in the pathogenesis of ICRPs, we analyzed several pro-inflammatory cytokine (IL-1β, IL-6, TNF-α, IL-8, IL-12p35, IL-12/23p40, and IL-23p19) mRNA expressions in colorectal polyps in ICRP dogs by quantitative PCR. Among these cytokines, IL-8 mRNA expression was markedly up-regulated in large polyps. To examine IL-8 protein expression, we analyzed IL-8 protein level and its location in colorectal mucosal specimens of ICRP dogs by ELISA and immunofluorescence microscopy. IL-8 protein was significantly increased in large polyps and serum in dogs with ICRPs compared to controls. By immunofluorescence microscopy, IL-8 was only localized in macrophages, but not in mucosal epithelial cells or neutrophils. IL-8-positive macrophages were significantly increased in large polyps compared to controls. These results suggest that IL-8 is produced mainly by macrophages and may induce neutrophil infiltration in the colorectal area of ICRP dogs.

Rationale and Means to Target Pro-Inflammatory Interleukin-8 (CXCL8) Signaling in Cancer

It is well established that chronic inflammation underpins the development of a number of human cancers, with pro-inflammatory signaling within the tumor microenvironment contributing to tumor progression and metastasis. CXCL8 is an ELR⁺ pro-inflammatory CXC-chemokine which mediates its effects via signaling through two G protein-coupled receptors, CXCR1 and CXCR2. Elevated CXCL8-CXCR1/2 signaling within the tumor microenvironment of numerous cancers is known to enhance tumor progression via activation of signaling pathways promoting proliferation, angiogenesis, migration, invasion and cell survival. This review provides an overview of established roles of CXCL8-CXCR1/2 signaling in cancer and subsequently, discusses the possible strategies of targeting CXCL8-CXCR1/2 signaling in cancer, covering indirect strategies (e.g., anti-inflammatories, NFκB inhibitors) and direct CXCL8 or CXCR1/2 inhibition (e.g., neutralizing antibodies, small molecule receptor antagonists, pepducin inhibitors and siRNA strategies). Reports of pre-clinical cancer studies and clinical trials using CXCL8-CXCR1/2-targeting strategies for the treatment of inflammatory diseases will be discussed. The future translational opportunities for use of such agents in oncology will be discussed, with emphasis on exploitation in stratified populations.