Cytokine blockade in inflammatory bowel diseases

Identification of OLA1 as a Novel Protein Target of Vitexin to Ameliorate Dextran Sulfate Sodium-Induced Colitis with Tissue Thermal Proteome Profiling

Vitexin, which exists in various medicinal plants and food sources, has recently received increasing attention because of its anti-inflammatory properties. This study aims to identify the protein target of vitexin that ameliorates dextran sulfate sodium (DSS)-induced colitis. The results showed that vitexin not only alleviated the clinical symptoms and colonic damage in mice with DSS-induced colitis but also suppressed the colonic production of inflammatory cytokines (IL-1β, IL-6, ICAM, and VCAM) and enhanced the expression of barrier-associated proteins (ZO-1, Occludin, and E-cadherin). Based on tissue thermal proteome profiling (Tissue-TPP) and molecular docking, OLA1 was creatively identified as a potential protein target for vitexin. Further siRNA-mediated knockdown of the OLA1 gene in Caco-2 cells demonstrated the ability of OLA1 to increase Nrf2 protein expression and, thus, mediated the anti-inflammatory effects of vitexin. Interaction of the OLA1-vitexin complex with Keap1 protein to disrupt the Keap1-Nrf2 interaction may be required for activating Nrf2. Our findings revealed a novel role for OLA1 as a protein target of vitexin that contributes to its anti-inflammatory action by activating Nrf2, which may provide a promising molecular mechanism for novel therapeutic strategies to treat colitis and the associated systemic inflammation.

Association between 6-thioguanine nucleotide levels and preventing production of antibodies to infliximab in patients with inflammatory bowel disease

OBJECTIVE

Combination therapy with infliximab and a thiopurine has been shown to be more effective than monotherapy in patients with inflammatory bowel disease (IBD). The therapeutic efficacy of thiopurines is correlated with 6-thioguanine (6-TGN) levels between 235 and 450 pmol/8×108 erythrocytes. The primary aim of the study was to investigate the association between 6-TGN levels and inhibition prevention of the production of antibodies to infliximab (ATI).

DESIGN

We performed a retrospective review of the medical records of patients being treated with infliximab for IBD at University Hospitals Bristol NHS Foundation Trust. Demographic and biochemical data were extracted, alongside thiopurine metabolite levels, trough levels of infliximab and the presence of ATI. χ2 tests were used to investigate the association between 6-TGN levels and prevention of ATI. Logistic regression was used to compare the odds of prevented ATI between those with a 6-TGN level between 235 and 450 pmol/8×108 erythrocytes, those with a 6-TGN level outside of this range, and the baseline group who were on infliximab monotherapy.

RESULTS

Data were extracted for 100 patients. Six of 32 patients with a 6-TGN level between 235 and 450 pmol/8×108 erythrocytes developed ATI (18.8%) compared with 14 out of 22 (63.6%) patients with a 6-TGN outside of this range and 32 out of 46 (69.6%) patients on monotherapy (p=0.001). The OR (95% CI) for prevented ATI in those with a 6-TGN between 235 and 450 pmol/8×108 erythrocytes compared with a 6-TGN outside of this range was 7.6 (2.2, 26.3) (p=0.001) and compared with monotherapy was 9.9 (3.3, 29.4) (p=0.001).

CONCLUSION

6-TGN levels between 235 and 450 pmol/8×108 erythrocytes prevented production of ATI. This supports therapeutic drug monitoring to help guide treatment and maximise the beneficial effects of combination therapy for patients with IBD.

Identification of anti-inflammatory components in Panax ginseng of Sijunzi Decoction based on spectrum-effect relationship

Objective

This study aimed to identify the main medicinal active components of Panax ginseng (P. ginseng) in the compatibility environment of clinical application. For this purpose, the anti-inflammatory ingredients of P. ginseng were investigated based on its therapeutic effect in Sijunzi Decoction (SJD) which is a widely used traditional Chinese formula.

Methods

The fingerprints of 10 batches of SJD consisting of different sources of P. ginseng were established by UPLC technique to investigate the chemical components. At the same time, the anti-inflammatory effects of these components were evaluated by dextran sulfate sodium-induced ulcerative colitis mouse model. Grey relational analysis was applied to explore the correlation degree between fingerprints and anti-inflammatory effects in SJD. Lipopolysaccharide-stimulated RAW264.7 murine macrophages were established to evaluate the anti-inflammatory action of the screened effective substances of P. ginseng.

Results

According to grey relational analysis, notoginsenoside R₁, ginsenoside Rg₂ and ginsenoside Rb₃ of P. ginseng were the major anti-inflammatory contributions in SJD. They had been proven to be closely associated with the anti-inflammatory process of SJD and displayed a close effect compared with SJD by LPS-stimulated RAW264.7 murine macrophages.

Conclusion

Our work provides a general strategy for exploring the pharmacological ingredients of P. ginseng in traditional Chinese formulas which is beneficial for establishing the quality standards of traditional herbs in traditional Chinese medicine prescription based on their clinical therapeutic effect.

HLAII peptide presentation of infliximab increases when complexed with TNF

CD4+ T-cell activation through recognition of Human Leukocyte Antigen II (HLAII)-presented peptides is a key step in the development of unwanted immune response against biotherapeutics, such as the generation of anti-drug antibodies (ADA). Therefore, the identification of HLAII-presented peptides derived from biotherapeutics is a crucial part of immunogenicity risk assessment and mitigation strategies during drug development. To date, numerous CD4+ T-cell epitopes have been identified by HLAII immunopeptidomics in antibody-based biotherapeutics using either their native or aggregated form. Antibody-target immune complexes have been detected in patients with ADA and are thought to play a role in ADA development by enhancing the presentation of CD4+ T-cell epitopes at the surface of antigen presenting cells (APCs). The aim of this study was to investigate the effect of biotherapeutic antibody-target immune complexes on the HLAII peptide presentation of biotherapeutics in human primary monocyte-derived dendritic cells (DCs). The trimeric tumor necrosis factor (TNF) and its biotherapeutic antagonists infliximab (INFL), adalimumab (ADAL), and a single armed Fab’ were used as a model system. The HLAII immunopeptidome of DCs loaded with antagonists or their immune complexes with TNF was analyzed by trapped ion mobility time-of-flight mass spectrometry (timsTOF MS) leading to the identification of ~ 12,000 unique HLAII-associated peptides per preparation. Anti-TNF sequences were detected at a median of 0.3% of the total immunopeptidome, against a majority background of peptides from endogenous and media-derived proteins. TNF antagonist presentation spanned the variable and constant regions in a widespread manner in both light and heavy chains, consistent with previously discovered HLAII peptides. This investigation extends the collection of observed HLAII peptides from anti-TNF biotherapeutics to include sequences that at least partially span the complementary determining regions (CDRs), such as the LCDR1 for both INFL and ADAL. Although antagonist presentation varied significantly across donors, peptides from both bivalent antagonists INFL and ADAL were more highly presented relative to the Fab’. While TNF immune complexes did not alter overall HLAII presentation, a moderate increase in presentation of a subset of peptide clusters was observed in the case of INFL-TNF, which included HCDR2, HCDR3 and LCDR2 sequences.

Effects of Jian Pi Qing Chang Hua Shi decoction on mucosal injuries in a 2,4,6-trinitrobenzene sulphonic acid-induced inflammatory bowel disease rat model

CONTEXT

Jian Pi Qing Chang Hua Shi decoction (JPQCHSD) has been considered as an effective remedy for the treatment of inflammatory bowel disease (IBD) in Chinese traditional medicine.

OBJECTIVE

We evaluated the efficacy of JPQCHSD on 2-4-6-trinitrobenzene sulphonic acid (TNBS)-induced IBD rats and the responsible mechanisms.

MATERIALS AND METHODS

Except the rats of the control group (50% ethanol), Sprague-Dawley rats (180 ± 20 g) induced by TNBS (150 mg/kg in 50% ethanol), received water extract of JPQCHSD daily at 0, 9.5, 19, or 38 g/kg for 12 days. The rats were sacrificed, and their colons were removed to evaluate the disease activity index. Malondialdehyde (MDA), superoxide dismutase (SOD), myeloperoxidase (MPO), immunoglobulin A (IgA), tumour necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and nuclear factor-κB were evaluated.

RESULTS

JPQCHSD extract significantly reduced the disease activity index of TNBS-induced colitis with a median effective dose (ED₅₀) of 26.93 g/kg. MPO and MDA were significantly reduced in the 19 and 38 g/kg groups (ED₅₀ values 37.38 and 53.2 g/kg, respectively). The ED₅₀ values for the increased SOD and IgA were 48.98 and 56.3 g/kg. ED₅₀ values for inhibition of TNF-α, IL-1β, and IL-6 were 32.66, 75.72, and 162.06 g/kg, respectively.

DISCUSSION

JPQCHSD promoted mucosal healing in IBD rats via its anti-inflammation, immune regulation, and antioxidation properties.

CONCLUSIONS

JPQCHSD has healing function on IBD. Further clinical trials are needed to demonstrate its efficacy and tolerance to IBD.

MicroRNA-602 prevents the development of inflammatory bowel diseases in a microbiota-dependent manner

Inflammatory bowel diseases (IBD) are a group of chronic disorders occurring in the intestinal tract. Previous studies demonstrated that genetics and microbiota play critical roles in the pathogenesis of IBD. Discoveries of genes that may regulate the homeostasis of gut microbiota and pathogenesis of IBD have the potential to provide new therapeutic targets for IBD treatment. The results suggested that the expression level of microRNA (miR)-602 is negatively related to the development of IBD, and that miR-602 overexpression in mice may prevent inflammation and intestinal barrier injuries in dextran sulfate sodium (DSS)-induced IBD mice. It was also found that the microbiota is important for miR-602-mediated prevention of IBD, as the inhibitory effect of miR-602 was lost when the microbiota was depleted using antibiotics. Furthermore, co-housing or adoptive transfer of microbiota from miR-602 could attenuate the pathogenesis of IBD. In addition, it was demonstrated that miR-602 could target tumor necrosis factor receptor-associated factor 6 (TRAF6) in intestinal epithelial cells. Collectively, the present results suggest that miR-602 plays a protective role in DSS-induced IBD by targeting TRAF6 in a microbiota-dependent manner.

MiR-146b-5p targets IFI35 to inhibit inflammatory response and apoptosis via JAK1/STAT1 signalling in lipopolysaccharide-induced glomerular cells

The dysregulated microRNAs (miRNAs) are implicated in the malignancy of lupus nephritis (LN). This work aims to analyse the effect and mechanism of miR-146b-5p in lipopolysaccharides (LPS)-induced model of LN in vitro. The serum samples of LN patients and normal volunteers were collected. HK-2 cells were challenged via LPS. miR-146b-5p and interferon-induced protein 35 (IFI35) abundances were detected via quantitative real-time polymerase chain reaction (qRT-PCR) or western blot. The inflammatory response was assessed via inflammatory cytokines levels via qRT-PCR and enzyme-linked immunosorbent assay. Cell apoptosis was analysed via flow cytometry and apoptotic protein levels. The protein levels of JAK1/STAT1 signalling were detected via western blot. The relationship of miR-146b-5p and IFI35 was analysed via bioinformatics and dual-luciferase reporter assays. This study revealed that miR-146b-5p level was declined and IFI35 abundance was elevated in serum of LN patients and LPS-challenged HK-2 cells. Functionally, IFI35 overexpression promoted LPS-caused inflammatory response and cell apoptosis, and knockdown of IFI35 caused an opposite trend. Meanwhile, miR-146b-5p targeted IFI35 to suppress inflammatory response and cell inflammatory response and apoptosis via inactivating the JAK1/STAT1 pathway. MiR-146b-5p suppressed inflammatory response and cell apoptosis by IFI35 mediated-JAK1/STAT1 signalling in HK-2 cells, which provided a new mechanism for understanding the pathogenesis of LN.

Redundant cytokine requirement for intestinal microbiota-induced Th17 cell differentiation in draining lymph nodes

Differentiation of intestinal T helper 17 (Th17) cells, which contribute to mucosal barrier protection from invasive pathogens, is dependent on colonization with distinct commensal bacteria. Segmented filamentous bacteria (SFB) are sufficient to support Th17 cell differentiation in mouse, but the molecular and cellular requirements for this process remain incompletely characterized. Here, we show that intestine-draining mesenteric lymph nodes (MLNs), not intestine proper, are the dominant site of SFB-induced intestinal Th17 cell differentiation. Subsequent migration of these cells to the intestinal lamina propria is dependent on their upregulation of integrin β7. Stat3-dependent induction of RORγt, the Th17 cell-specifying transcription factor, largely depends on IL-6, but signaling through the receptors for IL-21 and IL-23 can compensate for absence of IL-6 to promote SFB-directed Th17 cell differentiation. These results indicate that redundant cytokine signals guide commensal microbe-dependent Th17 cell differentiation in the MLNs and accumulation of the cells in the lamina propria.

Telfairia occidentalis mitigates dextran sodium sulfate-induced ulcerative colitis in rats via suppression of oxidative stress, lipid peroxidation, and inflammation

Ulcerative colitis (UC), a subcategory of inflammatory bowel diseases, affects more than 2 million people globally. This study sought to investigate the curative ability of aqueous leaf extract of Telfairia occidentalis (ATO) on dextran sodium sulfate (DSS)-mediated colitis in rats. UC was induced by 5% of DSS in drinking water, and the curative ability of ATO was assessed at 200 mg/kg by oral administration for 10 days. The effect of ATO was deduced on anti-inflammatory, preclinical features [disease activity index (DAI)], redox assays, and alterations both microscopic and macroscopic of the colonic mucosa. DSS mediated inflammation in colons of rats with a significant increase in nitric oxide, myeloperoxidase, IL-1β, IL-6, and TNF-α levels compared with a control group. Lipid peroxidation was also induced following exposure of rats to DSS. There is a marked decrease in antioxidant enzymes activities in DSS group. However, treatment with ATO markedly inhibited the colonic inflammation by reversing the elevated levels of inflammatory markers. Furthermore, ATO suppressed the lipid peroxidation chain reaction by reducing the level of malondialdehyde and hydrogen peroxide. ATO attenuates DSS-induced oxidative stress by increase the level of GSH and enhancing the activities of the cytoprotective enzymes (catalase, glutathione-S-transferase, and superoxide dismutase). Taken together, ATO reduced DAI score, inhibited inflammation, suppressed lipid peroxidation, attenuated oxidative stress, and enhanced the antioxidant enzymes activities. These therapeutic effects of ATO might be due to its phytochemicals as showed in gas chromatography-mass spectroscopy results. The findings of this study indicate that aqueous leaf extract of T. occidentalis has could be a drug candidate for the treatment of UC. PRACTICAL APPLICATIONS: The study focused on the curative ability of aqueous leaf extract of Telfairia occidentalis on dextran sodium sulfate (DSS) mediated colitis in rats. The extract elicits beneficial effects against colitis via its ability to reduce mucosal inflammation, suppress lipid peroxidation, attenuate oxidative stress, enhance the antioxidant enzymes activities, and reduce both infiltration of inflammatory cells and mucosal damage in colon. This study provides scientific evidence to the therapeutic ability of aqueous leaf extract of T. occidentalis in the treatment of DSS-induced ulcerative colitis and could be a drug candidate for the treatment of inflammatory bowel diseases in humans.

Dendrobium huoshanense Polysaccharides Prevent Inflammatory Response of Ulcerative Colitis Rat through Inhibiting the NF-κB Signaling Pathway

The polysaccharides of the Chinese herbal medicine Dendrobium huoshanense exhibit anti-inflammatory effects in multiple organs through regulating the immune responses. In the present study, we constructed ulcerative colitis (UC) model rats using dextran sulfate sodium to investigate the anti-inflammatory effects of D. huoshanense polysaccharides (DHP). After oral administration of DHP for two weeks, the indices of UC symptoms, including the ratio of colon weight to length, Disease Activity Index (DAI), and Colon Mucosal Damage Index (CMDI), all decreased significantly compared with the UC model group. The histological sections also revealed better cell orders in DHP treatments than in the UC model rats. Moreover, in treatment with high dose of DHP (200 mg/kg), the treatment efficacy arrived the similar levels to those in the treatment with 300 mg/kg sulfasalazine, which is a typical medicine to treat UC. These results indicated that DHP has a high efficacy to treat UC in model rats. Furthermore, serum levels of interleukin-1β, tumor necrosis factor-α, interleukin-17, and transforming growth factor-β were assessed using the enzyme linked immunosorbent assay (ELISA) method, and the levels of nuclear factor-κB in colon tissue sections were determined using the immunohistochemical method. The results showed that all these indices decreased significantly after administration of DHP in UC model rats, which might be the mechanisms underlying the DHP-suppressed UC inflammation. Overall, this study indicated that DHP might be directly used to treat UC and is a promising source to develop novel drugs against UC.

Mogrol, an aglycone of mogrosides, attenuates ulcerative colitis by promoting AMPK activation

BACKGROUND

Ulcerative colitis (UC) is a non-specific chronic inflammatory disease. The incidence of UC in China has been increasing in recent years. Mogrol is an aglycone of mogrosides. Studies have shown that mogrosides have anti-oxygenation, anti-inflammatory, and laxative effects as well as other biological activities.

PURPOSE

To investigate the beneficial effects of mogrol on UC and identify its underlying mechanisms.

STUDY DESIGN

We used the dextran sodium sulphate (DSS)-induced UC model in mice, TNF-α-damaged NCM460 colonic epithelial cells, macrophage cells THP-M stimulated with lipopolysaccharide (LPS) / adenosine triphosphate (ATP) and compound C (an AMPK inhibitor) to confirm the key role of AMPK (AMP-activated protein kinase) activation.

METHODS

Histological evaluation, immunohistochemical staining, Western blot analysis, immunofluorescence assay and quantitative real time-PCR were used in the study.

RESULTS

Oral administration of mogrol (5 mg/kg/daily) in vivo significantly attenuated pathological colonic damage, inhibited inflammatory infiltration and improved the abnormal expression of NLRP3 inflammasome in colonic mucosa via the AMPK and NF-κB signaling pathways. In vitro, mogrol protected against intestinal epithelial barrier dysfunction by activating AMPK in TNF-α-treated NCM460 cells and inhibited the production of inflammatory mediator in LPS-stimulated THP-M cells. Furthermore, mogrol's effects were reversed by compound C intervention in DSS-induced UC model.

CONCLUSION

Mogrol exerts protective effects in experimental UC and inhibits production of inflammatory mediators through activation of AMPK-mediated signaling pathways.

Preparation, characterization, and in vivo evaluation of anti-inflammatory activities of selenium nanoparticles synthesized by Kluyveromyces lactis GG799

Selenium (Se) is an essential micronutrient that has implications in human diseases, including inflammatory bowel disease (IBD), especially with respect to Se deficiencies. Recently, selenium nanoparticles (SeNPs) have attracted significant attention due to their diversity of biological activities and unique advantages including low toxicity and high biological availability. In this study, an eco-friendly, efficient and low-cost method for synthesis of SeNPs by Kluyveromyces lactis GG799 (K. lactis GG799) was established, and the SeNPs were investigated for their physicochemical properties and anti-inflammatory activities in vivo. K. lactis GG799 was able to successfully transform sodium selenite into bright-red SeNPs with particle sizes of 80 and 150 nm and the nanoparticles accumulated intracellularly. Upon isolation, the SeNPs were found to be mainly capped by proteins and polysaccharides by components analysis. Dietary supplementation with 0.6 mg kg-1 Se (in the form of biogenic SeNPs) effectively attenuated dextran sulphate sodium (DSS)-induced ulcerative colitis (UC) in mice by alleviating oxidative stress and intestinal inflammation. These findings suggested that SeNPs synthesized by K. lactis GG799 may be a promising and safe Se supplement for the prevention and treatment of IBD.

Characterization of Low Molecular Weight Sulfate Ulva Polysaccharide and its Protective Effect against IBD in Mice

Inflammatory bowel disease (IBD) has been gradually considered a public health challenge worldwide. Sulfated polysaccharides, extracted from seaweed, have been shown to have an anti-inflammatory effect on the disease. In this study, LMW-ulvan, a unique sulfate Ulva polysaccharide with low molecular weight, was prepared using the enzymatic method. The structural characterization of LMW-ulvan and its protective effect on colitis induced by dextran sulfate sodium (DSS) were studied. The results showed that LMW-ulvan with molecular weight of 2.56 kDa consists of 57.23% rhamnose (Rha), 28.76% xylose (Xyl), 7.42% glucuronic acid (GlcA), and 1.77% glucose (Glc). Its backbone contains (1→3,4)-linked Rha, (1→4)-linked Xyl, and (1→4)-linked GlcA with small amounts of (1→4)-linked Rha residues; sulfate substitution was at C-3 of Rha. LMW-ulvan was found to reduce DSS-induced disease activity index, colon shortening, and colonic tissue damage, which were associated with decreased oxidative stresses and inflammation, thus improving the expression of tight junction proteins. These results indicate that LMW-ulvan is able to improve colitis and may be a promising application for IBD.

Protective effects of Lizhong decoction on ulcerative colitis in mice by suppressing inflammation and ameliorating gut barrier

ETHNOPHARMACOLOGICAL RELEVANCE

Lizhong Decoction (LZD) is a classical prescription firstly recorded in "Shanghan Lun". It has been used to clinically treat ulcerative colitis (UC) for thousands of years. However, its mechanism is not clear up to now.

AIM OF THE STUDY

The goal of this study was to assess the amelioration of LZD on dextran sodium sulfate (DSS)-induced colitis in mice and further clarify its mechanism.

MATERIALS AND METHODS

The ulcerative colitis model induced by DSS was successfully established and applied to evaluate the intervention effect after oral administration of LZD. Furthermore, the expression of key targets in inflammatory signaling pathways and intestinal tight junction proteins were investigated by enzyme-linked immunosorbent assay (ELISA) and quantitative real time polymerase chain reaction (qPCR) analysis.

RESULTS

The results showed that all doses of LZD could notably improve DSS-induced colon lesions, reduce histological scores, prolong colon length and increase body weight. Colonic inflammation in UC mice was significantly alleviated by inhibiting the activities of myeloperoxidase (MPO) and superoxide dismutase (SOD), reducing the yield of nitric oxide (NO) and inflammatory cytokines such as interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and interleukin-6 (IL-6), and along with promoting the production of anti-inflammatory cytokines such as interleukin-4 (IL-4) and interleukin-10 (IL-10) after LZD treatment. Furthermore, LZD remarkably down-regulated the level of toll-like receptor 4 (TLR4) and nuclear factor-κB (NF-κB) mRNA and up-regulated the expression of tight junction proteins (zonula occluden-1, occludin and claudin-1) in UC mice.

CONCLUSION

In summary, this study indicated that LZD could notably improve UC symptoms by suppressing inflammation and ameliorating gut barrier, which provided scientific basis for its clinical application in the future.

CU06-1004 Alleviates Experimental Colitis by Modulating Colonic Vessel Dysfunction

Inflammatory bowel disease is an autoimmune disease that causes chronic inflammation of the gastrointestinal tract. Endothelial dysfunction, defined by a reduced endothelial barrier and an increase in the expression of adhesion molecules, is part of the pathology of inflammatory bowel disease. In this study, we assessed the therapeutic effect of CU06-1004, an endothelial dysfunction blocker that reduces vascular hyperpermeability and inflammation in a mouse model of colitis. Acute colitis was induced in mice using 3% (w/v) dextran sodium sulfate added to their drinking water for 7 days. Twenty-four hours after the addition of dextran sodium sulfate, either mesalazine or CU06-1004 was administered orally each day. Administration of CU06-1004 significantly reduced the clinical manifestations (weight loss, diarrhea, and bloody stool) and histological changes (epithelium loss, inflammatory cell infiltration, and crypt destruction) induced by dextran sodium sulfate. Proinflammatory cytokines were also reduced, indicating that inflammation was ameliorated. From a vascular perspective, CU06-1004 reduced interrupted and tortuous vessels, enhanced junction protein expression, and reduced inflammatory adhesion molecules, indicating a broad improvement of endothelial dysfunction. Endothelial protection induced epithelial barrier restoration and decreased epithelial inflammation. Blocking endothelial dysfunction with CU06-1004 significantly ameliorated the progression of inflammatory bowel disease. Therefore, CU06-1004 may represent a potential therapeutic agent for the treatment of inflammatory bowel disease as well as other inflammatory diseases.

Onion bulb extract reduces colitis severity in mice via modulation of colonic inflammatory pathways and the apoptotic machinery

ETHNOPHARMACOLOGICAL RELEVANCE

The use of nutraceutical-based products has increased in recent years due to their demonstrated efficacy and their good safety profile. Onion is one of the most commonly used plants in the traditional medicine for the management of various conditions including inflammatory and gastrointestinal diseases. However, little is known regarding the molecular mechanism of the anti-inflammatory effects of onion particularly in inflammatory bowel disease (IBD).

AIM OF THE STUDY

To test the anti-inflammatory effects of onion bulb extract (OBE) in an IBD mouse model and the molecular mechanisms responsible for these effects such as modulation of the expression and/or the activity profile of various pro-inflammatory molecules.

MATERIALS AND METHODS

Colitis was induced in mice by dextran sulfate sodium (DSS) daily administration for 5 days. Animals were sacrificed, colons were removed and the severity of the inflammation was determined by the gross and histological assessments. The colonic level/activity of various cytokines and chemokines were measured using proteome profiling-based assay, western blotting, and immunofluorescence techniques.

RESULTS

DSS-induced colitis was significantly reduced by the daily OBE treatment and 5-aminosalicylic acid (5-ASA, positive control), particularly at 100-200 mg/kg doses, at both the gross and histological levels. OBE was also shown to reduce colonic expression and activity of several pro-inflammatory molecules and signaling pathways, such as mitogen activated protein kinase family, mammalian target of rapamycin, cyclooxygenase-2, and tissue inhibitors of metalloproteinases. In addition, OBE reduced the expression of interferon-γ, various C-C and C-X-C chemokines, and molecules involved in the apoptotic machinery such as cytochrome c, caspase-3 and -8, B-cell lymphoma-extra-large and -2.

CONCLUSIONS

OBE showed anti-inflammatory actions in IBD mouse model, which is attributed, in part, to the modulation of the expression and the activity of important pro-inflammatory molecules and signaling pathways involved in the inflammatory response. These data suggest that OBE may be a promising lead in the therapeutic management of IBD.

Adoptive transfer of dendritic cells expressing CD11c reduces the immunological response associated with experimental colitis in BALB/c mice

INTRODUCTION

In addition to conventional therapies, several new strategies have been proposed for modulating autoimmune diseases, including the adoptive transfer of immunological cells. In this context, dendritic cells (DCs) appear to be one of the most promising treatments for autoimmune disorders. The present study aimed to evaluate the effects of adoptive transfer of DCs obtained from both naïve and ovalbumin (OVA)-tolerant mice on the severity of TNBS induced colitis and analyze the eventual protective mechanisms.

METHODS AND RESULTS

To induce oral tolerance, BALB/c mice were fed 4mg/mL OVA solution for seven consecutive days. Spleen DCs were isolated from tolerant (tDC) and naïve (nDC) mice, and then adoptively transferred to syngeneic mice. Three days later, colitis was induced in DC treated mice by intrarectal instillation of 100μg2,4,6-trinitrobenzenesulfonic acid (TNBS) dissolved in 50% ethanol. Control subjects received only intrarectal instillation of either TNBS solution or a vehicle. Five days later, mice from all groups were euthanized and examined for physiological and immunological parameters. Regarding the phenotype, we observed that the frequencies of CD11+ MHC II+ and CD11+ MHCII+ CD86+ cells were significantly lower in DCs isolated from tolerant mice than in those from naive mice. However, pretreatment with both types of DCs was able to significantly reduce clinical signs of colitis such as diarrhea, rectal prolapse, bleeding, and cachexia, although only treatment with tDCs was able to prevent weight loss from instillation of TNBS. In vitro proliferation of spleen cells from mice treated with either type of DCs was significantly lower than that observed in splenic cell cultures of naïve mice. Although no significant difference was observed in the frequencies of Treg cells in the experimental groups, the frequency of Th17+CD4+cellsand the secretion of IL-17 were more reduced in the cultures of spleen cells from mice treated with either type of DCs. The levels of IL-9 and IFN-γ were lower in supernatants of cells from mice treated with nDCs.

CONCLUSION

The results allow us to conclude that the adoptive transfer of cells expressing CD11c is able to reduce the clinical and immunological signs of drug-induced colitis. Adoptive transfer of CD11c+DC isolated from both naive and tolerant mice altered the proliferative and T cell responses. To the best of our knowledge, there is no previously published data showing the protective effects of DCs from naïve or tolerant mice in the treatment of colitis.

Berberrubine attenuates mucosal lesions and inflammation in dextran sodium sulfate-induced colitis in mice

Ulcerative colitis (UC) is a chronic relapsing disease without satisfactory treatments, in which intestinal inflammation and disrupted intestinal epithelial barrier are two main pathogeneses triggering UC. Berberrubine (BB) is deemed as one of the major active metabolite of berberine (BBR), a naturally-occurring isoquinoline alkaloid with appreciable anti-UC effect. This study aimed to comparatively investigate the therapeutic effects of BB and BBR on dextran sodium sulfate (DSS)-induced mouse colitis model, and explore the potential underlying mechanism. Results revealed that BB (20 mg/kg) produced a comparable therapeutic effect as BBR (50 mg/kg) and positive control sulfasalazine (200 mg/kg) by significantly reducing the disease activity index (DAI) with prolonged colon length and increased bodyweight as compared with the DSS group. BB treatment was shown to significantly ameliorate the DSS-induced colonic pathological alternations and decreased histological scores. In addition, BB markedly attenuated colonic inflammation by alleviating inflammatory cell infiltration and inhibiting myeloperoxidase (MPO) and cytokines (TNF-α, IFN-γ, IL-1β, IL-6, IL-4 and IL-10) productions in DSS mice. Furthermore, BB treatment substantially upregulated the expression of tight junction (TJ) proteins (zonula occludens-1, zonula occludens-2, claudin-1, occludin) and mRNA expression of mucins (mucin-1 and mucin-2), and decreased the Bax/Bcl-2 ratio. In summary, BB exerted similar effect to its analogue BBR and positive control in attenuating DSS-induced UC with much lower dosage and similar mechanism. The protective effect observed may be intimately associated with maintaining the integrity of the intestinal mucosal barrier and mitigating intestinal inflammation, which were mediated at least partially, via favorable modulation of TJ proteins and mucins and inhibition of inflammatory mediators productions in the colonic tissue. This is the first report to demonstrate that BB possesses pronounced anti-UC effect similar to BBR and sulfasalazine with much smaller dosage. BB might have the potential to be further developed into a promising therapeutic option in the treatment of UC.

Comparative Evaluation between Sulfasalazine Alone and in Combination with Herbal Medicine on DSS-Induced Ulcerative Colitis Mice

The present study aimed to investigate the comparative evaluation of pharmacological efficacy between sulfasalazine alone and sulfasalazine in combination with herbal medicine on dextran sodium sulfate- (DSS-) induced UC in mice. Balb/c mice received 5% DSS in drinking water for 7 days to induce colitis. Animals were divided into five groups (n = 9): Group I (normal group), Group II (DSS control group), Group III (DSS + sulfasalazine (30 mg/kg)), Group IV (DSS + sulfasalazine (60 mg/kg)), and Group V (DSS + sulfasalazine (30 mg/kg) + Cinnamomi Cortex and Bupleuri Radix mixture (30 mg/kg) (SCB)). Colonic pathological changes were analyzed using hematoxyline/eosin staining. The antioxidant, inflammatory, and apoptotic protein levels were determined using western blotting. SCB supplementation, as well as sulfasalazine, suppressed colonic length and mucosal inflammatory infiltration. In addition, SCB treatment significantly reduced the expression of proinflammatory signaling molecules through suppression of both mitogen-activated protein kinases (MAPK) and nuclear factor-kappa B (NF-κB) signaling pathways and prevented the apoptosis of the colon. Moreover, SCB administration significantly led to the upregulation of antioxidant enzymes including SOD and catalase. Taken together, SCB treatment might offer a better treatment for human UC than sulfasalazine alone or may be useful as an alternative therapeutic strategy against UC, without any evidence of side effects.

Cytokine production in vitro and in rat model of colitis in response to Lactobacillus plantarum LS/07

Over the past decade, it has become clear that specific probiotic lactobacilli are valuable in the prevention and treatment of infectious and inflammatory diseases of gastrointestinal tract but their successful application would benefit greatly from a better understanding of the mechanisms of individual strains. Hence, each probiotic strain should be characterized for their immune activity before being proposed for clinical applications. The aim of the study was to characterize the immunomodulatory activity of the strain Lactobacillus (L.) plantarum LS/07 in vitro using functional gut model and to study its anti-inflammatory potential in dextran sulphate sodium (DSS)-induced colitis in rats. We showed that L. plantarum LS/07 induced production of IL-10 in macrophages derived from blood monocytes as well as monocyte/macrophages cell line stimulated indirectly via enterocytes in vitro. In rat model of colitis, L. plantarum LS/07 attenuated the DSS-induced signs of inflammatory process in colon such as weight loss, diarrhoea, infiltration of inflammatory cells associated with decreased colon weight/length ratio, inhibited gut mucosa destruction and depletion of goblet cells. Moreover, the strain increased the concentration of anti-inflammatory cytokine IL-10 in mucosal tissue. In conclusion, the protective effects of L. plantarum LS/07 in the DSS-induced colitis model seem to be related to the stimulation of IL-10 and the restoration of goblet cells and indicate it as a good candidate to prevent and treat diseases associated with inflammation.

Risk of tuberculosis in patients treated with TNF-α antagonists: a systematic review and meta-analysis of randomised controlled trials

OBJECTIVES

An increased risk of tuberculosis (TB) has been reported in patients treated with TNF-α antagonists, an issue that has been highlighted in a WHO black box warning. This review aimed to assess the risk of TB in patients undergoing TNF-α antagonists treatment.

METHODS

A systematic literature search for randomised controlled trials (RCTs) was performed in MEDLINE, Embase and Cochrane library and studies selected for inclusion according to predefined criteria. ORs with 95% CIs were calculated using the random-effect model. Subgroup analyses considered the effects of drug type, disease and TB endemicity. The quality of evidence was assessed using the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach.

RESULTS

29 RCTs involving 11 879 patients were included (14 for infliximab, 9 for adalimumab, 2 for golimumab, 1 for etanercept and 3 for certolizumab pegol). Of 7912 patients allocated to TNF-α antagonists, 45 (0.57%) developed TB, while only 3 cases occurred in 3967 patients allocated to control groups, resulting in an OR of 1.94 (95% CI 1.10 to 3.44, p=0.02). Subgroup analyses indicated that patients of rheumatoid arthritis (RA) had a higher increased risk of TB when treated with TNF-α antagonists (OR 2.29 (1.09 to 4.78), p=0.03). The level of the evidence was recommended as 'low' by the GRADE system.

CONCLUSIONS

Findings from our meta-analysis indicate that the risk of TB may be significantly increased in patients treated with TNF-α antagonists. However, further studies are needed to reveal the biological mechanism of the increased TB risk caused by TNF-α antagonists treatment.

Selenium nanoparticles decorated with Ulva lactuca polysaccharide potentially attenuate colitis by inhibiting NF-κB mediated hyper inflammation

Background

Selenium (Se) is an essential micronutrient trace element and an established nutritional antioxidant. Low Se status exacerbates inflammatory bowel diseases progression, which involves hyper inflammation in the digestive tract. Se nanoparticles (SeNPs) exhibit anti-inflammatory activity accompanied by low toxicity, especially when decorated with natural biological compounds. Herein, we explored the beneficial effects of SeNPs decorated with Ulva lactuca polysaccharide (ULP) in mice subjected to the acute colitis model.

Results

We constructed SeNPs coated with ULP (ULP-SeNPs) in average diameter ~130 nm and demonstrated their stability and homogeneity. Supplementation with ULP-SeNPs (0.8 ppm Se) resulted in a significant protective effect on DSS-induced acute colitis in mice including mitigation of body weight loss, and colonic inflammatory damage. ULP-SeNPs ameliorated macrophage infiltration as evidenced by decreased CD68 levels in colon tissue sections. The anti-inflammatory effects of ULP-SeNPs were found to involve modulation of cytokines including IL-6 and TNF-α. Mechanistically, ULP-SeNPs inhibited the activation of macrophages by suppressing the nuclear translocation of NF-κB, which drives the transcription of these pro-inflammatory cytokines.

Conclusions

ULP-SeNPs supplementation may offer therapeutic potential for reducing the symptoms of acute colitis through its anti-inflammatory actions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12951-017-0252-y) contains supplementary material, which is available to authorized users.

The relationship between the immune system and oral manifestations of inflammatory bowel disease: a review

Inflammatory bowel diseases (IBDs) are chronic, relapsing inflammatory diseases characterized by exacerbations and remissions of the gastrointestinal tract, clinically manifested as Crohn's disease and ulcerative colitis. The etiology of IBDs is considered to be multi factorial, comprising environmental, immune, microbial and genetic factors. Clinical signs may include abdominal pain, frequent bloody diarrheas, mucorrhea, vomiting, fever, fatigue or weight loss. Changes in the oral cavity often precede intestinal symptoms. Inflammatory bowel disease leads to a significant deterioration of oral health, which indicates that cooperation between the dentist and the gastroenterologist is necessary when considering patients' welfare. Patients with IBD have an altered immune response, but microorganisms of the oral cavity may also be responsible for its modification. This review paper discusses the correlation between the immune system and inflammatory bowel disease manifestations in the oral cavity.

Standardization of the homogeneous mobility shift assay protocol for evaluation of anti-infliximab antibodies. Application of the method to Crohn's disease patients treated with infliximab

BACKGROUND

The availability of a quantitative method to measure anti-infliximab (IFX) antibodies (ATI) would facilitate the implementation of therapeutic drug monitoring in clinical decision-making. Our aim was to standardize the homogeneous mobility shift assay (HMSA) used in the measure of ATI levels.

METHODS

In this prospective longitudinal multicenter study, 50 IFX-treated Crohn's disease (CD) patients were followed up for 54weeks. During this period 360 human serum samples were analysed. Monomeric ATI levels were measured by a quantitative HMSA-method using an anti-IFX calibrator. IFX trough levels measured by ELISA were correlated with ATI levels.

RESULTS

Using HMSA and a pure anti-idiotypic monoclonal antibody specific for IFX (anti-IFX calibrator), we measured the levels of monomeric ATI generated in Crohn's disease patients treated with IFX. Anti-IFX calibrator allowed to quantify monomeric antibodies against IFX with a low limit of quantification (3nM). The threshold level of ATI in order to classify the immunogenicity of the patients was 10nM. We observed that 24% (12/50) of IFX-treated patients developed ATI (>10nM) during the observation period (54weeks). Serum concentration of ATI higher than 10nM dramatically increased the probability (OR=51.1; 95% CI: 20.4-128.0; p<0.0001) of presenting low levels of IFX (⩽1.5nM) in serum, as observed in some CD patients treated with standard doses of the drug.

CONCLUSIONS

The HMSA-method described here allows an accurate quantification of ATI concentration in international units (IU) and therefore it could be useful in the study of the relationship between ATI concentration, infliximab level and the clinical response to the drug.

Protective Effect of Amphipterygium adstringens Extract on Dextran Sulphate Sodium-Induced Ulcerative Colitis in Mice

Amphipterygium adstringens is an endemic species in Mexico commonly known as “cuachalalate.” Healers to treat gastritis, gastric ulcers, and gastrointestinal cancer have traditionally used the bark. We investigated the effects of alcoholic extract of A. adstringens (AaEE) in DSS-induced colitis in mice. The protective effect of AaEE was determined at 200 mg/kg by oral gavage for 10 days. We determine the effect of AaEE on clinical features (disease activity index), antioxidants, anti-inflammatory, and immunomodulatory activities in relation to the activity of SOD, CAT, and GPx, levels of proinflammatory cytokines, and changes both macroscopic and microscopic of the colonic mucosa. AaEE significantly reduced the inflammation of colon and significantly increased SOD and GPx activities. AaEE also significantly decreased TNF-α, IFN-γ, and IL-1β cytokine levels compared to DSS-treated mice and reduced both infiltration of inflammatory cells and the mucosal damage in colon. The results suggested the protective potential of AaEE in DSS-induced colitis and this might be attributed to its phytochemicals compounds that have been found to induce a wide spectrum of activities such as reduction in oxidative stress, suppression of inflammation, modulating numerous signal transduction pathways, and induction of apoptosis. The findings of this study suggest that AaEE has substantial potential for the treatment of inflammatory colitis.

Beneficial Effects of Fecal Microbiota Transplantation on Ulcerative Colitis in Mice

BACKGROUND

Ulcerative colitis (UC) is a chronic condition and the most common form of inflammatory bowel disease. The goal of standard treatment is mainly to induce and maintain remission with anti-inflammatory, immunosuppressive agents, and/or colectomy. Fecal microbiota transplantation (FMT) has been used successfully to treat relapsing or refractory Clostridium difficile infection. The alteration of microbiota in mouse models of UC as well as in patients suggested the possibility of treating UC with FMT.

AIMS

To study the effects of FMT on dextran sodium sulfate (DSS)-induced UC model in mice.

METHODS

Littermates of BALB/c and C57BL/6J were randomized into four groups: normal control , treatment with DSS for 7 days (DSS - FMT), treatment with DSS followed by FMT for another 8 days (DSS + FMT), and treatment with DSS and FMT followed by another 5 days for recovery (remission). Body weight, survival rate, and DAI scores of mice in each group were recorded. Changes in distal colon were studied by histopathology. Alterations of spleen and lamina propria regulatory lymphocytes, major bacterial species in feces and inflammatory cytokines in colon were also studied.

RESULTS

C57BL/6J mice experienced more significant weight loss than BALB/c mice after DSS treatment, regardless of whether the two strains of mice were co-housed or not. FMT caused reversal of DAI scores in BALB/c but not in C57BL/6J mice. In BALB/c mice, FMT also reduced colon inflammation that was paralleled by decreased inflammatory cytokine levels, altered bacterial microbiota, and regulatory lymphocyte proportions.

CONCLUSIONS

FMT is effective in a mouse model of UC through its modulation on gut microbiota and the host immune system.

Characterization of TNF-α- and IL-17A-Mediated Synergistic Induction of DEFB4 Gene Expression in Human Keratinocytes through IκBζ

Human β-defensin 2 (hBD2), encoded by the DEFB4 gene, is an antimicrobial peptide playing an essential role in inflammatory processes in the skin. hBD2 expression is regulated synergistically by tumor necrosis factor-α (TNF-α) and IL-17A; however, the underlying regulatory mechanisms are unknown. The purpose of this study was to characterize the molecular mechanism by which TNF-α and IL-17A synergistically induce hBD2 expression. In cultured human keratinocytes we show that a constitutive noninducible binding of the transcription factor organic cation transporter 1 (OCT1) to the DEFB4 promoter is crucial for IL-17A/TNF-α-mediated synergistic induction of hBD2 but not the synergistic induction of CCL20, IL8, IL17C and LCN2. Interestingly, stimulation with IL-17A results in a p38 mitogen-activated protein kinase-dependent accumulation of inhibitor of nuclear factor κB ζ (IκBζ), which is a necessity for synergistic induction of hBD2. Finally, co-stimulation with TNF-α induces DNA binding of NF-κB and activator protein 1 (AP-1) to two specific sites in the DEFB4 promoter region. Hence, our study shows how two inflammatory stimuli are integrated by three different signaling pathways into the regulation of one specific target gene involving the three specific transcription factors OCT1, NF-κB, and AP-1 as well as the transcriptional cofactor IκBζ. These findings may be important in psoriasis, where TNF-α and IL-17A have been identified as key pathogenic cytokines.

Anti-inflammatory Actions of (+)-3'α-Angeloxy-4'-keto-3',4'-dihydroseselin (Pd-Ib) against Dextran Sulfate Sodium-Induced Colitis in C57BL/6 Mice

The immunoregulatory protective properties of (+)-3'α-angeloxy-4'-keto-3',4'-dihydroseselin (Pd-Ib) isolated from Bupleurum malconense has not been reported. In the present study, the therapeutic effect of Pd-Ib (30, 60, and 120 mg/kg/day) was examined in a mouse model of dextran sulfate sodium (DSS)-induced acute colitis. Administration of Pd-Ib significantly reduced the disease activity index, inhibited the shortening of colon length, reduced colonic tissue damage, and suppressed colonic myeloperoxidase activity and nitric oxide levels in mice with DSS-induced colitis. Moreover, Pd-Ib greatly suppressed the secretion of pro-inflammatory cytokines TNF-α, IFN-γ, IL-6, and IL-17A while enhancing the level of anti-inflammatory cytokine IL-4. The protein levels of phosphorylated STAT3 (p-STAT3) and phosphorylated p38 (p-p38) were down-regulated in the colonic tissues of DSS-treated mice. Importantly, the anti-inflammatory effect of Pd-Ib against acute colitis was comparable to the anti-inflammatory sulfa drug sulfasalazine (300 mg/kg). Furthermore, the in vitro study showed that the inhibitory effect of Pd-Ib on p-STAT3 and IL-6 protein levels was accompanied by the reduction of MAPKs (JNK and p38). In conclusion, this study suggested that Pd-Ib attenuated DSS-induced acute colitis via the regulation of interleukins principally through the STAT3 and MAPK pathways.

Natural Nuclear Factor Kappa Beta Inhibitors: Safe Therapeutic Options for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic and debilitating condition classified as ulcerative colitis and Crohn's disease. IBD usually happens as result of immune dysfunction in the intestinal mucosa resulting in epithelial barrier dysfunction, which leads to exposure of the mucosal immune system to luminal antigenic material. This results in activation of inflammation, which is our bodies natural defense system; however, chronic inflammation leads to barrier dysfunction, which triggers a cycle of inflammation and further barrier dysfunction. This barrier breakdown results in the uncontrolled progression of IBD throughout the intestine. Despite the therapeutic advances made over the last decade, the current first line of treatment of IBD is limited to immunosuppressive and anti-inflammatory drugs, which need to be taken regularly and have significant side effects to the patients. Prolonged inflammation may increase the risk of intestinal malignancy. The role of nuclear factor kappa beta (NF-κβ) has been established in the regulation of innate immunity and inflammation. NF-κβ has also shown to be involved in critical events linking inflammation and cancer development. Recent investigations suggest that the NF-κβ signaling cascade may be the central mediator of gastrointestinal inflammation in IBD and malignancies including esophageal, gastric, and colorectal cancers. In this review, the therapeutic potential of natural NF-κβ inhibitors as safe therapeutic options for the treatment of IBD will be discussed.

Extracellular ATP mediates inflammatory responses in colitis via P2 × 7 receptor signaling

Extracellular purinergic products, particularly ATP, have recently been implicated to regulate immune cell functions and contribute to aberrant inflammatory responses of immune diseases. However, regulation of immune responses of colitis by extracellular ATP and its main receptor, P2 × 7, remains to be elucidated. In the study, we induced murine colitis by feeding mice with 4% dextran sulfate sodium (DSS), and noted dramatically heightened extracellular ATP levels in colon tissues during the progression of experimental colitis. Blockade of ATP release by carbenoxolone (CBX) treatment, or promoting ATP degradation by ATP diphosphohydrolase (apyrase), decreased extracellular ATP levels in colon tissues, attenuated DSS-induced colitis, whereas inhibition of extracellular ATP degradation by sodium metatungstate (POM-1) exacerbated tissue damage in the mice with colitis. Moreover, treatment with inhibitor of P2 × 7 receptor, A438079, decreased NFκB activation and active caspase-1 expression in lamina propria immune cells, downregulated proinflammatory cytokine production in colon tissues, and attenuated murine colitis. Collectively, these data suggest extracellular ATP participates in regulation of inflammatory responses of experimental colitis, through P2 × 7 receptor and inflammasome and NFκB signaling, which provides potential alternatives to the current clinical approaches to suppress extracellular ATP-mediated immune responsiveness.

NADH oxidase-dependent CD39 expression by CD8(+) T cells modulates interferon gamma responses via generation of adenosine

Interferon gamma (IFNγ)-producing CD8⁺ T cells (Tc1) play important roles in immunological disease. We now report that CD3/CD28-mediated stimulation of CD8⁺ T cells to generate Tc1 cells, not only increases IFNγ production but also boosts the generation of reactive oxygen species (ROS) and augments expression of CD39. Inhibition of NADPH oxidases or knockdown of gp91phox in CD8⁺ T cells abrogates ROS generation, which in turn modulates JNK and NFκB signalling with decreases in both IFNγ levels and CD39 expression. CD39⁺CD8⁺ T cells substantially inhibit IFNγ production by CD39⁻CD8⁺ T cells via the paracrine generation of adenosine, which is operational via adenosine type 2A receptors. Increases in numbers of CD39⁺CD8⁺ T cells and associated enhancements in ROS signal transduction are noted in cells from patients with Crohn's disease. Our findings provide insights into Tc1-mediated IFNγ responses and ROS generation and link these pathways to CD39/adenosine-mediated effects in immunological disease.

The ectonucleotidase CD39 ultimately generates extracellular adenosine, modulating paracrine purinergic signaling. Here the authors show that IFNγ induction in CD8+ T cells is accompanied by NADH oxidase-dependent CD39 expression, which then inhibits IFNγ production in CD39-CD8+ T cells.

Inflammation-Induced Downregulation of Butyrate Uptake and Oxidation Is Not Caused by a Reduced Gene Expression

In ulcerative colitis (UC) the butyrate metabolism is impaired, leading to energy-deficiency in the colonic cells. The effect of inflammation on the butyrate metabolism was investigated. HT-29 cells were incubated with pro-inflammatory cytokines (TNF-α and/or IFN-γ) for 1 and 24 h. Cells were additionally stimulated with butyrate to investigate its anti-inflammatory potential. Butyrate uptake and oxidation were measured using (14)C-labeled butyrate. Gene expression of the butyrate metabolism enzymes, interleukin 8 (IL-8; inflammatory marker) and villin-1 (VIL-1; epithelial cell damage marker) was measured via quantitative RT-PCR. Significantly increased IL-8 expression and decreased VIL-1 expression after 24 h incubation with TNF-α and/or IFN-γ confirmed the presence of inflammation. These conditions induced a decrease of both butyrate uptake and oxidation, whereas the gene expression was not reduced. Simultaneous incubation with butyrate counteracted the reduced butyrate oxidation. In contrast, 1 h incubation with TNF-α induced a significant increased IL-8 expression and decreased butyrate uptake. Incubation with TNF-α and/or IFN-γ for 1 h did not induce cell damage nor influence butyrate oxidation. The inflammation-induced downregulation of the butyrate metabolism was not caused by a reduced gene expression, but appeared consequential to a decreased butyrate uptake. Increasing the luminal butyrate levels might have therapeutic potential in UC.

Protective Effect of Calculus Bovis Sativus on Dextran Sulphate Sodium-Induced Ulcerative Colitis in Mice

Calculus Bovis Sativus (CBS) is a commonly used traditional Chinese medicine, which has been reported to exhibit antispasmodic, fever-reducing, anti-inflammatory, and gallbladder-repairing effects. The present study aims to investigate the protective effect of CBS on dextran sulphate sodium- (DSS-) induced ulcerative colitis (UC) in mice. C57BL/6 male mice were exposed to 5% DSS in drinking water. CBS was given orally at 50 and 150 mg/kg once per day for 7 days. Body weight, disease activity index (DAI), colon length, colonic myeloperoxidase (MPO) activity, superoxide dismutase (SOD) activity, and malondialdehyde (MDA) and nitric oxide (NO) levels were measured. Administration of CBS significantly reserved these changes, decreased the MPO activity and MDA and NO level, and increased the SOD activity in the colon tissue. Histological observation suggested that CBS alleviated edema, mucosal damage, and inflammatory cells infiltration induced by DSS in the colon. Moreover, CBS significantly downregulated the mRNA expression of tumor necrosis factor-α (TNF-α), interleukin- (IL-) 1β and IL-6 in the colon tissue. Our data suggested that CBS exerted protective effect on DSS-induced UC partially through the antioxidant and anti-inflammatory activities.

Dietary squalene supplementation improves DSS-induced acute colitis by downregulating p38 MAPK and NFkB signaling pathways

SCOPE

Squalene is a polyunsaturated triterpene, which has exhibited anticancer and antioxidant activities among others. We investigated dietary squalene supplementation effect on an acute colitis model induced by dextran sulfate sodium (DSS) in C57BL/6 mice.

METHODS AND RESULTS

Mice were fed from weaning with squalene at 0.02% and 0.1%. After 4 weeks, mice were exposed to 3% DSS for 5 days developing acute colitis. After DSS removal (5 days), colons were histological and biochemically processed. Our results showed that dietary squalene treatment exerts anti-inflammatory action in DSS-induced acute colitis. Western blot revealed that squalene downregulated COX-2 (where COX is cyclooxygenase) and inducible nitric oxide synthase system by inhibition of mitogen-activated protein kinase p38 and the nuclear factor-kappa B signaling pathways, preventing an increase in the cytokines levels. Under our experimental conditions, STAT3 and FOXP3 (where FOXP3 is forkhead box P3) were not modified and the transcriptional regulation of antioxidant and/or detoxifying enzymes, Nrf2 (where Nrf2 is nuclear factor (erythroid-derived 2)-like 2), was reduced in DSS-induced colitis. However, any change could be observed after squalene supplementation.

CONCLUSION

Squalene was able to improve the oxidative events and returned proinflammatory proteins expression to basal levels probably through p38 mitogen-activated protein kinase and nuclear factor-kappa B signaling pathways. However, supplementary studies are needed in order to provide a basis for developing a new dietary supplementation strategy.

Central muscarinic cholinergic activation alters interaction between splenic dendritic cell and CD4+CD25- T cells in experimental colitis

BACKGROUND

The cholinergic anti-inflammatory pathway (CAP) is based on vagus nerve (VN) activity that regulates macrophage and dendritic cell responses in the spleen through alpha-7 nicotinic acetylcholine receptor (a7nAChR) signaling. Inflammatory bowel disease (IBD) patients present dysautonomia with decreased vagus nerve activity, dendritic cell and T cell over-activation. The aim of this study was to investigate whether central activation of the CAP alters the function of dendritic cells (DCs) and sequential CD4+/CD25-T cell activation in the context of experimental colitis.

METHODS

The dinitrobenzene sulfonic acid model of experimental colitis in C57BL/6 mice was used. Central, intracerebroventricular infusion of the M1 muscarinic acetylcholine receptor agonist McN-A-343 was used to activate CAP and vagus nerve and/or splenic nerve transection were performed. In addition, the role of α7nAChR signaling and the NF-kB pathway was studied. Serum amyloid protein (SAP)-A, colonic tissue cytokines, IL-12p70 and IL-23 in isolated splenic DCs, and cytokines levels in DC-CD4+CD25-T cell co-culture were determined.

RESULTS

McN-A-343 treatment reduced colonic inflammation associated with decreased pro-inflammatory Th1/Th17 colonic and splenic cytokine secretion. Splenic DCs cytokine release was modulated through α7nAChR and the NF-kB signaling pathways. Cholinergic activation resulted in decreased CD4+CD25-T cell priming. The anti-inflammatory efficacy of central cholinergic activation was abolished in mice with vagotomy or splenic neurectomy.

CONCLUSIONS

Suppression of splenic immune cell activation and altered interaction between DCs and T cells are important aspects of the beneficial effect of brain activation of the CAP in experimental colitis. These findings may lead to improved therapeutic strategies in the treatment of IBD.

Combination of everolimus and tacrolimus: a potentially effective regimen for recalcitrant psoriasis

Severe forms of psoriasis that are refractory to conventional therapies are often difficult to manage. The mammalian target of rapamycin (mTOR) inhibitors potentially have versatile effects toward putative psoriatic pathologic pathways. Therefore, mTOR inhibitors may offer a range of new therapeutic options for patients with psoriasis. We describe a 55-year-old male renal transplant patient with refractory psoriasis. We adjusted his antirejection regimen and put him on everolimus (Certican(®); Novartis, Basel, Switzerland; a semisynthetic macrolide, belonging to the mTOR inhibitors family) with low-dose tacrolimus. This combination regimen maintained his graft function and successfully controlled his psoriasis. His skin lesions never recurred in the next 18 months. To our knowledge, this is the first report showing that the combination of everolimus and tacrolimus could be used to treat recalcitrant psoriasis. The relative benefit-risk profiles of such therapies worth further investigation.

Translational research and efficacy of biologics in Crohn's disease: a cautionary tale

In the last several years many biologic agents for Crohn's disease have been developed. Due to their unique molecular specificity biologics are de facto indicators of the ultimate significance of the molecule targeted by the biologic itself. Here, we have reviewed many clinical studies that have used biologics for Crohn's disease. Their results show that despite potentially sound theoretical mechanisms of action and some initially promising data, most biologics - with few notable exceptions - have failed. Pharmacologic, study design or patient-related issues might explain these findings in some studies. However in many cases clinical failure of biologics might highlight the complexity of in vivo events and the potential deficiencies of current experimental settings. Hence, these observations call for new and efficient ways of predicting drug efficacy in clinical trials based on bench research. Conceivably, computer-based pathogenetic models could be used to simulate and predict clinical studies results in vivo.

A novel TLR2-triggered signalling crosstalk synergistically intensifies TNF-mediated IL-6 induction

Toll-like receptors (TLR) recognize pathogens and trigger the production of vigorous pro-inflammatory cytokines [such as tumour necrosis factor (TNF)] that induce systemic damages associated with sepsis and chronic inflammation. Cooperation between signals of TLR and TNF receptor has been demonstrated through the participation of TNF receptor 1 (TNFR) adaptors in endotoxin tolerance. Here, we identify a TLR2-mediated synergy, through a MyD88-independent crosstalk, which enhances subsequent TNF-mediated nuclear factor-kappa B activation and interleukin-6 induction. Membrane-associated adaptor MAL conduces the link between TNF receptor-associated factor 6 (TRAF6) and TNFR-associated death domain, leading to a distinctive K63-ubiquitinylated TRAF6 recruitment into TNFR complex. In summary, our results reveal a novel route of TLR signal that synergistically amplifies TNF-mediated responses, indicating an innovative target for inflammation manipulation.

Pu-erh tea has in vitro anticancer activity in TCA8113 cells and preventive effects on buccal mucosa cancer in U14 cells injected mice in vivo

Pu-erh tea is a functional tea production in China. The functional effects should be proved. The oral cancer preventive and antimetastatic effects of Pu-erh tea in vitro and in vivo have been studied respectively. Pu-erh tea showed an inhibitory effect on human tongue carcinoma TCA8113 cells proliferation tested by 3-(4,5-Dimethyl-2-Thiazolyl)-2,5-Diphenyltetrazolium Bromide assay and induced TCA8113 apoptosis shown anticancer effect. The antimetastatic effect of Pu-erh tea in TCA8113 cells was proved by the decreasing of matrix metalloproteinases (MMPs) and increasing of tissue inhibitors of metalloproteinases (TIMPs) mRNA transcription. In the animal experiments, the tumor volumes and lymph node metastasis rates of Pu-erh tea-treated mice were smaller than control mice. Pu-erh tea reduced the levels of the serum proinflammatory cytokines interleukin (IL)-6, IL-12, tumor necrosis factor-α, and interferon-γ to a greater extent compared with the control mice, and the levels of 200 μg/mL treatment was more close to the normal mice than 100 μg/mL treated mice. Pu-erh tea also significantly induced apoptosis in tissues of mice (P < 0.05) by upregulating Bax and downregulating Bcl-2. These results demonstrate Pu-erh tea has cancer preventive and anti-metastatic effects on buccal mucosa cancer, the higher concentration get better efficiency.

Central cholinergic activation of a vagus nerve-to-spleen circuit alleviates experimental colitis

The cholinergic anti-inflammatory pathway is an efferent vagus nerve-based mechanism that regulates immune responses and cytokine production through α7 nicotinic acetylcholine receptor (α7nAChR) signaling. Decreased efferent vagus nerve activity is observed in inflammatory bowel disease. We determined whether central activation of this pathway alters inflammation in mice with colitis and the mediating role of a vagus nerve-to-spleen circuit and α7nAChR signaling. Two experimental models of colitis were used in C57BL/6 mice. Central cholinergic activation induced by the acetylcholinesterase inhibitor galantamine or a muscarinic acetylcholine receptor agonist treatments resulted in reduced mucosal inflammation associated with decreased major histocompatibility complex II level and pro-inflammatory cytokine secretion by splenic CD11c⁺ cells mediated by α7nAChR signaling. The cholinergic anti-inflammatory efficacy was abolished in mice with vagotomy, splenic neurectomy, or splenectomy. In conclusion, central cholinergic activation of a vagus nerve-to-spleen circuit controls intestinal inflammation and this regulation can be explored to develop novel therapeutic strategies.

Administration of reconstituted polyphenol oil bodies efficiently suppresses dendritic cell inflammatory pathways and acute intestinal inflammation

Polyphenols are natural compounds capable of interfering with the inflammatory pathways of several in vitro model systems. In this study, we developed a stable and effective strategy to administer polyphenols to treat in vivo models of acute intestinal inflammation. The in vitro suppressive properties of several polyphenols were first tested and compared for dendritic cells (DCs) production of inflammatory cytokines. A combination of the polyphenols, quercetin and piperine, were then encapsulated into reconstituted oil bodies (OBs) in order to increase their stability. Our results showed that administration of low dose reconstituted polyphenol OBs inhibited LPS-mediated inflammatory cytokine secretion, including IL-6, IL-23, and IL-12, while increasing IL-10 and IL-1Rα production. Mice treated with the polyphenol-containing reconstituted OBs (ROBs) were partially protected from dextran sodium sulfate (DSS)-induced colitis and associated weight loss, while mortality and inflammatory scores revealed an overall anti-inflammatory effect that was likely mediated by impaired DC immune responses. Our study indicates that the administration of reconstituted quercetin and piperine-containing OBs may represent an effective and potent anti-inflammatory strategy to treat acute intestinal inflammation.

Heat shock factor 2 levels are associated with the severity of ulcerative colitis

BACKGROUND AND AIMS

The morbidity of ulcerative colitis (UC) is increasing in China every year. In addition, there is a lack of accurate diagnostic indices with which to evaluate the activity of the disease. The aim of this study was to identify UC-associated proteins as biomarkers for the diagnosis, and objective assessment of disease activity.

METHODS

Differential expression of serum proteins from UC patients compared to normal controls was analyzed by two-dimensional electrophoresis (2-DE) and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF-MS). The expression of heat shock factor 2(HSF2)in colonic mucosa in Crohn's disease, Behcet's disease, ulcerative colitis, intestinal tuberculosis, infective enteritis, intestinal lymphoma, and normal controls was investigated by immunohistochemistry (IHC). The expression of the HSF2 in colonic mucosa of UC subjects with varying severity of disease was measured by real time-PCR and Western Blots. The expression of HSF2 was inhibited by HSF2 small interfering RNA (siRNA) transfection in Caco-2 cells. The concentrations of HSF2, IL-1β, and TNF-α in serum and IL-1β, and TNF-α in the supernatants of transfected Caco-2 cells were determined by ELISA.

RESULTS

HSF2 was differentially expressed in UC patients compared to normal controls. HSF2 expression was significantly higher in the intestinal mucosa of UC patients compared to other six groups. The results of immunohistochemistry, real time-PCR, Western Blots, and ELISA showed that the expression of HSF2 increased in parallel with the severity of UC. The serum concentration of HSF2 also positively correlated with levels of IL-1β and TNF-α. After down-regulation expression of HSF2 in Caco-2 cells by RNA interference, the productions of IL-1β and TNF-α stimulated by lipopolysaccharide (LPS) increased dramatically.

CONCLUSIONS

HSF2 appears to be a potential novel molecular marker for UC activity, and may provide a basis for studies on the pathogenesis and novel therapeutic targets for UC.

Increased preventive effect on colon carcinogenesis by use of resistant starch (RS3) as the carrier for polysaccharide of Larimichthys crocea swimming bladder

The preventive effect of polysaccharide of Larimichthys crocea swimming bladder (PLCSB) and the increase of this effect by use of resistant starch (RS3) as the carrier for PLCSB on azoxymethane (AOM) and dextran sulfate sodium (DSS)-inducing colon carcinogenesis in C57BL/6 mice has been studied. RS3 microspheres carrying PLCSB (RS3 + PLCSB) were produced and evaluated as a potentially improved colon carcinogenesis therapy for this study. The body weight, colon length, and colon weight of mice were determined, and colonic tissues were histologically observed. The serum levels of proinflammatory cytokines and the inflammation and apoptosis-related genes in colonic tissue were also tested. The PLCSB or RS3 + PLCSB significantly suppressed AOM and DSS-induced body weight loss, colon length shortening and decreased the colon weight to length ratio. PLCSB or RS3 + PLCSB reduced the levels of the serum pro-inflammatory cytokines IL-6, IL-12, TNF-α, and IFN-γ to a greater extent compared with the control mice, and the levels of RS3 + PLCSB were more close to the normal mice than PLCSB treated mice. Histopathological examination of sections of colon tissues showed that the RS3 + PLCSB group recovered well from colon carcinogenesis; however, the tissue sections of the stachyose + starch could reduce the necrosis degree. PLCSB significantly induced apoptosis in tissues of mice (p < 0.05) by up-regulating Bax, caspase-3, and caspase-9, and down-regulating Bcl-2. The expression of genes associated with inflammation-related NF-κB, iNOS, and COX-2 genes, was significantly down-regulated, and IκB-α was up-regulated (p < 0.05). These results suggest that PLCSB is a potent preventive against in vivo colon carcinogenesis and that PLCSB with an RS3 carrier could increase the preventative effect in mice.

Anti-inflammatory effects of kudingcha methanol extract (Ilex kudingcha C.J. Tseng) in dextran sulfate sodium-induced ulcerative colitis

The present study aimed to investigate the anti‑inflammatory effects of Ilex kudingcha C.J. Tseng methanol extracts (KME) on 3% dextran sulfate sodium (DSS)‑induced ulcerative colitis (UC) in mice (C57BL/6J strain). Body weight, disease activity index (DAI), colon length, colon weight to length ratio, colonic myeloperoxidase (MPO), glutathione (GSH) and malondialdehyde (MDA) levels were measured. Histological changes were observed by hematoxylin and eosin staining. Colonic levels of tumor necrosis factor‑α (TNF‑α), interleukin(IL)‑1β and IL‑6 were measured with an enzyme‑linked immunosorbent assay. The mRNA expression of TNF‑α, IL‑1β, ‑6, inducible nitric oxide synthase (iNOS) and cyclooxygenase‑2 (COX-2) in the colon tissue, was quantified by RT‑PCR. KME significantly suppressed DSS‑induced body weight loss, colon length shortening and decreased the colon weight to length ratio. It also resulted in increased GSH and reduced MPO and MDA levels in the colon tissue. Histological observation suggested that KME prevented edema, mucosal damage and loss of crypts, which are induced by DSS. In addition, KME decreased the levels of TNF‑α, IL‑1β and ‑6 in the colon tissues, while inhibiting the mRNA expression of these cytokines, as well as iNOS and COX‑2. The results of this study suggested that KME has anti‑inflammatory effects on DSS‑induced UC in mice (C57BL/6J strain) by reducing the colonic levels and inhibiting the mRNA expression of pro‑inflammatory cytokines.

The complement anaphylatoxin C3a receptor (C3aR) contributes to the inflammatory response in dextran sulfate sodium (DSS)-induced colitis in mice

Inflammatory bowel diseases are a critical public health issue, and as treatment options remain limited, there is a need to unravel the underlying pathomechanisms in order to identify new therapeutic targets. Complement activation was found in patients suffering from inflammatory bowel disease, and the complement anaphylatoxin C5a and its receptor C5aR have been implicated in disease pathogenesis in animal models of bowel inflammation. To further characterize complement-related pathomechanisms in inflammatory bowel disease, we have investigated the role of the anaphylatoxin C3a receptor in acute dextran sulfate sodium-induced colitis in mice. For this, colitis was induced in C3a receptor-deficient BALB/c and C57BL/6 mice, and disease severity was evaluated by clinical and histological examination, and by measuring the mRNA expression or protein levels of inflammatory mediators in the tissue. C3a receptor deficiency was partially protective in BALB/c mice, which had significantly reduced weight loss, clinical and histological scores, colon shortening, and CXCL-1/KC mRNA, myeloperoxidase and interleukin-6 tissue levels compared to the corresponding wild type mice. In C57BL/6 mice the differences between wild type and C3a receptor-deficient animals were much smaller and reached no significance. Our data demonstrate that the contribution of C3a receptor to disease pathogenesis and severity of dextran sulfate sodium-induced colitis in mice depends on the genetic background. Further studies will be required to clarify whether targeting of C3a receptor, possibly in combination with C5a receptor, might be considered as a therapeutic strategy for inflammatory bowel disease.