Cytokine Networks in the Pathophysiology of Inflammatory Bowel Disease

Translating Treg Therapy for Inflammatory Bowel Disease in Humanized Mice

Crohn's disease and ulcerative colitis, two major forms of inflammatory bowel disease (IBD) in humans, afflicted in genetically predisposed individuals due to dysregulated immune response directed against constituents of gut flora. The defective immune responses mounted against the regulatory mechanisms amplify and maintain the IBD-induced mucosal inflammation. Therefore, restoring the balance between inflammatory and anti-inflammatory immunepathways in the gut may contribute to halting the IBD-associated tissue-damaging immune response. Phenotypic and functional characterization of various immune-suppressive T cells (regulatory T cells; Tregs) over the last decade has been used to optimize the procedures for in vitro expansion of these cells for developing therapeutic interventional strategies. In this paper, we review the mechanisms of action and functional importance of Tregs during the pathogenesis of IBD and modulating the disease induced inflammation as well as role of mouse models including humanized mice repopulated with the human immune system (HIS) to study the IBD. "Humanized" mouse models provide new tools to analyze human Treg ontogeny, immunobiology, and therapy and the role of Tregs in developing interventional strategies against IBD. Overall, humanized mouse models replicate the human conditions and prove a viable tool to study molecular functions of human Tregs to harness their therapeutic potential.

High Red Meat Intake Exacerbates Dextran Sulfate-Induced Colitis by Altering Gut Microbiota in Mice

Inflammatory bowel disease (IBD) is a serious hazard to public health, but the precise etiology of the disease is unclear. High intake of red meat diet is closely related to the occurrence of IBD. In this study, we investigated whether the high intake of red meat can increase the sensitivity of colitis and the underlying mechanism. Mice were fed with different levels of red meat for 8 weeks and then the colonic contents were analyzed by 16S rRNA sequencing. Then 3% dextran sulfate sodium was used to induce colitis in mice. We observed the severity of colitis and inflammatory cytokines. We found that high-dose red meat caused intestinal microbiota disorder, reduced the relative abundance of Lachnospiraceae_NK4A136_group, Faecalibaculum, Blautia and Dubosiella, and increased the relative abundance of Bacteroides and Alistipes. This in turn leads to an increase in colitis and inflammatory cytokine secretion. Moreover, we found that high red meat intake impaired the colon barrier integrity and decreased the expression of ZO-1, claudin, and occludin. We also found high red meat intake induced the production of more inflammatory cytokines such as IL-1β, TNF-α, IL-17, and IL-6 and inflammatory inducible enzymes such as COX-2 and iNOS in dextran sulfate sodium-induced colitis. These results suggest that we should optimize the diet and reduce the intake of red meat to prevent the occurrence of IBD.

Natural Anti-Inflammatory Compounds as Drug Candidates for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) represents chronic recurrent intestinal inflammation resulting from various factors. Crohn’s disease (CD) and ulcerative colitis (UC) have been identified as the two major types of IBD. Currently, most of the drugs for IBD used commonly in the clinic have adverse reactions, and only a few drugs present long-lasting treatment effects. Moreover, issues of drug resistance and disease recurrence are frequent and difficult to resolve. Together, these issues cause difficulties in treating patients with IBD. Therefore, the development of novel therapeutic agents for the prevention and treatment of IBD is of significance. In this context, research on natural compounds exhibiting anti-inflammatory activity could be a novel approach to developing effective therapeutic strategies for IBD. Phytochemicals such as astragalus polysaccharide (APS), quercetin, limonin, ginsenoside Rd, luteolin, kaempferol, and icariin are reported to be effective in IBD treatment. In brief, natural compounds with anti-inflammatory activities are considered important candidate drugs for IBD treatment. The present review discusses the potential of certain natural compounds and their synthetic derivatives in the prevention and treatment of IBD.

Mint Oils: In Vitro Ability to Perform Anti-Inflammatory, Antioxidant, and Antimicrobial Activities and to Enhance Intestinal Barrier Integrity

The objectives of the study were to test the biological activities of peppermint and spearmint oils via (i) measuring in vitro anti-inflammatory effects with porcine alveolar macrophages (PAMs), (ii) determining the barrier integrity of IPEC-J2 by analyzing transepithelial electrical resistance (TEER), (iii) testing their antioxidant activities, and (iv) investigating the antimicrobial activity against enterotoxigenic Escherichia coli (ETEC) F18+. Briefly, (i) macrophages were seeded at 10⁶ cells/mL and treated (24 h) with mint oils and lipopolysaccharide (LPS). The treatments were 2 (0 or 1 μg/mL of LPS) × 5 (0, 25, 50, 100, 200 µg/mL of mint oils). The supernatants were collected for TNF-α and IL-1β measurement by ELISA; (ii) IPEC-J2 cells were seeded at 5 × 10⁵ cells/mL and treated with mint oils (0, 25, 50, 100, and 200 μg/mL). TEER (Ωcm²) was measured at 0, 24, 48, and 72 h; (iii) the antioxidant activity was assessed (0, 1, 50, 100, 200, 500, and 600 mg/mL) using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and reducing power assays; (iv) overnight-grown ETEC F18+ were quantified (CFU/mL) after supplementing with peppermint and spearmint oils (0, 1.44, 2.87, 5.75, 11.50, and 23.00 mg/mL). All data were analyzed using the MIXED procedure. Both mint oils significantly inhibited (p < 0.05) IL-1β and TNF-α secretion from LPS-stimulated PAMs. Mint oil treatments did not affect TEER in IPEC-J2. Spearmint and peppermint oils exhibited (p < 0.05) strong antioxidant activities in DPPH and reducing power assays. Both mint oils also dose-dependently inhibited (p < 0.05) the growth of ETEC F18+ in vitro. The results of the study indicated that both mint oils are great candidate feed additives due to their in vitro anti-inflammatory, antioxidant, and antimicrobial effects. Further research is needed to evaluate their efficacy in vivo.

An epithelial Nfkb2 pathway exacerbates intestinal inflammation by supplementing latent RelA dimers to the canonical NF-κB module

Aberrant inflammation, such as that associated with inflammatory bowel disease (IBD), is fueled by the inordinate activity of RelA/NF-κB factors. As such, the canonical NF-κB module mediates controlled nuclear activation of RelA dimers from the latent cytoplasmic complexes. What provokes pathological RelA activity in the colitogenic gut remains unclear. The noncanonical NF-κB pathway typically promotes immune organogenesis involving Nfkb2 gene products. Because NF-κB pathways are intertwined, we asked whether noncanonical signaling aggravated inflammatory RelA activity. Our investigation revealed frequent engagement of the noncanonical pathway in human IBD. In a mouse model of experimental colitis, we established that Nfkb2-mediated regulations escalated the RelA-driven proinflammatory gene response in intestinal epithelial cells, exacerbating the infiltration of inflammatory cells and colon pathologies. Our mechanistic studies clarified that cell-autonomous Nfkb2 signaling supplemented latent NF-κB dimers, leading to a hyperactive canonical RelA response in the inflamed colon. In sum, the regulation of latent NF-κB dimers appears to link noncanonical Nfkb2 signaling to RelA-driven inflammatory pathologies and may provide for therapeutic targets.

Interaction between Lipopolysaccharide and Gut Microbiota in Inflammatory Bowel Diseases

Lipopolysaccharides (LPSs) are bacterial surface glycolipids, produced by Gram-negative bacteria. LPS is known to determine acute inflammatory reactions, particularly in the context of sepsis. However, LPS can also trigger chronic inflammation. In this case, the source of LPS is not an external infection, but rather an increase in endogenous production, which is usually sustained by gut microbiota (GM), and LPS contained in food. The first site in which LPS can exert its inflammatory action is the gut: both GM and gut-associated lymphoid tissue (GALT) are influenced by LPS and shift towards an inflammatory pattern. The changes in GM and GALT induced by LPS are quite similar to the ones seen in IBD: GM loses diversity, while GALT T regulatory (Tregs) lymphocytes are reduced in number, with an increase in Th17 and Th1 lymphocytes. Additionally, the innate immune system is triggered, through the activation of toll-like receptor (TLR)-4, while the epithelium is directly damaged, further triggering inflammation. In this review, we will discuss the importance of the crosstalk between LPS, GM, and GALT, and discuss the possible implications.

Deconvolution of monocyte responses in inflammatory bowel disease reveals an IL-1 cytokine network that regulates IL-23 in genetic and acquired IL-10 resistance

OBJECTIVE

Dysregulated immune responses are the cause of IBDs. Studies in mice and humans suggest a central role of interleukin (IL)-23-producing mononuclear phagocytes in disease pathogenesis. Mechanistic insights into the regulation of IL-23 are prerequisite for selective IL-23 targeting therapies as part of personalised medicine.

DESIGN

We performed transcriptomic analysis to investigate IL-23 expression in human mononuclear phagocytes and peripheral blood mononuclear cells. We investigated the regulation of IL-23 expression and used single-cell RNA sequencing to derive a transcriptomic signature of hyperinflammatory monocytes. Using gene network correlation analysis, we deconvolved this signature into components associated with homeostasis and inflammation in patient biopsy samples.

RESULTS

We characterised monocyte subsets of healthy individuals and patients with IBD that express IL-23. We identified autosensing and paracrine sensing of IL-1α/IL-1β and IL-10 as key cytokines that control IL-23-producing monocytes. Whereas Mendelian genetic defects in IL-10 receptor signalling induced IL-23 secretion after lipopolysaccharide stimulation, whole bacteria exposure induced IL-23 production in controls via acquired IL-10 signalling resistance. We found a transcriptional signature of IL-23-producing inflammatory monocytes that predicted both disease and resistance to antitumour necrosis factor (TNF) therapy and differentiated that from an IL-23-associated lymphocyte differentiation signature that was present in homeostasis and in disease.

CONCLUSION

Our work identifies IL-10 and IL-1 as critical regulators of monocyte IL-23 production. We differentiate homeostatic IL-23 production from hyperinflammation-associated IL-23 production in patients with severe ulcerating active Crohn's disease and anti-TNF treatment non-responsiveness. Altogether, we identify subgroups of patients with IBD that might benefit from IL-23p19 and/or IL-1α/IL-1β-targeting therapies upstream of IL-23.

Targeting the TGF-β signaling pathway for fibrosis therapy: a patent review (2015-2020)

INTRODUCTION

Fibrosis is a serious disease that occurs in many organs, such as kidney, liver and lung. The deterioration of these organs ultimately leads to death. Due to the complex mechanisms of fibrosis, research and development of antifibrotic drugs is difficult. One solution is to focus on core pathways, one of which is the TGF-β signaling pathway. In virtually every type of fibrosis, TGF-β signaling is recognized as a critical pathway.

AREA COVERED

This review discusses patents on active molecules related to the TGF-β signaling. Molecules targeting components related to the activation of TGF-β are introduced. Several strategies preventing signal propagation from active TGF-β to downstream targets are also introduced, including TGF-β antibodies, TGF-β ligand traps, and inhibitors of TGF-β receptor kinases. Finally, molecules affecting downstream targets in both canonical and noncanonical TGF-β signaling pathways are described.

EXPERT OPINION

Since the approval of pirfenidone, targeting TGF-β signaling has been anticipated as an effective therapy for fibrosis. The potential of this therapy has been further supported by emerging patents on the TGF-β signaling. This pathway can be entirely inhibited, from the activation of TGF-β to downstream signaling. Inhibiting TGF-β signaling is expected to provide more effective treatments for fibrosis.

Novel mechanisms and clinical trial endpoints in intestinal fibrosis

The incidence of inflammatory bowel diseases (IBD) worldwide has resulted in a global public health challenge. Intestinal fibrosis leading to stricture formation and bowel obstruction is a frequent complication in Crohn's disease (CD), and the lack of anti-fibrotic therapies makes elucidation of fibrosis mechanisms a priority. Progress has shown that mesenchymal cells, cytokines, microbial products, and mesenteric adipocytes are jointly implicated in the pathogenesis of intestinal fibrosis. This recent information puts prevention or reversal of intestinal strictures within reach through innovative therapies validated by reliable clinical trial endpoints. Here, we review the role of immune and non-immune components of the pathogenesis of intestinal fibrosis, including new cell clusters, cytokine networks, host-microbiome interactions, creeping fat, and their translation for endpoint development in anti-fibrotic clinical trials.

Dynamic landscape of immune cell-specific gene regulation in immune-mediated diseases

Genetic studies have revealed many variant loci that are associated with immune-mediated diseases. To elucidate the disease pathogenesis, it is essential to understand the function of these variants, especially under disease-associated conditions. Here, we performed a large-scale immune cell gene-expression analysis, together with whole-genome sequence analysis. Our dataset consists of 28 distinct immune cell subsets from 337 patients diagnosed with 10 categories of immune-mediated diseases and 79 healthy volunteers. Our dataset captured distinctive gene-expression profiles across immune cell types and diseases. Expression quantitative trait loci (eQTL) analysis revealed dynamic variations of eQTL effects in the context of immunological conditions, as well as cell types. These cell-type-specific and context-dependent eQTLs showed significant enrichment in immune disease-associated genetic variants, and they implicated the disease-relevant cell types, genes, and environment. This atlas deepens our understanding of the immunogenetic functions of disease-associated variants under in vivo disease conditions.

B cell-activating factor (BAFF) in children with inflammatory bowel disease

BACKGROUND

Assessing the inflammation is important in the follow-up of paediatric patients with inflammatory bowel disease (IBD). We aim to evaluate the value of B cell-activating factor (BAFF) in paediatric IBD as a potential biomarker for follow-up.

METHOD

We determined BAFF in serum and faeces and faecal calprotectin (CP) in 32 IBD children-16 Crohn's disease (CD) and 16 ulcerative colitis (UC). Twenty-six healthy children and 10 children with irritable bowel syndrome (IBS) were included as controls.

RESULTS

No differences were found in serum BAFF between IBD, IBS, and healthy group: 1037.35, 990.9 and 979.8 pg/ml, respectively, all p > 0.05, but faecal BAFF was higher in the IBD group: 15.1, 8.5 and 8.2 pg/ml, respectively, p < 0.05, and higher in the UC group (55.975 pg/ml) compared to the CD group (10.95 pg/ml), p = 0.015. Splitting the IBD group in relation to the CP level, the serum BAFF had no significantly different values between the subgroups, but the faecal BAFF was significantly higher in the >250 μg/g subgroup. Cut-off values of BAFF were calculated.

CONCLUSION

Faecal BAFF is a promising marker for monitoring the children with IBD, higher levels of BAFF being correlated with high CP.

IMPACT

Faecal BAFF is a promising marker in monitoring the children with IBD, higher levels of BAFF being correlated with high faecal calprotectin. To our knowledge, this is the first paediatric study concerning BAFF evaluation in IBD. Faecal BAFF levels could be considered a potential non-invasive marker in monitoring IBD activity in paediatric population with clinically mild or inactive disease.

Oxyresveratrol Ameliorates Dextran Sulfate Sodium-Induced Colitis in Rats by Suppressing Inflammation

Colitis causes destruction of the intestinal mucus layer and increases intestinal inflammation. The use of antioxidants and anti-inflammatory agents derived from natural sources has been recently highlighted as a new approach for the treatment of colitis. Oxyresveratrol (OXY) is an antioxidant known to have various beneficial effects on human health, such as anti-inflammatory, antibacterial activity, and antiviral activity. The aim of this study was to investigate the therapeutic effect of OXY in rats with dextran sulfate sodium (DSS)-induced acute colitis. OXY ameliorated DSS-induced colitis and repaired damaged intestinal mucosa. OXY downregulated the expression of pro-inflammatory cytokine genes (TNF-α, IL-6, and IL-1β) and chemokine gene MCP-1, while promoting the production of anti-inflammatory cytokine IL-10. OXY treatment also suppressed inflammation via inhibiting cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression in the colon, as well as the activity of myeloperoxidase (MPO). OXY exhibited anti-apoptotic effects, shifting the Bax/Bcl-2 balance. In conclusion, OXY might improve DSS-induced colitis by restoring the intestinal mucus layer and reducing inflammation within the intestine.

Control of Immunity by the Microbiota

The immune system has coevolved with extensive microbial communities living on barrier sites that are collectively known as the microbiota. It is increasingly clear that microbial antigens and metabolites engage in a constant dialogue with the immune system, leading to microbiota-specific immune responses that occur in the absence of inflammation. This form of homeostatic immunity encompasses many arms of immunity, including B cell responses, innate-like T cells, and conventional T helper and T regulatory responses. In this review we summarize known examples of innate-like T cell and adaptive immunity to the microbiota, focusing on fundamental aspects of commensal immune recognition across different barrier sites. Furthermore, we explore how this cross talk is established during development, emphasizing critical temporal windows that establish long-term immune function. Finally, we highlight how dysregulation of immunity to the microbiota can lead to inflammation and disease, and we pinpoint outstanding questions and controversies regarding immune system-microbiota interactions.

Soluble ligands as drug targets for treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD), which includes Crohn's disease and ulcerative colitis, is characterized by persistent inflammation in a hereditarily susceptible host. In addition to gastrointestinal symptoms, patients with IBD frequently suffer from extra-intestinal complications such as fibrosis, stenosis or cancer. Mounting evidence supports the targeting of cytokines for effective treatment of IBD. Cytokines can be included in a newly proposed classification "soluble ligands" that has become the third major target of human protein therapeutic drugs after enzymes and receptors. Soluble ligands have potential significance for research and development of anti-IBD drugs. Compared with traditional drug targets for IBD treatment, such as receptors, at least three factors contribute to the increasing importance of soluble ligands as drug targets. Firstly, cytokines are the main soluble ligands and targeting of them has demonstrated efficacy in patients with IBD. Secondly, soluble ligands are more accessible than receptors, which are embedded in the cell membrane and have complex tertiary membrane structures. Lastly, certain potential target proteins that are present in membrane-bound forms can become soluble following cleavage, providing further opportunities for intervention in the treatment of IBD. In this review, 49 drugs targeting 25 distinct ligands have been evaluated, including consideration of the characteristics of the ligands and drugs in respect of IBD treatment. In addition to approved drugs targeting soluble ligands, we have also assessed drugs that are in preclinical research and drugs inhibiting ligand-receptor binding. Some new types of targetable soluble ligands/proteins, such as epoxide hydrolase and p-selectin glycoprotein ligand-1, are also introduced. Targeting soluble ligands not only opens a new field of anti-IBD drug development, but the circulating soluble ligands also provide diagnostic insights for early prediction of treatment response. In conclusion, soluble ligands serve as the third-largest protein target class in medicine, with much potential for the drugs targeting them.

Precision Medicine in Inflammatory Bowel Diseases

During the last decades, a better understanding of the mechanisms sustaining the pathogenic process in inflammatory bowel diseases (IBD) has contributed to expand the therapeutic armamentarium for patients with these disorders. Alongside with traditional therapies, monoclonal antibodies against tumor necrosis factor-α, the interleukin (IL)-12/IL-23 p40 subunit and the α4β7 integrin, and tofacitinib, a small molecule inhibiting intracellular pathways downstream to cytokine receptors, have entered into the clinic. However, these drugs are not effective in all patients and some responders can lose response over time. Such a therapeutic failure is, at least in part, dependent on the fact that, in IBD, the tissue damage is driven by simultaneous activation of multiple and distinct immune-inflammatory signals and the detrimental mucosal immune response changes over time even in the same patient. Therefore, personalized approaches aimed at identifying which patient should be treated with a specific drug at a precise time point are worth pursuing. A such approach has the advantage to improve efficacy of the drug and limit adverse reactions, thereby improving quality of the life of the patients and reducing costs. In this review, we summarize all the available evidence about the possible role of precision medicine in IBD.

Pharmacologycal activity of peperina (Minthostachys verticillata) on gastrointestinal tract

ETHNOPHARMACOLOGICAL RELEVANCE

Minthostachys verticillata (Griseb.) Epling (Lamiaceae), known as Peperina is a medicinal native plant, with a traditional use as a digestive, antispasmodic and antidiarrheic.

AIM OF THE STUDY

Despite its folkloric use, no scientific evaluation of this plant related to the gastrointestinal inflammatory process has been carried out to date. The present study aims to assess the effects of M. verticillata on gastrointestinal system in experimental models.

MATERIALS AND METHODS

M. verticillata (250 and 500 mg/kg) was orally tested in a colitis model induced by acetic acid. Colon weight/length ratio, oxidative stress (oxidized and reduced glutathione), histological changes using Alcian blue and hematoxylin & eosin staining and expression of IL1β, TNFα, iNOS, COX-2 were evaluated. The effect of the extract in three additional in vivo models were studied: intestinal motility and diarrhea induced by ricin oil, and visceral pain induced by intracolonic administration of capsaicin. Finally, the activity on concentration response curves of acetylcholine, calcium chloride, potassium and serotonin were achieved in isolated rat jejunum.

RESULTS

In the colitis model, M. verticillata induced a significant reduction in the colon weight/length ratio, oxidative stress and expression levels of IL-1β, iNOS and COX-2. Also, the extract diminished the severity of microscopic tissue damage and showed protective effect on goblet cells. Intestinal motility, diarrhea, visceral pain-related behaviors and referred hyperalgesia were significantly reduced when the animals were treated with the extract. Furthermore, in isolated jejunum, M. verticillata significantly reduced the contraction induced by serotonin and acetylcholine. Likewise, the extract non-competitively inhibited the response-concentration induced by CaCl2 and inhibited both low and high K+-induced contractions.

CONCLUSIONS

This is the first study to validate traditional use of M. verticillata for digestive disorders and demonstrated that its aqueous extract could represent a promising strategy in targeting the multifactorial pathophysiology of inflammatory bowel disease.

Single-Cell Transcriptional Survey of Ileal-Anal Pouch Immune Cells From Ulcerative Colitis Patients

BACKGROUND & AIMS

Restorative proctocolectomy with ileal pouch-anal anastomosis is a surgical procedure in patients with ulcerative colitis refractory to medical therapies. Pouchitis, the most common complication, is inflammation of the pouch of unknown etiology. To define how the intestinal immune system is distinctly organized during pouchitis, we analyzed tissues from patients with and without pouchitis and from patients with ulcerative colitis using single-cell RNA sequencing (scRNA-seq).

METHODS

We examined pouch lamina propria CD45+ hematopoietic cells from intestinal tissues of ulcerative colitis patients with (n = 15) and without an ileal pouch-anal anastomosis (n = 11). Further in silico meta-analysis was performed to generate transcriptional interaction networks and identify biomarkers for patients with inflamed pouches.

RESULTS

In addition to tissue-specific signatures, we identified a population of IL1B/LYZ+ myeloid cells and FOXP3/BATF+ T cells that distinguish inflamed tissues, which we further validated in other scRNA-seq datasets from patients with inflammatory bowel disease (IBD). Cell-type-specific transcriptional markers obtained from scRNA-seq was used to infer representation from bulk RNA sequencing datasets, which further implicated myeloid cells expressing IL1B and S100A8/A9 calprotectin as interacting with stromal cells, and Bacteroidales and Clostridiales bacterial taxa. We found that nonresponsiveness to anti-integrin biologic therapies in patients with ulcerative colitis was associated with the signature of IL1B+/LYZ+ myeloid cells in a subset of patients.

CONCLUSIONS

Features of intestinal inflammation during pouchitis and ulcerative colitis are similar, which may have clinical implications for the management of pouchitis. scRNA-seq enables meta-analysis of multiple studies, which may facilitate the identification of biomarkers to personalize therapy for patients with IBD. The processed single cell count tables are provided in Gene Expression Omnibus; GSE162335. Raw sequence data are not public and are protected by controlled-access for patient privacy.

Linking the IL-17A immune response with NMR-based faecal metabolic profile in IBD patients treated with Mastiha

Dysregulation of intestinal immune response plays a critical role in the pathogenesis of Inflammatory Bowel Disease (IBD). Mastiha's anti-inflammatory properties are well established. Our aim was to investigate Mastiha's regulatory effect on IL-17A serum levels in IBD patients. Alterations of the faecal metabolome as a functional readout of microbial activity were explored. A randomized, double-blind, placebo-controlled, parallel-group design was applied for a total of 3 months in active and 6 months in inactive IBD patients. Serum IL-17A increased significantly in Mastiha group (p = 0.006), and the mean change differed significantly between Mastiha and placebo (p = 0.003) even after adjusting for age, sex and BMI (p = 0.001) in inactive patients. In inactive UC patients IL-17A decreased significantly only in placebo (p = 0.033). No significant differences were detected in active disease. Faecal metabolomics indicated that intervention with Mastiha influenced considerably the metabolic profile of IBD patients in remission exhibiting, in between others, increased levels of glycine and tryptophan. Glycine has been proposed to have a therapeutic effect against IBD, while tryptophan derivatives are involved in immunoregalutory mechanisms, such as the Th17 cells differentiation. Thus, it is quite possible that the immunoregulatory role of Mastiha in quiescent IBD involves the regulation of Th17 cells function and differentiation.

DSS-induced colitis is associated with adipose tissue dysfunction and disrupted hepatic lipid metabolism leading to hepatosteatosis and dyslipidemia in mice

Considering high prevalence of non-alcoholic fatty liver diseases (NAFLD) in patients with inflammatory bowel disease (IBD), this study aimed to elucidate molecular mechanisms for how intestinal inflammatory conditions are causally linked to hepatic steatosis and dyslipidemia. Both younger and older mice treated with acute or chronic dextran sodium sulfate (DSS) developed colitis, which was evidenced by weight loss, colon length shortening, and elevated disease activity index and inflammation score. They also showed decreased expression of intestinal barrier function-related proteins and elevated plasma lipopolysaccharide level, indicating DSS-induced barrier dysfunction and thereby increased permeability. Interestingly, they displayed phenotypes of hepatic fat accumulation and abnormal blood lipid profiles. This DSS-induced colitis-associated lipid metabolic dysfunction was due to overall disruption of metabolic processes including fatty acid oxidation, lipogenesis, lipolysis, reverse cholesterol transport, bile acid synthesis, and white adipose tissue browning and brown adipose tissue thermogenesis, most of which are mediated by key regulators of energy homeostasis such as FGF21, adiponectin, and irisin, via SIRT1/PGC-1α- and LXRα-dependent pathways. Our study suggests a potential molecular mechanism underlying the comorbidity of NAFLD and IBD, which could provide a key to understanding how the two diseases are pathogenically linked and discovering critical therapeutic targets for their treatment.

Roles of Macrophages in the Development and Treatment of Gut Inflammation

Macrophages, which are functional plasticity cells, have the ability to phagocytize and digest foreign substances and acquire pro-(M1-like) or anti-inflammatory (M2-like) phenotypes according to their microenvironment. The large number of macrophages in the intestinal tract, play a significant role in maintaining the homeostasis of microorganisms on the surface of the intestinal mucosa and in the continuous renewal of intestinal epithelial cells. They are not only responsible for innate immunity, but also participate in the development of intestinal inflammation. A clear understanding of the function of macrophages, as well as their role in pathogens and inflammatory response, will delineate the next steps in the treatment of intestinal inflammatory diseases. In this review, we discuss the origin and development of macrophages and their role in the intestinal inflammatory response or infection. In addition, the effects of macrophages in the occurrence and development of inflammatory bowel disease (IBD), and their role in inducing fibrosis, activating T cells, reducing colitis, and treating intestinal inflammation were also reviewed in this paper.

Transgenic overexpression of ITGB6 in intestinal epithelial cells exacerbates dextran sulfate sodium-induced colitis in mice

Integrins, as a large family of cell adhesion molecules, play a crucial role in maintaining intestinal homeostasis. In inflammatory bowel disease (IBD), homeostasis is disrupted. Integrin αvβ6, which is mainly regulated by the integrin β6 subunit gene (ITGB6), is a cell adhesion molecule that mediates cell-cell and cell-matrix interactions. However, the role of ITGB6 in the pathogenesis of IBD remains elusive. In this study, we found that ITGB6 was markedly upregulated in inflamed intestinal tissues from patients with IBD. Then, we generated an intestinal epithelial cell-specific ITGB6 transgenic mouse model. Conditional ITGB6 transgene expression exacerbated experimental colitis in mouse models of acute and chronic dextran sulphate sodium (DSS)-induced colitis. Survival analyses revealed that ITGB6 transgene expression correlated with poor prognosis in DSS-induced colitis. Furthermore, our data indicated that ITGB6 transgene expression increased macrophages infiltration, pro-inflammatory cytokines secretion, integrin ligands expression and Stat1 signalling pathway activation. Collectively, our findings revealed a previously unknown role of ITGB6 in IBD and highlighted the possibility of ITGB6 as a diagnostic marker and therapeutic target for IBD.

Understanding intestinal health in nursery pigs and the relevant nutritional strategies

In the modern pig production, pigs are weaned at early age with immature intestine. Dietary and environmental factors challenge the intestine, specifically the jejunum, causing inflammation and oxidative stress followed by destruction of epithelial barrier and villus structures in the jejunum. Crypt cell proliferation increases to repair damages in the jejunum. Challenges to maintain the intestinal health have been shown to be related to changes in the profile of mucosa-associated microbiota in the jejunum of nursery pigs. All these processes can be quantified as biomarkers to determine status of intestinal health related to growth potential of nursery pigs. Nursery pigs with impaired intestinal health show reduced ability of nutrient digestion and thus reduced growth. A tremendous amount of research effort has been made to determine nutritional strategies to maintain or improve intestinal health and microbiota in nursery pigs. A large number of feed additives have been evaluated for their effectiveness on improving intestinal health and balancing intestinal microbiota in nursery pigs. Selected prebiotics, probiotics, postbiotics, and other bioactive compounds can be used in feeds to handle issues with intestinal health. Selection of these feed additives should aim modulating biomarkers indicating intestinal health. This review aims to define intestinal health and introduce examples of nutritional approaches to handle intestinal health in nursery pigs.

Searching for host immune-microbiome mechanisms in obsessive-compulsive disorder: A narrative literature review and future directions

Obsessive-compulsive disorder (OCD) is disabling and often treatment-refractory. Host immunity and gut microbiota have bidirectional communication with each other and with the brain. Perturbations to this axis have been implicated in neuropsychiatric disorders, but immune-microbiome signaling in OCD is relatively underexplored. We review support for further pursuing such investigations in OCD, including: 1) gut microbiota has been associated with OCD, but causal pathogenic mechanisms remain unclear; 2) early environmental risk factors for OCD overlap with critical periods of immune-microbiome development; 3) OCD is associated with increased risk of immune-mediated disorders and changes in immune parameters, which are separately associated with the microbiome; and 4) gut microbiome manipulations in animal models are associated with changes in immunity and some obsessive-compulsive symptoms. Theoretical pathogenic mechanisms could include microbiota programming of cytokine production, promotion of expansion and trafficking of peripheral immune cells to the CNS, and regulation of microglial function. Immune-microbiome signaling in OCD requires further exploration, and may offer novel insights into pathogenic mechanisms and potential treatment targets for this disabling disorder.

Preventive and Therapeutic Spermidine Treatment Attenuates Acute Colitis in Mice

Inflammatory bowel disease (IBD) is associated with acute and chronic inflammation of the gastrointestinal tract and has emerged to be a global disease. Spermidine, a natural polyamine, plays a critical role in maintaining cellular homeostasis. Herein, we investigated the impact and mechanism of spermidine on both dextran sulfate sodium (DSS)- and 2,4,6-trinitrobenzenesulfonic acid solution (TNBS)-induced colitis in mice. We found that spermidine exerted protective effects against acute colitis, evidenced by reduced disease activity index (DAI) and colonic inflammation, increased colonic length, and upregulated tight junction proteins in these two colitis models. Importantly, spermidine exerted significant therapeutic and preventive effects against DSS-induced colitis. Pre- and post-treatment with spermidine reduced the expression of proinflammatory cytokines, phosphorylation of (nuclear factor-κB) NF-κB and (mitogen-activated protein kinase) MAPK, and the activation of F4/80 macrophages and T cells in the colon. Furthermore, spermidine upregulated M2 macrophage markers, whereas it downregulated M1 markers in the inflamed colons. In parallel, spermidine reduced M1 pro-inflammatory markers and enhanced M2 anti-inflammatory genes in RAW264.7 cells. These results revealed that spermidine-ameliorated colitis might be through the regulation of M1/M2 macrophage polarization. In addition, spermidine treatment also alleviated LPS/TNF-α-induced inflammation in Caco-2 cells. Taken together, spermidine prevented and reversed colonic inflammation in colitis mice and might be a promising candidate for IBD intervention.

Chitosan and chitooligosaccharides attenuate soyabean meal-induced intestinal inflammation of turbot (Scophthalmus maximus): possible involvement of NF-кB, activator protein-1 and mitogen-activated protein kinases pathways

An 8-week feeding experiment was conducted to investigate and confront the putative functions of chitosan (CTS) and chitooligosaccharide (COS) in the growth and homoeostasis of distal intestine in juvenile turbots fed diets containing soyabean meal (SBM). Three isolipidic and isonitrogenous diets were formulated by supplemented basal diet (based on a 400 g/kg SBM) with 7·5 g/kg CTS or with 2·0 g/kg COS. Our results indicated that both CTS and COS supplementation could significantly improve (i) the growth performance and feed efficiency ratio; (ii) antioxidant activity driven by metabolic enzymes (i.e. catalase, glutathione reductase, glutathione peroxidase and superoxide dismutase); (iii) glutathione levels; (iv) acid phosphatase and lysozyme activity and (v) IgM content. As a result, these two particular prebiotics were able to significantly attenuate the histological alterations due to local inflammation as well as to decrease the transcriptional levels of proinflammatory cytokines (i.e. IL-1β, IL-8 and TNF-α) and major pathway effectors (i.e. activator protein-1 (AP-1), NF-кB, p38 mitogen-activated protein kinase, c-Jun N-terminal kinase and extracellular regulated kinase). High-throughput sequencing data indicated that dietary CTS and COS could significantly decrease the diversity of intestinal bacteria but elevate the relative abundances of Bacillus, Lactobacillus and Pseudomonas genera. Altogether, these findings suggest that CTS and COS can improve growth of turbot, enhance intestinal immune and anti-oxidant systems and promote the balance of intestinal microbiota. The protective effects, elicited by these two prebiotics, against SBM-induced inflammation could be attributed to their roles in alleviating the overexpression of inflammatory cytokines by possibly down-regulating NF-кB, AP-1 and/or mitogen-activated protein kinases pathways.

TREM-1+ Macrophages Define a Pathogenic Cell Subset in the Intestine of Crohn's Disease Patients

BACKGROUND AND AIMS

Uncontrolled activation of intestinal mononuclear phagocytes [MNPs] drives chronic inflammation in inflammatory bowel disease [IBD]. Triggering receptor expressed on myeloid cells 1 [TREM-1] has been implicated in the pathogenesis of IBD. However, the role of TREM-1+ cell subsets in driving IBD pathology and the link with clinical parameters are not understood. We investigated TREM-1 expression in human intestinal MNP subsets and examined blocking TREM-1 as a potential IBD therapy.

METHODS

TREM-1 gene expression was analysed in intestinal mucosa, enriched epithelial and lamina propria [LP] layers, and purified cells from controls and IBD patients. TREM-1 protein on immune cells was assessed by flow cytometry and immunofluorescence microscopy. Blood monocyte activation was examined by large-scale gene expression using a TREM-1 agonist or LP conditioned media [LP-CM] from patients in the presence or absence of TREM-1 and tumour necrosis factor [TNF] antagonist antibodies.

RESULTS

TREM-1 gene expression increases in intestinal mucosa from IBD patients and correlates with disease score. TREM-1+ cells, which are mainly immature macrophages and CD11b+ granulocytes, increase among LP cells from Crohn's disease patients and their frequency correlates with inflammatory molecules in LP-CM. LP-CM from Crohn's disease patients induces an inflammatory transcriptome in blood monocytes, including increased IL-6 expression, which is reduced by simultaneous blocking of TREM-1 and TNF.

CONCLUSIONS

High intestinal TREM-1 expression, reflecting a high frequency of TREM-1+ immature macrophages and TREM-1+CD11b+ granulocytes, is linked to the deleterious inflammatory microenvironment in IBD patients. Therefore, blocking the TREM-1 pathway, especially simultaneously with anti-TNF therapy, has potential as a new IBD therapy.

Curcumin Regulated the Homeostasis of Memory T Cell and Ameliorated Dextran Sulfate Sodium-Induced Experimental Colitis

Immune memory is protective against reinvasion by pathogens in the homeostatic state, while immune memory disorders can cause autoimmune disease, including inflammatory bowel disease. Curcumin is a natural compound shown to be effective against human inflammatory bowel disease and experimental colitis, but the underlying mechanism is unclear. Here, experimental colitis was induced by dextran sulfate sodium (DSS) in this study. Significant changes in the percentages of naïve, central memory T (TCM), and effector memory (TEM) cells and their CD4⁺ and CD8⁺ subsets were found in the peripheral blood of mice with colitis using flow cytometry. After 7 days of continuous curcumin (100 mg/kg/day) administration, the DSS-induced experimental colitis was effectively relieved, with significant decreases in the ratio of day weight to initial body weight, colonic weight, pathological injury score, levels of proinflammatory cytokines IL-7, IL-15, and IL-21, colonic mucosal ulceration, and amount of inflammatory infiltrate. Importantly, curcumin significantly restored the percentages of naïve, TCM, and TEM cells and their CD4⁺ and CD8⁺ subpopulations. In addition, curcumin significantly inhibited the activation of the JAK1/STAT5 signaling pathway, downregulation of JAK1, STAT5, and p-STAT5 proteins in colon tissue, and upregulation of PIAS1 proteins. These results suggested that curcumin effectively regulated the differentiation of naïve, TCM, and TEM cells in the peripheral blood to alleviate DSS-induced experimental colitis, which might be related to the inhibition of JAK1/STAT5 signaling activity.

The Cytokine Expression in Patients with Cardiac Complication after Immune Checkpoint Inhibitor Therapy

We herein report the cytokine expression at different stages for three patients who developed cardiac complications after immune checkpoint inhibitor (ICI) therapy. Case 1 with biopsy-proven myocarditis showed increased levels of interleukin (IL)-8, monocyte chemotactic and activating factor, and granulocyte macrophage colony-stimulating factor (GM-CSF) when he developed Takotsubo cardiomyopathy. Case 2 with subclinical myocarditis showed predominant activation of IL-8 during the progressive clinical course. Case 3 with cytokine-releasing syndrome showed substantial activations of IL-6, IL-8, GM-CSF, and interferon-γ. Our data suggest the development of unique cytokine activation in individual patients with cardiac complications after ICI therapy.

Application of Polymeric Nano-Materials in Management of Inflammatory Bowel Disease

Inflammatory Bowel Disease (IBD) is an umbrella term used to describe disorders that involve Crohn's disease (CD), ulcerative colitis (UC) and pouchitis. The disease occurrence is more prevalent in the working group population which not only hampers the well being of an individual but also has negative economical impact on society. The current drug regime used therapy is very costly owing to the chronic nature of the disease leading to several side effects. The condition gets more aggravated due to the lower concentration of drug at the desired site. Therefore, in the present scenario, a therapy is needed which can maximize efficacy, adhere to quality of life, minimize toxicity and doses, be helpful in maintaining and stimulating physical growth of mucosa with minimum disease complications. In this aspect, nanotechnology intervention is one promising field as it can act as a carrier to reduce toxicity, doses and frequency which in turn help in faster recovery. Moreover, nanomedicine and nanodiagnostic techniques will further open a new window for treatment in understanding pathogenesis along with better diagnosis which is poorly understood till now. Therefore the present review is more focused on recent advancements in IBD in the application of nanotechnology.

Inflammatory bowel disease and risk of gastric, small bowel and colorectal cancer: a meta-analysis of 26 observational studies

PURPOSE

The purpose of this meta-analysis was to assess the associations between inflammatory bowel disease (IBD) and risk of the gastric, small bowel and colorectal cancer.

METHODS

We searched the PubMed and Web of Science for observational studies published before June 2020, and the quality of each included study was evaluated according to the Newcastle-Ottawa-Scale.

RESULTS

Twenty-six studies comprising 531 449 IBD patients and more than 65 million reference individuals were included. Although IBD was significantly associated with 67% increased risk of the total gastric, small bowel and colorectal cancer. After stratifying by cancer location, IBD mainly increased the risk of intestinal cancer instead of gastric cancer. Furthermore, Crohn's disease (CD) significantly increased the risk of both small bowel cancer and colorectal cancer, while ulcerative colitis (UC) only increased the risk of colorectal cancer. In subgroup analysis, associations between IBD and risk of total gastric, small bowel and colorectal cancer were similar between male and female, except for that male IBD patients but not female had a significantly higher risk of small bowel cancer. Additionally, IBD patients in different geographical areas had different associations with risk of various gastrointestinal tract cancers.

CONCLUSIONS

IBD is mainly associated with increased risk of cancers in the lower gastrointestinal tract, including small bowel cancer and colorectal cancer. Because studies about the association between IBD and risk of gastric cancer and the populations in Asia are limited, more observational studies are required in the future.

Cytokine-Mediated Crosstalk between Immune Cells and Epithelial Cells in the Gut

Cytokines are small proteins that are secreted by a vast majority of cell types in the gut. They not only establish cell-to-cell interactions and facilitate cellular signaling, but also regulate both innate and adaptive immune responses, thereby playing a central role in genetic, inflammatory, and infectious diseases of the gut. Both, immune cells and gut epithelial cells, play important roles in intestinal disease development. The epithelium is located in between the mucosal immune system and the gut microbiome. It not only establishes an efficient barrier against gut microbes, but it also signals information from the gut lumen and its composition to the immune cell compartment. Communication across the epithelial cell layer also occurs in the other direction. Intestinal epithelial cells respond to immune cell cytokines and their response influences and shapes the microbial community within the gut lumen. Thus, the epithelium should be seen as a translator or a moderator between the microbiota and the mucosal immune system. Proper communication across the epithelium seems to be a key to gut homeostasis. Indeed, current genome-wide association studies for intestinal disorders have identified several disease susceptibility loci, which map cytokine signatures and their related signaling genes. A thorough understanding of this tightly regulated cytokine signaling network is crucial. The main objective of this review was to shed light on how cytokines can orchestrate epithelial functions such as proliferation, cell death, permeability, microbe interaction, and barrier maintenance, thereby safeguarding host health. In addition, cytokine-mediated therapy for inflammation and cancer are discussed.

Current overview of opioids in progression of inflammatory bowel disease; pharmacological and clinical considerations

Inflammatory bowel diseases (IBD) belong to a subgroup of persistent, long-term, progressive, and relapsing inflammatory conditions. IBD may spontaneously develop in the colon, resulting in tumor lesions in inflamed regions of the intestine, such as invasive carcinoma. The benefit of opioids for IBD treatment is still questionable, thereby we investigated databases to provide an overview in this context. This review demonstrates the controversial role of opioids in IBD therapy, their physiological and pharmacological functions in attenuating the IBD symptoms, and in improving inflammatory, oxidative stress, and the quality of life factors in IBD subjects. Data were extracted from clinical, in vitro, and in vivo studies in English, between 1995 and 2019, from PubMed, Google Scholar, Scopus, and Cochrane library. Based on recent reports, there are promising opportunities to target the opioid system and control the IBD symptoms. This study suggests a novel approach for future treatment of functional and inflammatory disorders such as IBD.

Fenretinide regulates macrophage polarization to protect against experimental colitis induced by dextran sulfate sodium

Fenretinide (4-HPR), a synthetic retinoid, has attracted attention for its anti-inflammation activity. However, few studies have evaluated the effects of 4-HPR on ulcerative colitis (UC). The present study was performed to investigate the therapeutic effects of 4-HPR on UC, and to explore the mechanisms mainly focused on macrophage polarization involved in this progress. Intraperitoneally administered 4-HPR particularly at dose of 100 mg/kg obviously alleviated UC symptoms and restrained the mRNA expression of colonic IL-1β, IL-6, and TNF-α in dextran sulfate sodium (DSS)-induced mice. Further analysis showed that 4-HPR decreased the mRNA expression of M1 macrophage markers IL-12 and iNOS, while increased M2 macrophage markers Ym1, Arg1 and MRC1 in colonic tissue of mice received DSS. Consistently, an in vitro study revealed that 4-HPR decreased inflammatory response and M1 polarization, while enhanced M2 polarization in LPS-induced RAW264.7 cells. Interestingly, 4-HPR remarkably activated PPAR-γ which was an important regulator of macrophage polarization both in colonic tissue of UC mice and in LPS-induced RAW264.7 cells. Furthermore, these effects of 4-HPR in vivo and in vitro including anti-inflammation and modulation of macrophage polarization were partially abolished by treatment with PPAR-γ antagonist GW9662, indicating that 4-HPR activated PPAR-γ to exert its activities. Taken together, this study demonstrated that 4-HPR might be a potent anti-UC agent that works by regulating macrophage polarization via PPARγ.

Structure-based discovery of 1H-indole-2-carboxamide derivatives as potent ASK1 inhibitors for potential treatment of ulcerative colitis

Apoptosis signal-regulating kinase 1 (ASK1), a member of the mitogen-activated protein kinase (MAPK) family, is implicated in many human diseases. Here, we describe the structural optimization of hit compound 7 and conduct further structure-activity relationship (SAR) studies that result in the development of compound 19 with a novel indole-2-carboxamide hinge scaffold. Compound 19 displays potent anti-ASK1 kinase activity and stronger inhibitory effect on ASK1 in AP1-HEK293 cells than previously described ASK1 inhibitor GS-4997. Besides improved in vitro activity, compound 19 also exhibits an appropriate in vivo PK profile. In a dextran sulfate sodium (DSS)-induced mouse model of ulcerative colitis (UC), compound 19 shows significant anti-UC efficacy and markedly attenuates DSS-induced body weight loss, colonic shortening, elevation in disease activity index (DAI) and inflammatory cell infiltration in colon tissues. Mechanistically, compound 19 represses the phosphorylation of ASK1-p38/JNK signaling pathways and suppresses the overexpression of inflammatory cytokines. Together, these findings suggest that ASK1 inhibitors can potentially be used as a therapeutic strategy for UC.

Immunocompetent Human Intestinal Models in Preclinical Drug Development

The intestinal epithelial barrier, together with the microbiome and local immune system, is a critical component that maintains intestinal homeostasis. Dysfunction may lead to chronic inflammation, as observed in inflammatory bowel diseases. Animal models have historically been used in preclinical research to identify and validate new drug targets in intestinal inflammatory diseases. Yet, limitations about their biological relevance to humans and advances in tissue engineering have forced the development of more complex three-dimensional reconstructed intestinal epithelium. By introducing immune and commensal microbial cells, these models more accurately mimic the gut's physiology and the pathophysiological changes occurring in vivo in the inflamed intestine. Specific advantages and limitations of two-dimensional (2D) and three-dimensional (3D) intestinal models such as coculture systems, organoids, and microfluidic devices to study inflammatory and immune-related responses are highlighted. While current cell culture models lack the cellular and molecular complexity observed in vivo, the emphasis is put on how these models can be used to improve preclinical drug development for inflammatory diseases of the intestine.

Immuno-hippo: Research progress of the hippo pathway in autoimmune disease

Extensive research in Drosophila and mammals has identified the core components of Hippo signaling, which controls gene expression. Studies of Drosophila have demonstrated the highly conserved Hippo pathway controls tissue homeostasis and organ size by regulating the balance between cell proliferation and apoptosis. Recent work has indicated a potential role of the Hippo pathway in regulating the immune system, which is the key player in autoimmune disease (AID). Therefore, the Hippo pathway may become a novel target for curing AID. Although the pivotal role of both the Hippo pathway in tumorigenesis has been thoroughly investigated, the role of it in AID is still poorly understood. Elucidating the role of Hippo signaling pathways in the activation and expression of specific molecules involved in immune regulation is important for understanding the pathogenesis of AID and exploring novel therapeutic targets. To aid in further research, this review describes the relationship between the Hippo pathway and inflammatory signals such as NF-κB and JAK-STAT, the function of the Hippo pathway in the formation and differentiation of immune cells, and the regulatory role of the Hippo pathway in AID.

Effects of Dietary Supplementation with Clostridium butyricum on Growth Performance, Serum Immunity, Intestinal Morphology, and Microbiota as an Antibiotic Alternative in Weaned Piglets

This study investigated the effects of Clostridium butyricum (C. butyricum) use on growth performance, serum immunity, intestinal morphology, and microbiota as an antibiotic alternative in weaned piglets. Over the course of 28 days, 120 piglets were allocated to four treatments with six replicates of five piglets each. The treatments were: CON (basal diet); AGP (basal diet supplemented with 0.075 g/kg chlortetracycline, 0.055 g/kg kitasamycin, and 0.01 g/kg virginiamycin); CBN (basal diet supplemented with normal dosage of 2.5 × 10⁸ CFU/kg C. butyricum); and CBH (basal diet supplemented with high dosage of 2.5 × 10⁹ CFU/kg C. butyricum). Body weight (BW) and feed consumption were recorded at the beginning and on days 14 and 28 of the experiment, and representative feed samples and fresh feces were collected from each pen between days 26 and 28. Average fecal score of diarrhea was visually assessed each morning during the experimental period. On the morning of days 14 and 28, blood samples were collected to prepare serum for immune and antioxidant parameters measurement. One male piglet close to the average group BW was selected from each replicate and was slaughtered on day 21 of the experiment. Intestinal crypt villi, and colonic microbiota and its metabolites short-chain fatty acids were measured. Compared to the CON group, the CBN and AGP groups significantly decreased (p < 0.05) the ratio of feed to weight gain by 8.86% and 8.37% between days 1 and 14, 3.96% and 13.36% between days 15 and 28, 5.47% and 11.44% between days 1 and 28. Dietary treatment with C. butyricum and AGPs significantly decreased the average fecal score during the experimental period (p < 0.05). The apparent total tract digestibility of dry matter, organic matter, and total carbohydrates in the CBH group were higher respectively at 3.27%, 2.90%, and 2.97%, than those in the CON or AGP groups (p < 0.05). Compared to the CON group, the CBH group significantly increased short-chain fatty acids in colon and villus height in the jejunum (p < 0.05). The CBN group had higher serum levels of immunoglobulins, interleukin 2 (IL-2), and glutathione peroxidase (GSH-PX) activity, but lower serum levels of IL-1β and IL-6, and a lower aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyl transpeptidase (γ-GT) activity (p < 0.05), while compared to the CON group. Dietary treatment with C. butyricum significantly increased the relative abundance of Streptococcus and Bifidobacterium (p < 0.05). In summary, diet with C. butyricum increased the growth performance and benefited the health of weaned piglets.

Anti-inflammatory effects of Lactobacillus reuteri LM1071 via MAP kinase pathway in IL-1β-induced HT-29 cells

Lactic acid bacteria are well-known probiotics, conferring several health benefits. In this study, we isolated lactobacilli from human breast milk and identified Lactobacillus reuteri LM1071 (RR-LM1071) using 16S rDNA sequencing. We tested the hemolytic activity, biogenic amine production, and antibiotic susceptibility of this strain to assess its safety. RR-LM1071 was found to be negative for hemolytic activity and biogenic amine production, as well as was measured in susceptible level for antibiotics in the minimal inhibitory concentration (MIC) test. The adhesive properties of RR-LM1071 were higher than those of LGG in HT-29 cells, and showed a greater hydrophobicity than LGG in hexadecane solvent. Under inflammatory conditions, RR-LM1071 suppressed the mRNA expression of IL-6, TNF-α, and IL-4 produced in IL-1β-induced HT-29 cells. Our results suggest that RR-LM1071 is a safe and valuable probiotic that can be used for the treatment of inflammatory bowel disease.

Interleukin-4 Receptor α Subunit Deficiency Alleviates Murine Intestinal Inflammation In Vivo Through the Enhancement of Intestinal Mucosal Barrier Function

Disturbance of epithelial barrier function causes chronic intestinal inflammation such as inflammatory bowel disease. Several studies have reported that Th2 cytokines such as interleukin (IL)-4 and IL-13 play an important role in the regulation of intestinal barrier function. However, the precise role of the IL-4 receptor α subunit (IL-4Rα) in intestinal inflammation remains unclear. Thus, we used an experimental colitis model to investigate the role of IL-4Rα in intestinal inflammation. IL-4Rα-deficient (IL-4Rα-/-) mice and their littermate wild-type (WT) mice were used. Experimental colitis was induced by administration of 3% dextran sulfate sodium (DSS) in the drinking water for seven days. Treatment with DSS caused body weight loss, an increase in the disease activity index and histological abnormalities in WT colitis mice, all of which were significantly attenuated in IL-4Rα-/- colitis mice. Neutrophil infiltration in the colonic mucosa was reduced in IL-4Rα-/- colitis mice compared with WT colitis mice. NADPH oxidase 1 expression and reactive oxygen species production were increased in the colons of IL-4Rα-/- mice. Furthermore, elevated intestinal permeability induced by DSS treatment was suppressed in IL-4Rα-/- colitis mice. These results demonstrate that IL-4Rα-/- mice exhibit reduced susceptibility to DSS-induced colitis. Our present findings suggest that IL-4Rα deficiency enhances intestinal mucosal barrier function through the upregulation of NADPH oxidase 1-dependent reactive oxygen species production, thereby suppressing the development of intestinal inflammation.

The MARVEL trial: a phase 2b randomised placebo-controlled trial of oral MitoQ in moderate ulcerative colitis

Ulcerative colitis (UC) is an inflammatory disease of the large bowel which is characterised by dysregulated immunity and death to epithelial cells in the bowel, leading to prolonged inflammation. This can ultimately lead to surgery to remove the large bowel, with a risk of cancer developing if inflammation persists. Current therapies – which target the incoming immune cells or the cytokines they produce – are improving significantly but they are expensive and are immunosuppressive, leading to risk of infection. Here, we discuss a new trial which targets an early inducer of inflammation – the production of reactive oxygen species (ROS) by mitochondria. Previous work has shown that excessive mitochondrial ROS induces inflammatory signalling through the cGAS-STING pathway, leading to dysregulated immunity and death of epithelial cells. In this MARVEL trial (Mitochondrial Anti-oxidant therapy to Resolve Inflammation in Ulcerative Colitis) individuals with an active UC flare-up will be given a mitochondrial anti-oxidant (MitoQ) or placebo tablet in addition to standard medical treatment, in order to suppress inflammation as it develops. This phase 2b trial will repurpose MitoQ, which has been previously tested in other large trials in different disease settings, and will measure clinical response and markers of inflammation over 24 weeks. It is hoped that this trial will develop a new target for UC through re-purposing a relatively cheap, non-toxic and well-characterised drug.

A polysaccharide from Fagopyrum esculentum Moench bee pollen alleviates microbiota dysbiosis to improve intestinal barrier function in antibiotic-treated mice

Antibiotics are the most commonly used clinical drugs for anti-infection, but they can also destroy normal microorganisms and cause intestinal barrier dysfunction. To elucidate the effects and mechanism of a water-soluble polysaccharide from Fagopyrum esculentum Moench bee pollen (WFPP) on intestinal barrier integrity in antibiotic-treated mice, BALB/c mice were exposed to a broad-spectrum antibiotic (ceftriaxone) or not (control), and were administered low-, medium- and high-dose WFFP (100 mg kg^-1, 200 mg kg^-1 and 400 mg kg^-1, respectively) daily by oral gavage for 3 weeks. Mice treated with ceftriaxone displayed symptoms of growth retardation, atrophy of immune organs including thymus and spleen, increased gut permeability, and intestinal barrier damage, which were restored after intervention with WFFP at different doses. Moreover, the beneficial effects of WFFP were closely associated with enhanced intestinal sIgA secretion and reduced inflammatory response. Furthermore 16S rDNA gene sequencing revealed that WFPP elevated microbial diversity and richness and changed the community structure, therefore, alleviating microbiota dysbiosis caused by ceftriaxone. Interestingly, WFPP could modulate the abundance of sIgA secretion-related bacteria (e.g. Proteobacteria) and inflammation-related bacteria (e.g. Enterococcus). Therefore, WFPP can relieve antibiotic-induced microbiota dysbiosis to improve intestinal barrier integrity by increasing intestinal sIgA secretion and inhibiting inflammation.

Elevated adenomatous polyposis coli in goblet cells is associated with inflammation in mouse and human colon

NEW FINDINGS

What is the central question of this study? What is the localization and distribution pattern of adenomatous polyposis coli (APC) in intestinal epithelial cells? Does this distribution change in different regions of the colon or in the condition of inflammation? What is the main finding and its importance? Colonic epithelia from mice and humans contain a subset of goblet cells displaying high APC levels. The number of APC^high goblet cells increases in inflamed tissue, which also displays increased GRP78, indicating potential stress from mucin production. In cultured human colon cells, expression of interleukin 1 pathway components (inducers of MUC2 expression) is reduced upon APC depletion raising the potential for APC participation in an inflammatory response.

ABSTRACT

Adenomatous polyposis coli (APC) serves as a gatekeeper of intestinal homeostasis by promoting cellular differentiation and maintaining crypt architecture. Although appreciated as a critical colon tumour suppressor, roles for APC in disease states such as inflammation have yet to be fully delineated. This study aimed to characterize the localization of APC protein in gastrointestinal tissues from human patients with active inflammatory bowel disease and mice with dextran sodium sulfate (DSS)-induced colitis. Fluorescence immunohistochemistry revealed a subset of goblet cells with elevated Apc staining intensity in the small intestines and proximal/medial colons of mice. Upon induction of colitis with DSS, these 'APC^high ' goblet cells remained in the proximal and medial colon, but now were also observed in the distal colon. This phenotype was recapitulated in humans, with APC^high goblet cells observed only in the descending colons of patients with active ulcerative colitis. In cultured human colon cells derived from normal tissue, APC depletion reduced expression of mRNAs encoding the interleukin 1 (IL1) signalling pathway components IL1β and interleukin-1 receptor (IL1R), known regulators of Muc2 expression. Treating cancer cells lacking wild-type APC with IL1β, or induction of full-length APC in these cells led to increases in IL1R and MUC2 expression. Combining IL1β treatment with APC induction led to an increase of MUC2 expression greater than expected for additive affects, suggesting that APC sensitizes cells to IL1 signalling. These findings suggest that APC has novel roles in maintaining proper goblet cell function, thus providing further evidence for APC as an important factor in intestinal tissue homeostasis and disease.

Effects of the Use of Curcumin on Ulcerative Colitis and Crohn's Disease: A Systematic Review

Inflammatory bowel disease (IBD) is an umbrella term used to describe chronic inflammatory disorders related to a substantial reduction in the quality of life of patients. Some patients with Crohn's disease (CD) and ulcerative colitis (UC) are refractory to conventional therapies, and Curcuma longa derivatives have been considered as adjuvants. Owing to the anti-inflammatory and antioxidant effects, some clinical trials used this plant in the therapeutic approach of IBD, and some meta-analyses evaluated the outcomes found in these studies. Owing to controversial findings, our systematic review aimed to evaluate these studies to show whether C. longa compounds can still be considered in the therapeutic approach of patients with CD and UC. MEDLINE-PubMed, EMBASE, and Cochrane were searched, and Preferred Reporting Items for a Systematic Review and Meta-Analysis guidelines were followed. The results of the randomized clinical trials (RCTs) showed promising results with the use of curcumin in the therapeutic approach of both UC and CD patients. Some meta-analyses show controversial results, possibly due to the presence of bias in the included studies. The actions of curcumin are achieved by several mechanisms, such as reducing the expression of interleukin (IL)-1, IL-6, IL-12, and tumor necrosis factor-α. Moreover, it reduces the levels of reactive oxygen species, such as superoxide anions and malondialdehyde. The results of using curcumin in CD and UC patients are challenging to be evaluated because RCTs are variable in the dose and the formulations of curcumin, in the time of treatment, and the route of administration. The number of patients in the samples is also usually small.

Gallic and butyric acids modulated NLRP3 inflammasome markers in a co-culture model of intestinal inflammation

Bioactive compounds from food products made from natural ingredients such as corn and common bean could target the NLRP3 inflammasome, protein scaffolds with a key role in the moderation of intestinal inflammation. This research aimed to evaluate the anti-inflammatory effect from the fermented non-digestible fraction of baked corn and common bean snack (FNDF), and its main components, on the modulation of NLRP3 inflammasome markers in vitro. For this, a THP-1 macrophage/differentiated Caco-2 cell co-culture was used as a model of intestinal inflammation. A disease control (DC) (LPS/human IFN-γ, 10 ng/mL) was compared with FNDF (40-300 μg/mL) and its pure components: gallic (38.85 μM) and butyric acids (6 μM), verbascose (0.06 μM), their mixture, and an anti-inflammatory control (tofacitinib, 5 μM). Compared to DC, FNDF (40 μg/mL) reduced the 48 h-basolateral nitrites (40-60%), IL-1β/IL-18, and TNF-α production. Additionally, it decreased the total reactive oxygen species (36.3%) and nitric oxide synthase (6.9%) activities, increasing superoxide dismutase (228.2%) activity. Compared to NLRP3 positive control, FNDF components decreased NLRP3 markers (caspase-1 activity, IL-1β, and apoptosis). These results highlight NLRP3-anti-inflammatory effects from FNDF components. This is the first report of the NLRP3 inflammasome modulation by digested food matrix components, using a co-culture approach.

Reproducibility of serum cytokines in an elderly population

Background

It is important to assess the temporal reproducibility of circulating cytokines for their utility in epidemiological studies. However, existing evidence is limited and inconsistent, especially for the elderly population.

Methods

Sixty-five elderly (mean age = 77.89 ± 6.14 years) subjects were randomly selected from an existing prospective cohort study. Levels of 41 cytokines in 195 serum samples, collected at three separate visits that were up to 15.26 years apart, were measured by the Luminex technology. The temporal reproducibility of cytokines was estimated by the intraclass correlation coefficient (ICC) calculated using a mixed-effects model. In addition, data analyses were stratified by the median (4.49 years) of time intervals across sample collection. Sensitivity analyses were performed when excluding subjects with undetectable samples.

Results

A total of 23 cytokines were detectable in more than 60% of samples. Fair to good (ICC = 0.40 to 0.75) and excellent (ICC > 0.75) reproducibility was found in 10 (Eotaxin, VEGF, FGF-2, G-CSF, MDC, GM-CSF, TGFα, IP-10, MIP-1β, IL-1RA) and 5 (GRO, IFNγ, IL-17, PDGF-AA, IL-4) cytokines, respectively. The results were not changed dramatically in the stratification and sensitivity analyses.

Conclusions

Serum levels of the selected 15 cytokines measured with Luminex technology displayed fair to excellent within-person temporal reproducibility among elderly population.

Euterpe oleracea Mart. (Açaí) attenuates experimental colitis in rats: involvement of TLR4/COX-2/NF-ĸB

Euterpe oleracea Mart., commonly known as açaí, has been demonstrated to exhibit significantly antioxidant and inflammatory activities in experimental models. These effects of the hydroalcoholic extract from the açaí seed (ASE) were investigated in TNBS-induced (2,4,6-trinitrobenzenesulfonic acid) acute colitis model in rats. Wistar rats (180-220 g) were orally pretreated with saline (0.3 mL), ASE (10, 30 and 100 mg/kg) and dexamethasone (control group, 1 mg/kg) once daily for 3 days starting before TNBS instillation. On day 3 after TNBS, the animals were euthanized, the portion of distal colon was collected and washed with 0.9% saline for macroscopy and histological evaluation, glutathione (GSH) and malonyldialdehyde (MDA) levels, myeloperoxidase (MPO) and catalase (CAT) activity, nitrate and nitrite (NO₃/NO₂) concentration, pro-inflammatory cytokines levels and intestinal barrier integrity. We also evaluated Toll-like Receptor 4/cyclooxygenase-2/nuclear factor kappa B expression as a possible mechanism related to the ASE effects. Treatment with ASE 100 mg/kg decreased significantly macroscopic and microscopic damage induced by TNBS. In addition, MPO activity, TNF-α (tumor necrosis factor-alpha) and IL-1β (interleukin 1) levels were reduced in rats with colitis. ASE 100 mg/kg restored GSH and MDA levels, CAT activity, NO₃/NO₂ concentration and improved the intestinal barrier integrity in the TNBS group. ASE 100 mg/kg significantly reduced TNBS-induced expression of the TLR4, COX-2 and NF-κB p65. ASE 100 mg/kg improved macroscopy and histological parameters, inflammation, intestinal barrier integrity and nitric and oxidative stress through the TLR-4/COX-2/NF-κB pathway.

Polar functional group-containing glycolipid CD1d ligands modulate cytokine-biasing responses and prevent experimental colitis

The MHC class I-like molecule CD1d is a nonpolymorphic antigen-presenting glycoprotein, and its ligands include glycolipids, such as α-GalCer. The complexes between CD1d and ligands activate natural killer T cells by T cell receptor recognition, leading to the secretion of various cytokines (IFN-γ, IL-4, IL-17A, etc.). Herein, we report structure-activity relationship studies of α-GalCer derivatives containing various functional groups in their lipid acyl chains. Several derivatives have been identified as potent CD1d ligands displaying higher cytokine induction levels and/or unique cytokine polarization. The studies also indicated that flexibility of the lipid moiety can affect the binding affinity, the total cytokine production level and/or cytokine biasing. Based on our immunological evaluation and investigation of physicochemical properties, we chose bisamide- and Bz amide-containing derivatives 2 and 3, and evaluated their in vivo efficacy in a DSS-induced model of ulcerative colitis. The derivative 3 that exhibits Th2- and Th17-biasing responses, demonstrated significant protective effects against intestinal inflammation in the DSS-induced model, after a single intraperitoneal injection.