The immunological and genetic basis of inflammatory bowel disease

The Role of IL-23 in the Pathogenesis and Therapy of Inflammatory Bowel Disease

Interleukin-23 (IL-23) is a proinflammatory cytokine produced mainly by macrophages and antigen-presenting cells (APCs) after antigenic stimulation. IL-23 plays a significant role as a mediator of tissue damage. Indeed, the irregularities in IL-23 and its receptor signaling have been implicated in inflammatory bowel disease. IL-23 interacts with both the innate and adaptive immune systems, and IL-23/Th17 appears to be involved in the development of chronic intestinal inflammation. The IL-23/Th17 axis may be a critical driver of this chronic inflammation. This review summarizes the main aspects of IL-23's biological function, cytokines that control cytokine production, effectors of the IL-23 response, and the molecular mechanisms associated with IBD pathogenesis. Although IL-23 modulates and impacts the development, course, and recurrence of the inflammatory response, the etiology and pathophysiology of IBD are not completely understood, but mechanism research shows huge potential for clinical applications as therapeutic targets in IBD treatment.

Gut Protective Effect from D-Methionine or Butyric Acid against DSS and Carrageenan-Induced Ulcerative Colitis

Microbiome dysbiosis resulting in altered metabolite profiles may be associated with certain diseases, including inflammatory bowel diseases (IBD), which are characterized by active intestinal inflammation. Several studies have indicated the beneficial anti-inflammatory effect of metabolites from gut microbiota, such as short-chain fatty acids (SCFAs) and/or D-amino acids in IBD therapy, through orally administered dietary supplements. In the present study, the potential gut protective effects of d-methionine (D-Met) and/or butyric acid (BA) have been investigated in an IBD mouse model. We have also built an IBD mouse model, which was cost-effectively induced with low molecular weight DSS and kappa-carrageenan. Our findings revealed that D-Met and/or BA supplementation resulted in the attenuation of the disease condition as well as the suppression of several inflammation-related gene expressions in the IBD mouse model. The data shown here may suggest a promising therapeutic potential for improving symptoms of gut inflammation with an impact on IBD therapy. However, molecular metabolisms need to be further explored.

Socs3 expression in myeloid cells modulates the pathogenesis of dextran sulfate sodium (DSS)-induced colitis

Introduction

Myeloid cells play a critical role in the pathogenesis of Inflammatory Bowel Diseases (IBDs), including Ulcerative Colitis (UC) and Crohn's Disease (CD). Dysregulation of the JAK/STAT pathway is associated with many pathological conditions, including IBD. Suppressors Of Cytokine Signaling (SOCS) are a family of proteins that negatively regulate the JAK/STAT pathway. Our previous studies identified that mice lacking Socs3 in myeloid cells developed a hyper-activated phenotype of macrophages and neutrophils in a pre-clinical model of Multiple Sclerosis.

Methods

To better understand the function of myeloid cell Socs3 in the pathogenesis of colitis, mice with Socs3 deletion in myeloid cells (Socs3 ^ΔLysM) were utilized in a DSS-induced colitis model.

Results

Our results indicate that Socs3 deficiency in myeloid cells leads to more severe colitis induced by DSS, which correlates with increased infiltration of monocytes and neutrophils in the colon and increased numbers of monocytes and neutrophils in the spleen. Furthermore, our results demonstrate that the expression of genes related to the pathogenesis and diagnosis of colitis such as Il1β, Lcn2, S100a8 and S100a9 were specifically enhanced in Socs3-deficient neutrophils localized to the colon and spleen. Conversely, there were no observable differences in gene expression in Ly6C⁺ monocytes. Depletion of neutrophils using a neutralizing antibody to Ly6G significantly improved the disease severity of DSS-induced colitis in Socs3-deficient mice.

Discussion

Thus, our results suggest that deficiency of Socs3 in myeloid cells exacerbates DSS-induced colitis and that Socs3 prevents overt activation of the immune system in IBD. This study may provide novel therapeutic strategies to IBD patients with hyperactivated neutrophils.

Gut Microbial Metabolite Butyrate and Its Therapeutic Role in Inflammatory Bowel Disease: A Literature Review

Background and objective: Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic inflammatory disorder characterized by aberrant immune responses and compromised barrier function in the gastrointestinal tract. IBD is associated with altered gut microbiota and their metabolites in the colon. Butyrate, a gut microbial metabolite, plays a crucial role in regulating immune function, epithelial barrier function, and intestinal homeostasis. In this review, we aim to present an overview of butyrate synthesis and metabolism and the mechanism of action of butyrate in maintaining intestinal homeostasis and to discuss the therapeutic implications of butyrate in IBD. Methods: We searched the literature up to March 2023 through PubMed, Web of Science, and other sources using search terms such as butyrate, inflammation, IBD, Crohn's disease, and ulcerative colitis. Clinical studies in patients and preclinical studies in rodent models of IBD were included in the summary of the therapeutic implications of butyrate. Results: Research in the last two decades has shown the beneficial effects of butyrate on gut immune function and epithelial barrier function. Most of the preclinical and clinical studies have shown the positive effect of butyrate oral supplements in reducing inflammation and maintaining remission in colitis animal models and IBD patients. However, butyrate enema showed mixed effects. Butyrogenic diets, including germinated barley foodstuff and oat bran, are found to increase fecal butyrate concentrations and reduce the disease activity index in both animal models and IBD patients. Conclusions: The current literature suggests that butyrate is a potential add-on therapy to reduce inflammation and maintain IBD remission. Further clinical studies are needed to determine if butyrate administration alone is an effective therapeutic treatment for IBD.

Deep into the niche: Deciphering local endoderm-microenvironment interactions in development, homeostasis, and disease of pancreas and intestine

Unraveling molecular and functional heterogeneity of niche cells within the developing endoderm could resolve mechanisms of tissue formation and maturation. Here, we discuss current unknowns in molecular mechanisms underlying key developmental events in pancreatic islet and intestinal epithelial formation. Recent breakthroughs in single-cell and spatial transcriptomics, paralleled with functional studies in vitro, reveal that specialized mesenchymal subtypes drive the formation and maturation of pancreatic endocrine cells and islets via local interactions with epithelium, neurons, and microvessels. Analogous to this, distinct intestinal niche cells regulate both epithelial development and homeostasis throughout life. We propose how this knowledge can be used to progress research in the human context using pluripotent stem cell-derived multilineage organoids. Overall, understanding the interactions between the multitude of microenvironmental cells and how they drive tissue development and function could help us make more therapeutically relevant in vitro models.

Wheat Germ Supplementation Reduces Inflammation and Gut Epithelial Barrier Dysfunction in Female Interleukin-10 Knockout Mice Fed a Pro-Atherogenic Diet

BACKGROUND

Mice lacking IL-10 are prone to gut inflammation. Additionally, decreased production of short-chain fatty acids (SCFAs) plays a significant role in the high-fat (HF) diet-induced loss of gut epithelial integrity. We have previously shown that wheat germ (WG) supplementation increased ileal expression of IL-22, an important cytokine in maintaining gut epithelial homeostasis.

OBJECTIVES

This study investigated the effects of WG supplementation on gut inflammation and epithelial integrity in IL-10 knockout mice fed a pro-atherogenic diet.

METHODS

Eight-week-old female C57BL/6 wild type mice were fed a control diet (10% fat kcal), and age-matched knockout mice were randomly assigned to 1 of 3 diets (n = 10/group): control, high-fat high-cholesterol (HFHC) [(43.4% fat kcal (∼49% saturated fat, 1% cholesterol)], or HFHC + 10% WG (HFWG) for 12 wk. Fecal SCFAs and total indole, ileal, and serum proinflammatory cytokines, gene or protein expression of tight junctions, and immunomodulatory transcription factors were assessed. Data were analyzed by 1-way ANOVA, and P < 0.05 was considered statistically significant.

RESULTS

Fecal acetate, total SCFAs, and indole increased (P < 0.05) by at least 20% in HFWG compared with the other groups. WG increased (P < 0.0001, 2-fold) ileal Il22 (interleukin 22) to Il22ra2 (interleukin 22 receptor, alpha 2) mRNA ratio and prevented the HFHC diet-mediated increase in ileal protein expression of indoleamine 2,3 dioxygenase and pSTAT3 (phosphorylated signal transducer and activator of transcription 3). WG also prevented the HFHC diet-mediated reduction (P < 0.05) in ileal protein expression of the aryl hydrocarbon receptor and the tight junction protein, zonula occludens-1. Serum and ileal concentrations of the proinflammatory cytokine, IL-17, were lower (P < 0.05) by at least 30% in the HFWG group than in the HFHC group.

CONCLUSIONS

Our findings demonstrate that the anti-inflammatory potential of WG in IL-10 KO mice consuming an atherogenic diet is partly attributable to its effects on the IL-22 signaling and pSTAT3-mediated production of T helper 17 proinflammatory cytokines.

Biodegradable Polymeric Nanoparticles Loaded with Flavonoids: A Promising Therapy for Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a group of disorders that cause chronic non-specific inflammation in the gastrointestinal (GI) tract, primarily affecting the ileum and colon. The incidence of IBD has risen sharply in recent years. Despite continuous research efforts over the past decades, the aetiology of IBD is still not fully understood and only a limited number of drugs are available for its treatment. Flavonoids, a ubiquitous class of natural chemicals found in plants, have been widely used in the prevention and treatment of IBD. However, their therapeutic efficacy is unsatisfactory due to poor solubility, instability, rapid metabolism, and rapid systemic elimination. With the development of nanomedicine, nanocarriers can efficiently encapsulate various flavonoids and subsequently form nanoparticles (NPs), which greatly improves the stability and bioavailability of flavonoids. Recently, progress has also been made in the methodology of biodegradable polymers that can be used to fabricate NPs. As a result, NPs can significantly enhance the preventive or therapeutic effects of flavonoids on IBD. In this review, we aim to evaluate the therapeutic effect of flavonoid NPs on IBD. Furthermore, we discuss possible challenges and future perspectives.

Periodontal Inflamed Surface Area (PISA) associates with composites of salivary cytokines

BACKGROUND

Periodontal disease (PerioD) is a chronic, complex inflammatory condition resulting from the interaction between subgingival dysbiotic bacteria and the host immune response leading to local inflammation. Since periodontal inflammation is characterized by multiple cytokines effects we investigated whether Periodontal Inflamed Surface Area (PISA), a continuous measure of clinical periodontal inflammation is a predictor of composite indexes of salivary cytokines.

METHODS AND FINDINGS

In a cross-sectional study of 67 healthy, well-educated individuals, we evaluated PISA and several cytokines expressed in whole stimulated saliva. Two salivary cytokine indexes were constructed using weighted and unweighted approaches based on a Principal Component Analysis [named Cytokine Component Index (CCI)] or averaging the (standardized) level of all cytokines [named Composite Inflammatory Index (CII)]. In regression analysis we found that PISA scores were significantly associated with both salivary cytokine constructs, (CCI: part R = 0.51, p<0.001; CII: part R = 0.40, p = 0.001) independent of age, gender and BMI showing that single scores summarizing salivary cytokines correlated with severity of clinical periodontal inflammation.

CONCLUSIONS

Clinical periodontal inflammation may be reflected by a single score encompassing several salivary cytokines. These results are consistent with the complexity of interactions characterizing periodontal disease. In addition, Type I error is likely to be avoided.

Akkermansia muciniphila as a Next-Generation Probiotic in Modulating Human Metabolic Homeostasis and Disease Progression: A Role Mediated by Gut-Liver-Brain Axes?

Appreciation of the importance of Akkermansia muciniphila is growing, and it is becoming increasingly relevant to identify preventive and/or therapeutic solutions targeting gut-liver-brain axes for multiple diseases via Akkermansia muciniphila. In recent years, Akkermansia muciniphila and its components such as outer membrane proteins and extracellular vesicles have been known to ameliorate host metabolic health and intestinal homeostasis. However, the impacts of Akkermansia muciniphila on host health and disease are complex, as both potentially beneficial and adverse effects are mediated by Akkermansia muciniphila and its derivatives, and in some cases, these effects are dependent upon the host physiology microenvironment and the forms, genotypes, and strain sources of Akkermansia muciniphila. Therefore, this review aims to summarize the current knowledge of how Akkermansia muciniphila interacts with the host and influences host metabolic homeostasis and disease progression. Details of Akkermansia muciniphila will be discussed including its biological and genetic characteristics; biological functions including anti-obesity, anti-diabetes, anti-metabolic-syndrome, anti-inflammation, anti-aging, anti-neurodegenerative disease, and anti-cancer therapy functions; and strategies to elevate its abundance. Key events will be referred to in some specific disease states, and this knowledge should facilitate the identification of Akkermansia muciniphila-based probiotic therapy targeting multiple diseases via gut-liver-brain axes.

Effects of Medicinal Plants and Phytochemicals in Nrf2 Pathways during Inflammatory Bowel Diseases and Related Colorectal Cancer: A Comprehensive Review

Inflammatory bowel diseases (IBDs) are related to nuclear factor erythroid 2-related factor 2 (Nrf2) dysregulation. In vitro and in vivo studies using phytocompounds as modulators of the Nrf2 signaling in IBD have already been published. However, no existing review emphasizes the whole scenario for the potential of plants and phytocompounds as regulators of Nrf2 in IBD models and colitis-associated colorectal carcinogenesis. For these reasons, this study aimed to build a review that could fill this void. The PubMed, EMBASE, COCHRANE, and Google Scholar databases were searched. The literature review showed that medicinal plants and phytochemicals regulated the Nrf2 on IBD and IBD-associated colorectal cancer by amplifying the expression of the Nrf2-mediated phase II detoxifying enzymes and diminishing NF-κB-related inflammation. These effects improve the bowel environment, mucosal barrier, colon, and crypt disruption, reduce ulceration and microbial translocation, and consequently, reduce the disease activity index (DAI). Moreover, the modulation of Nrf2 can regulate various genes involved in cellular redox, protein degradation, DNA repair, xenobiotic metabolism, and apoptosis, contributing to the prevention of colorectal cancer.

Patched 1 and C-C Motif Chemokine Receptor 6 Distinguish Heterogeneous T Helper 17 Subsets in Colitic Lamina Propria

T helper 17 (Th17) cells contribute to the pathogenesis of inflammatory bowel diseases (IBD). However, their heterogeneity and regulatory mechanisms in IBD are not completely disclosed. A mouse colitis model was established. Th17 cells were enriched from the mesenteric lymph nodes (mLN) and lamina propria (LP). The phenotypes and functions of Th17 subsets were analyzed by flow cytometry, Immunoblotting, and real-time RT-PCR. The contributions of the Th17 subsets to colitis pathogenesis were evaluated by histology, ELISA, and flow cytometry after adoptive transfer. Smoothened (SMO), GLI family zinc finger 1 (Gli1), and GLI family zinc finger 3 (Gli3) were markedly up-regulated while Patched 1 (PTCH1) was down-regulated in LP Th17 cells in colitic lamina propria. Based on the expression of PTCH1 and C-C motif chemokine receptor 6 (CCR6), LP Th17 cells were divided into a PTCH1^lowCCR6^low Th17 subset and a PTCH1^highCCR6^high Th17 subset. The former expressed higher T-bet, IFN-γ, TNF-α, IL-1β, and GM-CSF but lower IL-17A, IL-22, IL-17F, and Gli3 than the latter. The PTCH1^highCCR6^high Th17 subset was more resistant to polarization towards T helper 1 (Th1) than the PTCH1^lowCCR6^low Th17 subset. Moreover, the PTCH1^highCCR6^high Th17 subset was more competent to maintain Th17 identity. The PTCH1^highCCR6^high Th17 subset induced less severe colitis than the PTCH1^lowCCR6^low Th17 subset. PTCH1^highCCR6^high Th17 cells are Th17 cells whereas PTCH1^lowCCR6^low Th17 cells are Th1-like Th17 cells. Our study deepens the understanding of Th17 heterogeneity and plasticity in colitis.

Skin microbiota signature distinguishes IBD patients and reflects skin adverse events during anti-TNF therapy

Crohn's disease (CD) and ulcerative colitis (UC) are two forms of inflammatory bowel disease (IBD), where the role of gut but not skin dysbiosis is well recognized. Inhibitors of TNF have been successful in IBD treatment, but up to a quarter of patients suffer from unpredictable skin adverse events (SkAE). For this purpose, we analyzed temporal dynamics of skin microbiota and serum markers of inflammation and epithelial barrier integrity during anti-TNF therapy and SkAE manifestation in IBD patients. We observed that the skin microbiota signature of IBD patients differs markedly from healthy subjects. In particular, the skin microbiota of CD patients differs significantly from that of UC patients and healthy subjects, mainly in the retroauricular crease. In addition, we showed that anti-TNF-related SkAE are associated with specific shifts in skin microbiota profile and with a decrease in serum levels of L-FABP and I-FABP in IBD patients. For the first time, we showed that shifts in microbial composition in IBD patients are not limited to the gut and that skin microbiota and serum markers of the epithelium barrier may be suitable markers of SkAE during anti-TNF therapy.

Alginate Oligosaccharides Prevent Dextran-Sulfate-Sodium-Induced Ulcerative Colitis via Enhancing Intestinal Barrier Function and Modulating Gut Microbiota

Alginate oligosaccharides are degradation products of alginate and have attracted increasing attention due to their versatile biological functions. In the present study, C57BL/6 mice were used to assess the ameliorative effects and mechanisms of guluronate oligosaccharides (GAOS), mannuronic oligosaccharides (MAOS), and heterozygous alginate oligosaccharides (HAOS), which are the three alginate oligosaccharides of dextran sulfate sodium (DSS)-induced ulcerative colitis. The study showed that alginate oligosaccharides alleviated pathological histological damage by slowing down weight loss, inhibiting colonic length shortening, and reducing disease activity index (DAI) and histopathological scores. Alginate oligosaccharides modulated the colonic inflammatory response by reducing colonic MPO levels and downregulating the expression of IL-6 and IL-1β. Alginate oligosaccharides reduced intestinal permeability and reversed intestinal barrier damage by increasing the number of goblet cells, decreasing LPS levels, downregulating Bax protein levels, upregulating Bcl-2 protein levels, and enhancing the expression of the E-cadherin. Furthermore, alginate oligosaccharides modulated the composition of the gut microbiota and restored the production of short-chain fatty acids (SCFAs), especially acetate and butyrate. In conclusion, our study provides a scientific basis for the role of alginate oligosaccharides in relieving ulcerative colitis.

Klebsiella pneumoniae Induces Inflammatory Bowel Disease Through Caspase-11-Mediated IL18 in the Gut Epithelial Cells

BACKGROUND & AIMS

Klebsiella pneumoniae (KLP), a Gram-negative bacterium belonging to the family of Enterobacteriaceae, is a common cause of antimicrobial-resistant opportunistic infections in hospitalized patients. KLP can colonize in the human gastrointestinal tract, especially in patients with inflammatory bowel diseases. However, effects of KLP on the onset and development of inflammatory bowel disease remain unclear.

METHODS

We analyzed the relationship between Mayo indexes of ulcerative colitis and KLP using quantitative reverse-transcription polymerase chain reaction and endoscopy. Using caspase-1/11-/-, NLRP3-/-, NLRC4-/-, interleukin (IL)18-/-, and IL22-/- mice, we showed that KLP could induce colitis through caspase-11-mediated release of mature IL18. Through in vitro gut organoid culture, we determined the mechanism for KLP to induce colitis.

RESULTS

We first found that there was a positive relationship between the Mayo indexes of ulcerative colitis and KLP. Then, we isolated a strain of KLP, named Klebsiella pneumoniae J (KLPJ), from the colon tissues of patients with colitis. This strain of bacteria could induce the production of mature IL18 in colon epithelial cells and gut organoids, and also induce colitis and promote dextran sodium sulfate-mediated colitis. Using caspase-1/11-/-, NLRP3-/-, NLRC4-/-, IL18-/-, and IL22-/- mice, we showed that KLPJ-mediated colitis occurred through activation of caspase-11, and was dependent on IL18 and partly on IL22. Our data also showed that lipopolysaccharide from KLPJ could bind with caspase-11 to induce mature IL18 in mouse and human colon organoids.

CONCLUSIONS

KLPJ from the colon tissues of patients with ulcerative colitis can colonize the colon, activate caspase-11 inflammasomes, and contribute to intestinal inflammation.

Natural Flavonoids as Potential Therapeutics in the Management of Diabetic Wound: A Review

Flavonoids are important bioactive phenolic compounds abundant in plants and exhibit different therapeutic potentials. A wound is a significant problem in diabetic individuals. A hyperglycaemic environment alters the normal wound-healing process and increases the risk of microbial infection, leading to hospitalization, morbidity, and amputation. Flavonoids are an important class of phytochemicals with excellent antioxidant, anti-inflammatory, antimicrobial, antidiabetic, antitumor, and wound healing property. Quercetin, hesperidin, curcumin, kaempferol, apigenin, luteolin, morin, etc. have shown their wound healing potential. Flavonoids effectively exhibit antimicrobial activity, scavenge reactive oxygen species, augment endogenous antioxidants, reduce the expression and synthesis of inflammatory cytokines (i.e. IL-1β, IL-6, TNF-α, NF-κB), inhibit inflammatory enzymes, enhance anti-inflammatory cytokine (IL-10), enhance insulin section, reduce insulin resistance, and control blood glucose level. Several flavonoids like hesperidin, curcumin, quercetin, rutin, naringin, and luteolin have shown their potential in managing diabetic wounds. Natural products that maintain glucose haemostatic, exert anti-inflammatory activity, suppress/inhibit microbial growth, modulate cytokines, inhibit matrix metalloproteinase (MMP), stimulate angiogenesis and extracellular matrix, and modulate growth factor can be considered as a potential therapeutic lead to treat diabetic wound. Flavonoids were found to play a positive role in management of diabetic wounds by regulating MMP-2, MMP-8, MMP-9, MMP-13, Ras/Raf/ MEK/ERK, PI3K/Akt, and nitric oxide pathways. Therefore, it can be assumed that flavonoids could be potential therapeutics to prevent devastating effects of diabetic wounds. This paper focused on the potential role of flavonoids in managing diabetic wounds and discussed their possible mechanism of action.

Molecular Mechanisms Underlying IL-33-Mediated Inflammation in Inflammatory Bowel Disease

Interleukin-33 (IL-33) is a cytokine defined by its pleiotropic function, acting either as a typical extracellular cytokine or as a nuclear transcription factor. IL-33 and its receptor, suppression of tumorigenicity 2 (ST2), interact with both innate and adaptive immunity and are considered critical regulators of inflammatory disorders. The IL-33/ST2 axis is involved in the maintenance of intestinal homeostasis; on the basis of their role as pro- or anti-inflammatory mediators of first-line innate immunity, their expression is of great importance in regard to mucosal defenses. Mucosal immunity commonly presents an imbalance in inflammatory bowel disease (IBD). This review summarizes the main cellular and molecular aspects of IL-33 and ST2, mainly focusing on the current evidence of the pro- and anti-inflammatory effects of the IL-33/ST2 axis in the course of ulcerative colitis and Crohn's disease, as well as the molecular mechanisms underlying the association of IL-33/ST2 signaling in IBD pathogenesis. Although IL-33 modulates and impacts the development, course, and recurrence of the inflammatory response, the exact role of this molecule is elusive, and it seems to be associated with the subtype of the disease or the disease stage. Unraveling of IL-33/ST2-mediated mechanisms involved in IBD pathology shows great potential for clinical application as therapeutic targets in IBD treatment.

Therapy Used to Promote Disease Remission Targeting Gut Dysbiosis, in UC Patients with Active Disease

Ulcerative colitis (UC) is a relapsing non-transmural chronic inflammatory disease of the colon characterized by bloody diarrhea. The etiology of UC is unknown. The goal is to reduce the inflammation and induce disease remission in UC patients with active disease. The aim of this study is to investigate the innovative treatment method used to promote disease remission in UC patients with active disease targeting gut dysbiosis. Immunosuppressants such as TNF-α blocker are used to promote disease remission in UC, but it is expensive and with side effects. Probiotic, prebiotic and diet are shown to be effective in maintaining disease remission. Fecal microbiota transplantation (FMT) might be the future therapy option to promote disease remission in UC patients with active disease. However, correct manufacturing and administration of the FMT are essential to achieve successful outcome. A few cohorts with FMT capsules show promising results in UC patients with active disease. However, randomized controlled clinical trials with long-term treatment and follow-up periods are necessary to show FMT capsules' efficacy to promote disease remission in UC patients.

Cannabinoids as Immune System Modulators: Cannabidiol Potential Therapeutic Approaches and Limitations

Introduction: Cannabidiol (CBD) is the second most abundant Phytocannabinoid in Cannabis extracts. CBD has a binding affinity for several cannabinoid and cannabinoid-associated receptors. Epidiolex (oral CBD solution) has been lately licensed by the Food and Drug Administration (FDA) for the treatment of pediatric epileptic seizures. Methods: In this review, we discussed the most promising applications of CBD for chronic inflammatory conditions, namely CBD's anti-inflammatory effects during inflammatory bowel disease, coronavirus disease (antiviral effect), brain pathologies (neuroprotective and anti-inflammatory properties), as well as CBD immunomodulatory and antitumoral activities in the tumor microenvironment. Special focus was shed on the main therapeutic mechanisms of action of CBD, particularly in the control of the immune system and the endocannabinoid system. Results: Findings suggest that CBD is a potent immunomodulatory drug as it has manifested immunosuppressive properties in the context of sterile inflammation (e.g., inflammatory bowel disease, rheumatoid arthritis, and neurodegenerative diseases), and immunoprotective effects during viral infections (e.g. COVID-19) Similarly, CBD has exhibited a selective response toward cancer types by engaging different targets and signaling pathways. These results are in favor of the primary function of the endocannabinoid system which is homeostatic maintenance. Conclusion: The presented evidence suggests that the endocannabinoid system is a prominent target for the treatment of inflammatory and autoimmune diseases, rheumatoid diseases, viral infections, neurological and psychological pathologies, and cancer. Moreover, the antitumoral activities of CBD have been suggested to be potentially used in combination with chemo- or immunotherapy during cancer. However, clinical results are still lacking, which raises a challenge to apply translational cannabis research to the human immune system.

Integrated analysis of multiple microarray studies to establish differential diagnostic models of Crohn's disease and ulcerative colitis based on a metalloproteinase-associated module

Background

The ulcerative colitis (UC) and Crohn's disease (CD) subtypes of inflammatory bowel disease (IBD) are autoimmune diseases influenced by multiple complex factors. The clinical treatment strategies for UC and CD often differ, indicating the importance of improving their discrimination.

Methods

Two methods, robust rank aggregation (RRA) analysis and merging and intersection, were applied to integrate data from multiple IBD cohorts, and the identified differentially expressed genes (DEGs) were used to establish a protein-protein interaction (PPI) network. Molecular complex detection (MCODE) was used to identify important gene sets. Two differential diagnostic models to distinguish CD and UC were established via a least absolute shrinkage and selection operator (LASSO) logistic regression, and model evaluation was performed in both the training and testing groups, including receiver operating characteristic (ROC) curves, calibration plots and decision curve analysis (DCA). The potential value of MMP-associated genes was further verified using different IBD cohorts and clinical samples.

Results

Four datasets (GSE75214, GSE10616, GSE36807, and GSE9686) were included in the analysis. Both data integration methods indicated that the activation of the MMP-associated module was significantly elevated in UC. Two LASSO models based on continuous variable (Model_1) and binary variable (Model_2) MMP-associated genes were established to discriminate CD and UC. The results showed that Model_1 exhibited good discrimination in the training and testing groups. The calibration analysis and DCA showed that Model_1 exhibited good performance in the training group but failed in the testing group. Model_2 exhibited good discrimination, calibration and DCA results in the training and testing groups and exhibited greater diagnostic value. The effects of Model_1 and Model_2 were further verified in a new IBD cohort of GSE179285. The MMP genes exhibited high value as biomarkers for the discrimination of IBD patients using published cohort and immunohistochemistry (IHC) staining data. The MMP-associated gene levels were statistically significantly positively correlated with the levels of the differentially expressed cell types, indicating their potential value in differential diagnosis. The single-cell analysis confirmed that the expression of ANXA1 in UC was higher than that in CD.

Conclusion

MMP-associated modules are the main differential gene sets between CD and UC. The established Model_2 overcomes batch differences and has good clinical applicability. Subsequent in-depth research investigating how MMPs are involved in the development of different IBD subtypes is necessary.

Resolved Hypereosinophilic Syndrome and Immune Thrombocytopenic Purpura in Ulcerative Colitis Patients Post Colectomy: A Case Series and Literature Review

Introduction

Hypereosinophilic syndrome (HES) and immune thrombocytopenic purpura (ITP) have been reported to co-occur with ulcerative colitis (UC). However, the exact pathogenic mechanisms of their occurrence remain elusive. In this article, we aim to describe two cases of UC patients who developed refractory HES and ITP and elaborate on their potential pathogenesis.

Case Study

We report two middle-aged patients diagnosed with UC. The first patient developed HES that was refractory to conventional medical therapy of idiopathic HES, and the second developed refractory ITP that failed steroid and immunosuppressive therapy. Both conditions improved considerably following colectomy, suggesting they are of a reactive rather than idiopathic nature.

Conclusion

In patients with UC and refractory comorbid HES or ITP, the reactive nature of these comorbidities should be taken into consideration, and colectomy, therefore, should be considered if clinically indicated.

Exposure to dechlorane 602 induces perturbation of gut immunity and microbiota in female mice

The homeostasis of gut immunity and microbiota are associated with the health of the gut. Dechlorane 602 (Dec 602) with food web magnification potential has been detected in daily food. People who were orally exposed to Dec 602 may encounter increased risk of health problems in the gut. In order to reveal the influence of short-term exposure of Dec 602 on gut immunity and microbiota, adult female C57BL/6 mice were administered orally with Dec 602 (low/high doses: 1.0/10.0 μg/kg body weight per day) for 7 days. Lymphocytes were examined by flow cytometry. Gut microbiota was measured by 16S rRNA gene sequencing. Results showed that fecal IgA was upregulated after exposure to the high dose of Dec 602, suggesting that there might be inflammation in the gut. Then, changes of immune cells in mesenteric lymph nodes and colonic lamina propria were examined. We found that exposure to the high dose of Dec 602 decreased the percentages of the anti-inflammatory T regulatory cells in mesenteric lymph nodes. In colonic lamina propria, the production of gut protective cytokine interleukin-22 by CD4⁺ T cells was decreased, and a decreased trend of interleukin-22 production was also observed in type 3 innate lymphoid cells in the high dose group. Furthermore, an altered microbiota composition toward inflammation in the gut was observed after exposure to Dec 602. Additionally, the altered microbiota correlated with changes of immune parameters, suggesting that there were interactions between influenced microbiota and immune parameters after exposure to Dec 602. Taken together, short-term exposure to Dec 602 induced gut immunity and microbiota perturbations, and this might be the mechanisms for Dec 602 to elicit inflammation in the gut.

Patients with inflammatory bowel disease have a higher chance of developing periodontitis: A systematic review and meta-analysis

Background and objective

Periodontitis affects up to one billion people worldwide, and has been proven to be associated with several systemic inflammatory conditions. This study investigates the specific relationship between two multifactorial diseases: Inflammatory bowel disease (IBD) and periodontitis. To thoroughly explore this issue, we investigated separately whether IBD patients have a higher chance of developing periodontitis, and equally, whether patients with periodontitis have a higher chance of developing IBD.

Methods

The systematic search was performed in three databases: MEDLINE, Cochrane Trials, and Embase, up to 26 October 2021. The protocol was registered in PROSPERO. All eligible studies investigating the association between IBD and periodontitis from either direction were included. The Newcastle-Ottawa Scale was used to assess the risk of bias. As a primary outcome, we investigated the prevalence of IBD and periodontitis, and calculated the odds ratio (OR). Our secondary outcomes involved comparing the clinical periodontal outcomes of IBD patients to those of IBD-free patients.

Results

The systematic search resulted in 1,715 records, 14 of which were eligible for qualitative synthesis and 8 for quantitative synthesis. On the basis of the results of the primary outcome, IBD diagnosis was associated with significantly higher odds of periodontitis: OR = 2.65 (CI: 2.09-3.36, I 2 = 0 (CI: 0-0.75)). For subgroup analysis, we investigated separately the odds in Crohn's disease (CD) patients: OR = 2.22 (CI: 1.49-3.31, I 2 = 0.05 (CI: 0-0.76)) and in ulcerative colitis (UC) patients: OR = 3.52 (CI: 2.56 to 4.83, I 2 = 0 (CI: 0-0.75)); the odds were significantly higher in all cases. Two studies investigated whether patients with periodontitis were more susceptible to IBD, and both found that periodontitis was significantly associated with the risk of subsequent UC, but not with subsequent CD. However, more studies are needed to prove an association.

Conclusion

Our analysis confirmed that IBD patients have a higher chance of developing periodontitis, and are a higher risk population in dentistry. Both dentists and gastroenterologists should be aware of this relationship and should emphasize the importance of prevention even more than in the healthy population.

Systematic review registration

[https://www.crd.york.ac.uk/prospero/], identifier [CRD42021286161].

Oral Macrocystis pyrifera Fucoidan Administration Exhibits Anti-Inflammatory and Antioxidant Properties and Improves DSS-Induced Colitis in C57BL/6J Mice

Inflammatory bowel disease (IBD) is a complex and multifactorial disorder characterised by relapsing and remitting inflammation of the intestinal tract. Oxidative stress (OS) is the result of an imbalance between production and accumulation of reactive oxygen species (ROS), which has been associated with inflammatory responses and implicated in the exacerbation of IBD. Fucoidan, a sulfated polysaccharide from brown seaweed, is a well-known anti-inflammatory agent and emerging evidence indicates that fucoidan extracts from Macrocystis pyrifera (MPF and DP-MPF) may also modulate oxidative stress. This study investigated the impact of fucoidan extracts, MPF and DP-MPF in a dextran sodium sulphate (DSS)-induced mouse model of acute colitis. 3% DSS was administered in C57BL/6J male mice over a period of 7 days, and MPF and DP-MPF were co-administered orally at a dose of 400 mg/kg body weight. Our results indicated that MPF and DP-MPF significantly prevented body weight loss, improved the disease activity index (DAI), restored colon lengths, reduced the wet colon weight, reduced spleen enlargement, and improved the overall histopathological score. Consistent with the reported anti-inflammatory functions, fucoidan extracts, MPF and DP-MPF significantly reduced the colonic levels of myeloperoxidase (MPO), nitric oxide (NO), malondialdehyde (MDA) and increased the levels of antioxidant enzymes, superoxide dismutase (SOD) and catalase (CAT). In addition, MPF and DP-MPF significantly inhibited levels of pro-inflammatory cytokines in colon-derived tissues. Collectively, our results indicate that MPF and DP-MPF exhibited anti-inflammatory and antioxidant effects representing a promising therapeutic strategy for the cure of IBD.

Formulation of a 3D Printed Biopharmaceutical: The Development of an Alkaline Phosphatase Containing Tablet with Ileo-Colonic Release Profile to Treat Ulcerative Colitis

Powder bed printing is a 3D-printing process that creates freeform geometries from powders, with increasing traction for personalized medicine potential. Little is known about its applications for biopharmaceuticals. In this study, the production of tablets containing alkaline phosphatase using powder bed printing for the potential treatment of ulcerative colitis (UC) was investigated, as was the coating of these tablets to obtain ileo-colonic targeting. The printing process was studied, revealing line spacing as a critical factor affecting tablet physical properties when using hydroxypropyl cellulose as the binder. Increasing line spacing yielded tablets with higher porosity. The enzymatic activity of alkaline phosphatase (formulated in inulin glass) remained over 95% after 2 weeks of storage at 45 °C. The subsequent application of a colonic targeting coating required a PEG 1500 sub-coating. In vitro release experiments, using a gastrointestinal simulated system, indicated that the desired ileo-colonic release was achieved. Less than 8% of the methylene blue, a release marker, was released in the terminal ileum phase, followed by a fast release in the colon phase. No significant impact from the coating process on the enzymatic activity was found. These tablets are the first to achieve both biopharmaceutical incorporation in powder bed printed tablets and ileo-colonic targeting, thus might be suitable for on-demand patient-centric treatment of UC.

Patient-derived Enterococcus faecium with inflammatory genotypes promote colitis

BACKGROUND

Dysbiosis of gut microbiota promotes colitis in ulcerative colitis (UC). Enterococcus faecium is an important constituent of dysbiotic microbiota. However, the mechanisms underlying E. faecium-induced colitis remain unclear.

METHODS

Overall, 23 E. faecium strains isolated from human feces and 3 commercial strains were inoculated into Il10^-/- mice. Mouse colons were histologically evaluated and analyzed using real-time PCR analysis of cytokines. Genes in 26 E. faecium strains were identified by whole-genome shotgun sequencing of genomic DNA. The production of reactive oxygen species (ROS) from each strain was measured. An antioxidant, lipoic acid, was orally administered to the colitis mouse model.

RESULTS

Inoculation of E. faecium derived from patients with UC resulted in colitis in Il10^-/- mice. The genotypes of 26 strains were characterized by identifying 1893 known genes; clustering all the strains based on the genotypes showed two major groups-inflammatory and probiotic clusters. Additionally, linear discriminant analysis clarified that lipoic acid metabolism was a significantly abundant pathway in the probiotic cluster compared to the inflammatory cluster. Further, the production of ROS was greater in inflammatory than in probiotic strains. Administration of lipoic acid in E. faecium-inoculated mice ameliorated colitis.

CONCLUSIONS

Enterococcus faecium strains in the inflammatory cluster promoted colitis with higher production of ROS than the strains in the probiotic cluster.

Peptides derived from hookworm anti-inflammatory proteins suppress inducible colitis in mice and inflammatory cytokine production by human cells

A decline in the prevalence of parasites such as hookworms appears to be correlated with the rise in non-communicable inflammatory conditions in people from high- and middle-income countries. This correlation has led to studies that have identified proteins produced by hookworms that can suppress inflammatory bowel disease (IBD) and asthma in animal models. Hookworms secrete a family of abundant netrin-domain containing proteins referred to as AIPs (Anti-Inflammatory Proteins), but there is no information on the structure-function relationships. Here we have applied a downsizing approach to the hookworm AIPs to derive peptides of 20 residues or less, some of which display anti-inflammatory effects when co-cultured with human peripheral blood mononuclear cells and oral therapeutic activity in a chemically induced mouse model of acute colitis. Our results indicate that a conserved helical region is responsible, at least in part, for the anti-inflammatory effects. This helical region has potential in the design of improved leads for treating IBD and possibly other inflammatory conditions.

The effect of combining basil seeds and gum Arabic on the healing process of experimental acetic acid-induced ulcerative colitis in rats

Background & aim

Ulcerative colitis (UC) is a chronic recurrent inflammatory disease of the large intestine and rectum that oxidative stress and severe inflammation are the main features of this disease. Previous studies have shown that separate consumption of basil and gum arabic can reduce inflammation and oxidative stress. The aim of the study was evaluating the effect of treatment with basil seeds given together with gum arabic on healing, inflammation and oxidative stress in the course of experimental colitis in rats.

Experimental procedure

A total number of 50 male rats were used, randomly assigned to five groups of 10 rats each. Colitis was induced in rats by enemas with 4% solution od acetic acid. Four days after induction of colitis, rats were treated for next 4 days with saline or combination of basil seeds plus gum arabic (1 mg/kg) or sulfasalazine (100 mg/g) rectally. The experiment was terminated after last dose of treatment. Rats without induction of colitis were used as a sham group.

Results

Acetic acid-induced colitis increased the macroscopic and histopathological damage scores of the colon as well as colon levels of MDA(Malondialdehyde), MPO(Myeloperoxidase), TNFα(Tissue necrosis factor α), IL6 (Interleukin 6)and IL17(Interleukin 17) and decreased SOD(Superoxide Dismutase), GPx (Glutathione Peroxidase) and IL10 (Interleukin 10) levels compared with the control group(P < 0.001). Treatment with basil and gum arabic reduced macroscopic and histopathological damage scores (P < 0.01) of the colon, MDA, MPO, TNFα, IL6(P < 0.001) and IL17 (P < 0.01) levels of the colon and increased SOD, GPx and IL10 levels compared to the colitis group (P < 0.01).

Conclusion

Rectal administration of combination of basil seeds plus gum arabic after induction of colitis, exhibits antioxidant and anti-inflammatory effects, and accelerates the healing of the colon in experimental colitis evoked by acetic acid.

Effect of Crohn's disease mesenteric mesenchymal stem cells and their extracellular vesicles on T-cell immunosuppressive capacity

Crohn's disease (CD) is a chronic inflammatory disease of the gastrointestinal intestinal tract and has characteristic hypertrophic adipose changes observed in the mesentery. To better understand the role of the mesentery in the pathophysiology of Crohn's disease (CD), we evaluated the immunomodulatory potential of mesenchymal stem cells (MSCs) and their secreted extracellular vesicles (EVs) derived from Crohn's patients. MSCs and EVs were isolated from the mesentery and subcutaneous tissues of CD patients and healthy individuals subcutaneous tissues, and were analysed for differentiation, cytokine expression, self‐renewal and proliferation. The varying capacity of these tissue‐derived MSCs and EVs to attenuate T‐cell activation was measured in in vitro and an in vivo murine model. RNA sequencing of inflamed Crohn's disease mesentery tissue revealed an enrichment of T‐cell activation compared to non‐inflamed subcutaneous tissue. MSCs and MSC‐derived EVs isolated from Crohn's mesentery lose their ability to attenuate DSS‐induced colitis compared to subcutaneous tissue‐derived cell or EV therapy. We found that treatment with subcutaneous isolated MSCs and their EV product compared to Crohn's mesentery MSCs or EVs, the inhibition of T‐cell proliferation and IFN‐γ, IL‐17a production increased, suggesting a non‐inflamed microenvironment allows for T‐cell inhibition by MSCs/EVs. Our results demonstrate that Crohn's patient‐derived diseased mesentery tissue MSCs lose their immunosuppressive capacity in the treatment of colitis by distinct regulation of pathogenic T‐cell responses and/or T‐cell infiltration into the colon.

Nucleic acid strategies for infectious disease treatments: The nanoparticle-based oral delivery route

Therapies based on orally administrated nucleic acids have significant potential for the treatment of infectious diseases, including chronic inflammatory diseases such as inflammatory bowel disease (IBD)-associated with the gastrointestinal (GI) tract, and infectious and acute contagious diseases like coronavirus disease 2019 (COVID-19). This is because nucleic acids could precisely regulate susceptibility genes in regulating the pro- and anti-inflammatory cytokines expression related to the infections. Unfortunately, gene delivery remains a major hurdle due to multiple intracellular and extracellular barriers. This review thoroughly discusses the challenges of nanoparticle-based nucleic acid gene deliveries and strategies for overcoming delivery barriers to the inflammatory sites. Oral nucleic acid delivery case studies were also present as vital examples of applications in infectious diseases such as IBD and COVID-19.

The role of diet in genotoxicity of fecal water derived from IBD patients and healthy controls

Certain dietary factors with anti-inflammatory and/or anti-cancer properties would be a promising preventive strategy for inflammatory bowel disease (IBD) patients against developing colitis-associated colorectal cancer (CAC). In this study, fecal water (FW) was obtained from 80 IBD patients and 20 healthy controls (HCs). The comet assay was applied to determine the DNA damage induced by FW, and the protective potential of FW against hydrogen peroxide (H₂O₂) induced DNA damage in Caco-2 cells. Information on diet was obtained via food frequency questionnaires. The results showed that FW from IBD patients, especially patients with flares, induced higher levels of direct DNA damage in Caco-2 cells and showed less protection against H₂O₂-induced DNA damage, when compared to HCs. The DNA damage induced by FW was positively associated with consumption of processed meat and sugary foods, and nutrient intakes including heme iron and added sugars, whereas negatively correlated to intakes of soy products, and a dietary pattern characterized by high consumption of potatoes, white meat, nuts and seeds, eggs, legumes and soy products. FW from subjects with high coffee consumption protected against H₂O₂-induced DNA damage. These results can help to develop potential preventive strategies for IBD patients to reduce the CAC risk.

The first association study of Protein Tyrosine Phosphatase, Non-Receptor Type 2 (PTPN2) gene polymorphisms in Malaysian patients with Crohn's disease

Crohn's disease (CD) is one of the sub-entities of Inflammatory Bowel Disease which causes chronic inflammation in the gastrointestinal tract. The development of CD has shown to have a strong genetic association. Therefore, the present study aimed to investigate the association between genetic polymorphisms in a susceptible locus of CD, the protein tyrosine phosphatase, non-receptor type 2 (PTPN2) gene and the development of CD in Malaysian patients. A total of 137 CD patients and 274 matched healthy controls were recruited in the present study. Genomic DNA was extracted from the venous blood of participants and five targeted single nucleotide polymorphisms (SNPs) in the PTPN2 gene were genotyped using polymerase chain reaction. Associations between the SNPs and CD were determined using Fisher's exact test and odds ratio. Findings showed that all five selected SNPs were not significantly associated with the development of CD in Malaysian patients, which was in contrast to studies among the European populations. Malaysian Chinese with rs487273 heterozygous G/T genotype was found to have a lower occurrence of CD (P-value = 0.0253; OR = 0.4396). Patients with rs2542152 homozygous T genotype were associated with stricturing behaviour (P-value = 0.0302, OR = 2.9944). The rs16939895 A/G genotype was associated with inflammation at the ileum site (P-value = 0.0387, OR = 2.2105)while homozygous G genotype was associated with colonic CD (P-value = 0.0164, OR = 2.3917). Functional studies of these SNPs are needed to evaluate their potential use as a biomarker for disease phenotypes among Asian patients.

Smad4-deficient T cells promote colitis-associated colon cancer via an IFN-γ-dependent suppression of 15-hydroxyprostaglandin dehydrogenase

Immune cells and the cytokines they produce are important mediators of the transition from colitis to colon cancer, but the mechanisms mediating this disease progression are poorly understood. Interferon gamma (IFN-γ) is known to contribute to the pathogenesis of colitis through immune modulatory mechanisms, and through direct effects on endothelial and epithelial homeostasis. Here we explore whether IFN-γ influences tumor progression by expanding the effector memory T cells (T_EM) population and restricting the expression of tumor suppressors in a preclinical model of spontaneous colitis-associated colorectal cancer (CAC). We show that IFN-γ expression is significantly increased both in the T cells and the colonic mucosal epithelia of mice with a T cell-restricted deletion of the TGF-β intermediate, SMAD4 (Smad4^TKO). The increase of IFN-γ expression correlates with the onset of spontaneous CAC in Smad4^TKO mice by 6 months of age. This phenotype is greatly ameliorated by the introduction of a germline deletion of IFN-γ in Smad4^TKO mice (Smad4^TKO/IFN-γ^KO, DKO). DKO mice had a significantly reduced incidence and progression of CAC, and a decrease in the number of mucosal CD4⁺ T_EM cells, when compared to those of Smad4^TKO mice. Similarly, the colon epithelia of DKO mice exhibited a non-oncogenic signature with a decrease in the expression of iNOS and p-STAT1, and a restoration of the tumor suppressor gene, 15-hydroxyprostaglandin dehydrogenase (15-PGDH). In vitro, treatment of human colon cancer cells with IFN-γ decreased the expression of 15-PGDH. Our data suggest that Smad4-deficient T cells promote CAC through mechanisms that include an IFN-γ-dependent suppression of the tumor suppressor 15-PGDH.

Therapeutic effect of the sulforaphane derivative JY4 on ulcerative colitis through the NF-κB-p65 pathway

The efficacy of the sulforaphane derivative JY4 was evaluated in acute and chronic mouse models of ulcerative colitis induced by dextran sodium sulfate. Oral administration of JY4 led to significant improvements in symptoms, with recovery of body weight and colorectal length, together with reduced diarrhoea, bloody stools, ulceration of colonic tissue and infiltration of inflammatory cells. The oral bioavailability of JY4, determined by comparing oral dosing with injection into the tail vein, was 5.67%, which was comply with the idea in the intestinal function. Using a dual-luciferase reporter assay, immunofluorescence studies, western blot analysis and immunohistochemical staining, JY4 was shown to significant interfere with the NF-κB-p65 signaling pathway. By preventing the activation of NF-κB-p65, JY4 inhibited the overexpression of downstream inflammatory factors, thereby exerting an anti-inflammatory effect on the intestinal tract. This study thus provides a promising candidate drug, and a new concept for the treatment of ulcerative colitis.

Inhibition of the Occurrence and Development of Inflammation-Related Colorectal Cancer by Fucoidan Extracted from Sargassum fusiforme

Fucoidan has many biological activities, including the inhibitory effect on the development of various cancer types. This study showed that lipopolysaccharide-induced inflammation in FHC cells (normal human colonic epithelial cells) could be reversed using fucoidan at different concentrations. The fucoidan-induced anti-inflammatory effect was also confirmed through in vivo experiments in mice. Compared to the mice of the model group, the ratio of Firmicutes/Bacteroidetes in feces increased and the diversity of gut microbial composition was restored in mice after fucoidan intervention. In colorectal cancer (CRC) cells DLD-1 and SW480, fucoidan inhibited cell proliferation and promoted cell apoptosis. It also blocked the cell cycle of DLD-1 and SW480 at the G0/G1 phase. The animal model of inflammation-related CRC showed that the incidence of tumors in mice was significantly reduced by fucoidan intervention. Furthermore, the administration of fucoidan decreased the expression levels of inflammatory factors such as TNF-α IL-6 and IL-1β in the colonic tissues. Therefore, fucoidan can effectively prevent the development of colitis-associated CRC.

Anti-inflammatory Effects of Ivermectin in the Treatment of Acetic Acid-Induced Colitis in Rats: Involvement of GABAB Receptors

BACKGROUND

Recent investigations have proposed the potential role of gamma-aminobutyric acid (GABA) in regulating motility and immunity of the gastrointestinal system.

AIMS

We aimed to investigate the anti-inflammatory effects of ivermectin (IVM) through GABAB receptors following acetic acid-induced colitis in rats.

METHODS

In a controlled experimental study, we enrolled 78 male Wistar rats (13 groups; 6 rats/group). After colitis induction using acetic acid (4%), IVM, baclofen (a standard GABAB agonist) or the combination of both agents was delivered to rats orally (by gavage), with the same dosage continued for 5 days. The control group received the vehicle, and prednisolone (a standard anti-inflammatory agent) was administered in a separate group as the positive control. Colon samples were collected on the sixth day for histopathological evaluations and measurement of myeloperoxidase (MPO) activity, TNF-α levels, and p-NF-ĸB p65, COX-2 and iNOS expression levels.

RESULTS

The greatest recovery was found after administering IVM 0.5, baclofen 0.5, or IVM 0.2 + baclofen 0.2 mg/kg/day (ulcer index [UI] = 1.4 ± 0.4, 1.7 ± 0.6, and 1.4 ± 0.3, respectively; p  < 0.001 vs. the control [UI = 6.5 ± 0.7]). Histopathological evaluations revealed a significant decrease in the inflammation severity in the three above-mentioned groups. P-NF-ĸB p65, COX-2, and iNOS expression, MPO activity, and TNF-α levels also decreased dramatically following treatment with IVM 0.5, baclofen 0.5, or the combination therapy (p < 0.001 vs. the control).

CONCLUSIONS

IVM exerted promising anti-inflammatory effects in treating acetic acid-induced colitis in rats. Its synergistic effect with baclofen also signified the possible involvement of GABAB receptors in this process.

Protective effect of 17S‑epoxy‑docosapentaenoic acid against dextran sulfate sodium induced ulcerative colitis in BALB/c mice

Ulcerative colitis (UC) is difficult to eradicate as it leads to chronic inflammation in the digestive tract due to immune system malfunction. The present study demonstrated the protective effect of 7S,15R-dihydroxy-16S,17S-epoxy-docosapentaenoic acid (diHEP-DPA), which had been previously synthesized, on a dextran sulfate sodium (DSS)-induced BALB/c mouse model of UC. UC was induced with 4% DSS drinking water for 7 days. Initially, the anti-inflammatory effect of diHEP-DPA was confirmed by demonstrating that lipopolysaccharide-stimulated THP1 cells treated with diHEP-DPA decreased IL-6, TNF-α and nitrite levels by fluorescence-activated cell sorting (FACS) and Griess reagent kit. The results indicated that the administration of diHEP-DPA at 20 µg/kg significantly reduced the severity of colitis, as determined by hematoxylin and eosin staining. The levels of TNF-α, IL-6 and IL-1β in the colon tissue and serum were significantly reduced in the diHEP-DPA + DSS-treated group compared with in the control group, as determined by FACS and ELISA kit. It was also observed that diHEP-DPA decreased myeloperoxidase (MPO) and nitrite levels in the colon tissues of diHEP-DPA + DSS-treated mice, as indicated using commercial MPO and nitric oxide kits. The diHEP-DPA+DSS-treated mice also exhibited decreased expression levels of phosporylated (p)-inhibitor κB protein, p-p65 and inducible nitric oxide synthase in the colon tissue by inhibiting inflammation, which were measured by reverse transcription-quantitative PCR and weatern blot analysis. Overall, the present study demonstrated the protective effect of diHEP-DPA against a severe colitis condition in vivo.

Investigating the Role of the NLRP3 Inflammasome Pathway in Acute Intestinal Inflammation: Use of THP-1 Knockout Cell Lines in an Advanced Triple Culture Model

The NLRP3 inflammasome plays an important role in intestinal homeostasis as well as inflammation. However, in vivo studies investigating the role of the NLRP3 inflammasome in inflammatory bowel disease (IBD) report contrasting results, leaving it unclear if the NLRP3 inflammasome augments or attenuates intestinal inflammation. To investigate the role of the NLRP3/caspase-1 pathway in a model of acute intestinal inflammation, we modified a previously established in vitro triple culture model of the healthy and inflamed intestine (Caco-2/HT29-MTX-E12/THP-1). Using THP-1 knockout cell lines, we analyzed how the NLRP3 inflammasome and its downstream enzyme caspase-1 (CASP1) affect inflammatory parameters including barrier integrity and cytotoxicity, as well as gene expression and secretion of pro-inflammatory cytokines and mucus. Furthermore, we investigated differences in inflammation-mediated cytotoxicity towards enterocyte-like (Caco-2) or goblet-like (HT29-MTX-E12) epithelial cells. As a complementary approach, inflammation-related cytotoxicity and gene expression of cytokines was analyzed in intestinal tissue explants from wildtype (WT) and Nlrp3^-/- mice. Induction of intestinal inflammation impaired the barrier, caused cytotoxicity, and altered gene expression of pro-inflammatory cytokines and mucins in vitro, while the knockout of NLRP3 and CASP1 in THP 1 cells led to attenuation of these inflammatory parameters. The knockout of CASP1 tended to show a slightly stronger attenuating effect compared to the NLRP3 knockout model. We also found that the inflammation-mediated death of goblet-like cells is NLRP3/caspase-1 dependent. Furthermore, inflammation-related cytotoxicity and upregulation of pro-inflammatory cytokines was present in ileal tissue explants from WT, but not Nlrp3^-/- mice. The here presented observations indicate a pro-inflammatory and adverse role of the NLRP3 inflammasome in macrophages during acute intestinal inflammation.

Novel Gut Microbiota Modulator, Which Markedly Increases Akkermansia muciniphila Occupancy, Ameliorates Experimental Colitis in Rats

BACKGROUND

Since gut microbiota is involved in the pathogenesis of inflammatory bowel disease (IBD), antibiotics or probiotics may be attractive options for the treatment of IBD. Akkermansia muciniphila is expected as a next-generation probiotic for IBD, and OPS-2071 is a novel quinolone with potent antibacterial activity against Clostridioides difficile.

AIMS

The aim of this study is to assess the potential of OPS-2071 as a gut microbiota modulator for IBD.

METHODS

Minimum inhibitory concentrations of several bacteria in the human intestinal microbiota were determined. Microbiota changes in the feces were typed using metagenomic analysis after oral administration of OPS-2071 (100 mg/kg) twice a day to normal rats. The amounts of mucin were determined using the Fecal Mucin Assay Kit. The effects of OPS-2071 (1, 3, 10 mg/kg) twice a day on fecal symptoms and fecal microbiota were evaluated in a colitis rat model induced by free access to drinking water containing 3% dextran sulfate sodium for 10 days.

RESULTS

OPS-2071 showed notably low antibacterial activity against only A. muciniphila in spite of higher antimicrobial activity against other strains of intestinal bacteria. OPS-2071 rapidly and dramatically increased the occupancy of A. muciniphila as well as the amount of mucin in the feces of normal rats. OPS-2071 (10 mg/kg) significantly suppressed the exacerbation of stool scores, especially the bloody stool score, with the increase in A. muciniphila occupancy.

CONCLUSIONS

OPS-2071 is expected to be a new therapeutic option for IBD as a gut microbiota modulator by significantly increasing A. muciniphila occupancy.

Elucidating the Role of Innate and Adaptive Immune Responses in the Pathogenesis of Canine Chronic Inflammatory Enteropathy-A Search for Potential Biomarkers

Simple Summary

Canine chronic inflammatory enteropathy (CIE) is a chronic disease affecting the small or large intestine and, in some cases, the stomach of dogs. This gastrointestinal disorder is common and is characterized by recurrent vomiting, diarrhea, and weight loss in affected dogs. The pathogenesis of IBD is not completely understood. Similar to human IBD, potential disease factors include genetics, environmental exposures, and dysregulation of the microbiota and the immune response. Some important components of the innate and adaptive immune response involved in CIE pathogenesis have been described. However, the immunopathogenesis of the disease has not been fully elucidated. In this review, we summarized the literature associated with the different cell types and molecules involved in the immunopathogenesis of CIE, with the aim of advancing the search for biomarkers with possible diagnostic, prognostic, or therapeutic utility.

Abstract

Canine chronic inflammatory enteropathy (CIE) is one of the most common chronic gastrointestinal diseases affecting dogs worldwide. Genetic and environmental factors, as well as intestinal microbiota and dysregulated host immune responses, participate in this multifactorial disease. Despite advances explaining the immunological and molecular mechanisms involved in CIE development, the exact pathogenesis is still unknown. This review compiles the latest reports and advances that describe the main molecular and cellular mechanisms of both the innate and adaptive immune responses involved in canine CIE pathogenesis. Future studies should focus research on the characterization of the immunopathogenesis of canine CIE in order to advance the establishment of biomarkers and molecular targets of diagnostic, prognostic, or therapeutic utility.

Intervention and potential mechanism of non-starch polysaccharides from natural resources on ulcerative colitis: A review

Ulcerative colitis (UC) is a chronic inflammatory bowel disease of unknown etiology that affects the colon and rectum. It has evolved into a global burden due to the high incidence in developed countries and the highly-increased incidence in developing countries. Non-starch polysaccharides (NSPs) from natural resources, as a type of functional carbohydrates, have a significant therapeutic effect on UC because of their good anti-inflammatory and immunomodulatory activities. Based on the etiology and pathogenesis of UC, this review summarizes the intervention effects and mechanisms of NSPs in the prevention and treatment of UC. The results showed that NSPs can improve UC by protecting the intestinal mucosal barrier, regulating the immune response of the intestinal mucosa, and remodeling the intestinal flora and metabolites. These contents provide theoretical basis for the application of polysaccharides in the prevention and treatment of UC.

A Black Raspberry-Rich Diet Protects From Dextran Sulfate Sodium-Induced Intestinal Inflammation and Host Metabolic Perturbation in Association With Increased Aryl Hydrocarbon Receptor Ligands in the Gut Microbiota of Mice

Dietary modulation of the gut microbiota recently received considerable attention, and ligand activation of aryl hydrocarbon receptor (AHR) plays a pivotal role in intestinal immunity. Importantly, black raspberry (BRB, Rubus occidentalis) is associated with a variety of beneficial health effects. We aim to investigate effects of a BRB-rich diet on dextran sulfate sodium (DSS)-induced intestinal inflammation and to determine whether its consequent anti-inflammatory effects are relevant to modulation of the gut microbiota, especially its production of AHR ligands. A mouse model of DSS-induced intestinal inflammation was used in the present study. C57BL/6J mice were fed either AIN-76A or BRB diet. Composition and functions of the gut microbiota were assessed by 16S rRNA sequencing and comparative metagenome analysis. Metabolic profiles of host and the gut microbiome were assessed by serum and fecal metabolomic profiling and identification. BRB diet was found to ameliorate DSS-induced intestinal inflammation and host metabolic perturbation. BRB diet also protected from DSS-induced perturbation in diversity and composition in the gut microbiota. BRB diet promoted AHR ligand production by the gut microbiota, as revealed by increased levels of fecal AHR activity in addition to increased levels of two known AHR ligands, hemin and biliverdin. Accordingly, enrichment of bacterial genes and pathways responsible for production of hemin and biliverdin were found, specific gut bacteria that are highly correlated with abundances of hemin and biliverdin were also identified. BRB dietary intervention ameliorated intestinal inflammation in mice in association with promotion of AHR ligand production by the gut microbiota.

Modulating Effect of Paeonol on Piglets With Ulcerative Colitis

Piglet enteritis is a major problem that needs to be solved urgently in modern pig production. Paeonol (Pae) has been used as a novel treatment option due to its good medicinal value. This study purported to elucidate the regulatory mechanism of Pae on dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) in weaned piglets. A total of 36 crossbred (Duroc × Landrace × Yorkshire) weaned piglets were stochastically split into six groups: the control group, DSS group, 0.2% Pae group, 0.4% Pae group, 0.8% Pae group, and mesalazine group. The control and DSS groups were fed with a basic diet, the three Pae and mesalazine groups were fed with 0.2, 0.4, 0.8%, and 2 g mesalazine per kilogram of basic diet throughout the study. On the 15th day of the test period, the control group was gavaged with 10 ml of normal saline, while the remaining five groups were gavaged with 10 ml 5% DSS solution for 13 days. The study lasted for 27 days. The results showed that the 0.8% Pae group significantly increased the average daily feed intake (ADFI) and Occludin mRNA expression in the colon of piglets (P < 0.05). The 0.2% Pae group markedly increased the average daily gain (ADG) and zonula occludens-1 (ZO-1) mRNA expression (P < 0.05). In the 0.2% and 0.4% Pae groups, the feed-to-gain ratio (F/G) was significantly reduced and the mRNA expression levels of Caspase-8, respectively, markedly enhanced the mRNA expression levels of transforming growth factor-β (TGF-β) and interleukins-4 (IL-4) (P < 0.05). In the 0.8% Pae group, the relative abundance of Campilobacterota was significantly reduced (P < 0.05). In the 0.4% Pae group, the relative abundance of Firmicutes was notably increased (P < 0.05). In the 0.2 and 0.8% Pae groups, the relative abundance of Prevotella was markedly increased (P < 0.05). In the 0.2% Pae group, the contents of propionic acid, butyric acid, and valerate acid were markedly higher (P < 0.05). Thus, it is speculated that Pae may regulate the balance of anti-inflammatory/pro-inflammatory factors, improve intestinal tight junction expression, reduce apoptosis, and improve intestinal microflora structure and growth performance of piglets, thereby restoring intestinal barrier function and alleviating DSS-induced UC in piglets.

Biomarkers for the Prediction and Diagnosis of Fibrostenosing Crohn's Disease: A Systematic Review

BACKGROUND AND AIMS

Intestinal strictures are a common complication of Crohn's disease (CD). Biomarkers of intestinal strictures would assist in their prediction, diagnosis, and monitoring. Herein we provide a comprehensive systematic review of studies assessing biomarkers that may predict or diagnose CD-associated strictures.

METHODS

We performed a systematic review of PubMed, EMBASE, ISI Web of Science, Cochrane Library, and Scopus to identify citations pertaining to biomarkers of intestinal fibrosis through July 6, 2020, that used a reference standard of full-thickness histopathology or cross-sectional imaging or endoscopy. Studies were categorized based on the type of biomarker they evaluated (serum, genetic, histopathologic, or fecal).

RESULTS

Thirty-five distinct biomarkers from 3 major groups were identified: serum (20 markers), genetic (9 markers), and histopathology (6 markers). Promising markers include cartilage oligomeric matrix protein, hepatocyte growth factor activator, and lower levels of microRNA-19-3p (area under the curves were 0.805, 0.738, and 0.67, respectively), and multiple anti-flagellin antibodies (A4-Fla2 [odds ratio, 3.41], anti Fla-X [odds ratio, 2.95], and anti-CBir1 [multiple]). Substantial heterogeneity was observed and none of the markers had undergone formal validation. Specific limitations to acceptance of these markers included failure to use a standardized definition of stricturing disease, lack of specificity, and insufficient relevance to the pathogenesis of intestinal strictures or incomplete knowledge regarding their operating properties.

CONCLUSIONS

There is a lack of well-defined studies on biomarkers of intestinal stricture. Development of reliable and accurate biomarkers of stricture is a research priority. Biomarkers can support the clinical management of CD patients and aid in the stratification and monitoring of patients during clinical trials of future antifibrotic drug candidates.

A polyphenol-assisted IL-10 mRNA delivery system for ulcerative colitis

With the development of synthesis technology, modified messenger RNA (mRNA) has emerged as a novel category of therapeutic agents for a broad of diseases. However, effective intracellular delivery of mRNA remains challenging, especially for its sensitivity to enzymatic degradation. Here, we propose a polyphenol-assisted handy delivery strategy for efficient in vivo delivery of IL-10 mRNA. IL-10 mRNA binds to polyphenol ellagic acid through supramolecular binding to yield a negatively charged core, followed by complexing with linear polyetherimide and coating with bilirubin-modified hyaluronic acid to obtain a layer-by-layer nanostructure. The nanostructure specifically up-regulated the level of IL-10, effectively inhibited the expression of inflammatory factors, promoted mucosal repair, protected colonic epithelial cells against apoptosis, and exerted potent therapeutic efficacy in dextran sulfate sodium salt-induced acute and chronic murine models of colitis. The designed delivery system without systemic toxicity has the potential to facilitate the development of a promising platform for mRNA delivery in ulcerative colitis treatment.

Online Mindfulness Intervention for Inflammatory Bowel Disease: Adherence and Efficacy

The impact of stress and other psychological variables on Inflammatory Bowel Disease (IBD) prognosis, treatment response, and functional level is well-established; however, typical IBD treatment focuses on the physiological pathology of the disease and neglects complementary stress-reducing interventions. Recent pilot studies report the benefits of mindfulness-based interventions (MBIs) in people living with IBD, but are limited by small sample sizes. Recruitment challenges to in-person studies may be in part due to the difficulty IBD patients often have adhering to fixed schedules and travel as a result of IBD symptoms such as pain, fatigue, and incontinence. The current study aimed to address this barrier by offering participants access to online mindfulness training, allowing individuals to engage with intervention materials to fit their own schedule. Online mindfulness programs have gained popularity in recent years, as they increase access and flexibility and decrease cost to the user; however, the dropout rate tends to be high. The current study compared the rate of adherence and efficacy of mindfulness training as a function of level of support: self-guided versus supported. Analysis revealed no significant difference in the benefits received between participants in the two groups; however, a significant difference group (χ2 = 15.75; p = 0.000, r = 0.38) was found in terms of rate of completion, with 44.1% of the supportive group completing the protocol compared to 11.7% of the self-guided. Common challenges to meditation were measured, but did not significantly predict adherence to the intervention, and experience of these challenges did not significantly change (increase or decrease) over the duration of the study. Implications of the current research, future directions for the use of MBI for IBD patients, and a discussion of methodological considerations are provided.

Immunology of Inflammatory Bowel Disease: Molecular Mechanisms and Therapeutics

As a main digestive organ and an important immune organ, the intestine plays a vital role in resisting the invasion of potential pathogens into the body. Intestinal immune dysfunction remains important pathogenesis of inflammatory bowel disease (IBD). In this review, we explained the interactions among symbiotic flora, intestinal epithelial cells, and the immune system, clarified the operating mechanism of the intestinal immune system, and highlighted the immunological pathogenesis of IBD, with a focus on the development of immunotherapy for IBD. In addition, intestinal fibrosis is a significant complication in patients with long-term IBD, and we reviewed the immunological pathogenesis involved in the development of intestinal fibrogenesis and provided novel antifibrotic immunotherapies for IBD.

ROS-responsive nanoparticles for oral delivery of luteolin and targeted therapy of ulcerative colitis by regulating pathological microenvironment

Oxidative stress, caused by excessive production of reactive oxygen species (ROS), plays a crucial role in the occurrence and development of ulcerative colitis (UC). We developed ROS-responsive nanoparticles (NPs) as an efficacious nanomedicine against UC with oral administration. The NPs were fabricated with a d-α-tocopherol polyethylene glycol succinate-b-poly(β-thioester) copolymer (TPGS-PBTE) for ROS cleavage via the colitis-targeted delivery of luteolin (LUT), a natural flavonoid with good anti-inflammation and radical-scavenging activity. Owing to the thioether bond in the polymer main chain, the TPGS-PBTE NPs exhibited an ROS-responsive size change and drug release, which benefited the ROS-scavenging and selective accumulation of LUT in the inflamed colon. In a dextran sulfate sodium-induced acute colitis murine model, LUT@TPGS-PBTE NPs alleviated body weight loss, colon length shortening, and damage to the colonic tissues due to the suppression of ROS and proinflammatory cytokines (e.g., IL-17A, IL-6, interferon-γ, tumor necrosis factor-α), as well as upregulation of glutathione and anti-inflammatory factors (e.g., IL-10, IL-4). More importantly, LUT@TPGS-PBTE NPs regulated the inflammatory microenvironment by modulating the T helper (Th)1/Th2 and Th17/regulatory T cell (Treg) balance (i.e., increased numbers of Tregs and Th2 cells and decreased numbers of Th1 and Th17 ​cells), thus resolving inflammation and accelerating the healing of the intestinal mucosa. Additionally, the LUT@TPGS-PBTE NPs formulation enabled the reduction of the effective dose of LUT and showed excellent biosafety in the mouse model, demonstrating its potential as a targeted UC therapeutic oral preparation.

Curcumin Mitigates TNFα-Induced Caco-2 Cell Monolayer Permeabilization Through modulation of NF-κB, ERK1/2 and JNK Pathways

SCOPE

This work studied the capacity of curcumin to inhibit TNFα-induced inflammation, oxidative stress, and loss of intestinal barrier integrity, characterizing the underlying mechanisms.

METHODS AND RESULTS

Caco-2 cell monolayers were incubated with TNFα (10 ng/ml), in the absence or presence of curcumin. TNFα caused an increase in interleukin (IL)-6 and IL-8 release which was inhibited by curcumin in a dose-dependent manner (IC₅₀ = 3.4 μM for IL-6). Moreover, TNFα led to: i) increased ICAM-1 and NLRP3 expression; ii) increased cell monolayer permeability and decreased levels of tight junction proteins; iii) increased cellular and mitochondrial oxidant production; iv) decreased mitochondrial membrane potential and complex I-III activity; v) activation of redox-sensitive pathways, i.e., NF-κB, ERK1/2 and JNK; and vi) increased MLCK expression and phosphorylation levels of MLC. Curcumin (2-8 μM) inhibited all these TNFα-triggered undesirable outcomes, mostly showing dose-dependent effects.

CONCLUSION

The inhibition of NF-κB, ERK1/2 and JNK activation could be in part involved in the capacity of curcumin to mitigate intestinal inflammation, oxidant production, activation of redox-sensitive pathways, and prevention of monolayer permeabilization. These results support an action of dietary curcumin in sustaining gastrointestinal tract physiology. This article is protected by copyright. All rights reserved.