Immunopathology of inflammatory bowel disease

Lactoferrin: A Nutraceutical with Activity against Colorectal Cancer

Homeostasis in the human body results from the tight regulation of several events, since too little inflammation disrupts the process of tissue repair and remodeling, whereas too much exerts a collateral effect by causing tissue damage with life-threatening consequences. In some clinical conditions, such as inflammatory bowel disease (IBD), inflammation functions as a double-edged sword by either enabling or inhibiting cancer development and progression. Generally, cancer develops through evasion mechanisms that regulate cell growth, causing a high rate of uncontrolled proliferation, and mechanisms for evading cell death, such as apoptosis. Moreover, chronic inflammation is a factor that contributes to colorectal cancer (CRC), as observed in individuals with IBD; all these conditions favor an increased rate of angiogenesis and eventual metastasis. Lactoferrin (Lf) is a mammalian iron-binding multifunctional glycoprotein regarded as a natural compound that up- and downregulates both humoral and cellular components of immunity involved in regulating the inflammatory response and maintaining gut homeostasis. Human and bovine Lf share high sequence homology and have very similar antimicrobial, anti-inflammatory, and immunomodulatory activities. Bovine Lf from milk is considered a safe molecule and is commercially available in large quantities. This review mainly focuses on the regulatory effects of orally administered bovine Lf on the inflammatory response associated with CRC; this approach indicates that CRC is one of the most frequently diagnosed cancers and affects the intestinal tract with high clinical and epidemiologic relevance. Thus, this review may provide foundations for the potential use of bovine Lf alone or as a natural adjunct agent to increase the effectiveness and reduce the side effects of anticancer chemotherapy.

Relevance of Biotin Deficiency in Patients with Inflammatory Bowel Disease and Utility of Serum 3 Hydroxyisovaleryl Carnitine as a Practical Everyday Marker

Background: Biotin, a water-soluble B vitamin, has demonstrable anti-inflammatory properties. A biotin-deficient diet induced a colitis-like phenotype in mice, alleviable by biotin substitution. Mice with dextran sulfate sodium (DSS)-induced colitis showed biotin deficiency and diminished levels of sodium-dependent multivitamin transporter, a protein involved in biotin absorption. Biotin substitution induced remission by reducing activation of NF-κB, a transcription factor involved in intestinal permeability and inflammatory bowel disease (IBD). We investigated for the first time a possible clinical role of biotin status in IBD. Methods: In a comparative, retrospective, cross-sectional study, serum samples of 138 patients with IBD (67 female; 72 Crohn’s disease (CD), 66 ulcerative colitis (UC)) aged 18–65 years and with a mean age (±SD) of 42.5 ± 14.3 years as well as 80 healthy blood donors (40 female; 40.0 ± 10.0 years; range 20–60 years) were analyzed. Inflammation was defined as hsCRP ≥5 mg/L, and to determine biotin status, serum 3-hydroxyisovaleryl carnitine (3HIVc) levels were measured by LC-MS/MS. Results: A total of 138 patients with IBD (67f; 72CD/66 UC; 42.5 ± 14.3 years) were enrolled: 83/138 had inflammation. Mean serum 3HIVc levels were significantly higher in IBD patients but unaffected by inflammation. Biotin deficiency (95th percentile of controls: >30 nmol/L 3HIVc) was significantly more common in IBD patients versus controls. Conclusion: High serum 3HIVc levels and biotin deficiency were associated with IBD but not inflammatory activity or disease type. Our findings suggest biotin may play a role as cause or effect in IBD pathogenesis. Routine assessment and supplementation of biotin may ameliorate IBD and support intestinal integrity.

The exercise-induced inflammatory response in inflammatory bowel disease: A systematic review and meta-analysis

BACKGROUND

This study investigated selected inflammatory responses to acute and chronic exercise in individuals with inflammatory bowel disease (IBD).

METHODS

A systematic review and meta-analysis was conducted on all relevant exercise-based intervention publications with IBD participants. The study included articles that utilised a broad range of acute and chronic exercise interventions, with inflammatory biomarkers measured and symptoms documented, both pre- and post-exercise for those with IBD. The search was limited to studies published in English, the use of human participants, and primary studies, with no restrictions on date of publication or participant's age. Articles were retrieved through the electronic databases: PubMed, SPORTDiscus, and Scopus. This study adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines.

RESULTS

Six inflammatory markers were included in the meta-analysis which consisted of five studies. Exercise interventions resulted in no significant difference in IL-6 (SMD = -0.09; 95% CI = -0.49, 0.30; P = 0.64), TNF-α (SMD = 0.08; 95% CI = -0.31, 0.48; P = 0.68), CRP (SMD = -0.04; 95% CI = -0.58, 0.50; P = 0.89), IL-17 (SMD = 0.15; 95% CI = -0.45, 0.76; P = 0.62), leukocytes (SMD = 0.40; 95% CI = -0.53, 1.33; P = 0.40) or lymphocytes (SMD = 0.32; 95% CI = -0.33, 0.97; P = 0.33), thus, indicating exercise may have no effect on inflammatory markers in IBD. Bowel symptoms improved following regular moderate exercise that incorporated stress management.

CONCLUSION

Heterogeneity among the identified literature may have led to exercise interventions being ineffective in reducing inflammation. Although the limited number of eligible studies may reduce the reliability of results, it emphasises the need for additional research in this domain. Importantly, no adverse symptomatic responses to exercise indicate that exercise is safe for IBD patients.

Primary Hypogammaglobulinaemia with Inflammatory Bowel Disease-Like Features: An ECCO CONFER Multicentre Case Series

BACKGROUND

Hypogammaglobulinaemia is a disorder characterized by low serum immunoglobulin levels and a high prevalence of gastrointestinal manifestations. In some cases, clinical and endoscopic features are indistinguishable from those of inflammatory bowel disease [IBD].

METHODS

This was a multicentre case series performed as a part of the European Crohn's and Colitis Organisation [ECCO] Collaborative Network of Exceptionally Rare case reports [CONFER] project.

RESULTS

This report includes 27 patients with primary hypogammaglobulinaemia and IBD-like features: 20 males and seven females, median age 45.6 years (interquartile range [IQR] 35.2-59). Crohn's disease-like features were noted in 23 patients, and four patients had ulcerative colitis-like features. The diagnosis of hypogammaglobulinaemia preceded a diagnosis of IBD-like features in 20 patients [median of 7 years prior, IQR 2.6-20.6 years], and followed the appearance of IBD-like features in seven cases [median of 1 year after, IQR 0.45-5.6 years]. Hypogammaglobulinaemia aetiologies were common variable immunodeficiency [66.6%], agammaglobulinaemia [7.4%], selective IgA-deficiency [11.1%], Good's syndrome [7.4%], IgG subclass deficiency with IgA deficiency [3.7%] and hyper-IgM [3.7%]. In addition to antibiotics and intravenous immunoglobulin [IVIG] for hypogammaglobulinaemia, 12 patients received IBD-related treatment including 5-aminosalicylate agents [two patients], corticosteroids [one patient], thiopurines [three patients], anti-tumour necrosis factor [four patients] and vedolizumab [two patients]. By the end of the follow-up (44.5 months [IQR 18-81]), 21/27 [77%] patients were in clinical remission.

CONCLUSION

This case series describes IBD-like features in patients with hypogammaglobulinaemia. The diagnosis of IBD-like features mainly occurred after that of hypogammaglobulinaemia, with successful recovery in the majority of cases after appropriate treatment.

New translational and experimental insights into the role of pro-resolving lipid mediators in inflammatory bowel disease

The resolution of inflammation is an active process, guided by specialized pro-resolution lipid mediators (SPMs). These mediators originate from polyunsaturated fatty acids, such as omega-3. Sufficient evidence suggests that the beneficial effects attributed to omega-3 are, at least in part, the result of the immunomodulatory action of the SPMs, which act systemically by overcoming inflammation and repairing tissue damage, without suppressing the immune response. Recent studies suggest that an imbalance in the synthesis and/or activity of these compounds may be associated with the pathogenesis of several inflammatory conditions, such as inflammatory bowel disease (IBD). Thus, this review highlights the advances made in recent years with regard to the endo-genous synthesis and the biological role of lipoxins, resolvins, protectins, and maresins, as well as their precursors, in the regulation of inflammation; and provides an update on the participation of these mediators in the development and evolution of IBD and the therapeutic approaches that these immunomodulating substances are involved in this context.

Penfluridol targets acid sphingomyelinase to inhibit TNF signaling and is therapeutic against inflammatory autoimmune diseases

BACKGROUND

Penfluridol, isolated from an FDA-approved small-molecule drug library as an inhibitor of tumor necrosis factor α (TNFα)-stimulated NF-κB activation, is clinically used to treat chronic schizophrenia and related disorders. This study is aimed to investigate the therapeutic effect of penfluridol on TNFα-stimulated inflammatory autoimmune diseases, particularly inflammatory arthritis.

METHODS

Various in vitro studies to confirm the inhibitory effect of penfluridol on TNFα-induced NF-κB activity in bone marrow-derived macrophages or Raw 264.7 macrophage cell line. In vivo studies assessed the therapeutic effects of penfluridol in various disease models, including TNFα transgenic mice, collagen-induced arthritis, DSS-induced colitis, and TNBS-induced colitis. Identification and characterization of the binding of penfluridol to acid sphingomyelinase using bioinformatics and drug affinity responsive target stability assay. Acid sphingomyelinase activity assays to reveal penfluridol-mediated inhibition of acid sphingomyelinase activity. siRNA knockdown experiments to illustrate the dependence of penfluridol's anti-TNF activity on acid sphingomyelinase.

RESULTS

Penfluridol effectively inhibited TNFα-induced NF-κB activation in vitro and alleviated the severity of arthritis and colitis in vivo. Mechanistic studies revealed that penfluridol bound to acid sphingomyelinase and inhibited its activation. In addition, knockdown of acid sphingomyelinase largely abolished the inhibitory effects of penfluridol on TNFα-induced inflammatory cytokine production. Furthermore, penfluridol suppressed the differentiation of spleen naive CD4+T cells to TH1 and TH17 and inhibited M1 macrophage polarization.

CONCLUSION

This study provides the rationale for the possible innovative use of penfluridol as a newly identified small-molecule drug for TNFα-driven diseases, such as inflammatory arthritis and colitis.

Potential role of MALT1 as a candidate biomarker of disease surveillance and treatment response prediction in inflammatory bowel disease patients

BACKGROUND

Mucosa-associated lymphoid tissue lymphoma translocation protein 1 (MALT1) regulates adaptive and innate immune responses in several inflammatory disease. However, clinical involvement of MALT1 in inflammatory bowel disease (IBD) patients remains unclear. Hence, this study was intended to investigate the correlation of blood MALT1 with disease activity, inflammation indexes as well as treatment response of IBD patients.

METHODS

Blood MALT1 expression in 100 IBD patients [including 25 active (A)-Crohn's disease (CD) patients, 25 remission (R)-CD patients, 25 A-ulcerative colitis (UC) patients, and 25 R-UC patients] and 25 health controls (HCs) was detected by reverse transcription-quantitative polymerase chain reaction; besides, serum tumor necrosis factor-alpha (TNF-α) and interleukin-17A (IL-17A) in IBD patients were detected by enzyme-linked immunosorbent assay.

RESULTS

MALT1 was increased in A-UC patients than in R-UC patients (p = 0.038) and in HCs (p < 0.001), and also elevated in A-CD patients than in R-CD patients (p = 0.048) and in HCs (p < 0.001). MALT1 was positively related to C-reactive protein (CRP, p = 0.011), TNF-α (p = 0.036), IL-17A (p = 0.023), and Mayo score (p = 0.005) in A-UC patients, CRP (p = 0.017), erythrocyte sedimentation rate (p = 0.033), TNF-α (p = 0.004), and Crohn's disease activity index score (p = 0.028) in A-CD patients. But MALT1 was not correlated with either inflammation indexes or disease activity score in R-UC and R-CD patients. MALT1 gradually declined from baseline to W12 in A-UC and A-CD patients (both p < 0.001). Moreover, MALT1 at W4 (p = 0.031) and W12 (p = 0.003) in A-UC patients as well as MALT1 at W12 (p = 0.008) in A-CD patients associated with clinical response.

CONCLUSION

MALT1 serves as a potential biomarker for disease surveillance and treatment response prediction of IBD patients.

Microbial pathogenesis in inflammatory bowel diseases

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal system. Previously, it is considered the disease of the western world but now the incidence and prevalence of IBD are increasing globally with urbanization and modernization. Additionally, the major problem is the highest incidence of IBD among children and adolescents. The precise etiology of IBD is unknown and there is no cure for IBD, which is also the reason for increasing the number of cases worldwide. The IBD is a complex interplay of environment, immune system, and microbiota in a genetically susceptible host. Among these factors, the alteration in intestinal microbiota has been detected in IBD patients. The bacterial species associated with IBD include Mycobacterium paratuberculosis, adherent-invasive E. coli (AIEC), Helicobacter pylori, and Campylobacter concisus. Moreover, the efficacy of antibiotics and probiotics further suggests the role of microbes in IBD. However, no study confirmed the bacterial species as a cause of IBD as per Koch's postulates. Thus, still controversies exist regarding the role of microbes in IBD. Therefore, this paper aims to review the current literature to evaluate the role of microbes in IBD that would be a useful inventory of researchers working in this area.

The Potential Role of Phytonutrients Flavonoids Influencing Gut Microbiota in the Prophylaxis and Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), characterized by the chronic inflammation of the gastrointestinal tract, is comprised of two idiopathic chronic intestinal inflammatory diseases. As the incidence of IBD increases, so does the need for safe and effective treatments. Trillions of microorganisms are colonized in the mammalian intestine, coevolve with the host in a symbiotic relationship. Gut microbiota has been reported to be involved in the pathophysiology of IBD. In this regard, phytonutrients flavonoids have received increasing attention for their anti-oxidant and anti-inflammatory activities. In this review, we address recent advances in the interactions among flavonoids, gut microbiota, and IBD. Moreover, their possible potential mechanisms of action in IBD have been discussed. We conclude that there is a complex interaction between flavonoids and gut microbiota. It is expected that flavonoids can change or reshape the gut microbiota to provide important considerations for developing treatments for IBD.

Intestinal Macrophage Autophagy and its Pharmacological Application in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), comprised of Crohn’s disease (CD) and ulcerative colitis (UC), is a group of chronic inflammatory disorders. IBD is regarded as a severe healthcare problem worldwide, with high morbidity and lethality. So far, despite of numerous studies on this issue, the specific mechanisms of IBD still remain unclarified and ideal treatments are not available for IBD. The intestinal mucosal barrier is vital for maintaining the function of the intestinal self-defensive system. Among all of the components, macrophage is an important one in the intestinal self-defensive system, normally protecting the gut against exotic invasion. However, the over-activation of macrophages in pathological conditions leads to the overwhelming induction of intestinal inflammatory and immune reaction, thus damaging the intestinal functions. Autophagy is an important catabolic mechanism. It has been proven to participate the regulation of various kinds of inflammation- and immune-related disorders via the regulation of inflammation in related cells. Here in this paper, we will review the role and mechanism of intestinal macrophage autophagy in IBD. In addition, several well-studied kinds of agents taking advantage of intestinal macrophage autophagy for the treatment of IBD will also be discussed. We aim to bring novel insights in the development of therapeutic strategies against IBD.

Anti-Inflammatory Activity of Fucoidan Extracts In Vitro

Fucoidans are sulfated, complex, fucose-rich polymers found in brown seaweeds. Fucoidans have been shown to have multiple bioactivities, including anti-inflammatory effects, and are known to inhibit inflammatory processes via a number of pathways such as selectin blockade and enzyme inhibition, and have demonstrated inhibition of inflammatory pathologies in vivo. In this current investigation, fucoidan extracts from Undaria pinnatifida, Fucus vesiculosus, Macrocystis pyrifera, Ascophyllum nodosum, and Laminaria japonica were assessed for modulation of pro-inflammatory cytokine production (TNF-α, IL-1β, and IL-6) by human peripheral blood mononuclear cells (PBMCs) and in a human macrophage line (THP-1). Fucoidan extracts exhibited no signs of cytotoxicity in THP-1 cells after incubation of 48 h. Additionally, all fucoidan extracts reduced cytokine production in LPS stimulated PBMCs and human THP-1 cells in a dose-dependent fashion. Notably, the 5-30 kDa subfraction from Macrocystis pyrifera was a highly effective inhibitor at lower concentrations. Fucoidan extracts from all species had significant anti-inflammatory effects, but the lowest molecular weight subfractions had maximal effects at low concentrations. These observations on various fucoidan extracts offer insight into strategies that improve their efficacy against inflammation-related pathology. Further studies should be conducted to elucidate the mechanism of action of these extracts.

Cinacalcet Targets the Neurokinin-1 Receptor and Inhibits PKCδ/ERK/P65 Signaling to Alleviate Dextran Sulfate Sodium-Induced Colitis

Objective: Inflammatory bowel disease is an immune-mediated chronic inflammatory disease of the gastrointestinal tract for which curative drugs are currently not available. This study was performed to assess the therapeutic effects of cinacalcet on dextran sulfate sodium (DSS)-induced colitis. Methods: Primary macrophages obtained from bone marrow and the macrophage cell line RAW264.7 were used to examine the inhibitory effect of cinacalcet on cytokine production, the PKCδ/ERK/P65 signaling pathway, and NF-κB P65 translocation. Colitis was induced using DSS to assess the treatment effect of cinacalcet. Bioinformatics approaches were adopted to predict potential targets of cinacalcet, and a drug affinity responsive target stability (DARTs) assay was performed to confirm binding between cinacalcet and potential target. Results: In vivo analysis showed that cinacalcet reduced the disease activity score, prevented shortening of the colon, diminished inflammatory cell infiltration, and protected the structural integrity of the intestinal wall. Cinacalcet also reduced production of the inflammatory cytokines TNFα, IL-1β, and IL-6 in the colon and sera of mice with DSS-induced colitis. In vitro studies revealed that cinacalcet suppressed the translocation of P65 and inhibited production of the inflammatory cytokines IL-1β and IL-6. Mechanistic studies revealed that the target of cinacalcet was neurokinin-1 receptor (NK1R) and their binding was confirmed by a DARTs assay. Furthermore, the inhibition of NK-κB P65 activation was found to occur via the suppression of PKCδ/ERK/P65 signaling mediated by cinacalcet. Conclusion: Cinacalcet inhibits the activation of NF-κB and reduces the production of inflammatory cytokines by suppressing the PKCδ/ERK/P65 signaling pathway via targeting NK1R, suggesting that it can be used to treat inflammatory diseases, particularly colitis.

Immunological Aspect in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic inflammation in the alimentary tract due to improper immune response toward external and internal antigens. The disease consists of 2 entities: ulcerative colitis (UC) and Crohn’s disease (CD). The disease’s prevalence is increasing worldwide due to westernization and industrialization. Europe still holds the highest prevalence of IBD in the world. There are 2 peaks of disease incidence. The first is in the third decade of life and the second is in the fourth decade. Slight male predominance is observed in IBD. Internal and external risk factors play important role in the occurrence of IBD including genetic, smoking, reduced fibre intake, less or absent breastfeeding, sedentary occupation, pollution exposure, and medications. The disease carries heavy economic burden and hampers patient’s quality of life. The immune concept of IBD was hypothesized in 1950s since the symptoms resolved with the administration of steroid. Innate and adaptive immune systems are involved in the pathogenesis of IBD. Antigen presenting cells are found hyperactive, intestinal barrier is disrupted, and autophagy activity is increased. Molecular mimicry occurs between foreign and self antigen. The activity of T helper (Th)1, Th2, and Th17 is amplified while regulatory T cell’s activity is suppressed. Pro-inflammatory cytokine production is elevated but anti-inflammatory cytokines is lowered. Finally, there is increased immunoglobulin G level in intestinal mucosa and imbalance of gut microorganism. All the above immune disturbances lead to chronic inflammation in IBD.

Kirenol: A promising bioactive metabolite from siegesbeckia species: A detailed review

ETHNOPHARMACOLOGICAL RELEVANCE

Kirenol (Kr) is an ent-pimarane type diterpenoid that has been reported from Siegesbeckiaorientalis, S. pubescens, and S. glabrescens (family Asteraceae). These plants have been used traditionally for treating various ailments such as hypertension, neurasthenia, rheumatoid arthritis, asthma, snakebites, allergic disorders, paralysis, soreness, cutaneous disorders, rubella, menstrual disorders, numbness of limbs, dizziness, headache, and malaria. Importantly, in recent years, Kr has received great attention due to its diversified pharmacological activities.

AIM OF THE STUDY

The current work aims to give an overview on the reported pharmacological activities of Kr. Furthermore, the findings regarding its methods for extraction, quantitative analysis, purification, pharmacokinetics, pharmaceutical and food preparations, biosynthesis, identification, semisynthetic analogues, and toxicity are highlighted to provide a reference and perspective for its further investigation.

METHODS

Electronic databases including ScienceDirect, Web of Knowledge, SCOPUS, Wiley Online Library, Taylor & Francis, PubMed, Springer, JACS, and Google Scholar were searched up to the beginning of 2021 to identify the reported studies.

RESULTS

A total of 93 articles have been reviewed. The reported data suggested that Kr possessed various bioactivities including cytotoxic, apoptotic, anticancer, anti-inflammatory, cardio-protective, anti-photo-aging, anti-adipogenic, antimicrobial, muscle function improvement, fracture and wound healing, and anti-arthritic. In addition, studies revealed that the antioxidative and anti-inflammatory activities of Kr may mediate many of its therapeutic potentials as confirmed by several in-vitro and in-vivo studies.

CONCLUSION

This review provides an updated summary of the recent studies on Kr, including methods for extraction, quantitative analysis, purification, pharmacokinetics, pharmaceutical and food preparations, biosynthesis, and identification, as well as semisynthetic analogues, pharmacological activities, and toxicity. Thus, this work can provide useful considerations for planning and design future research on Kr.

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

CONTEXT

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

OBJECTIVE

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

MATERIALS AND METHODS

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

RESULTS

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

DISCUSSION

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

CONCLUSIONS

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

Serum inter-alpha-trypsin inhibitor heavy chain 4 in patients with inflammatory bowel disease: correlation with disease risk, inflammation, activity, and its variation after treatment

BACKGROUND

Inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4) plays vital roles in inflammatory and auto-immune diseases, but its correlations with disease risk and clinical features in inflammatory bowel disease (IBD) need further investigation. The present study intended to explore the correlation of ITIH4 with disease activity and inflammation, as well as its change after treatment in IBD patients.

METHODS

Totally, 40 active Crohn's disease (A-CD) patients, 40 clinical-remission CD (R-CD) patients, 40 active ulcerative colitis (A-UC) patients, 40 clinical-remission UC (R-UC) patients, and 40 health controls (HCs) were enrolled. ITIH4 in serum was assessed by ELISA.

RESULTS

ITIH4 was lower in A-CD, R-CD, A-UC, and R-UC patients than in HCs (P < 0.001). Notably, ITIH4 reduced in A-CD patients than in R-CD patients (P = 0.017), and in A-UC patients compared with R-UC patients (P = 0.010). Besides, in A-CD patients, ITIH4 negatively correlated with tumor necrosis factor-alpha (TNF-α), interleukin (IL)-17A, IL-1β, C-reactive protein (CRP), and clinical disease activity index score (all P < 0.05). In A-UC patients, ITIH4 negatively correlated with TNF-α, IL-17A, IL-1β, IL-6, CRP, and Mayo score (all P < 0.05). However, in R-CD and R-UC patients, these correlations were less obvious than in A-CD and A-UC patients. ITIH4 was increased after treatment (all P < 0.05), and its expression at W12 after treatment was higher in response patients compared with no response patients in A-CD (P = 0.022) and A-UC groups (P = 0.038).

CONCLUSION

ITIH4 correlates with IBD susceptibility, active risk, inflammation level, and its elevation after treatment relates to clinical response in IBD patients.

Investigation of H2S Donor Treatment on Neutrophil Extracellular Traps in Experimental Colitis

Inflammatory bowel diseases (IBD) are chronic, immune-mediated disorders, which affect the gastrointestinal tract with intermittent ulceration. It is increasingly clear that neutrophil extracellular traps (NETs) seem to have a role in IBD; however, the associated pathogenesis is still not known. Furthermore, several conventional therapies are available against IBD, although these might have side effects. Our current study aimed to investigate the effects of hydrogen sulfide (H₂S) treatment on NETs formation and on the expression of inflammatory mediators in experimental rat colitis. To model IBD, 2,4,6-trinitrobenzenesulfonic acid (TNBS) was administered intracolonically (i.c.) to Wistar-Harlan male rats. Animals were treated (2 times/day) with H₂S donor Lawesson's reagent per os. Our results showed that H₂S treatment significantly decreased the extent of colonic lesions. Furthermore, the expression of members of NETs formation: peptidyl arginine deiminase 4 (PAD4), citrullinated histone H3 (citH3), myeloperoxidase (MPO) and inflammatory regulators, such as nuclear transcription factor-kappa B (NF-κB) and high-mobility group box 1 (HMGB1) were reduced in H₂S treated group compared to TNBS. Additionally, H₂S donor administration elevated the expression of ubiquitin C-terminal hydroxylase L1 (UCHL-1), a potential anti-inflammatory mediator. Taken together, our results showed that H₂S may exert anti-inflammatory effect through the inhibition of NETs formation, which suggests a new therapeutic approach against IBD.

Association Between Peripheral Blood Monocyte Count and Mucosal Healing in Japanese Patients With Ulcerative Colitis

INTRODUCTION

Monocytes play an important role in innate immunity. Some epidemiological evidence indicates an association between peripheral blood monocytes and ulcerative colitis (UC). The association between peripheral blood monocytes and mucosal healing (MH), however, remains unclear. We evaluated this issue in patients with UC.

METHODS

Study subjects consisted of 272 Japanese patients with UC. Monocyte counts were taken in the morning after overnight fasting. Monocyte count was divided into tertiles based on the distribution of values among all study subjects. Information on clinical remission was obtained from medical records. MH was assessed using the Mayo endoscopic subscore.

RESULTS

The mean monocyte count was 360.1 ± 155.3/mm3. Rates of clinical remission, MH, and complete MH were 61.0%, 66.2%, and 27.9%, respectively. High monocyte count was significantly inversely associated with clinical remission, MH, and complete MH (adjusted odds ratio [OR] 0.45 [95% confidence interval [CI]: 0.23-0.89], OR 0.45 [95% CI: 0.23-0.89], and OR 0.48 [95% CI: 0.23-0.97], respectively). Patients were also classified according to C-reactive protein (CRP) levels; in the low CRP group (<0.1 mg/dL), high monocyte count was independently inversely associated with complete MH but not with clinical remission or MH (OR 0.33 [95% CI: 0.10-0.92], P for trend = 0.027). In the high CRP group, there was no association between monocyte count and clinical outcomes.

DISCUSSION

Our findings suggest that peripheral blood monocyte count can be used as a serum supplemental marker for MH in UC patients with low CRP levels.

Therapeutic Potential of SphK1 Inhibitors Based on Abnormal Expression of SphK1 in Inflammatory Immune Related-Diseases

Sphingosine kinase 1(SphK1) a key enzyme that catalyzes the conversion of sphingosine (Sph) to sphingosine 1-phosphate (S1P), so as to maintain the dynamic balance of sphingolipid-rheostat in cells and participate in cell growth and death, proliferation and migration, vasoconstriction and remodeling, inflammation and metabolism. The normal expression of SphK1 maintains the balance of physiological and pathological states, which is reflected in the regulation of inflammatory factor secretion, immune response in traditional immune cells and non-traditional immune cells, and complex signal transduction. However, abnormal SphK1 expression and activity are found in various inflammatory and immune related-diseases, such as hypertension, atherosclerosis, Alzheimer’s disease, inflammatory bowel disease and rheumatoid arthritis. In view of the therapeutic potential of regulating SphK1 and its signal, the current research is aimed at SphK1 inhibitors, such as SphK1 selective inhibitors and dual SphK1/2 inhibitor, and other compounds with inhibitory potency. This review explores the regulatory role of over-expressed SphK1 in inflammatory and immune related-diseases, and investigate the latest progress of SphK1 inhibitors and the improvement of disease or pathological state.

Anti-TL1A Antibody PF-06480605 Safety and Efficacy for Ulcerative Colitis: A Phase 2a Single-Arm Study

BACKGROUND & AIMS

An immune component of inflammatory bowel disease is up-regulated tumor necrosis factor-like ligand 1A (TL1A). Anti-TL1A antibodies such as PF-06480605, a fully human immunoglobulin G1 monoclonal antibody, may have therapeutic potential.

METHODS

This Phase 2a, multicenter, single-arm, open-label study (TUSCANY) evaluated safety, tolerability, efficacy, pharmacokinetics, and immunogenicity in PF-06480605-treated participants with moderate to severe ulcerative colitis (UC). Participants received 500 mg intravenous PF-06480605 every 2 weeks, 7 doses total, with a 3-month follow-up period. Primary safety and efficacy endpoints were the incidence of adverse events (AEs) and week 14 endoscopic improvement (EI) (Mayo endoscopic subscore = 0 or 1), respectively. Secondary endpoints included total soluble TL1A (free/drug-bound) (sTL1A), incidence of anti-drug and neutralizing antibodies, PF-06480605 concentrations, and changes in fecal calprotectin and high-sensitivity C-reactive protein. Histology was assessed at week 14.

RESULTS

The study enrolled 50 participants; 42 completed. Of 109 treatment-emergent AEs, 18 were treatment-related. The most common AEs were UC disease exacerbation and arthralgia (6 participants each). Four serious AEs, no deaths, and no malignancies were reported. Week 14 EI was observed in a statistically significant proportion of participants (38.2% [uniformly minimum-variance unbiased estimator, per protocol population]). Minimal histologic disease was observed after treatment (Robarts Histopathology Index ≤5: 33.3%; Geboes Index ≤3.2: 47.6%). sTL1A increase over time from baseline indicated sustained target engagement. Forty-one participants (82%) tested positive for anti-drug antibodies and 5 (10%) for neutralizing antibodies.

CONCLUSIONS

PF-06480605 demonstrated an acceptable safety profile and statistically significant EI in participants with moderate to severe UC, warranting further study in a larger participant cohort. Tissue histopathology analyses support this conclusion.

TRIAL REGISTRATION NUMBER

https://clinicaltrials.gov/NCT02840721.

The endoscopic diagnosis of mucosal healing and deep remission in inflammatory bowel disease

The therapeutic goal in inflammatory bowel disease (IBD) patients has shifted from controlling the clinical activity alone to managing other associated problems. The concept of mucosal healing (MH) and deep remission (DR) are advocated and regarded as new therapeutic goals in IBD. However, the definition of MH still remains controversial. It is unclear whether or not the histological structures or functional factors should be included in the definition of DR in addition to clinical remission and MH. The classifications of white-light imaging (e.g. Mayo endoscopic subscore, UCEIS, CD Endoscopic Index of Severity, simple Endoscopic Score-CD) have been proposed and are now widely used to assess the severity as well as the MH of inflammation in IBD. In ulcerative colitis, magnifying chromoendoscopy has been shown to be useful to assess the MH of inflammation while other types of image-enhanced endoscopy, such as narrow-band imaging, have not. Endocytoscopy and confocal laser endomicroscopy (CLE) are also applied to assess the activity in IBD. These endoscopic procedures can estimate MH with more precision through observing the details of superficial structures, such as crypt openings. In addition, CLE can partially assess the mucosal function by detecting fluorescence leakage. Molecular imaging can possibly detect the molecules associated with inflammation, intestinal regeneration and differentiation, and various functions including the intestinal barrier and mucus secretion. These novel procedures may improve the diagnosis strategy of DR through the assessment of DR-associated factors such as the histological structures and functional factors in the near future.

Gut relief formula attenuates dextran sulfate sodium-induced colitis by regulating NF-κB signaling and the intestinal microbiota in mice

Background. Inflammatory bowel disease (IBD) is a chronic relapsing disorder of the gastrointestinal tract. The nutrition care gut relief formula (GR), a combination of natural products and nutrients, has been shown to benefit gastrointestinal health. However, the underlying mechanism responsible for this effect is incompletely defined. Objective. This study was conducted to evaluate the hypothesis that GR could attenuate dextran sulfate sodium (DSS)-induced colitis by enhancing intestinal mucosal immunity and regulating intestinal microflora in mice. Methods. Six-week-old C57BL/6J mice orally administered with GR (7.5 mg per mouse per day) or an equal volume of vehicle were treated with sterile water or 2.5% DSS for 6 days to induce colitis. Histological damage, inflammatory cell infiltration, and colonic microbiome community were analyzed to evaluate the beneficial effect of GR. Results. GR administration ameliorated the severity of colitis as evidenced by reduced body weight loss, decreased colon shortening, reduced myeloperoxidase (MPO) activity, inhibited proinflammatory cytokine secretion, and decreased histological damage in DSS-challenged mice. Additionally, enhancement of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) in response to DSS was attenuated by GR administration. Meanwhile, DSS treatment resulted in reduction of the glutathione (GSH) level and tight junction protein abundance, as compared with the controls. Of note, these adverse effects were remarkably eliminated by GR administration. Further study showed that the protective effect of GR was associated with the inhibited activation of STAT3 and NF-κB signaling pathways, as well as upregulated abundances of Lactobacillus in the colon tissues of mice. Conclusion. Collectively, the data provided herein demonstrated that GR administration alleviated intestinal mucosal inflammation and mucosal barrier dysfunction. These beneficial effects were associated with inhibited activation of STAT3 and NF-κB signaling pathways, as well as upregulated abundances of Lactobacillus in the colon tissues of mice.

Gum Arabic Supplementation Suppresses Colonic Fibrosis After Acute Colitis by Reducing Transforming Growth Factor β1 Expression

Ulcerative colitis is a chronic inflammation of the colonic mucosa. Gum Arabic (GA) has been reported to exert anti-inflammatory and antifibrotic activity. This study aimed to evaluate the effect of GA on disease activity in an experimental model of colitis. Dextran sodium sulfate (DSS) was used to induce colitis in C57BL/6 mice and the animals were then switched to normal drinking water to monitor recovery. Mice received 140 g/L GA before (pre-GA group) or after (post-GA group) induction of colitis. Disease activity and recovery were assessed by changes in body weight, disease activity index (DAI), and histological assessment. Gene expression of proinflammatory, anti-inflammatory, and fibrotic markers was measured in colonic tissues. Mice in the pre-GA group showed an increase in body weight, with no differences in DAI scores, during the recovery phase and had lower histological colitis scores than mice in the post-GA group, which showed higher DAI and histological scores during the recovery phase. During the recovery phase, mice in the pre-GA group showed increased expression of proinflammatory markers, while gene expression of the fibrotic markers, transforming growth factor β1 (TGFβ1) and procollagen I, was reduced. The reduced fibrotic marker expression was associated with reduced collagen staining and increased epithelial cell proliferation. Administration of GA had protective and alleviative effects on the severity of DSS-induced colitis, with a reduction in colonic fibrosis and TGFβ1 expression. These data warrant further in vitro and in vivo investigations on the effect of GA on fibroblast activity.

Impairment of CD4+ T and Memory B Cell Responses but Normal Memory CD8+T-Cell Activation on Crohn's Disease after COVID-19 Vaccination: A Twin Case

Vaccines to prevent the impact of SARS-CoV-2 are now available, including for patients with autoimmune diseases. However, there is no information about how inflammatory bowel disease (IBD) treatment could impact the cellular and humoral immune responses. This study evaluated SARS-CoV-2-specific humoral and cellular responses after vaccination with a two-dose schedule in a Crohn’s disease patient treated with Infliximab (10 mg/kg); we included comparisons with a monozygotic twin. The results showed that the Crohn’s disease’s twin (twin 2) had no antibody detection and reduced activation of CD4+ T cell responses, unlike the twin without the autoimmune disease (twin 1). Twin 2 developed antigen-specific central memory CD8+ T-cells and IFNγ production after the second dose of COVID-19 vaccination, similar to twin 1. These findings elucidated the role of T-cell immunity after COVID-19 immunization on IBD patients despite the lack of antibody production. Finally, our observation supports the consensus recommendation for IBD patients to receive COVID-19 vaccines.

Lactobacillus rhamnosus and Bifidobacterium longum alleviate colitis and cognitive impairment in mice by regulating IFN-γ to IL-10 and TNF-α to IL-10 expression ratios

Gut lactobacilli and bifidobacteria on the immune homeostasis. Therefore, to understand the mechanism in vivo, we selected human fecal Lactobacillus rhamnosus NK210 and Bifidobacterium longum NK219, which strongly suppressed the IFN-γ to IL-10 expression (IIE) ratio in lipopolysaccharide-stimulated macrophages. Thereafter, we examined their effects on the endotoxin, antibiotics, or antitumor drug-stimulated immune imbalance in mice. Intraperitoneal injection of lipopolysaccharide and oral gavage of ampicillin increased IFN-γ and TNF-α expression in the spleen, colon, and hippocampus, while IL-10 expression decreased. However, intraperitoneal injection of cyclophosphamide suppressed IFN-γ, TNF-α, and IL-10 expression. LPS exposure induced splenic natural killer cell cytotoxicity against YAC-1 cells (sNK-C) and peritoneal macrophage phagocytosis against Candida albicans (pMA-P) activities, while cyclophosphamide and ampicillin treatments suppressed sNK-C and pMA-P activities. However, LPS, ampicillin, cyclophosphamide all increased IIE and TNF-α to IL-10 expression (TIE) ratios. Oral administration of NK210 and/or NK219 significantly reduced LPS-induced sNK-C, pMA-P, and IFN-γ expression, while cyclophosphamide- or ampicillin-suppressed sNK-C and pMA-P activities, cyclophosphamide-suppressed IFN-γ, TNF-α, and IL-10 expression, and ampicillin-suppressed IL-10 expression increased. Nevertheless, they suppressed LPS-, ampicillin-, or cyclophosphamide-induced IIE and TIE ratios, cognitive impairment, and gut dysbiosis. In particular, NK219, but not NK210, increased the IIE expression ratio in vitro and in vivo, and enhanced sNK-C and pMA-P activities in normal control mice, while cognitive function and gut microbiota composition were not significantly affected. These findings suggest that NK210, Lactobacillus sp, and NK219, Bifidobacterium additively or synergistically alleviate gut dysbiosis, inflammation, and cognitive impairment with immune imbalance by controlling IIE and TIE ratios.

Immunomodulatory assessment of Portulaca oleracea L. extract in a mouse model of colitis

Ulcerative colitis (UC) is a gastrointestinal inflammatory disease with a multifactorial pathophysiology. This study aims to investigate the immunomodulatory effect of Portulaca oleracea leaf ethanolic extract (POE) on acetic acid (AA)-induced UC in mice. Experimental animals received oral doses of POE (200 mg/kg for 7 days) after an induction of colitis by intrarectal AA administration. In mice with AA-induced UC treated with POE, the results revealed a significant modulation in body weight and colon length. Moreover, treatment with POE downregulated the interleukin 1, 6, and 17, tumor necrosis factor-alpha, gamma interferon, and nuclear factor-kappa B levels compared with the colitis group. Furthermore, POE markedly inhibited histological damage, decreased myeloperoxidase activity and reduced fecal calprotectin level compared with the colitis group. These data are consistent with the reduction in total bacterial content in the colon. Taken together, treatment with POE may reduce colonic inflammation by alleviating the immune response and inhibiting the severity of colitis. The HPLC analysis of POE resulted in the identification of seven medicinal compounds comprising two phenolic acids (ferulic and caffeic acids) and five flavonoids (kaempferol, quercetin, rutin, narenginin and hesperidin). Subsequent analysis of POE by GC-MS revealed ten phytocomponents; the major percentages were hexadecenoic acid, methyl ester (29.8119%), α-linolenic acid (25.8431%), 16-octadecenoic acid, methyl ester (15.1578%) and α-tocopherol (10.7848%). Delta-lactams and alkanes were the minor components. Such natural plant-derived substances and their probable synergistic action appear to contribute to a promising therapeutic protocol for colitis.

Inflammatory Bowel Disease and Sarcopenia: Its Mechanism and Clinical Importance

Malnutrition is a major contributor to muscle loss and muscle dysfunction, known as sarcopenia. Malnutrition is common in patients with inflammatory bowel disease (IBD). IBD includes ulcerative colitis (UC) and Crohn’s disease (CD). The number of patients with IBD has recently been increasing. More severe malnutrition is often seen in CD compared to UC, probably due to CD affecting the main site of nutrient absorption, extensive mucosal lesions, fistulas, short bowel syndrome after resection, or obstruction of the gastrointestinal tract. A recent meta-analysis showed the high prevalence of sarcopenia in patients with IBD, and thus sarcopenia is a very important problem for IBD. Although IBD is more common in younger patients, sarcopenia can develop through a variety of mechanisms, including malnutrition, chronic inflammation, increased inflammatory status in adipose tissue, vitamin deficiency, and imbalance of the muscle–gut axis. In addition, sarcopenia has a negative impact on postoperative complications and hospital stay in patients with IBD. Appropriate intervention for sarcopenia may be important, in addition to clinical remission and endoscopic mucosal healing in patients with IBD. Much more attention will thus be paid to sarcopenia in patients with IBD. In this review, we outline IBD and sarcopenia, based on the current evidence.

Activated Mucosal-associated Invariant T Cells Have a Pathogenic Role in a Murine Model of Inflammatory Bowel Disease

BACKGROUND & AIMS

Mucosal-associated invariant T (MAIT) cells are innate-like T cells restricted by major histocompatibility complex-related molecule 1 (MR1) and express a semi-invariant T cell receptor. Previously, we reported the activation status of circulating MAIT cells in patients with ulcerative colitis (UC) was associated with disease activity and that these cells had infiltrated the inflamed colonic mucosa. These findings suggest MAIT cells are involved in the pathogenesis of inflammatory bowel disease. We investigated the role of MAIT cells in the pathogenesis of colitis by using MR1^-/- mice lacking MAIT cells and a synthetic antagonistic MR1 ligand.

METHODS

Oxazolone colitis was induced in MR1^-/- mice (C57BL/6 background), their littermate wild-type controls, and C57BL/6 mice orally administered an antagonistic MR1 ligand, isobutyl 6-formyl pterin (i6-FP). Cytokine production of splenocytes and colonic lamina propria lymphocytes from mice receiving i6-FP was analyzed. Intestinal permeability was assessed in MR1^-/- and i6-FP-treated mice and their controls. The effect of i6-FP on cytokine production by MAIT cells from patients with UC was assessed.

RESULTS

MR1 deficiency or i6-FP treatment reduced the severity of oxazolone colitis. i6-FP treatment reduced cytokine production in MAIT cells from mice and patients with UC. Although MR1 deficiency increased the intestinal permeability, i6-FP administration did not affect gut integrity in mice.

CONCLUSIONS

These results indicate MAIT cells have a pathogenic role in colitis and suppression of MAIT cell activation might reduce the severity of colitis without affecting gut integrity. Thus, MAIT cells are potential therapeutic targets for inflammatory bowel disease including UC.

Molecular and Pathophysiological Links between Metabolic Disorders and Inflammatory Bowel Diseases

Despite considerable epidemiological evidence indicating comorbidity between metabolic disorders, such as obesity, type 2 diabetes, and non-alcoholic fatty liver disease, and inflammatory bowel diseases (IBD), such as Crohn’s disease and ulcerative colitis, as well as common pathophysiological features shared by these two categories of diseases, the relationship between their pathogenesis at molecular levels are not well described. Intestinal barrier dysfunction is a characteristic pathological feature of IBD, which also plays causal roles in the pathogenesis of chronic inflammatory metabolic disorders. Increased intestinal permeability is associated with a pro-inflammatory response of the intestinal immune system, possibly leading to the development of both diseases. In addition, dysregulated interactions between the gut microbiota and the host immunity have been found to contribute to immune-mediated disorders including the two diseases. In connection with disrupted gut microbial composition, alterations in gut microbiota-derived metabolites have also been shown to be closely related to the pathogeneses of both diseases. Focusing on these prominent pathophysiological features observed in both metabolic disorders and IBD, this review highlights and summarizes the molecular risk factors that may link between the pathogeneses of the two diseases, which is aimed at providing a comprehensive understanding of molecular mechanisms underlying their comorbidity.

Immunoglobulin subtype-coated bacteria are correlated with the disease activity of inflammatory bowel disease

Immune response involving various immunoglobulin (Ig) isotypes and subtypes to microbiome is involved in the pathogenesis and disease activity of inflammatory bowel diseases (IBDs). To clarify the presence of Ig-coated bacteria in the intestine and its association with disease activity in ulcerative colitis (UC) and Crohn’s disease (CD), we extracted and classified Ig-coated bacteria from fecal samples of 42 patients with IBD and 12 healthy controls (HCs) using flow cytometry and 16S ribosomal RNA sequence analysis. The percentage of bacteria coated with IgA and IgM was higher in patients with IBD than in HCs, and IgG-coated bacteria were found only in patients with IBD. Moreover, the percentages of bacteria coated with IgG1, IgG2, IgG3, and IgM in UC samples and IgG3, IgG4, and IgM in CD samples were correlated with disease activities. The proportions of Bacteroides ovatus and Streptococcus increased during the active phase of CD. Hence, the detailed analysis of Ig-coated bacteria and Ig subtypes using flow cytometry could aid in developing useful indicators of disease activity and identifying more disease-related bacteria, which could become novel treatment targets for IBDs.

Cross Talk between Gut Microbiota and Intestinal Mucosal Immunity in the Development of Ulcerative Colitis

Ulcerative colitis (UC), a nonspecific inflammatory disease, is characterized by inflammation and mucosal damage in the colon, and its prevalence in the world is increasing. Nevertheless, the exact pathogenesis of UC is still unclear. Accumulating data have suggested that its pathogenesis is multifactorial, involving genetic predisposition, environmental factors, microbial dysbiosis, and dysregulated immune responses. Generally, UC is aroused by inappropriate immune activation based on the interaction of host and intestinal microbiota. The relationship between microbiota and host immune system in the pathogenesis of UC is complicated. However, increasing evidence indicates that the shift of microbiota composition can substantially influence intestinal immunity. In this review, we primarily focus on the delicate balance between microbiota and gut mucosal immunity during UC progression.

Drug delivery to the inflamed intestinal mucosa - targeting technologies and human cell culture models for better therapies of IBD

Current treatment strategies for inflammatory bowel disease (IBD) seek to alleviate the undesirable symptoms of the disorder. Despite the higher specificity of newer generation therapeutics, e.g. monoclonal antibodies, adverse effects still arise from their interference with non-specific systemic immune cascades. To circumvent such undesirable effects, both conventional and newer therapeutic options can benefit from various targeting strategies. Of course, both the development and the assessment of the efficiency of such targeted delivery systems necessitate the use of suitable in vivo and in vitro models representing relevant pathophysiological manifestations of the disorder. Accordingly, the current review seeks to provide a comprehensive discussion of the available preclinical models with emphasis on human in vitro models of IBD, along with their potentials and limitations. This is followed by an elaboration on the advancements in the field of biology- and nanotechnology-based targeted drug delivery systems and the potential rooms for improvement to facilitate their clinical translation.

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

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

Tissue-Resident T Cells in Chronic Relapsing-Remitting Intestinal Disorders

Tissue-resident memory T (TRM) cells critically contribute to the rapid immunoprotection and efficient immunosurveillance against pathogens, particularly in barrier tissues, but also during anti-tumor responses. However, the involvement of TRM cells also in the induction and exacerbation of immunopathologies, notably in chronically relapsing auto-inflammatory disorders, is becoming increasingly recognized as a critical factor. Thus, TRM cells may also represent an attractive target in the management of chronic (auto-) inflammatory disorders, including multiple sclerosis, rheumatoid arthritis, celiac disease and inflammatory bowel diseases. In this review, we focus on current concepts of TRM cell biology, particularly in the intestine, and discuss recent findings on their involvement in chronic relapsing-remitting inflammatory disorders. Potential therapeutic strategies to interfere with these TRM cell-mediated immunopathologies are discussed.

hucMSC-derived exosomes attenuate colitis by regulating macrophage pyroptosis via the miR-378a-5p/NLRP3 axis

Background

Human umbilical cord mesenchymal stem cell (hucMSC)-derived exosomes are recognized as novel cell-free therapeutic agents for inflammatory bowel disease (IBD), a condition caused by dysregulated intestinal mucosal immunity. In this event, macrophage pyroptosis, a process of cell death following the activation of NLRP3 (NOD-like receptor family, pyrin domain-containing 3) inflammasomes, is believed to partially account for inflammatory reactions. However, the role of macrophage pyroptosis in the process of hucMSC-derived exosomes alleviating colitis remains unknown. This study aimed at exploring the therapeutic effect and mechanism of hucMSC-derived exosomes on colitis repair.

Methods

In vivo, we used BALB/c mice to establish a dextran sulfate sodium (DSS)-induced colitis model and administrated hucMSC-derived exosomes intravenously to estimate its curative effect. Human myeloid leukemia mononuclear (THP-1) cells and mouse peritoneal macrophages (MPMs) were stimulated with lipopolysaccharides (LPS) and Nigericin to activate NLRP3 inflammasomes, which simulated an inflammation environment in vitro. A microRNA mimic was used to verify the role of miR-378a-5p/NLRP3 axis in the colitis repair.

Results

hucMSC-derived exosomes inhibited the activation of NLRP3 inflammasomes in the mouse colon. The secretion of interleukin (IL)-18, IL-1β, and Caspase-1 cleavage was suppressed, resulting in reduced cell pyroptosis. The same outcome was observed in the in vitro cell experiments, where the co-culture of THP-1 cells and MPMs with hucMSC-derived exosomes caused decreased expression of NLRP3 inflammasomes and increased cell survival. Furthermore, miR-378a-5p was highly expressed in hucMSC-derived exosomes and played a vital function in colitis repair.

Conclusion

hucMSC-derived exosomes carrying miR-378a-5p inhibited NLRP3 inflammasomes and abrogated cell pyroptosis to protect against DSS-induced colitis.

Neutrophil extracellular traps in inflammatory bowel diseases: Implications in pathogenesis and therapeutic targets

Crohn's disease (CD) and ulcerative colitis (UC) are the two main forms of inflammatory bowel disease (IBD). Among the various immune cells involved in IBD, neutrophils are the first to infiltrate and appear to contribute to the impairment of the epithelial barrier, destruction of tissues by oxidative and proteolytic damage, as well as to the perpetuation of inflammation by the release of cytokines and chemokines associated with pro-inflammatory effects. In addition to basic effector mechanisms, such as phagocytosis and chemotaxis, neutrophils can also form extracellular traps (NETs), which is made up of a mesh-like structure - which contains its chromatin (DNA + histones) together with granules and enzymes, such as myeloperoxidase (MPO) and neutrophilic elastase (NE) - and that acts as a trap that can result in the death of extracellular pathogens and/or can promote tissue damage. Recent evidence indicates that NETs also play an important and significant role in the pathogenesis of IBD. Previous studies have reported increased levels of NETs in tissue and serum samples from patients with IBD, as well as in experimental colitis. In this review, we discuss current knowledge about the formation of NETs and their role in the pathophysiology of IBD, pointing out potential mechanisms by which NETs promote tissue damage, as well as their involvement in complications associated with IBD. In addition, we propose potential targets for therapy to regulate the production of NETs, making it possible to expand the current spectrum of therapies for IBD.

Lactobacillus ruminis Alleviates DSS-Induced Colitis by Inflammatory Cytokines and Gut Microbiota Modulation

Lactobacillus ruminis can stimulate the immune response in vitro, but previous studies were only carried out in vitro and the anti-inflammatory effects of L. ruminis needs more in vivo evidences. In this study, the immune regulation and potential mechanisms of L. ruminis was investigated in DSS-induced colitis mice. L. ruminis FXJWS27L3 and L. ruminis FXJSW17L1 relieved the symptoms of colitis, including inhibition of colon shortening and colon tissue damage. L. ruminis FXJWS27L3 significantly reduced the pro-inflammatory cytokines IL-1β, TNF-α, and IL-17, while L. ruminis FXJSW17L1 significantly increased short chain fatty acids in mice feces. Moreover, L. ruminis FXJWS27L3 and L. ruminis FXJSW17L1 treatments significantly increased the gut microbiota diversity and balance the intestine microbiota profiles, which improved the imbalance of intestine microbiota composition to a certain extent. The results showed that L. ruminis can alleviate DSS-induced colitis, which possibly was related to promoting the expression of pro-inflammatory cytokines, up-regulating SCFAs and restoring the imbalance of gut microbiota.

Dysbiosis of gut microbiota in inflammatory bowel disease: Current therapies and potential for microbiota-modulating therapeutic approaches

There is a growing body of evidence reinforcing the unique connections between the host microbiome, health, and diseases. Due to the extreme importance of the symbiotic relationship between the intestinal microbiome and the host, it is not surprising that any alteration in the gut microbiota would result in various diseases, including inflammatory bowel disease (IBD), Crohn's disease, (CD) and ulcerative colitis (UC). IBD is a chronic, relapsing-remitting condition that is associated with significant morbidity, mortality, compromised quality of life, and costly medical care. Dysbiosis is believed to exacerbate the progression of IBD. One of the currently used treatments for IBD are anti-tumor necrosis factor (TNF) drugs, representing a biologic therapy that is reported to have an impact on the gut microbiota composition. The efficacy of anti-TNF agents is hindered by the possibility of non-response, which occurs in 10-20% of treated patients, and secondary loss of response, which occurs in up to 30% of treated patients. This underscores the need for novel therapies and studies that evaluate the role of the gut microbiota in these conditions. The success of any therapeutic strategy for IBD depends on our understanding of the interactions that occur between the gut microbiota and the host. In this review, the health and disease IBD-associated microbiota patterns will be discussed, in addition to the effect of currently used therapies for IBD on the gut microbiota composition, as well as new therapeutic approaches that can be used to overcome the current treatment constraints.

Enterocytes, fibroblasts and myeloid cells synergize in anti-bacterial and anti-viral pathways with IL22 as the central cytokine

IL22 is an important cytokine involved in the intestinal defense mechanisms against microbiome. By using ileum-derived organoids, we show that the expression of anti-microbial peptides (AMPs) and anti-viral peptides (AVPs) can be induced by IL22. In addition, we identified a bacterial and a viral route, both leading to IL22 production by T cells, but via different pathways. Bacterial products, such as LPS, induce enterocyte-secreted SAA1, which triggers the secretion of IL6 in fibroblasts, and subsequently IL22 in T cells. This IL22 induction can then be enhanced by macrophage-derived TNFα in two ways: by enhancing the responsiveness of T cells to IL6 and by increasing the expression of IL6 by fibroblasts. Viral infections of intestinal cells induce IFNβ1 and subsequently IL7. IFNβ1 can induce the expression of IL6 in fibroblasts and the combined activity of IL6 and IL7 can then induce IL22 expression in T cells. We also show that IL22 reduces the expression of viral entry receptors (e.g. ACE2, TMPRSS2, DPP4, CD46 and TNFRSF14), increases the expression of anti-viral proteins (e.g. RSAD2, AOS, ISG20 and Mx1) and, consequently, reduces the viral infection of neighboring cells. Overall, our data indicates that IL22 contributes to the innate responses against both bacteria and viruses.

Pathological Role of Pin1 in the Development of DSS-Induced Colitis

Inflammatory bowel diseases (IBDs) are serious disorders of which the etiologies are not, as yet, fully understood. In this study, Peptidyl-prolyl cis-trans isomerase NIMA-interacting 1 (Pin1) protein was shown to be dramatically upregulated in the colons of dextran sodium sulfate (DSS)-induced ulcerative colitis model mice. Interestingly, Pin1 knockout (KO) mice exhibited significant attenuation of DSS-induced colitis compared to wild-type (WT) mice, based on various parameters, including body weight, colon length, microscopic observation of the intestinal mucosa, inflammatory cytokine expression, and cleaved caspase-3. In addition, a role of Pin1 in inflammation was suggested because the percentage of M1-type macrophages in the colon was decreased in the Pin1 KO mice while that of M2-type macrophages was increased. Moreover, Pin1 KO mice showed downregulation of both Il17 and Il23a expression in the colon, both of which have been implicated in the development of colitis. Finally, oral administration of Pin1 inhibitor partially but significantly prevented DSS-induced colitis in mice, raising the possibility of Pin1 inhibitors serving as therapeutic agents for IBD.

Single- and Multiple-Dose Pharmacokinetics and Pharmacodynamics of PN-943, a Gastrointestinal-Restricted Oral Peptide Antagonist of α4β7, in Healthy Volunteers

PN‐943 is an orally stable, gastrointestinal‐restricted peptide that binds specifically to α4ß7 integrin on leukocytes, blocking leukocyte trafficking to and activation in the gut, inhibiting colon inflammation and reducing signs and symptoms of active ulcerative colitis. Two pharmacokinetic/pharmacodynamic studies were conducted in healthy volunteers. Study 1 was a first‐in‐human study with 40 male subjects receiving PN‐943, 100 to 1400 mg or placebo, as single doses and 57 male subjects receiving PN‐943, 100 to 1000 mg or placebo, as multiple doses. Study 2 was a randomized, crossover study comparing multiple doses of 450‐mg PN‐943 twice daily as a liquid solution and as an immediate‐release tablet in 10 subjects. No subjects discontinued due to treatment‐emergent adverse events. Consistent with the gastrointestinal‐restricted nature of the peptide, systemic exposure was minimal; there was an approximate dose‐proportional increase in area under the plasma concentration–time curve. There was minimal accumulation with once‐daily dosing and an absence of time‐dependent changes in pharmacokinetics. Administration of PN‐943 after a high‐fat meal reduced peak plasma concentration and area under the plasma concentration–time curve. There was minimal (<0.1%) urinary excretion of intact drug, and there was a dose‐related increase in fecal excretion of intact PN‐943. Dose‐dependent increases in blood receptor occupancy and reduction in blood receptor expression were observed, supporting target engagement. Twice‐daily dosing resulted in sustained receptor occupancy with low plasma fluctuations (143%). PN‐943 was generally well tolerated following single and multiple oral doses with low systemic exposure. Twice‐daily dosing resulted in sustained pharmacokinetics and pharmacodynamics, supporting further investigation in efficacy studies.

A study on the potential role of autophagy-related protein 10 as a biomarker for ulcerative colitis

PURPOSE

Ulcerative colitis (UC) is a lifelong disease with unclear etiology and increasing prevalence worldwide. Autophagy has been reported to play roles in the pathogenesis and progression of UC. Here, we aimed to analyze the expression of autophagy related protein 10 (ATG10) and its regulator, micro-RNA (miR) 519a, in UC patients.

METHODS

The level of ATG10 in the serum, stool, and colon biopsies from 15 UC patients and 30 non-UC healthy individuals (HC) group was measured by ELISA. Also, the blood level of miR-519a was investigated by quantitative real-time PCR.

RESULTS

We found 13.63 ng/ml versus 0.99 ng/ml, 11.01 ng/ml versus 1.11 ng/ml and 6.41 ng/ml versus 3.21 ng/ml of ATG10 in the stool, colon tissue, and serum of UC and HC, respectively. There was no significant difference in the expression of miR-519a in the blood samples of UC and HC.

CONCLUSIONS

ATG10 might be a potential non-invasive diagnostic biomarker for UC.

Si-Ni-San ameliorates chronic colitis by modulating type I interferons-mediated inflammation

BACKGROUND

Ulcerative colitis (UC) is a chronic relapsing inflammatory disease that markedly elevates the risk of colon cancers and results in disability. The disrupted immune homeostasis has been recognized as a predominant player in the pathogenesis of UC. However, the overall remission rate of current therapies based on immunoregulation is still unsatisfactory. Si-Ni-San (SNS) has been found effective in relieving UC through thousands of years of clinical practice, yet the specific mechanisms of the protective effect of SNS were not fully elucidated.

PURPOSE

We aim to investigate the therapeutic effects of SNS against the development of chronic colitis and the underlying mechanisms.

METHODS

We established a DSS-induced chronic experimental colitis mouse model to evaluate the effect of SNS. RNA-sequencing, bioinformatic analysis, and in vitro studies were performed to investigate the underlying mechanisms.

RESULTS

Our data demonstrated that SNS significantly ameliorated chronic experimental colitis via inhibiting the expression of genes associated with inflammatory responses. Interestingly, SNS significantly suppressed DSS-induced type I interferon (IFN) responses instead of directly downregulating the production of pro-inflammatory cytokines, such as Il-6. In vitro study further found that SNS selectively inhibited STING and RIG-I pathway-induced type I IFN responses by modulating TBK1- and IRF3-dependent signaling transduction. SNS also suppressed the expression of IFN-stimulated genes by directly inhibiting STAT1 and STAT2 activation.

CONCLUSION

Our study not only provides novel insights into the pathogenic role of type I IFN responses in colitis but also suggested that SNS or bioactive compounds derived from SNS may serve as novel therapeutic strategies for the treatment of UC via interfering type I IFN-mediated inflammation.

The Interplay between Immune System and Microbiota in Inflammatory Bowel Disease: A Narrative Review

The importance of the gut microbiota in human health is currently well established. It contributes to many vital functions such as development of the host immune system, digestion and metabolism, barrier against pathogens or brain–gut communication. Microbial colonization occurs during infancy in parallel with maturation of the host immune system; therefore, an adequate cross-talk between these processes is essential to generating tolerance to gut microbiota early in life, which is crucial to prevent allergic and immune-mediated diseases. Inflammatory bowel disease (IBD) is characterized by an exacerbated immune reaction against intestinal microbiota. Changes in abundance in the gut of certain microorganisms such as bacteria, fungi, viruses, and archaea have been associated with IBD. Microbes that are commonly found in high abundance in healthy gut microbiomes, such as F. prausnitzii or R. hominis, are reduced in IBD patients. E. coli, which is usually present in a healthy gut in very low concentrations, is increased in the gut of IBD patients. Microbial taxa influence the immune system, hence affecting the inflammatory status of the host. This review examines the IBD microbiome profile and presents IBD as a model of dysbiosis.

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.