TNF-Alpha Blockers in Inflammatory Bowel Diseases: Practical Recommendations and a User's Guide: An Update

Anti-Inflammatory Effects of Algae-Derived Biomolecules in Gut Health: A Review

Under physiological conditions, the inflammatory response acts as a biological defense against tissue damage or infection, and is rapidly resolved once the infection is cleared. However, chronic inflammatory diseases, including inflammatory bowel disease (IBD), have become increasingly widespread in the last decades, placing a burden on the quality of life of affected people and on healthcare systems worldwide. Available drug therapies are often ineffective due to the chronic nature of these diseases, and prolonged administration of drugs can result in severe side effects for the patient or a lack of efficacy. In addition, there is the growing problem of bacterial resistance to synthetic antibiotics. Together, these factors have led to a strong research focus on the discovery of natural products capable of treating IBD. Recently, there has been a growing interest in compounds derived from marine sources, mainly algae, due to their bioactive secondary metabolites with anti-inflammatory properties well known in the literature. Based on this evidence, this review aimed to evaluate the anti-inflammatory potential of algae-derived biomolecules in IBD. In particular, interesting species from green algae (e.g., Chlorella vulgaris and Ulva pertusa), brown algae (e.g., Macrocystis pyrifera and Ecklonia cava) and red algae (e.g., Porphyra tenera and Grateloupia turuturu) are included in this review due to their proven anti-inflammatory properties. For this purpose, an extensive literature search was conducted using several databases. The results suggest that both macroalgae and microalgae have remarkable potential for IBD therapy due to the anti-inflammatory and antioxidant activities of their bioactive compounds. However, while the preclinical evidence is encouraging, further and long-term clinical studies are needed to better understand their mechanisms of action in order to determine the true efficacy of marine algae in the treatment of IBD.

Cellular Plasticity in Gut and Liver Regeneration

The intestine and liver share a unique regenerative property that sets them apart from other mammalian visceral organs. The intestinal epithelium exhibits rapid renewal, making it one of the fastest renewing tissues in humans. Under physiological conditions, intestinal stem cells within each intestinal crypt continuously differentiate into the different types of intestinal epithelial cells to maintain intestinal homeostasis. However, when exposed to tissue damage or stressful conditions such as inflammation, intestinal epithelial cells in the gastrointestinal tract exhibit plasticity, allowing fully differentiated cells to regain their stem cell properties. Likewise, hepatic epithelial cells possess a remarkable regenerative capacity to restore lost liver mass through proliferation-mediated liver regeneration. When the proliferation-mediated regenerative capacity is impaired, hepatocytes and biliary epithelial cells (BECs) can undergo plasticity-mediated regeneration and replenish each other. The transition of mammalian liver progenitor cells to hepatocytes/BECs can be observed under tightly controlled experimental conditions such as severe hepatocyte injury accompanied by the loss of regenerative capacity. In this review, we will discuss the mechanism by which cellular plasticity contributes to the regeneration process and the potential therapeutic implications of understanding and harnessing cellular plasticity in the gut and liver.

Advances in hematopoietic stem cell transplantation for autoimmune diseases

Autoimmune diseases (ADs) are a collection of immunological disorders in which the immune system responds to self-antigens by producing autoantibodies or self-sensitized cells. Current treatments are unable to cure ADs, and achieving long-term drug-free remission remains a challenging task. Hematopoietic stem cell transplantation (HSCT) stands out from other therapies by specifically targeting ADs that target various cell subpopulations, demonstrating notable therapeutic benefits and resulting in sustained drug-free remission. Since different ADs have distinct mechanisms of action, the comprehensive understanding of how HSCT works in treating ADs is crucial. This review provides a detailed overview of the latest research and clinical applications of HSCT in treating ADs, offering new insights for clinicians aiming to optimize its use for ADs management.

Application of chitosan as nano carrier in the treatment of inflammatory bowel disease

Inflammatory bowel disease (IBD), encompassing ulcerative colitis (UC) and Crohn's disease (CD), is characterized by persistent and recurrent gastrointestinal inflammation. Conventional IBD therapies often involve the use of antibiotics, NSAIDs, biological agents, and immunomodulators. While these medications can mitigate acute inflammatory symptoms, their long-term efficacy is frequently compromised due to cumulative toxic effects. In recent years, significant attention has shifted toward nanoparticle (NP)-based therapies as potential alternatives for IBD management. Various drug delivery strategies, including those targeting microbiota interactions, ligand-receptor binding, pH sensitivity, biodegradability, pressure response, and specific charge and size parameters, have been explored and optimized in animal studies. This review provides a comprehensive overview of the current landscape of chitosan NP-mediated drug delivery systems for IBD treatment. Additionally, it will discuss the prevailing challenges and propose future research directions to advance chitosan NP-based therapeutic strategies for IBD.

Small bowel pyloric metaplasia is associated with lower rates of earlier recurrence of Crohn's disease after resection

Recurrence within one or two years is common after Crohn's disease (CD) resection. In this study, we seek to identify histologic features in CD resections that may predict earlier (≤18 months) recurrence to potentially guide post-operative management. A single-institution, retrospective review was performed on patients with first-time CD bowel resection specimens (2002-2007). Patient demographics and CD course were also documented. Slides were reviewed for inflammatory distribution and composition, small bowel (SB) pyloric metaplasia (PM), and presence and characteristics of submucosal fibrosis and granulomas. In our cohort, 14 of 41 patients experienced earlier clinical or endoscopic recurrence after initial resection. In the 38 patients who underwent SB resection (3 were colon only), PM was less common in those with earlier recurrence (6/12 [50%]) compared to those with later (>18 months) or no known recurrence (22/26 [85%]) (P = 0.045). PM was present even in patients with <1 year of known CD. Additionally, therapy with anti-tumor necrosis factor (TNF) prior to surgery was more common in earlier recurrence patients (7/14 [50%]) than later or no recurrence patients (4/27 [15%]) (P = 0.026). There was no significant difference in age, sex, smoking status, duration of CD, post-operative CD medication, distribution or features of inflammation, granulomas, or fibrosis. Overall, our results indicate that SB PM and pre-surgical anti-TNF therapy are possible helpful clinicopathologic features to evaluate for recurrence risk.

[Old and New Biologics and Small Molecules in Inflammatory Bowel Disease: Anti Integrins]

Recently, novel biologics or small molecular drugs have been introduced for overcoming the unmet needs associated with anti-tumor necrosis factor α agents for inflammtory bowel disease (IBD) treatment. Among these novel drugs, anti integrin agents block leukocyte trafficking to the intestine by blocking the interaction between integrin and cell adhesion molecules. Vedolizumab (anti-α4β7) is most widely used anti-integrin approved in both ulcerative colitis and Crohn's disease .It has been shown to be effective in both induction and maintenance therapy with a favorable safety profile due to gut selectivity. Several models incorporating clinical, genetic, immune and gut microbial markers to predict response to vedolizumab in IBD have been developed. Etrolizumab (anti-β7) blocks leukocyte trafficking via α4β7 and cell adhesion via αEβ7 integrins. In addition, the introduction of subcutaneous vedolizumab showed similar efficacy and safety with improved patients' convenience. Other investigational anti-integrin therapies include abrilumab (anti-α4β7 IgG2), PN-943 (orally administered and gut-restricted α4β7 antagonist peptide), AJM300 (orally active small molecule inhibitor of α4), and ontamalimab (anti-MAdCAM-1 IgG).

Role of Cytokines and Chemokines in Vitiligo and Their Therapeutic Implications

Vitiligo is a persistent autoimmune disease characterized by progressive depigmentation of the skin caused by the selective destruction of melanocytes. Although its etiopathogenesis remains unclear, multiple factors are involved in the development of this disease, from genetic and metabolic factors to cellular oxidative stress, melanocyte adhesion defects, and innate and adaptive immunity. This review presents a comprehensive summary of the existing knowledge on the role of different cellular mechanisms, including cytokines and chemokines interactions, in the pathogenesis of vitiligo. Although there is no definitive cure for vitiligo, notable progress has been made, and several treatments have shown favorable results. A thorough understanding of the basis of the disease uncovers promising drug targets for future research, providing clinical researchers with valuable insights for developing improved treatment options.

Dopamine β-hydroxylase shapes intestinal inflammation through modulating T cell activation

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic and relapsing disease characterized by immune-mediated dysfunction of intestinal homeostasis. Alteration of the enteric nervous system and the subsequent neuro-immune interaction are thought to contribute to the initiation and progression of IBD. However, the role of dopamine beta-hydroxylase (DBH), an enzyme converting dopamine into norepinephrine, in modulating intestinal inflammation is not well defined.

METHODS

CD4+CD45RBhighT cell adoptive transfer, and 2,4-dinitrobenzene sulfonic acid (DNBS) or dextran sodium sulfate (DSS)-induced colitis were collectively conducted to uncover the effects of DBH inhibition by nepicastat, a DBH inhibitor, in mucosal ulceration, disease severity, and T cell function.

RESULTS

Inhibition of DBH by nepicastat triggered therapeutic effects on T cell adoptive transfer induced chronic mouse colitis model, which was consistent with the gene expression of DBH in multiple cell populations including T cells. Furthermore, DBH inhibition dramatically ameliorated the disease activity and colon shortening in chemically induced acute and chronic IBD models, as evidenced by morphological and histological examinations. The reshaped systemic inflammatory status was largely associated with decreased pro-inflammatory mediators, such as TNF-α, IL-6 and IFN-γ in plasma and re-balanced Th1, Th17 and Tregs in mesenteric lymph nodes (MLNs) upon colitis progression. Additionally, the conversion from dopamine (DA) to norepinephrine (NE) was inhibited resulting in increase in DA level and decrease in NE level and DA/NE showed immune-modulatory effects on the activation of immune cells.

CONCLUSION

Modulation of neurotransmitter levels via inhibition of DBH exerted protective effects on progression of murine colitis by modulating the neuro-immune axis. These findings suggested a promising new therapeutic strategy for attenuating intestinal inflammation.

Tissue markers may predict treatment response to antitumor necrosis factor-α agents in children with Crohn's disease

OBJECTIVES

Patients with moderate-severe Crohn's disease (CD) who are treated with antitumor necrosis factor alpha (TNF-α) agents may be subjected to primary nonresponse or partial response. We aimed to identify tissue markers that may predict response to these agents.

METHODS

Pediatric patients (6-18 years) with either ileal or ileo-colonic CD who were treated with anti-TNF-α were stratified into three different groups based on their overall response to therapy at the end of induction including clinical and laboratory parameters (group 1-full responders [FR], group 2-partial responders [PR], group 3-nonresponders [NR]). Seven tissue markers (fibronectin, interleukin [IL]-23R, IL-23, TNF-α, collagen-III, IL-13R, and hypoxia-inducible factors [HIF]-1α) were evaluated. Immunofluorescence (IF) analyses were performed on biopsies from the terminal ileum, which were retrieved up to 6 months before treatment initiation.

RESULTS

Twenty-six CD patients (16 [61.5%] males; age 13.9 ± 2.9 years), including 8 (30.8%) with ileal disease and 18 (69.2%) with ileo-colonic disease, were enrolled. Terminal ileum biopsies from nine patients from group 1, nine from group 2, and eight from group 3 were evaluated. Three antibodies were found to be significantly different between NR and FR groups; Collagen III and fibronectin stains were significantly more prominent in NR patients, while TNF-α stain was significantly more pronounced in FR, p < 0.05 for each. PR could not have been predicted with neither of markers.

CONCLUSIONS

Decreased tissue IF intensity of fibronectin and collagen III and increased intensity of TNF-α may predict response to anti-TNF-α treatment.

Dendritic cells: the yin and yang in disease progression

Dendritic cells (DCs) are antigen presenting cells that link innate and adaptive immunity. DCs have been historically considered as the most effective and potent cell population to capture, process and present antigens to activate naïve T cells and originate favorable immune responses in many diseases, such as cancer. However, in the last decades, it has been observed that DCs not only promote beneficial responses, but also drive the initiation and progression of some pathologies, including inflammatory bowel disease (IBD). In line with those notions, different therapeutic approaches have been tested to enhance or impair the concentration and role of the different DC subsets. The blockade of inhibitory pathways to promote DCs or DC-based vaccines have been successfully assessed in cancer, whereas the targeting of DCs to inhibit their functionality has proved to be favorable in IBD. In this review, we (a) described the general role of DCs, (b) explained the DC subsets and their role in immunogenicity, (c) analyzed the role of DCs in cancer and therapeutic approaches to promote immunogenic DCs and (d) analyzed the role of DCs in IBD and therapeutic approaches to reduced DC-induced inflammation. Therefore, we aimed to highlight the "yin-yang" role of DCs to improve the understand of this type of cells in disease progression.

Real-world effectiveness and safety of ustekinumab in bio-naive patients with moderate-to-severe Crohn's disease: A Canadian multi-center study

BACKGROUND

Clinical practice guidelines recommend ustekinumab as a first-line biological treatment option for moderately-to-severely active Crohn's disease (CD). However, there is limited real-world effectiveness and safety data in bio-naïve patients.

AIMS

To assess ustekinumab effectiveness and safety in bio-naïve CD patients.

METHODS

Medical charts were reviewed retrospectively at seven Canadian centers. The primary outcome was the proportion of patients achieving clinical remission at Month 6 following ustekinumab initiation. Secondary outcomes included clinical, biochemical, and endoscopic response, and remission at Months 4, 6 and 12. Ustekinumab safety was assessed over the one-year follow-up period.

RESULTS

158 charts were reviewed. Clinical remission was achieved by 50.0% (36/72), 67.7% (105/155), and 73.7% (84/114) of patients at Months 4, 6, and 12, respectively. At these study timepoints, biochemical remission was observed in 65.2% (43/66), 71.6% (63/88), and 73.9% (68/92) of patients. At Months 6 and 12, endoscopic remission was observed in 40.5% (15/37) and 56.3% (27/48) of patients, respectively. Most participants (93.5%; 145/155) persisted on ustekinumab through Month 12. No serious adverse drug reactions were reported.

CONCLUSION

In this real-world study, ustekinumab presents as an effective first-line biologic for induction and maintenance of remission among bio-naïve Canadian patients with moderately-to-severely active CD.

Dual function of fungi-derived cytokines in inflammatory bowel diseases: protection or inflammation

Inflammatory bowel disease (IBD) is an immune-mediated inflammatory condition involving both the innate and adaptive immune systems. Recently, the role of intestinal fungal flora and their downstream immune pathways has been highlighted in the pathogenesis of IBD. Cytokines as primary immune mediators require a delicate balance for maintaining intestinal homeostasis. Although most cytokines have a predictable role in either amplifying or attenuating inflammation in IBD, a few cytokines have shown a dual function in the inflammatory state of the intestine. Some of these dual-faced cytokines are also involved in mucosal anti-microbial defense pathways, particularly against intestinal fungal residents. Here, we reviewed the role of these cytokines in IBD pathogenesis to achieve a better understanding of the fungal interactions in the development of IBD.

HLA-DQA1*05 and upstream variants of PPARGC1B are associated with infliximab persistence in Japanese Crohn's disease patients

Recently, the HLA-DQA1*05 (rs2097432) genetic variation has been reported to be linked to early infliximab (IFX) treatment failure in the Caucasian Crohn's disease (CD) population, but that evidence is scarce in the Asian population. This study aimed to investigate the relationship between rs2097432 and the cumulative discontinuation-free time of IFX (IFX persistence) in 189 Japanese biologics-naive CD patients. We also performed a genome-wide association study (GWAS) to discover novel genetic predictors for IFX persistence. The C allele of rs2097432 significantly increased the risk of early discontinuation of IFX [Hazard ratio (HR) = 2.23 and P-value = 0.026]. In GWAS, one locus tagged by rs73277969, located upstream of PPARGC1B which attenuates macrophage-mediated inflammation, reached genome-wide significance (HR = 6.04 and P-value = 7.93E-9). Pathway analysis suggested association of signaling by PDGF and FCGR activation signaling with IFX persistence (P-value = 8.56E-5 and 5.80E-4, respectively).

Prediction of anti-TNF therapy failure in ulcerative colitis patients by ensemble machine learning: A prospective study

Nowadays, anti-TNF therapy remarkably improves the medical management of ulcerative colitis (UC), but approximately 40 % of patients do not respond to this treatment. In this study, we used 79 anti-TNF-naive patients with moderate-to-severe UC from four cohorts to discover alternative therapeutic targets and develop a personalized medicine approach that can diagnose UC non-responders (UCN) prior to receiving anti-TNF therapy. To this end, two microarray data series were integrated to create a discovery cohort with 35 UC samples. A comprehensive gene expression and functional analysis was performed and identified 313 significantly altered genes, among which IL6 and INHBA were highlighted as overexpressed genes in the baseline mucosal biopsies of UCN, whose cooperation may lead to a decrease in the Tregs population. Besides, screening the abundances of immune cell subpopulations showed neutrophils' accumulation increasing the inflammation. Furthermore, the correlation of KRAS signaling activation with unresponsiveness to anti-TNF mAb was observed using network analysis. Using 50x repeated 10-fold cross-validation LASSO feature selection and a stack ensemble machine learning algorithm, a five-mRNA prognostic panel including IL13RA2, HCAR3, CSF3, INHBA, and MMP1 was introduced that could predict the response of UC patients to anti-TNF antibodies with an average accuracy of 95.3 %. The predictive capacity of the introduced biomarker panel was also validated in two independent cohorts (44 UC patients). Moreover, we presented a distinct immune cell landscape and gene signature for UCN to anti-TNF drugs and further studies should be considered to make this predictive biomarker panel and therapeutic targets applicable in the clinical setting.

Foodomics-Based Approaches Shed Light on the Potential Protective Effects of Polyphenols in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic and progressive inflammatory disorder affecting the gastrointestinal tract (GT) caused by a wide range of genetic, microbial, and environmental factors. IBD is characterized by chronic inflammation and decreased gut microbial diversity, dysbiosis, with a lower number of beneficial bacteria and a concomitant increase in pathogenic species. It is well known that dysbiosis is closely related to the induction of inflammation and oxidative stress, the latter caused by an imbalance between reactive oxygen species (ROS) production and cellular antioxidant capacity, leading to cellular ROS accumulation. ROS are responsible for intestinal epithelium oxidative damage and the increased intestinal permeability found in IBD patients, and their reduction could represent a potential therapeutic strategy to limit IBD progression and alleviate its symptoms. Recent evidence has highlighted that dietary polyphenols, the natural antioxidants, can maintain redox equilibrium in the GT, preventing gut dysbiosis, intestinal epithelium damage, and radical inflammatory responses. Here, we suggest that the relatively new foodomics approaches, together with new technologies for promoting the antioxidative properties of dietary polyphenols, including novel delivery systems, chemical modifications, and combination strategies, may provide critical insights to determine the clinical value of polyphenols for IBD therapy and a comprehensive perspective for implementing natural antioxidants as potential IBD candidate treatment.

VDUP1 Deficiency Promotes the Severity of DSS-Induced Colitis in Mice by Inducing Macrophage Infiltration

The loss of vitamin D3 upregulated protein 1 (VDUP1) has been implicated in the pathogenesis of various inflammation-related diseases. Notably, reduced expression of VDUP1 has been observed in clinical specimens of ulcerative colitis (UC). However, the role of VDUP1 deficiency in colitis remains unclear. In this study, we investigated the role of VDUP1 in dextran sulfate sodium (DSS)-induced experimental colitis in mice. VDUP1-deficient mice were more susceptible to DSS-induced colitis than their wild-type (WT) littermates after 2% DSS administration. VDUP1-deficient mice exhibited an increased disease activity index (DAI) and histological scores, as well as significant colonic goblet cell loss and an increase in apoptotic cells. These changes were accompanied by a significant decrease in MUC2 mRNA expression and a marked increase in proinflammatory cytokines and chemokines within damaged tissues. Furthermore, phosphorylated NF-κB p65 expression was significantly upregulated in damaged tissues in the context of VDUP1 deficiency. VDUP1 deficiency also led to significant infiltration of macrophages into the site of ulceration. An in vitro chemotaxis assay confirmed that VDUP1 deficiency enhanced bone marrow-derived macrophage (BMDM) chemotaxis induced by CCL2. Overall, this study highlights VDUP1 as a regulator of UC pathogenesis and a potential target for the future development of therapeutic strategies.

Anti-tumor necrosis factor therapy in Bulgarian pediatric patients with inflammatory bowel disease - an 8-year experience of a referral center

INTRODUCTION

Anti-tumor necrosis factor (anti-TNF) therapy has become a mainstay in the treatment of patients with inflammatory bowel disease over the past few decades.

Vaccination therapy for inflammatory bowel disease

Recently, several novel medications, such as Ustekinumab, Infliximab, and Vedolizumab, have emerged as potential options for inflammatory bowel disease(IBD) management. Despite achieving some effects in clinical applications, these therapies are still plagued by inadequate response rates and adverse side effects. With rapid progress in immunological research, therapeutic vaccines are gaining traction as an alternative. These vaccines aim to activate the body's immune system to generate specific antibodies, thereby offering a potential avenue for treating IBD. The efficacy and safety of vaccines, coupled with their potential to mitigate the financial and healthcare burden associated with disease treatment, render therapeutic vaccines a more favorable approach for managing patients with IBD. In this review, we critically examine the existing literature pertaining to therapeutic vaccines for IBD, aiming to offer researchers a comprehensive understanding of their applications and prospects and stimulate novel vaccine development by presenting innovative ideas in this field.

Hypoxia in the Pathophysiology of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an idiopathic disease of disordered chronic inflammation in the intestines that affects many people across the world. While the disease is still being better characterized, greater progress has been made in understanding the many components that intersect in the disease. Among these components are the many pieces that compose the intestinal epithelial barrier, the various cytokines and immune cells, and the population of microbes that reside in the intestinal lumen. Since their discovery, the hypoxia-inducible factors (HIFs) have been found to play an expansive role in physiology as well as diseases such as inflammation due to their role in oxygen sensing-related gene transcription, and metabolic control. Making use of existing and developing paradigms in the immuno-gastroenterology of IBD, we summarized that hypoxic signaling plays as another component in the status and progression of IBD, which may include possible functions at the origins of inflammatory dysregulation. © 2023 American Physiological Society. Compr Physiol 13:4767-4783, 2023.

Early Life Stress in Mice Leads to Impaired Colonic Corticosterone Production and Prolonged Inflammation Following Induction of Colitis

BACKGROUND

Early life stress (ELS) is an environmental trigger believed to promote increased risk of IBD. Our goal was to identify mechanisms whereby ELS in mice affects susceptibility to and/or severity of gut inflammation.

METHODS

We utilized 2 published animal models of ELS. In the first model, newborn mice were separated from the dam daily for 4 to 8 hours starting on postnatal day 2 and then weaned early on postnatal day 17. Control mice were left undisturbed with the dams until weaning on postnatal day 21. In the second model, dams were fed dexamethasone or vehicle ad libitum in drinking water on postpartum days 1 to 14. Plasma and colonic corticosterone were measured in juvenile and adult mice. Colitis was induced in 4-week-old mice via intraperitoneal injection of interleukin (IL)-10 receptor blocking antibody every 5 days for 15 days. Five or 15 days later, colitis scores and transcripts for Tnf, glucocorticoid receptors, and steroidogenic enzymes were measured.

RESULTS

Mice exposed to ELS displayed reduced plasma and colonic corticosterone. Control animals showed improvements in indices of inflammation following cessation of interleukin-10 receptor blockade, whereas ELS-exposed animals maintained high levels of Tnf and histological signs of colitis. In colitic animals, prior exposure to ELS was associated with significantly lower expression of genes associated with corticosterone synthesis and responsiveness. Finally, TNF stimulation of colonic crypt cells from ELS mice led to increased inhibition of corticosterone synthesis.

CONCLUSIONS

Our study identifies impaired local glucocorticoid production and responsiveness as a potential mechanism whereby ELS predisposes to chronic colitis in susceptible hosts.

Dietary (poly)phenols mitigate inflammatory bowel disease: Therapeutic targets, mechanisms of action, and clinical observations

Inflammatory bowel diseases (IBD), which include Crohn's disease and ulcerative colitis, are a rapidly growing public health concern worldwide. These diseases are heterogeneous at the clinical, immunological, molecular, genetic, and microbial level, but characteristically involve a disrupted immune-microbiome axis. Shortcomings in conventional treatment options warrant the need for novel therapeutic strategies to mitigate these life-long and relapsing disorders of the gastrointestinal tract. Polyphenols, a diverse group of phytochemicals, have gained attention as candidate treatments due to their array of biological effects. Polyphenols exert broad anti-inflammatory and antioxidant effects through the modulation of cellular signaling pathways and transcription factors important in IBD progression. Polyphenols also bidirectionally modulate the gut microbiome, supporting commensals and inhibiting pathogens. One of the primary means by which gut microbiota interface with the host is through the production of metabolites, which are small molecules produced as intermediate or end products of metabolism. There is growing evidence to support that modulation of the gut microbiome by polyphenols restores microbially derived metabolites critical to the maintenance of intestinal homeostasis that are adversely disrupted in IBD. This review aims to define the therapeutic targets of polyphenols that may be important for mitigation of IBD symptoms, as well as to collate evidence for their clinical use from randomized clinical trials.

The role of upadacitinib in the treatment of ulcerative colitis

The JAK signaling pathway plays a major role in the immunopathology of autoimmune diseases, including inflammatory bowel disease. JAK enzymes provide novel targets for rapidly effective inflammatory bowel disease therapy, particularly in ulcerative colitis. Upadacitinib is a targeted JAK1 inhibitor. In multiple phase III clinical trials, upadacitinib has demonstrated significant improvement in clinical and endoscopic outcomes and quality of life for patients with moderate-to-severe ulcerative colitis. In this drug evaluation we describe the role of the JAK signaling pathway in ulcerative colitis, the mechanism of action of upadacitinib and the current clinical evidence for its use in ulcerative colitis; we also review its safety and tolerability, including for special populations.

Selenoprotein W Ameliorates Experimental Colitis and Promotes Intestinal Epithelial Repair

Selenoprotein W (Selenow) is a ~9 kDa selenoprotein suggested to play a beneficial role in resolving inflammation. However, the underlying mechanisms are poorly understood. SELENOW expression in the human GI tract using ScRNAseq Gut Cell Atlas and Gene Expression Omnibus (GEO) databases revealed its expression in the small intestine and colonic epithelial, endothelial, mesenchymal, and stem cells and correlated with a protective effect in ulcerative colitis patients. Selenow KO mice treated with 4% dextran sodium sulfate (DSS) showed exacerbated acute colitis, with greater weight loss, shorter colons, and increased fecal occult blood compared to the WT counterparts. Selenow KO mice expressed higher colonic Tnfα, increased Tnfα+ macrophages in the colonic lamina propria, and exhibited loss in epithelial barrier integrity and decreased zonula occludens 1 (Zo-1) expression following DSS treatment. Expression of epithelial cellular adhesion marker (EpCam), yes-associated protein 1 (Yap1), and epidermal growth factor receptor (Egfr) were decreased along with CD24lo cycling epithelial cells in Selenow KO mice. Colonic lysates and organoids confirmed a crosstalk between Egfr and Yap1 that was regulated by Selenow. Overall, our findings suggest Selenow expression is key for efficient resolution of inflammation in experimental colitis that is mediated through the regulation of Egfr and Yap1.

Vedolizumab is superior to infliximab in biologic naïve patients with ulcerative colitis

There are no prospective, head-to-head, controlled trials comparing the efficacy and safety of Infliximab (IFX) and Vedolizumab (VDZ) for the treatment of moderate-to-severe ulcerative colitis (UC), while only a few real-life retrospective studies have been published so far. We assessed the efficacy of IFX vs. VDZ in two cohorts of biologic-naïve outpatients with moderate-to-severe UC or mild, but refractory, disease. Data were extracted from patients' files and reviewed. The duration of follow-up (FU) was 52 weeks. The primary endpoint was the clinical remission (CR) at the end of FU. Secondary endpoints were: drug persistency, time to obtain CR, clinical response at the end of the induction phase (IP), steroid-free CR (compared to patients who used steroids at baseline) at the end of FU, need for drug optimization, adverse events (AEs), and normalization of C-reactive protein (CRP). We also analyzed the causes of dropping out (primary non-response), or secondary loss of response (immunogenic or not), for each group. We enrolled 82 patients (50 IFX and 32 VDZ) who met the inclusion criteria. At the end of FU, CR was obtained in 32% of the patients on IFX and 75% on VDZ (p = 0.0003). Drug persistency was superior for VDZ compared to IFX (78% vs. 52%, p = 0.033). Clinical response at the end of induction was reached in 54% and in 81% in the IFX and VDZ group, respectively (p = 0.014). Steroid-free clinical remission at the end of FU was 62% and 94% in the IFX vs. VDZ group, respectively (p = 0.036). The need for drug optimization was higher for VDZ than for IFX (28% vs. 57%, p = 0.009), while the time to obtain CR, the incidence of AEs, mean duration of FU, and rate of CRP normalization at the end of IP were comparable between the two groups. There was a prevalence of patients dropping out because of primary non-response in IFX group (p = 0.027), while the incidence of secondary loss of response was similar in the two groups. At the multivariate analysis, CRP and Partial Mayo Score (PMS) at T0 did not correlate with CR at the end of FU in both groups. In this retrospective, real world data study in biologic-naïve patients, VDZ was superior to IFX in CR, clinical response rate at the end of IP, drug persistency, steroid-free remission, and need for optimization at the end of FU.

Uncovering the Genetic Link between Acute Myocardial Infarction and Ulcerative Colitis Co-Morbidity through a Systems Biology Approach

Background: Cardiovascular diseases, particularly acute myocardial infarction, are the leading cause of disability and death. Atherosclerosis, the pathological basis of AMI, can be accelerated by chronic inflammation. Ulcerative colitis (UC), a chronic inflammatory disease associated with immunity, contributes to the risk of AMI development. However, controversy continues to surround the relationship between these two diseases. The present study unravels the pathogenesis of AMI and UC, to provide a new perspective on the clinical management of patients with these comorbidities.

Methods: Microarray datasets GSE66360 and GSE87473 were downloaded from the Gene Expression Omnibus database. Common differentially expressed genes (co-DEGs) between AMI and UC were identified, and the following analyses were performed: enrichment analysis, protein-protein interaction network construction, hub gene identification and co-expression analysis.

Results: A total of 267 co-DEGs (233 upregulated and 34 downregulated) were screened for further analysis. GO enrichment analysis suggested important roles of chemokines and cytokines in AMI and UC. In addition, the lipopolysaccharide-mediated signaling pathway was found to be closely associated with both diseases. KEGG enrichment analysis revealed that lipid and atherosclerosis, NF-κB, TNF and IL-17 signaling pathways are the core mechanisms involved in the progression of both diseases. Finally, 11 hub genes were identified with cytoHubba: TNF, IL1B, TLR2, CXCL8, STAT3, MMP9, ITGAX, CCL4, CSF1R, ICAM1 and CXCL1.

Conclusion: This study reveals a co-pathogenesis mechanism of AMI and UC regulated by specific hub genes, thus providing ideas for further mechanistic studies, and new perspectives on the clinical management of patients with these comorbidities.

Colon-Targeted eNAMPT-Specific Peptide Systems for Treatment of DSS-Induced Acute and Chronic Colitis in Mouse

Nicotinamide phosphoribosyl transferase (NAMPT) is required to maintain the NAD⁺ pool, among which extracellular (e) NAMPT is associated with inflammation, mainly mediated by macrophages. However, the role of (e) NAMPT in inflammatory macrophages in ulcerative colitis is insufficiently understood. Here our analyses of single-cell RNA-seq data revealed that the levels of NAMPT and CYBB/NOX2 in macrophages were elevated in patients with colitis and in mouse models of acute and chronic colitis. These findings indicate the clinical significance of NAMPT and CYBB in colitis. Further, we found that eNAMPT directly binds the extracellular domains of CYBB and TLR4 in activated NLRP3 inflammasomes. Moreover, we developed a recombinant 12-residue TK peptide designated colon-targeted (CT)-conjugated multifunctional NAMPT (rCT-NAMPT), comprising CT as the colon-targeting moiety, which harbors the minimal essential residues required for CYBB/TLR4 binding. rCT-NAMPT effectively suppressed the severity of disease in DSS-induced acute and chronic colitis models through targeting the colon and inhibiting the interaction of NAMPT with CYBB or TLR4. Together, our data show that rCT-NAMPT may serve as an effective novel candidate therapeutic for colitis by modulating the NLRP3 inflammasome-mediated immune signaling system.

Amniotic Fluid-Derived Mesenchymal Stem/Stromal Cell-Derived Secretome and Exosomes Improve Inflammation in Human Intestinal Subepithelial Myofibroblasts

Inflammatory Bowel Diseases (IBDs) are characterized by chronic relapsing inflammation of the gastrointestinal tract. The mesenchymal stem/stromal cell-derived secretome and secreted extracellular vesicles may offer novel therapeutic opportunities in patients with IBD. Thus, exosomes may be utilized as a novel cell-free approach for IBD therapy. The aim of our study was to examine the possible anti-inflammatory effects of secretome/exosomes on an IBD-relevant, in vitro model of LPS-induced inflammation in human intestinal SubEpithelial MyoFibroblasts (SEMFs). The tested CM (Conditioned Media)/exosomes derived from a specific population of second-trimester amniotic fluid mesenchymal stem/stromal cells, the spindle-shaped amniotic fluid MSCs (SS-AF-MSCs), and specifically, their secreted exosomes could be utilized as a novel cell-free approach for IBD therapy. Therefore, we studied the effect of SS-AF-MSCs CM and exosomes on LPS-induced inflammation in SEMF cells. SS-AF-MSCs CM and exosomes were collected, concentrated, and then delivered into the cell cultures. Administration of both secretome and exosomes derived from SS-AF-MSCs reduced the severity of LPS-induced inflammation. Specifically, IL-1β, IL-6, TNF-α, and TLR-4 mRNA expression was decreased, while the anti-inflammatory IL-10 was elevated. Our results were also verified at the protein level, as secretion of IL-1β was significantly reduced. Overall, our results highlight a cell-free and anti-inflammatory therapeutic agent for potential use in IBD therapy.

Updates on conventional therapies for inflammatory bowel diseases: 5-aminosalicylates, corticosteroids, immunomodulators, and anti-TNF-α

The incidence and prevalence of inflammatory bowel diseases (IBDs) are rapidly increasing worldwide. IBDs are considered an emerging problem not only in Western countries but also in developing counties. The relapses and complications of active IBD mandate various medications. Nevertheless, hospitalization, emergency room visits, or surgery may be required, resulting in a socioeconomic burden. Great advances have been made in the development of new therapeutic options for IBD to achieve induction and maintenance remission. Nevertheless, conventional therapy is still the mainstay in the treatment of IBD. This review article provides an update on recent advances in conventional therapies, including 5-aminosalicylates, corticosteroids, immunomodulators, and anti-tumor necrosis factor-α agents to treat IBD.

Management of inflammatory bowel disease beyond tumor necrosis factor inhibitors: novel biologics and small-molecule drugs

The incidence and prevalence of inflammatory bowel disease (IBD), comprising Crohn's disease and ulcerative colitis, have increased in Asia and developing countries. In the past two decades, anti-tumor necrosis factor (TNF) agents have revolutionized the treatment of IBD, in part by decreasing the rates of complications and surgery. Although anti-TNF agents have changed the course of IBD, there are unmet needs in terms of primary and secondary non-responses and side effects such as infections and malignancies. Novel biologics and small-molecule drugs have been developed for IBD, and the medical treatment options have improved. These drugs include sphingosine-1-phosphate receptor modulators and anti-integrins to block immune cell migration, and cytokine and Janus kinase inhibitors to block immune cell communications. In this review, we discuss the approved novel biologics and small-molecule drugs, including several of those in the late stages of development, for the treatment of IBD.

Anti-Colitic Effect of an Exopolysaccharide Fraction from Pediococcus pentosaceus KFT-18 on Dextran Sulfate Sodium-Induced Colitis through Suppression of Inflammatory Mediators

We previously reported the immunostimulatory effect of an exopolysaccharide fraction from Pediococcus pentosaceus KFT18 (PE-EPS), a lactic acid bacterium, in macrophages and primary splenocytes, as well as in cyclophosphamide-induced immunosuppressed mice. In this study, the anti-colitic activity of PE-EPS was investigated in a dextran sulfate sodium (DSS)-induced colitis animal model. PE-EPS relieved DSS-induced colitis symptoms, such as stool blood, decreased colon length, crypt disruption, and mucus layer edema. Regarding the molecular mechanism, PE-EPS reduced the enhanced expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and pro-inflammatory cytokines (TNF-α, IL-6, and IL-1) in the colon tissue of colitis-induced mice. Additionally, PE-EPS protected against DSS-induced phosphorylation of p65 and signal transducer and activator of transcription 1 (STAT1). These findings suggested that the exopolysaccharide fraction from Ped. pentosaceus KFT18 can be used to treat inflammatory bowel disease by alleviating colonic inflammation.

Renal and Urological Disorders Associated With Inflammatory Bowel Disease

Renal and urinary tract complications related to inflammatory bowel disease (IBD) have been relatively understudied in the literature compared with other extraintestinal manifestations. Presentation of these renal manifestations can be subtle, and their detection is complicated by a lack of clarity regarding the optimal screening and routine monitoring of renal function in IBD patients. Urolithiasis is the most common manifestation. Penetrating Crohn's disease involving the genitourinary system as an extraintestinal complication is rare but associated with considerable morbidity. Some biologic agents used to treat IBD have been implicated in progressive renal impairment, although differentiating between drug-related side effects and deteriorating kidney function due to extraintestinal manifestations can be challenging. The most common findings on renal biopsy of IBD patients with renal injury are tubulointerstitial nephritis and IgA nephropathy, the former also being associated with drug-induced nephrotoxicity related to IBD medication. Amyloidosis, albeit rare, must be diagnosed early to reduce the chance of progression to renal failure. In this review, we evaluate the key literature relating to renal and urological involvement in IBD and emphasize the high index of suspicion required for the prompt diagnosis and treatment of these manifestations and complications, considering the potential severity and implications of acute or chronic loss of renal function. We also provide suggestions for future research priorities.

Anti-TNFα Treatment Impairs Long-Term Immune Responses to COVID-19 mRNA Vaccine in Patients with Inflammatory Bowel Diseases

Patients with inflammatory bowel disease (IBD) treated with anti-tumor-necrosis factor-alpha (TNFα) exhibited lower serologic responses one-month following the second dose of the COVID-19 BNT162b2 vaccine compared to those not treated with anti-TNFα (non-anti-TNFα) or to healthy controls (HCs). We comprehensively analyzed long-term humoral responses, including anti-spike (S) antibodies, serum inhibition, neutralization, cross-reactivity and circulating B cell six months post BNT162b2, in patients with IBD stratified by therapy compared to HCs. Subjects enrolled in a prospective, controlled, multi-center Israeli study received two BNT162b2 doses. Anti-S levels, functional activity, specific B cells, antigen cross-reactivity, anti-nucleocapsid levels, adverse events and IBD disease score were detected longitudinally. In total, 240 subjects, 151 with IBD (94 not treated with anti-TNFα and 57 treated with anti-TNFα) and 89 HCs participated. Six months after vaccination, patients with IBD treated with anti-TNFα had significantly impaired BNT162b2 responses, specifically, more seronegativity, decreased specific circulating B cells and cross-reactivity compared to patients untreated with anti-TNFα. Importantly, all seronegative subjects were patients with IBD; of those, >90% were treated with anti-TNFα. Finally, IBD activity was unaffected by BNT162b2. Altogether these data support the earlier booster dose administration in these patients.

Helper-Like Type-1 Innate Lymphoid Cells in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an idiopathic condition characterized by chronic relapsing inflammation in the intestine. While the precise etiology of IBD remains unknown, genetics, the gut microbiome, environmental factors, and the immune system have all been shown to contribute to the disease pathophysiology. In recent years, attention has shifted towards the role that innate lymphoid cells (ILCs) may play in the dysregulation of intestinal immunity observed in IBD. ILCs are a group of heterogenous immune cells which can be found at mucosal barriers. They act as critical mediators of the regulation of intestinal homeostasis and the orchestration of its inflammatory response. Despite helper-like type 1 ILCs (ILC1s) constituting a particularly rare ILC population in the intestine, recent work has suggested that an accumulation of intestinal ILC1s in individuals with IBD may act to exacerbate its pathology. In this review, we summarize existing knowledge on helper-like ILC1 plasticity and their classification in murine and human settings. Moreover, we discuss what is currently understood about the roles that ILC1s may play in the progression of IBD pathogenesis.

Long-term effectiveness and safety of ustekinumab in bio-naïve and bio-experienced anti-tumor necrosis factor patients with Crohn's disease: a real-world multicenter Brazilian study

BACKGROUND

The effectiveness of ustekinumab (UST) in the treatment of Crohn's disease (CD) has been demonstrated in the pivotal Phase 3 UNITI 1 and 2 and IM-UNITI studies in both anti-TNF-naïve and anti-TNF-exposed patients. Given the selective nature of pivotal trial designs, real-world effectiveness and safety studies are warranted. We report our experience with UST treatment in a large, real-world multicenter cohort of Brazilian patients with CD.

METHODS

We performed a retrospective multicenter study including patients with CD, predominantly biologically refractory CD, who received UST. The primary endpoint was the proportion of patients in clinical remission at weeks 8, 24 and 56. Possible predictors of clinical and biological response/remission and safety outcomes were also assessed.

RESULTS

Overall, 245 CD (mean age 39.9 [15-87]) patients were enrolled. Most patients (86.5%) had been previously exposed to biologics. According to nonresponder imputation analysis, the proportions of patients in clinical remission at weeks 8, 24 and 56 were 41.0% (n = 98/239), 64.0% (n = 153/239) and 39.3% (n = 94/239), respectively. A biological response was achieved in 55.4% of patients at week 8, and 59.3% were in steroid-free remission at the end of follow-up. No significant differences in either clinical or biological remission were noted between bio-naïve and bio-experienced patients. Forty-eight patients (19.6%) presented 60 adverse events during the follow-up, of which 8 (13.3%) were considered serious adverse events (3.2% of 245 patients). Overall, a proximal disease location, younger age, perianal involvement, and smoking were associated with lower rates of clinical remission over time.

CONCLUSIONS

UST therapy was effective and safe in the long term in this large real-life cohort of Brazilian patients with refractory CD, regardless of previous exposure to other biological agents.

An Update on Current Pharmacotherapeutic Options for the Treatment of Ulcerative Colitis

The main goals of Ulcerative Colitis (UC) treatment are to both induce and maintain the clinical and endoscopic remission of disease, reduce the incidence of complications such as dysplasia and colorectal carcinoma and improve quality of life. Although a curative medical treatment for UC has not yet been found, new therapeutic strategies addressing specific pathogenetic mechanisms of disease are emerging. Notwithstanding these novel therapies, non-biological conventional drugs remain a mainstay of treatment. The aim of this review is to summarize current therapeutic strategies used as treatment for ulcerative colitis and to briefly focus on emerging therapeutic strategies, including novel biologic therapies and small molecules. To date, multiple therapeutic approaches can be adopted in UC and the range of available compounds is constantly increasing. In this era, the realization of well-designed comparative clinical trials, as well as the definition of specific therapeutic models, would be strongly suggested in order to achieve personalized management for UC patients.

Comparative effectiveness of second-line biological therapies for ulcerative colitis and Crohn’s disease in patients with prior failure of anti-tumour necrosis factor treatment

Background

Therapeutic options for inflammatory bowel disease (IBD) have increased since the introduction of tumour necrosis factor (TNF) inhibitors a few decades ago. However, direct comparisons of the effectiveness of second-line biological agents in patients with ulcerative colitis (UC) and Crohn’s disease (CD) are lacking.

Methods

Patients with UC or CD who experienced anti-TNF treatment failure and subsequently used vedolizumab, ustekinumab, or tofacitinib as a second-line drug were retrospectively recruited. The primary outcomes were the clinical remission rate at week 16 and the cumulative relapse rate 48 weeks after receiving induction therapy.

Results

A total of 94 patients with UC or CD experienced anti-TNF treatment failure and received vedolizumab (UC: 37; CD: 28), ustekinumab (CD: 16), or tofacitinib (UC: 13). The clinical remission rates were not significantly different between the vedolizumab and tofacitinib groups in UC patients (56.8% vs. 46.2%, p = 0.509). In CD patients, the clinical remission rates were not significantly different between the vedolizumab and ustekinumab groups (53.6% vs. 50.0%, p = 0.820). Moreover, the cumulative rates of clinical relapse were not significantly different between the vedolizumab and tofacitinib groups in UC patients and between the vedolizumab and ustekinumab groups in CD patients (p = 0.396 and p = 0.692, respectively). Safety profiles were also similar among the treatment groups in both UC and CD patients.

Conclusions

After prior anti-TNF therapy failure, vedolizumab and tofacitinib in UC patients and vedolizumab and ustekinumab in CD patients were not significantly different in terms of the efficacy in inducing and maintaining a clinical response.

Molecular docking and dynamics approach to in silico drug repurposing for inflammatory bowels disease by targeting TNF alpha

Inflammatory bowel disease is a chronic disorder of the large intestine with the prevalence of approximately 400 cases in 100000, and it is rising day by day. However, several drugs like sulfasalazine (composed of sulfapyridine and 5-aminosalicylic acid or 5-ASA), corticosteroids, and immunosuppressants manage the disease. But there are no absolute treatments for the pain and inflammation of the disease. TNFα is an important target, and drugs like infliximab and adalimumab have pharmacological potency but with pronounced toxicity. So, we choose this major target TNFα for the virtual screening of US-FDA-approved drugs for its repurposing using the in silico method. The protein TNFα (PDB ID: 2AZ5) with small molecule inhibitor and the US-FDA-approved drug molecules (from Zinc database) were first imported and prepared using Protein Preparation Wizard and LigPrep, respectively, followed by molecular docking, ADMET analysis and prime MMGBSA. After that, the drugs were shortlisted according to dock score, ADMET parameters and MM GBSA dG binding score. After that, the shortlisted drug molecules were subjected to an induced-fit docking analysis. Two of the most promising molecules, ZINC000003830957 (Iopromide) and ZINC000003830635 (Deferoxamine), were chosen for molecular dynamics simulation. Finally, the bioisosteric replacement was used to improve the ADMET properties of these molecules. This research provides an idea for drug exploration and computational tools for drug discovery in treating inflammatory bowel disease.Communicated by Ramaswamy H. Sarma.

Cell Type-Specific Induction of Inflammation-Associated Genes in Crohn’s Disease and Colorectal Cancer

Based on the rapid increase in incidence of inflammatory bowel disease (IBD), the identification of susceptibility genes and cell populations contributing to this condition is essential. Previous studies suggested multiple genes associated with the susceptibility of IBD; however, due to the analysis of whole-tissue samples, the contribution of individual cell populations remains widely unresolved. Single-cell RNA sequencing (scRNA-seq) provides the opportunity to identify underlying cellular populations. We determined the enrichment of Crohn’s disease (CD)-induced genes in a publicly available Crohn’s disease scRNA-seq dataset and detected the strongest induction of these genes in innate lymphoid cells (ILC1), highly activated T cells and dendritic cells, pericytes and activated fibroblasts, as well as epithelial cells. Notably, these genes were highly enriched in IBD-associated neoplasia, as well as sporadic colorectal cancer (CRC). Indeed, the same six cell populations displayed an upregulation of CD-induced genes in a CRC scRNA-seq dataset. Finally, after integrating and harmonizing the CD and CRC scRNA-seq data, we demonstrated that these six cell types display a gradual increase in gene expression levels from a healthy state to an inflammatory and tumorous state. Together, we identified cell populations that specifically upregulate CD-induced genes in CD and CRC patients and could, therefore, contribute to inflammation-associated tumor development.

Advances in the treatment of inflammatory bowel disease: Focus on polysaccharide nanoparticulate drug delivery systems

The complex pathogenesis of inflammatory bowel disease (IBD) explains the several hurdles for finding an efficient approach to cure it. Nowadays, therapeutic protocols aim to reduce inflammation during the hot phase or maintain remission during the cold phase. Nonetheless, these drugs suffer from severe side effects or poor efficacy due to low bioavailability in the inflamed region of the intestinal tract. New protocols based on antibodies that target proinflammatory cytokines are clinically relevant. However, besides being expensive, their use is associated with a primary nonresponse or a loss of response following a long administration period. Accordingly, many researchers exploited the physiological changes of the mucosal barrier for designing nanoparticulate drug delivery systems to target inflamed tissues. Others exploited biocompatibility and relative affordability of polysaccharides to test their intrinsic anti-inflammatory and healing properties in IBD models. This critical review updates state of the art on advances in IBD treatment. Data on using polysaccharide nanoparticulate drug delivery systems for IBD treatment are reviewed and discussed.

Alterations in Kynurenine and NAD+ Salvage Pathways during the Successful Treatment of Inflammatory Bowel Disease Suggest HCAR3 and NNMT as Potential Drug Targets

A meta-analysis of publicly available transcriptomic datasets was performed to identify metabolic pathways profoundly implicated in the progression and treatment of inflammatory bowel disease (IBD). The analysis revealed that genes involved in tryptophan (Trp) metabolism are upregulated in Crohn’s disease (CD) and ulcerative colitis (UC) and return to baseline after successful treatment with infliximab. Microarray and mRNAseq profiles from multiple experiments confirmed that enzymes responsible for Trp degradation via the kynurenine pathway (IDO1, KYNU, IL4I1, KMO, and TDO2), receptor of Trp metabolites (HCAR3), and enzymes catalyzing NAD⁺ turnover (NAMPT, NNMT, PARP9, CD38) were synchronously coregulated in IBD, but not in intestinal malignancies. The modeling of Trp metabolite fluxes in IBD indicated that changes in gene expression shifted intestinal Trp metabolism from the synthesis of 5-hydroxytryptamine (5HT, serotonin) towards the kynurenine pathway. Based on pathway modeling, this manifested in a decline in mucosal Trp and elevated kynurenine (Kyn) levels, and fueled the production of downstream metabolites, including quinolinate, a substrate for de novo NAD⁺ synthesis. Interestingly, IBD-dependent alterations in Trp metabolites were normalized in infliximab responders, but not in non-responders. Transcriptomic reconstruction of the NAD⁺ pathway revealed an increased salvage biosynthesis and utilization of NAD⁺ in IBD, which normalized in patients successfully treated with infliximab. Treatment-related changes in NAD⁺ levels correlated with shifts in nicotinamide N-methyltransferase (NNMT) expression. This enzyme helps to maintain a high level of NAD⁺-dependent proinflammatory signaling by removing excess inhibitory nicotinamide (Nam) from the system. Our analysis highlights the prevalent deregulation of kynurenine and NAD⁺ biosynthetic pathways in IBD and gives new impetus for conducting an in-depth examination of uncovered phenomena in clinical studies.

Sam68 contributes to intestinal inflammation in experimental and human colitis

Sam68 is an RNA-binding protein with an adaptor role in signal transduction. Our previous work identified critical proinflammatory and apoptotic functions for Sam68, downstream of the TNF/TNFR1 and TLR2/3/4 pathways. Recent studies have shown elevated Sam68 in inflamed tissues from rheumatoid arthritis and ulcerative colitis (UC) patients, suggesting that Sam68 contributes to chronic inflammatory diseases. Here, we hypothesized that deletion of Sam68 is protective against experimental colitis in vivo, via reductions in TNF-associated inflammatory signaling. We used Sam68 knockout (KO) mice to study the role of Sam68 in experimental colitis, including its contributions to TNF-induced inflammatory gene expression in three-dimensional intestinal organoid cultures. We also studied the expression of Sam68 and inflammatory genes in colon tissues of UC patients. Sam68 KO mice treated with an acute course of DSS exhibited significantly less weight loss and histopathological inflammation compared to wild-type controls, suggesting that Sam68 contributes to experimental colitis. Bone marrow transplants showed no pathologic role for hematopoietic cell-specific Sam68, suggesting that non-hematopoietic Sam68 drives intestinal inflammation. Gene expression analyses showed that Sam68 deficiency reduced the expression of proinflammatory genes in colon tissues from DSS-treated mice, as well as TNF-treated three-dimensional colonic organoids. We also found that inflammatory genes, such as TNF, CCR2, CSF2, IL33 and CXCL10, as well as Sam68 protein, were upregulated in inflamed colon tissues of UC patients. This report identifies Sam68 as an important inflammatory driver in response to intestinal epithelial damage, suggesting that targeting Sam68 may hold promise to treat UC patients.

Chronic tissue inflammation and metabolic disease

In this review, Lee and Olefsky discuss the characteristics of chronic inflammation in the major metabolic tissues and how obesity triggers these events, including a focus on the role of adipose tissue hypoxia and macrophage-derived exosomes.

Obesity is the most common cause of insulin resistance, and the current obesity epidemic is driving a parallel rise in the incidence of T2DM. It is now widely recognized that chronic, subacute tissue inflammation is a major etiologic component of the pathogenesis of insulin resistance and metabolic dysfunction in obesity. Here, we summarize recent advances in our understanding of immunometabolism. We discuss the characteristics of chronic inflammation in the major metabolic tissues and how obesity triggers these events, including a focus on the role of adipose tissue hypoxia and macrophage-derived exosomes. Last, we also review current and potential new therapeutic strategies based on immunomodulation.

Receptor-mediated targeted drug delivery systems for treatment of inflammatory bowel disease: Opportunities and emerging strategies

Inflammatory bowel disease (IBD) is a chronic intestinal disease with painful clinical manifestations and high risks of cancerization. With no curative therapy for IBD at present, the development of effective therapeutics is highly advocated. Drug delivery systems have been extensively studied to transmit therapeutics to inflamed colon sites through the enhanced permeability and retention (EPR) effect caused by the inflammation. However, the drug still could not achieve effective concentration value that merely utilized on EPR effect and display better therapeutic efficacy in the inflamed region because of nontargeted drug release. Substantial researches have shown that some specific receptors and cell adhesion molecules highly expresses on the surface of colonic endothelial and/or immune cells when IBD occurs, ligand-modified drug delivery systems targeting such receptors and cell adhesion molecules can specifically deliver drug into inflamed sites and obtain great curative effects. This review introduces the overexpressed receptors and cell adhesion molecules in inflamed colon sites and retrospects the drug delivery systems functionalized by related ligands. Finally, challenges and future directions in this field are presented to advance the development of the receptor-mediated targeted drug delivery systems for the therapy of IBD.

Dynamics of serum concentrations of antibodies to infliximab: a new approach for predicting secondary loss of response in inflammatory bowel diseases

BACKGROUND

Antibodies to infliximab (ATI) in serum are associated with secondary loss of response (LOR) to infliximab (IFX) therapy in patients with inflammatory bowel disease (IBD). However, feasible ATI-related predictors of therapy success are lacking and knowledge about individual ATI dynamics is limited. Therefore, this study analyzed whether ATI dynamics are able to predict LOR to IFX therapy and compared their predictive power with known predictors of LOR to IFX.

METHODS

This was a retrospective study of patients with Crohn's disease (CD) or ulcerative colitis (UC) on IFX maintenance therapy and proactive IFX and immunogenicity monitoring in an outpatient clinic in Germany. Slopes of ATI (S _ATI) and IFX levels (dynamic parameters) and medians of ATI, IFX, C-reactive protein, and fecal calprotectin (static parameters) were calculated over a defined period of time after ATI emergence. Dynamic and static parameters were analyzed for associations with end points infliximab discontinuation due to secondary LOR and total IFX discontinuation.

RESULTS

In all, 500 visits from 38 IBD patients (28 CD, 10 UC) with a median IFX maintenance duration of 68.2 weeks were evaluated. Grouping by S _ATI (ATI-N = ATI nondetectable, ATI- ↓  = negative S _ATI, ATI- ↑  = positive S _ATI) yielded significant differences for outcomes LOR (p = 0.004) and total IFX discontinuation (p = 0.01). Patients in the ATI-↓ group survived significantly longer LOR-free compared with the ATI-↑ group (p = 0.02). Cox regression confirmed S _ATI to be a significant risk factor for LOR (p = 0.002). An S _ATI cut-off of approximately 2.0 AU mL^-1 week^-1 was determined to predict LOR with 83.3% sensitivity and 93.8% specificity.

CONCLUSION

The ATI slope-based index S _ATI is a new feasible diagnostic predictor of LOR in IBD patients. S _ATI may facilitate quick therapeutic decisions after ATI emerge.

Translating Treg Therapy for Inflammatory Bowel Disease in Humanized Mice

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

Therapeutic use of specific tumour necrosis factor inhibitors in inflammatory diseases including COVID-19

Coronavirus disease 2019 (COVID-19) has caused significant devastation globally. Despite the development of several vaccines, with uncertainty around global uptake and vaccine efficacy, the need for effective therapeutic agents remains. Increased levels of cytokines including tumour necrosis factor are significant in the pathogenesis of COVID-19 and associated with poor outcomes including ventilator requirement and mortality. Repurposing tumour necrosis factor blocker therapy used in conditions such as rheumatoid arthritis and inflammatory bowel disease seems promising, with early feasibility data showing a reduction in circulation of pro-inflammatory cytokines and encouraging the evaluation of such interventions in preventing disease progression and clinical deterioration in patients with COVID-19. Here, we examine the biological activities of tumour necrosis factor inhibitors indicative of their potential in COVID-19 and briefly outline the randomised control trials assessing their benefit-risk profile in COVID-19 therapy.

An Update for Pharmacologists on New Treatment Options for Inflammatory Bowel Disease: The Clinicians' Perspective

The introduction of anti-tumor necrosis factor antibodies resulted in a considerable expansion of the options available for the treatment of inflammatory bowel disease. Unfortunately, approximately one third of treated patients do not respond to these modalities, and drug efficacy may be lost over time. These drugs are also associated with contraindications, adverse events, and intolerance. As such, there is an ongoing need for new therapeutic strategies. Despite several recent advances, including antibodies against pro-inflammatory cytokines and cell adhesion molecules, Janus kinase inhibitors, and modulators of sphingosine-1-phosphate receptors, not all problems associated with IBD have been solved. In this manuscript, we review the current state of development of several new treatment options. Ongoing evaluation will require specific proof of efficacy as well as direct comparisons with established treatments. Results from head-to-head comparisons are needed to provide clinicians with critical information on how to formulate effective therapeutic approaches for each patient.

Crohn's disease: a population-based study of surgery in the age of biological therapy

PURPOSE

Despite primary conservative therapy for Crohn's disease, a considerable proportion of patients ultimately needs to undergo surgery. Presumably, due to the increased use of biologics, the number of surgeries might have decreased. This study aimed to delineate current case numbers and trends in surgery in the era of biological therapy for Crohn's disease.

METHODS

Nationwide standardized hospital discharge data (diagnosis-related groups statistics) from 2010 to 2017 were used. All patients who were admitted as inpatient Crohn's disease cases in Germany were included. Time-related development of admission numbers, rate of surgery, morbidity, and mortality of inpatient Crohn's disease cases were analyzed.

RESULTS

A total number of 201,165 Crohn's disease cases were included. Within the analyzed time period, the total number of hospital admissions increased by 10.6% (n = 23,301 vs. 26,069). While gender and age distribution remained comparable, patients with comorbidities such as stenosis formation (2010: 10.1%, 2017: 13.4%) or malnutrition (2010: 0.8%, 2017: 3.2%) were increasingly admitted. The total number of all analyzed operations for Crohn's disease increased by 7.5% (2010: n = 1567; 2017: n = 1694). On average, 6.8 ± 0.2% of all inpatient patients received ileocolonic resections. Procedures have increasingly been performed minimally invasive (2010: n = 353; 2017: n = 687). The number of postoperative complications remained low.

CONCLUSION

Despite the development of novel immunotherapeutics, the number of patients requiring surgery for Crohn's disease remains stable. Interestingly, patients have been increasingly hospitalized with stenosis and malnutrition. The trend towards more minimally invasive operations has not relevantly changed the rate of overall complications.

Bioactive lipids in inflammatory bowel diseases - From pathophysiological alterations to therapeutic opportunities

Inflammatory bowel diseases (IBDs), such as Crohn's disease and ulcerative colitis, are lifelong diseases that remain challenging to treat. IBDs are characterized by alterations in intestinal barrier function and dysregulation of the innate and adaptive immunity. An increasing number of lipids are found to be important regulators of inflammation and immunity as well as gut physiology. Therefore, the study of lipid mediators in IBDs is expected to improve our understanding of disease pathogenesis and lead to novel therapeutic opportunities. Here, through selected examples - such as fatty acids, specialized proresolving mediators, lysophospholipids, endocannabinoids, and oxysterols - we discuss how lipid signaling is involved in IBD physiopathology and how modulating lipid signaling pathways could affect IBDs.