Intestinal fibrosis is one of the most threatening complications of Crohn's disease (CD). Although our previous study identified the profibrotic role of amphiregulin (AREG) in intestinal fibrosis, the underlying molecular mechanisms remain poorly understood. This study aimed to elucidate the mechanisms by which AREG mediates intestinal fibrosis. Specimens from stenotic and non-stenotic lesions in CD patients were collected, alongside normal specimens from individuals with intestinal diverticula, for the assessment of AREG levels. A dextran sulfate sodium (DSS)-induced chronic colitis model was established in wild type (WT) and Areg-knockout (Areg-/-) mice. RNA-sequencing (RNA-seq) was performed on human intestinal fibroblasts (HIFs) to elucidate the underlying mechanisms. Additionally, the single-cell RNA-seq data of full-thickness CD, obtained from Prof. Rieder, was reanalyzed. Elevated levels of AREG were detected at stenotic sites in patients with CD. Areg-/- colitis mice exhibited decreased intestinal fibrosis. AREG enhanced the activation and proliferation of HIFs by activating the PI3K/AKT pathway. The inhibitor of the PI3K/AKT pathway effectively suppressed AREG-induced activation and proliferation of HIFs and attenuated colitis-associated fibrosis in mice. In stricturing CD, inflammatory monocytes exhibited higher AREG levels, contributing to the activation and proliferation of intestinal fibroblasts. Adoptive transfer of Ly6chi inflammatory monocytes from WT but not Areg-/- mice exacerbated intestinal fibrosis in DSS-induced colitis mice. These findings reveal that inflammatory monocytes derived-AREG promotes intestinal fibrosis in experimental colitis and CD patients by promoting intestinal fibroblasts activation and proliferation through the PI3K/AKT pathway. Inflammatory monocytes serve as the primary source of AREG in stricturing CD, critically mediating fibroblast-related fibrotic progression in an AREG-dependent manner. Therefore, AREG, the PI3K/AKT pathway and inflammatory monocytes may serve as potential therapeutic targets for intestinal fibrosis in CD.

B cells display several immunoregulatory mechanisms including the production of interleukin-10. Ectonucleotidases like CD39 and CD73 influence immune homeostasis by metabolizing eATP and generating immunosuppressive adenosine. The major objective was to examine the expression of those immunoregulatory molecules on B-cell subsets, and, more specifically, to determine their association with an infliximab (IFX) treatment in a pediatric inflammatory bowel disease (IBD) cohort. 42 IBD patients were assessed for IFX response after 12 mo of therapy and compared against 14 healthy controls (HC). Although IL10-producing plasmablasts were decreased in IFX nonresponders (NRS), we detected an up-regulation of CD39 on plasmablasts and increased fractions of CD39/CD73-co-expressing naïve and memory B cells in responding patients (RS). In addition, B cells of responders proved to have superior ATP degradation capacities and adenosine production before therapy initiation compared with NRS and HC. Moreover, IFX nonresponders had a marked deficiency of α4β7hi plasmablasts, whereas both cohorts had fewer CCR9-expressing plasmablasts. Consequently, CD39+ plasmablasts were decreased in biopsies of inflamed mucosal tissues, especially in IFX nonresponders. Our results highlight the regulatory potential of CD39/CD73-expressing B cells in pediatric IBD and suggest CD39+ plasmablasts as a potential determinant of a successful immunosuppressive therapy with IFX.

Recent advances in machine learning have revolutionized molecular design; however, a gap remains in integrating generative models with physics-based simulations to develop functional modulators, such as stable peptides, for challenging targets like the interleukin-23 receptor (IL23R) and its associated cytokine, interleukin-23 (IL23). The IL23R/IL23 axis plays a critical role in autoimmune diseases, and current therapies have largely been limited to antibody-based approaches. To address this gap, we employed a hybrid computational approach that combines Long Short-Term Memory (LSTM) networks for peptide generation, a Gated Recurrent Unit (GRU)-based classifier for anti-inflammatory property prediction, and molecular dynamics (MD) simulations to assess structural dynamics, binding interactions, as well as key properties such as binding affinity and stability. Using this hybrid framework, we identified novel inhibitory peptides, particularly P4, with an IC50 of 2 μM. Systematic experimental validation established its inhibitory activity, elucidated its binding mechanism, confirmed its specificity toward the IL23R, and demonstrated its ability to disrupt IL23R/IL23 interaction. This integrated approach highlights the significant potential of combining deep learning and simulations to accelerate the identification of peptide-based therapeutics targeting key protein targets.

The association between vascular cell adhesion molecule-1 (VCAM-1) expression and intestinal mucosal inflammation and between VCAM-1 expression and the clinical course in patients with ulcerative colitis (UC) remains unclear. Therefore, we investigated not only the association between mucosal VCAM-1 expression and mucosal inflammation but also its association with subsequent relapse in UC patients with clinical remission.

Fifty-eight patients with UC in clinical remission and 16 patients in clinical active who visited Kyoto Prefectural University of Medicine for a 2-year follow-up period were included. VCAM-1 expression was compared between patients who subsequently relapsed and those who remained in remission, and it was examined in relation to endoscopic findings, histological activity, and cytokine expression. We also investigated the expression of mucosal addressin cell adhesion molecule-1 (MAdCAM-1).

VCAM-1 was associated with clinical disease activity and endoscopic severity and was significantly elevated in histologically active mucosa compared with inactive mucosa. VCAM-1 expression co-localized with MAdCAM-1 in the mucosal and submucosal microvessels of the colon and was significantly higher in the relapse group than in the remission group. Similar results were observed for MAdCAM-1 expression. VCAM-1 expression levels were also closely correlated with those of several other cytokines.

VCAM-1 expression in the colonic mucosa of patients with UC is associated with mucosal inflammation and subsequent relapse. These results suggest that VCAM-1 may serve as a marker for relapse and therapeutic effectiveness in UC, and that treatment targeting α4 integrin is efficient and rational.

Mechanisms by which mucosal regeneration is abrogated in inflammatory bowel disease (IBD) are still under investigation, and a role for an intestinal stem cell (ISC) defect is now emerging. Herein, we report an abnormal ISC death that occurs in Crohn's disease, which exacerbates colitis, limits ISC-dependent mucosal repair, and is controlled through the death factor Transmembrane protein 219 (TMEM219). Large alterations in TMEM219 expression were observed in patients with Crohn's disease, particularly in those with active disease and/or those who were nonresponders to conventional therapy, confirming that TMEM219 signaling is abnormally activated and leads to failure of the mucosal regenerative response. Mechanistic studies revealed a proapoptotic TMEM219-mediated molecular signature in Crohn's disease, which associates with Caspase-8 activation and ISC death. Pharmacological blockade of the IGFBP3/TMEM219 binding/signal with the recombinant protein ecto-TMEM219 restored the self-renewal abilities of miniguts generated from patients with Crohn's disease in vitro and ameliorated DSS-induced and T cell-mediated colitis in vivo, ultimately leading to mucosal healing. Genetic tissue-specific deletion of TMEM219 in ISCs in newly generated TMEM219fl/flLGR5cre mice revived their mucosal regenerative abilities both in vitro and in vivo. Our findings demonstrate that a TMEM219-dependent ISC death exacerbates colitis and that TMEM219 blockade reestablishes intestinal self-renewal properties in IBD.

A mutualistic co-evolution exists between the host and its associated microbiota in the human body. Bacteria establish ecological niches in various tissues of the body, locally influencing their physiology and functions, but also contributing to the well-being of the whole organism through systemic communication with other distant niches (axis). Emerging evidence indicates that when the composition of the microbiota inhabiting the niche changes toward a pathogenic state (dysbiosis) and interactions with the host become unbalanced, diseases may present. In addition, imbalances within a single niche can cause dysbiosis in distant organs. Current research efforts are focused on elucidating the mechanisms leading to dysbiosis, with the goal of restoring tissue homeostasis. In vitro models can provide critical experimental platforms to address this need, by reproducing the niche cyto-architecture and physiology with high fidelity. This review surveys current in in vitro host-microbiota research strategies and provides a roadmap that can guide the field in further developing physiologically relevant in vitro models of ecological niches, thus enabling investigation of the role of the microbiota in human health and diseases. Lastly, given the Food and Drug Administration Modernization Act 2.0, this review highlights emerging in vitro strategies to support the development and validation of new therapies on the market.

The global prevalence of inflammatory bowel disease (IBD) has significantly increased in recent decades. IBD is a long-term, recurring, gastrointestinal inflammatory condition that mainly comprises two primary clinical types: ulcerative colitis and Crohn's disease. The current treatment paradigm for IBD primarily focuses on symptom management. However, this approach does not support mucosal epithelial repair, maintenance of barrier homeostasis, or regulation of biological functions in the gut. Conventional therapies rely on the frequent use of high-dose medications, including antibiotics, nonsteroidal anti-inflammatory drugs, biological agents, and immunomodulators. Recently, mesenchymal stem/stromal cells (MSCs) have gained interest in tissue regeneration owing to their unique ability to differentiate and secrete regulatory factors, including extracellular vesicles (EVs), which play crucial roles in abnormal organization. Various routes of administration have been explored in preclinical and clinical studies to deliver MSCs from diverse tissue sources. The routes include intraperitoneal, intravenous, and local (intracolonic or rectal) delivery. The MSCs employed were obtained from various tissues, including bone marrow, umbilical cord, and adipose tissue. This article reviews the research framework for the application of MSCs and EVs secretion in the treatment of IBD, emphasizing key immunological effects, such as immune microenvironment regulation, intestinal barrier stabilization, and therapeutic approaches targeting intestinal barrier disorders. The discussion primarily focuses on the advantages of MSCs over other biologics, impairment of gut mucosal tissue-resident mesenchymal stem cells in IBD development, immune targets (at the cellular and molecular levels) within the framework of IBD, and the reparative effects of MSCs in the microenvironment of IBD. We aimed to present an overview of the current trends in MSC research and therapy, as well as to identify the challenges and future directions that must be addressed to advance research on MSC-mediated therapeutic strategies for IBD.

Real-world studies on vedolizumab in inflammatory bowel disease (IBD) are often limited by small sample size and short follow-up. In this study, we investigated the 2-year effectiveness and safety of vedolizumab in patients with IBD, and applied eXplainable Artificial Intelligence (XAI) to identify predictors of both.

The Long-term Italian Vedolizumab Effectiveness (LIVE) study is multicentric, ambispective, observational study enrolling 1111 IBD patients (563 Crohn's disease, CD, 542 ulcerative colitis, UC). Steroid-free clinical remission (SFCR) at 24 months was the primary endpoint. A XAI model (eXtreme Gradient Boosting, XGB) was applied to identify the main clinical predictors of SFCR and development of adverse events (AEs).

Rates of SFCR at 24 months were 31.6 % and 39.7 % in CD and UC patients, and 0.14 AEs per patient-year was recorded. On XGB analysis, previous exposure to anti-TNFα and older age were the most important drivers for the prediction of SFCR; lower baseline CRP levels and fewer comorbidities were the most important features associated with no development of AEs.

Vedolizumab is effective and safe in IBD patients. XAI yielded promising results in identifying the most important predictors of SFCR and development of AEs.

The enteric nervous system (ENS) is a highly conserved, yet complicated network of neurons and glial cells located throughout the gut wall that controls digestive processes and gastrointestinal (GI) homeostasis. The intestinal epithelium, the immune system, and the gut microbiota are just a few examples of the cellular networks that the ENS interacts with on a variety of levels to maintain GI function. The presence or absence of nutrients in the intestinal lumen may cause short- and/or long-term changes in neurotransmitter expression, excitability, and neuronal survival, which ultimately affect gut motility, secretion, and permeability. Hence, the ENS should be identified as a key factor in initiating coordinated responses to nutrients. In this review we summarize current knowledge on nutrient-dependent ENS activity and how ENS secondary to nutrition may affect likelihood of developing inflammatory bowel disease. Our findings highlight that nutrients interact with enteroendocrine cells in the gut, triggering hormone secretion that plays a crucial role in signaling food-related information to the brain and regulating metabolic processes such as feeding behavior, insulin secretion, and energy balance; however, the complex interactions between nutrients, the ENS, and the immune system require further research to understand their contributions to GI disorders and potential therapeutic applications in treating obesity and metabolic diseases. Lay Summary: The enteric nervous system (ENS) controls digestion and interacts with nutrients in the gut to regulate processes like gut movement and hormone release, affecting metabolism and overall gut health. This review highlights the need for further research on how nutrient-ENS interactions contribute to conditions like inflammatory bowel disease, obesity, and metabolic disorders.

Gastrointestinal disorders originate in the gastrointestinal tract (GIT), and the therapies can benefit from direct access to the GIT achievable through the oral route. RNA molecules show great promise therapeutically but are highly susceptible to degradation and often require a carrier for cytoplasmic access. Lipid nanoparticles (LNPs) are clinically proven drug-delivery agents, primarily administered parenterally. An ideal Orally Delivered (OrD) LNP formulation should overcome the diverse GI environment, successfully delivering the drug to the site of action. A versatile OrD LNP formulation has been developed to encapsulate and deliver siRNA and mRNA in this paper. The formulations were prepared by the systematic addition of cationic lipid to the base LNP formulation, keeping the total of cationic lipid and ionizable lipid to 50 mol%. Biorelevant media stability depicted increased resistance to bile salt mediated destabilization upon the addition of the cationic lipid, however the in vitro efficacy data underscored the importance of the ionizable lipid. Based on this, OrD LNP was selected comprising of 20% cationic lipid and 30% ionizable lipid. Further investigation revealed the enhanced efficacy of OrD LNP in vitro after incubation in different dilutions of fasted gastric, fasted intestinal media, and mucin. Confocal imaging and flow cytometry confirmed uptake while in vivo studies demonstrated efficacy with siRNA and mRNA as payloads. Taken together, this research introduces OrD LNP to deliver nucleic acid locally to the GIT.

Commencing with the breakdown of the intestinal barrier, various pathogenic factors, such as dysbiosis of the gut microbiota, harmful inflammatory cytokines, and immune system imbalance, collectively contribute to the development of colitis. Numerous interventions focusing on single factors have been developed to provide short-term therapeutic benefits, but the continued existence of unresolved pathogenic factors can lead to disease exacerbation. Here we have designed a multicomponent system-inulin microspheres encapsulating selenium-containing nanomicelles, aiming to tackle the multiple factors associated with colitis. This micro-nano drug delivery platform achieves sequential release of drugs in the inflamed colon, with each component of the system functioning independently and jointly. The outer layer of inulin supplies nutrients for probiotics. The inner core comprises selenocystamine and 3-oxolithocholic acid, which polarize macrophages towards an anti-inflammatory phenotype and regulate adaptive immunity by inhibiting TH17-cell differentiation, respectively. In an acute colitis mouse model, this therapeutic system ameliorates colonic inflammation, enhances the abundance of gut microbiota, and modulates the mucosal immune system, showing potential in preventing colitis.

Inflammation is an essential physiological defense mechanism against harmful stimuli, yet dysregulated inflammatory responses are closely associated with the pathogenesis of numerous acute and chronic diseases. Recent advances highlight the remarkable anti-inflammatory potential of bioactive macromolecules, particularly cyclodextrins (CDs) and their engineered derivatives, which are emerging as promising therapeutic agents. This review systematically introduces different CDs and CD-derived macromolecules that demonstrate anti-inflammatory properties, with emphasis on their molecular mechanisms of action. Native CDs exhibit direct therapeutic effects through host-guest interactions, enabling selective sequestration of pathogenic components such as cholesterol crystals and proteins that drive inflammatory cascades. Moreover, chemically modified CD derivatives incorporating functional groups demonstrate enhanced capabilities in neutralizing inflammatory mediators and modulating immune cell responses. This work further discusses the expanding therapeutic applications of these macromolecules across diverse inflammatory conditions, ranging from acute tissue injuries to chronic autoimmune disorders. Finally, this work critically analyzes the crucial challenges and emerging opportunities in translating CD-based macromolecular therapies into clinical practice, addressing key considerations in biocompatibility, targeted delivery, and therapeutic efficacy optimization.

This study aimed at investigating the effects of pomegranate juice (POMJ) consumption on inflammatory biomarkers and gene expression in patients with inflammatory bowel disease (IBD) in clinical remission. In this randomized, placebo-controlled trial, 16 subjects with IBD in remission consumed POMJ or placebo for 12 weeks. POMJ consumption significantly reduced fecal calprotectin (FC) and plasma endotoxin levels. Transcriptomic analysis of peripheral blood mononuclear cells revealed upregulation of genes involved in mucosal immunity, including aryl hydrocarbon receptor (AHR), neutrophil cytosolic factor 4 (NCF4), and nuclear factor, interleukin 3 regulated (NFIL3). Urolithin metabotypes were predominantly of the B type, associated with intestinal dysbiosis. No significant changes were observed in serum inflammatory markers or colonic mucosal cytokine expression. POMJ consumption reduced markers of intestinal inflammation and modulated gene expression related to mucosal immunity and barrier function in patients with IBD. These findings suggest the potential of POMJ as a beneficial dietary intervention for maintaining remission in IBD, highlighting the promise of targeted nutritional strategies in managing chronic inflammatory conditions. Further research is needed to elucidate the long-term clinical implications of these molecular changes. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT03000101.

Inflammatory bowel diseases (IBD) are chronic, remitting, and relapsing conditions of the gastrointestinal tract with incompletely elucidated etiology. The anti-TNF-α mAbs represent one of aflash nanocomplexation and flash nanoprecipitation process, resulting in particles with a narrow size distribution and tunable release profile, with the longest in vitro release lasting over four months. These mAb-releasing NPs are then incorporated into hyaluronic acid hydrogel microparticles (MPs) to enhance tissue retention, thus extending the duration of mAb release in vivo. A single i.m. injection of the LAI can maintain the serum mAb level above the therapeutically effective concentration for over 100 days in healthy mice. In a 9-week study using a dextran sulfate-induced chronic colitis model, the anti-TNF-α LAI formulation demonstrates substantial therapeutic efficacy and a better safety profile than free mAb injections. This work demonstrates the effectiveness of this LAI system in maintaining a persistent serum mAb level and its potential as a versatile, safer, and effective delivery system for antibody therapeutics.

We utilized patient samples from the large, phase 2b/3 SELECTION trial to identify circulating biomarkers of ulcerative colitis (UC) and potential early mediators of filgotinib treatment effects.

Samples were collected at baseline and during the induction phase of the SELECTION trial. Evaluated biomarkers comprised serum and stool proteins (measured by enzyme-linked immunosorbent assay), whole-blood cell counts, and whole-blood RNA-seq-derived gene-expression factors identified via exploratory factor analysis. Biomarker levels were assessed by baseline disease severity (endoscopy/bleeding/stool and Mayo Clinic Score) and biologic status (naive vs experienced). Effects of filgotinib on biomarker levels, including week 4 biomarker changes that may mediate week 10 clinical improvements, were assessed.

The biomarker analysis set included 598 biologic-naive patients and 592 biologic-experienced patients. Systemic inflammatory biomarkers (C-reactive protein [CRP], interleukin-6 [IL-6], serum amyloid A [SAA], and platelet cell counts) had the strongest positive correlations with baseline UC disease severity. CRP, IL-6, SAA, and neutrophil activation biomarkers (including neutrophil gelatinase-associated lipocalin [NGAL], tumor necrosis factor ɑ, and oncostatin M [OSM]), as well as platelet, neutrophil, and monocyte cell counts were increased in biologic-experienced versus biologic-naive patients. Gene-expression-derived plasmablast and cell proliferation factors were positively correlated with disease severity; B cell, T-cell activation, and plasmacytoid dendritic cell factors were negatively correlated. Filgotinib reduced nearly all proinflammatory biomarkers correlated with baseline UC disease activity; reduced SAA, CRP, IL-6, NGAL, and OSM at week 4 were identified as mediators of improved week 10 clinical scores.

Filgotinib significantly impacted circulating biomarkers related to UC pathology. Several proinflammatory and neutrophil activation biomarkers may be early mediators of filgotinib treatment effects.

NCT02914522.

Inflammation can generate pathogenic Th17 cells and cause an inflammatory dysbiosis. In the context of inflammatory bowel disease (IBD), these inflammatory Th17 cells and dysbiotic microbiota may perpetuate injury to intestinal epithelial cells. However, many models of IBD like T-cell transfer colitis and IL-10-/- mice rely on the absence of regulatory pathways, so it is difficult to tell if inflammation can also induce protective Th17 cells.

We subjected C57BL6, RAG1-/-, or JH-/- mice to systemic or gastrointestinal (GI) Citrobacter rodentium (Cr). Mice were then subjected to 2.5% dextran sodium sulfate (DSS) to cause epithelial injury. Fecal microbiota transfer was performed by bedding transfer and co-housing. Flow cytometry, qPCR, and histology were used to assess mucosal and systemic immune responses, cytokines, and tissue inflammation. 16s sequencing was used to assess gut bacterial taxonomy.

Transient inflammation with GI but not systemic Cr was protective against subsequent intestinal injury. This was replicated with sequential DSS collectively indicating that transient inflammation provides tissue-specific protection. Inflammatory Th17 cells that have a tissue-resident memory (TRM) signature expanded in the intestine. Experiments with reconstituted RAG1-/-, JH-/- mice, and cell trafficking inhibitors showed that inflammation-induced Th17 cells were required for protection. Fecal microbiota transfer showed that the inflammation-trained microbiota was necessary for protection, likely by maintaining protective Th17 cells in situ.

Inflammation can generate protective Th17 cells that synergize with the inflammation-trained microbiota to provide host resiliency against subsequent injury, indicating that inflammation-induced Th17 TRM T cells are heterogenous and contain protective subsets.

Eosinophils are granulocytes involved in the effector phase of type 2 T cell immune responses, which are elevated in inflammatory conditions like ulcerative colitis (UC) and other allergic diseases. UC is a chronic inflammatory colon disease, marked by excessive eosinophil infiltration and elevated Th2 cytokines, which contribute to mucosal inflammation and tissue damage. Dietary factors, including certain organic acids, can influence UC progression by modulating gut immune responses. This research is the first to explore the dose-dependent effects of tartaric acid (TA), a naturally occurring organic acid widely used in the food industry, on eosinophil activation and Th2 cytokine response in both normal mice and a dextran sulfate sodium (DSS)-induced colitis model. Normal mice were treated with TA at varying doses (5 µg, 25 µg, and 50 µg/mouse/day), while colitis mice received 50 µg TA. Eosinophil activation markers (CD11b+, SiglecF+, and CCR3+), Th2 cytokines (IL-4, IL-13, and IL-31), and IL-17 were assessed in peripheral blood leukocytes, lymph nodes, and splenocytes using flow cytometry. Additionally, mRNA expression levels of eosinophil-associated chemokines and cytokines in the splenocytes were quantified with real-time qPCR. Our results demonstrate a dose-dependent effect of TA, with the highest dose (50 µg) significantly increasing eosinophil activation markers, Th2 cytokines, IL-17, and mRNA expression of SiglecF, CCL11, and toll-like receptor 4 in normal mice. In colitis mice, treatment with 50 µg TA showed marked increases in IL-13 levels compared to those of untreated colitis mice, reflecting increased eosinophil recruitment to inflamed tissues. Moreover, mRNA expression of IL-5Rα was elevated in normal mice and colitis mice administered with TA. These results suggest that TA enhances eosinophil proliferation, the upregulation of their regulatory molecules, and Th2 immune profiles, potentially worsening the severity of colitis.

Inflammatory bowel diseases (IBD) affect both enteric neurons and enteric glia, with tumor necrosis factor-alpha (TNF-α) playing a role as an inflammatory mediator.

Analyze the effects of the anti-TNF monoclonal antibody on the myenteric plexus in an experimental model of colitis.

C57BL/6 mice received 3% dextran sodium sulfate (DSS) in drinking water for 7 days in both the DSS and DSS + ADA groups. The Sham group received water. The DSS + ADA group received ADA anti-TNF-α on day 2 of DSS intake. The ADA group was given water throughout the period and received an anti-TNF-α injection on day 2. The study evaluated the number of neurons per ganglion, and the area of the neuronal nitric oxide synthase (nNOS), choline acetyltransferase (ChAT), pan-neuronal marker (PGP9.5), and tumor necrosis factor receptor 2 (TNFR2) immunoreactive (-ir). Double labeling of PGP9.5 with an enteric glial marker (GFAP) was also performed.

DSS successfully induced experimental colitis (EC). TNFR2 was detected in the myenteric neurons in all groups. EC affected the enteric neurons, showing a decrease in the number of TNFR2-ir, ChAT-ir, nNOS-ir, and PGP9.5-ir neurons, whereas enteric glial cells increased in both the DSS and DSS + ADA groups. The DSS + ADA group showed number of nNOS-ir, ChAT-ir, and PGP9.5-ir neurons per ganglion similar to Sham group. EC also affected the neuronal profile, resulting in smaller areas in the DSS and DSS + ADA groups.

Myenteric neurons are immunoreactive to the TNFR2. DSS altered the myenteric plexus, and anti-TNF monoclonal antibody treatment proved effective against EC due to preventing the pathology from developing.

Shengjiang Xiexin Decoction (SJXXD) is a recognized formulation in traditional Chinese medicine that is commonly employed in diarrhea treatment. It has the potential to be a viable alternative for treating ulcerative colitis (UC), but its therapeutic effects and mechanisms remain unclear.

This study aims to explore the effects and underlying mechanism of SJXXD in a mouse model of UC induced by dextran sulfate sodium (DSS).

The components of SJXXD were analyzed using HPLC-Q/TOF-MS. UC mice model was established by freely drinking of 3% DSS, and SJXXD was administered as an intervention. After 7 days, body weight change, diarrhea, blood stools, colon length, cytokine levels, and key barrier proteins were evaluated to assess the therapeutic effect of SJXXD on UC. Additionally, transcriptome sequencing, quantitative polymerase chain reaction (qPCR), western blotting, intestinal organoids, 16S rRNA sequencing, and heat correlation analysis were employed to investigate the potential mechanisms of SJXXD on treating UC.

SJXXD significantly inhibited weight loss, reduce diarrhea and bloody stools, lower disease activity index (DAI) score, suppressed inflammatory cell infiltration and cytokines secretion in colonic tissues in UC mice. Additionally, SJXXD also enhances the expression of tight junction and mucins. Transcriptome sequencing results indicate that SJXXD primarily activates the Wnt/β-Catenin pathway, thereby enhancing the expression of genes linked to intestinal stem cells and intestinal regeneration markers. At phylum level, SJXXD significantly increases the relative abundance of Verrucomicrobiota, while inhibiting Campylobacterota and Fusobacteriota. Importantly, the relative abundance of these bacterial phyla is significantly correlated with UC and Wnt/β-Catenin signaling pathway.

These results indicate that SJXXD can significantly treat DSS-induced mouse UC model by activating the Wnt/β-Catenin pathway and modulating intestinal flora. SJXXD may serve as a promising therapeutic approach for the management of UC.

Tissue-resident memory T (TRM) cells are a specialized T cell population that reside in tissues and provide a rapid protective response upon activation. Here, we showed that human and mouse CD4+ TRM cells existed in a poised state and stored messenger RNAs encoding proinflammatory cytokines without protein production. At steady state, cytokine mRNA translation in TRM cells was suppressed by the integrated stress response (ISR) pathway. Upon activation, the central ISR regulator, eIF2α, was dephosphorylated and stored cytokine mRNA was translated for immediate cytokine production. Genetic or pharmacological activation of the ISR-eIF2α pathway reduced cytokine production and ameliorated autoimmune kidney disease in mice. Consistent with these results, the ISR pathway in CD4+ TRM cells was downregulated in patients with immune-mediated diseases of the kidney and the intestine compared to healthy controls. Our results indicated that stored cytokine mRNA and translational regulation in CD4+ TRM cells facilitate rapid cytokine production during local immune response.

The interleukin-17 (IL-17) mediated aberrant immune-inflammatory response plays a paramount role in ulcerative colitis (UC). γδT17 cells are one of the critical sources of IL-17, but the role they play in UC remains under debate.

To clarify the role of γδT17 cells in patients with mild-to-moderate UC.

A single-centre observational pragmatic study was conducted on patients with UC who attended the outpatient and inpatient departments of Xiyuan Hospital of the China Academy of Traditional Chinese Medicine from September 2020 to December 2022. The research population consisted of two groups of adult patients. The first group consisted of healthy volunteers with no significant abnormalities on colonoscopy, and the other group consisted of patients with mild-to-moderate ulcerative colitis. Serum samples from healthy volunteers and patients with UC were collected for the detection of relevant inflammatory factors. Moreover, five colon mucosa samples were randomly selected from each group for testing and analyses.

An increased number of γδT17 cells and hyperactivation of the NLR family pyrin domain containing 3/IL-1β signaling pathway were observed in colonic mucosal tissues from patients with UC.

Hyperactivation of the NLR family pyrin domain containing 3/IL-1β signaling pathway promotes the activation of γδT17 cells in colonic mucosal tissues of patients with UC.

Electrogenic Na+/HCO3- co-transporter 1 (NBCe1) plays a pivotal role in epithelial bicarbonate transport involved in the maintenance of the intestinal mucus barrier. However, the specific role of NBCe1 in colitis remains unknown.

NBCe1 was identified by bioinformatics analysis methods including GO/KEGG/GSEA, protein-protein interaction (PPI) network analysis, immune infiltration analysis, and Mendelian randomization (MR) analysis. Expression level of NBCe1 was detected in patients with IBD and in DSS-induced colitis mice. The role of NBCe1 in intestinal mucus barrier and colitis was accessed by S0859 pretreatment in DSS model. The function of NBCe1 and related bicarbonate secretion were evaluated using short-circuit current (Isc) measurements in Ussing chamber system.

Bioinformatic analyses indicated that SLC4A4 (NBCe1) was a signature gene in bicarbonate transport implicated in ulcerative colitis (UC) development and was negatively associated with the risk of UC. NBCe1's expression was significantly diminished in colonic mucosa of UC patients and DSS-treated mice. More severe intestinal inflammation and impaired mucus barrier were observed in S0859-treated mice. Moreover, S0859 administration led a significant decrease in mucus secretion rate and an significant increase in Isc of colonic mucosa. The forskolin-induced ΔIsc was also suppressed by S0859 pretreatment.

NBCe1 has been identified as a valuable signature gene may have a protective effect against the onset of colitis. Function of NBCe1 is diminished in colitis, which is associated with impaired mucus barrier and declined HCO3- secretion both contributing to the development of IBD.

As a traditional Chinese herb, Glycyrrhiza uralensis Fisch. exhibits a range of pharmacological activities, including anti-inflammatory, immunomodulatory and antifibrotic, which suggests its therapeutic potential for inflammatory bowel disease, and related mechanisms need to be further clarified.

To evaluate in vivo anti-inflammatory effects of Glycyrrhiza uralensis Fisch. aqueous extract (GE) on 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)-induced acute experimental colitis rat model and its potential mechanisms.

The protective effects of GE on IBD were evaluated in vivo using a TNBS and 75% ethanol-induced ulcerative colitis (UC) model. The evaluated clinical and anatomical indexes included body weight, colon length, disease activity index (DAI) score, Colonic Mucosal Damage Index (CMDI) score. The percentages of T, B lymphocytes, NK cells, and macrophages in the colon, spleen and peripheral blood were investigated by flow cytometry. Colon tissues were stained with Hematoxylin and Eosin (H&E) for histopathological examination. After using transcriptome sequencing to screen targeted genes, the expression of related genes was detected by Real-Time Quantitative Polymerase Chain Reaction (RT-qPCR) and Western blot (WB).

The decrease of food intake, soft feces, and colon histopathological injury were observed in colitis rats, which were alleviated by GE, with the best therapeutic effect in the 100 mg/kg GE group. The average CMDI scores of colon in UC rats were decreased from 4.0 to 1.5. The percentages of CD161a+ NK cells, CD68+ total macrophages, CD68+/CD161a+ M1 type macrophages, CD3+ T lymphocytes, and CD45RA+ B lymphocytes were decreased in the spleen and colon. The transcriptomics analysis of colon showed that the results were mainly related to the TNF signaling pathway and NF-κB signaling pathway. The RT-qPCR and WB results determined that the upregulated expression of nucleotide-binding oligomerization domain 2 (NOD2), receptor-interacting protein 2 (RIP2), nuclear factor-kappa B (NF-κB), tumor necrosis factor-α (TNF-α) in the colon of the colitis rats were downregulated by GE treatment.

The research results indicate that GE can exert therapeutic effects on TNBS-induced UC in rats by alleviating cell injury and inflammatory responses, and its mechanisms may be related to the regulation of NOD2/RIP2/NF-κB signaling pathway.

Inflammatory bowel disease (IBD) represents a significant disease burden marked by chronic inflammation and complications that adversely affect patients' quality of life. Effective diagnostic strategies involve clinical assessments, endoscopic evaluations, imaging studies, and biomarker testing, where early diagnosis is essential for effective management and prevention of long-term complications, highlighting the need for continual advancements in diagnostic methods. The intricate interplay between genetic factors and the outcomes of biological therapy is of critical importance. Unraveling the genetic determinants that influence responses and failures to biological therapy holds significant promise for optimizing treatment strategies for patients with IBD on biologics. Through an in-depth examination of current literature, this review article synthesizes critical genetic markers associated with therapeutic efficacy and resistance in IBD. Understanding these genetic actors paves the way for personalized approaches, informing clinicians on predicting, tailoring, and enhancing the effectiveness of biological therapies for improved outcomes in patients with IBD.

Blood orange peel flour (BO-pf)-a by-product of the citrus supply chain-still contains bioactive molecules with known health benefits, such as antiradical scavenging activity or an antiproliferative activity regarding tumors. In vitro studies have demonstrated that orange polyphenols showed potential involvement in necroptosis. In addition to previous research, we tested BO-pf on two colorectal cancer cell lines. Using HT29 and Caco2 cells, our experiments confirmed the regulation of inflammasome expression. They provided valuable insights into how BO-pf influences the cancer cell features (i.e., viability, proliferation, and pro- and anti-inflammatory activity). Notably, BO-pf extract is a rich source of polyphenolic compounds with antioxidant properties. Western blot and real-time PCR analyses showed that treatment with BO-pf extract demonstrated beneficial effects by influencing the expression of both pro-inflammatory cytokines (IL-1β, IL-6) through the modulation of the TLR4/NF-kB/NLRP3 inflammasome signaling. Moreover, the results of this study demonstrate that BO-pf extracts can enhance the expression of anti-inflammatory cytokines, such as IL-10 and TGFβ, suggesting that BO-pf extracts may represent a promising functional ingredient to counteract the intestinal inflammatory responses involved in IBD.

This study compared the protective effects of both live Lacticaseibacillus paracasei 6235 (LLP 6235) and heat-killed Lacticaseibacillus paracasei 6235 (HK-LP 6235) on ulcerative colitis. Using a dextran sulfate sodium (DSS)-induced colitis mouse model, we evaluated physiological state, colon tissue integrity, inflammatory factors, tight junction (TJ) proteins, and intestinal microbiota variations. The findings demonstrated that both LLP 6235 and HK-LP 6235 have the capacity to mitigate colitis damage, enhance TJ protein levels, and restore colon morphology. In addition, these interventions modulated the intestinal inflammatory response by inhibiting pro-inflammatory factors and upregulating anti-inflammatory factors through the mitogen-activated protein kinase (MAPK) and nuclear factor kappa B (NF-κB) signaling pathways. Moreover, treatment with LLP 6235 and HK-LP 6235 significantly altered intestinal microbiota diversity, increased the relative abundance of beneficial bacteria, and regulated the short-chain fatty acid (SCFA) levels. Spearman correlation analysis revealed a strong association between TJ proteins, SCFAs, intestinal microbiota, and inflammatory response, suggesting that LLP 6235 and HK-LP 6235 may provide an effective approach to colitis prevention. In conclusion, LLP 6235 and HK-LP 6235 have similar abilities; furthermore, HK-LP 6235 modulated the intestinal microbiota through lipid metabolic pathways, resulting in a greater improvement. Moreover, considering the high stability and safety of prebiotics and their wide applicability, HK-LP 6235 is recommended for use as a modulator of intestinal inflammatory diseases.

GPR171 suppresses T cell immune responses involved in antitumour immunity, while its role in inflammatory bowel disease (IBD) pathogenesis remains unclear.

We aimed to investigate the role of GPR171 in modulating CD4+ T cell effector functions in IBD and evaluate its therapeutic potential.

We analysed GPR171 expression in colon biopsies and peripheral blood samples from patients with IBD and assessed the impact of GPR171 on CD4+ T cell differentiation through administration of its endogenous ligand (BigLEN). We further determined the role of GPR171 in dextran sulfate sodium (DSS)-induced colitis and CD45RBhighCD4+ T-cell transfer colitis model and deciphered the underlying mechanisms using RNA sequencing (RNA-seq) and lipidomics. We developed a novel BigLEN-based Fc fusion protein (BigLEN-Fc) and evaluated its potential in preventing and treating colitis.

GPR171 was markedly increased in inflamed mucosa and CD4+ T cells of patients with IBD compared with controls. BigLEN-triggered GPR171 activation inhibited Th17 cell differentiation in vitro. GPR171 deficiency exacerbated DSS- and CD45RBhighCD4+ T cell-induced colitis in mice, characterised by increased Th17 cell responses in intestinal mucosa. Mechanistically, GPR171 deficiency promoted Th17 cell differentiation and altered lipidome profile in Th17 cells via the cAMP-pCREB-FABP5 axis. Blockage of FABP5 reduced Th17 cell differentiation in vitro and ameliorated DSS-induced colitis in Gpr171 -/- mice. Furthermore, BigLEN-mutFc administration potently mitigated colitis in mice.

GPR171 deficiency promotes Th17 cell differentiation and causes lipid metabolism perturbation, contributing to intestinal inflammation in a FABP5-dependent manner. Target therapy (eg, BigLEN-Fc) represents a novel therapeutic approach for IBD treatment.

Fibrosis is a pathological condition characterised by excessive accumulation of extracellular matrix (ECM) components, particularly collagens, leading to tissue scarring and organ dysfunction. In fibrosis, an imbalance between collagen synthesis (fibrogenesis) and degradation (fibrolysis) results in the deposition of fibrillar collagens disrupting the structural integrity of the ECM and, consequently, tissue architecture. Fibrosis is associated with a wide range of chronic diseases, including cirrhosis, kidney fibrosis, pulmonary fibrosis, and autoimmune diseases. Recently, the concept of "hot" and "cold" fibrosis has emerged, referring to the immune status within fibrotic tissues and the nature of fibrogenic signalling. Hot fibrosis is characterised by active immune cell infiltration and inflammation, while cold fibrosis is associated with auto- and paracrine myofibroblast activation, immune cell exclusion and quiescence. In this article, we explore the relationship between hot and cold fibrosis, the role of various types of collagens and their biologically active fragments in modulating the immune system, and how serological ECM biomarkers can help improve our understanding of the disease-relevant interactions between immune and mesenchymal cells in fibrotic tissues. Additionally, we draw lessons from immuno-oncology research in solid tumours to shed light on potential strategies for fibrosis treatment and highlight the advantage of having a "hot fibrotic environment" to treat fibrosis by enhancing collagen degradation through modulation of the immune system.

Regulatory T cells (Tregs) are key regulators in maintaining tissue homeostasis. Disrupted immune homeostasis is associated with Crohn's disease (CD) pathogenesis. Thus, Treg therapy represents a promising long-acting treatment to restore immune balance in the diseased intestine. Chimeric antigen receptor (CAR) T-cell therapy has revolutionized cancer treatment. This innovative approach also provides the opportunity to improve therapy for CD. By targeting a disease-relevant protein, interleukin-23 receptor (IL23R), we engineered Tregs expressing IL23R-CAR for treating active CD.

Intestinal IL23R expression from active CD was verified by immunohistochemical analysis. Phenotypic and functional characteristics of IL23R-CAR Tregs were assessed using in vitro assays and their migration capacity was monitored in a xenograft tumor model. Transcriptomic and proteomic analyses were performed to associate molecular profiles with IL23R-CAR Treg activation against colon biopsy-derived cells from active CD patients.

Our study showed that IL23R-CAR displayed negligible tonic signaling and a strong signal-to-noise ratio. IL23R-CAR Tregs maintained regulatory phenotype during in vitro expansion, even when chronically exposed to proinflammatory cytokines and target antigen. IL23R engagement on IL23R-CAR Tregs triggered CAR-specific activation and significantly enhanced their suppressive activity. Also, IL23R-CAR Tregs migrated to IL23R-expressing tissue in humanized mice. Finally, IL23R-CAR Tregs elicited a specific activation against colon biopsy-derived cells from active CD, suggesting an efficient CAR engagement in active CD. Molecular profiling of CD patient biopsies also revealed transcriptomic and proteomic patterns associated with IL23R-CAR activation.

Overall, our results demonstrate that IL23R-CAR Tregs represent a promising therapy for active CD.

Ceria-based nanoparticles are versatile in treating various inflammatory diseases, but their feasibility in clinical translation is undermined by safety concerns and a limited delivery system. Meanwhile, the idiopathic nature of inflammatory bowel disease (IBD) calls for a wider variety of therapeutics via moderation of the intestinal immune system. In this regard, the synthesis and oral formulation of iron-ceria nanoparticles (CF NPs) with enhanced nanozymic activity and lower toxicity risk than conventional ceria-based nanoparticles are reported. CF NPs are clustered in calcium phosphate (CaP) and coated with a pH-responsive polymer to provide the enteric formulation of iron-ceria nanotablets (CFNT). CFNT exhibits a marked alleviative efficacy in the dextran sodium sulfate (DSS)-induced enterocolitis model in vivo by modulating the pro-inflammatory behavior of innate immune cells including macrophages and neutrophils, promoting anti-inflammatory cytokine profiles, and downregulating key transcription factors of inflammatory pathways.

70 % of the ulcerative colitis (UC) linked gene loci are associated with other autoimmune or immunodeficient diseases. The phosphatase activity of PTPN22 can regulate the development of T cells and contribute to regulate the level of inflammation in autoimmune diseases. We produced PTPN22-CS thymus-specific transgenic mice, which suppressed PTPN22 enzyme activity in the thymocytes. Overexpressed PTPN22-CS facilitated the development of the thymocytes towards CD4+T cells and resulted in an increased proportion of the Th1 and Treg cells in the UC mesenteric lymph nodes. PTPN22-CS promoted the activation of the JAK/STAT signaling pathway in the Th1 and Treg cells that localized in the colon, resulting in an excessive production of inflammatory mediators such as IL-2 and IFN-γ. Consequently, PTPN22-CS contributes to the inflammatory response of ulcerative colitis. In summary, the tyrosine phosphatase activity of PTPN22 plays a role in modulating UC by regulating T cell differentiation and modulating the JAK/STAT signaling pathway, thereby influencing the inflammatory response in colonic. These findings provide new insight into the association between PTPN22 and the pathogenesis of UC.