Crohn's disease

Biological functions and affected signaling pathways by Long Non-Coding RNAs in the immune system

Recently, the various regulative functions of long non-coding RNAs (LncRNAs) have been well determined. Recently, the vital role of LncRNAs as gene regulators has been identified in the immune system, especially in the inflammatory response. All cells of the immune system are governed by a complex and ever-changing gene expression program that is regulated through both transcriptional and post-transcriptional processes. LncRNAs regulate gene expression within the cell nucleus by influencing transcription or through post-transcriptional processes that affect the splicing, stability, or translation of messenger RNAs (mRNAs). Recent studies in immunology have revealed substantial alterations in the expression of lncRNAs during the activation of the innate immune system as well as the development, differentiation, and activation of T cells. These lncRNAs regulate key aspects of immune function, including the manufacturing of inflammatory molecules, cellular distinction, and cell movement. They do this by modulating protein-protein interactions or through base pairing with RNA and DNA. Here we review the current understanding of the mechanism of action of lncRNAs as novel immune-related regulators and their impact on physiological and pathological processes related to the immune system, including autoimmune diseases. We also highlight the emerging pattern of gene expression control in important research areas at the intersection between immunology and lncRNA biology.

Exploring the therapeutic potential of Xiangsha Liujunzi Wan in Crohn's disease: from network pharmacology approach to experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Xiangsha Liujunzi Wan (LJZW) is a traditional Chinese medicine (TCM) formula containing a variety of traditional Chinese herb components. Its principal components are often used in the treatment of gastrointestinal diseases and contribute to the treatment of Crohn's disease (CD).

AIM OF THE STUDY

To explore the therapeutic potential of LJZW in CD through network pharmacology, bioinformatics, molecular docking, and experimental verification.

METHODS

The principal bioactive components and corresponding targets of LJZW were ascertained from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP). Potential targets for CD were identified in GeneCards, OMIM, DrugBank, DisGeNET, CTD, and Gene Expression Omnibus (GEO) databases. Intersection targets of LJZW and CD were identified using a Venn diagram and visualized using Cytoscape 3.8.0 to construct a protein-protein interaction (PPI) network. Gene Ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were employed to assess the function of intersection targets. AutoDockTools and PyMOL were used for molecular docking to recognize the association between the core ingredients of LJZW and the core targets of CD. Subsequently, a series of experiments were conducted for validation.

RESULTS

The network pharmacology results indicated that there were 156 bioactive components and 268 corresponding targets for LJZW, 3023 primary relevant targets for CD, and 169 intersection targets for LJZW and CD. The PPI network was employed to identify five hub genes and six clusters. The GO functional analysis indicated that intersection targets are primarily correlated with oxidative stress and inflammatory responses. KEGG pathway analysis revealed that these targets were primarily associated with the phosphotylinosital 3 kinase (PI3K)-protein kinase B (AKT) and mitogen-activated protein kinase (MAPK) signaling pathways. The molecular docking results showed that the core ingredients of LJZW had good binding ability with the core targets of CD. A series of experiments demonstrated that LJZW could effectively attenuate TNBS-induced colitis symptoms, inhibit the inflammatory response, and protect intestinal barrier function by inhibiting the PI3K-AKT and MAPK signaling pathways, thus preventing and treating CD.

CONCLUSION

LJZW has the characteristics of multi-component, multi-target, and multi-pathway treatment, which helps to improve the treatment of CD, protect the intestinal barrier, and exert the effect of anti-inflammatory therapy by inhibiting PI3K-AKT and MAPK signaling pathways.

Computed tomography enterography-based radiomics for assessing mucosal healing in patients with small bowel Crohn's disease

BACKGROUND

Mucosal healing (MH) is the major therapeutic target for Crohn's disease (CD). As the most commonly involved intestinal segment, small bowel (SB) assessment is crucial for CD patients. Yet, it poses a significant challenge due to its limited accessibility through conventional endoscopic methods.

AIM

To establish a noninvasive radiomic model based on computed tomography enterography (CTE) for MH assessment in SBCD patients.

METHODS

Seventy-three patients diagnosed with SBCD were included and divided into a training cohort (n = 55) and a test cohort (n = 18). Radiomic features were obtained from CTE images to establish a radiomic model. Patient demographics were analysed to establish a clinical model. A radiomic-clinical nomogram was constructed by combining significant clinical and radiomic features. The diagnostic efficacy and clinical benefit were evaluated via receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA), respectively.

RESULTS

Of the 73 patients enrolled, 25 patients achieved MH. The radiomic-clinical nomogram had an area under the ROC curve of 0.961 (95% confidence interval: 0.886-1.000) in the training cohort and 0.958 (0.877-1.000) in the test cohort and provided superior clinical benefit to either the clinical or radiomic models alone, as demonstrated by DCA.

CONCLUSION

These results indicate that the CTE-based radiomic-clinical nomogram is a promising imaging biomarker for MH and serves as a potential noninvasive alternative to enteroscopy for MH assessment in SBCD patients.

Engeletin attenuates the inflammatory response via inhibiting TLR4-NFκB signaling pathway in Crohn's disease-like colitis

ETHNOPHARMACOLOGICAL RELEVANCE

Smilax glabra rhizome has a long history been used for clinical purposes in traditional Chinese medicinal for treating various inflammatory conditions. Engeletin1 (ENG) is one of the most abundant bioactive compounds found in Smilax glabra rhizome, with anti-inflammatory, antioxidant, and ulcer-preventing activities.

AIM OF THE STUDY

The purpose of this study was to investigate the ability of ENG to alleviate inflammatory symptoms and improve epithelial barrier integrity utilize a 2,4,6-trinitrobenzene sulfonic acid2 (TNBS)-induced murine model in Crohn's disease3 (CD)-like colitis, and to characterize the underlying anti-inflammatory mechanisms of action.

MATERIALS AND METHODS

A colitis model was established in BALB/c mice and treated with ENG for 7 days. RAW264.7 macrophages were pre-treated with ENG and lipopolysaccharide4 (LPS) stimulation. The mice's weight and colon length were assessed. qPCR and Western blotting were used to analyze gene expression and TLR4-NFκB pathway. Flow cytometry was used to analyze the polarization states of the macrophages.

RESULTS

Treatment with ENG was sufficient to significantly alleviate symptoms of inflammation and colonic epithelial barrier integrity in treated mice. Significant inhibition of TNF-α, IL-1β, and IL-6 expression was observed following ENG treatment in vivo and in vitro. ENG was also determined to be capable of inhibiting the expression of iNOS and CD86, inhibited M1 macrophage polarization in vitro, as well as the TLR4-NFκB signaling pathway. Molecular docking showed a highly stable binding between ENG and TLR4.

CONCLUSION

ENG has been proven to alleviate inflammation and ameliorate the damage of epithelial barrier in CD-like colitis. ENG also suppressed the M1 macrophages polarization and the inhibited inflammatory cytokines. TLR4-NFκB signaling pathway, especially TLR4, may be the target of ENG. These data offer a new insight into the therapeutic mechanisms of ENG.

Integrative multi-omics analysis of Crohn's disease and metabolic syndrome: Unveiling the underlying molecular mechanisms of comorbidity

OBJECTIVES

The focus of this study is on identifying a potential association between Crohn's disease (CD), a chronic inflammatory bowel condition, and metabolic syndrome (Mets), characterized by a cluster of metabolic abnormalities, including high blood pressure, abnormal lipid levels, and overweight. While the link between CD and MetS has been suggested in the medical community, the underlying molecular mechanisms remain largely unexplored.

METHODS

Using microarray data from the Gene Expression Omnibus (GEO) database, we conducted a differential gene expression analysis and applied Weighted Gene Co-expression Network Analysis (WGCNA) to identify genes shared between CD and MetS. To further elucidate the functions of these shared genes, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses and constructed protein-protein interaction (PPI) networks. For key gene screening, we used Random Forest and Least Absolute Shrinkage and Selection Operator (LASSO) regression and constructed a diagnostic prediction model with the Extreme Gradient Boosting (XGBoost) algorithm. Additionally, CIBERSORT and Gene Set Variation Analysis (GSVA) were employed to examine the relationships between these genes and immune cell infiltration, as well as metabolic pathways. Mendelian randomization and colocalization analyses were also conducted to explore causal links between genes and disease. Lastly, single-cell RNA sequencing (scRNA-seq) was used to validate the functionality of these key genes.

RESULTS

Through the use of the limma R package and WGCNA, we identified 1767 co-expressed genes common to both CD and MetS, which are notably enriched in pathways related to immune responses and metabolic regulation. After thorough analysis, 34 key genes were highlighted, demonstrating their potential utility in prognostic models. These genes were closely linked to tissue immune responses and metabolic functions. Subsequent scRNA-seq analysis confirmed the strong diagnostic potential of PIM2 and PBX2, with especially prominent expression in T and B cells.

CONCLUSION

This study identifies shared regulatory genes between CD and MetS, advancing the development of precise diagnostic tools. In particular, PIM2 and PBX2 were found to be positively associated with hypoxia and hemoglobin metabolism pathways, suggesting their involvement in the modulation of cellular processes. These findings improve our understanding of the molecular mechanisms underlying the comorbidity of CD and MetS, offering novel targets for integrated therapeutic interventions.

Potential interventions and interactions of bioactive polyphenols and functional polysaccharides to alleviate inflammatory bowel disease - A review

Inflammatory bowel disease is a multifaceted condition that is influenced by nutritional, microbial, environmental, genetic, psychological, and immunological factors. Polyphenols and polysaccharides have gained recognition for their therapeutic potential. This review emphasizes the biological effects of polyphenols and polysaccharides, and explores their antioxidant, anti-inflammatory, and microbiome-modulating properties in the management of inflammatory bowel disease (IBD). However, polyphenols encounter challenges, such as low stability and low bioavailability in the colon during IBD treatment. Hence, polysaccharide-based encapsulation is a promising solution to achieve targeted delivery, improved bioavailability, reduced toxicity, and enhanced stability. This review also discusses the significance of covalent and non-covalent interactions, and simple and complex encapsulation between polyphenols and polysaccharides. The administration of these compounds in appropriate quantities has proven beneficial in preventing the development of Crohn's disease and ulcerative colitis, ultimately leading to the management of IBD. The use of polyphenols and polysaccharides has been found to reduce histological scores and colon injury associated with IBD, increase the abundance of beneficial microbes, inhibit the development of colitis-associated cancer, promote the production of microbial end-products, such as short-chain fatty acids (SCFAs), and improve anti-inflammatory properties. Despite the combined effects of polyphenols and polysaccharides observed in both in vitro and in vivo studies, further human clinical trials are needed to comprehend their effectiveness on inflammatory bowel disease.

Type III interferons induce pyroptosis in gut epithelial cells and impair mucosal repair

Tissue damage and repair are hallmarks of inflammation. Despite a wealth of information on the mechanisms that govern tissue damage, mechanistic insight into how inflammation affects repair is lacking. Here, we investigated how interferons influence tissue repair after damage to the intestinal mucosa. We found that type III, not type I or type II, interferons delay epithelial cell regeneration by inducing the upregulation of Z-DNA-binding protein 1 (ZBP1). Z-nucleic acids formed following intestinal damage are sensed by ZBP1, leading to caspase-8 activation and the cleavage of gasdermin C (GSDMC). Cleaved GSDMC drives epithelial cell death by pyroptosis and delays repair of the large or small intestine after colitis or irradiation, respectively. The type III interferon/ZBP1/caspase-8/GSDMC axis is also active in patients with inflammatory bowel disease (IBD). Our findings highlight the capacity of type III interferons to delay gut repair, which has implications for IBD patients or individuals exposed to radiation therapies.

Butyrate attenuates intestinal inflammation in Crohn's disease by suppressing pyroptosis of intestinal epithelial cells via the cGSA-STING-NLRP3 axis

Butyrate can strengthen the intestinal epithelial barrier. However, the mechanisms by which butyrate affects intestinal epithelial cells (IECs) pyroptosis in Crohn's disease (CD) remain unclear. In this study, we collected colonic biopsy samples from CD patients and healthy controls to assess pyroptosis levels. Our findings indicated elevated expression of pyroptosis markers in CD patients, alongside distinct morphological evidence of pyroptosis in IECs. We further investigated the effects of tributyrin on pyroptosis and the cGAS-STING pathway in a trinitrobenzene sulfonic acid-induced colitis rat model. Tributyrin significantly mitigated intestinal inflammation, reduced pathological progression, and inhibited pyroptosis and cGAS-STING pathway activation in the colitis rat model. Similarly, in an in vitro model of IECs pyroptosis, sodium butyrate inhibited pyroptosis and cGAS-STING pathway activation in HT-29 cells. Co-treatment with a cGAS-STING pathway activator and butyrate demonstrated that the activator reversed the inhibitory effects of butyrate on pyroptosis and cGAS-STING pathway activation in both the colitis rat model and HT-29 cells. Mechanistically, the cGAS-STING pathway was found to interact with NLRP3. Taken together, butyrate may mitigate intestinal inflammation in CD by suppressing cGAS-STING-NLRP3 axis-mediated IECs pyroptosis. These findings offer new insights into potential therapeutic strategies for managing CD.

Anti-inflammatory effects of heat-killed Lactiplantibacillus argentoratensis BBLB001 on a gut inflammation co-culture cell model and dextran sulfate sodium-induced colitis mouse model

Dysbiosis caused by dietary changes can alter the intestinal bacterial species and is closely associated with inflammatory bowel disease (IBD). Among the possible treatment options, postbiotics, which act to balance the constituent intestinal microflora, have gained substantial attention. Herein, we investigated the anti-inflammatory effects of heat-killed Lactiplantibacillus argentoratensis (hk-LA) BBLB001 isolated from a marine environment using both cell (Caco2/RAW264.7 cell co-culture) and animal (dextran sodium sulfate [DSS]-induced colitis in mice) models. hk-LA BBLB001 markedly reduced IL-8 secretion in Caco-2 cell culture medium after lipopolysaccharide-mediated stimulation of RAW264.7 cells by enhancing the expression of cell adhesion factors.The body weight loss, reduced inflammatory cytokine levels in the serum and colon tissues, colon shortening, and myeloperoxidase activation caused by DSS in mice were alleviated by hk-LA BBLB001. Similar to that in the intestinal cell model, the gene and protein expressions of cell adhesion molecules in the colon tissue were increased upon hk-LA BBLB001 treatment in DSS-induced colitis mice. We observed increased mucin expression and secretory IgA concentration in colon tissues, suggesting that hk-LA BBLB001 intake may benefit pathogen defense and the regulation of intestinal commensal bacteria. Thus, hk-LA BBLB001 may serve as an instrumental postbiotic material in IBD treatment.

Deep Learning-Enabled Rapid Metabolic Decoding of Small Extracellular Vesicles via Dual-Use Mass Spectroscopy Chip Array

The increasing focus of small extracellular vesicles (sEVs) in liquid biopsy has created a significant demand for streamlined improvements in sEV isolation methods, efficient collection of high-quality sEV data, and powerful rapid analysis of large data sets. Herein, we develop a high-throughput dual-use mass spectroscopic chip array (DUMSCA) for the rapid isolation and detection of plasma sEVs. The DUMSCA realizes more than a 50% increase in speed compared to traditional method and confirms proficiency in robust storage, reuse, high-efficiency desorption/ionization, and metabolite quantification. With the collected metabolic data matrix of sEVs, a deep learning model achieves high-performance diagnosis of Crohn's disease. Furthermore, discovered biomarkers by feature sparsification and tandem mass spectrometry experiments also exhibited remarkable performance in diagnosis. This work demonstrates the rapidity and validity of DUMSCA for disease diagnosis, enabling the diagnosis of diseases without the necessity for prior knowledge and providing a high-throughput technology for sEV-based liquid biopsy that will empower its vigorous development.

Oxytocin Analogues for the Oral Treatment of Abdominal Pain

Abdominal pain presents an onerous reality for millions of people affected by gastrointestinal disorders such as irritable bowel syndrome (IBS) and inflammatory bowel diseases (IBD). The oxytocin receptor (OTR) has emerged as a new analgesic drug target with OTR expression upregulated on colon-innervating nociceptors in chronic visceral hypersensitivity states, accessible via luminal delivery. However, the low gastrointestinal stability of OTR's endogenous peptide ligand oxytocin (OT) is a bottleneck for therapeutic development. Here, we report the development of potent and fully gut-stable OT analogues, laying the foundation for a new area of oral gut-specific peptide therapeutics. Ligand optimisation guided by structure-gut-stability-activity relationships yielded highly stable analogues (t1/2>24 h, compared to t1/2<10 min of OT in intestinal fluid) equipotent to OT (~3 nM) and with enhanced OTR selectivity. Intra-colonic administration of the lead ligand significantly reduced colonic mechanical hypersensitivity in a concentration-dependent manner in a mouse model of chronic abdominal pain. Moreover, oral administration of the lead ligand also displayed significant analgesia in this abdominal pain mouse model. The generated ligands and employed strategies could pave the way to a new class of oral gut-specific peptides to study and combat chronic gastrointestinal disorders, an area with substantial unmet medical needs.

C-X-C Motif Chemokine 12 Was Identified as a Potential Gene Target in the Treatment of Crohn's Disease

Object

The present study aimed to identify hub genes associated with the treatment and control of active and inactive Crohn's disease (CD).

Methods

Differentially expressed genes (DEGs) were identified in normal, active CD, and inactive CD samples from GSE95095 dataset. Intersection genes screened by Venn diagram in DEGs. Subsequently, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses were conducted on the intersection genes. The protein-protein interaction (PPI) network was used to screen of hub gene. The expression and mRNA levels of CXCL12 in CD and ROC curves in GSE95095 dataset. Signaling pathways of hub genes and their correlation with immune cells were analyzed by gene set enrichment analysis (GSEA), EPIC, and ESTIMATE, respectively. Finally, immunohistochemistry (IHC) and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) were used to detect the expression of the hub gene in normal, inactive, and active CD tissues.

Results

In GSE95095 dataset, CXCL12 was identified as the most hub gene by limma analysis, Venn diagram and A protein-protein interaction (PPI) network. CXCL12 expression was highest in active CD (p < 0.001) followed by inactive CD (p < 0.01). Subsequently, it was validated through IHC and RT-PCR in normal intestinal mucosal, active CD, and inactive CD. CXCL12 was overexpressed in active and inactive CD (IHC: p < 0.001 and RT-PCR: p < 0.001, respectively). CXCL12 expression in active CD was determined via analysis with receiver operating characteristic (ROC) curves. The specificity and sensitivity were 0.875 and 0.625, respectively, the accuracy was 72.92%, the area under the curve (AUC) was 0.780, and the 95% confidence interval (CI) was in the range of 0.648-0.912. CXCL12 expression was closely correlated with various immune cells.

Conclusion

CXCL12 is overexpressed in active CD and is closely correlated with various immune cells. We propose that CXCL12 as a potential target genes for the treatment and management of both active and inactive CD.

Cell-type-resolved chromatin accessibility in the human intestine identifies complex regulatory programs and clarifies genetic associations in Crohn's disease

Crohn's disease (CD) is a complex inflammatory bowel disease resulting from an interplay of genetic, microbial, and environmental factors. Cell-type-specific contributions to CD etiology and genetic risk are incompletely understood. Here we built a comprehensive atlas of cell-type- resolved chromatin accessibility comprising 557,310 candidate cis-regulatory elements (cCREs) in terminal ileum and ascending colon from patients with active and inactive CD and healthy controls. Using this atlas, we identified cell-type-, anatomic location-, and context-specific cCREs and characterized the regulatory programs underlying inflammatory responses in the intestinal mucosa of CD patients. Genetic variants that disrupt binding motifs of cell-type-specific transcription factors significantly affected chromatin accessibility in specific mucosal cell types. We found that CD heritability is primarily enriched in immune cell types. However, using fine- mapped non-coding CD variants we identified 29 variants located within cCREs several of which were accessible in epithelial and stromal cells implicating cell types from additional lineages in mediating CD risk in some loci. Our atlas provides a comprehensive resource to study gene regulatory effects in CD and health, and highlights the cellular complexity underlying CD risk.

Monitoring-Based Model for Personalizing Fecal Incontinence in Patients With Crohn's Disease: A Multicenter Inception Cohort Study

BACKGROUND AND AIMS

Fecal incontinence (FI) is a common complaint that greatly affects the quality of life of patients with Crohn's disease (CD) and is associated with the clinical characteristics of CD. We aimed to identify risk factors related to FI and construct a risk prediction model for FI in patients with CD.

METHODS

This retrospective study included 600 Chinese patients with CD from 4 IBD centers between June 2016 and October 2021. The patients were assigned to the training (n = 480) and testing cohorts (n = 120). Two nomograms were developed based on the logistic regression and Cox regression models to predict the risk factors for FI in patients with CD. The discriminatory ability and accuracy of the nomograms were evaluated using the receiver operating characteristic (ROC) curves and the area under the ROC curves (AUCs). Additionally, the Kaplan-Meier survival curve was also used further to validate the clinical efficacy of the Cox regression model.

RESULTS

The overall prevalence of FI was 22.3% (n = 134 of 600). In the logistic regression model, age at diagnosis (odds ratio [OR], 1.032; P = .033), penetrating behavior of disease (OR, 3.529; P = .008) and Perianal Disease Activity Index score >4 (OR, 3.068; P < .001) were independent risk factors for FI. In the Cox regression model, age at diagnosis (hazard ratio [HR], 1.027; P = .018), Montreal P classification (HR, 2.608; P = .011), and Perianal Disease Activity Index score >4 (HR, 2.190; P = .001) were independent predictors of the prevalence of FI over time. Two nomograms were developed to facilitate risk score calculation, and they showed good discrimination ability according to AUCs.

CONCLUSIONS

In this study, we identified 4 risk factors related to the prevalence of FI and developed 2 models to effectively predict the risk scores of FI in CD patients, helping to delay the course of FI and improve the prognosis with timely intervention.

Anti-CdtB and anti-vinculin antibodies to diagnose irritable bowel syndrome in inflammatory bowel disease patients

BACKGROUND

Despite adequate treatment, a subgroup of patients with inflammatory bowel disease (IBD), including Crohn`s disease and ulcerative colitis, have persistent gastrointestinal symptoms that are not always related to mucosal damage. Recently, two autoantibodies, anti-CdtB and anti-vinculin, were validated as post-infectious IBS (PI-IBS) markers, however there is limited evidence of its diagnostic role in IBD population.

METHODS

Patients with more than 3 bowel movements/day and indication of colonoscopy were enrolled. Samples were collected at the time of colonoscopy for assessment of serum levels of anti-CdtB and anti-vinculin antibodies.

RESULTS

A total of 160 subjects were included in 4 groups: active IBD (n = 44); quiescent IBD and chronic diarrhea IBD-IBS (n = 25); predominant-diarrhea IBS (n = 45) and controls (n = 46). The mean value of the optical density for anti-CdtB was 1.2 ± 0.65 in group 1, 1.27 ± 0.64 in group 2, 1.49 ± 0.47 in the group 3 and 1.6 ± 0.68 in group 4, p = 0.012. For anti-vinculin, optical densities were: 1.34 ± 0.78 in group 1, 1.46 ± 0.92 in group 2, 1.31 ± 0.79 in group 3 and 1.41 ± 0.86 for controls (p = 0.875). Using a cut-off of 1.56 for anti-CdtB, the positivity between groups was n = 10 (22.7%) in group 1, n = 9 (34.6%) in group 2, 19 (43.2%) in group 3, 21 (45.7%) in group 4 (p = 0.106). The positivity of anti-vinculin using a cut-off of 1.6 was n = 18 (40.9%) in group 1, n = 11 (42.3%), n = 15 (34.1%), n = 22 (47.8%) (p = 0.622).

CONCLUSIONS

Our findings show that anti-CdtB and anti-vinculin could not identify IBD-IBS patients or discriminate IBS-D from healthy controls.

Impact of exercise on outcomes among Chinese patients with Crohn's disease: a mixed methods study based on social media and the real world

OBJECTIVE

The effects of exercise on the health of people with Crohn's disease (CD) remain unclear. This study aimed to explore the perspective of Chinese CD patients on exercise and the quantitative relationship between exercise and patient-reported outcomes.

METHODS

This study used a mixed methods design consisting of three components. (1) Big data were mined from social media, and latent Dirichlet allocation (LDA) was used to perform cluster analysis on topics related to physical exercise. (2) A seven-step Colaizzi process was used to conduct semistructured interviews to obtain in-depth information about exercise. (3) A cross-sectional study was performed to examine this relationship using the Global Physical Activity Questionnaire (GPAQ) and Patient-reported Outcome Measurement Information System (PROMIS).

RESULTS

LDA yielded a total of 1536 exercise-related posts; eight topics concerning CD patients were obtained through clustering (peer support, exercise therapy, diet, fatigue, exercise type, intestinal symptoms, body constitution and mental health), and 11 patients were interviewed to validate the results of LDA and explore the insight of Chinese CD. We identified two themes: the effects of exercise on people with CD and factors that promote and hinder exercise. A total of 119 patients with CD were surveyed. Considering confounding factors such as disease activity and medication, moderate-intensity recreational PA increased patients' physical function and improved anxiety, depression, fatigue, pain intensity, and pain impact (all p < 0.05). In contrast, high-intensity work may lead to anxiety, depression, fatigue, pain, and pain effects (all p < 0.001). In addition, sedentary behaviour may lead to depression (p = 0.006).

CONCLUSION

Patients with CD tend to seek guidance on exercise through social media, and they generally believe that exercise is beneficial, especially for their psychological and spiritual health, despite difficulties in exercising. Physical activity may be an important factor affecting patients' psychological health. Crohn's disease has a profound impact on mental and emotional health, reducing patients' quality of life. Exercise is a good habit that can enhance mental, emotional and social health, but there is currently no standard exercise program for patients with Crohn's disease. The exercise experience of Chinese patients with Crohn's disease can be helpful in formulating exercise plans.

Opportunities for Therapeutic Modulation of O-GlcNAc

O-Linked β-N-acetylglucosamine (O-GlcNAc) is an essential, dynamic monosaccharide post-translational modification (PTM) found on serine and threonine residues of thousands of nucleocytoplasmic proteins. The installation and removal of O-GlcNAc is controlled by a single pair of enzymes, O-GlcNAc transferase (OGT) and O-GlcNAcase (OGA), respectively. Since its discovery four decades ago, O-GlcNAc has been found on diverse classes of proteins, playing important functional roles in many cellular processes. Dysregulation of O-GlcNAc homeostasis has been implicated in the pathogenesis of disease, including neurodegeneration, X-linked intellectual disability (XLID), cancer, diabetes, and immunological disorders. These foundational studies of O-GlcNAc in disease biology have motivated efforts to target O-GlcNAc therapeutically, with multiple clinical candidates under evaluation. In this review, we describe the characterization and biochemistry of OGT and OGA, cellular O-GlcNAc regulation, development of OGT and OGA inhibitors, O-GlcNAc in pathophysiology, clinical progress of O-GlcNAc modulators, and emerging opportunities for targeting O-GlcNAc. This comprehensive resource should motivate further study into O-GlcNAc function and inspire strategies for therapeutic modulation of O-GlcNAc.

Lipid Nanoparticles With Fine-Tuned Composition Show Enhanced Colon Targeting as a Platform for mRNA Therapeutics

Lipid Nanoparticles (LNPs) recently emerged as an invaluable RNA delivery platform. With many LNP-based therapeutics in the pre-clinical and clinical pipelines, there is extensive research dedicated to improving LNPs. These efforts focus mainly on the tolerability and transfectability of new ionizable lipids and RNAs, or modulating LNPs biodistribution with active targeting strategies. However, most formulations follow the well-established lipid proportions used in clinically approved products. Nevertheless, investigating the effects of LNPs composition on their biodistribution can expand the toolbox for particle design, leading to improved delivery strategies. Herein, a new LNPs (30-n-LNPs) formulation with increasing amounts of phospholipids is investigated as a possible mRNA delivery system for treating Inflammatory Bowel Diseases. Compared to LNPs with benchmark composition (b-LNPs), n-LNPs containing 30% distearoylphosphatidylcholine (DSPC) are well tolerated following intravenous administration and display natural targeting toward the inflamed colon in dextran sodium sulfate (DSS)-colitis bearing mice, while de-targeting clearing organs such as the liver and spleen. Using interleukin-10-encoding mRNA as therapeutic cargo, n-LNPs demonstrated a reduction of pathological burden in colitis-bearing mice. n-LNPs represent a starting point to further investigate the influence of LNPs composition on systemic biodistribution, ultimately opening new therapeutic modalities in different pathologies.

STARD7 maintains intestinal epithelial mitochondria architecture, barrier integrity, and protection from colitis

Susceptibility to inflammatory bowel diseases (IBDs), Crohn's disease (CD), and ulcerative colitis (UC) is linked with loss of intestinal epithelial barrier integrity and mitochondria dysfunction. Steroidogenic acute regulatory (StAR) protein-related lipid transfer (START) domain-containing protein 7 (STARD7) is a phosphatidylcholine-specific (PC-specific) lipid transfer protein that transports PC from the ER to the mitochondria, facilitating mitochondria membrane stabilization and respiration function. The aim of this study was to define the contribution of STARD7 in the regulation of the intestinal epithelial mitochondrial function and susceptibility to colitis. In silico analyses identified significantly reduced expression of STARD7 in patients with UC, which was associated with downregulation of metabolic function and a more severe disease phenotype. STARD7 was expressed in intestinal epithelial cells, and STARD7 knockdown resulted in deformed mitochondria and diminished aerobic respiration. Loss of mitochondria function was associated with reduced expression of tight junction proteins and loss of intestinal epithelial barrier integrity that could be recovered by AMPK activation. Stard7+/- mice were more susceptible to the development of DSS-induced and Il10-/- spontaneous models of colitis. STARD7 is critical for intestinal epithelial mitochondrial function and barrier integrity, and loss of STARD7 function increases susceptibility to IBD.

Psoriasis and inflammatory bowel disease: concomitant IMID or paradoxical therapeutic effect? A scoping review on anti-IL-12/23 and anti-IL-23 antibodies

Inflammatory bowel diseases (IBD) and psoriasis are chronic inflammatory conditions belonging to the heterogeneous group of immune-mediated inflammatory diseases (IMIDs). A significant bidirectional link between these two entities has been observed, conditioning an increased risk of IBD in patients with psoriasis and vice-versa. Biological therapies used for IBD may lead to the occurrence of psoriasis as a "paradoxical reaction." The objective of this study is to analyze the current evidence on the association between psoriasis and IBD, particularly finding case reports of the appearance or aggravation of psoriasis under therapy with interleukin-12/23 (IL-12/23) and IL-23 inhibitors. We conducted comprehensive research to identify studies examining the association between psoriasis and IBD and to find case presentations that reported the appearance or aggravation of psoriasis under biologic therapy with IL-12/23 and IL-23 inhibitors up to March 2024. Clinical trials for IL-12/23 and IL-23 inhibitors in IBD were analyzed to find cases of paradoxical psoriasis as registered adverse events. The sources of evidence are PubMed and ClinicalTrials.gov. For each included case report, data on patient characteristics concerning their age, sex, and comorbidities were selected. Moreover, information regarding the indication for biologic therapy, time to onset of paradoxical psoriasis after starting treatment, clinical presentation, and management of the paradoxical psoriasis was extracted. We found 10 reported cases of ustekinumab-induced new-onset or worsening psoriasis and one reported case of paradoxical psoriasis induced by risankizumab in the literature. Four cases of paradoxical psoriasis have been also registered in clinical trials involving ustekinumab treatment in IBD. Psoriasis can constitute a rare paradoxical adverse event of ustekinumab treatment, but further studies are needed to better clarify the cytokine imbalance that leads to this phenomenon induced by inhibition of IL-12/23 and IL-23. Still, few real-world data exist to draw any conclusions, but risankizumab may positively treat psoriasis induced by ustekinumab.

Crohn's disease after multiple doses of rituximab treatment in a child with refractory nephrotic syndrome and an ATG2A mutation: a case report

De novo inflammatory bowel disease (IBD) in response to rituximab (RTX) has been documented on multiple occasions as a severe adverse effect. However, none of these reports mentioned any genetic variation associated with this complication. We describe the case of a 16-year-old patient with refractory nephrotic syndrome (NS) diagnosed at the age of 6 years, notably with a heterozygous mutation of the ATG2A gene, who developed Crohn's disease (CD) following ten administrations of RTX. Seventy months after the first and 6 months after the last RTX dose, the patient developed recurrent abdominal pain, hematochezia, oral aphthous ulcers and weight loss. On the basis of clinical evaluation and ileo-colonoscopy findings, the patient was diagnosed with CD and treated with mesalazine. A significant amelioration of clinical symptoms was achieved after 11 days of mesalazine treatment. A repeat ileo-colonoscopy performed 4 months later revealed near-complete resolution of the ulcers and marked mucosal healing. The underlying pathophysiology of RTX-induced IBD has not yet been clarified. Autophagy associated with ATG2A mutation is likely involved in the pathogenesis. This case underscores the need for vigilance in monitoring children with NS with gastrointestinal symptoms following RTX treatment, especially those who have hereditary susceptibility and have received multiple administrations.

Bacteroides uniformis ameliorates pro-inflammatory diet-exacerbated colitis by targeting endoplasmic reticulum stress-mediated ferroptosis

INTRODUCTION

A pro-inflammatory diet is positively associated with the risk and progression of inflammatory bowel diseases (IBD). Recently, ferroptosis has been observed in patients with different dietary patterns-associated intestinal inflammation, while the mechanisms underlying the effects of a pro-inflammatory diet and whether it mediates ferroptosis are unknown.

OBJECTIVES

This study aims to elucidate the mechanisms underlying pro-inflammatory diet-mediated colitis and explore potential intervention strategies.

METHODS

Mice were fed a dietary inflammatory index-based pro-inflammatory diet for 12 weeks. Subsequently, colitis was chemically induced using 2.5 % dextran sulfate sodium. The body weight, pathological score, immune response and mucosal barrier function were evaluated to assess intestinal inflammation. Intestine tissue transcriptomics, fecal microbiome analysis and serum metabolomics were applied to identify diet-microbe-host interactions. Additionally, the dietary inflammatory index (DII) scores and intestinal specimens of 32 patients with Crohn's disease were evaluated. The biological functions of Bacteroides uniformis were observed in vitro and in vivo.

RESULTS

Pro-inflammatory diet induces low-grade intestinal inflammation in mice and exacerbates colitis by activating glutathione peroxidase 4-associated ferroptosis in the endoplasmic reticulum stress-mediated pathway. These effects are reversed by ferrostatin-1 treatment. Additionally, the pro-inflammatory diet triggers colitis by modulating the gut microbiota and metabolites. Notably, supplementation with B. uniformis improves the pro-inflammatory diet-aggravated colitis by inhibiting endoplasmic reticulum stress-mediated ferroptosis. Moreover, B. uniformis is non-enterotoxigenic and non-enteroinvasive in co-cultures with intestinal epithelial cells.

CONCLUSIONS

Pro-inflammatory diet drives colitis by targeting endoplasmic reticulum stress-mediated ferroptosis, possibly in a gut microbiota-dependent manner. Pro-inflammatory diet restriction and microbial-based therapies may be effective strategies for preventing and treating IBD.

Improved Diagnostic Performance Using Dual-Energy CT-Derived Slope Parameter Images in Crohn's Disease

The objective of the study is to explore the image quality and diagnosis performance of the dual-energy CT-derived slope parameter images (SPI) generated by the algorithm based on the slope function in the diagnosis of Crohn's disease (CD). Seventy-six CD patients and 53 disease-free control group subjects who underwent dual-energy CT enterography were retrospectively collected. Portal venous phase 120kVp-like and virtual monoenergetic images at 40-100 keV (VMI40-100) were reconstructed. SPIs corresponding to the spectral curve between 40 and 100 keV (SPI40-100) were generated using Python. Signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) of normal and abnormal intestinal walls were calculated. Image quality, noise, and contrast were independently scored by two radiologists using a 5-point scale. Four radiologists conducted CD diagnosis with three reading models (120kVp-like, 120kVp-like with optimal VMI, and 120kVp-like with SPI40-100). The diagnostic performances of the three reading models for diagnosing CD were evaluated using receiver operating characteristic (ROC) curves. The CNR in SPI40-100 was higher than in the other images (P < 0.05). The subjective evaluation showed that there was no statistical difference between the contrast of SPI40-100 and VMI40 (P > 0.05), but that of the two images was higher than the other images (P < 0.05). The scoring on the overall image quality of VMI50 was superior to that of other images (P < 0.05). The combined model of 120kVp-like with SPI40-100 had the strongest confidence (cases with high confidence: 36, 58, 49, 47 for radiologists 1, 2, 3, 4) and the highest efficiency in diagnosing CD (areas under the ROC curve: 0.973, 0.977, 0.982, 0.991 for radiologists 1, 2, 3, 4). SPI40-100 generated by the algorithm based on the slope function exhibited good image quality. The combined model of 120kVp-like with SPI40-100 could improve radiologists' diagnostic efficiency and confidence in diagnosing CD.

IL-22, a vital cytokine in autoimmune diseases

Interleukin-22 (IL-22) is a vital cytokine that is dysregulated in various autoimmune conditions including rheumatoid arthritis (RA), multiple sclerosis (MS), and Alzheimer's disease (AD). As the starting point for the activation of numerous signaling pathways, IL-22 plays an important role in the initiation and development of autoimmune diseases. Specifically, imbalances in IL-22 signaling can interfere with other signaling pathways, causing cross-regulation of target genes which ultimately leads to the development of immune disorders. This review delineates the various connections between the IL-22 signaling pathway and autoimmune disease, focusing on the latest understanding of the cellular sources of IL-22 and its effects on various cell types. We further explore progress with pharmacological interventions related to targeting IL-22, describing how such therapeutic strategies promise to usher in a new era in the treatment of autoimmune disease.

Recurrence rates after strictureplasty for small bowel Crohn's disease remain high in the era of biologics

AIM

Despite advancements in therapeutic options for Crohn's disease (CD), strictureplasty is a mainstay bowel-preserving technique for small bowel CD. We sought to audit international practice across three high-volume centres since the widespread use of biologic medication.

METHODS

A retrospective audit was performed for all strictureplasties undertaken for small bowel CD, over a 15-year period (2006-2021), in three high-volume centres in the United Kingdom and Italy. Primary endpoints were clinical recurrence and reoperation for recurrence.

RESULTS

In all, 123 patients were included; 58% were men, 25% smoked and 60% had previous abdominal surgery for CD. Median age was 40 years (interquartile range 30-52 years), mean body mass index 22 (15-31) and median disease duration 138 months (81-255 months). 42% had been treated with biologics preoperatively. In total 338 strictureplasties were performed in 123 patients, with a median of two per patient (interquartile range 1-3). Complications occurred in 35%, with 8% scoring Clavien-Dindo Grade 3. There were no Grade 4/5 complications. Postoperative biologic treatment was administered to 84/123 patients (68.3%). Median follow-up was 54 months. 41/123 patients (33.3%) developed clinical recurrence. Reoperation for recurrent stricturing was performed in 26/123 patients (21%). Clinical recurrence and reoperation rates were significantly higher in patients who continued to smoke after their index surgery.

CONCLUSION

Strictureplasty remains a safe and effective surgical treatment for small bowel CD. Recurrence and reoperation rates remain high, regardless of postoperative biologic therapy. Smoking significantly increases the risk of recurrence.

Fusobacterium Nucleatum Aggravates Intestinal Barrier Impairment and Colitis Through IL-8 Induced Neutrophil Chemotaxis by Activating Epithelial Cells

Background

Inflammatory bowel disease (IBD) is affected by interactions between intestinal microbial factors, abnormal inflammation, and an impaired intestinal mucosal barrier. Neutrophils (NE) are key players in IBD. Fusobacterium nucleatum (F. nucleatum) is reported to contribute to IBD progression. However, the relationship between F. nucleatum, abnormal inflammation, and intestinal barrier impairment should be interpreted to understand the role of F. nucleatum in IBD.

Methods

Dextran sulfate sodium (DSS)-induced colitis model was established and mice were orally administered with F. nucleatum. F. nucleatum colonization was confirmed by fluorescence in situ hybridization (FISH) and PCR. Intestinal barrier impairment was investigated by tight junction protein expression. Immuno-histochemistry (IHC) for Ly6G and flow cytometry detection to measure NE chemotaxis in mouse colon tissues. Caco-2 monolayers were used to evaluate epithelial integrity and permeability in vitro. A transwell model involving caco-2 cells and NE co-culture was used to assess NE chemotaxis. NE chemokines were measured by ELISA. A mouse model of NE exhaustion using an anti-Ly6G antibody was used to identify the role of NEs in F. nucleatum-induced colitis. Transcriptome sequencing and bioinformatics analysis were applied to screen cytokines and signaling pathways.

Results

Administration of F. nucleatum aggravated colitis in the DSS model. F. nucleatum infection downregulates ZO-1 and Occludin expression and increases intestinal permeability. Additionally, F. nucleatum-induced NE chemotaxis decreases the integrity and permeability of the caco-2 monolayer. F. nucleatum-induced NE chemotaxis is dependent on IEC-derived interleukin 8 (IL-8) secretion, mediated by the TLR2/ERK signaling pathway. In addition, NE exhaustion in mice inhibited F. nucleatum-induced intestinal barrier impairment and colitis.

Conclusion

F. nucleatum improves NE chemotaxis by infecting intestinal epithelial cells (IECs) to secrete IL-8 and aggravate intestinal barrier impairment, contributing to the progression of intestinal inflammation. Examining and eliminating F. nucleatum could be a valuable microbiome-based method for IBD surveillance and prevention.

A bidirectional Mendelian randomization analysis of the causal relationship between inflammatory bowel disease and breast cancer based on estrogen receptor status

The incidence of patients diagnosed with either breast cancer (BC) or inflammatory bowel disease (IBD) is increasing each year. IBD has been shown to be strongly associated with the development of a variety of solid tumors, but the relationship with breast cancer is not yet definitive. We explored the causative relationship between IBD and BC using a Mendelian randomization (MR) strategy. MR-Egger regression, weighted median (WM), simple median (SM), maximum likelihood (ML), and inverse variance weighting (IVW) methods were among the analytical techniques used in this work. The examination of heterogeneity was conducted by the use of Cochran's Q test and Rucker's Q test. The sensitivity analysis in this study used the IVW and MR-Egger methodologies. The results of our investigation suggested that IBD had a beneficial impact on estrogen receptor-negative (ER-) breast cancer (odds ratio (OR) = 0.92, P = 0.02). The study did not find a significant association between IBD and the risk of developing overall breast cancer (OR = 0.99, P = 0.60), as well as estrogen receptor-positive (ER+) breast cancer (OR = 1.02, P = 0.60) specifically. In addition, our study findings indicated that there was a detrimental association between ER+ breast cancer and IBD as determined using reverse MR analysis (OR = 1.07, P = 0.04). Furthermore, this analysis failed to observe any significant association between overall breast cancer (OR = 1.07, P = 0.07) or ER- breast cancer (OR = 0.99, P = 0.89) and IBD. Our bidirectional MR study yielded a correlation between IBD and some specific hormone receptor status of BC.

Naringin Alleviates Intestinal Fibrosis by Inhibiting ER Stress-Induced PAR2 Activation

Fibrosis characterized by intestinal strictures is a common complication of Crohn's disease (CD), without specific antifibrotic drugs, which usually relies on surgical intervention. The transcription factor XBP1, a key component of endoplasmic reticulum (ER) stress, is required for degranulation of mast cells and linked to PAR2 activation and fibrosis. Many studies have confirmed that naringin (NAR) can inhibit ER stress and reduce organ fibrosis. We hypothesized that ER stress activated the PAR2-induced epithelial-mesenchymal transition process by stimulating mast cell degranulation to release tryptase and led to intestinal fibrosis in CD patients; NAR might play an antifibrotic role by inhibiting ER stress-induced PAR2 activation. We report that the expression levels of XBP1, mast cell tryptase, and PAR2 are upregulated in fibrotic strictures of CD patients. Molecular docking simulates the interaction of NAR and spliced XBP1. ER stress stimulates degranulation of mast cells to secrete tryptase, activates PAR2-induced epithelial-mesenchymal transition process, and promotes intestinal fibrosis in vitro and vivo experiments, which is inhibited by NAR. Moreover, F2rl1 (the coding gene of PAR2) deletion in intestinal epithelial cells decreases the antifibrotic effect of NAR. Hence, the ER stress-mast cell tryptase-PAR2 axis can promote intestinal fibrosis, and NAR administration can alleviate intestinal fibrosis by inhibiting ER stress-induced PAR2 activation.

Targeting mucosal healing in Crohn's disease: efficacy of novel pathways and therapeutic targets

INTRODUCTION

Crohn's disease (CD) is a chronic inflammatory bowel disease affecting the entire gastrointestinal tract with a progressive and relapsing course. Achieving mucosal healing has emerged as a critical therapeutic goal, as it is associated with sustained clinical remission, reduced hospitalizations, and fewer surgery rates. Therefore, targeting mucosal healing is essential for long-term control in CD.

AREAS COVERED

This review evaluates the efficacy of novel biologic therapies and small molecules in inducing mucosal healing, specifically targeting pathways like IL-12/23, IL-23, α4β7 integrins, Janus kinase 1 (JAK1), and sphingosine-1-phosphate receptor (S1PR) in adults (≥18 years) with moderate-to-severe CD. The rationale for selecting these specific pathways is their central role in modulating key inflammatory processes implicated in CD pathogenesis. We compare these therapies with placebo for both induction and maintenance of remission, based on a PubMed literature review for published articles and ClinicalTrials.gov for ongoing trials.

EXPERT OPINION

Upadacitinib and anti-IL23p19 agents (risankizumab, guselkumab and mirikizumab) are promising advanced non-TNF-targeting therapies for inducing endoscopic remission and mucosal healing but further studies are needed to integrate mucosal healing into a broader definition of endoscopic response, with a unified and precise definition.

Bidirectional association between inflammatory bowel disease and type 1 diabetes: a nationwide matched cohort and case-control study

Background

Co-occurrence of inflammatory bowel disease (IBD) and type 1 diabetes (T1D) has been linked to poor clinical outcomes, but evidence on their bidirectional associations remain scarce. This study aims to investigate their bidirectional associations.

Methods

A nationwide matched cohort and case-control study with IBD patients identified between 1987 and 2017. The cohort study included 20,314 IBD patients (≤28 years; Crohn's disease [CD, n = 7277], ulcerative colitis [UC, n = 10,112], and IBD-unclassified [IBD-U, n = 2925]) and 99,200 individually matched reference individuals, with a follow-up until December 2021. The case-control study enrolled 87,001 IBD patients (no age restriction) and 431,054 matched controls. We estimated adjusted hazard ratio (aHR) of incident T1D in the cohort study with flexible parametric survival model and adjusted odds ratio (aOR) of having a prior T1D in the case-control study with conditional logistic regression model, with 95% confidence intervals (CI).

Findings

During a median follow-up of 14 years, 116 IBD patients and 353 reference individuals developed T1D. Patients with IBD had a higher hazard of developing T1D (aHR = 1.58 [95% CI = 1.27-1.95]). The hazard was increased in UC (aHR = 2.02 [1.51-2.70]) but not in CD or IBD-U. In the case-control study, a total of 1018 (1.2%) IBD patients and 3496 (0.8%) controls had been previously diagnosed with T1D. IBD patients had higher odds of having prior T1D (aOR = 1.36 [1.26-1.46]). Such positive association was observed in all IBD subtypes. The sibling comparison analyses showed similar associations between IBD and T1D (aHR = 1.44 [0.97-2.15] and aOR = 1.32 [1.18-1.49]).

Interpretation

Patients with IBD had a moderately increased hazard of developing T1D and higher odds of having prior T1D. Their bidirectional associations may be partially independent of shared familial factors.

Funding

European Crohn's and Colitis Organisation, Stiftelsen Professor Nanna Svartz Fond, SSMF (project#: PG-23-0315-H-02), Ruth and Richard Julin Foundation; and FORTE (project#: 2016-00424).

Sex and gender in inflammatory bowel disease outcomes and research

Extensive patient heterogeneity is a challenge in the management of inflammatory bowel disease (IBD). Sex and gender, as well as the interaction of sex and gender with other social identities, referred to as intersectionality, contribute to this heterogeneity and might affect IBD outcomes. An interdisciplinary team of clinicians, researchers, patients, and sex and gender experts reviewed current literature on the effect of sex and gender dimensions on IBD outcomes. The team also investigated the role that stakeholders have in advancing sex-based and gender-based IBD knowledge, as comprehensive studies are scarce. Acknowledging and integrating sex and gender into the organisation and content of research (eg, study design, participant recruitment, data analysis, data interpretation, data dissemination, and impact evaluation) could enhance the validity, relevance, and applicability of research. Such gendered innovation has potential for advancing personalised medicine and improving the quality of life for people with IBD.

YOD1 sustains NOD2-mediated protective signaling in colitis by stabilizing RIPK2

Inflammatory bowel disease (IBD) is a disorder causing chronic inflammation in the gastrointestinal tract, and its pathophysiological mechanisms are still under investigation. Here, we find that mice deficient of YOD1, a deubiquitinating enzyme, are highly susceptible to dextran sulfate sodium (DSS)-induced colitis. The bone marrow transplantation experiment reveals that YOD1 derived from hematopoietic cells inhibits DSS colitis. Moreover, YOD1 exerts its protective role by promoting nucleotide-binding oligomerization domain 2 (NOD2)-mediated physiological inflammation in macrophages. Mechanistically, YOD1 inhibits the proteasomal degradation of receptor-interacting serine/threonine kinase 2 (RIPK2) by reducing its K48 polyubiquitination, thereby increasing RIPK2 abundance to enhance NOD2 signaling. Consistently, the protective function of muramyldipeptide, a NOD2 ligand, in experimental colitis is abolished in mice deficient of YOD1. Importantly, YOD1 is upregulated in colon-infiltrating macrophages in patients with colitis. Collectively, this study identifies YOD1 as a novel regulator of colitis.

Molecular Mechanisms Underlying Loss of Vascular and Epithelial Integrity in Irritable Bowel Syndrome

BACKGROUND & AIMS

The pathophysiology of irritable bowel syndrome (IBS) is multifactorial and includes epithelial barrier dysfunction, a key element at the interface between the gut lumen and the deeper intestinal layers. Beneath the epithelial barrier there is the vascular one representing the last barrier to avoid luminal antigen dissemination The aims of this study were to correlate morpho-functional aspects of epithelial and vascular barriers with symptom perception in IBS.

METHODS

Seventy-eight healthy subjects (controls) and 223 patients with IBS were enrolled in the study and phenotyped according to validated questionnaires. Sugar test was used to evaluate in vivo permeability. Immunohistochemistry, western blot, and electron microscopy were used to characterize the vascular barrier. Vascular permeability was evaluated by assessing the mucosal expression of plasmalemma vesicle-associated protein-1 and vascular endothelial cadherin. Caco-2 or human umbilical vein endothelial cell monolayers were incubated with soluble mediators released by mucosal biopsies to highlight the mechanisms involved in permeability alteration. Correlation analyses have been performed among experimental and clinical data.

RESULTS

The intestinal epithelial barrier was compromised in patients with IBS throughout the gastrointestinal tract. IBS-soluble mediators increased Caco-2 permeability via a downregulation of tight junction gene expression. Blood vessel density and vascular permeability were increased in the IBS colonic mucosa. IBS mucosal mediators increased permeability in human umbilical vein endothelial cell monolayers through the activation of protease-activated receptor-2 and histone deacetylase 11, resulting in vascular endothelial cadherin downregulation. Permeability changes correlated with intestinal and behavioral symptoms and health-related quality of life of patients with IBS.

CONCLUSIONS

Epithelial and vascular barriers are compromised in patients with IBS and contribute to clinical manifestations.

Exosomes derived from cancer cells relieve inflammatory bowel disease in mice

Exosome therapy has garnered significant attention due to its natural delivery capabilities, low toxicity, high biocompatibility, and potential for personalised treatment through engineering modifications. Recent studies have highlighted the ability of tumour cell-derived exosomes (TDEs) to interact with immune cells or modify the immune microenvironment to suppress host immune responses, as well as their unique homing ability to parental cells. The core question of this study is whether this immunomodulatory property of TDEs can be utilised for the immunotherapy of inflammatory diseases. In our experiments, we prepared exosomes derived from murine colon cancer cells CT26 (CT26 exo) using ultracentrifugation, characterised them, and conducted proteomic analysis. The therapeutic potential of CT26 exo was evaluated in our dextran sulphate sodium salt (DSS)-induced inflammatory bowel disease (IBD) mouse model. Compared to the control and 293 T exo treatment groups, mice treated with CT26 exo showed a reduction in the disease activity index (DAI) and colon shortening rate, with no noticeable weight loss. Haematoxylin and eosin (H&E) staining of colon paraffin sections revealed reduced inflammatory infiltration and increased epithelial goblet cells in the colons of CT26 exo-treated group. Furthermore, we conducted preliminary mechanistic explorations by examining the phenotyping and function of CD4+ T cells and dendritic cells (DCs) in the colonic lamina propria of mice. The results indicated that the ameliorative effect of CT26 exosomes might be due to their inhibition of pro-inflammatory cytokine secretion by colonic DCs and selective suppression of Th17 cell differentiation in the colon. Additionally, CT26 exo exhibited good biosafety. Our findings propose a novel exosome-based therapeutic approach for IBD and suggest the potential application of TDEs in the treatment of inflammatory diseases.

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.

The landscape of new therapeutic opportunities for IBD

This chapter presents an overview of the emerging strategies to address the unmet needs in the management of inflammatory bowel diseases (IBD). IBD poses significant challenges, as over half of patients experience disease progression despite interventions, leading to irreversible complications, and a substantial proportion do not respond to existing therapies, such as biologics. To overcome these limitations, we describe a diverse array of novel therapeutic approaches. In the area of immune homeostasis restoration, the focus is on targeting cytokine networks, leukocyte trafficking, novel immune pathways, and cell therapies involving regulatory T cells and mesenchymal stem cells (MSC). Recognizing the critical role of impaired intestinal barrier integrity in IBD, we highlight therapies aimed at restoring barrier function and promoting mucosal healing, such as those targeting cell proliferation, tight junctions, and lipid mediators. Addressing the challenges posed by fibrosis and fistulas, we describe emerging targets for reversing fibrosis like kinase and cytokine inhibitors and nuclear receptor agonists, as well as the potential of MSC for fistulas. The restoration of a healthy gut microbiome, through strategies like fecal microbiota transplantation, rationally defined bacterial consortia, and targeted antimicrobials, is also highlighted. We also describe innovative approaches to gut-targeted drug delivery to enhance efficacy and minimize side effects. Reinforcing these advancements is the critical role of precision medicine, which emphasizes the use of multiomics analysis for the discovery of biomarkers to enable personalized IBD care. Overall, the emerging landscape of therapeutic opportunities for IBD holds great potential to surpass the therapeutic ceiling of current treatments.

Effectiveness comparison between ustekinumab and infliximab for Crohn's disease complicated with intestinal stenosis: a multicenter real-world study

Background

The efficacy of ustekinumab (UST) and infliximab (IFX) in Crohn's disease (CD) patients with intestinal stenosis remains uncertain.

Objective

This study aims to compare the efficacy of UST and IFX in the treatment of CD patients with intestinal stenosis.

Design

This was a retrospective and multicenter cohort study.

Methods

In this retrospective study, we included CD patients treated with IFX or UST at five centers. We assessed the clinical response rate at weeks 12 and 24, steroid-free clinical remission rate at weeks 24 and 52 for overall patients and those with stenosis, and objective examination (intestinal ultrasound and/or endoscopy) response rate at week 52 for stenosis patients.

Results

A total of 211 CD patients (106 IFX and 105 UST) were included, with 119 (56 IFX and 63 UST) having intestinal stenosis. In the overall patient population, there were no significant differences in clinical response rate and steroid-free clinical remission rate at weeks 12, 24, and 52 between the IFX and UST groups. In patients with stenosis, the steroid-free clinical remission rate at week 52 was significantly lower in the IFX group compared to the UST group (51.79% IFX vs 69.84% UST, p = 0.044). The objective examination response rate did not significantly differ between the IFX and UST groups at week 52 (66.67% IFX vs 76.19% UST, p = 0.690). In the UST group, steroid-free clinical remission rate was higher in bio-naïve patients than bio-experienced patients at week 24 (75.00% bio-naïve vs 55.38% bio-experienced, p = 0.043).

Conclusion

UST may be considered a more advantageous treatment option for those CD patients with intestinal stenosis, as it has better steroid-free clinical remission rates compared to IFX.

Global burden of inflammatory bowel disease in the elderly: trends from 1990 to 2021 and projections to 2051

Background

This study aims to analyze the historical trends of inflammatory bowel disease (IBD) burden in the elderly from 1990 to 2021 and forecast future trends up to 2051.

Methods

Data from the Global Burden of Disease Study 2021 were utilized. Age-standardized rates (ASR) for incidence, prevalence, mortality, and disability-adjusted life years (DALYs) were calculated. Estimated annual percentage changes (EAPCs) were computed to quantify temporal trends. A Bayesian Age-Period-Cohort model was employed to project future trends.

Results

From 1990 to 2021, the global number of elderly IBD increased from 573,500 to 1,278,190. The age-standardized incidence rate (ASIR) rose from 8.01 to 8.77 per 100,000, while the age-standardized prevalence rate (ASPR) slightly decreased from 118.14 to 117.29 per 100,000. Death number increased from 14,400 to 33,490, but the age-standardized mortality rate decreased from 3.21 to 2.84 per 100,000. DALYs increased from 324,100 to 683,750, with the age-standardized DALYs rate declining from 68.78 to 60.88 per 100,000. Significant geographical variations were observed, with high Socio-demographic Index regions showing the highest burden. Projections suggest that by 2051, elderly IBD prevalence number may reach 2,316,000, with ASIR and ASPR potentially rising after 2035 and 2042, respectively. Deaths and DALYs are projected to increase to 75,000 and 1,401,000 respectively, despite continued declines in ASRs.

Conclusion

The absolute burden of IBD in the elderly population is projected to increase substantially by 2051, despite decreasing ASRs. These findings underscore the need for tailored healthcare strategies and resource allocation to address the growing challenge of elderly IBD globally.

Metaproteomics reveals diet-induced changes in gut microbiome function according to Crohn's disease location

BACKGROUND

Crohn's disease (CD) is characterized by chronic intestinal inflammation. Diet is a key modifiable factor influencing the gut microbiome (GM) and a risk factor for CD. However, the impact of diet modulation on GM function in CD patients is understudied. Herein, we evaluated the effect of a high-fiber, low-fat diet (the Mi-IBD diet) on GM function in CD patients. All participants were instructed to follow the Mi-IBD diet for 8 weeks. One group of CD patients received one-time diet counseling only (Gr1); catered food was supplied for the other three groups, including CD patients (Gr2) and dyads of CD patients and healthy household controls (HHCs) residing within the same household (Gr3-HHC dyads). Stool samples were collected at baseline, week 8, and week 36, and analyzed by liquid chromatography-tandem mass spectrometry.

RESULTS

At baseline, the metaproteomic profiles of CD patients and HHCs differed. The Mi-IBD diet significantly increased carbohydrate and iron transport and metabolism. The predicted microbial composition underlying the metaproteomic changes differed between patients with ileal only disease (ICD) or colonic involvement: ICD was characterized by decreased Faecalibacterium abundance. Even on the Mi-IBD diet, the CD patient metaproteome displayed significant underrepresentation of carbohydrate and purine/pyrimidine synthesis pathways compared to that of HHCs. Human immune-related proteins were upregulated in CD patients compared to HHCs.

CONCLUSIONS

The Mi-IBD diet changed the microbial function of CD patients and enhanced carbohydrate metabolism. Our metaproteomic results highlight functional differences in the microbiome according to disease location. Notably, our dietary intervention yielded the most benefit for CD patients with colonic involvement compared to ileal-only disease. Video Abstract.

Multifunctional MnGA Nanozymes for the Treatment of Ulcerative Colitis by Reducing Intestinal Inflammation and Regulating the Intestinal Flora

In ulcerative colitis (UC), the formation of an inflammatory environment is due to the combined effects of excess production of reactive oxygen species (ROS) and reactive nitrogen species (RNS), overproduction of proinflammatory cytokines, and disruption of immune system function. There are many kinds of traditional drugs for the clinical treatment of UC, but long-term drug use can cause toxic side effects and drug resistance and can also reduce patient compliance and other drawbacks. Hence, in light of the clinical challenges associated with UC, including the limitations of existing treatments, intense adverse reactions and the development of resistance to medications, no novel therapeutic agents that offer effective relief and maintain a high level of biosafety are urgently needed. Although many anti-inflammatory nanomedicines have been developed by researchers, the development of efficient and nontoxic nanomedicines is still a major challenge in clinical medicine. Using the natural product gallic acid and the metal compound manganese chloride, a highly effective and nontoxic multifunctional nanoenzyme was developed for the treatment of UC. Nanozymes can effectively eliminate ROS and RNS to reduce the inflammation of intestinal epithelial cells caused by oxidation, facilitate the restoration of the intestinal epithelial barrier through the upregulation of tight junction protein expression, and balance the intestinal microbiota to maintain the stability of the intestinal environment. Using a rodent model designed to mimic UC, we monitored body weight, colon length, the spleen index, and the degree of tissue damage and demonstrated that manganese gallate (MnGA) nanoparticles can reduce intestinal inflammation by clearing ROS and active nitrogen. Intestinal flora sequencing revealed that MnGA nanoparticles could regulate the intestinal flora, promote the growth of beneficial bacteria and decrease the levels of detrimental bacteria within the intestinal tract in a mouse model of UC. Thus, MnGA nanoparticles can maintain the balance of the intestinal flora. This study demonstrated that MnGA nanoparticles are excellent antioxidant and effective anti-inflammatory agents, have good biosafety, and can effectively treat UC.

Therapeutic Effects of Zanthoxyli Pericarpium on Intestinal Inflammation and Network Pharmacological Mechanism Analysis in a Dextran Sodium Sulfate-Induced Colitis Mouse Model

(1) Background: IBD (inflammatory bowel disease) is characterized by chronic intestinal inflammation leading to persistent symptoms and a lack of effective treatments. ZP (Zanthoxyli Pericarpium) has been used in traditional Chinese medicine for its anti-inflammatory and antioxidant properties for the management of intestinal disorders. (2) Methods: This study aimed to investigate the components of ZP, their specific targets, and associated diseases using the TCMSP (Traditional Chinese Medicine Systems Pharmacology) analysis platform, TCMBank database, and ETCM2.0 (Encyclopedia of Traditional Chinese Medicine 2.0) database. Additionally, we explored the protective effects of ZP on the colon and the underlying molecular mechanisms in the treatment of IBD. (3) Results: We identified 59 compounds in ZP that target 38 genes related to IBD, including PTGS2, PPARG, and GPBAR1. In a mice model of DSS (dextran sodium sulfate)-induced colitis, ZP significantly reduced colonic epithelial damage and oxidative stress markers, such as iNOS and nitrotyrosine, demonstrating its antioxidant properties. (4) Conclusions: These findings suggest that ZP has protective effects against DSS-induced colonic damage owing to its anti-inflammatory and antioxidant properties, making it a potential candidate for IBD treatment. However, further research and clinical trials are required to confirm its therapeutic potential and safety in humans.

Worldwide research trends in Crohn's disease treatment over the past 2 decades: a bibliometric analysis

Background

The treatment of Crohn's disease (CD) has received widespread attention in clinical practice, but there is currently a lack of quantitative evaluation of the literature published in this field. This study aimed to describe the development trends and research hotspots of CD treatment through bibliometric analysis.

Methods

Publications related to CD treatment published from 2004 to 2023 were searched in the WoSCC. Microsoft Office Excel 2021 was used for the analysis and visualization of the annual number of publications. CiteSpace was used to visualize the collaboration networks of authors, institutions, and countries, as well as to construct a reference timeline visualization map and identify keywords with the strongest citation bursts.

Results

The bibliometric analysis included 25,608 publications between 2004 and 2023. The most productive year was 2021. The United States of America (n = 7,891) and the University of California System (n = 939) are the country and institution with the most published papers, respectively. Among the 97,564 authors, Peyrin-Biroulet, Laurent (n = 424) published the most articles. The core journals were Inflammatory Bowel Diseases, Journal of Crohns and Colitis, Alimentary Pharmacology and Therapeutics, etc. The timeline view showed that "#5 JAK Inhibitor" was the most recent topic. The keywords that burst and persist from 2020 to 2023 include "ustekinumab" and "vedolizumab".

Conclusion

An increasing number of researchers are dedicating their efforts to exploring the treatment of CD, with the United States making the largest contribution to this field. Currently, the research hotspots predominantly involve drug therapy including ustekinumab, vedolizumab, and JAK inhibitors. Our study provides valuable information for scholars studying CD treatment.

Patient Perspectives of Bowel Urgency and Bowel Urgency-Related Accidents in Ulcerative Colitis and Crohn's Disease

BACKGROUND

Bowel urgency is bothersome in patients with ulcerative colitis (UC) or Crohn's disease (CD) and impacts their well-being but remains underappreciated in clinical trials and during patient-healthcare provider interactions. This study explored the experiences of bowel urgency and bowel urgency-related accidents to identify the concepts most relevant and important to patients.

METHODS

Adults with a diagnosis of moderate-to-severe UC or CD for ≥6 months and experience of bowel urgency in the past 6 months were included. Qualitative, semi-structured interviews were conducted via telephonic/Web-enabled teleconference. Interview transcripts were coded and analyzed in ATLAS.ti 9 using a systematic thematic analysis.

RESULTS

In total, 30 participants with UC or CD (n = 15 each) (mean age 52 and 50 years, respectively) participated in the interviews. The majority of participants were receiving biologic and/or conventional therapy (80% and 87%, respectively). Most participants with UC (87%) and all with CD experienced bowel urgency-related accidents. The most frequently reported symptoms co-occurring with bowel urgency were abdominal pain, fatigue, and abdominal cramping. Abdominal pain and abdominal cramping were the most bothersome co-occurring symptoms of bowel urgency and bowel urgency-related accidents. In both groups, participants reported decreased frequency of bowel urgency and not wanting to experience bowel urgency-related accidents at all as a meaningful improvement.

CONCLUSIONS

Participants with UC or CD expressed bowel urgency and bowel urgency-related accidents to be bothersome and impactful on their daily lives despite use of biologic and/or conventional therapy. These findings underscore the need for development of patient-reported outcome measures to assess bowel urgency in clinical settings.

Real-World Persistence of Successive Biologics in Patients With Inflammatory Bowel Disease: Findings From ROTARY

BACKGROUND

Patients with inflammatory bowel disease (IBD) may receive multiple successive biologic treatments in clinical practice; however, data are limited on the comparative effectiveness of biologics and the impact of treatment sequence on outcomes.

METHODS

The ROTARY (Real wOrld ouTcomes Across tReatment sequences in inflammatorY bowel disease patients) study was a retrospective, observational cohort study conducted using data from the Optum Clinical Database between January 1, 2012, and February 29, 2020. Adult patients with Crohn's disease (CD) or ulcerative colitis (UC) who received 2 biologics successively were included. Biologic treatment sequences were analyzed descriptively. Cox proportional hazards models, adjusted for baseline demographics and clinical characteristics, were used to estimate the hazard ratio of switching or discontinuation for each first- and second-line biologic compared with first- and second-line adalimumab, respectively.

RESULTS

In total, 4648 patients with IBD (CD, n = 3008; UC, n = 1640) were identified. Most patients received tumor necrosis factor α antagonist (anti-TNFα) treatment followed by another anti-TNFα treatment or vedolizumab. Vedolizumab and infliximab had 39.4% and 34.6% lower rates of switching or discontinuation than adalimumab, respectively, as first-line biologics in patients with CD and 30.8% and 34.3% lower rates as first-line biologics in patients with UC, respectively. Vedolizumab, infliximab, and ustekinumab had 47.2%, 40.0%, and 43.5% lower rates of switching or discontinuation than adalimumab, respectively, as second-line biologics in CD and 56.5%, 43.0%, and 45.6% lower rates as second-line biologics in patients with UC, respectively.

CONCLUSIONS

Although anti-TNFα treatments were most commonly prescribed, the adjusted rates of discontinuation for adalimumab as both a first- and second-line biologic were higher than for vedolizumab, infliximab, or ustekinumab.

PCK2 maintains intestinal homeostasis and prevents colitis by protecting antibody-secreting cells from oxidative stress

Maintaining intracellular redox balance is essential for the survival, antibody secretion, and mucosal immune homeostasis of immunoglobulin A (IgA) antibody-secreting cells (ASCs). However, the relationship between mitochondrial metabolic enzymes and the redox balance in ASCs has yet to be comprehensively studied. Our study unveils the pivotal role of mitochondrial enzyme PCK2 in regulating ASCs' redox balance and intestinal homeostasis. We discover that PCK2 loss, whether globally or in B cells, exacerbates dextran sodium sulphate (DSS)-induced colitis due to increased IgA ASC cell death and diminished antibody production. Mechanistically, the absence of PCK2 diverts glutamine into the TCA cycle, leading to heightened TCA flux and excessive mitochondrial reactive oxygen species (mtROS) production. In addition, PCK2 loss reduces glutamine availability for glutathione (GSH) synthesis, resulting in a decrease of total glutathione level. The elevated mtROS and reduced GSH expose ASCs to overwhelming oxidative stress, culminating in cell apoptosis. Crucially, we found that the mitochondria-targeted antioxidant Mitoquinone (Mito-Q) can mitigate the detrimental effects of PCK2 deficiency in IgA ASCs, thereby alleviating colitis in mice. Our findings highlight PCK2 as a key player in IgA ASC survival and provide a potential new target for colitis treatment.

Bergapten enhances mitophagy to regulate intestinal barrier and Th17/Treg balance in mice with Crohn's disease-like colitis via PPARγ/NF-κB signaling pathway

This study aimed to investigate whether bergapten (BG), a furanocoumarin phytohormone, holds promise for Crohn's disease (CD)-like colitis treatment and to preliminarily explore its potential mechanisms. 2,4,6-Trinitrobenzenesufonic acid (TNBS)-treated mice were applied to establish an in vivo research model, and BG was administered with different concentrations. The status of mice in each group was evaluated by disease activity index (DAI), and the severity was evaluated by pathological sections. The intestinal barrier was assessed by measuring in vivo intestinal permeability, peripheral blood intestinal fatty acid-binding protein (I-FABP) levels, epithelial resistance values, and tight junction protein levels. Markers were then used to assess Th17/Treg levels, mitophagy, and the peroxisome proliferator-activated receptor (PPAR)γ/ nuclear factor kappa B (NF-κB) signaling pathway. BG significantly reduced colon tissue damage in a concentration-dependent manner. DAI scores showed that the loose feces, occult blood, and weight loss of mice in the BG treatment were significantly reduced, and pathological section results revealed reduced inflammatory infiltration and fibrosis. Reduced serum FITC-dextran and I-FABP and increased levels of epithelial resistance and tight junction proteins support that the intestinal barrier was protected upon BG. The proportion of Th17 in mesenteric lymph nodes increased while Treg decreased in the model group. BG treatment effectively reduced the conversion of Treg to Th17. Additionally, BG was found to enhance mitophagy and activate the PPARγ/NF-κB signaling. BG demonstrates promising effects in ameliorating intestinal barrier damage and Th17/Treg imbalance in a murine model of CD-like colitis, while also promoting intracellular mitophagy. The PPARγ/NF-κB signaling pathway may serve as a key mediator of BG's regulatory mechanisms.

Peak enhancement in contrast-enhanced ultrasound for assessing endoscopic disease activity in patients with Crohn's disease: a meta-analysis

BACKGROUND

Contrast-enhanced ultrasound (CEUS) has been proposed as a valuable tool for detecting disease activity in patients with Crohn's disease (CD). However, previous studies have utilized different parameters, leading to variation in clinical assessment of this technique.

PURPOSE

To assess the effectiveness of peak enhancement (PE) in CEUS for evaluating endoscopic disease activity in patients with CD.

MATERIAL AND METHODS

Articles were obtained by searching PubMed, Embase, Web of Science, Wanfang, and CNKI databases. Only studies that investigated the effectiveness of PE in CEUS to discriminate endoscopic disease activity in patients with CD were considered. Pooled sensitivity and specificity were then calculated using a random effects model.

RESULTS

Overall, seven studies were included. The endoscopic disease activity of CD was determined based on the simple endoscopic score for Crohn's disease and Crohn's Disease Endoscopic Index of Severity scores. Pooled results showed that a high PE was associated with increased detection efficacy for endoscopic disease activity in CD. Pooled sensitivity, specificity, and positive and negative likelihood ratios were 0.88 (95% confidence interval [CI] = 0.71-0.96), 0.88 (95% CI = 0.81-0.93), 7.60 (95% CI = 4.61-12.53), and 0.14 (95% CI = 0.05-0.35), respectively. The pooled receiver operating characteristic was 0.90 (95% CI = 0.87-0.92), suggesting a good discriminating efficacy of PE in CEUS for endoscopic disease activity of patients with CD.

CONCLUSIONS

A high PE in CEUS displayed substantial distinguishing accuracy for assessing endoscopic disease activity of patients with CD.

Deubiquitination of RIPK2 by OTUB2 augments NOD2 signalling and protective effects in intestinal inflammation

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic inflammatory disorder of the gastrointestinal tract, but the molecular mechanisms underlying IBD are incompletely understood. In this study, we explored the role and regulating mechanism of otubain 2 (OTUB2), a deubiquitinating enzyme, in IBD.

METHODS

To study the function of OTUB2 in IBD, we generated Otub2-/- mice and treated them with dextran sulfate sodium (DSS) to induce experimental colitis. Bone marrow transplantation was performed to identify the cell populations that were affected by OTUB2 in colitis. The molecular mechanism of OTUB2 in signal transduction was studied by various biochemical methods.

RESULTS

OTUB2 was highly expressed in colon-infiltrating macrophages in both humans with IBD and mice with DSS-induced experimental colitis. Colitis was significantly aggravated in Otub2-/- mice and bone marrow chimeric mice receiving Otub2-/- bone marrow. OTUB2-deficiency impaired the production of cytokines and chemokines in macrophages in response to the NOD2 agonist muramyl dipeptide (MDP). Upon MDP stimulation, OTUB2 promoted NOD2 signaling by stabilizing RIPK2. Mechanistically, OTUB2 inhibited the proteasomal degradation of RIPK2 by removing K48-linked polyubiquitination on RIPK2, which was mediated by the active C51 residue in OTUB2. In mice, OTUB2 ablation abolished the protective effects of MDP administration in colitis.

CONCLUSION

This study identified OTUB2 as a novel regulator of intestinal inflammation.