Targeting Leukocyte Trafficking in Inflammatory Bowel Disease

The role of macrophage polarization in ulcerative colitis and its treatment

Macrophages have great plasticity. Typically, there are two of activated macrophages: M1 macrophages and M2 macrophages. Of them, M1 macrophages play a major role in responses that are pro-inflammatory, while M2 macrophages play an important part in responses that are anti-inflammatory. Ulcerative colitis (UC) is a chronic, non-specific inflammatory disease of the intestine. The pathophysiology and course of UC are significantly influenced by the inflammatory response triggered by macrophage activation. M1 is a possible cause of increased inflammation in UC whereas M2 has a significant function in the healing of inflammation. The polarization imbalance of intestinal M1/M2 macrophages is closely linked to UC. Thus, by suppressing M1 polarization, encouraging M2 polarization, and reestablishing macrophage polarization balance, the treatment of UC based on macrophage polarization is beneficial for UC. Not only chemical drugs, but also traditional Chinese medicine compounds and herbal extracts have been shown to restore the balance of macrophage polarization, providing a new idea in the treatment of UC.

Defining predictors of responsiveness to advanced therapies in Crohn's disease and ulcerative colitis: protocol for the IBD-RESPONSE and nested CD-metaRESPONSE prospective, multicentre, observational cohort study in precision medicine

INTRODUCTION

Characterised by chronic inflammation of the gastrointestinal tract, inflammatory bowel disease (IBD) symptoms including diarrhoea, abdominal pain and fatigue can significantly impact patient's quality of life. Therapeutic developments in the last 20 years have revolutionised treatment. However, clinical trials and real-world data show primary non-response rates up to 40%. A significant challenge is an inability to predict which treatment will benefit individual patients.Current understanding of IBD pathogenesis implicates complex interactions between host genetics and the gut microbiome. Most cohorts studying the gut microbiota to date have been underpowered, examined single treatments and produced heterogeneous results. Lack of cross-treatment comparisons and well-powered independent replication cohorts hampers the ability to infer real-world utility of predictive signatures.IBD-RESPONSE will use multi-omic data to create a predictive tool for treatment response. Future patient benefit may include development of biomarker-based treatment stratification or manipulation of intestinal microbial targets. IBD-RESPONSE and downstream studies have the potential to improve quality of life, reduce patient risk and reduce expenditure on ineffective treatments.

METHODS AND ANALYSIS

This prospective, multicentre, observational study will identify and validate a predictive model for response to advanced IBD therapies, incorporating gut microbiome, metabolome, single-cell transcriptome, human genome, dietary and clinical data. 1325 participants commencing advanced therapies will be recruited from ~40 UK sites. Data will be collected at baseline, week 14 and week 54. The primary outcome is week 14 clinical response. Secondary outcomes include clinical remission, loss of response in week 14 responders, corticosteroid-free response/remission, time to treatment escalation and change in patient-reported outcome measures.

ETHICS AND DISSEMINATION

Ethical approval was obtained from the Wales Research Ethics Committee 5 (ref: 21/WA/0228). Recruitment is ongoing. Following study completion, results will be submitted for publication in peer-reviewed journals and presented at scientific meetings. Publications will be summarised at www.ibd-response.co.uk.

TRIAL REGISTRATION NUMBER

ISRCTN96296121.

Influential factors on disease activity in Crohn's disease and their Roc curve evaluation: a cross-sectional study

OBJECTIVE

This study aims to investigate the factors influencing disease activity in patients with Crohn's disease (CD) and provide insights and references for the management and prevention of CD.

METHODS

We recruited CD patients who met the inclusion and exclusion criteria and were treated at the First Affiliated Hospital of Soochow University from November 2022 to June 2023. Generalized linear mixed models were used to analyze the factors affecting disease activity in CD patients. Receiver operating characteristic (ROC) curve analysis was employed to assess the predictive value of these factors for disease activity.

RESULTS

A total of 268 CD participants aged 18 to 65 were included in the study, with over 68% of them in remission or experiencing mild disease activity, indicating relatively good disease control. The results of the generalized linear mixed models showed that older age, absence of diabetes, high levels of physical activity, and a low dietary inflammatory index (DII) were protective factors for lower disease activity in CD patients (p < 0.05). ROC curve analysis demonstrated that physical activity level, age, and DII all had ROC areas greater than 0.6 in predicting disease activity in CD patients (p < 0.05).

CONCLUSION

The factors influencing the disease activity of CD patients are numerous and should be given attention. CD patients who are younger, have low levels of physical activity, high DII, and have diabetes are at a higher risk of increased disease activity. By reducing or avoiding the mentioned risk factors and leveraging protective factors, it is possible to mitigate the disease activity of CD to some extent.

Identification of platelet-related subtypes and diagnostic markers in pediatric Crohn's disease based on WGCNA and machine learning

Background

The incidence of pediatric Crohn's disease (PCD) is increasing worldwide every year. The challenges in early diagnosis and treatment of PCD persist due to its inherent heterogeneity. This study's objective was to discover novel diagnostic markers and molecular subtypes aimed at enhancing the prognosis for patients suffering from PCD.

Methods

Candidate genes were obtained from the GSE117993 dataset and the GSE93624 dataset by weighted gene co-expression network analysis (WGCNA) and differential analysis, followed by intersection with platelet-related genes. Based on this, diagnostic markers were screened by five machine learning algorithms. We constructed predictive models and molecular subtypes based on key markers. The models were evaluated using the GSE101794 dataset as the validation set, combined with receiver operating characteristic curves, decision curve analysis, clinical impact curves, and calibration curves. In addition, we performed pathway enrichment analysis and immune infiltration analysis for different molecular subtypes to assess their differences.

Results

Through WGCNA and differential analysis, we successfully identified 44 candidate genes. Following this, employing five machine learning algorithms, we ultimately narrowed it down to five pivotal markers: GNA15, PIK3R3, PLEK, SERPINE1, and STAT1. Using these five key markers as a foundation, we developed a nomogram exhibiting exceptional performance. Furthermore, we distinguished two platelet-related subtypes of PCD through consensus clustering analysis. Subsequent analyses involving pathway enrichment and immune infiltration unveiled notable disparities in gene expression patterns, enrichment pathways, and immune infiltration landscapes between these subtypes.

Conclusion

In this study, we have successfully identified five promising diagnostic markers and developed a robust nomogram with high predictive efficacy. Furthermore, the recognition of distinct PCD subtypes enhances our comprehension of potential pathogenic mechanisms and paves the way for future prospects in early diagnosis and personalized treatment.

Gentianine alleviates dextran sulfate sodium-induced ulcerative colitis via inhibition of TLR4/NLRP3-mediated pyroptosis

OBJECTIVES

Ulcerative colitis (UC) is a common inflammatory bowel disorder. Gentiana scabra Bunge is a traditional medicinal plant that is used to treat a variety of diseases. Studies have shown that gentianine (GTN) from Gentiana scabra inhibits the development of inflammatory diseases. The purpose of this study was to investigate the effect and possible mechanism of action of GTN on UC in mice.

METHODS

An animal model of UC was established using dextran sulfate sodium (DSS). Mice were administered intraperitoneally with GTN (12.5, 25, or 50 mg/kg/day) for seven days. Body weight and disease activity index (DAI) were monitored daily during GTN administration. Colon length, pathological changes, and myeloperoxidase (MPO) activity were measured following GTN administration. The signalling pathways regulated by GTN were analysed using machine learning. HT-29 cells were used to verify the effect and mechanism of action of GTN on UC in vitro.

RESULTS

GTN suppressed weight loss, shortened colon length, alleviated colon injury, and reduced the DAI score and MPO activity of mice with UC in a dose-dependent manner. Further analysis showed that GTN inhibited the NOD-like receptor (NLR) signalling pathway. GTN markedly decreased the levels of NLR signalling pathway-related proteins. Moreover, GTN decreased the levels of pyroptosis-related proteins, IL-1β and IL-18. The in vitro data were consistent with those of animal experiments. Furthermore, TLR4 and NLRP3 overexpression eliminated the protective effects of GTN in HT-29 cells.

CONCLUSION

Gentianine alleviated DSS-induced UC by inhibiting TLR4/NLRP3-mediated pyroptosis.

Ozanimod: A Review in Ulcerative Colitis

Ozanimod (Zeposia®) is the first sphingosine-1-phosphate receptor (S1PR) modulator to be approved for the treatment of adults with moderately to severely active ulcerative colitis in the USA, and in adults with moderately to severely active ulcerative colitis who have had an inadequate or lost response to, or were intolerant of, either conventional therapy or a biologic in the EU. An oral agent, ozanimod is administered once daily as induction and maintenance therapy. In the randomized, double-blind, multinational phase 2 Touchstone and phase 3 True North clinical trials, ozanimod was effective in inducing clinical remission and maintaining remission relative to placebo in adults with moderately to severely active ulcerative colitis. Ozanimod was generally well tolerated in these studies, with manageable or transient adverse events (AEs). Current data from the Touchstone and True North open-label extensions are consistent with the primary studies with respect to therapeutic efficacy and tolerability, with no new safety signals observed. Although further data will be beneficial, ozanimod expands the treatment options for adults with moderately to severely active ulcerative colitis.

Liver-side of inflammatory bowel diseases: Hepatobiliary and drug-induced disorders

Hepatobiliary disorders are among the most common extraintestinal manifestations in inflammatory bowel diseases (IBD), both in Crohn’s disease and ulcerative colitis (UC), and therefore represent a diagnostic challenge. Immune-mediated conditions include primary sclerosing cholangitis (PSC) as the main form, variant forms of PSC (namely small-duct PSC, PSC-autoimmune hepatitis overlap syndrome and IgG4-related sclerosing cholangitis) and granulomatous hepatitis. PSC is by far the most common, presenting in up to 8% of IBD patients, more frequently in UC. Several genetic foci have been identified, but environmental factors are preponderant on disease pathogenesis. The course of the two diseases is typically independent. PSC diagnosis is based mostly on typical radiological findings and exclusion of secondary cholangiopathies. Risk of cholangiocarcinoma is significantly increased in PSC, as well as the risk of colorectal cancer in patients with PSC and IBD-related colitis. No disease-modifying drugs are approved to date. Thus, PSC management is directed against symptoms and complications and includes medical therapies for pruritus, endoscopic treatment of biliary stenosis and liver transplant for end-stage liver disease. Other non-immune-mediated hepatobiliary disorders are gallstone disease, whose incidence is higher in IBD and reported in up to one third of IBD patients, non-alcoholic fatty liver disease, pyogenic liver abscess and portal vein thrombosis. Drug-induced liver injury (DILI) is an important issue in IBD, since most IBD therapies may cause liver toxicity; however, the incidence of serious adverse events is low. Thiopurines and methotrexate are the most associated with DILI, while the risk related to anti-tumor necrosis factor-α and anti-integrins is low. Data on hepatotoxicity of newer drugs approved for IBD, like anti-interleukin 12/23 and tofacitinib, are still scarce, but the evidence from other rheumatic diseases is reassuring. Hepatitis B reactivation during immunosuppressive therapy is a major concern in IBD, and adequate screening and vaccination is warranted. On the other hand, hepatitis C reactivation does not seem to be a real risk, and hepatitis C antiviral treatment does not influence IBD natural history. The approach to an IBD patient with abnormal liver function tests is complex due to the wide range of differential diagnosis, but it is of paramount importance to make a quick and accurate diagnosis, as it may influence the therapeutic management.