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

Antioxidants as Modulators of NETosis: Mechanisms, Evidence, and Therapeutic Potential

Neutrophil extracellular trap (NET) formation is a process known as NETosis and is a critical innate immune response mechanism that can become pathologically dysregulated in various inflammatory, autoimmune, infectious, and neoplastic diseases. Reactive oxygen species (ROS) play a central role in NETosis induction, making antioxidants a promising therapeutic approach. This review outlines the molecular mechanisms underlying NET formation and highlights three principal antioxidant-based inhibitory strategies: NADPH oxidase (NOX) inhibition, ROS scavenging, and myeloperoxidase (MPO) inhibition. Evidence supports the use of agents such as diphenylene iodonium (NOX inhibitor), N-acetylcysteine and glutathione (ROS scavengers), and thiocyanate (MPO inhibitor), which significantly reduce NETosis in vitro and in vivo. Moreover, natural compounds like resveratrol show pleiotropic effects by modulating neutrophil activation, ROS production, and protease activity. Combination therapies that enhance total antioxidant capacity are particularly effective, though their translation to clinical practice faces challenges such as stimulus specificity, bioavailability, and maintaining immune competence. Antioxidant-based therapies thus represent a promising avenue for targeted NETosis modulation. Future research should focus on improving delivery systems, identifying NET-specific biomarkers, and integrating antioxidants into broader immunomodulatory strategies.

Quercetin protected the gut barrier in ulcerative colitis by activating aryl hydrocarbon receptor

BACKGROUND

Ulcerative colitis (UC) is characterized by abdominal pain and bloody diarrhoea and restoring the gut barrier is the core goal of UC treatment. Activation of aryl hydrocarbon receptor (Ahr) was reported to effectively alleviate symptoms and repair the gut barrier damage. Neutrophil extracellular traps (NETs) have been recognized as potential targets in the treatment of UC. Ahr activation has been found to be capable of upregulating Nqo1, thereby reducing the production of reactive oxygen species (ROS), which is important in the formation of NETs. Quercetin (QUE), which is derived from natural plants and herbs used in traditional Chinese medicine (TCM), is able to strengthen gut barrier function by activating Ahr.

PURPOSE

The aim of this study is to investigate how QUE suppresses NETs in UC and activates Ahr in neutrophils.

METHODS

In this study, the dextran sulfate sodium (DSS)-induced UC model was used. Histopathological assessments were performed in the paraffin slides of tissues after H&E, PAS, Masson and alcian blue staining. The concentration of cytokines was also detected using cytometric beads array kits. Based on the transcriptomic analysis of colon tissues, western blot (WB) analysis, immunohistochemistry (IHC) assays and immunofluorescence (IF) assays were conducted to validate the significantly regulated genes and pathways. In vitro, the binding of quercetin to Ahr was calculated by molecular dynamic simulations (MDS) and biolayer interferometry (BLI) analysis. Primary neutrophils isolated from mice were cocultured with LPS or PMA with or without quercetin. The regulated genes were detected using WB, real-time quantitative PCR, enzyme-linked immunosorbent assay (ELISA) and IF analysis. The agonists and antagonist of Ahr were used as the control.

RESULTS

After the administration of quercetin, colon inflammation and gut barrier disruption was significantly prevented through inhibiting the NF-κB pathway and upregulating the expression of Ahr/Arnt and Nqo1. The transcriptomic analysis and IHC assays showed that inflammation and NETs were greatly decreased by QUE treatment. In vitro, quercetin inhibited LPS-induced inflammatory responses through NF-κB pathway. Furthermore, MDS and BLI analysis revealed that QUE is an agonist of AHR. QUE activated Ahr translocation and reduced ROS production via regulation of Arnt and Nqo1.

CONCLUSION

This study proved that quercetin greatly improved gut barrier function in the DSS-induced colitis model by regulating NET formation and that quercetin was able to activate Ahr and upregulate Arnt in neutrophils to regulate NET formation.

Neutrophil Elastase and Elafin in Inflammatory Bowel Diseases: Urinary Biomarkers Reflecting Intestinal Barrier Dysfunction and Proteolytic Activity

Background: Inflammatory bowel disease (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), is a chronic inflammatory disorder driven by a complex interplay of immune and proteolytic mechanisms. Neutrophil elastase (NE), released at sites of inflammation, plays a central role by promoting inflammation, degrading the extracellular matrix (ECM), and disturbing intestinal barrier integrity via NF-κB activation and E-cadherin degradation. Elafin, an endogenous NE inhibitor, mitigates proteolytic damage, reinforces the intestinal barrier, and exerts anti-inflammatory effects by suppressing NF-κB and reducing pro-inflammatory cytokines. Since the NE/elafin balance is critical in IBD, assessing their ratio may provide a more precise measure of proteolytic dysregulation. This study aimed to evaluate the diagnostic and prognostic utility of urinary NE, elafin, and their ratio in IBD patients. Methods: Urinary concentrations of NE and elafin were measured by immunoassay in 88 subjects including ulcerative colitis and Crohn's disease patients and healthy individuals. The diagnostic accuracy of these biomarkers was assessed using receiver operating characteristic (ROC) curve analysis. Results: Urinary NE levels were significantly elevated in both UC and CD patients compared to controls, with a 17-fold increase in the UC patients and a 28-fold increase in the CD patients (p < 0.0001). Elafin levels were also increased in IBD patients. The NE/elafin ratio was significantly increased in both disease groups, with a 4.5-fold increase in the UC and 5.6-fold increase in the CD patients compared to healthy controls. The ROC curve analysis demonstrated that the NE/elafin ratio is the most effective biomarker for distinguishing CD patients from healthy individuals (AUC = 0.896), with a high sensitivity (92.9%) and specificity (69.7%), making it a strong diagnostic tool. NE also showed an excellent diagnostic performance both in CD (AUC = 0.842) and UC (AUC = 0.880). The elafin urinary profile had a high diagnostic value, with a better accuracy in the UC patients (AUC = 0.772) than the CD patients (AUC = 0.674), though it was inferior to NE and NE/elafin. Conclusions: Our findings indicate that urinary NE, elafin, the and NE/elafin ratio have significant diagnostic value in differentiating IBD patients from healthy controls. The NE/elafin ratio and NE proved to be the most reliable urinary biomarkers in both CD and UC diagnosis, with a high predictive value and strong discriminatory power.

Mendelian randomization study of circulating leukocytes counts reveals causal associations with inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic recurrent IBD, whose cause involves the interaction between genetic and environmental factors. Although there is a recognized link between immune response and IBD, the causal relationship between circulating immune cell counts and IBD remains controversial. This study aimed to elucidate the causal relationship between genetically predicted circulating immune cell counts and IBD. We conducted a bidirectional 2-sample Mendelian randomization (MR) study using aggregated statistics from genome-wide association studies. The causal relationship between 5 circulating leukocytes cells (monocytes, lymphocytes, eosinophils, basophils and neutrophils) counts and IBD, including ulcerative colitis (UC) and Crohn disease (CD) was analyzed. Horizontal pleiotropy test and heterogeneity test were used to ensure the stability of the results. Our findings indicated that monocytes, lymphocytes, eosinophils, and basophils count were not significantly associated with IBD, however, elevated circulating neutrophils count was significantly associated with higher risk of IBD [odds ratio (OR) = 1.0017; 95% confidence interval (CI) = 1.0004-1.003; P = .009] and UC [OR = 2.465; 95% CI = 1.236-4.916; P = .01]. In addition, we also found that IBD [OR: 12.07; 95% CI = 1.909-76.316; P = .008] and CD [OR = 1.014; 95% CI = 1.004-1.023; P = .005] were significantly associated with higher circulating neutrophils count in reverse MR. This MR study provides genetic evidence for the causal relationship between the genetically predicted increase in circulating neutrophils count and the risk of IBD (UC and CD). This finding stresses the need for further exploring physiological functions of neutrophils in order to develop effective strategies against IBD.

HDAC inhibitors and IBD: Charting new approaches in disease management

Inflammatory bowel disease (IBD) represents a group of chronic inflammatory disorders of the gastrointestinal tract. Despite substantial advances in our understanding of IBD pathogenesis, the currently available therapeutic options remain limited in their efficacy and often come with significant side effects. Therefore, there is an urgent need to explore novel approaches for the management of IBD. One promising avenue of investigation revolves around the use of histone deacetylase (HDAC) inhibitors, which have garnered considerable attention for their potential in modulating gene expression and curbing inflammatory responses. This review emphasizes the pressing need for innovative drugs in the treatment of IBD, and drawing from a wealth of preclinical studies and clinical trials, we underscore the multifaceted roles and the therapeutic effects of HDAC inhibitors in IBD models and patients. This review aims to contribute significantly to the understanding of HDAC inhibitors' importance and prospects in the management of IBD, ultimately paving the way for improved therapeutic strategies in this challenging clinical landscape.

Ferroptosis Induces gut microbiota and metabolic dysbiosis in Collagen-Induced arthritis mice via PAD4 enzyme

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic inflammation and joint destruction, with emerging evidence implicating gut microbiota dysbiosis in its pathogenesis. The current study explores the role of ferroptosis, a form of regulated cell death driven by iron-dependent lipid peroxidation, in modulating gut microbiota and metabolic dysregulation through the enzyme peptidyl arginine deiminase 4 (PAD4) in collagen-induced arthritis (CIA) mouse model. Our findings demonstrate that ferroptosis exacerbates RA-related inflammatory responses and joint damage by upregulating PAD4 expression, which, in turn, influences the gut microbial composition and associated metabolite profiles. Erastin, a known ferroptosis agonist, significantly increased the relative abundance of pro-inflammatory bacteria such as Proteobacteria while reducing beneficial taxa like Firmicutes and Bacteroidetes. This microbial shift was associated with heightened oxidative stress and an imbalance in key metabolites, such as lysophosphatidyl ethanolamine 14:0 (LysoPE 14:0), further exacerbated by ferroptosis. Co-treatment with GSK484, a PAD4 inhibitor, reversed these effects, restoring microbial homeostasis and reducing joint inflammation. This study suggests that ferroptosis-mediated PAD4 activity contributes to RA pathogenesis by disrupting the gut-joint axis, providing novel insights into potential therapeutic targets for RA. Our results highlight the intricate interplay between immune-mediated cell death, gut microbiota, and systemic inflammation, emphasizing the importance of ferroptosis as a therapeutic target in mitigating RA progression.

Neutrophils: From Inflammatory Bowel Disease to Colitis-Associated Colorectal Cancer

Inflammatory bowel disease (IBD) is a non-specific inflammatory disease of digestive tract, primarily manifesting as ulcerative colitis (UC) and Crohn's disease (CD). The precise etiology of IBD remains elusive. The interplay of genetic factors, environmental influences, and intestinal microbiota contributes to the establishment of an uncontrolled immune environment within the intestine, which can progressively lead to atypical hyperplasia and ultimately to malignancy over a long period. This colorectal malignant tumor that arises from chronic IBD is referred to as colitis-associated colorectal cancer (CAC). Dysregulation in the quantity and functionality of neutrophils plays a significant role in the onset, progression, and recurrence of IBD, as well as in the transition from IBD to CAC. Neutrophils affect the pathophysiology of IBD through various mechanisms, including the production of reactive oxygen species (ROS), degranulation, the release of inflammatory mediators and chemokines, and the formation of neutrophil extracellular traps (NETs). These processes can induce DNA mutations, thereby facilitating the development of colon cancer. Given the incomplete understanding of the disease mechanisms underlying IBD and CAC, effective treatment and prevention strategies remain challenging. Consequently, a comprehensive review of the functional roles of neutrophils in IBD and CAC is essential for advancing our understanding of IBD pathogenesis and identifying potential therapeutic targets.

Advancing Inflammatory Bowel Disease Treatment by Targeting the Innate Immune System and Precision Drug Delivery

Inflammatory bowel disease (IBD), encompassing Crohn's disease and ulcerative colitis, involves chronic inflammation of the gastrointestinal tract. Current immune-modulating therapies are insufficient for 30-50% of patients or cause significant side effects, emphasizing the need for new treatments. Targeting the innate immune system and enhancing drug delivery to inflamed gut regions are promising strategies. Neutrophils play a central role in IBD by releasing reactive oxygen species (ROS) and neutrophil extracellular traps (NETs) -DNA-based structures with cytotoxic proteins-that contribute to mucosal damage and inflammation. Recent studies linking ROS production, DNA repair, and NET formation have identified NETs as potential therapeutic targets, with preclinical models showing positive outcomes from NET inhibition. Innovative oral drug delivery systems designed to target gut inflammation directly-without systemic absorption-could improve treatment precision and reduce side effects. Advanced formulations utilize properties such as particle size, surface modifications, and ROS-triggered release to selectively target the distal ileum and colon. A dual strategy that combines a deeper understanding of IBD pathophysiology to identify inflammation-related therapeutic targets with advanced drug delivery systems may offer significant promise. For instance, pairing NET inhibition with ROS-responsive nanocarriers could enhance treatment efficacy, though further research is needed. This synergistic approach has the potential to greatly improve outcomes for IBD patients.

The Impact of Peptidyl Arginine Deiminase 4-Dependent Neutrophil Extracellular Trap Formation on the Early Development of Intestinal Fibrosis in Crohn's Disease

BACKGROUND AND AIMS

During early phases of inflammation, activated neutrophils extrude neutrophil extracellular traps (NETs) in a peptidyl arginine deiminase 4 (PAD4)-dependent manner, aggravating tissue injury and remodeling. In this study, we investigated the potential pro-fibrotic properties and signaling of NETs in Crohn's disease (CD).

METHODS

NETs and activated fibroblasts were labeled on resected ileum from CD patients by multiplex immunofluorescence staining. NETs-treated human primary intestinal fibroblasts were analyzed by bulk RNA sequencing to uncover cell signaling pathways, and by high-throughput imaging to assess collagen production and migratory activity. Consequentially, TLR2/NF-κB pathway was evaluated by transfection of CCD-18Co fibroblasts with an NF-κB-luciferase reporter plasmid, incorporating C29 to block TLR2 signaling. A chronic dextran sulfate sodium (DSS) mouse model was used to define the specific role of PAD4 deletion in neutrophils (MRP8-Cre, Pad4fl/fl).

RESULTS

Immunofluorescence showed spatial colocalization of NETs and activated fibroblasts in ileal ulcerations of CD patients. Transcriptomic analysis revealed upregulation of pro-fibrotic genes and activation of Toll-like receptor signaling pathways in NETs-treated fibroblasts. NETs treatment induced fibroblast proliferation, diminished migratory capability, and increased collagen release. Transfection experiments indicated a substantial increase in an NF-κB expression with NETs, whereas C29 led to decreased expression and release of collagen. In line, a significant reduction in collagen content was observed in the colon of MRP8-Cre, Pad4fl/fl mice subjected to chronic DSS colitis.

CONCLUSIONS

NETs potentially serve as an initial stimulus for pathological activation of fibroblasts within the intestine via the TLR2/NF-κB pathway. Given their early involvement in inflammation, inhibition of PAD4 might offer a strategy to modulate both inflammation and fibrogenesis in CD.

Kuiyangling Enema Alleviates Ulcerative Colitis Mice by Reducing Levels of Intestinal NETs and Promoting HuR/VDR Signaling

Purpose

Kuiyangling is a traditional Chinese medicine formula used for the treatment of ulcerative colitis, but the specific mechanism remains unclear. Imbalance in NETs regulation is one of the important factors contributing to the onset of ulcerative colitis (UC). The HuR/VDR signaling pathway plays a significant role in restoring the intestinal mucosal barrier in UC. The aim of this study is to explore the mechanism of Kuiyangling in the treatment of ulcerative colitis.

Methods

A mouse model of ulcerative colitis using 3% DSS water was considered, and model, normal, Kuiyangling medium- (5 g·kg-1) and high-dose (10 g·kg-1), and mesalazine (50 mg·kg-1) groups were created. Measurements of colon length, spleen index, histopathological variances, subcellular structure observations, ROS content, and NET-related proteins (PAD4, MPO, citH3) were obtained through HE staining, electron microscopy, live imaging, and Western blotting assays. Immunohistochemistry and immunofluorescence analyses were conducted to assess the levels of HuR/VDR protein complex, ZO-1, Occludin, Claudin-7, and intestinal NETs. An ELISA kit was utilized to determine cytokine levels, LC-MS was performed to analyze the composition of Kuiyangling, and next-generation sequencing was conducted for detection of the intestinal mucosal transcriptome.

Results

Kuiyangling reduced DAI, splenic index, and ROS content; maintained mucosal structure; decreased inflammation; and increased colon length and body mass index. Western blotting indicated that Kuiyangling reduced PAD4,MPO, and citH3 levels. Kuiyangling decreased NETs and increased the expression levels of ZO-1, Occludin, and Claudin-7, as well as up-regulating HuR, VDR, and HuR/VDR proteins. Kuiyangling reduced IL-1β, IL-6, and TNF-α levels while increasing TGF-β, IL-10, and IL-37 levels. Kuiyangling reduced inflammatory response proteins and elevated the levels of anti-inflammatory and intestinal barrier proteins, possibly inhibiting the TNF and oxidative phosphorylation signaling pathways.

Conclusion

Kuiyangling enema in treating ulcerative colitis in mice, associated with a reduction in intestinal NETs and enhancement of HuR-mediated intestinal barrier signaling pathways.

PANoptosis-related genes: Molecular insights into immune dysregulation in ulcerative colitis

BACKGROUND AND AIM

Ulcerative colitis (UC) is a chronic inflammatory disease driven by immune dysregulation. PANoptosis, a novel form of programmed cell death, has been implicated in inflammatory diseases, but its specific role in UC remains unclear. This study aimed to identify PANoptosis-related genes (PRGs) that may contribute to immune dysregulation in UC.

METHODS

Using bioinformatics analysis of the GEO databases, we identified seven hub PRGs. Based on these genes, we developed a predictive model to differentiate UC patients from healthy controls, and evaluated its diagnostic performance using ROC curve analysis. We further conducted functional enrichment, GSVA, and immune infiltration analyses. Immunohistochemistry (IHC) was used to validate the expression of hub genes in UC patients.

RESULTS

The prediction model, based on the seven hub genes, exhibited diagnostic ability in discriminating UC patients from controls. Furthermore, these hub PRGs were found to be associated with immune cells, including dendritic cells, NK cells, macrophages, regulatory T cells (Tregs), and CD8+ T cells. They were also linked to key signaling pathways implicated in UC pathogenesis, such as IFNγ, TNFα, IL6-and JAK-STAT3, as well as hypoxia and apoptosis. Immunohistochemistry analysis validated the expression levels of hub PRGs in UC patients using paraffin sections of intestinal biopsy specimens.

CONCLUSIONS

This study identified PANoptosis-related genes with potential diagnostic value for UC and suggest that PANoptosis may contribute to the pathogenesis of UC by regulating specific immune cells and interacting with key signaling pathways. This highlights the potential importance of PANoptosis-related genes as therapeutic targets in UC management.

The role of neutrophil extracellular traps in Crohn's disease

Crohn's disease (CD) is an idiopathic and chronic inflammation of the gastrointestinal (GI) tract. The underlying pathogenesis of CD is multifaceted, with complex interactions between genetic predisposition, environmental triggers, and abnormalities within the immune system. Neutrophil extracellular traps (NETs) have gained significant attention as a novel component in the pathogenesis of CD. NETs are intricate structures fashioned from DNA, histones, and granule proteins, and are actively released by neutrophils to entangle and eliminate pathogenic microbes. This review article delves into the intricate role of NETs in the pathogenesis of CD. We examine how NETs may serve as a pivotal mechanism for the recruitment of immune cells to the site of inflammation. NETs are known to influence the function of epithelial cells, which line the GI tract, potentially contributing to the structural integrity and barrier dysfunction observed in CD. NETs stimulate inflammation, a hallmark of the disease, by releasing pro-inflammatory molecules and activating immune cells. We also investigate the promising therapeutic potential of targeting NETs in CD. By intercepting the formation or function of NETs, it may be possible to mitigate the chronic inflammation, reduce tissue damage, and alleviate the symptoms associated with CD. Strategies to inhibit NET formation, such as the use of DNase I and approaches to disrupt NET-mediated signaling pathways, are discussed in CD therapeutics. Understanding the detailed mechanisms of NETs is crucial for the development of targeted treatments that could potentially revolutionize the management of CD.

Bioinformatics analysis reveals potential crosstalk genes and molecular mechanisms between ulcerative colitis and psoriasis

Ulcerative colitis (UC) and psoriasis are highly correlated clinically; however, it is unclear whether they have a common pathophysiological mechanism. The purpose of this study is to investigate the important molecules and pathways that mediate the coexistence of UC and psoriasis through quantitative bioinformatics analysis of public RNA-sequencing databases. The UC (GSE38713) and psoriasis (GSE30999) datasets were downloaded from the Gene Expression Omnibus database. Differentially expressed genes were analysed using the "limma" package and their biological functions were investigated using Gene Ontology and the Kyoto Encyclopedia of Genes and Genomes. The Search Tool for the Retrieval of Interacting Genes database was used to create the protein-protein interaction (PPI) network, which was visualised by Cytoscape. The CytoHubba plugin was used to select the hub genes. The hub genes of psoriasis and UC were verified in GSE75214, GSE78097, GSE14905, and GSE87466. The predicted value of the hub gene was evaluated by the receiver operating characteristic curve (ROC). Gene Set Enrichment Analysis (GSEA) and immune infiltration were performed for the hub genes. Finally, we performed transcription factor (TF)-gene interaction network analysis, TF-miRNA co-regulation network analysis and candidate drug prediction. A total of 114 genes (89 ascending genes and 25 descending genes) with similar expression trends between UC and psoriasis were identified. Enrichment analysis revealed that the two signaling pathways were primarily related to immune and inflammatory responses. PPI network screened 13 hub genes (IL-1B, CXCL10, TLR2, CD274, CXCR2, CXCL9, MMP9, CXCL1, CASP1, IL-7R, IL-1RN, CCL18 and LCN2). Using NetworkAnalyst, we constructed a co-regulatory network diagram of TF-gene and TF-miRNA. Finally, diacerein was predicted to be effective in the treatment of UC and psoriasis. Our research revealed the common pathogenesis of UC and psoriasis, and examined the hub genes, TF and miRNA and potential therapeutic drugs (diacerein). These findings may provide new perspectives for further mechanism research and clinical treatment.

Unraveling the intricacies of neutrophil extracellular traps in inflammatory bowel disease: Pathways, biomarkers, and promising therapies

The development of inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, involves various factors and is characterized by persistent inflammation of the mucosal lining. However, the role of neutrophils in this process remains controversial. Neutrophil extracellular traps (NETs), which consist of chromatin, antimicrobial proteins, and oxidative enzymes, are released by neutrophils to trap pathogens. They are also involved in various immune-mediated and vascular diseases. NETs act as a vital defense mechanisms at the gut-mucosal interface and are frequently exposed to bacterial, viral, and fungal threats. However, they can also contribute to inflammation and worsen imbalances in the gut bacteria. Recent studies have suggested that NETs have a significant impact on IBD development. Previous studies have shown increased levels of NETs in tissue and blood samples from patients with IBD, as well as in experimental colitis mouse models. Therefore, this review discusses how NETs are formed and their role in the pathophysiology of IBD. It discusses how NETs may lead to tissue damage and contribute to IBD-associated complications. Moreover, non-invasive biomarkers are needed to replace invasive procedures such as endoscopy to better evaluate the disease status. Given the crucial role of NETs in IBD progression, this review focuses on potential NET biomarkers that can help predict the evolution of IBD. Furthermore, this review identifies potential therapeutic targets for regulating NET production, which could expand the range of available treatment options for IBD.

Morin alleviates DSS-induced ulcerative colitis in mice via inhibition of inflammation and modulation of intestinal microbiota

Ulcerative colitis (UC) is a chronic inflammatory condition with recurrent and challenging symptoms. Effective treatments are lacking, making UC management a critical research area. Morin (MO), a flavonoid from the Moraceae family, shows potential as an anti-UC agent, but its mechanisms are not fully understood. Using a dextran sulfate sodium (DSS)-induced UC mouse model, we employed network pharmacology to predict MO's therapeutic effects. Assessments included changes in body weight, disease activity index (DAI), and colon length. Immunofluorescence, hematoxylin and eosin (H&E), and PAS staining evaluated colon damage. ELISA and western blot analyzed inflammatory factors, tight junction (TJ)-associated proteins (Claudin-3, Occludin, ZO-1), and Mitogen-Activated Protein Kinase (MAPK)/ Nuclear Factor kappa B (NF-κB) pathways. 16S rRNA sequencing assessed gut microbiota diversity, confirmed by MO's modulation via Fecal Microbial Transplantation (FMT). Early MO intervention reduced UC severity by improving weight, DAI scores, and colon length, increasing goblet cells, enhancing barrier function, and inhibiting MAPK/NF-κB pathways. MO enriched gut microbiota, favoring beneficial bacteria like Muribaculaceae and Erysipelotrichaceae while reducing harmful Erysipelotrichaceae and Muribaculaceae. This study highlights MO's potential in UC management through inflammation control, mucosal integrity maintenance, and gut flora modulation.

β-arrestin2: an emerging player and potential therapeutic target in inflammatory immune diseases

β-arrestin2, a pivotal protein within the arrestin family, is localized in the cytoplasm, plasma membrane and nucleus, and regulates G protein-coupled receptors (GPCRs) signaling. Recent evidence shows that β-arrestin2 plays a dual role in regulating GPCRs by mediating desensitization and internalization, and by acting as a scaffold for the internalization, kinase activation, and the modulation of various signaling pathways, including NF-κB, MAPK, and TGF-β pathways of non-GPCRs. Earlier studies have identified that β-arrestin2 is essential in regulating immune cell infiltration, inflammatory factor release, and inflammatory cell proliferation. Evidently, β-arrestin2 is integral to the pathological mechanisms of inflammatory immune diseases, such as inflammatory bowel disease, sepsis, asthma, rheumatoid arthritis, organ fibrosis, and tumors. Research on the modulation of β-arrestin2 offers a promising strategy for the development of pharmaceuticals targeting inflammatory immune diseases. This review meticulously describes the roles of β-arrestin2 in cells associated with inflammatory immune responses and explores its pathological relevance in various inflammatory immune diseases.

Role of myeloid cells in mediating the effects of lipids on ulcerative colitis

Objective

To evaluate the causal relationship between lipids and ulcerative colitis (UC) through Mendelian Randomization (MR), and to further investigate the involvement of immune cells in mediating this process.

Methods

Utilizing summary statistics from genome-wide association studies (GWAS) of individuals with European ancestry, we analyzed the causal link between 179 lipid types and UC (2,569 UC cases and 453,779 controls) through Two-sample Mendelian randomization (2SMR) and Bayesian-weighted MR (BWMR). Based on this, a mediation screening of 731 immune cell phenotypes was conducted to identify exposure and mediator factors. Lastly, the role and proportion of immune cells in mediating the causal effects of lipids on UC were assessed via reverse MR (RMR) and two-step MR.

Results

The results of MR showed that there was a causal relationship between the six genetically predicted lipid types and UC (P <0.05), and the four immune cell phenotypes were identified as mediators of the association between lipids and UC. Notably, Phosphatidylcholine (PC) (16:0_0:0) served as the exposure factor, and myeloid cells CD11b on CD33+ HLA DR+ CD14dim acted as the mediator. Mediation analysis showed that CD11b on CD33+ HLA DR+ CD14dim had a mediation effect of -0.0205 between PC (16:0_0:0) and UC, with the mediation effect ratio at 15.38%.

Conclusion

Our findings elucidate the causal effect of lipids on UC and identify the significant mediating role of myeloid cells CD11b on CD33+ HLA DR+ CD14dim in regulating UC through PC (16:0_0:0), offering new pathways and strategies for UC clinical treatment.

Effects of the N-Butanol Extract of Pulsatilla Decoction on Neutrophils in a Mouse Model of Ulcerative Colitis

Ulcerative colitis (UC) is a chronic inflammatory disease, the incidence of which is increasing worldwide. However, the etiology and pathogenesis of UC remains unclear. The n-butanol extract of Pulsatilla decoction (BEPD), a traditional Chinese medicine, has been shown to be effective in treating UC. This study aimed to explore the molecular mechanism underlying the effects of BEPD on UC, in particular its effects on neutrophil extracellular trap (NET) formation by neutrophils. High-performance liquid chromatography was used to determine the principal compounds of BEPD. UC was induced in mice using dextran sodium sulfate, and mice were treated with 20, 40, or 80 mg/kg BEPD daily for seven days. Colonic inflammation was determined by assessing the disease activity index, histopathology, colonic mucosal damage index, colonic mucosal permeability, and pro- and anti-inflammatory cytokine levels. The infiltration and activation status of neutrophils in the colon were determined by analyzing the levels of chemokine (C-X-C motif) ligand (CXCL) 1 and CXCL2, reactive oxygen species, Ly6G, and numerous NET proteins. The findings suggest that BEPD improved the disease activity index, histopathology, and colonic mucosal damage index scores of mice with UC, and restored colonic mucosal permeability compared with untreated mice. The expression levels of the pro-inflammatory cytokines interleukin-1β, interleukin-6, and tumor necrosis factor-α in colon tissues were significantly decreased, while the expression levels of anti-inflammatory cytokines in colon tissues were significantly increased, exceeding those of control mice. In addition, BEPD reduced the expression of the neutrophil chemokines CXCL1 and CXCL2 in the colon tissue of mice with UC, reduced neutrophil infiltration, reduced reactive oxygen species levels, and significantly reduced the expression of NET proteins. BEPD also significantly reduced NET formation. The results of this study suggest that BEPD exerts therapeutic effects in a murine model of UC by inhibiting neutrophil infiltration and activation in the colon, as well as by inhibiting the expression of key proteins involved in NET formation and reducing NET formation, thereby alleviating local tissue damage and disease manifestations.

Unravelling the Oral-Gut Axis: Interconnection Between Periodontitis and Inflammatory Bowel Disease, Current Challenges, and Future Perspective

As the opposite ends of the orodigestive tract, the oral cavity and the intestine share anatomical, microbial, and immunological ties that have bidirectional health implications. A growing body of evidence suggests an interconnection between oral pathologies and inflammatory bowel disease [IBD], implying a shift from the traditional concept of independent diseases to a complex, reciprocal cycle. This review outlines the evidence supporting an 'oral-gut' axis, marked by a higher prevalence of periodontitis and other oral conditions in IBD patients and vice versa. We present an in-depth examination of the interconnection between oral pathologies and IBD, highlighting the shared microbiological and immunological pathways, and proposing a 'multi-hit' hypothesis in the pathogenesis of periodontitis-mediated intestinal inflammation. Furthermore, the review underscores the critical need for a collaborative approach between dentists and gastroenterologists to provide holistic oral-systemic healthcare.

Berbamine ameliorates DSS-induced colitis by inhibiting peptidyl-arginine deiminase 4-dependent neutrophil extracellular traps formation

Ulcerative colitis (UC) is a chronic inflammatory bowel disease with immune dysregulation affecting colon inflammatory response. Recent studies have highlighted that neutrophil extracellular traps (NETs) play an important role in the pathogenesis of UC. Berbamine (BBM), one of the bioactive ingredients extracted from Chinese herbal medicine Berberis vulgaris L, has attracted intensive attentions due to its significant anti-inflammatory activity and a marketing drug for treating leukemia in China. However, the exact role and potential molecular mechanism of BBM against UC remains elusive. In the present study, our results showed that BBM could markedly improve the pathological phenotype and the colon inflammation in mice with dextran sulfate sodium (DSS)-induced colitis. Then, comprehensive approaches combining network pharmacology and molecular docking analyses were employed to predict the therapeutic potential of BBM in treating UC by peptidyl-arginine deiminase 4 (PAD4), a crucial molecule involved in NETs formation. The molecular docking results showed BBM had a high affinity for PAD4 with a binding energy of -9.3 kcal/mol Moreover, PAD4 expression and NETs productions, including citrullination of histone H3 (Cit-H3), neutrophil elastase (NE), myeloperoxidase (MPO) in both neutrophils and colonic tissue were reduced after BBM administration. However, in the mice with DSS-induced colitis pretreated with GSK484, a PAD4-specific inhibitor, BBM could not further reduce disease related indexes, expression of PAD4 and NETs productions. Above all, the identification of PAD4 as a potential target for BBM to inhibit NETs formation in colitis provides novel insights into the development of BBM-derived drugs for the clinical management of UC.

An Oxidative Cleavage-Based Cruciform DNA Nanostructure for In Vivo Hypochlorous Acid Visualization to Monitor Intestinal Inflammation

Ulcerative colitis is a persistent inflammatory bowel disease characterized by inflammation and ulceration in the colon and gastrointestinal tract. It was indicated that the generation of hypochlorous acid (HClO) through the enzymatic activity of myeloperoxidase is significantly linked to ulcerative colitis. In this study, by assembling two hairpins (Hpa and Hpb) onto a quadrivalent cruciform DNA nanostructure, a novel HClO-activatable fluorescent probe was developed based on DNA nanomaterials (denoted MHDNA), which is sensitive, economic, simple, and stable. In the presence of HClO, the Trigger (T) was liberated from the MHDNA probe through a hydrolysis reaction between HClO and phosphorothioate (PS), which is modified on the MHDNA probe and has proved to exhibit particular susceptibility to the HClO. The liberated T subsequently initiated the opening of Hpa and Hpb to facilitate the catalyzed hairpin assembly (CHA) reaction, resulting in the changes of fluorescence and releasing T for recycled signal amplification to achieve sensitive detection of HClO (with a limit of detection 9.83 nM). Additionally, the MHDNA-based spatial-confinement effect shortens the physical distance between Hpa and Hpb and yields a high local concentration of the two reactive hairpins, achieving more rapid reaction kinetics in comparison to conventional CHA methods. Inspirationally, the MHDNA probe was effectively utilized for imaging HClO in ulcerative colitis mice, yielding valuable diagnostic insights for ulcerative colitis.

Neutrophil Extracellular Traps: A Crucial Factor in Post-Surgical Abdominal Adhesion Formation

Post-surgical abdominal adhesions, although poorly understood, are highly prevalent. The molecular processes underlying their formation remain elusive. This review aims to assess the relationship between neutrophil extracellular traps (NETs) and the generation of postoperative peritoneal adhesions and to discuss methods for mitigating peritoneal adhesions. A keyword or medical subject heading (MeSH) search for all original articles and reviews was performed in PubMed and Google Scholar. It included studies assessing peritoneal adhesion reformation after abdominal surgery from 2003 to 2023. After assessing for eligibility, the selected articles were evaluated using the Critical Appraisal Skills Programme checklist for qualitative research. The search yielded 127 full-text articles for assessment of eligibility, of which 7 studies met our criteria and were subjected to a detailed quality review using the Critical Appraisal Skills Programme (CASP) checklist. The selected studies offer a comprehensive analysis of adhesion pathogenesis with a special focus on the role of neutrophil extracellular traps (NETs) in the development of peritoneal adhesions. Current interventional strategies are examined, including the use of mechanical barriers, advances in regenerative medicine, and targeted molecular therapies. In particular, this review emphasizes the potential of NET-targeted interventions as promising strategies to mitigate postoperative adhesion development. Evidence suggests that in addition to their role in innate defense against infections and autoimmune diseases, NETs also play a crucial role in the formation of peritoneal adhesions after surgery. Therefore, therapeutic strategies that target NETs are emerging as significant considerations for researchers. Continued research is vital to fully elucidate the relationship between NETs and post-surgical adhesion formation to develop effective treatments.

Neutrophil-derived PAD4 induces citrullination of CKMT1 exacerbates mucosal inflammation in inflammatory bowel disease

Peptidyl arginine deiminase 4 (PAD4) plays a pivotal role in infection and inflammatory diseases by facilitating the formation of neutrophil extracellular traps (NETs). However, the substrates of PAD4 and its exact role in inflammatory bowel disease (IBD) remain unclear. In this study, we employed single-cell RNA sequencing (scRNA-seq) and substrate citrullination mapping to decipher the role of PAD4 in intestinal inflammation associated with IBD. Our results demonstrated that PAD4 deficiency alleviated colonic inflammation and restored intestinal barrier function in a dextran sulfate sodium (DSS)-induced colitis mouse model. scRNA-seq analysis revealed significant alterations in intestinal cell populations, with reduced neutrophil numbers and changes in epithelial subsets upon PAD4 deletion. Gene expression analysis highlighted pathways related to inflammation and epithelial cell function. Furthermore, we found that neutrophil-derived extracellular vesicles (EVs) carrying PAD4 were secreted into intestinal epithelial cells (IECs). Within IECs, PAD4 citrullinates mitochondrial creatine kinase 1 (CKMT1) at the R242 site, leading to reduced CKMT1 protein stability via the autophagy pathway. This action compromises mitochondrial homeostasis, impairs intestinal barrier integrity, and induces IECs apoptosis. IEC-specific depletion of CKMT1 exacerbated intestinal inflammation and apoptosis in mice with colitis. Clinical analysis of IBD patients revealed elevated levels of PAD4, increased CKMT1 citrullination, and decreased CKMT1 expression. In summary, our findings highlight the crucial role of PAD4 in IBD, where it modulates IECs plasticity via CKMT1 citrullination, suggesting that PAD4 may be a potential therapeutic target for IBD.

The shared circulating diagnostic biomarkers and molecular mechanisms of systemic lupus erythematosus and inflammatory bowel disease

Background

Systemic lupus erythematosus (SLE) is a multi-organ chronic autoimmune disease. Inflammatory bowel disease (IBD) is a common chronic inflammatory disease of the gastrointestinal tract. Previous studies have shown that SLE and IBD share common pathogenic pathways and genetic susceptibility, but the specific pathogenic mechanisms remain unclear.

Methods

The datasets of SLE and IBD were downloaded from the Gene Expression Omnibus (GEO). Differentially expressed genes (DEGs) were identified using the Limma package. Weighted gene coexpression network analysis (WGCNA) was used to determine co-expression modules related to SLE and IBD. Pathway enrichment was performed using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis for co-driver genes. Using the Least AbsoluteShrinkage and Selection Operator (Lasso) regressionand Support Vector Machine-Recursive Feature Elimination (SVM-RFE), common diagnostic markers for both diseases were further evaluated. Then, we utilizedthe CIBERSORT method to assess the abundance of immune cell infiltration. Finally,we used the single-cell analysis to obtain the location of common diagnostic markers.

Results

71 common driver genes were identified in the SLE and IBD cohorts based on the DEGs and module genes. KEGG and GO enrichment results showed that these genes were closely associated with positive regulation of programmed cell death and inflammatory responses. By using LASSO regression and SVM, five hub genes (KLRF1, GZMK, KLRB1, CD40LG, and IL-7R) were ultimately determined as common diagnostic markers for SLE and IBD. ROC curve analysis also showed good diagnostic performance. The outcomes of immune cell infiltration demonstrated that SLE and IBD shared almost identical immune infiltration patterns. Furthermore, the majority of the hub genes were commonly expressed in NK cells by single-cell analysis.

Conclusion

This study demonstrates that SLE and IBD share common diagnostic markers and pathogenic pathways. In addition, SLE and IBD show similar immune cellinfiltration microenvironments which provides newperspectives for future treatment.

Retinoic acid-loaded liposomes induce human mucosal CD103+ dendritic cells that inhibit Th17 cells and drive regulatory T-cell development in vitro

The active vitamin A metabolite, all-trans-retinoic acid (RA), primes precursor dendritic cells (DCs) into a mucosal phenotype with tolerogenic properties characterized by the expression of integrin CD103. CD103+ DCs can counteract pathogenic Th1 and Th17 in inflammatory bowel disease (IBD) or celiac disease (CD). Tolerogenic manipulation of DCs using nanoparticles carrying tolerogenic adjuvants and disease-specific antigens is a valuable treatment strategy to induce antigen-specific mucosal tolerance in vivo. Here, we investigated the effects of RA-loaded liposomes on human DC phenotype and function, including DC-driven T-cell development, both during the generation of monocyte-derived DCs (moDCs) as well as by priming immature moDCs. RA liposomes drove CD103+ DC differentiation as well as ALDH1A2 expression in DCs. Neutrophil-dependent Th17 cell development was reduced by RA-liposome-differentiated and RA-liposome-primed DCs. Moreover, RA liposome treatment shifted T-cell development toward a Th2 cell profile. Importantly, RA liposomes induced the development of IL-10-producing and FoxP3+ regulatory T cells (Tregs) of various Treg subsets, including ICOS+ Tregs, that were potent inhibitors of bystander memory T-cell proliferation. Taken together, RA-loaded liposomes could be a novel treatment avenue for IBD or CD patients.

Multitasking functions of bacterial extracellular DNA in biofilms

Bacterial biofilms are intricate ecosystems of microbial communities that adhere to various surfaces and are enveloped by an extracellular matrix composed of polymeric substances. Within the context of bacterial biofilms, extracellular DNA (eDNA) originates from cell lysis or is actively secreted, where it exerts a significant influence on the formation, stability, and resistance of biofilms to environmental stressors. The exploration of eDNA within bacterial biofilms holds paramount importance in research, with far-reaching implications for both human health and the environment. An enhanced understanding of the functions of eDNA in biofilm formation and antibiotic resistance could inspire the development of strategies to combat biofilm-related infections and improve the management of antibiotic resistance. This comprehensive review encapsulates the latest discoveries concerning eDNA, encompassing its origins, functions within bacterial biofilms, and significance in bacterial pathogenesis.

Inhibition of HMGB1 improves experimental mice colitis by mediating NETs and macrophage polarization

OBJECTIVE

Inflammatory bowel disease (IBD) is listed by the World Health Organization as one of the modern intractable diseases. High mobility histone box 1 (HMGB1), originally described as a non-histone nucleoprotein involved in transcriptional regulation, was later identified as a pro-inflammatory cytokine that may contribute to the pathogenesis of inflammatory diseases such as IBD. Neutrophil extracellular traps (NETs) play an important role in the pathophysiology of IBD The aim of this study was to investigate the role of HMGB1 in experimental colitis mice and its potential mechanisms of action.

METHODS

We first constructed the experimental colitis mouse model. Intervention of mice by rhHMGB1 supplementation or HMGB1 inhibition. The pathological morphology of the colon was observed using HE staining. Apoptosis of colonic tissue intestinal epithelial cells was evaluated using Tunel assay. The expression of HMGB1, ZO-1 and occludin in colon tissue was detected by immunohistochemistry, ELISA and western-blot. We also assessed the effects of HMGB1 on colonic injury, NETs content, macrophage polarization and inflammatory cells in mice. The regulatory effect of HMGB1 inhibition on NETs was assessed by combining DNase I.

RESULTS

Inhibition of HMGB1 significantly reduced the inflammatory model in experimental colitis mice, as evidenced by reduced body weight, increased colonic length, reduced DAI scores and apoptosis, reduced inflammatory response, and improved colonic histopathological morphology and intestinal mucosal barrier function. Meanwhile, inhibition of HMGB1 was able to reduce the expression of CD86, citH3 and MPO and increase the expression of CD206 in the colonic tissue of mice. In addition, DNase I intervention was also able to improve colonic inflammation in mice. And the best effect was observed when DNase I and inhibition of HMGB1 were intervened together.

CONCLUSION

Inhibition of HMGB1 ameliorates IBD by mediating NETs and macrophage polarization.

Targeted delivery of Fc-fused PD-L1 for effective management of acute and chronic colitis

The PD-1/PD-L1 pathway in mucosal immunity is currently actively explored and considered as a target for inflammatory bowel disease (IBD) treatment. However, systemic PD-L1 administration may cause unpredictable adverse effects due to immunosuppression. Here we show that reactive oxygen species (ROS)-responsive nanoparticles enhance the efficacy and safety of PD-L1 in a mouse colitis model. The nanoparticles control the accumulation and release of PD-L1 fused to Fc (PD-L1-Fc) at inflammatory sites in the colon. The nanotherapeutics shows superiority in alleviating inflammatory symptoms over systemic PD-L1-Fc administration and mitigates the adverse effects of PD-L1-Fc administration. The nanoparticles-formulated PD-L1-Fc affects production of proinflammatory and anti-inflammatory cytokines, attenuates the infiltration of macrophages, neutrophils, and dendritic cells, increases the frequencies of Treg, Th1 and Tfh cells, reshapes the gut microbiota composition; and increases short-chain fatty acid production. In summary, PD-L1-Fc-decorated nanoparticles may provide an effective and safe strategy for the targeted treatment of IBD.

TH17 cell: a double-edged sword in the development of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic nonspecific inflammatory disease of the gastrointestinal tract, and its pathogenesis has not been fully understood. Extensive dysregulation of the intestinal mucosal immune system is critical in the development and progression of IBD. T helper (Th) 17 cells have the characteristics of plasticity. They can transdifferentiate into subpopulations with different functions in response to different factors in the surrounding environment, thus taking on different roles in regulating the intestinal immune responses. In this review, we will focus on the plasticity of Th17 cells as well as the function of Th17 cells and their related cytokines in IBD. We will summarize their pathogenic and protective roles in IBD under different conditions, respectively, hoping to further deepen the understanding of the pathological mechanisms underlying IBD and provide insights for future treatment.

Application of SWATH Mass Spectrometry and Machine Learning in the Diagnosis of Inflammatory Bowel Disease Based on the Stool Proteome

Inflammatory bowel disease (IBD) flare-ups exhibit symptoms that are similar to other diseases and conditions, making diagnosis and treatment complicated. Currently, the gold standard for diagnosing and monitoring IBD is colonoscopy and biopsy, which are invasive and uncomfortable procedures, and the fecal calprotectin test, which is not sufficiently accurate. Therefore, it is necessary to develop an alternative method. In this study, our aim was to provide proof of concept for the application of Sequential Window Acquisition of All Theoretical Mass Spectra-Mass spectrometry (SWATH-MS) and machine learning to develop a non-invasive and accurate predictive model using the stool proteome to distinguish between active IBD patients and symptomatic non-IBD patients. Proteome profiles of 123 samples were obtained and data processing procedures were optimized to select an appropriate pipeline. The differentially abundant analysis identified 48 proteins. Utilizing correlation-based feature selection (Cfs), 7 proteins were selected for proceeding steps. To identify the most appropriate predictive machine learning model, five of the most popular methods, including support vector machines (SVMs), random forests, logistic regression, naive Bayes, and k-nearest neighbors (KNN), were assessed. The generated model was validated by implementing the algorithm on 45 prospective unseen datasets; the results showed a sensitivity of 96% and a specificity of 76%, indicating its performance. In conclusion, this study illustrates the effectiveness of utilizing the stool proteome obtained through SWATH-MS in accurately diagnosing active IBD via a machine learning model.

Gut microbiome-based thiamine metabolism contributes to the protective effect of one acidic polysaccharide from Selaginella uncinata (Desv.) Spring against inflammatory bowel disease

Inflammatory bowel disease (IBD) is a serious disorder, and exploration of active compounds to treat it is necessary. An acidic polysaccharide named SUSP-4 was purified from Selaginella uncinata (Desv.) Spring, which contained galacturonic acid, galactose, xylose, arabinose, and rhamnose with the main chain structure of →4)-α-d-GalAp-(1→ and →6)-β-d-Galp-(1→ and the branched structure of →5)-α-l-Araf-(1→ . Animal experiments showed that compared with Model group, SUSP-4 significantly improved body weight status, disease activity index (DAI), colonic shortening, and histopathological damage, and elevated occludin and zonula occludens protein 1 (ZO-1) expression in mice induced by dextran sulfate sodium salt (DSS). 16S ribosomal RNA (rRNA) sequencing indicated that SUSP-4 markedly downregulated the level of Akkermansia and Alistipes. Metabolomics results confirmed that SUSP-4 obviously elevated thiamine levels compared with Model mice by adjusting thiamine metabolism, which was further confirmed by a targeted metabolism study. Fecal transplantation experiments showed that SUSP-4 exerted an anti-IBD effect by altering the intestinal flora in mice. A mechanistic study showed that SUSP-4 markedly inhibited macrophage activation by decreasing the levels of phospho-nuclear factor kappa-B (p-NF-κB) and cyclooxygenase-2 (COX-2) and elevating NF-E2-related factor 2 (Nrf2) levels compared with Model group. In conclusion, SUSP-4 affected thiamine metabolism by regulating Akkermania and inhibited macrophage activation to adjust NF-κB/Nrf2/COX-2-mediated inflammation and oxidative stress against IBD. This is the first time that plant polysaccharides have been shown to affect thiamine metabolism against IBD, showing great potential for in-depth research and development applications.

Xihuang pill ameliorates colitis in mice by improving mucosal barrier injury and inhibiting inflammatory cell filtration through network regulation

ETHNOPHARMACOLOGICAL RELEVANCE

The prevalence of colitis is on the rise, and effective treatment options are currently lacking. Xihuang pill (XHP) is a traditional Chinese medicine formula mentioned in the "Volume 4 of Surgical Evidence and Treatment of the Whole Life" authored by the renowned doctor Hong-Xu Wang during the Qing Dynasty. It is now part of the "Volume 9 of Chinese medicine formula preparation in Drug Standard." XHP and its primary ingredients have been demonstrated anti-inflammatory properties against colitis. However, the specific effects and underlying mechanisms of XHP in treating colitis remain unknown.

AIM OF THE STUDY

This study aimed to investigate the potential impact of XHP on colitis and uncover the underlying mechanisms involved.

MATERIALS AND METHODS

An acute colitis model was developed in C57BL/6N mice, and the effects on weight loss, colon length, the permeability of the colonic mucosa barrier, Claudin-5 and Occludin expression, number of both infiltrating MPO-positive cells and CD68-positive cells, and the content of pro-inflammatory cytokines (IL-6, IL-22, IL-1β, and TNF-α) in the colon tissue were investigated. Low-, medium-, and high-dose XHP (0.45, 0.9, and 1.8 g/kg/day) (batch number: z21021222) were administered to the mice by gavage over the course of two weeks. Additionally, the protein expression levels in colon tissue from the control group, colitis group, and XHP low-dose administration group mice were analyzed by quantitative proteomics techniques. The comprehensive profiling and characterization of absorbed components in mice blood following oral administration of XHP were identified by HPLC/Q-TOF-MS techniques, and the absorbed components in blood were combined with proteomics to reveal the mechanism of enteritis inhibition by XHP.

RESULTS

Our findings indicated that XHP enhanced weight loss and colonic shortening of colitis mice. Additionally, XHP reduced the increase in permeability of the colonic mucosa barrier and decreased expression of Claudin-5 and Occludin, while significantly reducing the number of infiltrating MPO-positive cells and CD68-positive cells in the colon tissue. We found that XHP reduced the production of pro-inflammatory cytokines, including IL-6, IL-22, IL-1β, and TNF-α in colon tissue. Pharmacokinetic analysis suggested that XHP contained 24 blood-entering prototype ingredients, which improved colitis through the regulation of various proteins (e.g., Ctsb, Sting1, and Abat) linked to mucosal barrier injury and inflammation.

CONCLUSION

XHP improved intestinal mucosal barrier injury and reduced MPO-positive cells and CD68-positive cell infiltration through multiple targets and pathways, providing support for XHP as a promising therapy for colitis.

Neutrophil extracellular traps in adult diseases and neonatal bacterial infectious diseases: A review

Neutrophils, the most abundant type of white blood cells, are pivotal in fighting bacterial infections due to their immunological and anti-infection capabilities. In recent years, scientists have discovered a novel mechanism known as neutrophil extracellular traps, which are fibrous networks primarily released by neutrophils that combat bacterial infections. There is a growing interest in studying NETs and their role in human infectious diseases, particularly in neonates susceptible to bacterial infections. NETs and their components have been found in various samples from neonatal-infected patients, providing a new route for early diagnosis of neonatal infectious diseases. This paper aims to summarize the studies on NETs in adult diseases and mainly discuss NETs in neonatal sepsis, necrotizing enterocolitis, and purulent meningitis, to provide scientific evidence for early monitoring, diagnosis, and treatment of neonatal infections.

Neutrophil extracellular traps and neutrophilic dermatosis: an update review

Neutrophils have both antimicrobial ability and pathogenic effect in the immune system, neutrophil extracellular traps (NETs) formation is one of the representative behaviors of their dual role. NETs formation was triggered by pathogen-related components and pathogen non-related proteins as cytokines to exert its effector functions. Recent studies indicate that the pathogenicity of NETs contributed to several skin diseases such as psoriasis, Stevens-Johnson syndrome, toxic epidermal necrolysis, and neutrophilic dermatosis. Especially in neutrophilic dermatosis, a heterogeneous group of inflammatory skin disorders characterized with sterile neutrophilic infiltrate on dermis, NETs formation was reported as the way of participation of neutrophils in the pathogenesis of these diseases. In this review, we describe the different processes of NETs formation, then summarized the most recent updates about the pathogenesis of neutrophilic dermatosis and the participation of NETs, including pyoderma gangrenosum and PAPA syndrome, Behçet syndrome, hidradenitis suppurativa, Sweet Syndrome, pustular dermatosis and other neutrophilic dermatosis. Furthermore, we discuss the link between NETs formation and the development of neutrophilic dermatosis.

Unveiling the covert interaction between gut microbiota and neutrophils to drive colorectal cancer metastasis

The formation of the microenvironment preceding liver metastasis is intricately linked to the intestinal tract. In recent years, mounting evidence has revealed the significant involvement of neutrophil extracellular traps (NETs) in tumor metastasis, particularly in liver metastasis. Disruption of the intestinal barrier can lead to the translocation of bacteria and their metabolites, such as lipopolysaccharide, into the liver. As the primary defense against pathogens, NETs help eliminate gut-derived toxins and shape the liver's inflammatory and immunosuppressive environment. However, this double-edged sword effect can potentially stimulate tumor metastasis by creating a fertile ground for the growth of intestinal tumor cells due to impaired liver tissue and reduced activity of killer immune cells. This comprehensive review systematically describes the influence factors and mechanisms of NETs in colon cancer metastasis and explores their potential as biomarkers and therapeutic targets for liver metastasis.

Identification of neutrophil extracellular traps and crosstalk genes linking inflammatory bowel disease and osteoporosis by integrated bioinformatics analysis and machine learning

Musculoskeletal deficits are among the most common extra-intestinal manifestations and complications of inflammatory bowel disease (IBD). This study aimed to identify crosstalk genes between IBD and osteoporosis (OP) and potential relationships between crosstalk and neutrophil extracellular traps (NETs)-related genes. Three common hub genes from different compared groups are actually the same, namely HDAC6, IL-8, and PPIF. ROC showed that the combined diagnostic value of HDAC6, IL-8, and PPIF was higher than each of the three key hub genes. Immune infiltration results showed that HDAC6 and IL-8 key genes negatively correlated with CD65 bright natural killer cells. USF1 was the common upstream TFs between HDAC6 and PPIF, and MYC was the common upstream TFs between IL-8 and PPIF in RegNetwork. Taken together, this study shows a linked mechanism between IBD and OP via NETs and crosstalk genes. These findings may show light on better diagnosis and treatment of IBD complicated with OP.

Pomegranate (Punica granatum L.) and Its Rich Ellagitannins as Potential Inhibitors in Ulcerative Colitis

Ulcerative colitis, an immune-mediated inflammatory disease of the gastrointestinal tract, places a significant financial burden on patients and the healthcare system. Recently, reviews of the pomegranate and the abundant medicinal applications of its ellagitannins, as well as its pharmacological action, phytochemicals, metabolism, and pharmacokinetics, have been completed. However, summaries on their anti-ulcerative colitis effects are lacking. Numerous preclinical animal investigations and clinical human trial reports demonstrated the specific therapeutic effects of pomegranate and the effect of its ellagitannins against ulcerative colitis. According to the literature collected by Sci-finder and PubMed databases over the past 20 years, this is the first review that has compiled references regarding how the rich ellagitannins found in pomegranate have altered the ulcerative colitis. It was suggested that the various parts of pomegranates and their rich ellagitannins (especially their primary components, punicalagin, and ellagic acid) can inhibit oxidant and inflammatory processes, regulate the intestinal barrier and flora, and provide an anti-ulcerative colitis resource through dietary management.

Cyclosporine A alleviates colitis by inhibiting the formation of neutrophil extracellular traps via the regulating pentose phosphate pathway

BACKGROUND

The aberrant formation of neutrophil extracellular traps (NETs) has been implicated in ulcerative colitis (UC), a chronic recurrent intestinal inflammation. Cyclosporine A (CsA) is now applied as rescue therapy for acute severe UC. In addition, it has been certained that CsA inhibits the formation of NETs in vitro and the mechanism of which was still vague. The study aimed to explore the mechanism CsA inhibits the NETs formation of colitis in vivo and in vitro.

METHODS

NETs enrichment in clinical samples was analyzed using databases from Gene Expression Omnibus and verified in our center. Dextran sulfate sodium (DSS)-induced acute colitis mice model was used to investigate the effect of CsA on NETs of colonic tissue expression. To clarify the mechanism, intracellular energy metabolites were examined by Liquid Chromatograph Mass Spectrometer, and reactive oxygen species (ROS) levels were examined by fluorescence intensity in neutrophils treated with CsA after LPS stimulation. The transcriptional level and activity of G6PD of neutrophils were also assessed using qRT-PCR and WST-8. RNA Sequencing was used to detect differentially expressed genes of neutrophils stimulated by LPS with or without CsA. The expression levels of related proteins were detected by western blot.

RESULTS

NETs enrichment was especially elevated in moderate-to-severe UC patients compared to HC. NETs expression in the colon from DSS colitis was decreased after CsA treatment. Compared with neutrophils stimulated by LPS, NETs formation and cellular ROS levels were decreased in LPS + CsA group. Cellular ribulose 5-phosphate and NADPH/NADP + related to the pentose phosphate pathway (PPP) were reduced in LPS + CsA group. In addition, CsA could decrease G6PD activity in neutrophils stimulated with LPS, and the results were further verified by inhibiting G6PD activity. At last, P53 protein was highly expressed in LPS + CsA group compared with the LPS group. Intracellular G6PD activity, ROS level and NETs formation, which were downregulated by CsA, could be reversed by a P53 inhibitor.

CONCLUSION

Our results indicated CsA could alleviate the severity of colitis by decreasing the formation of NETs in vivo. In vitro, CsA reduced ROS-dependent NETs release via downregulating PPP and cellular ROS levels by decreasing G6PD activity directly by activating the P53 protein.

Crosstalk between neutrophil extracellular traps and immune regulation: insights into pathobiology and therapeutic implications of transfusion-related acute lung injury

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-associated death, occurring during or within 6 hours after transfusion. Reports indicate that TRALI can be categorized as having or lacking acute respiratory distress syndrome (ARDS) risk factors. There are two types of TRALI in terms of its pathogenesis: antibody-mediated and non-antibody-mediated. The key initiation steps involve the priming and activation of neutrophils, with neutrophil extracellular traps (NETs) being established as effector molecules formed by activated neutrophils in response to various stimuli. These NETs contribute to the production and release of reactive oxygen species (ROS) and participate in the destruction of pulmonary vascular endothelial cells. The significant role of NETs in TRALI is well recognized, offering a potential pathway for TRALI treatment. Moreover, platelets, macrophages, endothelial cells, and complements have been identified as promoters of NET formation. Concurrently, studies have demonstrated that the storage of platelets and concentrated red blood cells (RBC) can induce TRALI through bioactive lipids. In this article, recent clinical and pre-clinical studies on the pathophysiology and pathogenesis of TRALI are reviewed to further illuminate the mechanism through which NETs induce TRALI. This review aims to propose new therapeutic strategies for TRALI, with the hope of effectively improving its poor prognosis.

Comprehensive analysis reveals key genes and environmental toxin exposures underlying treatment response in ulcerative colitis based on in-silico analysis and Mendelian randomization

BACKGROUND

UC is increasingly prevalent worldwide and represents a significant global disease burden. Although medical therapeutics are employed, they often fall short of being optimal, leaving patients struggling with treatment non-responsiveness and many related complications.

MATERIALS AND METHODS

The study utilized gene microarray data and clinical information from GEO. Gene enrichment and differential expression analyses were conducted using Metascape and Limma, respectively. Lasso Regression Algorithm was constructed using glmnet and heat maps were generated using pheatmap. ROC curves were used to assess diagnostic parameter capability, while XSum was employed to screen for small-molecule drugs exacerbating UC. Molecular docking was carried out using Autodock Vina. The study also performed Mendelian randomization analysis based on TwoSampleMR and used CTD to investigate the relationship between exposure to environmental chemical toxicants and UC therapy responsiveness.

RESULTS

Six genes (ELL2, DAPP1, SAMD9L, CD38, IGSF6, and LYN) were found to be significantly overexpressed in UC patient samples that did not respond to multiple therapies. Lasso analysis identified ELL2 and DAPP1 as key genes influencing UC treatment response. Both genes accurately predicted intestinal inflammation in UC and impacted the immunological infiltration status. Clofibrate showed therapeutic potential for UC by binding to ELL2 and DAPP1 proteins. The study also reviews environmental toxins and drug exposures that could impact UC progression.

CONCLUSIONS

We used microarray technology to identify DAPP1 and ELL2 as key genes that impact UC treatment response and inflammatory progression. Clofibrate was identified as a promising UC treatment. Our review also highlights the impact of environmental toxins on UC treatment response, providing valuable insights for personalized clinical management.

Thymopentin ameliorates experimental colitis via inhibiting neutrophil extracellular traps

BACKGROUND

The long-term prognosis of Crohn's disease (CD) remains unsatisfactory. Therefore, we assessed the therapeutic effect of thymopentin (TP5) in a mouse model of 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis, which mimics CD, and analyzed its impact on neutrophil extracellular traps (NETs).

METHODS

NET markers, including myeloperoxidase (MPO), neutrophil elastase (NE), citrullinated histone H3 (CitH3), peptidyl arginine deiminase IV (PAD4), and double-stranded DNA (dsDNA) were assessed by immunostaining and enzyme-linked immunosorbent assay. NET formation was evaluated in vitro. Neoseptin 3, a specific NET agonist, was used to reverse the effect of TP5 on TNBS-induced colitis. The action mechanism of TP5 was investigated using RNA-seq.

RESULTS

TP5 ameliorated weight loss (P < 0.001), disease activity index (DAI) (P = 0.05), colon shrinkage (P = 0.04), and elevated levels of tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, IL-6, and neutrophils in the TNBS group. The TNBS group exhibited increased MPO, NE, CitH3, PAD4, dsDNA and MPO-DNA levels (all P < 0.001), which decreased after TP5 administration (P = 0.01, P < 0.001, P < 0.001, P < 0.001, P = 0.02, and P = 0.02 respectively). Tissue CitH3 levels were positively correlated with DAI and TNF-α levels (P < 0.05). Furthermore, phorbol 12-myristate 13-acetate-stimulated NET formation increased by 1.8-, 2.8-, and 2.3-fold in vitro in the control, TNBS + saline, and TNBS + TP5 groups, respectively. Neoseptin 3 significantly reversed the effect of TP5. RNA-seq revealed potential pathways underlying the effect of TP5.

CONCLUSION

TP5 effectively ameliorated colitis by suppressing NETs in the experimental CD model.

Sijunzi Decoction Targets IL1B and TNF to Reduce Neutrophil Extracellular Traps (NETs) in Ulcerative Colitis: Evidence from Silicon Prediction and Experiment Validation

Purpose

This study was conducted to explore the mechanism of Sijunzi Decoction (SJZ) in the treatment of ulcerative colitis (UC).

Methods

The study aimed to investigate the active components and targets of SJZ in the treatment of UC by screening databases such as TCMSP, GeneCards, OMIM, Distinct, TTD, and Drugbank. An online Venn tool, Cytoscape 3.7.2, and Autodock Tools were used to analyze the components and targets. The study also used a mouse model of UC to further investigate the effects of SJZ. HE staining, immunofluorescence, ELISA, qPCR, and Western blot were used to detect various indices.

Results

Eighty-three active components and 112 action targets were identified from SJZ, including 67 targets for treating UC-related NETs. The five core targets identified were AKT1, JUN, IL1B, PTGS2, and TNF, and molecular docking studies indicated that the five targets were well-docked with ginsenoside Rh2, isoflavones, and formononetin. Animal experiments demonstrated that SJZ could alleviate various parameters such as weight, colon length, spleen index, disease activity index, and intestinal pathology of the UC mice. Immunofluorescence and Western blot showed that SJZ could reduce the expression of IL1B and TNF in intestinal neutrophils while increasing the expression of Occludin. Cellular immunofluorescence suggests that SJZ can reduce the expression of TNF and IL1B in NETs. The qPCR results also suggested that SJZ could inhibit TNF signal. Furthermore, ELISA results suggested that SJZ could inhibit the expression of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6) while promoting the expression of anti-inflammatory cytokines (IL-10, IL-37, TGF-β).

Conclusion

SJZ treats UC by reducing the content of intestinal NETs, with primary targets on the NETs being IL1B and TNFand suppress TNF signal. The practical components of SJZ may be ginsenoside Rh2, isoflavones, and formononetin.

Salivary Alterations of Myeloperoxidase in Patients with Systemic Diseases: A Systematic Review

Salivary myeloperoxidase (MPO) is a key mediator of the oral immune system, acting as an enzyme that utilises H2O2 to generate molecules with high bactericidal activity. While MPO determination in plasma is quite common, the use of saliva is still rare. Our systematic review was designed to answer the question "Are salivary levels of myeloperoxidase altered in patients with systemic diseases?". Following the inclusion and exclusion criteria, we included twenty-six studies. Altered MPO levels in saliva were most commonly found in patients with cardiovascular and gastrointestinal diseases. Most studies concerned unstimulated whole saliva, and only a few of them stimulated, mainly by chewing paraffin. Enzyme-linked immunosorbent assay (ELISA) was the most common method for determination of MPO concentrations in saliva. Increased salivary MPO levels were more often observed for inflammatory diseases, except patients with inflammatory bowel diseases who were eligible for biologic therapy. In conclusion, MPO could be altered in the saliva of patients with systematic diseases, especially cardiovascular or gastrointestinal diseases. However, further investigations are recommended to validate these outcomes.

Research progress on the neutrophil components and their interactions with immune cells in the development of psoriasis

BACKGROUND

Psoriasis is an immune-mediated chronic inflammatory disease, and currently it is widely believed that the IL-23/IL-17 axis and Th17 cells play a critical and central role. However, increasing evidence suggests that neutrophils may interact with a variety of immune cells to play an indispensable role in psoriasis.

MATERIALS AND METHODS

We searched the recent literature on psoriasis and neutrophils through databases such as PubMed and CNKI, and summarized the findings to draw conclusions.

RESULTS

Neutrophils can promote the development of psoriasis by secreting IL-23, IL-17, and cytokines with TH17 cell chemotaxis. Activated keratinocytes (KCs) can attract and activate neutrophils, induce the formation of neutrophil extracellular traps (NETs). KCs can also expose self-antigens which lead to strong autoimmune reactions. The granule proteins secreted by activated neutrophils can activate IL-36, which converts vulgaris psoriasis to generalized pustular psoriasis (GPP).

CONCLUSION

The function of neutrophils components and the interaction between neutrophils and immune cells play an essential role in the pathogenesis of psoriasis. The aim is to provide a theoretical basis for the exploration of targeted clinical treatments and fundamental research on the pathogenesis of psoriasis.

Inflammation, Autoinflammation and Autoimmunity in Inflammatory Bowel Diseases

In this review, the role of innate and adaptive immunity in the pathogenesis of inflammatory bowel diseases (IBD) is reported. In IBD, an altered innate immunity is often found, with increased Th17 and decreased Treg cells infiltrating the intestinal mucosa. An associated increase in inflammatory cytokines, such as IL-1 and TNF-α, and a decrease in anti-inflammatory cytokines, such as IL-10, concur in favoring the persistent inflammation of the gut mucosa. Autoinflammation is highlighted with insights in the role of inflammasomes, which activation by exogenous or endogenous triggers might be favored by mutations of NOD and NLRP proteins. Autoimmunity mechanisms also take place in IBD pathogenesis and in this context of a persistent immune stimulation by bacterial antigens and antigens derived from intestinal cells degradation, the adaptive immune response takes place and results in antibodies and autoantibodies production, a frequent finding in these diseases. Inflammation, autoinflammation and autoimmunity concur in altering the mucus layer and enhancing intestinal permeability, which sustains the vicious cycle of further mucosal inflammation.

Oxidative Stress, Inflammation, Gut Dysbiosis: What Can Polyphenols Do in Inflammatory Bowel Disease?

Inflammatory bowel disease (IBD) is a long-term, progressive, and recurrent intestinal inflammatory disorder. The pathogenic mechanisms of IBD are multifaceted and associated with oxidative stress, unbalanced gut microbiota, and aberrant immune response. Indeed, oxidative stress can affect the progression and development of IBD by regulating the homeostasis of the gut microbiota and immune response. Therefore, redox-targeted therapy is a promising treatment option for IBD. Recent evidence has verified that Chinese herbal medicine (CHM)-derived polyphenols, natural antioxidants, are able to maintain redox equilibrium in the intestinal tract to prevent abnormal gut microbiota and radical inflammatory responses. Here, we provide a comprehensive perspective for implementing natural antioxidants as potential IBD candidate medications. In addition, we demonstrate novel technologies and stratagems for promoting the antioxidative properties of CHM-derived polyphenols, including novel delivery systems, chemical modifications, and combination strategies.

3-aminobenzamide protects against colitis associated diabetes mellitus in male BALB/c mice: Role of PARP-1, NLRP3, SIRT-1, AMPK

Diabetes and ulcerative colitis are chronic diseases associated with inflammation, dysbiosis, impaired immune function and infection risk. In patients with type 1 diabetes enteropathy, gastrointestinal manifestations are seen relatively frequently. The current investigation was aimed to decipher the role of 3-aminobenzamide (3-AB) in ulcerative colitis associated Diabetes mellitus in male BALB/c mice. Ulcerative colitis associated Diabetes mellitus experimental murine model was developed by 3 cycles (each cycle consists of seven days) of Dextran Sulphate Sodium (DSS; 2.5 %w/v) with recovery time of one week in-between along with Streptozotocin (STZ; 40 mg/kg; i.p. x 5 days; consecutively) was given at the I^st recovery period. As an intervention, 3-aminobenzamide (3-AB; 5 and 10 mg/kg; intraperitoneally) was given beginning with the second DSS cycle and then continue till sacrifice. 3-aminobenzamide treatment significantly reduced the severity of colitis-associated diabetes mellitus by altering the expression of a number of molecular targets, including sirtuin 1 (SIRT 1), proliferating cell nuclear antigen (PCNA), poly[ADP-ribose] polymerase 1 (PARP-1), cysteine protease-1 (Caspase-1), nuclear factor kappa-light-chain-enhancer of activated B cells (NFkBp65), NLR family pyrin domain containing 3 (NLRP3), insulin growth factor 1 (IGF-1), interleukin-1β (IL-1β), interleukin-10 (IL-10) and β-catenin. Further, 3-AB at high dose (10 mg/kg; intraperitoneally) significantly restored the epithelial tight junction integrity as evaluated by TEM analysis and restored occludin expression analysed by immunofluorescence analysis. Present study revealed that the high dose of 3-AB (10 mg/kg; intraperitoneally) showed significant and consistent protective effects against colitis associated Diabetes mellitus by modulating various molecular targets.

Roxadustat protect mice from DSS-induced colitis in vivo by up-regulation of TLR4

BACKGROUND

The incidence of inflammatory bowel disease (IBD) is growing in the population. At present, the etiology of inflammatory bowel disease remains unclear, and there is no effective and low-toxic therapeutic drug. The role of the PHD-HIF pathway in relieving DSS-induced colitis is gradually being explored.

METHODS

Wild-type C57BL/6 mice were used as a model of DSS-induced colitis to explore the important role of Roxadustat in alleviating DSS-induced colitis. High-throughput RNA-Seq and qRT-PCR methods were used to screen and verify the key differential genes in the colon of mice between normal saline (NS) and Roxadustat groups.

RESULTS

Roxadustat could alleviate DSS-induced colitis. Compared with the mice in the NS group, TLR4 were significantly up-regulated in the Roxadustat group. TLR4 KO mice were used to verify the role of TLR4 in the alleviation of DSS-induced colitis by Roxadustat.

CONCLUSION

Roxadustat has a repairing effect on DSS-induced colitis, and may alleviate DSS-induced colitis by targeting the TLR4 pathway and promote intestinal stem cell proliferation.

Identifying neutrophil-associated subtypes in ulcerative colitis and confirming neutrophils promote colitis-associated colorectal cancer

Background

Ulcerative colitis (UC) is a chronic inflammatory disease of the intestinal mucosa, the incidence of which has increased worldwide. There is still a lack of clear understanding of the pathogenesis of ulcerative colitis that ultimately leads to colitis-associated colorectal cancer.

Method

We download UC transcriptome data from the GEO database and pass the limma package in order to identify differentially expressed genes. Gene Set Enrichment Analysis (GSEA) was used to identify potential biological pathways. We identified immune cells associated with UC by CIBERSORT and Weighted co-expression network analysis (WGCNA). We used validation cohorts and mouse models to verify the expression of the hub genes and the role of neutrophils.

Result

We identified 65 differentially expressed genes in UC samples and healthy controls. GSEA, KEGG, and GO analyses displayed that DEGs were enriched in immune-related pathways. CIBERSORT analysis revealed increased infiltration of neutrophils in UC tissues. The red module, obtained by WGCNA analysis, was considered to be the most relevant module for neutrophils.Based on neutrophil-associated differentially expressed genes, UC patients were classified into two subtypes of neutrophil infiltration. We discovered that the highly neutrophil-infiltrated subtype B of UC patients had a higher risk of developing CAC. Five genes were identified as biomarkers by searching for DEGs between distinct subtypes. Finally, using the mouse model, we determined the expression of these five genes in the control, DSS, and AOM/DSS groups. The degree of neutrophil infiltration in mice and the percentage of MPO and pSTAT3 expression in neutrophils were analyzed by flow cytometry. In the AOM/DSS model, MPO and pSTAT3 expressions were significantly increased.

Conclusions

These findings suggested neutrophils might promote the conversion of UC into CAC. These findings improve our understanding of the pathogenesis of CAC and provide new and more effective insights into the prevention and treatment of CAC.

The involvement of TH17 cells in the pathogenesis of IBD

The pathogenesis of inflammatory bowel disease (IBD) is still unclear. Immune dysfunction may play a key role in the pathogenesis of IBD, in which the role of CD4⁺ T helper (Th) cells is particularly important. Th17 cells are a major component of CD4⁺ T cells, and their differentiation is regulated by a variety of extracellular signals, transcription factors, RNA, and posttranslational modifications. Th17 cells specifically produce IL-17 and play an important role in the protection of mucous membranes and epithelial tissues against infection by extracellular microbes. However, when immune regulation is dysfunctional, Th17 cells abnormally proliferate and produce large amounts of proinflammatory cytokines that can recruit other inflammatory cells, which together induce abnormal immune responses and result in the development of many autoimmune diseases. In recent years, studies have confirmed that Th17 cells play an important role in the pathogenesis of IBD, which makes it a possible target for IBD therapy. This article reviews the recent progress of Th17 cells involved in the pathogenesis of IBD and its targeted therapy.