Analysis of the interferon-γ-induced secretome of intestinal endothelial cells: putative impact on epithelial barrier dysfunction in IBD

Polysaccharide from Pyrus pashia Buch ameliorates DSS-induced colitis in mice via MAPKP38/NF-κB P65 and SCFAs/ERK/MSK signaling pathways

PURPOSE

In this experiment, we investigated the effect of Pyrus pashia Buch on the relevant inflammatory disease indexes, intestinal microbiota, and short-chain fatty acids in mice with dextran sodium sulfate (DSS)-induced ulcerative colitis.

METHODS

The anti-inflammatory effect of PPBP was assessed by measuring inflammatory markers (ELISA), colonic pathological changes (H&E), qPCR of relevant gene expression, 16S rRNA sequencing of intestinal contents, and short-chain fatty acids (SCFAs).

RESULTS

Pyrus pashia Buch polysaccharide (PPBP) alleviated the main symptoms of UC (Weight down, reduced diet, increased disease activity index) and ameliorated pathological damage to colonic tissues by reducing the release of cytokines TNF-α, IL-6, IL-1β, and iNOS. Furthermore, PPBP enhanced the expression of tight junction proteins (ZO-1, Occludin, and Claudin-1) and elevated intestinal mucin MUC2 and MUC3 levels. qPCR analysis showed that PPBP activated MAPK/NF-κB and verified that it regulated the MAPK signaling pathway through the SCFA-ERK-MSK pathway and downregulated the phosphorylation levels of p38 and p65. Using the 16S rRNA method to analyze the level of microbial changes in the mouse gut, it was shown that Pyrus pashia Buch polysaccharide (PPBP) restored the intestinal microbial diversity and species richness in the UC model, and gas chromatography-mass spectrometry analysis demonstrated that Pyrus pashia Buch polysaccharide (PPBP) was able to increase beneficial short chain fatty acids.

CONCLUSION

PPBP is a resourceful edible herb. By studying the mechanism of action of P38/IκBα/P65 in MAPK/NF-κB and SCFA with ERK/MSK in MAPK, we have demonstrated that PPBP can attenuate inflammatory responses to repair intestinal mucosal damage, balance abnormalities in the intestinal microbiota, and improve the function of the damaged intestinal barrier. It provides preliminary experiments for developing PPBP as an IκBα stabilizer and P65 inhibitor.

Zatariamultiflora hydroalcoholic extract: A triple-blind randomized controlled trial on immune genes, inflammation, and ulcerative colitis symptoms

ETHNOPHARMACOLOGICAL RELEVANCE

Zataria multiflora Boiss. (Shirazi thyme) is traditionally used for digestive disorders and inflammatory conditions. Despite its known anti-inflammatory, immunomodulatory, and antioxidant properties, there is limited clinical evidence on its efficacy for ulcerative colitis (UC).

AIM OF THE STUDY

To evaluate the effectiveness of Zataria multiflora Boiss. (Z. multiflora) extract in alleviating UC symptoms, reducing inflammatory markers, and modulating immune-related gene expression.

MATERIALS AND METHODS

In a multicenter, randomized, placebo-controlled, triple-blind trial in Iran, 92 participants received Z. multiflora extract (6 mg/kg/day) or a placebo for two months. Inflammatory markers and gene expression were analyzed from blood samples. Disease activity was assessed using the Partial Mayo Score (p-Mayo) and the Gastrointestinal Symptom Rating Scale (GSRS). Data were analyzed with SPSS software.

RESULTS

The Z. multiflora group showed significant reductions in C-reactive protein (CRP) (p < 0.001), Interleukin-17 (IL-17) (p = 0.001), Interferon-gamma (IFN-γ) (p = 0.002), Nuclear Factor kappa B (NF-κB) (p = 0.002), T-box Transcription Factor T-bet (T-bet) (p = 0.006), and Retinoic Acid-Related Orphan Receptor gamma t (ROR-γt) (p < 0.001). No significant changes were observed in Erythrocyte Sedimentation Rate (ESR) (p = 0.25), GATA Binding Protein 3 (GATA3) (p = 0.09), and Forkhead Box P3 (FOXP3) (p = 0.17). Symptoms such as heartburn, acid reflux, bloating, diarrhea, and fecal urgency improved (p < 0.05). The GSRS score improved (p < 0.001), while the p-Mayo score did not show a significant change (p = 0.24).

CONCLUSION

Z. multiflora extract significantly alleviated UC symptoms and reduced inflammatory markers, indicating its potential as a complementary treatment for UC. However, the study was limited by its short intervention period and the absence of biopsy analysis to assess local tissue effects. Further longitudinal studies are required to validate these findings and determine long-term efficacy.

S1PR1-biased activation drives the resolution of endothelial dysfunction-associated inflammatory diseases by maintaining endothelial integrity

G protein-coupled sphingosine-1-phosphate receptor 1 (S1PR1), a drug target for inflammatory bowel disease (IBD), enables immune cells to egress from lymph nodes, but the treatment increases the risk of immunosuppression. The functional signaling pathway triggered by S1PR1 activation in endothelial cells and its therapeutic application remains unclear. Here, we showed that S1PR1 is highly expressed in endothelial cells of IBD patients and positively correlated with endothelial markers. Gi-biased agonist-SAR247799 activated S1PR1 and reversed pathology in male mouse and organoid IBD models by protecting the integrity of the endothelial barrier without affecting immune cell egress. Cryo-electron microscopy structure of S1PR1-Gi signaling complex bound to SAR247799 with a resolution of 3.47 Å revealed the recognition mode for the biased ligand. With the efficacy of SAR247799 in treating other endothelial dysfunction-associated inflammatory diseases, our study offers mechanistic insights into the Gi-biased S1PR1 agonist and represents a strategy for endothelial dysfunction-associated disease treatment.

Intestinal tissue levels of anti-TNF alpha, antibodies, and cytokines in paediatric Crohn disease

The aim was to explore factors associated with intestinal tissue levels of anti-TNF alpha (anti-TNF), anti-TNF antibodies, and cytokines in pediatric patients with Crohn Disease (CD). In a prospective exploratory study of CD patients undergoing ileocecal resection or colonoscopy between 6/2020 and 1/2023, we analysed tissue levels of anti-TNF, anti-TNF antibodies, and cytokines (TNF-α, IL-17, IL-1β, IFN-γ) from intestinal biopsies. Mixed-effects regression models, adjusted for potential confounders, were used. Data from 27 CD patients (18 females, 66.7%) were analysed. Fourteen (52%) received adalimumab (ADA) and thirteen received infliximab (IFX), with a median therapy duration of 17 (IQR 4.5-41.5) months. Higher levels of free anti-TNF were found in macroscopically inflamed tissue compared to non-inflamed tissue (β = 3.42, 95% CI 1.05-6.10). No significant association was found between serum and tissue anti-TNF levels (β= -0.06, 95% CI - 0.70-0.58). Patients treated longer with anti-TNF had increased IL-17 levels (β = 0.19, 95% CI 0.05-0.33), independent of disease duration and age. IFN-γ levels were linked with both follow-up duration and anti-TNF length. Our study shows significantly higher free drug levels in inflamed tissue. Long-term anti-TNF treatment has been linked to increased IL-17 levels, suggesting a possible impact on the cytokine response pathway. We did not observe a relationship between serum and tissue anti-TNF levels.

Interferon γ Expressing Mucosal Cells in Pediatric Chronic Inflammatory Bowel Disease

The pathogenesis of Crohn's disease (CD) and ulcerative colitis (UC) is multifactorial and includes aberrations in the composition of gastrointestinal mucosal inflammatory cells. Accurate identification of CD and UC is important as treatment and prognosis differs; however, CD and UC may be difficult to differentiate. Interferon γ (IFNγ) expression appears to be increased in ileal mucosa from CD patients, implying that IFNγ could be a diagnostically useful marker to differentiate CD from UC. This study uses automated assessment of IFNγ immunohistochemical expression in archival GI mucosal biopsies from stomach, duodenum, terminal ileum, and colon in a pediatric population to address this possibility. IFNγ positive mucosal cells are increased in the colon in both CD and UC compared to normal colon and in the ileum of CD compared to normal and UC. The abundance of IFNγ positive cells is not correlated with the presence of active inflammation, indicating that active inflammation is not responsible for the variance in abundance of IFNγ positive cells between cohorts and sites. Overlap between CD, UC, and normal suggests that IFNγ immunohistochemistry may only be clinically useful in select situations such as undetermined inflammatory bowel disease and additional study in these areas is warranted.

Interferons in Colorectal Cancer Pathogenesis and Therapy

As key modulators of the immune response, interferons play critical roles following infection and during the pathogenesis of cancer. The idea that these cytokines might be developed as new therapies emerged soon after their discovery. While enthusiasm for this approach to cancer therapy has waxed and waned over the ensuing decades, recent advances in cancer immunotherapy and our improved understanding of the tumor immune environment have led to a resurgence of interest in this unique class of biologic drug. Here, we review how interferons influence the growth of colorectal cancers (CRCs) and highlight new insights into how interferons and drugs that modulate interferon expression might be most effectively deployed in the clinic.

Isofraxidin attenuates dextran sulfate sodium-induced ulcerative colitis through inhibiting pyroptosis by upregulating Nrf2 and reducing reactive oxidative species

BACKGROUND

Ulcerative colitis (UC), a non-specific gastrointestinal disease, is commonly managed with aminosalicylic acids and immunosuppressive agents to control inflammation and relieve symptoms, despite frequent relapses. Isofraxidin is a coumarin compound extracted from traditional Chinese medicine, exhibiting anti-inflammatory and antioxidant properties; however, its alleviating effect on UC remains unclear. Therefore, we investigated the mechanism of isofraxidin in lipopolysaccharide (LPS)-induced cell inflammation in human intestinal epithelial cell (HIEC) and human colorectal adenocarcinoma cells (Caco-2), as well as in dextran sulfate sodium (DSS)-induced UC in mice.

METHODS

We established colitis models in HIEC and Caco-2 cells and mice with LPS and DSS, respectively. Additionally, NLRP3 knockout mice and HIEC cells transfected with NLRP3 silencing gene and ML385 illustrated the role of isofraxidin in pyroptosis and oxidative stress. Data from cells and mice analyses were subjected to one-way analysis of variance or a paired t-test.

RESULTS

Isofraxidin significantly alleviated LPS-induced cell inflammation and reduced lactic dehydrogenase release. Isofraxidin also reversed DSS- or LPS-induced pyroptosis in vivo and in vitro, increasing the expression of pyroptosis-related proteins. Moreover, isofraxidin alleviated oxidative stress induced by DSS or LPS, reducing reactive oxidative species (ROS), upregulation nuclear factor erythroid 2-related factor 2 (Nrf2), and promoting its entry into the nucleus. Mechanistically, ML385 reversed the inhibitory effect of isofraxidin on ROS and increased pyroptosis.

CONCLUSION

Isofraxidin can inhibit pyroptosis through upregulating Nrf2, promoting its entry into the nucleus, and reducing ROS, thereby alleviating DSS-induced UC. Our results suggest isofraxidin as a promising therapeutic strategy for UC treatment.