Interferon Lambda in the Pathogenesis of Inflammatory Bowel Diseases

Effect of sitagliptin therapy on IL-29 and its associated signaling molecules in patients with type 2 diabetes mellitus

OBJECTIVE

The potential immunoregulatory capacity of sitagliptin on interleukin-29 (IL-29) and genes involved in its intracellular pathway were explored in type 2 diabetes mellitus (T2D).

MATERIALS AND METHODS

T2D patients treated with six months of sitagliptin (Sita+), patients not treated with sitagliptin (Sita-), and healthy controls (HCs) were included. IL-29 levels in the supernatant of stimulated mononuclear immune cells was determined with ELISA. The mRNA expression levels of IL-29, FOS, JUN, NF-AT2, NF-KB1, STAT1-2, IRF1, IRF3, IRF7, and IRF9 was assessed with real-time qPCR.

RESULTS

Increased protein and gene levels of IL-29 were observed in Sita- group compared to HCs (p < 0.001 and p = 0.026), while those levels were diminished in Sita+ group in comparison with Sita- group (p < 0.001 and p = 0.008). Expression of FOS, NF-AT2 and NF-KB1 in Sita- patients was higher than HCs (p = 0.018, p = 0.021, and p = 0.001). A significant decrease in expression of FOS, NF-AT2, and NF-KB1 was found in Sita+ group versus Sita- parients (p = 0.027, p = 0.003, and p = 0.002). In Sita- patients, IL-29 levels were correlated to glucose metabolism parameters including FPG and HbA1c (p < 0.05 for all).

CONCLUSION

Sitagliptin administration has a regulatory effect on the aggressive expression of IL-29 and its signaling molecules including FOS, NF-AT2 and NF-KB1 in T2D.

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.

Role of type-I and type-III interferons in gastrointestinal homeostasis and pathogenesis

Interferon (IFN) was discovered based on interference with virus production, and three types of IFN are now defined. Since its discovery, IFN's roles have expanded beyond viruses to diverse pathogen types, tissue homeostasis, and inflammatory disease. The gastrointestinal (GI) tract is arguably the tissue where the roles of IFN types are most distinct, with a particularly prominent role for type-III IFN in antiviral protection of the intestinal epithelium. Current studies continue to deepen our understanding of the type- and tissue-specific roles of IFN. This review highlights these advances within the GI tract, including discovery of protective roles for type-III IFNs against nonviral GI pathogens, and discovery of an antiviral homeostatic type-III IFN response within the intestinal epithelium.

An Engineered Probiotic Produces a Type III Interferon IFNL1 and Reduces Inflammations in in vitro Inflammatory Bowel Disease Models

The etiology of inflammatory bowel diseases (IBDs) frequently results in the uncontrolled inflammation of intestinal epithelial linings and the local environment. Here, we hypothesized that interferon-driven immunomodulation could promote anti-inflammatory effects. To test this hypothesis, we engineered probiotic Escherichia coli Nissle 1917 (EcN) to produce and secrete a type III interferon, interferon lambda 1 (IFNL1), in response to nitric oxide (NO), a well-known colorectal inflammation marker. We then validated the anti-inflammatory effects of the engineered EcN strains in two in vitro models: a Caco-2/Jurkat T cell coculture model and a scaffold-based 3D coculture IBD model that comprises intestinal epithelial cells, myofibroblasts, and T cells. The IFNL1-expressing EcN strains upregulated Foxp3 expression in T cells and thereafter reduced the production of pro-inflammatory cytokines such as IL-13 and -33, significantly ameliorating inflammation. The engineered strains also rescued the integrity of the inflamed epithelial cell monolayer, protecting epithelial barrier integrity even under inflammation. In the 3D coculture model, IFNL1-expressing EcN treatment enhanced the population of regulatory T cells and increased anti-inflammatory cytokine IL-10. Taken together, our study showed the anti-inflammatory effects of IFNL1-expressing probiotics in two in vitro IBD models, demonstrating their potential as live biotherapeutics for IBD immunotherapy.

Interferon lambda modulates proinflammatory cytokines production in PBMCs from patients with chronic kidney disease

BACKGROUND

CKD is a major cause of morbidity and mortality worldwide. Considerable evidence now indicates that renal inflammation plays a central role in the initiation and progression of CKD. Recent investigations have demonstrated that IFNλ plays an important role in the pathogenesis of autoimmune and inflammatory diseases. However, the association of IFNλ with CKD is still poorly understood.

OBJECTIVE

To analyze the correlation between IFNλ levels and pro-inflammatory cytokines, and to investigate the effect of IFNλ on PBMCs in patients with CKD.

METHODS

PBMCs were harvested from patients with CKD and healthy controls for measuring the expression level of inflammatory cytokines by RT-qPCR. Spearman correlation test was used to analyze correlation between IFNλ and cytokines as well as eGFR. PBMCs from healthy individuals and CKD patients were subjected to IFNλ protein stimulation. IL6, TNFα, IL10, ISG15 and MX1 mRNA level were measured by RT-PCR, STAT1 and phosphorylated STAT1 protein level were measured by Western blot.

RESULTS

Patients with CKD showed higher levels of IFNλ in PBMCs compared to healthy controls. IFNλ mRNA levels were associated with cytokines and eGFR. The transcription of IL6, TNFα, and IL10 was significantly increased in healthy human PBMCs after IFNλ stimulation. In addition, IFNλ acts on PBMCs by p-STAT1 and ISG15 as well as MX1.

CONCLUSION

High expression of IFNλ was found in CKD patients and was associated with eGFR and disease-related cytokines. More importantly, IFNλ promoted the expression of pro-inflammatory cytokines in PBMCs, suggesting a potential pro-inflammatory role of IFNλ in CKD.

Therapeutic Effects of Valeriana jatamansi on Ulcerative Colitis: Insights into Mechanisms of Action through Metabolomics and Microbiome Analysis

Ulcerative colitis (UC), belonging to inflammatory bowel disease (IBD), is a chronic and relapsing inflammatory disorder of the gastrointestinal tract, which has not been completely cured in patients so far. Valeriana jatamansi is a Chinese medicine used clinically to treat "diarrhea," which is closely related to UC. This study was to elucidate the therapeutic effects of V. jatamansi extract (VJE) on dextran sodium sulfate (DSS)-induced UC in mice and its underlying mechanism. In this work, VJE effectively ameliorates the symptoms and histopathological scores and reduces the production of inflammatory factors in UC mice. The colon untargeted metabolomics analysis and 16S rDNA sequencing showed remarkable differences in colon metabolite profiles and intestinal microbiome composition between the control and DSS groups, and VJE intervention can reduce these differences. Thirty-two biomarkers were found and modulated the primary pathways including pyrimidine metabolism, arginine biosynthesis, and glutathione metabolism. Meanwhile, twelve significant taxa of gut microbiota were found. Moreover, there is a close relationship between endogenous metabolites and intestinal flora. These findings suggested that VJE ameliorates UC by inhibiting inflammatory factors, recovering intestinal maladjustment, and regulating the interaction between intestinal microbiota and host metabolites. Therefore, the intervention of V. jatamansi is a potential therapeutic treatment for UC.

Interferon-lambda: New role in intestinal symptoms of COVID-19

The tremendous public health and economic impact of coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has become a huge challenge globally. There is increasing evidence that SARS-CoV-2 induces intestinal infections. Type III interferon (IFN-λ) has an antiviral role in intestinal infection, with focused, long-lasting, and non-inflammatory characteristics. This review presents a summary of the structure of SARS-CoV-2, including its invasion and immune escape mechanisms. Emphasis was placed on the gastrointestinal impact of SARS-CoV-2, including changes to the intestinal microbiome, activation of immune cells, and inflammatory responses. We also describe the comprehensive functions of IFN-λ in anti-enteric SARS-CoV-2 infection, and discuss the potential application of IFN-λ as a therapeutic agent for COVID-19 with intestinal symptoms.

Colon-specific delivery of methotrexate using hyaluronic acid modified pH-responsive nanocarrier for the therapy of colitis in mice

Oral immunosuppressant methotrexate (MTX) is an effective method for the treatment of inflammatory bowel disease (IBD). To overcome the defects of clinical application of MTX, poly (lactic-co-glycolic acid) (PLGA), Eudragits® S100 (ES100), chitosan (CS) and hyaluronic acid (HA) were used to structure the MTX-loaded HA-CS/ES100/PLGA nanoparticles (MTX@hCEP). MTX@hCEP had a hydrodynamic particle size of approximately 202.5 nm, narrow size distribution, negative zeta potential (-18.7 mV), and smooth surface morphology. In vitro drug release experiments under simulated gastrointestinal conditions indicated that MTX@hCEP exhibited colonic pH-sensitive drug release properties. The cellular uptake capacity of hCEP nanoparticles was significantly enhanced in RAW 264.7 macrophages. Moreover, we further found that the MTX@hCEP also inhibited the proliferation and the secretion of pro-inflammatory cytokines in the LPS-stimulated macrophages. In vivo imaging results not only demonstrated that the accumulated in the colon of colitis mice, but also indicated the extended retention time of MTX in the colon. Additionally, MTX@hCEP alleviated inflammatory symptoms via decreasing the activities of myeloperoxidase and pro-inflammatory factors, promoting mucosal repair in vivo. Collectively, these results clearly demonstrated that MTX@hCEP with properties of colon-specific and macrophages targeting can be exploited as an efficient nanotherapeutic for IBD therapy.

Modified Gegen Qinlian decoction ameliorates DSS-induced chronic colitis in mice by restoring the intestinal mucus barrier and inhibiting the activation of γδT17 cells

BACKGROUND

Current therapeutics for ulcerative colitis (UC) have limitations. Classical Formula Gegen Qinlian decoction (GQD) is derived from Shang Han Lun and has a long history of treating gastrointestinal diseases such as diarrhea and UC. Nevertheless, the exact mechanism of it needs to be further clarified.

PURPOSE

We aimed to investigate the treatment effects of modified GQD (MGQD) on dextran sodium sulfate (DSS)-induced chronic colitis in mice and conduct further exploration of its underlying mechanisms.

METHODS

The protective effect of MGQD was estimated in a DSS-induced chronic colitis mouse model. Model evaluation included body weight, disease activity index (DAI) score, colon length and histopathology. Alcian Blue/Phosphoric Acid Schiff (AB/PAS) staining, transmission electron microscopy (TEM), immunofluorescence and real time‒PCR (RT-PCR) were used to assess goblet cell function. ELISA, flow cytometry and immunofluorescence were applied to estimate the immunoinflammatory status. Western blot was performed to test the protein expression levels of relevant pathways and related receptors. All experiments were conducted in duplicate.

RESULTS

MGQD alleviated DSS‑induced chronic colitis symptoms in mice, protected goblet cell function and restored the intestinal mucus barrier. Furthermore, MGQD efficiently suppressed the abnormal immune inflammatory response and the activate of γδT17 cells and NLRP3 inflammasome.

CONCLUSION

The mechanisms by which MGQD protects against DSS-induced chronic colitis may involve restoring goblet cell function, repairing the intestinal mucus barrier, and modulating the immune inflammatory response. More importantly, MGQD inhibited NLRP3 inflammasome-associated signaling pathway activation, which consequently reduced the activation of γδT17 cells.

Exposing the Two Contrasting Faces of STAT2 in Inflammation

Inflammation is a natural immune defense mechanism of the body's response to injury, infection, and other damaging triggers. Uncontrolled inflammation may become chronic and contribute to a range of chronic inflammatory diseases. Signal transducer and activator of transcription 2 (STAT2) is an essential transcription factor exclusive to type I and type III interferon (IFN) signaling pathways. Both pathways are involved in multiple biological processes, including powering the immune system as a means of controlling infection that must be tightly regulated to offset the development of persistent inflammation. While studies depict STAT2 as protective in promoting host defense, new evidence is accumulating that exposes the deleterious side of STAT2 when inappropriately regulated, thus prompting its reevaluation as a signaling molecule with detrimental effects in human disease. This review aims to provide a comprehensive summary of the findings based on literature regarding the inflammatory behavior of STAT2 in microbial infections, cancer, autoimmune, and inflammatory diseases. In conveying the extent of our knowledge of STAT2 as a proinflammatory mediator, the aim of this review is to stimulate further investigations into the role of STAT2 in diseases characterized by deregulated inflammation and the mechanisms responsible for triggering severe responses.

Tackling Inflammatory Bowel Diseases: Targeting Proinflammatory Cytokines and Lymphocyte Homing

Inflammatory bowel diseases (IBDs) are characterized by chronic inflammatory disorders that are a result of an abnormal immune response mediated by a cytokine storm and immune cell infiltration. Proinflammatory cytokine therapeutic agents, represented by TNF inhibitors, have developed rapidly over recent years and are promising options for treating IBD. Antagonizing interleukins, interferons, and Janus kinases have demonstrated their respective advantages in clinical trials and are candidates for anti-TNF therapeutic failure. Furthermore, the blockade of lymphocyte homing contributes to the excessive immune response in colitis and ameliorates inflammation and tissue damage. Factors such as integrins, selectins, and chemokines jointly coordinate the accumulation of immune cells in inflammatory regions. This review assembles the major targets and agents currently targeting proinflammatory cytokines and lymphatic trafficking to facilitate subsequent drug development.