Involvement of IL-6 in the pathogenesis of inflammatory bowel disease and colon cancer

Exploiting bacteria for cancer immunotherapy

Immunotherapy has revolutionized the treatment of cancer but continues to be constrained by limited response rates, acquired resistance, toxicities and high costs, which necessitates the development of new, innovative strategies. The discovery of a connection between the human microbiota and cancer dates back 4,000 years, when local infection was observed to result in tumour eradication in some individuals. However, the true oncological relevance of the intratumoural microbiota was not recognized until the turn of the twentieth century. The intratumoural microbiota can have pivotal roles in both the pathogenesis and treatment of cancer. In particular, intratumoural bacteria can either promote or inhibit cancer growth via remodelling of the tumour microenvironment. Over the past two decades, remarkable progress has been made preclinically in engineering bacteria as agents for cancer immunotherapy; some of these bacterial products have successfully reached the clinical stages of development. In this Review, we discuss the characteristics of intratumoural bacteria and their intricate interactions with the tumour microenvironment. We also describe the many strategies used to engineer bacteria for use in the treatment of cancer, summarizing contemporary data from completed and ongoing clinical trials. The work described herein highlights the potential of bacteria to transform the landscape of cancer therapy, bridging ancient wisdom with modern scientific innovation.

Therapeutic potential of Capparis spinosa in experimental model of acute acetic acid-induced colitis: Anti-inflammatory and antioxidant effects

Introduction

This study examined the anti-inflammatory and antioxidant properties of Capparis spinosa L. (caper) in order to determine its medicinal potential in the treatment of acute colitis.

Method

Sixty male rats were divided into six groups. After the experimental period, distal colonic extension was collected for determination of colonic damage, oxidative stress markers, along with antioxidant markers. The impact of altered levels of inflammatory cytokines in colon tissues on the underlying mechanisms examined.

Results

The results showed that administering different doses of caper led to significant decreases in TNF-α and IL-6 levels when compared to the control colitis group (p < 0.001). Caper treatment effectively lowered elevated oxidative stress factors (MDA, NO, and MPO) compared to the control colitis group (p < 0.001). Caper treatment resulted in a significant increase in antioxidant factors (CAT, SOD, and GSH) compared with the control colitis group (p < 0.001).Significant improvements in tissue repair were observed in caper-treated groups compared to positives and control colitis (p < 0.001).

Conclusion

The study highlights caper may be useful in the treatment of acute colitis due to its ameliorative effects on inflammation, oxidative stress, and tissue repair.

Dietary Supplementation of Haskap Berry (Lonicera caerulea L.) Anthocyanins and Probiotics Attenuate Dextran Sulfate Sodium-Induced Colitis: Evidence from an Experimental Animal Model

Haskap berry (Lonicera caerulea L.) is a rich dietary source of anthocyanins with potent anti-inflammatory properties. In this study, isolated haskap berry anthocyanins were encapsulated in maltodextrin and inulin (3:1) by freeze-drying to improve stability and bioavailability. The structural properties of microcapsules, encapsulation yield, efficiency, recovery, and powder retention were evaluated. The microcapsules that exhibited the highest encapsulation efficiency (60%) and anthocyanin recovery (89%) were used in the dextran sulfate sodium (DSS)-induced acute colitis in mice. Thirty-five BALB/c male mice of seven weeks old were divided into seven dietary supplementation groups (n = 5) to receive either free anthocyanins, encapsulated anthocyanins (6.2 mg/day), or probiotics (1 × 109 CFU/day) alone or as combinations of anthocyanin and probiotics. As observed by clinical data, free anthocyanin and probiotic supplementation significantly reduced the severity of colitis. The supplementary diets suppressed the DSS-induced elevation of serum inflammatory (interleukin (IL)-6 and tumor necrosis factor) and apoptosis markers (B-cell lymphoma 2 and Bcl-2-associated X protein) in mice colon tissues. The free anthocyanins and probiotics significantly reduced the serum IL-6 levels. In conclusion, the dietary supplementation of haskap berry anthocyanins and probiotics protects against DSS-induced colitis possibly by attenuating mucosal inflammation, and this combination has the potential as a health-promoting dietary supplement and nutraceutical.

YTHDC1 inhibits autophagy-dependent NF-κB signaling by stabilizing Beclin1 mRNA in macrophages

BACKGROUND

YTHDC1, a key m(6)A nuclear reader, plays a crucial role in regulating mRNA splicing, export, and stability. However, the functional significance and regulatory mechanisms of YTHDC1 in inflammatory bowel disease (IBD) remain to be explored.

METHODS

We established a dextran sulfate sodium (DSS)-induced murine colitis model in vivo and LPS/IFN-γ-stimulated macrophage inflammation in vitro. The expression of YTHDC1 was determined. Colocalization of YTHDC1 and macrophages was assayed by immunofluorescence staining. LV-YTHDC1 or shYTHDC1 lentiviruses were applied for YTHDC1 overexpression or inhibition. For NF-κB inhibition, JSH-23 was utilized. The interaction of YTHDC1 and Beclin1 mRNA was determined by RIP, and the m6A modification of Beclin1 was confirmed by MeRIP.

RESULTS

In DSS-induced colitis and LPS/IFN-γ-treated RAW264.7 macrophages, we observed a significant downregulation of YTHDC1. Overexpression of YTHDC1 resulted in decreased levels of iNOS, CD86, and IL-6 mRNA, along with inhibited NF-κB activation in LPS/IFN-γ-treated RAW264.7 cells. Conversely, downregulation of YTHDC1 promoted iNOS expression and inhibited autophagy. Additionally, the effect of YTHDC1 knockdown on CD86 and IL-6 mRNA induced by LPS/IFN-γ was abolished by the NF-κB inhibitor JSH-23. Mechanistically, YTHDC1 interacted with Beclin1 mRNA, thereby stabilizing Beclin1 mRNA and enhancing Beclin1 expression and autophagy. These effects ultimately led to the inhibition of NF-κB signaling in LPS/IFN-γ-challenged macrophages.

CONCLUSIONS

YTHDC1 inhibited the macrophage-mediated inflammatory response by stabilizing Beclin1 mRNA, which may be a potential therapeutic target for the treatment of IBD.

How the Western Diet Thwarts the Epigenetic Efforts of Gut Microbes in Ulcerative Colitis and Its Association with Colorectal Cancer

Ulcerative colitis (UC) is an autoimmune disease in which the immune system attacks the colon, leading to ulcer development, loss of colon function, and bloody diarrhea. The human gut ecosystem consists of almost 2000 different species of bacteria, forming a bioreactor fueled by dietary micronutrients to produce bioreactive compounds, which are absorbed by our body and signal to distant organs. Studies have shown that the Western diet, with fewer short-chain fatty acids (SCFAs), can alter the gut microbiome composition and cause the host's epigenetic reprogramming. Additionally, overproduction of H2S from the gut microbiome due to changes in diet patterns can further activate pro-inflammatory signaling pathways in UC. This review discusses how the Western diet affects the microbiome's function and alters the host's physiological homeostasis and susceptibility to UC. This article also covers the epidemiology, prognosis, pathophysiology, and current treatment strategies for UC, and how they are linked to colorectal cancer.

Simultaneous Treatment of 5-Aminosalicylic Acid and Treadmill Exercise More Effectively Improves Ulcerative Colitis in Mice

Ulcerative colitis (UC) is characterized by continuous mucosal ulceration of the colon, starting in the rectum. 5-Aminosalicylic acid (5-ASA) is the main therapy for ulcerative colitis; however, it has side effects. Physical exercise effectively increases the number of anti-inflammatory and anti-immune cells in the body. In the current study, the effects of simultaneous treatment of treadmill exercise and 5-ASA were compared with monotherapy with physical exercise or 5-ASA in UC mice. To induce the UC animal model, the mice consumed 2% dextran sulfate sodium dissolved in drinking water for 7 days. The mice in the exercise groups exercised on a treadmill for 1 h once a day for 14 days after UC induction. The 5-ASA-treated groups received 5-ASA by enema injection using a 200 μL polyethylene catheter once a day for 14 days. Simultaneous treatment improved histological damage and increased body weight, colon weight, and colon length, whereas the disease activity index score and collagen deposition were decreased. Simultaneous treatment with treadmill exercise and 5-ASA suppressed pro-inflammatory cytokines and apoptosis following UC. The benefits of this simultaneous treatment may be due to inhibition on nuclear factor-κB/mitogen-activated protein kinase signaling activation. Based on this study, simultaneous treatment of treadmill exercise and 5-ASA can be considered as a new therapy of UC.

Woodfordia fruticosa fermented with lactic acid bacteria impact on foodborne pathogens adhesion and cytokine production in HT-29 cells

Introduction

The study into the interplay between foodborne pathogens and human health, particularly their effects on intestinal cells, is crucial. The importance of lactic acid bacteria (LAB) in promoting a healthy balance of gut microbiota, inhibiting harmful bacteria, and supporting overall gastrointestinal health is becoming more apparent.

Methods

Our study delved into the impact of fermenting Woodfordia fruticosa (WF), a plant known for its antimicrobial properties against gastrointestinal pathogens, with LAB. We focused on the influence of this fermentation process on the binding of foodborne pathogens to the gut lining and cytokine production, aiming to enhance gut health and control foodborne infections in HT-29 cells.

Results and discussion

Post-fermentation, the WF exhibited improved antimicrobial effects when combined with different LAB strains. Remarkably, the LAB-fermented WF (WFLC) substantially decreased the attachment of pathogens such as L. monocytogenes (6.87%  ±  0.33%) and V. parahaemolyticus (6.07%  ±  0.50%) in comparison to the unfermented control. Furthermore, WFLC was found to upregulate IL-6 production in the presence of pathogens like E. coli O157:H7 (10.6%) and L. monocytogenes (19%), suggesting it may activate immune responses. Thus, LAB-fermented WF emerges as a potential novel strategy for fighting foodborne pathogens, although additional studies are warranted to thoroughly elucidate WF's phytochemical profile and its contribution to these beneficial outcomes.

S/O/W Emulsion with CAPE Ameliorates DSS-Induced Colitis by Regulating NF-κB Pathway, Gut Microbiota and Fecal Metabolome in C57BL/6 Mice

Inflammatory bowel disease (IBD) has attracted much attention worldwide due to its prevalence. In this study, the effect of a solid-in-oil-in-water (S/O/W) emulsion with Caffeic acid phenethyl ester (CAPE, a polyphenolic active ingredient in propolis) on dextran sulfate sodium (DSS)-induced colitis in C57BL/6 mice was evaluated. The results showed that CAPE-emulsion could significantly alleviate DSS-induced colitis through its effects on colon length, reduction in the disease activity index (DAI), and colon histopathology. The results of ELISA and Western blot analysis showed that CAPE-emulsion can down-regulate the excessive inflammatory cytokines in colon tissue and inhibit the expression of p65 in the NF-κB pathway. Furthermore, CAPE-emulsion promoted short-chain fatty acids production in DSS-induced colitis mice. High-throughput sequencing results revealed that CAPE-emulsion regulates the imbalance of gut microbiota by enhancing diversity, restoring the abundance of beneficial bacteria (such as Odoribacter), and suppressing the abundance of harmful bacteria (such as Afipia, Sphingomonas). The results of fecal metabolome showed that CAPE-emulsion restored the DSS-induced metabolic disorder by affecting metabolic pathways related to inflammation and cholesterol metabolism. These research results provide a scientific basis for the use of CPAE-emulsions for the development of functional foods for treating IBD.

Navigating IL-6: From molecular mechanisms to therapeutic breakthroughs

This concise review navigates the intricate realm of Interleukin-6 (IL-6), an important member of the cytokine family. Beginning with an introduction to cytokines, this narrative review unfolds with the historical journey of IL-6, illuminating its evolving significance. A crucial section unravels the three distinct signaling modes employed by IL-6, providing a foundational understanding of its versatile interactions within cellular landscapes. Moving deeper, the review meticulously dissects IL-6's signaling mechanisms, unraveling the complexities of its pleiotropic effects in both physiological responses and pathological conditions. A significant focus is dedicated to the essential role IL-6 plays in inflammatory diseases, offering insights into its associations and implications for various health conditions. The review also takes a therapeutic turn by exploring the emergence of anti-IL-6 monoclonal inhibitors, marking a profound stride in treatment modalities. Diving into the molecular realm, the review explores small molecules as agents for IL-6 inhibition, providing a nuanced perspective on diverse intervention strategies. As the review embarks on the final chapters, it contemplates future aspects, offering glimpses into potential research trajectories and the evolving landscape of IL-6-related studies.

The emerging role of hypoxia and environmental factors in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic and debilitating disorder characterized by inflammation of the gastrointestinal tract. Despite extensive research, the exact cause of IBD remains unknown, hampering the development of effective therapies. However, emerging evidence suggests that hypoxia, a condition resulting from inadequate oxygen supply, plays a crucial role in intestinal inflammation and tissue damage in IBD. Hypoxia-inducible factors (HIFs), transcription factors that regulate the cellular response to low oxygen levels, have gained attention for their involvement in modulating inflammatory processes and maintaining tissue homeostasis. The two most studied HIFs, HIF-1α and HIF-2α, have been implicated in the development and progression of IBD. Toxicological factors encompass a wide range of environmental and endogenous agents, including dietary components, microbial metabolites, and pollutants. These factors can profoundly influence the hypoxic microenvironment within the gut, thereby exacerbating the course of IBD and fostering the progression of colitis-associated colorectal cancer. This review explores the regulation of hypoxia signaling at the molecular, microenvironmental, and environmental levels, investigating the intricate interplay between toxicological factors and hypoxic signaling in the context of IBD, focusing on its most concerning outcomes: intestinal fibrosis and colorectal cancer.

Structural characteristics of steamed Polygonatum cyrtonema polysaccharide and its bioactivity on colitis via improving the intestinal barrier and modifying the gut microbiota

Steamed Polygonatum cyrtonema has been commonly used clinically for its gaining effect, whose main active ingredient is a polysaccharide. A water-soluble polysaccharide named PSP-W-1 was isolated from steamed Polygonatum cyrtonema. PSP-W-1 was characterized as a galactan having a backbone consisting predominately of 1,4-β-linked Galp branched at the C-6 position by T-β-linked Galp with a molecular weight of 14.4 kDa. PSP-W-1 could inhibit the overproduction of inflammatory factors and inflammatory mediators (iNOS, IL-6, COX-2) in dextran sodium sulfate-induced colitis mice. Oral administration of PSP-W-1 dramatically alleviated colonic pathological damage, repaired the intestinal barrier (occludin and ZO-1) and regulated the intestinal microbiota by increasing the abundance of norank_f_Muribaculaceae, Lactobacillus and norank_f_norank_o_Clostridia UCG-014, while decreasing the abundance of Bacteroides and Escherichia-Shigella to alleviate colitis symptoms. Overall, our findings suggest that PSP-W-1 might be a therapeutic option for both the prevention and treatment of colitis.

A Versatile Intestine-on-Chip System for Deciphering the Immunopathogenesis of Inflammatory Bowel Disease

The multifactorial nature of inflammatory bowel disease (IBD) necessitates reliable and practical experimental models to elucidate its etiology and pathogenesis. To model the intestinal microenvironment at the onset of IBD in vitro, it is important to incorporate relevant cellular and noncellular components before inducing stepwise pathogenic developments. A novel intestine-on-chip system for investigating multiple aspects of IBD's immunopathogenesis is presented. The system includes an array of tight and polarized barrier models formed from intestinal epithelial cells on an in-vivo-like subepithelial matrix within one week. The dynamic remodeling of the subepithelial matrix by cells or their secretome demonstrates the physiological relevance of the on-chip barrier models. The system design enables introduction of various immune cell types and inflammatory stimuli at specific locations in the same barrier model, which facilitates investigations of the distinct roles of each cell type in intestinal inflammation development. It is showed that inflammatory behavior manifests in an upregulated expression of inflammatory markers and cytokines (TNF-α). The neutralizing effect of the anti-inflammatory antibody Infliximab on levels of TNF-α and its inducible cytokines could be explicitly shown. Overall, an innovative approach to systematically developing a microphysiological system to comprehend immune-system-mediated disorders of IBD and to identify new therapeutic strategies is presented.

Effect of chronic low-dose treatment with chitooligosaccharides on microbial dysbiosis and inflammation associated chronic ulcerative colitis in Balb/c mice

The study aimed to investigate the potential of low dose chitooligosaccharide (COS) in ameliorating dextran sodium sulfate (DSS) induced chronic colitis by regulating microbial dysbiosis and pro-inflammatory responses. Chronic colitis was induced in BALB/c mice by DSS (4% w/v, 3 cycles of 5 days) administration. The mice were divided into four groups: vehicle, DSS, DSS + mesalamine and DSS+COS. COS and mesalamine were administered orally, daily once, from day 1 to day 30 at a dose of 20 mg/kg and 50 mg/kg respectively. The disease activity index (DAI), colon length, histopathological score, microbial composition, and pro-inflammatory cytokine expression were evaluated. COS (20 mg/kg, COSLow) administration reduced the disease activity index, and colon shortening, caused by DSS significantly. Furthermore, COSLow restored the altered microbiome in the gut and inhibited the elevated pro-inflammatory cytokines (IL-1 and IL-6) in the colon against DSS-induced chronic colitis in mice. Moreover, COSLow treatment improved the probiotic microflora thereby restoring the gut homeostasis. In conclusion, this is the first study where microbial dysbiosis and pro-inflammatory responses were modulated by chronic COSLow treatment against DSS-induced chronic colitis in Balb/c mice. Therefore, COS supplementation at a relatively low dose could be efficacious for chronic inflammatory bowel disease.

Molecular Mechanism of Salvia miltiorrhiza in the Treatment of Colorectal Cancer Based on Network Pharmacology and Molecular Docking Technology

Purpose

This study aimed to investigate the effect of Salvia miltiorrhiza on colorectal cancer, as well as the mechanisms involved.

Methods

The active compounds of Salvia miltiorrhiza and the associated genes in colorectal cancer were sourced from publicly available databases. Targets associated with colorectal cancer were identified by searching the GeneCards and OMIM databases. Subsequently, the Cytoscape 3.6.0 software was employed to create a regulatory network that illustrates the relationships among active ingredients, colorectal cancer, and their corresponding targets. The String database was utilized to generate a PPI network. Molecular docking studies, conducted with AutoDock Vina, verified the binding capabilities of these active components to core targets. The findings from network pharmacology analysis were corroborated through in vitro experiments.

Results

In this study, we identified 39 active components derived from Salvia miltiorrhiza that are predicted to target 544 genes associated with colorectal cancer through network pharmacology. Through a combined analysis of network pharmacology, we isolated three key targets: SRC, IL6, and INS. Molecular docking results convincingly demonstrated Salvia miltiorrhiza's strong binding affinity to these targets. Additionally, in vitro experiments confirmed that Salvia miltiorrhiza effectively inhibited the progression of colorectal cancer via regulating the INS/SRC/IL6 pathway.

Conclusion

Salvia miltiorrhiza emerges as a compelling herbal intervention for colorectal cancer. This study lays the foundation for potential future clinical trials assessing the efficacy of Salvia miltiorrhiza in the management of colorectal cancer.

Baricitinib relieves DSS-induced ulcerative colitis in mice by suppressing the NF-κB and JAK2/STAT3 signalling pathways

Ulcerative colitis (UC) is a relapsing inflammatory disease with a unique aetiology. The treatment of UC is challenging, and the current clinical therapeutics for colitis have limited efficacy. Thus, finding new and effective treatment options remains urgent. Baricitinib, an inhibitor of Janus kinase (JAK), has been clinically used to treat rheumatoid arthritis (RA). However, its potential effects on UC have not been fully elucidated. In this study, we aimed to explore the effects of baricitinib on UC and its underlying mechanism. Dextran sulphate sodium (DSS)-induced murine model of chronic colitis was used to investigate the intervention efficacy following oral administration of baricitinib. The levels of key cytokines, such as IL-6, IFN-γ and IL-17A, were determined. Moreover, western blotting for IκBα, p-IκBα, JAK2, p-JAK2, STAT3 and p-STAT3 protein expression was performed to investigate the associated signalling pathways. Our findings demonstrated that baricitinib can significantly relieve DSS-induced UC in mice. After baricitinib intervention, IL-6, IFN-γ and IL-17A levels were decreased both in vitro and in vivo. Moreover, the elevated expression levels of p-IκBα, p-JAK2, and p-STAT3 were significantly reduced after treatment. Collectively, these results suggest that baricitinib is a potential therapeutic agent for alleviation of DSS-induced colitis. This study provides a method for subsequent investigations on potential curative drugs development of the for colitis.

Butyrogenic, bifidogenic and slight anti-inflammatory effects of a green kiwifruit powder (Kiwi FFG®) in a human gastrointestinal model simulating mild constipation

Green kiwi (Actinidia deliciosa var. Hayward) is a fruit with important nutritional attributes and traditional use as a laxative. In this work, we studied in vitro the colonic fermentation of a standardized green kiwifruit powder (Kiwi FFG®) using representative intestinal microbial content of mildly constipated women. Static (batch) and dynamic configurations of the Simulator of the Human Intestinal Microbial Ecosystem (SHIME®) were used to estimate the impact of Kiwi FFG® in the human gut. Analysis of metabolites revealed a significant butyrogenic effect of the kiwifruit powder and, consistently, butyrate-producing bacterial populations (i.e., Faecalibacterium prausnitzii, Cluster IV, Roseburia spp.) were greatly increased in the dynamic gastrointestinal model. Bifidobacterium spp. was also found boosted in the microflora of ascending and transverse colon sections, and a significant rise of Akkermansia muciniphila was identified in the transverse colon. Reporter gene assays using human intestinal cells (HT-29) showed that kiwifruit fermentation metabolites activate the aryl hydrocarbon receptor (AhR) transcriptional pathway, which is an important regulator of intestinal homeostasis and immunity. Moreover, modulation in the production of human interleukins (IL-6 and IL-10) in Caco-2 cells suggested a potential mild anti-inflammatory effect of the kiwifruit powder and its gut microbiota-derived metabolites. Our results suggested a potential health benefit of Kiwi FFG® in the gut microbiota, particularly in the context of constipated people.

Natural polysaccharides protect against diet-induced obesity by improving lipid metabolism and regulating the immune system

Unhealthy dietary patterns-induced obesity and obesity-related complications pose a great threat to human health all over the world. Accumulating evidence suggests that the pathophysiology of obesity and obesity-associated metabolic disorders is closely associated with dysregulation of lipid and energy metabolism, and metabolic inflammation. In this review, three potential anti-obesity mechanisms of natural polysaccharides are introduced. Firstly, natural polysaccharides protect against diet-induced obesity directly by improving lipid and cholesterol metabolism. Since the immunity also affects lipid and energy metabolism, natural polysaccharides improve lipid and energy metabolism by regulating host immunity. Moreover, diet-induced mitochondrial dysfunction, prolonged endoplasmic reticulum stress, defective autophagy and microbial dysbiosis can disrupt lipid and/or energy metabolism in a direct and/or inflammation-induced manner. Therefore, natural polysaccharides also improve lipid and energy metabolism and suppress inflammation by alleviating mitochondrial dysfunction and endoplasmic reticulum stress, promoting autophagy and regulating gut microbiota composition. Specifically, this review comprehensively summarizes underlying anti-obesity mechanisms of natural polysaccharides and provides a theoretical basis for the development of functional foods. For the first time, this review elucidates anti-obesity mechanisms of natural polysaccharides from the perspectives of their hypolipidemic, energy-regulating and immune-regulating mechanisms.

Experiment-based computational model predicts that IL-6 classic and trans-signaling exhibit similar potency in inducing downstream signaling in endothelial cells

Inflammatory cytokine mediated responses are important in the development of many diseases that are associated with angiogenesis. Targeting angiogenesis as a prominent strategy has shown limited effects in many contexts such as cardiovascular diseases and cancer. One potential reason for the unsuccessful outcome is the mutual dependent role between inflammation and angiogenesis. Inflammation-based therapies primarily target inflammatory cytokines such as interleukin-6 (IL-6) in T cells, macrophages, cancer cells, and muscle cells, and there is a limited understanding of how these cytokines act on endothelial cells. Thus, we focus on one of the major inflammatory cytokines, IL-6, mediated intracellular signaling in endothelial cells by developing a detailed computational model. Our model quantitatively characterized the effects of IL-6 classic and trans-signaling in activating the signal transducer and activator of transcription 3 (STAT3), phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt), and mitogen-activated protein kinase (MAPK) signaling to phosphorylate STAT3, extracellular regulated kinase (ERK) and Akt, respectively. We applied the trained and validated experiment-based computational model to characterize the dynamics of phosphorylated STAT3 (pSTAT3), Akt (pAkt), and ERK (pERK) in response to IL-6 classic and/or trans-signaling. The model predicts that IL-6 classic and trans-signaling induced responses are IL-6 and soluble IL-6 receptor (sIL-6R) dose-dependent. Also, IL-6 classic and trans-signaling showed similar potency in inducing downstream signaling; however, trans-signaling induces stronger downstream responses and plays a dominant role in the overall effects from IL-6 due to the in vitro experimental setting of abundant sIL-6R. In addition, both IL-6 and sIL-6R levels regulate signaling strength. Moreover, our model identifies the influential species and kinetic parameters that specifically modulate the downstream inflammatory and/or angiogenic signals, pSTAT3, pAkt, and pERK responses. Overall, the model predicts the effects of IL-6 classic and/or trans-signaling stimulation quantitatively and provides a framework for analyzing and integrating experimental data. More broadly, this model can be utilized to identify potential targets that influence IL-6 mediated signaling in endothelial cells and to study their effects quantitatively in modulating STAT3, Akt, and ERK activation.

Influenza A virus infection during pregnancy causes immunological changes in gut-associated lymphoid tissues of offspring mice

Maternal influenza A virus (IAV) infection during pregnancy can affect offspring immune programming and development. Offspring born from influenza-infected mothers are at increased risk of neurodevelopmental disorders and have impaired respiratory mucosal immunity against pathogens. The gut-associated lymphoid tissue (GALT) represents a large proportion of the immune system in the body and plays an important role in gastrointestinal (GI) homeostasis. This includes immune modulation to antigens derived from food or microbes, gut microbiota composition, and gut-brain axis signaling. Therefore, in this study, we investigated the effect of maternal IAV infection on mucosal immunity of the GI tract in the offspring. There were no major anatomical changes to the gastrointestinal tract of offspring born to influenza-infected dams. In contrast, maternal IAV did affect the mucosal immunity of offspring, showing regional differences in immune cell profiles within distinct GALT. Neutrophils, monocytes/macrophages, CD4+ and CD8+ T cells infiltration was increased in the cecal patch offspring from IAV-infected dams. In the Peyer's patches, only activated CD4+ T cells were increased in IAV offspring. IL-6 gene expression was also elevated in the cecal patch but not in the Peyer's patches of IAV offspring. These findings suggest that maternal IAV infection perturbs homeostatic mucosal immunity in the offspring gastrointestinal tract. This could have profound ramifications on the gut-brain axis and mucosal immunity in the lungs leading to increased susceptibility to respiratory infections and neurological disorders in the offspring later in life.NEW & NOTEWORTHY Influenza A virus (IAV) infection during pregnancy is associated with changes in gut-associated lymphoid tissue (GALT) in the offspring in a region-dependent manner. Neutrophils and monocytes/macrophages were elevated in the cecal patch of offspring from infected dams. This increase in innate immune cell infiltration was not observed in the Peyer's patches. T cells were also elevated in the cecal patch but not in the Peyer's patches.

The tale of antibiotics beyond antimicrobials: Expanding horizons

Antibiotics had proved to be a godsend for mankind since their discovery. They were once the magical solution to the vexing problem of infection-related deaths. German scientist Paul Ehrlich had termed salvarsan as the silver bullet to treatsyphilis.As time passed, the magic of newly discovered silver bullets got tarnished with raging antibiotic resistance among bacteria and associated side-effects. Still, antibiotics remain the primary line of treatment for bacterial infections. Our understanding of their chemical and biological activities has increased immensely with advancement in the research field. Non-antibacterial effects of antibiotics are studied extensively to optimise their safer, broad-range use. These non-antibacterial effects could be both useful and harmful to us. Various researchers across the globe including our lab are studying the direct/indirect effects and molecular mechanisms behind these non-antibacterial effects of antibiotics. So, it is interesting for us to sum up the available literature. In this review, we have briefed the possible reason behind the non-antibacterial effects of antibiotics, owing to the endosymbiotic origin of host mitochondria. We further discuss the physiological and immunomodulatory effects of antibiotics. We then extend the review to discuss molecular mechanisms behind the plausible use of antibiotics as anticancer agents.

Influence of food emulsifiers on cellular function and inflammation, a preliminary study

Emulsifiers are extensively used as food additives and their consumption is increasing in Western countries. However, so far only few studies examined their potential effects on intestinal cellular functions and gut inflammation. The aim of this preliminary analysis was to study the emulsifiers and their concentrations capable of causing cellular damage compared to extra virgin olive oil (EVOO). We tested two commonly used emulsifiers (EMI, EMII) and EVOO on Caco-2 cells, derived from a colon carcinoma and widely used as a model of the intestinal inflammation. The diphenyltetrazolium bromide test MTT and clonogenic assay were used to study the effect of emulsifiers on cell viability. Cell migration was determined by the wound-healing assay. The inflammation was studied by measuring the levels of interleukin 6 (IL-6) and monocyte chemoattractant protein-1/C-C motif chemokine ligand 2 (CCL2), multifunctional cytokines with a major role in the acute-phase response. Furthermore, we analyzed the effect of conditioned media of Caco-2 cells treated with EMs on macrophages activation. In conclusion, our preliminary data provide evidence that EMs increase the proliferation and migration rate of Caco-2 cells. Moreover, Caco-2 cells treated with EMs enhance the IL-6 and CCL2 release and activated macrophages, supporting their role as proinflammatory molecules.

IL-6-Dependent STAT3 Activation and Induction of Proinflammatory Cytokines in Primary Sclerosing Cholangitis

INTRODUCTION

Primary sclerosing cholangitis (PSC) is a rare cholestatic liver disease with periductal inflammation and fibrosis. Genetic studies suggest inflammatory cytokines and IL-6-dependent activation of transcription factor STAT3 as pivotal steps in PSC pathogenesis. However, details of inflammatory regulation remain unclear.

METHODS

We recruited 50 patients with PSC (36 with inflammatory bowel disease, 14 without inflammatory bowel disease), 12 patients with autoimmune hepatitis, and 36 healthy controls to measure cytokines in the serum, bile, and immune cell supernatant using bead-based immunoassays and flow cytometry and immunohistochemistry to analyze phosphorylation of STATs in immune cells. Finally, we analyzed cytokines and STAT3 phosphorylation of T cells in the presence of JAK1/2 inhibitors.

RESULTS

In PSC, IL-6 specifically triggered phosphorylation of STAT3 in CD4 + T cells and lead to enhanced production of interferon (IFN) gamma and interleukin (IL)-17A. Phospho-STAT3-positive CD4 + T cells correlated with systemic inflammation (C-reactive protein serum levels). Combination of immunohistology and flow cytometry indicated that phospho-STAT3-positive cells were enriched in the peribiliary liver stroma and represented CD4 + T cells with prominent production of IFN gamma and IL-17A. JAK1/2 inhibitors blocked STAT3 phosphorylation and production of IFN gamma and IL-6, whereas IL-17A was apparently resistant to this inhibition.

DISCUSSION

Our results demonstrate systemic and local activation of the IL-6/STAT3 pathway in PSC. Resistance of IL-17A to STAT3-targeted inhibition points to a more complex immune dysregulation beyond STAT3 activation.

Monocyte-derived IL-6 programs microglia to rebuild damaged brain vasculature

Cerebrovascular injury (CVI) is a common pathology caused by infections, injury, stroke, neurodegeneration and autoimmune disease. Rapid resolution of a CVI requires a coordinated innate immune response. In the present study, we sought mechanistic insights into how central nervous system-infiltrating monocytes program resident microglia to mediate angiogenesis and cerebrovascular repair after an intracerebral hemorrhage. In the penumbrae of human stroke brain lesions, we identified a subpopulation of microglia that express vascular endothelial growth factor A. These cells, termed 'repair-associated microglia' (RAMs), were also observed in a rodent model of CVI and coexpressed interleukin (IL)-6Ra. Cerebrovascular repair did not occur in IL-6 knockouts or in mice lacking microglial IL-6Ra expression and single-cell transcriptomic analyses revealed faulty RAM programming in the absence of IL-6 signaling. Infiltrating CCR2⁺ monocytes were the primary source of IL-6 after a CVI and were required to endow microglia with proliferative and proangiogenic properties. Faulty RAM programming in the absence of IL-6 or inflammatory monocytes resulted in poor cerebrovascular repair, neuronal destruction and sustained neurological deficits that were all restored via exogenous IL-6 administration. These data provide a molecular and cellular basis for how monocytes instruct microglia to repair damaged brain vasculature and promote functional recovery after injury.

Carboxymethyl Cellulose as a Food Emulsifier: Are Its Days Numbered?

Carboxymethyl cellulose use in industry is ubiquitous. Though it is recognized as safe by the EFSA and FDA, newer works have raised concerns related to its safety, as in vivo studies showed evidence of gut dysbiosis associated with CMC's presence. Herein lies the question, is CMC a gut pro-inflammatory compound? As no work addressed this question, we sought to understand whether CMC was pro-inflammatory through the immunomodulation of GI tract epithelial cells. The results showed that while CMC was not cytotoxic up to 25 mg/mL towards Caco-2, HT29-MTX and Hep G2 cells, it had an overall pro-inflammatory behavior. In a Caco-2 monolayer, CMC by itself increased IL-6, IL-8 and TNF-α secretion, with the latter increasing by 1924%, and with these increases being 9.7 times superior to the one obtained for the IL-1β pro-inflammation control. In co-culture models, an increase in secretion in the apical side, particularly for IL-6 (692% increase), was observed, and when RAW 264.7 was added, data showed a more complex scenario as stimulation of pro-inflammatory (IL-6, MCP-1 and TNF-α) and anti-inflammatory (IL-10 and IFN-β) cytokines in the basal side was observed. Considering these results, CMC may exert a pro-inflammatory effect in the intestinal lumen, and despite more studies being required, the incorporation of CMC in foodstuffs must be carefully considered in the future to minimize potential GI tract dysbiosis.

Echinacea purpurea (L.) Moench extract suppresses inflammation by inhibition of C3a/C3aR signaling pathway in TNBS-induced ulcerative colitis rats

ETHNOPHARMACOLOGICAL RELEVANCE

Echinacea purpurea (L.) Moench (EP) is a perennial herbaceous flowering plant, commonly known as purple conical flower. It was widely used to treat skin inflammation and gastrointestinal diseases.

AIM OF STUDY

Ulcerative colitis (UC) is a chronic and nonspecific inflammatory disease. Recent evidence shows that immune disorders are involved in the pathogenesis of UC. To evaluate the protective effect of Echinacea purpurea (L.) Moench exact (EE) on UC and explore the role of complement system in the treatment of UC.

MATERIALS AND METHODS

UC model was induced in rats by 2,4,6-trinitrobenzene sulfonic acid (TNBS), and then rats were administered with EE for 10 days. Collect colon tissues for analysis of relevant mechanisms.

RESULTS

EE could reduce the weight loss and diarrhea of UC rats. In addition, EE could improve the integrity of intestinal epithelial barrier in UC rats. EE inhibited the level of proinflammatory cytokines and promoted the antioxidation. Furthermore, EE suppressed the expression of C3aR, CFB, CD55, TLR4 and NLRP3.

CONCLUSION

These results indicate that EE may achieve therapeutic effect by inhibiting C3a/C3aR signal pathway, suggesting that EE may be used as a medicinal plant to alleviate UC.

Unsaturated Fatty Acids Complex Regulates Inflammatory Cytokine Production through the Hyaluronic Acid Pathway

In this study, we aimed to develop natural and/or functional materials with antioxidant and anti-inflammatory effects. We obtained extracts from natural plants through an oil and hot-water extraction process and prepared an extract composite of an effective unsaturated fatty acid complex (EUFOC). Furthermore, the antioxidant effect of the extract complex was evaluated, and the anti-inflammatory effect was explored by assessing its inhibitory effect on nitric oxide production through its HA-promoting effect. We conducted a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay to evaluate the cell viability of the EUFOC, and the results showed that EUFOC was not cytotoxic at the test concentrations. In addition, it showed no endogenous cytotoxicity in HaCaT (human keratinocyte) cells. The EUFOC showed excellent 1,1-diphenyl-2-picrylhydrazyl- and superoxide-scavenging abilities. Moreover, it exerted an inhibitory effect on NO production at concentrations that did not inhibit cell viability. The secretion of all the cytokines was increased by lipopolysaccharide (LPS) treatment; however, this was inhibited by the EUFOC in a concentration-dependent manner. In addition, hyaluronic acid content was markedly increased by the EUFOC in a dose-dependent manner. These results suggest that the EUFOC has excellent anti-inflammatory and antioxidant properties, and hence, it can be used as a functional material in various fields.

Association between Inflammatory Bowel Disease and Subsequent Development of Restless Legs Syndrome and Parkinson’s Disease: A Retrospective Cohort Study of 35,988 Primary Care Patients in Germany

Background: In addition to the gastrointestinal symptoms, inflammatory bowel disease (IBD), which includes Crohn’s disease (CD) and ulcerative colitis (UC), is associated with extraintestinal manifestations, including neurological disorders, which are gaining increasing attention due to a recently increased focus on the gut–brain axis. Here we aim to evaluate the association between IBD and restless legs syndrome (RLS) as well as Parkinson’s disease (PD) in a cohort of primary care patients in Germany. Methods: The study included 17,994 individuals with a diagnosis of IBD (7544 with CD and 10,450 with UC) and 17,994 propensity-score-matched individuals without IBD from the Disease Analyzer database (IQVIA). An initial diagnosis of RLS or PD was assessed as a function of IBD. Associations between CD and UC with RLS and PD were analyzed using Cox regression models. Results: During the 10-year observation period, 3.6% of CD patients vs. 1.9% of matched non-IBD pairs (p < 0.001) and 3.2% of UC patients vs. 2.7% of matched pairs (p < 0.001) were diagnosed with RLS. The results were confirmed by Cox regression analysis, which showed a significant association between UC (HR: 1.26; 95% CI: 1.02–1.55) and CD (HR: 1.60; 95% CI: 1.23–2.09) and subsequent RLS. The incidence of PD in IBD patients was not significantly increased. However, we observed a non-significant trend towards a higher incidence of PD in male patients with CD but not UC (HR: 1.55; 95%CI: 0.98–2.45, p = 0.064). Conclusions: The present analysis suggests a significant association between IBD and the subsequent development of RLS. These findings should stimulate further pathophysiological research and may eventually lead to specific screening measures in patients with IBD.

Antimicrobial peptide cathelicidin LL-37 preserves intestinal barrier and organ function in rats with heat stroke

Global warming increases the incidence of heat stroke (HS) and HS causes the reduction of visceral blood flow during hyperthermia, leading to intestinal barrier disruption, microbial translocation, systemic inflammation and multiple organ failure. Cathelicidin LL-37 exhibits antimicrobial activities, helps innate immunity within the gut to maintain intestinal homeostasis, and augments intestinal wound healing and barrier function. Thus, we evaluated the effects and possible mechanisms of cathelicidin LL-37 on HS. Wistar rats were placed in a heating-chamber of 42 ̊C to induce HS. Changes in rectal temperature, hemodynamic parameters, and survival rate were measured during the experimental period. Blood samples and ilea were collected to analyze the effects of LL-37 on systemic inflammation, multiple organ dysfunction, and intestinal injury. Furthermore, LS174T and HT-29 cells were used to assess the underlying mechanisms. Our data showed cathelicidin LL-37 ameliorated the damage of intestinal cells induced by HS. Intestinal injury, systemic inflammation, and nitrosative stress (high nitric oxide level) caused by continuous hyperthermia were attenuated in HS rats treated with cathelicidin LL-37, and hence, improved multiple organ dysfunction, coagulopathy, and survival rate. These beneficial effects of cathelicidin LL-37 were attributed to the protection of intestinal goblet cells (by increasing transepithelial resistance, mucin-2 and Nrf2 expression) and the improvement of intestinal barrier function (less cyclooxygenase-2 expression and FITC-dextran translocation). Interestingly, high cathelicidin expression in the ileal samples of inflammatory bowel disease patients was associated with better clinical outcome. These results suggest that cathelicidin LL-37 could prevent heat stress-induced intestinal damage and heat-related illnesses.

Acute Exposure to Pyridostigmine Bromide Disrupts Cholinergic Myenteric Neuroimmune Function in Mice

Gulf War Illness (GWI) results from chemical exposure during the Gulf War, with notable impacts on gastrointestinal motility. Due to the limited demographic impacted by this ailment, an in-depth investigation of the GWI has yielded little regarding the underlying pathophysiological mechanisms. Here, the hypothesis that exposure to pyridostigmine bromide (PB) results in severe enteric neuro-inflammation, that cascades to disruptions in colonic motility, is tested. The analyses are performed on male C57BL/6 mice that are treated with physiologically similar doses of PB given to GW veterans. When colonic motility is assessed, GWI colons have significantly reduced forces in response to acetylcholine or electrical field stimulation. GWI is also accompanied by high levels of pro-inflammatory cytokines and chemokines, associated with increased numbers of CD40⁺ pro-inflammatory macrophages within the myenteric plexus. Enteric neurons responsible for mediating colonic motility reside within the myenteric plexus, and PB exposure reduced their numbers. Significant smooth muscle hypertrophy is also observed due to increased inflammation. Together, the results show that PB exposure caused functional and anatomical dysfunction, promoting impaired motility within the colon. Achieving a greater understanding of the mechanisms of GWI will allow more refinement in therapeutic options that improve veterans' quality of life.

Experiment-based Computational Model Predicts that IL-6 Trans-Signaling Plays a Dominant Role in IL-6 mediated signaling in Endothelial Cells

Inflammatory cytokine mediated responses are important in the development of many diseases that are associated with angiogenesis. Targeting angiogenesis as a prominent strategy has shown limited effects in many contexts such as peripheral arterial disease (PAD) and cancer. One potential reason for the unsuccessful outcome is the mutual dependent role between inflammation and angiogenesis. Inflammation-based therapies primarily target inflammatory cytokines such as interleukin-6 (IL-6) in T cells, macrophages, cancer cells, muscle cells, and there is a limited understanding of how these cytokines act on endothelial cells. Thus, we focus on one of the major inflammatory cytokines, IL-6, mediated intracellular signaling in endothelial cells by developing a detailed computational model. Our model quantitatively characterized the effects of IL-6 classic and trans-signaling in activating the signal transducer and activator of transcription 3 (STAT3), phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt), and mitogen-activated protein kinase (MAPK) signaling to phosphorylate STAT3, extracellular regulated kinase (ERK) and Akt, respectively. We applied the trained and validated experiment-based computational model to characterize the dynamics of phosphorylated STAT3 (pSTAT3), Akt (pAkt), and extracellular regulated kinase (pERK) in response to IL-6 classic and/or trans-signaling. The model predicts that IL-6 classic and trans-signaling induced responses are IL-6 and soluble IL-6 receptor (sIL-6R) dose-dependent. Also, IL-6 trans-signaling induces stronger downstream signaling and plays a dominant role in the overall effects from IL-6. In addition, both IL-6 and sIL-6R levels regulate signaling strength. Moreover, our model identifies the influential species and kinetic parameters that specifically modulate the pSTAT3, pAkt, and pERK responses, which represent potential targets for inflammatory cytokine mediated signaling and angiogenesis-based therapies. Overall, the model predicts the effects of IL-6 classic and/or trans-signaling stimulation quantitatively and provides a framework for analyzing and integrating experimental data. More broadly, this model can be utilized to identify targets that influence inflammatory cytokine mediated signaling in endothelial cells and to study the effects of angiogenesis- and inflammation-based therapies.

Inflammatory bowel diseases, interleukin-6 and interleukin-6 receptor subunit alpha in causal association with cerebral cortical structure: a Mendelian randomization analysis

Background

Neurological involvement and psychiatric manifestations have been documented in clinical cases of inflammatory bowel disease (IBD); however, the presence of a causal relationship remains elusive. The objective of this study is to investigate the modifications occurring in the cerebral cortex as a result of IBD.

Methods

A compendium of data extracted from a genome-wide association study (GWAS) involving a maximum of 133,380 European subjects. A series of Mendelian random analyses were applied to exclude heterogeneity and pleiotropy, ensuring the stability of the results.

Results

Neither IBDs nor inflammatory cytokines (IL-6/IL-6Rα) were found to have a significant causality with surface area (SA) and thickness (TH) at the global level. At the regional functional brain level, Crohn's disease (CD) significantly decreased the TH of pars orbitalis (β=-0.003mm, Se=0.001mm, p_ivw =4.85×10^-4). IL-6 was observed to reduce the SA of middle temporal (β=-28.575mm², Se=6.482mm², p_ivw=1.04×10^-5) and increase the TH of fusiform (β=0.008mm, Se=0.002mm, p_ivw=8.86×10^-5) and pars opercularis (β=0.009mm, Se=0.002mm, p_ivw=2.34×10^-4). Furthermore, a causal relationship between IL-6Rα and an increase in the SA of superior frontal (β=21.132mm², Se=5.806mm², p_ivw=2.73×10^-4) and the TH of supramarginal (β=0.003mm, Se=0.0002mm, p_ivw=7.86×10^-37). All results passed sensitivity analysis and no heterogeneity and pleiotropy were detected.

Conclusion

The correlation between IBD and changes in cerebral cortical structures implies the existence of a gut-brain axis at the organismal level. It is recommended that clinical patients with IBD prioritize long-term management of inflammation, as changes at the organismal level can lead to functional pathologies. Magnetic resonance imaging (MRI) may be considered as an additional screening option for IBD.

Assessment of Dietary Adequacy and Quality in a Sample of Patients with Crohn's Disease

Both under-and over-nutrition are prevalent in patients with Crohn's Disease (CD). The aim of the present study was to evaluate dietary intake and compare it with relevant recommendations during active disease and remission, also taking into consideration the adequacy of energy reporting. Dietary quality was assessed through adherence to the Mediterranean diet and to the European dietary guidelines for cardiovascular disease prevention (CVD-score). Malnutrition was diagnosed with the GLIM criteria. There were 237 patients evaluated (54.9% males, 41.3 ± 14.1 years and 37.6% with active disease). In the total sample, high prevalence of overweight/obesity (61.6%) and low prevalence of malnutrition (11.4%) were observed, whereas 25.5% reported low protein intake in the sub-sample of adequate energy reporters. The mean MedDietScore was 28.0 ± 5.5 and the mean CVD-score was 5.25 ± 1.36, both reflecting moderate dietary quality. Patients with active disease reported higher prevalence of low protein intake, lower carbohydrate, fibers, fruits, vegetables, legumes, and sweets consumption and a lower MedDietScore compared to patients in remission. Consumption of fibers, fruits, vegetables, and legumes while in remission did not result in reaching the recommended intakes, and dietary quality was low as reflected by the MedDietScore. In conclusion, both protein undernutrition and energy overconsumption were prevalent in the current sample and overall patients adhered to a moderate quality diet irrespective of disease stage.

PU.1-driven Th9 Cells Promote Colorectal Cancer in Experimental Colitis Models Through Il-6 Effects in Intestinal Epithelial Cells

BACKGROUND AND AIMS

Colorectal cancer [CRC] is one of the most frequent malignancies, but the molecular mechanisms driving cancer growth are incompletely understood. We characterised the roles of the cytokine IL-9 and Th9 cells in regulating CRC development.

METHODS

CRC patient samples and samples from AOM/DSS treated mice were analysed for expression of IL-9, CD3, and PU.1 by FACS analysis and immunohistochemistry. IL-9 citrine reporter mice, IL-9 knockout mice, and PU.1 and GATA3 CD4-Cre conditional knockout mice were studied in the AOM/DSS model. DNA minicircles or hyper-IL-6 were used for overexpression of cytokines in vivo. Effects of IL-6 and IL-9 were determined in organoid and T cell cultures. Claudin2/3 expression was studied by western blotting and bacterial translocation by FISH.

RESULTS

We uncovered a significant expansion of IL-9- and PU.1-expressing mucosal Th9 cells in CRC patients, with particularly high levels in patients with colitis-associated neoplasias. PU.1+ Th9 cells accumulated in experimental colorectal neoplasias. Deficiency of IL-9 or inactivation of PU.1 in T cells led to impaired tumour growth in vivo, suggesting a protumoral role of Th9 cells. In contrast, GATA3 inactivation did not affect Th9-mediated tumour growth. Mechanistically, IL-9 controls claudin2/3 expression and T cell-derived IL-6 production in colorectal tumours. IL-6 abrogated the anti-proliferative effects of IL-9 in epithelial organoids in vivo. IL-9-producing Th9 cells expand in CRC and control IL-6 production by T cells.

CONCLUSIONS

IL-9 is a crucial regulator of tumour growth in colitis-associated neoplasias and emerges as potential target for therapy.

The Study of the Extracellular Matrix in Chronic Inflammation: A Way to Prevent Cancer Initiation?

Bidirectional communication between cells and their microenvironment has a key function in normal tissue homeostasis, and in disease initiation, progression and a patient's prognosis, at the very least. The extracellular matrix (ECM), as an element of all tissues and cellular microenvironment, is a frequently overlooked component implicated in the pathogenesis and progression of several diseases. In the inflammatory microenvironment (IME), different alterations resulting from remodeling processes can affect ECM, progressively inducing cancer initiation and the passage toward a tumor microenvironment (TME). Indeed, it has been demonstrated that altered ECM components interact with a variety of surface receptors triggering intracellular signaling that affect cellular pathways in turn. This review aims to support the notion that the ECM and its alterations actively participate in the promotion of chronic inflammation and cancer initiation. In conclusion, some data obtained in cancer research with the employment of decellularized ECM (dECM) models are described. The reported results encourage the application of dECM models to investigate the short circuits contributing to the creation of distinct IME, thus representing a potential tool to avoid the progression toward a malignant lesion.

Deletion of cystathionine-γ-lyase in bone marrow-derived cells promotes colitis-associated carcinogenesis

Ulcerative colitis (UC) is characterized by widespread relapsing inflammation of the colonic mucosa. Colitis-associated cancer (CAC) is one of the most serious complications of a prolonged history of UC. Hydrogen sulfide (H2S) has emerged as an important physiological mediator of gastrointestinal homeostasis, limiting mucosal inflammation and promoting tissue healing in response to injury. Inhibition of cystathionine-γ-lyase (CSE)-dependent H2S production in animal models of UC has been shown to exacerbate colitis and delay tissue repair. It is unknown whether CSE plays a role in CAC, or the downregulation of CSE expression and/or activity promotes CAC development. In humans, we observed a significant decrease in CSE expression in colonic biopsies from patients with UC. Using the dextran sodium sulfate (DSS) model of epithelium injury-induced colitis and global CSE KO mouse strain, we demonstrated that CSE is critical in limiting mucosal inflammation and stimulating epithelial cell proliferation in response to injury. In vitro studies showed that CSE activity stimulates epithelial cell proliferation, basal and cytokine-stimulated cell migration, as well as cytokine regulation of transepithelial permeability. In the azoxymethane (AOM)/DSS model of CAC, the loss of CSE expression accelerated both the development and progression of CAC. The increased tumor multiplicity and severity of CAC observed in CSE-KO mice were associated with reduced levels of mucosal IL-10 expression and increased levels of IL-6. Restoring CSE expression in bone marrow (BM) cells of CSE-KO mice through reciprocal BM transplantation raised mucosal IL-10 expression, decreased IL-6 level, and reduced the number of aberrant crypt foci and tumors in AOM/DSS-treated mice. These studies demonstrate that CSE expression in BM cells plays a critical role in suppressing CAC in mice. Furthermore, the data suggest that the inhibitory effects of CSE on the development of CAC are due, in part, to the modulation of mucosal pro-and anti-inflammatory cytokine expression.

Meprin β expression modulates the interleukin-6 mediated JAK2-STAT3 signaling pathway in ischemia/reperfusion-induced kidney injury

Meprin metalloproteinases have been implicated in the pathophysiology of ischemia/reperfusion (IR)-induced kidney injury. Previous in vitro data showed that meprin β proteolytically processes interleukin-6 (IL-6) resulting in its inactivation. Recently, meprin-β was also shown to cleave the IL-6 receptor. The goal of this study was to determine how meprin β expression impacts IL-6 and downstream modulators of the JAK2-STAT3-mediated signaling pathway in IR-induced kidney injury. IR was induced in 12-week-old male wild-type (WT) and meprin β knockout (βKO) mice and kidneys obtained at 24 h post-IR. Real-time PCR, western blot, and immunostaining/microscopy approaches were used to quantify mRNA and protein levels respectively, and immunofluorescence counterstaining with proximal tubule (PT) markers to determine protein localization. The mRNA levels for IL-6, CASP3 and BCL-2 increased significantly in both genotypes. Interestingly, western blot data showed increases in protein levels for IL-6, CASP3, and BCL-2 in the βKO but not in WT kidneys. However, immunohistochemical data showed increases in IL-6, CASP3, and BCL-2 proteins in select kidney tubules in both genotypes, shown to be PTs by immunofluorescence counterstaining. IR-induced increases in p-STAT-3 and p-JAK-2 in βKO at a global level but immunoflourescence counterstaining demonstrated p-JAK2 and p-STAT3 increases in select PT for both genotypes. BCL-2 increased only in the renal corpuscle of WT kidneys, suggesting a role for meprins expressed in leukocytes. Immunohistochemical analysis confirmed higher levels of leukocyte infiltration in WT kidneys when compared to βKO kidneys. The present data demonstrate that meprin β modulates IR-induced kidney injury in part via IL-6/JAK2/STAT3-mediated signaling.

Anti-Colitic Effect of an Exopolysaccharide Fraction from Pediococcus pentosaceus KFT-18 on Dextran Sulfate Sodium-Induced Colitis through Suppression of Inflammatory Mediators

We previously reported the immunostimulatory effect of an exopolysaccharide fraction from Pediococcus pentosaceus KFT18 (PE-EPS), a lactic acid bacterium, in macrophages and primary splenocytes, as well as in cyclophosphamide-induced immunosuppressed mice. In this study, the anti-colitic activity of PE-EPS was investigated in a dextran sulfate sodium (DSS)-induced colitis animal model. PE-EPS relieved DSS-induced colitis symptoms, such as stool blood, decreased colon length, crypt disruption, and mucus layer edema. Regarding the molecular mechanism, PE-EPS reduced the enhanced expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and pro-inflammatory cytokines (TNF-α, IL-6, and IL-1) in the colon tissue of colitis-induced mice. Additionally, PE-EPS protected against DSS-induced phosphorylation of p65 and signal transducer and activator of transcription 1 (STAT1). These findings suggested that the exopolysaccharide fraction from Ped. pentosaceus KFT18 can be used to treat inflammatory bowel disease by alleviating colonic inflammation.

Targeting IL-6 by engineered Lactococcus lactis via surface-displayed affibody

BACKGROUND

Dysregulated production of interleukin (IL)-6 is implicated in the pathology of inflammatory bowel disease (IBD). Neutralization of IL-6 in the gut by safe probiotic bacteria may help alleviate intestinal inflammation. Here, we developed Lactococcus lactis with potent and selective IL-6 binding activity by displaying IL-6-specific affibody on its surface.

RESULTS

Anti-IL-6 affibody (designated as ZIL) was expressed in fusion with lactococcal secretion peptide Usp45 and anchoring protein AcmA. A high amount of ZIL fusion protein was detected on bacterial surface, and its functionality was validated by confocal microscopy and flow cytometry. Removal of IL-6 from the surrounding medium by the engineered L. lactis was evaluated using enzyme-linked immunosorbent assay. ZIL-displaying L. lactis sequestered recombinant human IL-6 from the solution in a concentration-dependent manner by up to 99% and showed no binding to other pro-inflammatory cytokines, thus proving to be highly specific for IL-6. The removal was equally efficient across different IL-6 concentrations (150-1200 pg/mL) that were found to be clinically relevant in IBD patients. The ability of engineered bacteria to capture IL-6 from cell culture supernatant was assessed using immunostimulated human monocytic cell lines (THP-1 and U-937) differentiated into macrophage-like cells. ZIL-displaying L. lactis reduced the content of IL-6 in the supernatants of both cell lines in a concentration-dependent manner by up to 94%. Dose response analysis showed that bacterial cell concentrations of 10⁷ and 10⁹ CFU/mL (colony forming units per mL) were required for half-maximal removal of recombinant and macrophage-derived IL-6, respectively.

CONCLUSION

The ability of ZIL-displaying L. lactis to bind pathological concentrations of IL-6 at common bacterial doses suggests physiological significance.

Bringing to Light the Risk of Colorectal Cancer in Inflammatory Bowel Disease: Mucosal Glycosylation as a Key Player

Colitis-associated cancer is a major complication of inflammatory bowel disease remaining an important clinical challenge in terms of diagnosis, screening, and prognosis. Inflammation is a driving factor both in inflammatory bowel disease and cancer, but the mechanism underlying the transition from colon inflammation to cancer remains to be defined. Dysregulation of mucosal glycosylation has been described as a key regulatory mechanism associated both with colon inflammation and colorectal cancer development. In this review, we discuss the major molecular mechanisms of colitis-associated cancer pathogenesis, highlighting the role of glycans expressed at gut epithelial cells, at lamina propria T cells, and in serum proteins in the regulation of intestinal inflammation and its progression to colon cancer, further discussing its potential clinical and therapeutic applications.

Dietary manipulation of the gut microbiome in inflammatory bowel disease patients: Pilot study

Diet is a modifiable, noninvasive, inexpensive behavior that is crucial in shaping the intestinal microbiome. A microbiome "imbalance" or dysbiosis in inflammatory bowel disease (IBD) is linked to inflammation. Here, we aim to define the impact of specific foods on bacterial species commonly depleted in patients with IBD to better inform dietary treatment. We performed a single-arm, pre-post intervention trial. After a baseline period, a dietary intervention with the IBD-Anti-Inflammatory Diet (IBD-AID) was initiated. We collected stool and blood samples and assessed dietary intake throughout the study. We applied advanced computational approaches to define and model complex interactions between the foods reported and the microbiome. A dense dataset comprising 553 dietary records and 340 stool samples was obtained from 22 participants. Consumption of prebiotics, probiotics, and beneficial foods correlated with increased abundance of Clostridia and Bacteroides, commonly depleted in IBD cohorts. We further show that specific foods categorized as prebiotics or adverse foods are correlated to levels of cytokines in serum (i.e., GM-CSF, IL-6, IL-8, TNF-alpha) that play a central role in IBD pathogenesis. By using robust predictive analytics, this study represents the first steps to detangle diet-microbiome and diet-immune interactions to inform personalized nutrition for patients suffering from dysbiosis-related IBD.

Xiaoyao-Qingluoyin Cure Adjuvant-Induced Arthritis by Easing LPS Response-Related Pathway-Mediated Immune Abnormality

Qingluoyin (QLY) is a representative herbal formula prescribed for hot symptom-related rheumatoid arthritis treatment. Among its derivatives, Xiaoyao-Qingluoyin (XYQLY) attracts increasing attention due to the notable clinical efficacy. In this study, we compared its effects with QLY on adjuvant-induced arthritis (AIA) in rats and partially elucidated the antirheumatic mechanism using a network pharmacology-based strategy. After continuous oral treatments, clinical outcomes were systematically evaluated by radiographic, histological, immunohistochemical, and serological analyses. Possibly altered pathways were predicted based on reported interactions between the related chemicals and proteins/genes. The obtained conclusion was further validated by experiments in vitro. QLY and XYQLY eased polyarthritis in AIA rats after repeated doses, which reflected in reduced inflammation and bone degradation and downregulated p-p65, MMP3, and TLR4 expressions in joints. Meanwhile, they restored oxidative stress (MDA, SOD, GSH, T-AOC, and NO) and inflammatory indicators (TNF-α and CO) in serum. Synovium-based immunoblotting assay revealed that QLY and XYQLY were similarly effective in downregulating MMP3 and COX-2, but XYQLY treatment exhibited notable merit in suppressing p-p65 expression. Network pharmacology analysis hinted that XYQLY should exert greater impacts on LPS signaling and the downstream. Based on results from LC-MS analysis, we treated AIA rat-derived peripheral blood mononuclear cells with either QLY or XYQLY-based chemical combinations and confirmed that XYQLY had the better potential in inhibiting TLR4/NF-κB-controlled IL-6 production. Consequently, it led to a more profound decrease in Th17 cells counts. Overall evidence demonstrated that XYQLY was especially effective in regulating innate immunity and, therefore, improved immune environment in AIA rats as a whole.

UHMK1 aids colorectal cancer cell proliferation and chemoresistance through augmenting IL-6/STAT3 signaling

UHMK1, a serine/threonine kinase with a U2AF homology motif, is implicated in RNA processing and protein phosphorylation. Increasing evidence has indicated its involvement in tumorigenesis. However, it remains to be elucidated whether UHMK1 plays a role in the development of colorectal cancer (CRC). Here, we demonstrated that UHMK1 was frequently upregulated in CRC samples compared with adjacent normal tissue and high expression of UHMK1 predicted poor outcomes. Knockdown of UHMK1 by siRNAs restrained CRC cell proliferation and increased oxaliplatin sensitivity, whereas overexpression of UHMK1 promoted CRC cell growth and oxaliplatin resistance, suggesting that UHMK1 plays important oncogenic roles in CRC. Mechanistically, we showed that UHMK1 had a significant effect on IL6/STAT3 signaling by interacting with STAT3. The interaction of UHMK1 with STAT3 enhanced STAT3 activity in regulating gene transcription. Furthermore, we found that STAT3 could in turn transcriptionally activate UHMK1 expression in CRC cells. The complementary experiments for cell growth and oxaliplatin resistance indicated the interdependent relationship between UHMK1 and STAT3. Thus, these collective findings uncovered a new UHMK1/STAT3 positive feedback regulatory loop contributing to CRC development and chemoresistance.

IBD Subtype-Regulators IFNG and GBP5 Identified by Causal Inference Drive More Intense Innate Immunity and Inflammatory Responses in CD Than Those in UC

Background: The pathological differences between Crohn’s disease (CD) and ulcerative colitis (UC) are substantial and unexplained yet. Here, we aimed to identify potential regulators that drive different pathogenesis of CD and UC by causal inference analysis of transcriptome data.

Methods: Kruskal–Wallis and Dunnett’s tests were performed to identify differentially expressed genes (DEGs) among CD patients, UC patients, and controls. Subsequently, differentially expressed pathways (DEPs) between CD and UC were identified and used to construct the interaction network of DEPs. Causal inference was performed to identify IBD subtype-regulators. The expression of the subtype-regulators and their downstream genes was validated by qRT-PCR with an independent cohort.

Results: Compared with the control group, we identified 1,352 and 2,081 DEGs in CD and UC groups, respectively. Multiple DEPs between CD and UC were closely related to inflammation-related pathways, such as NOD-like receptor signaling, IL-17 signaling, and chemokine signaling pathways. Based on the priori interaction network of DEPs, causal inference analysis identified IFNG and GBP5 as IBD subtype-regulators. The results with the discovery cohort showed that the expression level of IFNG, GBP5, and NLRP3 was significantly higher in the CD group than that in the UC group. The regulation relationships among IFNG, GBP5, and NLRP3 were confirmed with transcriptome data from an independent cohort and validated by qRT-PCR.

Conclusion: Our study suggests that IFNG and GBP5 were IBD subtype-regulators that trigger more intense innate immunity and inflammatory responses in CD than those in UC. Our findings reveal pathomechanical differences between CD and UC that may contribute to personalized treatment for CD and UC.

Effect of Ramadan intermittent fasting on inflammatory markers, disease severity, depression, and quality of life in patients with inflammatory bowel diseases: A prospective cohort study

Background

Intermittent fasting (IF) during the month of Ramadan is part of the religious rituals of Muslims. The effect of intermittent fasting on disease activity in inflammatory bowel diseases (IBD) is still unknown. This is the first study to assess the effect of IF during Ramadan on inflammatory markers in patients diagnosed with IBD. The effects on clinical disease activity, quality of life, and levels of depression were also assessed.

Methods

Patients diagnosed with ulcerative colitis (UC) or Crohn’s disease (CD) who intended to observe Ramadan fasting were recruited. The following were assessed immediately before and at the end of Ramadan: Serum CRP and stool calprotectin, partial Mayo score, Harvey Bradshaw index (HBI), Simple IBD questionnaire (SIBDQ), and Hamilton depression scale questionnaire.

Results

80 patients diagnosed with IBD were recruited (60 UC, 20 CD). Serum CRP and stool calprotectin did not show a significant change before vs after fasting (median CRP 0.53 vs 0.50, P value = 0.27, Calprotectin 163 vs 218 respectively, P value = 0.62). The partial Mayo score showed a significant rise after fasting (median 1 before vs 1 after fasting, mean: 1.79 vs 2.33 respectively, P value = 0.02). Harvey-Bradshaw index did not show a significant change after fasting (median 4 vs 5, P value = 0.4). Multiple linear regression revealed that older age and a higher baseline calprotectin were associated with a higher change in Mayo score after fasting (P value = 0.02 and P value = 0.01, respectively). No significant change was detected in SIBDQ or Hamilton depression scale scores.

Conclusions

In patients diagnosed with UC, IF during Ramadan was associated with worsening of clinical parameters, the effect was more pronounced in older patients and those with higher baseline calprotectin levels. However, IF during Ramadan was not associated with an adverse effect on objective inflammatory markers (CRP and calprotectin).

Latilactobacillus curvatus BYB3 Isolated from Kimchi Alleviates Dextran Sulfate Sodium (DSS)-Induced Colitis in Mice by Inhibiting IL-6 and TNF-R1 Production

Recent studies have shown that probiotics have health-promoting effects, particularly intestinal immune modulation. In this study, we focused on the immunomodulatory properties of Latilactobacillus curvatus BYB3, formerly called Lactobacillus curvatus, isolated from kimchi. In a mouse model of 14-day dextran sulfate sodium (DSS)-induced colitis, treatment with L. curvatus BYB3 significantly decreased the disease activity index, colon length, and weight loss. Moreover, histological analyses showed that L. curvatus BYB3 protected the structural integrity of the intestinal epithelial layer and mucin-secreting goblet cells from DSS-induced damage, with only slight infiltration by immune cells. To evaluate the molecular mechanisms underlying L. curvatus BYB3-driven inhibition of interleukin 6 production, possible in vivo anti-inflammatory effects of L. curvatus BYB3 were examined in the same mouse model. In addition, significantly lower levels of IL-6 and tumor necrosis factor receptor 1 upregulation were seen in the DSS+BYB3 group (compared to that in the DSS group). These results indicate that L. curvatus BYB3 exhibits health-promoting effects via immune modulation; and therefore, it can be used to treat various inflammatory diseases.

Inflammatory bowel disease-related colorectal cancer: Past, present and future perspectives

Inflammatory bowel disease-related colorectal cancer (IBD-CRC) is one of the most serious complications of IBD contributing to significant mortality in this cohort of patients. IBD is often associated with diet and lifestyle-related gut microbial dysbiosis, the interaction of genetic and environmental factors, leading to chronic gut inflammation. According to the “common ground hypothesis”, microbial dysbiosis and intestinal barrier impairment are at the core of the chronic inflammatory process associated with IBD-CRC. Among the many underlying factors known to increase the risk of IBD-CRC, perhaps the most important factor is chronic persistent inflammation. The persistent inflammation in the colon results in increased proliferation of cells necessary for repair but this also increases the risk of dysplastic changes due to chromosomal and microsatellite instability. Multiple pathways have been identified, regulated by many positive and negative factors involved in the development of cancer, which in this case follows the ‘inflammation-dysplasia-carcinoma’ sequence. Strategies to lower this risk are extremely important to reduce morbidity and mortality due to IBD-CRC, among which colonoscopic surveillance is the most widely accepted and implemented modality, forming part of many national and international guidelines. However, the effectiveness of surveillance in IBD has been a topic of much debate in recent years for multiple reasons — cost-benefit to health systems, resource requirements, and also because of studies showing conflicting long-term data. Our review provides a comprehensive overview of past, present, and future perspectives of IBD-CRC. We explore and analyse evidence from studies over decades and current best practices followed globally. In the future directions section, we cover emerging novel endoscopic techniques and artificial intelligence that could play an important role in managing the risk of IBD-CRC.

Pro-Inflammatory Cytokines Trigger the Overexpression of Tumour-Related Splice Variant RAC1B in Polarized Colorectal Cells

Simple Summary

Tumours are now known to develop more quickly when the tumour cell mass is located in a tissue that shows signs of chronic inflammation. Under such conditions, inflammatory cells from the surrounding tumour microenvironment provide survival signals to which cancer cells respond. We have previously found that some colorectal tumours overexpress the protein RAC1B that sustains tumour cell survival. Here we used a colon mucosa-like in vitro cell model and found that the presence of cancer-associated fibroblasts and pro-inflammatory macrophages stimulated colorectal cells to increase their RAC1B levels. Under these conditions, the secreted survival signals were analysed, and interleukin-6 identified as the main trigger for the increase in RAC1B levels. The results contribute to understand the tumour-promoting effect of inflammation at the molecular level.

Abstract

An inflammatory microenvironment is a tumour-promoting condition that provides survival signals to which cancer cells respond with gene expression changes. One example is the alternative splicing variant Rat Sarcoma Viral Oncogene Homolog (Ras)-Related C3 Botulinum Toxin Substrate 1 (RAC1)B, which we previously identified in a subset of V-Raf Murine Sarcoma Viral Oncogene Homolog B (BRAF)-mutated colorectal tumours. RAC1B was also increased in samples from inflammatory bowel disease patients or in an acute colitis mouse model. Here, we used an epithelial-like layer of polarized Caco-2 or T84 colorectal cancer (CRC) cells in co-culture with fibroblasts, monocytes or macrophages and analysed the effect on RAC1B expression in the CRC cells by RT-PCR, Western blot and confocal fluorescence microscopy. We found that the presence of cancer-associated fibroblasts and M1 macrophages induced the most significant increase in RAC1B levels in the polarized CRC cells, accompanied by a progressive loss of epithelial organization. Under these conditions, we identified interleukin (IL)-6 as the main trigger for the increase in RAC1B levels, associated with Signal Transducer and Activator of Transcription (STAT)3 activation. IL-6 neutralization by a specific antibody abrogated both RAC1B overexpression and STAT3 phosphorylation in polarized CRC cells. Our data identify that pro-inflammatory extracellular signals from stromal cells can trigger the overexpression of tumour-related RAC1B in polarized CRC cells. The results will help to understand the tumour-promoting effect of inflammation and identify novel therapeutic strategies.