New therapeutic avenues in ulcerative colitis: thinking out of the box

PLGA microspheres carrying EMSCs-CM for the effective treatment of murine ulcerative colitis

Ectodermal mesenchymal stem cells-derived conditioned medium (EMSCs-CM) has been reported to protect against ulcerative colitis (UC) in mice, but its underlying mechanism in alleviating UC need to be further elucidated. Here, it is reported that EMSCs-CM could attenuate pro-inflammatory response of LPS-induced IEC-6 cells and regulate the polarization of macrophages towards anti-inflammatory type in vitro. Furthermore, PLGA microspheres prepared by the double emulsion method were constructed for oral delivery of EMSCs-CM (EMSCs-CM-PLGA), which are beneficial for colon-targeted adhesion of EMSCs-CM to the damaged colon mucosa. The results showed that orally-administered of EMSCs-CM-PLGA microspheres reduced inflammatory cells infiltration and maintained the intestinal mucosal barrier. Further investigation found that EMSCs-CM-PLGA microspheres treatment gradually inhibited the activation of NF-κB pathway to regulate M1/M2 polarization balance in colon tissue macrophages, thereby alleviating DSS-induced UC. These results of this study will provide a theoretical basis for clinical application of EMSCs-CM in UC repair.

Unlocking the potential of methionine: a dietary supplement for preventing colitis

The incidence rate of colitis and conversion of colitis into colorectal cancer is increasing. However, the results of drug treatments are inconsistent with variable side effects; therefore, it is necessary to find alternative ways of treating colitis, e.g. through dietary supplements. One such dietary supplement could be sulfur-containing amino acids, which are known to have anti-inflammatory, antioxidant, and gut microbiota homeostasis effects. Therefore, the aim of the present study was to explore the effect of methionine supplementation in the diet of mice on experimental dextran sulfate sodium (DSS)-induced colitis. Here, 24 male C57BL/6J mice were split into three experimental treatment groups in such a way that each treatment group had four replicates and each replicate had two mice. The control group was colitis-free, while colitis was induced by the administration of DSS in the DSS groups. In the DSS and DSS plus methionine (DSS + Met) groups, DSS was provided in drinking water containing 3% DSS on days 1-5 and later provided with purified water on days 6-7. It was found that supplementing with methionine could activate pathways like Nrf2, and inhibit pathways like TLR4 and Nlrp3 to realize anti-inflammatory and antioxidant effects. Moreover, methionine could alter the microbiota of the gut in the experimental mice, whereby exploration of the gut microbiota demonstrated that methionine supplementation in the diet increased the abundance of parabacteroides and the production of propionate and butyrate. The current study shows that the dietary prophylactic supplementation of methionine has a beneficial effect on resisting colitis, providing new insights for the prevention of colitis.

Identification and experimental validation of immune-related gene PPARG is involved in ulcerative colitis

BACKGROUND

The pathophysiology of ulcerative colitis (UC) is believed to be heavily influenced by immunology, which presents challenges for both diagnosis and treatment. The main aims of this study are to deepen our understanding of the immunological characteristics associated with the disease and to identify valuable biomarkers for diagnosis and treatment.

METHODS

The UC datasets were sourced from the GEO database and were analyzed using unsupervised clustering to identify different subtypes of UC. Twelve machine learning algorithms and Deep learning model DNN were developed to identify potential UC biomarkers, with the LIME and SHAP methods used to explain the models' findings. PPI network is used to verify the identified key biomarkers, and then a network connecting super enhancers, transcription factors and genes is constructed. Single-cell sequencing technology was utilized to investigate the role of Peroxisome Proliferator Activated Receptor Gamma (PPARG) in UC and its correlation with macrophage infiltration. Furthermore, alterations in PPARG expression were validated through Western blot (WB) and immunohistochemistry (IHC) in both in vitro and in vivo experiments.

RESULT

By utilizing bioinformatics techniques, we were able to pinpoint PPARG as a key biomarker for UC. The expression of PPARG was significantly reduced in cell models, UC animal models, and colitis models induced by dextran sodium sulfate (DSS). Interestingly, overexpression of PPARG was able to restore intestinal barrier function in H2O2-induced IEC-6 cells. Additionally, immune-related differentially expressed genes (DEGs) allowed for efficient classification of UC samples into neutrophil and mitochondrial metabolic subtypes. A diagnostic model incorporating the three disease-specific genes PPARG, PLA2G2A, and IDO1 demonstrated high accuracy in distinguishing between the UC group and the control group. Furthermore, single-cell analysis revealed that decreased PPARG expression in colon tissue may contribute to the polarization of M1 macrophages through activation of inflammatory pathways.

CONCLUSION

In conclusion, PPARG, a gene related to immunity, has been established as a reliable potential biomarker for the diagnosis and treatment of UC. The immune response it controls plays a key role in the progression and development of UC by enabling interaction between characteristic biomarkers and immune infiltrating cells.

Allium tuberosum-derived nanovesicles with anti-inflammatory properties prevent DSS-induced colitis and modify the gut microbiome

Edible plant-derived nanovesicles (ePDNs) have shown potential as a non-pharmacological option for inflammatory bowel disease (IBD) by maintaining gut health and showing anti-inflammatory effects. However, the effects of Allium tuberosum-derived nanovesicles (ADNs) on colitis have not been studied to date. Here, we extracted exosome-like nanovesicles from Allium tuberosum and investigated whether they have an anti-inflammatory effect in RAW 264.7 cells and colitis mice. The results showed that ADNs reduced the elevated levels of inflammatory factors such as IL-1β, IL-6, TNF-α, and NF-κB pathway-related proteins as a consequence of lipopolysaccharide (LPS) stimulation in RAW 264.7 cells. Furthermore, our mouse experiments demonstrated that ADNs could ameliorate dextran sulfate sodium (DSS)-induced colitis symptoms (e.g., increased disease activity index score, intestinal permeability, and histological appearance). Additionally, ADNs counteracted DSS-induced colitis by downregulating the expression of serum amyloid A (SAA), IL-1β, IL-6, and TNF-α and increasing the expression of tight junction proteins (ZO-1 and occludin) and the anti-inflammatory cytokine IL-10. 16S rRNA gene sequencing showed that ADN intervention restored the gut microbial composition, which was similar to that of the DSS non-treated group, by decreasing the ratio of Firmicutes to Bacteroidetes and the relative abundance of Proteobacteria. Furthermore, ADNs induced acetic acid production along with an increase in the abundance of Lactobacillus. Overall, our findings suggest that ADN supplementation has a crucial role in maintaining gut health and is a novel preventive therapy for IBD.

Bioinspired and bioderived nanomedicine for inflammatory bowel disease

Due to its chronic nature and complex pathophysiology, inflammatory bowel disease (IBD) poses significant challenges for treatment. The long-term therapies for patients, often diagnosed between the ages of 20 and 40, call for innovative strategies to target inflammation, minimize systemic drug exposure, and improve patients' therapeutic outcomes. Among the plethora of strategies currently pursued, bioinspired and bioderived nano-based formulations have garnered interest for their safety and versatility in the management of IBD. Bioinspired nanomedicine can host and deliver not only small drug molecules but also biotherapeutics, be made gastroresistant and mucoadhesive or mucopenetrating and, for these reasons, are largely investigated for oral administration, while surprisingly less for rectal delivery, recommended first-line treatment approach for several IBD patients. The use of bioderived nanocarriers, mostly extracellular vesicles (EVs), endowed with unique homing abilities, is still in its infancy with respect to the arsenal of nanomedicine under investigation for IBD treatment. An emerging source of EVs suited for oral administration is ingesta, that is, plants or milk, thanks to their remarkable ability to resist the harsh environment of the upper gastrointestinal tract. Inspired by the unparalleled properties of natural biomaterials, sophisticated avenues for enhancing therapeutic efficacy and advancing precision medicine approaches in IBD care are taking shape, although bottlenecks arising either from the complexity of the nanomedicine designed or from the lack of a clear regulatory pathway still hinder a smooth and efficient translation to the clinics. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology.

The Janus face of HIF-1α in ischemic stroke and the possible associated pathways

Stroke is the most devastating disease, causing paralysis and eventually death. Many clinical and experimental trials have been done in search of a new safe and efficient medicine; nevertheless, scientists have yet to discover successful remedies that are also free of adverse effects. This is owing to the variability in intensity, localization, medication routes, and each patient's immune system reaction. HIF-1α represents the modern tool employed to treat stroke diseases due to its functions: downstream genes such as glucose metabolism, angiogenesis, erythropoiesis, and cell survival. Its role can be achieved via two downstream EPO and VEGF strongly related to apoptosis and antioxidant processes. Recently, scientists paid more attention to drugs dealing with the HIF-1 pathway. This review focuses on medicines used for ischemia treatment and their potential HIF-1α pathways. Furthermore, we discussed the interaction between HIF-1α and other biological pathways such as oxidative stress; however, a spotlight has been focused on certain potential signalling contributed to the HIF-1α pathway. HIF-1α is an essential regulator of oxygen balance within cells which affects and controls the expression of thousands of genes related to sustaining homeostasis as oxygen levels fluctuate. HIF-1α's role in ischemic stroke strongly depends on the duration and severity of brain damage after onset. HIF-1α remains difficult to investigate, particularly in ischemic stroke, due to alterations in the acute and chronic phases of the disease, as well as discrepancies between the penumbra and ischemic core. This review emphasizes these contrasts and analyzes the future of this intriguing and demanding field.

Marine phospholipid nanoliposomes: A promising therapeutic approach for inflammatory bowel disease: Preparation, safety, and efficacy evaluation

Promising findings have been emerged from studies utilizing n3 polyunsaturated fatty acids (PUFA) supplementation in animal models of inflammatory bowel disease (IBD). Introduction of marine phospholipids which combine n3 PUFA with phosphatidylcholine in a nanoliposome formulation offers enhanced pharmacological efficacy due to physical stability, improved bioavailability, and specific targeting to inflamed colitis tissues. In the present study, a marine phospholipid-based nanoliposome formulation was developed and optimized, resulting in nanovesicles of approximately 107.7 ± 1.3 nm in size, 0.18 ± 0.01 PDI, and - 32.03 ± 3.16 mV ZP. The nanoliposomes exhibited spherical vesicles with stable properties upon incubation at SGF as shown by the TEM, DLS, and turbidity measurements over 3 h. MPL nanoliposomes were cytocompatible until the concentration of 500 µg/mL as per MTT assay and taken by macrophages through macropinocytosis and caveolae pathways, and demonstrated significant inhibitory activity against reactive oxygen species (ROS) in LPS-stimulated macrophages. They were also shown to be blood-compatible and safe for administration in healthy mice. In a colitis mouse model, the nanoliposomes displayed preferential distribution in the inflamed gut, delaying the onset of colitis when administered prophylactically. These findings highlight the potential of marine phospholipid nanoliposomes as a promising therapeutic approach for managing inflammatory bowel disease.

Emerging roles of host and microbial bioactive lipids in inflammatory bowel diseases

The intestinal tract harbors diverse microorganisms, host- and microbiota-derived metabolites, and potentially harmful dietary antigens. The epithelial barrier separates the mucosa, where diverse immune cells exist, from the lumen to avoid excessive immune reactions against microbes and dietary antigens. Inflammatory bowel disease (IBD), such as ulcerative colitis and Crohn's disease, is characterized by a chronic and relapsing disorder of the gastrointestinal tract. Although the precise etiology of IBD is still largely unknown, accumulating evidence suggests that IBD is multifactorial, involving host genetics and microbiota. Alterations in the metabolomic profiles and microbial community are features of IBD. Advances in mass spectrometry-based lipidomic technologies enable the identification of changes in the composition of intestinal lipid species in IBD. Because lipids have a wide range of functions, including signal transduction and cell membrane formation, the dysregulation of lipid metabolism drastically affects the physiology of the host and microorganisms. Therefore, a better understanding of the intimate interactions of intestinal lipids with host cells that are implicated in the pathogenesis of intestinal inflammation might aid in the identification of novel biomarkers and therapeutic targets for IBD. This review summarizes the current knowledge on the mechanisms by which host and microbial lipids control and maintain intestinal health and diseases.

Identification of gene signatures associated with ulcerative colitis and the association with immune infiltrates in colon cancer

Background

Inflammatory bowel diseases, including ulcerative colitis (UC) and Crohn's disease, are some of the most common inflammatory disorders of the gastrointestinal tract. The dysfunction of the immune system in the intestines is suggested to be the underlying cause of the pathogenesis of UC. However, the mechanisms regulating these dysfunctional immune cells and inflammatory phenotypes are still unclear.

Methods

The differential expression analysis on microarray datasets were performed including GSE24287, GSE87466, GSE102133, and GSE107499, including 376 samples. "Gene Ontology" and "Kyoto Encyclopedia of Genes and Genomes" pathway enrichment analyses were conducted to identify the common differentially expressed genes (DEGs) in these datasets and explore their underlying biological mechanisms. Further algorithms like "Cell-type Identification by Estimating Relative Subsets of RNA Transcripts" were used to determine the infiltration status of immune cells in patients with UC. "Cytoscape" and "Gene Set Enrichment Analysis" were used to screen for hub genes and to investigate their biological mechanisms. The Tumor Immune Estimation Resource database was used to study the correlation between hub genes and infiltrating immune cells in patients with UC. A total of three hub genes, CCL3, MMP3, and TIMP1, were identified using Cytoscape.

Results

A positive correlation was observed between these hub genes and patients with active UC. These genes served as a biomarker for active UC. Moreover, a decrease in CCL3, MMP3, and TIMP1 expression was observed in the mucosa of the intestine of patients with active UC who responded to Golimumab therapy. In addition, results show a significant positive correlation between CCL3, MMP3, and TIMP1 expression and different immune cell types including dendritic cells, macrophages, CD8+ T cells, and neutrophils in patients with colon cancer. Moreover, CCL3, MMP3, and TIMP1 expression were strongly correlated with different immune cell markers.

Conclusion

Study results show the involvement of hub genes like CCL3, MMP3, and TIMP1 in the pathogenesis of UC. These genes could serve as a novel pharmacological regulator of UC. These could be used as a therapeutic target for treating patients with UC and may serve as biomarkers for immune cell infiltration in colon cancer.

Impact of Obesity on the Course of Management of Inflammatory Bowel Disease—A Review

It is already well-known that visceral adipose tissue is inseparably related to the pathogenesis, activity, and general outcome of inflammatory bowel disease (IBD). We are getting closer and closer to the molecular background of this loop, finding certain relationships between activated mesenteric tissue and inflammation within the lumen of the gastrointestinal tract. Recently, relatively new data have been uncovered, indicating a direct impact of body fat on the pattern of pharmacological treatment in the course of IBD. On the other hand, ileal and colonic types of Crohn’s disease and ulcerative colitis appear to be more diversified than it was thought in the past. However, the question arises whether at this stage we are able to translate this knowledge into the practical management of IBD patients or we are still exploring the scientific background of this pathology, having no specific tools to be used directly in patients. Our review explores IBD in the context of obesity and associated disorders, focusing on adipokines, creeping fat, and possible relationships between these disorders and the treatment of IBD patients.

Identifying predictive signalling networks for Vedolizumab response in ulcerative colitis

BACKGROUND

In ulcerative colitis (UC), the molecular mechanisms that drive disease development and patient response to therapy are not well understood. A significant proportion of patients with UC fail to respond adequately to biologic therapy. Therefore, there is an unmet need for biomarkers that can predict patients' responsiveness to the available UC therapies as well as ascertain the most effective individualised therapy. Our study focused on identifying predictive signalling pathways that predict anti-integrin therapy response in patients with UC.

METHODS

We retrieved and pre-processed two publicly accessible gene expression datasets (GSE73661 and GSE72819) of UC patients treated with anti-integrin therapies: (1) 12 non-IBD controls and 41 UC patients treated with Vedolizumab therapy, and (2) 70 samples with 58 non-responder and 12 responder UC patient samples treated with Etrolizumab therapy without non-IBD controls. We used a diffusion-based signalling model which is mainly focused on the T-cell receptor signalling network. The diffusion model uses network connectivity between receptors and transcription factors.

RESULTS

The network diffusion scores were able to separate VDZ responder and non-responder patients before treatment better than the original gene expression. On both anti-integrin treatment datasets, the diffusion model demonstrated high predictive performance for discriminating responders from non-responders in comparison with 'nnet'. We have found 48 receptor-TF pairs identified as the best predictors for VDZ therapy response with AUC ≥ 0.76. Among these receptor-TF predictors pairs, FFAR2-NRF1, FFAR2-RELB, FFAR2-EGR1, and FFAR2-NFKB1 are the top best predictors. For Etrolizumab, we have identified 40 best receptor-TF pairs and CD40-NFKB2 as the best predictor receptor-TF pair (AUC = 0.72). We also identified subnetworks that highlight the network interactions, connecting receptors and transcription factors involved in cytokine and fatty acid signalling. The findings suggest that anti-integrin therapy responses in cytokine and fatty acid signalling can stratify UC patient subgroups.

CONCLUSIONS

We identified signalling pathways that may predict the efficacy of anti-integrin therapy in UC patients and personalised therapy alternatives. Our results may lead to the advancement of a promising clinical decision-making tool for the stratification of UC patients.

Lysophosphatidylserines derived from microbiota in Crohn’s disease elicit pathological Th1 response

Microbiota alteration and IFN-γ–producing CD4⁺ T cell overactivation are implicated in Crohn’s disease (CD) pathogenesis. However, it remains unclear how dysbiosis enhances Th1 responses, leading to intestinal inflammation. Here, we identified key metabolites derived from dysbiotic microbiota that induce enhanced Th1 responses and exaggerate colitis in mouse models. Patients with CD showed elevated lysophosphatidylserine (LysoPS) concentration in their feces, accompanied by a higher relative abundance of microbiota possessing a gene encoding the phospholipid-hydrolyzing enzyme phospholipase A. LysoPS induced metabolic reprogramming, thereby eliciting aberrant effector responses in both human and mouse IFN-γ–producing CD4⁺ T cells. Administration of LysoPS into two mouse colitis models promoted large intestinal inflammation. LysoPS-induced aggravation of colitis was impaired in mice lacking P2ry10 and P2ry10b, and their CD4⁺ T cells were hyporesponsive to LysoPS. Thus, our findings elaborate on the mechanism by which metabolites elevated in patients with CD harboring dysbiotic microbiota promote Th1-mediated intestinal pathology.

Oral administration of turmeric-derived exosome-like nanovesicles with anti-inflammatory and pro-resolving bioactions for murine colitis therapy

BACKGROUND

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) characterized by diffuse inflammation of the colonic mucosa and a relapsing and remitting course. The current therapeutics are only modestly effective and carry risks for unacceptable adverse events, and thus more effective approaches to treat UC is clinically needed.

RESULTS

For this purpose, turmeric-derived nanoparticles with a specific population (TDNPs 2) were characterized, and their targeting ability and therapeutic effects against colitis were investigated systematically. The hydrodynamic size of TDNPs 2 was around 178 nm, and the zeta potential was negative (- 21.7 mV). Mass spectrometry identified TDNPs 2 containing high levels of lipids and proteins. Notably, curcumin, the bioactive constituent of turmeric, was evidenced in TDNPs 2. In lipopolysaccharide (LPS)-induced acute inflammation, TDNPs 2 showed excellent anti-inflammatory and antioxidant properties. In mice colitis models, we demonstrated that orally administrated of TDNPs 2 could ameliorate mice colitis and accelerate colitis resolution via regulating the expression of the pro-inflammatory cytokines, including TNF-α, IL-6, and IL-1β, and antioxidant gene, HO-1. Results obtained from transgenic mice with NF-κB-RE-Luc indicated that TDNPs 2-mediated inactivation of the NF-κB pathway might partially contribute to the protective effect of these particles against colitis.

CONCLUSION

Our results suggest that TDNPs 2 from edible turmeric represent a novel, natural colon-targeting therapeutics that may prevent colitis and promote wound repair in colitis while outperforming artificial nanoparticles in terms of low toxicity and ease of large-scale production.

Identification of Immune-Related Gene Signature and Prediction of CeRNA Network in Active Ulcerative Colitis

Background

Ulcerative colitis (UC) is an inflammatory disease of the intestinal mucosa, and its incidence is steadily increasing worldwide. Intestinal immune dysfunction has been identified as a central event in UC pathogenesis. However, the underlying mechanisms that regulate dysfunctional immune cells and inflammatory phenotype remain to be fully elucidated.

Methods

Transcriptome profiling of intestinal mucosa biopsies were downloaded from the GEO database. Robust Rank Aggregation (RRA) analysis was performed to identify statistically changed genes and differentially expressed genes (DEGs). Gene Set Enrichment Analysis (GSEA), Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to explore potential biological mechanisms. CIBERSORT was used to evaluate the proportion of 22 immune cells in biopsies. Weighted co-expression network analysis (WGCNA) was used to determine key module-related clinical traits. Protein-Protein Interaction (PPI) network and Cytoscape were performed to explore protein interaction network and screen hub genes. We used a validation cohort and colitis mouse model to validate hub genes. Several online websites were used to predict competing endogenous RNA (ceRNA) network.

Results

RRA integrated analysis revealed 1838 statistically changed genes from four training cohorts (adj. p-value < 0.05). GSEA showed that statistically changed genes were enriched in the innate immune system. CIBERSORT analysis uncovered an increase in activated dendritic cells (DCs) and M1 macrophages. The red module of WGCNA was considered the most critical module related to active UC. Based on the results of the PPI network and Cytoscape analyses, we identified six critical genes and transcription factor NF-κB. RT-PCR revealed that andrographolide (AGP) significantly inhibited the expression of hub genes. Finally, we identified XIST and three miRNAs (miR-9-5p, miR-129-5p, and miR-340-5p) as therapeutic targets.

Conclusions

Our integrated analysis identified four hub genes (CXCL1, IL1B, MMP1, and MMP10) regulated by NF-κB. We further revealed that AGP decreased the expression of hub genes by inhibiting NF-κB activation. Lastly, we predicted the involvement of ceRNA network in the regulation of NF-κB expression. Collectively, our results provide valuable information in understanding the molecular mechanisms of active UC. Furthermore, we predict the use of AGP and small RNA combination for the treatment of UC.

Exploring the Early Phase of Crohn's Disease

The development of Crohn's disease (CD) is characterized by a breakdown of homeostatic immune-bacterial communication, which takes place at the intestinal mucosa when environmental triggers impact genetically predisposed individuals. Converging lines of evidence support the hypothesis that this pathogenetic model develops through sequential, although inter-related, steps that indicate failure of mucosal defense mechanisms at various stages. In this context, immunologic phenomena that mediate the initial appearance of inflammatory lesions across the intestinal tissue may differ substantially from those that mediate and perpetuate chronic inflammatory responses. A compromise in the integrity of the epithelial barrier is among the earliest events and leads to accelerated influx of intraluminal antigens and intact microorganisms within the immunologically rich lamina propria. Inadequate clearance of invading microorganisms also may occur as a result of defects in innate immunity, preventing the timely and complete resolution of acute inflammatory responses. The final step is the development of persistent adaptive responses, which also differ between early and late Crohn's disease. Current progress in our ability to delineate single-cell transcriptomics and proteomics has allowed the discovery of cellular and molecular mechanisms that participate in each sequential step of CD development. This not only will advance our understanding of CD pathogenesis, but also facilitate the design of targeted therapeutic approaches.

Interference With the AMPKα/mTOR/NLRP3 Signaling and the IL-23/IL-17 Axis Effectively Protects Against the Dextran Sulfate Sodium Intoxication in Rats: A New Paradigm in Empagliflozin and Metformin Reprofiling for the Management of Ulcerative Colitis

Empagliflozin and metformin are widely used for the treatment of type 2 diabetes. These drugs showed marked anti-inflammatory effects in different animal models via enhancing AMPK activity. Yet, the protective anti-inflammatory effects of their combination against ulcerative colitis have not been previously investigated. The current study aimed to explore the potential of empagliflozin/metformin combination to mitigate the DSS-induced rat colitis model. The modulating effects of empagliflozin and metformin on the AMPK/mTOR/NLRP3 axis and T cell polarization were delineated. In this study, distal colons were examined for macroscopic and microscopic pathological alterations. ELISA, qRT-PCR, and immunohistochemistry techniques were applied to detect proteins and cytokines involved in AMPK/mTOR/NLRP3 axis and T Cell polarization. Oral administration of empagliflozin (10 mg/kg/day) and metformin (200 mg/kg/day) combination alleviated colitis as revealed by the reduced disease activity index, macroscopic damage index, colon weight/length ratio, and histopathologic scoring values. Interestingly, empagliflozin/metformin combination significantly enhanced AMPK phosphorylation and depressed mTOR and NLRP3 expression leading to a subsequent reduction in caspase-1 cleavage and inhibition of several inflammatory cytokines, including IL-1β, and IL-18. Reduced mTOR expression and reduced IL-6 levels led to a reduction in Th17 cell polarization and maintenance. Together, the current study reveals that the protective effects of empagliflozin and metformin against DSS-induced colitis are fundamentally mediated via enhancing AMPK phosphorylation. Since adult humans with diabetes mellitus are at greater risk for developing inflammatory bowel diseases, clinical application of empagliflozin/metformin combination represents a novel therapeutic approach for treating diabetic patients with ulcerative colitis.

Nanoparticle-mediated gene therapy strategies for mitigating inflammatory bowel disease

Inflammatory bowel disease (IBD) is an autoimmune disorder of the gastrointestinal tract (GIT) where Ulcerative Colitis (UC) displays localized inflammation in the colon, and Crohn's Disease (CD) affects the entire GIT. Failure of current therapies and associated side-effects bring forth serious social, economic, and health challenges. The gut epithelium provides the best target for gene therapy delivery vehicles to combat IBD. Gene therapy involving the use of nucleic acid (NA) therapeutics faces major challenges due to the hydrophilic, negative-charge, and degradable nature of NAs. Recent success in the engineering of biomaterials for gene therapy and their emergence in clinical trials for various diseases is an inspiration for scientists to develop gene therapy vehicles that can be easily targeted to the desired tissues for IBD. Advances in nanotechnology have enabled the formulations of numerous nanoparticles for NA delivery to mitigate IBD that still faces challenges of stability in the GIT, poor therapeutic efficacy, and targetability. This review presents the challenges of gene therapeutics, gastrointestinal barriers, and recent advances in the engineering of nanoparticles for IBD treatment along with future directions for successful translation of nanoparticle-mediated gene therapeutics in clinics.

Repeated Fecal Microbial Transplantations and Antibiotic Pre-Treatment Are Linked to Improved Clinical Response and Remission in Inflammatory Bowel Disease: A Systematic Review and Pooled Proportion Meta-Analysis

The response of patients with inflammatory bowel disease (IBD) to fecal microbial transplantation (FMT) has been inconsistent possibly due to variable engraftment of donor microbiota. This failure to engraft has resulted in the use of several different strategies to attempt optimization of the recipient microbiota following FMT. The purpose of our study was to evaluate the effects of two distinct microbial strategies-antibiotic pre-treatment and repeated FMT dosing-on IBD outcomes. A systematic literature review was designed and implemented in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A medical librarian conducted comprehensive searches in MEDLINE, Embase, Scopus, Web of Science Core Collection, and Cochrane Library on 25 November 2019 and updated on 29 January 2021. Primary outcomes of interest included comparing relapse and remission rates in patients with IBD for a single FMT dose, repeated FMT dosages, and antibiotic pre-treatment groups. Twenty-eight articles (six randomized trials, 20 cohort trials, two case series) containing 976 patients were identified. Meta-analysis revealed that both repeated FMT and antibiotic pre-treatment strategies demonstrated improvements in pooled response and remission rates. These clinical improvements were associated with increases in fecal microbiota richness and α-diversity, as well as the enrichment of several short-chain fatty acid (SCFA)-producing anaerobes including Bifidobacterium, Roseburia, Lachnospiraceae, Prevotella, Ruminococcus, and Clostridium related species.

Inflammatory bowel disease: tri-directional relationship between microbiota, immune system and intestinal epithelium

Human gut microbiota contributes to host nutrition and metabolism, sustains intestinal cell proliferation and differentiation, and modulates host immune system. The alterations in their composition lead to severe gut disorders, including inflammatory bowel disease (IBD) or inflammatory bowel syndrome (IBS). IBD including ulcerative colitis (UC) and Crohn's disease (CD) are gamut of chronic inflammatory disorders of gut, mediated by complex interrelations among genetic, environmental, and internal factors. IBD has debateable aetiology, however in recent years, exploring the central role of a tri-directional relationship between gut microbiota, mucosal immune system, and intestinal epithelium in pathogenesis is getting the most attention. Increasing incidences and early onset explains the exponential rise in IBD burden on health-care systems. Industrialization, hypersensitivity to allergens, lifestyle, hygiene hypothesis, loss of intestinal worms, and gut microbial composition, explains this shifted rise. Hitherto, the interventions modulating gut microbiota composition, microfluidics-based in vitro gastrointestinal models, non-allergic functional foods, nutraceuticals, and faecal microbiota transplantation (FMT) from healthy donors are some of the futuristic approaches for the disease management.

Glochidion ellipticum Wight extracts ameliorate dextran sulfate sodium-induced colitis in mice by modulating nuclear factor kappa-light-chain-enhancer of activated B cells signalling pathway

OBJECTIVES

Glochidion ellipticum Wight is a medicinal plant, rich in polyphenols, frequently used by the indigenous communities of Bangladesh and possess with multiple health benefits. It exerts anti-inflammatory and antidiarrheal properties, but the detailed chemical constituents are yet to be elucidated.

METHODS

Glochidion ellipticum extracts were analyzed using ultra-high performance liquid chromatography/quadrupole time-of-flight mass spectrometry and then tested by both lipopolysaccharide (LPS) induced inflammation of Raw 264.7 macrophage cells and dextran sulfate sodium (DSS) induced acute colitis model. Blood serum was taken for fluorescein isothiocyanate-dextran (FITC-dextran) measurement and tissue samples were used to perform histology, RT-PCR and Western blotting.

KEY FINDINGS

The extracts could lower the levels of nitric oxide (NO), reactive oxygen species (ROS) and pro-inflammatory cytokines significantly in LPS induced macrophage cells. The extracts could also reduce disease activity index (DAI) score, restore antioxidants and pro-oxidants and improve macroscopic and microscopic features of colonic tissues in DSS induced mice. Expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in protein level was markedly diminished (up to 51.21% and 71.11%, respectively) in the treatment groups compared to the model group of colitic mice.

CONCLUSIONS

Our findings suggested that G. ellipticum extracts ameliorate DSS colitis via blocking nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signaling pathway, which make them to be potential candidates for further research against inflammation and colitis.

Biomarkers for Early Detection of Colitis-associated Colorectal Cancer - Current Concepts, Future Trends

Colitis-associated colorectal cancer (CAC) remains a critical complication of ulcerative colitis (UC) with a mortality of approximately 15%, which makes early CAC diagnosis crucial. The current standard of surveillance, with repetitive colonoscopies and histological testing of biopsied mucosa samples, is burdensome and expensive, and therefore less invasive methods and reliable biomarkers are needed. Significant progress has been made, thanks to continuous extensive research in this field, however, no clinically relevant biomarker has been established so far. This review of the current literature presents the genetic and molecular differences between CAC and sporadic colorectal cancer and covers progress made in the early detection of CAC carcinogenesis. It focuses on biomarkers under development, which can easily be tested in samples of body fluids or breath and, once made clinically available, will help to differentiate between progressors (UC patients who will develop dysplasia) from non-progressors and enable early intervention to decrease the risk of cancer development.

The Anti-colitis Effect of Schisandra chinensis Polysaccharide Is Associated With the Regulation of the Composition and Metabolism of Gut Microbiota

Background: The pathogenesis of inflammatory bowel disease (IBD) is linked to an intricate association of environmental, microbial, and host-related factors. Polysaccharide affects host immunity by regulating the composition and metabolism of gut microbiota is the common mechanism of disease resistance. However, the efficacy and mechanism of Schisandra chinensis polysaccharide (SCP) in the treatment of inflammatory bowel disease have not been studied.

Objective: To explore the effect and mechanism of SCP on dextran sodium sulfate (DSS) - induced ulcerative colitis (UC) in mice.

Materials/Methods: In this study, we established a mouse model of UC, and used SCP for treatment intervention. The biochemical indexes related to inflammation were determined by ELISA kit, and the therapeutic effect of SCP on UC was clarified. Then, 16S rDNA sequencing was used to study the effect of SCP on the composition and diversity of gut microbiota. At the same time, GC-MS was used to determine the content of short chain fatty acids in intestinal contents. Finally, the relationship among gut microbiota, short chain fatty acids and inflammatory factors was analyzed, and to comprehensively explain the effect and mechanism of SCP on UC.

Results: The results showed that SCP could significantly improve the physiological state of UC mice and regulate the level of inflammatory factors to normal levels. Meanwhile, SCP could significantly regulate the imbalance of gut microbiota and increase the content of SCFAs. In addition, the results of the correlation between gut microbiota and SCFAs showed that butyric acid, isobutyric acid and valeric acid had the highest correlation with gut microbiota.

Conclusion: In conclusion, this research showed that SCP can inhibit inflammatory bowel disease by regulating the composition and metabolism of gut microbiota, and indicating that SCP may be used as adjuvant therapy for IBD patients.

Weissella paramesenteroides WpK4 plays an immunobiotic role in gut-brain axis, reducing gut permeability, anxiety-like and depressive-like behaviors in murine models of colitis and chronic stress

The relationship between inflammatory bowel disease (IBD) and mood disorders is complex and involves overlapping metabolic pathways, which may determine comorbidity. Several studies have been shown that this comorbidity could worsen IBD clinical course. The treatment of ulcerative colitis is complex, and involves traditional therapy to promote the function of epithelial barrier, reducing exacerbated inflammatory responses. Recently, it has been shown that some probiotic strains could modulate gut-brain axis, reducing depressive and anxiety scores in humans, including IBD patients. Accordingly, this study aimed to evaluate the role of Weissella paramesenteroides WpK4 in murine models of ulcerative colitis and chronic stress. It was observed that bacterium ingestion improved health of colitis mice, reducing intestinal permeability, besides improving colon histopathological appearance. In stressed mice, bacterial consumption was associated with a reduced anxiety-like and depressive-like behaviors. In both assays, the beneficial role of W. paramesenteroides WpK4 was related to its immunomodulatory feature. It is possible to state that W. paramesenteroides WpK4 exerted their beneficial roles in gut-brain axis through their immunomodulatory effects with consequences in several metabolic pathways related to intestinal permeability and hippocampal physiology.

Ulcerative colitis: understanding its cellular pathology could provide insights into novel therapies

Dynamic interactions between the gastrointestinal epithelium and the mucosal immune system normally contribute to ensuring intestinal homeostasis and optimal immunosurveillance, but destabilisation of these interactions in genetically predisposed individuals can lead to the development of chronic inflammatory diseases. Ulcerative colitis is one of the main types of inflammatory diseases that affect the bowel, but its pathogenesis has yet to be completely defined. Several genetic factors and other inflammation-related genes are implicated in mediating the inflammation and development of the disease. Some susceptibility loci associated with increased risk of ulcerative colitis are found to be implicated in mucosal barrier function. Different biomarkers that cause damage to the colonic mucosa can be detected in patients, including perinuclear ANCA, which is also useful in distinguishing ulcerative colitis from other colitides. The choice of treatment for ulcerative colitis depends on disease severity. Therapeutic strategies include anti-tumour necrosis factor alpha (TNF-α) monoclonal antibodies used to block the production of TNF-α that mediates intestinal tract inflammation, an anti-adhesion drug that prevents lymphocyte infiltration from the blood into the inflamed gut, inhibitors of JAK1 and JAK3 that suppress the innate immune cell signalling and interferons α/β which stimulate the production of anti-inflammatory cytokines, as well as faecal microbiota transplantation. Although further research is still required to fully dissect the pathophysiology of ulcerative colitis, understanding its cellular pathology and molecular mechanisms has already proven beneficial and it has got the potential to identify further novel, effective targets for therapy and reduce the burden of this chronic disease.

Anti-inflammation of Erianin in dextran sulphate sodium-induced ulcerative colitis mice model via collaborative regulation of TLR4 and STAT3

Ulcerative colitis (UC) is a chronic, idiopathic and inflammatory disease of the rectal and colonic mucosa. Studies have shown that Toll-like receptors (TLR) 4 and Signal Transducer and Activator of Transcription 3 (STAT3)-mediated the decline in immune function and inflammatory infiltration are potential pathomechanism of UC occurrence and development. In this study, the anti-inflammation of Erianin, a natural bibenzyl compound with the antioxidant, antitumor, and anti-inflammatory activities, was investigated in a dextran sodium sulphate-induced UC mouse model. Three-week Erianin administration resulted in the increment on the body weight and colon length, and the reduction on the activity index score of UC mice. Liver, spleen, and renal organ indexes and pathological observations confirmed that Erianin was not cytotoxic and had an effect of improving immune organ function. The haematoxylin and eosin staining sections of colon tissue show Erianin's effect of reversing inflammation in the mucosal laye. Proteomic analysis and enzyme-linked immunosorbent assay indicated that Erianin regulated the levels of inflammatory and oxidative stress-related factors and immunochemokines in serum and colon tissues thereby reducing cell peroxidative damage and reducing immune inflammatory responses. Further data obtained by Western Blotting confirmed that Erianin's anti-UC activity was mediated by inhibiting the TLR4 and STAT3 signaling.

Krill Oil-Incorporated Liposomes As An Effective Nanovehicle To Ameliorate The Inflammatory Responses Of DSS-Induced Colitis

Background

Phosphatidylcholine (PC) and Omega-3 fatty acid (Omega-3) are promising therapeutic molecules for treating inflammatory bowel disease (IBD).

Purpose

Based on the IBD therapeutic potential of nanoparticles, we herein sought to develop Omega-3-incorporated PC nanoparticles (liposomes) as an orally administrable vehicle for treating IBD.

Methods

Liposomes prepared with or without Omega-3 incorporation were compared in terms of colloidal stability and anitiinflammatory effects.

Results

The incorporation of free Omega-3 (alpha-linolenic acid, eicosapentaenoic acid or docosahexaenoic acid) into liposomes induced time-dependent membrane fusion, resulting in particle size increase from nm to μm during storage. In contrast, krill oil incorporation into liposomes (KO liposomes) did not induce the fusion and the particle size maintained <250 nm during storage. KO liposomes also maintained colloidal stability in simulated gastrointestinal conditions and exhibited a high capacity to entrap the IBD drug, budesonide (BDS). KO liposomes greatly suppressed the lipopolysaccharide-induced production of pro-inflammatory cytokines in cultured macrophages and completely restored inflammation-impaired membrane barrier function in an intestinal barrier model. In mice subjected to dextran sulfate sodium-induced colitis, oral administration of BDS-entrapped KO liposomes suppressed tumor necrosis factor-α production (by 84.1%), interleukin-6 production (by 35.3%), and the systemic level of endotoxin (by 96.8%), and slightly reduced the macroscopic signs of the disease.

Conclusion

Taken together, KO liposomes may have great potential as a nanovehicle for oral delivery of IBD drugs.

Hypoxia-inducible factor hydroxylase inhibition enhances the protective effects of cyclosporine in colitis

Inflammatory bowel disease (IBD) is characterized by epithelial barrier dysfunction with resultant inflammation as the mucosal immune system becomes exposed to luminal antigens. The hydroxylase inhibitor dimethyloxalylglycine (DMOG) reduces symptoms in experimental colitis through the upregulation of genes promoting barrier function and inhibition of epithelial cell apoptosis. The immunosuppressive drug cyclosporine reduces inflammation associated with IBD via suppression of immune cell activation. Given the distinct barrier protective effect of DMOG and the anti-inflammatory properties of cyclosporine, we hypothesized that combining these drugs may provide an enhanced protective effect by targeting both barrier dysfunction and inflammation simultaneously. We used the dextran sulfate sodium model of colitis in C57BL/6 mice to determine the combinatorial efficacy of cyclosporine and DMOG. While cyclosporine and DMOG ameliorated disease progression, in combination they had an additive protective effect that surpassed the level of protection afforded by either drug alone. The ability of DMOG to augment the anti-inflammatory effects of cyclosporine was largely due to preservation of barrier function and at least in part due to zonula occludens-1 regulation. We propose that combining the barrier protective effects of a hydroxylase inhibitor with the anti-inflammatory effects of cyclosporine provides added therapeutic benefit in colitis.NEW & NOTEWORTHY Inflammatory bowel disease is the result of decreased intestinal epithelial barrier function leading to exposure of the mucosal immune system to luminal antigens causing inflammation, which in turn further decreases epithelial barrier function. We demonstrate for the first time that strengthening the epithelial barrier with a hydroxylase inhibitor in combination with the administration of the immunosuppressive cyclosporine provides additive therapeutic advantage in a murine model of colitis.

The Role of Adipose Tissue in the Pathogenesis and Therapeutic Outcomes of Inflammatory Bowel Disease

Though historically regarded as an inert energy store, adipose tissue is a complex endocrine organ, which is increasingly implicated in the pathogenesis of inflammatory bowel disease (IBD). Accumulating evidence points to visceral adipose tissue and specifically to its mesenteric component, or “creeping fat” as impacting on the disease course through its immunomodulatory properties. On the one hand, mesenteric fat acts as a physical barrier to inflammation and is involved in controlling host immune response to translocation of gut bacteria. On the other hand, however, there exists a strong link between visceral fat and complicated course of the disease with unfavorable therapeutic outcomes. Furthermore, “creeping fat” appears to play different roles in different IBD phenotypes, with the greatest pathogenetic contribution probably to an ileal form of Crohn’s disease. In this review, we summarize and discuss the existing literature on the subject and identify high-priority areas for future research. It may be that a better understanding of the role of mesenteric fat in IBD will determine new therapeutic targets and translate into improved clinical outcomes.

Aesculin protects against DSS-Induced colitis though activating PPARγ and inhibiting NF-кB pathway

Aesculin, a natural product from the traditional and widely-used Chinese medicine named Cortex fraxini, has attracted attention as a novel therapeutic modulator of inflammation. However, little is known about its effect on ulcerative colitis (UC). This study aimed to investigate the protective effects and mechanisms of aesculin on colitis. The results showed that, few cytotoxicity of aesculin were shown in vivo and in the RAW264.7 macrophages, while aesculin significantly relieved the symptoms of DSS-induced colitis and restrained the expression of inflammatory factors including iNOS, IL-1β, TNF-α in both peritoneal macrophages and colonic tissues from DSS-induced mice and RAW264.7 macrophages. Of note, aesculin attenuated the activity of NF-κB signaling while promoted the nuclear localization of PPAR-γ in both rectal tissues from DSS-induced mice and LPS-stimulated macrophages. These findings demonstrated that the protection of aesculin against ulcerative colitis might be due to its regulation on the PPAR-γ and NF-κB pathway. Thus, aesculin could serve as a potential therapeutic agent for the treatment of ulcerative colitis.

Constitutive androstane receptor and pregnane X receptor cooperatively ameliorate DSS-induced colitis

BACKGROUND

Nuclear receptor pregnane X receptor (PXR) was shown to be protective in case of dextran sulfate sodium (DSS)-induced colitis. Constitutive androstane receptor (CAR) belongs to the same nuclear receptor subfamily with PXR. The roles of both receptors in DSS-induced colitis were evaluated.

METHODS

Wild-type, Car-null, Pxr-null, and Car/Pxr-null mice were treated with a CAR/PXR agonist or vehicle and administered 2.5% DSS in the drinking water. The typical clinical symptoms, histological scoring, proinflammatory cytokine, and apoptosis were analyzed.

RESULTS

Mice treated with the PXR agonist pregnenolone-16α-carbonitrile (PCN) were protected from DSS-induced colitis, as in a previous study. Mice treated with the CAR agonist, 4-bis[2-(3,5-dichloropyridyloxy)]benzene (TCPOBOP) were also protected from DSS-induced colitis. Interestingly, the protective effects of PCN in the Car-null mice and those of TCPOBOP in the Pxr-null mice both decreased. PCN or TCPOBOP pretreatment significantly decreased the macrophage and monocyte infiltration in DSS-induced colitis. PXR and CAR agonists reduced the mRNA expression of several proinflammatory cytokines in a PXR- and CAR-dependent manner, respectively. CAR inhibited apoptosis by inducing Gadd45b. PXR inhibited TNF-α and IL-1b and CAR induced Gadd45b in in vitro cell analyses.

CONCLUSIONS

We showed that CAR and PXR cooperatively ameliorate DSS-induced colitis. PXR and CAR protected against DSS-induced colitis by inhibiting proinflammatory cytokines and apoptosis, respectively.

Current, experimental, and future treatments in inflammatory bowel disease: a clinical review

Inflammatory bowel diseases (IBDs) may result from dysregulated mucosal immune responses directed toward the resident intestinal microbiota. This review describes the hallmark immunobiology of Crohn's disease and ulcerative colitis as well as therapeutic targets and mechanisms of action for current, experimental, and future treatments in IBD. Conventional therapies include 5-aminosalicylic acid, glucocorticosteroids, thiopurines, and methotrexate. Since 1997, monoclonal antibodies have gained widespread use. These consist of antibodies directed against pro-inflammatory cytokines such as tumor necrosis factor α, interleukin (IL)-12, and IL-23, or anti-homing antibodies directed against α4β7 integrin. Emerging oral therapies include modulators of intracellular signal transduction such as Janus kinase inhibitors. Vitamin D may help to regulate innate and adaptive immune responses. Modulation of the intestinal microbiota, using live microorganisms (probiotics), substrates for the colonic microbiota (prebiotics), or fecal microbiota transplantation (FMT), is in development. Dietary supplements are in widespread use, but providing evidence for their benefit is challenging. Stem cell treatment and nervous stimulation are promising future treatments.

Endoplasmic reticulum stress-induced apoptosis in intestinal epithelial cells: a feed-back regulation by mechanistic target of rapamycin complex 1 (mTORC1)

Background

Endoplasmic reticulum (ER) stress is associated with multiple pathological processes of intestinal diseases. Despite a critical role of mechanistic target of rapamycin complex 1 (mTORC1) in regulating cellular stress response, the crosstalk between mTORC1 and ER stress signaling and its contribution to the intestinal barrier function is unknown.

Results

In the present study, we showed that intestinal epithelial cells (IEC-6) incubated with tunicamycin led to caspase-3-dependent apoptotic cell death. The induction of cell death was accompanied by activation of unfolded protein response as evidenced by increased protein levels for BiP, p-IRE1α, p-eIF2α, p-JNK, and CHOP. Further study demonstrated that tunicamycin-induced cell death was enhanced by rapamycin, a specific inhibitor of mTORC1. Consistently, tunicamycin decreased transepithelial electrical resistance (TEER) and increased permeability of the cells. These effects of tunicamycin were exacerbated by mTORC1 inhibitor.

Conclusions

Taken together, the data presented here identified a previously unknown crosstalk between an unfold protein response and mTORC1 signaling in the intestinal epithelium. This feed-back loop regulation on ER stress signaling by mTORC1 is critical for cell survival and intestinal permeability in epithelial cells.

miR-130a and miR-212 Disrupt the Intestinal Epithelial Barrier through Modulation of PPARγ and Occludin Expression in Chronic Simian Immunodeficiency Virus-Infected Rhesus Macaques

Intestinal epithelial barrier dysfunction is a well-known sequela of HIV/SIV infection that persists despite antiretroviral therapy. Although inflammation is a triggering factor, the underlying molecular mechanisms remain unknown. Emerging evidence suggests that epithelial barrier function is epigenetically regulated by inflammation-induced microRNAs (miRNAs). Accordingly, we profiled and characterized miRNA/mRNA expression exclusively in colonic epithelium and identified 46 differentially expressed miRNAs (20 upregulated and 26 downregulated) in chronically SIV-infected rhesus macaques (Macaca mulatta). We bioinformatically crossed the predicted miRNA targets to transcriptomic data and characterized miR-130a and miR-212 as both were predicted to interact with critical epithelial barrier-associated genes. Next, we characterized peroxisome proliferator-activated receptor γ (PPARγ) and occludin (OCLN), predicted targets of miR-130a and miR-212, respectively, as their downregulation has been strongly linked to epithelial barrier disruption and dysbiosis. Immunofluorescence, luciferase reporter, and overexpression studies confirmed the ability of miR-130a and miR-212 to decrease protein expression of PPARγ and OCLN, respectively, and reduce transepithelial electrical resistance. Because Δ-9-tetrahydrocannabinol exerted protective effects in the intestine in our previous studies, we successfully used it to reverse miR-130a- and miR-212-mediated reduction in transepithelial electrical resistance. Finally, ex vivo Δ-9-tetrahydrocannabinol treatment of colon tissue from chronically SIV-infected rhesus macaques significantly increased PPARγ expression. Our findings suggest that dysregulated miR-130a and miR-212 expression in colonic epithelium during chronic HIV/SIV infection can facilitate epithelial barrier disruption by downregulating OCLN and PPARγ expression. Most importantly, our results highlight the beneficial effects of cannabinoids on epithelial barrier function in not just HIV/SIV but potentially other chronic intestinal inflammatory diseases.

Magnolol treatment attenuates dextran sulphate sodium-induced murine experimental colitis by regulating inflammation and mucosal damage

Magnolol, the main and active ingredient of the Magnolia officinalis, has been widely used in traditional prescription to the human disorders. Magnolol has been proved to have several pharmacological properties including anti-bacterial, anti-oxidant and anti-inflammatory activities. However, the effects of magnolol on ulcerative colitis (UC) have not been reported. The aim of this study was to investigate the protective effects and mechanisms of magnolol on dextran sulphate sodium (DSS)-induced colitis in mice. The results showed that magnolol significantly alleviated DSS-induced body weight loss, disease activities index (DAI), colon length shortening and colonic pathological damage. In addition, magnolol restrained the expression of TNF-α, IL-1β and IL-12 via the regulation of nuclear factor-κB (NF-κB) and Peroxisome proliferator-activated receptor-γ (PPAR-γ) pathways. Magnolol also enhanced the expression of ZO-1 and occludin in DSS-induced mice colonic tissues. These results showed that magnolol played protective effects on DSS-induced colitis and may be an alternative therapeutic reagent for colitis treatment.

Expression of ATF6 as a marker of pre-cancerous atypical change in ulcerative colitis-associated colorectal cancer: a potential role in the management of dysplasia

BACKGROUND

Diagnosis of low-grade dysplasia (LGD) is important in the management of ulcerative colitis (UC), but it is often difficult to distinguish LGD from inflammatory regenerative epithelium. The unfolded protein response (UPR) is activated in inflammatory bowel disease and malignancies. We aimed to identify a UPR-related gene that is involved in the development of non-UC and UC-associated colorectal cancer (CRC), and to investigate whether the target gene is useful for the diagnosis of LGD.

METHODS

Using our microarray gene expression database of 152 CRCs, we identified activating transcription factor 6 (ATF6) as a target gene. Immunohistochemistry (IHC) of ATF6 were analyzed in 137 surgically resected CRCs, 95 endoscopically resected adenomas and pTis cancers, and 136 samples from 51 UC patients (93 colitis without neoplasia, 31 dysplasia, and 12 UC-associated CRC). The diagnostic accuracy of ATF6 and p53 as markers of LGD was assessed.

RESULTS

ATF6 expression was detectable in all CRCs but not in normal colonic mucosa, was elevated with increase in cellular atypia (adenoma with moderate atypia < severe atypia < pTis CRC, p < 0.001), and higher in dysplasia and CRC than in non-neoplastic colitis (p < 0.001). Notably, the difference between colitis and LGD was significant. Compared to p53-IHC, ATF6-IHC had better diagnostic accuracy for distinguishing LGD from background inflammatory mucosa (sensitivity 70.8 vs. 16.7%, specificity 78.5 vs.71.0%, respectively).

CONCLUSIONS

ATF6 was expressed in lesions undergoing pre-cancerous atypical change in both non-UC and UC-associated CRC and may be used to distinguish LGD from inflammatory regenerative epithelium in UC patients.

Role of DDX3 in the pathogenesis of inflammatory bowel disease

When crypt stem cells of the gastrointestinal tract become injured, the result is increased synthesis of pro-inflammatory cytokines and matrix metalloproteinases by their progeny – the colonic epithelium. Chronic inflammation of the gastrointestinal tract is a characteristic of inflammatory bowel disease, which includes Crohn’s Disease and Ulcerative Colitis. In our ongoing investigation to decipher the characteristic functions of a RNA helicase gene, DDX3, we identified high DDX3 expression by immunohistochemistry of colon biopsy samples, which included chronic/mild Morbus Crohn, active Morbus Crohn, Chronic/mild Colitis Ulcerosa and active Colitis Ulcerosa in epithelium and stromal compartments. We used a small molecule inhibitor of DDX3, RK-33, on two human colonic epithelial cell lines, HCEC1CT and HCEC2CT and found that RK-33 was able to decrease expression of MMP-1, MMP-2, MMP-3, and MMP-10. Moreover, forced differentiation of a human colonic cancer cell line, HT29, resulted in decreased DDX3 levels, indicating that DDX3 contributes to the modulation of colonic epithelium differentiation. In conclusion, our results revealed novel functions of DDX3 in inflammatory bowel disease and indicate a potential for using RK-33 as a systemic therapy to promote not only differentiation of transformed colonic epithelium but also to reduce MMP expression and thus elicit a decreased inflammatory response.

Accumulation of HLA-DR4 in Colonic Epithelial Cells Causes Severe Colitis in Homozygous HLA-DR4 Transgenic Mice

BACKGROUND

Homozygous HLA-DR4/I-E transgenic mice (tgm) spontaneously developed colitis similar to human ulcerative colitis. We explored whether endoplasmic reticulum stress in colonic epithelial cells due to overexpression of HLA-DR4/I-E was involved in the pathogenesis of colitis.

METHODS

Major histocompatibility complex class II transactivator-knockout (CIITAKO) background tgm were established to test the involvement of HLA-DR4/I-E expression in the pathogenesis of colitis. Histological and cellular analyses were performed and the effect of oral administration of the molecular chaperone tauroursodeoxycholic acid (TUDCA) and antibiotics were investigated. IgA content of feces and serum and presence of IgA-coated fecal bacteria were also investigated.

RESULTS

Aberrantly accumulated HLA-DR4/I-E molecules in colonic epithelial cells were observed only in the colitic homozygous tgm, which was accompanied by upregulation of the endoplasmic reticulum stress marker Binding immunoglobulin protein (BiP) and reduced mucus. Homozygous tgm with CIITAKO, and thus absent of HLA-DR4/I-E expression, did not develop colitis. Oral administration of TUDCA to homozygotes reduced HLA-DR4/I-E and BiP expression in colonic epithelial cells and restored the barrier function of the intestinal tract. The IgA content of feces and serum, and numbers of IgA-coated fecal bacteria were higher in the colitic tgm, and antibiotic administration suppressed the expression of HLA-DR4/I-E and colitis.

CONCLUSIONS

The pathogenesis of the colitis observed in the homozygous tgm was likely due to endoplasmic reticulum stress, resulting in goblet cell damage and compromised mucus production in the colonic epithelial cells in which HLA-DR4/I-E molecules were heavily accumulated. Commensal bacteria seemed to be involved in the accumulation of HLA-DR4/I-E, leading to development of the colitis.

Butyrate-producing bacteria supplemented in vitro to Crohn's disease patient microbiota increased butyrate production and enhanced intestinal epithelial barrier integrity

The management of the dysbiosed gut microbiota in inflammatory bowel diseases (IBD) is gaining more attention as a novel target to control this disease. Probiotic treatment with butyrate-producing bacteria has therapeutic potential since these bacteria are depleted in IBD patients and butyrate has beneficial effects on epithelial barrier function and overall gut health. However, studies assessing the effect of probiotic supplementation on microbe-microbe and host-microbe interactions are rare. In this study, butyrate-producing bacteria (three mono-species and one multispecies mix) were supplemented to the fecal microbial communities of ten Crohn’s disease (CD) patients in an in vitro system simulating the mucus- and lumen-associated microbiota. Effects of supplementation in short-chain fatty acid levels, bacterial colonization of mucus environment and intestinal epithelial barrier function were evaluated. Treatment with F. prausnitzii and the mix of six butyrate-producers significantly increased the butyrate production by 5–11 mol%, and colonization capacity in mucus- and lumen-associated CD microbiota. Treatments with B. pullicaecorum 25-3^T and the mix of six butyrate-producers improved epithelial barrier integrity in vitro. This study provides proof-of-concept data for the therapeutic potential of butyrate-producing bacteria in CD and supports the future preclinical development of a probiotic product containing butyrate-producing species.

Carnosic acid prevents dextran sulfate sodium-induced acute colitis associated with the regulation of the Keap1/Nrf2 pathway

Crohn's disease and ulcerative colitis are inflammatory bowel diseases (IBDs) with high prevalence in humans. Carnosic acid (CA) has been reported to possess antioxidative properties; however, its role in IBDs has not been determined. In the present study, we found that CA significantly prevented the loss of body weight and shortening of colon length in acute colitis induced by dextran sodium sulfate (DSS). Pronounced infiltration of immune cells and a loss of crypt architecture and goblet cells were ameliorated by CA. CA significantly decreased the activity of MPO and infiltration of F4/80⁺ macrophages in the colon. DSS-induced pro-inflammatory cytokine mRNA and protein levels in the colon were also attenuated by CA. CA decreased the activation of p65 and c-Jun signalling. CA inhibited DSS-induced NLRP3 inflammasome activation by reducing caspase 1 activity. In addition, CA increased the level of Nrf2 and prevented the degradation of Nrf2 via ubiquitination by blocking the interaction between Cullin3 and Keap1, which resulted in the decrease of Nrf2 target genes. Finally, GSH levels and SOD activity were increased after CA treatment, while MDA and iNOS levels were significantly reduced. Taken together, our data showed that CA may be useful as a potential therapeutic candidate for IBDs.

Protocol for a randomised, placebo-controlled pilot study for assessing feasibility and efficacy of faecal microbiota transplantation in a paediatric ulcerative colitis population: PediFETCh trial

INTRODUCTION

Ulcerative colitis (UC) is a chronic, relapsing condition characterised by colonic inflammation. Increasing prevalence in early-age diagnosis provides opportunities for additional complications in later life as a result of prolonged exposure to inflammatory and therapeutic insults, necessitating novel avenues for therapeutics which may result in fewer side effects. Faecal microbiota transplantation (FMT) has previously demonstrated potential therapeutic benefit in an adult randomised-controlled trial and several recurrent Clostridium difficile infection studies. This phase Ib pilot will be the first randomised, single-blinded, placebo-controlled trial to assess feasibility and patient outcomes in a paediatric inflammatory bowel disease (IBD) population.

METHODS AND ANALYSIS

Fifty patients will be randomised 1:1 to receive normal saline control or active sample. Enema administrations will be performed two times per week for 6 weeks, followed at a 6-month follow-up period. Feasibility outcomes will include measures of patient eligibility, recruitment, willingness to participate, samples collections, hospitalizations and drop-out rate. Improvements in disease symptoms will determine the efficacy of treatment. Clinical disease scores will be taken throughout the study period using the Paediatric Ulcerative Colitis Activity Index (PUCAI). Monitoring of inflammatory markers in blood and stool will be performed at regular intervals. Microbiome analysis will be conducted on stool samples collected throughout the trials period. Imaging and endoscopic surveillance will be conducted if clinically necessary.

ETHICS AND DISSEMINATION

Ethics was obtained from local hospital research ethics boards across all three sites. Health Canada and FDA approval was obtained for the use of an Investigatory New Drug product. Results from this trial will be presented in international conferences and published in peer-review journals.

TRIAL REGISTRATION NUMBER

Trial registration number: NCT02487238; preresults.

Long-Term Effects of Bone Marrow-Derived Mesenchymal Stem Cells in Dextran Sulfate Sodium-Induced Murine Chronic Colitis

Background/Aims

Bone marrow-derived mesenchymal stem cells (BM-MSCs) have shown beneficial effects in experimental colitis models, but the underlying mechanisms are not fully understood. We investigated the long-term effects of BM-MSCs, particularly in mice with chronic colitis.

Methods

Chronic colitis was induced by administering 3% dextran sulfate sodium (DSS) in a series of three cycles. BM-MSCs were injected intravenously into DSS-treated mice three times during the first cycle. On day 33, the therapeutic effects were evaluated with clinicopathologic profiles and histological scoring. Inflammatory mediators were measured with real-time polymerase chain reaction.

Results

Systemic infusion of BM-MSCs ameliorated the severity of colitis, and body weight restoration was significantly promoted in the BM-MSC-treated mice. In addition, BM-MSC treatment showed a sustained beneficial effect throughout the three cycles. Microscopic examination revealed that the mice treated with BM-MSCs had fewer inflammatory infiltrates, a lesser extent of inflammation, and less crypt structure damage compared with mice with DSS-induced colitis. Anti-inflammatory cytokine levels of interleukin-10 were significantly increased in the inflamed colons of BM-MSC-treated mice compared with DSS-induced colitis mice.

Conclusions

Systemic infusion of BM-MSCs at the onset of disease exerted preventive and rapid recovery effects, with long-term immunosuppressive action in mice with repeated DSS-induced chronic colitis.

Ursodeoxycholic acid and lithocholic acid exert anti-inflammatory actions in the colon

Ward JB, Lajczak NK, Kelly OB, O'Dwyer AM, Giddam AK, Ní Gabhann J, Franco P, Tambuwala MM, Jefferies CA, Keely S, Roda A, Keely SJ. Ursodeoxycholic acid and lithocholic acid exert anti-inflammatory actions in the colon. Am J Physiol Gastrointest Liver Physiol 312: G550-G558, 2017. First published March 30, 2017; doi:10.1152/ajpgi.00256.2016.-Inflammatory bowel diseases (IBD) comprise a group of common and debilitating chronic intestinal disorders for which currently available therapies are often unsatisfactory. The naturally occurring secondary bile acid, ursodeoxycholic acid (UDCA), has well-established anti-inflammatory and cytoprotective actions and may therefore be effective in treating IBD. We aimed to investigate regulation of colonic inflammatory responses by UDCA and to determine the potential impact of bacterial metabolism on its therapeutic actions. The anti-inflammatory efficacy of UDCA, a nonmetabolizable analog, 6α-methyl-UDCA (6-MUDCA), and its primary colonic metabolite lithocholic acid (LCA) was assessed in the murine dextran sodium sulfate (DSS) model of mucosal injury. The effects of bile acids on cytokine (TNF-α, IL-6, Il-1β, and IFN-γ) release from cultured colonic epithelial cells and mouse colonic tissue in vivo were investigated. Luminal bile acids were measured by gas chromatography-mass spectrometry. UDCA attenuated release of proinflammatory cytokines from colonic epithelial cells in vitro and was protective against the development of colonic inflammation in vivo. In contrast, although 6-MUDCA mimicked the effects of UDCA on epithelial cytokine release in vitro, it was ineffective in preventing inflammation in the DSS model. In UDCA-treated mice, LCA became the most common colonic bile acid. Finally, LCA treatment more potently inhibited epithelial cytokine release and protected against DSS-induced mucosal inflammation than did UDCA. These studies identify a new role for the primary metabolite of UDCA, LCA, in preventing colonic inflammation and suggest that microbial metabolism of UDCA is necessary for the full expression of its protective actions.NEW & NOTEWORTHY On the basis of its cytoprotective and anti-inflammatory actions, the secondary bile acid ursodeoxycholic acid (UDCA) has well-established uses in both traditional and Western medicine. We identify a new role for the primary metabolite of UDCA, lithocholic acid, as a potent inhibitor of intestinal inflammatory responses, and we present data to suggest that microbial metabolism of UDCA is necessary for the full expression of its protective effects against colonic inflammation.

Eldelumab [Anti-IP-10] Induction Therapy for Ulcerative Colitis: A Randomised, Placebo-Controlled, Phase 2b Study

BACKGROUND AND AIMS

Interferon-γ-inducible protein-10 [IP-10] mediates immune cell trafficking from the circulation to the inflamed colon and decreases gut epithelial cell survival. IP-10 expression is increased in patients with ulcerative colitis [UC]. We report efficacy and safety results from a dose-ranging induction study of eldelumab, a fully human monoclonal antibody to IP-10, in moderately to severely active UC.

METHODS

A total of 252 adults with UC [Mayo score ≥ 6 and endoscopic subscore ≥ 2] were randomised 1:1:1 to placebo or eldelumab 15 or 25 mg/kg administered intravenously on Days 1 and 8 and every other week thereafter. The primary endpoint was clinical remission [Mayo score ≤ 2; no individual subscale score > 1] at Week 11. Key secondary endpoints included Mayo score clinical response and mucosal healing at Week 11.

RESULTS

Neither eldelumab 15 or 25 mg/kg resulted in significant increases vs placebo in the proportion of patients achieving Week 11 clinical remission. Remission and response rates were 17.6% and 47.1% with eldelumab 25mg/kg, 13.1% and 44.0% with eldelumab 15mg/kg, and 9.6% and 31.3% with placebo. Clinical remission and response rates were higher in anti-tumour necrosis factor [TNF]-naïve patients treated with eldelumab compared with placebo. Eldelumab treatment was well tolerated and no immunogenicity was observed.

CONCLUSIONS

The primary endpoint was not achieved with induction treatment with eldelumab 15 or 25 mg/kg in patients with UC. Trends towards clinical remission and response were observed in the overall population and were more pronounced in anti-TNF naïve patients. Eldelumab safety signals were consistent with those reported previously [ClinicalTrials.gov number, NCT01294410].

Pathway-based approaches to the treatment of inflammatory bowel disease

Crohn's disease and ulcerative colitis, collectively termed inflammatory bowel disease (IBD), are immunologic disorders that represent the prototypes of chronic intestinal inflammation. Their pathogenesis involves the dysregulated interaction between the intestinal microbiota and the gut-associated mucosal immune system that takes place when genetically predisposed individuals are exposed to detrimental environmental triggers. In recent years, the therapeutic dogma in IBD has shifted away from the administration of nonspecific immunosuppressives toward a pathway-based approach. In this review, we present an outlook of IBD treatment based on this new conceptual approach. Firstly, we will provide an overview of the major aspects of IBD pathogenesis with emphasis on specific pathway-based defects. Secondly, we will examine in detail the development of novel therapeutic approaches that can be used to target genetics, dysbiosis, the epithelial barrier, proinflammatory cytokines, and leukocyte trafficking. Most of these strategies are still in the developmental phase, but promising approaches include fecal microbiota transplantation as a means to correct IBD-related dysbiosis; administration of modified phosphatidylcholine to enhance the function of the intestinal mucous and tighten the defective epithelial barrier; the reduction of over-reactive proinflammatory pathways through the blockade of novel, nontumor necrosis factor inflammatory mediators via monoclonal antibodies against the common p40 chain of interleukin (IL-12) and IL-23, Janus kinase inhibitors, or antisense oligonucleotides against inhibitors of the immunosuppressive cytokine transforming growth factor-β1; and finally, inhibition of leukocyte trafficking to the gut via neutralization of the gut-specific α4β7 integrin. Availability of such diverse treatment modalities with specific pathway-based targets will increase the therapeutic options for patients with IBD.

Current stage in inflammatory bowel disease: What is next?

In recent years, the incidence of inflammatory bowel disease (IBD) has been on the rise, extending to countries where it was infrequent in the past. As a result, the gap between high and low incidence countries is decreasing. The disease, therefore, has an important economic impact on the healthcare system. Advances in recent years in pharmacogenetics and clinical pharmacology have allowed for the development of treatment strategies adjusted to the patient profile. Concurrently, new drugs aimed at inflammatory targets have been developed that may expand future treatment options. This review examines advances in the optimization of existing drug treatments and the development of novel treatment options for IBD.