Inflammatory bowel disease: Established and evolving considerations on its etiopathogenesis and therapy

Exploring the role of IL-1β in inflammatory bowel disease pathogenesis

Interleukin 1β (IL-1β) is a significant mediator of inflammation and tissue damage in IBD. The balance between IL-1β and its endogenous inhibitor-IL-1Ra-, plays a critical role in both initiation and regulation of inflammation. However, the precise role of IL-1β as a causative factor in IBD or simply a consequence of inflammation remains unclear. This review summarizes current knowledge on the molecular and cellular characteristics of IL-1β, describes the existing evidence on the role of this cytokine as a modulator of intestinal homeostasis and an activator of inflammatory responses, and also discusses the role of microRNAs in the regulation of IL-1β-related inflammatory responses in IBD. Current evidence indicates that IL-1β is involved in several aspects during IBD as it greatly contributes to the induction of pro-inflammatory responses through the recruitment and activation of immune cells to the gut mucosa. In parallel, IL-1β is involved in the intestinal barrier disruption and modulates the differentiation and function of T helper (Th) cells by activating the Th17 cell differentiation, known to be involved in the pathogenesis of IBD. Dysbiosis in the gut can also stimulate immune cells to release IL-1β, which, in turn, promotes inflammation. Lastly, increasing evidence pinpoints the central role of miRNAs involvement in IL-1β-related signaling during IBD, particularly in the maintenance of homeostasis within the intestinal epithelium. In conclusion, given the crucial role of IL-1β in the promotion of inflammation and immune responses in IBD, the targeting of this cytokine or its receptors represents a promising therapeutic approach. Further research into the IL-1β-associated post-transcriptional modifications may elucidate the intricate role of this cytokine in immunomodulation.

Potential Application of Intestinal Organoids in Intestinal Diseases

To accurately reveal the scenario and mecahnism of gastrointestinal diseases, the establishment of in vitro models of intestinal diseases and drug screening platforms have become the focus of attention. Over the past few decades, animal models and immortalized cell lines have provided valuable but limited insights into gastrointestinal research. In recent years, the development of intestinal organoid culture system has revolutionized in vitro studies of intestinal diseases. Intestinal organoids are derived from self-renewal and self-organization intestinal stem cells (ISCs), which can replicate the genetic characteristics, functions, and structures of the original tissues. Consequently, they provide new stragety for studying various intestinal diseases in vitro. In the review, we will discuss the culture techniques of intestinal organoids and describe the use of intestinal organoids as research tools for intestinal diseases. The role of intestinal epithelial cells (IECs) played in the pathogenesis of inflammatory bowel diseases (IBD) and the treatment of intestinal epithelial dysfunction will be highlighted. Besides, we review the current knowledge on using intestinal organoids as models to study the pathogenesis of IBD caused by epithelial dysfunction and to develop new therapeutic approaches. Finally, we shed light on the current challenges of using intestinal organoids as in vitro models.

The Role of IL-23 in the Pathogenesis and Therapy of Inflammatory Bowel Disease

Interleukin-23 (IL-23) is a proinflammatory cytokine produced mainly by macrophages and antigen-presenting cells (APCs) after antigenic stimulation. IL-23 plays a significant role as a mediator of tissue damage. Indeed, the irregularities in IL-23 and its receptor signaling have been implicated in inflammatory bowel disease. IL-23 interacts with both the innate and adaptive immune systems, and IL-23/Th17 appears to be involved in the development of chronic intestinal inflammation. The IL-23/Th17 axis may be a critical driver of this chronic inflammation. This review summarizes the main aspects of IL-23's biological function, cytokines that control cytokine production, effectors of the IL-23 response, and the molecular mechanisms associated with IBD pathogenesis. Although IL-23 modulates and impacts the development, course, and recurrence of the inflammatory response, the etiology and pathophysiology of IBD are not completely understood, but mechanism research shows huge potential for clinical applications as therapeutic targets in IBD treatment.

miRNA Molecules-Late Breaking Treatment for Inflammatory Bowel Diseases?

MicroRNAs (miRNAs) are a group of non-coding RNAs that play a critical role in regulating epigenetic mechanisms in inflammation-related diseases. Inflammatory bowel diseases (IBDs), which primarily include ulcerative colitis (UC) and Crohn's disease (CD), are characterized by chronic recurrent inflammation of intestinal tissues. Due to the multifactorial etiology of these diseases, the development of innovative treatment strategies that can effectively maintain remission and alleviate disease symptoms is a major challenge. In recent years, evidence for the regulatory role of miRNAs in the pathogenetic mechanisms of various diseases, including IBD, has been accumulating. In light of these findings, miRNAs represent potential innovative candidates for therapeutic application in IBD. In this review, we discuss recent findings on the role of miRNAs in regulating inflammatory responses, maintaining intestinal barrier integrity, and developing fibrosis in clinical and experimental IBD. The focus is on the existing literature, indicating potential therapeutic application of miRNAs in both preclinical experimental IBD models and translational data in the context of clinical IBD. To date, a large and diverse data set, which is growing rapidly, supports the potential use of miRNA-based therapies in clinical practice, although many questions remain unanswered.

The role of intestinal immune cells and matrix metalloproteinases in inflammatory bowel disease

Inflammatory bowel disease (IBD) has become globally intractable. MMPs play a key role in many inflammatory diseases. However, little is known about the role of MMPs in IBD. In this study, IBD expression profiles were screened from public Gene Expression Omnibus datasets. Functional enrichment analysis revealed that IBD-related specific functions were associated with immune pathways. Five MMPS-related disease markers, namely MMP-9, CD160, PTGDS, SLC26A8, and TLR5, were selected by machine learning and the correlation between each marker and immune cells was evaluated. We then induced colitis in C57 mice using sodium dextran sulfate and validated model construction through HE staining of the mouse colon. WB and immunofluorescence experiments confirmed that the expression levels of MMP-9, PTGDS, SLC26A8, and CD160 in colitis were significantly increased, whereas that of TLR5 were decreased. Flow cytometry analysis revealed that MMPs regulate intestinal inflammation and immunity mainly through CD8 in colitis. Our findings reveal that MMPs play a crucial role in the pathogenesis of IBD and are related to the infiltration of immune cells, suggesting that MMPs may promote the development of IBD by activating immune infiltration and the immune response. This study provides insights for further studies on the occurrence and development of IBD.

Should the Mediterranean diet be recommended for inflammatory bowel diseases patients? A narrative review

Inflammatory bowel diseases (IBD) are chronic, progressive and relapsing inflammatory disorders of unknown etiology that may cause disability over time. Data from epidemiologic studies indicate that diet may play a role in the risk of developing and the course of IBD. It is known that the group of beneficial bacteria was reduced in the IBD and that the Mediterranean diet (MD)-which is defined as eating habits characterized by high consumption of plant foods, mainly cereals, vegetables, fruit as well as olive oil, and small portions of dairy products, sweets, sugar and meat products-affects gut microbiota, enriching beneficial bacteria, which support gut barrier function and reduce inflammation. Although several studies support different favorable effects of MD on IBD, adherence to MD by IBD patients is generally low, including patients from the Mediterranean Basin. Patients avoid many products which are elements of MD because there cause gastrointestinal symptoms. Patients should be encouraged to have a healthy and well-balanced diet according to individual tolerance of products. A good option seems to be good modified MD, changing hard-to-digest products to easy digest.

Molecular Mechanisms Underlying IL-33-Mediated Inflammation in Inflammatory Bowel Disease

Interleukin-33 (IL-33) is a cytokine defined by its pleiotropic function, acting either as a typical extracellular cytokine or as a nuclear transcription factor. IL-33 and its receptor, suppression of tumorigenicity 2 (ST2), interact with both innate and adaptive immunity and are considered critical regulators of inflammatory disorders. The IL-33/ST2 axis is involved in the maintenance of intestinal homeostasis; on the basis of their role as pro- or anti-inflammatory mediators of first-line innate immunity, their expression is of great importance in regard to mucosal defenses. Mucosal immunity commonly presents an imbalance in inflammatory bowel disease (IBD). This review summarizes the main cellular and molecular aspects of IL-33 and ST2, mainly focusing on the current evidence of the pro- and anti-inflammatory effects of the IL-33/ST2 axis in the course of ulcerative colitis and Crohn's disease, as well as the molecular mechanisms underlying the association of IL-33/ST2 signaling in IBD pathogenesis. Although IL-33 modulates and impacts the development, course, and recurrence of the inflammatory response, the exact role of this molecule is elusive, and it seems to be associated with the subtype of the disease or the disease stage. Unraveling of IL-33/ST2-mediated mechanisms involved in IBD pathology shows great potential for clinical application as therapeutic targets in IBD treatment.

Schisandrin C improves leaky gut conditions in intestinal cell monolayer, organoid, and nematode models by increasing tight junction protein expression

BACKGROUND

Leaky gut symptoms and inflammatory bowel disease (IBD) are associated with damaged intestinal mucosa, intestinal permeability dysfunction by epithelial cell cytoskeleton contraction, disrupted intercellular tight junction (TJ) protein expression, and abnormal immune responses and are intractable diseases.

PURPOSE

We evaluated the effects of schisandrin C, a dibenzocyclooctadiene lignan from Schisandra chinensis, on intestinal inflammation and permeability dysfunction in gut mimetic systems: cultured intestinal cells, intestinal organoids, and a Caenorhabditis elegans model.

METHODS

Schisandrin C was selected from 9 lignan compounds from S. chinensis based on its anti-inflammatory effects in HT-29 human intestinal cells. IL-1β and Pseudomonas aeruginosa supernatants were used to disrupt intestinal barrier formation in vitro and in C. elegans, respectively. The effects of schisandrin C on transepithelial electrical resistance (TEER) and intestinal permeability were evaluated in intestinal cell monolayers, and its effect on intestinal permeability dysfunction was tested in mouse intestinal organoids and C. elegans by measuring fluorescein isothiocyanate (FITC)-dextran efflux. The effect of schisandrin C on TJ protein expression was investigated by western blotting and fluorescence microscopy. The signaling pathway underlying these effects was also elucidated.

RESULTS

Schisandrin C ameliorated intestinal permeability dysfunction in three IBD model systems and enhanced epithelial barrier formation via upregulation of ZO-1 and occludin in intestinal cell monolayers and intestinal organoids. In Caco-2 cells, schisandrin C restored IL-1β-mediated increases in MLCK and p-MLC expression, in turn blocking cytoskeletal contraction and subsequent intestinal permeabilization. Schisandrin C inhibited NF-ĸB and p38 MAPK signaling, which regulates MLCK expression and structural reorganization of the TJ complex in Caco-2 cells. Schisandrin C significantly improved abnormal FITC-dextran permeabilization in both intestinal organoids and C. elegans.

CONCLUSION

Schisandrin C significantly improves abnormal intestinal permeability and regulates the expression of TJ proteins, long MLCK, p-MLC, and inflammation-related proteins, which are closely related to leaky gut symptoms and IBD development. Therefore, schisandrin C is a candidate to treat leaky gut symptoms and IBDs.

Science Evidence of Chinese Herbal Medicine (Gegen Qinlian Decoction) in the Treatment of Ulcerative Colitis

Objectives. Gegen Qinlian decoction (GQD), a Chinese herbal compound, has been widely used in the treatment of ulcerative colitis (UC) in China. However, evidence from systematic reviews (SRs)/meta-analyses (MAs) of GQD in UC remains highly controversial. To collate, evaluate, and synthesize the current evidence, we carried out this study. Methods. SRs/MAs of GQD for UC were obtained from eight databases. Methodological Quality of Systematic Reviews 2 (AMSTAR-2) was utilized to appraise the methodological quality, Preferred Reporting Item for Systematic Reviews and Meta-Analyses (PRISMA) for reporting quality, and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) for evidence quality. Results. Four eligible SRs/MAs were obtained. According to AMSTAR 2, all SRs/MAs were graded as critically low quality. According to PRISMA checklist, all SRs/MAs failed to report the information of protocol and registration. With GRADE, no outcome measure with high-quality evidence was found, and the evidence quality for outcome measures was in the moderate to critically low levels. Conclusions. GQD with conventional medicine (CM) seems to be more effective in UC than CM alone. This finding provides a new alternative strategy for the treatment of UC. However, owing to the limitations of the evidence provided by the included SRs/MAs, this conclusion must be treated with caution.

Role of B-Cell Activating Factor (BAFF) in Inflammatory Bowel Disease

As early commencement of inflammatory bowel disease (IBD) treatment has been shown to substantially improve outcomes, it is of utmost importance to make a timely diagnosis of this disease. Despite undisputed sensitivity of fecal calprotectin, the most widely accepted IBD biomarker, in discriminating between irritable bowel syndrome (IBS) and IBD, as well as recognized role in monitoring disease activity and response to therapy, perhaps the biggest setback of calprotectin use in IBD is lack of specificity. Therefore, an additional biomarker in IBD is warranted. B-cell activating factor (BAFF), a member of the tumor necrosis factor (TNF) superfamily, recently emerged as a viable candidate for this role. So far, overproduction of BAFF has been observed in various autoimmune diseases, most notably in systemic lupus erythematosus, where BAFF-inhibitor belimumab was approved for treatment. As BAFF levels were also shown to correlate with indices of IBD, in this review we aimed to summarize the current evidence with respect to the role of BAFF in diagnosis and assessing the activity of IBD, as well as putative therapeutic implications that may arise from exploring of this relation.

Influence of systemic manifestations of inflammatory bowel diseases on endothelial function and cardiovascular risk

BACKGROUND

Inflammatory bowel diseases (IBD) may be complicated by extraintestinal manifestations (EIM). Both conditions may be implicated in the overall increase of cardiovascular (CV) risk profile of the patients. The study aimed to assess CV risk in IBD patients with EIMs in relation to the stages of both diseases.

METHODS

A total of 70 (38 men, mean age 51.7±12.4 years) patients with IBD and 22 controls (12 men, mean age 49.2±13.6 years) were enrolled. All patients and controls were screened for extraintestinal manifestations and underwent physical and anthropometric examinations, standard laboratory investigations, ultrasound evaluation of carotid arteries and flow-mediated vasodilatation (FMD). Patients were divided into four groups in relation to their active or remission stage of disease: 1. IBD+ EIM+; 2. IBD+ EIM-; 3. IBD- EIM+; 4. IBD- EIM-.

RESULTS

The groups were homogenous according to their clinical characteristics. Patients with both IBD and EIM in active phase showed significantly lower values in FMD than controls (p=0.024). Carotid intima-media thickness values (cIMT) were similar among groups. Patients with active phases of IBD and/or EIM showed statistically significant lower values in FMD measurements (p=0.0008 and p=0.0011, respectively). Multivariate regression did not reveal any independent predictors for FMD values.

CONCLUSIONS

The active phase of IBD or EIM or both may promote endothelial dysfunction in patients, thus increasing their CV risk profile. Patients in remission phase showed endothelial function similar at controls.

Colonisation with endogenous Lactobacillus reuteri R28 and exogenous Lactobacillus plantarum AR17-1 and the effects on intestinal inflammation in mice

The beneficial effects of probiotics on inflammatory bowel disease (IBD) are well known, although an understanding of colonisation by endogenous and exogenous bacterial strains and the effects on intestinal inflammation remains elusive. In this study, the colonisation of endogenous Lactobacillus reuteri R28 and exogenous Lactobacillus plantarum AR17-1 was investigated in healthy or PEG-treated mice using a 5(6)-carboxyfluorescein diacetate N-succinimidyl ester (cFDA-SE) labelling technique. The effects of these strains on mice with colitis induced by DSS and treated with PEG + DSS were also studied. Endogenous L. reuteri R28 and exogenous L. plantarum AR17-1 exhibited no significant differences in colonisation in healthy mice, whereas after PEG treatment, colonisation of the intestinal mucosa by L. reuteri R28 was greatly enhanced. L. reuteri R28 more effectively reduced diarrhoea caused by PEG, and L. plantarum AR17-1 more effectively reduced the colitis induced by PEG + DSS and downregulated the expression of the pro-inflammatory cytokines TNF-α, IL-1β, and IL-6. These results suggest that endogenous L. reuteri R28 may easily adapt to the intestinal environment, leading to better colonisation, whereas L. plantarum AR17-1 has a stronger inhibitory effect on inflammation. This finding is relevant to the selection of probiotics.

GUT MICROBIOTA, PREBIOTICS, PROBIOTICS, AND SYNBIOTICS IN GASTROINTESTINAL AND LIVER DISEASES: PROCEEDINGS OF A JOINT MEETING OF THE BRAZILIAN SOCIETY OF HEPATOLOGY (SBH), BRAZILIAN NUCLEUS FOR THE STUDY OF HELICOBACTER PYLORI AND MICROBIOTA (NBEHPM), AND BRAZILIAN FEDERATION OF GASTROENTEROLOGY (FBG)

Over the last years, there is growing evidence that microorganisms are involved in the maintenance of our health and are related to various diseases, both intestinal and extraintestinal. Changes in the gut microbiota appears to be a key element in the pathogenesis of hepatic and gastrointestinal disorders, including non-alcoholic fatty liver disease, alcoholic liver disease, liver cirrhosis, inflammatory bowel disease, irritable bowel syndrome, and Clostridium difficile - associated diarrhea. In 2019, the Brazilian Society of Hepatology (SBH) in cooperation with the Brazilian Nucleus for the Study of Helicobacter Pylori and Microbiota (NBEHPM), and Brazilian Federation of Gastroenterology (FBG) sponsored a joint meeting on gut microbiota and the use of prebiotics, probiotics, and synbiotics in gastrointestinal and liver diseases. This paper summarizes the proceedings of the aforementioned meeting. It is intended to provide practical information about this topic, addressing the latest discoveries and indicating areas for future studies.

Epidemiological profile of inflammatory bowel disease in Caxias do Sul, Brazil: a cross-sectional study

BACKGROUND

Inflammatory bowel diseases affect mostly young patients and have a huge impact on their quality of life and growing treatment costs. Currently, there are few Brazilian studies concerning their epidemiological profile.

OBJECTIVE

The aim of this study was to describe the regional clinical and epidemiological profile of these pathological conditions in Caxias do Sul, Brazil.

DESIGN AND SETTING

Cross-sectional study in Caxias do Sul (RS), Brazil.

METHODS

A search for patients was conducted in the municipality's special medications pharmacy using the International Classification of Diseases, and medical records were manually reviewed for data collection. Sixty-seven patients were included.

RESULTS

The patients' mean age was 46.5 years and females predominated (71.6%). Ulcerative colitis was the most prevalent disease (70%) and Montreal E3 was the most prevalent presentation. The mean age at diagnosis was 39 years. Most patients had recently undergone colonoscopy (67%). Only five patients (7.4%) had records of hospital admission due to the disease, while 12 (18%) underwent a surgical procedure during follow-up. Sixty patients (89.5%) were using aminosalicylates, while less than one fifth were using immunosuppressants or immunobiological drugs: 19.4% and 14.9%, respectively.

CONCLUSION

The profile of inflammatory bowel disease patients in this region of Brazil is similar in some characteristics to other published Brazilian data, although it differs in others such as higher frequency of pancolitis. A prospective study on these patients is planned in this region, in order to improve the data quality.

The role of the gut microbiota in the treatment of inflammatory bowel diseases

The human intestinal microbiota coevolves with its host through a symbiotic relationship and exerts great influence on substantial functions including aspects of physiology, metabolism, nutrition and regulation of immune responses leading to physiological homeostasis. Over the last years, several studies have been conducted toward the assessment of the host-gut microbiota interaction, aiming to elucidate the mechanisms underlying the pathogenesis of several diseases. A defect on the microbiota-host crosstalk and the concomitant dysregulation of immune responses combined with genetic and environmental factors have been implicated in the pathogenesis of inflammatory bowel diseases (IBD). To this end, novel therapeutic options based on the gut microbiota modulation have been an area of extensive research interest. In this review we present the recent findings on the association of dysbiosis with IBD pathogenesis, we focus on the role of gut microbiota on the treatment of IBD and discuss the novel and currently available therapeutic strategies in manipulating the composition and function of gut microbiota in IBD patients. Applicable and emerging microbiota treatment modalities, such as the use of antibiotics, prebiotics, probiotics, postbiotics, synbiotics and fecal microbiota transplantation (FMT) constitute promising therapeutic options. However, the therapeutic potential of the aforementioned approaches is a topic of investigation and further studies are needed to elucidate their position in the present treatment algorithms of IBD.

Desmethylbellidifolin From Gentianella acuta Ameliorate TNBS-Induced Ulcerative Colitis Through Antispasmodic Effect and Anti-Inflammation

Desmethylbellidifolin (DMB) is a natural xanthone extracted from Gentianella acuta, which is used as the antidiarrhea drug in traditional Mongolian medicines. It remains unknown whether DMB can ameliorate ulcerative colitis (UC). In this study, trinitrobenzenesulfonic acid (TNBS)-induced colitis rats were treated with G. acuta extract (GAE) or DMB for 10 days. Body weight, food and water intake, rectal bleeding score, diarrhea score, and histopathological parameters were measured. Rat colon were collected to determine myeloperoxidase, nitric oxide levels, and inflammatory cytokines expression. In addition, the role of DMB on lipopolysaccharide stimulated RAW264.7 cell inflammatory response and intestine smooth muscle contraction was determined. The results showed that GAE and DMB treatment could significantly alleviate TNBS-induced UC. Colon morphological alteration, nitric oxide level, and inflammatory cytokines level, such as nitric oxide synthase, interleukin-6, tumor necrosis factor-α, and cyclooxygenase-2, were decreased. In addition, DMB attenuated lipopolysaccharide-induced nitric oxide release and proinflammatory cytokine expression in RAW264.7 cells. In isolated mice intestinal tissue, DMB also reduced the intestine smooth muscle spontaneous contraction and inhibited KCl, acetylcholine, BaCl₂, or histamine-induced intestine smooth muscle active tension, while the active frequency was unaffected. Our results demonstrated that GAE and its active constituent DMB could inhibit TNBS-induced UC, reducing inflammatory response and alleviate colon muscle spasm, suggesting that DMB may be a good candidate for subsequent development as a multitargeting drug for UC treatment.

TRIM33 deficiency in monocytes and macrophages impairs resolution of colonic inflammation

BACKGROUND

Mature myeloid cells play a crucial role in Crohn's disease (CD) but the molecular players that regulate their functions in CD are not fully characterized. We and others have shown that TRIM33 is involved in the innate immune response and in the inflammatory response but TRIM33 role in intestinal inflammation is not known. In this study, we investigated the role of TRIM33 in myeloid cells during dextran sulfate sodium (DSS)-induced colitis.

METHODS

We study the role of TRIM33 during DSS-induced colitis which mimics intestinal inflammation using mice deleted for Trim33 only in mature myeloid cells (Trim33-/- mice) FINDINGS: We first show that Trim33 mRNA level is decreased in CD patient's blood monocytes suggesting a role of TRIM33 in CD. Using Trim33-/- mice, we show that these mice display an impaired resolution of colonic inflammation with an increased number of blood and colon monocytes and a decreased number of colonic macrophages. Trim33-/- monocytes are less competent for recruitment and macrophage differentiation. Finally, during resolution of inflammation, Trim33-/- colonic macrophages display an impaired M1/M2 switch and express a low level of membrane-bound TNF that is associated with an increased number of colonic neutrophils.

INTERPRETATION

Our study shows an important role of TRIM33 in monocytes/macrophages during DSS-induced colitis and suggests that the decreased expression of TRIM33 in CD patient's blood monocytes might not be a consequence but might be involved in CD progression. FUND: La Ligue contre le Cancer (équipe labelisée), INSERM, CEA, Université Paris-Diderot, Université Paris-Sud.

Identification and Analysis of Human Microbe-Disease Associations by Matrix Decomposition and Label Propagation

Studies have shown that microbes exist widely in the human body and are closely related to human complex diseases. Predicting potential associations between microbes and diseases is conducive to understanding the mechanisms of complex diseases and can also facilitate the diagnosis and prevention of human diseases. In this paper, we put forward the Matrix Decomposition and Label Propagation for Human Microbe-Disease Association prediction (MDLPHMDA) on the basis of the dataset of known microbe-disease associations collected from the database of HMDAD and the Gaussian interaction profile kernel similarity for diseases and microbes, disease symptom similarity. Moreover, the performance of our model was evaluated by means of leave-one-out cross validation and five-fold cross validation, and the corresponding AUCs of 0.9034 and 0.8954 ± 0.0030 were gained, respectively. In case studies, 10, 9, 9, and 8 out of the top 10 predicted microbes for asthma, colorectal carcinoma, liver cirrhosis, and type 1 diabetes were confirmed by literatures, respectively. Overall, evaluation results showed that MDLPHMDA has good performance in potential microbe-diseasepositive free parameter, which associations prediction.

A single administration of human adipose tissue-derived mesenchymal stromal cells (MSC) induces durable and sustained long-term regulation of inflammatory response in experimental colitis

Current therapies for inflammatory bowel diseases (IBD) are aimed at controlling the exacerbated response in the gut, but no treatment is fully effective for many refractory patients. Mesenchymal stromal cells (MSC) are multi-potent cells with regulatory immunosuppressive activity that may control inflammatory diseases. In this study, we investigated the short- and especially the long-term protective effects of MSC on experimental colitis. We show that MSC elicited protection to acute intestinal inflammation with gain of weight, improvement in the clinical disease score and expressive reduction in the mortality rate of treated mice. MSC changed the population of neutrophils, eosinophils and augmented the frequency of CD4 T lymphocytes in the gut-draining lymph nodes, together with reduced accumulation of these cells in the colon intraepithelial compartment. Interestingly, there were increased levels of programmed death 1 (PD-1) and glucocorticoid-induced tumour necrosis factor receptor family-related receptor (GITR) in the spleen regulatory T cells of mice that received MSC treatment, which also presented a reversal in the pattern of immune response in the gut, with diminished inflammatory, T helper type 1 (Th1) and Th17 profile, in contrast to augmented Th2 responses. Most strikingly, this balanced response elicited by a single administration of MSC during the acute colitis persisted long-term, with restored goblet cells, eosinophils and maintenance of elevated gut interleukin (IL)-4, besides increased CD4⁺ CD25⁺ PD-1⁺ cells in the spleen and reduced Th17 response in mesenteric lymph nodes (MLN) of treated mice on day 60. Taken together, our findings provided a significant contribution to translational immunology by pointing human adipose tissue-derived MSC as a novel therapeutic approach with long-term beneficial regulatory effects in experimental colitis.

Docosapentaenoic acid (DPA, 22:5n-3) ameliorates inflammation in an ulcerative colitis model

DPA showed an anti-inflammatory profile by competing with AA to decrease the synthesis of pro-inflammatory eicosanoids (LTB₄ and PGE₂).

Metabolic Activity of Sulfate-Reducing Bacteria from Rodents with Colitis

Sulfate-reducing bacteria (SRB) are anaerobic microorganisms, which use sulfate as an electron acceptor in the process of dissimilatory sulfate reduction. The final metabolic product of these anaerobic microorganisms is hydrogen sulfide, which is known as toxic and can lead to damage to epithelial cells of the large intestine at high concentrations. Different genera of SRB are detected in the large intestine of healthy human and animals, and with diseases like Crohn's disease and ulcerative colitis. SRB isolated from rodents with ulcerative colitis have produced 1.14 (mice) and 1.03 (rats) times more sulfide ions than healthy rodents. The species of Desulfovibrio genus are the most widespread among all SRB in the intestine. The object of our research was to observe and compare the difference of production of sulfide and reduction of sulfate in intestinal SRB isolated from healthy rodents and rodents with ulcerative colitis.

Cannabinoid pharmacology and therapy in gut disorders

Cannabis sp. and their products (marijuana, hashish…), in addition to their recreational, industrial and other uses, have a long history for their use as a remedy for symptoms related with gastrointestinal diseases. After many reports suggesting these beneficial effects, it was not surprising to discover that the gastrointestinal tract expresses endogenous cannabinoids, their receptors, and enzymes for their synthesis and degradation, comprising the so-called endocannabinoid system. This system participates in the control of tissue homeostasis and important intestinal functions like motor and sensory activity, nausea, emesis, the maintenance of the epithelial barrier integrity, and the correct cellular microenvironment. Thus, different cannabinoid-related pharmacological agents may be useful to treat the main digestive pathologies. To name a few examples, in irritable bowel syndrome they may normalize dysmotility and reduce pain, in inflammatory bowel disease they may decrease inflammation, and in colorectal cancer, apart from alleviating some symptoms, they may play a role in the regulation of the cell niche. This review summarizes the main recent findings on the role of cannabinoid receptors, their synthetic or natural ligands and their metabolizing enzymes in normal gastrointestinal function and in disorders including irritable bowel syndrome, inflammatory bowel disease, colon cancer and gastrointestinal chemotherapy-induced adverse effects (nausea/vomiting, constipation, diarrhea).

The Dynamics of Interleukin-10-Afforded Protection during Dextran Sulfate Sodium-Induced Colitis

Inflammatory bowel disease encompasses a group of chronic-inflammatory conditions of the colon and small intestine. These conditions are characterized by exacerbated inflammation of the organ that greatly affects the quality of life of patients. Molecular mechanisms counteracting this hyperinflammatory status of the gut offer strategies for therapeutic intervention. Among these regulatory molecules is the anti-inflammatory cytokine interleukin (IL)-10, as shown in mice and humans. Indeed, IL-10 signaling, particularly in macrophages, is essential for intestinal homeostasis. We sought to investigate the temporal profile of IL-10-mediated protection during chemical colitis and which were the underlying mechanisms. Using a novel mouse model of inducible IL-10 overexpression (pMT-10), described here, we show that mice preconditioned with IL-10 for 8 days before dextran sulfate sodium (DSS) administration developed a milder colitic phenotype. In IL-10-induced colitic mice, Ly6C cells isolated from the lamina propria showed a decreased inflammatory profile. Because our mouse model leads to transcription of the IL-10 transgene in the bone marrow and elevated seric IL-10 concentration, we investigated whether IL-10 could imprint immune cells in a long-lasting way, thus conferring sustained protection to colitis. We show that this was not the case, as IL-10-afforded protection was only observed if IL-10 induction immediately preceded DSS-mediated colitis. Thus, despite the protection afforded by IL-10 in colitis, novel strategies are required, specifically to achieve long-lasting protection.

Update on intestinal microbiota in Crohn's disease 2017: Mechanisms, clinical application, adverse reactions, and outlook

The pathogenesis of Crohn's disease (CD) is complex, and it is thought to be associated with the environment, immune, hereditary, microbe, and other factors. If the balance between the host and the intestinal microbes in CD patients was broken, immune-inflammatory response of susceptible individuals might be triggered. Probiotics could improve the intestinal microbial flora balance and treat human effectively. There are several new mechanisms that might explain the role of probiotics. Fecal microbiota transplantation (FMT) is becoming more and more attractive in treating a large amount of digestive system diseases that are related to the dysbiosis of intestinal microbiota. FMT has been widely used in recurrent Clostridium difficile infection. More and more attention has been paid on the clinical application of FMT in CD, while the exact mechanism is still a mystery. So in this review, we explore the mechanism, clinical application, and adverse reactions of intestinal microbiota in CD so that we can use the tool to cure more diseases. Enteric microbiota leads to new therapeutic strategies for CD.

Brassica-Derived Plant Bioactives as Modulators of Chemopreventive and Inflammatory Signaling Pathways

A high consumption of vegetables belonging to the Brassicaceae family has been related to a lower incidence of chronic diseases including different kinds of cancer. These beneficial effects of, e.g., broccoli, cabbage or rocket (arugula) intake have been mainly dedicated to the sulfur-containing glucosinolates (GLSs)-secondary plant compounds nearly exclusively present in Brassicaceae-and in particular to their bioactive breakdown products including isothiocyanates (ITCs). Overall, the current literature indicate that selected Brassica-derived ITCs exhibit health-promoting effects in vitro, as well as in laboratory mice in vivo. Some studies suggest anti-carcinogenic and anti-inflammatory properties for ITCs which may be communicated through an activation of the redox-sensitive transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) that controls the expression of antioxidant and phase II enzymes. Furthermore, it has been shown that ITCs are able to significantly ameliorate a severe inflammatory phenotype in colitic mice in vivo. As there are studies available suggesting an epigenetic mode of action for Brassica-derived phytochemicals, the conduction of further studies would be recommendable to investigate if the beneficial effects of these compounds also persist during an irregular consumption pattern.

Human Gut Microbiota: Toward an Ecology of Disease

Composed of trillions of individual microbes, the human gut microbiota has adapted to the uniquely diverse environments found in the human intestine. Quickly responding to the variances in the ingested food, the microbiota interacts with the host via reciprocal biochemical signaling to coordinate the exchange of nutrients and proper immune function. Host and microbiota function as a unit which guards its balance against invasion by potential pathogens and which undergoes natural selection. Disturbance of the microbiota composition, or dysbiosis, is often associated with human disease, indicating that, while there seems to be no unique optimal composition of the gut microbiota, a balanced community is crucial for human health. Emerging knowledge of the ecology of the microbiota-host synergy will have an impact on how we implement antibiotic treatment in therapeutics and prophylaxis and how we will consider alternative strategies of global remodeling of the microbiota such as fecal transplants. Here we examine the microbiota-human host relationship from the perspective of the microbial community dynamics.

Effects of probiotics on Toll‑like receptor expression in ulcerative colitis rats induced by 2,4,6‑trinitro‑benzene sulfonic acid

The present study aimed to investigate the regulatory effect of probiotics on the expression of Toll‑like receptors (TLRs) in an ulcerative colitis (UC) rat model, and to determine the role of probiotics in the underlying mechanisms through which UC develops and progresses in rat models. Rats were randomly allocated to one of the four following groups: i) The healthy control, ii) the model, iii) the Golden bifid treatment group, and iv) the TLR4 monoclonal antibody (TLR4mAb) intervention group. The UC rat model was established using 2,4,6‑trinitro‑benzene sulfonic acid. The general status and histological changes of rats were scored using the disease activity index and the histopathological scoring method, respectively. In these rats, the expression of TLR4 and TLR2 was measured using reverse transcription‑quantitative polymerase chain reaction. The expression of TLR4 and TLR2 in the model group was significantly higher than that in the healthy control group. However, when compared with the model rats, those that received either Golden bifid treatment or TLR4mAb intervention exhibited significantly decreased mRNA expression levels of TLR4 and TLR2 (P<0.05). The development of UC is characterized by an abnormal immune response in the intestines. Probiotics alleviated inflammatory reactions in rats with UC. The underlying mechanism of UC may be associated with the expression of TLRs and the subsequent release of inflammatory cytokines.

Opportunities and challenges of whole-genome and -exome sequencing

Recent advances in the development of sequencing technologies provide researchers with unprecedented possibilities for genetic analyses. In this review, we will discuss the history of genetic studies and the progress driven by next-generation sequencing (NGS), using complex inflammatory bowel diseases as an example. We focus on the opportunities, but also challenges that researchers are facing when working with NGS data to unravel the genetic causes underlying diseases.

IKKα controls ATG16L1 degradation to prevent ER stress during inflammation

Inhibition of the IκB kinase complex (IKK) has been implicated in the therapy of several chronic inflammatory diseases including inflammatory bowel diseases. In this study, using mice with an inactivatable IKKα kinase (Ikkα^AA/AA), we show that loss of IKKα function markedly impairs epithelial regeneration in a model of acute colitis. Mechanistically, this is caused by compromised secretion of cytoprotective IL-18 from IKKα-mutant intestinal epithelial cells because of elevated caspase 12 activation during an enhanced unfolded protein response (UPR). Induction of the UPR is linked to decreased ATG16L1 stabilization in Ikkα^AA/AA mice. We demonstrate that both TNF-R and nucleotide-binding oligomerization domain stimulation promote ATG16L1 stabilization via IKKα-dependent phosphorylation of ATG16L1 at Ser278. Thus, we propose IKKα as a central mediator sensing both cytokine and microbial stimulation to suppress endoplasmic reticulum stress, thereby assuring antiinflammatory function during acute intestinal inflammation.

The Immunological Basis of Inflammatory Bowel Disease

Inflammatory bowel diseases (IBDs) are chronic ailments, Crohn's disease and ulcerative colitis being the most important. These diseases present an inflammatory profile and they differ according to pathophysiology, the affected area in the gastrointestinal tract, and the depth of the inflammation in the intestinal wall. The immune characteristics of IBD arise from abnormal responses of the innate and adaptive immune system. The number of Th17 cells increases in the peripheral blood of IBD patients, while Treg cells decrease, suggesting that the Th17/Treg proportion plays an important role in the development and maintenance of inflammation. The purpose of this review was to determine the current state of knowledge on the immunological basis of IBD. Many studies have shown the need for further explanation of the development and maintenance of the inflammatory process.

Germ-free and Antibiotic-treated Mice are Highly Susceptible to Epithelial Injury in DSS Colitis

BACKGROUND AND AIMS

Intestinal microbiota is required to maintain immune homeostasis and intestinal barrier function. At the same time, intraluminal bacteria are considered to be involved in inflammatory bowel disease and are required for colitis induction in animal models, with the possible exception of dextran sulphate sodium [DSS] colitis. This study was carried out to ascertain the mechanism underlying the induction of colitis by DSS in the absence of bacteria.

METHODS

Conventional and germ-free [GF] Naval Medical Research Institute [NMRI] mice were used, plus conventional mice treated with an antibiotic cocktail to deplete the intestinal microbiota ['pseudo-GF' or PGF mice]. The differential response to DSS was assessed.

RESULTS

Conventional mice developed DSS-induced colitis normally, whereas GF mice showed only minimal inflammation [no colonic thickening, lower myeloperoxidase activity, IL-6, IL-17, TNF-α, and IFN-γ secretion by splenocytes and mesenteric cell cultures, etc.]. However, these mice suffered enhanced haemorrhage, epithelial injury and mortality as a consequence of a weakened intestinal barrier, as shown by lower occludin, claudin 4, TFF3, MUC3, and IL-22. In contrast, PGF mice had a relatively normal, albeit attenuated, inflammatory response, but were less prone to haemorrhage and epithelial injury than GF mice. This was correlated with an increased expression of IL-10 and Foxp3 and preservation barrier-related markers.

CONCLUSIONS

We conclude that enteric bacteria are essential for the development of normal DSS-induced colitis. The absence of microbiota reduces DSS colonic inflammation dramatically but it also impairs barrier function, whereas subtotal microbiota depletion has intermediate effects at both levels.

Effects of Glutamine and Omega-3 Fatty Acids on Erythrocyte Deformability and Oxidative Damage in Rat Model of Enterocolitis

Background

The aim of the study was to investigate preventive effects of glutamine (Gln), omega-3 fatty acids (FA) on erythrocyte deformability (EDEF) in rat model of indomethacin-induced enterocolitis.

Methods

Nineteen Wistar albino male rats were divided into three groups: control group, colitis induced by indomethacin and were fed with a standard laboratory diet (group 1), and colitis induced by indomethacin and were also fed with Gln, omega-3 FA (group 2). An investigation was performed in a rat model of experimental colitis induced by subcutaneous injections of 2 mL intdomethacine solution applied at 24 and 48 hours intervals to male Wistar rats for 14 days. Gln and omega-3 FA were added to the daily standard diets of the animals during 14 days of injections. During the study, changes in body weight were evaluated. The intestines were examined, and colitis was macroscopic and histologically scored. The circulating tumor necrosis factor alpha (TNF-α) and interleukine-1β (IL-1β), erythrocyte transit time (ETT) and thiobarbituric acid reactive substances (TBARS) levels were determined in addition to calculation of EDEF indices in all groups.

Results

No significant differences in body weight changes could be determined between the standard diet and special diet groups at the end of the experiment. After macroscopic and microscopic scoring, in all of the groups that colitis was found induced, the lowest microscopic score was observed in the group 2. But Gln and omega-3 FA supplemented diet did not change the mean macroscopic and histological scores in all rats. The proliferating cell nuclear antigen (PCNA) levels were significantly higher in group 1 and group 2 compared to the control group. Effects of the diet on circulating TNF-α and IL-1β levels were found correlated with inflammation but statistically significant differences were not found in the group 1 and group 2 (P < 0.05). The ETT and TBARS levels in standard and special diet groups were significantly increased (P < 0.05). However, EDEF indices which are an important parameter of the study were decreased in indomethacin-induced enterocolitis groups that fed with standard and special diet.

Conclusions

Increases in ETT and TBARS levels did not return to normal by addition of Gln and omega-3 FA to diet. Our results suggest that determination of effective optimal doses and route of administration for these nutrients may play an important role in reducing EDEF and microvascular changes.

Integrin antagonists as potential therapeutic options for the treatment of Crohn's disease

INTRODUCTION

Anti-integrin therapy for the treatment of patients with Crohn's disease is rapidly evolving. Two agents, natalizumab and vedolizumab, are approved by the United States Food and Drug Administration for the treatment of Crohn's disease, with vedolizumab the primary anti-integrin used due to a more favorable safety profile. Several other anti-integrins are in various stages of development.

AREAS COVERED

This review discusses the current state of anti-integrin therapy as well as suggestions for positioning of these agents in clinical practice. Emerging anti-integrin therapies, their underlying mechanisms of action, and available safety and clinical data are also reviewed.

EXPERT OPINION

Anti-integrins are effective for the treatment of Crohn's disease, even in patients refractory to other therapies. Their use should be considered in patients with Crohn's disease who do not respond to, develop non-response to, or have contraindications to anti-TNF therapy. Anti-integrin therapies can be offered as a first biologic therapy, in particular for older patients, patients with concurrent multiple sclerosis (natalizumab only), and in patients with contraindications to anti-TNF therapy. In patients with more severe symptoms, providers should consider co-induction with corticosteroids if possible to hasten remission.

Effect of Early Versus Late Azathioprine Therapy in Pediatric Ulcerative Colitis

BACKGROUND

We aimed at describing the efficacy of azathioprine (AZA) in pediatric ulcerative colitis, comparing the outcomes of early (0-6 months) versus late (6-24 months) initiation of therapy.

METHODS

Children with ulcerative colitis treated with AZA within 24 months of diagnosis were included. Corticosteroid (CS)-free remission and mucosal healing (MH), assessed by endoscopy or fecal calprotectin, at 12 months were the primary outcomes. Patients were also compared for CS-free remission and MH, need for treatment escalation or surgery, number of hospitalizations, and adverse events during a 24-month follow-up.

RESULTS

A total of 121 children entered the study (median age 10.5 ± 4.0 years, 59% girls). Seventy-six (63%) started AZA between 0 and 6 months (early group) and 45 (37%) started between 6 and 24 months (late group). Seventy-five percent and 53% of patients in the early and late group, respectively, received CS at the diagnosis (P = 0.01). CS-free remission at 1 year was achieved by 30 (50%) of the early and 23 (57%) of the late patients (P = 0.54). MH occurred in 37 (37%) patients at 1 year, with no difference between the 2 groups (33% early, 42% late; P = 0.56). No difference was found for the other outcomes.

CONCLUSIONS

Introduction of AZA within 6 months of diagnosis seems not more effective than later treatment to achieve CS-free remission in pediatric ulcerative colitis. MH does not depend on the timing of AZA initiation; however, because of the incomplete comparability of the 2 groups at the diagnosis and the use of fecal calprotectin as a surrogate marker of MH, our results should be further confirmed by prospective studies.

Can exercise affect the course of inflammatory bowel disease? Experimental and clinical evidence

The inflammatory bowel disease (IBD) consisting of Crohn's disease (CD) and ulcerative colitis (UC) are defined as idiopathic, chronic and relapsing intestinal disorders occurring in genetically predisposed individuals exposed to environmental risk factors such as diet and microbiome changes. Since conventional drug therapy is expensive and not fully efficient, there is a need for alternative remedies that can improve the outcome in patients suffering from IBD. Whether exercise, which has been proposed as adjunct therapy in IBD, can be beneficial in patients with IBD remains an intriguing question. In this review, we provide an overview of the effects of exercise on human IBD and experimental colitis in animal models that mimic human disease, although the information on exercise in human IBD are sparse and poorly understood. Moderate exercise can exert a beneficial ameliorating effect on IBD and improve the healing of experimental animal colitis due to the activity of protective myokines such as irisin released from working skeletal muscles. CD patients with higher levels of exercise were significantly less likely to develop active disease at six months. Moreover, voluntary exercise has been shown to exert a positive effect on IBD patients' mood, weight maintenance and osteoporosis. On the other hand, depending on its intensity and duration, exercise can evoke transient mild systemic inflammation and enhances pro-inflammatory cytokine release, thereby exacerbating the gastrointestinal symptoms. We discuss recent advances in the mechanism of voluntary and strenuous exercise affecting the outcome of IBD in patients and experimental animal models.

Dysbiosis in intestinal inflammation: Cause or consequence

The intestinal microbiota encompasses hundreds of bacterial species that constitute a relatively stable ecosystem. Alteration in the microbiota composition may arise from infections, immune defects, metabolic alterations, diet or antibiotic treatment. Dysbiosis is considered as an alteration in microbiota community structure and/or function, capable of causing/driving a detrimental distortion of microbe-host homeostasis. A variety of pathologies are associated with changes in the community structure and function of the gut microbiota, suggesting a link between dysbiosis and disease etiology. With an emphasis in this review on inflammatory bowel diseases (IBD), the non-trivial question is whether dysbiosis is the cause or consequence of inflammation. It is important to understand whether changes in microbial ecosystems are causally linked to the pathology and to what extend disease risk is predicable based on characteristic changes in community structure and/or function. Local changes in tissue integrity associated with focal areas of inflammation may result in the selection of a dysbiotic bacterial community associated with the propagation of a disease phenotype. This review outlines the role of dysbiosis in intestinal inflammation with particular focus on IBD-relevant gnotobiotic mouse models, the factors implicated in the development of dysbiosis and the means available to investigate dysbiosis in the context of human diseases.

Characteristics of Pediatric Crohn's Disease in Saudi Children: A Multicenter National Study

Background and Aims. Crohn's disease (CD) is an evolving disease in KSA. Little is known about its characteristics in the Saudi population. The aims of this study were to describe the characteristics of Saudi children with CD and to determine whether the characteristics of CD in KSA are different from those seen in Western countries. Methods. In this study, children younger than eighteen years of age diagnosed with CD between January 2003 and December 2012 were included. Results. Of 330 patients identified, 186 (56.4%) were males. The median age at diagnosis was 15.8 years. A positive family history for IBD in first-degree relatives occurred in 13.6% of patients. The most common symptoms were abdominal pain (84.2%), weight loss (75.2%), and diarrhea (71.8%). The main disease location was ileocolonic (42.1%) and the main disease behavior was nonstricturing and nonpenetrating (63.6%). Perianal involvement was seen in 60 (18.2%) patients. Laboratory findings revealed anemia in 57.9% of patients, low albumin in 34.5%, and high CRP in 39.4%. Conclusions. Saudi children with CD have lower frequency of first-degree relatives with IBD, lower prevalence of early onset disease, longer diagnostic delay, higher prevalence of growth failure, and greater frequency of stricturing and penetrating disease behavior compared to Western patients.

Emerging treatments in Neurogastroenterology: Perspectives of guanylyl cyclase C agonists use in functional gastrointestinal disorders and inflammatory bowel diseases

BACKGROUND

Functional gastrointestinal disorders (FGID) and inflammatory bowel diseases (IBD) are the most frequent pathologic conditions affecting the gastrointestinal (GI) tract and both significantly reduce patients' quality of life. Recent studies suggest that guanylyl cyclase C (GC-C) expressed in the GI tract constitutes a novel pharmacological target in the treatment of FGID and IBD. Endogenous GC-C agonists - guanylin peptides: guanylin and uroguanylin, by the regulation of water and electrolyte transport, are involved in the maintenance of homeostasis in the intestines and integrity of the intestinal mucosa. Linaclotide, a synthetic agonist of GC-C was approved by Food and Drug Administration and European Medicines Agency as a therapeutic in constipation-predominant irritable bowel syndrome (IBS-C) and chronic idiopathic constipation (CIC). Lately, several preclinical and clinical trials focused on assessment of therapeutic properties of synthetic agonists of uroguanylin, plecanatide, and SP-333. Plecanatide is currently tested as a potential therapeutic in diseases related to constipation and SP-333 is a promising drug in ulcerative colitis treatment.

PURPOSE

Here, we discuss the most recent findings and future trends on the development of GC-C agonists and their use in clinical trials.

Fructooligosaccharides exert intestinal anti-inflammatory activity in the CD4+ CD62L+ T cell transfer model of colitis in C57BL/6J mice

PURPOSE

Fructooligosaccharides (FOS) are used as functional foods due to their prebiotic effects. Intestinal anti-inflammatory activity has been established in most, but not all, studies in animal models of colitis, using mainly chemically induced inflammation. Our goal was to test the effect of FOS (degree of polymerization 2-8) in the chronic, lymphocyte-driven CD4+ CD62L+ T cell transfer model of colitis.

METHODS

Colitis was induced by transfer of CD4+ CD62L+ T cells to C57BL/6J Rag1(-/-) mice. FOS (75 mg day(-1)) was administered by gavage as a post-treatment. Three groups were established: non-colitic (NC), colitic control (C, CD4+ CD62L+ transferred mice treated with vehicle) and colitic+FOS (C+FOS, similar but treated with FOS). Mice were killed after 13 days.

RESULTS

Treatment of mice with FOS ameliorated colitis, as evidenced by an increase in body weight, a lesser myeloperoxidase and alkaline phosphatase activities, a lower secretion of proinflammatory cytokines by mesenteric lymph node cells ex vivo (IFN-γ, IL-17, and TNF-α), and a higher colonic expression of occludin (C+FOS vs. C, p < 0.05). Increased relative abundance of lactic acid bacteria was observed in FOS-treated mice (p < 0.05).

CONCLUSIONS

FOS exert intestinal anti-inflammatory activity in T lymphocyte-dependent colitis, suggesting it may be useful in the management of inflammatory bowel disease in appropriate conditions.

Lulling immunity, pain, and stress to sleep with cortistatin

Cortistatin is a neuropeptide isolated from cortical brain regions, showing high structural homology and sharing many functions with somatostatin. However, cortistatin exerts unique functions in the central nervous and immune systems, including decreasing locomotor activity, inducing sleep-promoting effects, and deactivating inflammatory and T helper (TH )1/TH 17-driven responses in preclinical models of sepsis, arthritis, multiple sclerosis, and colitis. Besides its release by cortical and hippocampal interneurons, cortistatin is produced by macrophages, lymphocytes, and peripheral nociceptive neurons in response to inflammatory stimuli, supporting a physiological role of cortistatin in the immune and nociceptive systems. Cortistatin-deficient mice have been shown to have exacerbated nociceptive responses to neuropathic and inflammatory pain sensitization. However, a paradoxical effect has been observed in studies of immune disorders, in which, despite showing competent inflammatory/autoreactive responses, cortistatin-deficient mice were partially resistant to systemic autoimmunity and inflammation. This unexpected phenotype was associated with elevated circulating glucocorticoids and anxiety-like behavior. These findings support cortistatin as a novel multimodal therapeutic approach to treat autoimmunity and clinical pain and identify it as a key endogenous component of the neuroimmune system related to stress responses.

Colonic mucosal expression of heat-shock proteins may have a potential prognostic value in ulcerative colitis

BACKGROUND AND STUDY AIMS

Ulcerative colitis (UC) is a lifelong, chronic, progressive, and relapsing inflammatory disease. Endoscopy with biopsies is the mainstay in diagnosis and assessment. The development of biomarkers is important for the diagnosis and follow-up of UC. We investigated the expression of molecular chaperones/heat-shock proteins (HSP70 and HSP90) in relation to the grades of inflammation and dysplasia in patients with UC before and after treatment.

PATIENTS AND METHODS

A total of 104 naïve patients with UC of varying severity were admitted to the Department of Tropical Medicine and Infectious Diseases, Tanta University Hospital. Ten biopsies from the healthy mucosa of patients with irritable bowel syndrome (IBS) served as a control. Disease activity was assessed clinically using the Mayo score system. Endoscopic mucosal biopsies were taken at diagnosis and 6 months after treatment. Histopathological activity was graded for inflammation and dysplasia. Immunohistochemistry was used to determine the percentage of cells positive for HSPs. The results were expressed in a semiquantitative scale.

RESULTS

The expression of both HSP70 and HSP90 increased in patients with UC at the time of disease activity, and it decreased after treatment and remission. There was a significant correlation between the expression of both proteins and the grades of dysplasia as well as inflammation (P < 0.05). Strong expression of HSPs that persisted after treatment has been associated with cases of true dysplasia.

CONCLUSIONS

The results indicated that HSP70 and HSP90 had the potential for assessment of the activity and prognosis of UC. They can also predict the presence of dysplasia and differentiate it from reactive atypia. Larger studies are needed to confirm this diagnostic and prognostic value of HSPs.

Modulation of nuclear factor-κB-mediated pro-inflammatory response is associated with exogenous administration of bone marrow-derived mesenchymal stem cells for treatment of experimental colitis

Mesenchymal stem cells (MSCs) inhibit the immune response in vitro and prevent the induction of disease in certain experimental models. As a result, MSC‑mediated therapy is a rapidly growing field of research. However, the efficacy of MSCs in the treatment of inflammatory bowel disease (IBD) has remained to be determined. In the present study, rats with 2,4,6‑trinitrobenzene sulfonic acid (TNBS)‑induced colitis were injected with prepared MSCs (1x106) into the tail vein. Two weeks following intravenous MSC administration, the concentration of tumor necrosis factor‑α (TNF‑α) in the serum was measured by an ELISA. The protein expression of nuclear factor‑κB (NF‑κBp65) in the colonic mucosa was assessed by western blot analysis. mRNA expression of TNF‑α and NF‑κBp65 was determined by reverse‑transcription quantitative polymerase chain reaction. MSCs were shown to exert an immunomodulatory effect on TNBS‑induced colitis and may be of use in the treatment of IBD. In addition, modulation of the NF‑κB‑mediated pro‑inflammatory response may contribute to the underlying mechanism by which MSCs ameliorate the clinical and histological changes associated with IBD.

eNOS plays an important role in the regulation of colonic inflammation: a novel therapeutic target and a predictive marker for the prognosis of ulcerative colitis

BACKGROUND

We reported that deficiency of the eNOS protein exacerbates colitis induced by dextran sodium sulfate (DSS-induced colitis). However, the role of eNOS in colitis remains controversial. Therefore, we studied how over-expression of eNOS affected this inflammatory condition, using vascular endothelial cells and mice as in vitro and in vivo models, respectively. Furthermore, we investigated the influence of a polymorphism in the eNOS gene on the clinical features of ulcerative colitis (UC).

METHODS

We examined the effect of eNOS overexpression on the expression of adhesion molecules in the endothelium and assessed the degree of DSS-induced colitis in eNOS transgenic (eNOS-Tg) mice. We also investigated the relationship between a polymorphism in the eNOS gene and clinical features of patients with UC.

RESULTS

The expression of adhesion molecules, under inflammatory conditions, was attenuated in eNOS gene-transfected vascular endothelial cells, as measured by western blot analysis. Symptoms of DSS-induced colitis were likewise attenuated in eNOS-Tg mice, which exhibited lower weight loss, mortality, histological damage (by inflammation score and crypt damage score), and colonic myeloperoxidase activity, tumor necrosis factor-α expression, and MAdCAM-1 expression than in wild-type mice. Furthermore, there was a significant relationship between intractable cases of UC and a polymorphism in the eNOS gene promoter (c.-786 T > C) that decreases eNOS expression.

CONCLUSION

The eNOS gene plays an important role in the regulation of colonic inflammation. The level of eNOS expression may be a predictive marker for prognosis of UC, and eNOS expression may be a novel therapeutic target.

Current overview of colitis-associated colorectal cancer

Colitis-associated colorectal cancer (CACRC) constitutes a severe complication of inflammatory bowel diseases (IBD) and occurs in more than one third of IBD patients. In this short review we focus on the mechanisms underlying CACRC pathogenesis, and discuss the approaches for prevention and therapy in CACRC.