Proinflammatory Cytokines and Signaling Pathways in Intestinal Innate Immune Cells

Intestinal Inflammation and Regeneration-Interdigitating Processes Controlled by Dietary Lipids in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a disease of chronic inflammatory conditions of the intestinal tract due to disturbance of the inflammation and immune system. Symptoms of IBD include abdominal pain, diarrhea, bleeding, reduced weight, and fatigue. In IBD, the immune system attacks the intestinal tract's inner wall, causing chronic inflammation and tissue damage. In particular, interlukin-6 and interlukin-17 act on immune cells, including T cells and macrophages, to amplify the immune responses so that tissue damage and morphological changes occur. Of note, excessive calorie intake and obesity also affect the immune system due to inflammation caused by lipotoxicity and changes in lipids supply. Similarly, individuals with IBD have alterations in liver function after sustained high-fat diet feeding. In addition, excess dietary fat intake, along with alterations in primary and secondary bile acids in the colon, can affect the onset and progression of IBD because inflammatory cytokines contribute to insulin resistance; the factors include the release of inflammatory cytokines, oxidative stress, and changes in intestinal microflora, which may also contribute to disease progression. However, interfering with de novo fatty acid synthase by deleting the enzyme acetyl-CoA-carboxylase 1 in intestinal epithelial cells (IEC) leads to the deficiency of epithelial crypt structures and tissue regeneration, which seems to be due to Lgr5+ intestinal stem cell function. Thus, conflicting reports exist regarding high-fat diet effects on IBD animal models. This review will focus on the pathological basis of the link between dietary lipids intake and IBD and will cover the currently available pharmacological approaches.

Protective and therapeutic potential of melatonin against intestinal diseases: updated review of current data based on molecular mechanisms

INTRODUCTION

Intestinal diseases, a leading global cause of mortality and morbidity, carry a substantial socioeconomic burden. Small and large intestines play pivotal roles in gastrointestinal physiology and food digestion. Pathological conditions, such as gut dysbiosis, inflammation, cancer, therapy-related complications, ulcers, and ischemia, necessitate the urgent exploration of safe and effective complementary therapeutic strategies for optimal intestinal health.

AREAS COVERED

This article evaluates the potential therapeutic effects of melatonin, a molecule with a wide range of physiological actions, on intestinal diseases including inflammatory bowel disease, irritable bowel syndrome, colon cancer, gastric/duodenal ulcers and other intestinal disorders.

EXPERT OPINION

Due to anti-inflammatory and antioxidant properties as well as various biological actions, melatonin could be a therapeutic option for improving digestive disorders. However, more researches are needed to fully understand the potential benefits and risks of using melatonin for digestive disorders.

Integrated Analysis of Multiomics Data Identified Molecular Subtypes and Oxidative Stress-Related Prognostic Biomarkers in Glioblastoma Multiforme

Glioblastoma multiforme (GBM) is a glioma in IV stage, which is one of the most common primary malignant brain tumors in adults. GBM has the characters of high invasiveness, high recurrence rate, and low survival rate and with a poor prognosis. GBM implicates various genetic changes and epigenetic and gene transcription disorders, which are crucial in developing GBM. With the progression and enhancement of high-throughput sequencing technologies, the acquirement and administering approaches of diverse biological omics data on distinctive levels are developing more advanced. However, the research of GBM with multiomics remains largely unknown. We identified GBM-related molecular subtypes by integrated multiomics data and exploring the connections of gene copy number variation (CNV) and methylation gene (MET) change data. The expression of CNV and MET genes was examined through cluster integration analysis. The present study confirmed three clusters (iC1, iC2, and iC3) with distinctive prognosis and molecule peculiarities. We also recognized three oxidative stress protecting molecules (OSMR, IGFBP6, and MYBPH) by contrasting gene expression, MET, and CNV in the three subtypes. OSMR, IGFBP6, and MYBPH were differentially expressed in the clusters, suggesting they might be recognized as characteristic markers for the three clusters in GBM. Through integrative investigation of genomics, epigenomics, and transcriptomics, we offer novel visions into the multilayered molecules of GBM and facilitate the accuracy remedy for GBM sufferers.

Role of intestinal extracellular matrix-related signaling in porcine epidemic diarrhea virus infection

Porcine epidemic diarrhea virus (PEDV) is emerging as a major threat to the global swine industry. Clinical PEDV infection is associated with severe intestinal lesions, resulting in absorptive dysfunction and high mortality rates in suckling piglets. The extracellular matrix (ECM) is an important component of intestinal tissue, providing a structural framework and conveying tissue-specific signals to nearby enterocytes. In this study, we investigated the extensive ECM remodeling observed in intestinal epithelial cells infected with PEDV and elucidated the associated activated ECM receptor-related pathways. Protein-protein interaction network analysis revealed two significantly differentially expressed genes (cluster of differentiation 44 [CD44] and serpin family E member 1 [SERPINE1]) associated with the ECM. At the transcriptional level, both genes exhibited significant positive correlation with the extent of PEDV replication. Similarly, the expression of CD44 and PAI-1 (encoded by SERPINE1) was also increased in the intestines of piglets during viral infection. Furthermore, CD44 exhibited antiviral activity by enhancing the expression of antiviral cytokines (e.g., interleukin [IL]-6, IL-18, IL-11, and antimicrobial peptide beta-defensin 1) by activating nuclear factor-κB signaling. Conversely, PAI-1 was found to promote the release of progeny virions during PEDV infection, despite a decreased intracellular viral load. Nevertheless, the underlying mechanisms are still unclear. Taken together, our results highlighted the biological roles of specific ECM-regulated genes, i.e., CD44 and SERPINE1 in suppressing and promoting PEDV infection, thereby providing a theoretical foundation for the role of the ECM in intestinal infections and identifying potential therapeutic targets for PEDV.

Efficacy and tolerability of certolizumab pegol in Crohn's disease in clinical practice

AIM

To assess the efficacy and tolerance of certolizumab pegol (CP) in patients with Crohn's disease (CD) treated in the Department of inflammatory bowel diseases of the A.S. Loginov Moscow Clinical Research Center and to determine the predictors of response to therapy.

MATERIALS AND METHODS

All patients with CD who had received the treatment of CP were observed prospectively for at least 6 months or until the date of discontinuation of the drug. The effectiveness of the study was assessed response to therapy by the 6th week, maintaining the clinical response (6th and 26th weeks), the dynamics of endoscopic parameters by the 10th and 54th week of therapy, long-term maintenance of remission, healing fistula. Used univariant and multivariate analyses of predictors of response to treatment.

RESULTS

The study included 39 patients: 12 (30.7%) men and 27 (69.3%) female, the average duration of observation was 104 weeks. The interdepartmental range was in the range from 28 to 158 weeks. Clinical improvement occurred in 38 out of 39 (97.4 %) patients with CD. Comparative analysis of response to treatment with CP have bionaive patients previously treated with another inhibitor of TNF-α. In the group of bionaive response to therapy in a month, 6 months and at the end of the observation period occurred at 100.0%, 95.0% and 95.0%, respectively. In the group of patients previously treated with GSI, the response rate was about 94.4 %, 88.9 % and 77.7% week 54 endoscopic response and endoscopic remission was maintained in 46,2% and 30,1% patients, complete healing of the mucosa on the background of maintenance therapy, CP, was preserved in 20.5% of patients with Crohn's disease. In the group of patients with perianal lesions (n=13) complete closure of all fistulas was observed in 5 (38.6 %) patients, partial response was observed in 4 patients (30,7%) patients, in 4 (30.7 %) closure of fistulas occurred. The frequency of adverse events was 0 cases (0.0%). The dose escalation was required in 3 patients (7,7%) patients with CD. Dose escalation in our study required patients with high initial CDAI and previous inefficiencies of the other two inhibitors of TNF-α. Reliable predictors of secondary loss of response and need for dose escalation of the drug has been the continued level of CRP >5 mg/l after 2 weeks initiation of therapy CP and smoking.

CONCLUSION

The obtained results demonstrate the efficacy and tolerability profile of CP appropriate for long-term CD therapy in real clinical practice.

[Efficacy of adalimumab for Crohn's disease in real clinical practice]

AIM

To evaluate the efficacy and safety of adalimumab (ADA) in patients with Crohn's disease (CD) treated at the Department of Inflammatory Bowel Diseases, Moscow Clinical Research and Practical Center, and to determine the predictors of a therapy response.

SUBJECTS AND METHODS

All the patients with CD treated with ADA were followed up for at least 6 months or until the drug was discontinued. Therapeutic effectiveness was evaluated at 4 weeks and 6 months after the initiation of treatment and at the end of a follow-up. Complete intestinal mucosal healing was assessed at 3 and 12 months following treatment initiation. Univariate and multivariate analyses were used to determine the predictors of treatment response.

RESULTS

A clinical analysis covered 70 patients (57.1% male); the follow-up period averaged 112 weeks. Perianal fistulas were at baseline established in 22 (31.4%) patients with CD. 12 (17.4%) patients had been previously treated with infliximab (INF), 7 of them discontinued the drug for secondary loss of response and 5 for adverse reactions. 68 (97.1%) patients responded to an induction course of ADA. At 4 weeks, 6 months, and at the end of the follow-up, clinical remission occurred in 66.7, 80.4 and 67.4 % of patients with luminal CD and in 45.4, 36.5, and 36.4% of those with perianal CD, respectively. At 3 and 12 months and at the end of the follow-up, there was complete healing of the intestinal mucosa in 23.5, and 41.2 and 29.5% of cases, respectively. Six (8.8%) patients responding to the induction course needed to be optimized with ADA to 40 mg weekly. The time interval between treatment initiation and dose optimization averaged 30 weeks (range 12-120 months). There were 15 (21,4%) adverse events that were responsible for ADA discontinuation in 3 (4,2%) patients.

CONCLUSION

The findings demonstrate the efficacy and safety of ADA used in clinical practice.

New paradigms in chronic intestinal inflammation and colon cancer: role of melatonin

In intestinal bowel disease (IBD), immune-mediated conditions exert their effects through various cells and proinflammatory mediators. Recent data support a participation of the endoplasmic reticulum stress and mitochondrial dysfunctions in IBD. Moreover, it is evident that chronic degenerative pathologies, including IBD, share comparable disease mechanisms with alteration in the autophagy mechanisms. Chronic inflammation in IBD exposes these patients to a number of signals known to have tumorigenic effects. This circuitry of inflammation and cancer modifies apoptosis and autophagy, and promotes cellular cycle progression, invasion, and angiogenesis. Melatonin has been shown as a specific antioxidant reducing oxidative damage in both lipid and aqueous cell environments. However, several studies provide further insight into the molecular mechanisms of melatonin action in the colon. In this line, recent data suggest that melatonin modulates autophagy and sirtuin activity. An anti-autophagic property of melatonin has been demonstrated, and it could contribute to its anti-oncogenic activity. Nevertheless, there is no information about whether antitumoral effects of melatonin on colon cancer are dependent on autophagy. Sirtuins have pleiotropic effects on cancer development, being reported both as facilitator and as suppressor of colon cancer development. Sirtuins and melatonin are connected through the circadian clock machinery, and melatonin seems able to correct the alterations in sirtuin activity associated with several pathological conditions. Autophagy and sirtuin activities are linked through 5'AMP-activated protein kinase (AMPK) activation, which switches on autophagy and increases sirtuin. The effect of melatonin on AMPK and the impact of this effect on IBD and colon cancer remain an open question.

Qingdai Granules up-regulate MUC2 mRNA expression but down-regulate iNOS mRNA expression in the colonic mucosa of rats with ulcerative colitis

AIM: To investigate the effects of Qingdai Granules (QDG) on the expression of mucin 2 (MUC2) and inducible nitric oxide synthase (iNOS) mRNAs in the colonic mucosa of rats with ulcerative colitis.

METHODS: Ulcerative colitis was induced in rats by giving an enema of trinitrobenzene sulphonic acid (TNBS) and ethanol. The experimental animals were randomly divided into six groups: normal group, model group, sulfasalazine (SASP) group (500 mg/kg), and low-, medium- and high-dose QDG groups (600, 900 and 1 200 mg/kg). Except the normal group, the other groups were given intragastrically normal saline, SASP, and different concentrations of QDG, respectively, from day 3 after model establishment for 10 d. On day 14, rats were killed to evaluate disease activity index (DAI) and colon mucosa damage index (CMDI). The expression of MUC2 and iNOS mRNAs in the colonic mucosa of rats was detected by reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS: Compared with the model group, the DAI and CMDI in the medium- and high-dose QDG groups significantly decreased, the expression of MUC2 mRNA in the colon of rats in the medium- and high-dose QDG groups was significantly up-regulated (2.06 ± 0.70 vs 1.24 ± 0.47 and 2.34 ± 0.86 vs 1.24 ± 0.47; both P < 0.01), and the expression of iNOS mRNA in the high-dose QDG group was significantly down-regulated (0.35 ± 0.12 vs 0.62 ± 0.31, P < 0.05).

CONCLUSION: QDG can exert protective effects against rat ulcerative colitis perhaps by up-regulating MUC2 mRNA expression and down-regulating iNOS mRNA expression.

Microbial host interactions in IBD: implications for pathogenesis and therapy

Crohn's disease (CD), ulcerative colitis (UC), and pouchitis appear to be caused by pathogenic T-cell responses to discrete antigens from the complex luminal microbiota, with susceptibility conferred by genetic polymorphisms that regulate bacterial killing, mucosal barrier function, or immune responses. Environmental triggers initiate or reactivate inflammation and modulate genetic susceptibility. New pathogenesis concepts include defective bacterial killing by innate immune cells in CD, colonization of the ileum in CD with functionally abnormal Escherichia coli that adhere to and invade epithelial cells and resist bacterial killing, and alterations in enteric microbiota composition in CD, UC, and pouchitis detected by molecular probes. The considerable therapeutic potential of manipulating the enteric microbiota in inflammatory bowel disease patients has not been realized, probably due to failure to recognize heterogenic disease mechanisms that require individualized use of antibiotics, probiotics, prebiotics, combination therapies, and genetically engineered bacteria to restore mucosal homeostasis.

Mechanisms of disease: pathogenesis of Crohn's disease and ulcerative colitis

Crohn's disease and ulcerative colitis are idiopathic, chronic, relapsing, inflammatory conditions that are immunologically mediated. Although their exact etiologies remain uncertain, results from research in animal models, human genetics, basic science and clinical trials have provided important new insights into the pathogenesis of chronic, immune-mediated, intestinal inflammation. These studies indicate that Crohn's disease and ulcerative colitis are heterogeneous diseases characterized by various genetic abnormalities that lead to overly aggressive T-cell responses to a subset of commensal enteric bacteria. The onset and reactivation of disease are triggered by environmental factors that transiently break the mucosal barrier, stimulate immune responses or alter the balance between beneficial and pathogenic enteric bacteria. Different genetic abnormalities can lead to similar disease phenotypes; these genetic changes can be broadly characterized as causing defects in mucosal barrier function, immunoregulation or bacterial clearance. These new insights will help develop better diagnostic approaches that identify clinically important subsets of patients for whom the natural history of disease and response to treatment are predictable.

Adoptive transfer of nontransgenic mesenteric lymph node cells induces colitis in athymic HLA-B27 transgenic nude rats

HLA-B27 transgenic (TG) rats develop spontaneous colitis when colonized with intestinal bacteria, whereas athymic nude (rnu/rnu) HLA-B27 TG rats remain disease free. The present study was designed to determine whether or not HLA-B27 expression on T cells is required for development of colitis after transfer of mesenteric lymph node (MLN) cells into rnu/rnu HLA-B27 recipients. Athymic nontransgenic (non-TG) and HLA-B27 TG recipients received MLN cells from either TG or non-TG rnu/+ heterozygous donor rats that contain T cells. HLA-B27 TG rnu/rnu recipients receiving either non-TG or TG MLN cells developed severe colitis and had higher caecal MPO and IL-1beta levels, and their MLN cells produced more IFN-gamma and less IL-10 after in vitro stimulation with caecal bacterial lysate compared to rnu/rnu non-TG recipients that remained disease free after receiving either TG or non-TG cells. Interestingly, proliferating donor TG T cells were detectable one week after adoptive transfer into rnu/rnu TG recipients but not after transfer into non-TG recipients. T cells from either non-TG or TG donors induce colitis in rnu/rnu TG but not in non-TG rats, suggesting that activation of effector T cells by other cell types that express HLA-B27 is pivotal for the pathogenesis of colitis in this model.