MiRNAs and inflammatory bowel disease: An interesting new story

Research progress of ferroptosis and inflammatory bowel disease

Inflammatory bowel disease (IBD) is a non-specific chronic inflammatory disorder of the gastrointestinal tract, imposing significant burdens on both society and individuals. As a new type of regulated cell death (RCD), ferroptosis is different from classic RCDs such as apoptosis and necrosis in cell morphology, biochemistry and genetics. The main molecular mechanisms of ferroptosis include dysregulation of iron metabolism, impaired antioxidant capacity, mitochondrial dysfunction, accumulation of lipid-associated super-oxides, and membrane disruption. In recent years, increasing evidence has shown that ferroptosis is involved in the pathophysiology of inflammatory bowel disease. However, the exact roles and underlying molecular mechanisms have not been fully elucidated. This article reviews the mechanism of ferroptosis in the occurrence and development of inflammatory bowel disease, in order to provide new ideas for the pathophysiological research of inflammatory bowel disease. Additionally, we discuss potential strategies for the prevention and treatment of inflammatory bowel disease by targeting ferroptosis.

MicroRNAs in inflammatory bowel disease: What do we know and what can we expect?

MicroRNAs (miRNAs), small non-coding RNAs composed of 18-24 nucleotides, are potent regulators of gene expression, contributing to the regulation of more than 30% of protein-coding genes. Considering that miRNAs are regulators of inflammatory pathways and the differentiation of intestinal epithelial cells, there is an interest in exploring their importance in inflammatory bowel disease (IBD). IBD is a chronic and multifactorial disease of the gastrointestinal tract; the main forms are Crohn's disease and ulcerative colitis. Several studies have investigated the dysregulated expression of miRNAs in IBD, demonstrating their important roles as regulators and potential biomarkers of this disease. This editorial presents what is known and what is expected regarding miRNAs in IBD. Although the important regulatory roles of miRNAs in IBD are clearly established, biomarkers for IBD that can be applied in clinical practice are lacking, emphasizing the importance of further studies. Discoveries regarding the influence of miRNAs on the inflammatory process and the exploration of their role in gene regulation are expected to provide a basis for the use of miRNAs not only as potent biomarkers in IBD but also as therapeutic targets for the control of inflammatory processes in personalized medicine.

Therapeutic applications of melatonin in disorders related to the gastrointestinal tract and control of appetite

Most animals have large amounts of the special substance melatonin, which is controlled by the light/dark cycle in the suprachiasmatic nucleus. According to what is now understood, the gastrointestinal tract (GIT) and other areas of the body are sites of melatonin production. According to recent studies, the GIT and adjacent organs depend critically on a massive amount of melatonin. Not unexpectedly, melatonin's many biological properties, such as its antioxidant, anti-inflammatory, pro-apoptotic, anti-proliferative, anti-metastasis, and antiangiogenic properties, have drawn the attention of researchers more and more. Because melatonin is an antioxidant, it produces a lot of secretions in the GIT's mucus and saliva, which shields cells from damage and promotes the development of certain GIT-related disorders. Melatonin's ability to alter cellular behavior in the GIT and other associated organs, such as the liver and pancreas, is another way that it functions. This behavior alters the secretory and metabolic activities of these cells. In this review, we attempted to shed fresh light on the many roles that melatonin plays in the various regions of the gastrointestinal tract by focusing on its activities for the first time.

microRNA-mRNA Networks Linked to Inflammation and Immune System Regulation in Inflammatory Bowel Disease

The molecular processes linked to the development and progression of Crohn's disease (CD) and ulcerative colitis (UC) are not completely understood. MicroRNAs (miRNAs) regulate gene expression and are indicated as diagnostic, prognostic, and predictive biomarkers in chronic degenerative diseases. Our objectives included the identification of global miRNA expression in CD and UC, as well as miRNA target genes, miRNA-mRNA interaction networks, and biological functions associated with these different forms of inflammatory bowel disease (IBD).

METHODS

By performing a comprehensive meta-analysis, we integrated miRNA expression data from nine studies in IBD. We obtained detailed information on significantly deregulated miRNAs (fold change, FC ≥ 2 and p < 0.05), sample type and number, and platform applied for analysis in the training and validation sets. Further bioinformatic analyses were performed to identify miRNA target genes, by using the microRNA Data Integration Portal tool. We also sought to identify statistically enriched pathways of genes regulated by miRNAs using ToppGene Suite. Additional analyses were performed to filter for genes expressed in intestinal tissue using the European Bioinformatics Institute (EBI) database.

RESULTS

Our findings showed the upregulation of 15 miRNAs in CD and 33 in UC. Conversely, six miRNAs were downregulated in CD, while seven were downregulated in UC. These results indicate a greater deregulation of miRNAs in UC compared to CD. Of note, miRNA target genes were enriched for immune system regulation pathways. Among significantly deregulated miRNAs with a higher number of miRNA-target gene interactions, we identified miR-199a-5p and miR-362-3p altered in CD, while among UC case patients, miRNA-target gene interactions were higher for miR-155-5p.

CONCLUSIONS

The identified miRNAs play roles in regulating genes associated with immune system regulation and inflammation in IBD. Such miRNAs and their target genes have the potential to serve as clinically relevant biomarkers. These findings hold promise for enhancing the accuracy of diagnoses and facilitating the development of personalized treatment strategies for individuals with various forms of IBD.

Overcoming cancer risk in inflammatory bowel disease: new insights into preventive strategies and pathogenesis mechanisms including interactions of immune cells, cancer signaling pathways, and gut microbiota

Inflammatory bowel disease (IBD), characterized primarily by gastrointestinal inflammation, predominantly manifests as Crohn's disease (CD) and ulcerative colitis (UC). It is acknowledged that Inflammation plays a significant role in cancer development and patients with IBD have an increased risk of various cancers. The progression from inflammation to carcinogenesis in IBD is a result of the interplay between immune cells, gut microbiota, and carcinogenic signaling pathways in epithelial cells. Long-term chronic inflammation can lead to the accumulation of mutations in epithelial cells and the abnormal activation of carcinogenic signaling pathways. Furthermore, Immune cells play a pivotal role in both the acute and chronic phases of IBD, contributing to the transformation from inflammation to tumorigenesis. And patients with IBD frequently exhibit dysbiosis of the intestinal microbiome. Disruption of the gut microbiota and subsequent immune dysregulation are central to the pathogenesis of both IBD and colitis associated colorectal cancer (CAC). The proactive management of inflammation combined with regular endoscopic and tumor screenings represents the most direct and effective strategy to prevent the IBD-associated cancer.

Differential expression of serum miR-486 and miR-25 in ulcerative colitis and Crohn's disease: Correlations with disease activity, extent, and location

Novel reliable biomarkers of inflammatory bowel disease (IBD) are clinically imperative due to potential limitations of endoscopic techniques. MicroRNAs (miRNAs) have emerged as non-invasive biomarkers of IBD; however, the full disease-specific miRNAs signature for IBD subtypes remains elusive. We evaluated the diagnostic role of circulating miR-486 and miR-25 in IBD patients and their potential ability to discriminate IBD subtypes; ulcerative colitis (UC) and Crohn's disease (CD). Sixty UC patients, 60 CD patients, and 60 healthy controls were recruited. Serum miRNA expression was determined using RT-qPCR. Bioinformatics was employed for target gene and protein-protein interaction (PPI) network analyses. Serum miR-486 was upregulated in CD patients, but didn't change in UC patients compared to controls. Conversely, serum miR-25 was decreased in both CD and UC patients compared to controls. Only miR-486 was differentially expressed between UC and CD patients. Receiver-operating characteristic analysis revealed that serum miR-486 was superior in CD diagnosis (AUC=0.945) and significantly distinguished CD and UC patients, whereas miR-25 showed discriminative potential for both UC and CD from controls. In the multivariate logistic analysis only miR-486 was associated with the risk of CD diagnosis. Serum miR-486 was correlated with CD activity index and location of disease in CD patients, whereas miR-25 was correlated with the type/extent of UC. PPI network analysis revealed common target genes and signaling pathways for both miRNAs. Conclusively, serum miR-486 and miR-25 might serve as new biomarkers of IBD, with serum miR-486 could be employed in risk stratification of IBD subtypes and has the ground for clinical utility in CD diagnosis, whereas miR-25 has potential for UC and CD diagnosis.

Exploring the theranostic potentials of miRNA and epigenetic networks in autoimmune diseases: A comprehensive review

BACKGROUND

Autoimmune diseases (AD) are severe pathophysiological ailments that are stimulated by an exaggerated immunogenic response towards self-antigens, which can cause systemic or site-specific organ damage. An array of complex genetic and epigenetic facets majorly contributes to the progression of AD, thus providing significant insight into the regulatory mechanism of microRNA (miRNA). miRNAs are short, non-coding RNAs that have been identified as essential contributors to the post-transcriptional regulation of host genome expression and as crucial regulators of a myriad of biological processes such as immune homeostasis, T helper cell differentiation, central and peripheral tolerance, and immune cell development.

AIMS

This article tends to deliberate and conceptualize the brief pathogenesis and pertinent epigenetic regulatory mechanism as well as miRNA networks majorly affecting five different ADs namely rheumatoid arthritis (RA), type 1 diabetes, multiple sclerosis (MS), systemic lupus erythematosus (SLE) and inflammatory bowel disorder (IBD) thereby providing novel miRNA-based theranostic interventions.

RESULTS & DISCUSSION

Pertaining to the differential expression of miRNA attributed in target tissues and cellular bodies of innate and adaptive immunity, a paradigm of scientific expeditions suggests an optimistic correlation between immunogenic dysfunction and miRNA alterations.

CONCLUSION

Therefore, it is not astonishing that dysregulations in miRNA expression patterns are now recognized in a wide spectrum of disorders, establishing themselves as potential biomarkers and therapeutic targets. Owing to its theranostic potencies, miRNA targets have been widely utilized in the development of biosensors and other therapeutic molecules originating from the same.

Systematic analysis and characterization of long non-coding RNA genes in inflammatory bowel disease

The cases of inflammatory bowel disease (IBD) are increasing rapidly around the world. Due to the multifactorial causes of IBD, there is an urgent need to understand the pathogenesis of IBD. As such, the usage of high-throughput techniques to profile genetic mutations, microbiome environments, transcriptome and proteome (e.g. lipidome) is increasing to understand the molecular changes associated with IBD, including two major etiologies of IBD: Crohn disease (CD) and ulcerative colitis (UC). In the case of transcriptome data, RNA sequencing (RNA-seq) technique is used frequently. However, only protein-coding genes are analyzed, leaving behind all other RNAs, including non-coding RNAs (ncRNAs) to be unexplored. Among these ncRNAs, long non-coding RNAs (lncRNAs) may hold keys to understand the pathogenesis of IBD as lncRNAs are expressed in a cell/tissue-specific manner and dysregulated in a disease, such as IBD. However, it is rare that RNA-seq data are analyzed for lncRNAs. To fill this gap in knowledge, we re-analyzed RNA-seq data of CD and UC patients compared with the healthy donors to dissect the expression profiles of lncRNA genes. As inflammation plays key roles in the pathogenesis of IBD, we conducted loss-of-function experiments to provide functional data of IBD-specific lncRNA, lung cancer associated transcript 1 (LUCAT1), in an in vitro model of macrophage polarization. To further facilitate the lncRNA research in IBD, we built a web database, IBDB (https://ibd-db.shinyapps.io/IBDB/), to provide a one-stop-shop for expression profiling of protein-coding and lncRNA genes in IBD patients compared with healthy donors.

MicroRNA-based therapeutics for inflammatory disorders of the microbiota-gut-brain axis

An emerging but less explored shared pathophysiology across microbiota-gut-brain axis disorders is aberrant miRNA expression, which may represent novel therapeutic targets. miRNAs are small, endogenous non-coding RNAs that are important transcriptional repressors of gene expression. Most importantly, they regulate the integrity of the intestinal epithelial and blood-brain barriers and serve as an important communication channel between the gut microbiome and the host. A well-defined understanding of the mode of action, therapeutic strategies and delivery mechanisms of miRNAs is pivotal in translating the clinical applications of miRNA-based therapeutics. Accumulating evidence links disorders of the microbiota-gut-brain axis with a compromised gut-blood-brain-barrier, causing gut contents such as immune cells and microbiota to enter the bloodstream leading to low-grade systemic inflammation. This has the potential to affect all organs, including the brain, causing central inflammation and the development of neurodegenerative and neuropsychiatric diseases. In this review, we have examined in detail miRNA biogenesis, strategies for therapeutic application, delivery mechanisms, as well as their pathophysiology and clinical applications in inflammatory gut-brain disorders. The research data in this review was drawn from the following databases: PubMed, Google Scholar, and Clinicaltrials.gov. With increasing evidence of the pathophysiological importance for miRNAs in microbiota-gut-brain axis disorders, therapeutic targeting of cross-regulated miRNAs in these disorders displays potentially transformative and translational potential. Further preclinical research and human clinical trials are required to further advance this area of research.

MicroRNAs and Periodontal Disease: Helpful Therapeutic Targets?

Periodontal disease is the most common oral disease. This disease can be considered as an inflammatory disease. The immune response to bacteria accumulated in the gum line plays a key role in the pathogenesis of periodontal disease. In addition to immune cells, periodontal ligament cells and gingival epithelial cells are also involved in the pathogenesis of this disease. miRNAs which are small RNA molecules with around 22 nucleotides have a considerable relationship with the immune system affecting a wide range of immunological events. These small molecules are also in relation with periodontium tissues especially periodontal ligament cells. Extensive studies have been performed in recent years on the role of miRNAs in the pathogenesis of periodontal disease. In this review paper, we have reviewed the results of these studies and discussed the role of miRNAs in the immunopathogenesis of periodontal disease comprehensively. miRNAs play an important role in the pathogenesis of periodontal disease and maybe helpful therapeutic targets for the treatment of periodontal disease.

Intestinal Microbiota and miRNA in IBD: A Narrative Review about Discoveries and Perspectives for the Future

Inflammatory bowel disease (IBD) includes Crohn's disease (CD) and ulcerative colitis (UC) and comprises a chronic gastrointestinal tract disorder characterized by hyperactive and dysregulated immune responses to environmental factors, including gut microbiota and dietary components. An imbalance of the intestinal microbiota may contribute to the development and/or worsening of the inflammatory process. MicroRNAs (miRNAs) have been associated with various physiological processes, such as cell development and proliferation, apoptosis, and cancer. In addition, they play an important role in inflammatory processes, acting in the regulation of pro- and anti-inflammatory pathways. Differences in the profiles of miRNAs may represent a useful tool in the diagnosis of UC and CD and as a prognostic marker in both diseases. The relationship between miRNAs and the intestinal microbiota is not completely elucidated, but recently this topic has gained prominence and has become the target of several studies that demonstrate the role of miRNAs in the modulation of the intestinal microbiota and induction of dysbiosis; the microbiota, in turn, can regulate the expression of miRNAs and, consequently, alter the intestinal homeostasis. Therefore, this review aims to describe the interaction between the intestinal microbiota and miRNAs in IBD, recent discoveries, and perspectives for the future.

Bovine milk-derived extracellular vesicles prevent gut inflammation by regulating lipid and amino acid metabolism

Inflammatory bowel disease (IBD) is a global health problem in which metabolite alteration plays an important pathogenic role. Bovine milk-derived extracellular vesicles (mEVs) have been shown to regulate nutrient metabolism in healthy animal models. This study investigated the effect of oral mEVs on metabolite changes in DSS-induced murine colitis. We performed metabolomic profiling on plasma samples and measured the concentrations of lipids and amino acids in both fecal samples and colonic tissues. Plasma metabolome analysis found that mEVs significantly upregulated 148 metabolite levels and downregulated 44 metabolite concentrations (VIP > 1, and p < 0.05). In the fecal samples, mEVs significantly increased the contents of acetate and butyrate and decreased the levels of tridecanoic acid (C13:0), methyl cis-10-pentadecenoate (C15:1) and cis-11-eicosenoic acid (C20:1). Moreover, the concentrations of eicosadienoic acid (C20:2), eicosapentaenoic acid (C20:5), and docosahexaenoic acid (C22:6) were decreased in colonic tissues with mEV supplementation. In addition, compared with the DSS group, mEVs significantly increased the content of L-arginine, decreased the level of L-valine in the fecal samples, and also decreased the levels of L-serine and L-glutamate in the colonic tissues. Collectively, our findings demonstrated that mEVs could recover the metabolic abnormalities caused by inflammation and provided novel insights into mEVs as a potential modulator for metabolites to prevent and treat IBD.

Interactions of melatonin with various signaling pathways: implications for cancer therapy

Melatonin is a neuro-hormone with conserved roles in evolution. Initially synthetized as an antioxidant molecule, it has gained prominence as a key molecule in the regulation of the circadian rhythm. Melatonin exerts its effect by binding to cytoplasmic and intra-nuclear receptors, and is able to regulate the expression of key mediators of different signaling pathways. This ability has led scholars to investigate the role of melatonin in reversing the process of carcinogenesis, a process in which many signaling pathways are involved, and regulating these pathways may be of clinical significance. In this review, the role of melatonin in regulating multiple signaling pathways with important roles in cancer progression is discussed, and evidence regarding the beneficence of targeting malignancies with this approach is presented.

Melatonin and inflammatory bowel disease: From basic mechanisms to clinical application

Inflammatory bowel disease is a chronic inflammatory disease and has periods of recurrence and remission. Improper immune responses to gut flora bacteria, along with genetic susceptibility, appear to be involved in causing this complex disease. It seems dysbiosis and oxidative stress may also be involved in IBD pathogenesis. A significant number of clinical studies have shown an interesting association between sleep disturbances and IBD. Studies in animal models have also shown that sleep deprivation has a significant effect on the pathogenesis of IBD and can aggravate inflammation. These interesting findings have drawn attention to melatonin, a sleep-related hormone. Melatonin is mainly produced by the pineal gland, but many tissues in the body, including the intestines, can produce it. Melatonin can have an interesting effect on the pathogenesis of IBD. Melatonin can enhance the intestinal mucosal barrier, alter the composition of intestinal bacteria in favor of bacteria with anti-inflammatory properties, regulate the immune response, alleviate inflammation and attenuate oxidative stress. It seems that, melatonin supplementation is effective in relieving inflammation and healing intestinal ulcers in IBD animal models. Some clinical studies have also shown that melatonin supplementation as an adjuvant therapy may be helpful in reducing disease activity in IBD patients. In this review article, in addition to reviewing the effects of sleep disturbances and melatonin on key mechanisms involved in the pathogenesis of IBD, we will review the findings of clinical studies regarding the effects of melatonin supplementation on IBD treatment.

Cancer Immunotherapy: The Checkpoint between Chronic Colitis and Colorectal Cancer

Inflammatory Bowel Disease (IBD) is a group of diseases that cause intestinal inflammation and lesions because of an abnormal immune response to host gut microflora. Corticosteroids, anti-inflammatories, and antibiotics are often used to reduce non-specific inflammation and relapse rates; however, such treatments are ineffective over time. Patients with chronic colitis are more susceptible to developing colorectal cancer, especially those with a longer duration of colitis. There is often a limit in using chemotherapy due to side effects, leading to reduced efficacy, leaving an urgent need to improve treatments and identify new therapeutic targets. Cancer immunotherapy has made significant advances in recent years and is mainly categorized as cancer vaccines, adoptive cellular immunotherapy, or immune checkpoint blockade therapies. Checkpoint markers are expressed on cancer cells to evade the immune system, and as a result checkpoint inhibitors have transformed cancer treatment in the last 5-10 years. Immune checkpoint inhibitors have produced long-lasting clinical responses in both single and combination therapies. Winnie mice are a viable model of spontaneous chronic colitis with immune responses like human IBD. Determining the expression levels of checkpoint markers in tissues from these mice will provide insights into disease initiation, progression, and cancer. Such information will lead to identification of novel checkpoint markers and the development of treatments with or without immune checkpoint inhibitors or vaccines to slow or stop disease progression.

Polyphenols and inflammatory bowel disease: Natural products with therapeutic effects?

Inflammatory bowel disease (IBD) is a long-life disease with periods of recurrence and relief. Oxidative stress plays an important role in the pathogenesis of this disease. Recent years' studies in the field of IBD treatment mostly have focused on targeting cytokines and immune cell trafficking using antibodies and inhibitors, altering the composition of intestinal bacteria in the line of attenuation of inflammation using probiotics and prebiotics, and attenuating oxidative stress through antioxidant supplementation. Studies in animal models of IBD have shown that some polyphenolic compounds including curcumin, quercetin, resveratrol, naringenin, and epigallocatechin-3-gallate can affect almost all of the above aspects and are useful compounds in the treatment of IBD. Clinical studies performed on IBD patients have also confirmed the findings of animal model studies and have shown that supplementation with some of the above-mentioned polyphenolic compounds has positive effects in reducing disease clinical and endoscopic activity, inducing and maintaining remission, and improving quality of life. In this review article, in addition to a detailed reviewing the effects of the above-mentioned polyphenolic compounds on the events involved in the pathogenesis of IBD, the results of these clinical studies will also be reviewed.

MicroRNA-16 inhibits the TLR4/NF-κB pathway and maintains tight junction integrity in irritable bowel syndrome with diarrhea

Irritable bowel syndrome with diarrhea (IBS-D) is a chronic and relapsing inflammatory disorder in which pathogenesis has been shown to be in part the result of miRNA-mediated signaling. Here, we investigated the alleviatory role of miR-16 in IBS-D. First, we established an IBS-D mouse model using colonic instillation of acetic acid and developed an IBS-D cell model using lipopolysaccharide exposure. The experimental data demonstrated that miR-16 was underexpressed in the serum of IBS-D patients, as well as in the colorectal tissues of IBS-D mouse models and lipopolysaccharide-exposed intestinal epithelial cells. Next, miR-16 and TLR4 were overexpressed or inhibited to characterize their roles in the viability and apoptosis of intestinal epithelial cells, inflammation, and epithelial tight junction. We found that miR-16 overexpression increased the viability of intestinal epithelial cells, maintained tight junction integrity, and inhibited cell apoptosis and inflammation. We showed that miR-16 targeted TLR4 and inhibited the TLR4/NF-κB signaling pathway. Additionally, inhibition of NF-κB suppressed the long noncoding RNA XIST, thereby promoting enterocyte viability, inhibiting apoptosis and cytokine production, and maintaining tight junction integrity. In vivo experiments further verified the alleviatory effect of miR-16 on IBS-D symptoms in mice. Taken together, we conclude that miR-16 downregulates XIST through the TLR4/NF-κB pathway, thereby relieving IBS-D. This study suggests that miR-16 may represent a potential target for therapeutic intervention against IBS-D.

A mean platelet volume in inflammatory bowel disease: A systematic review and meta-analysis

Background

Inflammatory bowel disease (IBD) is a chronic gastrointestinal tract inflammatory state, which is affecting millions of individuals in the world. It can affect alimentary canals such as colon, rectum, ileum and other parts. In IBD, platelet parameters underwent several changes. Therefore, the aim of this review was determining the estimated pooled mean platelet volume and mean difference in inflammatory bowel disease to elucidate its potential diagnostic value.

Methods

Articles were extensively searched in bibliographic databases using Medical Subject Heading and entry phrases or terms. In addition, articles were directly searched in Google Scholar to account for the studies omission in searching bibliographic databases. Observational (cohort, cross-sectional and case-control) studies, published in English language and conducted on IBD were included. For studies meeting the eligibility criteria, the first author’s name, publication year, population, study design, study area, sample size, mean platelet volume and standard deviation were extracted and entered in to Microsoft-excel. The analysis was done by Stata version 11. In order to estimate the pooled mean platelet volume and mean difference, random effect model was done. The heterogeneity was quantified using Higgin’s I² statistics. Publication bias was determined using Egger’s test statistics and funnel plot. Sub-group analysis based on population carried to reduce heterogeneity.

Results

A total of 17 relevant articles with 2957 participants (1823 IBD cases and 1134 healthy controls) were included to this study. The pooled estimated MPV was 9.29fl; 95% CI: 9.01–9.57 and 9.50fl; 95% CI: 8.81–10.20 in IBD and control groups, respectively. The standardized pooled estimate of mean difference in mean platelet volume was -0.83fl; 95% CI: -1.15, -0.51; I²: 93.1%; P-value < 0.001. In subgroup analysis based on population, the highest estimated mean difference in MPV was observed among patients of CD; -2.30; 95% CI: -3.46, -1.14; I²: 97.8%; P-value < 0.001.

Conclusion

According to the current systematic review and meta-analysis, mean platelet volume was lower in IBD compared to control. The decreased mean platelet volume could be attributed to platelet consumption or sequestration associated with the progression of IBD. As a result, in IBD, mean platelet volume can provide diagnostic and prognostic information.

Mesenchymal Stem Cells for the Treatment of Acetic Acid-Induced Ulcerative Colitis in Rats

Background: Ulcerative colitis (UC) is an autoimmune inflammatory bowel disease, characterized by chronic and relapsing inflammation of the intestinal mucosa. Clinical treatments fail to reduce inflammation and induce side effects in nearly 30% of patients. Mesenchymal stem cells (MSCs) are immunomodulatory agents that can encourage tissue repair and regeneration. Aim: To investigate the ability of MSCs to differentiate into enterocytes under the mediation of activin a, fibroblastic growth factor 2, and epidermal growth factors and to study the effect of administering MSCs to rats with acetic acid (AA)-induced UC. Methods: MSCs isolated from the umbilical cord were induced to differentiate into enterocytes. The induced cells were morphologically evaluated by flow cytometry and immunocytochemistry. Forty rats were divided into four groups: control, AA-induced UC, differentiated, and undifferentiated MSC treated groups. The acute UC in rats was induced by 3% AA transrectal administration. Body weight changes, disease activity index (DAI), and histopathological and immunohistochemical CD105 and CD34 staining were recorded. IL-17, IL-10, and TGF- β levels were measured as well. Results: In Both differentiated and undifferentiated MSCs, induced MSCs improved the DAI score and significantly recovered the pathological changes. The favorable effect of MSCs was significantly linked to CD105 overexpression and CD34 low expression. IL-10 and TGF-β levels increased while IL-17 levels decreased. Conclusion: Both differentiated and undifferentiated MSCs showed anti-inflammatory and immunomodulatory effects in our study. Based on our results, MSCs could become potentially useful for regenerative medicine and the clinical treatment of UC.

Exercise and colorectal cancer: prevention and molecular mechanisms

Exercise and physical activity have been shown to be strongly associated with a decreased incidence rate of various chronic diseases especially numerous human malignancies. A huge number of clinical trials and meta-analysis have demonstrated that exercise is significantly effective in lowering the risk of colorectal cancer. In addition, it is suggested as an effective therapeutic modality against this cancer type. Therefore, in this review, we will review comprehensibly the effects of exercise in preventing, treating, and alleviating the adverse effects of conventional therapeutic options in colorectal cancer. Moreover, the possible mechanisms underlying the positive effects of exercise and physical activity in colorectal cancer, including regulation of inflammation, apoptosis, growth factor axis, immunity, epigenetic, etc. will be also discussed.

Exercise is an effective post-treatment management program in colorectal cancer survivals

Exercise improves muscle strength, cardiorespiratory fitness, emotional distress, physical activity, fatigue, and sleep quality in colorectal patients undergoing chemotherapy

Targeting and modulating insulin-like growth factor (IGF) system, inflammation, apoptosis, immunity, epigenetic, Leptin and Ghrelin, and signaling pathways are major underlying mechanisms for preventive effects of exercise in colorectal cancer

Renshen Baidu Powder Attenuated Intestinal Inflammation and Apoptosis in Ulcerative Colitis Rats through the Inhibition of PI3K/AKT/NF-κB Signaling Pathway

Objective

Renshen Baidu Powder (RBP) is a famous classic compound of traditional Chinese medicine (TCM) and is commonly used for treating ulcerative colitis (UC). However, the pharmacological mechanism of RBP in treating UC remains unclear. This study investigates the possible mechanism of RBP for UC treatment by network pharmacological analysis and rat validation.

Methods

First, the main chemical constituents of RBP were identified using ultrahigh-performance liquid chromatography quadrupole Orbitrap high-resolution mass spectrometry (UHPLC-Q-Orbitrap-HRMS). Then, we obtained targets of identified compounds from the SwissTargetPrediction database and targets associated with UC from GeneCards database. Furthermore, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) were used to analyze the metabolism-related signaling pathways affected by RBP. Hematoxylin-eosin (HE) staining was used to observe the pathological change of colon in UC rats after treating RBP, and terminal deoxynucleotidyl-transferase (TdT)-mediated dUTP Nick end labeling (TUNEL) staining was used to detect apoptosis after RBP treatment. The enzyme-linked immunosorbent assay (ELISA) was employed to evaluate cytokine levels of TNF-α, IL-1β, and IL-6. The protein expressions of Bax, Bcl-2, PI3K, AKT, and NF-κB in colonic tissue were detected using immunohistochemistry (IHC). Real-time quantitative polymerase chain reaction (RT-QPCR) was employed to evaluate mRNA expression of PI3K, AKT, and NF-κB.

Results

We found a total of 24 main compounds and 329 potential targets related to UC. According to KEGG results, 3 main pathways were identified as responsible for UC, including PI3K-AKT, HIF-1, and VEGF signaling pathway. Animal experiments showed that RBP treatment significantly attenuated colon damage in rats with UC. Mechanistically, RBP could inhibit PI3K/AKT/NF-κB pathway; decrease cell apoptosis; and downregulate the expression of TNF-α, IL-1β, and IL-6.

Conclusions

This study demonstrated that RBP may exert anti-inflammatory and antiapoptotic therapeutic benefits in UC by regulating the PI3K/AKT/NF-κB signaling pathways, providing a scientific basis for understanding the mechanism of RBP against UC.

CRISPR/Cas9 gene editing: a new approach for overcoming drug resistance in cancer

The CRISPR/Cas9 system is an RNA-based adaptive immune system in bacteria and archaea. Various studies have shown that it is possible to target a wide range of human genes and treat some human diseases, including cancers, by the CRISPR/Cas9 system. In fact, CRISPR/Cas9 gene editing is one of the most efficient genome manipulation techniques. Studies have shown that CRISPR/Cas9 technology, in addition to having the potential to be used as a new therapeutic approach in the treatment of cancers, can also be used to enhance the effectiveness of existing treatments. Undoubtedly, the issue of drug resistance is one of the main obstacles in the treatment of cancers. Cancer cells resist anticancer drugs by a variety of mechanisms, such as enhancing anticancer drugs efflux, enhancing DNA repair, enhancing stemness, and attenuating apoptosis. Mutations in some proteins of different cellular signaling pathways are associated with these events and drug resistance. Recent studies have shown that the CRISPR/Cas9 technique can be used to target important genes involved in these mechanisms, thereby increasing the effectiveness of anticancer drugs. In this review article, studies related to the applications of this technique in overcoming drug resistance in cancer cells will be reviewed. In addition, we will give a brief overview of the limitations of the CRISP/Cas9 gene-editing technique.

MicroRNAs and osteosarcoma: Potential targets for inhibiting metastasis and increasing chemosensitivity

Osteosarcoma (OS) is the third most common cancer in young adults after lymphoma and brain cancer. Metastasis, like other cellular events, is dependent on signaling pathways; a series of changes in some proteins and signaling pathways pave the way for OS cells to invade and migrate. Ezrin, TGF-β, Notch, RUNX2, matrix metalloproteinases (MMPs), Wnt/β-catenin, and phosphoinositide 3-kinase (PI3K)/AKT are among the most important of these proteins and signaling pathways. Despite the improvements in treating OS, the overall survival of patients suffering from the metastatic disease has not experienced any significant change after surgical treatments and chemotherapy and 5-years overall survival in patients with metastatic OS is about 20%. Studies have shown that overexpression or inhibition of some microRNAs (miRNAs) has significant effects in limiting the invasion and migration of OS cells. The results of these studies highlight the potential of the clinical application of some miRNA mimics and miRNA inhibitors (antagomiRs) to inhibit OS metastasis in the future. In addition, some studies have shown that miRNAs are associated with the most important drug resistance mechanisms in OS, and some miRNAs are highly effective targets to increase chemosensitivity. The results of these studies suggest that miRNA mimics and antagomiRs may be helpful to increase the efficacy of conventional chemotherapy drugs in the treatment of metastatic OS. In this article, we discussed the role of various signaling pathways and the involved miRNAs in the metastasis of OS, attempting to provide a comprehensive review of the literature on OS metastasis and chemosensitivity.

Quercetin: an effective polyphenol in alleviating diabetes and diabetic complications

Various studies, especially in recent years, have shown that quercetin has beneficial therapeutic effects in various human diseases, including diabetes. Quercetin has significant anti-diabetic effects and may be helpful in lowering blood sugar and increasing insulin sensitivity. Quercetin appears to affect many factors and signaling pathways involved in insulin resistance and the pathogenesis of type 2 of diabetes. TNFα, NFKB, AMPK, AKT, and NRF2 are among the factors that are affected by quercetin. In addition, quercetin can be effective in preventing and ameliorating the diabetic complications, including diabetic nephropathy, cardiovascular complications, neuropathy, delayed wound healing, and retinopathy, and affects the key mechanisms involved in the pathogenesis of these complications. These positive effects of quercetin may be related to its anti-inflammatory and anti-oxidant properties. In this article, after a brief review of the pathogenesis of insulin resistance and type 2 diabetes, we will review the latest findings on the anti-diabetic effects of quercetin with a molecular perspective. Then we will review the effects of quercetin on the key mechanisms of pathogenesis of diabetes complications including nephropathy, cardiovascular complications, neuropathy, delayed wound healing, and retinopathy. Finally, clinical trials investigating the effect of quercetin on diabetes and diabetes complications will be reviewed.

From inflammatory bowel disease to colorectal cancer: what's the role of miRNAs?

Inflammatory Bowel Disease (IBD) is a chronic inflammatory disease with relapse and remission periods. Ulcerative colitis and Crohn's disease are two major forms of the disease. IBD imposes a lot of sufferings on the patient and has many consequences; however, the most important is the increased risk of colorectal cancer, especially in patients with Ulcerative colitis. This risk is increased with increasing the duration of disease, thus preventing the progression of IBD to cancer is very important. Therefore, it is necessary to know the details of events contributed to the progression of IBD to cancer. In recent years, the importance of miRNAs as small molecules with 20-22 nucleotides has been recognized in pathophysiology of many diseases, in which IBD and colorectal cancer have not been excluded. As a result, the effectiveness of these small molecules as therapeutic target is hopefully confirmed. This paper has reviewed the related studies and findings about the role of miRNAs in the course of events that promote the progression of IBD to colorectal carcinoma, as well as a review about the effectiveness of some of these miRNAs as therapeutic targets.

OUP accepted manuscript

This study aimed to investigate the molecular mechanisms through which the intestinal microbiota and microRNAs (miRNAs) participate in colon cancer metastasis. Intestinal flora data, and the GSE29621 (messenger RNA/long non-coding RNA [mRNA/lncRNA]) and GSE29622 (miRNA) datasets, were downloaded from The Cancer Gene Atlas and Gene Expression Omnibus databases, respectively. Immune-related cells in M1 vs. M0 samples were analyzed using the Wilcoxon test. Furthermore, an lncRNA-miRNA-mRNA (competing endogenous RNA [ceRNA]) network was constructed, and survival analysis of RNAs in the network was performed. A total of 16 miRNA-genus co-expression pairs containing eight microbial genera and 15 miRNAs were screened; notably, Porphyromonas and Bifidobacterium spp. were found to be associated with most miRNAs, and has-miR-3943 was targeted by most microbial genera. Furthermore, five immune cell types, including activated natural killer cells, M1 macrophages, resting mast cells, activated mast cells and neutrophils, were differentially accumulated between the M1 and M0 groups. Enrichment analysis suggested that mRNAs related to colon cancer metastasis were mainly involved in pathways related to bacterial and immune responses. Survival analysis revealed that TMEM176A and PALM3 in the ceRNA network were significantly associated with the prognosis of patients with colon cancer. In conclusion, this study revealed a potential mechanism by which the intestinal microbiota influences the colon cancer microenvironment by targeting miRNAs.

The role and mechanisms of miRNA in neonatal necrotizing enterocolitis

Neonatal necrotizing enterocolitis (NEC), the most significant causes of neonatal mortality, is a disease of acute intestinal inflammation. At present, it is not clear exactly how the disease is caused, but it has been suggested that this disorder is a result of a complex interaction among prematurity, enteral feeding and inappropriate pro-inflammation response and bacterial infection of the intestine. A microRNA (miRNA) is a class of endogenous non-coding single-stranded RNA that is about 23 nucleotides long engaging in the regulation of the gene expression. Recently, numerous studies have determined that abnormal miRNA expression plays important roles in various diseases, including NEC. Here, we summarized the role of miRNAs in NEC. We introduce the biosynthetic and function of miRNAs and then describe the possible mechanisms of miRNAs in the initiation and development of NEC, including their influence on the intestinal epithelial barrier's function and regulation of the inflammatory process. Finally, this review aids in a comprehensive understanding of the current miRNA to accurately predict the diagnosis of NEC and provide ideas to find potential therapeutic targets of miRNA for NEC. In conclusion, our aims are to highlight the close relationship between miRNAs and NEC and to summarize the practical value of developing diagnostic biomarkers and potential therapeutic targets of NEC.

Exploring the Inflammatory Pathogenesis of Colorectal Cancer

Colorectal cancer is one of the most commonly diagnosed cancers worldwide. Traditionally, mechanisms of colorectal cancer formation have focused on genetic alterations including chromosomal damage and microsatellite instability. In recent years, there has been a growing body of evidence supporting the role of inflammation in colorectal cancer formation. Multiple cytokines, immune cells such T cells and macrophages, and other immune mediators have been identified in pathways leading to the initiation, growth, and metastasis of colorectal cancer. Outside the previously explored mechanisms and pathways leading to colorectal cancer, initiatives have been shifted to further study the role of inflammation in pathogenesis. Inflammatory pathways have also been linked to some traditional risk factors of colorectal cancer such as obesity, smoking and diabetes, as well as more novel associations such as the gut microbiome, the gut mycobiome and exosomes. In this review, we will explore the roles of obesity and diet, smoking, diabetes, the microbiome, the mycobiome and exosomes in colorectal cancer, with a specific focus on the underlying inflammatory and metabolic pathways involved. We will also investigate how the study of colon cancer from an inflammatory background not only creates a more holistic and inclusive understanding of this disease, but also creates unique opportunities for prevention, early diagnosis and therapy.

Vitamin D in respiratory viral infections: a key immune modulator?

Respiratory viral infections are common respiratory diseases. Influenza viruses, RSV and SARS-COV2 have the potential to cause severe respiratory infections. Numerous studies have shown that unregulated immune response to these viruses can cause excessive inflammation and tissue damage. Therefore, regulating the antiviral immune response in the respiratory tract is of importance. In this regard, recent years studies have emphasized the importance of vitamin D in respiratory viral infections. Although, the most well-known role of vitamin D is to regulate the metabolism of phosphorus and calcium, it has been shown that this vitamin has other important functions. One of these functions is immune regulation. Vitamin D can regulate the antiviral immune response in the respiratory tract in order to provide an effective defense against respiratory viral infections and prevention from excessive inflammatory response and tissue damage. In addition, this vitamin has preventive effects against respiratory viral infections. Some studies during the COVID-19 pandemic have shown that vitamin D deficiency may be associated with a higher risk of mortality and sever disease in patients with COVID-19. Since, more attention has recently been focused on vitamin D. In this article, after a brief overview of the antiviral immune response in the respiratory system, we will review the role of vitamin D in regulating the antiviral immune response comprehensively. Then we will discuss the importance of this vitamin in influenza, RSV, and COVID-19.

Zinc and Selenium in Inflammatory Bowel Disease: Trace Elements with Key Roles?

Inflammatory bowel disease (IBD) is a chronic inflammatory condition that may emerge at a young age and often lasts for life. It often goes through phases of recurrence and remission and has a devastating effect on quality of life. The exact etiology of the disease is still unclear, but it appears that an inappropriate immune response to intestinal flora bacteria in people with a genetic predisposition may cause the disease. Managing inflammatory bowel disease is still a serious challenge. Oxidative stress and free radicals appear to be involved in the pathogenesis of this disease, and a number of studies have suggested the use of antioxidants as a therapeutic approach. The antioxidant and anti-inflammatory properties of some trace elements have led some of the research to focus on studying these trace elements in inflammatory bowel disease. Zinc and selenium are among the most important trace elements that have significant anti-inflammatory and antioxidant properties. Some studies have shown the importance of these trace elements in inflammatory bowel disease. In this review, we have attempted to provide a comprehensive overview of the findings of these studies and to gather current knowledge about the association of these trace elements with the inflammatory process and inflammatory bowel disease.

Mucosal microRNAs relate to age and severity of disease in ulcerative colitis

Despite significant evidence that the expression of several microRNAs (miRNAs) impacts disease activity in patients with ulcerative colitis (UC), it remains unknown if the more severe disease phenotype seen in pediatric onset UC can be explained by an altered miRNA expression. In this study, we assessed the relationship between miRNA expression, age, and disease severity in pediatric and adult patients with UC. Using RT-qPCR, we analyzed the expression of miR-21, miR-31, miR-126, miR-142 and miR-155 in paraffin embedded rectum biopsies from 30 pediatric and 30 adult-onset UC patients. We found that lesions from adult patients had significantly higher expression levels of miR-21 compared to pediatric patients and that the expression levels of miR-31 (all patients) and miR-155 (pediatric patients only) correlated inversely with histological assessed disease severity. Using in situ hybridization followed by image analysis, the expression level estimates of miR-21 and miR-126 correlated with histological assessed disease severity. In conclusion, we found that the expression of miRNAs depends on the age of the patient and/or the severity of the disease, suggesting that miRNAs may contribute to the regulation of inflammation in UC and could be useful biomarkers in the surveillance of disease severity.

Cell-to-Cell Communication by Host-Released Extracellular Vesicles in the Gut: Implications in Health and Disease

Communication between cells is crucial to preserve body homeostasis and health. Tightly controlled intercellular dialog is particularly relevant in the gut, where cells of the intestinal mucosa are constantly exposed to millions of microbes that have great impact on intestinal homeostasis by controlling barrier and immune functions. Recent knowledge involves extracellular vesicles (EVs) as mediators of such communication by transferring messenger bioactive molecules including proteins, lipids, and miRNAs between cells and tissues. The specific functions of EVs principally depend on the internal cargo, which upon delivery to target cells trigger signal events that modulate cellular functions. The vesicular cargo is greatly influenced by genetic, pathological, and environmental factors. This finding provides the basis for investigating potential clinical applications of EVs as therapeutic targets or diagnostic biomarkers. Here, we review current knowledge on the biogenesis and cargo composition of EVs in general terms. We then focus the attention to EVs released by cells of the intestinal mucosa and their impact on intestinal homeostasis in health and disease. We specifically highlight their role on epithelial barrier integrity, wound healing of epithelial cells, immunity, and microbiota shaping. Microbiota-derived EVs are not reviewed here.

Strictosamide alleviates the inflammation in an acute ulcerative colitis (UC) model

The ulcerative colitis (UC) is a typical inflammatory bowel disease (IBD) causing great damages, while strictosamide (STR) is a natural alkaloid that possesses strong anti-inflammatory property in infection and inflammation-related diseases. Our study is aimed at evaluating the anti-inflammatory activity of STR in the course of UC. Briefly, male Balb/c mice were treated with 3.5% dextran sulfate sodium (DSS) for 6 consecutive days to establish an acute model of UC, and the administration of gradient concentrations of STR was subsequently performed. Accordingly, colonic pathological alterations including the reduced ratio of colon weight/length, decreased disease activity index (DAI), and attenuated H&E damage were found in UC mice after STR treatment. Based on the analyses of real-time PCR and western blot, downregulation of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) was also determined in the colonic tissue of UC mice after the treatment of STR. ELISA and immunohistochemical staining further suggest the relief of inflammation in UC mice with decreased expressions of MPO and iNOS after STR treatment. In addition, STR was also validated to significantly inhibit NF-κB signaling in UC mice by western blot and Electrophoretic Mobility Shift Assay (EMSA). Meanwhile, restricted inflammation was also determined in STR-treated IEC6 and HT-29 cells. The utilization of PDTC, an inhibitor of NF-κB, further demonstrated that STR ameliorated the inflammation by inhibiting the NF-κB signaling in vitro. In summary, our study suggests that STR could be a potential candidate for IBD therapy.

Sensitivity and specificity of mean platelet volume as a laboratory marker for irritable bowel syndrome: Can it be added to Rome criteria?

BACKGROUND

Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder.

OBJECTIVE

This study aimed to evaluate red blood cell distribution width (RDW) and mean platelet volume (MPV) as laboratory markers to discriminate IBS patients from both healthy controls and patients with inflammatory bowel disease (IBD).

METHODS

This case-control study enrolled patients referred to Ayatollah Rouhani Hospital, Endoscopy Department, Babol, Iran, for colonoscopy examination from 2015 to 2017. Fifty IBS patients were selected from among patients who had undergone a normal colonoscopy and showed symptoms matching the Rome III criteria. Fifty healthy participants and 50 IBD patients, matched for sex and age, were also enrolled in this study. Both RDW and MPV were measured and analysed by independent sample t-test and receiver operating characteristic curve analysis. A p-value of less than 0.05 was considered statistically significant.

RESULTS

While RDW was higher and MPV was lower among IBS patients compared to healthy controls (p = 0.047 and p = 0.001), there were no significant differences in RDW or MPV levels between IBS and IBD patients. The area under the curve of RDW in the discrimination between IBS and IBD was 0.620 (p = 0.039), and the area under the curve of MPV in the discrimination between healthy controls and IBS patients was 0.801 (p = 0.001).

CONCLUSION

Mean platelet volume is potentially a useful laboratory marker for distinguishing between IBS patients and healthy individuals. Red blood cell distribution width should be considered as a potential marker to distinguish among IBS and IBD patients.

Association between serum folate with inflammatory markers, disease clinical activity and serum homocysteine in patients with inflammatory bowel disease. Does folate level have an effect on maintaining clinical remission?

Background:

Folate is an important vitamin with protective effect against some human diseases. The aim of this study was to evaluate the relationship between serum folate levels, inflammatory markers and disease clinical activity in patients with inflammatory bowel disease (IBD).

Methods:

The participants were classified into two groups in which 38 IBD patients and 38 healthy controls were studied. Disease clinical activities were evaluated by means of established score systems. Serum folate, homocysteine and C-reactive protein and ESR were measured. Obtained data were analyzed with proper statistical methods and P- value less than 0.05 was considered as statistical significant.

Results:

The level of serum folate was significantly reduced in IBD patients with active disease compared to patients with clinical remission (p=0.043) and also healthy controls (p=0.008). Moreover, there was a significant inverse correlation between serum folate levels and C-reactive protein in IBD patients (r=-0.563 p=0.001). Conclusion: Serum folate levels is associated with inflammatory markers and disease clinical activity in IBD patients, therefore there is a possibility that disease clinical activity is reduced with adequate folate level. (www.actabiomedica.it)

MicroRNA Biomarkers in IBD-Differential Diagnosis and Prediction of Colitis-Associated Cancer

Inflammatory bowel disease (IBD) includes Crohn's disease (CD) and ulcerative colitis (UC). These are chronic autoimmune diseases of unknown etiology affecting the gastrointestinal tract. The IBD population includes a heterogeneous group of patients with varying disease courses requiring personalized treatment protocols. The complexity of the disease often delays the diagnosis and the initiation of appropriate treatments. In a subset of patients, IBD leads to colitis-associated cancer (CAC). MicroRNAs are single-stranded regulatory noncoding RNAs of 18 to 22 nucleotides with putative roles in the pathogenesis of IBD and colorectal cancer. They have been explored as biomarkers and therapeutic targets. Both tissue-derived and circulating microRNAs have emerged as promising biomarkers in the differential diagnosis and in the prognosis of disease severity of IBD as well as predictive biomarkers in drug resistance. In addition, knowledge of the cellular localization of differentially expressed microRNAs is a prerequisite for deciphering the biological role of these important epigenetic regulators and the cellular localization may even contribute to an alternative repertoire of biomarkers. In this review, we discuss findings based on RT-qPCR, microarray profiling, next generation sequencing and in situ hybridization of microRNA biomarkers identified in the circulation and in tissue biopsies.

Genomics and Transcriptomics: The Powerful Technologies in Precision Medicine

In a clinical trial, people with the same disease can show different responses after treatment with the same drug and exactly under the same conditions. Some of them may improve, some may not show any response, and occasionally side effects may be observed. In other words, people with the same disease process under the same therapeutic conditions may have different responses. Today, some diseases are resistant to conventional (standard) treatment procedures. Why do people with the same disease show different responses to the treatment with the same drug? This is primarily due to differences in molecular pathways (especially genetic variations) associated with the disease. On the other hand, designing and delivery of a new drug is a time-consuming and costly process, so any mistake in any stage of this process can have irreparable consequences for pharmaceutical companies and consumer patients. Therefore, we can achieve more accurate and reliable treatments by acquiring precise insight into different aspects of precision medicine including genomics and transcriptomics. The aim of this paper is to address the role of genomics and transcriptomics in precision medicine.

MicroRNAs Regulate Intestinal Immunity and Gut Microbiota for Gastrointestinal Health: A Comprehensive Review

MicroRNAs are small non-coding RNAs regulating gene expression at the post-transcriptional level. The regulation of microRNA expression in the gut intestine is gradually recognized as one of the crucial contributors of intestinal homeostasis and overall health. Recent studies indicated that both the microRNAs endogenous in the gut intestine and exogenous from diets could play influential roles in modulating microbial colonization and intestinal immunity. In this review, we discuss the biological functions of microRNAs in regulating intestinal homeostasis by modulating intestinal immune responses and gut microbiota. We particularly focus on addressing the microRNA-dependent communication and interactions among microRNA, gut microbiota, and intestinal immune system. Besides, we also summarize the roles of diet-derived microRNAs in host-microbiome homeostasis and their benefits on intestinal health. A better understanding of the relationships among intestinal disorders, microRNAs, and other factors influencing intestinal health can facilitate the application of microRNA-based therapeutics for gastrointestinal diseases.

MicroRNAs and colorectal cancer chemoresistance: New solution for old problem

BACKGROUND

Colorectal cancer (CRC) is one of the most common gastrointestinal malignancies with a significant mortality rate. Despite the great advances in cancer treatment in the last few decades, effective treatment of CRC is still under challenge. One of the main problems associated with CRC treatment is the resistance of cancer cells to chemotherapy drugs.

METHODS

Many studies have been carried out to identify CRC chemoresistance mechanisms, and shed light on the role of ATP-binding cassette transporters (ABC transporters), enzymes as thymidylate synthase, some signaling pathways, and cancer stem cells (CSC) in chemoresistance and failed CRC chemotherapies. Other studies have also been recently carried out to find solutions to overcome chemoresistance. Some of these studies have identified the role of miRNAs in chemoresistance of the CRC cells and the effective use of these micro-molecules to CRC treatment.

RESULTS

Considering the results of these studies, more focus on miRNAs likely leads to a proper solution to overcome CRC chemoresistance.

CONCLUSION

The current study has reviewed the related literature while discussing the efficacy of miRNAs as potential clinical tools for overcoming CRC chemoresistance and reviewing the most important chemoresistance mechanisms in CRC cells.

Differential miRNA-Gene Expression in M Cells in Response to Crohn's Disease-Associated AIEC

Adherent-invasive Escherichia coli (AIEC), which abnormally colonize the ileal mucosa of Crohn’s disease (CD) patients, are able to invade intestinal epithelial cells (IECs) and translocate through M cells overlying Peyer’s patches. The levels of microRNA (miRNA) and gene expression in IECs and M cells upon AIEC infection have not been investigated. Here, we used human intestinal epithelial Caco-2 monolayers and an in vitro M-cell model of AIEC translocation to analyze comprehensive miRNA and gene profiling under basal condition and upon infection with the reference AIEC LF82 strain. Our results showed that AIEC LF82 translocated through M cells but not Caco-2 monolayers. Both differential gene expression and miRNA profile in M cells compared to Caco-2 cells were obtained. In addition, AIEC infection induces changes in gene and miRNA profiles in both Caco-2 and M cells. In silico analysis showed that certain genes dysregulated upon AIEC infection were potential targets of AIEC-dysregulated miRNAs, suggesting a miRNA-mediated regulation of gene expression during AIEC infection in Caco-2, as well as M cells. This study facilitates the discovery of M cell-specific and AIEC response-specific gene-miRNA signature and enhances the molecular understanding of M cell biology under basal condition and in response to infection with CD-associated AIEC.

Talk about micromanaging! Role of microRNAs in intestinal barrier function

Defective intestinal tight-junction (TJ) barrier has been implicated in the pathogenesis of inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC), and other inflammatory conditions of the gut. The role of microRNAs (miRNA's or miR's) has also been demonstrated in the last two decades in the pathogenesis of IBD and in the regulation of intestinal TJ barrier function. MiRNAs are noncoding regulators of gene expression at the posttranscription level that have an essential role in targeting transcripts encoding proteins of intestinal TJs and their regulators. Many miRNAs have been reported to regulate or deregulate the TJ proteins responsible for the intestinal barrier integrity and intestinal permeability. Many of those miRNAs have been reported to have essential roles in the pathogenesis of IBD. In this mini-review, we summarize the results of studies in the last three years that implicate miRNAs in the defective TJ barrier in relation to IBD. The therapeutic potential of using specific miRNAs to target the intestinal TJ barrier might be of great insight for IBD therapy.

IFN-γ promoted exosomes from mesenchymal stem cells to attenuate colitis via miR-125a and miR-125b

Bone marrow mesenchymal stem cells (MSCs) have demonstrated therapeutic effects for colitis through immunomodulation and anti-inflammation. However, whether MSC-derived exosomes possessed the similar function remains unclear. In present study, exosomes were isolated from control and IFN-γ-primed MSCs and was verified by transmission electron microscope (TEM) and immunofluorescence staining. Administration of exosomes to mice significantly improved the disease activity index and histological score of colitis, and decreased the ratio of Th17 cells with elevated Treg cells ratio in mice colitis model. Exosomes from IFN-γ-primed MSCs showed superior therapeutic effects to colitis. Exosomes treatment inhibited Th17 differentiation in vitro, and exosomes from IFN-γ-primed MSCs showed higher inhibition efficacy. Mechanistically, exosomes treatment significantly decreased the expression of Stat3 and p-Stat3 to inhibit Th17 cells differentiation. IFN-γ pretreatment increased the level of miR-125a and miR-125b of exosomes, which directly targeted on Stat3, to repress Th17 cell differentiation. Moreover, combination of miR-125a and miR-125b agmior infusion also showed therapeutic effects for colitis, accompanied by decreased Th17 cell ratio. Collectively, this study demonstrates that IFN-γ treatment promoted exosomes from MSCs to attenuate colitis through increasing the level of miR-125a and miR-125b, which binding on 3′-UTR of Stat3 to repress Th17 cell differentiation. This study provides a new approach of exocytosis on the treatment of colitis.

Autologous Exosome Transfer: A New Personalised Treatment Concept to Prevent Colitis in a Murine Model

BACKGROUND AND AIMS

Epigenetic information delivered by intestinal exosomes can be useful for diagnosing intestinal diseases, such as ulcerative colitis, but the therapeutic effects of intestinal exosomes have not been fully exploited. We herein developed an autologous exosome therapy that could treat intestinal disease without any risk of inducing a systemic immunological reaction.

METHODS

Intestinal exosomes were isolated and purified from faeces by our newly developed multi-step sucrose gradient ultracentrifugation method. Lipopolysaccharide [LPS]-activated macrophages were employed to test the in vitro anti-inflammatory ability of intestinal exosomes. To evaluate the in vivo anti-inflammatory activity of our system, we gavaged dextran sulphate sodium [DSS]-induced colitic mice with their own healing phase intestinal exosomes.

RESULTS

Mouse intestinal exosomes are round extracellular vesicles with a hydrodynamic diameter of ~140 [±20] nm and a surface charge of ~-12 [±3] mV. Among the exosomes obtained at four different stages of DSS-induced ulcerative colitis [1, before treatment; 2, DSS-treated; 3, healing phase; and 4, back to normal], the healing phase exosomes showed the best in vitro anti-inflammatory effects and promotion of wound healing. Moreover, oral co-administration of autologous healing phase exosomes with DSS was found to significantly reduce the risk of a second round of DSS-induced ulcerative colitis in mice.

CONCLUSIONS

Intestinal exosomes obtained during the healing phase that follows induced intestinal inflammation could strongly promote wound healing in the host. Oral administration of autologous exosomes from the healing phase could be a safe and effective approach for treating the ulcerative colitis of a given patient in the context of personalised medicine.

CRISPR/Cas9 gene editing: A new therapeutic approach in the treatment of infection and autoimmunity

CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/CRISPR-associated protein9) may be viewed as an adaptive bacterial immune system. When a virus infects a bacterium, a fragment of the virus genome is inserted into the CRISPR sequence of the bacterial genome as a memory. When the bacterium becomes infected again with the same virus, an RNA molecule that is a transcript of the memory sequence, directs Cas9, an endonuclease, to the complementary region of the virus genome, and Cas9 disables the virus by a double-strand break. In recent years, studies have shown that by designing synthetic RNA molecules and delivering them along with Cas9 into eukaryotic cells, different regions of the cell's genome can be targeted and manipulated. These findings have drawn much attention to this new technology and it has been shown that CRISPR/Cas9 gene editing can be used to treat some human diseases. These include infectious diseases and autoimmune diseases. In this review article, in addition to a brief overview of the biology of the CRISPR/Cas9 system, we collected the most recent findings on the applications of CRISPR/Cas9 technology for better investigation of the pathogenesis and treatment of viral infections (human immunodeficiency virus infection, hepatitis virus infections, and onco-virus infections), non-viral infections (parasitic, fungal, and bacterial infections), and autoimmune diseases.

Serum Biomarkers for Inflammatory Bowel Disease

Background: Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic, inflammatory disorder of the gastrointestinal tract. As the novel therapeutic goal and biologicals are widely recognized, accurate assessment of disease and prediction of therapeutic response have become a crucial challenge in clinical practice. Also, because of the continuously rising incidence, convenient and economical methods of diagnosis and clinical assessment are urgently needed. Recently, serum biomarkers have made a great progress and become a focus in IBD study because they are non-invasive, convenient, and relatively inexpensive than are markers in biopsy tissue, stool, breath, and other body fluids.

Aims: To review the available data on serological biomarkers for IBD.

Methods: We searched PubMed using predefined key words on relevant literatures of serum biomarkers regarding diagnosis, evaluation of therapeutic efficacy, surveillance of disease activity, and assessment of prognosis for IBD.

Results: We reviewed serological biomarkers that are well-established and widely used (e.g., C-reactive protein), newly discovered biomarkers (e.g., cytokines, antibodies, and non-coding RNAs), and also recently advancements in serological biomarkers (e.g., metabolomics and proteomics) that are used in different aspects of IBD management.

Conclusions: With such a wealth of researches, to date, there are still no ideal serum biomarkers for IBD. Serum profiling and non-coding RNAs are just starting to blossom but reveal great promise for future clinical practice. Combining different biomarkers can be valuable in improving performance of disease evaluation.

From Genetics to Epigenetics, Roles of Epigenetics in Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a destructive, recurrent, and heterogeneous disease. Its detailed pathogenesis is still unclear, although available evidence supports that IBD is caused by a complex interplay between genetic predispositions, environmental factors, and aberrant immune responses. Recent breakthroughs with regard to its genetics have offered valuable insights into the sophisticated genetic basis, but the identified genetic factors only explain a small part of overall disease variance. It is becoming increasingly apparent that epigenetic factors can mediate the interaction between genetics and environment, and play a fundamental role in the pathogenesis of IBD. This review outlines recent genetic and epigenetic discoveries in IBD, with a focus on the roles of epigenetics in disease susceptibility, activity, behavior and colorectal cancer (CRC), and their potential translational applications.

The value of mRNA expression of S100A8 and S100A9 as blood-based biomarkers of inflammatory bowel disease

BACKGROUND AND STUDY AIMS

Non-invasive biomarkers of inflammatory bowel diseases (IBD) are of critical importance. Here, we evaluated the S100A8 and S100A9 mRNA expression, as the heterodimers of calprotectin, in the blood leucocytes of IBD patients to find how their expression associates with the disease characteristics.

PATIENTS AND METHODS

In this cross-sectional study, 59 IBD patients and 30 healthy subjects were included. The flare and remission phases of disease were identified in 46 and 13 patients, respectively. Blood leucocytes were isolated, and the S100A8 and S100A9 mRNA expression were evaluated in the isolated leucocytes using relative quantification real-time PCR.

RESULTS

The mean S100A8 and S100A9 mRNA expression were significantly higher in IBD patients than in the controls (p = 0.03 and p = 0.02, respectively). The mean S100A8 and S100A9 mRNA expression were significantly higher in the flare phase of the disease compared with the remission phase (p = 0.01 and p = 0.007, respectively). S100A8 distinguished IBD patients from controls with the sensitivity and specificity of 73% and 64%, and flare phase of disease from remission with the sensitivity and specificity of 67% and 62%. On the other hand, S100A9 distinguished IBD patients from controls with the sensitivity and specificity of 81% and 70%, and flare phase of disease from remission with the sensitivity and specificity of 68% and 64%.

CONCLUSION

The S100A8 and S100A9 mRNA are differentially expressed in blood leucocytes of IBD patients compared to healthy controls as well as active versus quiescent disease. Thus, they can be potentially used as a blood-based biomarker in the monitoring of IBD.