Recent Advances: The Imbalance of Cytokines in the Pathogenesis of Inflammatory Bowel Disease

Interferon-gamma signaling drives epithelial TNF-alpha receptor-2 expression during colonic tissue repair

Interferon-gamma (IFNγ) is traditionally recognized for its pro-inflammatory role during intestinal inflammation. Here, we demonstrate that IFNγ also functions as a pro-repair molecule by increasing TNFα receptor 2 (TNFR2 protein/TNFRSF1B gene) expression on intestinal epithelial cells (IEC) following injury in vitro and in vivo. In silico analyses identified binding sites for the IFNγ signaling transcription factor STAT1 in the promoter region of TNFRSF1B. Scratch-wounded IEC exposed to IFNγ exhibited a STAT1-dependent increase in TNFR2 expression. In situ hybridization revealed elevated Tnfrsf1b mRNA levels in biopsy-induced colonic mucosal wounds, while intraperitoneal administration of IFNγ neutralizing antibodies following mucosal injury resulted in impaired IEC Tnfrsf1b mRNA and inhibited colonic mucosal repair. These findings challenge conventional notions that "pro-inflammatory" mediators solely exacerbate damage by highlighting latent pro-repair functions. Moreover, these results emphasize the critical importance of timing and amount in the synthesis and release of IFNγ and TNFα during the inflammatory process, as they are pivotal in restoring tissue homeostasis.

Efferocytosis: Unveiling its potential in autoimmune disease and treatment strategies

Efferocytosis is a crucial process whereby phagocytes engulf and eliminate apoptotic cells (ACs). This intricate process can be categorized into four steps: (1) ACs release "find me" signals to attract phagocytes, (2) phagocytosis is directed by "eat me" signals emitted by ACs, (3) phagocytes engulf and internalize ACs, and (4) degradation of ACs occurs. Maintaining immune homeostasis heavily relies on the efficient clearance of ACs, which eliminates self-antigens and facilitates the generation of anti-inflammatory and immunosuppressive signals that maintain immune tolerance. However, any disruptions occurring at any of the efferocytosis steps during apoptosis can lead to a diminished efficacy in removing apoptotic cells. Factors contributing to this inefficiency encompass dysregulation in the release and recognition of "find me" or "eat me" signals, defects in phagocyte surface receptors, bridging molecules, and other signaling pathways. The inadequate clearance of ACs can result in their rupture and subsequent release of self-antigens, thereby promoting immune responses and precipitating the onset of autoimmune diseases such as systemic lupus erythematosus, rheumatoid arthritis, type 1 diabetes, and multiple sclerosis. A comprehensive understanding of the efferocytosis process and its implications can provide valuable insights for developing novel therapeutic strategies that target this process to prevent or treat autoimmune diseases.

An Isofibrous Diet with Fiber Konjac Glucomannan Ameliorates Salmonella typhimurium-Induced Colonic Injury by Regulating TLR2-NF-κB Signaling and Intestinal Microbiota in Mice

This study aimed to investigate the hypothesis that dietary konjac glucomannan (KGM) could alleviate Salmonella typhimurium-induced colitis by modulating intestinal microbiota. Mice were fed an isocaloric and isofibrous diet supplemented with either 7% KGM or cellulose and were treated with 5 × 108 CFU of S. typhimurium. The results showed that KGM had an average molecular weight of 936 kDa and predominantly consisted of mannose and glucose at a molar ratio of 1:1.22. In vivo studies demonstrated that dietary KGM effectively mitigated colonic lesions, oxidative stress, disruption of tight junction protein 2 and occludin, and the inflammatory response induced by S. typhimurium. Moreover, KGM administration alleviated the dramatic upregulation of toll-like receptor 2 (TLR2) and phosphonuclear factor κB (NF-κB) protein abundance, induced by Salmonella treatment. Notably, dietary KGM restored the reduced Muribaculaceae and Lactobacillus abundance and increased the abundance of Blautia and Salmonella in S. typhimurium-infected mice. Spearman correlation analysis revealed that the gut microbiota improved by KGM contribute to inhibit inflammation and oxidative stress. These results demonstrated the protective effects of dietary KGM against colitis by modulating the gut microbiota and the TLR2-NF-κB signaling pathway in response to Salmonella infection.

Electroacupuncture blocked motor dysfunction and gut barrier damage by modulating intestinal NLRP3 inflammasome in MPTP-induced Parkinson's disease mice

Parkinson's disease (PD) is a neurodegenerative disorder commonly accompanied by gut dysfunction. EA has shown anti-inflammatory and neuroprotective effects. Here, we aim to explore whether EA can treat Parkinson's disease by restoring the intestinal barrier and modulating NLRP3 inflammasome. We applied 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) to establish a PD mouse model and EA at the GV16, LR3, and ST36 for 12 consecutive days. The open-field test results indicated that EA alleviated depression and behavioral defects, upregulated the expressions of tyrosine hydroxylase (TH) and brain-derived neurotrophic factor (BDNF), and blocked the accumulation of α-synuclein (α-syn) in the midbrain. Moreover, EA blocked the damage to intestinal tissues of PD mice, indicative of suppressed NLRP3 inflammasome activation and increased gut barrier integrity. Notably, the antibiotic-treated mouse experiment validated that the gut microbiota was critical in alleviating PD dyskinesia and intestinal inflammation by EA. In conclusion, this study suggested that EA exhibited a protective effect against MPTP-induced PD by alleviating behavioral defects, reversing the block of motor dysfunction, and improving the gut barrier by modulating intestinal NLRP3 inflammasome. Above all, this study could provide novel insights into the pathogenesis and therapy of PD.

Label-free electrochemical biosensor for direct detection of Oncostatin M (OSM) inflammatory bowel diseases (IBD) biomarker in human serum

Oncostatin M (OSM) is an interleukin-6 (IL-6) member family cytokine implicated in the pathogenesis of chronic diseases including inflammatory bowel disease (IBD). OSM is a novel diagnostic biomarker over-expressed in the serum of IBD patients. This paper reports on the first electrochemical OSM immunosensor, developed using a multistep fabrication process aimed at covalently immobilizing OSM antibodies on a mixed self-assembled monolayer coated gold working electrode. Cyclic voltammetry, atomic force microscopy (AFM), IR spectroscopy and optical characterizations were used to validate the sensor functionalization protocol. Electrochemical impedance spectroscopy (EIS) measurements were performed to assess the reliability of the immunosensor preparation and to verify the antibody-antigen complexes formation. The label-free immunosensor showed high sensitivity identifying OSM at clinically relevant concentrations (37-1000 pg mL-1) with low detection limit of 2.86 pg mL-1. Both sensitivity and selectivity of the proposed immunosensor were also demonstrated in human serum in the presence of interfering biomarkers, making it an innovative potential platform for the OSM biomarker detection in IBD patients' serum.

Function and inhibition of P38 MAP kinase signaling: Targeting multiple inflammation diseases

Inflammation is a natural host defense mechanism that protects the body from pathogenic microorganisms. A growing body of research suggests that inflammation is a key factor in triggering other diseases (lung injury, rheumatoid arthritis, etc.). However, there is no consensus on the complex mechanism of inflammatory response, which may include enzyme activation, mediator release, and tissue repair. In recent years, p38 MAPK, a member of the MAPKs family, has attracted much attention as a central target for the treatment of inflammatory diseases. However, many p38 MAPK inhibitors attempting to obtain marketing approval have failed at the clinical trial stage due to selectivity and/or toxicity issues. In this paper, we discuss the mechanism of p38 MAPK in regulating inflammatory response and its key role in major inflammatory diseases and summarize the synthetic or natural products targeting p38 MAPK to improve the inflammatory response in the last five years, which will provide ideas for the development of novel clinical anti-inflammatory drugs based on p38 MAPK inhibitors.

Preventive Anti-inflammatory Effects of Apocynin on Acetic Acid-Induced Colitis in Rats

Ulcerative colitis is an inflammatory bowel disease with a complex aetiology characterised by abnormal immune responses and oxidative stress-induced tissue injury. Inflammatory cells play an important role in the progression of this pathology through the overproduction of reactive oxygen species (ROS) from various sources including the NADPH oxidases (NOXs). The aim of this study was to investigate the preventive effect of apocynin, a natural antioxidant molecule and a selective inhibitor of NOXs, on acetic acid (AA)-induced ulcerative colitis in rats. Our results first confirmed that apocynin has a high free radical scavenging capacity as well as a potent iron chelating ability. Oral pretreatment of rats with apocynin (200 mg/kg and 400 mg/kg) for 7 days prior to AA-induced colitis suppressed the increase in pro-oxidant markers in colonic homogenates and preserved colonic cytoarchitecture from acetic acid-induced damage. Oral administration of apocynin (200 mg/kg and 400 mg/kg) also reduced several systemic inflammatory markers such as alkaline phosphatase, iron, pro-inflammatory cytokines, C-reactive protein and myeloperoxidase. This study shows that apocynin protects rats from acetic acid-induced colonic inflammation and suggests that apocynin may have a promising beneficial effect in the prevention of ulcerative colitis.

Unraveling the gut-Lung axis: Exploring complex mechanisms in disease interplay

The link between gut and lung starts as early as during organogenesis. Even though they are anatomically distinct, essential bidirectional crosstalk via complex mechanisms supports GLA. Emerging studies have demonstrated the association of gut and lung diseases via multifaceted mechanisms. Advancements in omics and metagenomics technologies revealed a potential link between gut and lung microbiota, adding further complexity to GLA. Despite substantial studies on GLA in various disease models, mechanisms beyond microbial dysbiosis regulating the interplay between gut and lung tissues during disease conditions are not thoroughly reviewed. This review outlines disease specific GLA mechanisms, emphasizing research gaps with a focus on gut-to-lung direction based on current GLA literature. Moreover, the review discusses potential gut microbiota and their products like metabolites, immune modulators, and non-bacterial contributions as a basis for developing treatment strategies for lung diseases. Advanced experimental methods, modern diagnostic tools, and technological advancements are also highlighted as crucial areas for improvement in developing novel therapeutic approaches for GLA-related diseases. In conclusion, this review underscores the importance of exploring additional mechanisms within the GLA to gain a deeper understanding that could aid in preventing and treating a wide spectrum of lung diseases.

The attenuating effect of fermented soymilk on DSS-induced colitis in mice by suppressing immune response and modulating gut microbiota

Fermented soymilk (FSM) as a new plant-based yoghurt has attracted attention for its nutritional and health benefits. The aim of this research is to explore the effect of consuming FSM before and during inflammatory bowel disease (IBD) on intestinal immune response, and to assess whether fermentation and sucrose can improve the anti-inflammatory activity of soymilk (SM) and FSM, and finally clarify their effect on the gut microbiota and levels of short-chain fatty acids (SCFAs). Consuming FSM in advance can effectively alleviate weight loss and bloody stools in mice with colitis and is associated with a 27% colon length repair rate. It can also prevent spleen and liver enlargement, inhibit immune response and oxidative stress, and increase the expression of the tight junction protein occludin gene (60%). Meanwhile, intaking FSM during IBD reduced weight loss, prevented liver damage, and repaired colon injury. In addition, fermentation enhance the inhibitory effects of FSM on colitis, whereas adding 3% sucrose to FSM had no effect on its intervention in colitis. Analysis of the composition of the gut microbiota in mice showed that the intake of FSM reduced the relative abundance of the pathogenic bacteria Parasutterella, Turicibater, and Bacteroide by 75%, 62%, and 50%, respectively, and increased the relative abundance of the beneficial bacteria Akkermansiaceae, Lachnospiraceae, Alloprevotella, and Dubosella by 28%, 50%, 80%, and 63%, respectively. It further restored the levels of SCFAs in the mouse intestine. The results provide a scientific basis for FSM as a natural anti-inflammatory food that can improve inflammatory intestinal microbiota imbalance and promote gut health.

The Antioxidant Properties of Salvia verbenaca Extract Contribute to Its Intestinal Antiinflammatory Effects in Experimental Colitis in Rats

Inflammatory bowel disease (IBD) is a chronic gastrointestinal inflammation with unpredictable symptom fluctuations. While there is no effective cure for IBD, various treatments aim to manage symptoms and improve the quality of life for affected individuals. In recent years, there has been growing interest in the potential benefits of certain natural plants and herbs in the management of IBD. In this regard, this study aimed to evaluate the immunomodulatory and anti-inflammatory effects of a well-characterized extract of Salvia verbenaca (S. verbenaca) in an experimental model of colitis in rats. Interestingly, the daily administration of S. verbenaca (10 and 25 mg/kg) effectively alleviated colitis symptoms, as evidenced by reduced weight/length ratio and colonic damage. Moreover, it reduced oxidative stress markers (MPO and GSH), decreased pro-inflammatory cytokine expression (Il-6, Il-12a, Il-1β, Il-23, Icam-1, Mcp-1, Cinc-1), and preserved the integrity of the intestinal barrier (Villin, Muc-2, Muc-3). These effects suggest S. verbenaca extract could represent a potential complementary candidate to treat gastrointestinal disorders. Its beneficial actions can be related to its antioxidant properties as well as the downregulation of the immune response, which can result in the improvement in the intestine epithelial barrier.

Comparison between local abdominal and transcutaneous tail vein photobiomodulation in experimental rat model of ulcerative colitis

Ulcerative colitis (UC) is a chronic autoimmune disease that impacts the quality of life, but current pharmacological treatments are limited. Photobiomodulation (PBM) is a light-based treatment that can be applied either locally or systemically. Here, we compare the effects of local and vascular PBM (VPBM) in an experimental rat model of UC. Male Wistar rats were induced with UC by rectal instillation of acetic acid and treated with either local abdominal PBM or VPBM to the tail vein using a 660-nm LED. The findings indicated that local PBM but not VPBM reduced intestinal histological scores. Both local and VPBM increased mucus production, decreased mast cell degranulation, and modulated TNF-α and IL-1 β levels in the intestines. Local PBM also affected the expression of the mRNAs for IL-6, TNF-α, and IFN-γ. In conclusion, we suggest that local PBM appears to be more promising than VPBM for treating UC. However, further research is needed to fully understand the mechanisms and to optimize the parameters of PBM for UC treatment.

The fungal-derived compound AM3 modulates pro-inflammatory cytokine production and skews the differentiation of human monocytes

The proper functioning of the immune system depends on an appropriate balance between pro-inflammation and anti-inflammation. When the balance is disrupted and the system is excessively biased towards inflammation, immune responses cannot return within the normal range, which favors the onset of diseases of autoimmune or inflammatory nature. In this scenario, it is fundamental to find new compounds that can help restore this balance and contribute to the normal functioning of the immune system in humans. Here, we show the properties of a fungal compound with a strong safety profile in humans, AM3, as an immunomodulatory molecule to decrease excessive cytokine production in human cells. Our results present that AM3 treatment of human peripheral blood mononuclear cells and monocytes decreased their pro-inflammatory cytokine secretion following the challenge with bacterial lipopolysaccharide. Additionally, AM3 skewed the differentiation profile of human monocytes to macrophages towards a non-inflammatory phenotype without inducing tolerance, meaning these cells kept their capacity to respond to different stimuli. These effects were similar in young and elderly individuals. Thus, the fungal compound, AM3 may help reduce excessive immune activation in inflammatory conditions and keep the immune responses within a normal homeostatic range, regardless of the age of the individual.

Exploring the potential function of trace elements in human health: a therapeutic perspective

A trace element, known as a minor element, is a chemical element whose concentration is very low. They are divided into essential and non-essential classes. Numerous physiological and metabolic processes in both plants and animals require essential trace elements. These essential trace elements are so directly related to the metabolic and physiologic processes of the organism that either their excess or deficiency can result in severe bodily malfunction or, in the worst situations, death. Elements can be found in nature in various forms and are essential for the body to carry out its varied functions. Trace elements are crucial for biological, chemical, and molecular cell activity. Nutritional deficits can lead to weakened immunity, increased susceptibility to oral and systemic infections, delayed physical and mental development, and lower productivity. Trace element enzymes are involved in many biological and chemical processes. These compounds act as co-factors for a number of enzymes and serve as centers for stabilizing the structures of proteins and enzymes, allowing them to mediate crucial biological processes. Some trace elements control vital biological processes by attaching to molecules on the cell membrane's receptor site or altering the structure of the membrane to prevent specific molecules from entering the cell. Some trace elements are engaged in redox reactions. Trace elements have two purposes. They are required for the regular stability of cellular structures, but when lacking, they might activate alternate routes and induce disorders. Therefore, thoroughly understanding these trace elements is essential for maintaining optimal health and preventing disease.

Phosphatidylinositol 3-kinase signaling pathway and inflammatory bowel disease: Current status and future prospects

Inflammatory bowel disease (IBD) is a chronic life-limiting disease of gastrointestinal tract characterized by widespread enteric inflammation. IBD is a multifactorial disease, and different environmental, microbial, and immune-related factors give rise to the development of disease. Among several factors, the preponderance of pro-inflammatory T helper 17 cells over the anti-inflammatory regulatory T cells augments inflammation in the intestinal mucosa. Prevailing evidence accentuates that PI3K signaling pathway plays a central role in the pathophysiology of the condition by regulating the inflammatory process in the gut mucosa. By recognizing the implications of PI3K in the pathogenesis of IBD, agents that could modulate this pathway have recently been at the focus of research, yielding encouraging results mainly in the experimental IBD models. In this review, we have summarized the recent advances, which may hold the keys to identify novel therapeutic strategies for IBD.

Monocyte/macrophage mediates the impact of depression on Crohn's disease

BACKGROUND

Depression increases the risk of Crohn's disease (CD) and worsens its prognosis. Monocytes/macrophages, immune modulate cells, play vital roles in both depression and CD.

OBJECTIVES

We investigated whether monocyte/macrophage could mediate the impact of depression on CD through induction of CD4 + T lymphocyte differentiation and epithelial barrier dysfunction, in addition to the alteration of their own phagocytic ability and cytokines production.

METHODS

Circulating monocytes and intestinal macrophages were isolated from eligible CD patients, divided into depressed and non-depressed groups. Phagocytosis was determined using flow cytometry while in vitro cytokine production was quantified using Luminex assay and qPCR. CD4 + T cells were cocultured with monocytes, then Type 1 Helper T Lymphocytes Th1/Type 2 Helper T Lymphocytes (Th2) /Type 17 Helper T Lymphocytes (Th17)/Treg subsets were analyzed using flow cytometry and qPCR. Caco-2 monolayers simulating epithelial barrier were cocultured with macrophages, and integrity and proliferation were evaluated. Tight junction protein expression was detected using immunofluorescence and western blot.

RESULTS

Decreased monocyte/macrophage phagocytosis and enhanced production of pro-inflammatory cytokines including Tumor necrosis factor-α (TNF-α), Interleukin-6 (IL-6) and Interleukin-1β (IL-1β) were revealed in the depressed versus non-depressed CD groups. Higher proportions of Th1 and Th17 cells with a lower proportion of Treg cell were observed after cocultured with monocytes from the depressed versus non-depressed CD patients. So were the expressions of their corresponding transcription factors T-bet, Retinoic Acid Related Orphan Nuclear Receptor gamma T (RORγt) and Forkhead box protein P3 (FoxP3). Caco-2 cells cocultured with macrophages from depressed CD displayed lower Transepithelial electric resistance (TEER), reduced proliferation activity, and decreased tight junction protein expressions compared with their counterpart cocultured with macrophages from non-depressed CD.

CONCLUSIONS

Monocyte/macrophage may underlie the impact of depression upon CD via decreased phagocytosis, increased pro-inflammatory cytokine production, inducing CD4 + T cell differentiation toward Th1/Th17 cells rather than Treg cell, and impairing macrophage-enhanced epithelial barrier.

Streptococcus lactarius MB622 and Streptococcus salivarius MB620 isolated from human milk reduce chemokine IL-8 production in response to TNF-α in Caco-2 cell line, an exploratory study

Streptococci are a predominant genera of the human milk microbiome. Among different lactic acid bacteria (LAB) a few Streptococcal strains are also considered as probiotics. Probiotic bacteria are reported to modulate immunity when consumed in adequate amount and bacterial hydrophobicity can be considered as a preliminary experiment for the adhesive capability of probiotic bacteria to the epithelial cells. The present study aimed to investigate the probiotic, hydrophobic and immune modulation property of Streptococcus lactarius MB622 and Streptococcus salivarius MB620, isolated from human milk. S. lactarius MB622 and S. salivarius MB620 displayed higher hydrophobicity (78 % and 59 % respectively) in addition to intrinsic probiotic properties such as gram positive classification, catalase negative activity, resistance to artificially stimulated gastric juice and gastrointestinal bile salt concentration. In conclusion Streptococcus lactarius MB622 and Streptococcus salivarius MB620 isolated from human milk when administered in sufficient amount and for certain duration could be used to reduce inflammation inside the colon by reducing the production of inflammatory booster (IL-8) in diseased state.

Gut Microbial Metabolite Butyrate and Its Therapeutic Role in Inflammatory Bowel Disease: A Literature Review

Background and objective: Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a chronic inflammatory disorder characterized by aberrant immune responses and compromised barrier function in the gastrointestinal tract. IBD is associated with altered gut microbiota and their metabolites in the colon. Butyrate, a gut microbial metabolite, plays a crucial role in regulating immune function, epithelial barrier function, and intestinal homeostasis. In this review, we aim to present an overview of butyrate synthesis and metabolism and the mechanism of action of butyrate in maintaining intestinal homeostasis and to discuss the therapeutic implications of butyrate in IBD. Methods: We searched the literature up to March 2023 through PubMed, Web of Science, and other sources using search terms such as butyrate, inflammation, IBD, Crohn's disease, and ulcerative colitis. Clinical studies in patients and preclinical studies in rodent models of IBD were included in the summary of the therapeutic implications of butyrate. Results: Research in the last two decades has shown the beneficial effects of butyrate on gut immune function and epithelial barrier function. Most of the preclinical and clinical studies have shown the positive effect of butyrate oral supplements in reducing inflammation and maintaining remission in colitis animal models and IBD patients. However, butyrate enema showed mixed effects. Butyrogenic diets, including germinated barley foodstuff and oat bran, are found to increase fecal butyrate concentrations and reduce the disease activity index in both animal models and IBD patients. Conclusions: The current literature suggests that butyrate is a potential add-on therapy to reduce inflammation and maintain IBD remission. Further clinical studies are needed to determine if butyrate administration alone is an effective therapeutic treatment for IBD.

Development of an Inflammation-Triggered In Vitro "Leaky Gut" Model Using Caco-2/HT29-MTX-E12 Combined with Macrophage-like THP-1 Cells or Primary Human-Derived Macrophages

The "leaky gut" syndrome describes a damaged (leaky) intestinal mucosa and is considered a serious contributor to numerous chronic diseases. Chronic inflammatory bowel diseases (IBD) are particularly associated with the "leaky gut" syndrome, but also allergies, autoimmune diseases or neurological disorders. We developed a complex in vitro inflammation-triggered triple-culture model using 21-day-differentiated human intestinal Caco-2 epithelial cells and HT29-MTX-E12 mucus-producing goblet cells (90:10 ratio) in close contact with differentiated human macrophage-like THP-1 cells or primary monocyte-derived macrophages from human peripheral blood. Upon an inflammatory stimulus, the characteristics of a "leaky gut" became evident: a significant loss of intestinal cell integrity in terms of decreased transepithelial/transendothelial electrical resistance (TEER), as well as a loss of tight junction proteins. The cell permeability for FITC-dextran 4 kDa was then increased, and key pro-inflammatory cytokines, including TNF-alpha and IL-6, were substantially released. Whereas in the M1 macrophage-like THP-1 co-culture model, we could not detect the release of IL-23, which plays a crucial regulatory role in IBD, this cytokine was clearly detected when using primary human M1 macrophages instead. In conclusion, we provide an advanced human in vitro model that could be useful for screening and evaluating therapeutic drugs for IBD treatment, including potential IL-23 inhibitors.

Highlights on two decades with microbiota and inflammatory bowel disease from etiology to therapy

Inflammatory Bowel diseases (IBDs) constitute a complex panel of disorders characterized with chronic inflammation affecting the alimentary canal along with extra intestinal manifestations. Its exact etiology is still unknown; however, it seems to be the result of uncharacterized environmental insults in the intestine and their immunological consequences along with dysbiosis, in genetically predisposed individuals. It was the main target of our team since 2002 to explore the etiology of IBD and the related role of bacteria. For almost two decades, our laboratory, among others, has been involved in the reciprocal interaction between the host gastrointestinal lining and the homing microbiota. In the first decade, the attention of scientists focused on the possible role of enteropathogenic E. coli and its relationship to the mechanistic pathways involved in IBD induced in both rats and mice by chemicals like Iodoacetamide, Dextran Sodium Sulfate, Trinitrobenzene, thus linking microbial alteration to IBD pathology. A thorough characterization of the various models was the focus of research in addition to exploring how to establish an active homeostatic composition of the commensal microbiota, including its wide diversity by restoration of gut microbiota by probiotics and moving from dysbiosis to eubiosis. In the last six years and in order to effectively translate such findings into clinical practice, it was critical to explore their relationship to colorectal cancer CRC both in solid tumors and chemically induced CRC. It was also critical to explore the degree of intestinal dysbiosis and linking to IBD, CRC and diabetes. Remarkably, the active mechanistic pathways were proposed as well as the role of microbiota or bacterial metabolites involved. This review covers two decades of investigations in our laboratory and sheds light on the different aspects of the relationship between microbiota and IBD with an emphasis on dysbiosis, probiotics and the multiple mechanistic pathways involved.

CD4 T-Cell Subsets and the Pathophysiology of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is an umbrella term for the chronic immune-mediated idiopathic inflammation of the gastrointestinal tract, manifesting as Crohn's disease (CD) or ulcerative colitis (UC). IBD is characterized by exacerbated innate and adaptive immunity in the gut in association with microbiota dysbiosis and the disruption of the intestinal barrier, resulting in increased bacterial exposure. In response to signals from microorganisms and damaged tissue, innate immune cells produce inflammatory cytokines and factors that stimulate T and B cells of the adaptive immune system, and a prominent characteristic of IBD patients is the accumulation of inflammatory T-cells and their proinflammatory-associated cytokines in intestinal tissue. Upon antigen recognition and activation, CD4 T-cells differentiate towards a range of distinct phenotypes: T helper(h)1, Th2, Th9, Th17, Th22, T follicular helper (Tfh), and several types of T-regulatory cells (Treg). T-cells are generated according to and adapt to microenvironmental conditions and participate in a complex network of interactions among other immune cells that modulate the further progression of IBD. This review examines the role of the CD4 T-cells most relevant to IBD, highlighting how these cells adapt to the environment and interact with other cell populations to promote or inhibit the development of IBD.

TDAG51 deficiency attenuates dextran sulfate sodium-induced colitis in mice

Inflammatory bowel disease (IBD), including ulcerative colitis and Crohn's disease, is a group of chronic inflammatory diseases of the gastrointestinal tract. Although the multifactorial etiology of IBD pathogenesis is relatively well documented, the regulatory factors that confer a risk of IBD pathogenesis remain less explored. In this study, we report that T-cell death-associated gene 51 (TDAG51/PHLDA1) is a novel regulator of the development of dextran sulfate sodium (DSS)-induced colitis in mice. TDAG51 expression was elevated in the colon tissues of DSS-induced experimental colitis mice. TDAG51 deficiency protected mice against acute DSS-induced lethality and body weight changes and disease severity. DSS-induced structural damage and mucus secretion in colon tissues were significantly reduced in TDAG51-deficient mice compared with wild-type mice. We observed similar results in a DSS-induced chronic colitis mouse model. Finally, we showed that the production of inflammatory mediators, including proinflammatory enzymes, molecules and cytokines, was decreased in DSS-treated TDAG51-deficient mice compared with DSS-treated wild-type mice. Thus, we demonstrated that TDAG51 deficiency plays a protective role against DSS-induced colitis by decreasing the production of inflammatory mediators in mice. These findings suggest that TDAG51 is a novel regulator of the development of DSS-induced colitis and is a potential therapeutic target for IBD.

Polysaccharide from Atractylodes macrocephala Koidz. ameliorates DSS-induced colitis in mice by regulating the Th17/Treg cell balance

Atractylodes macrocephala Koidz. is one of the most frequently used traditional Chinese medicines for the treatment of ulcerative colitis (UC). The beneficial effect of polysaccharide from Atractylodes macrocephala Koidz. (PAMK) on UC has been reported, while the underlying mechanism and target remain unclear. In this study, we systematically investigated the therapeutic effect and the underlying mechanism of PAMK in UC based on a mouse model of dextran sodium sulfate (DSS)-induced colitis. PAMK treatment (100 mg/kg, 200 mg/kg and 400 mg/kg) significantly ameliorated DSS-induced colitis, manifested as a reduction in weight loss, disease activity index (DAI), colon shortening, spleen index and histological score. Moreover, PAMK treatment inhibited inflammation and improved the integrity of the intestinal barrier in colitis mice. Mechanistically, microarray analysis determined the critical role of the immunoregulatory effect of PAMK in alleviating UC. Flow cytometry analysis further demonstrated that PAMK treatment regulated the balance between T helper (Th) 17 and regulatory T (Treg) cells in the mesenteric lymph nodes (MLN) and spleen in mice with colitis. In addition, PAMK treatment downregulated the expression of IL-6 and suppressed the phosphorylation of STAT3. Together, these data revealed that PAMK treatment alleviated DSS-induced colitis by regulating the Th17/Treg cell balance, which may be dependent on the inhibition of the IL-6/STAT3 signaling pathway. Our study is the first to elucidate that the underlying mechanism by which PAMK treatment alleviates DSS-induced colitis is associated with an improved the Th17/Treg cell balance. Collectively, the study provides evidence for the potential of PAMK to treat UC.

Identification and validation of the common pathogenesis and hub biomarkers in Hirschsprung disease complicated with Crohn’s disease

Background

Although increasing evidence has supported that Hirschsprung disease (HSCR) is the risk factor for children developing Crohn’s disease (CD), the common mechanism of its co-occurrence remains unknown. The purpose of this study is to further explore the underlying mechanism and biomarkers for the co-occurrence of HSCR and CD.

Methods

The Gene Expression Omnibus (GEO) database was used to obtain gene expression profiles for CD (GSE95095) and HSCR (GSE98502). Following the identification of the shared differentially expressed genes (DEGs) of CD and HSCR, functional annotation, protein–protein interaction (PPI) network creation, and module assembly were performed to discover hub genes. RT-qPCR was performed to validate the expression of the hub genes in HSCR samples. The receiver operating characteristic (ROC) curve was utilized to assess the accuracy of the hub genes as biomarkers in predicting CD in both the training dataset and test dataset.

Results

A total of 103 common DEGs (50 downregulated genes and 53 upregulated genes) were chosen for further investigation. The importance of chemokines and cytokines in these two disorders is highlighted by functional analysis. MCODE plug identified three important modules, which functionally enriched the immune system process. Finally, nine hub genes were identified using cytoHubba, including IL1B, IL10, CXCL10, ICAM1, EGR1, FCGR3A, S100A12, S100A9, and FPR1. The nine hub genes were mainly enriched in immune- and inflammation-related pathways. External data profiles and RT-qPCR confirmed the expression of the nine hub genes in HSCR and CD. ROC analysis revealed that the nine hub genes had a strong diagnostic value.

Conclusion

Our study reveals the common pathogenesis of HSCR and CD. These hub genes and diagnostic models may provide novel insight for the diagnosis and treatment of HSCR complicated with CD.

Pre-clinical Investigation of Protective Effect of Nutraceutical D-Glucosamine on TNBS-induced Colitis

The level of precursors involved in the biosynthesis of glycosaminoglycan (GAG), glucosamine synthase, and N-acetyl glucosamine (NAG), are significantly reduced in inflammatory bowel disease (IBD). This results in deficient GAG content in mucosa, which eventually disrupts the gut wall integrity, provoking abnormal immunological responses. This is characterized by colossal liberation of inflammatory mediators including tumor necrosis factor-alpha (TNF-α), interleukins (IL), and reactive oxygen species provoking colonic inflammation. D-glucosamine (D-GLU) is reported to suppress oxidative stress, and pro-inflammatory cytokines and acts as a starting material for biosynthesis of NAG. The potential of D-GLU and its combination with mesalamine (5-ASA) was investigated in 2,4,6-trinitrobenzene sulfonic acid (TNBS)-instigated IBD in Wistar rats. Standard and test drugs were given orally for five days to separate groups of rats. Colonic inflammation was evaluated by disease activity score rate (DASR), colon/body weight ratio, colon length, diameter, colon pH, histological injury and score. Inflammatory biomarkers IL-1β, TNF-α, along with reduced glutathione (GSH), and malondialdehyde (MDA) were assessed. Combination of D-GLU +5-ASA significantly ameliorated severity of colonic inflammation by lowering DASR (P < 0.001) and colon/body weight ratio (P < 0.001), restored the colonic architecture and suppressed the histopathological score (P < 0.001), along with the absence of major adverse reactions. The combination suppressed the levels of inflammatory markers (P < 0.001) and MDA (P < 0.001) while enhancing GSH level (P < 0.001). In comparison to individual 5-ASA and D-GLU, combination of drugs significantly diminished colitis severity through their combined anti-inflammatory and antioxidant effects by acting on multiple targets simultaneously. The combination holds remarkable potential in the management of IBD.

Opportunities and challenges for synthetic biology in the therapy of inflammatory bowel disease

Inflammatory bowel disease (IBD) is a complex, chronic intestinal inflammatory disorder that primarily includes Crohn’s disease (CD) and ulcerative colitis (UC). Although traditional antibiotics and immunosuppressants are known as the most effective and commonly used treatments, some limitations may be expected, such as limited efficacy in a small number of patients and gut flora disruption. A great many research studies have been done with respect to the etiology of IBD, while the composition of the gut microbiota is suggested as one of the most influential factors. Along with the development of synthetic biology and the continuing clarification of IBD etiology, broader prospects for novel approaches to IBD therapy could be obtained. This study presents an overview of the currently existing treatment options and possible therapeutic targets at the preclinical stage with respect to microbial synthesis technology in biological therapy. This study is highly correlated to the following topics: microbiota-derived metabolites, microRNAs, cell therapy, calreticulin, live biotherapeutic products (LBP), fecal microbiota transplantation (FMT), bacteriophages, engineered bacteria, and their functional secreted synthetic products for IBD medical implementation. Considering microorganisms as the main therapeutic component, as a result, the related clinical trial stability, effectiveness, and safety analysis may be the major challenges for upcoming research. This article strives to provide pharmaceutical researchers and developers with the most up-to-date information for adjuvant medicinal therapies based on synthetic biology.

Multi-Strain-Probiotic-Loaded Nanoparticles Reduced Colon Inflammation and Orchestrated the Expressions of Tight Junction, NLRP3 Inflammasome and Caspase-1 Genes in DSS-Induced Colitis Model

Gut modulation by multi-strain probiotics (MSPs) is considered an effective strategy for treating inflammatory bowel disease (IBD). The combination of nanomaterial-based MSPs can improve their viability and resistance and can allow their targeted release in the gastrointestinal tract to be achieved. Thus, our aim is to investigate the prospective role of MSP integration into nanomaterials (MSPNPs) and the underlying molecular mechanisms supporting their application as an alternative therapy for IBD using a colitis rat model. To induce the colitis model, rats received 5% DSS, and the efficacy of disease progression after oral administration of MSPNPs was assessed by evaluating the severity of clinical signs, inflammatory response, expressions of tight-junction-related genes and NLRP3 inflammasome and caspase-1 genes, microbial composition and histopathological examination of colonic tissues. The oral administration of MSPNPs successfully alleviated the colonic damage induced by DSS as proved by the reduced severity of clinical signs and fecal calprotectin levels. Compared with the untreated DSS-induced control group, the high activities of colonic NO and MPO and serum CRP levels were prominently reduced in rats treated with MSPNPs. Of note, colonic inflammation in the group treated with MSPNPs was ameliorated by downstreaming NLRP3 inflammasome, caspase-1, IL-18 and IL-1β expressions. After colitis onset, treatment with MSPNPs was more effective than that with free MSPs in restoring the expressions of tight-junction-related genes (upregulation of occludin, ZO-1, JAM, MUC and FABP-2) and beneficial gut microbiota. Interestingly, treatment with MSPNPs accelerated the healing of intestinal epithelium as detected in histopathological findings. In conclusion, the incorporation of MPSs into nanomaterials is recommended as a perspective strategy to overcome the challenges they face and augment their therapeutic role for treating of colitis.

Ophiopogonin D Inhibiting Epithelial NF-κB Signaling Pathway Protects Against Experimental Colitis in Mice

The sustained activation of the nuclear factor κB (NF-κB) signaling pathway has been observed in human inflammatory bowel disease (IBD). Ophiopogonin D (OP-D) is a small molecular compound isolated from Ophiopogon japonicus, a widely used herbal remedy. In this study, dextran sodium sulfate was used to make a mouse model of experimental colitis and verify the effect of OP-D on the mouse model of experimental colitis. Small molecule-protein molecular docking approaches were also used to discover the mechanisms underlying the OP-D-induced regulation of colitis. In colitis, the OP-D can inhibit the apoptosis of intestinal mucosa cells, restore the intestinal barrier, and alleviate inflammation. The molecular docking simulations showed that OP-D had a high affinity with the REL-homology domain of NF-κB-p65 that affected its translocation to the nucleus. In a cell study, the effects of OP-D on inflammation and barrier dysfunction were significantly decreased by a small interfering RNA targeting NF-κB-p65. Further, the LPS-induced increase in NF-κB-p65 in the nucleus was also significantly inhibited by OP-D. OP-D alleviated experimental colitis by inhibiting NF-κB. New insights into the pathogenesis and treatment options of colitis are provided through this study.

Miconazole Mitigates Acetic Acid-Induced Experimental Colitis in Rats: Insight into Inflammation, Oxidative Stress and Keap1/Nrf-2 Signaling Crosstalk

Ulcerative colitis (UC) is the most common type of inflammatory bowel disease, characterized by oxidative stress and elevated pro-inflammatory cytokines. Miconazole is an azole antifungal that stimulates the expression of antioxidant enzymes via Nrf2 activation, which consequently inhibits ROS formation and NF-κB activation. Hence, the present study aimed to investigate the protective effect of miconazole, sulfasalazine (as a reference drug) and their combination on acetic acid (AA)-induced UC in a rat model which was induced by intra-rectal administration of 4% AA. Rats were pretreated with miconazole (20 and 40 mg/kg, orally) or sulfasalazine (100 mg/kg, orally), or their combination (20 mg/kg miconazole and 50 mg/Kg of sulfasalazine, orally). Pretreatment with miconazole significantly reduced wet colon weight and macroscopic scores, accompanied by a significant amelioration of the colonic architecture disorder. Moreover, the treatment also significantly decreased the malondialdehyde (MDA) level and prevented the depletion of superoxide dismutase (SOD) activity and GSH content in inflamed colons. Additionally, the treatment showed suppressive activities on pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6) and C-reactive protein (CRP), and upregulated the anti-inflammatory cytokine interleukin-10 (IL-10). Moreover, the treatment upregulated the protein levels of Nrf-2 and heme oxygenase-1 (HO-1) in the colon tissue. Taken together, miconazole is effective in alleviating AA-induced colitis in rats, and the mechanism of its action is associated with the activation of Nrf2-regulated cytoprotective protein expression.

In Vitro Protective Effects of a Standardized Extract From Cynara Cardunculus L. Leaves Against TNF-α-Induced Intestinal Inflammation

Inflammatory bowel disease (IBD) represents a group of progressive disorders characterized by recurrent chronic inflammation of the gut. New unconventional therapies based on plant derived compounds capable of preventing and/or reducing acute or chronic inflammation could represent a valid alternative for the treatment or prevention of IBDs. Cynara cardunculus L. leaves, considered a food-waste suitable as a rich source of bioactive polyphenols including luteolin and chlorogenic acid, has been reported for its positive effects in digestive tract. The aim of the present work was to evaluate the in vitro molecular mechanisms of beneficial effects of a standardized polyphenol-rich extract obtained from the leaves of Cynara cardunculus L (CCLE) against acute intestinal inflammation induced by TNF-α on intestinal epithelial Caco-2 cells. CCLE prevented TNF-α-induced NF-κB inflammatory pathway and the overexpression of IL-8 and COX-2. In addition, CCLE was able to improve basal intracellular antioxidant power in both TNF-α-unexposed or -exposed Caco-2 cells and this effect was associated to the activation of Nrf2 pathway, a master regulator of redox homeostasis affecting antioxidant and phase II detoxifying genes, stimulating an adaptive cellular response. In conclusion, our data clearly evidenced that, although considered a waste, Cynara cardunculus leaves may be used to obtain extracts rich in bioactive polyphenols potentially useful for prevention and treatment of inflammatory intestinal diseases.

Advances in the treatment of inflammatory bowel disease: Focus on polysaccharide nanoparticulate drug delivery systems

The complex pathogenesis of inflammatory bowel disease (IBD) explains the several hurdles for finding an efficient approach to cure it. Nowadays, therapeutic protocols aim to reduce inflammation during the hot phase or maintain remission during the cold phase. Nonetheless, these drugs suffer from severe side effects or poor efficacy due to low bioavailability in the inflamed region of the intestinal tract. New protocols based on antibodies that target proinflammatory cytokines are clinically relevant. However, besides being expensive, their use is associated with a primary nonresponse or a loss of response following a long administration period. Accordingly, many researchers exploited the physiological changes of the mucosal barrier for designing nanoparticulate drug delivery systems to target inflamed tissues. Others exploited biocompatibility and relative affordability of polysaccharides to test their intrinsic anti-inflammatory and healing properties in IBD models. This critical review updates state of the art on advances in IBD treatment. Data on using polysaccharide nanoparticulate drug delivery systems for IBD treatment are reviewed and discussed.

A Review on the Immunomodulatory Mechanism of Acupuncture in the Treatment of Inflammatory Bowel Disease

Inflammatory bowel disease (IBD) is a chronic inflammatory disease with a high prevalence and canceration rate. The immune disorder is one of the recognized mechanisms. Acupuncture is widely used to treat patients with IBD. In recent years, an increasing number of studies have proven the effectiveness of acupuncture in the treatment of IBD, and some progress has been made in the mechanism. In this paper, we reviewed the studies related to acupuncture for IBD and focused on the immunomodulatory mechanism. We found that acupuncture could regulate the innate and adaptive immunity of IBD patients in many ways. Acupuncture exerts innate immunomodulatory effects by regulating intestinal epithelial barrier, toll-like receptors, NLRP3 inflammasomes, oxidative stress, and endoplasmic reticulum stress and exerts adaptive immunomodulation by regulating the balance of Th17/Treg and Th1/Th2 cells. In addition, acupuncture can also regulate intestinal flora.

Myrica salicifolia Hochst. ex A. Rich. suppress acetic acid-induced ulcerative colitis in rats by reducing TNF-alpha and interleukin-6, oxidative stress parameters and improving mucosal protection

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) with rising prevalence in developing countries, and limited success of current therapies, natural products have immense potential for therapy due to their "disease modifying and side-effect neutralizing" potential. Myrica salicifolia is traditionally used for gastrointestinal diseases and have reported antiinflammatory activities, but its use in IBD has not yet been studied. Therefore, in the present study, the effects of the root extract of M. salicifolia (Ms.Cr) were investigated using the acetic acid-induced UC model in rats. For 6 days, the rats were given either vehicle (10 mL/kg), lower (200 mg/kg), and higher (400 mg/kg) doses of Ms.Cr, or the positive control drug (prednisolone; 2 mg/kg) orally. A single dosage of 5% acetic acid (1.0 mL) was administered intrarectally to rats on day 6 to induce UC. Disease activity index (DAI), histological observations, the biochemical parameters related to oxidative stress, and specific cytokines such as interleukin-6 (IL-6) and the tumor necrosis factor-α (TNF-α) were determined to assess the effect of Ms.Cr. In comparison to the AA-induced colitis rats, Ms.Cr's pretreatment significantly decreased DAI, colonic ulceration, and inflammatory score. Total glutathione levels and catalase activity were considerably recovered in the colitis group treated with Ms.Cr, whereas enhanced lipid peroxidation in colon tissues was significantly decreased. Moreover, Ms.Cr pretreatment also caused inhibition of the activation of IL-6 and TNF-α in the colonic tissues of respective groups. Based on these findings, Ms.Cr might be developed to treat UC in the future.

Cherry Polyphenol Extract Ameliorated Dextran Sodium Sulfate-Induced Ulcerative Colitis in Mice by Suppressing Wnt/β-Catenin Signaling Pathway

Ulcerative colitis (UC) is a chronic and nonspecific inflammatory disease of the colon and rectum, and its etiology remains obscure. Cherry polyphenols showed potential health-promoting effects. However, both the protective effect and mechanism of cherry polyphenols on UC are still unclear. This study aimed to investigate the potential role of the free polyphenol extract of cherry in alleviating UC and its possible mechanism of action. Our study revealed that the free polyphenol extract of cherry management significantly alleviated UC symptoms, such as weight loss, colon shortening, the thickening of colonic mucous layer, etc. The free polyphenol extract of cherry treatment also introduced a significant reduction in levels of malondialdehyde (MDA), myeloperoxidase (MPO) and nitric oxide (NO), while causing a significant elevation in levels of catalase (CAT), glutathione (GSH-Px), superoxide dismutase (SOD), as well as the downregulation of pro-inflammatory cytokines. This indicated that such positive effects were performed through reducing oxidative damage or in a cytokine-specific manner. The immunofluorescence analysis of ZO-1 and occludin proteins declared that the free polyphenol extract of cherry had the potential to prompt intestinal barrier function. The reduced expression levels of β-catenin, c-myc, cyclin D1 and GSK-3β suggested that the cherry extract performed its positive effect on UC by suppressing the Wnt/β-ctenin pathway. This finding may pave the way into further understanding the mechanism of cherry polyphenols ameliorating ulcerative colitis.

Diosmetin attenuate experimental ulcerative colitis in rats via suppression of NF-κB, TNF-α and IL-6 signalling pathways correlated with down-regulation of apoptotic events

Introduction

Ulcerative colitis (UC) is a chronic inflammation of colon in which the innermost tissue of colon and rectum develops deep-rooted inflammation. Diosmetin is the aglycone of the flavonoid glycoside diosmin, commonly found in citrus fruits. Therapeutically diosmetin is indicated to demonstrate anticancer, antimicrobial, antioxidant, oestrogenic and anti-inflammatory activity.

Methods

In this research, we studied the action of diosmetin on TNBS (2,4,6-trinitrobenzene sulfonic acid)-induced UC in rats. Male Wister rats were anesthetised with pentobarbital and TNBS introduced by performing an enema. Diosmetin treatment was provided through oral gavage for the next 28 days. Animals were sacrificed on the 29th day and colon tissues were collected for further examinations.

Results

Diosmetin treatment decreased colonic ulceration dramatically and decreased the percentage of inflammation in the colonic mucosa. Depletion of the TNBS assisted of superoxide dismutase and catalase was substantially restricted, while lipid peroxidation was recorded in the colonic tissue as malondialdehyde content was also decreased. After treatment with diosmetin, the occurrence of TNF-α, IL-6and NF-κB was considerably lowered and the number of apoptotic cells observed was significantly reduced.

Conclusion

Taken together, these observations demonstrated the potential of diosmetin against ulcer formation and development.

Protective Effect of l-Theanine against DSS-Induced Colitis by Regulating the Lipid Metabolism and Reducing Inflammation via the NF-κB Signaling Pathway

The present study revealed the phylactic effects of l-theanine on a DSS-induced colitis mice model. The results showed that 3% DSS treatment significantly induced intestinal damage as reflected by DAI, histopathological feature, and colon length, while l-theanine pretreatment markedly prevented these trends to exert protective effects. Meanwhile, l-theanine pretreatment decreased the levels of TNF-α, IL-1β, IL-6, iNOS, and COX2 on DSS-induced colitis. Notably, DSS inhibited the proliferation and promoted the apoptosis of intestinal epithelial cells, thereby damaging the integrity of the intestinal epithelial barrier, whereas l-theanine also played a protective role by attenuating these deteriorated effects. It was also observed that l-theanine treatment downregulated the levels of p-p65, p65, p-p53, p53, and p-AKT protein expression in acute DSS-induced colitis, which showed the protective function of l-theanine, mainly via the NF-κB signaling pathway. Furthermore, the results of lipid analysis and transcriptome analysis show that l-theanine reversed transcriptional profiles and lipid profiles of colitis models, mainly via the inflammatory reactivity-related pathway. Interestingly, the correlation analysis between transcriptional profiles and lipid profiles showed that inflammatory response-related genes were almost significantly correlated with differential lipid metabolites. In summary, l-theanine plays a protective role in DSS-induced colitis via downregulating the NF-κB signaling pathway and regulating lipid metabolism disorders.

Intestinal Inflammation and Parkinson's Disease

Parkinson's disease (PD) is the second most common neurodegenerative disease which significantly influences the life quality of patients. The protein α-synuclein plays an important driving role in PD occurrence and development. Braak's hypothesis suggests that α-synuclein is produced in intestine, and then spreads into the central nervous system through the vagus nerve. The abnormal expression of α-synuclein has been found in inflammatory bowel disease (IBD). Intestinal inflammation and intestinal dysbiosis have been involved in the occurrence and development of PD. The present review aimed to summarize recent advancements in studies focusing on intestinal inflammation and PD, especially the mechanisms through which link intestinal inflammation and PD. The intestinal dysfunctions such as constipation have been introduced as non-motor manifestations of PD. The possible linkages between IBD and PD, including genetic overlaps, inflammatory responses, intestinal permeability, and intestinal dysbiosis, are mainly discussed. Although it is not confirmed whether PD starts from intestine, intestinal dysfunction may affect intestinal microenvironment to influence central nervous system, including the α-synuclein pathologies and systematic inflammation. It is expected to develop some new strategies in the diagnosis and treatment of PD from the aspect of intestine. It may also become an exciting direction to find better ways to regulate the composition of gut microorganism to treat PD.

Claudins: Beyond Tight Junctions in Human IBD and Murine Models

Claudins are transmembrane proteins constituting one of three tight junction protein families. In patients with inflammatory bowel disease (IBD), disease activity–dependent changes in expression of certain claudins have been noted, thus making certain claudin family members potential therapy targets. A study was undertaken with the aim of exploring expression of claudins in human disease and two different animal models of IBD: dextrane sulfate sodium–induced colitis and adoptive transfer model of colitis. The expression of sealing claudin-1, claudin-3, claudin-4, and claudin-8, and pore-forming claudin-2 in humans and rodents has been evaluated by immunohistochemistry and quantitative polymerase chain reaction. Claudins were expressed by epithelial and cells of mesodermal origin and were found to be situated at the membrane, within the cytoplasm, or within the nuclei. Claudin expression by human mononuclear cells isolated from lamina propria has been confirmed by Western blot and flow cytometry. The claudin expression pattern in uninflamed and inflamed colon varied between species and murine strains. In IBD and both animal models, diverse alterations in claudin expression by epithelial and inflammatory cells were recorded. Tissue mRNA levels for each studied claudin reflected changes within cell lineage and, at the same time, mirrored the ratio between various cell types. Based on the results of the study, it can be concluded that 1) claudins are not expressed exclusively by epithelial cells, but by certain types of cells of mesodermal origin as well; 2) changes in the claudin mRNA level should be interpreted in the context of overall tissue alterations; and 3) both IBD animal models that were analyzed can be used for investigating claudins as a therapy target, respecting their similarities and differences highlighted in this study.

MiR-125-5p/IL-6R axis regulates macrophage inflammatory response and intestinal epithelial cell apoptosis in ulcerative colitis through JAK1/STAT3 and NF-κB pathway

This study explored the effects of miR-125-5p and interleukin-6 receptor (IL-6 R) on ulcerative colitis (UC) cell models and mouse models. The sera derived from UC patients and healthy subjects were collected for expression analysis. UC in vitro models and in vivo model were constructed and used. Expressions of miR-125-5p, IL-6 R, AK1/STAT3 and NF-κB pathways, and inflammatory factors, histopathology and apoptosis were determined by conducting a series of molecular experiments. The relationship between miR-125-5p and IL-6 R was analyzed by TargetScan7.2 and verified by dual-luciferase assay. The disease activity index (DAI) score, weight change, and colon length of the mice were recorded and analyzed. Decreased expression of miR-125-5p in the sera of UC patients was related to the increased expression of its target gene IL-6 R. In vitro, up-regulation of miR-125-5p decreased IL-6 R expression, contents of inflammatory factors in THP-1 cells and cell apoptosis of NCM460, and inhibited the activation of JAK1/STAT3 and NF-κB pathway. However, down-regulation of miR-125-5p produced the opposite effects to its up-regulation. IL-6 R overexpression partially reversed the effects of miR-125-5p up-regulation on UC cell models. In vivo, miR-125-5p overexpression significantly improved the severity of colitis, including DAI score, colon length, tissue damage, apoptosis, and inflammatory response, in the mice in the UC group. In addition, miR-125-5p up-regulation significantly reduced the expression of IL-6 R in the UC mice, and reduced the expression levels of JAK1, STAT3 and p65 phosphorylation. MiR-125-5p targeting IL-6 R regulates macrophage inflammatory response and intestinal epithelial cell apoptosis in ulcerative colitis through JAK1/STAT3 and NF-κB pathway.

Elevated IgA and IL-10 levels in very-early-onset inflammatory bowel disease secondary to IL-10 receptor deficiency

OBJECTIVE

To report two patients with very-early-onset inflammatory bowel disease (VEOIBD) secondary to interleukin-10 receptor (IL-10R) mutations, explore immunophenotyping data and plasma cytokine profile on these cases compared to healthy controls, and describe the phenotype of IL-10/IL-10R mutations based on a literature review.

CASE DESCRIPTION

We report on two female infants referred to our tertiary center at the age of ten months, with severe colonic and perianal disease, as well as significant malnutrition, who had shown limited response to usual inflammatory bowel disease (IBD) therapy agents. In the first case, whole-exome sequencing (WES) revealed a homozygous (c.537G>A/p.T179T) mutation in exon 4 of the IL-10RA gene, while in the second patient, compound heterozygosity was identified, also in the IL-10RA gene (chr11:117.859.199 variant A>G/p.Tyr57Cys and chr11: 117.860.335 variant G>T/p.Val123Leu). Both patients underwent hematopoietic cell transplantation (HCT). Immunological work-up of these patients revealed increased IL-10 plasma levels and increased IgA.

COMMENTS

Our case reports disclose novel findings on plasma cytokine profile in IL-10R deficiency, and we describe the severe phenotype of IL-10/IL-10R deficiency that should be recognized by physicians.

Anti-inflammatory/anti-apoptotic impact of betulin attenuates experimentally induced ulcerative colitis: An insight into TLR4/NF-kB/caspase signalling modulation

Ulcerative colitis (UC) is an inflammatory bowel disease with limited therapeutic management approaches. The present study evaluated the potential therapeutic impact of betulin on acetic acid (AA)-induced UC in rats. UC was induced by intracolonic instillation of AA (3% v/v). Rats were treated with betulin (8 mg/kg, I.P., once daily) four days post AA instillation and for 14 consecutive days. Betulin attenuated AA-induced UC as evidenced by retracted macroscopic scores, serum CRP titre and LDH activity, attenuated histopathological hallmarks of UC including mucosal necrosis, haemorrhage, congestion and inflammatory cells infiltration. Moreover, betulin dampened UC-associated colonic inflammatory load with modulation of TLR4/NF-kB axis and reduction in colonic inflammatory cytokines; TNF-α, IL1β and IL-6. Nevertheless, betulin suppressed colonic apoptosis with reduced colonic caspase-3 and caspase-8 expression. The current findings confirm a beneficial therapeutic impact of betulin against UC. The prospective underlying mechanisms include down-regulation of TLR4/NF-κB and the subsequent downstream signalling pathways.

Curcumin functions as an anti-inflammatory and antioxidant agent on arsenic-induced hepatic and kidney injury by inhibiting MAPKs/NF-κB and activating Nrf2 pathways

Chronic arsenic exposure has been associated with various toxic effects, especially to the organs of liver and kidney. As a plant polyphenol, curcumin is the most vital bioactive ingredient of turmeric and has a wide range of pharmacological activities. In the present study, we investigated the potential roles of curcumin against arsenic-induced liver and kidney dysfunctions in mice. Curcumin treatment (200 mg/kg) not only decreased the deposition of arsenic in liver and kidney, but also relieved the hepatic and nephritic biochemical indexes (Glutamic oxaloacetic transaminase [AST], Alanine aminotransferase [ALT], albumin, and creatinine) altered by arsenic at doses of 10 and 25 mg/L via drinking water. What's more, curcumin exerted influences on the activities of myeloperoxidase and on the secretion of inflammatory cytokines in liver and kidney tissues. In addition, the levels of mitogen-activated protein kinases (MAPKs) and nuclear factor kappa B (NF-κB) phosphorylation were declining while NRF2-signaling targets were increasing in mice liver and kidney by curcumin administration. In conclusion, our results here suggest that curcumin could exert both anti-inflammatory and antioxidant functions on arsenic-induced hepatic and kidney injury by inhibiting MAPKs/NF-κB and activating Nrf2 pathways cooperatively.

Sinomenine hydrochloride ameliorates dextran sulfate sodium-induced colitis in mice by modulating the gut microbiota composition whilst suppressing the activation of the NLRP3 inflammasome

Sinomenine is a pure alkaloid that can be isolated from the root of Sinomenium acutum and has been found to exert anti-inflammatory and immunosuppressive effects. The present study investigated the effects of sinomenine hydrochloride (SIN) on inflammation and the gut microbiota composition in the colon of mouse models of dextran sulfate sodium (DSS)-induced colitis. DSS-induced mice colitis was established by treating the mice with drinking water containing 3% (w/v) DSS for 7 days. The disease activity index of each mouse was calculated on a daily basis. All mice were sacrificed on day 11, then the weight of their spleen and length of their colons were measured. The histological analysis was measured by hematoxylin-eosin staining. Oral administration of SIN (100 mg/kg/day) attenuated the DSS-induced increases in the disease activity indices and spleen indices, DSS-induced shortening of the colon length and histological damage. In addition, reverse transcription-quantitative PCR data showed that SIN treatment effectively regulated the expression of inflammatory mediators, specifically by suppressing the expression of proinflammatory gene (TNF-α, IL-6 and inducible nitric oxide synthase) whilst increasing those associated with inhibiting inflammation (IL-10 and arginine 1). Gut microbiota analysis was conducted using 16S ribosomal DNA sequencing. The results revealed that SIN improved bacterial community homeostasis and diversity, which were damaged by DSS. Furthermore, western blotting showed that the activation of the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome was markedly suppressed by SIN treatment. In conclusion, these results indicated that SIN may ameliorate experimental colitis by modulating the gut microbiota composition and suppressing the activation of the NLRP3 inflammasome in mice. Overall, these findings suggested a broad protective effect of SIN in treating inflammatory gut diseases, including ulcerative colitis.

Risk of autoimmune diseases in patients with RASopathies: systematic study of humoral and cellular immunity

BACKGROUND

Abnormalities of the immune system are rarely reported in patients affected by RASopathies. Aim of the current study was to investigate the prevalence of immune system dysfunction in a cohort of patients affected by RASopathies.

STUDY DESIGN

A group of 69 patients was enrolled: 60 at the Federico II University, Naples, 7 at University Magna Graecia of Catanzaro, 2 at "Scuola Medica Salernitana", Salerno. An age- and sex-matched control group was also enrolled. Autoimmune disorders were investigated according to international consensus criteria. Immune framework was also evaluated by immunoglobulin levels, CD3, CD4, CD8, CD19, CD56 lymphocyte subpopulations, autoantibodies levels and panel of inflammatory molecules, in both patients and controls.

RESULTS

Frequent upper respiratory tract infections were recorded in 2 patients; pneumonia, psoriasis and alopecia in single patients. Low IgA levels were detected in 8/44 patients (18.18%), low CD8 T cells in 13/35 patients (37.14%). Anti-tg and anti-TPO antibodies were detected in 3/24 patients (12.5%), anti r-TSH in 2 cases (8.33%), all in euthyroidism. Serum IgA and CD8 levels were significantly lower in patients than in controls (p 0.00685; p 0.000656 respectively). All tested patients showed increased inflammatory molecules compared to controls. These findings may anticipate the detection of overt autoimmune disease.

CONCLUSIONS

Patients affected by RASopathies are at risk to develop autoimmune disorders. Routine screening for autoimmunity is recommended in patients with RASopathy.

Hydroxytyrosol alleviate intestinal inflammation, oxidative stress and apoptosis resulted in ulcerative colitis

Hydroxytyrosol (HYT) is one of the main alcoholic compounds of the olive leaves extract (OLE), which is known for its beneficial effects. This study aimed to investigate the effectiveness of olive leaves extract standardized with 25% hydroxytyrosol (OLES-25%HYT) in treatment of induced ulcerative colitis. Three groups of albino rats, were divided as following, group 1 (normal control), group 2 (induced ulcerative colitis and untreated) and group 3 (induced ulcerative colitis and treated with OLES-25%HYT). Colonic tissue samples were collected from all studied groups, the antioxidant activity for malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPX), myeloperoxidase (MPO) and nitric oxide (NO) were performed. The expression of pro-inflammatory cytokines, the apoptotic gene Bax and the anti-apoptotic gene Bcl2 was obtained in colon tissue to evaluate the OLES-25%HYT effect on ulcerative colitis. OLES-25%HYT showed effectiveness on reduction of mortality rate and disease activity index (DAI). Also, reduced oxidative stress and inflammation in colon tissue, OLES-25%HYT showed a significant reduction in colon MDA, MPO and NO levels and a significant elevation in SOD, CAT and GPX levels and cause down regulation of pro-inflammatory cytokines. Also, the apoptotic gene Bax downregulated and the anti-apoptotic gene Bcl2 upregulated as a result of the treatment compared to untreated induced ulcerative colitis group. OLES-25%HYT showed intestinal anti-inflammatory, antioxidants and anti-apoptotic effects in experimental models of ulcerative colitis.

Inhibition of acetic acid-induced colitis in rats by new Pediococcus acidilactici strains, vitamin producers recovered from human gut microbiota

Our aim was to isolate, identify and characterize probiotic bacteria as vitamin producers in particular B2 and B9. 150 human fecal samples were collected and used for isolation of vitamin producers—probiotics. 49 isolates were chosen for screening their genome by PCR for the presence of riboflavin and folic acid genes. As a result, three isolates were selected and their production of the B2 and B9 were confirmed by HPLC. The three isolates were identified on species level by sequencing their 16S rRNA gene which showed 100% identical to strains of Pediococcus acidilactici. Thus, they were named as P. acidilactici WNYM01, P. acidilactici WNYM02, P. acidilactici WNYM03 and submitted to the Genbank database with accession numbers. They met the probiotic criteria by expressing 90–95% survival rate at pH (2.0–9.0) and bile salt up to 2% for 3 h in addition to their antimicrobial activity against gram positive and negative microorganisms. They also showed no hemolytic activity and common pattern for antibiotic susceptibility. Our three strains were tested individually or in mixture in vivo on rat colitis model compared to ulcerative group. The strains were administrated orally to rats in daily dose containing CFU 10⁹ for 14 days then followed by induction of colitis using acetic acid then the oral administration was continued for more four days. The histology results, the anti-inflammatory and anti-oxidative stress biomarkers showed the protective role of the strains compared to the ulcerative group. As a conclusion, we introduce novel three probiotic candidates for pharmaceutical preparations and health applications.

Translating Treg Therapy for Inflammatory Bowel Disease in Humanized Mice

Crohn's disease and ulcerative colitis, two major forms of inflammatory bowel disease (IBD) in humans, afflicted in genetically predisposed individuals due to dysregulated immune response directed against constituents of gut flora. The defective immune responses mounted against the regulatory mechanisms amplify and maintain the IBD-induced mucosal inflammation. Therefore, restoring the balance between inflammatory and anti-inflammatory immunepathways in the gut may contribute to halting the IBD-associated tissue-damaging immune response. Phenotypic and functional characterization of various immune-suppressive T cells (regulatory T cells; Tregs) over the last decade has been used to optimize the procedures for in vitro expansion of these cells for developing therapeutic interventional strategies. In this paper, we review the mechanisms of action and functional importance of Tregs during the pathogenesis of IBD and modulating the disease induced inflammation as well as role of mouse models including humanized mice repopulated with the human immune system (HIS) to study the IBD. "Humanized" mouse models provide new tools to analyze human Treg ontogeny, immunobiology, and therapy and the role of Tregs in developing interventional strategies against IBD. Overall, humanized mouse models replicate the human conditions and prove a viable tool to study molecular functions of human Tregs to harness their therapeutic potential.

Irritable bowel syndrome and subsequent risk of Parkinson's disease: a nationwide population-based matched-cohort study

BACKGROUND

Gastrointestinal dysfunction (GI) is the most prevalent non-motor symptom of Parkinson's disease (PD), and its role in the risk of PD has been studied. In this study, we tried to evaluate whether irritable bowel syndrome (IBS) increased the risk of PD development stratified by sex, age, and IBS duration using a large nationwide cohort in Korea.

METHODS

Patients aged ≥ 20 years with a primary diagnosis of IBS (ICD-10 codes: G56) more than three times were selected. A randomly matched cohort without IBS was enrolled by exact matching patients for sex, age, socioeconomic status, comorbidities, and year of enrollment to the IBS group with a ratio of 1:3. Cause-specific Cox regression models were used to identify hazards associated with PD development depending on the presence of IBS during the 11-year follow-up period.

RESULTS

In total, 285,064 patients were enrolled in the study: 71,806 in the IBS cohort and 213,258 in the comparison cohort. Cause-specific Cox regression model showed a hazard ratio of 1.436 (95% CI, 1.226-1.682) for PD development in the IBS cohort, which is consistent in both male and female sexes. Subgroup analyses according to age groups showed that IBS increased PD risk only in individuals ≥ 65 years (HR = 1.449, 95% CI, 1.207-1.741).

CONCLUSIONS

We found temporal relationship between IBS and PD at aged ≥ 65 years. There might be a possibility that IBS was an early manifestation of PD, and future studies for causal link between the two diseases to elucidate biomechanism are warranted.