Progression Of Colitis Research Articles

Characteristics of the gut microbiota and the effect of Bifidobacterium in very early-onset inflammatory bowel disease patients with IL10RA mutations

Very early-onset inflammatory bowel disease (VEO-IBD) is a distinct subtype of inflammatory bowel disease (IBD) characterized by onset before the age of 6 years, and patients often exhibit more severe clinical features. Interleukin 10 receptor alpha (IL10RA) is a hotspot mutation in the Chinese population and is associated with a poor prognosis closely linked to the onset of IBD. However, limited knowledge exists regarding how the IL10RA mutation influences the host microbiota and its role in disease development. We employed 16S rRNA sequencing to conduct a comprehensive assessment of microbial changes in different types of IBD, employed database to thoroughly examine the influence of Bifidobacterium in IBD and to demonstrate a potential positive effect exerted by Bifidobacterium breve M16V (M16V) through a mouse model. The study demonstrated a significant reduction in the abundance and diversity of the gut microbiota among children with IL10RA mutations compared to those with late-onset pediatric IBD and nonmutated VEO-IBD. Furthermore, the analysis identified genera capable of distinguishing between various types of IBD, with the genus Bifidobacterium emerging as a potential standalone diagnostic indicator and Bifidobacterium may also be involved in related pathways that influence the progression of IBD, such as the biosynthesis of amino acids and inflammation-related pathways. This study corroborated the efficacy of Bifidobacterium in alleviating intestinal inflammation. The impact of IL10RA mutations on VEO-IBD may be mediated by alterations in microbes. M16V demonstrates efficacy in alleviating colitis and holds promise as a novel microbial therapy.

Pickled radish alleviates the progression of colitis in mice by reducing inflammation and repairing intestinal barrier

Scope: Pickled radish is a traditional fermented food known for its health benefits, however, evidence supporting its role in regulating gastrointestinal function is limited. This study aimed to investigate the beneficial effect of pickled radish on DSS-induced colitis in mice. Method and Results: Divide the mice into four groups: control, DSS model, low-dose (DSS+ 5 % pickled radish powder), and high-dose (DSS+ 10 % pickled radish powder). Colitis was induced by 3 % DSS administration in drinking water for eight days. Body weight loss, disease activity index (DAI), colon length, histology, and levels of inflammatory markers were measured to evaluate the effects of pickled radish on colitis. The results indicate that pickled radish significantly eased symptoms of colitis in mice induced by DSS, dose-dependently reducing DAI, reversed colon shortening, alleviating pathological damage to colon tissue and inflammatory response. Mechanistic investigation revealed that pickled radish upregulated the expression of tight junction-related genes (Zo-1, E-cadherin) and down-regulated inflammation-related genes (Il-1β, Il-6, TNF-α). Moreover, low-dose pickled radish significantly reversed the imbalance of gut microbiota and increased SCFAs. Conclusion: These findings suggest the potential of pickled radish in functional foods targeting the improvement of gastrointestinal health.

Epithelial mitochondrial fission-mediated PANoptosis is crucial for ulcerative colitis and its inhibition by saquinavir through Drp1

Ulcerative colitis (UC) is characterized by increased cell death in intestinal epithelial cell (IEC), which compromises gut barrier function and activates inflammation. Aberrant mitochondrial dynamics have been implicated in various forms of cell death, but it is currently unclear if they play a role in IEC death and colitis pathogenesis. This study aims to investigate the contribution of aberrant mitochondrial dynamics to colitis progression using cellular models, animal models, and clinical samples. The results revealed that IEC in mice with Dextran sulfate sodium salt (DSS)-induced colitis exhibited dynamin-related protein 1 (Drp1)-mediated mitochondrial fission and Z-DNA binding protein 1 (ZBP1)-dependent PANoptosis, which is a combination of apoptosis, necroptosis, and pyroptosis. However, these processes and the pathogenesis of DSS-induced colitis were significantly attenuated in IEC-specific Drp1 heterozygous knockout mice. Importantly, ZBP1-PANoptosis and Drp1-mediated mitochondrial fission were observed in IEC of UC patients, exhibiting a positive correlation with disease severity. Mechanistically, hyperactivated mitochondrial fission induced mitochondrial reactive oxygen species production leading to PANoptosis through ZBP1 sulfenylation at Cys327 independently of its Zα domain. Saquinavir, an FDA-approved drug identified through in-silico screening alongside in vivo and in vitro experiments, inhibits mitochondrial fission thereby enhancing therapeutic efficacy in mice with colitis.

Gossypetin Alleviates DSS-induced Colitis by Regulating COX2 and ROS-JNK Signaling.

Inflammatory Bowel Disease (IBD) represents a chronic and recurrent inflammatory condition affecting the gastrointestinal tract, with a rising global incidence. Current treatment approaches include surgery and drugs. However, surgeries are invasive procedures, while drug treatments often present with various side effects. Gossypetin, a flavonoid found abundantly in plants such as hibiscus, exhibits anti-oxidant and anti-cancer properties. However, its potential impact on IBD remains unexplored. This study aimed to investigate the therapeutic potential of gossypetin on colitis. We employed the DSS-induced colitis model to evaluate the therapeutic potential of gossypetin on colitis. The efficacy of gossypetin was assessed within this model using the Disease Activity Index (DAI) score and histological analysis. Additionally, we utilized qRT-PCR to measure the levels of inflammatory cytokines and Superoxide Dismutase (SOD). Immunohistochemistry confirmed the expression of tight junction markers, COX-2, and phosphorylated JNK protein, normally associated with disease progression. Furthermore, Western blot analysis was conducted to examine the SOD levels and anti-apoptotic effects of gossypetin. In DSS-induced colitis mice, gossypetin treatment ameliorated weight loss and reduced colon length caused by DSS treatment. Additionally, gossypetin-treated groups exhibited DAI scores and reduced histological damage. Moreover, gossypetin treatment increased tight junction expression, decreased inflammatory responses, reduced ROS levels, attenuated JNK signaling, and decreased apoptosis. Gossypetin shows therapeutic potential for mitigating the symptoms and progression of colitis by targeting ROS-JNK signaling involved in inflammation and tissue damage. This highlights the potential of natural compounds such as gossypetin for targeted therapies with reduced side effects and improved efficacy.

Vagal stimulation ameliorates murine colitis by regulating SUMOylation.

Inflammatory bowel diseases (IBDs) are chronic debilitating conditions without cure, the etiologies of which are unknown, that shorten the lifespans of 7 million patients worldwide by nearly 10%. Here, we found that decreased autonomic parasympathetic tone resulted in increased IBD susceptibility and mortality in mouse models of disease. Conversely, vagal stimulation restored neuromodulation and ameliorated colitis by inhibiting the posttranslational modification SUMOylation through a mechanism independent of the canonical interleukin-10/α7 nicotinic cholinergic vagal pathway. Colonic biopsies from patients with IBDs and mouse models showed an increase in small ubiquitin-like modifier (SUMO)2 and SUMO3 during active disease. In global genetic knockout mouse models, the deletion of Sumo3 protected against development of colitis and delayed onset of disease, whereas deletion of Sumo1 halted the progression of colitis. Bone marrow transplants from Sumo1-knockout (KO) but not Sumo3-KO mice into wild-type mice conferred protection against development of colitis. Electric stimulation of the cervical vagus nerve before the induction of colitis inhibited SUMOylation and delayed the onset of colitis in Sumo1-KO mice and resulted in milder symptoms in Sumo3-KO mice. Treatment with TAK-981, a first-in-class inhibitor of the SUMO-activating enzyme, ameliorated disease in three murine models of IBD and reduced intestinal permeability and bacterial translocation in a severe model of the disease, suggesting the potential to reduce progression to sepsis. These results reveal a pathway of vagal neuromodulation that reprograms endogenous stress-adaptive responses through inhibition of SUMOylation and suggest SUMOylation as a therapeutic target for IBD.

MALAT1 promotes colonic epithelial cell apoptosis and pyroptosis by sponging miR-22-3p to enhance NLRP3 expression.

Colonic epithelial cell apoptosis and pyroptosis had a close relationship with the pathological progression of ulcerative colitis (UC). LncRNA play a crucial role in the progression of UC. However, the role of the lncRNA MALAT1 in colonic epithelial cell apoptosis and pyroptosis remains unclear. UC colitis cell model was established through lipopolysaccharide (LPS) treatment. MiR-22-3p and MALAT1 expression in fetal human colon (FHC) cells were analyzed by qRT-PCR. Proliferation and apoptosis of FHCs were measured using CCK-8 assay and flow cytometry, respectively. Pyroptosis indicators including interleukin (IL)-1β, IL-18, tumor necrosis factor-α (TNF-α), NLR family pyrin domain containing 3 (NLRP3), caspase-1, and N-gasdermin D (N-GSDMD) in FHCs were detected using ELISA, qRT-PCR, western blotting, and immunofluorescence. In this study, apoptosis was facilitated, IL-1β, IL-18, and TNF-α levels were enhanced, NLRP3, caspase-1, N-GSDMD protein were increased, and MALAT1 expression was markedly increased in LPS-treated FHCs (LTFs). MALAT1 knockdown remarkably facilitated proliferation and suppressed apoptosis, reduced IL-1β, IL-18, and TNF-α levels, and decreased the protein of NLRP3, caspase-1, N-GSDMD. Furthermore, NLRP3 overexpression remarkably reversed the effect of MALAT1-downexpression in LTFs. In addition, miR-22-3p could bind with MALAT1 and NLRP3 3' UTR. Furthermore, miR-22-3p inhibition remarkably reversed the effect of MALAT1 overexpression in LTFs. These findings suggest that MALAT1 represents a promising therapeutic target for the treatment of UC by modulating the miR-22-3p/NLRP3 pathway, potentially leading to novel strategies for reducing inflammation and cell death in the colon.

Differential contributions of the gut microbiota and metabolome to pathomechanisms in ulcerative colitis: an in vitro analysis

ABSTRACT The gut microbiota has been implicated in onset and progression of ulcerative colitis (UC). Here, we assess potential causal involvement of the microbiota and -associated fecal water (FW) metabolome in altering key functional parameters of the colonic epithelium. Fecal samples were collected from N = 51 healthy controls (HC), N = 36 patients with active UC (UC-A), and N = 41 subjects in remission N = 41 (UC-R). Using in vitro incubation experiments, the FW metabolome’s impact on butyrate oxidation rates/gene expression and cell death (cytotoxicity) of HT-29 cells, cytokine production by PBMC, and barrier integrity of Caco2 monolayers was evaluated. The FW metabolome from patients and individuals hosting the Bacteroides 2 (Bact2) enterotype (69% of UC-A, 31% of UC-R, 3% of HC), characterized by lower levels of median- and short-chain fatty acids and furan compounds, left butyrate oxidation rates unaltered but affected associated gene expression profiles. UC patients/Bact2-carriers’ FW lowered PBMC IL-8 production and increased IL-1β production. Patients’ FW increased cytotoxicity, associated with sulfide compound levels. Bact2 carriers’ FW, displaying higher levels of bile acids, lowered barrier function upon incubation of monolayers. The FW metabolome of patients and individuals hosting a dysbiotic microbiota could contribute to the disruption of functional processes of the colonic epithelium as observed in UC.

Advances in research on the role of high carbohydrate diet in the process of inflammatory bowel disease (IBD).

Inflammatory bowel disease (IBD) is a chronic, systemic gastrointestinal disorder characterized by episodic inflammation that requires life-long management. Although the etiology of IBD is not fully understood, it is hypothesized to involve a multifaceted interplay among genetic susceptibility, the host immune response, and environmental factors. Previous studies have largely concluded that IBD is associated with this complex interplay; however, more recent evidence underscores the significant role of dietary habits as risk factors for the development of IBD. In this review, we review the molecular mechanisms of high-sugar and high-fat diets in the progression of IBD and specifically address the impacts of these diets on the gut microbiome, immune system regulation, and integrity of the intestinal barrier, thereby highlighting their roles in the pathogenesis and exacerbation of IBD.

Early subclinical stages of the inflammatory bowel diseases - insights from human and animal studies.

The inflammatory bowel diseases (IBD) occur in genetically susceptible individuals that mount inappropriate immune responses to their microbiota leading to chronic intestinal inflammation. The natural history of IBD progression begins with early subclinical stages of disease that occur before clinical diagnosis. Improved understanding of those early subclinical stages could lead to new or improved strategies for IBD diagnosis, prognostication or prevention. Here we review our current understanding of the early subclinical stages of IBD in humans including studies from first-degree relatives of IBD patients and members of the general population who go on to develop IBD. We also discuss representative mouse models of IBD that can be used to investigate disease dynamics and host-microbiota relationships during these early stages. In particular, we underscore how mouse models of IBD that develop disease later in life with variable penetrance may present valuable opportunities to discern early subclinical mechanisms of disease before histological inflammation and other severe symptoms become apparent.

Development of interleukin-27 recombinant Lactococcus lactis and its efficacy in treating psoriasis and colitis in mice

Psoriasis and inflammatory bowel disease (IBD) are chronic immune-mediated diseases that adversely affect patients' quality of life. Interleukin (IL)-27 plays an important role in a variety of infectious diseases, autoimmune disorders, and cancers. However, its therapeutic effects in psoriasis and colitis remain underexplored. In this study, we evaluated the therapeutic potential of recombinant Lactococcus lactis (L. lactis) expressing IL-27 (pIL-27) in imiquimod-induced psoriasis and dextran sodium sulfate-induced colitis mouse models. In the psoriasis mouse model, oral administration of pIL-27 significantly reduced skin scaling, mitigated weight loss, lowered psoriasis area and severity index scores, diminished epidermal hyperplasia and inflammatory cell infiltration, and decreased inflammatory cytokine levels. In the colitis mouse model, oral administration of pIL-27 alleviated weight loss, improved disease activity index scores, prevented colon shortening, ameliorated histopathological changes, and decreased inflammatory cytokine levels. Furthermore, recombinant L. lactis expressing IL-27 could modulate the gut microbiota, increasing the amount of beneficial bacteria and reducing harmful bacteria in the intestine, thereby alleviating the progression of psoriasis and colitis. These results suggest the potential of IL-27 as a therapeutic option for treating psoriasis and IBD.

Human gut commensal Alistipes timonensis modulates the host lipidome and delivers anti-inflammatory outer membrane vesicles to suppress colitis in an Il10 -deficient mouse model.

Correlative studies have linked human gut microbes to specific health conditions. Alistipes is one such microbial genus negatively linked to inflammatory bowel disease (IBD). However, the protective role of Alistipes in IBD has not been studied and the underlying molecular mechanisms also remain unknown. In this study, colonization of Il10 -deficient mice with Alistipes timonensis DSM 27924 delays the development of colitis. Colonization with Alistipes does not significantly alter the gut microbiome composition during colitis development, but instead shifts the host plasma lipidome, increasing phosphatidic acids while decreasing triglycerides. Outer membrane vesicles (OMVs) derived from Alistipes are also detected in the plasma of colonized mice, which carry metabolites with immunomodulatory potential into the host circulatory system. We further demonstrate that fractions of A. timonensis OMVs suppress LPS-induced Il6 , Il1b , and Tnfa expression in vitro in murine macrophages. We detect immunomodulatory sulfonolipids (SoLs) in the active fraction, which are also increased in the blood of A. timonensis -colonized mice; and we identify other putative bioactive lipids in the A. timonensis OMVs. Thus, A. timonensis OMVs represent a potential mechanism for Alistipes -mediated delay of colitis progression in Il10 -deficient mice through the delivery of immunomodulatory lipids, including SoLs, and modulation of the host plasma lipidome.

Gut Microbiome as a Target of Intervention in Inflammatory Bowel Disease Pathogenesis and Therapy

Inflammatory bowel disease (IBD) is a chronic complicated inflammatory gut pathological disorder and is categorized into ulcerative colitis (UC) and Crohn’s disease (CD). Although the cause of IBD is unclear, dysbiosis of the gut microbiota is thought to be a key factor in the disease’s progression. The gut microbiome serves as a metabolic organ and promotes wellness by carrying out several biological activities. Any modification in the makeup of the gut microbiome leads to several pathological conditions, including IBD. In this review, we emphasize the key metabolic processes that control host–microbiome interaction and its impact on host health. We also discuss the association between microbiome dysbiosis (bacteriome, virome, and mycobiome) and the progression of IBD. Finally, we will highlight microbiome-based therapy as a novel and promising strategy to treat and manage IBD.

Advancements in the use of AI in the diagnosis and management of inflammatory bowel disease.

Inflammatory bowel disease (IBD) causes chronic inflammation of the colon and digestive tract, and it can be classified as Crohn's disease (CD) and Ulcerative colitis (UC). IBD is more prevalent in Europe and North America, however, since the beginning of the 21st century it has been increasing in South America, Asia, and Africa, leading to its consideration as a worldwide problem. Optical colonoscopy is one of the crucial tests in diagnosing and assessing the progression and prognosis of IBD, as it allows a real-time optical visualization of the colonic wall and ileum and allows for the collection of tissue samples. The accuracy of colonoscopy procedures depends on the expertise and ability of the endoscopists. Therefore, algorithms based on Deep Learning (DL) and Convolutional Neural Networks (CNN) for colonoscopy images and videos are growing in popularity, especially for the detection and classification of colorectal polyps. The performance of this system is dependent on the quality and quantity of the data used for training. There are several datasets publicly available for endoscopy images and videos, but most of them are solely specialized in polyps. The use of DL algorithms to detect IBD is still in its inception, most studies are based on assessing the severity of UC. As artificial intelligence (AI) grows in popularity there is a growing interest in the use of these algorithms for diagnosing and classifying the IBDs and managing their progression. To tackle this, more annotated colonoscopy images and videos will be required for the training of new and more reliable AI algorithms. This article discusses the current challenges in the early detection of IBD, focusing on the available AI algorithms, and databases, and the challenges ahead to improve the detection rate.

Inflammatory bowel disease uncovered in fecal immunochemical test positive patients in a Canadian provincial colon cancer screening program

Inflammatory Bowel Disease (IBD) is a chronic inflammatory condition that usually affects younger adults but has a second incidence peak in the older population. Although diagnosis of IBD is driven by symptoms, some patients are asymptomatic and incidentally discovered while participating in colon screening program (CSP). We aimed to identify the incidence and outcome of IBD in fecal immunochemical test (FIT) positive patients in the British Columbia CSP. We conducted a retrospective chart review of patients who had colonoscopies for positive FIT and were found to have colitis based on endoscopic and histological assessment. Of 93,994 patients who underwent screening colonoscopy for positive FIT between 2009 and 2017, 608 (0.6%) were found to have colitis. From 11 CSP sites, 191 patients met the inclusion criteria. 58 patients (30.4%) were diagnosed with ulcerative colitis, 109 (57.1%) with Crohn’s disease (CD), and 24 (12.6%) with IBD unclassified. 124 patients (64.9%) received treatment, of which 34 (17.8%) received biologics and 4 (2.1%) required surgery. Our study demonstrated a clinically significant incidence of IBD, with novel finding of CD predominance, within a Canadian provincial CSP. Further research is needed to guide management of older patients with varying rates of IBD progression after incidental diagnosis.

Identification and Validation of Biomarkers to Predict Early Diagnosis of Inflammatory Bowel Disease and Its Progression to Colorectal Cancer.

Inflammatory bowel disease (IBD) has become a common global health problem as prevalence continues to rise. It is often associated with increased risk of colorectal cancer (CRC) development. Limitations in current IBD biomarker-based diagnosis hinder the accuracy of early detection of CRC progression. Therefore, in this study, we proposed the use of transcription factor (TF)-based biomarkers that can potentially detect the transition of IBD to CRC. Various bioinformatic analysis and online database validations, and RT-qPCR validations were performed to identify possible diagnostic TFs. RUNX1 was identified as a promising TF that regulates 106 IBD/CRC-related genes. The incorporation of RUNX1 in combination with currently known IBD biomarkers, FEV + NFKB1 + RELA, achieved a comparable sensitivity and specificity scores of 99% and 87%, respectively, while RUNX1 in combination with known CRC markers, CEA + TIMP1 + CA724 + CA199, achieved a sensitivity and specificity score of 97% and 99%, respectively. Furthermore, a small pilot RT-qPCR-based analysis confirmed a demarcated shift in expression profiles in CA724, CEA, RUNX1 and TIMP1 in IBD patients compared to CRC patients' tissue samples. Specifically, CA724 is noticeably elevated in IBD, while the levels of CEA, RUNX1 with TIMP1 are probable genes that may be employed in discerning IBD progression to CRC. Therefore, these preliminary results once validated in large patient cohorts could potentially have a significant impact on CRC disease stratification, resulting in a more precise prediction for treatment and treatment outcomes, especially in South African patients.

Cross-talk between macrophages and gut microbiota in inflammatory bowel disease: a dynamic interplay influencing pathogenesis and therapy.

Inflammatory bowel disease (IBD), which includes ulcerative colitis (UC) and Crohn's disease (CD), is a group of chronic immune-mediated gastrointestinal disorders. The etiology of IBD is multifactorial, involving genetic susceptibility, environmental factors, and a complex interplay between the gut microbiota and the host's immune system. Intestinal resident macrophages play an important role in the pathogenesis and progress of IBD, as well as in maintaining intestinal homeostasis and facilitating tissue repair. This review delves into the intricate relationship between intestinal macrophages and gut microbiota, highlighting their pivotal roles in IBD pathogenesis. We discuss the impact of macrophage dysregulation and the consequent polarization of different phenotypes on intestinal inflammation. Furthermore, we explore the compositional and functional alterations in gut microbiota associated with IBD, including the emerging significance of fungal and viral components. This review also examines the effects of current therapeutic strategies, such as 5-aminosalicylic acid (5-ASA), antibiotics, steroids, immunomodulators, and biologics, on gut microbiota and macrophage function. We underscore the potential of fecal microbiota transplantation (FMT) and probiotics as innovative approaches to modulate the gut microbiome in IBD. The aim is to provide insights into the development of novel therapies targeting the gut microbiota and macrophages to improve IBD management.

Construction of chlorogenic acid nanoparticles for effective alleviation of ulcerative colitis.

The onset and progression of ulcerative colitis (UC) are intricately linked to the worsening of intestinal inflammation, an imbalance in oxidative stress, and impairment of the intestinal mucosal barrier. Although chlorogenic acid (CA) shows potential in effectively alleviating the symptoms of UC, its clinical application is hindered by its poor bioavailability, stability, rapid metabolism, and quick excretion. This study utilized a one-step enzyme-catalyzed polymerization technique to create chlorogenic acid nanoparticles (CA NPs), aiming to improve the bioavailability and stability of CA. The CA NPs exhibited an optimal nanosize (106.65 ± 4.12 nm) and showed increased cellular uptake over time. Importantly, CA NPs significantly prolonged retention time in inflamed colonic tissues, enhancing accumulation and providing a targeted therapy for UC. Animal studies confirmed the substantial benefits of CA NPs, including reduced weight loss, lessened reduction in colon length, and a lowered disease activity index (DAI) score in DSS-induced UC mice. Moreover, CA NPs effectively reduced oxidative stress and levels of inflammatory factors in the colonic tissues of UC mice, thus mitigating tissue damage and restoring the integrity of the intestinal mucosal barrier. In conclusion, our research proposes a novel approach to increase the bioavailability and stability of CA, offering a promising avenue for its effective application in preventing UC.

The Potential Benefits of Exercise in Managing Inflammatory Bowel Disease: A Systematic Review.

Adults with inflammatory bowel disease (IBD) experience a significant decline in quality of life due to various symptoms. Exercise has emerged as a potential therapeutic approach to improve IBD management, but its effectiveness requires further investigation. This systematic review, adhering to PRISMA 2020 guidelines, explored the effects of exercise on IBD progression and its potential as a treatment in adults. A comprehensive search strategy was conducted across three databases and two registries from May 12, 2024, to May 22, 2024. Methodological rigor and potential bias were minimized through quality assessment using the Cochrane risk-of-bias tool 2 (RoB 2) for randomized controlled trials (RCTs), the Newcastle-Ottawa Scale (NOS) for cohort studies, and the Joanna Briggs Institute (JBI) critical appraisal checklist for studies evaluating the effectiveness of non-randomized interventions. This process yielded 12 high-quality studies for analysis. The review identified positive evidence from both RCTs and observational studies. Exercise interventions demonstrated improvements in cardiorespiratory fitness, disease activity, quality of life, and mental health in adults with IBD. Studies explored various modalities, including aerobic exercise, resistance training, and mind-body interventions. However, further research is needed to optimize exercise prescription and elucidate the underlying mechanisms of action. This review strengthens the evidence for exercise as a beneficial intervention for IBD patients. Personalized exercise programs based on individual needs hold promise for improved IBD management and patient outcomes. However, limitations exist due to study design variations and the need for long-term follow-up studies.

The Role of Claudins in the Pathogenesis of Dextran Sulfate Sodium-Induced Experimental Colitis: The Effects of Nobiletin.

The pathogenesis of inflammatory bowel diseases such as ulcerative colitis and Crohn's disease is not well understood. This study investigated the roles and regulation of the claudin-1, -2, -3, and -4 isoforms in the pathogenesis of ulcerative colitis, and the potential therapeutic effects of nobiletin. Colitis was induced in rats by administering dextran sulfate sodium [DSS] in drinking water for seven days. Animals were treated daily with nobiletin [oral, 60 mg/Kg body weight] and studied in four groups, C [non-colitis control], D [DSS-induced colitis], CN [nobiletin-treated non-colitis control], and DN [nobiletin-treated DSS-induced colitis]. On day seven, the animals were sacrificed, and colonic tissues were collected and analyzed. Both macroscopic and microscopic findings suggest the progression of colitis. In the inflamed colon, claudin-1 and -4 proteins were decreased, claudin-2 increased, while the claudin-3 protein remained unchanged. Except for claudin-1, these changes were not paralleled by mRNA expression, indicating a complex regulatory mechanism. Uniform β-actin expression along with consistent quality and yield of total RNA indicated selectivity of these changes. Nobiletin treatment reversed these changes. Altered expression of the claudin isoforms -1, -2, and -4 disrupts tight junctions, exposing the lamina propria to microflora, leading to electrolyte disturbance and the development of ulcerative colitis. Nobiletin with its anti-inflammatory properties may be useful in IBD.

Oxidative Stress Regulator NRF2 Controls Inflammatory T-helper 1 (Th1) Subset Differentiation by Modulating Glycolysis and Protects against Colitis Progression in Mice

Oxidative Stress Regulator NRF2 Controls Inflammatory T-helper 1 (Th1) Subset Differentiation by Modulating Glycolysis and Protects against Colitis Progression in Mice