Factors In Inflammatory Bowel Disease Research Articles

Childhood and adolescent residential and farm pesticide exposures and inflammatory bowel disease incidence in a U.S. cohort of women

Background and aimsThere are few known risk factors for inflammatory bowel disease (IBD), an autoimmune disease characterized by chronic intestinal inflammation. Use of specific pesticides has been associated with higher incidence of IBD among pesticide applicators and their spouses, but no study has examined pesticide exposure in early life, a period where the human immune system undergoes rapid changes. We evaluated pesticide use during childhood and adolescence and incidence of IBD among US women enrolled in the Sister Study. MethodsIncident IBD diagnoses between enrollment (2003–2009) and 2021 were identified and validated with medication use and colectomy/colostomy surgery. We estimated hazard ratios (HR) and 95 % confidence intervals (CI) for the relationship of childhood/adolescent residential and farm pesticide exposures with IBD incidence using Cox models, accounting for age, race and ethnicity, education, smoking, and birth year. ResultsWe identified 277 incident IBD cases among 48,382 eligible participants. IBD hazard was elevated among those whose childhood residence was regularly treated with pesticides, especially among those who ever personally applied pesticides (HR = 1.39, 95%CI: 0.65, 2.99). We observed a positive association between IBD and exposure to broadcast pesticide sprays before DDT was banned (>6 times vs. never HR = 1.56, 95%CI: 1.06, 2.31). Among participants who lived on a farm during childhood/adolescence for ≥1 year (N = 9162), IBD hazards were higher among those who were in crop fields during pesticide application (HR = 2.06, 95%CI: 0.94, 4.51) and who ever personally applied pesticides on crops (HR = 1.85, 95%CI: 0.81, 4.18) or livestock (HR = 2.58, 95%CI: 1.14, 5.83). ConclusionEarly-life pesticide exposure may be a novel risk factor for IBD. Practices that reduce pesticide exposure during early life may help reduce the burden of this disease.

Umbrella review of risk factors for inflammatory bowel disease: a study protocol

IntroductionInflammatory bowel disease (IBD) is a chronic idiopathic inflammatory disorder that arises from complex interactions between genetics, environment and gut microbiota. It encompasses Crohn’s disease, ulcerative colitis and IBD-unclassified. The...

Pregnancy period and early-life risk factors for inflammatory bowel disease: a Northern Finland birth cohort 1966 study

BackgroundThe pathogenesis of inflammatory bowel disease (IBD) has not been fully elucidated. The aim of this study was to analyze the pregnancy period, perinatal period, and infancy period risk factors for IBD in a well-characterized birth cohort from Northern Finland.MethodsThe Northern Finland Birth Cohort 1966 (NFBC1966) population comprises mothers living in the two northernmost provinces of Finland, Oulu, and Lapland, with dates of delivery between Jan 1st and Dec 31st, 1966 (12 055 mothers, 12 058 live-born children, 96.3% of all births during 1966). IBD patients were identified using hospital registries (from 1966 to 2020) and Social Insurance Institution (SII) registry reimbursement data for IBD drugs (from 1978 to 2016). The data were analyzed by Fisher’s exact test and logistic regression.ResultsIn total, 6972 individuals provided informed consent for the use of combined SII and hospital registry data. Of those, 154 (2.1%) had IBD (113 [1.6%] had ulcerative colitis (UC), and 41 (0.6%) had Crohn’s disease (CD)). According to multivariate analysis, maternal smoking > 10 cigarettes/day during pregnancy was associated with a nearly 6-fold increased risk of CD in the offspring (OR 5.78, 95% CI 1.70–17.3). Breastfeeding (OR = 0.18, 95% CI 0.08–0.44) and iron supplementation during the first year of life (OR = 0.43, 95% CI 0.21–0.89) were negatively associated with CD.ConclusionsSmoking during pregnancy was associated with the risk of CD while Breastfeeding and oral iron supplementation at infancy were negatively associated with the risk of CD later in life.

Crohn’s disease in patients with Hirschsprung disease and Hirschsprung-associated enterocolitis: A review

In the last decade, the incidence of inflammatory bowel disease in children has been increasing. Some studies have reported the development of Crohn’s disease in patients with Hirschsprung disease and Hirschsprung-associated enterocolitis. Suggestions have been made about the possible causes of the development of Crohn’s-like lesions after intestinal resection in early childhood. This study aimed to summarize information about Hirschsprung-associated Crohn’s disease and Crohn’s-like lesions after surgical treatment of Hirschsprung disease. The search was carried out in scientific databases of eLibrary, PubMed, ScienceDirect, and Google Scholar. The search time interval was 2000–2023. Fourteen articles dedicated to Hirschsprung-associated Crohn’s disease were identified. Common pathogenesis factors in inflammatory bowel diseases and Hirschsprung-associated enterocolitis were identified, such as microbiota disturbance and chronic inflammation. Predisposing factors for pathological immune response to dysbiosis and incidence of enterocolitis included enteric nervous system dysfunction, impaired neuroimmune regulatory mechanisms, general immunological disturbance, and “immaturity” and abnormality of the barrier function of the intestinal mucosa. The “classic form” of Crohn’s disease may not develop in patients with Hirschsprung disease and recurrent attacks of enterocolitis but Crohn’s-like lesions. Persistent functional or organic obstruction after surgical treatment of Hirschsprung disease enhances the negative effect of predisposing factors, leading to chronic inflammation of the intestinal mucosa. Delayed occurrence of Hirschsprung-associated enterocolitis is a predisposing factor for the development of chronic inflammation. When Hirschsprung-associated enterocolitis occurs repeatedly, endoscopic assessment should be performed for the exclusion of Crohn’s disease and chronic inflammatory changes in the anastomosis area for treatment selection.

Physical Activity Is Associated With A Decreased Risk Of Developing Inflammatory Bowel Disease: A Systematic Review And Meta-Analysis.

Modifiable risk factors in Inflammatory Bowel Disease (IBD), such as physical activity, may be utilised as prevention strategies. However, the findings of previous studies on the association between physical activity and IBD risk have been inconsistent. We aimed to perform a systematic review and meta-analysis to estimate the effect of physical activity on IBD risk. A search was conducted for relevant studies published before April 2023 that assessed the effect of pre-IBD diagnosis levels of physical activity on IBD incidence. Individual summary statistics (relative risks; RR), and confidence intervals (CI) were extracted with forest plots generated. We used the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach to assess the quality of evidence. 10 observational studies were included. For cohort studies, there were 1,182 Crohn's disease (CD) and 2,361 ulcerative colitis (UC) patients, with 860,992 participants without IBD. For case-control studies, there were 781 CD to 2,636 controls, and 1,127 UC to 3,752 controls. Compared to individuals with low physical activity levels, the RRs of CD in individuals with high physical activity levels for cohort and case-control studies were 0.78 (95% CI 0.68-0.88, P = 0.0001) and 0.87 (95% CI 0.79-0.95, P = 0.003), respectively. For UC, the RRs were 0.62 (95% CI 0.43-0.88, P = 0.008) and 0.74 (95% CI 0.51-1.07, P = 0.11). This meta-analysis suggests that physical activity is inversely associated with the risk of developing IBD, more so in CD than in UC.

DHX9 maintains epithelial homeostasis by restraining R-loop-mediated genomic instability in intestinal stem cells

Epithelial barrier dysfunction and crypt destruction are hallmarks of inflammatory bowel disease (IBD). Intestinal stem cells (ISCs) residing in the crypts play a crucial role in the continuous self-renewal and rapid recovery of intestinal epithelial cells (IECs). However, how ISCs are dysregulated in IBD remains poorly understood. Here, we observe reduced DHX9 protein levels in IBD patients, and mice with conditional DHX9 depletion in the intestinal epithelium (Dhx9ΔIEC) exhibit an increased susceptibility to experimental colitis. Notably, Dhx9ΔIEC mice display a significant reduction in the numbers of ISCs and Paneth cells. Further investigation using ISC-specific or Paneth cell-specific Dhx9-deficient mice demonstrates the involvement of ISC-expressed DHX9 in maintaining epithelial homeostasis. Mechanistically, DHX9 deficiency leads to abnormal R-loop accumulation, resulting in genomic instability and the cGAS-STING-mediated inflammatory response, which together impair ISC function and contribute to the pathogenesis of IBD. Collectively, our findings highlight R-loop-mediated genomic instability in ISCs as a risk factor in IBD.

Accumulated LPS induced by colitis altered the activities of vitamin D-metabolizing hydroxylases and decreased the generation of 25-hydroxyvitamin D

It is generally accepted that low vitamin D (VD) levels are associated with a high prevalence factor for Inflammatory bowel disease (IBD). IBD patients have observed higher levels of lipopolysaccharide (LPS), ALT, and AST than healthy people. Gut-derived LPS causes inflammatory injury in the liver and kidney. The VD-metabolizing mechanism is involved in the liver and kidney, which means IBD might impact VD metabolism. However, whether IBD affects VD metabolism has not been studied. In vitro LPS resulted in decreased CYP2R1 in liver cells as well as decreased CYP27B1 and increased CYP24A1 in kidney cells, revealing that LPS changed the activities of several hydroxylases. Mice with acute colitis had an increased LPS in serum and liver with mild hepatic injuries, while mice with chronic colitis had a significant elevation of LPS in serum, liver, and kidney with hepatorenal injuries. Thus, the liver hydroxylase for VD metabolism would be the first to be affected in IBD. Consequently, serum 25-hydroxyvitamin D declined dramatically with a significant elevation of 24,25-dihydroxyvitamin D and 1,24,25-trihydroxyvitamin D. Unchanged serum levels of 1,25-dihydroxyvitamin D might be the result of other factors in vivo. In acute colitis, a small dosage (4 IU/day) of cholecalciferol could protect the colon, decrease the serum level of LPS, and finally increase serum 25-hydroxyvitamin D. However, this improvement of cholecalciferol was fading in chronic colitis. These results suggested that VD supplementations for preventing and curing IBD in the clinic should consider hepatorenal hydroxylases and be employed as soon as possible for a better outcome.

Increased bronchiectasis risk and related risk factors in inflammatory bowel disease: a 10-year Korean national cohort study.

The association between inflammatory bowel disease (IBD) and an increased risk of bronchiectasis, as well as contributing factors, remains unclear. Additionally, whether bronchiectasis increases disease burden in IBD remains unknown. Therefore, this study aimed to: 1) assess whether IBD increases the risk of incident bronchiectasis; 2) compare the risk of bronchiectasis between individuals with Crohn's disease (CD) and those with ulcerative colitis (UC); 3) identify risk factors for bronchiectasis in individuals with IBD; and 4) examine the disease burden in individuals with IBD and bronchiectasis versus those without. We conducted a population-based matched cohort study involving adults aged ≥20 years with IBD, using data acquired from the Korean National Health Insurance Service-National Sample Cohort database between 2002 and 2012. During the mean follow-up of 9.6 years, the incidence rate of bronchiectasis was 419.63 out of 100 000 person-years (PY) and 309.65 out of 100 000 PY in the IBD and matched cohorts (adjusted hazard ratio (aHR) 1.21, 95% CI 1.05-1.39), respectively. UC was associated with increased bronchiectasis risk (aHR 1.42, 95% CI 1.19-1.69), but CD was not. Multivariate Cox regression analyses showed that age, male sex, medical aid, underweight status, COPD and diabetes mellitus were associated with an increased risk of bronchiectasis in the IBD cohort (p<0.05). The mortality, emergency department visit and hospitalisation rates were significantly higher for individuals with IBD and bronchiectasis compared with those without bronchiectasis (p<0.05). IBD is associated with increased risk of bronchiectasis, which results in a greater disease burden in individuals with IBD.

Integrated 16S rRNA sequencing and metagenomics insights into microbial dysbiosis and distinct virulence factors in inflammatory bowel disease.

The escalation of urbanization correlates with rising rates of inflammatory bowel disease (IBD), necessitating research into new etiological factors. This study aims to elucidate the gut microbiota profiles in IBD patients and compare them with healthy controls in a western city of China. We conducted a multicenter case-control study from the end of 2020, using 16S rRNA gene sequencing (n = 36) and metagenomic sequencing (n = 12) to analyze the gut microbiota of newly diagnosed IBD patients, including those with Crohn's disease (CD) and ulcerative colitis (UC). Our results demonstrated a significant enrichment of the phylum Proteobacteria, particularly the genus Escherichia-Shigella, in CD patients. Conversely, the genus Enterococcus was markedly increased in UC patients. The core gut microbiota, such as the Christensenellaceae R-7 group, Fusicatenibacter, and Holdemanella, were primarily identified in healthy subjects. Additionally, significant interactions between the microbiome and virulence factors were observed. The findings suggest that oxidative stress may play a pivotal role in the pathology of IBD. This study contributes to the growing dialogue about the impact of gut microbiota on the development of IBD and its variations across different geographies, highlighting potential avenues for further research.

Human-derived bacterial strains mitigate colitis via modulating gut microbiota and repairing intestinal barrier function in mice

BackgroundUnbalanced gut microbiota is considered as a pivotal etiological factor in colitis. Nevertheless, the precise influence of the endogenous gut microbiota composition on the therapeutic efficacy of probiotics in colitis remains largely unexplored.ResultsIn this study, we isolated bacteria from fecal samples of a healthy donor and a patient with ulcerative colitis in remission. Subsequently, we identified three bacterial strains that exhibited a notable ability to ameliorate dextran sulfate sodium (DSS)-induced colitis, as evidenced by increased colon length, reduced disease activity index, and improved histological score. Further analysis revealed that each of Pediococcus acidilactici CGMCC NO.17,943, Enterococcus faecium CGMCC NO.17,944 and Escherichia coli CGMCC NO.17,945 significantly attenuated inflammatory responses and restored gut barrier dysfunction in mice. Mechanistically, bacterial 16S rRNA gene sequencing indicated that these three strains partially restored the overall structure of the gut microbiota disrupted by DSS. Specially, they promoted the growth of Faecalibaculum and Lactobacillus murinus, which were positively correlated with gut barrier function, while suppressing Odoribacter, Rikenella, Oscillibacter and Parasutterella, which were related to inflammation. Additionally, these strains modulated the composition of short chain fatty acids (SCFAs) in the cecal content, leading to an increase in acetate and a decrease in butyrate. Furthermore, the expression of metabolites related receptors, such as receptor G Protein-coupled receptor (GPR) 43, were also affected. Notably, the depletion of endogenous gut microbiota using broad-spectrum antibiotics completely abrogated these protective effects.ConclusionsOur findings suggest that selected human-derived bacterial strains alleviate experimental colitis and intestinal barrier dysfunction through mediating resident gut microbiota and their metabolites in mice. This study provides valuable insights into the potential therapeutic application of probiotics in the treatment of colitis.

ERCC4: a potential regulatory factor in inflammatory bowel disease and inflammation-associated colorectal cancer.

The pathogenesis of inflammatory bowel disease (IBD) remains unclear and is associated with an increased risk of developing colitis-associated cancer (CAC). Under sustained inflammatory stimulation in the intestines, loss of early DNA damage response genes can lead to tumor formation. Many proteins are involved in the pathways of DNA damage response and play critical roles in protecting genes from various potential damages that DNA may undergo. ERCC4 is a structure-specific endonuclease that participates in the nucleotide excision repair (NER) pathway. The catalytic site of ERCC4 determines the activity of NER and is an indispensable gene in the NER pathway. ERCC4 may be involved in the imbalanced process of DNA damage and repair in IBD-related inflammation and CAC. This article primarily reviews the function of ERCC4 in the DNA repair pathway and discusses its potential role in the processes of IBD-related inflammation and carcinogenesis. Finally, we explore how this knowledge may open novel avenues for the treatment of IBD and IBD-related cancer.

The role of granulocyte-macrophage colony-stimulating growth factor in inflammatory bowel diseases

Inflammatory bowel diseases, which include ulcerative colitis and Crohn's disease, are chronic immune-inflammatory diseases of the intestine that are increasing in prevalence and incidence worldwide. They are progressive, with the need for lifelong therapy, a high risk of surgical interventions and a decrease in the quality of life of patients. The results of clinical and population studies indicate that the possibilities of modern therapy for inflammatory bowel diseases have reached their maximum. Its effectiveness in achieving complete clinical and endoscopic remission, despite the use of genetically engineered biological drugs, is estimated at 35-40%, which is obviously insufficient. A possible solution to this problem could be the inclusion of granulocyte-macrophage colony-stimulating factors in treatment regimens for inflammatory bowel diseases in combination with glucocorticosteroids, cytostatics and biological therapy drugs. A review of a number of experimental and clinical studies that confirmed the clinical effectiveness of macrophage growth factors is the subject of this article.

P1143 Per- and poly-fluoroalkyl substances (PFAS) exposure is associated with later occurrence of inflammatory bowel disease

Abstract Background Environmental chemical exposures are increasingly acknowledged as risk factors for inflammatory bowel disease (IBD). Per- and poly-fluoroalkyl substances (PFAS), a large class of persistent fluorinated organic chemicals, widely used in the modern environment, may be implicated in IBD etiology, but data are conflicting. Methods We investigated the association of PFAS mixture concentrations in pre-diagnostic serum with adult-onset IBD in a pilot study within the pre-clinical Proteomic Evaluation and Discovery in an IBD Cohort of Tri-service Subjects (PREDICTS) study. This is a nested case-control study of military personnel with Crohn’s disease (CD), ulcerative colitis (UC), and age-, sex-, and race-matched healthy controls with serum samples obtained at four-time points 1-10 years prior to IBD diagnosis. Using untargeted liquid-chromatography high-resolution mass spectrometry analytical approach, we conducted an untargeted metabolomic analysis and semiquantitative measurement of fluorinated compounds, including legacy PFAS and emerging PFAS chemicals. We used weighted quantile sum regression models adjusted for confounders to study the association of PFAS as a mixture with the odds of CD and UC at each time point. Results Our study sample included individuals with CD, UC, and matched healthy controls (n=25, each group, 4 samples per individual). Baseline characteristics were similar across cases and controls. We identified nine well known PFAS compounds and 27 other known fluorinated compounds. The chemical mixture of fluorinated compounds, including the known PFAS, in the serum samples within one year of diagnosis was associated with higher odds of CD and UC [odds ratio (OR) 2.13, 95% CI 1.33, 3.41, and 1.76, 95% CI 1.15, 2.68, respectively] per one unit increase in decile. These associations remained consistent for the PFAS mixture measured in serum at all four time points up to 10 years prior to diagnosis for both CD and UC (Figure). Major contributors to the overall mixture indices included legacy PFAS, as well as emerging PFAS chemicals. Conclusion We observed a substantial increase in the odds of CD and UC among individuals with higher serum PFAS mixture levels up to 10 years prior to diagnosis. Studies to understand underlying mechanisms are ongoing.

P1159 Gene and environment interactions in inflammatory bowel disease: a systematic review of human epidemiologic studies

Abstract Background Complex gene-environment interaction for Inflammatory Bowel Disease (IBD) remains elusive. This systematic review aims to summarize the current evidence of gene and environment interactions in IBD. Methods PubMed, EMBASE, Web of Science and Scopus were systematically searched from inception through July 20, 2022 to identify publications examining the interaction effect of genetic variants and environmental factors in IBD. Two investigators independently screened the title/abstract and full text according to the predefined criteria. All eligible studies were graded using STREGA guideline. The protocol was registered on PROSPERO (CRD42023443071). Results 4,305 publications were identified and screened, resulting in 36 eligible studies. 17 studies reported statistically significant interactions. The interaction effect of NOD2 and smoking was most frequently investigated and showed variant-specific interaction at rs2066847 regrading risk of Crohn’s disease (CD). Gene-smoking interactions were further identified in 1) other IBD risk genes (ATG16L1, IL23R, CALM3), as well as the IBD-genetic risk score (GRS), 2) detoxification genes (GSTP1 and ΗΜΟΧ1), 3) smoking-associated genes (CHRNA3, CHRNA5, PPP1R3C, BDNF), as well as the general smoking-GRS, and 4) the inflammation cytokine gene (IL-1β) using the candidate gene approach. Using the Illumina immune-focused Chip, another 64 smoking interacting variants were identified. Gene-diet interactions were reported across different nutritional measures, including the intake of fatty acids with CYP4F3 and FADS2, serum level of selenium with SEPHS1and SEPSECS, dietary intake of potassium with IL21, alcohol consumption with IL12B, dietary heme iron intake with FcgRIIA and serum level of 25-hydroxyvitamin D with VDR. No genome wide environment interaction studies (GWEIS) of IBD have been conducted to date, while this strategy holds great potential to unravel the missing heritability influenced by environment factors for IBD. Conclusion While past studies have increased insights into potential gene-environmental interactions in the pathophysiology of IBD, current evidence is limited and inconclusive due to lack of replication of presented results, and limited study power. Further research, including GWEIS and clinical trials, is needed for future recommendations on lifestyle and dietary modification, based on individual genetic backgrounds.

P813 A questionnaire-based study on fatigue and associated factors in Inflammatory Bowel Disease

Abstract Background Although fatigue is common in patients with inflammatory bowel disease (IBD), it often goes unrecognized and untreated. We investigated the degree of fatigue, and associated factors, in patients with IBD. Methods A multicenter study involving 147 IBD patients was conducted at five academic hospitals from August 2019 to December 2021. Demographic, clinical, and laboratory data were collected. Disease activity was assessed by the Mayo score or Crohn’s Disease Activity Index, as appropriate. Fatigue was evaluated using the validated Korean version of the Multidimensional Fatigue Inventory (MFI-K). Anxiety and depression were measured using the Hospital Anxiety and Depression Scale Results Among 97 ulcerative colitis and 50 Crohn’s disease patients, the mean total MFI-K score was 59.0 ± 5.5. Age, sex, body mass index, disease duration, anemia, hypoalbuminemia, and use of steroids did not affect the total MFI-K score. The anxiety and depression scores did not correlate with the fatigue score. Moderate and high disease activity significantly increased the MFI-K general and physical fatigue subscale scores compared to remission and mild disease activity (17.6 ± 1.7 vs. 16.7 ± 2.0, P = 0.009), while the use of biologics significantly decreased the total MFI-K score (57.3 ± 5.0 vs. 59.5 ± 5.5, P = 0.031). Multiple linear regression showed that fatigue was significantly increased by a history of surgery for IBD and decreased by the use of biologics. Conclusion The degree of fatigue in patients with IBD is high, and disease activity is the most important contributing factor.

P478 Fatigue, physical fitness, and physical activity in patients with inflammatory bowel disease

Abstract Background Fatigue is a common and debilitating symptom in patients with Inflammatory Bowel Disease (IBD) with a great impact on quality of life and work productivity. A better comprehension of the contributing factors to fatigue could potentially pave the way for more targeted and effective strategies for managing fatigue in IBD. Fatigue may be associated with lower levels of physical activity and reduced physical fitness. Yet, the interaction between these factors in IBD, measured with validated tests, is not fully understood. Therefore, this study aimed to investigate the association between fatigue and physical fitness and physical activity in patients with IBD. Methods Adult patients with IBD in remission or with mild-to-moderate clinical disease activity with an ASA Physical Status &amp;lt;III were eligible for inclusion. Fatigue was defined as a Checklist Individual Strength-fatigue subscale score ≥35. Patient and clinical characteristics were collected, including age, sex, body mass index, comorbidities, disease duration, disease location and behavior, clinical and biochemical disease activity, smoking status, previous intestinal resection, and medication use. Cardiorespiratory fitness was measured using cardiopulmonary exercise testing to assess the oxygen uptake at peak exercise (VO2peak). Muscular strength (peak torque at 60°/s) and endurance (fatigue rate as percentage decline in peak torque over 30 repetitions at 180°/s) of the knee extensor and flexor muscles were assessed using an isokinetic dynamometer. Objective physical activity data were collected continuously for seven consecutive days utilizing the MOX accelerometer, with activities categorized into sedentary, standing, light (LPA), moderate (MPA), and vigorous physical activity (VPA) levels. Results In total, 50 patients were included, with 17 being classified as fatigued. Fatigued patients had significantly higher BMIs, a higher frequency of clinical disease activity, and a higher prevalence of smoking (Table 1). They also exhibited significantly lower VO2peak (mean [±SD] 28.1 [±7.9] vs. 36.0 [±9.8] mL·kg-1·min-1, p=0.007) and higher knee extensor fatigue rate (mean [±SD] 39.0% [±8.8] vs. 31.1% [±10.4], p=0.010) compared to non-fatigued patients. There was no statistical significant difference in physical activity between fatigued and non-fatigued patients. Conclusion Although physical activity did not differ between patients with and without fatigue, fatigued patients exhibited lower cardiorespiratory fitness and knee extensor muscular endurance. A larger population is needed to further investigate the influence of patient and disease characteristics on this relationship to work towards more targeted and effective strategies for managing fatigue in patients with IBD.

Corin deficiency alleviates mucosal lesions in a mouse model of colitis induced by dextran sulfate sodium

AimsHigh dietary salt consumption is a risk factor for inflammatory bowel disease (IBD). Corin is a protease that activates atrial natriuretic peptide (ANP), thereby regulating sodium homeostasis. Corin acts in multiple tissues, including the intestine. In mice, corin deficiency impairs intestinal sodium excretion. This study aims to examine if reduced intestinal sodium excretion alters the pathophysiology of IBD. Main methodsWild-type (WT), Corin knockout (KO), and Corin kidney conditional KO (kcKO) mice were tested in a colitis model induced by dextran sulfide sodium (DSS). Effects of ANP on DSS-induced colitis were tested in WT and Corin KO mice. Body weight changes in the mice were monitored. Necropsy, histological analysis, and immunostaining studies were conducted to examine colon length and mucosal lesions. Fecal sodium levels were measured. RT-PCR was done to analyze proinflammatory genes in colon samples. Key findingsDSS-treated Corin KO mice had an ameliorated colitis phenotype with less body weight loss, longer colon lengths, smaller mucosal lesions, lower disease scores, more preserved goblet cells, and suppressed proinflammatory genes in the colon. In longitudinal studies, the DSS-treated Corin KO mice had delayed onset of colon mucosal lesions. ANP administration lessened the colitis in WT, but not Corin KO, mice. Analyses of WT, Corin KO, and Corin kcKO mice indicated that fecal sodium excretion, controlled by intestinal corin, may regulate inflammatory responses in DSS-induced colitis in mice. SignificanceOur findings indicate a role of corin in intestinal pathophysiology, suggesting that reduced intestinal sodium level may offer protective benefits against IBD.

Dietary long-chain fatty acids promote colitis by regulating palmitoylation of STAT3 through CD36-mediated endocytosis

The Western diet, characterized by its high content of long-chain fatty acids (LCFAs), is widely recognized as a significant triggering factor for inflammatory bowel disease (IBD). While the link between a high-fat diet and colitis has been observed, the specific effects and mechanisms remain incompletely understood. Our study provides evidence that the diet rich in LCFAs can disrupt the integrity of the intestinal barrier and exacerbate experimental colitis in mice. Mechanistically, LCFAs upregulate the signal transducer and activator of transcription-3 (STAT3) pathway in the inflammatory model, and STAT3 knockout effectively counters the pro-inflammatory effects of LCFAs on colitis. Specifically, palmitic acid (PA), a representative LCFA, enters intestinal epithelial cells via the cluster of differentiation 36 (CD36) pathway and participates in the palmitoylation cycle of STAT3. Inhibiting this cycle using pharmacological inhibitors like 2-Bromopalmitate (2-BP) and ML349, as well as DHHC7 knockdown, has the ability to alleviate inflammation induced by PA. These findings highlight the significant role of dietary LCFAs, especially PA, in the development and progression of IBD. Diet adjustments and targeted modulation offer potential therapeutic strategies for managing this condition.Model of LCFAs involvement in the palmitoylation cycle of STAT3 upon internalization into cells. Following cellular uptake through CD36, LCFAs are converted to palmitoyl-CoA. In the presence of DHHC7, palmitoyl-CoA binds to STAT3 at the C108 site, forming palmitoylated STAT3. Palmitoylation further promotes phosphorylation at the Y705 site of STAT3. Subsequently, palmitoylated STAT3 undergoes depalmitoylation by APT2 and translocates to the nucleus to exert its biological functions.

Animal models of inflammatory bowel disease: category and evaluation indexes.

Inflammatory bowel disease (IBD) research often relies on animal models to study the etiology, pathophysiology, and management of IBD. Among these models, rats and mice are frequently employed due to their practicality and genetic manipulability. However, for studies aiming to closely mimic human pathology, non-human primates such as monkeys and dogs offer valuable physiological parallels. Guinea pigs, while less commonly used, present unique advantages for investigating the intricate interplay between neurological and immunological factors in IBD. Additionally, New Zealand rabbits excel in endoscopic biopsy techniques, providing insights into mucosal inflammation and healing processes. Pigs, with their physiological similarities to humans, serve as ideal models for exploring the complex relationships between nutrition, metabolism, and immunity in IBD. Beyond mammals, non-mammalian organisms including zebrafish, Drosophila melanogaster, and nematodes offer specialized insights into specific aspects of IBD pathology, highlighting the diverse array of model systems available for advancing our understanding of this multifaceted disease. In this review, we conduct a thorough analysis of various animal models employed in IBD research, detailing their applications and essential experimental parameters. These include clinical observation, Disease Activity Index score, pathological assessment, intestinal barrier integrity, fibrosis, inflammatory markers, intestinal microbiome, and other critical parameters that are crucial for evaluating modeling success and drug efficacy in experimental mammalian studies. Overall, this review will serve as a valuable resource for researchers in the field of IBD, offering insights into the diverse array of animal models available and their respective applications in studying IBD.

Metabolic dysfunction-associated steatotic liver disease prevalence and risk factors in inflammatory bowel disease in tertiary center.

The aim of this study was to evaluate the prevalence and risk factors related to metabolic dysfunction-associated steatotic liver disease in inflammatory bowel disease patients. This is a cross-sectional study conducted on adults with inflammatory bowel disease from 2019 to 2021. Metabolic dysfunction-associated steatotic liver disease encompasses patients with steatosis and at least one cardiometabolic risk factor. Patients with alcohol consumption ≥20 g/day, chronic liver diseases, or methotrexate use were excluded. Almost 140 patients were included: 67.1% were female, with a mean age of 49.7±13.7 years, and 63.6% had Crohn's disease. The mean duration of inflammatory bowel disease was 9.7±7.9 years. Metabolic dysfunction-associated steatotic liver disease was observed in 44.3% and advanced liver fibrosis was excluded in 63.5% by Fibrosis-4. Patients with metabolic dysfunction-associated steatotic liver disease were older (p = 0.003) and had a higher number of metabolic syndrome components (2.9±1.1 versus 1.6±1.0; p<0.001), greater abdominal circumference (p<0.001), and body mass index (p<0.001). The only factor related to inflammatory bowel disease associated with metabolic dysfunction-associated steatotic liver disease was disease duration (11.6±9.5 versus 8.3±6.2; p = 0.017). A higher number of metabolic syndrome components and obesity increase by 2.2 times and an altered waist circumference by 2.6 times the occurrence of metabolic dysfunction-associated steatotic liver disease. A high prevalence of metabolic dysfunction-associated steatotic liver disease was observed in patients with inflammatory bowel disease, with the main risk factors being associated with metabolic syndrome predicting it, but not with inflammatory bowel disease features and/or its treatment.