Clinical factors to predict flare-up in patients with inflammatory bowel disease during international air travel: A prospective study.

BACKGROUNDS AND AIMS: Inflammatory bowel disease (IBD) patients often experience disease flare-ups during international air travel. We aimed to identify risk factors associated with IBD flare-up during international air travel. METHODS: Patients with scheduled international air travel were enrolled in the study from the Seoul National University Bundang Hospital IBD clinic. Flight information and clinical data were collected via questionnaires and personal interviews, and risk factors associated with IBD flares were determined. RESULTS: Between May 2018 and February 2020, 94 patients were prospectively enrolled in the study (mean age, 33.0 years; males, 53.2%; mean disease duration, 56.7 months), including 56 (59.6%) with ulcerative colitis and 38 (40.4%) with Crohn's disease. Of the 94 patients enrolled, 15 (16.0%) experienced an IBD flare-up and 79 (84.0%) remained in remission throughout travel. Logistic regression analysis revealed that high fecal calprotectin levels before travel (odds ratio [OR]: 1.001, 95% confidence interval [CI]: 1.000-1.001, p = 0.016), the presence of a comorbidity (OR: 6.334, 95% CI: 1.129-35.526, p = 0.036), and history of emergency room visit (OR: 5.283, 95% CI: 1.085-25.724, p = 0.039) were positively associated with disease flare-up. The previous and current use of immunomodulators and biologics, time of flight, altitude, number countries visited, travel duration, objective of visit, and previous medical consultations were not associated with disease flare-up. CONCLUSIONS: Elevated fecal calprotectin levels, history of emergency room visits, and the presence of a comorbidity predicted IBD flare-up during international air travel.

Safety evaluation of ustekinumab for moderate-to-severe ulcerative colitis.

INTRODUCTION: Ustekinumab is a human IgG1 kappa monoclonal antibody that targets the p40 subunit of interleukin (IL)-12 and IL-23 and blocks the binding of these cytokines to the IL-12Rß1 chain of their receptors. Ustekinumab is approved for treating moderate-to-severe ulcerative colitis (UC). AREAS COVERED: We reviewed the mechanism of action, pharmacokinetics, efficacy, and safety of ustekinumab. Future challenges for optimizing UC treatment with ustekinumab are discussed. EXPERT OPINION: Ustekinumab has favorable clinical efficacy and safety profiles for moderately-to-severely active UC. Ustekinumab is the first biologic for targeting IL-12/IL-23 pathways. Therefore, ustekinumab can be a therapeutic option following the failure of other biologics, including anti-tumor necrosis factor-α antagonists and anti-α4ß7 integrin antagonists. However, the positioning of ustekinumab in the therapeutic strategy for UC remains unclear. The efficacy of combinations of ustekinumab and immunomodulators over ustekinumab monotherapy has not been supported in studies. Ustekinumab is a human immunoglobulin G monoclonal antibody with low immunogenicity. Therefore, ustekinumab monotherapy, which should be safe, could be sufficient for treating UC. Further studies are required to understand the efficacy and safety of ustekinumab in patients with UC, particularly in special situations, and to optimize UC treatment with ustekinumab.

Inflammatory Bowel Disease Patients Who Respond to Treatment with Anti-tumor Necrosis Factor Agents Demonstrate Improvement in Pre-treatment Frailty.

BACKGROUND: Frailty may be a risk factor for complications in inflammatory bowel diseases (IBD) patients. We examined the impact of treatment on IBD patients who were frail prior to treatment and identified predictors of post-treatment change in frailty. METHODS: In an electronic health record-based cohort of IBD patients initiating anti-tumor necrosis factor (TNF)-α agents, we applied a validated claims-based frailty index to determine frailty in the 1 year prior to and after treatment initiation. We characterized treatment non-response using a composite outcome of IBD-related hospitalization, surgery, change in therapy, or initiation of systemic steroids. We constructed multivariable logistic regression models to identify determinants of post-treatment frailty. RESULTS: The 1210 patients initiating anti-TNF therapy had a median age of 30 years; 20% were ≥ 50 years. In the first year after anti-TNF initiation, 40% were non-responders. Many more treatment non-responders were frail in the year following treatment compared with treatment responders (27% vs 7%, p < 0.001). Pre-treatment frailty (OR 2.01, 95% CI 1.35-3.00) and prior IBD-related hospitalization (OR 1.63, 95% CI 1.15-2.30) were independently predictive of higher likelihood of post-treatment frailty. Therapy response was associated with a lower likelihood (OR 0.24, 95% CI 0.16-0.34) of post-treatment frailty. Nearly 85% of patients who were frail prior to treatment demonstrated improvement in frailty following treatment CONCLUSIONS: Response to anti-TNF therapy is an important determinant of post-treatment frailty in patients with IBD. Our findings suggest that effectively treating inflammatory states in older patients with IBD may improve frailty.

Efficacy of Biologic Drugs in Short-Duration Versus Long-Duration Inflammatory Bowel Disease: A Systematic Review and an Individual-Patient Data Meta-Analysis of Randomized Controlled Trials.

BACKGROUND AND AIMS: Starting biologic treatment early in the course of inflammatory bowel disease (IBD) may be associated with higher efficacy, especially in Crohn's disease (CD). METHODS: This was a systematic review and individual-patient data meta-analysis of all placebo-controlled trials of biologics approved for IBD at study inception (October 2015), using Vivli data-sharing platform. The primary outcome was the proportional biologic/placebo treatment effect on induction of remission in patients with short-duration (≤18 months) vs long-duration disease (>18 months) analyzed separately for CD and ulcerative colitis (UC). We used meta-regression to examine the impact of patients' characteristics on the primary outcome. RESULTS: We included 25 trials, testing infliximab, adalimumab, certolizumab, golimumab, natalizumab, or vedolizumab (6168 patients with CD and 3227 patients with UC). In CD, remission induction rates were higher in pooled placebo and patients in active arms with short-duration disease of ≤18 months (41.4% [244 of 589]) compared with disease duration of >18 months (29.8% [852 of 2857], meta-analytically estimated odds ratio, 1.33; 95% confidence interval, 1.09-1.64). The primary outcome, proportional biologic/placebo treatment effect on induction of remission, was not different in short-duration disease of ≤18 months (n = 589, odds ratio, 1.47; 95% confidence interval, 1.01-2.15) compared with longer disease duration (n = 2857, odds ratio, 1.43; 95% confidence interval, 1.19-1.72). In UC trials, both the proportional biologic/placebo remission-induction effect and the pooled biologic-placebo effect were stable, regardless of disease duration. Primary outcome results remained unchanged when tested using alternative temporal cutoffs and when modeled for individual patient's covariates, including prior anti-tumor necrosis factor exposure. CONCLUSIONS: There are higher rates of induction of remission with biologics and with placebo in early CD, resulting in a treatment to placebo effect ratio that is similar across disease durations. No such relationships between disease duration and outcomes was found in UC. PROSPERO registration: CRD42018041961.

A Simple Emergency Department-Based Score Predicts Complex Hospitalization in Patients with Inflammatory Bowel Disease.

BACKGROUND AND AIMS: Thirty percent of inflammatory bowel disease (IBD) patients hospitalized with flare require salvage therapy or surgery. Additionally, 40% experience length of stay (LOS) > 7 days. No emergency department (ED)-based indices exist to predict these adverse outcomes at admission for IBD flare. We examined whether clinical, laboratory, and endoscopic markers at presentation predicted prolonged LOS, inpatient colectomy, or salvage therapy in IBD patients admitted with flare. METHODS: Patients with ulcerative colitis (UC) or colonic involvement of Crohn's disease (CD) hospitalized with flare and tested for Clostridioides difficile infection (CDI) between 2010 and 2020 at two urban academic centers were studied. The primary outcome was complex hospitalization, defined as: LOS > 7 days, inpatient colectomy, or inpatient infliximab or cyclosporine. A nested k-fold cross-validation identified predictive factors of complex hospitalization. RESULTS: Of 164 IBD admissions, 34% (56) were complex. Predictive factors included: tachycardia in ED triage (odds ratio [OR] 3.35; confidence interval [CI] 1.79-4.91), hypotension in ED triage (3.45; 1.79-5.11), hypoalbuminemia at presentation (2.54; 1.15-3.93), CDI (2.62; 1.02-4.22), and endoscopic colitis (4.75; 1.75-5.15). An ED presentation score utilizing tachycardia and hypoalbuminemia predicted complex hospitalization (area under curve 0.744; CI 0.671-0.816). Forty-four of 48 (91.7%) patients with a presentation score of 0 (heart rate < 99 and albumin ≥ 3.4 g/dL) had noncomplex hospitalization. CONCLUSIONS: Over 90% of IBD patients hospitalized with flare with an ED presentation score of 0 did not require salvage therapy, inpatient colectomy, or experience prolonged LOS. A simple ED-based score may provide prognosis at a juncture of uncertainty in patient care.

Systematic review: disease activity indices for immune checkpoint inhibitor-associated enterocolitis.

BACKGROUND: Although there is interest in developing pharmacotherapies for the treatment of immune checkpoint inhibitor-associated enterocolitis (ICIC), there is currently no consensus on how to optimally measure disease activity in this condition. AIMS: To identify all scoring indices used for the measurement of disease activity in ICIC, assess their operating properties, and explore their potential utility as outcome measures. METHODS: We searched MEDLINE, EMBASE and the Cochrane Library from inception to November 2020 to identify studies that evaluated disease activity and severity in patients with ICI-associated enterocolitis. These scoring tools could be designed specifically for ICIC or adapted from other diseases, and assessed clinical, endoscopic, or histologic disease activity. RESULTS: Sixty-four studies were included. The Common Terminology Criteria for Adverse Events is commonly used to describe symptoms, although has only been partially validated and was not designed as a disease activity index. Endoscopic and histologic indices used in inflammatory bowel disease have been adopted for ICIC including the Mayo Endoscopic Subscore, Ulcerative Colitis Endoscopic Index of Severity, Simple Endoscopic Score for Crohn's Disease, Nancy Histological Index, Robarts Histopathological Index, and Geboes Score, among others. None of these indices has been validated for use in ICIC, and all lacked content validity and responsiveness. CONCLUSIONS: There are no validated clinical, endoscopic, or histologic outcomes to assess disease activity in ICIC. Development and validation of reliable and responsive outcome measures that can be used to measure disease activity will be paramount for both clinical practice and for the development of treatments.

Assessment of patients' understanding of inflammatory bowel diseases: Development and validation of a questionnaire.

BACKGROUND: Educating patients regarding thier inflammatory bowel disease (IBD) is important for their empowerment and disease management. We aimed to develop a questionnaire to evaluate patient understanding and knowledge of IBD. METHODS: We have developed the Understanding IBD Questionnaires (U-IBDQ), consisting of multiple-choice questions in two versions [for Crohn's disease (CD) and ulcerative colitis (UC)]. The questionnaires were tested for content and face validity, readability, responsiveness and reliability. Convergent validity was assessed by correlating the U-IBDQ score with physician's subjective assessment scores. Discriminant validity was assessed by comparison to healthy controls (HC), patients with chronic gastrointestinal (GI) conditions other than IBD, and to GI nurses. Multivariate analysis was performed to determine factors associated with a high level of disease understanding. RESULTS: The study population consisted of IBD patients (n = 106), HC (n = 35), chronic GI disease patients (n = 38) and GI nurses (n = 19). Mean U-IBDQ score among IBD patients was 56.5 ± 21.9, similar for CD and UC patients (P = 0.941), but significantly higher than that of HC and chronic GI disease patients and lower than that of GI nurses (P < 0.001), supporting its discriminant validity. The U-IBDQ score correlated with physician's subjective score (r = 0.747, P < 0.001) and was found to be reliable (intra-class correlation coefficient = 0.867 P < 0.001). Independent factors associated with high U-IBDQ scores included academic education (OR = 1.21, 95% CI 1.10-1.33, P < 0.001), biologic therapy experience (OR = 1.24, 95% CI 1.01-1.53, P = 0.046), and IBD diagnosis at <21 years of age (OR = 2.97, 95% CI 1.05-8.87, P = 0.050). CONCLUSIONS: The U-IBDQ is a validated, reliable and short, self-reported questionnaire that can be used for assessing understanding of disease pathophysiology and treatment by IBD patients.

HLA-DQA1*05 Associates with Extensive Ulcerative Colitis at Diagnosis: An Observational Study in Children.

The human leukocyte antigen (HLA) allele group HLA-DQA1*05 predisposes to ulcerative colitis (UC) and is associated with the development of antibodies against infliximab in patients with inflammatory bowel disease (IBD). Therefore, we hypothesized that the presence of HLA-DQA1*05 correlates with characteristics of pediatric IBD. Within a multi-center cohort in Poland, the phenotype at diagnosis and worst flare was established and HLA-DQA1*05 status was assessed enabling genotype-phenotype analyses. HLA-DQA1*05 was present in 221 (55.1%) out of 401 children with IBD (UC n = 188, Crohn's disease n = 213). In UC, the presence of HLA-DQA1*05 was moderately associated with a large extent of colonic inflammation at diagnosis (E4 55% more frequent in HLA-DQA1*05-positive patients, p = 0.012). PUCAI at diagnosis (p = 0.078) and the time from UC diagnosis to the first administration of biologic treatment (p = 0.054) did not differ depending on HLA-DQA1*05 status. The number of days of hospitalization for exacerbation was analyzed in 98 patients for whom sufficient follow-up was available and did not differ depending on HLA-DQA1*05 carriership (p = 0.066). HLA-DQA1*05 carriers with CD were less likely to present with both stenosing and penetrating disease (B2B3, p = 0.048) and to have active disease proximal to the ligament of Treitz (L4a) at the worst flare (p = 0.046). Future research focusing on explaining and preventing anti-TNF immunogenicity should take into account that ADA may develop not only as an isolated reaction to anti-TNF exposure but also as a consequence of intrinsic differences in the early course of UC.

The association of the quality of sleep with proinflammatory cytokine profile in inflammatory bowel disease patients.

BACKGROUND: The role of circadian rhythm abnormalities in patients with inflammatory bowel disease (IBD) remains relatively unknown. The aim of this study was to identify the inflammatory cytokine profile in the IBD patients and its relationship with the quality of sleep. METHODS: Prospective, single-center observational cohort study was performed. In all enrolled adult IBD patients, the disease activity was assessed using Crohn's Disease Activity Index (CDAI) for Crohn's disease (CD) and Partial Mayo Score for ulcerative colitis (UC), respectively. To assess the quality of sleep, all patients were asked to respond to a questionnaire to define Pittsburgh Quality Sleep Index (PSQI). From all enrolled patients, 15 ml venous blood was taken to determine serum inflammatory cytokine levels and perform standard laboratory tests. RESULTS: Fifty-two IBD patients were enrolled in the study: 32 with CD and 20 with UC. The poor sleep was noted in 69.4% of patients with clinically active and in 6.3% of patients with inactive disease. In the group of IBD patients with poor sleep, the significantly higher level of serum IL-6, IL-17, and IL-23 were observed. In IBD patients with exacerbation, the significantly higher level of serum IL-6, IL-17, and IL-23 were recorded. CONCLUSIONS: The relationship between quality of sleep and proinflammatory cytokine profile may show us a predisposition for the development of inflammatory intestinal lesions in IBD patients with sleep disturbances. This knowledge may allow the pharmacological and behavioral therapies of circadian rhythm abnormalities to become new significant targets in IBD patients.

Cost-effectiveness of intravenous vedolizumab vs subcutaneous adalimumab for moderately to severely active ulcerative colitis.

BACKGROUND: The efficacy of intravenous (IV) vedolizumab vs subcutaneous (SC) adalimumab for the treatment of moderately to severely active ulcerative colitis (UC) was assessed in the VARSITY clinical trial, which demonstrated for the first time in a head-to-head clinical trial setting the superiority of IV vedolizumab with respect to clinical remission and endoscopic improvement. Both therapies offer better clinical outcomes compared with immunomodulators and corticosteroids but are often more expensive than other pharmacologic treatment options. Thus, payers and decision makers face the task of leveraging finite resources for optimal health benefits, which can be aided by the use of cost-effectiveness models. OBJECTIVE: To assess the cost-effectiveness of IV vedolizumab vs SC adalimumab from a US payer perspective using head-to-head data from the VARSITY trial. METHODS: A cohort decision tree was developed to estimate the costs and clinical outcomes associated with IV vedolizumab vs SC adalimumab to treat adults with moderately to severely active UC. Simulated cohorts began the model at treatment induction and continued to maintenance treatment with vedolizumab or adalimumab unless experiencing nonresponse or serious adverse drug reaction (ADR), in which case those patients transitioned to second-line treatment with tofacitinib, infliximab, or golimumab, where they could achieve response and/or remission or not. Those who still did not achieve response or remission or who had a serious ADR transitioned to a state of nonresponse for the remainder of the model or received surgery. The process was modeled for patients who were treatment naive and treatment experienced at baseline separately. Efficacy and safety inputs for vedolizumab and adalimumab were taken from the VARSITY trial, and corresponding inputs for other biologics were derived from a network meta-analysis. All clinical inputs were extrapolated over 2 years. Direct medical costs (expressed in 2019 US dollars) included those related to drug acquisition and administration, ADRs, routine monitoring, and additional treatment procedures. Outcomes were not discounted given the short time horizon. Univariate sensitivity and scenario analysis were applied to evaluate the robustness of the model to underlying parameter and structural uncertainty. RESULTS: Initial treatment with vedolizumab was associated with a higher remission rate at 2 years (73.5% vs 71.5%) and higher persistence (22.0% vs 14.4%) compared with adalimumab. Total direct medical costs were lower for the vedolizumab cohort ($100,022 vs $151,133), primarily driven by the lower annual drug acquisition cost of vedolizumab ($85,953 vs $137,492). When endoscopic improvement was used as the outcome measure, IV vedolizumab was also associated with higher endoscopic remission and lower overall costs. CONCLUSIONS: With better clinical outcomes and lower direct medical costs over a 2-year model horizon, vedolizumab IV was the dominant treatment strategy vs adalimumab SC in adults with moderately to severely active UC. Outcomes were driven primarily by the probability of major ADRs and induction response. DISCLOSURES: This study was supported by Takeda Pharmaceuticals U.S.A., Inc. (Lexington, MA). Schultz and Turpin are employees of Takeda Pharmaceuticals U.S.A., Inc. Turpin has stock or stock options in Takeda Pharmaceuticals. Diakite, Carter, and Snedecor are employees of OPEN Health (Bethesda, MD), which received payment from Takeda for the design and execution of this study. This study was presented at the European Crohn's and Colitis Organisation (ECCO) 2020 Congress and Digestive Disease Week (DDW), 2020 Virtual Congress.

The Tricky Trachea: Tracheitis and Mediastinitis Treated With Infliximab and Steroids in a Patient With Ulcerative Colitis.

Pulmonary extra-intestinal manifestations of inflammatory bowel disease are rare, comprising 0.21% to 0.4% of the inflammatory bowel disease population. Common symptoms include cough, chest pain, and dyspnea. Abnormal pulmonary function tests are common in these patients, with restrictive, obstructive, and diffusion capacity defects. CT scanning remains the most sensitive imaging technique to detect abnormalities. Pulmonary manifestations are diverse and include airway, parenchymal, and pleural disease. Large airway disease predominates, particularly bronchiectasis. Upper airway disease is rare but concerning for the development of acute airway compromise. To our knowledge, there are no reports of concurrent mediastinitis with tracheitis in the setting of inflammatory bowel disease. We present a case of a patient with ulcerative proctitis who experienced the development of inflammatory tracheitis and mediastinitis. Her disease responded to systemic steroids and biologic therapy. In addition to our case, we reviewed the literature and provide an approach to pulmonary complications as extra-intestinal manifestation of inflammatory bowel disease.

Correlation Between Sleep, Life, Mood, and Diet and Severity of Inflammatory Bowel Disease in China: A Retrospective Study.

BACKGROUND The aim of the present study was to assess the relationship between inflammatory bowel disease (IBD) and quality of sleep, quality of life (QoL), mental health, and dietary intake to identify potential risk factors for IBD. MATERIAL AND METHODS This was a retrospective analysis from September 2019 to August 2020. We enrolled 71 patients with IBD aged 14 to 69 years who completed the IBD-Life Habits Questionnaire, which included data on demographics, environmental factors, and dietary habits; the Pittsburgh Sleep Quality Index (PSQI); Patient Health Questionnaire (PHQ-9); Generalized Anxiety Disorder-7 (GAD-7); and the Inflammatory Bowel Disease Questionnaire (IBDQ). Of the patients, 46 had IBD that was in remission and in 25 the disease was active, based on scores used to assess clinical symptoms. The Crohn's Disease Activity Index (CDAI) and the Partial Mayo Score were used for Crohn disease (CD) and ulcerative colitis (UC), respectively. The patients were divided into 2 groups, based on disease status: remission (CDAI <150 or Mayo Score=0) and active (CDAI ≥150 or Mayo Score >0). Because sleep and dietary habits in the patients with UC and CD were not significantly different, the 2 groups of patients were eventually combined into a single IBD group. The IBD-Life Habits Questionnaire, except for IBDQ, was completed by 68 age- and sex-matched healthy controls. RESULTS Scores for PSQI (P=.001), PHQ-9 (P=.003), GAD-7 (P=.007), and IBDQ (P=.001) were significantly higher in the patients with active IBD. An IBDQ score >168.0 (PSQI score >7.5) indicates a clinically active state of IBD with a sensitivity of 84.8% (72.0%) and a specificity of 88.0% (82.6%). Diet composition was not related to disease activity. An analysis of patients and controls showed that lack of siblings could be a protective factor for onset of IBD (OR 0.300, 95% CI 0.119-0.785), while not being breastfed (OR 2.753, 95% CI 1.025-7.396) and consuming spicy foods could be risk factors for onset of IBD (OR 2.186, 95% CI 1.370-3.488). CONCLUSIONS In patients with IBD, poor sleep quality, poor QoL, depression, and anxiety were related to having active disease, whereas diet was not. Attempting to control dietary composition in patients with IBD may not be effective in preventing disease flare, but attention should be paid to intake of spicy foods.

Anti-integrin drugs in clinical trials for inflammatory bowel disease (IBD): insights into promising agents.

INTRODUCTION: Despite huge and increasing developments in the treatment of inflammatory bowel disease (IBD), a significant percentage of patients with Crohn's disease (CD) and ulcerative colitis (UC) is still in need of an effective and safe therapeutic option. Tackling the trafficking of leukocytes specifically within or directed to the inflamed gut appears to be a particularly promising strategy, and several new anti-integrin agents are currently under investigation in clinical trials. AREAS COVERED: This review summarizes efficacy and safety data from phase 1, 2 and 3 clinical trials on investigational drugs, including monoclonal antibodies (etrolizumab, abrilumab, ontamalimab) and oral small molecules (AJM300, PTG-100). It also discusses the future perspectives for the treatment of IBD patients with this class of agents. EXPERT OPINION: The pipeline of anti-integrin agents is well assorted, and it is reasonable to expect that some will be introduced in the market soon. Among the most exciting features of this class are the gut selectivity, the convenient subcutaneous and oral administrations and the reassuring safety profiles. Most of the new anti-integrins seem to improve outcomes in UC but not in CD, however these data are far from definitive and several pivotal trials are still under way.

Pathogenesis of Musculoskeletal Deficits in Children and Adults with Inflammatory Bowel Disease.

Musculoskeletal deficits are among the most commonly reported extra-intestinal manifestations and complications of inflammatory bowel disease (IBD), especially in those with Crohn's disease. The adverse effects of IBD on bone and muscle are multifactorial, including the direct effects of underlying inflammatory disease processes, nutritional deficits, and therapeutic effects. These factors also indirectly impact bone and muscle by interfering with regulatory pathways. Resultantly, individuals with IBD are at increased risk of osteoporosis and sarcopenia and associated musculoskeletal morbidity. In paediatric IBD, these factors may contribute to suboptimal bone and muscle accrual. This review evaluates the main pathogenic factors associated with musculoskeletal deficits in children and adults with IBD and summarises the current literature and understanding of the musculoskeletal phenotype in these patients.

An intercrypt subpopulation of goblet cells is essential for colonic mucus barrier function.

The intestinal mucus layer, an important element of epithelial protection, is produced by goblet cells. Intestinal goblet cells are assumed to be a homogeneous cell type. In this study, however, we delineated their specific gene and protein expression profiles and identified several distinct goblet cell populations that form two differentiation trajectories. One distinct subtype, the intercrypt goblet cells (icGCs), located at the colonic luminal surface, produced mucus with properties that differed from the mucus secreted by crypt-residing goblet cells. Mice with defective icGCs had increased sensitivity to chemically induced colitis and manifested spontaneous colitis with age. Furthermore, alterations in mucus and reduced numbers of icGCs were observed in patients with both active and remissive ulcerative colitis, which highlights the importance of icGCs in maintaining functional protection of the epithelium.

Transitional changes in gastrointestinal transit and rectal sensitivity from active to recovery of inflammation in a rodent model of colitis.

Patients with ulcerative colitis are typically suspected of an inflammatory flare based on suggestive symptoms of inflammation. The aim of this study was to evaluate the impact of inflammation on colonic motility and rectal sensitivity from active to recovery of inflammation. Male rats were given drinking water with 5% dextran sulfate sodium for 7 days. Inflammation, intestinal motor and sensory functions were investigated weekly for 6 weeks. (1) The disease activity index score, fecal calprotectin and tumor necrosis factor alpha were increased from Day 0 to Day 7 (active inflammation) and then decreased gradually until recovery. (2) Distal colon transit was accelerated on Day 7, and then remained unchanged. Whole gut transit was delayed on Day 7 but accelerated from Day 14 to Day 42. (3) Rectal compliance was unaffected from Day 0 to Day 7, but decreased afterwards. (4) Rectal hypersensitivity was noted on Day 7 and persistent. (5) Plasma acetylcholine was decreased on Day 7 but increased from Day 14 to Day 42. Nerve growth factor was increased from Day 7 to Day 42. DSS-induced inflammation leads to visceral hypersensitivity that is sustained until the resolution of inflammation, probably mediated by NGF. Rectal compliance is reduced one week after the DSS-induced inflammation and the reduction is sustained until the resolution of inflammation. Gastrointestinal transit is also altered during and after active colonic inflammation.

Extracellular vesicles of Fusobacterium nucleatum compromise intestinal barrier through targeting RIPK1-mediated cell death pathway.

Microbial factors that mediate microbes-host interaction in ulcerative colitis (UC), a chronic disease seriously affecting human health, are not fully known. The emerging oncobacterium Fusobacterium nucleatum (Fn) secretes extracellular vesicles carrying several types of harmful molecules in the intestine which can alter microbes-host interaction, especially the epithelial homeostasis in UC. However, the mechanism is not yet clear. Previously, we isolated EVs by the ultracentrifugation of Fn culture media and characterized them as the potent inducer of pro-inflammatory cytokines. Here, we examined the mechanism in detail. We found that in macrophage/Caco-2 co-cultures, FnEVs significantly promoted epithelial barrier loss and oxidative stress damage, which are related to epithelial necroptosis caused by the activation of receptor-interacting protein kinase 1 (RIPK1) and receptor-interacting protein kinase 3 (RIPK3). Furthermore, FnEVs promoted the migration of RIPK1 and RIPK3 into necrosome in Caco2 cells. Notably, these effects were reversed by TNF-α neutralizing antibody or Necrostatin-1 (Nec-1), a RIPK1 inhibitor. This suggested that FADD-RIPK1-caspase-3 signaling is involved in the process. Moreover, the observed effects were verified in the murine colitis model treated with FnEVs or by adoptive transfer of FnEVs-trained macrophages. In conclusion, we propose that RIPK1-mediated epithelial cell death promotes FnEVs-induced gut barrier disruption in UC and the findings can be used as the basis to further investigate this disease.

Gut microbiota shape the inflammatory response in mice with an epithelial defect.

Intestinal epithelial cell endoplasmic reticulum (ER) stress has been implicated in intestinal inflammation. It remains unclear whether ER stress is an initiator of or a response to inflammation. Winnie mice, carrying a Muc2 gene mutation resulting in intestinal goblet cell ER stress, develop spontaneous colitis with a depleted mucus barrier and increased bacterial translocation. This study aims to determine whether the microbiota was required for the development of Winnie colitis, and whether protein misfolding itself can initiate inflammation directly in absence of the microbiota. To assess the role of microbiota in driving Winnie colitis, WT and Winnie mice on the same background were rederived into the germ-free facility and housed in the Trexler-type soft-sided isolators. The colitis phenotype of these mice was assessed and compared to WT and Winnie mice housed within a specific pathogen-free facility. We found that Winnie colitis was substantially reduced but not abolished under germ-free conditions. Expression of inflammatory cytokine genes was reduced but several chemokines remained elevated in absence of microbiota. Concomitantly, ER stress was also diminished, although mucin misfolding persisted. RNA-Seq revealed that Winnie differentiated colon organoids have decreased expression of the negative regulators of the inflammatory response compared to WT. This data along with the increase in Mip2a chemokine expression, suggests that the epithelial cells in the Winnie mice are more responsive to stimuli. Moreover, the data demonstrate that intestinal epithelial intrinsic protein misfolding can prime an inflammatory response without initiating the unfolded protein response in the absence of the microbiota. However, the microbiota is necessary for the amplification of colitis in Winnie mice. Genetic predisposition to mucin misfolding in secretory cells initiates mild inflammatory signals. However, the inflammatory signal sets a forward-feeding cycle establishing progressive inflammation in the presence of microbiota.Abbreviations: Endoplasmic Reticulum: ER; Mucin-2: Muc-2; GF: Germ-Free; Inflammatory Bowel Disease: IBD.

Integrative transcriptomic and metabonomic profiling analyses reveal the molecular mechanism of Chinese traditional medicine huankuile suspension on TNBS-induced ulcerative colitis.

This study aimed to investigate the therapeutic mechanism of Huankuile suspension (HKL), a typical traditional Chinese medicine, on ulcerative colitis (UC) in a rat model. UC model was established by 2,4,6-trinitrobenzene sulfonic acid (TNBS) enema. Then, the rats were randomly divided into three groups: water treated group, HKL treated group and 5- amino salicylic acid (5-ASA) treated group. After 7 days treatment, the histological score in the HKL treated group was comparable with those in the control group. qRT-PCR and western blot demonstrated that HKL could significantly decreased pro-inflammatory cytokines, including TNF-α, IL-1ß and IL-6, while having less effect on anti-inflammatory cytokines, including IL-4 and IL-10. Transcriptomic analysis identified 670 differentially expressed genes (DEGs) between HKL treated UC rats and water treated UC rats. These DEGs were mostly related with immune response. Besides, metabonomic profile revealed 136 differential metabolites which were significantly enriched in "pyrimidine metabolism", "glutathione metabolism", "purine metabolism" and "citrate cycle". Finally, integrated analysis revealed that metabonomic pathways including "steroid hormone biosynthesis", "pyrimidine metabolism", "purine metabolism", and "glutathione metabolism" were altered by HKL at both transcriptomic and metabonomic levels. HKL could inhibit inflammation and regulate bile metabolism, pyrimidine metabolism, purine metabolism, glutathione metabolism and citrate cycle.