Treatment Targets in Ulcerative Colitis: Is It Time for All In, including Histology?

Novel outcomes in inflammatory bowel disease

Inflammatory bowel diseases (IBD), Crohn's disease (CD), and ulcerative colitis (UC) are lifelong chronic, relapsing, and remitting conditions that culminate in disease progression in many patients. Effective management of CD and UC requires consideration of both short- and long-term treatment outcomes. Historically, short-term outcomes such as clinical and endoscopic remission and symptom relief have been evaluated in clinical trials. With the expansion of treatments targeting underlying disease pathophysiology, there is the opportunity to develop management strategies that improve disease control and patients' lives in both the short and the long term. Researchers have been examining novel outcomes for assessing the efficacy of CD and UC treatments that are important to patients, and also those that go beyond symptomatic improvements or clinical remission. These include new patient-reported outcomes for symptoms, as well as transmural/histological healing and disease clearance that can be more reflective of deeper remission states and disease modification. This review analyses published clinical studies involving patients with UC and CD treated with biologics or small molecule therapies. It highlights novel IBD endpoints employed in published clinical trials and discusses their likely value for assessing disease activity and disease modification, and as predictors of reduced risk of complications and morbidities.

Cost-of-illness analysis of ulcerative colitis patients treated with biological therapy: a prospective observational study in Iran

BACKGROUND

No research has assessed the comprehensive annual costs of managing ulcerative colitis (UC) patients undergoing biological treatment. This study aimed to determine the annual costs and primary cost drivers for UC patients receiving biological therapy.

METHODS

This prospective observational study was conducted in Iran from a societal perspective, employing the cost-of-illness method, grounded in human capital theory. A prevalence-based approach and bottom-up technique were used for cost estimation. Inpatient costs were extracted from hospital records, while outpatient service usage and direct non-medical costs over a one-year follow-up were collected through patient interviews. Indirect costs were evaluated using a standardized questionnaire. The average costs per patient were calculated, and the factors affecting patient expenses were analyzed using the Mann-Whitney and Kruskal-Wallis statistical tests.

RESULTS

The study included 238 UC patients (50.8% male; mean age: 37.66 ± 12.13 years), with 32.8% receiving Infliximab (IFX) and 67.2% on Adalimumab (ADA), and an average disease duration of 9.29 ± 6.5 years. The total annual economic burden per UC patient was USD 2316.90. Of this, direct medical costs constituted 49.84%, direct non-medical costs 21.13%, and indirect costs 29.03%. Notably, higher expenses were significantly associated with patients under 20 years of age and those treated with ADA.

CONCLUSIONS

Biological therapies accounted for the largest share of direct medical expenses, while productivity losses, mainly resulting from temporary absenteeism, were identified as a major factor contributing to the economic burden of UC in Iran.

Is Disease Stability an Attainable Chronic Obstructive Pulmonary Disease Treatment Goal?

Chronic obstructive pulmonary disease (COPD) is a heterogeneous lung condition characterized by progressive airflow obstruction. Despite advancements in diagnosis and treatment, the disease burden remains high; although clinical trials have shown improvements in outcomes such as exacerbations, quality of life, and lung function, improvement may not be attainable for many patients. For patients who do experience improvement, it is challenging to set management goals given the progressive nature of COPD. We therefore propose disease stability as an appropriate and attainable treatment goal. Other disease areas have developed definitions of no disease activity or remission, which provide relevant information for defining and achieving stability for patients with COPD. Disease stability builds on related concepts already defined in COPD, such as clinical control and clinically important deterioration. Current components that could form part of a disease stability definition include exacerbations, health status (including quality of life and symptoms), and lung function. Considerations should be given to intervals over which stability is defined and assessed, appropriate thresholds, and defining a composite. Ensuring a holistic approach, objective measurements, and harmonious, clear communication between patients and physicians can further support establishing disease stability. Here we propose a preliminary definition of disease stability, informed by existing research in COPD. Further research will be needed to validate the framework for use in clinical and research settings. Exploring disease stability as a goal, however, is an opportunity to develop and validate an attainable treatment target to advance the standard of care for patients with COPD.

Sodium orthovanadate protects against ulcerative colitis and associated liver damage in mice: insights into modulations of Nrf2/Keap1 and NF-κB pathways

Ulcerative colitis (UC) is a prominent category of disease that is associated with bowel inflammation, it can occur at any period of life and is prevalently rising on a global scale. Dextran sulfate sodium (DSS) has been extensively used to develop colitis due to its ability to mimic human UC, providing consistent and reproducible inflammation, ulceration, and disruption of the epithelial barrier in the colon. Chronic inflammation in the gut can lead to alterations in the gut-liver axis, potentially impacting liver function over time, while direct evidence linking diversion colitis to liver damage is limited. Thus, the present study aims to assess the gut and liver damage against DSS and the possible molecular mechanisms. Forty-seven animals were randomly assigned to six groups. Ulcerative colitis was induced using 2.5% w/v DSS in three alternate cycles, each lasting 7 days, with 1-week remission periods in between. SOV (5 and 10 mg/kg, orally) and the standard drug 5-aminosalicylic acid (100 mg/kg, orally) were administered from the start of the 2nd DSS cycle until the end of the experiment. Biochemical parameters, ELISA, histopathological, and immunohistochemical analyses have been conducted to assess damage in the colon and liver. SOV significantly reduced colitis severity by lowering the DAI score, oxidative stress markers (LPS, IL-1β, MPO, nitrite), and restoring liver biomarkers (SGPT, SGOT). Histopathological findings supported these protective benefits in the liver and gut. Moreover, immunohistochemical analysis showed SOV enhanced the expression of the cytoprotective mediator Nrf2/Keap-1 and reduced the expression of inflammatory mediators NF-κB and IL-6. Present findings concluded that SOV demonstrated a dose-dependent effect against UC through anti-inflammatory and antioxidant pathways, with the highest dose of SOV 10 mg/kg having more significant (p < 0.001) results than the low dose of 5 mg/kg.

Advancing Therapeutic Targets in IBD: Emerging Goals and Precision Medicine Approaches

Inflammatory bowel diseases (IBD) including Crohn's disease (CD) and ulcerative colitis (UC) are chronic, relapsing conditions characterized by dysregulated immune responses and persistent intestinal inflammation. This review aims to examine new potential therapeutic targets in IBD starting from the STRIDE-II statements. Key targets now include clinical remission, endoscopic remission, and biomarker normalization (such as C-reactive protein and fecal calprotectin). Moreover, histologic remission, transmural remission, and in the future molecular targets are emerging as important indicators of sustained disease control. The treatment goals for inflammatory bowel disease are varied: to relieve symptoms, prevent permanent intestinal damage, promote inflammation remission, and minimize complications. Consequently, the therapeutic targets have evolved to become broader and more ambitious. Integrating these advanced therapeutic targets has the potential to redefine IBD management by promoting deeper disease control and improved patient outcomes. Further research is essential to validate these strategies and optimize their clinical implementation.

The Nancy Histopathological Index has limited value in predicting clinical outcomes in newly diagnosed pediatric patients with ulcerative colitis

The Nancy Histological Index (NHI) is used to score histologic disease activity in patients with ulcerative colitis (UC). Our goal was to assess the utility of NHI at diagnosis in predicting clinical outcomes in pediatric patients with UC, in comparison to clinical and endoscopic scores. We retrospectively reviewed data at diagnosis of 106 children with UC (59 [55.7%] females; median age 14.4 [11.2-15.9] years, median Pediatric Ulcerative Colitis Activity Index [PUCAI] 35 [25-55]). During a follow-up of 116 (55-171) weeks, 33 patients (31.1%) required azathioprine therapy, and 32 (30.2%) were escalated to anti-tumor necrosis factor alpha (anti-TNFa). The PUCAI and Mayo endoscopic scores at diagnosis were significantly associated with escalation to anti-TNFa (p = 0.036 and p = 0.02, respectively), but not with initiation of azathioprine or subsequent acute severe colitis (ASC) events. However, the NHI was not associated with subsequent immunomodulators or anti-TNFa therapy (p = 0.42 and p = 0.78, respectively), nor with future ASC events (p = 0.70). In conclusion, the NHI failed to predict clinical outcomes in newly diagnosed pediatric patients with UC.

Indigo naturalis as a potential drug in the treatment of ulcerative colitis: a comprehensive review of current evidence

CONTEXT

Ulcerative colitis (UC) is an intractable inflammatory bowel disease that threatens the health of patients. The limited availability of therapeutic strategies makes it imperative to explore more efficient and safer drugs. Indigo naturalis (IN) is a traditional Chinese medicine that possesses many pharmacological activities, including anti-inflammatory, antioxidant, and immunomodulatory activities. The treatment potential of IN for UC has been proven by numerous preclinical and clinical studies in recent years.

OBJECTIVE

This article provides a comprehensive review of the utility and potential of IN in the treatment of UC.

METHODS

'Indigo naturalis' 'Qing dai' 'Qingdai' 'Ulcerative colitis' and 'UC' are used as the keywords, and the relevant literature is collected from online databases (Elsevier, PubMed, and Web of Science).

RESULTS AND CONCLUSION

Indirubin, indigo, isatin, tryptanthrin, and β-sitosterol are considered the key components in the treatment of UC with IN. Both preclinical and clinical studies support the efficacy of IN for UC, especially in severe UC or in those who do not respond to or have poor efficacy with existing therapies. The mechanisms of IN for UC are associated with the aryl hydrocarbon receptor pathway activation, immune regulation, oxidative stress inhibition, and intestinal microbial modulation. However, the clinical use of IN has the risks of adverse events such as pulmonary hypertension, which suggests the necessity for its rational application. As a potential therapeutic agent for UC that is currently receiving more attention, the clinical value of IN has been initially demonstrated and warrants further evaluation.

Real-World Treatment Outcomes Associated With Early Versus Delayed Vedolizumab Initiation in Patients With Ulcerative Colitis

Background

Patients with ulcerative colitis (UC) typically receive a targeted inflammatory bowel disease therapy after treatment with conventional therapies and after the development of significant morbidity. Evidence suggests that early biologic treatment after diagnosis could improve treatment response and prevent disease complications compared with delayed biologic treatment after conventional therapy.

Methods

RALEE was a retrospective study using claims data from IBM® MarketScan® Research Databases between January 1, 2016 and December 31, 2019. Adults with UC and at least one claim for vedolizumab were categorized into Early or Delayed Vedolizumab groups according to whether they had received vedolizumab within 30 days of diagnosis or after conventional therapy (5-aminosalicylates, corticosteroids, and immunomodulators), respectively. Treatment response was assessed at 2, 6, and 12 months after vedolizumab treatment initiation and was analyzed with logistic regression (bivariate).

Results

At 2 months, Delayed Vedolizumab was associated with significantly higher odds of nonresponse than Early Vedolizumab (odds ratio [OR], 2.509; 95% confidence interval [CI], 1.28-4.90). Delayed Vedolizumab was not significantly associated with odds of nonresponse at 6 months (OR, 1.173; 95% CI, 0.72-1.90) or at 12 months (OR, 0.872; 95% CI, 0.55-1.37). Mean total healthcare costs were similar in the Early Vedolizumab ($6492) and Delayed Vedolizumab ($5897) groups, although there were small differences in costs from different types of claims.

Conclusions

Patients who received vedolizumab early after UC diagnosis were less likely to experience nonresponse at 2 months and incurred similar healthcare costs at 12 months compared with patients who received delayed vedolizumab.

Health-Related Quality of Life Outcomes With Etrasimod Treatment in Patients With Ulcerative Colitis: A Post Hoc Analysis of Data From ELEVATE UC 52 and ELEVATE UC 12

BACKGROUND

Etrasimod is an oral, once-daily (QD), selective sphingosine 1-phosphate1,4,5 receptor modulator for the treatment of moderately to severely active ulcerative colitis (UC). Here, we evaluate the impact of etrasimod 2 mg QD on health-related quality of life (HRQoL) in patients with UC.

METHODS

This post hoc analysis used data from the Phase 3 randomized controlled trials, ELEVATE UC 52 and ELEVATE UC 12. HRQoL measures included: Inflammatory Bowel Disease Questionnaire (IBDQ), 36-Item Short Form Survey (SF-36), and Work Productivity and Activity Impairment Questionnaire: Ulcerative Colitis (WPAI:UC) completed at baseline, Week 12 (both trials), and Week 52 (ELEVATE UC 52 only). For IBDQ analyses, patients were stratified by prior exposure to biologics/Janus kinase inhibitors (JAKi) and baseline modified Mayo score (MMS; 4-6 or 7-9).

RESULTS

Generally, significantly greater proportions of patients receiving etrasimod (N = 527) vs placebo (N = 260) achieved IBDQ remission (IBDQ total score ≥170) and IBDQ response (IBDQ total score increase from baseline ≥16), with significant improvement in all IBDQ domain scores at Week 12 and maintained through Week 52. Significant differences in IBDQ remission and IBDQ response rates between etrasimod and placebo were more consistent among biologic/JAKi-naive patients vs those who were biologic/JAKi-experienced and in those with baseline MMS 7-9 vs 4-6. Significant improvements were observed in several SF-36 domain and summary scores and WPAI:UC domain scores at Week 12 and Week 52.

CONCLUSIONS

Etrasimod 2 mg QD demonstrated significant and clinically meaningful improvements across multiple HRQoL measures, including WPAI, vs placebo.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT03945188; NCT03996369.

Lespedeza bicolor Turcz. Honey Prevents Inflammation Response and Inhibits Ferroptosis by Nrf2/HO-1 Pathway in DSS-Induced Human Caco-2 Cells

Lespedeza bicolor Turcz. (L. bicolor) honey, a monofloral honey, has garnered increased attention due to its origin in the L. bicolor plant. A previous study has shown that L. bicolor honey can ameliorate inflammation. In this study, we aimed to investigate the effects of L. bicolor honey extract and its biomarker (Trifolin) on DSS-induced ulcerative colitis (UC). Our results demonstrated that L. bicolor honey extract and Trifolin significantly increased the expression levels of the tight junction cytokines Claudin-1 and ZO-1. Additionally, they decreased the pro-inflammatory factors TNF-α and IL-6 and enhanced the antioxidant factors NQO1 and GSTA1. Based on metabolomic analyses, L. bicolor honey extract and Trifolin regulated the progression of UC by inhibiting ferroptosis. Mechanistically, they improved the levels of SOD and iron load, increased the GSH/GSSG ratio, reduced MDA content and ROS release, and upregulated the Nrf2/HO-1 pathway, thereby inhibiting DSS-induced UC. Moreover, the expression levels of ferroptosis-related genes indicated that they decreased FTL, ACSL4, and PTGS2 while increasing SLC7A11 expression to resist ferroptosis. In conclusion, our study found that L. bicolor honey improves DSS-induced UC by inhibiting ferroptosis by activating the Nrf2/HO-1 pathway. These findings further elucidate the understanding of anti-inflammatory and antioxidant activities of L. bicolor honey.

How close are we to a success stratification tool for improving biological therapy in ulcerative colitis?

INTRODUCTION

Biological therapies have become the standard treatment for ulcerative colitis (UC). However, clinical remission rates post-induction therapy remain modest at 40-50%, with many initial responders losing response over time. Current treatment strategies frequently rely on a 'trial and error' approach, leading to prolonged periods of ineffective and costly therapies for patients, accompanied by associated treatment complications.

AREA COVERED

This review discusses current evidence on risk stratification tools for predicting therapeutic efficacy and minimizing adverse events in UC management. Recent studies have identified predictive factors for biologic therapy response. In the context of personalized medicine, the goal is to identify patients at high risk of progression and complications, as well as those likely to respond to specific therapies. Essential risk stratification tools include clinical decision-making aids, biomarkers, genomics, multi-omics factors, endoscopic, imaging, and histological assessments.

EXPERT OPINION

Employing risk stratification tools to predict therapeutic response and prevent treatment-related complications is essential for precision medicine in the biological management of UC. These tools are necessary to select the most suitable treatment for each individual patient, thereby enhancing efficacy and safety.

Defining Comprehensive Disease Control for Use as a Treatment Target for Ulcerative Colitis in Clinical Practice: International Delphi Consensus Recommendations

BACKGROUND AND AIMS

Treatment of ulcerative colitis [UC] requires a patient-centric definition of comprehensive disease control that considers improvements in aspects not typically captured by classical landmark trial endpoints. In an international initiative, we reviewed aspects of UC that affect patients and/or indicate mucosal inflammation, to achieve consensus on which aspects to combine in a definition of comprehensive disease control, using a modified Delphi process.

METHODS

The Delphi panel comprised 12 gastroenterologists and one patient advocate. Two gastroenterologists were elected as chairs and did not vote. To inform statements, we asked 18 patients and the panel members about their experiences of remission and reviewed published literature. Panel members voted on statements anonymously in three rounds, with a live discussion before Round 3. Consensus was met if ≥67% of the panel agreed. Statements without consensus in Rounds 1 and 2 were revised or discarded after Round 3.

RESULTS

The panel agreed to measure individual patient benefit using a definition of comprehensive disease control that combines aspects currently measured in trials [rectal bleeding, stool frequency, disease-related quality of life, endoscopy, histological inflammatory activity, inflammatory biomarkers, and corticosteroid use] with additional patient-reported symptoms [bowel urgency, abdominal pain, extraintestinal manifestations, fatigue, and sleep disturbance]. The panel agreed on scoring systems and thresholds for many aspects.

CONCLUSIONS

Using a robust methodology, we defined comprehensive disease control in UC. Next, we will combine the measurement and scoring of these aspects into a multicomponent tool and will adopt comprehensive disease control as a treatment target in clinical practice and trials.

Histological Remission Placebo Rates in Ulcerative Colitis Trials: A Systematic Review and Meta-analysis

BACKGROUND

High histologic remission rates have been reported with placebos in randomized controlled trials (RCTs) evaluating ulcerative colitis (UC) therapies and have varied based on trial designs. We performed a systematic review and meta-analysis to quantify placebo histological remission rates and identify factors influencing those rates.

METHODS

MEDLINE, EMBASE, and the Cochrane library were searched from inception of the databases until December 2021. We included placebo-controlled RCTs of adult patients with UC treated with aminosalicylates, corticosteroids, immunosuppressives, biologics, and small molecules. We pooled estimates using a random-effects model and performed subgroup analysis and meta-regression to evaluate the effect of different covariates on placebo rates.

RESULTS

Thirty-three studies (30 induction and 3 maintenance) were included. The overall placebo histological remission rate was 15.7% (95% confidence interval, 12.9%-19%) across all 33 studies. High heterogeneity was observed among studies with I2 = 62.10%. The pooled estimate of histological remission was 15.8% in induction studies and 14.5% in maintenance studies. Subgroup analysis revealed statistically significant differences in placebo rates when accounting for background medications, the intervention drug class, and disease severity (P = .041, .025, and .025, respectively). There was no statistical difference between induction vs maintenance studies or between different histological scales (P = .771, and .075, respectively).

CONCLUSIONS

Placebo histological remission rates range from 13% to 19% in UC RCTs, but studies are highly heterogeneous. Factors found to influence placebo rates include presence of background medications, the drug used, and the disease severity. These observations inform future trial designs to minimize placebo rates and reduce heterogeneity.

Histologic assessments in ulcerative colitis: the evidence behind a new endpoint in clinical trials

INTRODUCTION

Treatment goals for ulcerative colitis (UC) are evolving from the achievement of clinical remission to more rigorous goals defined by endoscopic and histologic healing. Achievement of deeper remission targets aims to reduce the risk of colectomy, hospitalizations, and colorectal cancer.

AREAS COVERED

This review covers histologic assessments, histologic remission as a clinical trial endpoint, and the association between histologic disease activity and clinical outcomes. Future directions are also discussed, including the use of advanced imaging and artificial intelligence technologies, as well as potential future treatment targets beyond histologic remission.

EXPERT OPINION

Histologic assessments are used for their sensitivity in measuring mucosal inflammatory changes in UC. Due to correlation with disease activity, histologic assessments may support clinical decision-making regarding treatment decisions as such assessments can be associated with rates of clinical relapse, hospitalization, colectomy, and neoplasia. While histologic remission is limited by varying definitions and multiple histologic indices, work is ongoing to create a consensus on the use of histologic assessments in clinical trials. As research advances, aspirational targets beyond histologic remission, such as molecular healing and disease clearance, are being explored.

Mirikizumab Pharmacokinetics in Patients with Moderately to Severely Active Ulcerative Colitis: Results from Phase III LUCENT Studies

BACKGROUND AND OBJECTIVE

Mirikizumab is a humanized anti-interleukin-23-p19 monoclonal antibody being developed for ulcerative colitis and Crohn's disease. This analysis characterized mirikizumab pharmacokinetics using phase II and III trial data from patients with moderately to severely active ulcerative colitis.

METHODS

Serum pharmacokinetic data in patients receiving mirikizumab 50-1000 mg intravenously every 4 weeks as induction treatment and mirikizumab 200 mg subcutaneously every 4 or 12 weeks as maintenance treatment across three trials (N = 1362) were analyzed using non-linear mixed-effects modeling. Covariate effects on mirikizumab exposure were evaluated using simulation-based estimations.

RESULTS

Mirikizumab pharmacokinetics was best described by a linear two-compartment model with first-order absorption. Clearance, volume of distribution for central and peripheral compartments, and half-life were estimated at approximately 0.022 L/h (linear), 3.11 L and 1.69 L, and 9.5 days, respectively. Statistically significant effects of body weight and serum albumin levels on clearance, body weight on central and peripheral volumes of distribution, and body mass index on bioavailability were observed but effects were small relative to random inter-individual variability (% coefficient of variation: 18-64%). The subcutaneous bioavailability of mirikizumab was 48%.

CONCLUSIONS

Mirikizumab displayed pharmacokinetic characteristics typical of a monoclonal antibody where clearance increased with body weight and decreased with the albumin level, and bioavailability decreased with body mass index. These effects were small relative to random variability, indicating that a dose adjustment for patient factors is not required.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT02589665 (28 October, 2015), NCT03518086 (8 May, 2018), NCT03524092 (14 May, 2018).

Evaluation of intestinal ultrasound for disease activity assessment in patients with inflammatory bowel disease: A cross-sectional study at a tertiary centre in Malaysia

Background

The use of intestinal ultrasound (IUS) in the management of inflammatory bowel disease (IBD) is emerging. We aim to determine the performance of IUS in the assessment of disease activity in IBD.

Methods

This is a prospective cross-sectional study of IUS performed on IBD patients in a tertiary centre. IUS parameters including intestinal wall thickness, loss of wall stratification, mesenteric fibrofatty proliferation, and increased vascularity were compared with endoscopic and clinical activity indices.

Results

Among the 51 patients, 58.8% were male, with a mean age of 41 years. Fifty-seven percent had underlying ulcerative colitis with mean disease duration of 8.4 years. Against ileocolonoscopy, IUS had a sensitivity of 67% (95% confidence interval (CI): 41-86) for detecting endoscopically active disease. It had high specificity of 97% (95% CI: 82-99) with positive and negative predictive values of 92% and 84%, respectively. Against clinical activity index, IUS had a sensitivity of 70% (95% CI: 35-92) and specificity of 85% (95% CI: 70-94) for detecting moderate to severe disease. Among individual IUS parameters, presence of bowel wall thickening (>3 mm) had the highest sensitivity (72%) for detecting endoscopically active disease. For per-bowel segment analysis, IUS (bowel wall thickening) was able to achieve 100% sensitivity and 95% specificity when examining the transverse colon.

Conclusions

IUS has moderate sensitivity with excellent specificity in detecting active disease in IBD. IUS is most sensitive in detecting a disease at transverse colon. IUS can be employed as an adjunct in the assessment of IBD.

Intervention of 3-aminobenzamide against Dextran Sulphate Sodium induced colitis in mice: Investigations on molecular mechanisms

Various preclinical and clinical studies reported that Poly [ADP-ribose] polymerase 1 plays significant role in all acute and chronic inflammatory diseases with different etiopathogenesis. The present study aims to investigate the protective effect of 3-aminobenzamide in Dextran Sulphate Sodium induced ulcerative colitis and associated molecular mechanisms. Ulcerative colitis in male BALB/c mice was induced using Dextran sulphate sodium (3 %w/v) for 3 cycles with 7 days recovery period in-between. 3-aminobenzamide was administered at the doses of 5, 10 and 20 mg/kg starting from the I^st week of remission period and was continued till the termination of the experiment. The effect of 3-aminbenzamide was evaluated using biochemical parameters, histopathological evaluations, ELISA, immunohistochemistry, immunofluorescence and Western blot analysis. All the doses of 3-aminobenzamide (5 mg/kg; 10 mg/kg and 20 mg/kg) ameliorated the severity of ulcerative colitis by modulating various molecular targets such as poly[ADP-ribose] polymerase 1, nuclear factor kappa-light-chain-enhancer of activated B cells, NLR family pyrin domain containing 3, apoptosis-associated speck-like protein containing a caspase-recruitment domain, cysteine aspartases, interleukin-1β, proliferating cell nuclear antigen, sirtuin 1, adenosine monophosphate-activated protein kinase, tumour necrosis factor-α and catalase. However, the lower doses (5 and 10 mg/kg) exerted more prominent effects in comparison to the high dose (20 mg/kg). Further, 3-aminobenzamide treatment restored the intestinal integrity by increasing the expression of occludin and significantly ameliorated ulcerative colitis associated elevated lipopolysaccharides, oxidative and nitrosative stress, cellular damage and apoptosis. Lower doses of 3-aminobenzamide showed more prominent protective effects against ulcerative colitis associated damage as compared to higher dose.

Histological Scores in Patients with Inflammatory Bowel Diseases: The State of the Art

The histological assessment has been advocated as a detailed and accurate measure of disease activity in inflammatory bowel diseases (IBD). In ulcerative colitis (UC), histological activity has been demonstrated to be associated with higher rates of relapse, prolonged corticosteroid use and long-term complications, even when endoscopic remission is achieved. Therefore, histological healing may represent a potential treatment target. Several histological scores have been developed and are available today. The Robarts histopathology index (RHI) and the Nancy index (NI) are the only two recommended by the European Crohn’s and Colitis Organization (ECCO) for use in patients with UC. Conversely, in Crohn’s disease (CD), the discontinuous nature of lesions has limited standardized histological assessment. Most of the available histological scoring systems in CD are complex and not validated. The aim of this review is to comprehensively summarize the latest evidence regarding histological scoring systems in IBD. We guide the reader through understanding the importance of an accurate microscopic evaluation using validated scoring systems, highlighting the strengths and pitfalls of each score. The priorities of future research needs are also addressed.

YAP Activates STAT3 Signalling to Promote Colonic Epithelial Cell Proliferation in DSS-Induced Colitis and Colitis Associated Cancer

BACKGROUND AND AIMS

Yes-associated protein (YAP) is a key transcriptional coactivator of cell proliferation and differentiation. In this study, we sought to identify the roles of YAP in colonic epithelial regeneration and tumourigenesis.

METHODS

Murine DSS-induced colitis and YAP overexpression models were constructed via lentiviral intraperitoneal injection. Stable YAP-overexpressing cells, protein immunoprecipitation, and ChIP were used to deeply explore the molecular mechanism.

RESULTS

We found that the expression of YAP was dramatically diminished in the colonic crypts during the acute colitis phase, while YAP was strikingly enhanced to initiate tissue repair after DSS withdrawal. Overexpressing YAP in mice drastically accelerated epithelial regeneration, presenting with more intact structural integrity and reduced inflammatory cell infiltration in the mucosa. Further mechanistic studies showed that the expression of YAP in the nucleus was significantly increased by 2 h post-DSS removal, accompanied by upregulated protein levels of activated STAT3. Overexpression of YAP (YAP^WT) elevated the expression of activated STAT3 and its transcriptional targets and strengthened the proliferation and "wound healing" ability of colonic cells. However, these effects were reversed when STAT3 was silenced in YAP^WT cells. Moreover, YAP could directly interact with STAT3 in the nucleus, and c-Myc and CyclinD1 were the transcriptional targets. Finally, during colitis-associated cancer (CAC), YAP^WT promoted the progression of CAC, while the phosphomimetic YAP downregulated the expression of STAT3 and inhibited the development and progression of CAC.

CONCLUSION

YAP activates STAT3 signalling to facilitate mucosal regeneration after DSS-induced colitis. However, excessive YAP activation in the colonic epithelium promotes CAC development.