Gigantol ameliorates DSS-induced colitis via suppressing β2 integrin mediated adhesion and chemotaxis of macrophage

ETHNOPHARMACOLOGICAL RELEVANCE

Dendrobium, recognized as "Shihu" in traditional Chinese medicine, holds a rich history of medicinal utilization documented in the Chinese Pharmacopoeia. Ancient texts like "Shen Nong Ben Cao Jing" extol Dendrobium's virtues as a superior herbal medicine fortifying "Yin" and invigorating the five viscera. Dendrobium is extensively employed for the treatment of gastrointestinal inflammatory disorders, showcasing significant therapeutic efficacy, particularly against ulcerative colitis (UC), within the realm of Chinese ethnopharmacology. Dendrobium plays crucial pharmacological roles due to its rich content of polysaccharides, alkaloids, phenanthrenes, and bibenzyls. Gigantol, a prominent bibenzyl compound, stands out as one of the most vital active constituents within Dendrobium, the gigantol content of Dendrobium leaves can reach approximately 4.79 μg/g. Its significance lies in being recognized as a noteworthy anti-inflammatory compound derived from Dendrobium.

AIM OF THE STUDY

Given the pivotal role of gigantol as a primary active substance in Dendrobium, the therapeutic potential of gigantol for gastrointestinal diseases remains enigmatic. Our present investigation aimed to evaluate the therapeutic effects of gigantol on dextran sulfate sodium (DSS)-induced colitis and reveal its potential mechanism in countering UC activity.

MATERIALS AND METHODS

The protective efficacy of gigantol against colitis was assessed by examining the histopathological changes and conducting biochemical analyses of colon from DSS-challenged mice. Assessments focused on gigantol's impact on improving the intestinal epithelial barrier and its anti-inflammatory effects in colonic tissues of colitis mice. Investigative techniques included the exploration of the macrophage inflammatory signaling pathway via qPCR and Western blot analyses. In vitro studies scrutinized macrophage adhesion, migration, and chemotaxis utilizing transwell and Zigmond chambers. Furthermore, F-actin and Rac1 activation assays detailed cellular cytoskeletal remodeling. The potential therapeutic target of gigantol was identified and validated through protein binding analysis, competitive enzyme-linked immunosorbent assay (ELISA), cellular thermal shift assay (CETSA), and drug affinity responsive target stability (DARTS) assay. The binding sites between gigantol and its target were predicted via molecular docking.

RESULTS

Gigantol ameliorated symptoms of DSS-induced colitis, rectified damage to the intestinal barrier, and suppressed the production of pro-inflammatory cytokines in colonic tissues. Intriguingly, gigantol significantly curtailed NF-κB signaling activation in the colons of DSS-induced colitis mice. Notably, gigantol impaired the β2 integrin-dependent adhesion and migratory capacity of RAW264.7 cells. Moreover, gigantol notably influenced the cytoskeleton remodeling of RAW264.7 cells by suppressing Vav1 phosphorylation and Rac1 activation. Mechanistically, gigantol interacted with β2 integrin, subsequently diminishing binding affinity with intercellular adhesion molecule-1 (ICAM-1).

CONCLUSIONS

In conclusion, these findings elucidate that gigantol ameliorates DSS-induced colitis by antagonizing β2 integrin-mediated macrophage adhesion, migration, and chemotaxis, thus it may impede macrophage recruitment and infiltration into colonic tissues. This study suggests that gigantol shows promise as a viable candidate for clinical colitis therapy.

An investigation into the HIF-dependent intestinal barrier protective mechanism of Qingchang Wenzhong decoction in ulcerative colitis management

ETHNOPHARMACOLOGICAL RELEVANCE

Ulcerative colitis (UC) is a chronic, non-specific inflammatory disease affecting the colon and rectum with an etiology that remains elusive. Traditional Chinese medicine (TCM) has been widely used on long-term UC treatment to better maintain the efficacy than traditional aminosalicylic acid or glucocorticosteroids and to ease financial burden of patients. Qingchang Wenzhong Decoction (QCWZD) is a modern TCM decoction with established clinical efficacy but the mechanism of its protection on intestinal barrier function remains unclear.

AIM OF THE STUDY

Current findings highlight that the activation of the hypoxia inducible factor (HIF) pathway can facilitate the repair of intestinal epithelium barrier. This study is to investigate the protective effects of QCWZD and its HIF-targeted ingredients on hypoxia-dependent intestinal barrier.

METHODS

The mice model of UC was induced by dextran sulfate sodium (DSS). Disease activity index (DAI) and histopathology scores and colon length were used to measure the severity of colitis. The DAO activity in serum and protein expression of tight junction (TJ) proteins were detected to explore the function of intestinal barrier. The protein levels of HIF-1α and its downstream gene heme oxygenase-1 (HO-1) were measured as well. HIF-targeted active ingredients in QCWZD were selected by network pharmacology and molecular docking. Protective effects of six constituents on HIF-related anti-oxidative and barrier protective pathway were evaluated by lipopolysaccharide (LPS)-induced HT29 and RAW264.7 cells, through the measurement of the production of ROS and mRNA level of pro-inflammatory cytokines. HIF-1α knockdown was carried out to explore the correlation of protection effects with HIF-related pathway of the active ingredients.

RESULTS

QCWZD effectively alleviated colitis induced by DSS and demonstrated a protective effect on intestinal barrier function by upregulating HIF-related pathways. Six specific ingredients in QCWZD, targeting HIF, successfully reduced the production of cellular ROS and proinflammatory cytokines in LPS-induced cells. It is noteworthy that the barrier protection provided by these molecules is intricately linked with the HIF-related pathway.

CONCLUSIONS

This study elucidates the HIF-related molecular mechanism of QCWZD in protecting the function of the epithelial barrier. Six compounds targeting the activation of the HIF-dependent pathway were demonstrated to unveil a novel therapeutic approach for managing UC.

Deep Learning Models Capture Histological Disease Activity in Crohn's Disease and Ulcerative Colitis with High Fidelity

BACKGROUND AND AIMS

Histological disease activity in inflammatory bowel disease [IBD] is associated with clinical outcomes and is an important endpoint in drug development. We developed deep learning models for automating histological assessments in IBD.

METHODS

Histology images of intestinal mucosa from phase 2 and phase 3 clinical trials in Crohn's disease [CD] and ulcerative colitis [UC] were used to train artificial intelligence [AI] models to predict the Global Histology Activity Score [GHAS] for CD and Geboes histopathology score for UC. Three AI methods were compared. AI models were evaluated on held-back testing sets, and model predictions were compared against an expert central reader and five independent pathologists.

RESULTS

The model based on multiple instance learning and the attention mechanism [SA-AbMILP] demonstrated the best performance among competing models. AI-modelled GHAS and Geboes subgrades matched central readings with moderate to substantial agreement, with accuracies ranging from 65% to 89%. Furthermore, the model was able to distinguish the presence and absence of pathology across four selected histological features, with accuracies for colon in both CD and UC ranging from 87% to 94% and for CD ileum ranging from 76% to 83%. For both CD and UC and across anatomical compartments [ileum and colon] in CD, comparable accuracies against central readings were found between the model-assigned scores and scores by an independent set of pathologists.

CONCLUSIONS

Deep learning models based upon GHAS and Geboes scoring systems were effective at distinguishing between the presence and absence of IBD microscopic disease activity.

Ozanimod-exposed Patients with Ulcerative Colitis Undergoing Total Colectomy Exhibit Unique Lymph Node Histological Changes

INTRODUCTION

Ozanimod regulates lymphocyte egress from the spleen and lymph nodes into the systemic circulation. The histological changes which occur in the lymph nodes of patients on ozanimod is unknown.

MATERIALS AND METHODS

This retrospective study included patients with ulcerative colitis [UC] undergoing total colectomy for treatment-refractory disease who received ozanimod, and a cohort of patients with UC undergoing colectomy who did not have ozanimod exposure. Histology of the lymph nodes from the mesentery of colectomy specimens was reviewed and multiple features were scored by experienced pathologists.

RESULTS

Six [13%] ozanimod-treated patients with UC required surgery for treatment-refractory disease. Colectomy specimen data were available for five patients [one patient had surgery at an outside centre]. Lymph node specimens from six control patients with UC who had colectomy were examined. Histological examination of lymph nodes showed that patients treated with ozanimod had significantly greater extent of dilated sinuses [p = 0.03] and greater degrees of sinus histiocytosis [p = 0.03] compared with control patients. In addition, there was a trend towards more Castleman-like angiotrophic hyperplasia, plasma cell infiltration, and subcortical interfollicular expansion in ozanimod-treated patients.

CONCLUSION

This study identifies unique histological changes in the lymph nodes of patients with UC treated with ozanimod. The presence of sinus histiocytosis and dilated sinuses is in keeping with the known mechanism of action of ozanimod, and suggests that blocking lymphocyte egression from lymph nodes was insufficient to ameliorate disease severity in these patients. The possibility of Castleman-like features, identified in several of the cases, needs to be further investigated.

Janus Kinase Inhibitors Differentially Inhibit Specific Cytokine Signals in the Mesenteric Lymph Node Cells of Inflammatory Bowel Disease Patients

BACKGROUND

Janus kinase [JAK] inhibitors [JAKinibs] are effective small molecule therapies for treating Crohn's disease [CD] and ulcerative colitis [UC], collectively known as inflammatory bowel disease [IBD]. By preventing JAKs from phosphorylating signal transducer and activator of transcription proteins, JAKinibs disrupt cytokine signalling pathways that promote inflammation. Despite considerable overlap in the JAKs they target, first- and second-generation JAKinibs display different clinical efficacies in CD and UC.

METHODS

We conducted a comparative phosflow study of four JAKinibs [filgotinib, upadacitinib, tofacitinib, and deucravacitinib] to observe subtle mechanistic differences that may dictate their clinical behaviour. Resected mesenteric lymph node [MLN] cells from 19 patients [9 CD, 10 UC] were analysed by flow cytometry in the presence or absence of different cytokine stimuli and titrated JAKinibs.

RESULTS

We found a higher potency of the JAK 1/3-preferential inhibitor, tofacitinib, for JAK 3-dependent cytokine signalling pathways in comparison to filgotinib, but a higher potency of the JAK 1-preferential inhibitors, filgotinib and upadacitinib, for JAK 3-independent cytokine signalling pathways. Deucravacitinib, a TYK2-preferential inhibitor, demonstrated a much narrower selectivity by inhibiting only IL-10 and IFN-β pathways, albeit more potently than the other JAKinibs. Additionally, we found some differences in the sensitivity of immune cells from CD versus UC, and patients with versus without a CD-associated NOD2 polymorphism, to phosphorylate signal transducer and activator of transcriptions in response to specific cytokine stimulation.

CONCLUSIONS

Despite their similarities, differences exist in the relative potencies of different JAKinibs against distinct cytokine families, to explain their clinical efficacy.

Early Versus Late Use of Vedolizumab in Ulcerative Colitis: Clinical, Endoscopic, and Histological Outcomes

BACKGROUND AND AIMS

We explored the potential for differential efficacy of vedolizumab between early and late ulcerative colitis [UC] with evaluation of clinical, endoscopic, and histological endpoints.

METHODS

This was a multicentre, multinational, open-label study in patients with moderately-to-severely active UC, defining early UC by a disease duration <4 years and bio-naïve and late UC by a disease duration > 4 years and additional exposure to tumour necrosis factor antagonists. Patients received standard treatment with intravenous vedolizumab for 52 weeks [300 mg Weeks 0, 2, 6, every 8 weeks thereafter without escalation]. The primary endpoint was corticosteroid-free clinical remission with endoscopic improvement [total Mayo score ≤2 with no subscore >1] at both Weeks 26 and 52.

RESULTS

A total of 121 patients were included: in the "early" group, 25/59 [42.4%] achieved the primary endpoint versus 19/62 [30.6%] in the "late" group [p = 0.18]. There were no significant differences between the two groups in endoscopic improvement [Week 26: "early" 32/59 [54.2%] versus "late" 29/62 [46.8%]; p = 0.412; Week 52: 27/59 [45.8%] versus 25/62 [40.3%]; p = 0.546] or in histological remission [Robarts Histopathology Index <3 without neutrophils in the epithelium and lamina propria] [Week 26: 24/59 [40.7%] versus 21/62 [33.9%]; p = 0.439; Week 52: 22/59 [37.3%] versus 22/62 [35.5%]; p = 0.837].

CONCLUSIONS

No significant differences in clinical, endoscopic, and histological outcomes were observed between "early" and "late" disease.

The coumarin component isofraxidin targets the G-protein-coupled receptor S1PR1 to modulate IL-17 signaling and alleviate ulcerative colitis

OBJECTIVE

The increasing global prevalence of ulcerative colitis (UC) underscores the imperative to explore novel therapeutic approaches. Traditional Chinese medicine has historically shown potential in addressing this ailment. The current study aimed to elucidate the functional attributes and underlying mechanisms of isofraxidin, a coumarin derivative from Acanthopanax, in the context of UC.

METHODS

A murine model of dextran sodium sulfate (DSS)-induced UC was established, and we conducted a comprehensive assessment of the influence of isofraxidin on UC symptomatology, colonic histopathological manifestations, the inflammatory response, and apoptosis. The potential receptor of isofraxidin was initially identified through the Target database and molecular docking analysis. Subsequent in vivo and in vitro experiments were conducted to determine the effects of isofraxidin on the identified receptor and associated signaling pathways. Transfection was used to examine the receptor's role in the regulatory mechanism of isofraxidin.

RESULTS

Isofraxidin reduced UC symptoms and colonic histopathological impairments. Furthermore, isofraxidin ameliorated the DSS-induced inflammatory response and apoptosis in tissues. S1PR1 was identified as a target of isofraxidin and effectively suppressed activation of the IL-17 signaling pathway. Intriguingly, cellular experiments indicated that overexpression of S1PR1 counteracted the protective effect of isofraxidin.

DISCUSSION

In summary, our investigation revealed that isofraxidin could modulate S1PR1 and regulate the IL-17 signaling pathway, thus ameliorating DSS-induced UC. These findings establish a robust foundation for considering isofraxidin as a prospective therapeutic intervention to treat UC.

Level of interleukin 17 in inflammatory bowel disease and its relation with disease activity

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory disorder of the gastrointestinal tract (GIT).It results in progressive intestinal epithelium structural and functional damage that necessitates lifetime medication.Thereis imbalance in the production of T helper 1 (Th1), Th2 and Th17 cytokines. This plays a crucial role in the chronic inflammatory process and the defective immune response to pathogenic agents; thus promoting the recurrence of the disease.Our aim of this study was to detect serum IL-17 levels in IBD patients and its relation with disease activity.

METHODS

This was a single center case control study, conducted at hepatology and gastroenterology unit, Mansoura specialized Medical Hospital, Egypt.Patients who were included were aged 18-65 years, diagnosed either Ulcerative Colitis (UC)or Crohn's Disease (CD) based on previous colonoscopy.IBD activity was measured for UC using the MAYO score and CD using the CD activity index (CDAI). Fifty five patients were UC, 24 patients were CD, 21 patients were control.Patients who were excluded were under 15 years old, with history of GIT malignancy, or any serious comorbidities. Study protocol was approved by Institution Research Board (IRB) of Mansoura Medical College.All patients were subjected to full history taking, routine physical examination, colonoscopy and laboratory investigations including serum IL-17 levels by ELISA besides CBC, CRP, ESR and fecal calprotectin.

RESULTS

Serum IL-17 level was increased significantly among UC; median (min-max) = 72(21-502)pg/ml, in CD 54.5(25-260) versus control 19 (14-35), P < 0.001.However, it was not correlated to the disease activity either Mayo score of UC or CDAI of CD.There was significant correlation to the extent of inflammation in UC affecting the colon (either proctosigmoiditis, left sided colitis or pan colitis), also to the type of CD (either inflammatory, stricturing or fistulizing) by P < 0.05.It was not correlated significantly with any of the IBD activity markers (CRP, ESR, or fecal calprotectin).Yet there was negative significant correlation with Hb level (r =-0.28, p = 0.005).There was not significant association between median serum level of IL-17 & duration of disease (P = 0.6).However, median IL-17 was higher among hospitalized cases than non-hospitalized (73 & 55, pg/ml respectively; p < 0.002). AUC was significantly differentiating between IBD and control group = 0.993 with the best-detected cut off point from curve 32 pg/ml yielding sensitivity of 97.5% and specificity of 95.2%.

CONCLUSION

Serum IL-17 increases in colonic inflammation significantly more than in control group, however its increase is not correlated to IBD activity.

Drug-induced Interstitial Nephritis in a Patient with Ulcerative Colitis Treated with 5-Aminosalicylic Acid

This report describes the case of a 76-year-old man with ulcerative colitis who developed interstitial nephritis after starting 5-Aminosalicylic acid (5-ASA) therapy. The patient experienced an initial improvement in symptoms, but developed fatigue, anorexia, and severe renal dysfunction 2.5 months later. Renal biopsy confirmed drug-induced interstitial nephritis, and conservative treatment with fluid replacement and the discontinuation of 5-ASA improved the patient's condition. Clinicians should monitor patients receiving 5-ASA therapy for potential adverse effects, particularly renal injury, and promptly investigate symptoms of renal dysfunction. Early recognition and discontinuation of the offending agent may prevent further damage and improve patient outcomes.

Charting the cellular biogeography in colitis reveals fibroblast trajectories and coordinated spatial remodeling

Gut inflammation involves contributions from immune and non-immune cells, whose interactions are shaped by the spatial organization of the healthy gut and its remodeling during inflammation. The crosstalk between fibroblasts and immune cells is an important axis in this process, but our understanding has been challenged by incomplete cell-type definition and biogeography. To address this challenge, we used multiplexed error-robust fluorescence in situ hybridization (MERFISH) to profile the expression of 940 genes in 1.35 million cells imaged across the onset and recovery from a mouse colitis model. We identified diverse cell populations, charted their spatial organization, and revealed their polarization or recruitment in inflammation. We found a staged progression of inflammation-associated tissue neighborhoods defined, in part, by multiple inflammation-associated fibroblasts, with unique expression profiles, spatial localization, cell-cell interactions, and healthy fibroblast origins. Similar signatures in ulcerative colitis suggest conserved human processes. Broadly, we provide a framework for understanding inflammation-induced remodeling in the gut and other tissues.

Fibrosis in IBD: from pathogenesis to therapeutic targets

BACKGROUND

Intestinal fibrosis resulting in stricture formation and obstruction in Crohn's disease (CD) and increased wall stiffness leading to symptoms in ulcerative colitis (UC) is among the largest unmet needs in inflammatory bowel disease (IBD). Fibrosis is caused by a multifactorial and complex process involving immune and non-immune cells, their soluble mediators and exposure to luminal contents, such as microbiota and environmental factors. To date, no antifibrotic therapy is available. Some progress has been made in creating consensus definitions and measurements to quantify stricture morphology for clinical practice and trials, but approaches to determine the degree of fibrosis within a stricture are still lacking.

OBJECTIVE

We herein describe the current state of stricture pathogenesis, measuring tools and clinical trial endpoints development.

DESIGN

Data presented and discussed in this review derive from the past and recent literature and the authors' own research and experience.

RESULTS AND CONCLUSIONS

Significant progress has been made in better understanding the pathogenesis of fibrosis, but additional studies and preclinical developments are needed to define specific therapeutic targets.

Real-world Evidence Comparing Tofacitinib and Vedolizumab in Anti-TNF-experienced Patients With Ulcerative Colitis

BACKGROUND

Antitumor necrosis factor (anti-TNF) inhibitors are first-line treatment among patients with ulcerative colitis (UC). With time, patients tend to lose response or become intolerant, necessitating switching to small cell biologics such as tofacitinib or vedolizumab. In this real-world study of a large, geographically diverse US population of TNF-experienced patients with UC, we evaluated the effectiveness and safety of newly initiating treatment with tofacitinib vs vedolizumab.

METHODS

We conducted a cohort study using secondary data from a large US insurer (Anthem, Inc.). Our cohort included patients with UC newly initiating treatment with tofacitinib or vedolizumab. Patients were required to have evidence of treatment with anti-TNF inhibitors in the 6 months prior to cohort entry. The primary outcome was treatment persistence >52 weeks. Additionally, we evaluated the following secondary outcomes as additional measures of effectiveness and safety: (1) all-cause hospitalization; (2) total abdominal colectomy; (3) hospitalization for infection; (4) hospitalization for malignancy; (5) hospitalization for cardiac events; and (6) hospitalization for thromboembolic events. We used fine stratification by propensity scores to control for confounding by demographics, clinical factors, and treatment history at baseline.

RESULTS

Our primary cohort included 168 new users of tofacitinib and 568 new users of vedolizumab. Tofacitinib was associated with lower treatment persistence (adjusted risked ratio, 0.77; 95% CI, 0.60 -0.99). Differences in secondary measures of effectiveness or safety between tofacitinib initiators vs vedolizumab initiators were not statistically significant (all-cause hospitalization, adjusted hazard ratio, 1.23; 95% CI, 0.83-1.84; total abdominal colectomy, adjusted HR, 1.79; 95% CI, 0.93-3.44;and hospitalization for any infection, adjusted HR, 1.94; 95% CI, 0.83-4.52).

DISCUSSION

Ulcerative colitis patients with prior anti-TNF experience initiating tofacitinib demonstrated lower treatment persistence compared with those initiating vedolizumab. This finding is in contrast to other recent studies suggesting superior effectiveness of tofacitinib. Ultimately, head-to-head randomized, controlled trials that focus on directly measured end points may be needed to best inform clinical practice.

Revisiting the Role of Valeric Acid in Manipulating Ulcerative Colitis

BACKGROUND

Ulcerative colitis (UC) is characterized by a complicated interaction between mucosal inflammation, epithelial dysfunction, abnormal activation of innate immune responses, and gut microbiota dysbiosis. Though valeric acid (VA), one type of short-chain fatty acids (SCFAs), has been identified in other inflammatory disorders and cancer development, the pathological role of VA and underlying mechanism of VA in UC remain under further investigation.

METHODS

Studies of human clinical specimens and experimental colitis models were conducted to confirm the pathological manifestations of the level of SCFAs from human fecal samples and murine colonic homogenates. Valeric acid-intervened murine colitis and a macrophage adoptive transfer were applied to identify the underlying mechanisms.

RESULTS

In line with gut microbiota dysfunction in UC, alteration of SCFAs from gut microbes were identified in human UC patients and dextran sodium sulfate -induced murine colitis models. Notably, VA was consistently negatively related to the disease severity of UC, the population of monocytes, and the level of interluekin-6. Moreover, VA treatment showed direct suppressive effects on lipopolysaccharides (LPS)-activated human peripheral blood mononuclear cells and murine macrophages in the dependent manner of upregulation of GPR41 and GPR43. Therapeutically, replenishment of VA or adoptive transfer with VA-modulated macrophages showed resistance to dextran sodium sulfate-driven murine colitis though modulating the production of inflammatory cytokine interleukin-6.

CONCLUSIONS

In summary, the research uncovered the pathological role of VA in modulating the activation of macrophages in UC and suggested that VA might be a potential effective agent for UC patients.

Dynamics of the Gut Mycobiome in Patients With Ulcerative Colitis

BACKGROUND & AIMS

Intestinal fungi have been implicated in the pathogenesis of ulcerative colitis (UC). However, it remains unclear if fungal composition is altered during active versus quiescent disease.

METHODS

We analyzed clinical and metagenomic data from the Study of a Prospective Adult Research Cohort with Inflammatory Bowel Disease (SPARC IBD), available via the IBD Plexus Program of the Crohn's & Colitis Foundation. We evaluated the fungal composition of fecal samples from 421 patients with UC during clinical activity and remission. Within a longitudinal subcohort (n = 52), we assessed for dynamic taxonomic changes across alterations in clinical activity over time. We examined if fungal amplicon sequence variants and fungal-bacterial relationships were altered during activity versus remission. Finally, we classified activity in UC using a supervised machine learning random forest model trained on fungal abundance data.

RESULTS

During clinical activity, the relative abundance of genus Candida was increased 3.5-fold (P-adj < 1 × 10-4) compared with during remission. Patients with longitudinal reductions in clinical activity demonstrated parallel reductions in Candida relative abundance (P < .05). Candida relative abundance correlated with Parabacteroides diastonis, Faecalibacterium prausnitzii, and Bacteroides dorei relative abundance (P < .05) during remission; however, these correlations were disrupted during activity. Fungal abundance data successfully classified patients with active or quiescent UC (area under the curve ∼0.80), with Candida relative abundance critical to the success of the model.

CONCLUSIONS

Clinical activity in UC is associated with an increased relative abundance of Candida, cross-sectionally and dynamically over time. The role of fecal Candida as a target for therapeutics in UC should be evaluated.

Gastroduodenitis Associated with Active Ulcerative Colitis Treated with Infliximab: Different Clinical Course in the Colon and Gastroduodenal Lesions

A 29-year-old man with severe ulcerative colitis and gastroduodenitis was initially treated with oral mesalamine and high-dose intravenous steroid therapy; however, his epigastralgia and vomiting did not improve. After initiating infliximab, the patient experienced prompt improvement in symptoms and inflammation. Although steroids were effective for the colon, they proved ineffective for gastroduodenal lesions, highlighting the necessity for molecular-targeted agents, such as infliximab, in these cases. The timing for administering such agents should be carefully considered.

Similar geographic distribution of mortality from multiple sclerosis, Hodgkin lymphoma, and inflammatory bowel disease in the United States

BACKGROUND

Previous epidemiologic studies have suggested a linkage between the occurrence of multiple sclerosis (MS), Hodgkin lymphoma (HL), Crohn's disease (CD), and ulcerative colitis (UC). It was hypothesized that the 4 diagnoses would be characterized by similar geographic distributions within the United States.

AIMS

To compare the US geographic distributions of these 4 diagnoses in a cross-sectional study.

METHODS

Using the US vital statistics, state-specific death rates and age-specific proportional mortality ratios (PMR) were calculated for each diagnosis. Similarities in the geographic distributions of the 4 diagnoses were tested by linear and Poisson regression analyses. The PMR values from different states were correlated among pairs of consecutive age-groups.

RESULTS

The 6 linear correlation coefficients (r) among the geographic distributions of the 4 diseases were as follows: HL vs. MS (r = 0.28), HL vs. CD (r = 0.74), HL vs. UC (r = 0.64); MS vs. CD (r = 0.18), MS vs. UC (r = 0.66); CD vs. UC (r = 0.58). Using Poisson regression, the geographic distributions of MS, HL, CD, and UC were all found to be significantly correlated with each other. In MS, significant correlations between the PMR values of each two consecutive age-groups started with the age-group 25-44 years. In HL, such significant correlations started at age 10-14, in CD at age 20-24, and in UC at age 20-24 years.

CONCLUSIONS

Within the United States, mortality from MS, HL, CD, and UC are characterized by similar geographic distributions. The environmental influences responsible for these resembling geographic distributions start exerting their influence during early lifetime.

Histological healing induced by tofacitinib in ulcerative colitis: A multicentre study

BACKGROUND

While the efficacy of tofacitinib to induce and maintain clinical and endoscopic remission is well established in ulcerative colitis (UC), little is known about its efficacy to induce histological remission.

METHODS

We conducted a retrospective multicentric cohort study. UC patients ≥ 16 years treated by tofacitinib in whom histological activity has been evaluated before and after induction were eligible. The primary endpoint was the histological remission at the end of induction, assessed by the Nancy index and the epithelial neutrophilic infiltrate.

RESULTS

A total of 42 patients with UC (93% previously exposed to an anti-TNF and 81% to vedolizumab) were included between July 2018 and April 2022 and were followed for a median duration of 84 weeks [IQR, 35-134]. At the end of induction period (whether prolonged or not), 19% and 24% of patients achieved histological remission, using the Nancy index and the epithelial neutrophilic infiltrate, respectively. Survival without tofacitinib discontinuation was significantly longer in patients without epithelial neutrophilic infiltrate at the end of induction (whether prolonged or not) compared with patients with epithelial neutrophilic infiltrate (p = 0.036).

CONCLUSION

Tofacitinib induced histological remission in one fifth to one quarter of patients with UC who have previously failed anti-TNF or/and vedolizumab after induction (whether prolonged or not).

Characteristics of flat-type ulcerative colitis-associated neoplasia on chromoendoscopic imaging with indigo carmine dye spraying

OBJECTIVES

Despite recent advances in endoscopic equipment and diagnostic techniques, early detection of ulcerative colitis-associated neoplasia (UCAN) remains difficult because of the complex background of the inflamed mucosa of ulcerative colitis and the morphologic diversity of the lesions. We aimed to describe the main diagnostic patterns for UCAN in our cohort, including lateral extension surrounding flat lesions.

METHODS

Sixty-three lesions in 61 patients with flat-type dysplasia that were imaged with dye chromoendoscopy (DCE) were included in this analysis. These DCE images were analyzed to clarify the dye-chromoendoscopic imaging characteristics of flat dysplasia, and the lesions were broadly classified into dysplastic and nondysplastic mucosal patterns.

RESULTS

Dysplastic mucosal patterns were classified into two types: small round patterns with round to roundish structures, and mesh patterns with intricate mesh-like structures. Lesions with a nondysplastic mucosal pattern were divided into two major types: a ripple-like type and a gyrus-like type. Of note, 35 lesions (55.6%) had a small round pattern, and 51 lesions (80.9%) had some type of mesh pattern. About 70% of lesions with small round patterns and 49% of lesions with mesh patterns were diagnosed as high-grade dysplasia or carcinoma, while about 30% of lesions with small round patterns and 51% of lesions with mesh patterns were diagnosed as low-grade dysplasia.

CONCLUSION

When a characteristic mucosal pattern, such as a small round or mesh pattern, is found by DCE, the possibility of UCAN should be considered.

Synbiotic of Pediococcus acidilactici and Inulin Ameliorates Dextran Sulfate Sodium-Induced Acute Ulcerative Colitis in Mice

Colitis is a major gastrointestinal disease that threatens human health. In this study, a synbiotic composed of inulin and Pediococcus acidilactici (P. acidilactici) was investigated for its ability to alleviate dextran sulfate sodium (DSS)-induced colitis. The results revealed that the synbiotic, composed of inulin and P. acidilactici, attenuated the body weight loss and disease activity index (DAI) score in mice with DSS-mediated colitis. Determination of biochemical indicators found that the synbiotic increased anti-oxidation and alleviated inflammation in mice. Additionally, histopathological examination revealed that colonic goblet cell loss and severe mucosal damage in the model group were significantly reversed by the combination of inulin and P. acidilactici. Moreover, synbiotic treatment significantly reduced the levels of IL-1β, TNF-α, and IL-6 in the serum of mice. Thus, a synbiotic composed of inulin and P. acidilactici has preventive and therapeutic effects on DSSinduced colitis in mice.

Qingchang Wenzhong Decoction ameliorates intestinal inflammation and intestinal barrier dysfunction in ulcerative colitis via the GC-C signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Ulcerative colitis (UC) is an idiopathic, chronic inflammatory disorder of the colonic mucosa, accompanied with abdominal pain, and bloody diarrhea. Currently, clinical treatment options for UC are limited. Qingchang Wenzhong Decoction (QCWZD) is an effective prescription of traditional Chinese medicine for the treatment of UC. However, the mechanism of QCWZD in alleviating intestinal barrier dysfunction in UC has not been clearly explained.

AIM OF THE STUDY

To determine the mechanism whereby QCWZD promotes the recovery of intestinal barrier dysfunction in UC.

MATERIALS AND METHODS

A secondary analysis of colonic mucosa from UC patients acquired from a prior RCT clinical trial was performed. The effects of QCWZD on intestinal mucus and mechanical barriers in UC patients were evaluated using colon tissue paraffin-embedded sections from UC patients. The mechanism was further investigated by in vivo and in vitro experiments. UC mice were established in sterile water with 3.0% dextran sodium sulfate (DSS). Meanwhile, mice in the treatment group were dosed with QCWZD or mesalazine. In vitro, an intestinal barrier model was constructed using Caco-2 and HT29 cells in co-culture. GC-C plasmid was used to overexpress/knock down GC-C to clarify the target of QCWZD. HE, AB-PAS, ELISA, immunohistochemistry and immunofluorescence assays were used to assess the level of colonic inflammation and intestinal barrier integrity. Rt-qPCR, Western Blot were used to detect the expression of genes and proteins related to GC-C signaling pathway. Molecular docking was used to simulate the binding sites of major components of QCWZD to GC-C.

RESULTS

In UC patients, QCWZD increased mucus secretion, goblet cell number, and promoted MUC2 and ZO-1 expression. QCWZD accelerated the recovery of UC mice from DSS-induced inflammation, including weight gain, reduced disease activity index (DAI) scores, colon length recovery, and histological healing. QCWZD promoted mucus secretion and increased ZO-1 expression in in vivo and in vitro experiments, thereby repairing mucus mechanical barrier damage. The effects of QCWZD are mediated through regulation of the GC-C signaling pathway, which in turn affects CFTR phosphorylation and MUC2 expression to promote mucus secretion, while inhibiting the over-activation of MLCK and repairing tight junctions to maintain the integrity of the mechanical barrier. Molecular docking results demonstrate the binding of the main components of QCWZD to GC-C.

CONCLUSION

Our study demonstrated that QCWZD modulates the GC-C signaling pathway to promote remission of mucus-mechanical barrier damage in the UC. The clarification of the mechanism of QCWZD holds promise for the development of new therapies for UC.

DNA methylation fine-tunes pro-and anti-inflammatory signalling pathways in inactive ulcerative colitis tissue biopsies

DNA methylation has been implied to play a role in the immune dysfunction associated with inflammatory bowel disease (IBD) and the disease development of ulcerative colitis (UC). Changes of the DNA methylation and correlated gene expression in patient samples with inactive UC might reveal possible regulatory features important for further treatment options for UC. Targeted bisulfite sequencing and whole transcriptome sequencing were performed on mucosal biopsies from patients with active UC (UC, n = 14), inactive UC (RM, n = 20), and non-IBD patients which served as controls (NN, n = 11). The differentially methylated regions (DMRs) were identified by DMRseq. Correlation analysis was performed between DMRs and their nearest differentially expressed genes (DEGs). Principal component analysis (PCA) was performed based on correlated DMR regulated genes. DMR regulated genes then were functional annotated. Cell-type deconvolutions were performed based on methylation levels. The comparisons revealed a total of 38 methylation-regulated genes in inactive UC that are potentially regulated by DMRs (correlation p value < 0.1). Several methylation-regulated genes could be identified in inactive UC participating in IL-10 and cytokine signalling pathways such as IL1B and STAT3. DNA methylation events in inactive UC seem to be fine-tuned by the balancing pro- and anti- inflammatory pathways to maintain a prevailed healing process to restore dynamic epithelium homeostasis.

Are we ready to use new endoscopic scores for ulcerative colitis?

For ulcerative colitis (UC), the variability in inflammatory activity along the colon poses a challenge in management. The focus on achieving endoscopic healing in UC is evident, where the UC Endoscopic Index of Severity and Mayo Endoscopic Subscore are commonly used for evaluation. However, these indices primarily consider the most severely affected region. Liu et al recent study validates the Toronto Inflammatory Bowel Disease Global Endoscopic Reporting (TIGER) score offering a comprehensive assessment of inflammatory activity across diverse segments of the colon and rectum and a reliable index correlating strongly with UC Endoscopic Index of Severity and moderately with Mayo Endoscopic Subscore (MES). Despite recommendation, certain aspects warrant further investigation. Fecal calprotectin, an intermediate target, correlates with TIGER and should be explored. Determining TIGER scores defining endoscopic remission and response, evaluating agreement with histological activity, and assessing inter-endoscopist agreement for TIGER require scrutiny. Exploring the correlation between TIGER and intestinal ultrasound, akin to MES, adds value.

Gut microbiota-based discriminative model for patients with ulcerative colitis: A meta-analysis and real-world study

Gut microbiota directly interacts with intestinal epithelium and is a significant factor in the pathogenesis of ulcerative colitis (UC). A meta-analysis was performed to investigate gut microbiota composition of patients with UC in the United States. We also collected fecal samples from Chinese patients with UC and healthy individuals. Gut microbiota was tested using 16S ribosomal RNA gene sequencing. Meta-analysis and 16S ribosomal RNA sequencing revealed significant differences in gut bacterial composition between UC patients and healthy subjects. The Chinese UC group had the highest scores for Firmicutes, Clostridia, Clostridiales, Streptococcaceae, and Blautia, while healthy cohort had the highest scores for P-Bacteroidetes, Bacteroidia, Bacteroidales, Prevotellaceae, and Prevotella_9. A gut microbiota-based discriminative model trained on an American cohort achieved a discrimination efficiency of 0.928 when applied to identify the Chinese UC cohort, resulting in a discrimination efficiency of 0.759. Additionally, a differentiation model was created based on gut microbiota of a Chinese cohort, resulting in an area under the receiver operating characteristic curve of 0.998. Next, we applied the model established for the Chinese UC cohort to analyze the American cohort. Our findings suggest that the diagnostic efficiency ranged from 0.8794 to 0.9497. Furthermore, a combined analysis using data from both the Chinese and US cohorts resulted in a model with a diagnostic efficacy of 0.896. In summary, we found significant differences in gut bacteria between UC individuals and healthy subjects. Notably, the model from the Chinese cohort performed better at diagnosing UC patients compared to healthy subjects. These results highlight the promise of personalized and region-specific approaches using gut microbiota data for UC diagnosis.

Targeting P2Y14R protects against necroptosis of intestinal epithelial cells through PKA/CREB/RIPK1 axis in ulcerative colitis

Purinergic signaling plays a causal role in the pathogenesis of inflammatory bowel disease. Among purinoceptors, only P2Y14R is positively correlated with inflammatory score in mucosal biopsies of ulcerative colitis patients, nevertheless, the role of P2Y14R in ulcerative colitis remains unclear. Here, based on the over-expressions of P2Y14R in the intestinal epithelium of mice with experimental colitis, we find that male mice lacking P2Y14R in intestinal epithelial cells exhibit less intestinal injury induced by dextran sulfate sodium. Mechanistically, P2Y14R deletion limits the transcriptional activity of cAMP-response element binding protein through cAMP/PKA axis, which binds to the promoter of Ripk1, inhibiting necroptosis of intestinal epithelial cells. Furthermore, we design a hierarchical strategy combining virtual screening and chemical optimization to develop a P2Y14R antagonist HDL-16, which exhibits remarkable anti-colitis effects. Summarily, our study elucidates a previously unknown mechanism whereby P2Y14R participates in ulcerative colitis, providing a promising therapeutic target for inflammatory bowel disease.

Melanocortin 3,5 receptors immunohistochemical expression in colonic mucosa of inflammatory bowel disease patients: A matter of disease activity?

BACKGROUND

Melanocortin 3 and 5 receptors (i.e., MC3R and MC5R) belong to the melanocortin family. However, data regarding their role in inflammatory bowel diseases (IBD) are currently unavailable.

AIM

This study aims to ascertain their expression profiles in the colonic mucosa of Crohn's disease (CD) and ulcerative colitis (UC), aligning them with IBD disease endoscopic and histologic activity.

METHODS

Colonic mucosal biopsies from CD/UC patients were sampled, and immunohistochemical analyses were conducted to evaluate the expression of MC3R and MC5R. Colonic sampling was performed on both traits with endoscopic scores (Mayo endoscopic score and CD endoscopic index of severity) consistent with inflamed mucosa and not consistent with disease activity (i.e., normal appearing mucosa).

RESULTS

In both CD and UC inflamed mucosa, MC3R (CD: + 7.7 fold vs normal mucosa, P < 0.01; UC: + 12 fold vs normal mucosa, P < 0.01) and MC5R (CD: + 5.5 fold vs normal mucosa, P < 0.01; UC: + 8.1 fold vs normal mucosa, P < 0.01) were significantly more expressed compared to normal mucosa.

CONCLUSION

MC3R and MC5R are expressed in the colon of IBD patients. Furthermore, expression may differ according to disease endoscopic activity, with a higher degree of expression in the traits affected by disease activity in both CD and UC, suggesting a potential use of these receptors in IBD pharmacology.

Hippocampal and gut AMPK activation attenuates enterocolitis-like symptoms and co-occurring depressive-like behavior in ulcerative colitis model mice: Involvement of brain-gut autophagy

Patients with inflammatory bowel disease, including ulcerative colitis (UC) and Crohn's disease, have a high incidence of psychiatric disorders, including depression and anxiety. However, the underlying pathogenic mechanism remains unknown. Dextran sulfate sodium (DSS)-treated mice, a model of UC, exhibit depressive-like behavior and reduced adenosine monophosphate-activated protein kinase (AMPK) activity, which regulates various physiological functions in the brain and gut. However, comprehensive studies on UC pathophysiology with co-occurring depression focused on brain-gut AMPK activity are lacking. Therefore, we aimed to investigate whether resveratrol (RES), an AMPK activator, prevented DSS-induced UC-like symptoms and depressive-like behavior. DSS treatment induced UC-like pathology and depressive-like behavior, as assessed via the tail suspension test. Moreover, western blotting and immunohistochemical studies revealed that DSS increased p-p70S6 kinase (Thr389), p62, tumor necrosis factor-α, interleukin (IL)-1β, IL-18, NLR family pyrin domain containing 3 (NLRP3), cleaved caspase-1, cleaved Gasdermin-D (GSDMD), and cleaved caspase-3 expression levels in the rectum and hippocampus, and increased CD40, iNOS, and Kelch-like ECH-associated protein 1 expression levels, and the number of Iba1-positive cells in the hippocampus, and decreased p-AMPK and LC3II/I expression levels, and the number of NF-E2-related factor 2 (Nrf2)-positive cells, and reduced neurogenesis in the hippocampus. These changes were reversed by the RES administration. RES also enhanced PGC1α and SOD1 expression in the hippocampus of DSS-treated male mice. Moreover, NLRP3 staining was observed in the neurons and microglia, and cleaved GSDMD staining in neurons in the hippocampus of DSS-treated mice. Notably, RES prevented UC-like pathology and depressive-like behavior and enhancement of autophagy, decreased rectal and hippocampal inflammatory cytokines and inflammasome, and induced the Nrf2-PGC1α-SOD1 pathway in the hippocampus, resulting in neurogenesis in the hippocampal dentate gyrus. Our findings suggest that brain-gut AMPK activation may be an important therapeutic strategy in patients with UC and depression.

Pathology and Clinical Significance of Inflammatory Bowel Disease-Associated Colorectal Dysplastic Lesions

Timely diagnosis and effective management of colorectal dysplasia play a vital role in preventing mortality from colorectal cancer in patients with chronic inflammatory bowel disease. This review provides a contemporary overview of the pathologic and endoscopic classification of dysplasia in inflammatory bowel disease, their roles in determining surveillance and management algorithms, and emerging diagnostic and therapeutic approaches that might further enhance patient management.

Endoplasmic reticulum stress interferes with the development of type 1 regulating T cells

BACKGROUND

A variety of stimuli can cause endoplasmic reticulum (ER) stress, which is a common cellular reaction. It is not yet clear how ER stress contributes to the pathogenesis of ulcerative colitis (UC). The deregulation of regulatory T cell (Treg) is associated with UC. The goal of this study is to shed light on how ER stress affects Treg's development.

METHODS

CD4+ CD25- T cells were isolated from blood samples collected from UC patients and healthy control (HC) subjects. ER stress-associated molecule expression in CD4+ CD25- T cell was assessed by RNA sequencing and RT-qPCR.

RESULTS

The presence of ER stress in peripheral CD4+ CD25- T cells was observed in patients with UC compared to HC subjects. The induction of ER stress in HC CD4+ CD25- T cells by polyclonal activation was made worse by the presence of 3-methyl-4-nitrophenol (MNP; a common environmental pollutant). Exposure to MNP in culture resulted in an increase in the expression of ring finger protein 20 (Rnf20) in CD4+ CD25- T cells. The synergistic effects of MNP and ER stress on the reduction of IL-10 levels in CD4+ CD25- T cells are mediated by Rnf20, which prevents the development of Tr1 cells. Inhibition of Rnf20 resulted in the development of Tr1 cells from CD4+ CD25- T cells in UC patients.

CONCLUSIONS

The synergistic effects of ER stress and MNP interfere with the development of Tr1 cells. The development of Tr1 from CD4+ CD25- T cells in patients with UC is re-established by Rnf20 inhibition.

An inulin-type fructan CP-A from Codonopsis pilosula attenuates experimental colitis in mice by promoting autophagy-mediated inactivation of NLRP3 inflammasome

Inulin-type fructan CP-A, a predominant polysaccharide in Codonopsis pilosula, demonstrates regulatory effects on immune activity and anti-inflammation. The efficacy of CP-A in treating ulcerative colitis (UC) is, however, not well-established. This study employed an in vitro lipopolysaccharide (LPS)-induced colonic epithelial cell model (NCM460) and an in vivo dextran sulfate sodium (DSS)-induced colitis mouse model to explore CP-A's protective effects against experimental colitis and its underlying mechanisms. We monitored the clinical symptoms in mice using various parameters: body weight, disease activity index (DAI), colon length, spleen weight, and histopathological scores. Additionally, molecular markers were assessed through enzyme-linked immunosorbent assay (ELISA), quantitative real-time polymerase chain reaction (qRT-PCR), immunofluorescence (IF), immunohistochemistry (IHC), and Western blotting assays. Results showed that CP-A significantly reduced reactive oxygen species (ROS), tumor necrosis factor-alpha (TNF-α), and interleukins (IL-6, IL-1β, IL-18) in LPS-induced cells while increasing IL-4 and IL-10 levels and enhancing the expression of Claudin-1, ZO-1, and occludin proteins in NCM460 cells. Correspondingly, in vivo findings revealed that CP-A administration markedly improved DAI, reduced colon shortening, and decreased the production of myeloperoxidase (MPO), malondialdehyde (MDA), ROS, IL-1β, IL-18, and NOD-like receptor protein 3 (NLRP3) inflammasome-associated genes/proteins in UC mice. CP-A treatment also elevated glutathione (GSH) and superoxide dismutase (SOD) levels, stimulated autophagy (LC3B, P62, Beclin-1, and ATG5), and reinforced Claudin-1 and ZO-1 expression, thereby aiding in intestinal epithelial barrier repair in colitis mice. Notably, the inhibition of autophagy via chloroquine (CQ) diminished CP-A's protective impact against colitis in vivo. These findings elucidate that CP-A's therapeutic effect on experimental colitis possibly involves mitigating intestinal inflammation through autophagy-mediated NLRP3 inflammasome inactivation. Consequently, inulin-type fructan CP-A emerges as a promising drug candidate for UC treatment.

Long-term behavior and functional outcomes of ileal-pouch anal anastomosis in inflammatory bowel disease with changing phenotype

BACKGROUND

Ileal-pouch-anal anastomosis is the operation of choice after proctocolectomy for ulcerative colitis; some patients will develop Crohn's disease. We aim to determine long-term behavior and outcomes of inflammatory bowel disease-ileal-pouch-anal anastomosis after colectomy, where a specialist gastrointestinal pathologist re-evaluated the initial colectomy specimen.

METHODS

Patients with inflammatory bowel disease-ileal-pouch-anal anastomosis were identified from a single-surgeon prospective database containing 1,165 patients accrued from 1991 to 2017 and invited to complete pouch-function and quality-of-life assessments. Medical records were used to obtain clinical outcomes and subjective functional assessments for those unable to be contacted. Data were compared between patients with and without histological assessment disagreement and subsequent inflammatory bowel disease behavior subgroups.

RESULTS

For 138 patients included in the analysis, the median follow-up was 22.5 (range: 5-39) years. A total of 39.1% of patients had histologic diagnostic change after gastrointestinal pathologist review, and 19% and 39% developed Crohn's disease-like disease behavior at 10- and 20-year follow-ups. Pouch function and quality-of-life scores were similar across diagnostic change subgroups. Pouch failure was higher in Crohn's-like disease (31.1 vs 13.0%, P < .05). Intestinal continuity was maintained in 68.9% of Crohn's disease-like patients, 57.9% required biologics. Gastrointestinal pathologist review did not alter the time to new diagnosis (P = .419) or time to pouch failure (P = .320), mean: 11.0 and 11.41 years, respectively.

CONCLUSION

We describe equivocal patient-reported outcomes in patients with ileal-pouch-anal anastomosis and changing histologic and clinical diagnosis. Although pouch excision and biologic use rates are higher, many Crohn's disease-like patients maintain their pouch. Diagnostic change and pouch failure often occur >10 years after ileal-pouch-anal anastomosis creation. This supports the consideration of ileal-pouch-anal anastomosis after colectomy in carefully selected patients with inflammatory bowel disease, even those with ambiguous histology and the need for close long-term follow-up.

Extensive involvement of indolent T-cell lymphoma in a patient with ulcerative colitis

Indolent T-cell lymphoma is a rare disease. Here we presented a 53-year-old male patient initially diagnosed as ulcerative colitis in 2000 that finally developed into extensive indolent T-cell lymphoma in 2022. We also described the differences between indolent T-cell lymphoma and inflammatory bowel disease, and the possible disease progression into lymphoma after biological therapy.

Poor Diagnostic Reproducibility in the Identification of Nonconventional Dysplasia in Colitis Impacts the Application of Histologic Stratification Tools

Due to their increased cancer risk, patients with longstanding inflammatory bowel disease are offered endoscopic surveillance with concomitant histopathologic assessments, aimed at identifying dysplasia as a precursor lesion of colitis-associated colorectal cancer. However, this strategy is beset with difficulties and limitations. Recently, a novel classification criterion for colitis-associated low-grade dysplasia has been proposed, and an association between nonconventional dysplasia and progression was reported, suggesting the possibility of histology-based stratification of patients with colitis-associated lesions. Here, a cohort of colitis-associated lesions was assessed by a panel of 6 experienced pathologists to test the applicability of the published classification criteria and try and validate the association between nonconventional dysplasia and progression. While confirming the presence of different morphologic patterns of colitis-associated dysplasia, the study demonstrated difficulties concerning diagnostic reproducibility between pathologists and was unable to validate the association of nonconventional dysplasia with cancer progression. Our study highlights the overall difficulty of using histologic assessment of precursor lesions for cancer risk prediction in inflammatory bowel disease patients and suggests the need for a different diagnostic strategy that can objectively identify high-risk phenotypes.

Acute severe ulcerative colitis management: unanswered questions and latest insights

Acute severe ulcerative colitis (ASUC) is a distinctive ulcerative colitis flare presentation characterised by the presence of systemic inflammation as well as bloody diarrhoea, and occurs at least once in 25% of patients with ulcerative colitis during their disease course. Each episode carries a risk of complications, need for colectomy, and mortality. Little is known about ASUC pathogenesis, although impaired host-microbiota crosstalk involving pathobionts is suspected. In this Review, we discuss unanswered questions and results from the latest research on the medical-first-line, second-line, and potential third-line therapies-and surgical management of ASUC. We detail promising options for management, such as the use of enteral nutrition in combination with intravenous steroids, the ability to predict early failure of first-line or second-line therapies, and the emerging role of JAK inhibitors. An optimal framework to personalise therapy on the basis of multiomics tools is yet to be developed.

Histology of IBD and related colitides in the elderly

Inflammatory bowel disease (IBD) are chronic relapsing diseases, affecting both children and adults with a life-long duration. An increased co-morbidity gives raise to fragility in the elderly. In this regard it should consider that several non-IBD colitides may mimic both ulcerative colitis and Crohn's disease. Moreover, chronic diseases represent a clinical challenge, mostly about treatment effectiveness. Finally, it is worth noting that patients with long-standing diseases - and elderly patients among them - have an increased malignancy risk when compared to general (non-IBD) population. Our paper aims to review the three main histological topics that play a role in the clinical management of IBD in the elderly, namely differential diagnosis, mucosal healing and IBD-associated dysplasia.

S100a10 deficiency in neutrophils aggravates ulcerative colitis in mice

BACKGROUND AND AIMS

S100a10 is a member of the S100 family of proteins, which plays a key role in the depression and tumor metastasis. However, the role of S100a10 is unclear in ulcerative colitis.

METHODS

The effect of S100a10 was assessed using a murine ulcerative colitis model which was accompanied by parameters including body weight loss, disease activity index, histological score, colon weight and length. The quantity and role of immune cells was determined by flow cytometry and bone marrow chimeric mice. Neutrophils depletion, adoptive cell transfer and conditional knockout mice were used to ascertain which cells played the key role in ulcerative colitis. The function of neutrophils was evaluated by migration assay, phagocytosis assay, multiplex immunoassay and real-time PCR.

RESULTS

In this study, our data showed that S100a10-/- mice were prone to ulcerative colitis induced by dextran sodium sulfate. Neutrophils number increased in colon of S100a10-/- mice after dextran sodium sulfate treatment significantly. Meanwhile, adoptive transfer of neutrophils from wild type mice partially decreased the susceptibility of S100a10-/- mice to dextran sodium sulfate. There was no difference in ulcerative colitis between the groups of S100a10-/- mice without neutrophils and wild type mice. Finally, we found that S100a10-/- neutrophils had stronger function in secretion and synthesis of inflammatory factor.

CONCLUSIONS

In one word, these results suggest that S100a10 has a role in inhibiting the pathogenesis of ulcerative colitis through regulation of neutrophils function.

Microbial butyrate capacity is reduced in inflamed mucosa in patients with ulcerative colitis

Reduced butyrate-production capacity has been reported in fecal microbial communities in patients with active ulcerative colitis. However, the butyrate-production capacity of the mucosal microbiome from active vs quiescent mucosa in ulcerative colitis has been unexplored. We sought to determine the diversity and relative abundance of mucosal bacterial and fungal communities from endoscopically active vs quiescent mucosa in patients with UC, and aimed to predict contributions of mucosal microbial communities to butyrate synthesis. Systematic, segmental right- and left-sided biopsies were obtained from endoscopically active (n = 13) or quiescent (n = 17) colonic mucosa, among 15 patients with pan-colonic ulcerative colitis. Dietary fiber intake of patients was performed using the validated five-item FiberScreen questionnaire. Amplicon sequencing of mucosal bacteria and fungi was performed. The diversity and relative abundance of mucosal bacterial and fungal taxa were quantified, and predicted contributions to butyrate synthesis were ascertained. Bacterial alpha and beta diversity were similar between active vs quiescent mucosa. Butyrogenic taxa were significantly increased in quiescence, including Butyricimonas, Subdoligranulum, and Alistipes. Predicted butyrate kinase activity was significantly and concomitantly increased in quiescent mucosa. Fiber intake was positively correlated with butyrogenic microbes. Compared to mucosal bacterial prevalence, mucosal fungi were detected in low prevalence. Butyrogenic microbes are relatively increased in quiescent mucosa in ulcerative colitis, and may be related to increased fiber intake during quiescence. Manipulation of the mucosal microbiome towards butyrate-producing bacteria may be associated with endoscopic quiescence.

Bletilla striata carbon dots with alleviating effect of DSS-induced ulcerative colitis

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) that significantly affected quality of life for patients. In this study, carbon dots based on Bletilla striata (BS-CDs) were synthesized by hydrothermal method and characterized by optical property analysis. In addition, the study measured the potential effect of BS-CDs on colonic histopathology and inflammation in dextran sulfate sodium (DSS)-induced ulcerative colitis. The results suggested that BS-CDs significantly increased colon length, improved colonic histopathology, and reduced the levels of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6) in colitis mice. Taken together, BS-CDs alleviate clinical inflammation by blocking pro-inflammatory cytokines which were expected to be a potential agent for the treatment of colitis.

Mucin Expression Profiles in Ulcerative Colitis: New Insights on the Histological Mucosal Healing

A structural weakness of the mucus barrier (MB) is thought to be a cause of ulcerative colitis (UC). This study aims to investigate the mucin (MUC) composition of MB in normal mucosa and UC. Ileocolonic biopsies were taken at disease onset and after treatment in 40 patients, including 20 with relapsing and 20 with remitting UC. Ileocolonic biopsies from 10 non-IBD patients were included as controls. Gut-specific MUC1, MUC2, MUC4, MUC5B, MUC12, MUC13, MUC15, and MUC17 were evaluated immunohistochemically. The promoters of mucin genes were also examined. Normal mucosa showed MUC2, MUC5B, and MUC13 in terminal ileum and colon, MUC17 in ileum, and MUC1, MUC4, MUC12, and MUC15 in colon. Membranous, cytoplasmic and vacuolar expressions were highlighted. Overall, the mucin expression was abnormal in UC. Derangements in MUC1, MUC4, and MUC5B were detected both at onset and after treatment. MUC2 and MUC13 were unaffected. Sequence analysis revealed glucocorticoid-responsive elements in the MUC1 promoter, retinoic-acid-responsive elements in the MUC4 promoter, and butyrate-responsive elements in the MUC5B promoter. In conclusion, MUCs exhibited distinct expression patterns in the gut. Their expression was disrupted in UC, regardless of the treatment protocols. Abnormal MUC1, MUC4, and MUC5B expression marked the barrier dysfunction in UC.

Predictors of severe submucosal fibrosis during endoscopic submucosal dissection in patients with ulcerative colitis: Retrospective cohort study

OBJECTIVES

Severe submucosal fibrosis is a crucial technical difficulty encountered during endoscopic submucosal dissection (ESD) in patients with ulcerative colitis (UC). We aimed to identify predictors of severe submucosal fibrosis in patients with UC.

METHODS

We retrospectively included 55 tumors resected using ESD from 48 consecutive patients with UC. We analyzed the clinicopathological characteristics and treatment outcomes between the F0/1 (none to mild submucosal fibrosis) group (n = 28) and F2 (severe submucosal fibrosis) group (n = 27).

RESULTS

No significant difference was found between the F0/1 and F2 groups in en bloc resection rate (100% vs. 96%, P = 0.49), the R0 resection rate (100% vs. 93%, P = 0.24), and the dissection speed (0.18 vs. 0.13 cm2 /min, P = 0.07). Intraoperative perforation was more common in the F2 group (30%) than in the F0/1 group (8%; P = 0.01). Multivariable analysis showed that a longer duration of UC (≥10 years; odds ratio [OR] 6.11; 95% confidence interval [CI] 1.20-31.03; P = 0.03) and scarring of background mucosa of the tumor (OR 39.61; 95% CI 3.91-400.78; P < 0.01) were independent predictors of severe submucosal fibrosis.

CONCLUSION

Long UC duration and scarring background mucosa were predictors of severe submucosal fibrosis associated with perforation during ESD.

The alleviative effects comparison of four flavonoids from bamboo leaves on ulcerative colitis in an Alzheimer mouse model

BACKGROUND

Clinically, patients with dementia are at high risk of developing enteritis, especially those with AD. This study explored the potential therapeutic benefits of bamboo leaf flavonoids (BLF) for ulcerative colitis (UC) treatment in Alzheimer's disease (AD) mouse model.

METHODS

Various methods were employed, including pathological staining of brain/colon tissue, inflammatory cytokine detection in serum, and oxidative stress indicator assessment to compare ulcerative enteritis (UC) injury in normal and AD mice and determine whether AD mice were susceptible to colitis. Then, the effects of BLF on UC and AD were investigated via several unique indices further to determine whether it alleviated colitis injury and possessed beneficial properties. Moreover, four main components of BLF were utilized to treat primary colon epithelial cells and neuron cells to compare their effects in alleviating inflammation and oxidation. Furthermore, homoorientin embedded with ursolic acid was detected by HPLC and the in vitro release simulation experiments of the nanoparticles were performed.

RESULTS

BLF complexes positively impacted ulcerative colitis by reducing disease activity, it also helped to reduce inflammation. Moreover, the BLF complexes decreased oxidative stress in the brain and colon tissues, indicating its potential as a neuroprotective agent. The flavonoid complexes reduced the expression levels of GFAP, Iba-1, and Aβ in the brain tissue, highlighting its role in attenuating neuroinflammation and AD pathology. Additionally, the embedded homoorientin coated with ursolic acid showed stronger bioactivities when compared with the uncoated group.

CONCLUSION

These results suggest that BLF complexes and its four main chemicals may be useful for treating AD- and UC-related complications, the embedded homoorientin coated with ursolic acid even demonstrated stronger bioavailability than homoorientin. Considering BLF complexes were verified to suppress the progressions of AD and UC for the first time, and the embedded homoorientin was never reported in published articles, the present study might provide a new perspective on its potential applications.

Cynarin ameliorates dextran sulfate sodium-induced acute colitis in mice through the STAT3/NF-κB pathway

OBJECTIVE

Cynarin is a derivative of hydroxycinnamic acid presented in various medicinal plants, such as Cynara scolymus L. and Onopordum illyricum L. To date, the antioxidant and antihypertensive activities of cynarin have been reported. However, whether cynarin has a therapeutic impact on ulcerative colitis (UC) is unclear. Therefore, the aim of this study was to explore the potential effect of cynarin on dextran sulfate sodium (DSS)-induced acute colitis in vivo and on lipopolysaccharide (LPS)/interferon-γ (IFN-γ)-induced RAW264.7 and J774A.1 cellular inflammation model in vitro.

METHODS AND RESULTS

In this study, we investigated that cynarin alleviated clinical symptoms in animal models, including disease activity index (DAI) and histological damage. Furthermore, cynarin can attenuate colon inflammation through decreasing the proportion of neutrophils in peripheral blood, reducing the infiltration of neutrophils, and macrophages in colon tissue, inhibiting the release of pro-inflammatory cytokines and suppressing the expression of STAT3 and p65. In cellular inflammation models, cynarin inhibited the expression of M1 macrophage markers, such as TNF-α, IL-1β, and iNOS. Besides, cynarin suppressed the expression of STAT3 and p65 as well as the phosphorylation of STAT3, p65. Cynarin inhibited the polarization of RAW264.7 and J774A.1 cells toward M1 and alleviated LPS/IFN-γ-induced cellular inflammation.

CONCLUSION

Considering these results, we conclude that cynarin mitigates experimental UC partially through inhibiting the STAT3/NF-кB signaling pathways and macrophage polarization toward M1. Accordingly, cynarin might be a potential and effective therapy for UC.

Therapeutic Potential Evaluation of Silk Sericin Stabilized Fisetin to Ulcerative Colitis

Ulcerative colitis is a chronic inflammatory bowel disease with a high recurrence rate. Natural phytochemical compounds are increasingly being considered as preventative and supportive treatments for this condition. However, the poor water solubility and stability of many of these compounds limit their effectiveness in vivo. To address this issue, fisetin (FT), a natural phytochemical with poor solubility, is stabilized using silk sericin (SS) to create a composite (SS/FT). The therapeutic potential of the SS/FT on ulcerative colitis is extensively investigated, and the results showed that it effectively alleviated the body weight loss and colon length shortening induced by dextran sulfate sodium. Notably, SS/FT downregulated the immune response, decreased colonic histopathological lesions, and reduced the cGAS/STING signal activation. This suggests that SS/FT may offer a promising therapy for treating ulcerative colitis.

Quality of Surveillance Impacts the Colitis-Associated Advanced Neoplasia Risk: A Multicenter Case-Control Study

BACKGROUND AND AIMS

Although colorectal cancer (CRC) surveillance is embedded in clinical inflammatory bowel disease (IBD) practice, a subset of patients still develops advanced neoplasia (AN) (high-grade dysplasia [HGD] and/or CRC). We aimed to assess the impact of surveillance quality on AN risk in IBD.

METHODS

In this multicenter case-control study, we searched the Dutch nationwide pathology databank to identify IBD cases with AN and controls with indefinite or low-grade dysplasia. The surveillance colonoscopy preceding the index lesion (first indefinite for dysplasia [IND]/low-grade dysplasia [LGD] or AN) was used to assess the impact of surveillance quality. We assessed intervals, bowel preparation, cecal intubation, and absence of inflammation as primary quality indicators. In addition, we assessed chromoendoscopy, endoscopist expertise, hospital setting, and biopsy strategy. Associations of quality indicators with AN risk were determined with multivariable logistic regression analyses with Firth's correction.

RESULTS

We included 137 cases and 138 controls. Delayed intervals (58.2% vs 39.6%) and active inflammation (65.3% vs 41.8%) were frequently present in cases and controls and were associated with AN (delayed interval: adjusted odds ratio [aOR], 2.00; 95% confidence interval [CI], 1.07-3.81; P = .03; active inflammation: aOR, 2.46; 95% CI, 1.33-4.61; P < .01). Surveillance compliant with primary quality indicators was associated with a reduced AN risk (aOR, 0.43; 95% CI, 0.22-0.91; P = .03), similar to chromoendoscopy (OR, 0.11; 95% CI, 0.01-0.89; P = .01). Other indicators were not significantly associated with AN.

CONCLUSIONS

Surveillance compliant with primary quality indicators is associated with a reduced colitis-associated AN risk. Delayed surveillance intervals and active inflammation were associated with an increased AN risk. This underlines the importance of procedural quality, including endoscopic remission to optimize the effectiveness of endoscopic surveillance.

The Incidence of Pouch Neoplasia Following Ileal Pouch-Anal Anastomosis in Patients With Inflammatory Bowel Disease

BACKGROUND

Ileal pouch-anal anastomosis (IPAA) is the standard restorative procedure following proctocolectomy in patients with inflammatory bowel disease (IBD) who require colectomy. However, removal of the diseased colon does not eliminate the risk of pouch neoplasia. We aimed to assess the incidence of pouch neoplasia in IBD patients following IPAA.

METHODS

All patients at a large tertiary center with International Classification of Diseases-Ninth Revision/International Classification of Diseases-Tenth Revision codes for IBD who underwent IPAA and had subsequent pouchoscopy were identified using a clinical notes search from January 1981 to February 2020. Relevant demographic, clinical, endoscopic, and histologic data were abstracted.

RESULTS

In total, 1319 patients were included (43.9% women). Most had ulcerative colitis (95.2%). Out of 1319 patients, 10 (0.8%) developed neoplasia following IPAA. Neoplasia of the pouch was seen in 4 cases with neoplasia of the cuff or rectum seen in 5 cases. One patient had neoplasia of the prepouch, pouch, and cuff. Types of neoplasia included low-grade dysplasia (n = 7), high-grade dysplasia (n = 1), colorectal cancer (n = 1), and mucosa-associated lymphoid tissue lymphoma (n = 1). Presence of extensive colitis, primary sclerosing cholangitis, backwash ileitis, and rectal dysplasia at the time of IPAA were significantly associated with increased risk of pouch neoplasia.

CONCLUSIONS

The incidence of pouch neoplasia in IBD patients who have undergone IPAA is relatively low. Extensive colitis, primary sclerosing cholangitis, and backwash ileitis prior to IPAA and rectal dysplasia at the time of IPAA raise the risk of pouch neoplasia significantly. A limited surveillance program might be appropriate for patients with IPAA even with a history of colorectal neoplasia.

Ulcerative colitis: STRIDE-ing beyond symptoms with new standards

The landscape of ulcerative colitis has changed in the last two decades. Advancements in pharmacotherapeutics have heralded the introduction of new treatment options, with many agents in development. Better clinical outcomes are seen with tighter disease control, made possible with greater understanding of inflammatory pathways and their blockade with drugs. There has been a resultant shift in treatment targets, beyond symptoms to endoscopic and histological healing. Controlling the burden of disease activity also lowers the risk of developing colorectal cancer. Colorectal cancer screening now requires the use of dye-based agents and high-definition colonoscopy to improve the detection of colonic neoplasms.

Application of a pattern-based approach to histological diagnosis in very early onset IBD (VEO-IBD) in a multicentric cohort of children with emphasis on monogenic disease with IBD-like morphology

AIMS

Very early-onset inflammatory bowel disease (VEO-IBD) is a clinical umbrella term referring to IBD-like symptoms arising in children before the age of 6 years, encompassing both 'pure' IBD, such as ulcerative colitis (UC) and Crohn's disease (CD) and monogenic diseases (MDs), the latter often involving genes associated with primary immunodeficiencies. Moreover, histological features in gastrointestinal (GI) biopsies in MD can also have IBD-like morphology, making differential diagnosis difficult. Correct diagnosis is fundamental, as MDs show a more severe clinical course and their inadequate/untimely recognition leads to inappropriate therapy.

METHODS AND RESULTS

Biopsy samples from the lower and upper GI tract of 93 clinically diagnosed VEO-IBD children were retrospectively selected in a multicentre cohort and histologically re-evaluated by 10 pathologists blinded to clinical information. Each case was classified according to morphological patterns, including UC-like; CD-like; enterocolitis-like; apoptotic; eosinophil-rich; and IBD-unclassified (IBD-U). Nine (69%) MD children showed IBD-like morphology; only the IBD-U pattern correlated with MD diagnosis (P = 0.02) (available in 64 cases: 51 non-MD, true early-onset IBD/other; 13 MD cases). MD patients showed earlier GI symptom onset (18.7 versus 26.9 months) and were sent to endoscopy earlier (22 versus 37 months), these differences were statistically significant (P < 0.05). Upper GI histology was informative in 37 biopsies.

CONCLUSIONS

The diagnosis of the underlying cause of VEO-IBD requires a multidisciplinary setting, and pathology, while being one of the fundamental puzzle pieces, is often difficult to interpret. A pattern-based histological approach is therefore suggested, thus aiding the pathologist in VEO-IBD reporting and multidisciplinary discussion.

Composite Assessment Using Intestinal Ultrasound and Calprotectin Is Accurate in Predicting Histological Activity in Ulcerative Colitis: A Cohort Study

BACKGROUND

Beyond endoscopic remission, histological remission in ulcerative colitis (UC) is predictive of clinical outcomes. Intestinal ultrasound (IUS) may offer a noninvasive surrogate marker for histological activity; however, there are limited data correlating validated ultrasound and histological indices.

AIM

Our aim was to determine the correlation of IUS activity in UC with a validated histological activity index.

METHODS

Twenty-nine prospective, paired, same-day IUS/endoscopy/histology/fecal calprotectin (FC) cases were included. Intestinal ultrasound activity was determined using the Milan Ultrasound Criteria, histological activity using the Nancy Histological Index, endoscopic activity using Mayo endoscopic subscore and Ulcerative Colitis Endoscopic Index of Severity, and clinical activity using the Simple Clinical Colitis Activity Score.

RESULTS

Histological activity demonstrated a significant linear association with overall IUS activity (coefficient 0.14; 95% CI, 0.03-0.25; P = .011). Intestinal ultrasound activity was also significantly associated with endoscopic activity (0.32; 95% CI, 0.14-0.49; P < 0.001), total Mayo score (0.31; 95% CI, 0.02-0.60; P = .036) but not FC (0.10; 95% CI, -0.01 to 0.21; P = .064) or clinical disease activity (0.04; 95% CI, -0.21 to 0.28; P = .768). A composite of IUS and FC showed the greatest association (1.31; 95% CI, 0.43-2.18; P = .003) and accurately predicted histological activity in 88% of cases (P = .007), with sensitivity of 88%, specificity 80%, positive predictive value 95%, and negative predictive value 57%.

CONCLUSIONS

Intestinal ultrasound is an accurate noninvasive marker of histological disease activity in UC, the accuracy of which is further enhanced when used in composite with FC. This can reduce the need for colonoscopy in routine care by supporting accurate point-of-care decision-making in patients with UC.

Concurrent Ulcerative Colitis in a Pregnant Patient with Rheumatoid Arthritis

We herein report a rare concurrent case of ulcerative colitis (UC) in a pregnant woman with rheumatoid arthritis (RA), which was well managed by biologics. When a 32-year-old woman with seropositive RA became pregnant, she began experiencing hematochezia; colonoscopy revealed diffuse inflammation with multiple ulcers. Based on clinical examinations and pathological assessments, she was diagnosed with severe UC. Although prednisolone had no curative effect and infliximab caused an infusion reaction, golimumab successfully induced remission with normal delivery. This case report describes the successful treatment of a pregnant woman with UC and RA through biologics administration.

Early recapture of response with tofacitinib 10 mg twice daily in patients with ulcerative colitis in OCTAVE Open following dose reduction or treatment interruption in OCTAVE Sustain

BACKGROUND AND AIM

Tofacitinib is an oral Janus kinase inhibitor for the treatment of ulcerative colitis. These post hoc analyses evaluated early improvement in patient-reported outcomes with tofacitinib 10 mg twice daily (BID) in OCTAVE Open among patients with ulcerative colitis who experienced treatment failure with placebo (retreatment subpopulation) or tofacitinib 5 mg BID (dose escalation subpopulation) during maintenance.

METHODS

Endpoints based on Mayo subscores (rectal bleeding improvement, stool frequency improvement, and symptomatic [both rectal bleeding and stool frequency] improvement) were analyzed overall and by prior tumor necrosis factor inhibitor (TNFi) failure status from month (M)1-M6 in OCTAVE Open. Changes from baseline in partial Mayo score, rectal bleeding subscore, and stool frequency subscore at M1 were also analyzed, by M2 clinical response status.

RESULTS

At M1 of OCTAVE Open, 83.2%, 70.3%, and 64.4% of patients in the retreatment subpopulation (n = 101) had rectal bleeding improvement, stool frequency improvement, and symptomatic improvement, respectively. Corresponding values in the dose escalation subpopulation (n = 57) were 59.6%, 50.9%, and 38.6%. For both subpopulations, results were generally consistent regardless of prior TNFi failure. In the dose escalation subpopulation, mean decrease from baseline in partial Mayo score and stool frequency subscore at M1 was greater in patients with versus without a clinical response at M2.

CONCLUSIONS

Rectal bleeding improvement and stool frequency improvement were achieved by M1 in many patients receiving tofacitinib 10 mg BID in both subpopulations, with no apparent difference by prior TNFi failure. Analyses were limited by small sample sizes for some subgroups.

Dexamethasone-Loaded Lipid Calcium Phosphate Nanoparticles Treat Experimental Colitis by Regulating Macrophage Polarization in Inflammatory Sites

Background

The M1/M2 polarization of intestinal macrophages exerts an essential function in the pathogenesis of ulcerative colitis (UC), which can be adjusted to alleviate the UC symptoms.

Purpose

A kind of pH-sensitive lipid calcium phosphate core-shell nanoparticles (NPs), co-loading with dexamethasone (Dex) and its water-soluble salts, dexamethasone sodium phosphate (Dsp), was constructed to comprehensively regulate macrophages in different states towards the M2 phenotype to promote anti-inflammatory effects.

Methods

Dex and Dsp were loaded in the outer lipid shell and inner lipid calcium phosphate (Cap) core of the LdCaPd NPs, respectively. Then, the morphology of NPs and methods for determining drug concentration were investigated, followed by in vitro protein adsorption, stability, and release tests. Cell experiments evaluated the cytotoxicity, cellular uptake, and macrophage polarization induction ability of NPs. The in vivo distribution and anti-inflammatory effect of NPs were evaluated through a 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced BALB/c mice ulcerative colitis model.

Results

The LdCaPd NPs showed a particle size of about 200 nm and achieved considerable loading amounts of Dex and Dsp. The in vitro and in vivo studies revealed that in the acidic UC microenvironment, the cationic lipid shell of LdCaPd underwent protonated dissociation to release Dex first for creating a microenvironment conducive to M2 polarization. Then, the exposed CaP core was further engulfed by M1 macrophages to release Dsp to restrict the pro-inflammatory cytokines production by inhibiting the activation and function of the nuclear factor kappa-B (NF-κB) through activating the GC receptor and the NF kappa B inhibitor α (I-κBα), respectively, ultimately reversing the M1 polarization to promote the anti-inflammatory therapy.

Conclusion

The LdCaPd NPs accomplished the sequential release of Dex and Dsp to the UC site and the inflammatory M1 macrophages at this site, promoting the regulation of macrophage polarization to accelerate the remission of UC symptoms.