Analysis of Neuropeptides in the Intestinal Mucus of Patients with Ulcerative Colitis Using RNA Sequencing.

INTRODUCTION: Inflammation in ulcerative colitis (UC) originates in the colorectal mucosa. Transcriptome sequencing analysis of the colorectal mucosa allows the identification of potential neuropeptides related to local neurotransmission. The intestinal mucus lining the surface of the mucosa may harbor biomarkers of mucosal inflammation; however, this has not been sufficiently investigated, given the difficulty in obtaining human samples. We previously reported the feasibility of obtaining mucin samples for proteomic analysis by brushing during colonoscopy. Herein, we aimed to investigate the composition of the intestinal mucus and detect neuropeptides characteristic of UC. METHODS: Mucus and mucosal samples were collected from patients with UC from the colorectum in areas showing remission or active UC using a brush catheter and biopsy forceps during colonoscopy. RNA sequencing findings of mucus samples of active and remission areas were compared. RNA and protein expression levels of significantly upregulated neuropeptides were analyzed. RESULTS: Of the neuropeptides associated with UC, somatostatin (SST) was significantly elevated in areas of remission, according to RNA sequencing results of mucus and expression levels in mucus RNA and proteins. Conversely, SST expression in the mucosa was increased in the inflamed areas. Flow cytometry revealed that the fluorescence intensity of SST-positive cells in the remission zone was higher in the mucus than in the mucosa. CONCLUSION: SST expression in the mucus is considered to be an important factor associated with UC activity.

Initial tumor size and narrow-band image findings estimate growth speed in duodenal tumors.

INTRODUCTION: Recently, detection of superficial non-ampullary duodenal epithelial tumors (SNADETs) including adenomas and superficial duodenal carcinomas has increased. Various endoscopic treatment methods have also been reported for SNADETs, but there are few reports on the natural history. The aim of this study was to analyze factors related to tumor growth and determine the characteristics of SNADETs which need early therapeutic intervention. METHODS: A single-center, retrospective study was performed on medical records of 309 patients with SNADETs who underwent endoscopic or surgical resection between January 2010 and May 2021. Of these, 41 patients who were followed up for more than one year by endoscopy were analyzed. The primary outcome was analysis of the tumor growth speed. Secondary outcomes were the relationship between the tumor growth speed and mucin phenotype, tumor size and findings of magnifying endoscopy with narrow-band imaging (M-NBI). RESULTS: The observation period was 24 months (13-182). Tumor growth speed was 1.1 mm/year (0-21.6). Tumor diameter >10 mm at first detection (P=0.004; Odds ratio 19.5(2.03-186.96)) and mixed-type by M-NBI (p=0.036; Odds ratio 9.69(1.05-89.88)) were identified as risk factors of tumors growing at a rate of >3 mm/year. There was no statistically significant difference in the speed of tumor growth between the different mucin immunohistochemical phenotype. CONCLUSION: Initial tumor size and findings of M-NBI are useful to predict tumor growth and consider early intervention.

Long-Term Monitoring and Clinical Implications of Small Bowel Capsule Endoscopy in Patients with Crohn's Disease with Small Bowel Lesions: A Retrospective Analysis.

INTRODUCTION: Crohn's disease (CD) induces persistent inflammation throughout the gastrointestinal (GI) tract, potentially resulting in complications such as intestinal stenosis and fistulas, particularly in the small bowel. Small bowel capsule endoscopy (SBCE) is recommended for monitoring CD, especially when GI tract patency is maintained. This study aimed to retrospectively assess patients with CD who underwent SBCE to determine the timing of clinical changes and address the current lack of evidence regarding GI tract patency loss during CD treatment. METHODS: Of the 166 consecutive patients who underwent SBCE at our institution, 120 were followed up and included in this study. Forty-six patients were excluded due to colitis type or immediate treatment changes post-SBCE. This study focused on the primary and secondary endpoints, including the cumulative stricture-free rate of the GI tract, emergency hospitalization post-SBCE, and post-SBCE treatment strategies, at the discretion of the attending physicians. RESULTS: Demographic data revealed that the mean age of the study population was 43 years and that there was a male predominance (75%). The median disease duration was 12 years and the mean Crohn's Disease Activity Index was 98. During a 1,486-day observation period, 37% of patients experienced treatment changes. A Lewis score of >264 and perianal lesions were identified as independent risk factors for additional treatment needs. Emergency hospitalization occurred in 6% of patients and GI patency failure in 11%. Female sex and Lewis score>264 were associated with higher risks. GI patency rate declined 2 years after SBCE. CONCLUSIONS: For patients who experienced no treatment changes based on SBCE results, it is recommended to undergo SBCE monitoring at intervals of no longer than 2 years.

Monoclonal Antibodies Against Mature Interleukin-18 Ameliorate Colitis and Repair Goblet Cell Function.

BACKGROUND: Numerous biological interventions and small molecules are used to treat Crohn's disease; however, the effectiveness of these treatments varies largely. Non-responsiveness to biological therapies is associated with interleukin (IL)-18 gene polymorphisms and high IL-18 expression has been implicated in the pathogenesis of Crohn's disease. AIMS: The aim of this study was to elucidate the expression of precursor and mature IL-18 in patients with Crohn's disease who exhibited varied responses to cytokine-targeted treatments and determine whether selective inhibition of mature IL-18 offers a novel therapeutic avenue. METHODS: We generated a monoclonal antibody that specifically recognizes the neoepitope of caspase-cleaved mature IL-18. Expression of precursor and mature IL-18 was analyzed in patients with Crohn's disease. Anti-mature IL-18 monoclonal antibodies were intraperitoneally administered in an acute colitis mouse model, and the disease activity index, body weight loss, tissue pathology, proinflammatory cytokine expression, goblet cell function, and microbiota composition were assessed. RESULTS: Precursor and mature IL-18 expression was upregulated and goblet cell function was impaired in patients with Crohn's disease who were unresponsive to biological therapies. Administration of anti-mature IL-18 antibodies ameliorated induced colitis by repairing goblet cell function and restoring the mucus layer. CONCLUSIONS: The newly developed monoclonal antibody holds promise as a therapeutic alternative for Crohn's disease.

Intranasal administration of ceramide liposome suppresses allergic rhinitis by targeting CD300f in murine models.

Allergic rhinitis (AR) is caused by type I hypersensitivity reaction in the nasal tissues. The interaction between CD300f and its ligand ceramide suppresses immunoglobulin E (IgE)-mediated mast cell activation. However, whether CD300f inhibits the development of allergic rhinitis (AR) remains elusive. We aimed to investigate the roles of CD300f in the development of AR and the effectiveness of intranasal administration of ceramide liposomes on AR in murine models. We used ragweed pollen-induced AR models in mice. Notably, CD300f deficiency did not significantly influence the ragweed-specific IgE production, but increased the frequency of mast cell-dependent sneezing as well as the numbers of degranulated mast cells and eosinophils in the nasal tissues in our models. Similar results were also obtained for MCPT5-exprssing mast cell-specific loss of CD300f. Importantly, intranasal administration of ceramide liposomes reduced the frequency of sneezing as well as the numbers of degranulated mast cells and eosinophils in the nasal tissues in AR models. Thus, CD300f-ceramide interaction, predominantly in mast cells, alleviates the symptoms and progression of AR. Therefore, intranasal administration of ceramide liposomes may be a promising therapeutic approach against AR by targeting CD300f.

Artificial intelligence-based diagnostic imaging system with virtual enteroscopy and virtual unfolded views to evaluate small bowel lesions in Crohn's disease.

Since even subtle mucosal changes may be depicted using virtual endoscopy created by the three-dimensional reconstruction of MDCT images, we developed a novel diagnostic imaging system that integrates and displays virtual enteroscopy, curved planar reconstruction, and a virtual unfolded view, the width of which changes with increases/decreases in the inner luminal diameter. The system is also equipped with artificial intelligence that superimposes and displays depressed areas, generates an automatic small bowel centerline that connects fragmented small bowel regions, and performs electronic cleansing. We retrospectively evaluated the diagnostic performance of this system for small bowel lesions in Crohn's disease, which were divided into two groups: endoscopically-observable and endoscopically-unobservable. Lesion detection rates for stenoses, longitudinal ulcers with a cobblestone appearance, and scars were excellent in both groups. This system, when used in combination with endoscopy, shows slight mucosal changes in areas in which an endoscope cannot reach due to strictures, thereby extending the range of observation of the small bowel. This system is a useful diagnostic modality that has the capacity to assess mucosal healing and provide extraluminal information.

Monoclonal Antibody Against Mature Interleukin-18 Ameliorates Colitis in Mice and Improves Epithelial Barrier Function.

BACKGROUND: Antitumor necrosis factor (TNF)-α antibodies have improved the outcome of inflammatory bowel disease (IBD); but half of patients remain unresponsive to treatment. Interleukin-18 (IL-18) gene polymorphism is associated with resistance to anti-TNF-α antibodies, but therapies targeting IL-18 have not been clinically applied. Only the mature protein is biologically active, and we aimed to investigate whether specific inhibition of mature IL-18 using a monoclonal antibody (mAb) against a neoepitope of caspase-cleaved mature IL-18 could be an innovative treatment for IBD. METHODS: The expression of precursor and mature IL-18 in patients with UC was examined. Colitis was induced in C57/BL6 mice by administering dextran sulfate sodium (DSS), followed by injection with anti-IL-18 neoepitope mAb. Colon tissues were collected and subjected to histological analysis, immunohistochemistry, immunoblotting, and quantitative polymerase chain reaction. Colon epithelial permeability and microbiota composition were analyzed. RESULTS: Mature IL-18 expression was elevated in colon tissues of patients with active ulcerative colitis. Administration of anti-IL-18 neoepitope mAb ameliorated acute and chronic DSS-induced colitis; reduced interferon-γ, TNF-α, and chemokine (CXC motif) ligand-2 production and epithelial cell permeability; promoted goblet cell function; and altered the intestinal microbiome composition. The suppressive effect of anti-IL-18 neoepitope mAb was superior to that of anti-whole IL-18 mAb. Furthermore, combination therapy with anti-TNF-α Ab suppressed acute and chronic colitis additively by suppressing cytokine expressions and reducing cell permeability by upregulating claudin1 and occludin expression. CONCLUSIONS: Anti-IL-18 neoepitope mAb ameliorates acute and chronic colitis, suggesting that this mAb will be an innovative therapeutic option for IBD.

We investigate a novel monoclonal antibody that specifically recognizes a neoepitope of caspase-cleaved IL-18 and alleviates dextran sulfate sodium-induced colitis by suppressing the secretion of inflammatory cytokines, improving intestinal epithelial permeability, promoting goblet cell function, and regulating intestinal microbiota.