Intestinal Mucosal Healing Research Articles

Differential analysis of sorting nexin 10 and sterol regulatory element-binding protein 2 expression in inflammatory bowel disease.

Sorting nexin 10 (SNX10) expression induces intestinal barrier dysfunction and inflammatory responses; in contrast, its inhibition promotes intestinal mucosal healing through sterol regulatory element-binding protein 2 (SREBP2)-mediated cholesterol synthesis. However, its regulatory mechanism for the pathogenesis of inflammatory bowel disease (IBD) remains unclear. In this study, we examined SNX10 and SREBP2 expression in ulcerative colitis (UC) and Crohn's disease (CD). A total of 30 and 28 patients with UC and CD, respectively, were recruited. The expression of SNX10 and SREBP2 in the colonic mucosa was measured by immunohistochemistry (IHC). We discovered that patients with CD had significantly higher expression levels of SNX10 and SREBP2 than patients with UC and healthy controls. In addition, the expression of SREBP2 in patients with UC was significantly higher than that in healthy controls. In our study, we indicated that SNX10 and SREBP2 may serve as biomarkers for identifying patients with UC and CD, thereby providing a clinical therapeutic strategy for the treatment of IBD by inhibiting SNX10.

Critical role of thrombospondin-1 in promoting intestinal mucosal wound repair.

Thrombospondin-1 (TSP1) is a matricellular protein associated with the regulation of cell migration through direct binding interactions with integrin proteins and by associating with other receptors known to regulate integrin function, including CD47 and CD36. We previously demonstrated that deletion of an epithelial TSP1 receptor, CD47, attenuates epithelial wound repair following intestinal mucosal injury. However, the mechanisms by which TSP1 contributes to intestinal mucosal repair remain poorly understood. Our results show upregulated TSP1 expression in colonic mucosal wounds and impaired intestinal mucosal wound healing in vivo upon intestinal epithelium-specific loss of TSP1 (VillinCre/+ Thbs1fl/fl or Thbs1ΔIEC mice). We report that exposure to exogenous TSP1 enhanced migration of intestinal epithelial cells in a CD47- and TGF-β1-dependent manner and that deficiency of TSP1 in primary murine colonic epithelial cells resulted in impaired wound healing. Mechanistically, TSP1 modulated epithelial actin cytoskeletal dynamics through suppression of RhoA activity, activation of Rho family small GTPase (Rac1), and changes in filamentous-actin bundling. Overall, TSP1 was found to regulate intestinal mucosal wound healing via CD47 and TGF-β1, coordinate integrin-containing cell-matrix adhesion dynamics, and remodel the actin cytoskeleton in migrating epithelial cells to enhance cell motility and promote wound repair.

Tannic acid and zinc ion coordination of nanase for the treatment of inflammatory bowel disease by promoting mucosal repair and removing reactive oxygen and nitrogen species

Colon mucosal overexpression of reactive oxygen and nitrogen species (RONS) accelerates the development of inflammatory bowel disease (IBD) and destroys the mucosa and its barrier. IBD can be alleviated by removing RONS from the inflamed colon. The preparation of strong and efficient nanoantioxidants remains a challenge despite the development of numerous nanoantioxidants. In this paper, Zn-TA nanoparticles with fine hollow microstructure (HZn-TA) were successfully prepared and could be effectively used to treat IBD. In the first step, ZIF-8 nanoparticles were synthesized by a one-pot method. On this basis, HZn-TA nanoparticles were etched by TA, and a multifunctional nanase was developed for the treatment of IBD. RONS, including reactive oxygen species (ROS) and nitric oxide (NO), can be eliminated to increase cell survival following Hydrogen peroxide (H2O2) stimulation, including reactive oxygen species (ROS) and nitric oxide (NO with hydrogen peroxide (H2O2). In a model for preventing and delaying acute colitis, clearance of RONS has been shown to reduce intestinal inflammation in mice by reducing colon damage, proinflammatory cytokine levels, the spleen index, and body weight. Intestinal mucosal healing can be promoted by HZn-TA nanoparticles, which can upregulate zonula occludens protein 1 (ZO-1) and claudin-1 expression. Based on the results of this study, HZn-TA nanoparticles were able to effectively treat IBD with minimal adverse effects by being biocompatible, multienzyme active, and capable of scavenging RONS. Therefore, we pioneered the application of HZn-TA nanoparticles for the treatment of IBD, which are capable of clearing RONS without significant adverse effects. Statement of significance➢ HZn-TA nanoparticles were successfully prepared and could be effectively used to treat IBD.➢ Intestinal mucosal healing can be promoted by HZn-TA nanoparticles, which can upregulate ZO-1 and claudin-1 expression.➢ HZn-TA nanoparticles were able to effectively treat IBD with minimal adverse effects by being biocompatible, multienzyme active, and capable of scavenging RONS.

LEUCINE-RICH ALPHA 2 GLYCOPROTEIN: A USEFUL BIOMARKER TO DISCRIMINATE SMALL INTESTINAL MUCOSAL HEALING IN C-REACTIVE PROTEIN-NEGATIVE CROHN’S DISEASE

Abstract BACKGROUND The treatment goals for inflammatory bowel disease, including Crohn's disease (CD), have shifted from clinical remission to mucosal healing. However, frequent endoscopies burden patients. Leucine-rich alpha 2 glycoprotein (LRG), produced by hepatocytes, neutrophils, and the intestinal epithelium, is more gut-specific than C-reactive protein (CRP). We examined whether LRG, as a biomarker, can detect small intestinal mucosal healing in CD patients, especially in those who are CRP-negative. METHOD 1) This study examined CD patients who visited our department from May 2021 to April 2023, had LRG measured, and underwent image evaluation using capsule endoscopy or balloon-assisted endoscopy. We analyzed their clinical background, looked for a correlation between LRG and CRP, assessed the ROC-AUC of LRG and CRP for mucosal healing, and measured the LRG and CRP cutoff values to determine mucosal healing. 2) Next, in CRP-negative CD patients, we analyzed the ROC-AUC of LRG for mucosal healing and LRG cutoff value to determine mucosal healing. Endoscopic evaluation was done within 3 months before and after LRG measurement. Absent open ulcers indicated mucosal healing. The upper limit of normal CRP value was <3 mg/L. We used the Spearman correlation coefficient to determine the correlation. RESULTS 1) Here, 67 CD patients were analyzed; 43 (64%) were men. The median age (range) of onset was 25.6 (3-57) years. The median disease duration (range) was 7.6 (0-27) years. B1, B2, and B3 of Montreal Classification were established in 31 (46.2%), 21 (31.3%), and 15 (22.3%) patients, respectively. The median (range) of LRG was 21.7 (7.6-67.4) μg/mL. The median (range) of CRP was 10.8 (0.0-86.9) mg/L. LRG and CRP were strongly correlated (r=0.878, p<0.001). The ROC-AUC of LRG for mucosal healing was 0.839 (95% confidence interval [CI] 0.760-0.918). LRG cutoff value for discriminating mucosal healing was 15.5 μg/mL (sensitivity 77%, specificity 75%). The ROC-AUC of CRP for mucosal healing was 0.811 (95% CI 0.721-0.900). The CRP cutoff value to differentiate mucosal healing was 0.9 mg/L (sensitivity 55%, specificity 90%). 2) Forty CRP-negative CD patients were analyzed; 23 (57%) were men. The median age (range) of onset was 21.9 (3-57) years. The median disease duration (range) was 7.0 (0-27) years. B1, B2, and B3 of Montreal Classification were established in 17 (42.5%), 12 (30.0%), and 11 (27.5%) patients, respectively. The median (range) of LRG was 12.3 (7.6-23.5) μg/mL. The ROC-AUC of LRG for mucosal healing was 0.817 (95% CI 0.696-0.938). The LRG cutoff value to differentiate mucosal healing was 14.1 μg/mL (sensitivity 61%, specificity 76%). CONCLUSION LRG may be a better biomarker than CRP for assessing endoscopic remission of the small intestinal mucosa in CD. In CRP-negative CD patients, LRG level of ≥14.1 μg/mL could indicate small intestinal ulcers.

Pharmacological effects of ginseng and ginsenosides on intestinal inflammation and the immune system.

Intestinal inflammatory imbalance and immune dysfunction may lead to a spectrum of intestinal diseases, such as inflammatory bowel disease (IBD) and gastrointestinal tumors. As the king of herbs, ginseng has exerted a wide range of pharmacological effects in various diseases. Especially, it has been shown that ginseng and ginsenosides have strong immunomodulatory and anti-inflammatory abilities in intestinal system. In this review, we summarized how ginseng and various extracts influence intestinal inflammation and immune function, including regulating the immune balance, modulating the expression of inflammatory mediators and cytokines, promoting intestinal mucosal wound healing, preventing colitis-associated colorectal cancer, recovering gut microbiota and metabolism imbalance, alleviating antibiotic-induced diarrhea, and relieving the symptoms of irritable bowel syndrome. In addition, the specific experimental methods and key control mechanisms are also briefly described.

Restore Intestinal Barrier Integrity: An Approach for Inflammatory Bowel Disease Therapy.

The intestinal barrier maintained by various types of columnar epithelial cells, plays a crucial role in regulating the interactions between the intestinal contents (such as the intestinal microbiota), the immune system, and other components. Dysfunction of the intestinal mucosa is a significant pathophysiological mechanism and clinical manifestation of inflammatory bowel disease (IBD). However, current therapies for IBD primarily focus on suppressing inflammation, and no disease-modifying treatments specifically target the epithelial barrier. Given the side effects associated with chronic immunotherapy, effective alternative therapies that promote mucosal healing are highly attractive. In this review, we examined the function of intestinal epithelial barrier function and the mechanisms of behind its disruption in IBD. We illustrated the complex process of intestinal mucosal healing and proposed therapeutic approaches to promote mucosal healing strategies in IBD. These included the application of stem cell transplantation and organ-like tissue engineering approaches to generate new intestinal tissue. Finally, we discussed potential strategies to restore the function of the intestinal barrier as a treatment for IBD.

Visual foodborne nanoparticles for oral site-specific delivery of anthocyanins in the treatment of inflammatory bowel disease

The worldwide incidence and prevalence of inflammatory bowel disease (IBD) is increasing at an alarming rate, requiring the development of safe and effective therapeutic interventions. The use of oxidative stress and accelerated resolution of reactive oxygen species (ROS) has emerged as a potential new strategy for the management of inflammatory diseases. In this study, we described the development of a novel class of foodborne NPs-alginate-hyaluronic acid-anthocyanin nano-delivery system (FSHANPs) capable of visualizing inflammation-targeting sites and programmed release of anthocyanins in response to ROS surging from reactive lesion sites. FSHANPs are composed of abundant active functional groups on the surface of foodborne nanoparticles nano-self-assembled with alginate, hyaluronic acid, and anthocyanins. Alginate provided effective protection against enzyme degradation in the gastrointestinal tract of these anthocyanin molecules. The accumulation of FSHANPs at the site of the inflamed colon in IBD was contingent upon the fluorescence characteristics of the nanoparticles, which was subsequently followed by the specific recognition of the overexpressed CD44 protein by hyaluronic acid. Thus, facilitating the precise and targeted delivery of anthocyanins at the inflammatory site. Mechanically, FSHANPs containing anthocyanins effectively impeded the damage caused by ROS damage in RAW264.7 cells, alleviated lipopolysaccharide-induced apoptosis, and prevented the decline of mitochondrial membrane potential (p < 0.001). Additionally, the administration of FSHANPs reduced the expression of inflammatory factors, restored IBD-induced weight loss symptoms, and shortened colons due to the treatment with sodium dextran sulfate. Further studies showed that FSHANPs expedited intestinal mucosal healing and altered intestinal microbiota composition with increased abundance of beneficial bacteria such as Firmicutes and Muribaculaceae (p < 0.05). In conclusion, this study presents a promising therapy for IBD and a potential target for other inflammatory diseases, which can precisely deliver antioxidants into inflamed colon sites with oxidative stress-responsive and visualizing effects.

Serum leucine‐rich alpha‐2 glycoprotein in monitoring disease activity and intestinal mucosal healing for biotherapy‐naïve cases with ulcerative colitis

AbstractBackground and AimSerum leucine‐rich alpha‐2 glycoprotein level has been reported to be a useful biomarker in assessing mucosal healing in patients undergoing biotherapy, where mucosal lesions caused by ulcerative colitis are difficult to assess endoscopically. However, no such reports have been reported in biotherapy‐naïve cases.MethodsSixty‐eight patients with ulcerative colitis (UC) who were biotherapy‐naïve at Kindai University Hospital between October 2021 and October 2022 were enrolled. We prospectively examined the correlation between leucine‐rich alpha‐2 glycoprotein (LRG), C‐reactive protein (CRP), erythrocyte sedimentation rate (ESR), and Geboes scores with clinical endoscopic activity using the Mayo endoscopic subscore (MES).ResultsMucosal healing was achieved in 39 (57%) patients. Univariate analysis revealed that the factors associated with mucosal healing were LRG (P = 0.0024), CRP (P = 0.1078), ESR (P = 0.0372), and Geboes scores (P = 0.0075). Logistic regression analysis identified LRG and Geboes scores as independent factors associated with mucosal healing assessed using MES (P = 0.0431 for LRG and P = 0.0166 for Geboes scores).ConclusionLRG was found to be the easiest marker to monitor disease activity and mucosal inflammation in UC patients with biotherapy‐naïve cases, with a performance equivalent to that of Geboes scores.

Hematopoietic stem cell transplantation for CYBB heterozygous mutation resulting in very early onset inflammatory bowel disease in children: a case report

BackgroundInflammatory bowel disease (IBD) is a heterogeneous group of disorders associated with environmental triggers and dysregulated immune responses resulting in chronic, recurrent intestinal inflammation. Very early-onset IBD (VEO-IBD) refers to patients with symptoms or diagnosis before the age of 6 years and is widely thought to be associated with monogenic mutations. Traditional drug therapy is often ineffective in this patient population, while hematopoietic stem cell transplantation (HSCT) represents the definitive cure for patients with gene mutations.Case presentationWe report a case of VEO-IBD associated with a monogenic mutation in a 2-year-old girl presenting mainly with gastrointestinal symptoms, including recurrent hematochezia and abdominal pain for more than 3 months. A gastroscopy revealed erosive gastritis and bulbar duodenitis, while a colonoscopy indicated erosive colitis. Abnormal results were obtained from the dihydrohodamine (DHR) assay and immunoglobulin testing. Whole-exome sequencing identified a heterozygous and de novo nonsense mutation (c.388 C > T; p.R130X) in the CYBB gene leading to deficiency of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 2 (NOX2) (encoded by CYBB), a critical component of phagocytes. HSCT was performed successfully, and the DHR assay showed that normal neutrophil function was restored. Six months after HSCT, clinical remission was observed, and a repeat colonoscopy revealed intestinal mucosal healing was attained.ConclusionsPatients with CYBB mutations often develop recurrent or severe bacterial or fungal infections, mostly in the lungs, skin, lymph nodes, and liver. Here, we report on a young female child with CYBB mutations presenting predominantly with gastrointestinal symptoms. This study explores the mechanisms of inflammatory bowel disease caused by a monogenic mutation in CYBB to improve early diagnosis and effective treatment rates of this patient population.

Mitochondrial remodeling and energy metabolism adaptations in colonic crypts during spontaneous epithelial repair after colitis induction in mice

Mucosal healing has emerged as a therapeutic goal to achieve lasting clinical remission in ulcerative colitis. Intestinal repair in response to inflammation presumably requires higher energy supplies for the restoration of intestinal barrier and physiological functions. However, epithelial energy metabolism during intestinal mucosal healing has been little studied, whereas inflammation-induced alterations have been reported in the main energy production site, the mitochondria. The aim of the present work was to assess the involvement of mitochondrial activity and the events influencing their function during spontaneous epithelial repair after colitis induction in mouse colonic crypts. The results obtained show adaptations of colonocyte metabolism during colitis to ensure maximal ATP production for supporting energetic demand by both oxidative phosphorylation and glycolysis in a context of decreased mitochondrial biogenesis and through mitochondrial function restoration during colon epithelial repair. In parallel, colitis-induced mitochondrial ROS production in colonic epithelial cells was rapidly associated with transient expression of GSH-related enzymes. Mitochondrial respiration in colonic crypts was markedly increased during both inflammatory and recovery phases despite decreased expression of several mitochondrial respiratory chain complex subunits after colitis induction. Rapid induction of mitochondrial fusion was associated with mitochondrial function restoration. Finally, in contrast with the kinetics expression of genes involved in mitochondrial oxidative metabolism and in glycolysis, the expression of glutaminase was markedly reduced in the colonic crypts both during colitis and repair phases. Overall, our data suggest that the epithelial repair after colitis induction is characterized by a rapid and transient increased capacity for mitochondrial ATP production in a context of apparent restoration of mitochondrial biogenesis and metabolic reorientation of energy production. The potential implication of energy production adaptations within colonic crypts to sustain mucosal healing in a context of altered fuel supply is discussed.

Pomegranate Extract Affects Gut Biofilm Forming Bacteria and Promotes Intestinal Mucosal Healing Regulating the Crosstalk between Epithelial Cells and Intestinal Fibroblasts

Background: Pomegranate (Punica granatum) can be used to prepare a bioactive extract exerting anti-inflammatory activities. Clinical studies demonstrated an improvement in clinical response in inflammatory bowel disease (IBD) patients when pomegranate extract (PG) was taken as a complement to standard medications. However, the molecular mechanisms underlying its beneficial effects are still scarcely investigated. This study investigates the effect of PG on bacterial biofilm formation and the promotion of mucosal wound healing. Methods: The acute colitis model was induced in C57BL/6N mice by 3% dextran sodium sulfate administration in drinking water for 5 days. During the recovery phase of colitis, mice received saline or PG (200 mg/kg body weight) by oral gavage for 11 days. Colitis was scored daily by evaluating body weight loss, bleeding, and stool consistency. In vivo intestinal permeability was evaluated by fluorescein isothiocyanate-conjugated dextran assay, bacterial translocation was assessed by fluorescence in situ hybridization on tissues, whereas epithelial and mucus integrity were monitored by immunostaining for JAM-A and MUC-2 markers. Bacterial biofilm formation was assessed using microfluidic devices for 24 or 48 h. Primary fibroblasts were isolated from healthy and inflamed areas of 8 IBD patients, and Caco-2 cells were stimulated with or without PG (5 μg/mL). Inflammatory mediators were measured at the mRNA and protein level by RT-PCR, WB, or Bio-plex multiplex immunoassay, respectively. Results: In vivo, PG boosted the recovery phase of colitis, promoting a complete restoration of the intestinal barrier with the regeneration of the mucus layer, as also demonstrated by the absence of bacterial spread into the mucosa and the enrichment of crypt-associated fibroblasts. Microfluidic experiments did not highlight a specific effect of PG on Enterobacterales biofilm formation, even though Citrobacter freundii biofilm was slightly impaired in the presence of PG. In vitro, inflamed fibroblasts responded to PG by downregulating the release of metalloproteinases, IL-6, and IL-8 and upregulating the levels of HGF. Caco-2 cells cultured in a medium supplemented with PG increased the expression of SOX-9 and CD44, whereas in the presence of HGF or plated with a fibroblast-conditioned medium, they displayed a decrease in SOX-9 and CD44 expression and an increase in AXIN2, a negative regulator of Wnt signaling. Conclusions: These data provide new insight into the manifold effects of PG on promoting mucosal homeostasis in IBD by affecting pathogen biofilm formation and favoring the regeneration of the intestinal barrier through the regulation of the crosstalk between epithelial and stromal cells.

A179 MECHANISMS OF ACTION INVOLVED IN THE WOUND HEALING EFFECT OF THE DIETARY FIBRE RHAMNOGALACTURONAN

Abstract Background Inflammatory bowel diseases (IBD) are chronic and relapsing inflammatory conditions associated with impaired intestinal epithelial barrier. Mucosal healing is the primary goal for IBD treatment since it is a good predictor of clinical remission. We previously showed the direct beneficial effects of rhamnogalacturonan (RGal), a polysaccharide isolated from the plant Acmella oleracea, on intestinal epithelial barrier function with participation of TLR4 and PKC activation. RNAseq data and pathway analysis have indicated the involvement of the canonical nuclear factor kB (NF-kB) signaling pathway. Purpose We hypothesize that RGal increases intestinal epithelial wound healing through FAK-Src/PI3K/NF-kB signaling pathways. Method Caco-2 and T84 cells, and human primary cell monolayers grown from ulcerative colitis patient-derived organoids, were wounded and treated with vehicle (media or 0.5% DMSO in media) or RGal (1000 μg/ml) for 48 h. Wound healing was assessed using either the IncuCyte or ImageXpress Pico live cell imaging systems. Proliferation and apoptosis of cells were evaluated using EdU and TUNEL assays, respectively. Inhibitors were added at the same time (transcription inhibitor Actinomycin D, 5 μg/ml) or 1 h (FAK inhibitor FAK-14, 10 μM, Src inhibitor PP2, 5 μM, PI3K inhibitor LY294002, 20 μM, NF-kB inhibitors Bay 11-7082 and JSH-23, 10 and 20 μM, respectively, or COX-2 inhibitor NS-398, 20 μM) before RGal treatment. Unwounded Caco-2 monolayers treated with RGal (1000 μg/ml) were collected for Western blotting for COX-2 protein. Result(s) In the wound healing assay, RGal (1000 μg/ml) enhanced wound healing by 12.5% at 48 h in Caco-2 cells and by 14.7% at 24 h in T84 cells, compared to control group. RGal (1000 μg/ml) also accelerated the wound closure in colonoid monolayers obtained from ulcerative colitis patient biopsies by 81.3% at 48 h. Neither proliferation nor apoptosis were involved in the RGal effect on wound healing. Treatment of cells with FAK14 (10 μM), PP2 (5 μM), and PI3K (20 μM) significantly prevented the RGal-induced wound healing. Actinomycin D (5 μg/ml), Bay 11-7082 (10 μM) or JSH-23 (20 μM) treatment significantly reversed the effect of RGal on wound healing, showing that the response was transcriptionally dependent and involved NF-kB signaling. Treatment of cells with NS-398 (20 μM) also reversed the effect of RGal on wound healing. COX-2 protein expression was significantly increased at 6 and 12 h after RGal addition to Caco-2 monolayers. Conclusion(s) These data suggest that the plant-based polysaccharide RGal increases intestinal epithelial cell wound healing by increasing cell migration. The RGal effect is dependent on the activation of the FAK-Src/PI3K signaling pathways and subsequently the transcription factor NF-kB and downstream COX-2 protein expression and activity. Our findings show a novel mechanism of action of RGal in wound healing that could help in the resolution of intestinal inflammation and mucosal healing. Please acknowledge all funding agencies by checking the applicable boxes below Other Please indicate your source of funding; NSERC Disclosure of Interest None Declared

Microbiota signatures and mucosal healing in the use of enteral nutrition therapy v. corticosteroids for the treatment of children with Crohn's disease: a systematic review and meta-analysis.

Corticosteroids (CS) and exclusive and partial enteral nutrition (EEN and PEN) are effective therapies in paediatric Crohn's disease (CD). This systematic review of randomised controlled trials (RCT) and cohort studies analyses the impact of EEN/PEN v. CS on intestinal microbiota, mucosal healing as well as other clinically important outcomes, including clinical remission, relapse, adherence, adverse events and health-related quality of life (HRQL) in paediatric CD. Three RCT (n 76) and sixteen cohort studies (n 1104) compared EEN v. CS. With limited available data (one RCT), the effect on intestinal microbiome indicated a trend towards EEN regarding Shannon diversity. Based on two RCT, EEN achieved higher mucosal healing than CS (risk ratio (RR) 2·36, 95 % CI (1·22, 4·57), low certainty). Compared with CS, patients on EEN were less likely to experience adverse events based on two RCT (RR 0·32, 95 % CI (0·13, 0·80), low certainty). For HRQL, there was a trend in favour of CS based on data from two published abstracts of cohort studies. Based on thirteen cohort studies, EEN achieved higher clinical remission than CS (RR 1·18, 95 % CI (1·02, 1·38), very low certainty). Studies also reported no important differences in relapse and adherence. Compared with CS, EEN may improve mucosal healing with fewer adverse events based on RCT data. While limited data indicate the need for further trials, this is the first systematic review to comprehensively summarise the data on intestinal microbiome, mucosal healing and HRQOL when comparing enteral nutrition and CS in paediatric CD.

P644 Leucine-rich alpha 2 glycoprotein- A useful biomarker to discriminate small intestinal mucosal healing in asymptomatic CRP-negative Crohn’s disease

Abstract Background The long-term treatment goals for inflammatory bowel disease including Crohn’s disease (CD) have shifted from clinical remission to mucosal healing. However, frequent endoscopies are a great burden on the patients. Leucine-rich alpha 2 glycoprotein (LRG) is produced by hepatocytes, neutrophils, and the intestinal epithelium. Therefore, it is speculated to be more gut-specific than C-reactive protein (CRP) level. This study examined whether LRG could be used as a biomarker to determine the presence or absence of small intestinal mucosal healing in asymptomatic patients with CRP-negative CD. Methods The subjects of this study were asymptomatic CRP-negative CD patients who visited our department from May 2021 to October 2022, had their LRG measured, and underwent imaging evaluation by capsule endoscopy or balloon-assisted endoscopy. We analysed the patients’ clinical background, the ROC-AUC of LRG for mucosal healing, the cut-off value of LRG to discriminate mucosal healing. Endoscopic evaluation was performed within 3 months before and after the LRG measurement. Mucosal healing was defined as the absence of open ulcers. Clinical remission (no subjective symptoms) was defined as a Harvey-Bradshaw index (HBI) ≤4 points. The upper limit of the normal CRP value was set to &amp;lt;3 mg/L. Results A total of 28 cases were analysed; 13 (46%) were men. The median age (range) of onset was 21.2 years (7-52 years). The median disease duration (range) was 6.4 years (0-27). B1 was established in 13 (45%) cases, B2 in 7 (25%) cases and B3 of Montreal Classification in 8 (29%) cases. The median (range) of the HBI score was 2 (0-4). The median (range) of LRG was 12.3 g/ml (7.6-20.5 μg/ml). The ROC-AUC of LRG for mucosal healing was 0.743 (95% confidence interval 0.559-0.927). The cut-off value of LRG for discriminating mucosal healing was 12.2 μg/ml (sensitivity 0.769, specificity 0.682). Conclusion In asymptomatic CRP-negative CD patients, when LRG was 12.2 μg/ml or more, it was suggested that they might have small intestinal ulcers.

P092 Punica Granatum affects gut biofilm-forming bacteria and promotes intestinal mucosal healing regulating the crosstalk between epithelial cells and intestinal fibroblasts

Abstract Background Punica Granatum (PG), is a bioactive compound of Pomegranate exerting anti-inflammatory activities. Clinical studies have demonstrated an improvement of clinical response in inflammatory bowel diseases (IBD) patients when PG was taken as a complement to standard medications. However, the molecular mechanisms underlying its beneficial effects are still scarcely investigated. In this study, we assessed the effects of PG on bacterial biofilm formation, and we investigated the properties of the PG to promote mucosal wound healing. Methods Bacterial biofilm formation was assessed using microfluidic devices for 24 or 48 hours. Acute colitis model was induced in C57BL/6N mice by 3% dextran sodium sulfate administration in their drinking water for 5 days. During the recovery phase of colitis, mice received saline or PG (200 mg/kg body weight) oral gavage for 11 days. . Colitis was scored daily evaluating the body weight loss, bleeding and consistency of stool. In vivo intestinal permeability was performed by fluorescein isothiocyanate-conjugated dextran assay, bacterial translocation by Fluorescence in situ hybridization on tissues, whereas epithelial and mucus integrity by immunostaining for JAM-A and MUC-2 markers. Primary fibroblasts, isolated from healthy and inflamed area of 6 IBD patients, and Caco-2 cells were stimulated with or without PG (15 ug/ml). Inflammatory mediators were measured at mRNA and protein levels by RT-PCR, WB or by Bio-plex multiplex immunoassay respectively. Results Microfluidic experiments revealed beneficial effects of PG to inhibit biofilm formation of GRAM- bacteria and to promote the expansion of some intestinal commensal Gram+ bacteria. In vivo, PG boosted the recovery phase of colitis promoting a complete restoration of intestinal barrier with the regeneration of the mucus layer compared to saline group as also demonstrated by no traces of bacteria spread into the mucosa. The PG enriched crypt-associated fibroblasts. In vitro, inflamed fibroblasts responded to PG by down-regulating the release of metalloproteinases, IL-6, IL-8 and up-regulating the levels of HGF. Caco-2 cells cultured in medium supplemented with PG increased the expression of Sox-9 and CD44, whereas in the presence of HGF or when plated with fibroblast-conditioned medium displayed a decrease expression of Sox-9 and CD44 and increase of AXIN2, a negative regulator of Wnt signaling. Conclusion These data provide new insight of the multiple effects of PG on promoting mucosal homeostasis in IBD by affecting biofilm formation of pathogens, promoting expansion of commensals and favoring the regeneration of intestinal barrier by regulating the crosstalk between epithelial cells and stromal cells.

LMT503, A NOVEL THERAPY FOR INFLAMMATORY BOWEL DISEASE THROUGH MACROPHAGE POLARIZATIONS BY METABOLIC REPROGRAMMING OF ACTIVATED MACROPHAGE

Abstract Macrophages are the first line of defense against self-stimuli and non-self-pathogens and adopt diverse activation states by reprogramming their cell metabolism and thereby polarizing their phenotypes in order to drive their pro-inflammatory or pro-resolving responses. As the key gatekeeper of intestinal immune homeostasis, macrophage polarization has an important effect on maintaining tissue homeostasis with inducing resolution, and therefore macrophages phenotype alteration by modulating their cellular metabolism might be a novel therapeutic approach in IBD. LMT503 is an orally available organic small molecule and exerted the macrophage polarization from M1-like inflammatory macrophage to M2-like anti-inflammatory macrophages in LPS-induced bone marrow-derived macrophage in vitro experiment. The expression level of M1-related intracellular functional marker iNOS was suppressed by LMT503, while Arg-1 which is M2-associated marker was increased. LMT503 also performed metabolic reprogramming with decreasing anabolic metabolism but enhancing catabolic metabolism including mitochondrial metabolism. In the therapeutic settings using various IBD in vivo models such as DSS-induced acute/chronic mice models and adoptive T cell transfer mice model, LMT503 exerted macrophage polarization with showing reduced expression level of M1 markers such as iNOS, CD80, and CD86 but increased expression of M2 markers like Arg-1, CD168, and CD206. LMT503 mitigated inflammation with decreased production of inflammatory cytokines (TNF-a, IL-6, IL-1b, IL-18), increased anti-inflammatory cytokines (IL-10, IL-22), and reduced neutrophil infiltrations. In the addition to increased ratio of M2/M1 macrophages, LMT503 increased ratio of Treg/Th17. LMT503 also induced epithelial restitution with increased number of goblet cells, and showed decreased bacterial translocation from gut to mesenteric lymph node. In a chronic IBD mice model, LMT503 showed reduced intestinal fibrotic marker a-SMA which is one of critical complications for patients with long-term IBD. Mode of action through macrophage polarization was proved by using a macrophage-depleted IBD in vivo model, and LMT503 did not improve the disease associate index or inflammation. Also LMT503 showed re-storing immunity in an in vivo study of challenging pathogen to LMT503-treated and washed-out model, which avoids the possibility of an opportunistic infections. In summary, LMT503 was very efficacious in various IBD in vivo models with showing the resolution of intestinal inflammation and mucosal healing through improved epithelial restitution via macrophage polarizations, and this approach can be a very effective and safe therapy for multifaceted IBD. The first in human study with LMT503 will be initiating in 4Q 2022.

Activation of P2Y1R impedes intestinal mucosa repair during colitis.

Delayed intestinal mucosal healing is one of the pathogenic bases for the recurrence of inflammatory bowel disease (IBD), but how the IBD inflammatory environment impedes intestinal mucosa repair remains unclear. Adenosine diphosphate (ADP) is an endogenous ligand of P2Y1R that is highly produced at sites of inflammation. We herein identify a novel role of ADP to directly facilitate inflammation-induced epithelial permeability, delay wound healing, and disrupt tight junction integrity, and we found that P2Y1R, a receptor preferentially activated by ADP, was significantly upregulated in the colonic mucosa of ulcerative colitis (UC) patients and in colonic epithelial cells of colitis mice. Inhibition of P2Y1R significantly increased the epithelial permeability, decreased the wound healing capacity, and impaired the tight junction integrity in TNF-α-challenged Caco-2 cells. In parallel, the same effects in promoting intestinal mucosa repair were observed in DSS-induced colitis in P2Y1R-/- mice. Mechanistic investigation revealed that P2Y1R inhibition facilitated epithelial AMP-activated protein kinase (AMPK) phosphorylation and gut microbiota homeostasis reconstruction. Taken together, these findings highlight that P2Y1R activation plays an important role in impeding intestinal mucosa repair during colitis, and that P2Y1R is an attractive target for the therapy of IBD.

A novel drug-like water-soluble small molecule Focal Adhesion Kinase (FAK) activator promotes intestinal mucosal healing

Non-steroidal anti-inflammatory drugs (NSAIDs) injure the proximal and distal gut by different mechanisms. While many drugs reduce gastrointestinal injury, no drug directly stimulates mucosal wound healing. Focal adhesion kinase (FAK), a non-receptor tyrosine kinase, induces epithelial sheet migration.We synthesized and evaluated a water-soluble FAK-activating small molecule, M64HCl, with drug-like properties. Monolayer wound closure and Western blots measured migration and FAK phosphorylation in Caco-2 ​cells, in vitro kinase assays established FAK activation, and pharmacologic tests assessed drug-like properties. 30 ​mg/kg/day M64HCl was administered in two murine small intestine injury models for 4 days.M64HCl (0.1–1000 ​nM) dose-dependently increased Caco-2 FAK-Tyr 397 phosphorylation, without activating Pyk2 and accelerated Caco-2 monolayer wound closure. M64HCl dose-responsively activates the FAK kinase domain vs. the non-salt M64, increasing the Vmax of ATP-binding. Pharmacologic tests suggested M64HCl has drug-like properties and is enterally absorbed. M64HCl 25 ​mg/kg/day continuous infusion promoted healing of ischemic jejunal ulcers and indomethacin-induced small intestinal injury in C57Bl/6 mice. M64HCl-treated mice exhibited smaller ulcers 4 days after ischemic ulcer induction or indomethacin injury. Renal histology and plasma creatinine were normal. Mild hepatic inflammatory changes and ALT elevation were similar among M64HCl-treated mice and controls. M64HCl was concentrated in kidney and gastrointestinal mucosa and functional nephrectomy studies suggested predominantly urinary excretion. Little toxicity was observed in vitro or in single-dose mouse toxicity studies until >1000x higher than effective concentrations. M64HCl, a water-soluble FAK activator, promotes epithelial restitution and intestinal mucosal healing and may be useful to treat gut mucosal injury.

Aberrant Mucin Expression Profiles Associate With Pediatric Inflammatory Bowel Disease Presentation and Activity.

Intestinal mucosal healing is nowadays preferred as the therapeutic endpoint in inflammatory bowel disease (IBD), but objective measurements at the molecular level are lacking. Because dysregulated mucin expression is suggested to be involved in mucosal barrier dysfunction in IBD, we investigated mucin expression in association with barrier mediators and clinical characteristics in colonic tissue of a pediatric IBD population. In this cross-sectional monocentric study, we quantified messenger RNA (mRNA) expression of mucins, intercellular junctions, and cell polarity complexes in inflamed and noninflamed colonic biopsies from pediatric IBD (n = 29) and non-IBD (n = 15) patients. We then validated mucin expression at protein level and correlated mucin mRNA expression with expression of barrier mediators and clinical data. The expression of MUC1, MUC3A, MUC4, and MUC13 was increased in the inflamed colon of pediatric IBD patients compared with the noninflamed colon of non-IBD control subjects. Especially MUC13 mRNA expression associated with the expression of barrier mediators, including CDH1, OCLN, and TJP2. MUC1 and MUC3B mRNA expression in combination with calprotectin levels most accurately discriminated IBD patients from non-IBD control subjects (90.6% area under the receiver-operating characteristic curve [AUCROC], 92.0% sensitivity, 73.7% specificity), whereas aberrant mRNA expression of MUC1, MUC3A, MUC4, and MUC13 was distinctive for ulcerative colitis and of MUC3B for Crohn's disease. Furthermore, expression of MUC3A, MUC3B, and MUC4 correlated with clinical disease activity (ie, Pediatric Ulcerative Colitis Activity Index and Pediatric Crohn's Disease Activity Index), and of MUC1, MUC2, MUC4, and MUC13 with endoscopic colitis severity in ulcerative colitis patients. Colonic mucin expression is disturbed in pediatric IBD patients and associates with disease activity and presentation, suggesting its use as molecular marker to aid in disease diagnosis and management.

Phycocyanin stimulates ulcerative colitis healing via selective activation of cannabinoid receptor-2, intestinal mucosal healing, Treg accumulation, and p38MAPK/MK2 signaling inhibition

Ulcerative colitis (UC) is a chronic inflammatory condition that until this date, lacks curative treatments. Previously, synthetic selective CB2 receptor (CB2R) agonists demonstrated effective preclinical anti-inflammatory activities in UC. Phycocyanin (PC), photosynthetic assistant protein isolated from Microcystis aeruginosa Kützing blue green algae, has multiple pharmacological effects, however, it's effect against UC remains unexplored. Our study aimed at investigating the therapeutic effectiveness of PC against UC, and correlating its mechanisms with CB2R agonistic activities. In silico; PC showed structural similarity with endocannabinoid receptors' ligand “Δ9-tetrahydrocannabinol”, target prediction studies suggested high affinity for G-coupled protein family-receptors, and molecular docking affirmed preferable affinity towards CB2R vs CB1R. In LPS-exposed-Caco-2 cell line; PC demonstrated comparable interaction with CB2R, and downregulation of CB2R, p38 and MK2 gene expressions with reference agonist “6d”, and exhibited preferred selectivity towards CB2R over CB1R. In DSS-induced mice; PC-treatment ameliorated DSS-induced colon shortening, elevated disease activity index, and colonic pathological alterations. PC showed effective CB2R activation through potent anti-inflammatory activities, Treg-cell accumulation, suppression in p38MAPK/MK2 signaling, and tight junction barrier restoration as indicated by ultrastructural examinations, elevated ZO-1 and occludin protein expressions, and Ki67 immunohistochemical expression in colonic tissues. Additionally, PC alleviated intestinal dysbiosis via downregulating LPS/TLR4/NF-κB signaling and gut microbiota maintenance. Notably, PC-protective activities were abolished when co-administered with SR144528 (selective CB2 antagonist) except for gut microbiota maintenance, which was independent from CB2R activation. Our findings provide evidence of PC effectiveness against UC through acting as CB2R agonist, thus expanding its possible therapeutic application against other inflammatory diseases.