Serum Leucine-Rich α2 Glycoprotein: A Novel Biomarker for Transmural Inflammation in Crohn's Disease.

INTRODUCTION: Leucine-rich alpha-2 glycoprotein (LRG) is a newly studied biomarker for inflammatory diseases. This study aimed to investigate whether LRG can be used for evaluating transmural activity in patients with Crohn's disease (CD). METHODS: We performed magnetic resonance enterography (MRE) in 227 consecutive patients with CD from June 2020 to August 2021. We prospectively compared MRE findings with clinical and laboratory data including LRG. MRE was evaluated using 2 validated scoring systems, and transmural inflammation was defined as having a maximum simplified magnetic resonance index of activity (sMaRIA) score of ≥4 and a 5-point classification score of ≥9, respectively. RESULTS: The correlation between LRG and the total MRE score showed a positive correlation ( r = 0.576 for the sMaRIA score, P < 0.01, and r = 0.633 for the 5-point score, P < 0.01). Serum concentrations of LRG significantly increased as MRE scores increased ( P < 0.01). The area under the curve of LRG for a sMaRIA score of ≥4 and a 5-point score of ≥9 was 0.845 and 0.869, respectively, which was significantly higher than that of CDAI ( P < 0.01) or C-reactive protein ( P < 0.01). LRG levels of ≥14 µg/mL had a 67% sensitivity and 90% specificity for a sMaRIA score of ≥4 and a 73% sensitivity and 89% specificity for a 5-point score of ≥9. Patients with high LRG levels were also strongly associated with CD-related hospitalization, surgery, and clinical relapse compared with those with low LRG levels ( P < 0.01 for all). DISCUSSION: LRG is a highly accurate serum biomarker for detecting transmural activity in patients with CD. Results need to be validated in further multicenter studies.

Development and Application of Regenerative Medicine in Inflammatory Bowel Disease.

BACKGROUND: Inflammatory bowel disease (IBD) is characterized by idiopathic and chronic inflammation arising elsewhere within the gastrointestinal tract. Consequently, the mucosal tissue is destroyed during the active phase of the disease, and therefore, spontaneous repair of damaged tissue is required to restore the function and long-term homeostasis of the intestinal mucosa. Also, in patients with refractory Crohn's disease, loss of massive intestinal function can lead to short bowel syndrome or may lead to fatal intestinal failure. SUMMARY: The concept of mucosal healing shares the idea that both regulation of mucosal inflammation and repair of the damaged mucosa are critical to achieve the ideal clinical outcome in patients with IBD. However, current treatments lack the option of those targeted to mucosal repair, and therefore, patients must achieve mucosal healing depending on their intrinsic system. To counteract inflammation-induced mucosal damage, various biologics or cell-based treatments are currently being developed. In the early developmental phase, various growth factors have been tested for their ability to promote mucosal repair. However, most of these factors did not show clinical benefit, except the recombinant glucagon-like peptide-2 (GLP-2). On the contrary, cell-based treatments are rapidly emerging, using both somatic stem cells and pluripotent stem cells. KEY MESSAGES: In this review, we focus on the current state of factor-based or cell-based regenerative medicine in the treatment of IBD. Additionally, we would like to introduce current examples of tissue engineering technologies and provide future prospects for the application of regenerative medicine in IBD.

Mucosal healing of small intestinal stricture is associated with improved prognosis post-dilation in Crohn's disease.

BACKGROUND: Small intestinal stricture is a major cause for surgery in Crohn's disease (CD). Endoscopic balloon dilation (EBD) is performed for small intestinal strictures to avoid surgery, often repeatedly. However, factors that are associated with prognosis after EBD of small intestinal strictures remain poorly investigated. Mucosal healing is the therapeutic target in CD. We aimed to investigate the impact of mucosal healing defined by the presence of ulcers at the small intestinal stricture site on the prognosis of EBD in CD patients. METHODS: We retrospectively included patients with CD who underwent initial EBD for endoscopically impassable small intestinal strictures from January 2012 to March 2020 at a single center. The association between presence of ulcer at the stricture site and surgery after EBD was examined by Cox proportional hazards model. RESULTS: Of the 98 patients included, 63 (64.3%) had ulcer at the stricture site. 20 (31.7%) of these patients underwent surgery for the stricture in due course, whereas 4 (11.4%) of the patients without ulcer of the stricture underwent surgery. In multivariate analysis, patients with ulcer of the stricture had a significantly higher risk for surgery than those without ulcer (hazard ratio 4.84; 95% confidence interval 1.58-14.79). CONCLUSION: Mucosal healing at the stricture site indicated a favorable prognosis after EBD for small intestinal strictures in CD.

Development and Validation of a Deep Neural Network for Accurate Evaluation of Endoscopic Images From Patients With Ulcerative Colitis.

BACKGROUND & AIMS: There are intra- and interobserver variations in endoscopic assessment of ulcerative colitis (UC) and biopsies are often collected for histologic evaluation. We sought to develop a deep neural network system for consistent, objective, and real-time analysis of endoscopic images from patients with UC. METHODS: We constructed the deep neural network for evaluation of UC (DNUC) algorithm using 40,758 images of colonoscopies and 6885 biopsy results from 2012 patients with UC who underwent colonoscopy from January 2014 through March 2018 at a single center in Japan (the training set). We validated the accuracy of the DNUC algorithm in a prospective study of 875 patients with UC who underwent colonoscopy from April 2018 through April 2019, with 4187 endoscopic images and 4104 biopsy specimens. Endoscopic remission was defined as a UC endoscopic index of severity score of 0; histologic remission was defined as a Geboes score of 3 points or less. RESULTS: In the prospective study, the DNUC identified patients with endoscopic remission with 90.1% accuracy (95% confidence interval [CI] 89.2%-90.9%) and a kappa coefficient of 0.798 (95% CI 0.780-0.814), using findings reported by endoscopists as the reference standard. The intraclass correlation coefficient between the DNUC and the endoscopists for UC endoscopic index of severity scoring was 0.917 (95% CI 0.911-0.921). The DNUC identified patients in histologic remission with 92.9% accuracy (95% CI 92.1%-93.7%); the kappa coefficient between the DNUC and the biopsy result was 0.859 (95% CI 0.841-0.875). CONCLUSIONS: We developed a deep neural network for evaluation of endoscopic images from patients with UC that identified those in endoscopic remission with 90.1% accuracy and histologic remission with 92.9% accuracy. The DNUC can therefore identify patients in remission without the need for mucosal biopsy collection and analysis. Trial number: UMIN000031430.

Functional analysis of isoflavones using patient-derived human colonic organoids.

Inflammatory bowel disease (IBD) comprises two major subtypes, ulcerative colitis (UC) and Crohn's disease, which are multifactorial diseases that may develop due to genetic susceptibility, dysbiosis, or environmental factors. Environmental triggers of IBD include food-borne factors, and a previous nationwide survey in Japan identified pre-illness consumption of isoflavones as a risk factor for UC. However, the precise mechanisms involved in the detrimental effects of isoflavones on the intestinal mucosa remain unclear. The present study employed human colonic organoids (hCOs) to investigate the functional effect of two representative isoflavones, genistein and daidzein, on human colonic epithelial cells. The addition of genistein to organoid reformation assays significantly decreased the number and size of reformed hCOs compared with control and daidzein treatment, indicating an inhibitory effect of genistein on colonic cell/progenitor cell function. Evaluation of the phosphorylation status of 49 different receptor tyrosine kinases showed that genistein selectively inhibited phosphorylation of epidermal growth factor receptor (EGFR) and hepatocyte growth factor receptor (HGFR). We established a two-dimensional wound-repair model using hCOs and showed that genistein significantly delayed the overall wound-repair response. Our results collectively show that genistein may exert its detrimental effects on the intestinal mucosa via negative regulation of stem/progenitor cell function, possibly leading to sustained mucosal injury and the development of UC.

Intravenous tacrolimus is a superior induction therapy for acute severe ulcerative colitis compared to oral tacrolimus.

BACKGROUND: Intravenous corticosteroid is the mainstay for managing acute severe ulcerative colitis, but one-third of patients do not respond to intravenous corticosteroid. Tacrolimus, a salvage therapy before colectomy, is usually orally administered, though its bioavailability is low compared intravenous administration. The efficacy of intravenous tacrolimus has not been widely studied. AIM: To determine the efficacy and safety of intravenous tacrolimus for the treatment of acute severe ulcerative colitis. METHODS: Eighty-seven hospitalized acute severe ulcerative colitis patients were enrolled for a prospective cohort study between 2009 and 2017. Sixty-five patients received intravenous tacrolimus and 22 received oral tacrolimus. The primary outcome was the achievement of clinical remission within 2 weeks. Relapse and colectomy incidence and adverse events were assessed at 24 weeks. RESULTS: Response rates of both treatments exceeded 50% but were not significantly different. The remission rate was higher in intravenous tacrolimus compared with oral tacrolimus. At 24 weeks, oral and intravenous tacrolimus showed similar relapse-free survival rates; however, colectomy-free survival rates were higher in intravenous tacrolimus compared with oral tacrolimus. CONCLUSIONS: Patients receiving intravenous tacrolimus achieved superior remission and colectomy-free survival rates compared with patients receiving oral tacrolimus. Safety was similar between the two treatments.

Small Bowel Healing Detected by Endoscopy in Patients With Crohn's Disease After Treatment With Antibodies Against Tumor Necrosis Factor.

BACKGROUND & AIMS: It is important to objectively assess Crohn's disease (CD) activity in patients treated with antibodies against tumor necrosis factor (anti-TNF). Detection of healing by endoscopy (endoscopic healing) associates with patient outcome, based on evidence from studies of ileocolonoscopy. We assessed endoscopic healing after treatment, based on findings from balloon-assisted enteroscopy (BAE), in patients with CD. METHODS: We performed a post-hoc analysis of data from a clinical trial from 116 patients with CD (46 with ileal and 70 with ileocolonic type) who received induction and then maintenance therapy with anti-TNF agents from January 2013 through March 2018 at a single center in Japan. We compared findings from BAE before induction therapy and then again during maintenance therapy (median 13 months later). Endoscopic healing was defined as the modified simple endoscopic score for CD below 5. We also collected data on previous treatments, makers of inflammation, and disease type. RESULTS: Before treatment, small bowel ulcerations were present in 114 patients (98%); 42 patients (60%) with ileocolonic disease had colon ulcerations. During maintenance therapy, 41/114 patients (36%) had small bowel endoscopic healing; all the patients with small bowel endoscopic healing also had colonic endoscopic healing. Colonic endoscopic healing was observed in 33/42 patients (79%). The proportion of patients with small bowel endoscopic healing was significantly lower than that of colonic endoscopic healing (P < .001). Among all patients, failure to achieve small bowel endoscopic healing was significantly associated with structuring or penetrating disease (P = .014), lack of concomitant treatment with immunomodulators (P = .015), and having received previous treatment with an anti-TNF agents (P = .018). CONCLUSIONS: In a post-hoc analysis of patients with CD treated with anti-TNF agents, we found small bowel ulcerations, detected by BAE, to be more difficult to heal than colon ulcerations.

TGF-ß promotes fetal gene expression and cell migration velocity in a wound repair model of untransformed intestinal epithelial cells.

The early-phase wound repair response of the intestinal epithelium is characterized by rapid and organized cell migration. This response is regulated by several humoral factors, including TGF-ß. However, due to a lack of appropriate models, the precise response of untransformed intestinal epithelial cells (IECs) to those factors is unclear. In this study, we established an in vitro wound repair model of untransformed IECs, based on native type-I collagen. In our system, IECs formed a uniform monolayer in a two-chamber culture insert and displayed a stable wound repair response. Gene expression analysis revealed significant induction of Apoa1, Apoa4, and Wnt4 during the collagen-guided wound repair response. The wound repair response was enhanced significantly by the addition of TGF-ß. Surprisingly, addition of TGF-ß induced a set of genes, including Slc28a2, Tubb2a, and Cpe, that were expressed preferentially in fetal IECs. Moreover, TGF-ß significantly increased the peak velocity of migrating IECs and, conversely, reduced the time required to reach the peak velocity, as confirmed by the motion vector prediction (MVP) method. Our current in vitro system could be employed to assess other humoral factors involved in IEC migration and could contribute to a deeper understanding of the wound repair potentials of untransformed IECs.

Indispensable role of Notch ligand-dependent signaling in the proliferation and stem cell niche maintenance of APC-deficient intestinal tumors.

Ligand-dependent activation of Notch signaling is required to maintain the stem-cell niche of normal intestinal epithelium. However, the precise role of Notch signaling in the maintenance of the intestinal tumor stem cell niche and the importance of the RBPJ-independent non-canonical pathway in intestinal tumors remains unknown. Here we show that Notch signaling was activated in LGR5+ve cells of APC-deficient mice intestinal tumors. Accordingly, Notch ligands, including Jag1, Dll1, and Dll4, were expressed in these tumors. In vitro studies using tumor-derived organoids confirmed the intrinsic Notch activity-dependent growth of tumor cells. Surprisingly, the targeted deletion of Jag1 but not RBPJ in LGR5+ve tumor-initiating cells resulted in the silencing of Hes1 expression, disruption of the tumor stem cell niche, and dramatic reduction in the proliferation activity of APC-deficient intestinal tumors in vivo. Thus, our results highlight the importance of ligand-dependent non-canonical Notch signaling in the proliferation and maintenance of the tumor stem cell niche in APC-deficient intestinal adenomas.

Hes1 promotes the IL-22-mediated antimicrobial response by enhancing STAT3-dependent transcription in human intestinal epithelial cells.

Notch signaling plays an essential role in the proliferation and differentiation of intestinal epithelial cells (IECs). We have previously shown that Notch signaling is up-regulated in the inflamed mucosa of ulcerative colitis (UC) and thereby plays an indispensable role in tissue regeneration. Here we show that in addition to Notch signaling, STAT3 signaling is highly activated in the inflamed mucosa of UC. Forced expression of the Notch target gene Hes1 dramatically enhanced the IL-22-mediated STAT3-dependent transcription in human IECs. This enhancement of STAT3-dependent transcription was achieved by the extended phosphorylation of STAT3 by Hes1. Microarray analysis revealed that Hes1-mediated enhancement of IL-22-STAT3 signaling significantly increased the induction of genes encoding antimicrobial peptides, such as REG1A, REG3A and REG3G, in human IECs. Conversely, the reduction of Hes1 protein levels with a γ-secretase inhibitor significantly down-regulated the induction of those genes in IECs, resulting in a markedly poor response to IL-22. Our present findings identify a new role for the molecular function of Hes1 in which the protein can interact with cytokine signals and regulate the immune response of IECs.

Wnt5a signaling mediates biliary differentiation of fetal hepatic stem/progenitor cells in mice.

UNLABELLED: The molecular mechanisms regulating differentiation of fetal hepatic stem/progenitor cells, called hepatoblasts, which play pivotal roles in liver development, remain obscure. Wnt signaling pathways regulate the development and differentiation of stem cells in various organs. Although a ß-catenin-independent noncanonical Wnt pathway is essential for cell adhesion and polarity, the physiological functions of noncanonical Wnt pathways in liver development are unknown. Here we describe a functional role for Wnt5a, a noncanonical Wnt ligand, in the differentiation of mouse hepatoblasts. Wnt5a was expressed in mesenchymal cells and other cells of wild-type (WT) midgestational fetal liver. We analyzed fetal liver phenotypes in Wnt5a-deficient mice using a combination of histological and molecular techniques. Expression levels of Sox9 and the number of hepatocyte nuclear factor (HNF)1ß(+) HNF4α(-) biliary precursor cells were significantly higher in Wnt5a-deficient liver relative to WT liver. In Wnt5a-deficient fetal liver, in vivo formation of primitive bile ductal structures was significantly enhanced relative to WT littermates. We also investigated the function of Wnt5a protein and downstream signaling molecules using a three-dimensional culture system that included primary hepatoblasts or a hepatic progenitor cell line. In vitro differentiation assays showed that Wnt5a retarded the formation of bile duct-like structures in hepatoblasts, leading instead to hepatic maturation of such cells. Whereas Wnt5a signaling increased steady-state levels of phosphorylated calcium/calmodulin-dependent protein kinase II (CaMKII) in fetal liver, inhibition of CaMKII activity resulted in the formation of significantly more and larger-sized bile duct-like structures in vitro compared with those in vehicle-supplemented controls. CONCLUSION: Wnt5a-mediated signaling in fetal hepatic stem/progenitor cells suppresses biliary differentiation. These findings also suggest that activation of CaMKII by Wnt5a signaling suppresses biliary differentiation. (HEPATOLOGY 2013;).

A case of IgG4-related disease associated with ulcerative colitis that was successfully treated with a JAK inhibitor.

Glucocorticoids (GC) are the standard of care for the induction and maintenance of remission in immunoglobulin G4 (IgG4)-related diseases. However, IgG4-related diseases often relapse with GC dose reduction, not only making GC dose reduction difficult but also necessitating GC dose escalation in many cases. Therefore, other immunosuppressive drugs are required to maintain remission. Here, we report a 39-year-old man with ulcerative colitis and IgG4-related disease who experienced a relapse of both diseases despite treatment with tacrolimus and 6-mercaptopurine. Following the initiation of tofacitinib, a Janus-associated kinase inhibitor, it was possible to reduce the GC dose while maintaining remission of both diseases. This case highlights the potential utility of Janus-associated kinase inhibitors in managing complex cases of IgG4-related disease, especially those with concurrent conditions such as ulcerative colitis.

Combination of leucine-rich alpha-2 glycoprotein and fecal markers detect Crohn's disease activity confirmed by balloon-assisted enteroscopy.

BACKGROUND/AIMS: Endoscopic activity confirmed by enteroscopy is associated with poor clinical outcome in Crohn's disease (CD). We investigated which of the existing biomarkers best reflects endoscopic activity in CD patients including the small bowel, and whether their combined use can improve accuracy. METHODS: One hundred and four consecutive patients with ileal and ileocolonic type CD who underwent balloon-assisted enteroscopy (BAE) from October 2021 to August 2022 were enrolled, with clinical and laboratory data prospectively collected and analyzed. RESULTS: Hemoglobin, platelet count, C-reactive protein, leucine-rich alpha-2 glycoprotein (LRG), fecal calprotectin, and fecal hemoglobin all showed significant difference in those with ulcers found on BAE. LRG and fecal calprotectin showed the highest areas under the curve (0.841 and 0.853) for detecting ulcers. LRG showed a sensitivity of 78% and specificity of 80% at a cutoff value of 13 µg/mL, whereas fecal calprotectin showed a sensitivity of 91% and specificity of 67% at a cutoff value of 151 µg/g. Dual positivity for LRG and fecal calprotectin, as well as LRG and fecal hemoglobin, both predicted ulcers with an improved specificity of 92% and 100%. A positive LRG or fecal calprotectin/hemoglobin showed an improved sensitivity of 96% and 91%. Positivity for LRG and either of the fecal biomarkers was associated with increased risk of hospitalization, surgery, and relapse. CONCLUSIONS: The biomarkers LRG, fecal calprotectin, and fecal hemoglobin can serve as noninvasive and accurate tools for assessing activity in CD patients confirmed by BAE, especially when used in combination.

Efficacy and safety of filgotinib for ulcerative colitis: A real-world multicenter retrospective study in Japan.

BACKGROUND AND AIMS: While filgotinib, an oral Janus kinase (JAK) 1 preferential inhibitor, is approved for moderately to severely active ulcerative colitis (UC), real-world studies assessing its short- and long-term efficacy and safety are limited. METHODS: This is a multicenter, retrospective study of UC patients who started filgotinib between March 2022 and September 2023. The primary outcome was clinical remission, defined as a partial Mayo score ≤1 with a rectal bleeding score of 0, or Simple Clinical Colitis Activity Index (SCCAI) ≤2 with a blood-in-stool score of 0. Secondary outcomes included clinical response, corticosteroid-free remission, and endoscopic improvement. Outcomes were assessed at 10, 26, and 58 weeks based on patients with available follow-up. Adverse events were evaluated. RESULTS: We identified 238 UC patients and 54% had prior exposure to biologics/JAK inhibitors. The median baseline partial Mayo score and SCCAI were 5 (IQR 3-6) and 4 (IQR 2-7). Clinical remission rates based on per-protocol analysis at 10, 26, and 58 weeks were 47% (70/149), 55.8% (48/86), and 64.6% (31/48), respectively. At a median follow-up of 28 weeks (IQR 10-54) with a discontinuation rate of 39%, the rates of clinical remission, clinical response, corticosteroid-free remission, and endoscopic improvement were 39.9% (81/203), 54.7% (111/203), and 36.5% (74/203), and 43.5% (10/23), respectively. These rates were comparable between biologic/JAK inhibitor-naïve and -experienced patients. While three patients (1.3%) developed herpes zoster infection, no cases of thrombosis or death were reported. CONCLUSIONS: Real-world data demonstrate favourable clinical and safety outcomes of filgotinib for UC.

Salmonella type III effector SpvC, a phosphothreonine lyase, contributes to reduction in inflammatory response during intestinal phase of infection.

Salmonella phosphothreonine lyase SpvC inactivates the dual-phosphorylated host mitogen-activated protein kinases (MAPK) through ß-elimination. While SpvC can be secreted in vitro by both Salmonella pathogenicity island (SPI)-1 and SPI-2 type III secretion systems (T3SSs), translocation of this protein into the host cell cytosol has only been demonstrated by SPI-2 T3SS. In this study, we show that SpvC can be delivered into the host cell cytoplasm by both SPI-1 and SPI-2 T3SSs. Dephosphorylation of the extracellular signal-regulated protein kinases (ERK) was detected in an SPI-1 T3SS-dependent manner 2 h post infection. Using a mouse model for Salmonella enterocolitis, which was treated with streptomycin prior to infection, we observed that mice infected with Salmonella enterica serovar Typhimurium strains lacking the spvC gene showed pronounced colitis when compared with mice infected with the wild-type strain 1 day after infection. The effect of SpvC on the development of colitis was characterized by reduced mRNA levels of the pro-inflammatory cytokines and chemokines, and reduced inflammation with less infiltration of neutrophils. Furthermore, the reduction in inflammation by SpvC resulted in increased bacterial dissemination in spleen of mice infected with Salmonella. Collectively, our findings suggest that SpvC exerts as an anti-inflammatory effector and the attenuation of intestinal inflammatory response by SpvC is involved in systemic infection of Salmonella.

Transmural Remission Characterized by High Biologic Concentrations Demonstrates Better Prognosis in Crohn's Disease.

BACKGROUND: The importance and pathophysiology of transmural healing in patients with Crohn's disease [CD] remains to be verified. We aimed to examine the association between serum concentrations of biologics and transmural remission evaluated via magnetic resonance enterography [MRE]. METHODS: We enrolled patients with CD who received maintenance biologics 1 year after induction and prospectively followed up for at least 1 year after baseline laboratory, endoscopic and MRE examination. We evaluated the relationship between baseline factors including the presence of transmural remission and patient prognosis, as well as between serum concentrations and transmural remission. RESULTS: We included 134 patients, of whom 65, 31, 27 and 11 received infliximab, adalimumab, ustekinumab and vedolizumab, respectively. Those who achieved transmural remission showed a lower risk of hospitalization and surgery than those who did not achieve remission [p < 0.01]. Adjusted hazard ratios of transmural remission for predicting hospitalization and surgery were 0.11 and 0.02, respectively, which were lower than those of clinical remission, biochemical remission and endoscopic remission. Regarding serum concentrations, the median concentration was higher in patients with transmural remission than in patients with transmural activity for all agents [p < 0.01 for infliximab, p = 0.04 for adalimumab, p < 0.01 for ustekinumab, p = 0.08 for vedolizumab]. CONCLUSIONS: Transmural remission was the best predictor for prognosis in CD patients who received maintenance biologic therapy. High drug concentration levels were associated with transmural remission confirmed via MRE.

A case of venous stasis colitis possibly caused by eplerenone.

A 50-year-old man was referred to our hospital for colitis with abdominal pain and diarrhea that had persisted for more than 8 months. 9 months earlier, he had been treated for fulminant eosinophilic myocarditis. During steroid therapy, ulceration appeared in the esophagus, stomach and large intestine. The biopsy results showed cytomegalovirus (CMV) inclusion bodies, and the patient was diagnosed with CMV gastrocolitis and treated with ganciclovir. Colonoscopy 7 months earlier revealed ischemia-like segmental colitis 10 cm in length in the hepatic flexure without evidence of CMV infection. Colonoscopy after 1 month and 3 months showed no improvement. We suspected drug-induced focal ischemic colitis, and discontinued eplerenone. Colonoscopy 2 months after withdrawal of eplerenone showed improvement in colitis, and colonoscopy 8 months later showed ulcer healing. Venous disorders are cautioned as a known side effect of eplerenone, but this is the first report of venous stasis colitis thought to be caused by eplerenone.

Organoids transplantation as a new modality to design epithelial signature to create a membrane-protective sulfomucin-enriched segment.

BACKGROUND: The organoids therapy for ulcerative colitis (UC) is under development. It is important to dissect how the engrafted epithelium can provide benefits for overcoming the vulnerability to inflammation. We mainly focused on the deliverability of sulfomucin, which is reported to play an important role in epithelial function. METHODS: We analyzed each segment of colon epithelium to determine differences in sulfomucin production in both mice and human. Subsequently, we transplanted organoids established from sulfomucin-enriched region into the injured recipient epithelium following dextran sulfate sodium-induced colitis and analyzed the engrafted epithelium in mouse model. RESULTS: In human normal colon, sulfomucin production was increased in proximal colon, whereas it was decreased in the inflammatory region of UC. In murine colon epithelium, increased sulfomucin production was found in cecum compared to distal small intestine and proximal colon. RNA sequencing analysis revealed that several key genes associated with sulfomucin production such as Papss2 and Slc26a1 were enriched in isolated murine cecum crypts. Then we established murine cecum organoids and transplanted them into the injured epithelium of distal colon. Although the expression of sulfomucin was temporally decreased in cecum organoids, its secretion was restored again in the engrafted patches after transplantation. Finally, we verified a part of mechanisms controlling sulfomucin production in human samples. CONCLUSION: This study illustrated the deliverability of sulfomucin in the disease-relevant grafting model to design sulfomucin-producing epithelial units in severely injured distal colon. The current study is the basis for the better promotion of organoids transplantation therapy for refractory UC.