Search

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.

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).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.The correlation between LRG and the total MRE score showed a positive correlation (r = 0.576 for the sMaRIA score, P0.01, and r = 0.633 for the 5-point score, P0.01). Serum concentrations of LRG significantly increased as MRE scores increased (P0.01). 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 (P0.01) or C-reactive protein (P0.01). 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 (P0.01 for all).LRG is a highly accurate serum biomarker for detecting transmural activity in patients with CD. Results need to be validated in further multicenter studies.

Background Several studies have reported a positive correlation between serum drug concentrations and endoscopic remission in patients with Crohn's disease. Aim To examine the association between the concentrations of cytokine blockers (infliximab, adalimumab and ustekinumab) and endoscopic remission of small bowel lesions. Method This was a cross-sectional study conducted at a single tertiary referral centre. Patients with Crohn's disease who received maintenance cytokine blocker therapy were recruited from April 2018 to May 2020. We performed balloon-assisted enteroscopy and collected serum samples to measure drug concentrations. The primary endpoint was the relationship between the concentrations of cytokine blockers and endoscopic remission in the small bowel. Results We enrolled 143 patients, 66, 44 and 33 of whom were receiving infliximab, adalimumab and ustekinumab, respectively. Enteroscopic findings showed that the rate of endoscopic remission of small bowel lesions was significantly lower than that of colonic lesions (P 5, 14 and 4 µg/mL were nearly 5.3-, 9.4- and 14.7-times more likely to exhibit endoscopic remission of the small bowel, respectively. Conclusions Cytokine blocker treatment was less efficacious for small bowel inflammation than colonic inflammation. Higher serum concentrations were needed to achieve endoscopic remission of small bowel lesions.

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 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.

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.

Ulcerative colitis (UC) is an inflammatory bowel disease that causes chronic inflammation in the colon. 5-aminosalicylic acid and immunosuppressive medications such as corticosteroids, immunomodulators, and biologic agents are used to treat these patients. However, patients with UC who receive immunosuppressive medications may be at risk for certain opportunistic infections. Epstein-Barr virus (EBV) is one of those opportunistic infections, and its pathogenic role has been implicated in refractory UC, but its pathogenicity should be further investigated. Here, we report a surgical case of refractory UC that demonstrated a serologically post-infected pattern of EBV at admission but that later had a high load of EBV in both the peripheral blood and colonic mucosa. These findings suggest that EBV may have been reactivated in the colon, after which it damaged the colonic mucosa and aggravated inflammation in this patient with UC. Thus, EBV might lead to severity and a refractory response against corticosteroids and anti-TNFα agents, necessitating emergency surgery. Viral surveillance for EBV in patients with refractory UC may facilitate understanding of the patient's pathophysiology and predicting response to medications, and the development of antiviral intervention for those patients may improve their prognosis.

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.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.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).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.

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-β. 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-β. Surprisingly, addition of TGF-β induced a set of genes, including Slc28a2, Tubb2a, and Cpe, that were expressed preferentially in fetal IECs. Moreover, TGF-β 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.

Inflammatory bowel disease (IBD) consists of two major idiopathic gastrointestinal diseases: ulcerative colitis and Crohn's disease. Although a significant advance has been achieved in the treatment of IBD, there remains a particular population of patients that are refractory to the conventional treatments, including the biologic agents. Studies have revealed the importance of “mucosal healing” in improving the prognosis of those difficult-to-treat patients, which indicates the proper and complete regeneration of the damaged intestinal tissue. In this regard, organoid-based regenerative medicine may have the potential to dramatically promote the achievement of mucosal healing in refractory IBD patients, and thereby improve their long-term prognosis as well. So far, studies have shown that hematopoietic stem cells (HSCs) and mesenchymal stem cells (MSCs) may have some beneficial effect on IBD patients through their transplantation or transfusion. Recent advance in stem cell biology has added intestinal stem cells (ISCs) as a new player in this field. It has been shown that ISCs can be grown in vitro as organoids and that those ex-vivo cultured organoids can be employed as donor cells for transplantation studies. Further studies using mice colitis models have shown that ex-vivo cultured organoids can engraft onto the colitic ulcers and reconstruct the crypt-villus structures. Such transplantation of organoids may not only facilitate the regeneration of the refractory ulcers that may persist in IBD patients but may also reduce the risk of developing colitis-associated cancers. Endoscopy-assisted transplantation of organoids may, therefore, become one of the alternative therapies for refractory IBD patients. Keywords: Intestinal stem cells, Organoids, Ulcerative colitis, Crohn's disease, Organoid medicine

Inflammatory bowel disease (IBD) is an idiopathic, multi-etiological disease characterized by inflammation and mucosal destruction of the gastrointestinal tract. Despite the remarkable advance in immunomodulating therapies, there still remains a certain population of patients who are refractory to conventional as well as biologic therapies and fail to achieve mucosal healing. To improve the prognosis of those patients, at least 2 types of stem cells have been tested for their potential therapeutic use. Transplantation of hematopoietic stem cells or mesenchymal stem cells have been tested in several clinical studies, but their beneficial effect still remains controversial. In this review, we would like to overview the recent clinical challenges of stem cell-based therapies in IBD and also introduce our new therapeutic plan of intestinal stem cell transplantation for IBD, based on our ex vivo intestinal organoid culture technique.

Notch signaling is activated in the intestinal epithelial cells (IECs) of patients with inflammatory bowel disease (IBD), and contributes to mucosal regeneration. Our previous study indicated that TNF-α and Notch signaling may synergistically promote the expression of the intestinal stem cell (ISC) marker OLFM4 in human IECs. In the present study, we investigated the gene regulation and function of OLFM4 in human IEC lines. We confirmed that TNF-α and Notch synergistically upregulate the mRNA expression of OLFM4. Luciferase reporter assay showed that OLFM4 transcription is regulated by the synergy of TNF-α and Notch. At the protein level, synergy between TNF-α and Notch promoted cytoplasmic accumulation of OLFM4, which has potential anti-apoptotic properties in human IECs. Analysis of patient-derived tissues and organoids consistently showed cytoplasmic accumulation of OLFM4 in response to NF-κB and Notch activation. Cytoplasmic accumulation of OLFM4 in human IECs is tightly regulated by Notch and TNF-α in synergy. Such cytoplasmic accumulation of OLFM4 may have a cell-protective role in the inflamed mucosa of patients with IBD., Highlights • Notch and TNF-α signaling is important in IECs of patients with IBD. • Notch and TNF-α signaling promotes the cytoplasmic accumulation of OLFM4. • OLFM4 accumulation may have anti-apoptotic properties. • OLFM4 could protect against mucosal inflammation in IBD.

Mucosal healing is an important treatment target in patients with ulcerative colitis.To explore the optimal colonoscopic strategy to determine the risk for clinical relapse in patients with ulcerative colitis.We enrolled 325 consecutive patients with ulcerative colitis in clinical and biochemical remission from April 2018 to March 2019. Five colonic segments were endoscopically and histologically assessed systematically. For endoscopic evaluation, we used three different modes of the Ulcerative Colitis Endoscopic Index of Severity (UCEIS): "original," "worst affected," and "pancolonic." The Geboes score was used for histological evaluation. We prospectively followed up the patients and defined clinical relapse as the primary endpoint.Within 1 year after colonoscopy, 18.2% of patients experienced a clinical relapse. Receiver operating characteristic curve analysis showed areas under the curve of 0.755, 0.817, and 0.852 for the "original," "worst affected," and "pancolonic" groups, respectively; hence, pancolonic UCEIS obtained the highest predictive value. Using the pancolonic UCEIS cutoff value of 3, Kaplan-Meier curve analysis showed that patients with endoscopic activity had a significantly lower relapse-free rate than those with endoscopic remission (P 0.01). Multivariate analysis demonstrated endoscopic (pancolonic UCEIS3) and histological (Geboes3.0) activities as independent risks for relapse (HR: 3.96 and 3.48, respectively). Combining pancolonic UCEIS ≤3 and Geboes score ≤3.0 to provide 1-year relapse avoidance was 92.0% sensitive and 97.0% specific.Evaluating disease remission by complete colonoscopy is relevant, and the combination of pancolonic endoscopic and histological evaluations may appropriately evaluate mucosal healing.

Although 5-aminosalicylate (5-ASA) is the therapy of first choice in ulcerative colitis (UC), some patients cannot tolerate it because of side effects. Previous reports have not investigated whether 5-ASA intolerance is associated with the risk of colectomy.To investigate the associations between 5-ASA tolerance and colectomy among UC patients METHODS: The data of UC patients who visited any of three hospitals during 2014-2018 in and around Tokyo, Japan, were retrospectively obtained from the medical records. Patients were categorized as (a) tolerant to any 5-ASA compounds ("tolerant to 5-ASA") and (b) patients who were intolerant to one or more 5-ASA compounds leading to refrainment from their further use ("intolerant to 5-ASA"). The association between 5-ASA tolerance and colectomy was examined by Cox proportional hazards model adjusted for sex, age, smoking and extent of colitis.Of 1788 patients, 1684 were "tolerant to 5-ASA" while 104 were "intolerant to 5-ASA". Colectomy was performed in 43 (2.6%) of the patients tolerant to 5-ASA and 12 (11.5%) of the patients intolerant to 5-ASA. After adjusting for all covariates, the risk of undergoing colectomy was higher in the "intolerant to 5-ASA" group than in the "tolerant to 5-ASA" group (hazard ratio: 4.92; 95% confidence interval: 2.58-9.38).Patients in whom 5-ASA was discontinued due to intolerance had a higher risk of undergoing colectomy than patients tolerant to their first, second or third 5-ASA compounds.

Background and aims The intestinal epithelium of inflammatory bowel disease [IBD] patients is exposed to various pro-inflammatory cytokines, most notably tumour necrosis factor alpha [TNF-α]. We have previously shown that the Notch signalling pathway is also upregulated in such an epithelium, contributing to intestinal epithelial cell [IEC] proliferation and regeneration. We aimed to reproduce such environment in vitro and explore the gene regulation involved. Methods Human IEC cell lines or patient-derived organoids were used to analyse Notch- and TNF-α-dependent gene expression. Immunohistochemistry was performed to analyse expression of ubiquitin D [UBD] in various patient-derived intestinal tissues. Results In human IEC cell lines, we found that Notch signalling and TNF-α-induced NFκB signalling are reciprocally regulated to promote expression of a specific gene subset. Global gene expression analysis identified UBD to be one of the most highly upregulated genes, due to synergy of Notch and TNF-α. The synergistic expression of UBD was regulated at the transcriptional level, whereas the UBD protein had an extremely short half-life due to post-translational, proteasomal degradation. In uninflamed intestinal tissues from IBD patients, UBD expression was limited to IECs residing at the crypt bottom. In contrast, UBD-expressing IECs were seen throughout the crypt in inflamed tissues, indicating substantial induction by the local inflammatory environment. Analysis using patient-derived organoids consistently confirmed conserved Notch- and TNF-α-dependent expression of UBD. Notably, post-infliximab [IFX] downregulation of UBD reflected favourable outcome in IBD patients. Conclusion We propose that UBD is a novel inflammatory-phase protein expressed in IECs, with a highly rapid responsiveness to anti-TNF-α treatment.

Background Intestinal stem cells (ISCs) play indispensable roles in the maintenance of homeostasis, and also in the regeneration of the damaged intestinal epithelia. However, whether the inflammatory environment of Crohn’s disease (CD) affects properties of resident small intestinal stem cells remain uncertain. Methods CD patient-derived small intestinal organoids were established from enteroscopic biopsy specimens taken from active lesions (aCD-SIO), or from mucosa under remission (rCD-SIO). Expression of ISC-marker genes in those organoids was examined by immunohistochemistry, and also by microfluid-based single-cell multiplex gene expression analysis. The ISC-specific function of organoid cells was evaluated using a single-cell organoid reformation assay. Results ISC-marker genes, OLFM4 and SLC12A2, were expressed by an increased number of small intestinal epithelial cells in the active lesion of CD. aCD-SIOs, rCD-SIOs or those of non-IBD controls (NI-SIOs) were successfully established from 9 patients. Immunohistochemistry showed a comparable level of OLFM4 and SLC12A2 expression in all organoids. Single-cell gene expression data of 12 ISC-markers were acquired from a total of 1215 cells. t-distributed stochastic neighbor embedding analysis identified clusters of candidate ISCs, and also revealed a distinct expression pattern of SMOC2 and LGR5 in ISC-cluster classified cells derived from aCD-SIOs. Single-cell organoid reformation assays showed significantly higher reformation efficiency by the cells of the aCD-SIOs compared with that of cells from NI-SIOs. Conclusions aCD-SIOs harbor ISCs with modified marker expression profiles, and also with high organoid reformation ability. Results suggest modification of small intestinal stem cell properties by unidentified factors in the inflammatory environment of CD. Electronic supplementary material The online version of this article (10.1007/s00535-018-1437-3) contains supplementary material, which is available to authorized users.

Summary ATOH1 is a master transcription factor for the secretory lineage differentiation of intestinal epithelial cells (IECs). However, the comprehensive contribution of ATOH1+ secretory lineage IECs to the homeostasis, repair, and tumorigenesis of the intestinal epithelium remains uncertain. Through our ATOH1+ cell-lineage tracing, we show here that a definite number of ATOH1+ IECs retain stem cell properties and can form ATOH1+IEC-derived clonal ribbons (ATOH1+ICRs) under completely homeostatic conditions. Interestingly, colonic ATOH1+ IECs appeared to exhibit their stem cell function more frequently compared with those of the small intestine. Consistently, the formation of ATOH1+ICRs was significantly enhanced upon dextran sodium sulfate colitis-induced mucosal damage. In addition, colonic ATOH1+ IECs acquired tumor stem cell-like properties in the azoxymethane-DSS tumor model. Our results reveal an unexpected contribution of colonic ATOH1+ IECs to maintaining the stem cell population under both homeostatic and pathologic conditions and further illustrate the high plasticity of the crypt-intrinsic stem cell hierarchy., Graphical Abstract, Highlights • Intestinal ATOH1+ cells can exhibit stem cell properties under homeostatic conditions • Recruitment of ATOH1+ cell-derived stem cells is enhanced by inflammation • Cell-intrinsic NF-kB signaling promotes generation of ATOH1+ cell-derived stem cells • ATOH1+ tumor stem cells contribute to the development of colitis-associated tumors, Ishibashi et al. report the contribution of ATOH1+ intestinal epithelial cells to the maintenance, regeneration, and tumorigenesis in the colon. They find that a definite number of ATOH1+ intestinal epithelial cells retain stem cell properties under homeostatic conditions. Also, generation of ATOH1+ cell-derived stem cells is significantly enhanced by the inflammatory environment and contributes to the development of colitis-associated tumors.

The data on the immunohistochemical analysis of conditional Notch ligand knockout mice is presented. Targeted deletion of Jag1, Dll1, Dll4, or Dll1 plus Dll4 in Lgr5+ve cells was induced by a Cre-mediated gene recombination, and differentiation or proliferation of the intestinal epithelial cells was examined by immunohistochemistry. These data are the extension of the data presented and discussed in the paper entitled "Indispensable role of non-canonical Notch signaling in the proliferation of Apc-deficient intestinal tumors" (Nakata et al., Submitted for publication) [1].

Background 5-Aminosalicylates (5-ASA) are the key drugs in induction and maintenance therapy in ulcerative colitis (UC). Some UC patients are involved in 5-ASA intolerance after induction of oral 5-ASA compounds. There is no evidence of the prognosis including the risk of colectomy in 5-ASA intolerant UC patients. Methods The aim of this study is to establish the prognosis of 5-ASA intolerant UC patients in a multicenter cohort study. A retrospective review of a prospective multicenter database (2014–2018) of 1,574 UC patients was carried out and a total of 1,286 patients treated with oral 5-ASA compounds were enrolled. We compared the risk of colectomy and biologics induction between patients (i) tolerant to first 5-ASA compound (1079), (ii) intolerant to first 5-ASA compound but tolerant to other 5-ASA compound (107) and (iii) intolerant to 5-ASA compound and withdrawal of 5-ASA (100). Results We identified 1,286 patients with UC, of which 40 patients (3.1%) resulted in colectomy and 247 patients (19%) treated with biologics. Colectomy rate in patients (iii) intolerant to 5-ASA and withdrawal of 5-ASA were higher than (i) tolerant to first 5-ASA and (ii) intolerant to first 5-ASA but tolerant to other 5-ASA (9.0%, 2.7%, 1.9%, respectively). (iii) Patients withdrawal of 5-ASA showed higher risk of colectomy compared with (i) tolerant to first 5-ASA (Hazard ratio (HR) 4.71, 95% Confidence interval (CI): 2.04–10.8). The risk of colectomy among (ii) patients intolerant to first 5-ASA but tolerant to other 5-ASA showed no significant difference compared with (i) tolerant to first 5-ASA (HR 0.76, 95% CI: 0.43–1.35). The biologics induction rate in (iii) patients withdrawal of 5-ASA was significantly higher than (i) tolerant to first 5-ASA and (ii) intolerant to first 5-ASA but tolerant to other 5-ASA (37%, 18%, 16%, respectively). Also (iii) patients withdrawal of 5-ASA showed higher risk of induction with biologics compared with (i) tolerant to first 5-ASA (HR 2.35, 95% CI: 1.50–3.68). Those risk among (ii) patients intolerant to first 5-ASA but tolerant to other 5-ASA showed no significant difference compared with (i) tolerant to first 5-ASA (HR 0.76, 95% CI: 0.43–1.35). Conclusion Patients with UC who had 5-ASA intolerance and withdrew from 5-ASA showed poor prognosis. We should consider trying other 5-ASA compounds even if the patients had intolerance to one 5-ASA compound.

A20 (TNFAIP3) and ABIN-1 (TNIP1), two candidate inflammatory bowel disease (IBD) susceptibility genes, preserve intestinal homeostasis by cooperatively restricting intestinal epithelial cell death. A20 and ABIN-1 synergistically restrict both TNF-dependent and TNF-independent cell death., A20 (TNFAIP3) and ABIN-1 (TNIP1) are candidate susceptibility genes for inflammatory bowel disease and other autoimmune or inflammatory diseases, but it is unclear how these proteins interact in vivo to prevent disease. Here we show that intestinal epithelial cell (IEC)-specific deletion of either A20 or ABIN-1 alone leads to negligible IEC loss, whereas simultaneous deletion of both A20 and ABIN-1 leads to rapid IEC death and mouse lethality. Deletion of both A20 and ABIN-1 from enteroids causes spontaneous cell death in the absence of microbes or hematopoietic cells. Studies with enteroids reveal that A20 and ABIN-1 synergistically restrict death by inhibiting TNF-induced caspase 8 activation and RIPK1 kinase activity. Inhibition of RIPK1 kinase activity alone, or caspase inhibition combined with RIPK3 deletion, abrogates IEC death by blocking both apoptosis and necroptosis in A20 and ABIN-1 double-deficient cells. These data show that the disease susceptibility proteins A20 and ABIN-1 synergistically prevent intestinal inflammation by restricting IEC death and preserving tissue integrity.

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.

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 β-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)1β+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;)

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.

Intestinal epithelial cells (IECs) play an indispensable role in maintaining body fluid balance partly through their ability to regulate anion/fluid secretion. Yet in various inflammatory gastrointestinal diseases, over-secretion of anions results in symptoms such as severe diarrhoea. Endogenous mediators, such as vasoactive intestinal peptide or prostaglandin E2 (PGE2), regulate intestinal anion/fluid secretion, but their direct effect on purified human IECs has never been described in detail. Based on a previously described intestinal organoid swelling model, we established a 3D-scanner-assisted quantification method to evaluate the anion/fluid secretory response of cultured human IECs. Among various endogenous secretagogues, we found that PGE2 had the lowest EC50 value with regard to the induction of swelling of the jejunal and colonic organoids. This PGE2-mediated swelling response was dependent on environmental Cl− concentrations as well as on several channels and transporters as shown by a series of chemical inhibitor studies. The concomitant presence of various inflammatory cytokines with PGE2 failed to modulate the PGE2-mediated organoid swelling response. Therefore, the present study features PGE2 as a direct and robust mediator of anion/fluid secretion by IECs in the human intestine.

Intestinal epithelial cells (IECs) play an indispensable role in maintaining body fluid balance partly through their ability to regulate anion/fluid secretion. Yet in various inflammatory gastrointestinal diseases, over-secretion of anions results in symptoms such as severe diarrhoea. Endogenous mediators, such as vasoactive intestinal peptide or prostaglandin E2 (PGE2), regulate intestinal anion/fluid secretion, but their direct effect on purified human IECs has never been described in detail. Based on a previously described intestinal organoid swelling model, we established a 3D-scanner-assisted quantification method to evaluate the anion/fluid secretory response of cultured human IECs. Among various endogenous secretagogues, we found that PGE2 had the lowest EC50 value with regard to the induction of swelling of the jejunal and colonic organoids. This PGE2-mediated swelling response was dependent on environmental Cl− concentrations as well as on several channels and transporters as shown by a series of chemical inhibitor studies. The concomitant presence of various inflammatory cytokines with PGE2 failed to modulate the PGE2-mediated organoid swelling response. Therefore, the present study features PGE2 as a direct and robust mediator of anion/fluid secretion by IECs in the human intestine.

Salmonella phosphothreonine lyase SpvC inactivates the dual-phosphorylated host mitogen-activated protein kinases (MAPK) through β-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.

This study investigated the effects of administering vitamin E and selenium to pregnant heavy draft horsemares on the incidence of retained placenta and postpartum reproductive performance and on the prevention of the white muscle disease in their foals. In study A, 1,000 mg of vitamin E and 50 mg of selenium (E-SE 20 mL) were given to 22 mares 3 weeks before expected parturition (335 days counted from last mating), whereas 28 mares were used as controls. In study B, E-SE were administered 2 weeks before expected parturition at 2 dose levels, with 25 mares receiving 20 mL E-SE, 19 mares receiving 10 mL, and 29 mares kept as controls. Vitamin E and selenium were assayed in serum collected from some of the mares before administration of E-SE and again postpartum and from the foals immediately after birth. Serum selenium concentrations before E-SE administration were deficient ( 300 g/mL, P = .05). We conclude that maintaining high level serum vitamin E and selenium concentrations of prepartum mares is expected to increase fertility of selenium-deficient mares. Therefore, the regimen of vitamin E and selenium administrations to selenium deficient mares should be developed.

application/pdf, The aims of this study were to determine the relationship (1) between oxytocin release during parturition especially during the third stage of labor and placenta! retention time, and (2) between hand-milking or suckling and oxytocin release after foaling. Blood was sampled every 5 min from foaling to expulsion of the placenta in 9 heavy draft mares to evaluate circulating oxytocin. The relationship between the oxytocin concentration and recorded placental retention, hand milking and suckling times were investigated. Results: (1) High peak of oxytocin concentration observed around foaling in 7 mares. (2) Peaks of oxytocin were observed after expulsion of the placenta and suckling or after hand-milking about 2 hr after foaling in 2 mares. (3) The mean oxytocin concentration in mares which, had a shorter placental retention time (i.e.1 hr). (4) A significant negative correlation was observed between oxytocin concentrations immediately after foaling and placental retention times. (5) Oxytocin increased distinctly after hand-milking and suckling in 2 mares. The response was most extensive in the mare, which had the lowest oxytocin concentration immediately after foaling and the longest placental retention time. In conclusion, the oxytocin concentration immediately after foaling is negatively related to the placental retention time. Low circulating oxytocin immediately after foaling may result in placental retention.