A Cre-driven allele-conditioning line to interrogate CD4+ conventional T cells.

CD4+ T cells share common developmental pathways with CD8+ T cells, and upon maturation, CD4+ T conventional T (Tconv) cells lack phenotypic markers that distinguish these cells from FoxP3+ T regulatory cells. We developed a tamoxifen-inducible ThPOKCreERT2.hCD2 line with Frt sites inserted on either side of the CreERT2-hCD2 cassette, and a Foxp3Ametrine-FlpO strain, expressing Ametrine and FlpO in Foxp3+ cells. Breeding these mice resulted in a CD4conviCreERT2-hCD2 line that allows for the specific manipulation of a gene in CD4+ Tconv cells. As FlpO removes the CreERT2-hCD2 cassette, CD4+ Treg cells are spared from Cre activity, which we refer to as allele conditioning. Comparison with an E8IiCreERT2.GFP mouse that enables inducible targeting of CD8+ T cells, and deletion of two inhibitory receptors, PD-1 and LAG-3, in a melanoma model, support the fidelity of these lines. These engineered mouse strains present a resource for the temporal manipulation of genes in CD4+ T cells and CD4+ Tconv cells.

Conventional versus underwater endoscopic resection for superficial non-ampullary duodenal epithelial tumours.

BACKGROUND AND OBJECTIVE: Several endoscopic resection methods have been developed as less invasive treatments for superficial non-ampullary duodenal epithelial tumours. This study aimed to compare outcomes of conventional endoscopic mucosal resection and underwater endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumours, including resection depth and rate of the muscularis mucosa contained under the lesion. METHODS: This single-centre retrospective cohort study conducted from January 2009 to December 2021 enrolled patients who underwent conventional endoscopic mucosal resection and underwater endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumours and investigated their clinicopathological outcomes using propensity score matching. RESULTS: Of the 285 superficial non-ampullary duodenal epithelial tumours, 98 conventional endoscopic mucosal resections and 187 underwater endoscopic mucosal resections were included. After propensity score matching, 64 conventional endoscopic mucosal resections and 64 underwater endoscopic mucosal resections were analysed. The R0 resection rate was significantly higher in underwater endoscopic mucosal resection cases than in conventional endoscopic mucosal resection cases (70.3% vs. 50.0%; P = 0.030). In the multivariate analysis, a lesion diameter > 10 mm (odds ratio 7.246; P = 0.001), being in the 1st-50th treatment period (odds ratio 3.405; P = 0.008), and undergoing conventional endoscopic mucosal resection (odds ratio 3.617; P = 0.016) were associated with RX/R1 resection. Furthermore, in underwater endoscopic mucosal resection cases, the R0 rate was significantly higher for lesions diameter ≤10 mm than >10 mm, and was significantly higher in the 51st-treatment period than in the 1st-50th period. Conventional endoscopic mucosal resection and underwater endoscopic mucosal resection cases showed no significant difference in resection depth and muscularis mucosa containing rate. CONCLUSIONS: Underwater endoscopic mucosal resection may be more acceptable than conventional endoscopic mucosal resection for superficial non-ampullary duodenal epithelial tumours ≤ 10 mm. A steep early learning curve may be acquired for underwater endoscopic mucosal resection. Large multicentre prospective studies need to be conducted to confirm the effectiveness of underwater endoscopic mucosal resection.

Short- and long-term outcomes of endoscopic submucosal dissection and laparoscopic and endoscopic cooperative surgery for superficial non-ampullary duodenal epithelial tumors.

BACKGROUND AND AIMS: This retrospective study aimed to compare the short- and long-term outcomes of endoscopic submucosal dissection and laparoscopic and endoscopic cooperative surgery in patients with superficial non-ampullary duodenal epithelial tumors. PATIENTS AND METHODS: We investigated consecutive patients with SNADETs > 10 mm in size who underwent ESD (ESD group) or LECS (LECS group) between January 2015 and March 2021. The data was used to analyze the clinical course, management, survival status, and recurrence between the two groups. RESULTS: A total of 113 patients (100 and 13 in the ESD and LECS groups, respectively) were investigated. The rates of en bloc resection and curative resection were 100% vs. 100% and 93.0% vs. 77.0% in the ESD and LECS groups, respectively, with no significant difference. The ESD group had shorter resection and suturing times than the LECS group, but there were no significant difference after propensity score matching. There were also no differences in the rates of postoperative adverse event (7.0% vs. 23.1%; P = 0.161). The 3-year overall survival (OS) rate was high in both the ESD and LECS groups (97.6% vs. 100%; P = 0.334). One patient in the ESD group experienced recurrence due to liver metastasis; however, no deaths related to SNADETs were observed. CONCLUSION: ESD and LECS are both acceptable treatments for SNADETs in terms of a high OS rate and a low long-term recurrence rate, thereby achieving a comparable high rate of curative resection. Further studies are necessary to compare the outcomes of ESD and LECS for SNADETs once both techniques are developed further.

Efficacy of Glycicumarin and Isoliquiritigenin in Suppressing Colonic Peristalsis in Both an Animal Model and a Clinical Trial.

Patients with diarrhea-predominant irritable bowel syndrome (IBS-D) show excessive peristalsis, and antispasmodic agents may be useful therapeutic agents. There are few reports on the use of Kampo medicines for the treatment of IBS-D. Shakuyakukanzoto (SKT) is a Kampo medicine that is effective against abdominal pain. We examined the relationship between SKT and intestinal peristalsis in an animal model and a prospective study. In the animal model, SKT and its components were administered from the serosal side of the colon and colonic peristalsis was evaluated using intraluminal pressure and spatiotemporal mapping before and after the administration of SKT and its components. In this clinical trial, we used abdominal ultrasonography (US) to obtain long-axis images of the sigmoid colon of 11 patients. The frequency of intestinal peristalsis was measured using US in five patients with SKT and six patients without medication after the ingestion of a test meal. The primary outcome was the frequency of peristalsis. The Clinical Trial Registry Website (Trial No. UMIN-CTR; UMIN000051547). In the animal model, peony did not suppress peristalsis frequency, but SKT (p = 0.005) and glycyrrhiza (p = 0.001) significantly suppressed peristalsis frequency compared with saline and peony. Among the glycyrrhiza components, glycycoumarin and isoliquiritigenin suppressed the peristalsis frequency compared to dimethyl sulfoxide (control) (p = 0.001, 0.01, respectively). In a clinical trial, peristalsis was significantly suppressed after oral administration in patients taking SKT (p = 0.03). Administration of SKT was found to inhibit colonic peristalsis, with glycicumarin and isoliquiritigenin being particularly relevant among its components.

Risk and prognostic factors of invasive gastric cancer detection during surveillance endoscopy: Multi-institutional cross-sectional study.

OBJECTIVES: Esophagogastroduodenoscopy (EGD) is important for the detection of curable gastric cancer (GC). However, there are no appropriate surveillance data during routine endoscopic inspections. This study aimed to clarify the risk factors of pT1b or deeper GC detection during surveillance endoscopy. METHODS: This was a retrospective, multicenter, cross-sectional study conducted in 15 Japanese hospitals. We retrospectively analyzed patients with GC who had previously undergone surveillance endoscopy at each institution from January 2014 to March 2020. Patients who had undergone gastrectomy, non-infection of Helicobacter pylori (Hp), and those with intervals <3 months or >10 years from a previous endoscopy were excluded. RESULTS: In total, 1085 patients with GCs detected during surveillance endoscopy were enrolled. The multivariate logistic analysis revealed that current Hp infection (odds ratio [OR] 2.18; 95% confidence interval [CI] 1.50-3.16) and a surveillance interval of >1.5 years (OR 1.96; 95% CI 1.35-2.84) were independent risk factors for pT1b or deeper GC. The 5-year disease-specific survival (5y-DSS) rate of GC was significantly lower in patients with surveillance interval of >1.5 years than in those with surveillance interval of ≤1.5 years (93.7% vs. 98.3%, P < 0.001). Similarly, the 5y-DSS rate of GC was significantly lower in patients with active Hp infection than in those without (93.7% vs. 99.4%, P < 0.001). CONCLUSION: In this study, a surveillance interval of >1.5 years and current Hp infection were independent risk factors for detecting pT1b or deeper GC. Additionally, these factors were poor prognostic factors of the detected GC during surveillance endoscopy.

[A case report:the progress of fascioliasis from hepatic phase to biliary phase].

This is a case report of fascioliasis that progressed from the hepatic to the biliary phases over 2 years. A woman in her late 60s ate Zingiber mioga from the field, which was followed by abdominal pain that occurred 1 month later. Although CT and MRI studies revealed an increase in blood eosinophils as well as multiple hepatic nodules, they vanished quickly. After 2 years, an MRCP study revealed multiple flat lesions, which were diagnosed as adult fascioliasis. Definitive diagnosis was provided by enzyme-labeled antibody method using fasciola-specific antigen. Triclabendazole was administered once to complete the treatment.

Lycopene intake induces colonic regulatory T cells in mice and suppresses food allergy symptoms.

BACKGROUND: Food allergy (FA) is a common disease in children; thus, a high level of safety is required for its prevention and treatment. Colonic regulatory T cells (Tregs) have been suggested to attenuate FA. We investigated the Treg-inducing ability and anti-FA effects of carotenoids, a pigment contained in vegetables and fruits. METHODS: C57BL/6N mice were fed a diet containing 0.01% (w/w) of lycopene, ß-carotene, astaxanthin or lutein for 4 weeks, and the population of colonic Tregs was assessed. Subsequently, to evaluate the Treg-inducing ability of lycopene, splenic naïve CD4+ T cells from BALB/c mice were cultured with anti-CD3/CD28 antibody, TGF-ß and lycopene, and the frequencies of Tregs were examined. The effect of 0.1% (w/w) lycopene containing diet on FA was investigated in OVA-induced FA model BALB/c mice. RESULTS: In screening, only lycopene significantly increased the frequency and number of colonic Tregs. Lycopene also increased Treg differentiation in splenic naïve CD4+ T cells. In FA mice, lycopene feeding significantly increased the number of colonic Tregs and attenuated allergic symptoms. The expression levels of IL-4, IL-9 and IL-13 mRNA in colonic mucosa were also significantly reduced by lycopene. IL-9 is known to induce proliferation of mast cells, and we found that lycopene feeding significantly reduced the number of mast cells in the colonic mucosa of FA mice. CONCLUSION: Our results suggest that lycopene, a carotenoid present in many common foods on the market, may have the potential to induce colonic Tregs and suppress FA symptoms.

Endoscopic Submucosal Dissection for Early Gastric Cancer in Patients Aged 85 Years Old or Older Is Associated with a Good Prognosis Compared to Conservative Treatment without Any Invasive Procedure.

INTRODUCTION: Studies have reported the feasibility of endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) in elderly people with respect to both short- and long-term outcomes. As the elderly population in society increases, the requirement for managing super-elderly patients aged ≥85 years with EGC will also increase. This study aims to identify the long-term clinical outcomes of ESD for clinical T1N0 EGC in patients aged ≥85 years. METHODS: A total of 370 consecutive patients aged ≥85 years with clinical T1N0 EGC who were managed in 11 institutions were reviewed retrospectively. On the basis of treatment strategy, we compared the overall survival (OS) and disease-specific survival (DSS) after performing propensity score-matched analysis between patients undergoing ESD (ESD group) and those not undergoing treatment (conservative treatment group). The potential prognostic factors were also investigated in the propensity score-matched patients. RESULTS: After propensity score matching, we found that the 3-year OS and DSS rates were significantly higher in the ESD group than in the conservative treatment group (OS, 82.2% vs. 50.5%; p < 0.001; DSS, 100% vs. 80.1%; p = 0.008). Furthermore, ESD was identified as a significant factor for prolonged OS, whereas Charlson comorbidity index (CCI) ≥3 and prognostic nutritional index (PNI) <36.2 were associated with reduced OS. CONCLUSION: ESD was associated with improved OS in patients with clinical T1N0 EGC aged ≥85 years compared with the absence of treatment. Furthermore, CCI and PNI were helpful for patient selection.

Prognostic risk factors associated with esophageal squamous cell carcinoma patients undergoing endoscopic submucosal dissection: a multi-center cohort study.

BACKGROUND: Long-term outcomes of endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma (ESCC) have not been assessed in a large, multicenter cohort. We aimed to evaluate long-term outcomes of ESD for ESCC in a real-world setting. METHODS: We retrospectively recruited 659 patients who underwent ESD for ESCC at ten institutions from January 2007 to December 2015. Of these, 566 patients were analyzed and classified into three groups according to the pathologic invasion depth after ESD: epithelium/lamina propria mucosa (EP/LPM group: 454 patients), muscularis mucosa/submucosa invasion ≤ 200 µm below the inferior margin of the muscularis mucosa (MM/SM1 group: 81 patients), and submucosa invasion > 200 µm below the MM inferior margin (SM2 group: 31 patients). RESULTS: The 5-year overall survival rates in the EP/LPM, MM/SM1, and SM2 groups were 92.6%, 80.0%, and 62.7%, respectively, while the 5-year disease-specific survival rates were 99.7%, 96.9%, and 88.3%, respectively. Multivariate analyses revealed that the invasion depth, Charlson Comorbidity Index (CCI), and prognostic nutritional index (PNI) were independent prognostic factors. Hazard ratios in the MM/SM1 and SM2 groups were 2.25 (95% confidence interval [CI] 1.04-4.83; P = 0.038) and 3.18 (95% CI 1.08-9.34; P = 0.036), respectively, compared to those in the EP/LPM group, while those for patients with a CCI ≥ 3 and PNI ≤ 47.75 were 3.25 (95% CI 1.79-5.89; P < 0.001) and 2.42 (95% CI 1.26-4.65; P = 0.008), respectively. CONCLUSIONS: This study identified that invasion depth, presence of comorbid diseases and preoperative nutritional status are independent prognostic risk factors associated with ESCC patients undergoing ESD.

A cytokine network involving IL-36γ, IL-23, and IL-22 promotes antimicrobial defense and recovery from intestinal barrier damage.

The gut epithelium acts to separate host immune cells from unrestricted interactions with the microbiota and other environmental stimuli. In response to epithelial damage or dysfunction, immune cells are activated to produce interleukin (IL)-22, which is involved in repair and protection of barrier surfaces. However, the specific pathways leading to IL-22 and associated antimicrobial peptide (AMP) production in response to intestinal tissue damage remain incompletely understood. Here, we define a critical IL-36/IL-23/IL-22 cytokine network that is instrumental for AMP production and host defense. Using a murine model of intestinal damage and repair, we show that IL-36γ is a potent inducer of IL-23 both in vitro and in vivo. IL-36γ-induced IL-23 required Notch2-dependent (CD11b+CD103+) dendritic cells (DCs), but not Batf3-dependent (CD11b-CD103+) DCs or CSF1R-dependent macrophages. The intracellular signaling cascade linking IL-36 receptor (IL-36R) to IL-23 production by DCs involved MyD88 and the NF-κB subunits c-Rel and p50. Consistent with in vitro observations, IL-36R- and IL-36γ-deficient mice exhibited dramatically reduced IL-23, IL-22, and AMP levels, and consequently failed to recover from acute intestinal damage. Interestingly, impaired recovery of mice deficient in IL-36R or IL-36γ could be rescued by treatment with exogenous IL-23. This recovery was accompanied by a restoration of IL-22 and AMP expression in the colon. Collectively, these data define a cytokine network involving IL-36γ, IL-23, and IL-22 that is activated in response to intestinal barrier damage and involved in providing critical host defense.

Higher Levels of Streptococcus in Upper Gastrointestinal Mucosa Associated with Symptoms in Patients with Functional Dyspepsia.

BACKGROUND: Functional dyspepsia (FD) is associated with poor health-related quality of life. Recent evidence suggests that the main pathogenesis suspect is the gut mucosa-associated microbiota (MAM). However, little is known about the MAM in FD subjects. The aim of this study was to clarify the relationship between upper gastrointestinal symptoms in FD and the characteristics of the gastrointestinal MAM. SUMMARY: Five mucosa samples from the upper gut (intraoral, mid-esophagus, gastric body, gastric antrum, and descending portion of the duodenum) were collected with a brush under endoscopic examination from FD and healthy control subjects. MAM profiles of each sample were analyzed by 16S-rRNA -V3-V4 gene sequences. Questionnaire was used to assess gastrointestinal symptoms in FD. Between FD and healthy control subjects, although the comparison of MAM α-diversity showed no significant differences, the structure of MAM (ß-diversity) was clearly different. Only the phylum Firmicutes was increased in FD compared to healthy control subjects in all sites of the upper gut. At the genus level, Streptococcus was significantly increased in all sites in the upper gut in FD. The relative abundance of Streptococcus was positively correlated with upper gastrointestinal symptoms in each upper gut group. Furthermore, the relative abundance of OTU 90 was positively correlated with upper gastrointestinal symptoms in all sites in the upper gut in FD. Key Messages: Streptococcus is a bacterium strongly correlated with upper gastrointestinal symptoms in FD.

Insights on the impact of diet-mediated microbiota alterations on immunity and diseases.

The intestinal tract is inhabited by a large and diverse community of bacteria collectively referred to as the gut microbiota. The intestinal microbiota is composed by 500-1000 distinct species, and alterations in its composition are associated with a variety of diseases including obesity, diabetes, and inflammatory bowel disease (IBD). Importantly, microbiota transplantation from diseased patients or mice (IBD, metabolic syndrome, etc.) to germ-free mice was found to be sufficient to transfer some aspects of disease phenotypes, indicating that altered microbiota is playing a direct role in those particular conditions. Moreover, it is now well admitted that the intestinal microbiota is involved in shaping and maturating the immune system, with for example the observation that germ-free animals harbor a poorly developed intestinal immune system and that some single bacteria species, such as segmented filamentous bacteria (SFB), are sufficient to induce the expansion of Th17 cells (CD4+ T helper cells producing IL-17). We will present herein an overview of the interactions occurring between the intestinal microbiota and the immune system, and we will discuss how a dietary-induced disruption of the intestinal environment may influence transplantation outcomes.

Cutting Edge: IL-36 Receptor Promotes Resolution of Intestinal Damage.

IL-1 family members are central mediators of host defense. In this article, we show that the novel IL-1 family member IL-36γ was expressed during experimental colitis and human inflammatory bowel disease. Germ-free mice failed to induce IL-36γ in response to dextran sodium sulfate (DSS)-induced damage, suggesting that gut microbiota are involved in its induction. Surprisingly, IL-36R-deficient (Il1rl2(-/-)) mice exhibited defective recovery following DSS-induced damage and impaired closure of colonic mucosal biopsy wounds, which coincided with impaired neutrophil accumulation in the wound bed. Failure of Il1rl2(-/-) mice to recover from DSS-induced damage was associated with a profound reduction in IL-22 expression, particularly by colonic neutrophils. Defective recovery of Il1rl2(-/-) mice could be rescued by an aryl hydrocarbon receptor agonist, which was sufficient to restore IL-22 expression and promote full recovery from DSS-induced damage. These findings implicate the IL-36/IL-36R axis in the resolution of intestinal mucosal wounds.

Heme oxygenase-1 prevents murine intestinal inflammation.

Heme oxygenases (HOs) are rate-limiting enzymes catabolizing heme to biliverdin, ferrous iron, and carbon monoxide, and of the three HO isoforms identified, HO-1 plays a protective role against inflammatory processes. In this study, we investigated the possible role of HO-1 in intestinal inflammation. Acute colitis was induced in male C57BL/6 (wild-type) and homozygous BTB and CNC homolog 1 (Bach1)-deficient mice, which show high HO-1 expression in the colonic mucosa, using dextran sodium sulfate. The disease activity index, myeloperoxidase activity, and inflammatory cytokines in the colonic mucosa were evaluated 7 days after dextran sodium sulfate-dependent colitis induction. We also evaluated the impact of HO-1 inhibition using zinc protoporphyrin IX (25 mg/kg i.p., daily). After dextran sodium sulfate administration, HO-1 mRNA and protein expression increased in a time-dependent manner. Disease activity index score, myeloperoxidase activity, and colonic production of TNF-α and IFN-γ were increased after dextran sodium sulfate administration, and co-administration of zinc protoporphyrin IX enhanced their increase. In addition, disease activity index in Bach1-deficient was significantly lower after dextran sodium sulfate administration than that in wild type mice. These results indicate that HO-1 plays a protective role against dextran sodium sulfate-induced intestinal inflammation, possibly by regulating pro-inflammatory cytokines in intestinal tissues.

Intestinal Antigen-Presenting Cells: Key Regulators of Immune Homeostasis and Inflammation.

The microbiota that populate the mammalian intestine are critical for proper host physiology, yet simultaneously pose a potential danger. Intestinal antigen-presenting cells, namely macrophages and dendritic cells (DCs), are integral components of the mucosal innate immune system that maintain co-existence with the microbiota in face of this constant threat. Intestinal macrophages and DCs integrate signals from the microenvironment to orchestrate innate and adaptive immune responses that ultimately lead to durable tolerance of the microbiota. Tolerance is not a default response, however, because macrophages and DCs remain poised to vigorously respond to pathogens that breach the epithelial barrier. In this review, we summarize the salient features of macrophages and DCs in the healthy and inflamed intestine and discuss how signals from the microbiota can influence their function.

Preventive effect of agaro-oligosaccharides on non-steroidal anti-inflammatory drug-induced small intestinal injury in mice.

BACKGROUND AND AIM: Non-steroidal anti-inflammatory drugs (NSAIDs), which are commonly used in clinical medicine, cause erosion, ulcers, and bleeding in the gastrointestinal tract. No effective agent for the prevention and treatment of small intestinal injury by NSAIDs has been established. This study investigates the effects of agaro-oligosaccharides (AGOs) on NSAID-induced small intestinal injury in mice. METHODS: Mice were treated with indomethacin, an NSAID, to induce intestinal injury. The respective degrees of mucosal injury of mice that received AGO and control mice were compared. Heme oxygenase-1 (HO-1) expression using quantitative real-time polymerase chain reaction (qRT-PCR), Western blotting, and immunohistochemistry were measured. The expression of keratinocyte chemoattractant (KC) was measured using qRT-PCR and enzyme-linked immunosorbent assay. RESULTS: AGO administration induced HO-1 expression in mouse small intestinal mucosa. Induction was observed mainly in F4/80 positive macrophages. The increased ulcers score, myeloperoxidase activity, and KC expression by indomethacin were inhibited by AGO administration. Conversely, HO inhibitor cancelled AGO-mediated prevention of intestinal injury. In mouse peritoneal macrophages, AGOs enhanced HO-1 expression and suppressed lipopolysaccharide-induced KC expression. Furthermore, AGOs enhanced the expressions of alternatively activated macrophage markers arginase-1, mannose receptor-1, and chitinase 3-like 3. CONCLUSIONS: Results suggest that oral administration of AGOs prevents NSAID-induced intestinal injury.

Hemin ameliorates indomethacin-induced small intestinal injury in mice through the induction of heme oxygenase-1.

BACKGROUND AND AIM: Although non-steroidal anti-inflammatory drugs can induce intestinal injury, the mechanisms are not fully understood, and treatment has yet to be established. Heme oxygenase-1 (HO-1) has recently gained attention for anti-inflammatory and cytoprotective effects. This study aimed to investigate the effects of hemin, an HO-1 inducer, on indomethacin-induced enteritis in mice. METHODS: Enteritis was induced by single subcutaneous administration of indomethacin (10 mg/kg) in male C57BL/6 mice. Hemin (30 mg/kg) was administered by intraperitoneal administration 6 h before indomethacin administration. Mice were randomly divided into four groups: (i) sham + vehicle; (ii) sham + hemin; (iii) indomethacin + vehicle; or (iv) indomethacin + hemin. Enteritis was evaluated by measuring ulcerative lesions. Myeloperoxidase activity was measured as an index of neutrophil accumulation. The mRNA expression of inflammatory cytokines and chemokines, such as tumor necrosis factor-α, monocyte chemoattractant protein-1, macrophage inflammatory protein-1α, and keratinocyte chemoattractant, were analyzed by real-time polymerase chain reaction. RESULTS: The area of ulcerative lesions, myeloperoxidase activity, and mRNA expression of inflammatory cytokines and chemokines were significantly increased in mice administrated with indomethacin compared with vehicle-treated sham mice. Development of intestinal lesions, increased levels of myeloperoxidase activities, and mRNA expressions of inflammatory cytokines and chemokines were significantly suppressed in mice treated with hemin compared with vehicle-treated mice. Protective effects of hemin were reversed by co-administration of tin protoporphyrin, an HO-1 inhibitor. CONCLUSIONS: Induction of HO-1 by hemin inhibits indomethacin-induced intestinal injury through upregulation of HO-1. Pharmacological induction of HO-1 may offer a novel therapeutic strategy to prevent indomethacin-induced small intestinal injury.

Impact of particulate microplastics generated from polyethylene terephthalate on gut pathology and immune microenvironments.

Environmental microplastics have emerged as a critical issue in maintaining the planetary ecosystem. In this study, we generated particulate microplastics from polyethylene terephthalate (PM-PET) and investigated their impact in the gut by using mouse models and implementing histological examinations, as well as multi-omics analysis for colonic immune cells and microbiota. As a result, histological approaches showed that chronic and physiological low dose exposure of PM-PET did not affect intestinal pathology and mucin barriers, respectively. Moreover, immunohistochemical analysis demonstrated that the numbers of T cells, B cells, macrophages, and granulocytes were not affected by the exposure to PM-PET. However, RNA-seq analysis revealed that PM-PET had a substantial impact on the transcriptome in gut immune cells and their metabolisms, while 16s rRNA metagenomic analysis showed that the composition of microbiota was modestly affected. These results suggest an unexpected role played by the PM-PET in affecting gut immune homeostasis without detectable inflammation.

Protocol for acquiring samples to assess the impact of microplastics on immune microenvironments in the mouse intestine.

Environmental nano- and microplastics (NMPs) pose serious environmental issues, yet there is no established technique to assess their impact on health through oral ingestion. Here, we present a protocol to assess the impact of NMPs in the intestinal immune microenvironments by employing chronic exposure to NMPs in a mouse model. We describe steps for administration of NMPs, feces and tissue collection, and colonic gut digestion. We then detail procedures for isolation of intestinal immune cells and RNA isolation. For complete details on the use and execution of this protocol, please refer to Harusato et al.1.

N-acetylglucosamine-6-O sulfation on intestinal mucins prevents obesity and intestinal inflammation by regulating gut microbiota.

Intestinal mucins play an essential role in the defense against bacterial invasion and the maintenance of gut microbiota, which is instrumental in the regulation of host immune systems; hence, its dysregulation is a hallmark of metabolic disease and intestinal inflammation. However, the mechanism by which intestinal mucins control the gut microbiota as well as disease phenotypes remains nebulous. Herein, we report that N-acetylglucosamine (GlcNAc)-6-O sulfation of O-glycans on intestinal mucins performs a protective role against obesity and intestinal inflammation. Chst4-/- mice, lacking GlcNAc-6-O sulfation of the mucin O-glycans, showed significant weight gain and increased susceptibility to dextran sodium sulfate-induced colitis as well as colitis-associated cancer accompanied by significantly reduced immunoglobulin A (IgA) production caused by an impaired T follicular helper cell-mediated IgA response. Interestingly, the protective effects of GlcNAc-6-O sulfation against obesity and intestinal inflammation depend on the gut microbiota, evidenced by the modulation of the gut microbiota by cohousing or microbiota transplantation reversing disease phenotypes and IgA production. Collectively, our findings provide insight into the significance of host glycosylation, more specifically GlcNAc-6-O sulfation on intestinal mucins, in protecting against obesity and intestinal inflammation via regulation of the gut microbiota.