Butyrate Prevents the Pathogenic Anemia-Inflammation Circuit by Facilitating Macrophage Iron Export.

Most patients with inflammatory bowel disease (IBD) develop anemia, which is attributed to the dysregulation of iron metabolism. Reciprocally, impaired iron homeostasis also aggravates inflammation. How this iron-mediated, pathogenic anemia-inflammation crosstalk is regulated in the gut remains elusive. Herein, it is for the first time revealed that anemic IBD patients exhibit impaired production of short-chain fatty acids (SCFAs), particularly butyrate. Butyrate supplementation restores iron metabolism in multiple anemia models. Mechanistically, butyrate upregulates ferroportin (FPN) expression in macrophages by reducing the enrichment of histone deacetylase (HDAC) at the Slc40a1 promoter, thereby facilitating iron export. By preventing iron sequestration, butyrate not only mitigates colitis-induced anemia but also reduces TNF-α production in macrophages. Consistently, macrophage-conditional FPN knockout mice exhibit more severe anemia and inflammation. Finally, it is revealed that macrophage iron overload impairs the therapeutic effectiveness of anti-TNF-α antibodies in colitis, which can be reversed by butyrate supplementation. Hence, this study uncovers the pivotal role of butyrate in preventing the pathogenic circuit between anemia and inflammation.

Risk of Tuberculosis and Hepatitis B Reactivation in Patients With Crohn's Disease on Ustekinumab: A Nationwide Real-World Study.

BACKGROUND: Ustekinumab (UST) was approved in China for moderate-to-severe Crohn's disease (CD) in 2020. The prevalence rates of tuberculosis and hepatitis B virus (HBV) infection are high in China, and no guideline clearly states that tuberculosis chemoprophylaxis or prophylactic anti-HBV therapy should be prescribed before UST administration. This study aimed to assess the risk of tuberculosis and HBV reactivation in CD patients with latent tuberculosis infection (LTBI) and previous HBV infection receiving UST. METHODS: A multicenter retrospective cohort study was carried out at 68 hospitals in China to assess 721 adult CD cases administered UST between May 1, 2020, and December 31, 2021. CD and concurrent LTBI or HBV carrier were included. Hepatitis B serology, T-SPOT.TB, and tuberculin skin tests were performed at baseline. The primary outcome was tuberculosis or HBV reactivation. RESULTS: Patients with CD-concomitant LTBI or who were HBV carriers receiving UST therapy were retrospectively enrolled from 15 hospitals in China. A total of 53 CD with LTBI patients and 17 CD with HBV carrier patients receiving UST were included. Treatment and follow-up durations were 50 ± 20 weeks and 50 ± 15 weeks in the LTBI and HBV carrier groups, respectively. A total of 25 CD patients with LTBI underwent chemoprophylaxis and 28 did not. A total of 11 HBV carriers had antiviral prophylaxis and 6 did not. No patient experienced tuberculosis or HBV reactivation or liver dysfunction during follow-up. CONCLUSIONS: UST was safe for treatment of CD because no patient developed tuberculosis, persistent hepatitis, or acute liver failure during therapy, whether with a prophylactic regimen or not, based on our sample size and limited follow-up time.

Epithelial CRL4DCAF2 Is Critical for Maintaining Intestinal Homeostasis Against DSS-Induced Colitis by Regulating the Proliferation and Repair of Intestinal Epithelial Cells.

BACKGROUND AND AIMS: Inflammatory bowel disease (IBD) is currently gaining an increasing global interest. Intestinal epithelial barrier dysfunction is crucial toward developing IBD; however, the underlying mechanisms are not yet elucidated. This study is aimed at elucidating the function of CRL4DCAF2, an E3 ligase, toward mediating intestinal homeostasis. METHODS: Colon samples were collected from patients with IBD and healthy individuals to examine the expression of CRL4DCAF2. CRL4DCAF2 conditional knockdown in mouse intestinal epithelial cells (IECs) (DCAF2EKD) were constructed. DCAF2EKD and their littermate control (DCAF2EWT) were treated with dextran sodium sulfate (DSS) to induce acute colitis. Transcriptome analysis was performed on inflamed colon samples obtained from the mice. Cell cycle regulators were evaluated using real-time polymerase chain reaction (PCR), while tight junction and apoptosis proteins were examined via immunofluorescence and western blot. RESULTS: CRL4DCAF2 expression was significantly decreased in the inflamed IBD epithelium, and low expression of CRL4DCAF2 associated with high recurrence risk. Mice with DCAF2 specific knockout in IECs suffer from embryonic death. Multiple genes involved in cell proliferation, immune response, and gap junction were differentially expressed in inflamed colon from DCAF2EKD compared with DCAF2EWT. Furthermore, conditional downregulation of CRL4DCAF2 in the intestinal epithelium induced primarily epithelial damage, increased intestinal permeability, and diminished tight junction protein expression. In vivo and in vitro cell transfection experiments revealed that CRL4DCAF2 enhanced cell proliferation by promoting p21 ubiquitination and degradation, thereby inhibiting G2/M cell cycle. In addition, CRL4DCAF2 can also inhibit IEC apoptosis and promote cell autophagy. CONCLUSIONS: CRL4DCAF2 downregulation in IECs promotes intestinal barrier dysfunction and inhibits IEC proliferation, thus making it more susceptible to inflammation.

Development and validation of a deep learning-based approach to predict the Mayo endoscopic score of ulcerative colitis.

Background: The ulcerative colitis (UC) Mayo endoscopy score is a useful tool for evaluating the severity of UC in patients in clinical practice. Objectives: We aimed to develop and validate a deep learning-based approach to automatically predict the Mayo endoscopic score using UC endoscopic images. Design: A multicenter, diagnostic retrospective study. Methods: We collected 15120 colonoscopy images of 768 UC patients from two hospitals in China and developed a deep model based on a vision transformer named the UC-former. The performance of the UC-former was compared with that of six endoscopists on the internal test set. Furthermore, multicenter validation from three hospitals was also carried out to evaluate UC-former's generalization performance. Results: On the internal test set, the areas under the curve of Mayo 0, Mayo 1, Mayo 2, and Mayo 3 achieved by the UC-former were 0.998, 0.984, 0.973, and 0.990, respectively. The accuracy (ACC) achieved by the UC-former was 90.8%, which is higher than that achieved by the best senior endoscopist. For three multicenter external validations, the ACC was 82.4%, 85.0%, and 83.6%, respectively. Conclusions: The developed UC-former could achieve high ACC, fidelity, and stability to evaluate the severity of UC, which may provide potential application in clinical practice. Registration: This clinical trial was registered at the ClinicalTrials.gov (trial registration number: NCT05336773).

Why was this study done? The development of an auxiliary diagnostic tool can reduce the workload of endoscopists and achieve rapid assessment of ulcerative colitis (UC) severity. What did the researchers do? We developed and validated a deep learning-based approach to automatically predict the Mayo endoscopic score using UC endoscopic images. What did the researchers find? The model that was developed in this study achieved high accuracy, fidelity, and stability, and demonstrated potential application in clinical practice. What do the findings mean? Deep learning could effectively assist endoscopists in evaluating the severity of UC in patients using endoscopic images.

XAF1 prevents hyperproduction of type I interferon upon viral infection by targeting IRF7.

Interferon regulatory factor (IRF) 3 and IRF7 are master regulators of type I interferon (IFN-I)-dependent antiviral innate immunity. Upon viral infection, a positive feedback loop is formed, wherein IRF7 promotes further induction of IFN-I in the later stage. Thus, it is critical to maintain a suitably low level of IRF7 to avoid the hyperproduction of IFN-I. In this study, we find that early expression of IFN-I-dependent STAT1 promotes the expression of XAF1 and that XAF1 is associated specifically with IRF7 and inhibits the activity of XIAP. XAF1-knockout and XIAP-transgenic mice display resistance to viral infection, and this resistance is accompanied by increases in IFN-I production and IRF7 stability. Mechanistically, we find that the XAF1-XIAP axis controls the activity of KLHL22, an adaptor of the BTB-CUL3-RBX1 E3 ligase complex through a ubiquitin-dependent pathway. CUL3-KLHL22 directly targets IRF7 and catalyzes its K48-linked ubiquitination and proteasomal degradation. These findings reveal unexpected functions of the XAF1-XIAP axis and KLHL22 in the regulation of IRF7 stability and highlight an important target for antiviral innate immunity.

Development and Validation of a Deep Neural Network for Accurate Identification of Endoscopic Images From Patients With Ulcerative Colitis and Crohn's Disease.

Background and Aim: The identification of ulcerative colitis (UC) and Crohn's disease (CD) is a key element interfering with therapeutic response, but it is often difficult for less experienced endoscopists to identify UC and CD. Therefore, we aimed to develop and validate a deep learning diagnostic system trained on a large number of colonoscopy images to distinguish UC and CD. Methods: This multicenter, diagnostic study was performed in 5 hospitals in China. Normal individuals and active patients with inflammatory bowel disease (IBD) were enrolled. A dataset of 1,772 participants with 49,154 colonoscopy images was obtained between January 2018 and November 2020. We developed a deep learning model based on a deep convolutional neural network (CNN) in the examination. To generalize the applicability of the deep learning model in clinical practice, we compared the deep model with 10 endoscopists and applied it in 3 hospitals across China. Results: The identification accuracy obtained by the deep model was superior to that of experienced endoscopists per patient (deep model vs. trainee endoscopist, 99.1% vs. 78.0%; deep model vs. competent endoscopist, 99.1% vs. 92.2%, P < 0.001) and per lesion (deep model vs. trainee endoscopist, 90.4% vs. 59.7%; deep model vs. competent endoscopist 90.4% vs. 69.9%, P < 0.001). In addition, the mean reading time was reduced by the deep model (deep model vs. endoscopists, 6.20 s vs. 2,425.00 s, P < 0.001). Conclusion: We developed a deep model to assist with the clinical diagnosis of IBD. This provides a diagnostic device for medical education and clinicians to improve the efficiency of diagnosis and treatment.

Reasons and Factors Contributing to Chinese Patients' Preference for Ustekinumab in Crohn's Disease: A Multicenter Cross-Sectional Study.

Background and Aims: Ustekinumab (UST) was approved in China for treating moderate-to-severe Crohn's disease (CD) in 2020. We aimed to identify the reasons and possible contributing factors for UST preference in Chinese patients with CD. Methods: We conducted a multicenter cross-sectional survey among patients with moderate to severe CD who underwent UST treatment in 27 hospitals. Patients completed a 46-item questionnaire that included information on demographics, clinical characteristics, reasons in favor of UST and shared decision-making perception. Logistic regression analysis was performed to examine the predictive factors of different UST preferences. Results: Overall, 127 patients (73 males; mean age, 25.9 ± 9.9 years) completed the questionnaire. Most patients (74.8%) had biologic failure. The most common reason for the latest treatment disconnection was unresponsiveness to the previous medications. The major UST information sources were physicians (96.1%). Nearly half of the patients (44.9%) reported shared decision making regarding UST treatment. No difference was found in the decision-making patterns in terms of sex and age. The most influential reason for UST preference was "effectiveness" (77%, 98/127), followed by "safety" (65%, 83/127), "frequency of administration" (39%, 49/127), and "mode of administration" (37%, 47/127). Multivariate logistic regression analysis revealed that a positive self-rated health status was a contributing factor for UST preference with a low frequency of administration. Conclusion: This is the first multicenter survey of Chinese patients with CD to identify the possible contributing factors for UST preference. Treatment choice should be discussed with patients because individual preferences are determined by diverse factors.

Multiomics analyses reveal a critical role of selenium in controlling T cell differentiation in Crohn's disease.

Inflammatory bowel disease (IBD) mainly includes Crohn's disease (CD) and ulcerative colitis (UC). Immune disorders play an essential role in the pathogenesis of these two IBDs, but the differences in the immune microenvironment of the colon and their underlying mechanisms remain poorly investigated. Here we examined the immunological features and metabolic microenvironment of untreated individuals with IBD by multiomics analyses. Modulation of CD-specific metabolites, particularly reduced selenium, can obviously shape type 1 T helper (Th1) cell differentiation, which is specifically enriched in CD. Selenium supplementation suppressed the symptoms and onset of CD and Th1 cell differentiation via selenoprotein W (SELW)-mediated cellular reactive oxygen species scavenging. SELW promoted purine salvage pathways and inhibited one-carbon metabolism by recruiting an E3 ubiquitin ligase, tripartite motif-containing protein 21, which controlled the stability of serine hydroxymethyltransferase 2. Our work highlights selenium as an essential regulator of T cell responses and potential therapeutic targets in CD.

USP16-mediated deubiquitination of calcineurin A controls peripheral T cell maintenance.

Calcineurin acts as a calcium-activated phosphatase that dephosphorylates various substrates, including members of the nuclear factor of activated T cells (NFAT) family, to trigger their nuclear translocation and transcriptional activity. However, the detailed mechanism regulating the recruitment of NFATs to calcineurin remains poorly understood. Here, we report that calcineurin A (CNA), encoded by PPP3CB or PPP3CC, is constitutively ubiquitinated on lysine 327, and this polyubiquitin chain is rapidly removed by ubiquitin carboxyl-terminal hydrolase 16 (USP16) in response to intracellular calcium stimulation. The K29-linked ubiquitination of CNA impairs NFAT recruitment and transcription of NFAT-targeted genes. USP16 deficiency prevents calcium-triggered deubiquitination of CNA in a manner consistent with defective maintenance and proliferation of peripheral T cells. T cell-specific USP16 knockout mice exhibit reduced severity of experimental autoimmune encephalitis and inflammatory bowel disease. Our data reveal the physiological function of CNA ubiquitination and its deubiquitinase USP16 in peripheral T cells. Notably, our results highlight a critical mechanism for the regulation of calcineurin activity and a novel immunosuppressive drug target for the treatment of autoimmune diseases.

Phosphatase Shp2 exacerbates intestinal inflammation by disrupting macrophage responsiveness to interleukin-10.

Inflammatory cytokines produced by activated macrophages largely contribute to the pathological signs of inflammatory bowel disease (IBD). Interleukin-10 (IL-10) is the predominant anti-inflammatory cytokine in the intestine, and its therapeutic efficacy for IBD has been clinically tested. Nevertheless, how the function of IL-10 is regulated in the intestinal microenvironment remains unknown, which largely hinders the further development of IL-10-based therapeutic strategies. Here, we found that the expression of phosphatase Shp2 was increased in colonic macrophages and blood monocytes from IBD patients compared with those from healthy controls. Shp2 deficiency in macrophages protects mice from colitis and colitis-driven colon cancer. Mechanistically, Shp2 disrupts IL-10-STAT3 signaling and its dependent anti-inflammatory response in human and mouse macrophages. Furthermore, a Shp2-inducing role of TNF-α is unveiled in our study. Collectively, our work identifies Shp2 as a detrimental factor for intestinal immune homeostasis and hopefully will be helpful in the future exploitation of IL-10 immunotherapy for IBD.

CRL4DCAF2 is required for mature T-cell expansion via Aurora B-regulated proteasome activity.

The proliferation of T cells in peripheral lymphoid tissues requires T cell receptor (TCR)-mediated cell cycle entry. However, the underlying mechanism regulating cell cycle progression in mature T cells is incompletely understood. Here, we have identified an E3 ubiquitin ligase, CRL4DCAF2, as a critical mediator controlling M phase exit in activated T cells. DCAF2 expression is induced upon TCR stimulation and its deficiency attenuates T cell expansion. Additionally, DCAF2 T cell-specific knockout mice display impaired peripheral T cell maintenance and reduced severity of various autoimmune diseases. Continuous H4K20me1 modification caused by DCAF2 deficiency inhibits the induction of Aurkb expression, which regulates 26S proteasome activity during G2/M phase. CRL4DCAF2 deficiency causes M phase arrest through proteasome-dependent mechanisms in peripheral T cells. Our findings establish DCAF2 as a novel target for T cell-mediated autoimmunity or inflammatory diseases.

The clinicopathologic features of chronic active Epstein-Barr virus infective enteritis.

Chronic active Epstein-Barr virus infective enteritis (CAEBV enteritis) is rare and has not been well described yet. Therefore, we reported the clinicopathologic features of 11 patients with chronic active Epstein-Barr virus infective enteritis and their differences from inflammatory bowel disease. The major clinical presentations of chronic active Epstein-Barr virus infective enteritis were intermittent fever over 39 °C (100%), diarrhea (73%), abdominal pain (64%), lymphadenopathy (64%), splenomegaly (64%), and hepatomegaly (27%). The main endoscopic findings included numerous shallow, small, and irregular ulcers, mainly involving colon and small intestine together, no cobble-like appearance, and longitudinal ulcers. Compared to inflammatory bowel disease patients, the frequency of intermittent fever, hepatomegaly, splenomegaly, lymphadenopathy, the value of C-reactive protein, and serum Epstein-Barr virus DNA (EBV DNA) were significantly higher in chronic active Epstein-Barr virus infective enteritis patients (p < 0.01). The histologic findings show transmural inflammation with extended lymphoid infiltration, fissuring ulcers, and intraepithelial lymphocytosis. But chronic active Epstein-Barr virus infective enteritis lacked granulomas and connective tissue changes such as neural hypertrophy and thickened muscularis mucosae. Three chronic active Epstein-Barr virus infective enteritis patients died within 5 years of disease onset, and those three patients have received total colectomy, two of them died within 1 month after surgery. In this study, clinicopathologic features have been summarized to better recognize chronic active Epstein-Barr virus infective enteritis. There are resemblances between chronic active Epstein-Barr virus infective enteritis and inflammatory bowel disease, but some symptoms, signs, and indexes like intermittent fever, hepatomegaly, splenomegaly, lymphadenopathy, and elevated C-reactive protein, Epstein-Barr virus DNA are characteristics to differentiate chronic active Epstein-Barr virus infective enteritis and inflammation. Histopathological features also help the discrimination. Serum Epstein-Barr virus DNA and intestinal tissue in situ hybridization for Epstein-Barr virus-encoded RNA are recommended to exclude chronic active Epstein-Barr virus infective enteritis.

Altered Intestinal Microbiota with Increased Abundance of Prevotella Is Associated with High Risk of Diarrhea-Predominant Irritable Bowel Syndrome.

Alterations in gut microbiota are postulated to be an etiologic factor in the pathogenesis of irritable bowel syndrome (IBS). To determine whether IBS patients in China exhibited differences in their gut microbial composition, fecal samples were collected from diarrhea-predominant IBS (IBS-D) and healthy controls and evaluated by 16S ribosomal RNA gene sequence and quantitative real-time PCR. A mouse model of postinfectious IBS (PI-IBS) was established to determine whether the altered gut microbiota was associated with increased visceral hypersensitivity. The results indicated that there were significant differences in the bacterial community profiles between IBS-D patients and healthy controls. Prevotella was more abundant in fecal samples from IBS-D patients compared with healthy controls (p < 0.05). Meanwhile, there were significant reductions in the quantity of Bacteroides, Bifidobacteria, and Lactobacillus in IBS-D patients compared with healthy controls (p < 0.05). Animal models similarly showed an increased abundance of Prevotella in fecal samples compared with control mice (p < 0.05). Finally, after the PI-IBS mice were cohoused with control mice, both the relative abundance of Prevotella and visceral hypersensitivity of PI-IBS mice were decreased. In conclusion, the altered intestinal microbiota is associated with increased visceral hypersensitivity and enterotype enriched with Prevotella may be positively associated with high risk of IBS-D.

1-Day or 5-Day Fecal Samples, Which One is More Beneficial to be Used for DNA-Based Gut Microbiota Study.

Fecal sample collection is an important influential factor for DNA-based gut microbiota study. It is controversial whether the microbiome detected in fecal sample collected at one random day could fully represent the gut microbial community. The aim of the study is to figure out whether the use of fecal sample mixture collected at consecutive 5 days could more accurately represent gut microbial community. 1- and 5-day fecal samples were collected from 8 healthy adults and analyzed by 16S rRNA sequence. Our results indicated that both 1-day fecal samples and 5-day samples exhibited relatively high repeatability. The relative abundance of majority of bacterial taxa did not changed between 1-day fecal samples and 5-day fecal samples. However, the alpha diversity of 5-day fecal samples was higher than that of 1-day fecal samples. When the aims of studies are to analyze the relative abundance of specific OTUs among subjects, fecal samples collected at one day could be used. When microbial diversity is one of essential factors to be analyzed, the use of 5-day fecal samples may be more recommended.

Case report of a pair of siblings with cryptogenic multifocal ulcerating stenosing enteritis: A rare disease easily to be misdiagnosed as Crohn disease.

RATIONALE: The rare disease cryptogenic multifocal ulcerous stenosing enteritis (CMUSE) is characterized by multiple and recurring small intestinal ulcers with stenosis of unknown causes. In clinic, it is difficult to be differentiated from the inflammatory bowel disease, especially the Crohn disease. PATIENT CONCERNS: Here we report a pair of siblings who suffered from long-time anemia and abdominal pain and misdiagnosed with inflammatory bowel disease (IBD) for many years. DIAGNOSES: They were finally diagnosed with CMUSE with intestinal obstruction. INTERVENTIONS AND OUTCOMES: They both accepted surgical treatment and recovered well. No abdominal symptom appeared in the two-year follow-up. LESSONS: This report underscores that CMUSE patients may have a long course of suffering from anemia and abdominal pain, normal inflammatory markers and normal colon, and sometimes have a family history of CMUSE. Surgery of segmental bowel resection is a good way to solve intractable intestinal obstruction in CMUSE.

Esophageal cancer diagnosed by high-resolution manometry of the esophagus: A case report.

A 48-year-old female who presented with a history of dysphagia for 5 months and regurgitation for 1 week was referred to the Sir Run Run Shaw Hospital (Hangzhou, China) for further evaluation, since the gastroscopy and endoscopic ultrasound performed in local hospitals did not reveal the presence of cancer. High-resolution manometry (HRM) of the esophagus was performed to determine the patient's condition, and revealed an abnormal high-pressure zone that was located 33 cm from the incisor and did not relax upon swallowing. Synchronous waves were observed, and the pressure of the esophageal lumen was found to increase with secondary synchronous peristaltic waves. The lower esophageal sphincter was 39 cm from the incisor and relaxed upon swallowing. The abnormal high-pressure zone could have been caused by an obstruction, and therefore an upper gastrointestinal series (barium swallow) test and gastroscopy were recommended to further pinpoint the cause. Following the two examinations, mid-esophageal cancer was considered as a possible diagnosis. A biopsy was performed and the final diagnosis was that of basaloid squamous cell carcinoma. The findings of the present study suggest that, for patients with evident symptoms of esophageal motor dysfunction without significant gastroscopy findings, HRM is recommended.