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Germinal centers where B cells undergo clonal expansion and antibody affinity maturation are hypoxic microenvironments. However, the function of hypoxia-inducible factor (HIF)-1α in immunoglobulin production remains incompletely characterized. Here, we demonstrated that B cells lacking HIF-1α exhibited significantly lower glycolytic metabolism and impaired IgA production. Loss of HIF-1α in B cells affects IgA-producing B-cell differentiation and exacerbates dextran sodium sulfate (DSS)-induced colitis. Conversely, promoting HIF-1α stabilization via a PHD inhibitor roxadustat enhances IgA class switching and alleviates intestinal inflammation. Mechanistically, HIF-1α facilitates IgA class switching through acetyl-coenzyme A (acetyl-CoA) accumulation, which is essential for histone H3K27 acetylation at the Sα region. Consequently, supplementation with acetyl-CoA improved defective IgA production in Hif1a-deficient B cells and limited experimental colitis. Collectively, these findings highlight the critical importance of HIF-1α in IgA class switching and the potential for targeting the HIF-1α-dependent metabolic‒epigenetic axis to treat inflammatory bowel diseases and other inflammatory disorders., Competing Interests: Competing interests The authors declare no competing interests., (© 2024. The Author(s).)

Gasdermin C is one of the least studied members of the gasdermin family of proteins, known for their critical involvement in pyroptosis and host defense. Furthermore, evidence for the role of Gasdermin C in the intestine is scarce and partly controversial. Here, we tested the functional role of Gasdermin C in intestinal homeostasis, inflammation and tumorigenesis. : We studied Gasdermin C in response to cytokines in intestinal organoids. We evaluated epithelial differentiation, cell death and immune infiltration under steady state conditions in a new mouse line deficient in Gasdermin C. The role of Gasdermin C was analyzed in acute colitis, infection and colitis-associated cancer. Gasdemin C is highly expressed in the intestinal epithelium and strongly induced by the type 2 cytokines IL-4 and IL-13 in a STAT6-dependent manner. Gasdermin C-deficient mice show no changes in tissue architecture and epithelial homeostasis. Epithelial organoids deficient in Gasdermin C develop normally and show no alterations in proliferation or cell death. No changes were found in models of acute colitis, type 2 intestinal infection and colitis-associated cancer. Gasdermin C genes are upregulated by type 2 immunity, yet appear dispensable for the development of intestinal inflammation, infection and colitis-associated cancer., (© 2024. The Author(s).)

Background & Aims: Primary sclerosing cholangitis (PSC), often associated with inflammatory bowel disease (IBD), presents a multifactorial etiology involving genetic, immunologic, and environmental factors. Gut dysbiosis and bacterial translocation have been implicated in PSC-IBD, yet the precise mechanisms underlying their pathogenesis remain elusive. Here, we describe the role of gut pathobionts in promoting liver inflammation and fibrosis due to the release of bacterial outer membrane vesicles (OMVs)., Methods: Preclinical mouse models in addition to ductal organoids were used to acquire mechanistic data. A proof-of-concept study including serum and liver biopsies of a patient cohort of PSC (n = 22), PSC-IBD (n = 45), and control individuals (n = 27) was performed to detect OMVs in the systemic circulation and liver., Results: In both preclinical model systems and in patients with PSC-IBD, the translocation of OMVs to the liver correlated with enhanced bacterial sensing and accumulation of the NLRP3 inflammasome. Using ductal organoids, we were able to precisely attribute the pro-inflammatory and pro-fibrogenic properties of OMVs to signaling pathways dependent on Toll-like receptor 4 and NLRP3-gasdermin-D. The immunostimulatory potential of OMVs could be confirmed in macrophages and hepatic stellate cells. Furthermore, when we administered gut pathobiont-derived OMVs to Mdr2 -/- mice, we observed a significant enhancement in liver inflammation and fibrosis. In a translational approach, we substantiated the presence of OMVs in the systemic circulation and hepatic regions of severe fibrosis using a PSC-IBD patient cohort., Conclusions: This study demonstrates the contribution of gut pathobionts in releasing OMVs that traverse the mucosal barrier and, thus, promote liver inflammation and fibrosis in PSC-IBD. OMVs might represent a critical new environmental factor that interacts with other disease factors to cause inflammation and thus define potential new targets for fibrosis therapy., (Copyright © 2024 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Objective: Mutations in presenilin genes are the major cause of Alzheimer's disease. However, little is known about their expression and function in the gut. In this study, we identify the presenilins Psen1 and Psen2 as key molecules that maintain intestinal homoeostasis., Design: Human inflammatory bowel disease (IBD) and control samples were analysed for Psen1 expression. Newly generated intestinal epithelium-specific Psen1-deficient, Psen2-deficient and inducible Psen1/Psen2 double-deficient mice were used to dissect the functional role of presenilins in intestinal homoeostasis., Results: Psen1 expression was regulated in experimental gut inflammation and in patients with IBD. Induced deletion of Psen1 and Psen2 in mice caused rapid weight loss and spontaneous development of intestinal inflammation. Mice exhibited epithelial barrier disruption with bacterial translocation and deregulation of key pathways for nutrient uptake. Wasting disease was independent of gut inflammation and dysbiosis, as depletion of microbiota rescued Psen-deficient animals from spontaneous colitis development but not from weight loss. On a molecular level, intestinal epithelial cells lacking Psen showed impaired Notch signalling and dysregulated epithelial differentiation., Conclusion: Overall, our study provides evidence that Psen1 and Psen2 are important guardians of intestinal homoeostasis and future targets for barrier-promoting therapeutic strategies in IBD., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Abstract: Wirtz, S, Julian, R, Schmale, R, and Eils, E. Concurrent validity and reliability of in-field vertical jump performance measures on sand surfaces. J Strength Cond Res 38(4): 687-693, 2024-Beach sports, such as handball, volleyball, and soccer, involve dynamic actions, primarily jumps. Nonetheless, there is a need for more established measurement devices that are both valid and feasible in accurately evaluating jumping performance on sand surfaces. This study aims to assess the reliability and concurrent validity of MyJump2 and an inertial measurement unit (VERT) for quantifying countermovement jump performance on the sand. Twenty-one subjects performed 5 countermovement jumps on the sand. Jumping height was measured simultaneously by a force plate, VERT, and MyJump2. The VERT and MyJump2 reliability measures were evaluated using the intraclass correlation coefficients (ICC) for both absolute agreement (ICC 2,1 ) and consistency (ICC 3.1 ). The day-to-day reliability of both devices and the interrater and intrarater reliability of the MyJump2 were assessed. The concurrent validity of the VERT and MyJump2 was assessed using ICCs 2.1, 3.1 and Bland-Altman plots. A near-perfect agreement was seen for intrarater (ICC = 0.98) and interrater (ICC = 0.98) reliability of the MyJump2. Moreover, a near-perfect agreement was also observed when comparing the MyJump2 with the force plate (ICC = 0.92), with a mean bias of -2.31 cm. The VERT device only demonstrated a moderate agreement (ICC = 0.55) with a mean bias of 6.31 cm compared with the force plate, despite showing good day-to-day reliability (ICC = 0.79). The study's results indicate that MyJump2 is valid and reliable for assessing jump heights on sand surfaces, whereas VERT cannot be recommended., (Copyright © 2023 National Strength and Conditioning Association.)

Background/aims: Hypoxemia is a common side effect of propofol sedation during endoscopy. Applying mild positive airway pressure (PAP) using a nasal mask may offer a simple way to reduce such events and optimize the conditions for diagnostic and therapeutic upper gastrointestinal endoscopies., Methods: We compared overweight patients (body mass index >25 kg/m2) with a nasal PAP mask or standard nasal cannula undergoing upper gastrointestinal endoscopies by non-anesthesiologists who provided propofol sedation. Outcome parameters included the frequency and severity of hypoxemic episodes., Results: We analyzed 102 procedures in 51 patients with nasal PAP masks and 51 controls. Episodes of hypoxemia (oxygen saturation [SpO2] <90% at any time during sedation) occurred in 25 (49.0%) controls compared to 8 (15.7%) patients with nasal PAP masks (p<0.001). Severe hypoxemia (SpO2 <80%) occurred in three individuals (5.9%) in both groups. The mean delta between baseline SpO2 and the lowest SpO2 recorded was significantly decreased among patients with nasal PAP mask compared to controls (3.7 and 8.2 percentage points difference, respectively). There were significantly fewer airway interventions performed in the nasal PAP mask group (15.7% vs. 41.2%, p=0.008)., Conclusion: Using a nasal PAP mask may be a simple means of increasing patient safety and ease of examination.

Background: The use of eHealth technology in cardiac rehabilitation (CR) is a promising approach to enhance patient outcomes since adherence to healthy lifestyles and risk factor management during phase III CR maintenance is often poorly supported. However, patients' needs and expectations have not been extensively analyzed to inform the design of such eHealth solutions., Objective: The goal of this study was to provide a detailed patient perspective on the most important functionalities to include in an eHealth solution to assist them in phase III CR maintenance., Methods: A guided survey as part of a Living Lab approach was conducted in Germany (n=49) and Spain (n=30) involving women (16/79, 20%) and men (63/79, 80%) with coronary artery disease (mean age 57 years, SD 9 years) participating in a structured center-based CR program. The survey covered patients' perceived importance of different CR components in general, current usage of technology/technical devices, and helpfulness of the potential features of eHealth in CR. Questionnaires were used to identify personality traits (psychological flexibility, optimism/pessimism, positive/negative affect), potentially predisposing patients to acceptance of an app/monitoring devices., Results: All the patients in this study owned a smartphone, while 30%-40% used smartwatches and fitness trackers. Patients expressed the need for an eHealth platform that is user-friendly, personalized, and easily accessible, and 71% (56/79) of the patients believed that technology could help them to maintain health goals after CR. Among the offered components, support for regular physical exercise, including updated schedules and progress documentation, was rated the highest. In addition, patients rated the availability of information on diagnosis, current medication, test results, and risk scores as (very) useful. Of note, for each item, except smoking cessation, 35%-50% of the patients indicated a high need for support to achieve their long-term health goals, suggesting the need for individualized care. No major differences were detected between Spanish and German patients (all P>.05) and only younger age (P=.03) but not sex, education level, or personality traits (all P>.05) were associated with the acceptance of eHealth components., Conclusions: The patient perspectives collected in this study indicate high acceptance of personalized user-friendly eHealth platforms with remote monitoring to improve adherence to healthy lifestyles among patients with coronary artery disease during phase III CR maintenance. The identified patient needs comprise support in physical exercise, including regular updates on personalized training recommendations. Availability of diagnoses, laboratory results, and medications, as part of a mobile electronic health record were also rated as very useful., Trial Registration: ClinicalTrials.gov NCT05461729; https://clinicaltrials.gov/study/NCT05461729., (©Boris Schmitz, Svenja Wirtz, Manuela Sestayo-Fernández, Hendrik Schäfer, Emma R Douma, Marta Alonso Vazquez, Violeta González-Salvado, Mirela Habibovic, Dimitris Gatsios, Willem Johan Kop, Carlos Peña-Gil, Frank Mooren. Originally published in the Journal of Medical Internet Research (https://www.jmir.org), 22.02.2024.)

Background: Kidney graft rejection still represents the major cause of graft loss in kidney transplant recipients. Of growing interest is the bidirectional relationship between gut microbiome and immune system suggesting that gut microbiota can affect allograft outcome., Methods: In this cross-sectional case-control study, we characterized the gut microbial profile of adult renal transplant recipients with and without graft rejection to define a cohort-specific microbial fingerprint through 16S ribosomal RNA gene sequencing. We used very strict inclusion and exclusion criteria to address confounder of microbiota composition., Results: Different relative abundances in several gut microbial taxa were detectable in control patients compared with patients with kidney allograft rejection. Alpha diversity was lower in the rejection group and beta diversity revealed dissimilarity between patients with and without kidney graft rejection ( P  < 0.01). When the rejection group was stratified according to different types of allograft rejection, major changes were identified between patients with chronic T-cellular-mediated rejection and controls. Changes in alpha diversity within the gut microbiome were related to the probability of chronic T-cellular-mediated rejection ( P  < 0.05). Kidney transplant patients without rejection showed significant enrichment of rather anti-inflammatory taxa whereas in the rejection group bacteria well known for their role in chronic inflammation were increased. For example, amplicon sequence variant (ASV) 362 belonging to the genus Bacteroides and ASV 312 belonging to Tannerellaceae were enriched in no rejection ( P  < 0.001 and P  < 0.01), whereas ASV 365 was enriched in patients with allograft rejection ( P  = 0.04). Looking at metagenomic functions, a higher abundance of genes coding for enzymes involved in bacterial multidrug resistance and processing of short-chain fatty acids was found in patients without rejection but an increase in enzymes involved in nicotinamide adenine dinucleotide phosphate production was seen in patients with allograft rejection., Conclusions: A distinct microbial fingerprint of patients with allograft rejection might serve as noninvasive biomarker in the future., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2024 The Author(s). Transplantation Direct. Published by Wolters Kluwer Health, Inc.)

Background: Cardiac rehabilitation (CR) reduces recurrent cardiac events and mortality in patients with cardiovascular diseases (CVD). Innovative eHealth methods can facilitate CR uptake and effectiveness by addressing barriers associated with clinic-based rehabilitation. Tailoring eHealth-based CR to patient preferences is needed to further enhance CR., Purpose: To identify preferred behavior change techniques (BCTs) as well as barriers and facilitators for the different health behaviors targeted in eHealth-based CR among patients who have been referred to CR., Methods: Thirty-nine patients were interviewed in nine focus groups in The Netherlands, Germany, and Spain. A thematic analysis, using a combined deductive and inductive approach to coding, was conducted to identify BCTs and barriers and facilitators to behavior change. Behaviors under investigation included physical activity, medication adherence, eating a cardiac healthy-diet, stress reduction and smoking cessation., Results: The perceived helpfulness of BCTs depended on the specific behavior targeted. Common barriers were negative emotional state and physical limitations. A desire to feel physically or mentally well and having experienced a cardiac life event were the most common facilitators across health behaviors. Specific BCTs, barriers and facilitators were found for each of the health behavior., Conclusions: Behavior change techniques that patients preferred for each health behavior targeted in eHealth-based CR were identified. A negative emotional state, experiencing a life event, and improving physical functioning are important barriers and facilitators in multiple behaviors targeted in eHealth-based CR programs. Additional tailoring of interventions to patient preferences for BCTs and patient-specific barriers and facilitators per health behavior could lead to further improvement of eHealth-based CR., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Objective: We sought to investigate the role of interleukin (IL)-20 in IBD and experimental colitis., Design: Experimental colitis was induced in mice deficient in components of the IL-20 and signal transducer and activator of transcription (STAT)2 signalling pathways. In vivo imaging, high-resolution mini-endoscopy and histology were used to assess intestinal inflammation. We further used RNA-sequencing (RNA-Seq), RNAScope and Gene Ontology analysis, western blot analysis and co-immunoprecipitation, confocal microscopy and intestinal epithelial cell (IEC)-derived three-dimensional organoids to investigate the underlying molecular mechanisms. Results were validated using samples from patients with IBD and non-IBD control subjects by a combination of RNA-Seq, organoids and immunostainings., Results: In IBD, IL20 levels were induced during remission and were significantly higher in antitumour necrosis factor responders versus non-responders. IL-20RA and IL-20RB were present on IECs from patients with IBD and IL-20-induced STAT3 and suppressed interferon (IFN)-STAT2 signalling in these cells. In IBD, experimental dextran sulfate sodium (DSS)-induced colitis and mucosal healing, IECs were the main producers of IL-20. Compared with wildtype controls, Il20 -/- , Il20ra -/- and Il20rb -/- mice were more susceptible to experimental DSS-induced colitis. IL-20 deficiency was associated with increased IFN/STAT2 activity in mice and IFN/STAT2-induced necroptotic cell death in IEC-derived organoids could be markedly blocked by IL-20. Moreover, newly generated Stat2 ΔIEC mice, lacking STAT2 in IECs, were less susceptible to experimental colitis compared with wildtype controls and the administration of IL-20 suppressed colitis activity in wildtype animals., Conclusion: IL-20 controls colitis and mucosal healing by interfering with the IFN/STAT2 death signalling pathway in IECs. These results indicate new directions for suppressing gut inflammation by modulating IL-20-controlled STAT2 signals., Competing Interests: Competing interests: MFN has served as an advisor for Pentax, Giuliani, PPM, BMS, Janssen, MSD, Takeda and Boehringer. MFN has served as an Associate Editor of the journal/Editorial Board Member. BS has served as consultant for AbbVie, Arena, BMS, Boehringer, Celgene, Falk, Galapagos, Janssen, Lilly, Pfizer, Prometheus and Takeda and received speaker’s fees from AbbVie, CED Service, Falk, Ferring, Janssen, Novartis, Pfizer, Takeda (served as representative of the Charité). All other authors have nothing to disclose., (© Author(s) (or their employer(s)) 2024. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)