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BACKGROUND The role of direct oral anticoagulants as compared with vitamin K antagonists for atrial fibrillation after successful transcatheter aortic-valve replacement (TAVR) has not been well studied. METHODS We conducted a multicenter, prospective, randomized, open-label, adjudicator-masked trial comparing edoxaban with vitamin K antagonists in patients with prevalent or incident atrial fibrillation as the indication for oral anticoagulation after successful TAVR. The primary efficacy outcome was a composite of adverse events consisting of death from any cause, myocardial infarction, ischemic stroke, systemic thromboembolism, valve thrombosis, or major bleeding. The primary safety outcome was major bleeding. On the basis of a hierarchical testing plan, the primary efficacy and safety outcomes were tested sequentially for noninferiority, with noninferiority of edoxaban established if the upper boundary of the 95% confidence interval for the hazard ratio did not exceed 1.38. Superiority testing of edoxaban for efficacy would follow if noninferiority and superiority were established for major bleeding. RESULTS A total of 1426 patients were enrolled (713 in each group). The mean age of the patients was 82.1 years, and 47.5% of the patients were women. Almost all the patients had atrial fibrillation before TAVR. The rate of the composite primary efficacy outcome was 17.3 per 100 person-years in the edoxaban group and 16.5 per 100 person-years in the vitamin K antagonist group (hazard ratio, 1.05; 95% confidence interval [CI], 0.85 to 1.31; P���=���0.01 for noninferiority). Rates of major bleeding were 9.7 per 100 person-years and 7.0 per 100 person-years, respectively (hazard ratio, 1.40; 95% CI, 1.03 to 1.91; P���=���0.93 for noninferiority); the difference between groups was mainly due to more gastrointestinal bleeding with edoxaban. Rates of death from any cause or stroke were 10.0 per 100 person-years in the edoxaban group and 11.7 per 100 person-years in the vitamin K antagonist group (hazard ratio, 0.85; 95% CI, 0.66 to 1.11). CONCLUSIONS In patients with mainly prevalent atrial fibrillation who underwent successful TAVR, edoxaban was noninferior to vitamin K antagonists as determined by a hazard ratio margin of 38% for a composite primary outcome of adverse clinical events. The incidence of major bleeding was higher with edoxaban than with vitamin K antagonists. (Funded by Daiichi Sankyo; ENVISAGE-TAVI AF ClinicalTrials.gov number, NCT02943785.).

Purpose Reliable detection and fitting of macromolecules (MM) are crucial for accurate quantification of brain short-echo time (TE) 1 H-MR spectra. An experimentally acquired single MM spectrum is commonly used. Higher spectral resolution at ultra-high field (UHF) led to increased interest in using a parametrized MM spectrum together with flexible spline baselines to address unpredicted spectroscopic components. Herein, we aimed to: (1) implement an advanced methodological approach for post-processing, fitting, and parametrization of 9.4T rat brain MM spectra; (2) assess the concomitant impact of the LCModel baseline and MM model (ie, single vs parametrized); and (3) estimate the apparent T2 relaxation times for seven MM components. Methods A single inversion recovery sequence combined with advanced AMARES prior knowledge was used to eliminate the metabolite residuals, fit, and parametrize 10 MM components directly from 9.4T rat brain in vivo 1 H-MR spectra at different TEs. Monte Carlo simulations were also used to assess the concomitant influence of parametrized MM and DKNTMN parameter in LCModel. Results A very stiff baseline (DKNTMN ≥ 1 ppm) in combination with a single MM spectrum led to deviations in metabolite concentrations. For some metabolites the parametrized MM showed deviations from the ground truth for all DKNTMN values. Adding prior knowledge on parametrized MM improved MM and metabolite quantification. The apparent T2 ranged between 12 and 24 ms for seven MM peaks. Conclusion Moderate flexibility in the spline baseline was required for reliable quantification of real/experimental spectra based on in vivo and Monte Carlo data. Prior knowledge on parametrized MM improved MM and metabolite quantification.

Antiphagocytic capsular polysaccharides are key components of effective vaccines against pathogenic bacteria. Neisseria meningitidis groups B and C, as well as Escherichia coli serogroups K1 and K92, are coated with polysialic acid capsules. Although the chemical structure of these polysaccharides and the organization of the associated gene clusters have been described for many years, only recently have the details of the biosynthetic pathways been discovered. The polysialic acid chains are synthesized by polysialyltransferases on a proposed phosphatidylglycerol lipid acceptor with a poly keto-deoxyoctulosonate (KDO) linker. Synthesis of this acceptor requires at least three enzymes in E. coli K1: KpsS, KpsC, and NeuE. In this report, we have characterized the β-KDO glycosyltransferase KpsS, the first enzyme in the pathway for lipid acceptor synthesis. After purification of KpsS in a soluble active form, we investigated its function and substrate specificity and showed that KpsS can transfer a KDO residue to a fluorescently labeled phosphatidylglycerol lipid. The enzyme tolerated various lengths of fatty acid acyl chains on the phosphatidylglycerol, including fluorescent tags, but exhibited a preference for phosphatidylglycerol diacylated with longer fatty acid chains as indicated by the smaller Kd and Km values for substrates with chains with more than 14 members. Additional structural analysis of the KpsS product confirmed that KpsS transfers KDO from CMP-KDO to the 1-hydroxyl of phosphatidylglycerol to form a β-KDO linkage.

Glioblastoma (GBM) is the most aggressive brain tumor type in adults. GBM is heterogeneous, with a compact core lesion surrounded by an invasive tumor front. This front is highly relevant for tumor recurrence but is generally non-detectable using standard imaging techniques. Recent studies demonstrated distinct metabolic profiles of the invasive phenotype in GBM. Magnetic resonance (MR) of hyperpolarized 13C-labeled probes is a rapidly advancing field that provides real-time metabolic information. Here, we applied hyperpolarized 13C-glucose MR to mouse GBM models. Compared to controls, the amount of lactate produced from hyperpolarized glucose was higher in the compact GBM model, consistent with the accepted “Warburg effect”. However, the opposite response was observed in models reflecting the invasive zone, with less lactate produced than in controls, implying a reduction in aerobic glycolysis. These striking differences could be used to map the metabolic heterogeneity in GBM and to visualize the infiltrative front of GBM.

Supplemental Digital Content is available in the text., Background: Female sex is an independent risk factor for stroke and systemic embolic events in patients with atrial fibrillation. This study aimed to examine the efficacy and safety profile of edoxaban in women versus men. Methods: The ENGAGE AF-TIMI 48 trial (Effective Anticoagulation with Factor Xa Next Generation in Atrial Fibrillation-Thrombolysis in Myocardial Infarction 48) randomly assigned 21 105 patients (8040 women) with atrial fibrillation and CHADS2 score ≥2 either to a higher-dose edoxaban regimen, a lower-dose edoxaban regimen, or warfarin. The primary end points of the trial were the composite of stroke or systemic embolic events (efficacy), and International Society on Thrombosis and Haemostasis–defined major bleeding (safety). Results: In comparison with men, women were older, had lower body weight, were more likely to have hypertension and renal dysfunction, but less likely to smoke, drink alcohol, or have diabetes or coronary artery disease. Pretreatment endogenous factor Xa activity was significantly higher in women than in men (92.5% versus 86.1%, P

Contains fulltext : 232054.pdf (Publisher’s version ) (Open Access) Proximal tubule epithelial cells (PTEC) are susceptible to drug-induced kidney injury (DIKI). Cell-based, two-dimensional (2D) in vitro PTEC models are often poor predictors of DIKI, probably due to the lack of physiological architecture and flow. Here, we assessed a high throughput, 3D microfluidic platform (Nephroscreen) for the detection of DIKI in pharmaceutical development. This system was established with four model nephrotoxic drugs (cisplatin, tenofovir, tobramycin and cyclosporin A) and tested with eight pharmaceutical compounds. Measured parameters included cell viability, release of lactate dehydrogenase (LDH) and N-acetyl-β-d-glucosaminidase (NAG), barrier integrity, release of specific miRNAs, and gene expression of toxicity markers. Drug-transporter interactions for P-gp and MRP2/4 were also determined. The most predictive read outs for DIKI were a combination of cell viability, LDH and miRNA release. In conclusion, Nephroscreen detected DIKI in a robust manner, is compatible with automated pipetting, proved to be amenable to long-term experiments, and was easily transferred between laboratories. This proof-of-concept-study demonstrated the usability and reproducibility of Nephroscreen for the detection of DIKI and drug-transporter interactions. Nephroscreen it represents a valuable tool towards replacing animal testing and supporting the 3Rs (Reduce, Refine and Replace animal experimentation).

A rupture disc burst was recorded when conducting a calorimetric test by sensitive detection of exothermic reaction. The tested sample was a reaction mixture from a hydroamination process containing the solvent dimethyl sulfoxide (DMSO). Subsequent investigation indicated that the event was caused by the strong autocatalytic decomposition of DMSO. The hazardous decomposition of DMSO that could be initiated by an inadvertent contact with substances involved in the process was studied. Furthermore, risk evaluation on the process thermal runaway was carried out based on the cooling failure scenario. In this particular case, although Stoessel criticality class 2 was assigned, the boiling point of DMSO could not serve as the safety barrier. On the basis of the thermal safety evaluation, the hydroamination process was safely scaled up in the Novartis pilot plant and successfully launched in a commercial production unit. This investigation highlights that every scale-up process involving DMSO as a solvent should be carefully evaluated owing to the potential safety concern caused by its autocatalytic behavior.

Development of efficient drugs and therapies for the treatment of inflammatory conditions in the intestine is often hampered by the lack of reliable, robust, and high-throughput in vitro and in vivo models. Current models generally fail to recapitulate key aspects of the intestine, resulting in low translatability to the human situation. Here, an immunocompetent 3D perfused intestine-on-a-chip platform was developed and characterized for studying intestinal inflammation. Forty independent polarized 3D perfused epithelial tubular structures were grown from cells of mixed epithelial origin, including enterocytes (Caco-2) and goblet cells (HT29-MTX-E12). Immune cells THP-1 and MUTZ-3, which can be activated, were added to the system and assessed for cytokine release. Intestinal inflammation was mimicked through exposure to tumor necrosis factor-α (TNFα) and interleukin (IL)-1β. The effects were quantified by measuring transepithelial electrical resistance (TEER) and proinflammatory cytokine secretion on the apical and basal sides. Cytokines induced an inflammatory state in the culture, as demonstrated by the impaired barrier function and increased IL-8 secretion. Exposure to the known anti-inflammatory drug TPCA-1 prevented the inflammatory state. The model provides biological modularity for key aspects of intestinal inflammation, making use of well-established cell lines. This allows robust assays that can be tailored in complexity to serve all preclinical stages in the drug discovery and development process.

This paper reports densities, refractive indices, excess molar volumes, and changes of refractive indices on mixing for (2-butanone, 3-pentanone and 4-methyl-2-pentanone) with vegetable oils (olive or soybean) at temperatures from 283.15 to 298.15 K. Parameters of analytical expressions which represent the composition dependences of excess and variation of magnitudes are reported. Values of physical properties were compared with the results obtained by different theoretical procedures (equations of state and semiempirical mixing rules). A good agreement between the experimental and theoretical values both in magnitude and sign were obtained by these methods, despite the sharp non-ideality of the studied mixtures and the strong influence of temperature on the computed derived properties.

The DNA damage response (DDR) coordinates DNA metabolism with nuclear and non-nuclear processes. The DDR kinase Rad53CHK1/CHK2 controls histone degradation to assist DNA repair. However, Rad53 deficiency causes histone-dependent growth defects in the absence of DNA damage, pointing out unknown physiological functions of the Rad53-histone axis. Here we show that histone dosage control by Rad53 ensures metabolic homeostasis. Under physiological conditions, Rad53 regulates histone levels through inhibitory phosphorylation of the transcription factor Spt21NPAT on Ser276. Rad53-Spt21 mutants display severe glucose dependence, caused by excess histones through two separable mechanisms: dampening of acetyl-coenzyme A-dependent carbon metabolism through histone hyper-acetylation, and Sirtuin-mediated silencing of starvation-induced subtelomeric domains. We further demonstrate that repression of subtelomere silencing by physiological Tel1ATM and Rpd3HDAC activities coveys tolerance to glucose restriction. Our findings identify DDR mutations, histone imbalances and aberrant subtelomeric chromatin as interconnected causes of glucose dependence, implying that DDR kinases coordinate metabolism and epigenetic changes.

We present the enantioselective synthesis of sodium (3S)-5-(benzyloxy)-2-(diphenylacetyl)-6-methoxy-1,2,3,4-tetrahydroisoquinoline-3-carboxylate (EMA401, olodanrigan), an angiotensin II type 2 anta...

Background Diabetes mellitus is an independent risk factor for stroke and atrial fibrillation. Therefore, the risk/benefit profile of the oral factor Xa inhibitor edoxaban stratified by diabetes is of clinical interest. Methods 21,105 patients enrolled in ENGAGE AF-TIMI 48 were stratified into 2 pre-specified groups: without (N = 13,481) and with diabetes (N = 7,624). Results On average, patients with diabetes were younger, and had a higher body mass index, CHA2DS2-VASc score and baseline endogenous Factor Xa activity. After multivariate adjustments, patients with diabetes had a similar rate of stroke and systemic embolism compared to those without diabetes (adjusted hazard ratio (HRadj) 1.08; 95% confidence interval (CI) 0.94–1.24; p = 0.28). However, the risk of major bleeding was significantly higher in patients with diabetes (HRadj 1.28; 95% CI 1.14–1.44; p 0.05), a finding supported by the preserved edoxaban concentrations and inhibition of Factor Xa regardless of diabetes. The HRs of stroke and systemic embolism in patients receiving the higher-dose edoxaban regimen vs warfarin were 0.93 and 0.84 (p-interaction = 0.54) in those with and without diabetes respectively. The higher-dose edoxaban regimen reduced major bleeding (by 19–21%) and cardiovascular death (by 7–17%) regardless of diabetes (p-interactions = 0.81 and 0.33 respectively). Conclusion Patients with diabetes in ENGAGE AF-TIMI 48 had higher bleeding risk, but after adjustment similar stroke risk, compared to those without diabetes. The higher-dose edoxaban regimen had similar efficacy compared to warfarin, while reducing bleeding and cardiovascular mortality, irrespective of diabetes.

Posttranslational protein modification by ubiquitin (Ub) is a central eukaryotic mechanism that regulates a plethora of physiological processes. Recent studies unveiled an unconventional type of ubiquitination mediated by the SidE family of Legionella pneumophila effectors, such as SdeA, that catalyzes the conjugation of Ub to a serine residue of target proteins via a phosphoribosyl linker (hence named PR-ubiquitination). Comparable to the deubiquitinases in the canonical ubiquitination pathway, here we show that 2 paralogous Legionella effectors, Lpg2154 (DupA; deubiquitinase for PR-ubiquitination) and Lpg2509 (DupB), reverse PR-ubiquitination by specific removal of phosphoribosyl-Ub from substrates. Both DupA and DupB are fully capable of rescuing the Golgi fragmentation phenotype caused by exogenous expression of SdeA in mammalian cells. We further show that deletion of these 2 genes results in significant accumulation of PR-ubiquitinated species in host cells infected with Legionella In addition, we have identified a list of specific PR-ubiquitinated host targets and show that DupA and DupB play a role in modulating the association of PR-ubiquitinated host targets with Legionella-containing vacuoles. Together, our data establish a complete PR-ubiquitination and deubiquitination cycle and demonstrate the intricate control that Legionella has over this unusual Ub-dependent posttranslational modification.

The semi-insulating characteristics of GaAs substrates makes GaAs front end manufacturing sensitive to ESD events occurring during wafer processing. Charges induced to the wafer by these ESD events can harm or even destroy insulating structures like MIM capacitors because these charges cannot dissipate. This paper deals with the modelling and control of backside-induced ESD defects on MIM capacitors. It will highlight how charges can be induced to the wafer from its backside by wet-chemical processes and consequently destroy MIM capacitors at the wafer front side. Furthermore, we will explain how the DI water resistivity is the root cause for these defects and how it can be controlled to prevent the creation of ESD defects.

Acute respiratory inflammation, most commonly resulting from bacterial or viral infection, is one of the leading causes of death and disability worldwide. The inflammatory lipid mediator prostaglandin D2 (PGD2) and its rate-limiting enzyme, hematopoietic PGD synthase (hPGDS), are well-known drivers of allergic pulmonary inflammation. Here, we sought to investigate the source and role of hPGDS-derived PGD2 in acute pulmonary inflammation. Murine bronchoalveolar monocytes/macrophages from LPS- but not OVA-induced lung inflammation released significant amounts of PGD2. Accordingly, human monocyte-derived macrophages expressed high basal levels of hPGDS and released significant levels of PGD2 after LPS/IFN-γ, but not IL-4 stimulation. Human peripheral blood monocytes secreted significantly more PGD2 than monocyte-derived macrophages. Using human precision-cut lung slices (PCLS), we observed that LPS/IFN-γ but not IL-4/IL-13 drive PGD2 production in the lung. HPGDS inhibition prevented LPS-induced PGD2 release by human monocyte-derived macrophages and PCLS. As a result of hPGDS inhibition, less TNF-α, IL-6 and IL-10 could be determined in PCLS-conditioned medium. Collectively, this dataset reflects the time-dependent release of PGD2 by human phagocytes, highlights the importance of monocytes and macrophages as PGD2 sources and suggests that hPGDS inhibition might be a potential therapeutic option for acute, non-allergic lung inflammation.

The study of epithelial barrier properties in the human body is of paramount interest to a range of disciplines, including disease modeling, drug transport studies, toxicology, developmental biology, and regenerative biology. Current day in vitro studies largely rely on growing epithelial cells in a static environment on membrane cell culture inserts. With the advancement of microfluidic and organ-on-a-chip techniques it became possible to culture 3D intestinal tubules directly against an extracellular matrix (ECM) under flow and without the need for artificial membranes. Here we describe detailed protocols for culturing epithelial tubules in a high-throughput format, assessing their permeability and marker expression. The platform harbors 40 independent microfluidic chips in a microtiter plate format. The resulting 40 epithelial tubules are analyzed in parallel using a high-content microscopy. Protocols described here allow for adoption and routine application of microfluidic techniques by nonspecialized end-users.

Summary The mechanism of T cell antigen receptor (TCR-CD3) signaling remains elusive. Here, we identify mutations in the transmembrane region of TCRβ or CD3ζ that augment peptide T cell antigen receptor (pMHC)-induced signaling not explicable by enhanced ligand binding, lateral diffusion, clustering, or co-receptor function. Using a biochemical assay and molecular dynamics simulation, we demonstrate that the gain-of-function mutations loosen the interaction between TCRαβ and CD3ζ. Similar to the activating mutations, pMHC binding reduces TCRαβ cohesion with CD3ζ. This event occurs prior to CD3ζ phosphorylation and at 0°C. Moreover, we demonstrate that soluble monovalent pMHC alone induces signaling and reduces TCRαβ cohesion with CD3ζ in membrane-bound or solubilised TCR-CD3. Our data provide compelling evidence that pMHC binding suffices to activate allosteric changes propagating from TCRαβ to the CD3 subunits, reconfiguring interchain transmembrane region interactions. These dynamic modifications could change the arrangement of TCR-CD3 boundary lipids to license CD3ζ phosphorylation and initiate signal propagation., Graphical abstract, Highlights • Mutations in TCRβ and CD3ζ TMRs that reduce their interaction augment signaling • pMHC and anti-CD3 binding to TCR-CD3 induce similar quaternary structure relaxation • Soluble monovalent pMHC alone signals and reduces TCRαβ cohesion with CD3ζ • Allosteric changes in TCR-CD3 dynamics instigate T cell activation, T cell antigen receptor is central in adaptive immunity; however, the mechanism that couples ligand binding and intracellular signaling is still controversial. Here, Lanz et al. have taken an interdisciplinary approach demonstrating that binding of soluble monovalent pMHC to TCR-CD3 allosterically reduces TCRαβ cohesion with CD3ζ and initiates signal transduction.

Significance Carbon-13 MRI was used to assess exchange of hyperpolarized 13C label between injected [1-13C]pyruvate and the endogenous tumor lactate pool in breast cancer patients. Higher levels of 13C label exchange were observed in more-aggressive tumors, including all triple-negative cancers. The 13C label exchange correlated significantly with the expression of the transmembrane transporter mediating uptake of pyruvate into tumor cells and hypoxia inducible factor 1 (HIF1α), but no significant correlation with the expression of lactate dehydrogenase, the enzyme that catalyzes the exchange. The study has shown that 13C MRI can be used for metabolic imaging of breast cancer patients in the clinic, creating possibilities for noninvasive cancer monitoring in this patient group., Our purpose is to investigate the feasibility of imaging tumor metabolism in breast cancer patients using 13C magnetic resonance spectroscopic imaging (MRSI) of hyperpolarized 13C label exchange between injected [1-13C]pyruvate and the endogenous tumor lactate pool. Treatment-naïve breast cancer patients were recruited: four triple-negative grade 3 cancers; two invasive ductal carcinomas that were estrogen and progesterone receptor-positive (ER/PR+) and HER2/neu-negative (HER2−), one grade 2 and one grade 3; and one grade 2 ER/PR+ HER2− invasive lobular carcinoma (ILC). Dynamic 13C MRSI was performed following injection of hyperpolarized [1-13C]pyruvate. Expression of lactate dehydrogenase A (LDHA), which catalyzes 13C label exchange between pyruvate and lactate, hypoxia-inducible factor-1 (HIF1α), and the monocarboxylate transporters MCT1 and MCT4 were quantified using immunohistochemistry and RNA sequencing. We have demonstrated the feasibility and safety of hyperpolarized 13C MRI in early breast cancer. Both intertumoral and intratumoral heterogeneity of the hyperpolarized pyruvate and lactate signals were observed. The lactate-to-pyruvate signal ratio (LAC/PYR) ranged from 0.021 to 0.473 across the tumor subtypes (mean ± SD: 0.145 ± 0.164), and a lactate signal was observed in all of the grade 3 tumors. The LAC/PYR was significantly correlated with tumor volume (R = 0.903, P = 0.005) and MCT 1 (R = 0.85, P = 0.032) and HIF1α expression (R = 0.83, P = 0.043). Imaging of hyperpolarized [1-13C]pyruvate metabolism in breast cancer is feasible and demonstrated significant intertumoral and intratumoral metabolic heterogeneity, where lactate labeling correlated with MCT1 expression and hypoxia.

Glucose is the primary fuel for the brain, its metabolism is linked with cerebral function. Different magnetic resonance spectroscopy (MRS) techniques are available to assess glucose metabolism, providing complementary information. Our first aim was to investigate the difference between hyperpolarized 13C-glucose MRS and non-hyperpolarized 2H-glucose MRS to interrogate cerebral glycolysis. Isoflurane anesthesia is commonly employed in preclinical MRS, but it affects cerebral hemodynamics and functional connectivity. A combination of low doses of isoflurane and medetomidine is routinely used in rodent fMRI and shows similar functional connectivity, as in awake animals. As glucose metabolism is tightly linked to neuronal activity, our second aim was to assess the impact of these two anesthetic conditions on the cerebral metabolism of glucose. Brain metabolism of hyperpolarized 13C-glucose and 2H-glucose was monitored in two groups of mice in a 9.4 T MRI system. We found that the very different duration and temporal resolution of the two techniques enable highlighting the different aspects in glucose metabolism. We demonstrate (by numerical simulations) that hyperpolarized 13C-glucose reports on de novo lactate synthesis and is sensitive to CMRGlc. We show that variations in cerebral glucose metabolism, under different anesthesia, are reflected differently in hyperpolarized and non-hyperpolarized X-nuclei glucose MRS.

Iron and copper chelation restricts Plasmodium growth in vitro and in mammalian hosts. The parasite alters metal homeostasis in red blood cells to its favor, for example metabolizing hemoglobin to hemozoin. Metal interactions with the mosquito have not, however, been studied. Here, we describe the metallomes of Anopheles albimanus and Aedes aegypti throughout their life cycle and following a blood meal. Consistent with previous reports, we found evidence of maternal iron deposition in embryos of Ae. aegypti, but less so in An. albimanus. Sodium, potassium, iron, and copper are present at higher concentrations during larval developmental stages. Two An. albimanus phenotypes that differ in their susceptibility to Plasmodium berghei infection were studied. The susceptible white stripe (ws) phenotype was named after a dorsal white stripe apparent during larval stages 3, 4, and pupae. During larval stage 3, ws larvae accumulate more iron and copper than the resistant brown stripe (bs) phenotype counterparts. A similar increase in copper and iron accumulation was also observed in the susceptible ws, but not in the resistant bs phenotype following P. berghei infection. Feeding ws mosquitoes with extracellular iron and copper chelators before and after receiving Plasmodium-infected blood protected from infection and simultaneously affected follicular development in the case of iron chelation. Unexpectedly, the application of the iron chelator to the bs strain reverted resistance to infection. Besides a drop in iron, iron-chelated bs mosquitoes experienced a concomitant loss of copper. Thus, the effect of metal chelation on P. berghei infectivity was strain-specific., Author summary To establish a life cycle between insect and mammalian hosts, the malaria parasite has evolved mechanisms to manage metal ions from the distinct microenvironments it encounters. Previous work has addressed how interference using metal chelation affects parasite development in human, primate, and rodent hosts. Similar studies in mosquito species that harbor Plasmodium have not been performed. Here, we address such micronutrient relationships in three steps. First, we characterized how the metallome fluctuates during development in two species of mosquito. Second, we asked whether susceptibility to Plasmodium infection correlated with a differential response in mosquito metal homeostasis. Third, we tested the effects of iron and copper chelation treatment of adult mosquitoes concerning propensity of infection and mosquito reproduction. Metal ions offer a promising target in the ongoing efforts to control the mosquito-borne disease.

Lowe syndrome and Dent II disease are X-linked monogenetic diseases characterised by a renal reabsorption defect in the proximal tubules and caused by mutations in the OCRL gene, which codes for an inositol-5-phosphatase. The life expectancy of patients suffering from Lowe syndrome is largely reduced because of the development of chronic kidney disease and related complications. There is a need for physiological human in vitro models for Lowe syndrome/Dent II disease to study the underpinning disease mechanisms and to identify and characterise potential drugs and drug targets. Here, we describe a proximal tubule organ on chip model combining a 3D tubule architecture with fluid flow shear stress that phenocopies hallmarks of Lowe syndrome/Dent II disease. We demonstrate the high suitability of our in vitro model for drug target validation. Furthermore, using this model, we demonstrate that proximal tubule cells lacking OCRL expression upregulate markers typical for epithelial–mesenchymal transition (EMT), including the transcription factor SNAI2/Slug, and show increased collagen expression and deposition, which potentially contributes to interstitial fibrosis and disease progression as observed in Lowe syndrome and Dent II disease.

HER2-positive (HER2(+)) breast cancers (BrCs) contain approximately equal numbers of ERα(+)HER2(+) and ERα(−)HER2(+) cases. An enduring obstacle is the unclear cell lineage-related characteristics of these BrCs. Although ERα(+)HER2(+) BrCs could lose ERα to become ERα(−)HER2(+) BrCs, direct evidence is missing. To investigate ERα dependencies and their implications during BrC growth and metastasis, we generated ERα(Cre)RFP-T mice that produce an RFP-marked ERα(+) mammary gland epithelial cell (MGEC) lineage. RCAS virus-mediated expression of Erbb2, a rodent Her2 homolog, first produced comparable numbers of ERα(+)RFP(+)Erbb2(+) and ERα(−)RFP(−)Erbb2(+) MGECs. Early hyperplasia developed mostly from ERα(+)RFP(+)Erbb2(+) cells and ERα(−)RFP(−)Erbb2(+) cells in these lesions were rare. The subsequently developed ductal carcinomas in situ had 64% slow-proliferating ERα(+)RFP(+)Erbb2(+) cells, 15% fast-proliferating ERα(−)RFP(+)Erbb2(+) cells derived from ERα(+)RFP(+)Erbb2(+) cells, and 20% fast-proliferating ERα(−)RFP(−)Erbb2(+) cells. The advanced tumors had mostly ERα(−)RFP(+)Erbb2(+) and ERα(−)RFP(−)Erbb2(+) cells and only a very small population of ERα(+)RFP(+)Erbb2(+) cells. In ERα(−)RFP(+)Erbb2(+) cells, GATA3 and FoxA1 decreased expression and ERα promoter regions became methylated, consistent with the loss of ERα expression. Lung metastases consisted of mostly ERα(−)RFP(+)Erbb2(+) cells, a few ERα(−)RFP(−)Erbb2(+) cells, and no ERα(+)RFP(+)Erbb2(+) cells. The high metastatic capacity of ERα(−)RFP(+)Erbb2(+) cells was associated with ERK1/2 activation. These results show that the slow-proliferating, nonmetastatic ERα(+)RFP(+)Erbb2(+) cells progressively lose ERα during tumorigenesis to become fast-proliferating, highly metastatic ERα(−)RFP(+)Erbb2(+) cells. The ERα(−)Erbb2(+) BrCs with an ERα(+) origin are more aggressive than those ERα(−)Erbb2(+) BrCs with an ERα(−) origin, and thus, they should be distinguished and treated differently in the future.

SARS-CoV-2 neutralizing monoclonal antibodies (mAbs) can reduce the risk of hospitalization when administered early during COVID-19 disease. However, the emergence of variants of concern has negatively impacted the therapeutic use of some authorized mAbs. Using a high throughput B-cell screening pipeline, we isolated a highly potent SARS-CoV-2 spike glycoprotein receptor binding domain (RBD)-specific antibody called LY-CoV1404 (also known as bebtelovimab). LY-CoV1404 potently neutralizes authentic SARS-CoV-2 virus, including the prototype, B.1.1.7, B.1.351 and B.1.617.2). In pseudovirus neutralization studies, LY-CoV1404 retains potent neutralizing activity against numerous variants including B.1.1.7, B.1.351, B.1.617.2, B.1.427/B.1.429, P.1, B.1.526, B.1.1.529, and the BA.2 subvariant and retains binding to spike proteins with a variety of underlying RBD mutations including K417N, L452R, E484K, and N501Y. Structural analysis reveals that the contact residues of the LY-CoV1404 epitope are highly conserved with the exception of N439 and N501. Notably, the binding and neutralizing activity of LY-CoV1404 is unaffected by the most common mutations at these positions (N439K and N501Y). The breadth of reactivity to amino acid substitutions present among current VOC together with broad and potent neutralizing activity and the relatively conserved epitope suggest that LY-CoV1404 has the potential to be an effective therapeutic agent to treat all known variants causing COVID-19.In BriefLY-CoV1404 is a potent SARS-CoV-2-binding antibody that neutralizes all known variants of concern and whose epitope is rarely mutated.HighlightsLY-CoV1404 potently neutralizes SARS-CoV-2 authentic virus and known variants of concern including the B.1.1.529 (Omicron), the BA.2 Omicron subvariant, and B.1.617.2 (Delta) variantsNo loss of potency against currently circulating variantsBinding epitope on RBD of SARS-CoV-2 is rarely mutated in GISAID databaseBreadth of neutralizing activity and potency supports clinical development

The interaction between the mammalian host and its resident gut microbiota is known to license adaptive immune responses. Nutritional constituents strongly influence composition and functional properties of the intestinal microbial communities. Here, we report that omission of a single essential amino acid - tryptophan – from the diet abrogates CNS autoimmunity in a mouse model of multiple sclerosis. Dietary tryptophan restriction results in impaired encephalitogenic T cell responses and is accompanied by a mild intestinal inflammatory response and a profound phenotypic shift of gut microbiota. Protective effects of dietary tryptophan restriction are abrogated in germ-free mice, but are independent of canonical host sensors of intracellular tryptophan metabolites. We conclude that dietary tryptophan restriction alters metabolic properties of gut microbiota, which in turn have an impact on encephalitogenic T cell responses. This link between gut microbiota, dietary tryptophan and adaptive immunity may help to develop therapeutic strategies for protection from autoimmune neuroinflammation., Food intake shapes intestinal microbiome composition, which in turn shapes adaptive immune responses. Here the authors show that dietary tryptophan restriction (DTR) protects mice from subsequent autoimmune neuropathology challenge by altering intestinal microbiota, highlighting the potential of diet-regulated microbiota to prevent immune pathology.

Hypertension is a risk factor for both stroke and bleeding in patients with atrial fibrillation. Data are sparse regarding the interaction between blood pressure and the efficacy and safety of direct oral anticoagulants. In the ENGAGE AF-TIMI 48 trial (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation–Thrombolysis in Myocardial Infarction 48), 19,679 patients with atrial fibrillation and hypertension were categorized according to average systolic blood pressure (SBP) and diastolic blood pressure (DBP). The primary efficacy and safety end points were the time to the first stroke or systemic embolic event and the time to the first International Society of Thrombosis and Hemostasis major bleeding event, respectively. Risk was calculated using Cox proportional hazards models based on average SBP and DBP and adjusting for 18 clinical characteristics. The efficacy and safety of a higher dose edoxaban regimen (60/30 mg) versus warfarin were evaluated with stratification by average SBP and DBP. Stroke/systemic embolic event occurred significantly more frequently in patients with elevated average SBP (hazard ratio, 2.01; 95% CI, 1.50–2.70 for SBP ≥150 mm Hg relative to 130–139 mm Hg) or DBP (hazard ratio, 2.36; 95% CI, 1.76–3.16 for DBP ≥90 mm Hg relative to 75–P interaction =0.55) and DBP ( P interaction =0.44) compared with warfarin. The higher dose edoxaban regimen reduced the risk of major bleeding events, including intracranial hemorrhage, without modification by average SBP ( P interaction =0.29). The relative safety of edoxaban was most pronounced in patients with elevated DBP ( P interaction =0.007). The efficacy and safety of edoxaban were consistent across the full range of SBP, while the superior safety of edoxaban was most pronounced among patients with elevated DBP.

Background Patients with liver disease have increased risk of thrombosis and bleeding but are typically excluded from trials of direct oral anticoagulant agents. Objectives This study evaluated the pharmacokinetics (PK), pharmacodynamics (PD), clinical efficacy and safety of edoxaban versus warfarin in patients with atrial fibrillation (AF) and history of liver disease. Methods ENGAGE AF-TIMI 48 (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation–Thrombolysis In Myocardial Infarction Study 48) was a randomized, double-blind trial comparing edoxaban with warfarin in patients with AF followed for 2.8 years. History of liver disease was defined as investigator-reported liver disease or >2-fold transaminase elevation at randomization. The primary efficacy and safety endpoints of stroke or systemic embolic event (SSEE) and major bleeding were assessed stratified by history of liver disease. PK/PD assessments of edoxaban included endogenous and extrinsic factor Xa activity and edoxaban concentration. Results Among 21,105 patients, 1,083 (5.1%) had a history of liver disease; they had a higher prevalence of many comorbidities. The adjusted risks of SSEE were similar (adjusted hazard ratio [HRadj]: 0.90; 95% confidence interval [CI]: 0.67 to 1.22; p = 0.50), but major bleeding was more common in patients with liver disease (HRadj: 1.38; 95% CI: 1.10 to 1.74; p = 0.005). There were no significant differences in PK/PD assessment of edoxaban in patients with versus without liver disease. The HRs for higher-dose edoxaban versus warfarin for SSEE were 0.86 (95% CI: 0.73 to 1.01) in patients without and 1.11 (95% CI: 0.54 to 2.30) with liver disease (p for interaction [pint] = 0.47), major bleeding 0.80 (95% CI: 0.70 to 0.91) in patients without and 0.91 (95% CI: 0.56 to 1.47) with liver disease (pint = 0.63). There were no significant differences in hepatic adverse events between the 2 treatment groups. Conclusions Among patients with AF receiving oral anticoagulation, bleeding, but not thromboembolic events, was increased in patients with liver disease. A history of liver disease did not alter the relative efficacy and safety of edoxaban compared with warfarin. Hepatic adverse events were similar between edoxaban and warfarin.

SUMOylation (small ubiquitin-like modifier) in the DNA double-strand break (DSB) response regulates recruitment, activity, and clearance of repair factors. However, our understanding of a role for deSUMOylation in this process is limited. Here we identify different mechanistic roles for deSUMOylation in homologous recombination (HR) and nonhomologous end joining (NHEJ) through the investigation of the deSUMOylase SENP2. We found that regulated deSUMOylation of MDC1 prevents excessive SUMOylation and its RNF4-VCP mediated clearance from DSBs, thereby promoting NHEJ. In contrast, we show that HR is differentially sensitive to SUMO availability and SENP2 activity is needed to provide SUMO. SENP2 is amplified as part of the chromosome 3q amplification in many cancers. Increased SENP2 expression prolongs MDC1 focus retention and increases NHEJ and radioresistance. Collectively, our data reveal that deSUMOylation differentially primes cells for responding to DSBs and demonstrates the ability of SENP2 to tune DSB repair responses.

Background: Numerous scales exist for the classification of major bleeding events. Limited data compare the most commonly used bleeding scales within a single at-risk cohort of patients with atrial fibrillation. Here, we analyze bleeding outcomes according to the ISTH (International Society on Thrombosis and Hemostasis), TIMI (Thrombolysis in Myocardial Infarction), GUSTO (Global Usage of Strategies to Open Occluded Arteries), and BARC (Bleeding Academic Research Consortium) bleeding scales in the ENGAGE AF (Effective Anticoagulation With Factor Xa Next Generation in Atrial Fibrillation)–TIMI 48 trial (NCT00781391) of edoxaban versus warfarin. Methods: A total of 21 105 patients with atrial fibrillation at risk for stroke (CHADS 2 score ≥2) were enrolled in the ENGAGE AF-TIMI 48 trial comparing warfarin with a higher- (60/30 mg daily) or lower- (30/15 mg daily) dose edoxaban regimen. Median follow-up was 2.8 years. Bleeding events occurring among on-treatment patients were examined. Annualized event rates were calculated by the ISTH, TIMI, GUSTO, and BARC scales and compared across treatment arms. Cox proportional hazards for a first bleeding event of each type were calculated for higher-dose edoxaban regimen vs warfarin and lower-dose edoxaban regimen versus warfarin. Results: A total of 10 311 bleeding events were reported. In a comparison of the most severe events in each scale, ISTH major bleeding was the most common (n=1289), followed by TIMI major (n=548), GUSTO severe/life-threatening (n=347), and BARC 3c+5 (n=276) bleeding. Lower bleeding risk with edoxaban compared with warfarin was seen regardless of bleeding scale (higher-dose edoxaban regimen range: hazard ratio [HR], 0.47 [95% CI, 0.35–0.62] for BARC 3c+5 versus HR, 0.80 [95% CI, 0.71–0.91] for ISTH major; lower-dose edoxaban regimen range: HR, 0.32 [95% CI, 0.23–0.45] for BARC 3c+5 versus HR, 0.47 [95% CI, 0.41–0.55] for ISTH major). Furthermore, a gradient of more pronounced risk reduction with edoxaban was observed with greater severity of first bleeding event (higher-dose edoxaban regimen: HR, 0.47 [95% CI, 0.35–0.62] for BARC 3c+5 bleeds versus HR, 0.86 [95% CI, 0.81–0.91] for any BARC bleed; lower-dose edoxaban regimen: HR, 0.32 [95% CI, 0.23–0.45] for BARC 3c+5 bleeds versus HR, 0.68 [95% CI, 0.63–0.72] for any BARC bleed). The direction of this trend was consistent for both gastrointestinal bleeding and nongastrointestinal bleeding. Conclusions: Among patients with atrial fibrillation at risk for stroke, there was a >4-fold difference in the frequency of the most severe bleeding events across commonly used bleeding scales. Furthermore, the relative safety of edoxaban compared with warfarin tended to increase with greater severity of bleeding. Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT00781391.

62 p.-7 fig.-1 tab.-7 fig. suppl.-1 tab.supl., DNA polymerase ε (Polε) carries out high-fidelity leading strand synthesis owing to its exonuclease activity. Polε polymerase and exonuclease activities are balanced, because of partitioning of nascent DNA strands between catalytic sites, so that net resection occurs when synthesis is impaired. In vivo, DNA synthesis stalling activates replication checkpoint kinases, which act to preserve the functional integrity of replication forks. We show that stalled Polε drives nascent strand resection causing fork functional collapse, averted via checkpoint-dependent phosphorylation. Polε catalytic subunit Pol2 is phosphorylated on serine 430, influencing partitioning between polymerase and exonuclease active sites. A phosphormimetic S430D change reduces exonucleolysis in vitro and counteracts fork collapse. Conversely, non-phosphorylatable pol2-S430A expression causes resection-driven stressed fork defects. Our findings reveal that checkpoint kinases switch Polε to an exonuclease-safe mode preventing nascent strand resection and stabilizing stalled replication forks. Elective partitioning suppression has implications for the diverse Polε roles in genome integrity maintenance., This work was supported by the Spanish Ministry of Ministry of Science, Innovation and Universities (BFU2014-52529-R and BFU2017-87013-R to R.B.), the Junta de Castilla y León (SA042P17 and SA103P20 to R.B.). M.B.S. was supported by a grant from the National Institute of Health - NIGMS (R35GM141159).

Lanz et al. reveal that IFITM3, an effector protein of the IFN response, can compete with influenza virus glycoproteins for incorporation into viral particles. This decrease in viral glycoprotein content sensitizes influenza virus to antibody-mediated neutralization, thereby impacting the severity of influenza disease., The disease severity of influenza is highly variable in humans, and one genetic determinant behind these differences is the IFITM3 gene. As an effector of the interferon response, IFITM3 potently blocks cytosolic entry of influenza A virus (IAV). Here, we reveal a novel level of inhibition by IFITM3 in vivo: We show that incorporation of IFITM3 into IAV particles competes with incorporation of viral hemagglutinin (HA). Decreased virion HA levels did not reduce infectivity, suggesting that high HA density on IAV virions may be an antagonistic strategy used by the virus to prevent direct inhibition. However, we found that IFITM3-mediated reduction in HA content sensitizes IAV to antibody-mediated neutralization. Mathematical modeling predicted that this effect decreases and delays peak IAV titers, and we show that, indeed, IFITM3-mediated sensitization of IAV to antibody-mediated neutralization impacts infection outcome in an in vivo mouse model. Overall, our data describe a previously unappreciated interplay between the innate effector IFITM3 and the adaptive immune response., Graphical Abstract

Introduction The efficacy and safety of the oral factor Xa inhibitor edoxaban compared to warfarin stratified by CHA2DS2VASc scores have not been described. Methods The ENGAGE AF-TIMI 48 trial randomized patients with atrial fibrillation to once-daily edoxaban or warfarin. We classified patients based on CHA2DS2VASc score and compared pharmacokinetics (edoxaban concentration), pharmacodynamics (anti-factor Xa [FXa] with edoxaban, time-in-therapeutic range for warfarin), efficacy (stroke or systemic embolism [SSE]), safety (major bleeding [MB], intracranial hemorrhage), and cardiovascular mortality, for the approved edoxaban regimen vs warfarin. Results The distribution CHA2DS2VASc score were:≤3, N = 4159 (29.6%); 4, N = 4066 (28.9%); 5, N = 3165 (22.5%); and ≥6, N = 2681 (19.1%). Increasing rates of SSE (1.05 to 2.99%/year) and MB (2.27 to 4.66%/year) were observed in the warfarin arm as the CHA2DS2VASc score increased. The hazard ratios per unit increase of CHA2DS2VASc score were 1.29 (1.21-1.38) and 1.26 (1.17-1.36) for SSE, and 1.20 (1.13-1.27) and 1.19 (1.12-1.27) for MB, with warfarin and edoxaban, respectively. Time-in-therapeutic range in warfarin-treated patients was similar and high (median 68%-69%) across CHA2DS2VASc scores, whereas edoxaban trough concentration, exogenous anti-FXa activity and %inhibition of endogenous FXa were higher at increasing CHA2DS2VASc scores. Edoxaban reduced SSE, MB, intracranial hemorrhage, and cardiovascular mortality vs warfarin to a similar degree across the range of CHA2DS2VASc scores (P-int = 0.90, 0.96, 0.21, and 0.37, respectively). Because of higher event rates the number of events prevented with edoxaban tended to be greater in patients with higher CHA2DS2VASc scores. Conclusion The benefit and safety of edoxaban versus warfarin is maintained across CHA2DS2VASc scores. While the relative risk reductions remain similar, edoxaban provides incrementally larger absolute reductions in outcomes over warfarin in patients with higher CHA2DS2VASc scores.

Glucose is a major energy fuel for the brain, however, less is known about specificities of its metabolism in distinct cerebral areas. Here we examined the regional differences in glucose utilization between the hypothalamus and hippocampus using in vivo indirect 13C magnetic resonance spectroscopy (1H-[13C]-MRS) upon infusion of [1,6-13C2]glucose. Using a metabolic flux analysis with a 1-compartment mathematical model of brain metabolism, we report that compared to hippocampus, hypothalamus shows higher levels of aerobic glycolysis associated with a marked gamma-aminobutyric acid-ergic (GABAergic) and astrocytic metabolic dependence. In addition, our analysis suggests a higher rate of ATP production in hypothalamus that is accompanied by an excess of cytosolic nicotinamide adenine dinucleotide (NADH) production that does not fuel mitochondria via the malate-aspartate shuttle (MAS). In conclusion, our results reveal significant metabolic differences, which might be attributable to respective cell populations or functional features of both structures.

Aims This post hoc analysis of ELIMINATE-AF evaluated requirements of unfractionated heparin (UFH) and procedure-related bleeding in atrial fibrillation (AF) patients undergoing ablation with uninterrupted edoxaban or vitamin K antagonist (VKA) therapy. Methods and results Patients were randomized 2:1 to once-daily edoxaban 60 mg (or dose-reduced 30 mg) or dose-adjusted VKA (target international normalized ratio: 2.0–3.0). Uninterrupted anticoagulation was mandated for 21–28 days’ pre-ablation and 90 days’ post-ablation. During ablation, UFH administration targeted an activated clotting time (ACT) of 300–400 s. Periprocedural bleeding was differentiated between procedure-related (bleeding at puncture side, cardiac tamponade) and unrelated events. Of 614 randomized patients, 553 received study drug and underwent catheter ablation (edoxaban n = 375; VKA n = 178). The median (Q1–Q3) time from last dose to ablation procedure was 14.8 (13.3–16.5) vs. 16.5 (14.8–19.5) h (edoxaban vs. VKA group, respectively). Mean ACT (SD) ≥300 s was observed in 52% edoxaban- vs. 76% VKA-treated patients, despite a higher mean (SD) UFH dose in the edoxaban vs. VKA group [14 261 (6397) IU vs. 11 473 (4300) IU; exploratory P-value < 0.0001]. In the edoxaban group, 13 patients (3.5%) had procedure-related bleeds of whom 9 had received an UFH dose above the median (13 000 IU). In the VKA arm, 7 patients (3.9%) had procedure-related bleeds of whom 3 had received an UFH dose above the median (10 225 IU). Conclusion The rate of procedure-related major/clinically relevant non-major bleeding did not differ between the treatment arms despite higher doses of UFH used with edoxaban vs. VKA to achieve a target ACT during AF ablation.

Background The effects of anticoagulants at extremes of body weight (BW) are not well described. The aim of this study was to analyze the pharmacokinetics/pharmacodynamics and clinical outcomes in patients randomized to warfarin, higher dose edoxaban (HDER), and lower dose edoxaban (LDER) regimens at extremes of BW in ENGAGE AF-TIMI 48.Methods and Results We analyzed three BW groups: low BW (LBW: 95th percentile, ≥120 kg, N = 1,093). In the warfarin arm, LBW patients had higher rates of stroke/systemic embolism (SSE: 6.5 vs. 4.7 in MBW vs. 1.6% in HBW, P trend Conclusion Patients with LBW in ENGAGE AF-TIMI 48 had in general a more fragile clinical status and poorer international normalized ratio control. The pharmacokinetic/pharmacodynamic profile of edoxaban was consistent across extremes of BW, resulting in similar efficacy compared with warfarin, while major or clinically relevant non-MB and net outcomes were most favorable with edoxaban as compared to warfarin in LBW patients.

The liver is the central hub for processing and maintaining homeostatic levels of dietary nutrients especially essential amino acids such as tryptophan (Trp). Trp is required not only to sustain protein synthesis but also as a precursor for the production of NAD, neurotransmitters and immunosuppressive metabolites. In light of these roles of Trp and its metabolic products, maintaining homeostatic levels of Trp is essential for health and well-being. The liver regulates global Trp supply by the immunosuppressive enzyme tryptophan-2,3-dioxygenase (TDO2), which degrades Trp down the kynurenine pathway (KP). In the current study, we show that isolated primary hepatocytes when exposed to hypoxic environments, extensively rewire their Trp metabolism by reducing constitutive Tdo2 expression and differentially regulating other Trp pathway enzymes and transporters. Mathematical modelling of Trp metabolism in liver cells under hypoxia predicted decreased flux through the KP while metabolic flux through the tryptamine branch significantly increased. In line, the model also revealed an increased accumulation of tryptamines under hypoxia, at the expense of kynurenines. Metabolic measurements in hypoxic hepatocytes confirmed the predicted reduction in KP metabolites as well as accumulation of tryptamine. Tdo2 expression in cultured primary hepatocytes was reduced upon hypoxia inducible factor (HIF) stabilisation by dimethyloxalylglycine (DMOG), demonstrating that HIFs are involved in the hypoxic downregulation of hepatic Tdo2. DMOG abrogated hepatic luciferase signals in Tdo2 reporter mice, indicating that HIF stability also recapitulates hypoxic rewiring of Trp metabolism in vivo. Also in WT mice HIF stabilization drove homeostatic Trp metabolism away from the KP towards enhanced tryptamine production, leading to enhanced levels of tryptamine in liver, serum and brain. As tryptamines are the most potent hallucinogens known, the observed upregulation of tryptamine in response to hypoxic exposure of hepatocytes may be involved in the generation of hallucinations occurring at high altitude. KP metabolites are known to activate the aryl hydrocarbon receptor (AHR). The AHR-activating properties of tryptamines may explain why immunosuppressive AHR activity is maintained under hypoxia despite downregulation of the KP. In summary our results identify hypoxia as an important factor controlling Trp metabolism in the liver with possible implications for immunosuppressive AHR activation and mental disturbances.

Assessment of epithelial barrier function is critically important for studying healthy and diseased biological models. Here we introduce an instrument that measures transepithelial electrical resistance (TEER) of perfused epithelial tubes in the microfluidic OrganoPlate platform. The tubules are grown in microfluidic channels directly against an extracellular matrix, obviating the need for artificial filter membranes. We present TEER measurements on Caco-2 intestinal and renal proximal tubule epithelium. Forty tubules on one single plate were interrogated in less than a minute. We show that TEER measurement is significantly more sensitive than a fluorescent reporter leakage assay in response to staurosporine. We demonstrate a 40-channel time-lapse data acquisition over a 25 hour time period under flow conditions. We furthermore observed a 50% reduction in Caco-2 TEER values following exposure to a cocktail of inflammatory cytokines. To our best knowledge, this is the first instrument of its kind that allows routine TEER studies in perfused organ-on-a-chip systems without interference by artificial filter membranes. We believe the apparatus will contribute to accelerating routine adoption of perfused organ-on-a-chip systems in academic research and in industrial drug development.