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Background Septic cardiomyopathy worsens the prognosis of critically ill patients. Clinical data suggest that interleukin‐1β (IL‐1β), activated by the NLRP3 inflammasome, compromises cardiac function. Whether or not deleting Nlrp3 would prevent cardiac atrophy and improve diastolic cardiac function in sepsis was unclear. Here, we investigated the role of NLRP3/IL‐1β in sepsis‐induced cardiomyopathy and cardiac atrophy. Methods Male Nlrp3 knockout (KO) and wild‐type (WT) mice were exposed to polymicrobial sepsis by caecal ligation and puncture (CLP) surgery (KO, n = 27; WT, n = 33) to induce septic cardiomyopathy. Sham‐treated mice served as controls (KO, n = 11; WT, n = 16). Heart weights and morphology, echocardiography and analyses of gene and protein expression were used to evaluate septic cardiomyopathy and cardiac atrophy. IL‐1β effects on primary and immortalized cardiomyocytes were investigated by morphological and molecular analyses. IonOptix and real‐time deformability cytometry (RT‐DC) analysis were used to investigate functional and mechanical effects of IL‐1β on cardiomyocytes. Results Heart morphology and echocardiography revealed preserved systolic (stroke volume: WT sham vs. WT CLP: 33.1 ± 7.2 μL vs. 24.6 ± 8.7 μL, P < 0.05; KO sham vs. KO CLP: 28.3 ± 8.1 μL vs. 29.9 ± 9.9 μL, n.s.; P < 0.05 vs. WT CLP) and diastolic (peak E wave velocity: WT sham vs. WT CLP: 750 ± 132 vs. 522 ± 200 mm/s, P < 0.001; KO sham vs. KO CLP: 709 ± 152 vs. 639 ± 165 mm/s, n.s.; P < 0.05 vs. WT CLP) cardiac function and attenuated cardiac (heart weight–tibia length ratio: WT CLP vs. WT sham: −26.6%, P < 0.05; KO CLP vs. KO sham: −3.3%, n.s.; P < 0.05 vs. WT CLP) and cardiomyocyte atrophy in KO mice during sepsis. IonOptix measurements showed that IL‐1β decreased contractility (cell shortening: IL‐1β: −15.4 ± 2.3%, P < 0.001 vs. vehicle, IL‐1RA: −6.1 ± 3.3%, P < 0.05 vs. IL‐1β) and relaxation of adult rat ventricular cardiomyocytes (time‐to‐50% relengthening: IL‐1β: 2071 ± 225 ms, P < 0.001 vs. vehicle, IL‐1RA: 564 ± 247 ms, P < 0.001 vs. IL‐1β), which was attenuated by an IL‐1 receptor antagonist (IL‐1RA). RT‐DC analysis indicated that IL‐1β reduced cardiomyocyte size (P < 0.001) and deformation (P < 0.05). RNA sequencing showed that genes involved in NF‐κB signalling, autophagy and lysosomal protein degradation were enriched in hearts of septic WT but not in septic KO mice. Western blotting and qPCR disclosed that IL‐1β activated NF‐κB and its target genes, caused atrophy and decreased myosin protein in myocytes, which was accompanied by an increased autophagy gene expression. These effects were attenuated by IL‐1RA. Conclusions IL‐1β causes atrophy, impairs contractility and relaxation and decreases deformation of cardiomyocytes. Because NLRP3/IL‐1β pathway inhibition attenuates cardiac atrophy and cardiomyopathy in sepsis, it could be useful to prevent septic cardiomyopathy.

In life sciences, the material properties of suspended cells have attained significance close to that of fluorescent markers but with the advantage of label-free and unbiased sample characterization. Until recently, cell rheological measurements were either limited by acquisition throughput, excessive post processing, or low-throughput real-time analysis. Real-time deformability cytometry expanded the application of mechanical cell assays to fast on-the-fly phenotyping of large sample sizes, but has been restricted to single material parameters as the Young’s modulus. Here, we introduce dynamic real-time deformability cytometry for comprehensive cell rheological measurements at up to 100 cells per second. Utilizing Fourier decomposition, our microfluidic method is able to disentangle cell response to complex hydrodynamic stress distributions and to determine viscoelastic parameters independent of cell shape. We demonstrate the application of our technology for peripheral blood cells in whole blood samples including the discrimination of B- and CD4+ T-lymphocytes by cell rheological properties. Real-time deformability cytometry (RT-DC) is used for mechanical cell phenotyping but is limited to a single snapshot per cell and can only measure elastic modulus. Here the authors introduce dynamic RT-DC which can measure elasticity and viscosity in single cells by following dynamic cell shape changes.

Federated learning is a renowned technique for utilizing decentralized data while preserving privacy. However, real-world applications often face challenges like partially labeled datasets, where only a few locations have certain expert annotations, leaving large portions of unlabeled data unused. Leveraging these could enhance transformer architectures’ ability in regimes with small and diversely annotated sets. We conduct the largest federated cardiac CT analysis to date ( n = 8, 104) in a real-world setting across eight hospitals. Our two-step semi-supervised strategy distills knowledge from task-specific CNNs into a transformer. First, CNNs predict on unlabeled data per label type and then the transformer learns from these predictions with label-specific heads. This improves predictive accuracy and enables simultaneous learning of all partial labels across the federation, and outperforms UNet-based models in generalizability on downstream tasks. Code and model weights are made openly available for leveraging future cardiac CT analysis.

AimThe purpose of this study was to investigate the relationship between physical workload and injury risk in elite youth football players.MethodsThe workload data and injury incidence of 32 players were monitored throughout 2 seasons. Multiple regression was used to compare cumulative (1, 2, 3 and 4-weekly) loads and acute:chronic (A:C) workload ratios (acute workload divided by chronic workload) between injured and non-injured players for specific GPS and accelerometer-derived variables:total distance (TD), high-speed distance (HSD), accelerations (ACC) and total load. Workloads were classified into discrete ranges by z-scores and the relative risk was determined.ResultsA very high number of ACC (≥9254) over 3 weeks was associated with the highest significant overall (relative risk (RR)=3.84) and non-contact injury risk (RR=5.11). Non-contact injury risk was significantly increased when a high acute HSD was combined with low chronic HSD (RR=2.55), but not with high chronic HSD (RR=0.47). Contact injury risk was greatest when A:C TD and ACC ratios were very high (1.76 and 1.77, respectively) (RR=4.98).ConclusionsIn general, higher accumulated and acute workloads were associated with a greater injury risk. However, progressive increases in chronic workload may develop the players' physical tolerance to higher acute loads and resilience to injury risk.

Sepsis is the most common cause of death in medical intensive care units (ICU). If sepsis progresses to refractory septic shock, mortality may reach 90–100% despite optimum current therapy. Extracorporeal cytokine adsorption in addition to regular therapy was studied prospectively in refractory septic shock patients on a medical ICU. Refractory shock was defined as increasing vasopressor dose required to maintain mean arterial blood pressure above 65 mmHg or increasing lactate levels despite protocol-guided shock therapy for 6 h. We analysed noradrenaline requirements after 6 and 12 h (primary endpoint), lactate clearance after 6 and 12 h, SOFA-scores in the first days and achievement of shock reversal (i.e., normalization of lactate concentrations and sustained discontinuation of vasopressors; secondary endpoints). Twenty consecutive patients with refractory septic shock were included; CytoSorb ® treatment was started after 7.8 ± 3.7 h of shock therapy. Following the initiation of adsorption therapy, noradrenaline dose could be significantly reduced after 6 (−0.4 µg/kg/min; p  = 0.03) and 12 h (−0.6 µg/kg/min; p  = 0.001). Lactate clearance improved significantly. SOFA-scores on day 0, 1 and 2 remained unchanged. Shock reversal was achieved in 13 (65%) patients; 28-day survival was 45%. In severe septic shock unresponsive to standard treatment, haemodynamic stabilization was achieved using cytokine adsorption therapy, resulting in shock reversal in two-thirds of these patients. The study was registered in the German Register for Clinical Trials (DRKS) No. 00005149.

T cells drive post-stroke secondary brain injury, with the Th17/Treg balance shaping post-stroke inflammation. Soraphen A (SorA) inhibits Th17 polarization while preserving Tregs. We examined SorA's effects on post-stroke T cell activation - distinguishing antigen-specific from bystander activation - including inflammatory conditions induced by LPS. Male Nur77 mice (12-14 weeks) underwent tMCAO. At reperfusion, mice received intraperitoneal LPS or vehicle; SorA or vehicle was given 2 h later and daily thereafter. MRI at 16 h and 7 d confirmed infarcts and measured lesion volumes. Functional outcomes were assessed by daily scoring and behavioral tests before surgery and at 2 and 6 d. T cell activation and polarization were analyzed by flow cytometry in brain, lungs, spleen, blood, and lymph nodes at 16 h, 2, 3, and 7 d, with GFP indicating antigen-specific activation. LPS worsened functional outcomes and increased peripheral T cell activation post-stroke. SorA improved functional recovery, reduced peripheral T cell activation and enhanced antigen-specific T cell activation. SorA increased Treg in LPS-treated mice and reversed LPS-induced alterations in both T cell activation and behavior. Soraphen A modulates systemic and organ-specific T cell responses in experimental ischemic stroke and improves outcomes. SorA increases regulatory T cells, reverses LPS-associated T cell activation (CD25, CD69, PD-1) and behavioral deficits, and shifts responses toward antigen-specific T cell receptor-mediated activation. These results support SorA as a promising immunomodulatory strategy to refine post-stroke immunity, extend the therapeutic window, and improve outcomes with potential benefits in the context of post-stroke infections.

Squalene epoxidase (SQLE), also known as squalene monooxygenase, catalyzes the stereospecific conversion of squalene to 2,3( S )-oxidosqualene, a key step in cholesterol biosynthesis. SQLE inhibition is targeted for the treatment of hypercholesteremia, cancer, and fungal infections. However, lack of structure-function understanding has hindered further progression of its inhibitors. We have determined the first three-dimensional high-resolution crystal structures of human SQLE catalytic domain with small molecule inhibitors (2.3 Å and 2.5 Å). Comparison with its unliganded state (3.0 Å) reveals conformational rearrangements upon inhibitor binding, thus allowing deeper interpretation of known structure-activity relationships. We use the human SQLE structure to further understand the specificity of terbinafine, an approved agent targeting fungal SQLE, and to provide the structural insights into terbinafine-resistant mutants encountered in the clinic. Collectively, these findings elucidate the structural basis for the specificity of the epoxidation reaction catalyzed by SQLE and enable further rational development of next-generation inhibitors. Squalene epoxidase (SQLE) is a key enzyme in cholesterol biosynthesis and is a target for hypercholesteremia and cancer drug development. Here the authors present the crystal structures of the human SQLE catalytic domain alone and bound with small molecule inhibitors, which will facilitate the development of next-generation SQLE inhibitors.

A number of human cancers harbor somatic point mutations in the genes encoding isocitrate dehydrogenases 1 and 2 (IDH1 and IDH2). These mutations alter residues in the enzyme active sites and confer a gain-of-function in cancer cells, resulting in the accumulation and secretion of the oncometabolite (R)-2-hydroxyglutarate (2HG). We developed a small molecule, AGI-6780, that potently and selectively inhibits the tumor-associated mutant IDH2/R140Q. A crystal structure of AGI-6780 complexed with IDH2/R140Q revealed that the inhibitor binds in an allosteric manner at the dimer interface. The results of steady-state enzymology analysis were consistent with allostery and slow-tight binding by AGI-6780. Treatment with AGI-6780 induced differentiation of TF-1 erythroleukemia and primary human acute myelogenous leukemia cells in vitro. These data provide proof-of-concept that inhibitors targeting mutant IDH2/R140Q could have potential applications as a differentiation therapy for cancer.

The ( R )-enantiomer of 2-hydroxyglutarate, which is produced when IDH is mutated in human tumours, is shown to stimulate the activity of the EGLN prolyl 4-hydroxylases, leading to diminished levels of HIF and enhanced human astrocyte proliferation. Cancer induction by isocitrate dehydrogenase mutation Mutations in the isocitrate dehydrogenase genes IDH1 and IDH2 have been identified in gliomas, the most common form of brain tumour, and in other cancers including leukaemias. The mutated enzymes produce 2-hydroxyglutarate (2HG), which is a potential oncometabolite. Three papers in this issue of Nature examine the mechanisms through which IDH mutations promote cancers. Lu et al . show that 2HG-producing IDH mutants can prevent the histone demethylation that is required for progenitor cells to differentiate, potentially contributing to tumour-cell accumulation. Turcan et al . show that IDH1 mutation in primary human astrocytes induces DNA hypermethylation and reshapes the methylome to resemble that of the CIMP phenotype, a common feature of gliomas and other solid tumours. Koivunen et al . show that the ( R )-enantiomer of 2HG (but not the ( S )-enantiomer) can stimulate the activity of the EGLN prolyl 4-hydroxylases, leading to diminished levels of hypoxia-inducible factor (HIF), which in turn can enhance cell proliferation. These papers establish a framework for understanding gliomagenesis and highlight the interplay between genomic and epigenomic changes in human cancers. The identification of succinate dehydrogenase (SDH), fumarate hydratase (FH) and isocitrate dehydrogenase (IDH) mutations in human cancers has rekindled the idea that altered cellular metabolism can transform cells. Inactivating SDH and FH mutations cause the accumulation of succinate and fumarate, respectively, which can inhibit 2-oxoglutarate (2-OG)-dependent enzymes, including the EGLN prolyl 4-hydroxylases that mark the hypoxia inducible factor (HIF) transcription factor for polyubiquitylation and proteasomal degradation 1 . Inappropriate HIF activation is suspected of contributing to the pathogenesis of SDH-defective and FH-defective tumours but can suppress tumour growth in some other contexts. IDH1 and IDH2, which catalyse the interconversion of isocitrate and 2-OG, are frequently mutated in human brain tumours and leukaemias. The resulting mutants have the neomorphic ability to convert 2-OG to the ( R )-enantiomer of 2-hydroxyglutarate (( R )-2HG) 2 , 3 . Here we show that ( R )-2HG, but not ( S )-2HG, stimulates EGLN activity, leading to diminished HIF levels, which enhances the proliferation and soft agar growth of human astrocytes. These findings define an enantiomer-specific mechanism by which the ( R )-2HG that accumulates in IDH mutant brain tumours promotes transformation and provide a justification for exploring EGLN inhibition as a potential treatment strategy.

The assessment of cardiorespiratory fitness (CRF) is an important tool for prognosis evaluation of cardiovascular events. The gold standard to measure CRF is cardiopulmonary exercise testing (CPET) to determine peak oxygen uptake (VO2peak). However, CPET is not only time consuming but also expensive and is therefore not widely applicable in daily practice. The aim of our study was to analyze, whether and which anthropometric markers derived from a 3D body scanner were related to VO2peak in a general population-based study. We analyzed data (SHIP-START-3) from 3D body scanner and CPET of 1035 subjects (529 women; 51.1%, age range 36–93). A total of 164 anthropometric markers were detected with the 3D body scanner VITUS Smart XXL using the software AnthroScan Professional . Anthropometric measurements were standardized and associated with CRF by sex-stratified linear regression models adjusted for age and height. Anthropometric markers were ranked according to the  − log- p values derived from these regression models. In men a greater left and right thigh-knee-ratio, a longer forearm-fingertip length, a greater left thigh circumference and greater left upper arm circumference were most strongly associated with a higher VO2peak. In women a greater left and right thigh circumference, left calf circumference, thigh thickness and right calf circumference were most strongly associated with a higher VO2peak. The detected VO2peak-related anthropometric markers could be helpful in assessing CRF in clinical routine. Commonly used anthropometric markers, e.g. waist and hip circumference, were not among the markers associated with VO2peak.