Nature Cardiovascular Research

Endothelial senescence is increasingly recognized as a driver of vascular pathology, while immunoglobulin G (IgG) has recently been reported to accumulate in aging tissues and induce senescence in macrophages and microglia. In cerebral cavernous malformations (CCMs), IgG accumulation has been obviously observed in CCM lesions, but the contribution of IgG to endothelial injury remains unclear. Using multi-omic profiling, endothelial models, and CCM mice, we identified IgG-secreting plasma cells enriched in lesions associated with endothelial senescence, hemorrhage, and disease severity. CCM loss-associated mTOR activation impaired lysosomal acidification and IgG processing, promoting intracellular IgG accumulation. IgG, in turn, induced NF-kB-dependent endothelial senescence. In vivo, BCMA-mediated plasma cell depletion attenuated lesion progression, whereas IgG supplementation partially restored disease severity. Anti-CD38 treatment likewise reduced IgG accumulation, endothelial senescence, hemorrhage, and lesion progression. These findings identify lysosomal dysfunction-mediated IgG as a pathogenic trigger of endothelial senescence and support targeting the plasma cell-IgG axis in CCM.

Thoracic aortic aneurysm and dissection (TAAD) is a life-threatening disease characterized by progressive medial degeneration, impaired mechanical integrity, and extracellular matrix (ECM) degradation. However, no pharmacological therapy has been proven to halt aneurysm progression or prevent dissection or rupture. Vascular smooth muscle cells (VSMCs) are vital for maintaining medial architecture by sensing and remodeling the surrounding ECM; however, the mechanism by which abnormal ECM mechanics are transmitted to nuclear transcriptional programs that disrupt aortic wall matrix homeostasis remains incompletely understood. Integrative transcriptomic screening of Lysyl oxidase (LOX)-deficient and ?-aminopropionitrile (BAPN)-induced TAAD models identified vestigial-like family member 4 (VGLL4) as a mechanosensitive transcriptional regulator of TAAD. VGLL4 was enriched in VSMCs and markedly increased in aortas from patients with TAAD and BAPN-induced TAAD mice. VSMC specific deletion of Vgll4 protected mice from BAPN-induced aortic dilation, dissection, rupture-associated mortality, vascular stiffening, ECM degradation, and medial destruction. Mechanistically, pathological matrix remodeling and mechanical stress induced VGLL4 expression in VSMCs, where VGLL4 cooperated with specificity protein 1 (SP1) to activate Wisp1 transcription. In vivo, VSMC-enriched Wnt-inducible signaling pathway protein (WISP1) overexpression exacerbated TAAD progression, whereas Wisp1 knockdown protected against BAPN-induced TAAD and mitigated the severe aortic phenotype driven by VGLL4 overexpression. Secreted WISP1 bound Tissue Inhibitor of Metalloproteinases 3 (TIMP3) through its C-terminal domain and impaired TIMP3-mediated MMP9 inhibition, thereby increasing MMP9 proteolytic activity and accelerating ECM degradation. Consistently, in vivo Wisp1 knockdown protected against BAPN-induced TAAD. Together, these findings define the VGLL4-WISP1-TIMP3/MMP9 axis, which couples pathological ECM mechanics to nuclear transcriptional activation and protease-dependent matrix degradation in VSMCs. This pathway promotes medial structural failure, aortic mechanical stability loss, and TAAD progression, identifying WISP1 as a potential therapeutic target for preserving aortic wall matrix homeostasis.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and a major cause of cardioembolic stroke. Although polygenic risk scores (PRS) are well characterized to quantify inherited susceptibility for AF, they provide limited insight into the pathways and tissues underlying genetic risk, which are critical to uncover for individual risk prediction. In this study, we develop a pathway-level multi-omics representation learning framework that converts individual genetic profiles into interpretable biological features by integrating GWAS-derived pathway burden scores with tissue-specific transcriptomic pathway signals. We constructed machine learning models to assess population-level AF risk prediction performance across genomic and transcriptomic tissue contexts; the pathway-based global attention models substantially improved risk prediction performance over PRS and other baselines (AUROC improved from 0.601 to 0.738). Transformer and graph neural network frameworks then assessed individual-level pathway interpretability, revealing heterogeneous contributions from electrical signaling, cardiac development, and DNA repair pathways to AF risk. This added interpretability highlights the potential of this pathway approach to enable more mechanistically informed risk stratification than static PRS by capturing underlying heterogeneity. To independently assess whether prioritized pathways reflected cardiac regulatory biology, we compared pathway rankings with transcriptional effects predicted by the AlphaGenome foundation model. Variants in highly ranked pathways showed significantly greater predicted effects on expression in atrial and ventricular tissues (FDR = 0.032) relative to controls, providing orthogonal evidence that the model identifies biologically relevant mechanisms. Overall, this work reframes polygenic risk from a single measure of susceptibility to tissue-informed pathway mechanisms, providing a framework for interpretable genomic stratification in complex diseases.

Self-supervised models increasingly convert medical images into quantitative phenotypes for biological discovery, but statistical reproducibility does not establish that a learned phenotype represents the intended anatomy. We trained a video masked-autoencoder on 69,932 UK Biobank cardiac cine-MRI studies and performed genome-wide association analysis of its latent representation. Although 18 of 20 leading axes were heritable with well-calibrated statistics, the representation encoded substantial field-of-view information: body size, stature and imaging centre (linear-probe R^2=0.55 for site); standard genomic-control and LD-score diagnostics did not identify this source of phenotype-level confounding. Restricting the field of view to the heart and residualising body and acquisition covariates before dimensionality reduction substantially attenuated linear and non-linear nuisance information while retaining cardiac signal. Adjusting the same covariates only during association testing attenuated nuisance associations but recovered substantially less of the cardiac-associated genetic signal, consistent with nuisance variation having already influenced the principal-component basis. The corrected representation identified new associated loci beyond those detected using supervised phenotypes at matched sample size, which shared genetic architecture selectively with cardiac-conduction traits and were localised to cardiac structures within the imaged field of view. Confounding in learned medical phenotypes can arise upstream of association testing, highlighting the importance of auditing and, where appropriate, correcting learned representations before association testing.

Background: Cardiometabolic diseases frequently involve concurrent cardiovascular and hepatic dysfunction, yet the conserved molecular mechanisms underlying these systemic responses remain poorly defined. Objectives: To identify conserved molecular responses across complementary manifestations of cardiometabolic stress and determine whether integrated multi-organ analyses reveal therapeutically actionable targets for heart failure. Methods: Cardiac functional phenotyping, hepatic injury profiling, and bulk RNA sequencing were performed across three complementary mouse models representing distinct manifestations of cardiometabolic stress: high-fat diet plus L-NAME (HFD+LN)-induced heart failure with preserved ejection fraction (HFpEF; cardiovascular disease), Western diet (WD)-induced obesity (systemic metabolic stress), and choline-deficient, L-amino acid-defined, high-fat diet (CDAHFD)-induced steatotic liver disease (hepatic metabolic stress). Comparative transcriptomic analyses distinguished organ-specific responses from conserved molecular signatures. Results: Each model produced distinct systemic, hepatic, and cardiac phenotypes accompanied by divergent transcriptional responses within individual organs. Cross-model and cross-organ integration identified a limited set of conserved molecular responses to cardiometabolic stress, with Serpine1, encoding plasminogen activator inhibitor-1 (PAI-1), emerging as a highly conserved candidate that exhibited preferential induction in the heart. Pharmacologic inhibition of PAI-1 significantly improved cardiac function and attenuated adverse remodeling in established HFpEF, whereas hepatic pathology was comparatively less affected, indicating differential organ-specific dependence on this pathway. Conclusions: Integrated analyses across complementary manifestations of cardiometabolic stress identified conserved molecular signatures that transcend individual disease models and organs. These findings establish a comparative framework for discovering cardiovascular therapeutic targets and identify PAI-1 as a promising mediator of cardiac remodeling in cardiometabolic disease.

Background: Unstructured biomedical data, such as echocardiography reports, are rich in information but time consuming to analyze at scale. Rule-based, regular expression-driven terminology mapping can only extract individual variables while large language models (LLMs) offer scalable and clinically meaningful interpretations of heterogeneous disease processes. Right ventricular dysfunction (RVD) is an example of a multifactorial disease state in which key structural and physiologic features are captured both narratively and in structured fields, making it an ideal test case for evaluating whether LLMs can recover complex phenotypes that rules based methods routinely miss. Purpose: To compare an LLM-based extraction method to a conventional rules-based schema for identifying and phenotyping echocardiographic features associated with RVD in a large TTE dataset. Methods: MIMIC-III NOTE2NUM echocardiography reports (n = 45,794) were analyzed using GPT-4o-based LLM extraction deployed within a secure health system enclave and were benchmarked against echocardiographic measurements defined in the MIMIC-III dictionary schema. In MIMIC-III, PH was recorded qualitatively (mild/moderate/severe) based on tricuspid regurgitant (TR) jet velocity and then re-coded as present vs. absent. LLM based extraction defined RVD as (1) RV structural abnormality (>= 1 of hypertrophy, dilation, or wall hypo-/akinesis) or (2) RV pressure/volume overload (>= 2 of the following: estimated right atrial pressure > 8 mmHg, TR jet velocity > 2.8 m/s, fractional area change < 35%, tricuspid annular planar systolic excursion < 17 mm, S' < 9.5 cm/s, or E/e' > 14), with PH defined as estimated pulmonary artery systolic pressure > 35 mmHg or qualitative documentation of PH. Results: LLM extraction identified PH in 15,394 (33.6%), RV pressure/volume overload in 14,449 (31.6%), and RV structural abnormalities in 11,955 (26.1%). Co-occurrence was common: overload + structural changes in 9,380 (20.5%), overload + PH in 9,756 (21.3%), structural changes + PH in 6,183 (13.5%), and all three in 5,620 (12.3%). Using the MIMIC-III dictionary schema, PH prevalence was similar (15,371; 33.6%), but RV overload fields were captured less often (pressure overload 1,357 [3.0%], volume overload 1,128 [2.5%], pressure + volume overload 1,093 [2.4%]; any overload field 3,578 [7.8%]), and RV pressure/volume overload with PH was identified in only 731 (1.6%). Conclusions: LLM-based extraction outperforms rules-based schemas for identifying complex disease states not defined by any single variable. By synthesizing multifactorial signals, LLMs can phenotype RVD with higher fidelity and support population-level assessment. Further validation using multimodality imaging, invasive hemodynamics, and clinical outcome data is needed.

Migraine is a leading cause of disability, yet preventive treatment remains largely empirical despite the availability of several mechanistically distinct therapies. Genetic data can clarify mechanisms and therapeutic hypotheses when association signals are integrated with molecular and clinical data. We meta-analyzed migraine GWAS data from 12 European ancestry cohorts (206,893 cases and 2,093,175 controls) and four African ancestry cohorts (22,115 cases and 178,626 controls). We identified 311 lead variants in European-ancestry analyses and 316 lead variants in trans-ancestry analysis. Fine-mapping and transcriptome-wide analyses prioritized variants and genes implicated in sensory neuronal signaling, vascular tone, and immune regulation, with convergent evidence at several established loci including TRPM8 and PHACTR1. Drug-repurposing analyses identified therapeutic targets and compounds, including established migraine treatments and candidates requiring experimental validation. Genetic correlations, Mendelian randomization, and a phenome-wide scan linked migraine liability to psychiatric, pain, and gastrointestinal phenotypes. Together, these findings expand the known genetic architecture of migraine across ancestries and provide a genetics-led map connecting association signals with biological pathways, multimorbidity and candidate therapeutic mechanisms, providing a foundation for future functional and translational studies.

Background: HFpEF accounts for roughly half of heart failure admissions and lacks disease-modifying therapy. Autotaxin (ENPP2) generates lysophosphatidic acid (LPA), a profibrotic and pro-inflammatory bioactive lipid. Whether circulating lysophospholipid metabolism is altered in HFpEF, and whether autotaxin inhibition modifies an established experimental HFpEF phenotype, is untested. Methods: Plasma from patients with HFpEF (n=210) and non-heart-failure comparators (n=27) underwent untargeted and LPA-targeted mass spectrometry and a nine-analyte multiplex immunoassay. Male C57BL/6J mice received a high-fat diet plus L-NAME (0.85 g/L) or chow for 5 weeks; after phenotype confirmation, they received oral PF-8380 (30 mg/kg/day) or vehicle for 10 weeks. Endpoints were echocardiography, functional assessment, gravimetric studies, tail-cuff pressure, trichrome fibrosis, and flow cytometry of heart and spleen. Results: All nine analytes, including the autotaxin protein ENPP2, were higher in HFpEF than comparators. HFpEF plasma showed higher LPE O16:1, LPE O18:2, PS 38:4 and PC 36:4;O, and lower SM 39:2; O3 and PS 36:0. LPA 20:0 was 3.5-fold higher in both sexes, whereas LPA 18:2 was lower in women. Diet plus LNAME raised blood pressure, LV mass, and isovolumic relaxation time with preserved ejection fraction. PF-8380 reduced echocardiographic indices of diastolic dysfunction, fibrosis area, cardiomyocyte area, and cardiac CD11b+, CD64+, CD86+, and Ly6G+ frequencies, without altering fat or lean mass. Conclusion: In male mice with established two-hit HFpEF, autotaxin inhibition improved diastolic indices and reduced fibrosis, hypertrophy, and cardiac myeloid accumulation. Human data show altered lysophospholipid composition. Collectively, these findings nominate the autotaxin/LPA axis as a tractable therapeutic target and support further evaluation of autotaxin inhibition as a candidate disease-modifying strategy for HFpEF management.

Cardiac imaging enables quantitative assessment of cardiac structure and function but remains constrained by cost, infrastructure and specialist expertise. In contrast, electrocardiogram (ECG) is widely accessible yet underexploited, despite encoding latent information about cardiac physiology. Here we introduce visionECG, a conditional flow matching framework that learns a probabilistic mapping between two biological distributions - the space of cardiac electrical signals and the space of cardiac geometries. Using 71,132 paired ECG and cardiac mesh sequence datasets from the UK Biobank, with external assessment in 5,000 patients with ECG-echocardiogram pairs, the model reconstructs quantitatively accurate spatiotemporal representations of the left ventricle using ECG inputs and basic demographic information alone. These reconstructions enable discrimination of structural abnormalities and disease labels, provide visualisations of functional abnormalities, and support flexible quantification of both global and regional parameters. By reframing the ECG as a generative source of patient-specific left ventricular geometry and motion, this work establishes a scalable framework for translating low-dimensional signals into high-dimensional, physiologically grounded structured representations.

The cell-intrinsic complement system has emerged as an important orchestrator of a variety of cell-physiological processes, with complement components interacting with intracellular effector systems to regulate cellular responses to pathogens or noxious stimuli. For instance, intracellular C5 signaling through a mitochondrial C5a receptor (C5aR1) controls IL-1{beta} production in human monocytes and macrophages. Here, we investigated whether cell-intrinsic C3 similarly regulates inflammatory responses in macrophages. In LPS-stimulated C3 knockout THP-1-derived macrophages, interferon (IFN)-{beta} production was increased, accompanied by elevated expression of interferon-stimulated genes and enhanced secretion of IFN-induced cytokines and chemokines. C3-deficient cells showed increased phosphorylation of IRF3 at Ser396 and a stabilization of the interaction between IRF3 and TBK1, along with enhanced IRF3 dimerization and nuclear translocation. TBK1 phosphorylation was unaffected, indicating that C3 limits IRF3-TBK1 complex formation rather than upstream TBK1 activation. Small-molecule inhibitors of complement factors B and D restored full-length C3 abundance in LPS-stimulated primary human macrophages, consistent with inhibition of the C3 convertase. It also reduced LPS-induced IFN-{beta} production in primary human macrophages and THP-1 cells, suggesting that full-length, uncleaved C3 suppresses IFN-{beta} production. Collectively, these findings identify cell-intrinsic C3 as a suppressor of IFN-{beta} production in human macrophages, highlighting the importance of the cell-intrinsic complement system in fine-tuning inflammatory responses to pathogens.

Objective: Chronic atrial and intestinal dysrhythmia (CAID) syndrome is a rare autosomal recessive cohesinopathy classically defined by sick sinus syndrome and chronic intestinal pseudo-obstruction; however, emerging evidence suggests an association with cerebral small vessel disease (CSVD). We aimed to characterize the neurological and neuroimaging spectrum of CSVD in CAID syndrome. Methods: We conducted a cross-sectional, retrospective study of 16 French-Canadians with genetically confirmed CAID syndrome. All patients underwent comprehensive neurological assessment. Brain MRI was performed in 14 patients, with CSVD markers evaluated by an expert neuroradiologist according to the STRIVE-2 criteria. Results: The median age at last evaluation was 34 years (range, 19-60); 62.5% were women. Neurological manifestations included migraines (44.4%), mild cerebellar signs (16.7%), and ischemic or hemorrhagic cerebrovascular events (12.5%). MRI showed white matter hyperintensities (92.9%), lacunes (50%) and cerebral microbleeds (85.7%), affecting deep, lobar, and infratentorial regions, with marked cerebellar predominance (11/12; 91.7%); five patients exhibited innumerable microbleeds. Despite the young cohort, moderate-to-severe CSVD was common (median SVD score 1.5, IQR 0-4). Patients with countless microbleeds were older than those with discrete lesions (46.2 vs. 31.2 years; p=0.043). Management of atrial fibrillation required individualized strategies, including left atrial appendage closure, balancing ischemic and hemorrhagic risks. Interpretation: CAID syndrome represents a novel monogenic cause of CSVD, characterized by early, extensive cerebral microbleeds with mixed distribution and distinctive cerebellar predominance. Coexisting congenital cardiac disease and arrhythmias place patients at dual ischemic and hemorrhagic risk. Systematic neurological evaluation and MRI are warranted, particularly prior to antithrombotic therapy.

Abstract Calcific deposits in the arterial media have been associated with a number of metabolic and genetic disorders including diabetes, chronic kidney disease and generalized arterial calcification of infancy. While medial calcification and physiologic hard tissue mineralization in the skeleton are both regulated by several common determinants, emerging data suggest that there might be fundamental differences in the mechanisms underlying these two processes. Objective: We previously demonstrated that elastin haploinsufficiency delays medial calcification in MGP-deficient mice. Here, using mice in which a human ELN transgene rescues mouse elastin deficiency, we investigated whether the origin and abundance of arterial elastin differentially affect the initiation and progression of medial calcification. Approach and Results: We pursued a transgenic approach to alter the arterial elastin scaffold in MGP-deficient mice. Our analyses of a humanized MGP-deficient model with 40% reduction of medial elastin content showed a complete absence of the early-stage vascular calcification. Additionally, we showed that mouse and human elastin orthologues affect vascular calcification in a comparable manner. Conclusion: Arterial elastin abundance, rather than orthologue origin, modulates the initiation and progression of medial calcification in MGP-deficient mice. A further reduction in arterial elastin beyond that achieved by elastin haploinsufficiency profoundly delays mineral deposition and maturation, whereas restoration of elastin abundance through transgenic human ELN expression restores arterial calcification.

Background: Severe aortic stenosis is associated with systemic and splanchnic hemodynamic disturbances that may alter gut microbial metabolism and host inflammatory responses. Objectives: We aimed to determine whether TAVI remodels the gut microbiome-derived metabolome and whether post-procedural SCFA dynamics are associated with the inflammatory cytokine response. Methods: We conducted a prospective paired single-center study of patients undergoing elective TAVI at Bern University Hospital. Stool and blood samples were collected before and three months after the procedure. Gut microbial composition was profiled by full-length 16S rRNA sequencing, circulating short-chain fatty acids (SCFAs) by targeted metabolomics, and inflammatory mediators by multiplex cytokine analysis, and integrated with hemodynamic and clinical data. Results: Forty patients were enrolled. Following TAVI, microbial richness declined without significant restructuring of overall community composition. In contrast, circulating SCFA profiles were significantly remodeled, driven by selective reductions in butyrate and isovalerate. A greater decline in circulating butyrate was inversely associated with IL-18 elevation (rho=0.668, p<0.001, n=36), independent of aortic valve calcification burden, hemodynamic improvement, and cardiovascular medications. Baseline isovalerate was nominally associated with 1-month adjudicated adverse events (AUC 0.77; exploratory). Conclusions: TAVI is associated with selective changes in gut microbiome-derived metabolic output rather than broad alterations in microbial community structure. Declining circulating butyrate identifies a gut-metabolite-immune axis linked to IL-18 dynamics and represents a potential biomarker of inflammatory recovery following valve intervention.

Antral CCK2R+ stem cells are regulated by gastrin, but how endocrine and neural cues integrate under chronic injury remains unclear. Here we show that inducible hypogastrinemia shifts from asymmetric renewal to symmetric expansion of CCK2R+ stem cells. With carcinogenic stress, these cells acquire a cycling, injury responsive progenitor state revealed by single-cell RNA profiling. Acute gastrin loss activates a CCK2R+ nodose DMV vagal reflex that increases acetylcholine release, NGF production, cholinergic innervation, and Chrm3 expression, driving ERK and YAP signaling in CCK2R+ stem cells. Vagotomy, Trk inhibition, or Chrm3 deletion each suppressed stem cell expansion. In H. pylori and MNU injury models, hypogastrinemia amplified inflammation, dysplasia, and CCK2R+ clone expansion, whereas gastrin suppressed these responses. Human scRNA seq and spatial profiling confirmed G cell depletion and progenitor state enrichment. These findings define an endocrine neural epithelial axis in which gastrin loss boosts vagal M3R signaling to initiate antral preneoplasia, highlighting this pathway for early interception.

A developmental increase in cerebrospinal fluid (CSF) production during development is essential for neuronal growth and ventricular expansion. A key regulator of CSF production is the specialized sensory multicilia of the choroid plexus (ChP), which mediate non-canonical Sonic hedgehog (Shh) signaling to suppress water channel and ion transporter expression, thereby limiting CSF production. ChP multicilia progressively shortens during development, attenuating Shh signaling and promoting CSF production. Here, we identify miR-34/449 miRNAs as essential regulators of ChP multiciliogenesis. Whereas mutations in canonical ciliogenesis genes elevate CSF production and contribute to hydrocephaly, deletion of miR-34/449 reduces CSF volume and causes microcephaly. Loss of miR-34/449 miRNAs causes excessive basal body amplification, defective basal body docking, and failure of developmental multiciliary shortening. Consequently, miR-34/449-deficient ChP cilia remain abnormally long and fail to attenuate Shh signaling, resulting in sustained repression of water channel and ion transporter expression and reduced CSF production. Mechanistically, miR-34/449 miRNAs directly target Gmnc, a master transcriptional regulator of multiciliogenesis, to restrain basal body amplification and promote basal body docking. Together, our findings identify miR-34/449 miRNAs as critical regulators of ChP multiciliogenesis and establish the developmental remodeling of ChP multicilia as a mechanism to couple Shh signaling dynamics to developmental control of CSF production.

Skin, the bodys largest mechanosensitive organ, relies on a tension gradient across epidermal layers to maintain structure and function, but how mechanical force contributes to epidermal development and disease pathogenesis is poorly understood. By anchoring intermediate filaments (IF) to the plasma membrane, desmosomes, the most abundant intercellular junctions in the epidermis, help create a supracellular scaffolding that provides mechanical resilience to the tissue. However, the contribution of the desmosome-IF network to the epidermal response to mechanical strain remains unknown. Here we show that the desmosome-IF connection is not only required to induce a proper cellular mechano-response but is actively strengthened in response to stretch through the PP2A-mediated phospho-regulation of the cytoskeletal linker protein desmoplakin (DP). Additionally, we show in human skin dephosphorylated DP localizes to high tension layers, suggesting this mechano-response mechanism is coordinated with the epidermal tension gradient. Furthermore, in models of Carvajal syndrome, a cardio-cutaneous disorder caused by truncating DP mutations, cells lose mechano-responsive behavior and exhibit abnormal morphology in high-tension epidermal layers. Together, these findings identify the DP-IF network as a key component of the response to mechanical strain and show that its disruption compromises epidermal homeostasis and contributes to disease pathogenesis.

The X chromosome carries an unusually high density of immune genes and is a major contributor to sex differences in immune function and autoimmune diseases. In females, X-chromosome inactivation (XCI) has two major functional consequences: it shapes X-linked gene dosage through XCI escape and determines the cellular exposure of heterozygous X-linked variants through XCI skew. Yet because XCI creates a mosaic of cells expressing different parental X chromosomes, these properties have remained largely inaccessible in individual women, becoming measurable only where XCI is non-random or after aggregation across large cohorts. Consequently, how X-linked variation contributes to sex-biased immunity and differs between individual women has remained unresolved. Here we present scDaisyChain, a graph-based framework that reconstructs chromosome-scale X haplotypes directly from heterozygous SNPs and single-cell long-read transcriptomes. scDaisyChain achieves near-ground-truth accuracy in highly polymorphic mouse hybrids and shows strong concordance with orthogonal long-read whole-genome phasing in human samples. Applied to peripheral blood immune cells from healthy women, it reveals a lineage-specific escape program in which lymphoid cells escape XCI more broadly than monocytes, with corresponding gains in the inactive X chromatin accessibility and female-biased expression. Lineage-specific skew further alters the proportion of cells expressing each heterozygous X-linked variant, a property we term variant exposure. Predicted deleterious variants are preferentially found in low-exposure states, exemplified by a splice-altering TLR8 variant expressed in few cytotoxic T cells. In rheumatoid arthritis (RA), the monocyte compartment - which has the lowest escape in health - shows reproducible inactive X dysregulation converging on a trained-immunity programme linked to disease flare and synovial macrophage activation, with elevated escape of IL13RA1 and HDAC8. These findings establish lineage-specific escape, skew and variant exposure as quantifiable, patient-resolved determinants of sex-biased immune gene dosage and X-linked variant penetrance in health and autoimmune disease, resolving a dimension of female biology that has been previously inaccessible in individual donors.

Brown adipose tissue (BAT) is a mitochondria-rich thermogenic organ whose function depends on high oxidative capacity, yet how primary mitochondrial dysfunction remodels BAT identity and metabolism remains poorly defined. Using the Deletor mouse model of progressive mtDNA deletion disease, we identify a pseudohypoxiairon-NAD+ axis as a central organiser of BAT pathology. Deletor BAT underwent profound structural, transcriptional and metabolic remodelling, characterised by mitochondrial ultrastructural damage, loss of thermogenic identity, PHD3/HIF associated pseudohypoxic signalling, iron dysregulation and NAD+/NADH redox imbalance. Indirect calorimetry confirmed that this molecular disease program translates to functional thermogenic failure under physiological demand. Deletor mice showed significantly reduced heat production under acute cold challenge and failed to switch to fatty acid oxidation Metabolomic profiling revealed altered TCA cycle intermediates, glycolytic rewiring and selective amino acid accumulation. Pharmacological perturbation showed that the PHD inhibitor roxadustat worsened disease-associated features, whereas HIF-1 suppression with PX-478 attenuated the integrated stress response, indicating that pseudohypoxic signalling is maladaptive in this setting. Nicotinamide riboside broadly attenuated the disease metabolome and transcriptome, restoring NAD+/NADH balance, suppressing ISRmt, iron-stress and pseudohypoxic gene programs, and correcting selective carnitine and acylcarnitine abnormalities consistent with impaired fatty-acid handling. These findings define a therapeutically tractable pseudohypoxia-iron-NAD+ axis as a core determinant of BAT dysfunction in mitochondrial disease.

Endothelial dysfunction is a hallmark of numerous vascular pathologies and is strongly influenced by mechanobiological forces within the vascular microenvironment. While the effects of shear stress have been extensively investigated, the mechanisms by which elevated hydrostatic pressure regulates endothelial junctional organisation remain sparsely investigated. Here, we employed a microfluidic platform to investigate the combined effects of low shear stress (1.4 dyne/cm2) and elevated hydrostatic pressure (~3972 Pa) on endothelial junctional dynamics. Elevated hydrostatic pressure induced marked remodelling of VE-cadherin junctions, characterised by formation of serrated, finger-like structures accompanied by increased YAP1 nuclear localisation and reduced YAP1-VE-cadherin cytoplasmic colocalisation compared to shear stress alone conditions. Further, elevated hydrostatic pressure also demonstrated an increase in cytoplasmic accumulation of EPS8, an actin adaptor protein, and increased cytoplasmic EPS8-VE-cadherin colocalisation. These observations were accompanied by functional changes marked by increased endothelial permeability, and enhanced THP-1 monocyte adhesion, thus suggesting activation of mechanosensitive pathways linked to dynamic junctional reorganisation. Inhibition of PI3K at elevated hydrostatic pressure exhibited a thin VE-cadherin patterning and increased cytoplasmic EPS8-VE-cadherin colocalisation, thus demonstrating a prominent role for PI3K signalling in regulating the junction organisation. Interestingly, Piezo-1 activation using Yoda1 produced context-dependent effects. Under shear stress alone, Yoda1 promoted YAP1 nuclear translocation, reduced YAP1-VE-cadherin colocalisation, increased endothelial permeability but strikingly did not impact THP-1 adhesion compared to shear stress alone conditions. In contrast, under elevated hydrostatic pressure conditions, Yoda1 significantly reduced both endothelial permeability and THP-1 adhesion while increasing YAP1-VE-cadherin colocalisation and decreasing YAP1 nuclear accumulation. Collectively, these findings identify a previously underappreciated elevated hydrostatic pressure-Piezo-1-PI3K signalling axis that regulates endothelial barrier integrity and pro-adhesive endothelial activation through coordinated regulation of VE-cadherin, YAP1, and EPS8. These results highlight elevated hydrostatic pressure as a unique mechanobiological stimulus, distinct from that of shear stress alone and provide novel insights into mechanisms underlying microvascular dysfunction.

Contemporary national-scale electronic health record (EHR) trends in documented acute myocardial infarction (AMI) rates during the high-sensitivity cardiac troponin (hs-cTn) and Type 2 myocardial infarction (T2MI) era are not well characterized. We conducted a serial cross-sectional analysis of U.S. adults aged 18 years in Epic Cosmos from 2016-2024, encompassing 821,859,867 patient-years. Age- and sex-standardized AMI diagnosis rates increased 75.7%, from 343.1 to 602.7 per 100,000 patients. This increase was predominantly driven by T2MI, which increased 133.8% from 99.9 per 100,000 in 2018 to 233.4 per 100,000 in 2024; NSTEMI increased 13.8% while STEMI decreased 4.1%. Annual hs-cTn-tested encounters increased 34.5-fold from 2017 through 2024. The proportion of tested encounters associated with any AMI remained relatively stable after 2021, whereas T2MI continued to increase and surpassed NSTEMI in 2024 as the most frequently diagnosed AMI subtype per hs-cTn-tested encounters. Males had higher absolute AMI rates across all age groups, although relative increases were greater among females. Documented AMI epidemiology shifted substantially toward T2MI during expanding hs-cTn utilization, underscoring the need for evidence-based approaches to the evaluation and management of T2MI.