JACC: Basic to Translational Science

Background: The specific 3D morphological substrates distinguishing the newly defined massive and torrential functional tricuspid regurgitation (FTR) phenotypes from standard severe disease remain under-characterized. Objectives: This study investigates the 3D geometric changes of the tricuspid valve (TV) apparatus across the spectrum of FTR, specifically focusing on the structural definition of massive and torrential grades. Methods: Three-dimensional (3D) transesophageal echocardiography (TEE) was performed in 322 patients with FTR secondary to left-sided heart disease. Patients were stratified into mild-moderate (n=166), severe (n=82), and massive-torrential (n=74) groups. TV geometry, including annular dimensions, leaflet tethering, and subvalvular apparatus, was quantified using 3D modeling software. Results: Patients with massive-torrential TR were characterized by advanced age, female predominance, and atrial fibrillation (75%). 3D analysis demonstrated that massive-torrential TR represents a distinct phenotype defined by extreme annular circularization (ellipticity index 1.0) and planar flattening (P < 0.001). Furthermore, these patients exhibited a critical leaflet-annulus uncoupling, where compensatory leaflet growth (relative length < 80%) failed to match the massive annular dilation. Consequently, the regurgitant orifice in massive-torrential grades appeared highly complex, frequently manifesting as multiple irregular orifices. Conclusions: Massive and torrential FTR are characterized by a unique geometric profile involving extreme annular circularization, severe leaflet tethering, and leaflet-annulus uncoupling. These morphological insights suggest that conventional repair strategies may be insufficient for these advanced phenotypes, highlighting the necessity for pre-procedural 3D TEE to guide device selection.

The epidermal growth factor receptor (EGFR) family network comprises 4 receptors (EGFR, ERBB2, ERBB3, ERBB4) and numerous ligands, and is dysregulated in many cancers. Since anti-cancer drugs that target these receptors are cardiotoxic for some patients, it is important to understand the network in cardiac cells. Data from the Human Protein Atlas established that EGFR family members and their ligands are differentially expressed in cardiac cell types. Ligand expression was altered in human failing hearts and may contribute to disease. These ligands stimulated extracellular signal-regulated kinases 1/2 (ERK1/2) and Akt in rat cardiomyocytes but to different degrees. Afatinib (at a concentration to inhibit all EGF family receptors) was used to assess the role of the network in a mouse model of cardiac hypertrophy induced by angiotensin II (AngII). Echocardiography and segmental strain analysis demonstrated that afatinib reduced AngII-induced cardiac hypertrophy and caused cardiac dysfunction. This was associated with loss of cardiomyocyte hypertrophy, enhanced cardiac fibrosis, and reduced expression of Nrg1. NRG1 binds to ERBB4 in cardiomyocytes which homodimerizes or heterodimerises with ERBB2. The role of ERBB2 in the cardiomyocyte response to NRG1 compared with EGF was dissected using tucatinib (a selective ERBB2 inhibitor) and mRNA expression profiling. Most, but not necessarily all, of the response to NRG1 required ERBB2 signalling; most, but not all, of the response to EGF did not. Thus, the EGFR family network plays an important role in the heart. Understanding this network may identify therapeutic approaches to avoid cardiotoxicity associated with EGFR family anti-cancer drugs. Clinical perspectivesO_LIAnti-cancer drugs that target the epidermal growth factor receptor (EGFR) family are cardiotoxic for some patients; it is therefore important to understand the network in cardiac cells. C_LIO_LIThe EGFR family and their ligands are differentially expressed in cardiac cells with changes in ligand expression in heart failure; inhibition of all receptors in a mouse model of hypertrophy reduces cardiac hypertrophy and causes cardiac dysfunction with attenuation of cardiomyocyte hypertrophy and enhanced cardiac fibrosis and loss of neuregulin 1 (NRG1); in rat cardiomyocytes, NRG1 signalling to gene expression is largely mediated via ERBB2. C_LIO_LIThe EGFR family network plays an important role in the heart; understanding this network may identify therapeutic approaches to avoid cardiotoxicity associated with anti-cancer drugs targeted against it. C_LI

Background: Before transcatheter aortic valve replacement (TAVR), patients with severe aortic valve stenosis are at an increased risk of developing fluid volume overload and heart failure, which is associated with subsequent adverse outcomes after TAVR. Purpose: To quantify fluid volume status as whole-body fast-exchange extracellular volume (FE-ECV) in patients undergoing TAVR compared to healthy reference values using photon-counting CT (PCCT). Methods: Consecutive patients referred for TAVR and healthy living kidney donor candidates, respectively, underwent PCCT including the pelvis. FE-ECV (mL) was quantified using venous hematocrit, injected iodinated contrast concentration and volume, and blood iodine concentration and urinary bladder excreted iodine mass quantified in iodine map regions of interest from the inferior vena cava and covering the urinary bladder, acquired at one time point 6-10 minutes after intravenous iodinated contrast administration. Results: The study included 156 subjects (healthy: n=51, age 47{+/-}9 years, 55% female; TAVR: n=105, age 78{+/-}6 years, 39% female). In healthy subjects, FE-ECV was 160{+/-}22 mL/kg lean body mass (LBM), 95% limits 116-204 mL/kg LBM, and was independent of age, sex, contrast agent type, and scan delay time after contrast injection (p>0.66 for all). Compared to healthy subjects, FE-ECV in patients referred for TAVR was higher (174{+/-}34 mL/kg LBM, p=0.01), with 19 patients (18%) exceeding the normal range. Conclusion: One in five patients referred for TAVR demonstrated increased FE-ECV, revealing a substantial prevalence of fluid overload detectable by single-time point late-phase PCCT iodine mapping.

Background: A substantial proportion of coronary events originate from angiographically moderate lesions, indicating that stenosis severity alone does not reflect lesion biomechanical risk. Objectives: To test whether adding lesion-adjacent pericoronary adipose tissue (PCAT) and CTCA-derived anatomy-flow descriptors to quantitative plaque assessment improves identification of future culprit lesions, with a prespecified focus on moderate stenosis. Methods: We performed a within-patient, lesion-level case-control analysis in the GeoCAD cohort, including patients undergoing coronary revascularisation during follow-up. Culprit lesions were identified from longitudinal CTCA. Stenosis severity, quantitative plaque composition, and PCAT volume were quantified (MEDIS), and vessel centreline geometry and lesion haemodynamics derived using computational modelling. Incremental prognostic value was assessed using Cox models with drop-one and stepwise workflow analyses, including a prespecified subgroup analysis of moderate stenosis lesions (25 - 49% diameter stenosis). Results: Among 46 patients (212 lesions; 55 culprit), percent area stenosis (%AS) dominated culprit lesion discrimination (HR: 2.01; 95% CI: 1.54 - 2.62; p < 0.001). In 82 moderate-stenosis lesions (30 culprit), %AS provided minimal discrimination ({Delta}C-index: 0.01; p=0.895). Culprit lesions were characterised by greater PCAT volume (HR: 1.75; 95% CI: 1.29 - 2.37; p < 0.001), higher helical flow intensity (HR: 1.35; 95% CI: 1.16 - 1.57; p < 0.001), and lower torsion (HR: 0.50; 95% CI: 0.29 - 0.84; p=0.009). Adding anatomy-flow descriptors improved risk stratification for moderate lesions beyond CTCA stenosis and plaque/PCAT features (p=0.007). Conclusions: In moderate stenosis, lesion-adjacent PCAT and anatomy-flow descriptors provided incremental prognostic information beyond luminal narrowing and plaque composition, supporting integrated CTCA phenotyping to identify high-risk nonobstructive coronary lesions.

PurposeLeft ventricular hypertrophy (LVH) is a major complication of chronic hypertension and an independent risk factor for cardiovascular morbidity and mortality. There are currently no clinically validated markers available to identify hypertensive individuals at risk for developing LVH. In hearts of hypertensive rats, we previously described metabolic changes that precede LVH development, including in branched-chain amino acid (BCAA) metabolism. This study investigated whether cardiac leucine uptake, measured with dynamic 5-[18F]fluoroleucine positron emission tomography-computed tomography ([18F]FLE-PET/CT), was impaired and could serve as an in vivo marker for hypertension-induced LVH development. ProceduresWe synthesized [18F]FLE following established radiochemistry protocols and performed dynamic [18F]FLE-PET/CT imaging in 3-month-old spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto (WKY) control rats (n = 4 per group). Cardiac magnetic resonance (CMR) imaging was conducted on the same animals for structural co-registration. A dual-output reversible two-tissue compartment model with spill-over (SP) and partial volume (PV) corrections was developed to quantify the first-pass rate constant (K1) and total distribution volume (Vt = K1/k2) for [18F]FLE. Protein expression of L-type amino acid transporter 1 (LAT1) and branched-chain keto acid dehydrogenase (BCKDH) phosphorylation status were assessed by immunoblotting of isolated heart tissue. ResultsSHR demonstrated markedly lower first-pass leucine uptake rates (K1) and total distribution volumes (Vt) compared with WKY rats, consistent with reduced cardiac BCAA uptake. Concurrently, LAT1 (SLC7A5) expression was significantly reduced in SHR hearts compatible with decreased leucine uptake. Elevated BCKDH phosphorylation at Ser293 in SHR hearts indicated diminished BCKDH enzymatic activity and impaired BCAA catabolism. ConclusionsDynamic cardiac [18F]FLE-PET imaging successfully detects decreased leucine uptake in hypertensive rat hearts at 3 months of age, before LVH is established at 5 months. Reduced cardiac leucine uptake may thus serve as a surrogate marker for impaired cardiac BCAA metabolism and early in vivo indicator of cardiometabolic dysfunction that precedes LVH. The imaging approach holds translational potential for identifying hypertensive patients at risk for LVH progression.

The aorta, normally resilient to hemodynamic stresses, becomes vulnerable to structural failure due to diverse conditions that weaken the wall. We injected fluid into excised specimens of human ascending aorta with pressure monitoring to quantify the impact of clinical and histological factors on mural damage. Two modes of medial injury emerged with distinct pressure tracings. Extravasation was characterized by diffuse infiltration of fluid with widespread damage of smooth muscle cells and collagen fibers but limited separation of elastic lamellae. By contrast, delamination was characterized by marked separation of elastic lamellae along a single plane with damage to cells and fibrillar matrix restricted to adjacent laminae. Aging, aortic dilatation, and family history associated with lower pressures causing delamination, whereas a diagnosis of hypertension associated with higher pressures suggesting resilience to dissection. Collagen fraction adjacent to delamination correlated with higher pressures as did decreased smooth muscle cell density and increased glycosaminoglycan fraction, although several clinical and histological variables were interrelated. Protein cross-linking strengthened and enzymatic digestion of collagen weakened the aortic wall, while acute cell lysis with detergent had no effect. We conclude that increased functional medial collagen has an adaptive protective role in aortic remodeling rather than signifying medial degeneration.

BackgroundMarfan syndrome (MFS) is a life-threatening heritable connective tissue disorder caused by pathogenic variants in fibrillin-1, characterized by progressive cardiovascular disease. Current medical therapies slow disease progression but do not prevent major complications, underscoring the need for new treatment strategies and unbiased discovery approaches. MethodsWe used a zebrafish model of MFS lacking fibrillin-3 (fbn3-/-), which recapitulates key cardiovascular phenotypes including cardiac stress, valvular defects, arrhythmia, and aortic dilation. To enable sensitive, quantitative assessment of cardiac stress, we generated a novel transgenic zebrafish reporter expressing secreted nanoluciferase under control of the stress-responsive nppb promoter. This reporter was combined with morphological phenotyping and bulbus arteriosus (BA) imaging. We evaluated standard MFS therapies, targeted modulators of TGF-{beta} signaling, and performed an unbiased high-throughput drug screen of over 1 500 clinically approved compounds across multiple developmental treatment windows. Resultsfbn3-/- larvae exhibited markedly elevated nppb activity that correlated with phenotypic severity and peaked during stages of highest mortality. The nanoluciferase reporter provided a [~]1 000-fold dynamic range, substantially outperforming Firefly luciferase-based assays. Pharmacological inhibition of TGF-{beta} signaling produced transient or deleterious effects, while {beta}-blockers, losartan, and allopurinol failed to consistently improve cardiac stress, pericardial edema, or BA dilation. The unbiased high-throughput drug screen identified a small number of primary and secondary hits; however, none demonstrated reproducible phenotypic rescue upon rigorous multi-dose, multi-time window validation. ConclusionsThis study establishes a sensitive zebrafish-based platform for early, quantitative assessment of cardiovascular stress in MFS. Our findings highlight the limited efficacy of current therapies, the context-dependent nature of TGF-{beta} modulation, and the biological complexity underlying MFS pathogenesis. Although no definitive therapeutic candidates were identified, this work lays a robust foundation for expanded unbiased discovery efforts aimed at identifying disease-modifying interventions for MFS.

BackgroundThis study aimed to investigate whether combined PD-1/CTLA-4 immune checkpoint inhibition predisposes the heart to a hyperinflammatory state, thereby exacerbating cardiac injury following acute myocardial infarction (MI), a critical unresolved question in cardio-oncology. MethodsMyocardial infarction was induced in Pd1-/-Ctla4+/- mice, a genetic model mimicking combined checkpoint inhibition. Key mechanistic insights were gained through in vivodepletion of CD8+ T cells (using anti-CD8a antibody) and pharmacological inhibition of the JAK-STAT1 pathway (using Tofacitinib). Cardiac function, structural injury, and immune responses were comprehensively assessed via echocardiography, flow cytometry, immunofluorescence, and molecular analyses. ResultsCompared to wild-type controls, Pd1-/-Ctla4+/- mice exhibited significantly increased post-MI mortality, worse cardiac function, and larger infarct size. Mechanistically, the aggravated injury was driven by an amplified infiltration of activated, IFN-{gamma}-producing CD8+ T cells, which activated the JAK-STAT1 pathway in macrophages, polarizing them towards a pro-inflammatory state. Depleting CD8+ T cells or inhibiting the JAK-STAT1 pathway effectively attenuated macrophage-driven inflammation and improved all aspects of post-MI injury. ConclusionsCombined PD-1/CTLA-4 blockade exacerbates post-infarction cardiac injury by promoting CD8+ T cell-mediated activation of macrophages via the JAK-STAT1 axis. This work elucidates MI as a context-dependent immune-related adverse event in ICI therapy and identifies CD8+ T cells and the JAK-STAT1 pathway as promising therapeutic targets for cardioprotection in these patients. RESEARCH PERSPECTIVEO_ST_ABSWhat Is New?C_ST_ABSO_LIThis study identifies acute myocardial infarction (MI) as a potential, context-dependent immune-related adverse event in the setting of combined PD-1/CTLA-4 checkpoint inhibition, shifting the paradigm beyond the classic focus on myocarditis. C_LIO_LIIt elucidates a novel pathogenic axis where combined checkpoint deficiency exacerbates post-MI injury specifically through CD8+ T cell-derived IFN-{gamma}, which activates macrophages via the JAK-STAT1 pathway. C_LI What Question Should Be Addressed Next?O_LIFuture studies should employ anti-PD-1/CTLA-4 monoclonal antibodies in wild-type or humanized mouse models to validate findings and better recapitulate the pharmacokinetics of clinical ICI therapy, strengthening translational relevance. C_LIO_LIThe long-term consequences of this primed inflammatory state on chronic cardiac remodeling, heart failure development, and the potential interplay with atherosclerosis warrant further investigation. C_LI

IntroductionAortic stenosis (AS) is characterised by progressive aortic valve (AV) leaflet fibrosis and calcification, yet no medical therapies exist to slow disease progression. AV interstitial cells (VICs) that differentiate into myofibroblasts are central drivers of fibrosis. The Ca2+-activated K+ channel KCa3.1 promotes pro-fibrotic signalling in several fibrotic diseases, however its role in AS remains unknown. MethodsKCa3.1 protein expression was examined in paraffin embedded tissue by Immunohistochemistry from control and AS valve tissue. VICs were isolated, cultured and phenotypically characterised as myofibroblasts from AV tissue obtained from patients with severe tricuspid AS undergoing surgical AV replacement (n=19). KCa3.1 mRNA and protein expression were assessed by qRT-PCR and immunohistochemistry, and functional channel activity confirmed using patch-clamp electrophysiology. The effects of transforming growth factor-{beta}1 (TGF{beta}1) stimulation and pharmacological inhibition with the selective KCa3.1 blocker senicapoc were examined. ResultsImmunoreactive KCa3.1 channels and smooth muscle actin were detected in both control and AS aortic valve tissue, localised to elongated, nucleated interstitial cells, with significantly higher expression observed in AS tissue compared to control. Isolated VICs exhibited an activated myofibroblast phenotype, expressing THY-1, vimentin, collagen and -smooth muscle actin (SMA) (n=9). Myofibroblasts expressed KCa3.1 mRNA and protein and demonstrated functional plasma membrane channels. TGF{beta}1 stimulation increased KCa3.1, SMA and collagen type I mRNA expression, while KCa3.1 blockade with senicapoc (100 nM) significantly attenuated TGF{beta}1-induced SMA expression, stress fibre formation and collagen gel contraction. Senicapoc had no effect on myofibroblast proliferation or migration. ConclusionsWe show for the first time that functional KCa3.1 channels are expressed in human AS tissue and AV myofibroblasts, where they regulate myofibroblast contraction, -SMA expression, and differentiation, promoting pro-fibrotic activity. These responses are attenuated by the selective KCa3.1 inhibitor senicapoc. Given its established safety in phase 3 clinical trials, KCa3.1 inhibition represents a promising and readily translatable anti-fibrotic therapeutic strategy for AS.

Pulmonary arterial hypertension is a progressive, fatal disease driven by pathologic vascular remodeling including arterial medial hypertrophy, occlusive neointimal lesion formation, and venous muscularization. Current vasodilatory therapies improve hemodynamics but do not reverse established remodeling. Imatinib mesylate, a tyrosine kinase inhibitor targeting the PDGF-PDGFR signaling axis, has been proposed as an anti-remodeling therapy for pulmonary arterial hypertension and has demonstrated hemodynamic benefit in both preclinical models and clinical trials. However, prior preclinical models lack the neointimal lesions characteristic of human disease, effects on venous remodeling have not been examined, and direct histologic assessment in human trials is precluded by the invasiveness of serial lung biopsy. Here, leveraging the house dust mite mouse model of pulmonary hypertension, which recapitulates medial thickening, neointimal lesion formation, and venous muscularization, we rigorously evaluate the anti-remodeling and hemodynamic effects of imatinib during two defined remodeling stages: neointimal lesion growth and neointimal lesion maintenance. Imatinib treatment significantly reduced right ventricular systolic pressure at both stages. Despite this hemodynamic improvement, quantitative vessel-level analysis of over 1,700 arteries and 1,200 veins revealed no significant effect of imatinib on arterial medial thickness, neointimal lesion growth, neointimal lesion maintenance, or venous muscularization across any vessel size class. These findings dissociate imatinibs hemodynamic benefit from structural vascular remodeling and suggest that imatinib functions primarily as a pulmonary vasodilator rather than an anti-remodeling agent.

Background: Coronary artery calcium (CAC) scores inform subclinical atherosclerotic cardiovascular disease (ASCVD) burden, helping guide preventative treatments. However, prediction of cardiovascular (CV) events by CAC is largely limited to ASCVD outcomes. This study investigated whether a previously validated proteomic test for predicting a broad composite of four-year CV events could enhance the prognostic utility of CAC. Methods: We used a 27-protein CV risk score (Prot-CVR), derived from ~5,000 SomaScan? Assay plasma protein measurements, to predict four-year risk of a composite CV and mortality outcome (myocardial infarction, stroke/TIA, heart failure hospitalization, death) in 2,122 participants with ?1 CV risk factors from the Multi-Ethnic Study of Atherosclerosis (MESA) observational cohort at exam 5 and compared predictions to CAC Agatston scores. Discriminatory performance was assessed using C-Index and 4-year area under the curve (AUC). Cox Proportional Hazard (CoxPH) ratios were calculated for the composite outcome, ASCVD outcome (myocardial infarction, resuscitated cardiac arrest, stroke, coronary heart disease death), and individual events. Changes in Prot-CVR and CAC scores from baseline to MESA exam 5 (+10-years) in CV event versus event-free participants were assessed using 2-tailed paired t-tests. CoxPH regression models of CV event status distributed by Prot-CVR, CAC, and relevant co-variates were evaluated for performance relative to individual models. Results: Individual Prot-CVR and CAC models predicting the composite outcome had comparable 4-year AUCs, but Prot-CVR had a higher C-index (0.68 (0.65-0.70) versus 0.63 (0.60-0.65), p=0.001) and greater hazard ratios for the composite outcome (p<0.001), death (p<0.001), and heart failure (p=0.015). A combined CoxPH model of Prot-CVR + CAC + Age had a higher 4-year AUC (0.72, p<0.05) and C-Index (0.71, p<0.05) than Prot-CVR or CAC alone. Both Prot-CVR and CAC scores detected an increase in risk prior to an approaching CV event in ~10-year sensitivity-to-change analysis. For 49.6% of MESA population with CAC=0 at baseline, Prot-CVR was greater in composite event versus event free participants at 4 years (0.23 versus 0.15, p=0.006) and full follow-up (0.18 versus 0.13, p<0.001). Conclusion: Protein testing complements CAC for CV risk assessment although the improvement is modest. Prot-CVR may resolve which patients with CAC=0 are at heightened CV risk.

BackgroundBoth rare and common variants in the SRY-Box Transcription Factor 17 (SOX17) locus are associated with pulmonary arterial hypertension (PAH). SOX17 dysregulation leads to pulmonary artery endothelial cell (PAEC) dysfunction and the obstructive remodelling that characterises PAH. HypothesisImpaired SOX17 expression contributes to the pathogenesis of PAH. Restoring the function of SOX17 or its downstream targets using compounds that mimic its transcriptomic signature will rescue PAEC dysfunction and prevent PAH development. Methods and ResultsWe defined thousands of genes with direct SOX17 genomic binding sites and identified important potential binding partners, including ETS-transcription factors such as ERG by ChIP-seq in PAECs. Through the integration of three PAEC RNA-seq datasets involving overexpression and silencing of SOX17, we defined a robust SOX17 transcriptomic signature. In PAH patients, circulating plasma protein levels of 10 SOX17 signature genes were associated with the SOX17 common risk variants. This included EFNB2 and UNC5B; knockdown of these genes altered the viability and apoptosis of PAECs in response to TNF treatment. The drug-transcriptome database Connectivity Map (CMap) was used to predict novel potential therapeutic compounds to correct the SOX17 transcriptomic signature. Five compounds were selected for in vitro testing and were able to partially reinstate SOX17 target gene expression in PAECs. One compound, BX-912, was selected for in vivo testing as it corrected the levels of multiple target genes, including suppressing Runt-related transcription factor-1 (RUNX1). BX-912 blocked the development of pulmonary hypertension in mice lacking the SOX17 enhancer associated with human disease. ConclusionWe have demonstrated the therapeutic potential of targeting SOX17 in PAH through correction of its gene targets, identifying BX-912 as a lead compound with in vivo efficacy.

Bicuspid aortic valve (BAV) is one of the most common congenital heart defects but its genetic basis remains incompletely defined. Extracellular matrix components play key roles in outflow tract (OFT) and valve development, but their contribution to BAV is not fully established. Following the analysis of a cohort of BAV patients, we identified a family harbouring a rare human ELASTIN (ELN) variant (p.Gln691X). To assess its pathogenicity, we generated a zebrafish elna/b double knockout (KO) using an RNAless CRISPR Cas9 strategy to avoid genetic compensation. This mutant exhibited cardiovascular defects including OFT anomalies, reduced stroke volume and dysmorphic aortic valves, highlighting Elastins critical role in cardiac development. We then used this model to test the ELN variant identified in the BAV family. We found that wild-type ELN mRNA was able to restore normal cardiac function and morphology, whereas the variant ELN mRNA failed to do so. This study establishes a robust in vivo model to assess ELN variant pathogenicity and provides evidence linking ELASTIN to BAV, opening new avenues for uncovering the genetic mechanisms underlying BAV.

Objective: To compare RNA-sequencing-derived transcriptomic profiles of thoracic aortic aneurysm tissue from individuals with bicuspid versus trileaflet aortic valves. Methods: Human ascending aortic tissue was collected from patients undergoing cardiac surgery at a single institution between January 2021 and December 2022 with bicuspid aortic valves (BAV) and trileaflet aortic valves (TAV) with (-A) and without (-N) thoracic aortic aneurysm. TAV-N tissue was collected from heart transplant donors. The decision to perform ascending aortic replacement was at surgeon discretion following ACC/AHA guidelines. Bulk RNA was extracted from the aortic wall, and Illumina RNA Sequencing performed. Differential gene expression analysis, enrichment analyses, network analysis, and deconvolution single cell-mapping were performed in R. Cell-type specificity of differentially expressed genes was determined using an established Aorta single cell RNA sequencing matrix. Results: Tissue samples from 60 patients were included: 4 TAV-N, 16 BAV-N, 28 BAV-A, and 12 TAV-A. Average absolute aortic diameter was 5.1 +/- 0.38 cm for BAV-A and 5.3 +/- 0.44 cm for TAV-A, as measured on pre-operative CT. Gene ontology analyses of differentially expressed genes revealed enrichment of genes associated with extracellular matrix (ECM) organization, cellular receptor interactions and vascular smooth muscle cell (VSMC) function in BAV-A and BAV-N. In contrast, analysis of TAV-A versus TAV-N showed enrichment in genes associated with immune and inflammatory processes. Cell-type specificity analysis revealed a downregulation of genes associated with ECM components, cell signaling, and ECM remodeling in mesenchymal cells, VSMCs, and matrix fibroblasts specifically in BAV-A versus BAV-N. Conclusions: The transcriptome changes observed in aneurysmal aortas of BAV and TAV patients are distinct, suggesting mechanistic differences contributing to aneurysm development and progression. The observed differences in gene expression between the non-aneurysmal aortas may signify a predisposition to aneurysm development unique to BAV aortopathy.

BackgroundCurrent microphysiological models do not support long-term investigations into the chronic effects of vascular risk factors and the development of vascular diseases. Prolonged culture frequently leads to cellular senescence and loss of functional integrity, resulting in variability and inconsistency in modeling chronic vascular responses. Here we aimed to develop and sustain a long-term multicellular human vascular avatar, addressing the critical need for long-term disease modeling and drug testing. MethodsTo identify the optimal media for longevity, cell identity and function were assessed by morphology, qPCR, beta-gal staining, ELISA, bulk RNA-seq and single cell RNA-seq analysis. After optimizing the culture media, iPSCs-derived ECs and VSMCs from unaffected and Hutchinson-Gilford Progeria Syndrome (HGPS) donors were grown in Gravitational Lumen Patterning (GLP) Vessel- Chips for 1-6 months to generate a long-lived vascular avatar for the study of vascular aging. ResultsGuided by quantitative morphological analyses and bulk RNAseq profiling, we generated a novel optimized culture media VSL (VEGF, SB431542 as a TGF-{beta} inhibitor, low fetal bovine serum) that enhances the long-term health of vascular endothelial cells (ECs). Furthermore, we modified the VSL formulation (mVSL) by modulating 8Br-cAMP, FGF, PDGF, and a cell viability enhancer HMH1015 levels to enhance EC-VSMC (vascular smooth muscle cell) crosstalk and support long-term cellular viability. Subsequently, we maintained and characterized a human vascular avatar with a three-dimensional extracellular matrix environment and 3D vascular architecture for over 180 days. Finally, we demonstrated that this long-lived human vascular avatar enabled modeling vascular aging using iPSC-derived vascular cells from patients with Hutchinson-Gilford Progeria Syndrome (HGPS). ConclusionsWe have successfully engineered and maintained a human vascular avatar for over 180 days. The vascular avatar provides a robust platform for modeling disease-associated vascular aging and for evaluating therapeutic strategies targeting chronic vascular disorders.

Cells deploy adaptive programs to maintain homeostasis under stress, yet mechanisms counteracting damage triggered by transmembrane signaling remain poorly defined. Using a hyperaldosteronism model, we examined how autophagy regulates aldosterone-mediated mineralocorticoid receptor (MR) activation. In human umbilical vein endothelial cells (HUVECs), aldosterone induced autophagy, as evidenced by elevated Beclin-1, an increased LC3-II/LC3-I ratio, and reduced SQSTM1/p62. Aldosterone also promoted MR translocation from the cytosol to the nucleus. Co-immunoprecipitation and immunofluorescence revealed direct interaction and colocalization between MR and Beclin-1, as well as enhanced MR-lysosome association. Domain mapping showed that the Beclin-1 middle domain (161-241 AA) binds the MR C-terminal region (601-984 AA). Bioinformatic prediction and ChIP-qPCR confirmed that MR occupies the promoters of IL-1{beta}, IL-6, and TNF- upon aldosterone stimulation. Beclin-1 overexpression attenuated MR nuclear translocation, promoter binding, and inflammatory cytokine expression, whereas Beclin-1 knockdown reversed these effects. In vivo, aldosterone-infused Beclin-1 transgenic (Becn1-tg) mice exhibited lower blood pressure, reduced aortic medial thickening, and attenuated cardiac hypertrophy relative to wild-type controls, with no difference in body weight. Our findings identify Beclin-1 as a critical negative regulator of aldosterone signaling through an autophagy-dependent negative feedback loop. By interacting with MR and directing it toward lysosomal sequestration, Beclin-1 limits MR nuclear translocation and transcriptional activity, thereby mitigating aldosterone-induced vascular inflammation and cardiovascular injury. HighlightsAldosterone activates autophagy and promotes MR-Beclin-1 interaction in HUVECs Beclin-1 binds the C-terminal MR domain and directs MR to lysosomal degradation Beclin-1 overexpression suppresses MR nuclear translocation and cytokine gene activation Beclin-1 transgenic mice are protected from aldosterone-induced cardiovascular injury

BackgroundPeripheral artery disease is a major manifestation of atherosclerotic cardiovascular disease (ASCVD) that affects both men and women. In women, menopause increases the ASCVD risk. However, preclinical ASCVD research has historically been conducted predominantly in males, with relatively few studies focused on females and even fewer incorporating menopause models that more closely reflect human ASCVD pathobiology. Herein, we tested whether the chemical 4-vinylcyclohexene diepoxide (4-VCD)-induced ovarian failure or ovariectomy (OVX) would drive atherosclerotic development and worsen ischemic limb pathophysiology. MethodsFemale C57BL/6J mice were injected with adeno-associated virus-mediated encoding a gain-of-function mutant PCSK9 and fed an atherogenic diet for 23 weeks. Based on the baseline body weight, mice were randomly assigned to normally cycling controls (CON), 4-VCD, or OVX groups. Three weeks after the conformation of ovarian failure (4-VCD) or surgical ovarian removal (OVX), hindlimb ischemia (HLI) was induced via femoral artery ligation, and limb perfusion recovery and limb muscle performance were assessed. ResultsBoth 4-VCD treatment and OVX reduced uterus mass, without impacting body weight or composition, or circulating cholesterol levels compared to CON mice. Despite the similar metabolic and cholesterol profiles, atherosclerotic lesion areas were 1.5-1.7-fold greater in 4-VCD and OVX mice than CON mice. Perfusion recovery following HLI and plantar flexor muscle function in the ischemic limb were similar across groups, though muscle oxygenation was reduced in 4-VCD and OVX groups. ConclusionsOvarian failure and removal exacerbated atherosclerotic development but had minimal impacts on perfusion recovery and limb function following HLI. These findings confirm the inclusion of menopausal models, whether through ovarian failure or OVX, should be carefully considered to improve translatability of preclinical ASCVD studies, especially for womens health. Clinical PerspectiveO_ST_ABSWhat is New?C_ST_ABSWe demonstrate that both gradual ovarian failure (4-VCD) and surgical ovariectomy exacerbate atherosclerotic plaque development in a clinically relevant AAV-PCSK9 model, despite similar circulating lipid levels. In contrast, loss of ovarian function did not impair limb perfusion recovery or muscle functional outcomes following hindlimb ischemia, revealing a dissociation between atherosclerotic burden and limb functional recovery in experimental peripheral artery disease (PAD). What are the Clinical Implications?These findings provide new insight into why menopause increases atherosclerotic cardiovascular disease (ASCVD) risk while not necessarily demonstrating proportional impairments in limb recovery following ischemia. The data suggest that menopause-associated factors accelerate large-vessel atherosclerosis independent of circulating lipids, highlighting the need for targeted therapies beyond lipid lowering in postmenopausal women. Moreover, the dissociation between plaque burden and ischemic limb function underscores the importance of assessing functional outcomes in PAD independently of vascular imaging. Finally, these findings suggest that the incorporation of menopause-relevant models in preclinical research should be considered within the context of the specific biological endpoints and translational goals being evaluated.

Patients with Fontan circulation face evolving risk for cardiovascular morbidity and mortality, yet the interplay between cardiac function, vascular properties, and circulating proteins is incompletely defined. We hypothesized that biochemical biomarkers and multimodal cardiovascular profile differ significantly between Fontan patients and controls, and that selected markers may serve as predictors of reduced single ventricle function. We conducted a prospective observational study at a tertiary pediatric heart center including 31 individuals with Fontan circulation and 52 matched controls. Cardiac function was assessed by echocardiography; vascular phenotyping included carotid intima-media thickness, central and peripheral blood pressure, augmentation index corrected for heart rate, carotid-femoral pulse wave velocity, aging index, and reactive hyperemia index. Compared to controls, the Fontan group had increased pulse wave reflection and central systolic pressure as well as decreased echocardiographic markers of systolic and diastolic function, while pulse wave velocity and other vascular parameters were not significantly different between the groups. Levels of 92 circulating cardiovascular biomarkers were quantified in a subset of 25 of the Fontan cohort and 81 controls using a proximity extension assay. Twenty-two biomarkers differed significantly in the Fontan group compared to controls, including FGF23, REN, HAOX1, and IL17D. Levels of several of these biomarkers correlated with patient age. Most importantly, HAOX1 (a peroxisomal oxidase linked to redox metabolism) and FGF23 (a bone-derived hormone regulating phosphate and vitamin D homeostasis) correlated negatively with ejection fraction within the Fontan group. By contrast, BNP was not associated with cardiac function in the Fontan group. None of the biomarkers correlated with central arterial parameters. In summary, central arterial hemodynamics and biomarkers such as FGF23 and HOAX1 may improve monitoring of cardiovascular function in single ventricle patients with Fontan circulation.

AimsHeart failure with preserved ejection fraction (HFpEF) afflicts millions annually and current treatments provide symptomatic relief. Here, we investigate the therapeutic potential of synthetic human Relaxin-2 (RLX) at reversing diastolic dysfunction (DD) and reducing arrhythmia vulnerability. Methods and ResultsMale ZSF1 rats were placed on a normal diet (ND, N=10 controls) or a high-fat diet (HFD, N=11), resulting in the development of DD in 11-weeks, based on serial echocardiograms (enlarged left atrium (LA), wall thickness, doppler flow: E/e). Once HFpEF was confirmed, control and HFpEF rats were randomly treated with Relaxin (400{micro}g/kg/day RLX, N=6) or the vehicle (N=5) for 2-weeks using implanted minipumps. Echocardiograms were repeated at weeks 1 and 2, then hearts were isolated, optically mapped, subjected to programmed electrical stimulation (PES) and tissues dissected for immuno-fluorescence (IF), and qPCR analysis. Circulating levels of glucose, RLX and NT-pro-ANP were measured, pre- and post-treatment. Echocardiograms indicated that RLX reversed DD by reducing LA dimensions and E/e. Optical mapping revealed that 1/3 of HFpEF hearts exhibited sustained atrial and ventricular arrhythmia which were blocked by RLX as it tended to increase conduction velocity (CV). Based on IF, RLX increased Nav1.5, Connexin-43, {beta}-catenin and Wnt1 expression. There were no significant changes in fibrosis in this HFpEF model. NT-pro-ANP was elevated in HFpEF and reduced towards control values by RLX. qPCR analysis showed that RLX decreased DKK1 and MMP1A and increased SCN5A expression compared to Vehicle treatment (N=6 and 5, respectively). ConclusionsThe ZSF1 model showed clear signs of HFpEF, including DD, enlargement of the LA, enhanced hemodynamic stress, increased vulnerability to sustained AF and VF, and elevated glucose and blood pressure. RLX treatment largely reversed DD, hemodynamic stress, and suppressed sustained arrhythmias. RLX elicited cardiac genomic changes, most likely through Wnt/canonical signaling, demonstrating RLXs potential as a therapy for HFpEF.

Genome-wide association studies have identified rare and common mutations associated with increased risk of pulmonary arterial hypertension (PAH), but the mechanism by which impaired SOX17 expression increases PAH risk is not known. Notably, SOX17 plays a critical role in endothelial identity during development by suppressing RUNX1 through binding to its promoter and directing stem and progenitor cells toward an endothelial rather than a hematopoietic cell fate. RUNX1 functions as a key regulator of myeloid differentiation, aberrant angiogenesis and adverse cardiac remodeling. Previously, we found that RUNX1 inhibition reverses pulmonary hypertension (PH) in multiple animal models. Here, we hypothesize that impaired expression of SOX17 in PAH leads to endothelial cell (EC) dysfunction by failing to suppress RUNX1. METHODSHuman pulmonary artery endothelial cells (HPAECs) with stable SOX17 CRISPR/Cas9 knockout or RUNX1 overexpression were generated and examined for endothelial and hematopoietic gene expression, proliferation, migration, apoptosis, and angiogenesis. Immortalized lymphoblastoid cell lines (LCLs) from PAH patients with SOX17 mutations and healthy controls were reprogrammed into induced pluripotent stem cells (iPSCs) and differentiated into ECs. The effect of RUNX1 inhibition on Sugen/hypoxia-PH was examined in rats, SOX17 enhancer knockout (SOX17enhKO) mice, and Cdh5-CreERT2;Runx1(flox/flox);SOX17enhKO triple transgenic mice. SOX17 and RUNX1 expression were analyzed in peripheral blood samples from PAH patients (n=359). RESULTSHPAECs with SOX17 deletion or RUNX1 overexpression exhibited decreased expression of EC markers, enhanced proliferation and migration, defective angiogenesis, and decreased apoptosis. RUNX1 siRNA knockdown or RUNX1 inhibition by Ro5-3335 partially restored the endothelial properties in SOX17 KO HPAECs. ECs differentiated from SOX17 mutant PAH patient iPSCs exhibited upregulated RUNX1 expression and loss of endothelial identity, which was also partially restored by RUNX1 siRNA or Ro5-3335. In addition, SOX17enhKO mice had increased RUNX1 expression and susceptibility to Sugen/hypoxia-induced PH (SuHx-PH). Treatment with RUNX1 inhibitors or inducible endothelial-specific deletion of RUNX1 rescued SuHx-PH susceptibility in SOX17enhKO mice. RUNX1 inhibitors Ro5-3335 and Ro24-7429 also reversed SuHx-PH in wild-type rats. In addition, plasma RUNX1 expression was higher in PAH patients lacking detectable SOX17 expression than in patients with detectable SOX17 expression. CONCLUSIONSImpaired SOX17 expression increases the risk of PAH through insufficient suppression of RUNX1, leading to pulmonary endothelial dysfunction. RUNX1 inhibition mitigates PH associated with SOX17 deficiency and may represent a novel therapeutic strategy for PAH, especially those with rare or common SOX17 mutations.