Arteriosclerosis, Thrombosis, and Vascular Biology

Vascular endothelial (VE)-cadherin is essential for maintaining endothelial junctional barrier integrity. The Angiopoietin-1 (Ang-1)/Tie2 axis induced Akt1 activation is crucial for maintaining endothelial junctional barrier by inhibiting FoxO1 and suppressing expression of Angiopoietin-2 (Ang-2), a Tie2 antagonist. Systemic inflammatory conditions such as sepsis, Akt1 expression is reduced, whereas FoxO1-dependent Ang-2 expression is increased, resulting in endothelial barrier dysfunction. We previously showed that the TLR4/FoxO1 axis induces the ubiquitin E3 ligase CHFR, which promotes endothelial barrier disruption by targeting VE-cadherin for ubiquitylation and degradation. However, little is known about Akt1 expression during vascular inflammation. Here, we identified FoxO1-dependent CHFR expression as a key mechanism driving K48-linked polyubiquitylation and proteasomal degradation of Akt1 in endothelial cells (EC). LPS-induced K48-linked ubiquitylation of Akt1 was prevented in CHFR-depleted human EC and in endothelial-specific Chfr knockout (Chfr{Delta}EC) mice. Accordingly, CHFR depletion increased Akt1 and VE-cadherin expression in both human lung EC and Chfr{Delta}EC mice. Chfr{Delta}EC mouse lungs also exhibited elevated Ang-1 and Tie2 expression, and Ang-1 stimulation induced sustained Akt1 phosphorylation in CHFR-deficient EC. Moreover, CHFR depletion prevented LPS-induced expression of FoxO1 and Ang-2 in EC. Mechanistically, CHFR interacted with phosphorylated Akt1 and mediated its ubiquitylation at lysine residues K30, K39, K154, and K268. Expression of a ubiquitylation-deficient Akt1 mutant prevented LPS-induced VE-cadherin degradation and vascular injury. Collectively, these findings identify CHFR as a critical regulator of endothelial inflammatory responses by controlling Akt1 stability and VE-cadherin expression during inflammation.

BackgroundIndividuals with JAK2V617F-mutant myeloproliferative neoplasms or clonal hematopoiesis of indeterminate potential have a markedly increased risk of cardiovascular disease, yet the mechanisms by which mutant blood cells drive vascular and cardiac dysfunction remain incompletely understood. Although the thrombopoietin (TPO) receptor MPL is central to hematopoiesis and is expressed in vascular endothelial cells (ECs), its role in JAK2V617F-associated cardiovascular complications is unknown. Methods and ResultsWe generated chimeric mice with JAK2V617F-mutant blood cells and wild-type endothelium by bone marrow transplantation and challenged them with a high-fat/high-cholesterol diet to model cardiometabolic stress. These mice developed a distinct cardiovascular phenotype characterized by microvascular disease, increased left ventricular mass, and relatively preserved left ventricular ejection fraction. Histological analysis revealed coronary arteriole stenosis, perivascular fibrosis, reduced microvascular density, and endocardial injury, without evidence of epicardial coronary stenosis or myocardium infarction. Single-cell RNA sequencing revealed activation of inflammatory, stress-response, and endothelial-to-mesenchymal transition gene signatures in ECs, most prominently within the endocardial ECs. Immunohistochemistry identified MPL expression predominantly in endocardial ECs. TPO/MPL signaling was upregulated in endocardial ECs in mice with JAK2V617F-mutant hematopoiesis, and treatment with an anti-MPL neutralizing antibody markedly improved cardiac pathology, restored endocardial integrity, and increased coronary microvascular density despite persistent systemic inflammation. ConclusionsJAK2V617F-mutant hematopoiesis induces coronary microvascular dysfunction. Endocardial ECs represent a key cellular target under cardiometabolic stress, and endocardial MPL signaling constitutes a potential targetable pathway in JAK2V617F-associated cardiovascular disease. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=122 SRC="FIGDIR/small/715884v1_ufig1.gif" ALT="Figure 1"> View larger version (38K): org.highwire.dtl.DTLVardef@1b0c2d7org.highwire.dtl.DTLVardef@1c7da20org.highwire.dtl.DTLVardef@1c19af9org.highwire.dtl.DTLVardef@1a588b3_HPS_FORMAT_FIGEXP M_FIG C_FIG Key PointsO_LIJAK2V617F-mutant hematopoiesis induces cardiac microvascular disease C_LIO_LIMPL is expressed in endocardial ECs and MPL inhibition restores endocardial integrity and improves cardiac microvascular function C_LI

BACKGROUNDThe vascular endothelium is a dynamic tissue central to vascular homeostasis and disease, with endothelial cells (ECs) exhibiting plasticity that drives adaptive remodeling. Reelin, a secreted extracellular matrix glycoprotein critical for neuronal migration via ApoER2/VLDLR-DAB1 signaling, may also modulate vascular function and inflammation. However, its direct role in EC biology remains unclear. We investigated Reelin as a context-dependent signaling modulator in ECs, assessing its engagement of non-canonical pathways and regulation of endothelial plasticity relevant to cardiovascular pathology. METHODSHuman endothelial cells were stimulated with recombinant Reelin and analyzed by immunoblotting, immunofluorescence, and functional assays. Time-course studies assessed signaling, including phosphorylation of FAK, AKT, and DAB1 by Western blotting, while wound-healing assays quantified endothelial migratory capacity in vitro systems. RESULTSReelin rapidly robustly activated noncanonical signaling in endothelial cells, increasing FAK and AKT phosphorylation in a time-dependent manner consistent with cytoskeletal remodeling. Canonical DAB1 activation was limited. Functionally, Reelin enhanced migration, upregulated Endoglin/CD105, and induced a remodeling-associated phenotype. Reelin silencing altered endothelial phenotype, clearly indicating a role in homeostasis. Signaling was independent of VEGFR2 interaction. Overall, Reelin preferentially engages FAK/AKT pathways to drive partial phenotypic modulation without full endothelial-to-mesenchymal transition. CONCLUSIONWe show that Reelin is a previously unrecognized regulator of endothelial signaling and plasticity, acting via non-canonical FAK- and AKT-dependent pathways. By partially and dynamically modulating endothelial phenotype, Reelin promotes a remodeling-permissive state without triggering full mesenchymal transition. These findings identify Reelin as a novel modulator of endothelial function with potential implications for vascular remodeling and cardiovascular disease. What Are the Clinical Implications?Our findings identify Reelin as a modulator of endothelial signaling with a clear bias toward non-canonical FAK- and AKT-dependent pathways that regulate endothelial plasticity and remodeling. This signaling profile is highly relevant to vascular diseases in which endothelial dysfunction is driven by maladaptive cytoskeletal reorganization, altered migration, and persistent activation rather than complete loss of endothelial identity. The ability of Reelin to promote partial and dynamically regulated phenotypic modulation suggests that it may operate at early and potentially reversible stages of vascular pathology. In this context, dysregulated Reelin signaling could contribute to pathological vascular remodeling, including processes underlying atherosclerosis, fibrosis, and microvascular dysfunction. These results also raise the possibility that circulating or locally produced Reelin may serve as an indicator of endothelial activation state, providing a novel biomarker for vascular disease progression. Importantly, the identification of a signaling bias toward FAK- and AKT-dependent pathways highlights potential therapeutic targets downstream of Reelin that could be selectively modulated to limit maladaptive endothelial remodeling while preserving essential endothelial functions. Collectively, this study positions Reelin signaling as a previously unrecognized and potentially actionable pathway in the regulation of endothelial behavior, with direct implications for the development of targeted strategies aimed at preventing or attenuating cardiovascular disease progression

Preeclampsia (PE), or gestational hypertension, affects around 5% of pregnancies and leads to approximately 70,000 maternal and 500,000 fetal deaths per year worldwide, with increased cardiovascular and metabolic disease in survivors. PE is associated with elevated circulating levels of the alternative splice isoform of VEGF receptor 1 (sFlt1), defects in placental vasculature, kidney damage and, in severe disease, fetal growth restriction. Current mouse models induce PE via direct expression of sFlt1 or elevation of blood pressure, which bypass the natural risk factors for human disease, such as age, obesity, hypertension and diabetes. These risk factors have in common reduced expression of Kruppel-like factors 2 and 4 (KLF2/4), the endothelial transcription factors that protect against cardiovascular disease. We now report that inducible deletion of KLF4 in maternal endothelium (KLF4iECKO) results in gestational hypertension, elevated sFlt1, defective placental vasculature, kidney damage and fetal growth restriction. KLF4iECKO may thus serve as a mouse PE model suitable for mechanistic analysis and screening of treatments that address upstream risk factors.

BACKGROUNDInactivation of ANGPTL3 (angiopoietin-like protein 3, A3) is a proven therapeutic strategy for lowering plasma lipid levels independently of the LDL receptor (LDLR), yet the optimal approach to inactivate A3 remains unclear. A3 is proteolytically cleaved and circulates as full-length (A3-FL), N-terminal (A3-Nter) and C-terminal (A3-Cter) fragments. The specific contribution of each form of A3, and of its paralog, ANGPTL8 (A8), in modulating circulating levels of ApoB-Containing Lipoproteins (ABCLs) remain poorly defined. Clarifying these relationships will inform next-generation A3-directed therapies. METHODSWe performed liver perfusion studies to directly compare the number and composition of VLDL particles secreted from mice with and without A3. To amplify effects on cholesterol metabolism, we generated Ldlr-/- mice expressing wildtype A3 (A3-WT), A3-FL or A3-Nter, with or without co-expression of A8, and analyzed plasma lipids, circulating A3 and A8 complexes, and intravascular lipase activities. Complementary in vitro assays and structural modeling were used to assess relative endothelial lipase (EL) inhibition by A3 alone or in complex with A8. RESULTSLiver perfusion studies revealed that A3 inactivation does not alter the rates of hepatic secretion of VLDL in wildtype or Ldlr-/- mice. Inactivation of A8 alone lowered plasma LDL-cholesterol (C) levels by [~]20%, an effect dependent upon the expression of both EL and A3. Maximal inhibition of lipoprotein lipase (LPL) required co-expression of A8 plus both A3-FL and A3-Nter, indicating that A3 cleavage, in addition to A8 expression, is essential for maximal LPL inhibition. In contrast, A8 expression, but not A3 cleavage, was required for optimal EL inhibition. CONCLUSIONSA8 acts in concert with A3 to differentially modulate LPL- and EL-mediated lipolysis, which antagonizes hepatic clearance of newly-secreted atherogenic ABCLs. This mechanistic framework refines our understanding of A3-targeted lipid lowering and highlights the therapeutic potential of dual A3- plus A8-directed strategies to treat dyslipidemia and prevent atherosclerotic cardiovascular disease. Clinical perspectiveO_ST_ABSWhat is new?C_ST_ABSO_LIInactivation of A3 lowers circulating ABCL levels without altering hepatic secretion rates of VLDL-ApoB or -TG. C_LIO_LIProteolytic cleavage of A3 is required for maximal inhibition of LPL. C_LIO_LIInactivation of A8 lowers LDL-C levels through an A3- and EL-dependent, but LDLR-independent, mechanism. C_LI What are the clinical implications?O_LICombining A8 inhibition with A3-inactivating therapies offers a strategy to achieve greater reduction in LDL-C levels and atherosclerotic cardiovascular risk. C_LI

BackgroundSex-related differences in cardiovascular disease suggest the presence of intrinsic vasoprotective mechanisms, with estrogen recognized as an important modulator of endothelial function. Building on existing evidence, the present study provides mechanistic insights into how estrogen and nitric oxide (NO) signaling regulate selective pathways of oxLDL uptake, mitochondrial dynamics, and inflammatory responses during early atherogenesis. MethodsWe combined an in vitro endothelial cell-macrophage co-culture model with in vivo studies in low-density lipoprotein receptor-knockout (LDLr-/-) mice to investigate the role of estrogen in early atherosclerotic processes. Human aortic endothelial cells (HAECs) were exposed to oxidized low-density lipoprotein (oxLDL) in the presence or absence of 17{beta}-estradiol (E2) and the nitric oxide (NO*) donor S-nitroso-N-acetylcysteine (SNAC). Key outcomes included oxLDL uptake, mitochondrial oxidative stress, mitochondrial dynamics, and inflammatory signaling. In vivo, male and female LDLr-/- mice were exposed to a short-term high-fat diet with or without SNAC treatment. Plasma lipid levels, blood pressure, aortic lesion formation, and cardiac remodeling were evaluated. ResultsE2 reduced oxLDL uptake and oxidative stress, effects recapitulated by SNAC; however, these responses involved distinct entry pathways, with E2 preferentially modulating lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1) dependent uptake and SNAC targeting caveolae-associated mechanisms. In parallel, both E2 and SNAC reduced Scavenger Receptor Class B Type 1 (SR-B1) expression, suggesting an additional modulation on oxLDL transcytosis via this mechanism. Endothelial cells exposed to oxLDL exhibited altered mitochondrial regulatory proteins, including superoxide dismutase 2 (SOD-2), dynamin-related protein 1 (Drp-1), and optic atrophy protein 1 (OPA-1). Despite reducing oxidative stress, E2 increased the expression of adhesion molecules and enhanced monocyte adhesion in response to oxLDL exposure, particularly when combined with SNAC. Strikingly, E2 also modulated macrophage responses, increasing interleukin receptor antagonist (IL-1ra) expression and reducing GDF15, macrophage inhibitory factor (MIF), macrophage inflammatory protein 3 alfa (MIP-3), and matrix metalloproteinase 9 (MMP-9) levels, consistent with a less pro-inflammatory macrophage profile. In vivo, HFD increased plasma lipid levels and atherosclerotic lesion area in LDLr-/- mice, whereas SNAC partially attenuated these effects without affecting plasma lipid levels. In vivo, female LDLr-/- mice developed approximately 50% smaller aortic lesions than males, despite comparable or higher plasma lipid levels. A dyslipidemia led to increased blood pressure and a hypertensive phenotype in both males and females. SNAC treatment reduced lesion burden in both sexes and prevented diet-induced hypertension in females. ConclusionEstrogen limits early atherogenic injury by reducing endothelial uptake of oxLDL, preserving mitochondrial homeostasis, and modulating inflammatory signaling. Together, the E2 and NO pathways regulate early atherosclerosis through distinct yet complementary mechanisms, offering a potential framework for vascular-protective strategies.

BackgroundTranscatheter aortic valve replacement has transformed the management of aortic stenosis; however, adverse outcomes such as leaflet thrombosis and hypoattenuating leaflet thickening remain clinically significant concerns. Flow disturbances resulting from valve canting may alter local hemodynamics and promote thrombogenic conditions. We investigated how modest transcatheter heart valve canting alters cusp-specific sinus flow and washout and promotes localized thrombogenic microenvironments associated with leaflet surface thrombus formation using particle image velocimetry, a physiologic blood loop, and tissue analysis. MethodsA patient-derived aortic root model was used to evaluate the hemodynamic and thrombogenic effects of THV canting at -10{degrees} (anti-curvature), 0{degrees} (neutral), and +10{degrees} (along-curvature). High-resolution particle image velocimetry quantified sinus flow fields and washout characteristics, and complementary whole-blood loop experiments enabled histologic assessment of leaflet-associated thrombus formation. ResultsCanting redistributed systolic jet orientation and sinus recirculation in a direction-dependent manner while preserving global hemodynamic measurements. The most spatially constrained cusp showed the largest increase in stasis and the slowest washout. In the right coronary cusp, anti-curvature canting increased the fraction of sinus area with velocity magnitude <0.05 m/s to 92% versus 43% in neutral and 10% in along-curvature deployments, and prolonged neo-sinus (T90) washout to 4.7 cycles versus 2.9 and 1.8 cycles, respectively. Histology localized surface-adherent platelet/fibrin thrombus to these poorly washed regions, most prominently on the right coronary cusp leaflet in anti-curvature deployments. Left and noncoronary cusp responses shifted with tilt direction, indicating redistribution rather than uniform worsening of thrombogenic conditions. ConclusionsEven modest noncoaxial deployment is sufficient to create sinus-resolved throm-bogenic microenvironments that are not captured by global gradient or effective orifice area. Deployment configuration is therefore a modifiable determinant of post-TAVR leaflet throm-bosis risk and may contribute to HALT.

Background: SARS-CoV-2 infection is an established prothrombotic trigger, yet the population-level temporal relationship between circulating viral activity and pulmonary embolism (PE) remains poorly characterized. We aimed to evaluate the short-term association between respiratory viral activity and PE hospitalizations, accounting for specific temporal lags. Methods: We conducted a population-level time-series analysis of incident PE hospitalizations in Ontario, Canada, from 2011 to 2024. Using distributed lag non-linear models, we assessed the association between standardized weekly activity levels of SARS-CoV-2, influenza A/B, and respiratory syncytial virus (RSV) and PE risk over a 5-week lag period. Relative risks (RR) per standard deviation (SD) increase in viral activity were estimated via negative binomial regression using cross-basis terms to account for both exposure-response and lag-response non-linearities. Models were adjusted for Fourier seasonal terms and secular trends. Findings: Among 70,670 incident PE cases identified between 2011 and 2024, SARS-CoV-2 activity demonstrated a significant temporal association with PE. A cumulative RR increase of 20% per SD in SARS-CoV-2 activity was observed over the five weeks following exposure (RR 1.20; 95% CI 1.05-1.37). The risk followed a distinct delay trajectory: weekly cumulative RRs peaked at week 3 (RR 1.21; 95% CI 1.01-1.45). For the 2020-2024 period, influenza A also showed an association peaking at week 3 without statistical significance (RR 1.17; 95% CI 0.95-1.45). Interpretation: Increased population-level SARS-CoV-2 activity is associated with a heightened risk of PE, peaking at approximately the third week. This delayed peak suggests a protracted thrombo-inflammatory window, likely driven by sustained endothelial injury. These findings highlight the vascular burden of COVID-19 and suggest that infection prevention measures, including vaccination, may provide significant downstream protection against thromboembolic disease.

Acute kidney injury (AKI) is a serious and common clinical syndrome that currently has no effective treatment. Emerging evidence links coagulation pathways to kidney injury, particularly through coagulation proteases. Protease-activated receptors (PARs) are a family of G-protein coupled receptors (GPCRs) that are activated by proteolytic cleavage of their N termini, exposing a tethered ligand that initiates receptor signaling. PARs have been shown to play a major role in inflammation, vascular regulation, and tissue injury. PARs play key roles in inflammation, vascular regulation, and tissue injury. Previous work from the Hamm laboratory demonstrated that PAR4 contributes to AKI progression, as PAR4 knockout mice were protected in both unilateral ureteral obstruction and ischemia-reperfusion-based models of kidney disease. In this study, we investigated the potential of a PAR4 antagonist, VU6073819, at mitigating AKI progression in an ischemia-reperfusion injury (IRI) mouse model. PAR4 antagonism not only alleviated kidney injury and inflammatory response, but it significantly improved the survival. These findings identify PAR4 as a promising therapeutic target for AKI.

Background: Coronary artery bypass grafting (CABG) to physiologically non-significant coronary artery stenosis may result in graft failure due to competitive native flow. We evaluated whether an instantaneous wave-free ratio (iFR)-guided revascularization strategy improves graft patency and clinical outcomes compared to conventional angiography-guided CABG. Methods: In this prospective, randomized, single-blinded trial, patients with multivessel disease and at least one angiographically intermediate stenosis (50%-75%) were randomized to either CABG guided by angiography alone or angiography supplemented with iFR assessment groups. The primary endpoint was graft patency (occlusion or hypoperfusion of the graft) evaluated by coronary computed tomography angiography (CCTA) at 2, 12, and 36 months. Results: At 36 months, 78% of the patients completed follow-up. Left internal mammary artery (LIMA)-to-left anterior descending (LAD) artery graft patency was significantly higher in the iFR-guided group than in the angiography-guided group (80.5% vs. 56.8%; absolute risk difference, 23.7% [95% CI, 3.7%-43.8%]; RR, 1.42 [95% CI, 1.03-1.95]; P = 0.03). Saphenous vein graft patency also improved with iFR guidance (90.2% vs. 70.3%; P = 0.046). Major adverse cardiac and cerebrovascular events (MACCE) were similar between groups (28% vs. 20%; RR, 1.40 [95% CI, 0.69-2.85]; P = 0.48). Conclusions: iFR-guided CABG advocates significantly improved mid-term graft patency compared with angiography-guided CABG by optimizing surgical target selection and reducing competitive flow.

BackgroundAccumulating evidence indicates that moderate exercise may reduce the incidence of Stanford type A aortic dissection (TAAD), but the specific mechanisms remain unclear. This study aims to identify exercise-related biomarkers in TAAD patients and to investigate their underlying mechanisms. MethodsTranscriptome data related to TAAD and exercise-related genes were obtained from publicly available databases. Candidate biomarkers for TAAD were identified through an integrative approach incorporating differential expression analysis, machine learning, and expression level assessment, leading to the construction of a diagnostic model. Subsequently, functional enrichment, immune infiltration, regulatory network analysis, and computational drug prediction were conducted to systematically investigate the pathological mechanisms and translational potential of the indentified biomarkers. ResultsABCA3 and SCN4B were identified as exercise-related biomarkers in TAAD progression. A nomogram incorporating these two biomarkers exhibited strong diagnostic performance for identifying the disease. Functional enrichment analysis revealed potential involvement of these biomarkers in disease progression through pathways including circadian rhythm regulation and ribosome biosynthesis. Additionally, immune cells like M1 macrophages and naive B cells, as well as regulatory factors including hsa-miR-1343-3p and XIST, were found to be involved in this process. Finally, zonisamide and MRS1097 were identified through computation prediction as potential therapeutic drugs. ConclusionABCA3 and SCN4B were identified as exercise-related biomarkers associatied with TAAD and represent potential valuable targets for both diagnosis and treatment strategies.

BackgroundAlcohol consumption influences cardiovascular disease, but whether it does so by affecting endothelial plasticity is unknown. We tested whether alcohol regulates endothelial-to-mesenchymal transition (EndMT) to influence arterial pathology. MethodsHCAEC and HUVEC were exposed to inflammatory cytokines (TGF{beta} {+/-} IL1{beta}) or hypoxia in the presence of ethanol (0-100 mM). EndMT was assessed by changes in cell marker expression, SNAIL levels, and migration assays. In vivo, carotid ligation was performed in mice gavaged with/without either daily moderate ethanol (2-drink equivalent/d) or episodic binge exposure (7-drink equivalent, 2 days/week) and myo-endothelial cell population assessed. ResultsCytokines and hypoxia induced EndMT in vitro, characterized by loss of endothelial markers, increased mesenchymal markers, elevated SNAIL, and enhanced migratory capacity. Low-to-moderate dose ethanol (5-25 mM) attenuated these changes, preserving endothelial phenotype, whereas high dose ethanol (50-100 mM) either had no effect or exacerbated EndMT. The inhibitory effect of moderate ethanol on cytokine- and hypoxia-induced changes in SMA and Cdh5 expression was abrogated by {gamma}-secretase inhibition, consistent with involvement of Notch signaling. Carotid ligation induced neointimal formation and accumulation of myo-endothelial cells indicative of EndMT. Daily moderate ethanol significantly attenuated neointimal hyperplasia and diminished the myo-endothelial cell population, whereas in contrast, episodic binge ethanol exposure increased pathologic remodeling and myo-endothelial cell abundance. ConclusionsAlcohol modulates endothelial trans-differentiation in a biphasic manner. Low-to-moderate alcohol exposure suppresses EndMT and limits pathological remodeling, whereas binge-level exposure promotes these processes. These findings identify regulation of endothelial plasticity as a potential novel mechanism linking alcohol consumption patterns to vascular disease risk. NEW AND NOTEWORTHYWe identify a previously unrecognized biphasic effect of alcohol on endothelial phenotypic plasticity. Low-to-moderate dose alcohol suppresses endothelial-to-mesenchymal transition (EndMT), whereas high-level (binge) exposure promotes this pro-atherogenic process. Given the central role of EndMT in vascular remodelling and atherosclerosis, these findings provide a mechanistic framework linking alcohol consumption patterns and cardiovascular disease risk - potentially explaining both the protective effect at low/moderate levels, and the detrimental impact of heavy alcohol use. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=142 SRC="FIGDIR/small/718463v1_ufig1.gif" ALT="Figure 1"> View larger version (26K): org.highwire.dtl.DTLVardef@1febae2org.highwire.dtl.DTLVardef@9f5ff1org.highwire.dtl.DTLVardef@153ea69org.highwire.dtl.DTLVardef@42b1ed_HPS_FORMAT_FIGEXP M_FIG C_FIG Injurious stimuli can trigger endothelial cells (EC) to undergo endothelial-to-mesenchymal transition (EndMT) that contributes to arterial remodeling and disease. EndMT is regulated in a biphasic manner by alcohol with low-to-moderate levels (1-3 drink equivalent) suppressing EndMT and attenuating vascular remodeling, whereas higher level/binge exposure (7 drink equivalent) promotes these processes. Graphic created using Biorender.

Introduction: Accurate stratification of hard atherosclerotic cardiovascular disease (ASCVD) risk remains challenging despite advances in prevention. Liver function biomarkers (LFBs), particularly gamma - glutamyl transferase (GGT), have been linked to cardiovascular outcomes, yet their contribution to hard ASCVD risk prediction is not well defined. Methods: This study analyzed data from the National Health and Nutrition Examination Survey (NHANES, 2005 - 2018) to assess cross - sectional associations between LFBs and 10 - year hard ASCVD risk estimated by the ACC/AHA Pooled Cohort Equations. Multivariable regression, restricted cubic splines, and mediation analyses were applied to examine independent and dose - response relationships. External validation was performed in the China Health and Retirement Longitudinal Study (CHARLS) and NHANES using machine learning models (CoxBoost, Naive Bayes and Random Forest). Results: Among 5,731 NHANES participants, GGT showed an independent linear association with hard ASCVD risk (P - trend = 0.003), partly mediated by systolic blood pressure (44.8%), HbA1c (19.0%), and high density lipoprotein cholesterol (13.4%). Machine learning (ML) models incorporating GGT, alkaline phosphatase (ALP), and globulin alongside traditional risk factors improved predictive accuracy, with Naive Bayes achieving an AUC of 0.751 in NHANES validation. Conclusions: GGT is an independent and biologically plausible biomarker of hard ASCVD risk, acting through cardiometabolic pathways. Incorporating LFBs into risk prediction models, particularly with machine learning, enhances risk stratification and may facilitate early identification of high - risk individuals.

BackgroundWithin the kidney, (pro) renin receptor (PRR) is abundantly expressed in the collecting duct (CD) and modulate physiological and pathophysiological processes. We have recently reported that activation of CD PRR mediates obstructive renal fibrosis in a mouse model of unilateral ureteral obstruction (UUO). The current study addresses the underlying mechanisms by examining the profibrotic pathway mediated by soluble PRR (sPRR)-dependent alternative macrophage activation. MethodsWe performed UUO or sham surgery on mice with CD-specific deletion of PRR (CD PRR KO) and floxed controls. After 7 days, we assessed fibrosis-related parameters, inflammatory cytokines, M1/M2 macrophage markers, other gene expression markers of kidney injury, and the concentration of plasma sPRR. We also administered vehicle or site-1 protease (S1P) inhibitor PF-429242 (PF) to C57BL/6 mice with UUO to determine the role of sPRR. Experiments were performed in vitro to examine the mechanism of sPRR-His-mediated macrophage M2 polarization and activation of potential target genes in bone-marrow-derived macrophages (BMDMs). ResultsCompared with the floxed control, CD PRR KO decreased macrophage accumulation, M2 polarization, and Yap/Taz expression while improving renal fibrosis and suppressing plasma sPRR levels following UUO. In BMDMs, sPRR-His treatment promoted macrophage M2 polarization, fibrosis, and Yap/Taz expression, which was dependent on angiotensin type 1 receptor (AT1R). ConclusionCD PRR-derived sPRR acts via ATR to promote macrophage M2 polarization and stimulates the AT1R/Yap/Taz axis, which leads to renal fibrosis during UUO.

While Vegfc-Vegfr3 signaling is the primary driver of lymphangiogenesis, the role of G protein-coupled receptors (GPCRs), the most successful class of druggable targets in the human genome, remains far less understood. A previous study has implicated Apelin signaling and its receptor Apelin receptor (Aplnr), a class A GPCR, in lymphatic development, yet the underlying cellular and molecular mechanisms remain unclear. Here, we show that Apelin signaling is indispensable for Vegfc-Vegfr3-dependent lymphatic sprouting and promotes lymphatic endothelial cell (LEC) migration without affecting LEC specification. Loss of Apelin signaling resulted in defective sprouting of ECs from the posterior cardinal vein (PCV) and subsequent failure of lymphatic vessel formation. Conversely, Apelin overexpression induces ectopic endothelial extensions from the PCV, an effect that is suppressed by reducing Vegfr3 signaling. Mechanistically, we show that Vegfc signaling through ERK activation regulates Aplnr expression. We propose that the specific upregulation of Aplnrb in LECs renders them migration-competent, establishing Apelin signaling as a critical and non-redundant regulator of lymphatic sprouting. Overall, our results reveal a tightly coordinated signaling axis between growth factor and GPCR pathways that governs lymphatic endothelial behavior.

SHANK3 is a multidomain scaffolding protein critical for neuronal function, which has been linked to neurodevelopmental disorders such as autism spectrum disorder. More recently, SHANK3 has been shown to play a role in cell survival and actin dynamics outside the nervous system. Here, we show that SHANK3 is widely expressed in endothelial cells across different tissues, where its role is not well understood. SHANK3 localised to endothelial cell-cell junctions in cultured endothelial cells, and its depletion compromised endothelial barrier function. SHANK silencing altered cell mechanics including elongated cell morphology, reduced cell-matrix traction forces and alteration of cell migration rate. It further triggered dynamic heterogeneity in endothelial monolayers, with regions of coordinated long-range migration interspersed with areas exhibiting only local velocity fluctuations, consistent with a transition toward more fluid-like tissue behaviour. This change in collective dynamics was accompanied by increased spheroid spreading and fusion, suggestive of altered tissue viscosity, and coincided with disrupted cell-cell junction morphology and mechanical forces in SHANK3-depleted cells. In vivo, SHANK3 depletion impaired endothelial cell migration, resulting in delayed sprouting of intersegmental vessels and disruption of the vascular network in zebrafish embryos. Furthermore, inducible endothelial-specific deletion of SHANK3 in postnatal mice impaired angiogenic sprouting and reduced vascular complexity in the developing retina. Overall, we demonstrate that SHANK3 plays a role in endothelial cell motility and tissue mechanics, with implications for vascular processes during development.

Background: Despite optimal lipid-lowering and antithrombotic therapy, substantial residual cardiovascular risk persists in established atherosclerotic cardiovascular disease (ASCVD), partly driven by chronic vascular inflammation. Methods: Systematic review and meta-analysis of RCTs comparing colchicine to placebo or no treatment in adults with established ASCVD. Searches on March 21, 2026 (PubMed, Embase, CENTRAL, ClinicalTrials.gov, WHO ICTRP). PROSPERO CRD420261346516. Primary outcome: 4-point MACE (CV death, MI, stroke, urgent revascularization). DerSimonian-Laird random-effects with HKSJ adjustment. Exploratory trial-level meta-regression: time-to-initiation (TTI) and cumulative dose as continuous moderators. Results: DL pooled HR for 4-point MACE: 0.68 (95% CI 0.51-0.89; p=0.0060). HKSJ-adjusted HR: 0.68 (95% CI 0.27-1.70; p=0.3018). Substantial heterogeneity (I2=81.4%; 95% prediction interval 0.29-1.57, crossing 1.0). Exploratory meta-regression: TTI (beta=-0.00187/day, p=0.003) and cumulative dose (beta=-0.00163/mg-day, p=0.0003; k=5, explicitly underpowered). Non-CV mortality: HR 1.07 (0.76-1.50; p=0.694). GI discontinuation: pooled RR 1.95 (1.09-3.48; p=0.024). GRADE certainty: Moderate (4-point MACE). Conclusions: Low-dose colchicine is associated with reduced 4-point MACE in ASCVD (DL HR 0.68; HKSJ HR 0.68). The substantial heterogeneity and wide prediction interval indicate that effect size varies substantially across clinical settings. The divergence between CLEAR SYNERGY (acute; HR 0.99) and sub-acute/chronic trials (HR 0.33-0.77) drives heterogeneity. Meta-regression suggests TTI and cumulative exposure may be key moderators but is underpowered. The non-CV mortality signal is not confirmed. This analysis informs precision anti-inflammatory prescribing in ASCVD.

BackgroundLong COVID is characterised by persistent systemic inflammation and endothelial dysfunction, with increasing evidence implicating thromboinflammatory mechanisms. Platelet-monocyte aggregates (PMA) represent a sensitive marker of platelet activation and immune-vascular interactions, but their role in Long COVID remains incompletely defined. MethodsThis study quantified circulating PMA in 20 Long COVID patients and 20 healthy controls using a two-colour imaging flow cytometry assay targeting CD14 (a monocyte receptor for pathogen-associated molecular patterns, PAMPs) and CD62P (P-selectin). PMA were expressed as a percentage of total monocytes, and platelet attachment patterns were classified into single versus multiple platelet binding. Statistical analyses included Shapiro-Wilk normality testing, unpaired t-tests, Mann-Whitney U tests or two-way ANOVA as appropriate, and linear regression for correlation analysis. ResultsCirculating PMA were significantly elevated in Long COVID patients compared with controls (29.19 [20.02-37.26] vs 4.59 [2.67-7.16], p < 0.0001). Long COVID samples showed a reduced proportion of monocytes with single platelet attachment and a corresponding increase in multiple platelet binding (p < 0.0001). In controls, %PMA increased with age (p < 0.01), whereas no age association was observed in Long COVID, indicating an elevated baseline independent of age. ConclusionsLong COVID is associated with markedly increased platelet-monocyte aggregation and altered platelet attachment dynamics, consistent with sustained thromboinflammatory activity. PMA represent a sensitive cellular marker of platelet-driven immune activation and may have utility as an accessible biomarker for stratifying thromboinflammatory burden in Long COVID.

Background | Angina with nonobstructive coronary arteries (ANOCA) is a heterogeneous condition encompassing distinct endotypes representing different underlying pathophysiological mechanisms. Endothelial dysfunction is considered a central hallmark of ANOCA. However, studying patient-derived endothelial cells (ECs) remains challenging due to the limited availability of disease-specific endothelial samples. We therefore aimed to assess the feasibility of isolating and culturing ECs from catheterization material obtained during routine coronary function testing in ANOCA patients. Methods | Catheterization material was collected from 79 ANOCA patients (84% female, age 58{+/-}10 years) undergoing coronary function testing. ECs were isolated, expanded and characterized using immunostaining, flow cytometry, gene expression profiling and functional assays. Results | EC isolation was successful in 43% of cases and resulted in 34 primary EC cultures that were expanded up to passage 10. Isolation success was independent of clinical or procedural characteristics. Isolated cells exhibited typical EC morphology and expressed EC markers confirmed by immunostaining, flow cytometry and gene expression analyses. EC marker gene expression remained largely stable over passages. However, stress- and defense-related gene expression programs increased over time, while proliferation-related processes decreased. Functional assays demonstrated that the coronary catheterization-derived ECs showed typical properties of wound healing, angiogenesis, activation responses upon stimuli and monocyte adhesion. Conclusions | This study demonstrates the feasibility of isolating and expanding ECs directly from catheterization material collected during routine coronary function testing in ANOCA patients. These patient-derived ECs retain characteristic endothelial features and functionality. This approach offers primary EC cultures to study the mechanisms underlying endothelial dysfunction in ANOCA.

Background and Aims Despite treatment, patients with established atherosclerotic cardiovascular disease (ASCVD) are at high risk of recurrent events. Existing clinical risk scores for recurrence provide only moderate predictive performance and rely largely on the same conventional risk factors used to predict disease onset. Proteomics is a promising source of new biomarkers but the technologies need focused use cases in order to achieve utility and implementation. We aimed to determine whether plasma proteomics improves prediction of recurrent cardiovascular events beyond established clinical risk models in secondary prevention in a population-scale cohort. Methods Plasma proteomic profiles from ~9,300 participants in the UK Biobank with established ASCVD at baseline were analysed using machine learning methods to derive and evaluate proteomic predictors of recurrent cardiovascular events. The top performing model comprised proteins with non-zero weights (full protein score). Predictive performance of the proteomic predictors, an established clinical risk score (SMART2), and their combination was evaluated across six pre-defined testing datasets representing multiple ethnic and geographic groups. A parsimonious set of proteins with existing clinical-grade enzyme-linked immunosorbent assays (ELISAs) available was then derived. Results The full protein score achieved higher performance for recurrent ASCVD than the SMART2 risk score across all ethnic and geographic subgroups (mean C-index 0.743 vs 0.653). Adding the full protein score to SMART2 improved discrimination, with the largest increase in White Irish participants ({Delta}C-index, 0.140; 95% CI, 0.074-0.205; P<0.001). However, adding SMART2 to the protein score provided minimal additional value. The parsimonious score preserved most of the discrimination of the full protein model with C-indices of the recurrent ASCVD risk model comprising age, sex and the parsimonious protein score being nearly identical to the full protein model in the largest testing set (0.723 vs 0.728 for White British in England and Wales). The parsimonious protein score showed a marked gradient of risk with the top, middle and bottom quintiles showing 10-year recurrent ASCVD rates of ~27.4%, ~9.6% and ~2.4%, respectively. Conclusions In patients with established ASCVD, plasma protein measurements substantially improved prediction of recurrent events beyond conventional clinical risk factors, supporting their potential as a complementary tool to guide secondary prevention of cardiovascular disease.