Atherosclerosis

Objective: Impairments in efferocytosis, the phagocytic clearance of apoptotic cells, contribute to the development of chronic inflammation and promote the formation of large necrotic cores within atherosclerotic plaques. A better understanding of the factors that impair efferocytosis could lead to improved interventions. Many chronic inflammatory conditions feature excessive lipid peroxidation, which generates reactive lipid aldehydes that can potentially form N-aldehyde-modified phosphatidylethanolamines (NAMPs). We therefore investigated the extent to which levels of NAMPs are elevated under conditions of oxidative stress and whether exposure of macrophages to NAMPs inhibit efferocytosis. Approach and Results: The effects of synthetic NAMPs and lipid peroxidation on efferocytosis were measured using the Incucyte Live-Cell Analysis System to monitor rate of ingestion of CypHer-labeled apoptotic cells by cultured bone marrow-derived macrophages in real time. The extent of NAMP formation under various conditions was examined using liquid chromatography coupled with mass spectrometry. Several representative species of NAMPs (N-isolevuglandin-phosphatidylethanolamine, N-IsoLG-PE; N-4-hydroxynonenal-phosphatidylethanolamine, N-HNE-PE; and N-azeloyl-phosphatidylethanolamine, N-Aze-PE) inhibited efferocytosis in a concentration-dependent manner. Hydrolysis of NAMPs by recombinant N-acyl phosphatidylethanolamine hydrolyzing phospholipase D (NAPE-PLD) abolished their inhibitory activity, whereas genetic deletion of macrophage NAPE-PLD enhanced NAMP-mediated inhibition of efferocytosis. Blocking the inhibitor of lipid peroxidation, glutathione peroxidase 4 (GPX4), increased macrophage NAMP concentrations and impaired efferocytosis. Unmodified high-density lipoprotein (HDL) promoted efferocytosis, but exposing HDL to reactive lipid aldehydes or peroxidizing agents markedly increased NAMPs and this modified HDL inhibited efferocytosis. HDL isolated from subjects with familial hypercholesterolemia had elevated levels of multiple NAMP species. NAMPs impaired macrophage cholesterol efflux, which is required for continual efferocytosis. Conclusion: NAMPs accumulate under conditions associated with lipid peroxidation and inhibit the ability of macrophages to carry out efferocytosis.

Introduction: Cardiovascular disease is the leading cause of death worldwide (Dagenais et al. 2020), and its main risk factor is LDL-C (Hagenbeek et al. 2020). Only a few genes are associated with LDL-C concentrations, and only 2 genes, ANGPTL3 (Musunuru et al. 2010) and LIPC, are associated with familial combined hypocholesterolemia. Our team recently identified the second genetic cause associated with familial combined hypocholesterolemia, a gain-of-function mutant of the LIPC gene encoding hepatic lipase (HL), LIPC-E97G (Dijk et al. 2022). Although the mode of action of this variant remains largely unknown, we have demonstrated that it significantly increases the phospholipase activity of HL and affects lipoprotein metabolism by promoting plasma cholesterol clearance, particularly of LDL and HDL. Objective: The aim of this study was to explore the additive effect of our HL-E97G variant with a pharmacological inhibitor of the ANGPTL3 protein, evinacumab, on cholesterolemia and atherosclerosis. Materiel and methods: Atherosclerosis measurements were performed on Ldlr-/- mice fed a pro-atherogenic diet. These mice received a single injection of a liver-targeting AAV8 expressing the wild-type or E97G human form of the LIPC gene (1.10E11 genome copies/mouse) and a weekly injection of NaCl or evinacumab (25 mg/kg/week). Results: From a therapeutic approach, we demonstrated a cumulative effect of HL-E97G with evinacumab. Atherosclerotic lesions in the aortic arch of Ldlr-/- mice were reduced by 36% (p=0.4897) with evinacumab, by 65% (p-value=0.0028) with HL-E97G, and by 80% (p-value < 0.0001) with the combined therapy. Conclusion: Our data demonstrate that HL-E97G reduces the development of atherosclerosis in mice in an LDLR- and ANGPTL3-independent manner, strongly reinforcing the therapeutic potential of HL-E97G for patients at high risk of cardiovascular disease.

Objective: The immune response is linked to the progression of atherosclerotic cardiovascular disease (CVD). We sought to characterize a predictive cardiovascular antibody biomarker using two independent cohorts. Approach and Results: A human IgG profile serendipitously identified by ELISA was quantified in a well characterized cohort of 359 patients with a history of coronary artery disease (CAD) who experienced a total of 71 incident adverse CVD events (death, myocardial infarction, and stroke) over a median 4.1-year follow-up. Using Cox proportional hazard regression analysis, low biomarker levels were an independent predictor of adverse cardiovascular outcomes after adjustment for age, sex, diabetes mellitus, estimated glomerular filtration rate, presence of obstructive CAD, heart failure, total cholesterol, and high-density lipoprotein (HDL) cholesterol (adjusted hazard ratio of 1.90 [95% CI: 1.03 to 3.49; p=0.038] between lowest and highest tertiles). Validation was then performed in a larger secondary cohort using 4356 baseline samples from the Multi-Ethnic Study of Atherosclerosis (MESA), a prospective study of cardiovascular outcomes resulting in adjusted odds ratio of 50.5 per unit decrease in log-transformed biomarker [95% CI: 2.4 to 2773.1; p=0.030] over one year by logistic regression analysis. Conclusions: Low levels of human IgG antibodies targeting Bovidae IgG are independently associated with increased incidence of CVD events in patients with or without a history of CAD, indicating the potential clinical predictive power of this antibody profile as an inverse biomarker for CVD.

Background and Aims: Quantifying arterial inflammation can augment risk stratification and drug development in atherosclerosis. While perivascular adipose tissue (PVAT) density, captured as fat attenuation index (FAI) on CT angiography (CTA), is an emerging biomarker of coronary inflammation, it remains unclear whether this concept extends to carotid atherosclerosis. Methods: Using routine CTA data from hospital-based stroke cohorts, we developed a pipeline to quantify attenuation metrics of PVAT surrounding the distal common and proximal internal carotid arteries. We compared PVAT metrics between culprit and contralateral non-culprit plaques in patients with symptomatic carotid atherosclerosis and between culprit plaques and control carotid segments from patients without symptomatic atherosclerosis. In patients undergoing carotid endarterectomy, we assessed associations of CTA-derived PVAT metrics with histological and proteomic markers of plaque inflammation and stability. Results: Across 107 patients with symptomatic carotid atherosclerosis (75.5{+/-}8.7 years; 63% men), PVAT attenuation metrics did not show significant differences between culprit and contralateral non-culprit lesions (all p>0.2). We also found no evidence for higher PVAT attenuation in culprit lesions, when compared to arteries of patients without symptomatic atherosclerosis. In 82 patients undergoing endarterectomy, pre-operative CTA-derived metrics of PVAT attenuation showed no significant correlations with CD68+ macrophage areas in excised plaques (r -0.11 to 0.07, all p>0.3). Similarly, no PVAT attenuation metrics were associated with thinner fibrous cap or higher plaque levels of pro-inflammatory cytokines (IL-6, TNF). Conclusions: In contrast to coronary atherosclerosis, carotid PVAT attenuation was not associated with symptomatic culprit lesions or histological and molecular markers of plaque inflammation and vulnerability.

BackgroundOverweight and obese individuals often exhibit lower mortality rates or better prognoses than lean or normal-weight individuals with stroke and other diseases, a phenomenon called the "obesity paradox". Carotid atherosclerosis is the primary cause of ischemic stroke, and body weight serves as a reliable surrogate for adiposity in mice. MethodsPhenotypic and genetic connections of carotid atherosclerosis with body weight were evaluated in 299 F2 mice derived from BALB/cJ and LP/J Apoe knockout (Apoe-/-) mice. F2 mice were fed a Western diet for 12 weeks. Atherosclerotic lesion sizes in left carotid arteries, body weight, coat color, plasma lipids, glucose, small dense LDL ApoB, and malondialdehyde were measured, and 11,000 single nucleotide polymorphism (SNP) markers were genotyped. ResultsCarotid lesion sizes inversely correlated with body weight in both sexes. Genome-wide scans identified two significant quantitative trait loci (QTLs) for carotid atherosclerosis on chromosomes (Chr) 6 and 15 in an additive sex model, and five QTLs on Chr 6, 7, 12, 13, and 15 in an interactive sex model. Adjusting for body weight variation downgraded Chr 15 QTL (Cath5) in both models, whereas other QTLs upgraded in the additive sex model and downgraded in the interactive sex model. Human syntenic region of Cath5 associated with carotid intima-medial thickness (cIMT) and waist-to-hip ratio (WHR). ConclusionsThese findings indicate that the obesity paradox in carotid atherosclerosis is partially driven by shared genetic components that exert opposing effects on adiposity and plaque development and act through sex-dependent mechanisms.

Background: Phenotyping of atherosclerotic plaque vulnerability has largely relied on histopathology that captures structural features, but does not fully account for clinical presentation. Proteomic profiling could uncover molecular readouts of vulnerability that refine plaque phenotyping and provide mechanistic insights. Yet, the proteomic signatures associated with plaque rupture and symptomatic presentation are poorly characterized. Methods: We profiled paired carotid plaque tissue and preoperative plasma from 88 patients undergoing carotid endarterectomy (51 symptomatic, 37 asymptomatic) using the Olink Explore 3072 platform. We related plaque protein abundance to symptomatic presentation and quantitative histopathological features, and compared the performance of histopathology- vs. proteomics-based models for discriminating symptomatic disease. Next, we developed proteomic signatures of cellular abundance and explored their associations with plaque phenotypes by using plaque single-cell RNA-sequencing (scRNA-seq) data. Finally, we assessed plaque-plasma concordance across 2,837 shared proteins. Results: Across 2,837 plaque proteins, 19 were differentially expressed in symptomatic plaques related to distinct clinical events, highlighting pathways related to neutrophil degranulation and innate immune system. FGFBP1 showed the strongest association with symptomatic presentation (log2 fold change = 1.14; P = 1.82 x 10^-6). Proteins associated with a composite vulnerability index based on histopathology were enriched for inflammatory pathways, including TNF signaling through NF{kappa}B, complement activation, and IL6-JAK-STAT3 signaling. Individual proteins also mapped to specific histopathological features, including CXCL8 associated with macrophage burden and lipid core size, and EPHB4 and PKN3 with neovascularization. A proteomics-based model discriminated symptomatic from asymptomatic plaques substantially better than a histopathology-based model (AUC 0.83 vs. 0.66; P = 0.026). Integration with scRNA-seq data enabled the development of cell-class signatures that correlated with histopathology readouts, including macrophage burden, smooth muscle cell content, and neovascularization. Plaque and plasma protein levels showed limited overall correspondence (median {rho}=0.11), although selected proteins, including FGFBP1, demonstrated concordant associations in plasma. Conclusions: Deep proteomic profiling of human carotid plaques identifies molecular signatures of symptomatic atherosclerosis that extend beyond conventional histopathology. These signatures implicate neutrophil activation and inflammatory signaling pathways as key determinants of plaque vulnerability. Although plaque and plasma proteomes are largely distinct, selected proteins may represent promising circulating biomarkers for future risk stratification.

Objective: Lipoprotein(a) [Lp(a)] is a causal risk factor for atherosclerotic cardiovascular disease composed of apolipoprotein(a) [APO(a)] covalently linked to apolipoprotein B100 (APOB). Although plasma Lp(a) concentrations are largely genetically determined, the mechanisms governing Lp(a) metabolism after particle assembly remain poorly understood. We sought to define the Lp(a) proteome and determine the metabolic behavior of APO(a) and APOB within circulating Lp(a) particles using integrated proteomic, kinetic, and imaging approaches. Approach and Results: Sixteen healthy adults underwent stable isotope tracer studies with 2H3-L-leucine and 2H5-glycerol. Lp(a) particles were isolated by APO(a)-specific immunoprecipitation for high-resolution liquid chromatography-mass spectrometry and kinetic analyses, and extracellular vesicles (EVs) were characterized by imaging flow cytometry and super-resolution microscopy. Proteomic analysis identified 92 proteins associated with immuno-isolated Lp(a), enriched in pathways related to immunity, coagulation, and atherogenesis. Lp(a)-APO(a) exhibited a mean fractional clearance rate of 0.04 pools/day, whereas Lp(a)-APOB cleared approximately sevenfold faster (0.25 pools/day), independent of plasma Lp(a) concentration or APO(a) isoform size. Both APO(a) and APOB were detected on circulating EVs, suggesting that EVs may contribute to post-secretory Lp(a) particle remodeling. Conclusion: These integrated human studies demonstrate marked discordance between APO(a) and APOB turnover within circulating Lp(a) particles, challenging the prevailing assumption that both apolipoproteins behave as a single metabolic unit after Lp(a) assembly and supporting a revised model of human Lp(a) metabolism.

Background. Cuproptosis, a copper-dependent form of regulated cell death, has been repeatedly reported to be transcriptionally activated in atherosclerotic plaque, and cuproptosis- and copper-transport genes have been nominated as candidate biomarkers and therapeutic targets on the basis of descriptive expression studies. Whether genetically determined expression of these genes is causally related to atherosclerotic cardiovascular disease has not been tested. Methods. We first confirmed, across two independent carotid plaque transcriptomic cohorts (GSE43292 and GSE28829), that a panel of copper-metabolism and cuproptosis genes is concordantly dysregulated in plaque and that the copper importers track the degree of inflammatory-cell infiltration. We then performed two-sample cis-Mendelian randomization (MR) and Bayesian colocalization to test the causal effect of the genetically predicted expression of 11 cuproptosis/copper genes on coronary artery disease (CAD). Instruments were cis-eQTLs from whole-blood (eQTLGen, n = 31,684) and tibial artery (GTEx v8, n = 584); the outcome was CAD (CARDIoGRAMplusC4D/Aragam 2022; 181,522 cases, 1,165,690 participants, European ancestry). Large-artery atherosclerotic stroke (GIGASTROKE) was examined as a secondary outcome. LPL served as a positive control. The positive control was intended to validate the direction and harmonization of the MR pipeline, not to demonstrate that single-causal-variant colocalization must succeed at a known multi-signal locus such as LPL. Results. In plaque, copper-import genes (SLC31A2, SLC31A1) were upregulated and correlated strongly with myeloid/inflammatory infiltration (SLC31A2 vs. M1-macrophage r = +0.87), whereas the exporter ATP7B correlated inversely (r = -0.73). The positive control LPL showed the expected robust protective effect on CAD (IVW OR 0.90 per SD higher expression, 95% CI 0.87-0.93, P = 4.1 x 10-12), validating the pipeline. None of the 11 cuproptosis/copper genes showed colocalization-supported causal evidence for CAD. Two genes reached nominal MR significance in single-instrument analyses (MTF1 OR 1.16, P = 2.7 x 10-3, DLAT OR 1.41, P = 2.2 x 10-3,) but were not supported by colocalization (MTF1 PP.H4 = 4 x 10-6 with PP.H3 = 0.9998; DLAT PP.H4 = 0.29), indicating linkage-disequilibrium confounding rather than causality. For well-instrumented genes (e.g. ATP7B, SLC31A2, FDX1), estimates were null and precise enough to exclude odds ratios larger than {approx}1.05 per SD. Conclusions. Common cis-regulatory variation determining the baseline expression of cuproptosis/copper-transport genes in available eQTL tissues did not support a detectable causal effect on CAD risk. This does not exclude locally acquired plaque cuproptosis; rather, the reported upregulation of these genes in plaque is most consistent with a consequence or marker of established disease rather than a germline-encoded causal driver, and cautions against target nomination based on descriptive transcriptomics alone. Keywords: cuproptosis; atherosclerosis; coronary artery disease; Mendelian randomization; colocalization

DNA methylation is a key epigenetic mechanism regulating the expression of genes involved in numerous developmental and pathological processes. However, the contribution of DNA methylation of microRNA genes to atherosclerosis remains poorly understood. In this study, we profiled DNA methylation patterns of both the regulatory elements and gene bodies of five microRNA genes (MIR10B, MIR21, MIR100, MIR127, and MIR143) in vascular tissues and paired peripheral blood cells (PBC) of 92 patients with advanced carotid atherosclerosis and 32 PBC of control participants by targeted bisulfite sequencing. We identified distinct tissue-specific DNA methylation patterns for all five microRNA genes in patients with advanced carotid atherosclerosis. The regulatory regions of MIR10B, MIR127, and MIR100 were moderately hypomethylated in carotid atherosclerotic plaques compared with intact vascular tissues. We further integrated our findings with lab-internal and publicly available epigenome-wide methylation datasets and evaluated the influence of vascular and blood cell composition using computational deconvolution approaches. After adjustment for cellular heterogeneity in vascular tissues, DNA methylation at CpG sites in MIR100 and MIR127 remained independently associated with atherosclerosis. Increased DNA methylation at a single CpG site (chr11:122025143, GRCh37/hg19) located within the MIR100 E-box region was associated with metabolic syndrome. Moreover, DNA methylation levels of MIR10B, MIR21, and MIR127 in atherosclerotic plaques were linked with indicators of histological instability and history of acute cerebrovascular events. In peripheral blood, we observed moderate hypomethylation of the regulatory regions of MIR10B, MIR21, and the MIR100 E-box region in patients compared with the control group. However, only the MIR10B remained robust against blood cell composition. In blood, MIR10B and MIR143 methylation correlated with lipid metabolism and carotid stenosis, while the MIR21 CpG island showed strong blood-plaque concordance, confirming its potential as a surrogate biomarker. Overall, advanced carotid atherosclerosis is characterized by specific tissue-altering DNA methylation patterns of microRNA genes, where alterations mainly occur in the regulatory regions, predominantly featuring hypomethylation. The results underscore the complex, cell- and tissue-specific nature of DNA methylation of microRNA genes in both the regulatory elements and gene bodies in vascular tissue and blood, highlighting the critical need to decipher these intricate epigenetic landscapes to identify reliable, robust biomarkers for assessing plaque instability and cardiovascular risk.

Background: Preoperative risk assessment in vascular surgery relies on clinical scores and lipids that do not capture atherosclerotic disease activity. Circulating fatty acid synthase (cFAS) is a liver-derived enzyme whose concentration correlates with arterial plaque FAS content independent of LDL. The 5-item modified frailty index (mFI-5) is a validated predictor of postoperative mortality. Whether cFAS predicts outcomes after vascular surgery, and whether combining it with the mFI-5 improves risk discrimination, have not been examined. Methods: We studied 657 patients undergoing elective vascular surgery at a single center (2014 to 2023). cFAS was classified as non-detectable (n = 306) or, among detectable values, by tertiles (n = 117 each). Multivariable Cox models assessed associations with major adverse events (MAE), major adverse cardiovascular events (MACE), major adverse limb events (MALE), reintervention, and mortality, and Harrell's C-statistic quantified the incremental discrimination gained by adding cFAS and the mFI-5 to standard clinical covariates. Results: High serum cFAS was independently associated with 5-year MAE (adjusted hazard ratio [aHR] 1.94; 95% CI 1.31- 2.85), mortality (aHR 1.77; 1.05 to 3.00), MALE (aHR 4.53; 2.04 to 10.05), and reintervention (aHR 2.50; 1.37 to 4.57), but not MACE. Severe frailty (mFI-5 of 3 or higher) was associated with MACE (aHR 2.69; 1.29 to 5.58) and MAE (aHR 2.46; 1.30 to 4.65) but not limb endpoints at 1 year. Adding cFAS raised the 1-year MALE C-statistic from 0.649 to 0.764; the combined model yielded the highest discrimination. Conclusions: cFAS and mFI-5 were independently and additively associated with adverse outcomes after elective vascular surgery. cFAS was associated with limb events and mortality, the mFI-5 with cardiovascular events. Combining them improved discrimination over standard covariates.

BACKGROUND: The effect of neurovascular health on cardiovascular outcomes is not well-known. Cerebral small vessel disease (CSVD) signals subclinical vascular brain injury and its quantification may serve as a tool to stratify risk in healthy individuals. Studying the relations of CSVD to cardiovascular events and mortality could aid in targeted preventive efforts. METHODS: We included Framingham Heart Study participants free of diagnosed stroke and dementia. CSVD was assessed on brain MRI?considering covert infarcts, cerebral microbleeds, cortical superficial siderosis, high perivascular space burden, and extensive white matter hyperintensities?with 1 point assigned for each marker, to categorize CSVD scores as 0, 1, or 2+. We used a composite outcome and three components: stroke, myocardial infarction, and mortality. Cox regression analysis was used with models adjusted for age, sex, cohort, MRI-exam cycle time interval, and vascular risk factors. RESULTS: In our study, 31% of our 3263 participants (mean age 58.0 years [SD: 13.4], 54% women) had a CSVD score greater than 0, and those with higher scores were generally older and had higher prevalence of vascular risk factors. Over a median follow-up of 8.4 years, 454 participants (13.9%) experienced at least one outcome, with mortality being the most common. Increasing CSVD burden was associated with higher incidence rates of the composite outcome. Compared with participants with CSVD score 0, those with scores of 1 and 2 had significantly higher risk of any event (HR 1.48, 95% CI 1.19?1.85; HR 1.52, 95% CI 1.17?1.97 respectively). CSVD burden showed a dose-response relationship with all-cause mortality and was associated with increased stroke risk, while no significant association with MI was observed. CONCLUSION: Higher subclinical CSVD burden is independently associated with increased risk of adverse cardiovascular events and mortality in community-dwelling individuals. CSVD detected on brain MRI may serve as a valuable imaging biomarker for risk stratification and early prevention of life-threatening outcomes.

Background: Lipoprotein(a) [Lp(a)], is leading risk factor for premature atherosclerotic cardiovascular disease. Multi-societal guidelines recommend to test Lp(a) amongst adults at least once, however, real-world testing data in primary prevention populations remains scarce. Objectives: To investigate the utilization of Lp(a) testing in a primary prevention cohort and associated outcomes. Methods: We conducted a retrospective cohort study using data from the PITT-LIPID registry, an electronic health record (EHR) based database of primary prevention patients (ages 20-79 years) across a tristate healthcare network. Lp(a) testing status was assessed, and those with Lp(a) measurements were stratified by Lp(a) levels [&le;]125 versus >125 nmol/L. Multivariable Cox proportional hazards models were used to assess associations between Lp(a) levels and coronary artery interventions [percutaneous coronary intervention (PCI), coronary artery bypass grafting (CABG)], and mortality. Results: Among 687,780 patients without known coronary artery disease, only 6,340 (0.9%) patients underwent Lp(a) testing. Compared with untested patients, those tested for Lp(a) had higher low density lipoprotein cholesterol, greater percentages of statin and aspirin use, and lower prevalence of diabetes and smoking. Patients with Lp(a) testing had higher rates of PCI (4.5% vs 1.4%; p-value <0.001) and CABG (1.4% vs 0.4%; p-value <0.001) but lower all-cause mortality (2.0% vs 5.0%; p-value < 0.001) incidence. Lp(a) >125 nmol/L was independently associated with risk of PCI (HR 1.67, 95% CI [1.16-2.41]), p=0.006. Conclusion: Lp(a) testing was underutilized and associated with higher burden of PCI events in a primary prevention population across a contemporary healthcare network with diverse practice types.

Background: Lacunar stroke accounts for approximately 25% of ischaemic strokes and is linked to metabolic and vascular risk factors. Abdominal adiposity, measured as waist-to-hip ratio adjusted for BMI (WHRadjBMI), is a heritable predictor of cerebrovascular disease independent of overall adiposity, but its biological mediators remain unclear. We performed a two-sample Mendelian randomization (MR) mediation analysis of 16 candidate biomarkers. Methods: Summary-level GWAS data were obtained from the IEU Open GWAS and EBI GWAS Catalog for WHRadjBMI (exposure), 16 mediators, and lacunar stroke (outcome). Instruments met genome-wide significance (P < 5 x 10), LD clumping (r2 < 0.001, 10,000 kb; 1000 Genomes European panel), and F-statistic 10. Inverse variance weighted regression was the primary analysis, with MR-Egger, weighted median, and MR-PRESSO sensitivity analyses. Mediation was quantified using the product-of-coefficients method with delta-method standard errors. Results: Systolic blood pressure showed the largest mediation proportion (29.6%; 95% CI, 12.7%-46.5%), followed by diastolic blood pressure (29.2%; 12.1%-46.3%) and glycated hemoglobin (23.0%; 11.2% to 57.2%). Other mediators included triglycerides (10.8%), fasting insulin (9.9%), blood glucose (7.0%), HDL cholesterol (3.2%), and LDL cholesterol (1.1%). Sensitivity analyses were generally consistent, though MR-Egger intercepts suggested directional pleiotropy for glycoprotein acetyls and CRP (Path A only). Because mediators are intercorrelated, proportions cannot be summed; multivariable MR is needed for joint effects. The HbA1c estimate was imprecise and requires cautious interpretation. Conclusions: Blood pressure, and possibly glycemic control, are the leading mediators linking abdominal adiposity to lacunar stroke. These findings support prioritizing blood pressure management-and potentially glycemic control-to reduce small vessel cerebrovascular disease in individuals with elevated WHRadjBMI.

Elevated circulating low-density lipoprotein cholesterol (LDL-C) is a primary risk factor for atherosclerosis; however, the molecular mechanisms underlying lipid plaque formation within the artery wall remain poorly understood. Here, we identify GPR182, a recently characterized lipoprotein receptor of the atypical chemokine receptor family, as a key mediator of lipid deposition in the aortic endothelium during atherosclerosis. Genetic depletion of GPR182 protects against atherosclerosis across multiple mouse models without altering circulating cholesterol levels or immune cell recruitment to plaques. GPR182 is expressed by aortic endothelial cells (ECs) and is further upregulated during disease progression. GPR182 mediates LDL uptake by aortic ECs both in vitro and in vivo. Blockade of GPR182 with a monoclonal antibody reduces lipid uptake in the aorta and attenuates disease progression under hypercholesterolemic conditions. Collectively, these findings identify endothelial GPR182 as a critical regulator of aortic lipid deposition and atherosclerotic plaque formation and support GPR182 inhibition as a promising therapy for atherosclerotic cardiovascular disease.

Background: Spontaneous coronary artery dissection (SCAD) causes acute coronary syndrome that predominantly affects women. It is not known why SCAD occurs in specific coronary artery segments. We aimed to identify anatomical and hemodynamic factors that lead to SCAD. Methods: We studied 36 women with angiographically-confirmed SCAD from more than 20 hospital sites and 75 sex- and ethnicity-matched control participants with normal coronary anatomy. Coronary arteries were reconstructed from computed tomography coronary angiography (CTCA) to quantify vessel geometry (curvature, diameter, torsion) and flow-derived metrics (time-averaged endothelial shear stress [TAESS], topological shear variation index [TSVI], oscillatory shear index [OSI], and relative residence time [RRT]) at the tree (left/right), territory (LAD, LCx, RCA), and lesion levels. Results: Compared with controls, SCAD-affected coronary arteries had greater curvature and higher TAESS and TSVI at the whole-tree level (all p?0.007). At the vessel (territory) level, SCAD-affected arteries were smaller in average diameter and showed higher curvature, TAESS, and TSVI than matched control vessels (all p?0.047). Within the same patient, SCAD lesion segments were characterized by smaller diameter, lower torsion, and higher TAESS and TSVI than non-affected segments from the same coronary tree (all p?0.001; curvature borderline). A model combining curvature, TAESS, and TSVI discriminated SCAD from controls with AUC 0.95 (left tree) and 0.97 (right tree); adding diameter yielded AUCs >0.91 at the territory level. Conclusions: SCAD was associated with a reproducible multi-scale signature of smaller vessel caliber and higher, more variable endothelial shear stress supporting a hemodynamic contribution to SCAD clustering in specific coronary arteries and segments.

Background: Macrophage foam cell formation is a central event in atherosclerosis. Although protein ubiquitination is increasingly recognized as a regulator of macrophage lipid handling, whether deubiquitinating enzymes directly control lipid uptake and metabolic remodeling during atherogenesis remains unclear. Methods and Results: Here, transcriptomic profiling identified ubiquitin-specific protease 20 (USP20) as a previously unrecognized regulator of macrophage foam cell formation. Genetic and pharmacological studies demonstrated that USP20 promoted macrophage lipid accumulation and foam cell formation, whereas macrophage-specific Usp20 deficiency markedly attenuated atherosclerotic lesion formation, lipid deposition, and macrophage accumulation in mice. To elucidate the underlying mechanism, integrative analysis of USP20-interacting proteins and proteomic alterations in Usp20-deficient macrophages identified fatty acid-binding protein 5 (FABP5) as a substrate of USP20. Mechanistically, USP20 interacted with FABP5 and stabilized its protein abundance by preventing ubiquitin-dependent proteasomal degradation. Consequently, USP20-mediated stabilization of FABP5 enhanced PPAR{gamma} occupancy at the Cd36 promoter, thereby increasing Cd36 transcription, ox-LDL uptake, and foam cell formation. Accordingly, Fabp5 knockdown abolished USP20-induced CD36 expression, ox-LDL uptake, and foam cell formation, whereas pharmacological activation of PPAR{gamma} restored CD36 expression in Fabp5-deficient macrophages. Finally, macrophage-targeted delivery of the USP20 inhibitor GSK2643943A markedly reduced atherosclerotic burden without evident systemic toxicity, supporting the therapeutic potential of targeting USP20 in atherosclerosis. Conclusions: USP20 promotes macrophage foam cell formation by stabilizing FABP5 and enhancing PPAR{gamma}-dependent Cd36 transcription. Targeting the USP20-FABP5-PPAR{gamma}-CD36 axis may represent a therapeutic strategy to limit macrophage lipid accumulation, metabolic dysfunction, and atherosclerosis progression.

People living with HIV-1 (PWH) receiving antiretroviral therapy (ART) exhibit an increased cardiovascular disease (CVD) risk. Coronary atherosclerotic plaque formation is linked to chronic immune activation, a process fueled in PWH by additional mechanisms likely including residual HIV-1 production and microbial translocation from the gut during ART. Our previous studies demonstrated that aldehyde dehydrogenase (ALDH), an enzyme converting vitamin A into retinoic acid (RA), is upregulated in myeloid cells upon exposure to viral/bacterial/fungal products and that RA promotes HIV-1 production. To explore the link between ALDH/RA pathway and CVD risk, we used PBMC/plasma from ART-treated PWH (PWH+ART; n=51) and people without HIV-1 (Pw/oH; n=63) from the Canadian HIV/Aging Cohort Study, with/without subclinical coronary atherosclerosis, measured by coronary computed tomography angiography. ALDH expression was analyzed by flow cytometry on monocyte subsets, dendritic cells, and CD4+ T-cells. Unsupervised t-SNE-guided FlowSOM analysis associated top ALDH activity with a monocyte phenotype. The frequency of ALDH+ monocytes and plasma levels of RA and retinol binding protein 4 were increased in PWH+ART versus Pw/oH, with the highest RA levels coinciding with detectable plasma levels of soluble HIV-1 gp120. Multivariate regression models linked ALDH activity in monocytes to subclinical coronary atherosclerosis (i.e., total plaque volume, low attenuated plaque volume, coronary artery calcification score) presence/burden in PWH+ART, independently of Framingham risk score. Finally, ALDH+ monocyte frequency and RA levels positively correlated with pericoronary fat attenuation index, an emerging CVD predictor. Thus, ALDH/RA pathway may represent a new marker of metabolic/immune dysfunction contributing to CVD risk in ART-treated PWH.

Background: Spontaneous cervical artery dissection (sCeAD) is a rare vasculopathy whose pathophysiology remains incompletely understood. Impaired vascular extracellular matrix integrity, including elastic fibers, may contribute to its development. We investigated whether serum fibrillin-1 and soluble elastin fragments (sELF) differ between patients with sCeAD and controls during the acute and chronic stages. Methods: Patients with acute sCeAD were prospectively enrolled at four German stroke centers. Blood samples were collected at baseline and after 6{+/-}1 months. Patients with a first acute ischemic stroke unrelated to sCeAD and healthy individuals served as controls. Serum fibrillin-1 and sELF concentrations were measured using enzyme-linked immunosorbent assays. Results: 61 patients with sCeAD, 53 patients with first non-CeAD ischemic stroke, and 79 healthy controls were included. After sex-matching, serum fibrillin-1 concentrations were significantly lower in patients with acute sCeAD than in healthy controls (97 [60; 192] vs. 176 [113; 269] ng/mL; p=0.009). Fibrillin-1 concentrations were also lower in both male and female patients with sCeAD than in respective healthy controls. In patients with sCeAD, fibrillin-1 concentrations increased significantly after 6 months compared with baseline (171 [130; 270] vs. 104 [67; 205] ng/mL; p=0.021). Serum fibrillin-1 concentrations were higher in men than in women across all study groups. No significant differences in sELF concentrations were observed between groups or time points. Discussion: Serum fibrillin-1 concentrations were lower during acute sCeAD and increased significantly during follow-up, whereas sELF concentrations remained unchanged. These findings support an association between circulating fibrillin-1 and acute sCeAD and warrant further investigation of its role in sCeAD pathophysiology. Pronounced sex-related differences in fibrillin-1 concentrations highlight the importance of sex-specific analyses in future.

Atherosclerosis is a chronic inflammatory disease primarily initiated by the sub-endothelial retention and modification of low-density lipoproteins (LDL), such as oxidation and aggregation. While oxidized LDL (oxLDL) exists in atherosclerotic lesions, aggregated lipoproteins are also prominent. Aggregated LDL (agLDL), for instance, is viewed as a passive substrate for macrophages to uptake and form foam cells. Recent studies show that agLDL, through toll-like receptor 4 (TLR4), induces formation of lysosomal synapses, which drive agLDL degradation by macrophages, a process described as "digestive exophagy". As TLR4 is one of the pattern-recognition receptors for inflammatory responses in macrophages, we postulated that agLDL could initiate macrophage inflammation along with lipoprotein degradation/internalization, thereby contributing to a low degree of chronic inflammation in atherosclerosis. Here, we demonstrate that agLDL directly activates the canonical NF-{kappa}B signaling pathway and triggers a pro-inflammatory transcriptional program through TLR4, which closely resembles classical lipopolysaccharide (LPS)-mediated TLR4 activation. In addition, agLDL also activates TLR4 to generate inflammatory macrophages that recruit immune cells, a key process in the development of atherosclerotic lesions. Our findings therefore support a novel dual functionality of agLDL: a lipid donor and an inflammatory agonist. This establishes the agLDL-TLR4-NF-{kappa}B axis as a direct link between LDL aggregation in the intima and the initiation of sterile vascular inflammation. It also strengthens the understanding of the role of digestive exophagy with new mechanistic details.

Background: Growing evidence suggests persistent thrombotic endothelial damage (together with elevated (fibrinaloid) microclot complexes (FMCs)) and immune dysfunction in the pathophysiology of Long COVID. Recently we proposed that there are different FMC phenotypes. Here we seek to determine the nature of these FMCs and aggregates in platelet-poor plasma (PPP) by using different markers, as well as thromboelastography (TEG) to assess for hypercoagulability of samples. Material and Methods: Whole-blood and PPP from control (n=19) and Long COVID (n=20) participants were assessed by thromboelastography. FMCs were quantified by imaging flow cytometry of Thioflavin-T (ThT)-stained PPP, 10X diluted PPP, and resuspended PPP pellets. The resuspended pellets were separately stained with a CD62P-PE antibody or Hoechst 33342 to label aggregates and FMCs containing amyloid, platelet, and nuclear material. ThT and CellMask Red were co-stained for confocal microscopy. ThT and myeloperoxidase (MPO), and ThT, Congo Red, and Hoechst were co-stained for fluorescence and polarized microscopy. Whole-blood smears were imaged by scanning electron microscopy (SEM). Results: Long COVID samples showed pronounced hypercoagulability in both whole blood and PPP, with shortened R, K and TMRTG and elevated alpha-angle and MRTG, but unchanged MA and TTG, indicating altered clotting kinetics. Persistence of this phenotype in PPP implicates soluble plasma constituents. ThT-positive FMCs were significantly increased in Long COVID across undiluted, diluted, and resuspended pellet samples; counts were processing-sensitive and a substantial ThT-positive population remained in the supernatant after centrifugation, indicating heterogeneity in density. Across probes, leukocyte material was the most abundant, then platelet material, and ThT-positive FMCs were the least abundant, with the three populations exhibiting unique morphology and occupying distinct size domains. Platelet-derived material was significantly elevated in Long COVID, whereas nuclear material was not. Co-stained samples subject to confocal, fluorescence, and polarized microscopy imaging showed that FMCs are heterogeneous, including events positive for ThT, CellMask, Hoechst, MPO, and Congo Red, and also a distinct subset of membrane-free, ThT-only events. Conclusion: In this Long COVID cohort, plasma is characterised by hypercoagulability and an increased burden of ThT-positive FMCs that are numerically minor relative to, and morphologically distinct from, aggregates and amyloidogenic FMCs marked with platelet- and leukocyte-derived material. The increased burden of platelet debris in PPP is likely indicative of persistent platelet activity. The existence of membrane-free, ThT-only FMCs, in addition to FMCs associated with cellular material, confirms an amyloid-dominated FMC population. Furthermore, positive Congo Red signal further confirms the amyloid nature of FMCs in PPP.