Atherosclerosis

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.

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.

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.

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.

Rationale: Thrombi are fragile, heterogeneous, and difficult to study with available methods, yet understanding their molecular composition and local microenvironment in stroke is critical to elucidating stroke pathophysiology and improving patient outcomes. Objective: We used a novel platform for harvesting and analyzing intracranial thrombi from endovascular thrombectomy for large vessel occlusion to define the cellular and transcriptomic landscape of thrombi. Methods and results: We performed single-nuclei RNA sequencing (snRNA-seq) on three human intracranial thrombi to define their molecular composition and microenvironment. Across 5,143 nuclei, we identified 8 distinct cellular populations, including monocytes and T cells. Monocytes displayed transcriptional changes on gene and regulon levels suggestive of transdifferentiation. We integrated our snRNA-seq data with publicly available single cell RNA-sequencing (scRNA-seq) data from asymptomatic and symptomatic atherosclerotic carotid plaques, and scRNA-seq data from healthy brain vasculature. We identified shared transcriptional programs between carotid and thrombi monocytes along dimensions including inflammation and endothelial activation, supporting the notion that thrombi monocytes undergo transdifferentiation in stroke. We also inferred potential ligand-receptor interactions that may occur at the site and time of occlusion. Conclusion: Our novel application of snRNA-seq to thrombectomy specimens has allowed us to uncover the full diversity of cell types present in thrombi, including low-abundance and novel cell populations, and to provide evidence of cellular plasticity and intercellular communication at the site of occlusion. This detailed definition of the cellular populations involved in stroke will facilitate mapping of novel interventional targets with direct functional relevance and facilitate greater personalization of post-reperfusion therapy.

BackgroundThe progression of abdominal aortic aneurysm (AAA) is closely associated with the phenotypic switch of vascular smooth muscle cells (VSMC). While members of the Serine/Arginine-rich splicing factor (SRs) superfamily are increasingly acknowledged for their pivotal role in modulating cell phenotype, the specific contribution of these factors to AAA development has remained underexplored. MethodsThrough integrated analyses the whole transcriptome of human and murine AAA tissues derived from clinical samples and animal models, we identified serine-arginine repeat matrix 4 (SRRM4) as a candidate gene regulating AAA formation. To investigate the role of SRRM4 in AAA formation, we used global and VSMC-specific SRRM4-knockout mice to construct AAA mouse models in two different ways. The impact of SRRM4 on AAA was further investigated in in vivo and in vitro models ResultsElevated levels of SRRM4 mRNA and protein were observed in VSMC from both human and murine AAA tissues. Targeted silencing of SRRM4 in VSMC (but not in endothelial or myeloid cells) significantly attenuated AAA formation in both AngII- and CaCl2-induced mouse models. Our results identify the RE1 silencing transcription factor (REST) as a critical target gene of SRRM4 in AAA, a master regulator of cellular phenotypic stability. We show that SRRM4 modulates VSMC phenotype through alternative splicing of the REST gene, resulting in a non-functional REST4 isoform. Furthermore, our study shows that REST directly represses STAT1, a mechanism by which SRRM4 influences VSMC phenotypic transition. Regarding clinical significance, inhibition of both STAT1 expression and function was shown to be beneficial in preventing AAA formation and slowing disease progression in mouse models. ConclusionsThis investigation uncovers a previously unrecognized role of SRRM4-mediated splicing of the REST gene in the progression of AAA and identifies a novel REST/STAT1 axis critical in the phenotypic modulation of VSMC. The findings of this study may provide insights for the development of innovative therapeutic strategies for AAA. What is New?O_LIOur study demonstrates that the RNA splicing factor SRRM4 (serine/arginine repetitive matrix 4) expression is increased in human and murine abdominal aortic aneurysm (AAA) tissues and unveils a previously undescribed role of SRRM4 in regulating AAA development. C_LIO_LISRRM4 promotes AAA development and progression through inducing splicing of REST (RE1 silencing transcription factor) gene and upregulating STAT1 (signal transducer and activator of transcription 1) expression, which result in extracellular matrix degradation, inflammation, and VSMC phenotypic switching. C_LIO_LIOur study provides proof-of-concept evidence indicating the therapeutic value of STAT1 inhibition in AAA prevention and treatment. C_LI What Are the Clinical Implications?O_LIOur study defining a novel mechanism underlying the SRRM4/REST/STAT1 axis is crucial for developing new therapeutic strategies for AAA. C_LIO_LIBased on these findings, we have initiated a prospective study (REST4-AAA; ClinicalTrials.gov Identifier: NCT07056491) to evaluate REST4 expression levels in serum of AAA patients and explore its potential as a serum biomarker for AAA prediction C_LIO_LIOur findings indicate that fludarabine, a clinically available agent reported to selectively suppress STAT1, effectively attenuates AAA progression in mice, suggesting its potential for repurposing as a therapeutic strategy for AAA. C_LI

Background: Coronary perivascular fat attenuation index score (FAI-Score) on coronary computed tomography angiography (CCTA) quantifies vascular inflammation and predicts cardiac mortality in symptomatic cohorts. However, its prevalence, anatomical distribution, and clinical correlates in asymptomatic primary prevention populations remain uncharacterized. Methods: In an IRB-approved prospective study across two clinical sites, 84 consecutive asymptomatic adults (mean age 53.7 {+/-} 8.6 years; 63.1% men) with no prior coronary artery disease underwent screening CCTA and comprehensive clinical, metabolic, and biomarker profiling. AI-standardized FAI-Score was quantified across three epicardial vessels (LAD, LCx, RCA). High and very high perivascular inflammation were pre-specified as any vessel [&ge;]75th and [&ge;]90th percentiles, respectively. Luminal stenosis and plaque were graded using CAD-RADS 2.0. Results: Elevated FAI-Score ([&ge;]75th percentile) was present in 42.9% of participants (36/84; 95% CI 32.8% - 53.5%), with 17.9% (15/84; 95% CI 11.1% - 27.4%) exhibiting very high inflammation ([&ge;]90th percentile). Multi-vessel inflammation was identified in 17.9% (15/84), with the RCA most frequently involved ([&ge;]90th percentile in 13.1%). Standard circulating biomarkers, including ApoB, non-HDL-C, HbA1c, and PREVENT-ASCVD 10-year risk showed no association with binary inflammation. Systemic hs-CRP (median 0.8 mg/L) exhibited an inverse correlation with maximum vessel FAI-Score (Spearman {rho}=-0.27, p=0.014). Men demonstrated higher rates of elevated FAI-Score than women (52.8% vs. 25.8%, p=0.016; [&ge;]90th percentile: 26.4% vs. 3.2%, p=0.007). Strikingly, 46.2% (30/65) of participants with normal luminal anatomy (CAD-RADS 0) and 47.2% (25/53) with zero plaque burden harbored elevated FAI-Score; all 15 individuals with very high FAI-Score had CAD-RADS 0 (Fisher's exact p=0.018). Body mass index was the sole secondary correlate surviving false discovery rate correction (AUC = 0.71, p=0.001, all-test FDR q=0.028). Regularized multivariable models showed modest out-of-sample discrimination for FAI-Score elevation (cross-validated AUC = 0.71). Conclusions: Coronary perivascular inflammation is common among asymptomatic adults and frequently uncouples from structural plaque and luminal stenosis. Routine circulating biomarkers and clinical risk calculators fail to identify inflamed vessels, highlighting FAI-Score as an independent dimension of primary cardiovascular risk assessment.

Background and Objectives: More research is required to determine the associations of high-density lipoprotein (HDL) cholesterol concentration and particle count with mortality. The objectives of this analysis were to investigate whether there were non-linear associations of HDL concentration with all-cause mortality, whether cardiovascular disease (CVD) deaths, cancer deaths or other deaths drove these associations, and whether small, medium, or large HDL particle count was associated with mortality. Methods and Results: The sample included 47,123 men and 97,589 women from the Mexico City Prospective Study. Models were adjusted for confounders and competing risks. There were 11,264 deaths in men and 15,486 in women. There was a J-shaped association of HDL concentration with all-cause mortality in men driven by other deaths. For example, compared with the >40th-60th percentile, the hazard ratio (95% confidence interval) for other mortality was 1.27 (1.11, 1.44) in the >95th-99th percentile and 1.82 (1.45, 2.28) in the >99th-100th percentile. There was a U-shaped association in women driven by CVD deaths at lower concentrations and other deaths at higher concentrations: the hazard ratio for CVD mortality was 1.23 (1.05, 1.43) in the two lowest percentiles groups and the hazard ratio for other mortality was 1.33 (1.18, 1.50) in the two highest percentile groups. Small HDL particle count was associated with reduced risk of all-cause, CVD, and other mortality in men and women. For example, compared with the bottom quartile, the hazard ratio for all-cause mortality was 0.79 (0.73, 0.86) in the top quartile in men and 0.77 (0.72, 0.82) in the top quartile in women. Conclusions: There is a J-shaped association of HDL concentration with mortality in men and a U-shaped association in women. More research is required to confirm the novel finding that small HDL particle count reduces the risk of all-cause, CVD, and other mortality in men and women.

Cytosolic phospholipase A2 (cPLA2), encoded by PLA2G4A plays a crucial role in platelet activation through thromboxane A2 biosynthesis. Defects in this pathway can lead to bleeding disorders; however, the precise role of cPLA2 in Glanzmann thrombasthenia (GT) or GT-like syndromes remains poorly understood. The current study emerged from a fortuitous discovery of novel PLA2G4A variants, p.Asp455Val (D455V) and p.Glu119Lys (E119K), among 3 GT patients from two unrelated families in south India. We envisaged a hypothesis to identify a hitherto unknown role of cPLA2 that could be attributed to GT-like bleeding symptoms in these patients. An extensive computational workflow, including variant classification, conservation analysis, stability prediction, molecular docking, molecular dynamics simulations, principal component analysis, and binding free energy (MMPBSA) calculations, were employed to assess mutation-induced alterations in the cPLA2 protein. The current findings depicted that both variants affected conformational dynamics, ligand recognition patterns, and local interaction networks, without causing any drastic global structural destabilization. In particular, the D455V partially disrupted the catalytic domain, potentially reducing substrate (PAPC) stabilization and hampering interactions with catalytic products. Likewise, the E119K variant partially affected the C2 domain, potentially altered electrostatic interactions and enhanced regional flexibility, which may compromise product (AA) stabilization. Further analyses revealed mutation-induced changes in collective motions, protein-ligand interactions, solvent accessibility, and secondary structural elements. Overall, our findings promote the hypothesis that both E119K and D455V variants may partially alter phospholipid-associated interactions, and cPLA2-mediated downstream signaling. Moreover, this study underscores cPLA2 as a potential modifier of platelet function and bleeding severity.

Background: CADASIL caused by cysteine-altering NOTCH3 variants, the most frequent hereditary cerebral small vessel disease worldwide, is characterized by marked phenotypic variability. Mutation location within the EGFr domains of the NOTCH3 receptor has emerged as a key determinant of this variability. We investigated phenotypic variability and potential modifiers of CADASIL expression by comparing individuals harbouring the same pathogenic NOTCH3 variant across distinct recruitment settings in three European countries. Methods: We compared clinical features, MRI markers, and cardiovascular risk factors among individuals harbouring the p.Arg1231Cys NOTCH3 mutation across three distinct recruitment settings: a multigenerational founder population from Cilento, Italy (CILCAD), a population-based cohort from the UK Biobank (UKB), and a clinically referred cohort from a national referral centre in Lariboisiere Hospital, Paris, France (LRB). In addition, CILCAD carriers were compared with NON-Carriers from the same population. The NOTCH3 locus was finally analysed to define the shared haplotype in CILCAD and explore potential genetic contributions to phenotypic variability. Findings: By comparing populations from three European countries, this study showed marked context-dependent phenotypic variability associated with the sole pathogenic p.Arg1231Cys NOTCH3 variant. In CILCAD, a multigenerational founder population, the haplotype carrying the NOTCH3 mutation also predisposes to decreased LDL levels, resulting in an unusually low LDL cholesterol profile in this sample. Strikingly, these very low LDL levels were associated with a higher likelihood of stroke. Interpretation: In European carriers of NOTCH3 p.Arg1231Cys, factors beyond mutation location, including genetic background, may substantially shape disease expression, while exceptionally low LDL levels could paradoxically be associated with greater disease severity.

BACKGROUND: Regional stroke-prevention priorities usually rest on what a bloc's members share. Where members span multiple Global Burden of Disease (GBD) super-regions and genetic ancestry groups, population, individual, and genetic evidence face different transportability limits, and earlier combined studies did not prespecify what counts as disagreement. METHODS: We studied the Shanghai Cooperation Organisation, which spans four super-regions and five ancestry groups and is land-contiguous. For five metabolic risk factors we triangulated GBD 2023 attributable fractions of stroke DALYs in ten states, incident stroke among 7896 adults in the China Health and Retirement Longitudinal Study (2011-18; SHRs per 1 SD), and subtype-specific Mendelian randomisation in three ancestries. An explicit rule set, with one pre-submission amendment, classified convergence and divergence by whether a listed mechanism accounted for it. FINDINGS: High systolic blood pressure converged: 53-71% of attributable DALYs, the strongest cohort exposure (SHR 1.37, 95% CI 1.26-1.48), and genetically supported in both ancestries. LDL cholesterol (GBD attribution restricted to ischaemic stroke; European genetic evidence for that subtype; no cohort association) and body-mass index (last in attribution but second in the cohort, with a 1.80-fold [1.48-2.18] gradient inside the 20-25 kg/m2 minimum-risk window) showed structural discordance. The cohort lacked subtype data to establish LDL dilution. Fasting glucose and kidney dysfunction diverged without such a mechanism. INTERPRETATION: Systolic blood pressure had the strongest cross-stream support. LDL cholesterol and body-mass index require qualified interpretation; fasting glucose and kidney dysfunction could not be ranked reliably. The framework identifies where priorities require scrutiny. FUNDING: None.

Objectives: To compare high-sensitivity C-reactive protein (hsCRP) profiles in Korean and US adults with low-density lipoprotein cholesterol (LDL-C) below 100 mg/dL and examine differences after adiposity adjustment. Study design: Cross-sectional analysis of national health examination surveys. Methods: We analysed the Korea National Health and Nutrition Examination Survey 2022-2024 (n=5,785) and US National Health and Nutrition Examination Survey August 2021-August 2023 (n=1,056). Eligible adults had Sampson-calculated LDL-C below 100 mg/dL and hsCRP of 10 mg/L or less; elevated hsCRP was defined as 2-10 mg/L. We estimated survey-weighted prevalence differences and adjusted prevalence ratios (PRs). Results: LDL-C distributions closely overlapped (weighted medians, 79.7 vs 80.1 mg/dL), whereas median hsCRP was 0.50 vs 1.34 mg/L. Elevated-hsCRP prevalence was 12.2% in Korea and 35.7% in the United States (difference, 23.5 percentage points; 95% CI, 19.4-27.7); the age-sex-standardised difference was 23.4 percentage points. Among 6,235 common complete cases, the age-sex-adjusted US-versus-Korea PR was 2.86 (95% CI, 2.48-3.30), decreasing to 1.66 (1.40-1.98) after waist circumference adjustment and 1.92 (1.62-2.26) after body mass index adjustment. Conclusions: Similar LDL-C distributions coexisted with markedly different hsCRP profiles. Waist adjustment attenuated the between-country contrast more than BMI adjustment, supporting joint consideration of inflammatory, lipid and anthropometric measures in population surveillance.

BACKGROUND: The chromosome 9p21.3 locus is among the strongest genetic risk loci for cardiovascular disease (CVD), yet the regulatory mechanisms underlying this association remain poorly understood. Previous vascular disease studies focused predominantly on the role of this locus in smooth muscle cell (SMC) dysfunction, whereas its potential role in endothelial cells (ECs) remains less well characterized. Here, we sought to identify candidate regulatory variants at 9p21.3, their distal target genes, and effector transcripts that contribute to CVD-related phenotypes in ECs. METHODS: Promoter capture Hi-C was used to map chromatin interactions at 9p21.3 in primary human ascending aortic SMCs (n=6), supplementing the previously obtained ECs (n=16) dataset. To support the regulatory relevance of these interactions, expression quantitative trait locus analysis was performed in 136 vascular biopsies. Variant effects were prioritized in silico using AlphaGenome. The regulatory activity of the prioritized region was validated using CRISPR activation. RESULTS: Chromatin interaction mapping identified a complex regulatory architecture at the 9p21.3 locus involving 19 putative regulatory elements and 15 genes across ECs and SMCs. MIR31HG showed the most recurrent distal promoter connectivity with the 9p21.3 region. Consistent with the chromatin interaction map, expression of MIR31HG transcripts was associated with genetic variation at the 9p21.3 locus. In ECs, the lncRNA MIR31HG, but not miR-31, was responsive to hemodynamic flow. Depletion of MIR31HG in ECs was associated with endothelial activation. Epigenetic tracks and deep learning predictions highlighted an active enhancer element at 9p21.3, which was subsequently validated by CRISPR activation and increased MIR31HG expression, confirming its capacity to regulate MIR31HG over a large genomic distance of approximately 538 kb. CONCLUSIONS: Altogether, these data implicate lncRNA MIR31HG as a likely effector of the 9p21.3 CVD locus, linking the cis-regulatory element and heritable genetic variation in the respective region to endothelial activation through long-range enhancer regulation.

Background: Low-density lipoprotein cholesterol (LDL-C) is an established risk factor for atherosclerotic cerebrovascular disease, but its effects on the cerebral microcirculation are poorly defined. We investigated whether LDL-C is associated with pericyte dysfunction in acute ischemic stroke (AIS) and explored underlying mechanisms. Methods: Serum soluble platelet-derived growth factor receptor-{beta} (sPDGFR{beta}) was measured in two independent AIS cohorts (n=97 and n=86). Cerebral pericyte transcriptional responses to LDL-C were analyzed by single-cell RNA sequencing in Apoe-knockout mice fed control or high-fat diet (n=4 [male/female: 2/2]/group), and cultured human brain pericytes were exposed to purified human LDL cholesterol with or without N-acetyl-L-cysteine. Results: Higher serum sPDGFR{beta} was associated with greater neurological deficit and circulating neurofilament light chain. LDL-C positively correlated with sPDGFR{beta} in both clinical cohorts. High-fat diet induced coordinated suppression of type-I interferon pathways, and a positive shift in reactive oxygen species-related transcriptional programs in mouse pericytes; exploratory sex-by-diet analyses suggested larger transcriptional responses in females. In cultured human pericytes, LDL-C induced oxidative-stress, lipid-handling, and ferroptosis-associated transcriptional programs while suppressing type-I interferon signaling. Cross-species enrichment analysis showed that LDL-C-induced and -repressed signatures in cultured pericytes aligned with the sex-by-diet interaction in Apoe-knockout mice. LDL-C also reduced cell-surface PDGFR{beta} and increased sPDGFR{beta} release in cultured pericytes, which were significantly attenuated by N-acetyl-L-cysteine, whereas LDH activity increased numerically but not significantly. Conclusions: Clinical and experimental findings support an LDL-pericyte axis linking atherogenic lipid stress to cerebral microvascular dysfunction, with possible sex-dependent modulation of oxidative stress and type-I interferon signaling as potential mechanisms.

Objectives: To investigate whether genetic predisposition to hypertensive disorders of pregnancy (HDP), measured using polygenic risk scores (PRS), is associated with subsequent cardiovascular disease (CVD) outcomes in analyses stratified by HDP history. Study design and main outcome measures: This population-based cohort included 1,284 women from the 1994-95 Busselton Health Study with genotype data, pregnancy history, cardiovascular risk factors, and linked hospitalisation and death records to 2022. Four HDP-related PRS were assessed: two for preeclampsia, one for gestational hypertension, and one for broad HDP phenotype. Outcomes were incident first CVD events classified into categories. Fine-Gray competing-risk models adjusted for age, cardiovascular risk factors, and genetic principal components estimated subdistribution hazard ratios (sHR) per standard deviation increase in PRS. Results: Of 1,284 women, 309 reported a history of HDP and 651 experienced an incident CVD event during follow-up. In analyses stratified by HDP history, the largest estimates were observed for first cerebrovascular disease, although event numbers were small. The PGS003586 preeclampsia PRS showed the largest estimate (sHR 3.41, 95% confidence interval (CI) 1.54-7.58, p = 0.003), while PGS004593, another preeclampsia-related score, was also positively associated with cerebrovascular disease (sHR 1.86, 95% CI 1.05-3.30, p = 0.035). The gestational hypertension and broad HDP scores also showed positive estimates, but CI included 1.0, indicating inconclusive evidence. Conclusions: Among women with a history of HDP, preeclampsia-related PRS showed preliminary evidence of an association with incident cerebrovascular disease. Given the small number of events, findings should be interpreted cautiously and validated in larger, multi-ancestry cohorts.

Aims: The risks of dementia, stroke, and mortality increase from normoglycemia to prediabetes and type 2 diabetes (T2D). Blood pressure variability (BPV) is associated with adverse vascular and neurological outcomes, but its role in glycemia-associated risks remains unclear. We examined the interplay between glycemia, BPV, and these outcomes. Methods and Results: In a large prospective cohort, visit-to-visit BPV was quantified using absolute and directional measures of systolic (SBP), diastolic (DBP), mean arterial (MAP), and pulse pressure (PP). Glycemic status was defined as normoglycemia, prediabetes, and T2D. Time-updated Cox models estimated outcome associations, adjusting for confounders and mean blood pressure. We evaluated the joint and independent associations of BPV and glycemic status with outcomes, effect modification, and attenuation of glycemia-associated risks after BPV adjustment. Among 57,611 participants (median follow-up, 5.1 years; IQR, 3.3-9.5 years), compared with normoglycemia and low BPV, T2D with high SBP variability was associated with higher risks of all-cause mortality (HR 2.80, 95% CI 2.12-3.69) and nominally higher risk of all-cause dementia (HR 2.46, 95% CI 1.37-4.42). All absolute BPV measures were independently associated with mortality, while DBP and MAP variability were associated with overall stroke after FDR correction. Additional adjustment for BPV minimally attenuated glycemia-associated risk, and no multiplicative interaction remained significant after multiple-testing correction. Conclusions: Absolute BPV was associated with mortality, and DBP and MAP variability with overall stroke, after accounting for glycemic status and mean blood pressure. Additional BPV adjustment changed the glycemic association only minimally.

BackgroundClonal hematopoiesis of indeterminate potential (CHIP) is associated with ageing and atherosclerotic coronary artery disease (CAD), but evidence has largely come from peripheral blood. Whether somatic mutational profiles differ between arterial tissue and blood, and whether hematopoietic clones are represented in arterial tissue, remain poorly understood. MethodsWe performed deep whole-exome sequencing on 302 blood granulocytes and 263 arterial tissues from patients undergoing coronary artery bypass graft surgery, including 221 matched blood-tissue pairs, with mean sequencing depths of 130.5X and 120.8X, respectively. Somatic variants were identified using Mutect2. Associations with age and CAD complexity, assessed using SYNTAX score, were evaluated using multivariable regression. Primary analyses focused on variants with variant allele fractions of 10-25%. ResultsCHIP was detected in 24/302 (7.9%) blood granulocytes, predominantly involving DNMT3A, TET2, and ASXL1. In contrast, somatic mutations in CHIP-associated genes in arterial tissues showed a distinct profile dominated by CALR, SETDB1, and PDSS2. Somatic mutation carrier status increased with age in blood ({beta} = 0.07, p = 0.02) and arterial tissues ({beta} = 0.06, p = 0.04). Blood CHIP was associated with lower SYNTAX score ({beta} = -1.05, p = 2.66 x 10-3), partly driven by DNMT3A carriers ({beta} = -1.06, p = 0.04), whereas arterial CALR mutations were associated with higher SYNTAX score ({beta} = 1.14, p = 0.03). Among 221 matched pairs, only four identical variants, involving CHEK2, DNMT3A, GNB1, and SRSF1, were detected in both compartments. Genome-wide analyses showed compartment specificity, with bile acid metabolism enriched among arterial tissue-specific mutations (PAdj = 0.038). ConclusionBlood and arterial tissues in CAD harbour distinct somatic mutational landscapes with limited cross-compartment sharing. These findings suggest that cardiovascular somatic mutations may reflect both hematopoietic and arterial tissue-associated processes and motivate cell-resolved and spatial studies to define their origins and roles in cardiovascular ageing.

Background: Platelets are critical drivers of thrombo-inflammatory responses in different cardiovascular diseases. Abdominal aortic aneurysm (AAA) is a progressive, life-threatening vascular disorder mainly characterised by chronic inflammation, extracellular matrix degradation, and the formation of a platelet-rich intraluminal thrombus (ILT). Experimental and clinical evidence identified platelets as main players in AAA pathology as evidenced by elevated platelet activation and procoagulant activity that critically contribute to AAA progression. Methods: The present study investigated the contribution of glycoprotein (GP)Ib alpha, the von Willebrand factor (VWF)-binding subunit of the platelet GPIb-IX-V complex, to AAA initiation and progression in experimental AAA using the ePPE mouse model and in patients. Results: Genetic ablation of platelet GPIb alpha significantly attenuated early aneurysm expansion in experimental AAA, indicating a critical role for GPIb alpha during the initial stages of aneurysm development. This initial effect was compensated at later time points showing no differences in aneurysm progression between groups. Notably, genetic deletion of GPIb alpha induced a constitutively hyperactive platelet phenotype already in naive mice that was further amplified during experimental AAA. This elevated platelet hyperactivity was mainly due to increased GPVI activation of platelets 28 days post-surgery. To assess the clinical relevance, spatial profiles of human ILT specimens from patients with AAA were analysed. In the ILT, we detected a highly compartmentalised distribution of GPIb alpha and VWF with pronounced enrichment within the luminal layer. In parallel, circulating VWF activity as well as platelet surface expression of GPIb alpha were significantly increased in patients with AAA. Conclusion: Collectively, these findings identify a dysregulated GPIb alpha-VWF axis in human AAA pathology, mainly characterised by enhanced platelet GPIb alpha surface expression and increased activity of circulating VWF.

Myocardin (MYOCD) is the principal trigger-switch for vascular smooth muscle cell (VSMC) growth arrest and the cyto-contractile program of differentiation. While much is known about MYOCD-dependent VSMC differentiation, limited information exists as to its transcriptional regulation. Here, we report moderate mRNA expression of Myeloid Ecotropic viral Integration Site 1 (MEIS1) in both human and mouse VSMCs. MEIS1 mRNA is reduced in parallel with myocardin mRNA and protein under conditions of VSMC de-differentiation. Loss- and gain-of-Meis1 expression studies in cultured human VSMCs and the mouse carotid artery support MEIS1 as an activator of myocardin and VSMC differentiation. CRISPR-mediated knockout of the endogenous Meis1 gene in vitro and elicited lower levels of VSMC contractile markers and an increase in growth rate. Similarly, Femoral artery wire injury, in mice lacking Meis1 showed and increased of neointima formation. Mechanistically, we identified a conserved MEIS1 response element in the proximal promoter of myocardin, that appears to contribute to the promoter activity, suggesting a potential regulatory interaction. These results suggest a previously unrecognized role for the homeodomain protein MEIS1 in the activation of myocardin and the quiescent, VSMC differentiated state.

Observational studies suggest an association between COVID-19 and acute myocardial infarction (AMI), however, whether this relationship is causal remains unclear. We conducted a multi-ancestry Mendelian randomization (MR) study across European, East Asian, South Asian, and African populations, evaluating three COVID-19 phenotypes: very severe COVID-19, hospitalized COVID-19, and general infection association with AMI. GWAS summary statistics were obtained from the COVID-19 Host Genetics Initiative Round 7 and UK Biobank/Biobank Japan for AMI. Inverse-variance weighted (IVW) MR was the primary method, with fixed- or random-effects models selected according to heterogeneity test. MR-Egger, weighted median and weighted mode were conducted as sensitivity analyses. In European ancestry, genetic liability to very severe COVID-19 and hospitalized COVID-19 was slightly inversely associated with AMI risk, but without statistical significances across sensitivity analyses. Hospitalized COVID-19 showed a suggestive but non-significant inverse association in South Asian ancestry. No significant associations were identified in East Asian or African ancestries. Our findings did not support a robust causal association between COVID-19 susceptibility or severity and AMI risk across ancestries, suggesting that the observed cardiovascular burden may be driven more by acute pathophysiological mechanisms than shared genetic architecture.