Flow-induced reprogramming of endothelial cells in atherosclerosis

Therapeutic potential of natural flavonoids in atherosclerosis through endothelium-protective mechanisms: An update

Atherosclerosis and its associated cardiovascular complications remain significant global public health challenges, underscoring the urgent need for effective therapeutic strategies. Endothelial cells are critical for maintaining vascular health and homeostasis, and their dysfunction is a key contributor to the initiation and progression of atherosclerosis. Targeting endothelial dysfunction has, therefore, emerged as a promising approach for the prevention and management of atherosclerosis. Among natural products, flavonoids, a diverse class of plant-derived phenolic compounds, have garnered significant attention for their anti-atherosclerotic properties. A growing body of evidence demonstrates that flavonoids can mitigate endothelial dysfunction, highlighting their potential as endothelial dysfunction-targeted therapeutics for atherosclerosis. In this review, we summarize current knowledge on the roles of natural flavonoids in modulating various aspects of endothelial dysfunction and their therapeutic effects on atherosclerosis, focusing on the underlying molecular mechanisms. We also discuss the challenges and future prospects of translating natural flavonoids into clinical applications for cardiovascular medicine. This review aims to provide critical insights to advance the development of novel endothelium-protective pharmacotherapies for atherosclerosis.

The GRK2/AP-1 Signaling Axis Mediates Vascular Endothelial Dysfunction and Atherosclerosis Induced by Oscillatory Low Shear Stress

Disturbed blood flow and the resulting oscillatory low shear stress (OSS) are key contributors to vascular endothelial dysfunction and the initiation of atherosclerosis. However, the molecular mediators that translate abnormal hemodynamic signals into pathological vascular endothelial responses remain unclear. G protein-coupled receptors (GPCRs) are classical mechanosensors in the vascular endothelium. Here, using vascular endothelial-specific knockout mice, in vitro parallel plate flow chamber systems, and phosphoproteomic analysis, G protein-coupled receptor kinase 2 (GRK2) is identified as a central mediator of OSS-induced vascular endothelial dysfunction. Mechanistically, OSS promotes GRK2 phosphorylation at serine 29, which subsequently activates the transcription factor activator protein-1 (AP-1), increasing the expression of the proinflammatory adhesion molecules intercellular cell adhesion molecule-1 (ICAM1) and vascular cell adhesion molecule 1 (VCAM1). In parallel, AP-1 promotes nuclear receptor subfamily 4 group A 1 (NR4A1) transcription, which anchors liver kinase B1 (LKB1) to the nucleus and suppresses downstream AMP-activated protein kinase (AMPK) signaling, leading to metabolic dysregulation and impaired vascular endothelial homeostasis. These findings underscore the GRK2/AP-1 signaling axis as a crucial mechanotransduction cascade linking disturbed flow to vascular endothelial dysfunction. Given the important role of GPCRs in mechanotransduction, targeting GRK2 may offer a novel therapeutic approach for atherosclerosis.

Fluid Shear Stress-Regulated Vascular Remodeling: Past, Present, and Future

The vascular system remodels throughout life to ensure adequate perfusion of tissues as they grow, regress, or change metabolic activity. Angiogenesis, the sprouting of new blood vessels to expand the capillary network, versus regression, in which endothelial cells die or migrate away to remove unneeded capillaries, controls capillary density. In addition, upstream arteries adjust their diameters to optimize blood flow to downstream vascular beds, which is controlled primarily by vascular endothelial cells sensing fluid shear stress (FSS) from blood flow. Changes in capillary density and small artery tone lead to changes in the resistance of the vascular bed, which leads to changes in flow through the arteries that feed these small vessels. The resultant decreases or increases in FSS through these vessels then stimulate their inward or outward remodeling, respectively. This review summarizes our knowledge of endothelial FSS-dependent vascular remodeling, offering insights into potential therapeutic interventions. We first provide a historical overview, then discuss the concept of set point and mechanisms of low-FSS-mediated and high-FSS-mediated inward and outward remodeling. We then cover in vivo animal models, molecular mechanisms, and clinical implications. Understanding the mechanisms underlying physiological endothelial FSS-mediated vascular remodeling and their failure due to mutations or chronic inflammatory and metabolic stresses may lead to new therapeutic strategies to prevent or treat vascular diseases.

Advancing atherosclerosis treatment: Drug encapsulation nanosystems and synthetic HDL nanoparticles

Atherosclerosis, characterized by plaque accumulation in arterial walls, remains a leading cause of cardiovascular disease. Current pharmacological treatments often lack efficacy in halting disease progression or addressing systemic complications. Nanotechnology offers promising solutions, including targeted drug delivery, enhanced bioavailability, and the ability to overcome biological barriers. This review explores the integration of drug-delivery nanosystems and synthetic high-density lipoprotein (HDL) nanoparticles into therapeutic strategies. Synthetic HDL nanoparticles not only serve as effective carriers for antidyslipidemic drugs but also act directly as functional HDL, improving lipid profiles and reducing systemic side effects. By enabling localized treatment and enhancing therapeutic precision, nanotechnology and synthetic HDL nanoparticles represent a paradigm shift in managing atherosclerosis, offering safer and more effective alternatives for preventing its life-threatening complications.

Endothelial Krüppel-like factor 2/4: Regulation and function in cardiovascular diseases

This review presents an overview of the regulation, function, disease-relevance and pharmacological regulation of the critical endothelial transcription factors KLF2/4 in vasculature. The regulatory mechanisms of KLF2/4 expression and activity in vascular endothelium in response to hemodynamic forces and biochemical stimuli are depicted. The functional effects mediated by direct or indirect target genes of KLF2/4 in endothelial cells are systematically summarized. The contributory roles that dysregulated KLF2/4 play in relevant cardiovascular pathologies, such as atherosclerotic vascular lesions, pulmonary arterial hypertension and vascular complications of diabetes were reviewed. Moreover, this review also discusses the pharmacological regulation of KLF2/4 by drugs used in clinics and therapeutic possibility by directly targeting these two transcription factors for treating atherosclerotic cardiovascular diseases. Finally, prospective opinions on the gaps in disclosing novel vascular function mediated by KLF2/4 and future research needs are expressed.

Microenvironmental determinants of endothelial cell heterogeneity

During development, endothelial cells (ECs) undergo an extraordinary specialization by which generic capillary microcirculatory networks spanning from arteries to veins transform into patterned organotypic zonated blood vessels. These capillary ECs become specialized to support the cellular and metabolic demands of each specific organ, including supplying tissue-specific angiocrine factors that orchestrate organ development, maintenance of organ-specific functions and regeneration of injured adult organs. Here, we illustrate the mechanisms by which microenvironmental signals emanating from non-vascular niche cells induce generic ECs to acquire specific inter-organ and intra-organ functional attributes. We describe how perivascular, parenchymal and immune cells dictate vascular heterogeneity and capillary zonation, and how this system is maintained through tissue-specific signalling activated by vasculogenic and angiogenic factors and deposition of matrix components. We also discuss how perturbation of organotypic vascular niche cues lead to erasure of EC signatures, contributing to the pathogenesis of disease processes. We also describe approaches that use reconstitution of tissue-specific signatures of ECs to promote regeneration of damaged organs.

Opportunities for the treatment of atherosclerosis: selectins

Despite the widespread availability of selectins for tumor therapy, their contribution to atherosclerosis has long been under-emphasized due to their "cofactor's" status and technological limitations. However, advances in immunohistology, glycomics, and related technologies require us to reassess their relationship. Thus, this review identifies pivotal translational opportunities from the intricate mechanisms and explores the clinical promise of selectins in the diagnosis and treatment of atherosclerosis based on the latest clinical research. This review provides insights into selectin-specific tracers and inhibitors, providing lessons for more precise diagnosis and treatment of patients with atherosclerosis.

Oscillatory shear stress activates integrin β3, blocking autophagic flux in endothelial cells and promoting endothelial cells senescence

Atherosclerosis is an age-related cardiovascular disease. The intersections and bends of blood vessels under the direct action of oscillatory shear stress (OSS) are susceptible to atherosclerotic plaque formation, and the expression of age-related factors is significantly increased in plaques. However, the molecular mechanism by which OSS promotes vascular senescence is still unclear. In this study, we found that the expression of age-related factors, such as P16 and P21, was increased in human aortic endothelial cells (HAECs) exposed to OSS. We also found that the expression of autophagy-related gene 5 (ATG5), microtubule-associated protein 1 light chain 3β (MAP1LC3B), and beclin 1 (BECN1) was increased in HAECs exposed to OSS. The expression of sequestosome-1 (SQSTM1/P62) was also increased. Immunofluorescence confirmed that OSS impaired autophagic flux in HAECs by inhibiting the binding of autophagosomes to lysosome, thereby promoting endothelial cell (EC) senescence. The OSS-sensitive gene integrin β3 (ITGB3), which is closely related to EC autophagy and senescence, was screened by proteomics analysis of HAECs in the control and OSS-treated groups. The protein and mRNA expression of ITGB3 was significantly increased in HAECs exposed to OSS. ITGB3 overexpression in HAECs significantly affected the autophagic flux of ECs and promoted EC senescence, resulting in an increase in cells in the G0/G1 phase and cell cycle arrest. ITGB3 knockdown significantly inhibited the block of OSS-induced autophagic flux and senescence in ECs. In addition, in vivo studies showed that treatment with the ITGB3 inhibitor Cyclo(arginine-glycine-aspartate-tyrosine-lysine) [Cyclo(RGDyK)] significantly inhibited high-fat diet-induced plaque formation in the aortae of apolipoprotein E (ApoE)-/- mice. In conclusion, OSS blocks HAECs autophagic flux and promotes senescence via ITGB3 activation, thereby affecting the development of atherosclerosis.

A dual-targeting bio-liposomes nanodrug repair endothelial cell dysfunction and restore macrophage cholesterol flow homeostasis to treat early atherosclerosis

Hyperhomocysteinemia (HHy) can lead to vascular endothelial cell dysfunction, progressive inflammation and lipid metabolism disorder, which finally result in the onset and development of atherosclerosis, a major contributor to cardiovascular diseases. Given the complexity of pathological process, treatments based on a single target often showed limited therapeutic efficacy against AS. Thus, developing nanodrug for enhanced multi-targets therapy is promising. In this study, we constructed a dual-targeting nanodrug (HA-ML@ES NPs) co-loaded with Shikonin (SKN) and Evolocumab (Evol). In vitro results showed that HA-ML@ES NPs could simultaneously target dysfunctional endothelial cell and inflammatory macrophage through the interaction between HA and CD44. In vivo assay indicated that HA-ML@ES NPs with long circulation and plaque accumulation efficiently attenuate endothelial cell dysfunction by inhibiting glycolysis and restore cholesterol flow homeostasis in macrophage by reprogramming macrophage phenotype, which finally attenuated the development of atherosclerosis. Collectively, these results present a highly promising dual-cell therapeutic approach based on HA-ML@ES NPs for the management of early atherosclerosis.

Endothelial TDP-43 depletion disrupts core blood-brain barrier pathways in neurodegeneration

Endothelial cells (ECs) help maintain the blood-brain barrier but deteriorate in many neurodegenerative disorders. Here we show, using a specialized method to isolate EC and microglial nuclei from postmortem human cortex (92 donors, 50 male and 42 female, aged 20-98 years), that intranuclear cellular indexing of transcriptomes and epitopes enables simultaneous profiling of nuclear proteins and RNA transcripts at a single-nucleus resolution. We identify a disease-associated subset of capillary ECs in Alzheimer's disease, amyotrophic lateral sclerosis and frontotemporal degeneration. These capillaries exhibit reduced nuclear β-catenin and β-catenin-downstream genes, along with elevated TNF/NF-κB markers. Notably, these transcriptional changes correlate with the loss of nuclear TDP-43, an RNA-binding protein also depleted in neuronal nuclei. TDP-43 disruption in human and mouse ECs replicates these alterations, suggesting that TDP-43 deficiency in ECs is an important factor contributing to blood-brain barrier breakdown in neurodegenerative diseases.

Apolipoprotein M delays the development of atherosclerosis by regulating autophagy and mitochondrial function

Background

Apolipoprotein M (ApoM), a protein component of lipoproteins, is closely related to the development of atherosclerosis, but the specific mechanism remains elusive. Mitochondrial DNA damage can contribute to atherosclerosis, so this study was designed to investigate whether ApoM influences the structure and function of mitochondria during the progression of atherosclerosis and to explore the underlying mechanism.

Methods

Atherosclerosis models were established in male ApoM-deficient (ApoM-/- ) and wild-type (ApoM+/+ ) C57BL/6 mice fed a high-fat diet (HFD), and the development of atherosclerosis was verified by en face analysis of the aorta and Masson's trichrome staining. We utilized transmission electron microscopy (TEM) to examine the ultrastructure of the aorta, its endothelial cells and EA.hy926 cells. Mass spectrometry-based lipidomics was performed to measure lipidomes in the serum and liver tissue of ApoM- /- mice. In EA.hy926 cells, we modulated the levels of autophagy and ApoM expression, and investigated the mechanism by which ApoM influences the pathogenesis of atherosclerosis through western blotting, JC-1 staining, flow cytometry, and Seahorse extracellular flux analysis.

Results

In ApoM-/- mice fed an HFD, atherosclerotic markers such as aortic lipid accumulation, fibrosis, endothelial cell oedema, and mitochondrial swelling were observed, indicating early atherosclerotic development. Lipidomic analysis revealed that ApoM deficiency might lead to impaired autophagy and mitochondrial dysfunction. In EA.hy926 cells, overexpression of ApoM not only activated autophagy but also improved mitochondrial structure. Moreover, ApoM decreased the mitochondrial membrane potential (ΔΨm) of EA.hy926 cells, which was further reduced by autophagy activation. Additionally, overexpression of ApoM in EA.hy926 cells, which have a low basal metabolism and primarily rely on glycolysis for energy, significantly reduced basal mitochondrial respiration and adenosine triphosphate (ATP) production, suggesting that ApoM can facilitate mitochondrial fission.

Conclusions

ApoM exerts atheroprotective effects by promoting autophagy and regulating mitochondrial dynamics, thereby maintaining mitochondrial integrity and function. This study provides novel insights into the mechanisms underlying the protective role of ApoM in atherosclerosis and highlights its potential as a therapeutic target for cardiovascular diseases.

Optical Tweezer-Driven Mechanotransduction: Probing pN-Scale Forces and Calcium-Mediated Redox Signaling in Single Endothelial Cells

Endothelial cells (ECs) regulate vascular function by converting mechanical forces into biochemical signals; however, the molecular mechanisms of pN-scale mechanotransduction remain elusive. Here, we develop an optical tweezer-integrated confocal microscopy system that allows precise, noninvasive manipulation of the cell membrane localization with mechanical stimuli within the 0-100 pN range while monitoring Ca2+-mediated NO/ROS redox signaling in situ in single ECs under varying force parameters. We show that pN-scale mechanical stimulation regulates extracellular Ca2+ influx, triggering downstream production of NO and ROS, which subsequently affects intracellular redox homeostasis. Key mechanosensitive ion channels (e.g., Piezo1 and TRPV4) and cytoskeletal components (e.g., F-actin) facilitate force-induced redox signaling. We further delineate the roles of membrane tension-dominant versus hybrid tension-tether models in mechanotransduction, revealing their differential engagement in force transmission pathways. This mechanistic framework establishes direct connections between pN-scale mechanical input characteristics and redox-regulated vascular homeostasis.

Potentiation of macrophage Piezo1 by atherogenic 7-ketocholesterol

The mechanosensitive ion channel Piezo1 present in endothelial and smooth muscle cells, as well as in macrophages, is emerging as a novel, important player in the etiology of atherosclerosis. Here, we show that myeloid-specific deficiency of Piezo1 in atherogenic Ldlr-/- mice reduces plaque formation. Moreover, chronic oxLDL, as well as its main oxysterol 7-ketocholesterol (7-KC), promotes Piezo1 opening by pressure stimulation in both mouse macrophages and transfected HEK cells. 7-KC dramatically enhances Piezo1 current amplitude and slows down inactivation and deactivation. This up-modulation involves an increase in Piezo1 expression, as well as a potentiation of mechanical gating that depends on membrane cholesterol depletion and decreased order. By contrast, Piezo1 is inhibited by the athero-protective free docosahexaenoic acid, either without or with 7-KC. Altogether, these findings indicate that macrophage Piezo1 is differentially modulated by pro- and anti-atherogenic lipids, pointing to the role of Piezo1 and its potentiation by oxysterols in atherosclerosis.

Differential expression of endothelial derived galectins in response to shear stress

BACKGROUND

Endothelial cells function as mechanosensors, dynamically altering their functional response based on varying shear stress/flow patterns to maintain vascular homeostasis. Disturbed flow leads to endothelium dysfunction, promoting conditions such as atherosclerosis. Understanding the molecular impact of flow is crucial for the development of new therapeutic targets for vascular diseases. Galectins have been implicated in vascular diseases, specifically their role in inflammation. However, the regulation of endothelial galectins by shear stress remains unexplored.

METHODS

Galectin gene and protein expression were analysed from publicly available datasets or in human umbilical endothelial cells (HUVEC) and human arterial endothelial cells (HAEC) cultured under either shear stress induced by orbital shaking or static conditions by qPCR, immunofluorescence imaging and ELISA.

RESULTS

Laminar shear stress upregulated LGALS9 and downregulated LGALS1, while disturbed flow reversed these effects. Complex shear environments significantly increased Gal-3 and Gal-9 expression at both gene and protein levels, with distinct variations in surface expression and secretion. In vivo single-cell RNA sequencing (scRNAseq) revealed reduced Lgals9 expression in endothelial cells exposed to disturbed flow in carotid artery ligation models compared to laminar flow.

SIGNIFICANCE

These findings highlight that endothelial galectin expression is shear-regulated, which has significant implications for understanding galectin biology and there potential as therapeutic targets in vascular diseases influenced by shear stress.

Exploring the Roles of Liver X Receptors in Lipid Metabolism and Immunity in Atherosclerosis

Hypercholesterolemia causes atherosclerosis by inducing immune cell migration and chronic inflammation in arterial walls. Recent single-cell analyses reveal the presence of lipid-enriched foamy macrophages, as well as other macrophage subtypes, neutrophils, T cells, and B cells, in atherosclerotic plaques in both animal models and humans. These cells interact with each other and other cells, including non-immune cells such as endothelial cells and smooth muscle cells. They thereby regulate metabolic, inflammatory, phagocytic, and cell death processes, thus affecting the progression and stability of atherosclerotic plaques. The nuclear receptors liver X receptor (LXR)α and LXRβ are transcription factors that are activated by oxysterols and regulate lipid metabolism and immune responses. LXRs regulate cholesterol homeostasis by controlling cholesterol's transport, absorption, synthesis, and breakdown in the liver and intestine. LXRs are also highly expressed in tissue-resident and monocyte-derived macrophages and other immune cells, including both myeloid cells and lymphocytes, and they regulate both innate and adaptive immune responses. Interestingly, LXRs have immunosuppressive and immunoregulatory functions that are cell-type-dependent. In animal models of atherosclerosis, LXRs have been shown to be involved in both progression and regression phases. The pharmacological activation of LXR enhances cholesterol efflux from macrophages and promotes atherosclerosis progression. Deleting LXR in immune cells, especially myeloid cells, accelerates atherosclerosis by increasing monocyte migration, macrophage proliferation and activation, and neutrophil extracellular traps (NETs); furthermore, the deletion of hematopoietic LXRs impairs the regression of atherosclerotic plaques. Therefore, LXRs in immune cells may be a potent therapeutic target for atherosclerosis.

Engineering advanced in vitro models of endothelial dysfunction

Endothelial dysfunction is an important initiator of cardiovascular disease, the leading cause of death globally, and often manifests in arterial regions with disturbed blood flow. Experimental model advances have crucially helped unravel physiological mechanisms. While in vivo models provide a dynamic environment, they often fail to mimic human physiology precisely and face significant ethical barriers. Advanced in vitro models, including organs-on-chips and bioreactors, combine human cells and blood flow to accurately replicate endothelial dysfunction. Newer models have enhanced scalability and accuracy, with organs-on-chips commonly outperforming standard preclinical methods. Importantly, recent endothelial dysfunction discoveries leverage dynamic models to identify and evaluate clinically promising therapeutics. Here, we examine these developments and explore opportunities to develop next-generation in vitro models of endothelial dysfunction.

CXCL12 drives natural variation in coronary artery anatomy across diverse populations

Coronary arteries have a specific branching pattern crucial for oxygenating heart muscle. Among humans, there is natural variation in coronary anatomy with respect to perfusion of the inferior/posterior left heart, which can branch from either the right arterial tree, the left, or both-a phenotype known as coronary dominance. Using angiographic data for >60,000 US veterans of diverse ancestry, we conducted a genome-wide association study of coronary dominance, revealing moderate heritability and identifying ten significant loci. The strongest association occurred near CXCL12 in both European- and African-ancestry cohorts, with downstream analyses implicating effects on CXCL12 expression. We show that CXCL12 is expressed in human fetal hearts at the time dominance is established. Reducing Cxcl12 in mice altered coronary dominance and caused septal arteries to develop away from Cxcl12 expression domains. These findings indicate that CXCL12 patterns human coronary arteries, paving the way for "medical revascularization" through targeting developmental pathways.

Maximum admittance method for cerebrovascular outlet boundary conditions and importance of stenosis severity as a dominant factor on hemodynamics

In this study, we propose the maximum admittance method based on an analytical solution of two-element Windkessel model to generate pressure waveforms for imposing outlet boundary conditions in blood flow simulations in the absence of in vivo pressure data. The lumped parameters of the Windkessel model, which were not calibrated from the in vivo pressure, were determined to maximize peripheral admittance. By applying the pressure waveforms at outlet boundaries, hemodynamic characteristics of human cerebrovascular networks, including stenotic middle cerebral arteries (MCAs), were investigated through transient flow simulations. Two age-related flow waveforms, in addition to three different blood viscosities, were applied across each severity case (total 24 simulation cases). The age-related flow waveforms introduced normalized relative residence time disparities exceeding 30% in post-stenosis regions with over 50% severity. Additionally, stenosis exceeding 50% severity redirected more blood flow toward anterior cerebral artery, leading to MCA ischemia at 88% severity. The maximum pressure gradient on the stenotic walls and fractional pressure ratio exhibited changes below 9% and 3%, respectively, despite a 54.5% increase in viscosity. The stenosis severity was a dominant physiological factor, suggesting 50% severity as a critical transition point in cerebral hemodynamics. This threshold can help in quickly identifying risky locations.

Modulation of arterial wall remodeling by mechanical stress: Focus on abdominal aortic aneurysm

The rupture of an abdominal aortic aneurysm (AAA) poses a significant threat, with a high mortality rate, and the mechanical stability of the arterial wall determines both its growth and potential for rupture. Owing to extracellular matrix (ECM) degradation, wall-resident cells are subjected to an aberrant mechanical stress environment. In response to stress, the cellular mechanical signaling pathway is activated, initiating the remodeling of the arterial wall to restore stability. A decline in mechanical signal responsiveness, coupled with inadequate remodeling, significantly contributes to the AAA's progressive expansion and eventual rupture. In this review, we summarize the main stresses experienced by the arterial wall, emphasizing the critical role of the ECM in withstanding stress and the importance of stress-exposed cells in maintaining mechanical stability. Furthermore, we will discuss the application of biomechanical analyses as a predictive tool for assessing AAA stability.

Mechanism of disturbed endothelial cell function on angiogenesis following ischemic brain stroke (Review)

The present study focused on the mechanisms of post-ischemic stroke (IS) angiogenesis from the perspective of endothelial cells (ECs) dysfunction. First, it emphasized the importance of hypoxia-inducible factor-1α in the function of ECs under hypoxic conditions, particularly in promoting angiogenesis and improving cerebral blood supply. Secondly, inflammatory cytokines and adhesion factors (for example, selectins, the immunoglobulin superfamily and integrins) influence the function and angiogenesis of ECs through various mechanisms and signaling pathways following IS. In addition, the effects of oxidative stress on ECs function and angiogenesis were explored, along with the potential of antioxidant strategies to improve EC function and promote angiogenesis. Based on these insights, the present study proposed new therapeutic strategies to ameliorate endothelial dysfunction and promote angiogenesis following IS, including small-molecule drugs targeting specific molecules, gene therapy and traditional Chinese medicine treatments. Finally, the importance of translating these laboratory findings into clinical applications was emphasized, alongside the need for advanced imaging techniques to monitor the dynamic processes of post-IS angiogenesis and evaluate the efficacy of novel therapeutic interventions. These explorations aimed at providing a more comprehensive understanding of EC function and the regulatory mechanisms of a deeper understanding of angiogenesis following IS, offering new intervention strategies for IS treatment.

Disruption of the eEF1A1/ARID3A/PKC-δ Complex by Neferine Inhibits Macrophage Glycolytic Reprogramming in Atherosclerosis

Glycolytic reprogramming of macrophages is a decisive factor in atherosclerosis (AS) plaque formation. Eukaryotic elongation factor 1A1 (eEF1A1) plays an important role in protein synthesis, ubiquitination degradation, and nuclear translocation. However, the potential function of eEF1A1 in AS has not yet been fully understood. Here, the natural small molecule neferine (Nef), which targets eEF1A1 to suppress macrophage glycolytic reprogramming is discovered. In this work, chemical genetics and non-modified target confirmation assays are used to confirm that eEF1A1 is a direct target of Nef. Mechanically, Nef disrupted the formation of the eEF1A1/ARID3A/PKC-δ complex, inhibits phosphorylation of ARID3A at Thr491, and consequently prevents its nuclear translocation. Meanwhile, it is verified that ARID3A is a transcriptional regulator of enolase 2 (ENO2), an important enzyme in the glycolytic process. Nef suppresses ENO2 transcription activation by affecting ARID3A binding to the promoter region of ENO2, which results in macrophage glycolytic reprogramming inhibition and transformation of macrophages from M1 to M2. Collectively, these findings provide an attractive future direction for AS therapy by inhibiting ARID3A/ENO2-mediated macrophage glycolytic reprogramming by targeting eEF1A1.

Advances in the treatment of atherosclerotic plaque based on nanomaterials

Atherosclerosis is the leading cause of cardiovascular disease worldwide, posing not only a significant threat to cardiovascular health but also impairing the function of multiple organs, with severe cases potentially being life-threatening. Consequently, the effective treatment of atherosclerosis is of paramount importance in reducing the mortality associated with cardiovascular diseases. With the advancement of nanomedicine and a deeper understanding of the pathological mechanisms underlying atherosclerosis, nanomaterials have emerged as promising platforms for precise diagnosis and targeted therapeutic strategies. These materials offer notable advantages, including targeted drug delivery, enhanced bioavailability, improved drug stability, and controlled release. This review provides an overview of the mechanisms underlying atherosclerotic plaque development and examines nanomaterial-based therapeutic approaches for managing atherosclerotic plaques, including therapies targeting cholesterol metabolism, anti-inflammatory strategies, macrophage clearance, and immunotherapy. Additionally, the paper discusses the current technical challenges associated with the clinical transformation of these therapies. Finally, the potential future integration of nanomaterials, smart nanomaterials, and artificial intelligence in the treatment of atherosclerosis is also explored.

Macrophage KDM2A promotes atherosclerosis via regulating FYN and inducing inflammatory response

Macrophage inflammatory response is the key driver in atherosclerosis development. However, transcriptional remodeling of macrophage inflammatory response remains largely unknown. In this study, transcriptional regulatory networks were constructed from human plaque microarray datasets. Differential analysis and subsequent machine learning algorithms were used to identify key transcriptional regulons. Multiple immune cell inference methods (including CIBERSORT, ssGSEA, MCP-counter, and xCell), single-cell RNA-seq of human plaques and immunofluorescence of human and mouse plaque samples reveal that the macrophage-specific transcriptional regulator, KDM2A, is critical for inflammatory response. Diagnostic analyses validate KDM2A expression in peripheral monocytes/macrophages is an excellent predictor of atherosclerosis development and progression. RNA-seq of mouse bone marrow-derived macrophages under oxidized low-density lipoprotein stimulation reveal KDM2A knockdown significantly represses pro-inflammatory, oxidative, and lipid uptake pathways. In vitro experiments confirmed KDM2A activates inflammation, oxidative stress and lipid accumulation in macrophages. Mechanistically, FYN was identified as a direct target of KDM2A by chromatin immunoprecipitation followed by sequencing and qPCR analysis. Specific inhibition of FYN restored the inflammatory response, oxidative stress, and intracellular lipid accumulation after transfection with KDM2A overexpression plasmid. Importantly, macrophage-specific knockdown of KDM2A in ApoE-/- mice fed a high-fat diet apparently attenuated plaque progression. Furthermore, the genetic association of KDM2A with atherosclerosis was validated by Mendelian randomization and colocalization analysis. A group of small molecules with the potential to target KDM2A has been identified through virtual screening, offering promising strategies for atherosclerosis treatment. The current study provides the novel role of KDM2A in macrophage inflammatory response of atherosclerosis through transcriptional regulation of FYN.

Multifaceted Role of Notch Signaling in Vascular Health and Diseases

Notch signaling is evolutionarily conserved from Drosophila to mammals and it functions as an essential modulator of vascular growth and development by directing endothelial cell specification, proliferation, migration, arteriovenous differentiation, inflammation, and apoptosis. The interplay between Notch and other signaling pathways plays a homeostatic role by modulating multiple vascular functions, including permeability regulation, angiogenesis, and vascular remodeling. This review explores current knowledge on Notch signaling in vascular development, homeostasis, and disease. It also discusses recent developments in understanding how endothelial Notch signaling affects vascular inflammation via cytokines or aberrant shear stress in endothelial cells while addressing the reciprocal relationship between Notch signaling and inflammation.

Biophysical and Biochemical Roles of Shear Stress on Endothelium: A Revisit and New Insights

Hemodynamic shear stress, the frictional force exerted by blood flow on the endothelium, mediates vascular homeostasis. This review examines the biophysical nature and biochemical effects of shear stress on endothelial cells, with a particular focus on its impact on cardiovascular pathophysiology. Atherosclerosis develops preferentially at arterial branches and curvatures, where disturbed flow patterns are most prevalent. The review also highlights the range of shear stress across diverse human arteries and its temporal variations, including aging-related alterations. This review presents a summary of the critical mechanosensors and flow-sensitive effectors that respond to shear stress, along with the downstream cellular events that they regulate. The review evaluates experimental models for studying shear stress in vitro and in vivo, as well as their potential limitations. The review discusses strategies targeting shear stress, including pharmacological approaches, physiological means, surgical interventions, and gene therapies. Furthermore, the review addresses emerging perspectives in hemodynamic research, including single-cell sequencing, spatial omics, metabolomics, and multiomics technologies. By integrating the biophysical and biochemical aspects of shear stress, this review offers insights into the complex interplay between hemodynamics and endothelial homeostasis at the preclinical and clinical levels.

Pulsatile flow induces chromatin interaction with lamin-associated proteins to enrich H3K9 methylation in endothelial cells

Endothelial cells (ECs) are constantly exposed to hemodynamic forces, which play a crucial role in regulating EC functions. Pulsatile laminar shear stress (PS), representing atheroprotective flow, maintains the anti-inflammation and homeostatic phenotype of ECs, but the comprehensive mechanism underlying the PS-repression of inflammatory genes remains to be determined. In this study, we investigated the role of chromatin organization in mediating the effects of PS on inflammatory gene expression in ECs. We demonstrated that PS induced the expression of histone methyltransferase SUV39H1 to promote heterochromatin formation via H3K9 trimethylation (H3K9me3) enrichment, a hallmark gene repression mechanism. SUV39H1 interacts with lamin-associated proteins and facilitates the perinuclear localization of the H3K9me3-enrichment. Silencing the lamin-associated protein emerin (EMD) not only led to the reductions of cytoskeletal F-actin formation and perinuclear H3K9me3 enrichment; but also the impairment of PS-induced SUV39H1 expression, H3K9me3 enrichment at E-selectin and vascular cell adhesion molecule 1 loci to revert their PS-repressed expression. Hence, EMD acts as a hub to transmit mechanical cues from the cytoskeleton to the nucleus and recruits SUV39H1, which regulate nuclear organization, chromatin state, and gene expression. These results accentuate the critical role of nuclear architecture in mechanotransduction and EC responses to mechanical stimuli.

Endothelial dysfunction in the kidney transplant population: Current evidence and management strategies

The endothelium modulates vascular homeostasis owing to a variety of vasoconstrictors and vasodilators. Endothelial dysfunction (ED), characterized by impaired vasodilation, inflammation, and thrombosis, triggers future cardiovascular (CV) diseases. Chronic kidney disease, a state of chronic inflammation caused by oxidative stress, metabolic abnormalities, infection, and uremic toxins damages the endothelium. ED is also associated with a decline in estimated glomerular filtration rate. After kidney transplantation, endothelial functions undergo immediate but partial restoration, promising graft longevity and enhanced CV health. However, the anticipated CV outcomes do not happen due to various transplant-related and unrelated risk factors for ED, culminating in poor CV health and graft survival. ED in kidney transplant recipients is an under-recognized and poorly studied entity. CV diseases are the leading cause of death among kidney transplant candidates with functioning grafts. ED contributes to the pathogenesis of many of the CV diseases. Various biomarkers and vasoreactivity tests are available to study endothelial functions. With an increasing number of transplants happening every year, and improved graft rejection rates due to the availability of effective immunosuppressants, the focus has now shifted to endothelial protection for the prevention, early recognition, and treatment of CV diseases.

Remodeling of self-assembled microvascular networks under long term flow

The incorporation of a functional perfusable microvascular network (MVN) is a common requirement for most organ on-chip-models. Long-term perfusion of MVNs is often required for the maturation of organ phenotypes and disease pathologies and to model the transport of cells and drugs entering organs. In our microphysiological system, we observe that flow can recover perfusion in regressed MVNs and maintain perfusable MVNs for at least 51 days. Throughout the 51 days, however, the MVNs are continuously remodeling to align with the direction of bulk flow and only appear to attain morphological homeostasis with the use of maintenance medium without growth factors. We observed that the flow resistance of the MVNs decreases over time, and using a computational model, we show that stable vessels have higher flow rates and velocities compared to regressing vessels. Cytokine analysis suggests that static conditions generate an inflammatory state, and that continuous flow reduces inflammation over an extended period. Finally, through bulk RNA sequencing we identify that both the endothelial and fibroblast cells are actively engaged in vascular and matrix remodeling due to flow and that these effects persist for at least 2 weeks. This MPS can be applied to study hemodynamically driven processes, such as metastatic dissemination or drug distribution, or to model long-term diseases previously not captured by MPS, such as chronic inflammation or aging-associated diseases.

Disturbed Flow Induces Reprogramming of Endothelial Cells to Immune-like and Foam Cells under Hypercholesterolemia during Atherogenesis

Background

Atherosclerosis occurs preferentially in the arteries exposed to disturbed flow (d-flow), while the stable flow (s-flow) regions are protected even under hypercholesterolemic conditions. We recently showed that d-flow alone initiates flow-induced reprogramming of endothelial cells (FIRE), including the novel concept of partial endothelial-to-immune-cell-like transition (partial EndIT), but was not validated using a genetic lineage-tracing model. Here, we tested and validated the two-hit hypothesis that d-flow is an initial instigator of partial FIRE but requires hypercholesterolemia to induce a full-blown FIRE and atherosclerotic plaque development.

Methods

Mice were treated with adeno-associated virus expressing proprotein convertase subtilisin/kexin type 9 and a Western diet to induce hypercholesterolemia and/or partial carotid ligation (PCL) surgery to expose the left common carotid artery (LCA) to d-flow. Single-cell RNA sequencing (scRNA-seq) analysis was performed using cells obtained from the intima and leftover LCAs and the control right common carotid arteries at 2 and 4 weeks post-PCL. Comprehensive immunohistochemical staining was performed on EC-specific confetti mice treated with PCL and hypercholesterolemic conditions at 4 weeks post-PCL to validate endothelial reprogramming.

Results

Atherosclerotic plaques developed by d-flow under hypercholesterolemia at 2 and 4 weeks post-PCL, but not by d-flow or hypercholesterolemia alone, as expected. The scRNA-seq results of 98,553 single cells from 95 mice revealed 25 cell clusters; 5 EC, 3 vascular smooth muscle cell (SMC), 5 macrophage (MΦ), and additional fibroblast, T cell, natural killer cell, dendritic cell, neutrophil, and B cell clusters. Our scRNA-seq analyses showed that d-flow under hypercholesterolemia transitioned healthy ECs to full immune-like (EndIT) and, more surprisingly, foam cells (EndFT), in addition to inflammatory and mesenchymal cells (EndMT). Further, EC-derived foam cells shared remarkably similar transcriptomic profiles with foam cells derived from SMCs and MΦs. Comprehensive lineage-tracing studies using immunohistochemical staining of canonical protein and lipid markers in the EC-specific confetti mice clearly demonstrated direct evidence supporting the novel FIRE hypothesis, including EndIT and EndFT, when d-flow was combined with hypercholesterolemia. Further, reanalysis of the publicly available human carotid plaque scRNA-seq and Perturb-seq datasets supported the FIRE hypothesis and a potential mechanistic link between the genes and FIRE.

Conclusion

We provide evidence supporting the two-hit hypothesis: ECs in d-flow regions, such as the branching points, are partially reprogrammed, while hypercholesterolemia alone has minimal endothelial reprogramming effects. Under hypercholesterolemia, d-flow fully reprograms arterial ECs, including the novel EndIT and EndFT, in addition to inflammation and EndMT, during atherogenesis. This single-cell atlas provides a crucial roadmap for developing novel mechanistic understanding and therapeutics targeting flow-sensitive genes, proteins, and pathways of atherosclerosis.

Disturbed Flow Induces Reprogramming of Endothelial Cells to Immune-like and Foam Cells under Hypercholesterolemia during Atherogenesis

Background

Atherosclerosis occurs preferentially in the arteries exposed to disturbed flow (d-flow), while the stable flow (s-flow) regions are protected even under hypercholesterolemic conditions. We recently showed that d-flow alone initiates flow-induced reprogramming of endothelial cells (FIRE), including the novel concept of partial endothelial-to-immune-cell-like transition (partial EndIT), but was not validated using a genetic lineage-tracing model. Here, we tested and validated the two-hit hypothesis that d-flow is an initial instigator of partial FIRE but requires hypercholesterolemia to induce a full-blown FIRE and atherosclerotic plaque development.

Methods

Mice were treated with adeno-associated virus expressing proprotein convertase subtilisin/kexin type 9 and a Western diet to induce hypercholesterolemia and/or partial carotid ligation (PCL) surgery to expose the left common carotid artery (LCA) to d-flow. Single-cell RNA sequencing (scRNA-seq) analysis was performed using cells obtained from the intima and leftover LCAs and the control right common carotid arteries at 2 and 4 weeks post-PCL. Comprehensive immunohistochemical staining was performed on EC-specific confetti mice treated with PCL and hypercholesterolemic conditions at 4 weeks post-PCL to validate endothelial reprogramming.

Results

Atherosclerotic plaques developed by d-flow under hypercholesterolemia at 2 and 4 weeks post-PCL, but not by d-flow or hypercholesterolemia alone, as expected. The scRNA-seq results of 98,553 single cells from 95 mice revealed 25 cell clusters; 5 EC, 3 vascular smooth muscle cell (SMC), 5 macrophage (MΦ), and additional fibroblast, T cell, natural killer cell, dendritic cell, neutrophil, and B cell clusters. Our scRNA-seq analyses showed that d-flow under hypercholesterolemia transitioned healthy ECs to full immune-like (EndIT) and, more surprisingly, foam cells (EndFT), in addition to inflammatory and mesenchymal cells (EndMT). Further, EC-derived foam cells shared remarkably similar transcriptomic profiles with foam cells derived from SMCs and MΦs. Comprehensive lineage-tracing studies using immunohistochemical staining of canonical protein and lipid markers in the EC-specific confetti mice clearly demonstrated direct evidence supporting the novel FIRE hypothesis, including EndIT and EndFT, when d-flow was combined with hypercholesterolemia. Further, reanalysis of the publicly available human carotid plaque scRNA-seq and Perturb-seq datasets supported the FIRE hypothesis and a potential mechanistic link between the genes and FIRE.

Conclusion

We provide evidence supporting the two-hit hypothesis: ECs in d-flow regions, such as the branching points, are partially reprogrammed, while hypercholesterolemia alone has minimal endothelial reprogramming effects. Under hypercholesterolemia, d-flow fully reprograms arterial ECs, including the novel EndIT and EndFT, in addition to inflammation and EndMT, during atherogenesis. This single-cell atlas provides a crucial roadmap for developing novel mechanistic understanding and therapeutics targeting flow-sensitive genes, proteins, and pathways of atherosclerosis.

Metaboloepigenetics: Role in the Regulation of Flow-Mediated Endothelial (Dys)Function and Atherosclerosis

Endothelial dysfunction is the main initiating factor in atherosclerosis. Through mechanotransduction, shear stress regulates endothelial cell function in both homeostatic and diseased states. Accumulating evidence reveals that epigenetic changes play critical roles in the etiology of cardiovascular diseases, including atherosclerosis. The metabolic regulation of epigenetics has emerged as an important factor in the control of gene expression in diseased states, but to the best of our knowledge, this connection remains largely unexplored in endothelial dysfunction and atherosclerosis. In this review, we (1) summarize how shear stress (or flow) regulates endothelial (dys)function; (2) explore the epigenetic alterations that occur in the endothelium in response to disturbed flow; (3) review endothelial cell metabolism under different shear stress conditions; and (4) suggest mechanisms which may link this altered metabolism to the regulation of the endothelial epigenome by modulations in metabolite availability. We believe that metabolic regulation plays an important role in endothelial epigenetic reprogramming and could pave the way for novel metabolism-based therapeutic strategies.

Vinculin: A new target for the diagnosis and treatment of disease

Vinculin, a crucial adhesion plaque protein, plays a significant role in cell morphology and tissue development. Dysregulation of focal adhesion proteins has been linked to numerous diseases, including cardiovascular conditions, gastrointestinal disorders, and cancer. Recent studies increasingly highlight vinculin's involvement in the progression of these diseases; however, a comprehensive review remains lacking. Therefore, an in-depth and timely review is essential to consolidate the latest findings on vinculin's role in disease mechanisms. This study aims to examine how vinculin coordinates a complex network of signaling pathways across various pathological contexts.

Angiogenesis within atherosclerotic plaques: Mechanical regulation, molecular mechanism and clinical diagnosis

Atherosclerosis (AS) is a disease characterized by focal cholesterol accumulation and insoluble inflammation in arterial intima, leading to the formation of an atherosclerotic plaque consisting of lipids, cells, and fibrous matrix. The presence of plaque can restrict or obstruct blood flow, resulting in arterial stenosis and local mechanical microenvironment changes including flow shear stress, vascular matrix stiffness, and plaque structural stress. Neovascularization within the atherosclerotic plaque plays a crucial role in both plaque growth and destabilization, potentially leading to plaque rupture and fatal embolism. However, the exact interactions between neovessels and plaque remain unclear. In this review, we provide a comprehensive analysis of the origin of intraplaque neovessels, the contributing factors, underlying molecular mechanisms, and associated signaling pathways. We specifically emphasize the role of mechanical factors contributing to angiogenesis in atherosclerotic plaques. Additionally, we summarize the imaging techniques and therapeutic strategies for intraplaque neovessels to enhance our understanding of this field.

Diabetes-Driven Atherosclerosis: Updated Mechanistic Insights and Novel Therapeutic Strategies

The global rise in diabetes prevalence has significantly contributed to the increasing burden of atherosclerotic cardiovascular disease (ASCVD), a leading cause of morbidity and mortality in this population. Diabetes accelerates atherosclerosis through mechanisms such as hyperglycemia, oxidative stress, chronic inflammation, and epigenetic dysregulation, leading to unstable plaques and an elevated risk of cardiovascular events. Despite advancements in controlling traditional risk factors like dyslipidemia and hypertension, a considerable residual cardiovascular risk persists, highlighting the need for innovative therapeutic approaches. Emerging treatments, including sodium-glucose cotransporter 2 (SGLT2) inhibitors, glucagon-like peptide-1 (GLP-1) receptor agonists, epigenetic modulators, and RNA-based therapies, are showing promise in addressing the unique challenges of diabetes-associated ASCVD. Precision medicine strategies, such as nanoparticle-based drug delivery and cell-specific therapies, offer further potential for mitigating cardiovascular complications. Advances in multiomics and systems biology continue to deepen our understanding of the molecular mechanisms driving diabetes-associated atherosclerosis. This review synthesizes recent advances in understanding the pathophysiology and treatment of diabetes-related atherosclerosis, offering a roadmap for future research and precision medicine approaches to mitigate cardiovascular risk in this growing population.

Distinct inflammatory pathways shape atherosclerosis in different vascular beds

Studies suggest varying atherosclerotic cardiovascular disease (ASCVD) prevalence across arterial beds. Factors such as smoking expedite ASCVD progression in the abdominal aorta, while diabetes accelerates plaque development in lower limb arteries, and hypertension plays a significant role in ASCVD development in the coronary and carotid arteries. Moreover, superficial femoral atherosclerosis advances slower compared with atherosclerosis in coronary and carotid arteries. Furthermore, femoral atherosclerosis exhibits higher levels of ossification and calcification, but lower cholesterol concentrations compared with atherosclerotic lesions of other vascular beds. Such disparities exemplify the diverse progression of ASCVD across arterial beds, pointing towards differential mechanistic pathways in each vascular bed. Hence, this review summarizes current literature on immune-inflammatory mechanisms in various arterial beds in ASCVD to advance our understanding of this disease in an aging society with increased need of vascular bed and patient-specific treatment options.

Integrating microfluidics, hydrogels, and 3D bioprinting for personalized vessel-on-a-chip platforms

Thrombosis, a major cause of morbidity and mortality worldwide, presents a complex challenge in cardiovascular medicine due to the intricacy of clotting mechanisms in living organisms. Traditional research approaches, including clinical studies and animal models, often yield conflicting results due to the inability to control variables in these complex systems, highlighting the need for more precise investigative tools. This review explores the evolution of in vitro thrombosis models, from conventional polydimethylsiloxane (PDMS)-based microfluidic devices to advanced hydrogel-based systems and cutting-edge 3D bioprinted vascular constructs. We discuss how these emerging technologies, particularly vessel-on-a-chip platforms, are enabling researchers to control previously unmanageable factors, thereby offering unprecedented opportunities to pinpoint specific clotting mechanisms. While PDMS-based devices offer optical transparency and fabrication ease, their inherent limitations, including non-physiological rigidity and surface properties, have driven the development of hydrogel-based systems that better mimic the extracellular matrix of blood vessels. The integration of microfluidics with biomimetic materials and tissue engineering approaches has led to the development of sophisticated models capable of simulating patient-specific vascular geometries, flow dynamics, and cellular interactions under highly controlled conditions. The advent of 3D bioprinting further enables the creation of complex, multi-layered vascular structures with precise spatial control over geometry and cellular composition. Despite significant progress, challenges remain in achieving long-term stability, incorporating immune components, and translating these models to clinical applications. By providing a comprehensive overview of current advancements and future prospects, this review aims to stimulate further innovation in thrombosis research and accelerate the development of more effective, personalized approaches to thrombosis prevention and treatment.

The role of cellular senescence in endothelial dysfunction and vascular remodelling in arteriovenous fistula maturation

Haemodialysis (HD) is often required for patients with end-stage renal disease. Arteriovenous fistulas (AVFs), a surgical procedure connecting an artery to a vein, are the preferred vascular access for HD due to their durability and lower complication rates. The aim of AVFs is to promote vein remodelling to accommodate increased blood flow needed for dialysis. However, many AVFs fail to mature properly, making them unsuitable for dialysis. Successful maturation requires remodelling, resulting in an increased luminal diameter and thickened walls to support the increased blood flow. After AVF creation, haemodynamic changes due to increased blood flow on the venous side of the AVF initiate a cascade of events that, when successful, lead to the proper maturation of the AVF, making it suitable for cannulation. In this process, endothelial cells play a crucial role since they are in direct contact with the frictional forces exerted by the blood, known as shear stress. Patients requiring HD often have other conditions that increase the burden of senescent cells, such as ageing, diabetes and hypertension. These senescent cells are characterized by irreversible growth arrest and the secretion of pro-inflammatory and pro-thrombotic factors, collectively known as the senescence-associated secretory phenotype (SASP). This accumulation can impair vascular function by promoting inflammation, reducing vasodilatation, and increasing thrombosis risk, thus hindering proper AVF maturation and function. This review explores the contribution of senescent endothelial cells to AVF maturation and explores potential therapeutic strategies to alleviate the effects of senescent cell accumulation, aiming to improve AVF maturation rates.

Valsartan to Prevent Acquired Pulmonary Vein Stenosis in Pediatric Patients After Total Anomalous Pulmonary Venous Connection Surgery

BACKGROUND

Recurrent pulmonary vein stenosis (PVS) following surgical repair of total anomalous pulmonary venous connection is associated with poor prognosis. Preclinical studies have shown that use of an angiotensin receptor blocker can attenuate intimal hyperplasia; notwithstanding, its clinical utility is of uncertain benefit.

METHODS

This single-center study included patients undergoing total anomalous pulmonary venous connection repair in 2020 to 2021. Since August 2020, patients have been considered for valsartan therapy early after operation. Contemporaneous participants were subcategorized into study versus control groups based on valsartan exposure. Patients in the control group were treated with the same protocolized algorithm except valsartan administration. The primary end point was postoperative PVS (PPVS) progression.

RESULTS

Overall, 104 patients operated on at a median age of 1.3 months were included (valsartan group: 25 versus control group: 79). The baseline characteristics were similar between the 2 groups. Within a median follow-up of 28.6 months, 27 patients developed PPVS noted by echocardiography and computed tomography angiography, among which 22 with clinical PPVS underwent reoperations. No between-group difference was observed in the incidence of initial PPVS (P=0.80, Cohen's h=0.06 [95% CI, -0.38 to 0.50]) and reoperation (P=0.46, Cohen's h=-0.18[ 95% CI, -0.65 to 0.29]); however, patients in the valsartan group had a significantly lower risk of PPVS progression (P=0.019, Cohen's h=-1.12 [95% CI, -1.66 to -0.57]) and subsequent PPVS progression after reoperation (P=0.011, Cohen's h=-1.71 [95% CI, -2.61 to -0.82]) compared with the control group. PPVS-related death was observed in 9 cases (11.4%) in the control group versus none (0%) in the valsartan group. No adverse event related to valsartan occurred in this series.

CONCLUSIONS

Early use of valsartan after total anomalous pulmonary venous connection surgery appears to potentially be a feasible and effective adjunct to reoperation in treating pediatric acquired PVS.

The Interplay Between Immunity, Inflammation and Endothelial Dysfunction

The endothelium is pivotal in multiple physiological processes, such as maintaining vascular homeostasis, metabolism, platelet function, and oxidative stress. Emerging evidence in the past decade highlighted the immunomodulatory function of endothelium, serving as a link between innate, adaptive immunity and inflammation. This review examines the regulation of the immune-inflammatory axis by the endothelium, discusses physiological immune functions, and explores pathophysiological processes leading to endothelial dysfunction in various metabolic disturbances, including hyperglycemia, obesity, hypertension, and dyslipidaemia. The final section focuses on the novel, repurposed, and emerging therapeutic targets that address the immune-inflammatory axis in endothelial dysfunction.

Mapping the distribution of radial artery atherosclerosis by optical coherence tomography

BACKGROUND

Radial artery plaque (RAP) can influence the function of arterial conduits after revascularization and hinder the maturation of arteriovenous fistulas in patients undergoing hemodialysis patients. However, the preferred in vivo sites for RAP development have not been systematically investigated. This study measured and evaluated RAP to map the distribution of RAP in the radial artery (RA) using optical coherence tomography (OCT).

METHODS

OCT images of the entire RA in 300 patients at 1 mm intervals were analyzed to assess RAP phenotypes and measure the distance of RAP from the radial artery ostium. The RA was evenly divided into three segments: proximal, middle, and distal. Patients were categorized into two groups: the RAP group (n = 68) and the non-RAP group (n = 232).

RESULTS

Among the 300 patients with 300 radial arteries studied, 68 patients (22.7%) developed 180 distinct RAPs. The distal segment was the most susceptible to RAP formation (51 patients; 17.0%).In plaque level analysis, Most RAPs (55%) were located ≥ 150 mm from the RA ostium. The distal segment exhibited a significantly higher median cumulative plaque index compared with the proximal and middle segments (p = 0.031). Logistic regression analysis identified aging, smoking, diabetes mellitus, and multi-vessel coronary disease (MVCD) as independent risk factors for RAP occurrence.

CONCLUSIONS

RAP was observed in 22.7% of patients with acute coronary syndrome (ACS), with a predominant localization in the distal segment, both at the patient and plaque level. Significant risk factors included aging, smoking, diabetes mellitus, and MVCD.

Inhibiting MiR-33a-3p Expression Fails to Enhance ApoAI-Mediated Cholesterol Efflux in Pro-Inflammatory Endothelial Cells

Background and Objectives: Atherosclerosis is an inflammatory condition that results in cholesterol accumulating within vessel wall cells. Atherosclerotic cardiovascular disease is the leading cause of mortality worldwide due to this disease being a major contributor to myocardial infarctions and cerebrovascular accidents. Research suggests that cholesterol accumulation occurring precisely within arterial endothelial cells triggers atherogenesis and exacerbates atherosclerosis. Furthermore, inflamed endothelium acts as a catalyst for atherosclerotic development. Therefore, enhancing cholesterol removal specifically in pro-inflammatory endothelial cells may be a potential treatment option for atherosclerosis. While we have previously shown that inhibiting the microRNA guide strand miR-33a-5p within pro-inflammatory endothelial cells increases both ABCA1 expression and apoAI-mediated cholesterol efflux, it is unknown whether inhibiting the miR-33a-3p passenger strand in pro-inflammatory endothelial cells causes similar atheroprotective effects. In this study, this is what we aimed to test. Materials and Methods: We used plasmid transfection to knockdown miR-33a-3p expression within cultured pro-inflammatory immortalized mouse aortic endothelial cells (iMAECs). We compared ABCA1 expression and apoAI-mediated cholesterol efflux within these cells to cultured pro-inflammatory iMAECs transfected with a control plasmid. Results: The knockdown of miR-33a-3p expression within pro-inflammatory iMAECs resulted in a significant increase in ABCA1 mRNA expression. However, the inhibition of miR-33a-3p did not significantly increase ABCA1 protein expression within pro-inflammatory iMAECs. Moreover, we failed to detect a significant increase in apoAI-mediated cholesterol efflux within pro-inflammatory iMAECs from miR-33a-3p knockdown. Conclusions: Our results indicative that the knockdown of miR-33a-3p alone does not enhance ABCA1-dependent cholesterol efflux within pro-inflammatory endothelial cells. To gain any atheroprotective benefit from inhibiting miR-33a-3p within pro-inflammatory endothelium, additional anti-atherogenic strategies would likely be needed in unison.

Phosphorylation of endothelial histone H3.3 serine 31 by PKN1 links flow-induced signaling to proatherogenic gene expression

Atherosclerotic lesions develop preferentially in arterial regions exposed to disturbed blood flow, where endothelial cells acquire an inflammatory phenotype. How disturbed flow induces endothelial cell inflammation is incompletely understood. Here we show that histone H3.3 phosphorylation at serine 31 (H3.3S31) regulates disturbed-flow-induced endothelial inflammation by allowing rapid induction of FOS and FOSB, required for inflammatory gene expression. We identified protein kinase N1 (PKN1) as the kinase responsible for disturbed-flow-induced H3.3S31 phosphorylation. Disturbed flow activates PKN1 in an integrin α5β1-dependent manner and induces its translocation into the nucleus, and PKN1 is also involved in the phosphorylation of the AP-1 transcription factor JUN. Mice with endothelium-specific PKN1 loss or endothelial expression of S31 phosphorylation-deficient H.3.3 mutants show reduced endothelial inflammation and disturbed-flow-induced vascular remodeling in vitro and in vivo. Together, we identified a pathway whereby disturbed flow through PKN1-mediated histone phosphorylation and FOS/FOSB induction promotes inflammatory gene expression and vascular inflammation.

Biomimetic nanoparticles co-deliver hirudin and lumbrukinase to ameliorate thrombus and inflammation for atherosclerosis therapy

Atherosclerosis (AS) is a progressive inflammatory disease, and thrombosis most likely leads to cardiovascular morbidity and mortality globally. Thrombolytic drugs alone cannot completely prevent thrombotic events, and treatments targeting thrombosis also need to regulate the inflammatory process. Based on the dynamic pathological development of AS, biomimetic thrombus-targeted nanoparticles HMTL@PM were prepared. Hirudin and lumbrukinase, effective substances of traditional Chinese medicine, were self-assembled under the action of tannic acid and Mn2+. HMTL@PM dissociated in the weakly acidic microenvironment of atherosclerosis and exhibited excellent therapeutic effects, including alleviating inflammation, dissolving thrombus, anticoagulation, and promoting cholesterol efflux. HMTL@PM effectively regulated the progression of AS and provided a new perspective for the development of drug delivery systems for AS therapy, which holds important research significance for reducing the mortality of cardiovascular and cerebrovascular diseases.

Hemodynamic disturbance and mTORC1 activation: Unveiling the biomechanical pathogenesis of thoracic aortic aneurysms in Marfan syndrome

Thoracic aortic aneurysm (TAA) significantly endangers the lives of individuals with Marfan syndrome (MFS), yet the intricacies of their biomechanical origins remain elusive. Our investigation delves into the pivotal role of hemodynamic disturbance in the pathogenesis of TAA, with a particular emphasis on the mechanistic contributions of the mammalian target of rapamycin (mTOR) signaling cascade. We uncovered that activation of the mTOR complex 1 (mTORC1) within smooth muscle cells, instigated by the oscillatory wall shear stress (OSS) that stems from disturbed flow (DF), is a catalyst for TAA progression. This revelation was corroborated through both an MFS mouse model (Fbn1 +/C1039G) and clinical MFS specimens. Crucially, our research demonstrates a direct linkage between the activation of the mTORC1 pathway and the intensity in OSS. Therapeutic administration of rapamycin suppresses mTORC1 activity, leading to the attenuation of aberrant SMC behavior, reduced inflammatory infiltration, and restoration of extracellular matrix integrity-collectively decelerating TAA advancement in our mouse model. These insights posit the mTORC1 axis as a strategic target for intervention, offering a novel approach to manage TAAs in MFS and potentially pave insights for current treatment paradigms.

Endothelial IGFBP6 suppresses vascular inflammation and atherosclerosis

Beyond dyslipidemia, inflammation contributes to the development of atherosclerosis. However, intrinsic factors that counteract vascular inflammation and atherosclerosis remain scarce. Here we identify insulin-like growth factor binding protein 6 (IGFBP6) as a homeostasis-associated molecule that restrains endothelial inflammation and atherosclerosis. IGFBP6 levels are significantly reduced in human atherosclerotic arteries and patient serum. Reduction of IGFBP6 in human endothelial cells by siRNA increases inflammatory molecule expression and monocyte adhesion. Conversely, pro-inflammatory effects mediated by disturbed flow (DF) and tumor necrosis factor (TNF) are reversed by IGFBP6 overexpression. Mechanistic investigations further reveal that IGFBP6 executes anti-inflammatory effects directly through the major vault protein (MVP)-c-Jun N-terminal kinase (JNK)/nuclear factor kappa B (NF-κB) signaling axis. Finally, IGFBP6-deficient mice show aggravated diet- and DF-induced atherosclerosis, whereas endothelial-cell-specific IGFBP6-overexpressing mice protect against atherosclerosis. Based on these findings, we propose that reduction of endothelial IGFBP6 is a predisposing factor in vascular inflammation and atherosclerosis, which can be therapeutically targeted.

Endothelial Cu Uptake Transporter CTR1 Senses Disturbed Flow to Promote Atherosclerosis through Cuproptosis

Endothelial cells (ECs) lining blood vessels sense disturbed blood flow (D-flow), which drives mitochondrial dysfunction and atherosclerosis. Copper (Cu) is an essential micronutrient, and its disruption of homeostasis has been implicated in atherosclerosis. Cellular Cu levels are tightly controlled by Cu transport proteins including the Cu importer CTR1. Cuproptosis is a recently discovered form of regulated cell death triggered by mitochondrial Cu accumulation, but its endogenous stimulants and role in atherosclerosis remain unknown. Using EC-specific CTR1-deficient mice and cultured ECs, we show that endothelial CTR1 responds to D-flow by increasing mitochondrial Cu levels through its interaction with the mitochondrial Cu transporter SLC25A3 at caveolae/lipid rafts. This leads to the aggregation of lipoylated mitochondrial proteins, mitochondrial dysfunction, and cuproptosis, thereby exacerbating atherosclerosis. Importantly, mitochondria-targeted Cu-chelating nanoparticles effectively mitigate D-flow-induced cuproptosis and atherosclerosis, highlighting the endothelial CTR1-SLC25A3-mitochondrial Cu axis as a potential therapeutic target.

The BEnefit of LONGitudinal Micro-Incisions Prior to Paclitaxel-Coated Balloon Angioplasty (BELONG Study) in Patients With Lower Extremity Arterial Disease: Clinical Outcomes at 12 Months

PURPOSE

Angioplasty of lower extremity arteries with calcification may result in flow-limiting dissection requiring bail-out stenting with unfavorable long-term outcomes. Vessel preparation prior to angioplasty may improve immediate results of the angioplasty and long-term patency. This prospective study assessed the 12-month outcomes of patients who underwent novel vessel preparation catheter, the FLEX Vessel Prep™ System (FLEX VP), prior to drug-coated balloon angioplasty (DCB-PTA).

MATERIALS AND METHODS

This investigator-initiated single-arm prospective trial enrolled patients with symptomatic lower extremity peripheral artery disease with de novo, restenotic, or in-stent stenosis of the superficial femoral or popliteal arteries. Target lesions were prepared using FLEX VP that created 12 longitudinal micro-incisions before drug-coated balloon angioplasty.

RESULTS

Forty-three lesions in 41 patients were treated in this study with an average lesion length of 118 mm (10-291 mm), average stenosis of 82% (40-100%), and an occlusion rate of 27.9% with an average occlusion length of 89 mm (10-272 mm). Calcification was observed in 85.7% of the lesions, with 66.7% of lesions demonstrating grade 3 or 4 of the Peripheral Arterial Calcification Scoring System. After FLEX VP and DCB-PTA, 92.7% of patients were absent of flow-limiting dissections. Stenting occurred in 39% (16/41) patients (median stent length 40 mm) for residual stenosis (15 patients) and flow-limiting dissection (1 patient). There was one death prior to the 12-month follow-up, not related to the index procedure. Freedom from clinically driven target lesion revascularization at 12 months was 97.5% (39/40). Rutherford classification shifted from 41.5% Class ≥3 at baseline to 95% Class ≤1 at 12 months. There were no amputations at 12 months.

CONCLUSION

Vessel preparation with longitudinal micro-incisions of complex and calcified lesions prior to angioplasty was associated with few flow-limiting dissections. The majority of stents were placed to treat focal residual stenosis, using the shortest available stent length at the time of the study (40 mm) for the majority. Only one stent was needed to treat a flow-limiting dissection. The 97.5% freedom from clinically driven target lesion revascularization (CDTLR) and symptom relief at 12 months suggest that vessel preparation via FLEX VP provides value in maintaining long-term outcomes in patients with highly calcified superficial femoral artery (SFA) or popliteal lesions.

CLINICAL IMPACT

Vessel preparation with longitudinal micro-incisions is a short and efficient intervention associated with promising clinical outcomes and patency rate 12 months after treatment of long and calcified occlusions or stenosis of the femoral and popliteal arteries. This innovative vessel preparation provides post-procedure less residual stenosis and more favorable dissection morphology, decreasing the placement of stent and especially their length. Vessel preparation by longitudinal incisions also favors optimal distribution of anti-restenotic drug in the lesion and thus prevents further intervention due to restenosis.

Developing a Flow-Resistance Module for Elucidating Cell Mechanotransduction on Multiple Shear Stresses

Fluid shear stress plays a pivotal role in regulating cellular behaviors, maintaining tissue homeostasis, and driving disease progression. Cells in various tissues are specifically adapted to physiological levels of shear stress and exhibit sensitivity to variations in its magnitude, highlighting the requirement for a comprehensive understanding of cellular responses to both physiologically and pathologically relevant levels of shear stress. In this study, we developed an independent upstream flow-resistance module with high fluidic resistances comprising three microchannels. The validity of the flow-resistance module was confirmed via computational fluid dynamics (CFD) simulations and flow calibration experiments, resulting in the generation of steady wall shear stresses ranging from 0.06 to 11.57 dyn/cm2 within the interconnected cell culture chips. Gene expression profiles, cytoskeletal remodeling, and morphological changes, as well as Yes-associated protein (YAP) nuclear translocation, were investigated in response to various shear stresses to authenticate the reliability of our experimental platform, indicating an increasing trend as the shear stress increases, reaching its maximum at various shear stresses. Our findings suggest that this flow-resistance module can be readily employed for precise characterization of cellular responses under various shear stresses.

Atherosclerosis in diabetes mellitus: novel mechanisms and mechanism-based therapeutic approaches

Atherosclerosis is a disease of large and medium arteries that can lead to life-threatening cardiovascular and cerebrovascular consequences, such as myocardial infarction and stroke. Moreover, atherosclerosis is a major contributor to cardiovascular-related mortality in individuals with diabetes mellitus. Diabetes aggravates the pathobiological mechanisms that underlie the development of atherosclerosis. Currently available anti-atherosclerotic drugs or strategies solely focus on optimal control of systemic risk factors, including hyperglycaemia and dyslipidaemia, but do not adequately target the diabetes-exacerbated mechanisms of atherosclerotic cardiovascular disease, highlighting the need for targeted, mechanism-based therapies. This Review focuses on emerging pathological mechanisms and related novel therapeutic targets in atherosclerotic cardiovascular disease in patients with diabetes.

The Impact of Modifiable Risk Factors on the Endothelial Cell Methylome and Cardiovascular Disease Development

Cardiovascular disease (CVD) is the most prevalent cause of mortality and morbidity in the Western world. A common underlying hallmark of CVD is the plaque-associated arterial thickening, termed atherosclerosis. Although the molecular mechanisms underlying the aetiology of atherosclerosis remain unknown, it is clear that both its development and progression are associated with significant changes in the pattern of DNA methylation within the vascular cell wall. The endothelium is the major regulator of vascular homeostasis, and endothelial cell dysfunction (ED) is considered an early marker for atherosclerosis. Thus, it is speculated that changes in DNA methylation within endothelial cells may, in part, be causal in ED, leading to atherosclerosis and CVD generally. This review will evaluate the extensive evidence that environmental risk factors, known to be associated with atherosclerosis, such as diabetes, metabolic disorder, smoking, hypertension and hypercholesterolaemia etc. can affect the methylome of the endothelium and consequently act to alter gene transcription and function. Further, the potential mechanisms whereby such risk factors might impact upon the activities and/or specificities of the epigenetic writers and erasers which determine the methylome [the DNA methyl transferases (DNMTs) and Ten Eleven translocases (TETs)] are considered here. Notably, the TET proteins are members of the 2-oxoglutarate-dependent dioxygenase superfamily which require molecular oxygen (O2) and α-ketoglutarate (α-KG) as substrates and iron-2+ (Fe II) as a cofactor. This renders their activities subject to modulation by hypoxia, metabolic flux and cellular redox. The potential significance of this, with respect to the impact of modifiable risk factors upon the activities of the TETs and the methylome of the endothelium is discussed.