Atheroma transcriptomics identifies ARNTL as a smooth muscle cell regulator and with clinical and genetic data improves risk stratification.

Background And Aims: The role of vascular smooth muscle cells (SMCs) in atherosclerosis has evolved to indicate causal genetic links with the disease. Single cell RNA sequencing (scRNAseq) studies have identified multiple cell populations of mesenchymal origin within atherosclerotic lesions, including various SMC sub-phenotypes, but it is unknown how they relate to patient clinical parameters and genetics. Here, mesenchymal cell populations in atherosclerotic plaques were correlated with major coronary artery disease (CAD) genetic variants and functional analyses performed to identify SMC markers involved in the disease.

Transcriptomic and physiological analyses reveal temporal changes contributing to the delayed healing response to arterial injury in diabetic rats.

Objective: Atherosclerosis is a leading cause of mortality in the rapidly growing population with diabetes mellitus. Vascular interventions in patients with diabetes can lead to complications attributed to defective vascular remodeling and impaired healing response in the vessel wall. In this study, we aim to elucidate the molecular differences in the vascular healing response over time using a rat model of arterial injury applied to healthy and diabetic conditions.

Plaque Evaluation by Ultrasound and Transcriptomics Reveals BCLAF1 as a Regulator of Smooth Muscle Cell Lipid Transdifferentiation in Atherosclerosis.

Background: Understanding the processes behind carotid plaque instability is necessary to develop methods for identification of patients and lesions with stroke risk. Here, we investigated molecular signatures in human plaques stratified by echogenicity as assessed by duplex ultrasound.

Methods: Lesion echogenicity was correlated to microarray gene expression profiles from carotid endarterectomies (n=96).

Proteoglycan 4 Modulates Osteogenic Smooth Muscle Cell Differentiation during Vascular Remodeling and Intimal Calcification.

Calcification is a prominent feature of late-stage atherosclerosis, but the mechanisms driving this process are unclear. Using a biobank of carotid endarterectomies, we recently showed that Proteoglycan 4 (PRG4) is a key molecular signature of calcified plaques, expressed in smooth muscle cell (SMC) rich regions. Here, we aimed to unravel the PRG4 role in vascular remodeling and intimal calcification.

AMPA-Type Glutamate Receptors Associated With Vascular Smooth Muscle Cell Subpopulations in Atherosclerosis and Vascular Injury.

Vascular smooth muscle cells (VSMCs) are key constituents of both normal arteries and atherosclerotic plaques. They have an ability to adapt to changes in the local environment by undergoing phenotypic modulation. An improved understanding of the mechanisms that regulate VSMC phenotypic changes may provide insights that suggest new therapeutic targets in treatment of cardiovascular disease (CVD).

Lack of PCSK6 Increases Flow-Mediated Outward Arterial Remodeling in Mice.

Proprotein convertases (PCSKs) process matrix metalloproteases and cytokines, but their function in the vasculature is largely unknown. Previously, we demonstrated upregulation of PCSK6 in atherosclerotic plaques from symptomatic patients, localization to smooth muscle cells (SMCs) in the fibrous cap and positive correlations with inflammation, extracellular matrix remodeling and cytokines. Here, we hypothesize that PCSK6 could be involved in flow-mediated vascular remodeling and aim to evaluate its role in the physiology of this process using knockout mice.

PCSK6 Is a Key Protease in the Control of Smooth Muscle Cell Function in Vascular Remodeling.

Rationale: PCSKs (Proprotein convertase subtilisins/kexins) are a protease family with unknown functions in vasculature. Previously, we demonstrated PCSK6 upregulation in human atherosclerotic plaques associated with smooth muscle cells (SMCs), inflammation, extracellular matrix remodeling, and mitogens.

Objective: Here, we applied a systems biology approach to gain deeper insights into the PCSK6 role in normal and diseased vessel wall.

Noninvasive in vivo Assessment of the Re-endothelialization Process Using Ultrasound Biomicroscopy in the Rat Carotid Artery Balloon Injury Model.

Objectives: Ultrasound biomicroscopy (UBM), or ultra high-frequency ultrasound, is a technique used to assess the anatomy of small research animals. In this study, UBM was used to assess differences in intimal hyperplasia thickness as a surrogate measurement of the re-endothelialization process after carotid artery balloon injury in rats.

Methods: Ultrasound biomicroscopic data from 3 different experiments and rat strains (Sprague Dawley, Wistar, and diabetic Goto-Kakizaki) were analyzed.

Novel Multiomics Profiling of Human Carotid Atherosclerotic Plaques and Plasma Reveals Biliverdin Reductase B as a Marker of Intraplaque Hemorrhage.

Clinical tools to identify individuals with unstable atherosclerotic lesions are required to improve prevention of myocardial infarction and ischemic stroke. Here, a systems-based analysis of atherosclerotic plaques and plasma from patients undergoing carotid endarterectomy for stroke prevention was used to identify molecular signatures with a causal relationship to disease. Local plasma collected in the lesion proximity following clamping prior to arteriotomy was profiled together with matched peripheral plasma.

Cellular Uptake of Plain and SPION-Modified Microbubbles for Potential Use in Molecular Imaging.

Introduction: Both diagnostic ultrasound (US) and magnetic resonance imaging (MRI) accuracy can be improved by using contrast enhancement. For US gas-filled microbubbles (MBs) or silica nanoparticles (SiNPs), and for MRI superparamagnetic or paramagnetic agents, contribute to this. However, interactions of MBs with the vascular wall and cells are not fully known for all contrast media.

MicroRNA-210 Enhances Fibrous Cap Stability in Advanced Atherosclerotic Lesions.

Rationale: In the search for markers and modulators of vascular disease, microRNAs (miRNAs) have emerged as potent therapeutic targets.

Objective: To investigate miRNAs of clinical interest in patients with unstable carotid stenosis at risk of stroke.

Methods And Results: Using patient material from the BiKE (Biobank of Karolinska Endarterectomies), we profiled miRNA expression in patients with stable versus unstable carotid plaque.

Effects of Linagliptin on Vessel Wall Healing in the Rat Model of Arterial Injury Under Normal and Diabetic Conditions.

Diabetic patients suffer an increased risk of restenosis and late stent thrombosis after angioplasty, complications which are related to a defective reendothelialization. Dipeptidyl peptidase-4 inhibitors have been suggested to exert a direct effect on endothelial and smooth muscle cells (SMCs). Therefore, the objective was to study if the dipeptidyl peptidase-4 inhibitor linagliptin could influence vascular repair and accelerate reendothelialization after arterial injury in healthy and diabetic animals.

Phenotypic Modulation of Smooth Muscle Cells in Atherosclerosis Is Associated With Downregulation of LMOD1, SYNPO2, PDLIM7, PLN, and SYNM.

Objective: Key augmented processes in atherosclerosis have been identified, whereas less is known about downregulated pathways. Here, we applied a systems biology approach to examine suppressed molecular signatures, with the hypothesis that they may provide insight into mechanisms contributing to plaque stability.

Approach And Results: Muscle contraction, muscle development, and actin cytoskeleton were the most downregulated pathways (false discovery rate=6.

Gene expression signatures, pathways and networks in carotid atherosclerosis.

Background: Embolism from unstable atheromas in the carotid bifurcation is a major cause of stroke. Here, we analysed gene expression in endarterectomies from patients with symptomatic (S) and asymptomatic (AS) carotid stenosis to identify pathways linked to plaque instability.

Methods: Microarrays were prepared from plaques (n = 127) and peripheral blood samples (n = 96) of S and AS patients.

Glucagon-Like Peptide-1 Receptor Activation Does not Affect Re-Endothelialization but Reduces Intimal Hyperplasia via Direct Effects on Smooth Muscle Cells in a Nondiabetic Model of Arterial Injury.

Unlabelled: Diabetic patients have an increased risk of restenosis and late stent thrombosis after angioplasty, i.e. complications that are related to a defective re-endothelialization.

Liver parenchyma access and lesion marker via the endovascular route.

Background: Neoadjuvant chemotherapeutic regimens for metastatic colorectal cancer are now so effective that they can cause "vanishing" lesions. With new advances such as local ablation, intra-arterial treatments in bolus with pumps or with beads, and isolation of hepatic perfusion, the need for a working channel to the liver may be warranted, ideally reducing the risk of spreading neoplastic cells.

Materials And Methods: The endovascular trans-vessel wall Extroducer device makes it possible to gain direct access to the liver parenchyma.

Profiling of atherosclerotic lesions by gene and tissue microarrays reveals PCSK6 as a novel protease in unstable carotid atherosclerosis.

Objective: Carotid plaque instability is a major cause of ischemic stroke, but detailed knowledge about underlying molecular pathways is still lacking. Here, we evaluated large-scale transcriptomic and protein expression profiling in a biobank of carotid endarterectomies followed by characterization of identified candidates, as a platform for discovery of novel proteins differentially regulated in unstable carotid lesions.

Approach And Results: Genes highly upregulated in symptomatic versus asymptomatic plaques were selected from Affymetrix microarray analyses (n=127 plaques), and tissue microarrays constructed from 34 lesions were assayed for 21 corresponding proteins by immunohistochemistry.

Structure, Energy, and Vibrational Frequencies of Oxygen Allotropes On (n ≤ 6) in the Covalently Bound and van der Waals Forms: Ab Initio Study at the CCSD(T) Level.

Recent experiments on the UV and electron beam irradiation of solid O2 reveals a series of IR features near the valence antisymmetric vibration band of O3 which are frequently interpreted as the formation of unusual On allotropes in the forms of weak complexes or covalently bound molecules. In order to elucidate the question of the nature of the irradiation products, the structure, relative energies, and vibrational frequencies of various forms of On (n = 1-6) in the singlet, triplet, and, in some cases, quintet states were studied using the CCSD(T) method up to the CCSD(T,full)/cc-pCVTZ and CCSD(T,FC)/aug-cc-pVTZ levels. The results of calculations demonstrate the existence of stable highly symmetric structures O4 (D3h), O4 (D2d), and O6 (D3d) as well as the intermolecular complexes O2·O2, O2·O3, and O3·O3 in different conformations.

Serine protease inhibitor A3 in atherosclerosis and aneurysm disease.

Remodeling of extracellular matrix (ECM) plays an important role in both atherosclerosis and aneurysm disease. Serine protease inhibitor A3 (serpinA3) is an inhibitor of several proteases such as elastase, cathepsin G and chymase derived from mast cells and neutrophils. In this study, we investigated the putative role of serpinA3 in atherosclerosis and aneurysm formation.

The expression of IGFs and IGF binding proteins in human carotid atherosclerosis, and the possible role of IGF binding protein-1 in the regulation of smooth muscle cell proliferation.

Objective: Proliferation of smooth muscle cells (SMCs) in the fibrous cap of atherosclerotic lesions has been proposed to be important for plaque stability. Since the insulin-like growth factor (IGF) system has been implicated to play a role in atherosclerosis and plaque stability, we investigated the expression of members of the IGF system in carotid plaques, in particular IGFBP-1 and its role in the regulation of SMC proliferation.

Methods And Results: Gene expression profiles of the IGF system in 164 human carotid plaques obtained from our Biobank of Karolinska Endarterectomies (BiKE) were analyzed.

Correlations between clinical variables and gene-expression profiles in carotid plaque instability.

Objective: Strokes, a major cause of disability, are often caused by embolism from unstable carotid plaques. The aim of this study was to validate a biobank of human carotid endarterectomies as a platform for further exploration of pathways for plaque instability. For this purpose, we investigated the relationship between clinical parameters of plaque instability and expression of genes previously shown to be associated with either plaque instability or healing processes in the vessel wall.

Tissue factor pathway inhibitor-2 is induced by fluid shear stress in vascular smooth muscle cells and affects cell proliferation and survival.

Objective: Vascular smooth muscle cells (SMCs) are exposed to fluid shear stress (FSS) after interventional procedures such as balloon-angioplasty. Whereas the effects of hemodynamic forces on endothelial cells are explored in detail, the influence of FSS on smooth muscle cell function is poorly characterized. Here, we investigated the effect of FSS on SMC gene expression and function.

Endogenous control genes in complex vascular tissue samples.

Background: Gene expression microarrays and real-time PCR are common methods used to measure mRNA levels. Each method has a fundamentally different approach of normalization between samples. Relative quantification of gene expression using real-time PCR is often done using the 2(/\)(-DeltaDeltaCt) method, in which the normalization is performed using one or more endogenous control genes.