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Background and Aims: The N-terminal propeptide of type III collagen (PRO-C3) assay measures a pro-peptide released during type III collagen synthesis, an important feature of arterial stiffening and atherogenesis. There is a clinical need for improved non-invasive, cheap and easily accessible methods for evaluating individuals at risk of cardiovascular disease (CVD). In this study, we investigate the potential of using circulating levels of PRO-C3 to mark the degree of vascular stenosis and risk of cardiovascular events., Methods: Baseline plasma levels of PRO-C3 were measured by ELISA in subjects belonging to the SUrrogate markers for Micro- and Macro-vascular hard endpoints for Innovative diabetes Tools (SUMMIT) cohort (N = 1354). Associations between PRO-C3 levels with vascular characteristics, namely stiffness and stenosis, and risk of future cardiovascular events were explored. Subjects were followed up after a median of 35 months (interquartile range 34-36 months), with recorded outcomes cardiovascular death and all-cause mortality., Results: We found a correlation between PRO-C3 levels and pulse wave velocity (rho 0.13, p = 0.000009), a measurement of arterial stiffness. Higher PRO-C3 levels were also associated with elevated blood pressure (rho 0.07, p = 0.014), as well as risk of cardiovascular mortality over a three-year follow-up period (OR 1.56, confidence interval 1.008-2.43, p = 0.046)., Conclusions: Elevated circulating PRO-C3 levels are associated with arterial stiffness and future cardiovascular death, in the SUMMIT cohort, suggesting a potential value of PRO-C3 as a novel marker for declining vascular health., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: FG, SHN and MAK are full-time employees and shareholders at Nordic Bioscience, the company that produces and holds patents for the PRO-C3 assay. All other authors have no conflict of interest to report., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Background: The residual cardiovascular risk in subjects receiving guideline-recommended therapy is related to persistent vascular inflammation and IL-6 represents a target for its treatment. IL-6 binds to receptors on leukocytes and hepatocytes and/or by forming complexes with soluble IL-6 receptors (sIL-6R) binding to gp130 which is present on all cells. Here we aimed to estimate the associations of these two pathways with risk of cardiovascular disease (CVD)., Methods: IL-6 and sIL-6R were analyzed using the proximity extension assay. Baseline plasma samples were obtained from participants in the prospective Malmö Diet and Cancer (MDC) study (n = 4661), the SUMMIT VIP study (n = 1438) and the Carotid Plaque Imaging Project (CPIP, n = 285). Incident clinical events were obtained through national registers. Plaques removed at surgery were analyzed by immunohistochemistry and biochemical methods., Results: During 23.1 ± 7.0 years follow-up, 575 subjects in the MDC cohort suffered a first myocardial infarction. Subjects in the highest tertile of IL-6 had an increased risk compared to the lowest tertile (HR and 95% CI 2.60 [2.08-3.25]). High plasma IL-6 was also associated with more atherosclerosis, increased arterial stiffness, and impaired endothelial function in SUMMIT VIP, but IL-6 was only weakly associated with plaque inflammation in CPIP. sIL-6R showed no independent association with risk of myocardial infarction, atherosclerosis severity or vascular function, but was associated with plaque inflammation., Conclusions: Our findings show that sIL-6R is a poor marker of CVD risk and associated vascular changes. However, the observation that sIL-6R reflects plaque inflammation highlights the complexity of the role of IL-6 in CVD., Competing Interests: Declaration of Competing Interest The authors have no conflict of interest to disclose., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Aims: Transforming growth factor-beta (TGF-β) exists in three isoforms TGF-β1, -β2, and -β3. TGF-β1 has been suggested to be important for maintaining plaque stability, yet the role of TGF-β2 and -β3 in atherosclerosis remains to be investigated.This study explores the association of the three isoforms of TGF-β with plaque stability in the human atherosclerotic disease., Methods and Results: TGF-β1, -β2, and -β3 proteins were quantified in 223 human carotid plaques by immunoassays. Indications for the endarterectomy were: symptomatic carotid plaque with stenosis >70% or without symptoms and >80% stenosis. Plaque mRNA levels were assessed by RNA sequencing. Plaque components and extracellular matrix were measured histologically and biochemically. Matrix metalloproteinases and monocyte chemoattractant protein-1 (MCP-1) was measured with immunoassays. The effect of TGF-β2 on inflammation and protease activity was investigated in vitro using THP-1 and RAW264.7 macrophages. Patients were followed longitudinally for cardiovascular (CV) events.TGF-β2 was the most abundant isoform and was increased at both protein and mRNA levels in asymptomatic plaques. TGF-β2 was the main determinant separating asymptomatic plaques in an Orthogonal Projections to Latent Structures Discriminant Analysis. TGF-β2 correlated positively to features of plaque stability and inversely to markers of plaque vulnerability. TGF-β2 was the only isoform inversely correlated to the matrix-degrading matrix metalloproteinase-9 and inflammation in the plaque tissue. In vitro, TGF-β2 pre-treatment reduced MCP-1 gene and protein levels as well as matrix metalloproteinase-9 gene levels and activity. Patients with plaques with high TGF-β2 levels had a lower risk to suffer from future CV events., Conclusions: TGF-β2 is the most abundant TGF-β isoform in human plaques and may maintain plaque stability by decreasing inflammation and matrix degradation., Competing Interests: Conflict of interest: P.V. is now employed at Data Science and Quantitative Biology, Discovery Sciences, R&D, AstraZeneca and M.C. is employed at GUBRA. The remaining authors have nothing to disclose., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Aims: Recent studies have revealed a close connection between cellular metabolism and the chronic inflammatory process of atherosclerosis. While the link between systemic metabolism and atherosclerosis is well established, the implications of altered metabolism in the artery wall are less understood. Pyruvate dehydrogenase kinase (PDK)-dependent inhibition of pyruvate dehydrogenase (PDH) has been identified as a major metabolic step regulating inflammation. Whether the PDK/PDH axis plays a role in vascular inflammation and atherosclerotic cardiovascular disease remains unclear., Methods and Results: Gene profiling of human atherosclerotic plaques revealed a strong correlation between PDK1 and PDK4 transcript levels and the expression of pro-inflammatory and destabilizing genes. Remarkably, the PDK1 and PDK4 expression correlated with a more vulnerable plaque phenotype, and PDK1 expression was found to predict future major adverse cardiovascular events. Using the small-molecule PDK inhibitor dichloroacetate (DCA) that restores arterial PDH activity, we demonstrated that the PDK/PDH axis is a major immunometabolic pathway, regulating immune cell polarization, plaque development, and fibrous cap formation in Apoe-/- mice. Surprisingly, we discovered that DCA regulates succinate release and mitigates its GPR91-dependent signals promoting NLRP3 inflammasome activation and IL-1β secretion by macrophages in the plaque., Conclusions: We have demonstrated for the first time that the PDK/PDH axis is associated with vascular inflammation in humans and particularly that the PDK1 isozyme is associated with more severe disease and could predict secondary cardiovascular events. Moreover, we demonstrate that targeting the PDK/PDH axis with DCA skews the immune system, inhibits vascular inflammation and atherogenesis, and promotes plaque stability features in Apoe-/- mice. These results point toward a promising treatment to combat atherosclerosis., Competing Interests: Conflict of interest: I.K. reports personal fees from Orion Pharma unrelated to the submitted work. T.W.S. is a co-founder of Embark Biotech; T.W.S. and M.T. are co-founders of SOLID Therapeutics; unrelated to the submitted work. The remaining authors have nothing to disclose., (© The Author(s) 2023. Published by Oxford University Press on behalf of the European Society of Cardiology.)

Background and Aims: Extracellular matrix (ECM) remodeling is one of the key components in the formation of vulnerable atherosclerotic plaques and cardiovascular events. We recently showed that the full-length ECM-proteoglycan osteoglycin was associated with plaque vulnerability and future cardiovascular events. In the present study, we aimed to investigate the association of cleaved osteoglycin with plaque phenotype., Methods: Two-hundred human carotid plaques were analyzed by immunohistochemistry. Cleaved osteoglycin and active caspase-3 were assessed by ELISA. ECM components (collagen, elastin and glycosaminoglycans) were assessed by colorimetric assays in plaque tissue homogenates. Matrix metalloproteinases (MMPs) were assessed using Milliplex. MMP-cleavage of osteoglycin and its effect on apoptosis were studied in vitro. Cardiovascular events were recorded during follow-up using national registries., Results: Plaque levels of cleaved osteoglycin were significantly higher in asymptomatic plaques and correlated to α-actin plaque area, collagen, elastin and inversely to lipids, active. caspase-3 and a histological vulnerability index. Cleaved osteoglycin correlated to several MMPs, especially MMP-12, which was also shown to cleave osteoglycin in vitro. In vitro cleavage of osteoglycin was also associated with less smooth muscle cell apoptosis. Patients with high plaque levels of cleaved osteoglycin had a significantly lower risk to suffer from future cardiovascular events., Conclusions: The current study shows that cleaved osteoglycin is associated with a stable plaque phenotype and lower risk for future cardiovascular events. Potentially due to reduced cell apoptosis and ability to retain LDL. These results indicate that targeting the cleavage of osteoglycin may be a potential therapeutic strategy to stabilize plaques., (Copyright © 2022. Published by Elsevier B.V.)

Background: Stable atherosclerotic plaques are characterized by thick fibrous caps of smooth muscle cells, collagen, and macrocalcifications. Identifying factors of plaque stability is necessary to design drugs to prevent plaque rupture and symptoms. Osteomodulin, originally identified in bones, is expressed by bone synthesizing osteoblasts and involved in mineralization. In the present study, we analyzed osteomodulin expression in human carotid plaques, its link with plaque phenotype, calcification, and future cardiovascular events., Methods: Osteomodulin gene expression (OMD ; n=82) was determined by RNA sequencing and osteomodulin protein levels by immunohistochemistry (n=45) in carotid plaques obtained by endarterectomy from patients with or without cerebrovascular symptoms from the CPIP (Carotid Plaque Imaging Project) cohort, Skåne University Hospital, Sweden. Plaque components were assessed by immunohistochemistry, RNA sequencing, and multiplex analysis. Patients were followed for cardiovascular events or cardiovascular death during a median of 57 or 70 months, respectively, using national registers., Results: OMD levels were increased in plaques from asymptomatic patients compared to symptomatics. High OMD levels were associated with fewer cardiovascular events during follow-up. OMD correlated positively with smooth muscle α-actin ( ACTA2 ; r =0.73, P =10 -13 ) and collagen ( COL1A2 ; r =0.4, P =0.0002), but inversely with CD68 gene expression ( r =-0.67, P =10 -11 ), lipids ( r =-0.37, P =0.001), intraplaque hemorrhage ( r =-0.32, P =0.010), inflammatory cytokine, and matrix metalloproteinase plaque contents. OMD was positively associated with MSX2 (Msh Homeobox 2) ( r =0.32, P =0.003), a marker of preosteoblast differentiation, BMP4 (bone morphogenetic protein) ( r =0.50, P =0.000002) and BMP6 ( r =0.47, P =0.000007), plaque calcification ( r =0.35, P =0.016), and was strongly upregulated in osteogenically stimulated smooth muscle cells, which was further increased upon BMP stimulation. Osteomodulin protein was present in calcified regions. Osteomodulin protein levels were associated with plaque calcification ( r =0.41, P =0.006) and increased in macrocalcified plaques., Conclusions: These data show that osteomodulin mRNA and protein levels are associated with plaque calcification in human atherosclerosis. Furthermore, osteomodulin mRNA, but not protein levels, is associated with plaque stability.

Background The balance between stabilizing and destabilizing atherosclerotic plaque components is used in experimental studies and in imaging studies to identify rupture prone plaques. However, we lack the evidence that this balance predicts future cardiovascular events. Here we explore whether a calculated histological ratio, referred to as vulnerability index (VI), can predict patients at higher risk to suffer from future cardiovascular events. Methods and Results Carotid plaques and clinical information from 194 patients were studied. Tissue sections were used for histological analysis to calculate the VI (CD68 [cluster of differentiation 68], alpha-actin, Oil red O, Movat pentachrome, and glycophorin A). Postoperative cardiovascular events were identified through the Swedish National Inpatient Health Register (2005-2013). During the follow-up (60 months) 45 postoperative cardiovascular events were registered. Patients with a plaque VI in the fourth quartile compared with the first to third quartiles had significantly higher risk to suffer from a future cardiovascular event ( P =0.0002). The VI was an independent predictor and none of the 5 histological variables analyzed separately predicted events. In the 13 patients who underwent bilateral carotid endarterectomy, the VI of the right plaque correlated with the VI of the left plaque and vice versa ( r =0.7, P =0.01). Conclusions Our findings demonstrate that subjects with a high plaque VI have an increased risk of future cardiovascular events, independently of symptoms and other known cardiovascular risk factors . This strongly supports that techniques which image such plaques can facilitate risk stratification for subjects in need of more intense treatment.

Placental growth factor (PlGF) is a mitogen for endothelial cells, but it can also act as a proinflammatory cytokine. Because it promotes early stages of plaque formation in experimental models of atherosclerosis and was implicated in epidemiological associations with risk of cardiovascular disease (CVD), PlGF has been attributed a pro-atherogenic role. Here, we investigated whether PlGF has a protective role in CVD and whether elevated PlGF reflects activation of repair processes in response to vascular stress. In a population cohort of 4742 individuals with 20 years of follow-up, high baseline plasma PlGF was associated with increased risk of cardiovascular death, myocardial infarction, and stroke, but these associations were lost or weakened when adjusting for cardiovascular risk factors known to cause vascular stress. Exposure of cultured endothelial cells to high glucose, oxidized low-density lipoprotein (LDL) or an inducer of apoptosis enhanced the release of PlGF. Smooth muscle cells and endothelial cells treated with PlGF small interference RNA demonstrated that autocrine PlGF stimulation plays an important role in vascular repair responses. High expression of PlGF in human carotid plaques removed at surgery was associated with a more stable plaque phenotype and a lower risk of future cardiovascular events. When adjusting associations of PlGF with cardiovascular risk in the population cohort for plasma soluble tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor-2, a biomarker of cellular stress, a high PlGF/TRAIL receptor-2 ratio was associated with a lower risk. Our findings provide evidence for a protective role of PlGF in CVD., (Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Background and Purpose- Cellular apoptosis is an important feature in atherosclerosis, contributing to necrotic core formation, and plaque vulnerability. Activation of the death receptor TRAIL-R2 (TNF [tumor necrosis factor]-related apoptosis-inducing ligand receptor 2) through its ligand tumor necrosis factor-relate apoptosis-inducing ligand (TRAIL), induces apoptosis in cells in vitro. sTRAIL-R2 (soluble TRAIL-R2) was recently shown to predict cardiovascular events in healthy individuals. In the present study, we explored if plaque levels of sTRAIL-R2 and sTRAIL reflect plaque apoptosis and vulnerability and if plasma levels of these markers predict future events in subjects with advanced atherosclerosis. Methods- Plasma from 558 patients and 202 carotid plaques from the Carotid Plaque Imaging Project biobank were used. sTRAIL-R2, sTRAIL, and caspase-8 levels were assessed using a Proseek Multiplex CVD 96×96 assay. Active caspase-3 was measured using ELISA to assess plaque apoptosis. Plaque morphology was studied by immunohistochemistry. Inflammatory cytokines were assessed by Luminex. mRNA levels were quantified by RNA sequencing. Monocytes, T cells, B cells, and human coronary artery smooth muscle cells were used to study sTRAIL-R2 and sTRAIL release on cell apoptosis and inflammatory stimuli in vitro. Results- Plaque levels of sTRAIL-R2 and sTRAIL correlated to markers of extrinsic induced apoptosis (caspase-3 and -8). sTRAIL-R2 and sTRAIL protein expression were increased in symptomatic carotid plaques and patients with higher plasma levels of sTRAIL-R2 had a higher risk of future cardiovascular events. sTRAIL-R2 and sTRAIL were released upon activation of the extrinsic apoptosis pathway in vitro. sTRAIL-R2 and sTRAIL correlated with inflammatory cytokines, to CD68 expression and inversely to α-actin in the plaque tissue. Conclusions- The present study shows that sTRAIL-R2 and sTRAIL are associated to human plaque cell apoptosis, plaque inflammatory activity, and with symptomatic carotid plaques. Furthermore, high plasma levels of sTRAIL-R2 in plasma predict, independently, future cardiovascular events in individuals with manifest atherosclerotic disease.

Objectives: Autoimmune responses against oxidized-LDL (oxLDL) have been suggested to modulate inflammation in atherosclerosis. Previous studies showed an association between autoantibodies against the apolipoprotein B (apoB) p210 antigen and a lower risk of cardiovascular (CV) events. In the present study we investigated if autoantibodies against p210 at the time of carotid endarterectomy (CEA) predict risk for future CV events., Methods: Native (nat) and malondialdehyde (MDA)-modified apoB p210 autoantibodies (IgM-p210nat, IgG-p210nat, IgM-p210MDA and IgG-p210MDA) were analyzed by ELISA from plasma samples of 351 patients at the time they underwent CEA. The incidence of postoperative CV events was assessed using national registers., Results: A total of 52 non-fatal and 15 fatal CV events were registered during the follow-up period (35.1 ± 16.7 months). Patients who suffered from a fatal CV event had significantly lower plasma levels of IgG-p210nat and IgG-p210MDA. Kaplan-Meier curves of event-free survival showed increased CV mortality in patients with levels of IgG-p210nat and IgG-p210MDA below the median (Log Rank 7.813, p .005 and 9.105, p .003 respectively). The association between low levels of p210 IgG and fatal post-operative CV events remained significant when adjusting for age, sex, total cholesterol, HDL cholesterol, smoking habits and hypertension in a Cox Proportional Hazard model (hazard ratios (HR) IgG-p210nat below median: HR 6.7 (95% C.I. 1.5-30.6, p .013) and IgG-p210MDA below median: HR 7.8 (95% C.I. 1.7-35.5, p .008)., Conclusions: The present findings support the notion that autoantibodies against LDL antigens are involved in the atherosclerotic disease process and suggest that CEA patients with low levels of IgG-p210nat and IgG-p210MDA have an increased risk of post-operative CV death., (Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.)

Background: Apoptosis is central in both diabetes and atherosclerosis, linked to pancreatic beta cell death and plaque progression. Circulating Caspase-3 has also been associated with diabetes and coronary calcium score. Here, we explored if soluble Caspase-3 (sCaspase-3) is associated with cardio-metabolic risk factors and predicts incidence of diabetes and coronary artery disease (CAD).Methods: Clinical data and plasma from 4637 individuals from the Malmö Diet and Cancer cohort were studied. Plasma sCaspase-3 was measured by a Proximity Extension Assay. National registers were used to identify diabetes and CAD events during follow-up. Type 2 diabetes risk variants and expression quantitative trait loci (eQTL) for sCaspase-3 were retrieved from the DIAGRAM consortium and the Genotype-Tissue Expression project.Results: HbA1c was the factor with the strongest association with sCaspase-3 (r = 0.18, P = 1.3x10-36 ). During follow-up 666 individuals developed diabetes and 648 individuals suffered from CAD. Increasing sCaspase-3 was associated with a higher risk of developing diabetes (hazard ratio (HR) 1.18 per 1unit; P = 7 × 10-5 ) and CAD (HR 1.2 per 1 unit, P = 1 × 10-4 ) during follow-up. A genetic variant rs60780116, located upstream of CASP3, showed strong association with type 2 diabetes (OR 1.06, 95%CI 1.04-1.07, P = 8.4 × 10-11 ). An eQTL was identified between this variant and gene expression of CASP3, where the allele positively correlated with type 2 diabetes was associated with increased CASP3 expression in blood.Conclusions: The present study provides evidence for plasma sCaspase-3 as a marker of cardio-metabolic risk factors and as a predictor of future diabetes and CAD in a cohort without cardiovascular disease or diabetes at baseline. [ABSTRACT FROM AUTHOR]

Atherosclerosis is a major underlying cause of cardiovascular disease. Previous studies showed that inhibition of the co-stimulatory CD40 ligand (CD40L)-CD40 signaling axis profoundly attenuates atherosclerosis. As CD40L exerts multiple functions depending on the cell-cell interactions involved, we sought to investigate the function of the most relevant CD40L-expressing cell types in atherosclerosis: T cells and platelets. Atherosclerosis-prone mice with a CD40L-deficiency in CD4+ T cells display impaired Th1 polarization, as reflected by reduced interferon-γ production, and smaller atherosclerotic plaques containing fewer T-cells, smaller necrotic cores, an increased number of smooth muscle cells and thicker fibrous caps. Mice with a corresponding CD40-deficiency in CD11c+ dendritic cells phenocopy these findings, suggesting that the T cell-dendritic cell CD40L-CD40 axis is crucial in atherogenesis. Accordingly, sCD40L/sCD40 and interferon-γ concentrations in carotid plaques and plasma are positively correlated in patients with cerebrovascular disease. Platelet-specific deficiency of CD40L does not affect atherogenesis but ameliorates atherothrombosis. Our results establish divergent and cell-specific roles of CD40L-CD40 in atherosclerosis, which has implications for therapeutic strategies targeting this pathway. Previous studies have shown that the CD40L-CD40 signaling axis plays a role in atherosclerosis. Here the authors investigate the cell-specific functions of the most relevant CD40L-expressing cell types in atherosclerosis. Deficiency of T cell-derived CD40L reduces and stabilizes plaques through impaired Th1 polarization while platelet-derived CD40L ameliorates atherothrombosis. [ABSTRACT FROM AUTHOR]

Background: Type 2 diabetes (T2D) patients are at a greater risk of cardiovascular events due to aggravated atherosclerosis. Oxidized LDL (oxLDL) has been shown to be increased in T2D plaques and suggested to contribute to plaque ruptures. Despite intensified statin treatment during the last decade the higher risk for events remains. Here, we explored if intensified statin treatment was associated with reduced oxLDL in T2D plaques and if oxLDL predicts cardiovascular events, to elucidate whether further plaque oxLDL reduction would be a promising therapeutic target. Methods: Carotid plaque OxLDL levels and plasma lipoproteins were assessed in 200 patients. Plaque oxLDL was located by immunohistochemistry. Plaque cytokines, cells and scavenger receptor gene expression were quantified by Luminex, immunohistochemistry and RNA sequencing, respectively. Clinical information and events during follow-up were obtained from national registers. Results: Plaque oxLDL levels correlated with markers of inflammatory activity, endothelial activation and plasma LDL cholesterol (r = 0.22-0.32 and p ≤ 0.01 for all). T2D individuals exhibited lower plaque levels of oxLDL, sLOX-1(a marker of endothelial activation) and plasma LDL cholesterol (p = 0.001, p = 0.006 and p = 0.009). No increased gene expression of scavenger receptors was identified in T2D plaques. The lower oxLDL content in T2D plaques was associated with a greater statin usage (p = 0.026). Supporting this, a linear regression model showed that statin treatment was the factor with the strongest association to plaque oxLDL and plasma LDL cholesterol (p < 0.001 for both). However, patients with T2D more frequently suffered from symptoms and yet plaque levels of oxLDL did not predict cardiovascular events in T2D (findings are summarized in Fig. 1a). Conclusions: This study points out the importance of statin treatment in affecting plaque biology in T2D. It also implies that other biological components, beyond oxLDL, need to be identified and targeted to further reduce the risk of events among T2D patients receiving statin treatment. [ABSTRACT FROM AUTHOR]

An amendment to this paper has been published and can be accessed via the original article. [ABSTRACT FROM AUTHOR]

Background: Activation of the renin-angiotensin-aldosterone-system (RAAS) has been proposed to contribute to development of vascular complications in type 2 diabetes (T2D). The aim of the present study was to determine if plasma renin levels are associated with the severity of vascular changes in subjects with and without T2D.Methods: Renin was analyzed by the Proximity Extension Assay in subjects with (n = 985) and without (n = 515) T2D participating in the SUMMIT (SUrrogate markers for Micro- and Macro-vascular hard endpoints for Innovative diabetes Tools) study and in 205 carotid endarterectomy patients. Vascular changes were assessed by determining ankle-brachial pressure index (ABPI), carotid intima-media thickness (IMT), carotid plaque area, pulse wave velocity (PWV) and the reactivity hyperemia index (RHI).Results: Plasma renin was elevated in subjects with T2D and demonstrated risk factor-independent association with prevalent cardiovascular disease both in subjects with and without T2D. Renin levels increased with age, body mass index, HbA1c and correlated inversely with HDL. Subjects with T2D had more severe carotid disease, increased arterial stiffness, and impaired endothelial function. Risk factor-independent associations between renin and APBI, bulb IMT, carotid plaque area were observed in both T2D and non-T2D subjects. These associations were independent of treatment with RAAS inhibitors. Only weak associations existed between plasma renin and the expression of pro-inflammatory and fibrous components in plaques from 205 endarterectomy patients.Conclusions: Our findings provide clinical evidence for associations between systemic RAAS activation and atherosclerotic burden and suggest that this association is of particular importance in T2D. [ABSTRACT FROM AUTHOR]

Aims Inflammation is a key factor in the development of plaque rupture and acute cardiovascular events. Although imaging techniques can be used to identify vulnerable atherosclerotic plaques, we are lacking non-invasive methods, such as plasma markers of plaque inflammation that could help to identify presence of vulnerable plaques. The aim of the present study was to investigate whether increased plasma levels of pro-inflammatory cytokines reflects inflammatory activity within atherosclerotic plaques. Methods and results Cytokines were measured using Luminex immunoassay in 200 homogenized plaque extracts and plasma, obtained from 197 subjects undergoing carotid surgery. Plasma levels of macrophage inflammatory protein-1β (MIP-1β), tumor necrosis factor- α (TNF-α) and fractalkine correlated significantly, not only with plaque levels of the same cytokines but also with the abundance of several pro-inflammatory and atherogenic cytokines assessed in plaque tissue. High plasma levels (upper tertile) of MIP-1β, TNF-α and fractalkine identified the presence of a plaque with high inflammation (above median of a score based on the plaque content of MIP-1β, TNF-α, interferon-γ (IFN-γ) and fractalkine) with a sensitivity between 65 and 67% and a specificity between 78 and 83%. Furthermore, this study shows that high plasma levels of MIP-1β, TNF-α and fractalkine predict future transient ischemic attacks. Conclusions Our findings show that the plasma levels of MIP-1β, TNF-α and fractalkine reflect the levels of several pro-atherogenic cytokines in plaque tissue and might be possible plasma markers for a vulnerable atherosclerotic disease. We thereby propose that these cytokines can be used as surrogate markers for the identification of patients with high-risk plaques. [ABSTRACT FROM AUTHOR]

Background The leading cause of morbidity and mortality worldwide is atherosclerotic cardiovascular disease, most commonly caused by rupture of a high-risk plaque and subsequent thrombosis resulting in stroke, myocardial infarction or sudden death depending on the affected arterial territory. Accurate, non-invasive methods to identify such lesions known as vulnerable or high-risk plaques are currently sub-optimal. Our aim was to validate a new non-invasive ultrasound method to identify high-risk carotid plaques. Methods We evaluated a new method based on the center frequency shift (CFS) of the ultrasound radio frequency data obtained from carotid plaques compared to a reference phantom. We evaluated the method both ex vivo , on 157 sections from 18 plaques, and in vivo , in 39 patients 1-day prior to carotid plaque removal, and correlated the data with histology. Results The CFS correlated with a plaque vulnerability index based on histological areas stained for lipids, macrophages, hemorrhage, smooth muscle cells and collagen (r = −0.726, P = 1.7 × 10 −8 ). Plaques with CFS below median had larger cores, more macrophages and were less rich in collagen in agreement with the definition of rupture-prone plaques. The accuracy to detect plaques with high vulnerability index was 78% (confidence interval (CI) 61–89%), with sensitivity 77% (CI 61–89%) and specificity 78% (CI 62–89%). Conclusions Our method is the first to characterize atherosclerotic plaque components that affect plaque vulnerability using CFS. [ABSTRACT FROM AUTHOR]

A vulnerable plaque is an atherosclerotic plaque that is rupture-prone with a higher risk to cause cardiovascular symptoms such as myocardial infarction or stroke. Mimecan or osteoglycin is a small leucine-rich proteoglycan, important for collagen fibrillogenesis, that has been implicated in atherosclerotic disease, yet the role of mimecan in human atherosclerotic disease remains unknown. 196 human atherosclerotic carotid plaques were immunostained for mimecan. Smooth muscle cells, macrophages and intraplaque haemorrhage were also measured with immunohistochemistry. Neutral lipids were stained with Oil Red O and calcium deposits were quantified. Plaque homogenate levels of MCP-1, IL-6 and MIP-1β were measured using a Proximity Extension Assay and MMP-9 levels were measured using Mesoscale. Glycosaminoglycans, collagen and elastin were assessed by colorimetric assays and TGF-β1, β2 and β3 were measured using a multiplex assay. Mimecan gene expression in THP-1 derived macrophages was quantified by qPCR and protein expression in vitro was visualized with immunofluorescence. Cardiovascular events were registered using medical charts and national registers during follow-up. Mimecan correlated positively with plaque area of lipids, macrophages, intraplaque haemorrhage and inversely with smooth muscle cell staining. Mimecan also correlated positively with plaque levels of MMP-9 and MCP-1. Mimecan was upregulated in THP-1 derived macrophages upon stimulation with MCP-1. Patients with high levels of mimecan (above median) had higher risk for cardiovascular death. This study indicates that mimecan is associated with a vulnerable plaque phenotype, possibly regulated by plaque inflammation. In line, plaque levels of mimecan independently predict future cardiovascular death. Image 1 • Mimecan correlates with vulnerable histological features in human carotid plaques. • Mimecan correlates with extracellular matrix degrading enzyme MMP-9. • In vitro stimulation with MCP-1 increases mimecan expression in macrophages. • High levels of mimecan in carotid plaques predict future cardiovascular death. [ABSTRACT FROM AUTHOR]