Accumulation of Iron Oxide-Based Contrast Agents in Rabbit Atherosclerotic Plaques in Relation to Plaque Age and Vulnerability Features.

Purpose: In this study, a detailed characterization of a rabbit model of atherosclerosis was performed to assess the optimal time frame for evaluating plaque vulnerability using superparamagnetic iron oxide nanoparticle (SPION)-enhanced magnetic resonance imaging (MRI). Methods: The progression of atherosclerosis induced by ballooning and a high-cholesterol diet was monitored using angiography, and the resulting plaques were characterized using immunohistochemistry and histology. Morphometric analyses were performed to evaluate plaque size and vulnerability features. The accumulation of SPIONs (novel dextran-coated SPIONDex and ferumoxytol) in atherosclerotic plaques was investigated by histology and MRI and correlated with plaque age and vulnerability. Toxicity of SPIONDex was evaluated in rats. Results: Weak positive correlations were detected between plaque age and intima thickness, and total macrophage load. A strong negative correlation was observed between the minimum fibrous cap thickness and plaque age as well as the mean macrophage load. The accumulation of SPION in the atherosclerotic plaques was detected by MRI 24 h after administration and was subsequently confirmed by Prussian blue staining of histological specimens. Positive correlations between Prussian blue signal in atherosclerotic plaques, plaque age, and macrophage load were detected. Very little iron was observed in the histological sections of the heart and kidney, whereas strong staining of SPIONDex and ferumoxytol was detected in the spleen and liver. In contrast to ferumoxytol, SPIONDex administration in rabbits was well tolerated without inducing hypersensitivity. The maximum tolerated dose in rat model was higher than 100 mg Fe/kg. Conclusion: Older atherosclerotic plaques with vulnerable features in rabbits are a useful tool for investigating iron oxide-based contrast agents for MRI. Based on the experimental data, SPIONDex particles constitute a promising candidate for further clinical translation as a safe formulation that offers the possibility of repeated administration free from the risks associated with other types of magnetic contrast agents.

Dual action of macrophage miR-204 confines cyclosporine A-induced atherosclerosis.

BACKGROUND AND PURPOSE: Atherosclerosis induced by cyclosporine A (CsA), an inhibitor of the calcineurin/nuclear factor of activated T cells (NFAT) pathway, is a major concern after organ transplantation. However, the atherosclerotic mechanisms of CsA remain obscure. We previously demonstrated that calcineurin/NFAT signalling inhibition contributes to atherogenesis via suppressing microRNA-204 (miR-204) transcription. We therefore hypothesised that miR-204 is involved in the development of CsA-induced atherosclerosis. EXPERIMENTAL APPROACH: ApoE-/- mice with macrophage-miR-204 overexpression were generated to determine the effects of miR-204 on CsA-induced atherosclerosis. Luciferase reporter assays and chromatin immunoprecipitation sequencing were performed to explore the targets mediating miR-204 effects. KEY RESULTS: CsA alone did not significantly affect atherosclerotic lesions or serum lipid levels. However, it exacerbated high-fat diet-induced atherosclerosis and hyperlipidemia in C57BL/6J and ApoE-/- mice, respectively. miR-204 levels decreased in circulating monocytes and plaque lesions during CsA-induced atherosclerosis. The upregulation of miR-204 in macrophages inhibited CsA-induced atherosclerotic plaque formation but did not affect serum lipid levels. miR-204 limited the CsA-induced foam cell formation by reducing the expression of the scavenger receptors SR-BII and CD36. SR-BII was post-transcriptionally regulated by mature miR-204-5p via 3'-UTR targeting. Additionally, nuclear-localised miR-204-3p prevented the CsA-induced binding of Ago2 to the CD36 promoter, suppressing CD36 transcription. SR-BII or CD36 expression restoration dampened the beneficial effects of miR-204 on CsA-induced atherosclerosis. CONCLUSION AND IMPLICATIONS: Macrophage miR-204 ameliorates CsA-induced atherosclerosis, suggesting that miR-204 may be a potential target for the prevention and treatment of CsA-related atherosclerotic side effects.

In vitro and in vivo approaches to assess atherosclerosis following exposure to low-dose mixtures of arsenic and cadmium.

Worldwide, millions of people are co-exposed to arsenic and cadmium. Environmental exposure to both metals is linked with a higher risk of atherosclerosis. While studies have characterized the pro-atherosclerotic effects of arsenic and cadmium as single agents, little is known about the potential effects of metal mixtures, particularly at low doses. Here, we used a combination of in vitro and in vivo models to assess the effects of low-dose metals individually and as mixtures on early events and plaque development associated with atherosclerosis. In vitro, we investigated early pro-atherogenic changes in macrophages and endothelial cells with metal treatments. The combined cytotoxic effects of both metals at low concentrations were dose interactive, specifically, synergistic in macrophages, but antagonistic in endothelial cells. Despite this differential behavior across cell types, the mixtures did not initiate early pro-atherogenic events: neither reactive oxygen species generation in macrophages nor adhesion molecule expression on endothelial cells. In vivo, we utilized the well-characterized hyperlipidemic apolipoprotein E knock-out (ApoE-/-) mouse model. Previously, we have shown that low concentrations of arsenic (down to 10 ppb) enhance atherosclerosis in ApoE-/- mice. This model has also been used with cadmium to demonstrate pro-atherogenic effects, although at concentrations above human-relevant exposures. In both sexes, there are some small increases in atherosclerotic lesion size, but very few changes in plaque constituents in the ApoE-/- mouse model. Together, these results suggests that low-dose metal mixtures are not significantly more pro-atherogenic than either metal alone.

Alirocumab and plaque volume, calf muscle blood flow, and walking performance in peripheral artery disease: A randomized clinical trial.

BACKGROUND: The distal superficial femoral artery (SFA) is most commonly affected in peripheral artery disease (PAD). The effects of the proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitor alirocumab added to statin therapy on SFA atherosclerosis, downstream flow, and walking performance are unknown. METHODS: Thirty-five patients with PAD on maximally tolerated statin therapy were recruited. Patients were randomized to alirocumab 150 mg subcutaneously (n = 18) or matching placebo (n = 17) therapy every 2 weeks for 1 year. The primary outcome was change in SFA plaque volume by black blood magnetic resonance imaging (MRI). Secondary outcomes were changes in calf muscle perfusion by cuff/occlusion hyperemia arterial spin labeling MRI, 6-minute walk distance (6MWD), low-density lipoprotein (LDL) cholesterol, and other biomarkers. RESULTS: Age (mean ± SD) was 64 ± 8 years, 20 (57%) patients were women, 17 (49%) were Black individuals, LDL was 107 ± 36 mg/dL, and the ankle-brachial index 0.71 ± 0.20. The LDL fell more with alirocumab than placebo (mean [95% CI]) (-49.8 [-66.1 to -33.6] vs -7.7 [-19.7 to 4.3] mg/dL; p < 0.0001). Changes in SFA plaque volume and calf perfusion showed no difference between groups when adjusted for baseline (+0.25 [-0.29 to 0.79] vs -0.04 [-0.47 to 0.38] cm3; p = 0.37 and 0.22 [-8.67 to 9.11] vs 3.81 [-1.45 to 9.08] mL/min/100 g; p = 0.46, respectively), nor did 6MWD. CONCLUSION: In this exploratory study, the addition of alirocumab therapy to statins did not alter SFA plaque volume, calf perfusion or 6MWD despite significant LDL lowering. Larger studies with longer follow up that include plaque characterization may improve understanding of the effects of intensive LDL-lowering therapy in PAD (ClinicalTrials.gov Identifier: NCT02959047).

Efficacy of Treatment with and without Initial Clopidogrel Loading in Branch Atheromatous Disease.

Objective Despite aggressive therapeutic interventions during the acute phase of branch atheromatous disease (BAD)-type cerebral infarction, many patients, even those with a mild condition at the onset, experience neurological deterioration after hospitalization and develop serious deficits. We compared the therapeutic efficacy of multiple antithrombotic therapies for BAD between patients who received a clopidogrel loading dose (loading group; LG) and those without loading (non-loading group; NLG). Patients Between January 2019 and May 2022, patients with BAD-type cerebral infarction in the lenticulostriate artery admitted within 24 h of the onset were recruited. This study included 95 consecutive patients who received combination argatroban and dual antiplatelet therapy (aspirin and clopidogrel). Methods Patients were classified into the LG and NLG according to whether or not a loading dose of clopidogrel (300 mg) had been administered on admission. Changes in neurological severity [National Institutes of Health Stroke Scale (NIHSS) score] during the acute phase were retrospectively evaluated. Results There were 34 (36%) and 61 (64%) patients in the LG and NLG, respectively. On admission, the median NIHSS score was similar between the groups [LG: 2.5 (2-4) vs. NLG: 3 (2-4), p=0.771]. At 48 h following admission, the median NIHSS scores were 1 (0.25-4), and 2 (1-5) in the LG and NLG, respectively (p=0.045). Early neurological deterioration (END; defined as worsening of the NIHSS score by ≥4 points at 48 h after admission) occurred in 3% of LG and 20% of NLG patients (p=0.028). Conclusion Administration of a clopidogrel loading dose with combination antithrombotic therapy for BAD reduced END.

Cadmium contributes to atherosclerosis by affecting macrophage polarization.

Chronic cadmium (Cd) exposure contributes to the progression of atherosclerosis, but the direct role of Cd and its mechanisms in atherosclerosis remains incompletely understood. Atherosclerosis is a chronic inflammatory disease promoting macrophage polarization to M1 phenotype and producing pro-inflammations that are vital in regulating the inflammatory response. Herein, through a case-control study, we found that Cd exposure may promote the occurrence of carotid plaque via inflammation, where interleukin-6 (IL-6) may play an important role. We also combined in vivo and in vitro experiments to explore the underlying mechanism of Cd-promoted plaque formation and the production of IL-6. With or without cadmium chloride (CdCl2) fed ApoE-/- mouse and treated RAW264.7 cells, we found Cd accumulated in the aortas which significantly increased the plaque area in atherosclerotic mice, macrophage accumulation, and lipid accumulation, and Cd promoted M1 phenotype macrophage polarization reflected by the increased expression of CD86 which produced tumor necrosis factor-α (TNF-α) and IL-6. However, the influences on M2 phenotype and anti-inflammatory cytokines interleukin-4 (IL-4) and interferon-γ (IFN-γ) were non-significant. Moreover, we found that JAK2/STAT3 pathway was greatly activated in the plaques and CdCl2-treated macrophages. The inhibition of JAK2/STAT3 substantially reversed the Cd-stimulated macrophage M1 phenotype macrophage polarization and the expression of pro-inflammatory cytokines including TNF-α and IL-6. Altogether, Cd intensifies atherosclerosis by modulating macrophage polarization via JAK2/STAT3 to up-regulated the expression of IL-6.

The Impact of Cytokines in Coronary Atherosclerotic Plaque: Current Therapeutic Approaches.

Coronary atherosclerosis is a chronic pathological process that involves inflammation together with endothelial dysfunction and lipoprotein dysregulation. Experimental studies during the past decades have established the role of inflammatory cytokines in coronary artery disease, namely interleukins (ILs), tumor necrosis factor (TNF)-α, interferon-γ, and chemokines. Moreover, their value as biomarkers in disease development and progression further enhance the validity of this interaction. Recently, cytokine-targeted treatment approaches have emerged as potential tools in the management of atherosclerotic disease. IL-1ß, based on the results of the CANTOS trial, remains the most validated option in reducing the residual cardiovascular risk. Along the same line, colchicine was also proven efficacious in preventing major adverse cardiovascular events in large clinical trials of patients with acute and chronic coronary syndrome. Other commercially available agents targeting IL-6 (tocilizumab), TNF-α (etanercept, adalimumab, infliximab), or IL-1 receptor antagonist (anakinra) have mostly been assessed in the setting of other inflammatory diseases and further testing in atherosclerosis is required. In the future, potential targeting of the NLRP3 inflammasome, anti-inflammatory IL-10, or atherogenic chemokines could represent appealing options, provided that patient safety is proven to be of no concern.

Cholesterol crystals and atherosclerotic plaque instability: Therapeutic potential of Eicosapentaenoic acid.

Atherosclerotic plaques associated with acute coronary syndromes (ACS), i.e. culprit lesions, frequently feature a ruptured fibrous cap with thrombotic complications. On imaging, these plaques exhibit a low attenuation, lipid-rich, necrotic core containing cholesterol crystals and are inherently unstable. Indeed, cholesterol crystals are causally associated with plaque vulnerability in vivo; their formation results from spontaneous self-assembly of cholesterol molecules. Cholesterol homeostasis is a central determinant of the physicochemical conditions leading to crystal formation, which are favored by elevated membrane free cholesterol content in plaque endothelial cells, smooth muscle cells, monocyte-derived macrophages, and foam cells, and equally by lipid oxidation. Emerging evidence from imaging trials in patients with coronary heart disease has highlighted the impact of intervention involving the omega-3 fatty acid, eicosapentaenoic acid (EPA), on vulnerable, low attenuation atherosclerotic plaques. Thus, EPA decreased features associated with unstable plaque by increasing fibrous cap thickness in statin-treated patients, by reducing lipid volume and equally attenuating intraplaque inflammation. Importantly, atherosclerotic plaques rapidly incorporate EPA; indeed, a high content of EPA in plaque tissue is associated with decreased plaque inflammation and increased stability. These findings are entirely consistent with the major reduction seen in cardiovascular events in the REDUCE-IT trial, in which high dose EPA was administered as its esterified precursor, icosapent ethyl (IPE); moreover, clinical benefit was proportional to circulating EPA levels. Eicosapentaenoic acid is efficiently incorporated into phospholipids, where it modulates cholesterol-enriched domains in cell membranes through physicochemical lipid interactions and changes in rates of lipid oxidation. Indeed, biophysical analyses indicate that EPA exists in an extended conformation in membranes, thereby enhancing normal cholesterol distribution while reducing propagation of free radicals. Such effects mitigate cholesterol aggregation and crystal formation. In addition to its favorable effect on cholesterol domain structure, EPA/IPE exerts pleiotropic actions, including antithrombotic, antiplatelet, anti-inflammatory, and proresolving effects, whose plaque-stabilizing potential cannot be excluded. Docosahexaenoic acid is distinguished from EPA by a higher degree of unsaturation and longer carbon chain length; DHA is thus predisposed to changes in its conformation with ensuing increase in membrane lipid fluidity and promotion of cholesterol aggregation into discrete domains. Such distinct molecular effects between EPA and DHA are pronounced under conditions of high cellular cholesterol content and oxidative stress. This review will focus on the formation and role of cholesterol monohydrate crystals in destabilizing atherosclerotic plaques, and on the potential of EPA as a therapeutic agent to attenuate the formation of deleterious cholesterol membrane domains and of cholesterol crystals. Such a therapeutic approach may translate to enhanced plaque stability and ultimately to reduction in cardiovascular risk.

Reducing residual cardiovascular risk in Europe: Therapeutic implications of European medicines agency approval of icosapent ethyl/eicosapentaenoic acid.

Atherosclerotic cardiovascular disease (ASCVD) and its atherothrombotic complications impose a substantial disease burden in Europe, representing a cost of €210 billion per year for the European Union. Hypertriglyceridemia, a major risk factor for premature ASCVD, is present in more than 20% of the European population, and is a key feature of atherogenic dyslipidemia. Recent findings from the Progression of Early Subclinical Atherosclerosis (PESA) cohort in Spain showed that even in apparently healthy, middle-aged individuals without a history of cardiovascular (CV) risk, elevated triglyceride levels are associated with subclinical atherosclerosis and arterial inflammation. Emerging evidence from epidemiologic and genetic studies supports an independent causative role of triglycerides, triglyceride-rich lipoproteins, and their remnants in this pathology. Icosapent ethyl (IPE) is a highly purified, stable ethyl ester of eicosapentaenoic acid (EPA) that was initially approved by the United States Food and Drug Administration to treat severe hypertriglyceridemia, and subsequently received an expanded indication to reduce the risk of CV events in adult statin-treated patients. Approval was based on the pivotal, randomized, placebo-controlled, double-blind Reduction of Cardiovascular Events with Icosapent Ethyl-Intervention Trial (REDUCE-IT), which showed that high-dose IPE (4 g/day) significantly reduced the risk of primary and secondary composite endpoints comprising major CV events and CV death relative to placebo. In 2021, the European Medicines Agency (EMA) approved IPE to reduce the risk of CV events in adult statin-treated patients at high CV risk with elevated triglyceride levels (≥1.7 mmol/L [≥150 mg/dL]) and established CV disease, or diabetes and at least one other CV risk factor. Clinical studies in Europe, which included patients with acute myocardial infarction, coronary artery disease, and those undergoing cardiac rehabilitation, established that 12.5% to 23.3% of these high-risk populations may benefit from treatment with IPE. Such clinical benefit may in part result from the moderate triglyceride-lowering properties of IPE/EPA; equally however, concentrations of atherogenic remnant particle-cholesterol are markedly reduced. Furthermore, IPE/EPA exerts pleiotropic actions beyond its lipid-lowering properties, which include modulation of endothelial function, attenuation of intra-plaque inflammation and oxidative stress, and reduction in macrophage accumulation. Plasma phospholipids, into which EPA is primarily incorporated and transported, appear to serve as precursors for a series of anti-inflammatory metabolites involving the resolvins RvE1 to RvE3, a pathway which may confer cardioprotective benefits. In addition, plaque imaging data from the Effect of Icosapent Ethyl on Progression of Coronary Atherosclerosis in Patients With Elevated Triglycerides on Statin Therapy (EVAPORATE) and the Combination Therapy of Eicosapentaenoic Acid and Pitavastatin for Coronary Plaque Regression Evaluated by Integrated Backscatter Intravascular Ultrasonography (CHERRY) trials show that plaque stabilization may be favorably affected. These factors may act synergistically to stabilize atherosclerotic plaques and reduce CV risk. In addition to robust efficacy data, multiple cost-utility studies across several countries indicate that IPE/EPA is a cost-effective treatment option that is favorably situated relative to some common willingness-to-pay thresholds. This review will evaluate the relevance of hypertriglyceridemia to residual ASCVD burden in statin-treated dyslipidemic patients, the potential of IPE/EPA to reduce the risk of ASCVD and cardiovascular mortality in high-risk patient populations, and the mechanisms which may underlie these effects. Finally, the clinical implications of the EMA label for IPE will be critically appraised in light of the updated 2019 European Society of Cardiology/European Atherosclerosis Society guidelines on the management of dyslipidemia and the recent European Atherosclerosis Society consensus statement on triglyceride-rich lipoproteins and their remnants, together with considerations of its cost-effectiveness across several countries.

Long-term exposure to particulate air pollution and presence and progression of carotid artery plaques - A northern Sweden VIPVIZA cohort study.

AIMS: To estimate the association between long-term exposure to particulate air pollution and sub-clinical atherosclerosis based on the existence of plaque and the carotid intima-media thickness (cIMT). METHODS: Visualization of asymptomatic atherosclerotic disease for optimum cardiovascular prevention (VIPVIZA) is a randomised controlled trial integrated within the Västerbotten Intervention Programme, an ongoing population-based cardiovascular disease (CVD) prevention programme in northern Sweden. Individuals aged 40, 50, or 60 years with one or more conventional CVD risk factors in Umeå municipality were eligible to participate. The 1425 participants underwent an ultrasound assessment of cIMT and plaque formation during the period 2013-2016 and at 3-year follow-up. Source-specific annual mean concentrations of particulate matter with aerodynamic diameter ≤10 µm (PM10) and ≤2.5 µm (PM2.5), and black carbon (BC) at the individual's residential address were modelled for the calendar years 1990, 2001 and 2011. Poisson regression was used to estimate prevalence ratios for presence of carotid artery plaques, and linear regression for cIMT. RESULTS: The plaque prevalence was 43% at baseline and 47% at follow-up. An interquartile range (IQR) increase in PM10 (range in year 2011: 7.1-13.5 µg/m3) was associated with a prevalence ratio at baseline ultrasound of 1.11 (95% CI 0.99-1.25), 1.08 (95% CI 0.99-1.17), and 1.00 (95% CI 0.93-1.08) for lag 23, 12 and 2 years, and at follow-up 1.04 (95% CI 0.95-1.14), 1.08 (95% CI 1.00-1.16), and 1.01 (95% CI 0.95-1.08). Similar prevalence ratios per IQR were found for PM2.5 and BC, but with somewhat lower precision for the later. Particle concentrations were however not associated with the progression of plaque. No cross-sectional or longitudinal associations of change were found for cIMT. CONCLUSIONS: This study of individuals with low/moderate risk for CVD give some additional support for an effect of long-term air pollution in early subclinical atherosclerosis.

Pitavastatin: Coronary Atherosclerotic Plaques Changes and Cardiovascular Prevention.

Stains remain the first therapeutic approach in patients with dyslipidemia to control plasma lipids levels and cardiovascular risk. Multiple clinical trials have demonstrated the benefits of statins in reducing major cardiovascular adverse events in primary and secondary prevention. Moreover, in patients with coronary artery disease, statins decrease coronary atherosclerotic plaque volume and composition, inducing atheroma stabilization. Pitavastatin, is a new-generation lipophilic statin, indicated for the treatment of dyslipidemia and prevention of cardiovascular diseases. The purpose of this review, the first at our knowledge on this topic, is to summarize and examine the current knowledge about the effectiveness of pitavastatin in patients with coronary artery disease. The available data suggest that pitavastatin significantly, lowers the rate of adverse cardiovascular events, in patients at a high risk of atherosclerotic disease, with stable angina pectoris or with acute coronary syndrome. Moreover intravascular ultrasound have shown that pitavastatin induces favorable changes in plaque morphology, increasing the fibrous cap thickness, and decreasing both plaque and lipid volume indexes. Globally the efficacy of pitavastatin is greater or similar to other statins.

TCDD aggravates the formation of the atherosclerotic plaque in ApoE KO mice with a sexual dimorphic pattern.

Aryl hydrocarbon receptor (AhR) ligands are recognized as aggravating factors in cardiovascular diseases but little is known about the role of the AhR in atherosclerosis considering the effects of age and gender. We exposed male and female ApoE knock-out mice, a model to study the pathogenesis of atherosclerosis, to a potent AhR ligand, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) by an intraperitoneal injection of 1 µg/kg/week for 8 weeks. Atherosclerotic lesions, histological parameters and critical atherosclerotic markers in aorta were analysed. TCDD increased atherogenic lesions in 35-week old female mice, leading to a switch of vascular smooth muscle cells (VSMCs) from a contractile to a pro-atherogenic phenotype and increased expression for VCAM1. AhR activation accelerates the formation of atherosclerotic plaques with sex and age differences due to the phenotypical switch of VSMCs.

Transient central retina artery occlusion in patients undergoing intravitreal anti vegf injections.

PURPOSE: To evaluate the occurrence of transient central retinal artery occlusion following intravitreal anti-vascular endothelial growth factor injection. METHODS: Prospective, observational study of 807 patients (807 eyes) who were given intravitreal injections of ranibizumab or aflibercept to treat any cause of retinal vascular diseases between 1 January 2017 and 30 November 2018 at the Federal Fluminense University Hospital in Niteroi, and a private facility in Rio de Janeiro, Brazil. Patients who did not present transient central retinal artery occlusion were excluded. RESULTS: Among 4069 injections, only 18 patients (0.44%) presented transient central retinal artery occlusion, 14 mild cases (77.7%), and 4 severe cases (22.3%). The clinical factors associated with more severe cases of transient central retinal artery occlusion were the duration of the transient central retinal artery occlusion (p = 0.001), number of prior injections (p = 0.01), and a positive carotid Doppler test (p = 0.01). Twelve cases (66.6%) had positive carotid artery obstruction (atheroma plaque size ≥70%) while 6 cases (33.3%) had negative carotid artery obstruction (atheroma plaque size <70%). The age group >60 years old (p = 0.06), cup/disc ratio >0.6 (p = 0.06), and pseudophakic lens status were also factors with association with transient central retinal artery occlusion, although did not meet criteria for statistical significance. The only patient who experienced a recurrent episode of transient central retinal artery occlusion had diabetic macular edema, positive carotid Doppler test, and cup/optic disc ratio >0.6. CONCLUSION: Transient central retinal artery occlusion is a rare adverse event that can appear in patients with retinal vascular disease receiving anti-vascular endothelial growth factor therapy. The atheroma plaque size and the number of prior injections can be associated with the severity of the event.

Cumulative exposure amount of PM2.5 in the ambient air is associated with coronary atherosclerosis - Serial coronary CT angiography study.

BACKGROUND: We investigated the change of coronary atherosclerosis with long-term exposure to fine particulate matter of aerodynamic diameter <2.5 â€‹µm (PM2.5) using coronary computed tomography angiography (CCTA). METHODS: Subjects undergoing serial CCTAs between January 2007 and December 2017 (n â€‹= â€‹3,127) were analyzed. Each individual's cumulative amount of PM2.5 exposure between the two CCTAs was evaluated by Kriging interpolation and zonal analysis, considering the time interval between the two CCTAs. The main outcome was progression of coronary artery calcium (CAC) with additional semiquantitative analysis on the changes in the severity and composition of atherosclerotic plaques. RESULTS: The CAC scores increased by 30.8 Agatston units per-year under a median PM2.5 concentration 24.9 â€‹µg/m3 and tended to increase with the cumulative amount of PM2.5 exposure (r â€‹= â€‹0.321, p â€‹<0.001). The CAC progressed in 1,361 (43.5%) subjects during a median 53 months follow-up. The cumulative amount of PM2.5 exposure was independently associated with CAC progression (adjusted OR 1.09, p â€‹<0.001). By random forest analysis, the relative impact of cumulative amount of PM2.5 exposure on CAC progression was higher than that of traditional cardiovascular risk factors and the average concentration of PM2.5. The extent of coronary atherosclerosis and newly developed calcified plaque on follow-up were also significantly associated with the cumulative amount of PM2.5 exposure. CONCLUSIONS: Cumulative exposure to air pollution is associated with the progression of diffuse coronary calcification, the importance of which may be more significant than other traditional cardiovascular risk factors. Further investigations into the causality between PM2.5 and coronary atherosclerosis are warranted to improve global cardiovascular health.

Near-Infrared Fluorescence Imaging of Carotid Plaques in an Atherosclerotic Murine Model.

Successful imaging of atherosclerosis, one of the leading global causes of death, is crucial for diagnosis and intervention. Near-infrared fluorescence (NIRF) imaging has been widely adopted along with multimodal/hybrid imaging systems for plaque detection. We evaluate two macrophage-targeting fluorescent tracers for NIRF imaging (TLR4-ZW800-1C and Feraheme-Alexa Fluor 750) in an atherosclerotic murine cohort, where the left carotid artery (LCA) is ligated to cause stenosis, and the right carotid artery (RCA) is used as a control. Imaging performed on dissected tissues revealed that both tracers had high uptake in the diseased vessel compared to the control, which was readily visible even at short exposure times. In addition, ZW800-1C's renal clearance ability and Feraheme's FDA approval puts these two tracers in line with other NIRF tracers such as ICG. Continued investigation with these tracers using intravascular NIRF imaging and larger animal models is warranted for clinical translation.

Immune checkpoint inhibitor cardiotoxicity: Breaking barriers in the cardiovascular immune landscape.

Immune checkpoint inhibitors (ICI) have changed the landscape of cancer therapy, but their use carries a high risk of cardiac immune related adverse events (iRAEs). With the expanding utilization of ICI therapy, there is a growing need to understand the underlying mechanisms behind their anti-tumor activity as well as their immune-mediated toxicities. In this review, we will focus on clinical characteristics and immune pathways of ICI cardiotoxicity, with an emphasis on single-cell technologies used to gain insights in this field. We will focus on three key areas of ICI-mediated immune pathways, including the anti-tumor immune response, the augmentation of the immune response by ICIs, and the pathologic "autoimmune" response in some individuals leading to immune-mediated toxicity, as well as local factors in the myocardial immune environment predisposing to autoimmunity. Discerning the underlying mechanisms of these immune pathways is necessary to inform the development of targeted therapies for ICI cardiotoxicities and reduce treatment related morbidity and mortality.

Sex-Specific Effects of Prenatal and Early Life Inorganic and Methylated Arsenic Exposure on Atherosclerotic Plaque Development and Composition in Adult ApoE-/- Mice.

BACKGROUND: Epidemiologic studies indicate that early life arsenic exposures are linked to an increased risk of cardiovascular diseases. Different oxidation and methylation states of arsenic exist in the environment and are formed in vivo via the action of arsenic (+3 oxidation state) methyltransferase (As3MT). Methylated arsenicals are pro-atherogenic postnatally, but pre- and perinatal effects are unclear. This is particularly important because methylated arsenicals are known to cross the placenta. OBJECTIVES: We tested the effects of early life exposure to inorganic and methylated arsenicals on atherosclerotic plaque formation and its composition in apolipoprotein E knock-out (apoE-/-) mice and evaluated whether apoE-/- mice lacking As3MT expression were susceptible to this effect. METHODS: We exposed apoE-/- or apoE-/-/As3MT-/- mice to 200 ppb inorganic or methylated arsenic in the drinking water from conception to weaning and assessed atherosclerotic plaques in the offspring at 18 wk of age. Mixed regression models were used to estimate the mean difference in each outcome relative to controls, adjusting for sex and including a random effects term to account for within-litter clustering. RESULTS: Early life exposure to inorganic arsenic, and more profoundly methylated arsenicals, resulted in significantly larger plaques in the aortic arch and sinus in both sexes. Lipid levels in these plaques were higher without a substantial difference in macrophage numbers. Smooth muscle cell content was not altered, but collagen content was lower. Importantly, there were sex-specific differences in these observations, where males had higher lipids and lower collagen in the plaque, but females did not. In mice lacking As3MT, arsenic did not alter the plaque size, although the size was highly variable. In addition, control apoE-/-/As3MT-/- mice had significantly larger plaque size compared with control apoE-/-. CONCLUSION: This study shows that early life exposure to inorganic and methylated arsenicals is pro-atherogenic with sex-specific differences in plaque composition and a potential role for As3MT in mice. https://doi.org/10.1289/EHP8171.

Atorvastatin pleiotropically decreases intraplaque angiogenesis and intraplaque haemorrhage by inhibiting ANGPT2 release and VE-Cadherin internalization.

OBJECTIVE: Statins pleiotropically provide additional benefits in reducing atherosclerosis, but their effects on intraplaque angiogenesis (IPA) and hemorrhage (IPH) remain unclear. Therefore, we discriminated statin's lipid-lowering dependent and independent effects on IPA and IPH. APPROACH AND RESULTS: ApoE3*Leiden mice are statin-responsive due to ApoE and LDLR presence, but also allow to titrate plasma cholesterol levels by diet. Therefore, ApoE3*Leiden mice were fed a high-cholesterol-inducing-diet (HCD) with or without atorvastatin (A) or a moderate-cholesterol-inducing-diet (MCD). Mice underwent vein graft surgery to induce lesions with IPA and IPH. Cholesterol levels were significantly reduced in MCD (56%) and HCD + A (39%) compared to HCD with no significant differences between MCD and HCD + A. Both MCD and HCD + A have a similar reduction in vessel remodeling and inflammation comparing to HCD. IPA was significantly decreased by 30% in HCD + A compared to HCD or MCD. Atorvastatin treatment reduced the presence of immature vessels by 34% vs. HCD and by 25% vs. MCD, resulting in a significant reduction of IPH. Atorvastatin's anti-angiogenic capacity was further illustrated by a dose-dependent reduction of ECs proliferation and migration. Cultured mouse aortic-segments lost sprouting capacity upon atorvastatin treatment and became 30% richer in VE-Cadherin expression and pericyte coverage. Moreover, Atorvastatin inhibited ANGPT2 release and decreased VE-Cadherin(Y685)-phosphorylation in ECs. CONCLUSIONS: Atorvastatin has beneficial effects on vessel remodeling due to its lipid-lowering capacity. Atorvastatin has strong pleiotropic effects on IPA by decreasing the number of neovessels and on IPH by increasing vessel maturation. Atorvastatin improves vessel maturation by inhibiting ANGPT2 release and phospho(Y658)-mediated VE-Cadherin internalization.

Effect of oxytocin on lipid accumulation under inflammatory conditions in human macrophages.

INTRODUCTION AND AIMS: Oxytocin (OT) is a neuropeptide hormone secreted by the posterior pituitary gland. Deficits in OT action have been observed in patients with behavioral and mood disorders, some of which correlate with an increased risk of cardiovascular disease (CVD). Recent research has revealed a wider systemic role that OT plays in inflammatory modulation and development of atherosclerotic plaques. This study investigated the role that OT plays in cholesterol transport and foam cell formation in LPS-stimulated THP-1 human macrophages. METHODS: THP-1 differentiated macrophages were treated with media, LPS (100 ng/ml), LPS + OT (10 pM), or LPS + OT (100 pM). Changes in gene expression and protein levels of cholesterol transporters were analyzed by real time quantitative PCR (RT-qPCR) and Western blot, while oxLDL uptake and cholesterol efflux capacity were evaluated with fluorometric assays. RESULTS: RT-qPCR analysis revealed a significant increase in ABCG1 gene expression upon OT + LPS treatment, compared to LPS alone (p = 0.0081), with Western blotting supporting the increase in expression of the ABCG1 protein. Analysis of oxLDL uptake showed a significantly lower fluorescent value in LPS + OT (100pM) -treated cells when compared to LPS alone (p < 0.0001). While not statistically significant (p = 0.06), cholesterol efflux capacity increased with LPS + OT treatment. CONCLUSION: We demonstrate here that OT can attenuate LPS-mediated lipid accumulation in THP-1 macrophages. These findings support the hypothesis that OT could be used to reduce pro-inflammatory and potentially atherogenic changes observed in patients with heightened CVD risk. This study suggests further exploration of OT effects on monocyte and macrophage cholesterol handling in vivo.

Buyang Huanwu Decoction ameliorates atherosclerosis by regulating TGF-ß/Smad2 pathway to promote the differentiation of regulatory T cells.

ETHNOPHARMACOLOGICAL RELEVANCE: As a classic prescription of Traditional Chinese Medicine in Correction on the Errors of Medical Works, Buyang Huanwu Decoction (BYHWD) has a good curative effect on prevention of atherosclerosis (AS). AIM OF THE STUDY: This study aims to elucidate the anti-atherosclerosis mechanism of BYHWD, which may promote the differentiation of regulatory T cells by regulating the TGF-ß/Smad2 pathway. MATERIALS AND METHODS: ApoE-/- mice were fed a high-fat diet for 12 weeks, then drugs group were given BYHWD with intragastric administration once a day for 4 weeks. The effect of BYHWD on lipid content in peripheral blood and plaque was evaluated by blood lipid test and oil red O staining. The number of Tregs in peripheral blood was tested by flow cytometry, and that in the spleen was evaluated by immunohistochemistry methods. Gene and protein expression relating with Tregs differentiation pathway in mice were checked by RT-PCR and Western blot experiments. CD4+T cells were isolated and interfered by BYHWD drug-loaded serum. The proportion of Tregs was evaluated by flow cytometry. The chemical compositions of BYHWD and rat drug-loaded serum were analyzed by ultra-high performance liquid chromatograph and liquid chromatography-tandem mass spectrometry. RESULTS: BYHWD significantly reduced plaque area and cholesterol accumulation, increased the number of Tregs in spleen and peripheral blood of ApoE-/- AS mice, raised the proportion of Tregs in CD4+T cells, and regulated the levels of inflammatory factors. It also increased the TGF-ß and Smad2 mRNA and protein levels relating with Tregs differentiation pathway in vivo. The mRNA levels of Foxp3/TGF-ß/Smad2 were enhanced via BYHWD in vitro. CONCLUSIONS: BYHWD regulates TGF-ß/Smad2 signaling pathway to promotes the peripheral differentiation of Tregs, increases the number of Tregs, restores the immune balance between CD4+T cells, regulates lipid metabolism, inhibits inflammatory reaction and possesses the potential of enhancing plaque stability.