European Society of Cardiology quality indicators for the prevention and management of cancer therapy-related cardiovascular toxicity in cancer treatment.

AIMS: To develop quality indicators (QIs) for the evaluation of the prevention and management of cancer therapy-related cardiovascular toxicity. METHODS AND RESULTS: We followed the European Society of Cardiology (ESC) methodology for QI development which comprises (i) identifying the key domains of care for the prevention and management of cancer therapy-related cardiovascular toxicity in patients on cancer treatment, (ii) performing a systematic review of the literature to develop candidate QIs, and (iii) selecting of the final set of QIs using a modified Delphi process. Work was undertaken in parallel with the writing of the 2022 ESC Guidelines on Cardio-Oncology and in collaboration with the European Haematology Association, the European Society for Therapeutic Radiology and Oncology and the International Cardio-Oncology Society. In total, 5 main and 9 secondary QIs were selected across five domains of care: (i) Structural framework, (ii) Baseline cardiovascular risk assessment, (iii) Cancer therapy related cardiovascular toxicity, (iv) Predictors of outcomes, and (v) Monitoring of cardiovascular complications during cancer therapy. CONCLUSION: We present the ESC Cardio-Oncology QIs with their development process and provide an overview of the scientific rationale for their selection. These indicators are aimed at quantifying and improving the adherence to guideline-recommended clinical practice and improving patient outcomes.

Circulating microparticles are associated with clinical severity of persistent ST-segment elevation myocardial infarction complicated with cardiogenic shock.

BACKGROUND: Cardiogenic shock (CS) is the leading cause of death in patients admitted for acute myocardial infarction (MI). Despite the recent advances in reperfusion and medical treatment mortality remains unacceptably high. Whether cells of the blood compartment in CS-patients are activated and release microparticles (cMPs) that may be both messengers and biomarkers of cell damage is not known. We aimed to investigate the cMP subtypes and parental activated cells of ST-elevation MI (STEMI)-patients complicated by CS and that of non-CS STEMI-patients (non-CS) in order to identify a cMP signature that could aid CS patient's risk stratification. METHODS: Clinically-characterized STEMI-patients with and without CS (36/group) were included. Treatment was delivered according to guidelines and included primary percutaneous coronary intervention. cMPs were characterized by triple-labeling flow cytometry using Annexin V and cell surface-specific monoclonal antibodies. RESULTS: Increased levels of leukocyte-derived (neutrophil and granulocyte origin) and platelet-derived cMPs were detected in CS compared to non-CS patients. A signature of cMPs derived from platelets, leukocytes, and endothelium discriminated CS-patients (AUC of 0.743±0.059 [95% CI: 0.628-0.859], P<0.0001) and predicted mortality in CS (AUC of 0.869±0.06 [95% CI: 0.750-0.988], P<0.0001). In CS-patients, a higher number of platelet- and monocyte-cMPs and of tissue factor-rich cMPs associated to worse myocardial blush grade and thrombolysis in myocardial infarction flow. CONCLUSIONS: cMPs derived from proinflammatory and prothrombotic cells were found to be elevated in CS-patients. In treated as per guidelines CS patients, granulocytes and neutrophils remained activated and actively shed cMPs. These cMPs were biomarkers of adverse prognosis in CS. TRANSLATIONAL ASPECT: Increased levels of leukocyte and platelet-derived circulating microparticles (cMPs) are found in cardiogenic shock (CS) patients as compared to non-CS patients. In CS-patients, a higher number of platelet- and monocyte-cMPs and a higher number of tissue factor-rich cMPs were associated to worse myocardial reperfusion. A specific prothrombotic and proinflammatory cMPs signature in cardiogenic shock (CS) patients is a potential discriminator and survival prognostic biomarker for CS, which could aid management and improve clinical outcomes.

Tissue factor variants induce monocyte transformation and transdifferentiation into endothelial cell-like cells.

Essentials Monocytes (Mo) transdifferentiate into endothelial cell-like (ECL) cells. Mo induce tissue factor (TF) expression and secretion in microvascular endothelial cells (mECs). TF interacts with Mo in a paracrine fashion, inducing their transdifferentiation into ECL cells. TF generates a positive feedback crosstalk between Mo and mECs that promotes angiogenesis. SUMMARY: Background Monocytes (Mo) increase neovascularization by releasing proangiogenic mediators and/or transdifferentiating into endothelial cell-like (ECL) cells. Recently, we have reported that Mo-microvascular endothelial cells (mECs) crosstalk induces mEC-tissue factor (TF) expression and promotes angiogenesis. However, the effect of TF on Mo remains unknown. Objective Here, we analyzed whether TF might exert angiogenic effects by inducing transdifferentiation of Mo. Methods Full-length TF (flTF) and alternatively spliced TF (asTF) were overexpressed in mECs, and their supernatants were added to Mo cultures. CD16 positivity and expression of vascular endothelial cell (VEC) markers in Mo were analyzed by fluorescence activated cell sorting. The capacity to form tube-like structures were visualized in three-dimensional cultures. Results In mECs flTF and asTF expression and release were increased in cultures with Mo-conditioned media. TF variants induced expansion of a CD16+ Mo subset and Mo transdifferentiation into ECL-cells expressing VEC markers that can form new microvessels. CD16+ Mo exposed to TF showed an increased expression of VE-cadherin, von Willebrand factor (VWF) and eNOS. Mo cultured with supernatants obtained from TF-silenced mECs did not transdifferentiate to ECL-cells or expressed VEC markers. Blocking ß1-integrin in Mo significantly blocked the effects of the TF variants. Conclusions Mo induce mECs to express and release TF, which drives CD16- Mo to transform into CD16+ Mo and to transdifferentiate into ECL-cells that can form new microvessels. Our results reveal a TF-mediated positive feedback between mECs and Mo that stimulates Mo differentiation and induces angiogenesis.

LRP5/canonical Wnt signalling and healing of ischemic myocardium.

LRP5 (low-density lipoprotein receptor-related protein 5) activates canonical Wnt signalling. LRP5 plays multiple roles including regulation of lipoprotein and cholesterol homeostasis as well as innate immunity cell function. However, it is not known whether LRP5 has a role in the myocardium. The aim of this study was to investigate LRP5 and Wnt signalling in myocardial remodelling after acute myocardial infarction (MI). Wnt protein levels were determined in a hypercholesterolemic porcine model of MI, in Lrp5 -/- C57Bl6 mice, in cultured cardiomyocytes and in human explanted hearts with previous MI episodes. 21 days post-MI, there was upregulation of LRP5 in the ischemic myocardium of hypercholesterolemic pigs as well as an upregulated expression of proteins of the Wnt pathway. We demonstrate via overexpression and silencing experiments that LRP5 induces Wnt pathway activation in isolated cardiomyocytes. Hypoxia and lipid-loading induced the expression of Wnt proteins, whereas this effect is blocked in LRP5-silenced cardiomyocytes. To characterize the function of the LRP5-Wnt axis upregulation in the heart, we induced MI in wild-type and Lrp5 -/- mice. Lrp5 -/- mice had significantly larger infarcts than Wt mice, indicating a protective role of LRP5 in injured myocardium. The LRP5 upregulation in post-MI hearts seen in pigs and mice was also evident in human hearts as dyslipidemic patients with previous episodes of ischemia have higher expression of LRP5 and Wnt-signalling genes than non-ischemic dilated hearts. We demonstrate an upregulation of LRP5 and the Wnt signalling pathway that it is a prosurvival healing response of cardiomyocytes upon injury.

Bone Marrow Cell Transplant From Donors With Cardiovascular Risk Factors Increases the Pro-atherosclerotic Phenotype in the Recipients.

Improvement of long-term survival after hematopoietic stem cell transplantation has revealed that these patients have an increased appearance of de novo cardiovascular risk factors. Even though in these clinical studies no relation to transplant-related factors has been found, no attention has been paid to the influence of cardiovascular risk factors affecting the bone marrow donors on the cardiovascular risk of the recipients. Thus, the aim of this study was to analyze, using an animal model, whether transplantation of bone marrow from donors with cardiovascular risk factors increases cardiovascular risk in healthy recipients. Results from transplantation experiments have shown that bone marrow from donors with cardiovascular risk factors induced pro-atherogenic modifications in the cholesterol profile of healthy recipients, increasing the low-density lipoprotein cholesterol fraction in comparison to those transplanted with control bone marrow. Moreover, bone marrow from donors with cardiovascular risk factors induced significant alterations in liver pro-inflammatory state and lipid metabolism-related gene expression that could contribute to alter cholesterol homeostasis. Altogether, these results suggest that cardiovascular risk factors in the donor confer a cardiometabolic alteration to their bone marrow cells that is transferred to noncardiovascular disease transplant recipients, affecting their liver function and increasing their cardiovascular risk.

Effects of moderate beer consumption on health and disease: A consensus document.

A large evidence-based review on the effects of a moderate consumption of beer on human health has been conducted by an international panel of experts who reached a full consensus on the present document. Low-moderate (up to 1 drink per day in women, up to 2 in men), non-bingeing beer consumption, reduces the risk of cardiovascular disease. This effect is similar to that of wine, at comparable alcohol amounts. Epidemiological studies suggest that moderate consumption of either beer or wine may confer greater cardiovascular protection than spirits. Although specific data on beer are not conclusive, observational studies seem to indicate that low-moderate alcohol consumption is associated with a reduced risk of developing neurodegenerative disease. There is no evidence that beer drinking is different from other types of alcoholic beverages in respect to risk for some cancers. Evidence consistently suggests a J-shaped relationship between alcohol consumption (including beer) and all-cause mortality, with lower risk for moderate alcohol consumers than for abstainers or heavy drinkers. Unless they are at high risk for alcohol-related cancers or alcohol dependency, there is no reason to discourage healthy adults who are already regular light-moderate beer consumers from continuing. Consumption of beer, at any dosage, is not recommended for children, adolescents, pregnant women, individuals at risk to develop alcoholism, those with cardiomyopathy, cardiac arrhythmias, depression, liver and pancreatic diseases, or anyone engaged in actions that require concentration, skill or coordination. In conclusion, although heavy and excessive beer consumption exerts deleterious effects on the human body, with increased disease risks on many organs and is associated to significant social problems such as addiction, accidents, violence and crime, data reported in this document show evidence for no harm of moderate beer consumption for major chronic conditions and some benefit against cardiovascular disease.

Do physicians correctly calculate thromboembolic risk scores? A comparison of concordance between manual and computer-based calculation of CHADS2 and CHA2 DS2 -VASc scores.

BACKGROUND: Clinical risk scores, CHADS2 and CHA2 DS2 -VASc scores, are the established tools for assessing stroke risk in patients with atrial fibrillation (AF). AIM: The aim of this study is to assess concordance between manual and computer-based calculation of CHADS2 and CHA2 DS2 -VASc scores, as well as to analyse the patient categories using CHADS2 and the potential improvement on stroke risk stratification with CHA2 DS2 -VASc score. METHODS: We linked data from Atrial Fibrillation Spanish registry FANTASIIA. Between June 2013 and March 2014, 1318 consecutive outpatients were recruited. We explore the concordance between manual scoring and computer-based calculation. We compare the distribution of embolic risk of patients using both CHADS2 and CHA2 DS2 -VASc scores RESULTS: The mean age was 73.8 ± 9.4 years, and 758 (57.5%) were male. For CHADS2 score, concordance between manual scoring and computer-based calculation was 92.5%, whereas for CHA2 DS2 -VASc score was 96.4%. In CHADS2 score, 6.37% of patients with AF changed indication on antithrombotic therapy (3.49% of patients with no treatment changed to need antithrombotic treatment and 2.88% of patients otherwise). Using CHA2 DS2 -VASc score, only 0.45% of patients with AF needed to change in the recommendation of antithrombotic therapy. CONCLUSION: We have found a strong concordance between manual and computer-based score calculation of both CHADS2 and CHA2 DS2 -VASc risk scores with minimal changes in anticoagulation recommendations. The use of CHA2 DS2 -VASc score significantly improves classification of AF patients at low and intermediate risk of stroke into higher grade of thromboembolic score. Moreover, CHA2 DS2 -VASc score could identify 'truly low risk' patients compared with CHADS2 score.

LDL accelerates monocyte to macrophage differentiation: Effects on adhesion and anoikis.

BACKGROUND AND AIMS: High LDL triggers dyslipidemia and atherosclerosis, a chronic inflammatory disease with participation of the innate immunity system. Monocytes are recruited to areas of LDL-induced endothelial damage and initiate differentiation. This study was aimed to investigate the effects of LDL on the early transitional stages of monocyte differentiation into macrophages. METHODS: Blood monocytes, isolated from healthy donors by their adhesion properties, were exposed to native-LDL (1.80 mg/mL) for 48-h. Monocyte phenotype was assessed at transcript and miRNA levels by real-time PCR. Protein-expression was determined by western-blot and flow-cytometry. RESULTS: CD14 time-dependently decreased in adhered monocytes, reaching a >4 fold decrease at transcript- and protein-levels after 7-days in culture when cells were already differentiated into macrophages. At 4-days differentiation, monocytes exposed to LDL reduced CD14-transcrition >1.5 fold in mRNA (p = 0.002) and 34% CD14-protein (p = 0.039), whereas increased in CD16-expression (p = 0.019). Besides, LDL induced a significant increase in integrin CD49c (α3-subunit) at mRNA (>2 fold, p = 0.008) and protein (>3 fold, p = 0.045) level and a decrease in the apoptosis-effectors CASP8 and CASP3 (p = 0.002 and p = 0.035, respectively) as well as in the precursor form of the death-receptor DR5 (p = 0.045) without affecting its mRNA-expression level, suggesting a LDL-dependent post-transcriptional regulation of DR5. In silico prediction analysis indicated miR-126-3p as a candidate to regulate DR5-expression and miR-126-3p was shown affected by LDL reaching a significant increase (p = 0.033). CONCLUSIONS: In differentiating human monocytes, LDL stimulates expression of cell-adhesion molecules and downregulates apoptosis-effectors, regulating anoikis and survival programs in the early stage macrophages.

Circulating microparticle signature in coronary and peripheral blood of ST elevation myocardial infarction patients in relation to pain-to-PCI elapsed time.

BACKGROUND: Circulating microparticle (cMP) levels are increased in the acute phase of ST-elevation myocardial infarction (STEMI) and associate with microvascular obstruction; however, the precise cMP-parental cell signature and activation level are not elucidated. Here, we aimed to study the cMP signature in STEMI-patients and whether cMP phenotype changes in relation to onset of pain-to-PCI [ischemic time (IT)]-elapsed time. METHODS: Blood was taken at PCI from the culprit coronary and the peripheral circulation in STEMI-patients (N=40). Two control groups were included: peripheral blood of age-matched patients recovering from STEMI [after 72 h] and of control individuals (N=20/group). cMP-parental origin and activation level were characterized by triple-labeling flow cytometry. RESULTS: Procoagulant annexin V-positive cMPs bearing parental cell markers as well as markers of activated cells displayed a significantly different profile in STEMI-patients, in control individuals and in patients recovering from STEMI. cMPs derived from monocytes, endothelium, and activated vascular cells were higher in the culprit coronary artery than in peripheral blood in STEMI-patients, especially in patients intervened at short IT. Indeed, cMP levels in coronary blood were inversely related to IT duration (more abundant in thrombi with pain-to-PCI time<180 min). CONCLUSIONS: A characteristic [CD66b+/CD62E+/CD142+] cMP signature in the systemic circulation reflects the formation of coronary thrombotic occlusions in STEMI-patients. Changes in the cMP signature in the culprit coronary artery blood reveal the sensitivity of MPs to detect the ischemia-elapsed time. Interestingly, cMPs in peripheral blood may be sensitive markers of the thrombo-occlusive vascular process developing in the coronary arteries of STEMI-patients.

LRP5 associates with specific subsets of macrophages: Molecular and functional effects.

Innate and acquired immunity is involved in the progression of atherosclerosis. The molecular mechanisms ruling monocyte to macrophage (Mø) differentiation are not yet fully understood. Different subtypes of plaque macrophages that have differentiated from monocytes recruited from circulating blood, have been characterized based on surface epitopes. We have recently shown that LRP5, a member of the LDL receptor superfamily supporting Wnt signalling, has an important role in monocyte to macrophage differentiation. The aim of this study was to investigate whether the CD16- and CD16+ macrophage subsets found in human atherosclerotic plaques have a differential LRP5 expression/function and Wnt signalling potential. We show for the first time that LRP5 expression is significantly higher in human CD16+Mø derived from CD14(+)CD16(+) monocytes than in CD16-Mø macrophages derived from CD14(+)CD16(-) monocytes. LRP5 is not found in human healthy vessel or arterial intimal thickening but is found in advanced human atherosclerotic lesions co-localizing only with the CD16+Mø macrophage subset. LRP5 expressing macrophages infiltrate the deep layers of atherosclerotic plaques towards the intima-media boundaries showing increased migratory activity and higher phagocytic activity. The equivalent for human patrolling CD14(+)CD16(+) monocytes in mice, CD115(+)GR1(low) monocytes, also show an increased expression of LRP5. In summary, classical CD14(+)CD16(-)monocytes that differentiate into CD16-Mø do not express LRP5. Instead, human monocytes expressing LRP5 differentiate into CD16+Mø antiinflammatory macrophages. These antiinflammatory macrophages are found in advanced atherosclerotic human plaques. Thus LRP5 is a signature of the anti-inflammatory defensive phenotype of macrophages.

Monomeric C-reactive protein--a key molecule driving development of Alzheimer's disease associated with brain ischaemia?

Alzheimer's disease (AD) increases dramatically in patients with ischaemic stroke. Monomeric C-reactive protein (mCRP) appears in the ECM of ischaemic tissue after stroke, associating with microvasculature, neurons and AD-plaques, Aß, also, being able to dissociate native-CRP into inflammatory, mCRP in vivo. Here, mCRP injected into the hippocampal region of mice was retained within the retrosplenial tract of the dorsal 3rd ventrical and surrounding major vessels. Mice developed behavioural/cognitive deficits within 1 month, concomitant with mCRP staining within abnormal looking neurons expressing p-tau and in beta-amyloid 1-42-plaque positive regions. mCRP co-localised with CD105 in microvessels suggesting angiogenesis. Phospho-arrays/Western blotting identified signalling activation in endothelial cells and neurons through p-IRS-1, p-Tau and p-ERK1/2-which was blocked following pre-incubation with mCRP-antibody. mCRP increased vascular monolayer permeability and gap junctions, increased NCAM expression and produced haemorrhagic angiogenesis in mouse matrigel implants. mCRP induced tau244-372 aggregation and assembly in vitro. IHC study of human AD/stroke patients revealed co-localization of mCRP with Aß plaques, tau-like fibrils and IRS-1/P-Tau positive neurons and high mCRP-levels spreading from infarcted core regions matched reduced expression of Aß/Tau. mCRP may be responsible for promoting dementia after ischaemia and mCRP clearance could inform therapeutic avenues to reduce the risk of future dementia.

Growing thrombi release increased levels of CD235a(+) microparticles and decreased levels of activated platelet-derived microparticles. Validation in ST-elevation myocardial infarction patients.

BACKGROUND: Local fluid dynamics and exposed atherosclerotic lesions regulate thrombus formation. Activated cells in the attached thrombi release microparticles to the circulation (circulating microparticles [cMPs]); however, their phenotype is unknown. OBJECTIVES: To investigate the specific phenotype of the cMPs released by growing thrombi. METHODS/PATIENTS: cMPs released by thrombi growing in different well-characterized thrombogenic conditions were investigated. cMP contents just before and immediately after perfusion of the thrombogenic surfaces were analyzed by triple-labeling flow cytometry. cMPs were tested for their thrombin-generating capacity. The cMPs identified in the ex vivo perfusion experiments were validated in blood of ST-elevation myocardial infarction (STEMI) patients undergoing thrombectomy and percutaneous coronary intervention. Culprit coronary blood (STEMI-CCB) and peripheral artery blood (STEMI-PAB) were simultaneously analyzed and compared with peripheral artery blood from age-matched controls (C-PAB) and peripheral artery blood from patients who had recovered from acute coronary syndrome (ACS) (pSTEMI-PAB). RESULTS: The levels of annexin V(+) cMPs significantly increased in blood collected after perfusion of the exposed thrombogenic surfaces. cMP release was directly related to the formed thrombus mass and the plasma procoagulant activity. Post-thrombus blood showed higher thrombin generation potential and contained higher levels of cMPs carrying glycophorin-A (CD235a(+) ; erythrocyte-derived microparticles [ErMPs]) than preperfusion blood (P < 0.05), whereas the levels of cMPs carrying activated and adhesion platelet markers were decreased. STEMI-CCB and STEMI-PAB had significantly higher ErMP levels than control blood (P < 0.005). ErMP levels were also significantly higher in STEMI-PAB than in pSTEMI-PAB, validating the experimental mechanistic studies and suggesting that ErMPs are markers of ongoing coronary thrombosis (C-statistics: 0.950; 95% confidence interval 0.889-1.000; P < 0.001). CONCLUSION: Glycophorin-A-rich microparticles are released from evolving growing thrombi into the distal perfusing blood, and can be measured in peripheral blood. CD235a(+) cMPs may constitute a novel systemic biomarker of ongoing thrombosis.

Circulating soluble low-density lipoprotein receptor-related protein 1 (sLRP1) concentration is associated with hypercholesterolemia: A new potential biomarker for atherosclerosis.

BACKGROUND: There is clinical interest in identifying novel lipid biomarkers for evaluating cardiovascular risk and targeting lipid-lowering treatment. Low-density lipoprotein receptor-related protein 1 (LRP1) plays a crucial role in the dysregulated cholesterol transfer from modified lipoproteins to human coronary vascular smooth muscle cells (hVSMCs), promoting hVSMC-derived foam cell formation. LRP1 has a soluble and circulating form (sLRP1) generated from LRP1. Cholesterol modulates the release of the soluble form of LRP1. Using in vitro, ex vivo and patient-based approaches, we tested the association between circulating sLRP1 concentrations and hypercholesterolemia and the potential of sLRP1 as a biomarker of atherosclerosis. METHODS AND RESULTS: Circulating sLRP1 concentrations were higher in severe hypercholesterolemia compared to moderate hypercholesterolemia or normocholesterolemia (Study 1). Circulating sLRP1 was significantly associated with established pro-atherogenic lipid parameters in two different hypercholesterolemic populations (Studies 2 and 3). sLRP1 concentrations decreased after statin treatment and increased after statin withdrawal (Study 3). In vitro experiments showed that native LDL, aggregated LDL and VLDL+IDL lipoproteins induced the release of sLRP1 from hVSMC. sLRP1 levels were increased in the conditioned medium of coronary atherosclerotic plaque areas extracted from patients compared to non-atherosclerotic areas of the same coronary artery and patient. Circulating sLRP1 concentrations were independently associated with the occurrence of carotid atherosclerosis in a hypercholesterolemic population (Study 2). The later association was higher than that observed for other classical or novel lipid parameters. CONCLUSIONS: Circulating sLRP1 is a new lipid-related parameter potentially useful as a biomarker for atherosclerosis.

Latest evidence of the effects of the Mediterranean diet in prevention of cardiovascular disease.

The first step in the prevention of cardiovascular disease is healthy lifestyle and diet. Recent systematic reviews of observational studies ranked Mediterranean diet as the most likely dietary model to provide cardiovascular protection. This review updates the knowledge on the effects of Mediterranean diet from observational and randomized trials published in the last year. The results of the PREDIMED study, a randomized trial providing a higher level of scientific evidence than cohort studies, confirmed that the Mediterranean diet reduces the incidence of cardiovascular events. This effect may be exerted by reducing blood pressure; improving glucose metabolism, lipid profile, and lipoprotein particle characteristics; and decreasing inflammation and oxidative stress. It may also stem from a favorable interaction between diet and gene polymorphisms related to cardiovascular risk factors and events. These recent results allow us to recommend Mediterranean diet to subjects at high risk for cardiovascular disease with the highest level of scientific evidence.

Thrombosis formation on atherosclerotic lesions and plaque rupture.

Atherosclerosis is a silent chronic vascular pathology that is the cause of the majority of cardiovascular ischaemic events. The evolution of vascular disease involves a combination of endothelial dysfunction, extensive lipid deposition in the intima, exacerbated innate and adaptive immune responses, proliferation of vascular smooth muscle cells and remodelling of the extracellular matrix, resulting in the formation of an atherosclerotic plaque. High-risk plaques have a large acellular lipid-rich necrotic core with an overlying thin fibrous cap infiltrated by inflammatory cells and diffuse calcification. The formation of new fragile and leaky vessels that invade the expanding intima contributes to enlarge the necrotic core increasing the vulnerability of the plaque. In addition, biomechanical, haemodynamic and physical factors contribute to plaque destabilization. Upon erosion or rupture, these high-risk lipid-rich vulnerable plaques expose vascular structures or necrotic core components to the circulation, which causes the activation of tissue factor and the subsequent formation of a fibrin monolayer (coagulation cascade) and, concomitantly, the recruitment of circulating platelets and inflammatory cells. The interaction between exposed atherosclerotic plaque components, platelet receptors and coagulation factors eventually leads to platelet activation, aggregation and the subsequent formation of a superimposed thrombus (i.e. atherothrombosis) which may compromise the arterial lumen leading to the presentation of acute ischaemic syndromes. In this review, we will describe the progression of the atherosclerotic lesion along with the main morphological characteristics that predispose to plaque rupture, and discuss the multifaceted mechanisms that drive platelet activation and subsequent thrombus formation. Finally, we will consider the current scientific challenges and future research directions.

Cholesterol modulates LRP5 expression in the vessel wall.

OBJECTIVE: Macrophages are key players in atherosclerotic lesion formation and progression. We have recently demonstrated that lipid-loaded macrophages show activation of the canonical Wnt signaling pathway. METHODS: To test the in vivo role of the canonical Wnt pathway in atherosclerosis we used mice deficient in the Wnt signaling receptor LRP5 (LRP5(-/-)) fed a hypercholesterolemic diet (HC) to induce atherosclerosis. These dietary groups were further subdivided into two subgroups receiving their respective diets supplemented with 2% plant sterol esters (PSE). All mice remained on their assigned diets until age 18 weeks. RESULTS: HC WT mice had mildly increased non-HDL cholesterol levels, developed aortic atherosclerotic lesions and showed upregulated expression levels of aortic Lrp5. HC LRP5(-/-) mice develop larger aortic atherosclerotic lesions than WT mice indicating that LRP5 has a protective function in atherosclerosis progression. The oral administration of PSE, a dietary cholesterol-lowering agent, had an effect in the expression levels of the Wnt signaling receptor and in atherosclerosis progression. We found that PSE reduced serum total cholesterol levels, abolished HC-induced LRP5 overexpression and reduced aortic atherosclerotic plaques. CONCLUSION: The proatherogenic effects of the excess of plasma lipids are in part mediated by modulation of LRP5 in the aorta. LRP5 and canonical Wnt signaling exert a protective defense mechanism against hyperlipidemia and atherosclerosis lesion progression.

Molecular and functional characterization of LRP1 promoter polymorphism c.1-25 C>G (rs138854007).

The transcription of the Low-density lipoprotein receptor-related protein (LRP1) is upregulated by aggregated LDL (agLDL) and angiotensin II (AngII) in human vascular smooth muscle cells (hVSMC). The polymorphism c.1-25C>G creates a new GC-box in the LRP1 promoter recognized by Sp1/Sp3 transcription factors. The aims of this study were 1) to evaluate the impact of c.1-25C>G polymorphism on LRP1 transcriptional activity and expression, and 2) to examine the response of c.1-25C>G LRP1 promoter to LDL and AngII. EMSA and Luciferase assays in HeLa cells showed that -25G promoter has enhanced basal transcriptional activity and specific Sp1/Sp3 binding. hVSMC with GG genotype (GG-hVSMC) had higher LRP1 mRNA and protein levels, respectively than CC genotype (CC-hVSMC). EMSA assays showed that the polymorphism determines scarce amount of SRE-B/SREBP-2 complex formation and the failure of agLDL to further reduce these SRE-B/SREBP-2 complexes. Taken together, these results suggest that c.1-25C>G, by difficulting SREBP-2 binding, prevents SREBP-2 displacement required for LRP1 promoter response to LDL. In contrast, c.1-25C>G strongly favours Sp1/Sp3 binding and AngII-induced activity in Sp1/Sp3 dependent manner in GG-hVSMC. This increase is functionally translated into a higher capacity of GG-hVSMC to become foam cells from agLDL in presence of AngII. These results suggest that c.1-25C>G determines a lack of response to agLDL and an exacerbated response to AngII. It is thus conceivable that the presence of the polymorphism would be easily translated to vascular alterations in the presence of the pro-hypertensive autacoid, AngII.