Role Of Platelets In Atherosclerosis Research Articles

Fibrin clot properties in coronary artery disease: new determinants and prognostic markers.

Despite improved diagnosis and treatment options, coronary artery disease (CAD) is still the leading cause of mortality and morbidity worldwide. Established risk factors such as smoking, hypercholesterolemia, and hypertension only partly explain the pathophysiology of CAD. Besides the well-known role of platelets in atherosclerosis and arterial thrombus formation, reduced endogenous fibrinolytic activity may play a key role in CAD formation and progression. Thus, biomarkers of fibrinolysis may be future CAD risk markers. In this review, we provide an overview of regulators of fibrinolysis and the main factors of importance to fibrin clot formation including coagulation factor XIII, thrombin, and fibrinogen. We summarize markers of altered fibrinolysis and current laboratory methods applied in clinical practice and research. We present today’s evidence on fibrin clot properties in patients with stable CAD or acute coronary syndrome compared with healthy individuals and the significance of altered fibrinolysis as a risk for coronary thrombotic disease. In conclusion, we found evidence that altered fibrin clot properties and impaired fibrinolysis appear to contribute significantly to the thromboembolic risk in CAD patients. Therefore, more research is crucial in order to clarify whether modulation of the fibrinolytic system may pave the way for improved treatment of CAD.

Co-culture of Platelets with Monocytes Induced M2 Macrophage Polarization and Formation of Foam Cells: Shedding Light on the Crucial Role of Platelets in Monocyte Differentiation

Objective:Far beyond hemostasis and thrombosis, significant evidence has indicated the critical role of platelets in atherosclerosis. SDF-1 is among the pro-inflammatory chemokines that are increased in platelets of patients with coronary artery disease (CAD). The goal of the current work is to identify the in vitro effect of platelets from either CAD patients or healthy volunteers on the induction of macrophages and foam cells.Materials and Methods:The expression of SDF-1 on platelet surfaces in CAD patients and healthy volunteers was investigated using flow cytometry. We also evaluated the CXCR4/CXCR7 expression on monocytes from buffy coats of healthy volunteers. The effect of platelets from CAD patients and healthy volunteers on differentiation of monocytes and foam cell formation was evaluated using Oil Red O (ORO) staining. Flow cytometry and real-time PCR were also employed to evaluate surface markers and mRNA expression of genes involved in this process after co-culture of platelets with monocytes.Results:Monocytes in co-culture with platelets acquired a spindleshape appearance and ORO-positive lipid droplets. In addition, platelets could induce CD163 expression, as an important marker of M2 macrophage, and upregulate the mRNA expression of the SRB, CD36, ACAT, LXR-α, and ABCA1 genes in monocytes. Notably, platelets of CAD patients with higher expression of SDF-1, increased the expression of genes encoding SRB and CD36 as compared to platelets of healthy volunteers.Conclusion:Our results indicate that platelets from CAD patients could provoke monocyte differentiation into macrophages with an M2 phenotype, which in turn may participate in an atheroprotective process.

Platelet pathophysiology, pharmacology, and function in coronary artery disease.

Platelets play a key role in the pathophysiology of coronary artery disease and acute coronary syndromes. Our understanding of platelet function in thrombus formation has increased considerably, resulting in the development of clinically effective treatment strategies and identification of new targets. An underappreciated platelet function is their contribution toward acute and chronic inflammatory processes including atherogenesis. In this review, we discuss the role of platelets in atherosclerosis and thrombosis, platelet function testing, and the pharmacology of currently available antiplatelet drugs.

Role of Platelet-Derived Microvesicles As Crosstalk Mediators in Atherothrombosis and Future Pharmacology Targets: A Link between Inflammation, Atherosclerosis, and Thrombosis.

Reports in the last decade have suggested that the role of platelets in atherosclerosis and its thrombotic complications may be mediated, in part, by local secretion of platelet-derived microvesicles (pMVs), small cell blebs released during the platelet activation process. MVs are the most abundant cell-derived microvesicle subtype in the circulation. High concentrations of circulating MVs have been reported in patients with atherosclerosis, acute vascular syndromes, and/or diabetes mellitus, suggesting a potential correlation between the quantity of microvesicles and the clinical severity of the atherosclerotic disease. pMVs are considered to be biomarkers of disease but new information indicates that pMVs are also involved in signaling functions. pMVs evoke or promote haemostatic and inflammatory responses, neovascularization, cell survival, and apoptosis, processes involved in the pathophysiology of cardiovascular disease. This review is focused on the complex cross-talk between platelet-derived microvesicles, inflammatory cells and vascular elements and their relevance in the development of the atherosclerotic disease and its clinical outcomes, providing an updated state-of-the art of pMV involvement in atherothrombosis and pMV potential use as therapeutic agent influencing cardiovascular biomedicine in the future.

The Role of Platelets in Athero-Thrombotic Events

The crucial role of platelets in primary hemostasis and repair of injured endothelium is well established, as is their role in atherothrombosis. No other single cell type is responsible for as much morbidity and mortality, since death from ischemic heart disease or stroke is by far the leading cause of death worldwide. There is no doubt that our understanding of atherothrombosis has guided current antithrombotic strategies that have dramatically reduced ischemic complications and cardiovascular mortality within the last decades. Yet the rate of ischemic complications after optimal revascularization therapy remains disappointingly high. There is still a strong need for new and smart antiplatelet drugs. The ideal antithrombotic drug would spare physiological platelet function, hemostasis and vascular repair in order to avoid bleeding complications, but would exclusively target the pathological atherothrombotic process. As platelet activity might be determined early in the bone marrow, this review starts with insights into the birth of platelets, describes the essential and primary role of platelets in hemostasis with new evidence in signaling cascades, and closes with the deleterious role of platelets in atherosclerosis and atherothrombosis, with a focus on acute coronary syndromes.

Platelets and atherosclerosis.

Despite the broad array of mechanisms designed to protect the endothelial lining of every blood vessel in the body and maintain the fluid state of blood, injury does occur. Chronic and recurrent damage result in development of lesions characteristic of atherosclerosis. The loss of vascular integrity associated with the pathological process of atherogenesis triggers the haemostatic mechanism. As a result, fibrin and platelets become a part of atherosclerotic lesions and play a role in their progression. Growth of the plaques and destruction of normal endothelium triggers further involvement of platelets leading to occlusion of arteries in the heart and brain, resulting in myocardial infarction and stroke. Understanding the role of platelets in atherosclerosis and limiting its contribution may reduce morbidity and mortality of this dread disease.

Role of platelets in atherosclerosis and its complications: V. Fuster. Division of Cardiology, Mount Sinai School of Medicine, New York, New York

Role of platelets in atherosclerosis and its complications: V. Fuster. Division of Cardiology, Mount Sinai School of Medicine, New York, New York

Role of platelets in atherosclerosis.

Role of platelets in atherosclerosis.