Specific matrix metalloproteinases and calcification factors are associated with the vulnerability of human carotid plaque

Vulnerable Atherosclerotic Plaque: Is There a Molecular Signature?

Atherosclerosis and its clinical manifestations, coronary and cerebral artery diseases, are the most common cause of death worldwide. The main pathophysiological mechanism for these complications is the rupture of vulnerable atherosclerotic plaques and subsequent thrombosis. Pathological studies of the vulnerable lesions showed that more frequently, plaques rich in lipids and with a high level of inflammation, responsible for mild or moderate stenosis, are more prone to rupture, leading to acute events. Identifying the vulnerable plaques helps to stratify patients at risk of developing acute vascular events. Traditional imaging methods based on plaque appearance and size are not reliable in prediction the risk of rupture. Intravascular imaging is a novel technique able to identify vulnerable lesions, but it is invasive and an operator-dependent technique. This review aims to summarize the current data from literature regarding the main biomarkers involved in the attempt to diagnose vulnerable atherosclerotic lesions. These biomarkers could be the base for risk stratification and development of the new therapeutic drugs in the treatment of patients with vulnerable atherosclerotic plaques.

Plasma Concentrations of New Biochemical Markers of Atherosclerosis in Patients with Dyslipidemia-A Pilot Study

Background and Objectives: The process of atherosclerotic plaque formation and its destabilisation is a process in which many proteins and cytokines are involved. Examples of such proteins are osteopontin (OPN), osteoprotegerin (OPG), metalloproteinases (MMPs) and myeloperoxidase (MPO). The aim of our study is to compare the concentrations of the above-mentioned markers in the plasma of patients with the confirmed presence of rupture plaque in comparison with the plasma of healthy people. Materials and Methods: The study included people suffering from dyslipidemia in whom the presence of unstable atherosclerotic plaque was confirmed by ultrasound. The concentrations of OPN, OPG, MPO, metalloproteinase 2 (MMP-2), and metalloproteinase 9 (MMP-9) in the plasma of these people were determined and compared with the concentrations of these proteins in the plasma of healthy people. Results: Levels of MMP-2, MMP-9 (p < 0.001), OPN, and OPG (p < 0.05) were statistically significantly lower in the group of healthy people than in the study group. Differences in MPO concentration were not statistically significant (p = 0.073). Conclusions: In the plasma of people with confirmed presence of rupture plaque, the concentrations of OPN, OPG, and MMPs are higher compared to the group of healthy people, which may suggest the use of these proteins as novel markers of the presence of unstable atherosclerotic plaque.

Serum Biomarkers in Carotid Artery Disease

Carotid artery disease is considered a major cause of strokes and there is a need for early disease detection and management. Although imaging techniques have been developed for the diagnosis of carotid artery disease and different imaging-based markers have been proposed for the characterization of atherosclerotic plaques, there is still need for a definition of high-risk plaques in asymptomatic patients who may benefit from surgical intervention. Measurement of circulating biomarkers is a promising method to assist in patient-specific disease management, but the lack of robust clinical evidence limits their use as a standard of care. The purpose of this review paper is to present circulating biomarkers related to carotid artery diagnosis and prognosis, which are mainly provided by statistical-based clinical studies. The result of our investigation showed that typical well-established inflammatory biomarkers and biomarkers related to patient lipid profiles are associated with carotid artery disease. In addition to this, more specialized types of biomarkers, such as endothelial and cell adhesion, matrix degrading, and metabolic biomarkers seem to be associated with different carotid artery disease outputs, assisting vascular specialists in selecting patients at high risk for stroke and in need of intervention.

Status of biomarkers for the identification of stable or vulnerable plaques in atherosclerosis

Atherosclerosis is a systemic inflammation of the arteries characterized by atherosclerotic plaque due to the accumulation of lipids, inflammatory cells, apoptotic cells, calcium and extracellular matrix (ECM) proteins. Stable plaques present a chronic inflammatory infiltration, whereas vulnerable plaques present an 'active' inflammation involved in the thinning of the fibrous cap that predisposes to plaque rupture. Several complex biological cellular processes lead plaques to evolve from stable to vulnerable predisposing them to rupture and thrombosis. In this review, we analyze some emerging circulating biomarkers related to inflammation, ECM and lipid infiltration, angiogenesis, metalloproteinases and microRNA (miRNA), as possible diagnostic and prognostic indicators of plaque vulnerability.

Circulating Biomarkers Reflecting Destabilization Mechanisms of Coronary Artery Plaques: Are We Looking for the Impossible?

Despite significant strides to mitigate the complications of acute coronary syndrome (ACS), this clinical entity still represents a major global health burden. It has so far been well-established that most of the plaques leading to ACS are not a result of gradual narrowing of the vessel lumen, but rather a result of sudden disruption of vulnerable atherosclerotic plaques. As most of the developed imaging modalities for vulnerable plaque detection are invasive, multiple biomarkers were proposed to identify their presence. Owing to the pivotal role of lipids and inflammation in the pathophysiology of atherosclerosis, most of the biomarkers originated from one of those processes, whereas recent advancements in molecular sciences shed light on the use of microRNAs. Yet, at present there are no clinically implemented biomarkers or any other method for that matter that could non-invasively, yet reliably, diagnose the vulnerable plaque. Hence, in this review we summarized the available knowledge regarding the pathophysiology of plaque instability, the current evidence on potential biomarkers associated with plaque destabilization and finally, we discussed if search for biomarkers could one day bring us to non-invasive, cost-effective, yet valid way of diagnosing the vulnerable, rupture-prone coronary artery plaques.

Search for Reliable Circulating Biomarkers to Predict Carotid Plaque Vulnerability

Atherosclerosis is responsible for 20% of ischemic strokes, and the plaques from the internal carotid artery the most frequently involved. Lipoproteins play a key role in carotid atherosclerosis since lipid accumulation contributes to plaque progression and chronic inflammation, both factors leading to plaque vulnerability. Carotid revascularization to prevent future vascular events is reasonable in some patients with high-grade carotid stenosis. However, the degree of stenosis alone is not sufficient to decide upon the best clinical management in some situations. In this context, it is essential to further characterize plaque vulnerability, according to specific characteristics (lipid-rich core, fibrous cap thinning, intraplaque hemorrhage). Although these features can be partly detected by imaging techniques, identifying carotid plaque vulnerability is still challenging. Therefore, the study of circulating biomarkers could provide adjunctive criteria to predict the risk of atherothrombotic stroke. In this regard, several molecules have been found altered, but reliable biomarkers have not been clearly established yet. The current review discusses the concept of vulnerable carotid plaque, and collects existing information about putative circulating biomarkers, being particularly focused on lipid-related and inflammatory molecules.

Immune-Mediated Inflammation in Vulnerable Atherosclerotic Plaques

Atherosclerosis is a chronic long-lasting vascular disease leading to myocardial infarction and stroke. Vulnerable atherosclerotic (AS) plaques are responsible for these life-threatening clinical endpoints. To more successfully work against atherosclerosis, improvements in early diagnosis and treatment of AS plaque lesions are required. Vulnerable AS plaques are frequently undetectable by conventional imaging because they are non-stenotic. Although blood biomarkers like lipids, C-reactive protein, interleukin-6, troponins, and natriuretic peptides are in pathological ranges, these markers are insufficient in detecting the critical perpetuation of AS anteceding endpoints. Thus, chances to treat the patient in a preventive way are wasted. It is now time to solve this dilemma because clear results indicate a benefit of anti-inflammatory therapy per se without modification of blood lipids (CANTOS Trial, NCT01327846). This fact identifies modulation of immune-mediated inflammation as a new promising point of action for the eradication of fatal atherosclerotic endpoints.