Platelet microvesicles are associated with the severity of coronary artery disease: comparison between peripheral and coronary circulation

Circulating microvesicles across a population with various degree of cardiovascular burden are associated with systolic blood pressure

Circulating microvesicles (MVs) have been studied in heterogeneous, divergent, and rather small patient populations with cardiovascular risk . Therefore, we measured endothelial (EMVs), platelet (PMVs) and erythrocyte (RMVs) MVs in patients with divergent cardiovascular risk. We then compared them to coronary artery disease (CAD) and healthy subjects and identified independent MVs' predictors. We enrolled consecutive patients from our Cardiology, Hypertension, Diabetic, Rheumatic, and Nephrology Outpatient Units with MVs measurements. Central blood pressure (BP) was measured by either applanation tonometry or Mobil-O-graph device, while MVs by a standardized flow cytometry protocol. We studied 369 participants with increased cardiovascular risk: 63 with high cardiovascular risk (47 diabetes mellitus type II/DM and 16 end-stage renal disease/ESRD), 92 with chronic inflammatory disorders and 73 with untreated essential hypertension/UEH. We further included 53 subjects with CAD and 87 otherwise healthy individuals. All MVs were lower in patients with increased cardiovascular risk compared to CAD, showing predictive value with high sensitivity and specificity. Furthermore, PMVs and EMVs were increased in patients with cardiovascular risk compared to healthy individuals. DM and ESRD patients had increased EMVs versus UEH and chronic inflammatory disorders. In the whole study population, RMVs were associated only with history of essential hypertension. In multivariate analysis, systolic BP predicted PMVs. Aage, systolic BP, and DM predicted EMVs. In a large population of patients with divergent cardiovascular risk, MVs are independently associated with systolic blood pressure.

Assessment of microvesicles from different cell origins in patients with psoriasis: evidence of thrombogenic, proinflammatory microenvironment in the absence of established cardiovascular disease

Psoriasis is associated with increased cardiovascular risk. Endothelial, platelet, and erythrocyte microvesicles (MVs) are novel biomarkers of endothelial dysfunction and thromboinflammation. We explored whether MVs of different cell types are elevated in patients with psoriasis, and investigated potential associations with disease severity and macrovascular function. Endothelial, platelet and erythrocyte MVs were measured using a standardized flow cytometry protocol in psoriasis patients and controls free from established cardiovascular disease. Carotid intima-media thickness (IMT) and pulse wave velocity (PWV) were measured as markers of subclinical atherosclerosis and arterial stiffness. Psoriasis severity was assessed with PASI (Psoriasis Area Severity Index). Both platelet (p < 0.001) and erythrocyte MVs (p = 0.046), yet not endothelial MVs, were significantly increased in patients with psoriasis (n = 41) compared with controls (n = 41). Patients with higher PASI (≥10) presented significantly higher levels of ErMVs compared to those with lower PASI (<10) (p = 0.047). Carotid IMT and PWV were comparable between psoriasis patients and controls and did not significantly correlate with MVs. In the multivariate analysis, psoriasis was identified as an independent predictor of both platelet (p < 0.001) and erythrocyte MVs (p = 0.043), while hypertension was independently associated with endothelial MVs (p < 0.001). Increased formation of platelet and erythrocyte MVs may be evident in psoriasis patients and is indicative of prothrombotic, proinflammatory microenvironment, even in the absence of subclinical macrovascular dysfunction and before the clinical onset of overt cardiovascular complications. Potential mechanistic links and prognostic implications of increased MVs in psoriasis warrant further investigation.

Circulating Small Extracellular Vesicles Reflect the Severity of Myocardial Damage in STEMI Patients

Circulating small extracellular vesicles (sEVs) contribute to inflammation, coagulation and vascular injury, and have great potential as diagnostic markers of disease. The ability of sEVs to reflect myocardial damage assessed by Cardiac Magnetic Resonance (CMR) in ST-segment elevation myocardial infarction (STEMI) is unknown. To fill this gap, plasma sEVs were isolated from 42 STEMI patients treated by primary percutaneous coronary intervention (pPCI) and evaluated by CMR between days 3 and 6. Nanoparticle tracking analysis showed that sEVs were greater in patients with anterior STEMI (p = 0.0001), with the culprit lesion located in LAD (p = 0.045), and in those who underwent late revascularization (p = 0.038). A smaller sEV size was observed in patients with a low myocardial salvage index (MSI, p = 0.014). Patients with microvascular obstruction (MVO) had smaller sEVs (p < 0.002) and lower expression of the platelet marker CD41-CD61 (p = 0.039). sEV size and CD41-CD61 expression were independent predictors of MVO/MSI (OR [95% CI]: 0.93 [0.87-0.98] and 0.04 [0-0.61], respectively). In conclusion, we provide evidence that the CD41-CD61 expression in sEVs reflects the CMR-assessed ischemic damage after STEMI. This finding paves the way for the development of a new strategy for the timely identification of high-risk patients and their treatment optimization.

Platelet-Released Extracellular Vesicle Characteristics Differ in Chronic and in Acute Heart Disease

BACKGROUND

 Extracellular vesicles (EVs), shed in response to cell activation, stress, or injury, are increased in the blood of patients with cardiovascular disease. EVs are characterized by expressing parental-cell antigens, allowing the determination of their cellular origin. Platelet-derived EVs (pEVs) are the most abundant in blood. Although not universally given, EVs generally express phosphatidylserine (PS) in their membrane.

OBJECTIVES

 To investigate pEVs in chronic and acute conditions, such as chronic heart failure (CHF) and first-onset acute coronary syndrome (ACS), in patients treated as per guidelines.

METHODS

 EVs in CHF patients (n = 119), ACS patients (n = 58), their respective controls (non-CHF [n = 21] and non-ACS [n = 24], respectively), and a reference control group (n = 31) were characterized and quantified by flow cytometry, using monoclonal antibodies against platelet antigens, and annexin V (AV) to determine PS exposure.

RESULTS

 CHF patients had higher EVs-PS- numbers, while ACS had predominantly EVs-PS+. In contrast to ACS, CHF patients had significantly reduced numbers of pEVs carrying PECAM and αIIb-integrin epitopes (CD31+/AV+, CD41a+/AV+, and CD31+/CD41a+/AV+), while no differences were observed in P-selectin-rich pEVs (CD62P+/AV+) compared with controls. Additionally, background etiology of CHF (ischemic vs. nonischemic) or ACS type (ST-elevation myocardial infarction [STEMI] vs. non-STEMI [NSTEMI]) did not affect pEV levels.

CONCLUSION

 PS exposure in EV and pEV-release differ between CHF and ACS patients, with tentatively different functional capacities beyond coagulation to inflammation and cross-talk with other cell types.

Pravastatin reduces plasma levels of extracellular vesicles in pregnancies at high risk of term preeclampsia

Introduction: Elevated plasma levels of extracellular vesicles have been associated with impaired placentation, angiogenesis imbalance, intravascular inflammation, and endothelial dysfunction in women with preeclampsia, thus suggesting that circulating vesicles may be a good therapeutic target for the treatment of the disease. Recently, statins have been considered a potential treatment for the prevention of preeclampsia because of their pleiotropic effects, including the improvement of endothelial dysfunction and inhibition of inflammatory responses. However, the effects of these drugs on circulating vesicles concentration in women at risk of preeclampsia have not been established. Herein, we aimed to assess the effects of pravastatin on circulating extracellular vesicle generation in women at high risk of term preeclampsia. Methods: In a sample of 68 singleton pregnant women participating in the multicenter, double-blind, placebo-controlled STATIN trial (Nº EducraCT 2016-005206-19 ISRCTN), 35 women received a placebo and 33 women received a 20 mg/day dose of pravastatin for approximately 3 weeks (from 35 to 37 weeks of gestation until delivery). Large extracellular vesicles were characterized and quantified by flow cytometry using annexin V and cell-specific antibodies directed against platelet, endothelial, leukocyte, and syncytiotrophoblast cell surface markers. Results: In women who received the placebo, a significant increase in the plasma levels of large extracellular vesicles from platelets (34%, p < 0.01), leukocytes (33%, p < 0.01), monocytes (60%, p < 0.01), endothelial cells (40%, p < 0.05), and syncytiotrophoblast cells (22%, p < 0.05) were observed. However, treatment with pravastatin significantly reduced the plasma levels of large extracellular vesicles from platelets (42%, p < 0.001), leukocytes (25%, p < 0.001), monocytes (61%, p < 0.001), endothelial cells (69%, p < 0.001), activated endothelial cells (55%, p < 0.001), and syncytiotrophoblast cells (44%, p < 0.001). Discussion: These results indicate that pravastatin reduces the levels of activated cell-derived membrane vesicles from the maternal vasculature, blood, and placental syncytiotrophoblast of women at high risk of term preeclampsia, suggesting that this statin may be beneficial in reducing endothelial dysfunction and pro-inflammatory and pro-coagulatory state characteristics of the disease.

New factors in heart failure pathophysiology: Immunity cells release of extracellular vesicles

Leukocyte-shed extracellular vesicles (EVs) can play effector roles in the pathophysiological mechanisms of different diseases. These EVs released by membrane budding of leukocytes have been found in high amounts locally in inflamed tissues and in the circulation, indicating immunity cell activation. These EVs secreted by immune cell subsets have been minimally explored and deserve further investigation in many areas of disease. In this study we have investigated whether in heart failure there is innate and adaptive immune cell release of EVs. Patients with chronic heart failure (cHF) (n = 119) and in sex- and age-matched controls without this chronic condition (n = 60). Specifically, EVs were quantified and phenotypically characterized by flow cytometry and cell-specific monoclonal antibodies. We observed that even in well medically controlled cHF patients (with guideline-directed medical therapy) there are higher number of blood annexin-V⁺ (phosphatidylserine⁺)-EVs carrying activated immunity cell-epitopes in the circulation than in controls (p < 0.04 for all cell types). Particularly, EVs shed by monocytes and neutrophils (innate immunity) and by T-lymphocytes and natural-killer cells (adaptive immunity) are significantly higher in cHF patients. Additionally, EVs-shed by activated leukocytes/neutrophils (CD11b⁺, p = 0.006; CD29⁺/CD15⁺, p = 0.048), and T-lymphocytes (CD3⁺/CD45⁺, p < 0.02) were positively correlated with cHF disease severity (NYHA classification). Interestingly, cHF patients with ischemic etiology had the highest levels of EVs shed by lymphocytes and neutrophils (p < 0.045, all). In summary, in cHF patients there is a significant immune cell activation shown by high-release of EVs that is accentuated by clinical severity of cHF. These activated innate and adaptive immunity cell messengers may contribute by intercellular communication to the progression of the disease and to the common affectation of distant organs in heart failure (paracrine regulation) that contribute to the clinical deterioration of cHF patients.

Radiovesicolomics-new approach in medical imaging

This review introduce extracellular vesicles (EVs) to a molecular imaging field. The idea of modern analyses based on the use of omics studies, using high-throughput methods to characterize the molecular content of a single biological system, vesicolomics seems to be the new approach to collect molecular data about EV content, to find novel biomarkers or therapeutic targets. The use of various imaging techniques, including those based on radionuclides as positron emission tomography (PET) or single photon emission computed tomography (SPECT), combining molecular data on EVs, opens up the new space for radiovesicolomics—a new approach to be used in theranostics.

Endothelial Dysfunction in Psoriasis: An Updated Review

Although psoriasis is predominantly a chronic inflammatory skin disorder, epidemiological data provide a solid link between psoriasis, especially in its more severe forms, and increased risk for cardiovascular morbidity and mortality. Apart from the increased prevalence of traditional cardiovascular risk factors, chronic inflammation appears to act synergistically with the underlying process of endothelial dysfunction toward the development of accelerated atherosclerosis, subclinical vascular injury and subsequently, clinically evident cardiovascular manifestations. Endothelial dysfunction is regarded as an early precursor of atherosclerosis with a predictive value for the development of future cardiovascular events. A thorough understanding of the mechanisms of endothelial dysfunction in psoriasis might pave the path for the development of more accurate cardiovascular risk prediction tools and possible therapeutic targets aiming to alleviate the increased cardiovascular burden associated with the disease. The present review summarizes the available evidence about the role of chronic inflammation and other important pathophysiological mechanisms involved in the development of endothelial dysfunction in psoriasis. An overview of studies implementing the most widely applied circulating and vascular biomarkers of endothelial dysfunction in psoriasis patients will be provided, and the impact of systemic psoriasis treatments on endothelial dysfunction and patients’ cardiovascular risk will be discussed.

Neutrophil microvesicles and their role in disease

Microvesicles are formed through shedding from the plasma membrane, a process shared by almost all human cells. Microvesicles are highly abundant and have been detected in blood, urine, cerebrospinal fluid, and saliva. They contain a library of cargo derived from their parental cell during formation, including proteases, micro-RNAs and lipids and delivery of this parental cell-derived cargo to other cells can alter target cell function and drive disease. Cell specific molecules on the surface of microvesicles, obtained during microvesicle formation, allows their parental cell to be identified and populations of microvesicles to be investigated for roles in the pathogenesis of various diseases. For instance, recent work by our group has identified a role for neutrophil microvesicles in atherosclerosis. Microvesicle profiles could in future be associated with certain diseases and act as a biomarker to allow for earlier diagnosis. This short review will discuss some of the processes central to all microvesicles before focusing on neutrophil microvesicles, their potential role in cardiovascular disease and the mechanisms that may underpin this.

Platelet Mediated Inflammation in Coronary Artery Disease with Type 2 Diabetes Patients

BACKGROUND

Type 2 diabetes mellitus (T2DM) is a well-established risk factor for the development of atherosclerotic coronary artery disease. Platelet hyperactivity and inflammation are associated with the development of coronary artery disease (CAD) in T2DM patients. We investigated the status of immune cells, platelet activation, and platelet-immune cell interactions in T2DM_CAD patients.

METHODOLOGY

The study population consisted of four groups of subjects, healthy control (CT, n = 20), T2DM (n = 44), CAD (n = 20) and T2DM_CAD (n = 38). Platelet activation, immunome profiling and platelet-immune cell interactions were analysed by flow cytometry. The circulatory levels of inflammatory cytokines/chemokines were assessed using multiplex assay.

RESULTS

Increased platelet activation and increased platelet-immune cell aggregate formation were observed in T2DM and T2DM_CAD groups compared to the control and CAD groups (p < 0.05). Our immunome profile analysis revealed, altered monocyte subpopulations and dendritic cell populations in T2DM, CAD and T2DM_CAD groups compared to the control group (p < 0.05). Furthermore, significantly increased IL-1β, IL-2, IL-4, IL-6, IL-8, IL12p70, IL-13 IL-18, CCL2, and decreased CXCL1, CCL5 levels were observed in T2DM_CAD group compared to the control group. Our ex-vivo study increased platelet-monocyte aggregate formation was observed upon D-glucose exposure in a time and concentration dependent manner.

CONCLUSION

Our data suggests that T2DM, CAD and T2DM_CAD are associated with altered immune cell populations. Furthermore, it has been confirmed that hyperglycemia induces platelet activation and forms platelet-immune cell aggregation which may lead to the release of inflammatory cytokines and chemokines and contribute to the complexity of CAD and type 2 diabetes.

Patients with autoimmune chronic inflammatory diseases present increased biomarkers of thromboinflammation and endothelial dysfunction in the absence of flares and cardiovascular comorbidities

Cardiovascular risk is increased in patients with autoimmune rheumatic diseases. Endothelial, erythrocyte and platelet microvesicles (MVs) are elevated in patients with cardiovascular diseases and represent novel markers of endothelial dysfunction and thromboinflammation. We tested whether their levels are increased in patients with autoimmune rheumatic diseases (ARDs) in the absence of disease flare and cardiovascular comorbidities. Well-controlled patients with rheumatoid arthritis or systemic lupus erythematosus were studied, provided they were free from cardiovascular comorbidities and established cardiovascular disease. We additionally studied (a) a control group consisting of healthy volunteers and (b) a reference group including patients with stable coronary artery disease (CAD). MVs were measured using a standardized flow cytometry protocol. In a population of 74 participants, patients with ARDs (n = 17) presented increased levels of both endothelial (283.3 ± 195.0/μL vs 168.5 ± 54.8/μL, p = 0.029) and platelet MVs (374.0 ± 275.3/μL vs 225.7 ± 101.1/μL, p = 0.046) compared to controls (n = 34), whereas erythrocyte MVs did not significantly differ. In addition, patients with ARDs showed similar levels of endothelial MVs compared to CAD patients (n = 23) (283.3 ± 195.0/μL vs 297.0 ± 211.8/μL, p = 0.846). Platelet MVs were significantly associated with disease duration, and erythrocyte MVs with patients' perceived disease activity. In conclusion, increased levels of endothelial and platelet MVs may be evident in patients with ARDs, even in the absence of disease flares and before the establishment of cardiovascular complications. Levels of endothelial MVs resemble those of patients with profound atherothrombotic profile. The prognostic potential of MVs in terms of cardiovascular disease prevention warrants further investigation in patients with ARDs.

A study of endothelial and platelet microvesicles across different hypertension phenotypes

Rather than being mere biomarkers reflecting generalized vascular injury, endothelial- (EMVs) and platelet-derived (PMVs) microvesicles have emerged as potent regulators of intercellular communication with significant biologic effects in vascular homeostasis and several pathophysiological responses including inflammation and thrombosis. So far, studies in hypertension are scarce, whereas no studies exist in masked hypertension (MH). We measured EMVs and PMVs in untreated, newly diagnosed hypertensives (HTs) and MHs compared to normotensive controls (NTs), and associated them with various cardiovascular risk factors. Sustained hypertension (SHT) and MH were defined according to standard blood pressure (BP) criteria. All HTs were free of cardiovascular disease and medications. Microvesicles' quantitation and detection were performed by flow cytometry by using cell-specific antibodies and corresponding isotypes (anti-CD105 and anti-CD144 for EMVs, anti-CD42a for PMVs, and Annexin V-fluorescein isothiocyanate for all microvesicles). In this study, we included 59 HTs (44 SHTs and 15 MHs) and 27 NTs. HTs had significantly elevated EMVs (p = 0.004), but not PMVs compared to NTs. MHs had significantly elevated EMVs compared to NTs (p = 0.012) but not compared to SHTs. Furthermore, EMVs significantly correlated with ambulatory (r = 0.214-0.284), central BP (r = 0.247-0.262), and total vascular resistance (r = 0.327-0.361). EMVs are increased not only in SHTs but also in MHs, a hypertension phenotype with a cardiovascular risk close to SHT. EMVs have emerged as active contributors to thromboinflammation and vascular damage and may explain, in part, the adverse cardiovascular profile of SHTs and MHs.

Assessment of Endothelial Injury and Pro-Coagulant Activity Using Circulating Microvesicles in Survivors of Allogeneic Hematopoietic Cell Transplantation

(1) Background: survivors of allogeneic hematopoietic cell transplantation (alloHCT) suffer from morbidity and mortality due to cardiovascular events. We hypothesized that vascular injury and pro-coagulant activity are evident in alloHCT survivors without existing alloHCT complications or relapse. (2) Methods: we enrolled consecutive adult alloHCT survivors without established cardiovascular disease and control individuals matched for traditional cardiovascular risk factors (January-December 2019). Circulating microvesicles (MVs) of different cellular origins (platelet, erythrocyte, and endothelial) were measured by a standardized flow cytometry protocol as novel markers of vascular injury and pro-coagulant activity. (3) Results: we recruited 45 survivors after a median of 2.3 (range 1.1-13.2) years from alloHCT, and 45 controls. The majority of patients suffered from acute (44%) and/or chronic (66%) graft-versus-host disease (GVHD). Although the two groups were matched for traditional cardiovascular risk factors, alloHCT survivors showed significantly increased platelet and erythrocyte MVs compared to controls. Within alloHCT survivors, erythrocyte MVs were significantly increased in patients with a previous history of thrombotic microangiopathy. Interestingly, endothelial MVs were significantly increased only in alloHCT recipients of a myeloablative conditioning. Furthermore, MVs of different origins showed a positive association with each other. (4) Conclusions: endothelial dysfunction and increased thrombotic risk are evident in alloHCT recipients long after alloHCT, independently of traditional cardiovascular risk factors. An apparent synergism of these pathophysiological processes may be strongly involved in the subsequent establishment of cardiovascular disease.