Circulating cell-derived microparticles as biomarkers in cardiovascular disease

A Review of MicroRNAs and lncRNAs in Atherosclerosis as Well as Some Major Inflammatory Conditions Affecting Atherosclerosis

It is generally accepted that atherosclerosis is a chronic inflammatory disease. The link between atherosclerosis and other inflammatory diseases such as psoriasis, type 2 diabetes mellitus (T2DM), and rheumatoid arthritis (RA) via metabolic, inflammatory, and immunoregulatory pathways is well established. The aim of our review was to summarize the associations between selected microRNAs (miRs) and long non-coding RNAs (lncRNAs) and atherosclerosis, psoriasis, T2DM, and RA. We reviewed the role of miR-146a, miR-210, miR-143, miR-223, miR-126, miR-21, miR-155, miR-145, miR-200, miR-133, miR-135, miR-221, miR-424, let-7, lncRNA-H19, lncRNA-MEG3, lncRNA-UCA1, and lncRNA-XIST in atherosclerosis and psoriasis, T2DM, and RA. Extracellular vesicles (EVs) are a method of intracellular signal transduction. Their function depends on surface expression, cargo, and the cell from which they originate. The majority of the studies that investigated lncRNAs and some miRs had relatively small sample sizes, which limits the generalizability of their findings and indicates the need for more research. Based on the studies reviewed, miR-146a, miR-155, miR-145, miR-200, miR-133, and lncRNA-H19 are the most promising potential biomarkers and, possibly, therapeutic targets for atherosclerosis as well as T2DM, RA, and psoriasis.

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.

Extracellular Vesicles in Atrial Fibrillation—State of the Art

Extracellular vesicles are particles released from cells and delimited by a lipid bilayer. They have been widely studied, including extensive investigation in cardiovascular diseases. Many scientists have explored their role in atrial fibrillation. Patients suffering from atrial fibrillation have been evidenced to present altered levels of these particles as well as changed amounts of their contents such as micro-ribonucleic acids (miRs). Although many observations have been made so far, a large randomized clinical trial is needed to assess the previous findings. This review aims to thoroughly summarize current research regarding extracellular vesicles in atrial fibrillation.

Supervised and unsupervised learning to define the cardiovascular risk of patients according to an extracellular vesicle molecular signature

Cardiovascular (CV) disease represents the most common cause of death in developed countries. Risk assessment is highly relevant to intervene at individual level and implement prevention strategies. Circulating extracellular vesicles (EVs) are involved in the development and progression of CV diseases and are considered promising biomarkers. We aimed at identifying an EV signature to improve the stratification of patients according to CV risk and likelihood to develop fatal CV events. EVs were characterized by nanoparticle tracking analysis and flow cytometry for a standardized panel of 37 surface antigens in a cross-sectional multicenter cohort (n = 486). CV profile was defined by presence of different indicators (age, sex, body mass index, hypertension, hyperlipidemia, diabetes, coronary artery disease, cardiac heart failure, chronic kidney disease, smoking habit, organ damage) and according to the 10-year risk of fatal CV events estimated using SCORE charts of European Society of Cardiology. By combining expression levels of EV antigens using unsupervised learning, patients were classified into 3 clusters: Cluster-I (n = 288), Cluster-II (n = 83), Cluster-III (n = 30). A separate analysis was conducted on patients displaying acute CV events (n = 82). Prevalence of hypertension, diabetes, chronic heart failure, and organ damage (defined as left ventricular hypertrophy and/or microalbuminuria) increased progressively from Cluster-I to Cluster-III. Several EV antigens, including markers for platelets (CD41b-CD42a-CD62P), leukocytes (CD1c-CD2-CD3-CD4-CD8-CD14-CD19-CD20-CD25-CD40-CD45-CD69-CD86), and endothelium (CD31-CD105) were independently associated with CV risk indicators and correlated to age, blood pressure, glucometabolic profile, renal function, and SCORE risk. EV profiling, obtained from minimally invasive blood sampling, allows accurate patient stratification according to CV risk profile.

Microparticles in Autoimmunity: Cause or Consequence of Disease?

Microparticles (MPs) are small (100 nm - 1 um) extracellular vesicles derived from the plasma membrane of dying or activated cells. MPs are important mediators of intercellular communication, transporting proteins, nucleic acids and lipids from the parent cell to other cells. MPs resemble the state of their parent cells and are easily accessible when released into the blood or urine. MPs also play a role in the pathogenesis of different diseases and are considered as potential biomarkers. MP isolation and characterization is technically challenging and results in different studies are contradictory. Therefore, uniform guidelines to isolate and characterize MPs should be developed. Our understanding of MP biology and how MPs play a role in different pathological mechanisms has greatly advanced in recent years. MPs, especially if derived from apoptotic cells, possess strong immunogenic properties due to the presence of modified proteins and nucleic acids. MPs are often found in patients with autoimmune diseases where MPs for example play a role in the break of immunological tolerance and/or induction of inflammatory conditions. In this review, we describe the main techniques to isolate and characterize MPs, define the characteristics of MPs generated during cell death, illustrate different mechanism of intercellular communication via MPs and summarize the role of MPs in pathological mechanisms with a particular focus on autoimmune diseases.

The Role of Cell Derived Microparticles in Cardiovascular Diseases: Current Concepts

Abstract:

Cardiovascular disease remains the main cause of human morbidity and mortality in the developed countries. Microparticles (MPs) are small vesicles originating from the cell membrane as a result of various stimuli and particularly of biological processes that constitute the pathophysiology of atherosclerosis, such as endothelial damage. They form vesicles that can transfer various molecules and signals to remote target cells without direct cell to cell interaction. Circulating microparticles have been associated with cardiovascular diseases. Therefore, many studies have been designed to further investigate the role of microparticles as biomarkers for diagnosis, prognosis, and disease monitoring. To this concept the pro-thrombotic and atherogenic potential of platelets and endothelial derived MPs has gain research interest especially concerning accelerate atherosclerosis and acute coronary syndrome triggering and prognosis. MPs especially of endothelial origin have been investigated in different clinical scenarios of heart failure and in association of left ventricular loading conditions. Finally, most cardiovascular risk factors present unique patterns of circulating MPs population, highlighting their pathophysiologic link to cardiovascular disease progression. In this review article we present a synopsis of the biogenesis and characteristics of microparticles, as well as the most recent data concerning their implication in the cardiovascular settings.

Exosomes in atrial fibrillation: therapeutic potential and role as clinical biomarkers

Atrial fibrillation (AF), the most common cardiac arrhythmia, is a global epidemic. AF can cause heart failure and myocardial infarction and increase the risk of stroke, disability, and thromboembolic events. AF is becoming increasingly ubiquitous and is associated with increased morbidity and mortality at higher ages, resulting in an increasing threat to human health as well as substantial medical and social costs. Currently, treatment strategies for AF focus on controlling heart rate and rhythm with medications to restore and maintain sinus rhythm, but this approach has limitations. Catheter ablation is not entirely satisfactory and does not address the issues underlying AF. Research exploring the mechanisms causing AF is urgently needed for improved prevention, diagnosis, and treatment of AF. Exosomes are small vesicles (30-150 nm) released by cells that transmit information between cells. MicroRNAs in exosomes play an important role in the pathogenesis of AF and are established as a biomarker for AF. In this review, a summary of the role of exosomes in AF is presented. The role of exosomes and microRNAs in AF occurrence, their therapeutic potential, and their potential role as clinical biomarkers is considered. A better understanding of exosomes has the potential to improve the prognosis of AF patients worldwide, reducing the global medical burden of this disease.

Circulating microparticles in patients with chronic hepatitis C and changes during direct-acting antiviral therapy

BACKGROUND

Microparticles (MPs) are heterogeneous vesicles derived from membranes of different cells. Between 70 to 90% of MPs detected in blood originate from platelets. The release of MPs is associated with proinflammatory and procoagulant states. Elevated levels of MPs have been found in different diseases. We investigated MPs levels in patients with chronic hepatitis C (CHC) and changes in level during treatment using direct-acting antivirotics (DAA).

PATIENTS AND METHODS

Thirty-six patients with CHC and forty healthy volunteers were included in the study. Concentrations of MPs were determined indirectly by measuring their procoagulant activity in plasma at baseline, end of therapy (EOT), and 12 weeks after EOT when the sustained virological response was assessed (SVR12).

RESULTS

All patients achieved SVR12, which was associated with rapid improvement of markers of liver damage and function as well as liver stiffness (P=0.002). MPs levels were significantly higher in CHC patients than in healthy volunteers (P<0.001). No statistically significant decrease was found observed between baseline and SVR12 (P=0,330). Analysis of subpopulations with minimal fibrosis F0-1 (P=0.647), advanced fibrosis F2-4 (P=0.370), women(P=0.847), men (P=0.164) and genotype 1 (P=0.077) showed no significant changes during the follow-up period.

CONCLUSIONS

MPs levels are higher in CHC patients and remain elevated shortly after achieving SVR. Higher concentrations of MPs in plasma are probably caused by a chronic uncontrolled exaggerated inflammatory response caused by CHC. Longer observation would probably confirm the significance of MPs levels decrease because normalization of liver function, inflammation, and structure after SVR requires more than 12 weeks.

Pulmonary Endothelial Dysfunction and Thrombotic Complications in Patients with COVID-19

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), a new strain of a Coronaviridae virus that presents 79% genetic similarity to the severe acute respiratory syndrome coronavirus, has been recently recognized as the cause of a global pandemic by the World Health Organization, implying a major threat to world public health. SARS-CoV-2 infects host human cells by binding through the viral spike proteins to the ACE-2 (angiotensin-converting enzyme 2) receptor, fuses with the cell membrane, enters, and starts its replication process to multiply its viral load. Coronavirus disease (COVID-19) was initially considered a respiratory infection that could cause pneumonia. However, in severe cases, it extends beyond the respiratory system and becomes a multiorgan disease. This transition from localized respiratory infection to multiorgan disease is due to two main complications of COVID-19. On the one hand, it is due to the so-called cytokine storm: an uncontrolled inflammatory reaction of the immune system in which defensive molecules become aggressive for the body itself. On the other hand, it is due to the formation of a large number of thrombi that can cause myocardial infarction, stroke, and pulmonary embolism. The pulmonary endothelium actively participates in these two processes, becoming the last barrier before the virus spreads throughout the body. In this review, we examine the role of the pulmonary endothelium in response to COVID-19, the existence of potential biomarkers, and the development of novel therapies to restore vascular homeostasis and to protect and/or treat coagulation, thrombosis patients. In addition, we review the thrombotic complications recently observed in patients with COVID-19 and its potential threatening sequelae.

Multifaceted role of extracellular vesicles in atherosclerosis

Extracellular vesicles (EVs) are small vesicles released by the majority of cells in response to cell activation or death stimuli. They are grouped as small EVs or exosomes, large EVs such as microvesicles (MVs) and apoptotic bodies, resulting from distinct mechanisms of generation. EVs are released into the extracellular space, in most human biological fluids and tissues, including atherosclerotic plaques. They transport complex cargo of bioactive molecules, including proteins, lipids and genetic material and are therefore involved in pathophysiological pathways of cell-cell communication. Indeed, EVs are involved in several processes such as inflammation, coagulation, vascular dysfunction, angiogenesis and senescence, contributing to the initiation and progression of atherothrombotic diseases. Consequently, they behave as a determinant of atherosclerotic plaque vulnerability leading to major cardiovascular disorders. Over the last decade, the field of EVs research has grown, highlighting their involvement in atherosclerosis. However, limitations in both detection methodologies and standardisation have hindered implementation of EVs in the clinical settings. This review summarizes the effect of EVs in atherosclerosis development, progression and severity, with specific attention devoted to their ambivalent roles in senescence and hemostasis. This review will also highlight the role of MVs as multifaceted messengers, able to promote or to attenuate atherosclerosis progression. Finally, we will discuss the main technical challenges and prerequisites of standardization for driving EVs to the clinics and delineate their relevance as emergent biomarkers and innovative therapeutic approaches in atherosclerosis.

A new hybrid immunocapture bioassay with improved reproducibility to measure tissue factor-dependent procoagulant activity of microvesicles from body fluids

BACKGROUND

The procoagulant activity of tissue factor-bearing microvesicles (MV-TF) has been associated with the risk of developing venous thrombosis in cancer patients. However, MV-TF assays are limited either by i) a lack of specificity, ii) a low sensitivity, or iii) a lack of repeatability when high-speed centrifugation (HS-C) is used to isolate MV. Therefore, our objective was to develop a new hybrid "capture-bioassay" with improved reproducibility combining MV immunocapture from biofluids and measurement of their TF activity.

MATERIALS AND METHODS

Factor Xa generation and flow cytometry assays were used to evaluate IMS beads performance, and to select the most effective capture antibodies. The analytical performance between IMS-based and HS-C-based assays was evaluated with various models of plasma samples (from LPS-activated blood, spiked with tumoral MV, or with saliva MV) and different biofluids (buffer, plasma, saliva, and pleural fluid).

RESULTS

Combining both CD29 and CD59 antibodies on IMS beads was as efficient as HS-C to isolate plasmatic PS+ MV. The IMS-based strategy gave significantly higher levels of MV-TF activity than HS-C in tumor MV spiked buffer, and both pleural fluids and saliva samples. Surprisingly, lower TF values were measured in plasma due to TFPI (TF pathway inhibitor) non-specifically adsorbed onto beads. This was overcome by adding a TFPI-blocking antibody. After optimization, the new IMS-based assay significantly improved reproducibility of MV-TF bioassay versus the HS-C-based assay without losing specificity and sensitivity. In addition, this approach could identify the cellular origin of MV-TF in various biological fluids.

CONCLUSION

Compared to HS-C, the IMS-based measurement of MV-TF activity in body fluids improves reproducibility and makes the assay compatible with clinical practice. It can facilitate future automation.

Procoagulant microparticles are associated with arterial disease in patients with systemic lupus erythematosus

Microparticles (MPs) have been associated with inflammatory and thrombotic disease. High levels of MPs have been identified in patients with systemic lupus erythematosus (SLE) and associated with cardiovascular disease. We analyzed the procoagulant activity of MPs and its correlation with arteriosclerosis and arterial thrombosis in SLE patients. Eighty-seven patients with SLE were included: 22 (25.3%) with associated antiphospholipid syndrome (APS), 32 (36.8%) without antiphospholipid antibodies (aPL) and 33 (37.9%) with aPL but without APS. Subclinical arteriosclerosis, defined as the presence and number of plaques, was evaluated by ultrasonography of carotid arteries. Thrombotic events were confirmed by objective methods. The procoagulant activity of MPs was determined by a functional assay with annexin V. Subclinical arteriosclerosis was found in 19 (21.8%) patients. Thirteen episodes of arterial thrombosis and eight of venous thrombosis were recorded. The procoagulant activity of MPs was greater in patients with arterial thrombosis (17.28 ± 8.29 nM vs 12.96 ± 7.90 nM, p < 0.05). In patients without arterial thrombosis, greater procoagulant activity of MPs was identified in patients with multiple (≥ 2) carotid plaques (17.26 ± 10.63 nM vs 12.78 ± 7.15 nM, p = 0.04). In the multivariate analysis, the procoagulant activity of MPs was independently associated with multiple (≥ 2) carotid plaques and arterial thrombosis [OR = 1.094 (95%CI 1.010-1.185), p = 0.027 and OR = 1.101 (95%CI 1.025-1.182), p = 0.008; respectively]. In conclusion, the procoagulant activity of MPs is associated with arteriosclerosis burden and arterial thrombosis in patients with SLE.

Liquid Biopsies: Microvesicles in Cardiovascular Disease

Significance: Circulating microvesicles (cMV) are small (0.1-1 μm) phospholipid-rich blebs released by almost all cell types, and their release increases with cell activation and injury, thus reflecting the state of the cell from which they are originated. Microvesicles (MV) are found in the bloodstream, and they affect the phenotype of recipient cells, after local or systemic circulation, by intercellular transfer of their molecular content. Recent Advances: Several studies suggest the use of cell-specific MV subpopulations as predictive biomarkers for cardiovascular diseases (CVDs) at different stages and degrees of severity. In this review, we describe the state of the art of cMV as noninvasive surrogate biomarkers of vascular injury and dysfunction correlated with poor clinical outcomes in CVD. Critical Issues: Despite the growing body of evidence supporting the importance of cMV as hallmarks of CVD and their utility as biomarkers of CVD, the specific roles of each phenotype of cMV in CVD burden and prognosis still remain to be elucidated and validated in large cohorts. In addition, the development of standardized and reproducible techniques is required to be used as biomarkers for disease progression in the clinical setting. Future Directions: A multipanel approach with specific cMV phenotypes, added to current biomarkers and scores, will undoubtedly provide unique prognostic information to stratify patients for appropriate therapy on the basis of their risk of atherothrombotic disease and will open a new research area as therapeutic targets for CVD. MV will add to the implementation of precision medicine by helping the cellular and molecular characterization of CVD patients.

Extracellular vesicle signalling in atherosclerosis

Atherosclerosis is a major cardiovascular disease and in 2016, the World Health Organisation (WHO) estimated 17.5 million global deaths, corresponding to 31% of all global deaths, were driven by inflammation and deposition of lipids into the arterial wall. This leads to the development of plaques which narrow the vessel lumen, particularly in the coronary and carotid arteries. Atherosclerotic plaques can become unstable and rupture, leading to myocardial infarction or stroke. Extracellular vesicles (EVs) are a heterogeneous population of vesicles secreted from cells with a wide range of biological functions. EVs participate in cell-cell communication and signalling via transport of cargo including enzymes, DNA, RNA and microRNA in both physiological and patholophysiological settings. EVs are present in atherosclerotic plaques and have been implicated in cellular signalling processes in atherosclerosis development, including immune responses, inflammation, cell proliferation and migration, cell death and vascular remodeling during progression of the disease. In this review, we summarise the current knowledge regarding EV signalling in atherosclerosis progression and the potential of utilising EV signatures as biomarkers of disease.

Effects of Cell-Derived Microparticles on Immune Cells and Potential Implications in Clinical Medicine

In the past few years, interest has increased in cell-derived microparticles (MPs), which are defined by their size of from 0.1 to 1 μm, and can be derived from various cell types, including endothelial cells, leukocytes, red blood cells (RBCs), and platelets. These MPs carry negatively charged phosphatidylserine (PS) on their surfaces and proteins packaged from numerous cellular components. MPs that have been shed by the body can play important roles in the pathophysiology of diseases and can affect various biological systems. Among these systems, the immune components have been shown to be modulated by MPs. Therefore, understanding the roles of MPs in the immune system is crucial to developing alternative therapeutic treatments for diseases. This review describes the effects of MPs on various immune cells and provides plausible potential applications of the immune-modulating properties of MPs in clinical medicine.

Extracellular vesicles in atrial fibrillation and stroke

BACKGROUND

Atrial fibrillation (AF) is associated with a 5-fold increased risk of thromboembolic stroke. Extracellular vesicles (EVs) convey pathophysiological information and are possible biomarkers for risk of stroke.

METHODS

EVs were measured in 836 patients with AF (of which 280 were stroke cases) selected from the ARISTOTLE trial and in a cohort of unselected 70 year old individuals (n = 1007, reference material). EVs from platelets, leukocytes, erythrocytes and inflammatory endothelial cells were measured using flow cytometry and a solid-phase proximity ligation assay.

RESULTS

Concentrations of EVs were higher in the ARISTOTLE patients than in the PIVUS cohort for all the EV groups except EVs from endothelial cells (p < 0.0001). The distributions of the concentrations of the EVs were similar among the control group and the stroke cases for all of the sources of EVs in the ARISTOTLE study. EVs were modestly correlated with the levels of NT-ProBNP, Cystatin C, GDF-15 and D-dimer. Stronger correlations were found for platelet EVs as well as phosphatidyl serine positive EVs that were correlated with CD40 ligand in the ARISTOTLE study. Leukocyte EVs were correlated with IL-6 in both the ARISTOTLE and the PIVUS study, implicating them in different physiological processes.

CONCLUSIONS

Higher levels of EVs were found in anticoagulated patients with AF and a higher risk of stroke than in a general population of similar age, possibly due to the high disease burden in AF patients. Our data with EVs representing a broad repertoire of activated blood cells in AF patients suggest that EVs are likely not a key mediator of occurrence of stroke in this population.

Altered signature of apoptotic endothelial cell-derived microvesicles predicts chronic heart failure phenotypes

Aim: to evaluate the associations between signatures of apoptotic endothelial cell-derived microvesicles (MVs) with phenotypes of chronic heart failure (HF). Methods: The study cohort consisted of 388 prospectively involved subjects with HF patients with predominantly reduced left ventricular ejection fraction (HFrEF), HF with preserved ejection fraction (HFpEF) and HF with mid-range ejection fraction (HFmrEF). All biomarkers were measured at baseline. Results: The number of circulating CD31+/annexin V+ MVs in HFrEF and HFmrEF patients was similar. The number of circulating CD144+/annexin V+ MVs in HFrEF patients was significantly higher than HFmrEF and HFpEF. We determined that a combination of number of circulating CD31+/annexin V+ MVs and Gal-3 was the best predictor of HFpEF and that number of circulating CD144+/annexin V+ MVs is able to increase predictive capabilities of soluble ST2 (sST2) and Gal-3 for HFrEF. Conclusion: We found that the number of circulating CD31+/annexin V+ MVs may improve a predictive capacity for conventional HF biomarkers.

Extracellular Vesicles as Biomarkers in Cardiovascular Disease; Chances and Risks

The field of extracellular vesicles (EV) is rapidly expanding, also within cardiovascular diseases. Besides their exciting roles in cell-to-cell communication, EV have the potential to serve as excellent biomarkers, since their counts, content, and origin might provide useful information about the pathophysiology of cardiovascular disorders. Various studies have already indicated associations of EV counts and content with cardiovascular diseases. However, EV research is complicated by several factors, most notably the small size of EV. In this review, the advantages and drawbacks of EV-related methods and applications as biomarkers are highlighted.

Sensitive and Specific Detection of Platelet-Derived and Tissue Factor-Positive Extracellular Vesicles in Plasma Using Solid-Phase Proximity Ligation Assay

Extracellular vesicles (EVs) derived from blood cells are promising biomarkers for various diseases. However, they are difficult to measure accurately in plasma due to their small size. Here, we demonstrate that platelet-derived EVs in plasma can be measured using solid-phase proximity ligation assay with high sensitivity and specificity using very small sample volume of biological materials. The results correlate well with high-sensitivity flow cytometry with the difference that the smallest EVs are detected. Briefly, the EVs are first captured on a solid phase, using lactadherin binding, and detection requires recognition with two antibodies followed by qPCR. The assay, using cholera toxin subunit-B or lactadherin as capture agents, also allowed detection of the more rare population of tissue factor (TF)-positive EVs at a concentration similar to sensitive TF activity assays. Thus, this assay can detect different types of EVs with high specificity and sensitivity, and has the potential to be an attractive alternative to flow cytometric analysis of preclinical and clinical samples. Improved techniques for measuring EVs in plasma will hopefully contribute to the understanding of their role in several diseases.

[Membranous microparticles and respiratory disease]

Microparticles (MP) are plasmic membrane fragments released from cells after physiological stimulation or stress conditions like inflammation or infection. Their production is correlated to the rate of cell apoptosis. All types of cells can produce MP but they are produced mainly by platelets, endothelial cells, and leukocytes. They carry many bio-active molecules on their surface, specific to the parental cell, giving them the ability to be biomarkers and bio-effectors. MP are present in circulating blood, tissues and many biological fluids. Circulating MP levels can change during the course of many diseases. They have been the subject of many studies in the fields of cardiovascular disease and oncology. In the lungs, they are present in circulating blood and in the airways. They seem to have a role in pulmonary homeostasis in physiological situations and also in the expression of several disease processes. In this review of the literature, we were interested in the quantitative and qualitative variations in MP and their impact in airway diseases like chronic obstructive pulmonary disease (COPD) and asthma, pulmonary fibrosis and pulmonary hypertension.

Extracellular Vesicles in Cardiovascular Theranostics

Extracellular vesicles (EVs) are small bilayer lipid membrane vesicles that can be released by most cell types and detected in most body fluids. EVs exert key functions for intercellular communication via transferring their bioactive cargos to recipient cells or activating signaling pathways in target cells. Increasing evidence has shown the important regulatory effects of EVs in cardiovascular diseases (CVDs). EVs secreted by cardiomyocytes, endothelial cells, fibroblasts, and stem cells play essential roles in pathophysiological processes such as cardiac hypertrophy, cardiomyocyte survival and apoptosis, cardiac fibrosis, and angiogenesis in relation to CVDs. In this review, we will first outline the current knowledge about the physical characteristics, biological contents, and isolation methods of EVs. We will then focus on the functional roles of cardiovascular EVs and their pathophysiological effects in CVDs, as well as summarize the potential of EVs as therapeutic agents and biomarkers for CVDs. Finally, we will discuss the specific application of EVs as a novel drug delivery system and the utility of EVs in the field of regenerative medicine.

Assessment of the Procoagulant Activity of Microparticles and the Protein Z System in Patients Undergoing Off-Pump Coronary Artery Bypass Surgery

To understand the coagulation changes after off-pump coronary artery bypass (OPCAB) surgery, we evaluated the procoagulant activity of microparticles (MPs) and microparticles exposing tissue factor (MPs-TF), together with the levels of total tissue factor (TF), protein Z (PZ), protein Z-dependent protease inhibitor (ZPI), and factor X (FX) before (first day) and 1 week after surgery (seventh day) in plasma samples from 30 patients. Twenty healthy controls were also included. Compared to the controls, patients scheduled for surgery had significantly higher MPs-TF procoagulant activity and lower TF levels ( P = .0006, P = .02, respectively). In the whole cohort, median procoagulant activity of MPs-TF and median levels of TF and ZPI were significantly lower ( P = .02, P = .0003, and P = .004, respectively), while median levels of PZ and FX were significantly higher ( P = .02 and P = .002, respectively) on the seventh day compared to the first day. Our results suggest that OPCAB surgery has a significant effect on the procoagulant activity of MPs-TF and the PZ system.