Microparticles: targets and tools in cardiovascular disease. Trends Pharmacol Sci. 2011;32:659-665. [PMID: 21794929 DOI: 10.1016/j.tips.2011.06.005]

Acute effects of an anthocyanin-rich blackcurrant beverage on markers of cardiovascular disease risk in healthy adults: a randomized, double-blind, placebo-controlled, crossover trial

BACKGROUND

Epidemiological evidence suggests an inverse association between anthocyanin consumption and cardiovascular disease (CVD) risk. Modulation of vascular function and hemostasis may contribute to this, but there is limited clinical evidence.

OBJECTIVE

The present study investigated the acute effects of an anthocyanin-rich blackcurrant beverage, compared with a matched placebo, on selected markers of CVD risk in healthy middle-aged subjects in response to a high-fat meal.

METHODS

Twenty-three volunteers aged 39.9 ± 8.1 years (BMI 22.9 ± 2.3 kg/m2) completed a double-blind, randomized, placebo-controlled, crossover trial. Volunteers consumed either 200 mL blackcurrant beverage (744 mg polyphenols comprising 711 mg anthocyanins and 32 mg procyanidins) or a placebo, together with a high-fat breakfast (52.3 g fat) followed by a lunch (30 g fat) at 3 h, and the postprandial vascular response was compared. The primary endpoints were the assessment of vascular function by flow-mediated dilation (FMD) and the inhibition of collagen- and adenosine diphosphate-induced platelet aggregation. Secondary outcomes included blood pressure (BP), digital volume pulse waveforms, circulating numbers of endothelium- and platelet-derived extracellular vesicles (EVs), plasma concentrations of interleukin (IL)-8, and plasma and urinary concentrations of polyphenols and their metabolites were also evaluated.

RESULTS

There was a significant cumulative improvement in FMD following consumption of an anthocyanin-rich blackcurrant beverage compared with a matched placebo in conjunction with a high-fat meal over a 6 h postprandial period. There was a trend for an inhibitory effect of the blackcurrant beverage on agonist-induced platelet aggregation and significant effects on the secondary outcomes, SBP and IL-8, although these were exploratory and not adjusted for multiple testing. Plasma concentrations of hippuric acid and isovanillic acid were strong independent predictors of FMD and 4-hydroxybenzaldehyde and isoferulic acid glucuronide were predictors of SBP and DBP.

CONCLUSIONS

An anthocyanin-rich blackcurrant beverage mitigated the effects of a high fat meal on vascular function and markers of CVD risk, and this is associated with the appearance of specific plasma anthocyanin phenolic metabolites.

REGISTRATION

URL: https://classic.

CLINICALTRIALS

gov/ct2/show/NCT02459756; Unique identifier: NCT02459756.

Surface markers on microparticles involved in obesity-derived diseases

AIMS

This review aimed to investigate the different types of microparticles playing role in obesity-related diseases. Additionally, the factors participating in changing the microparticles amount in obese people will also be discussed.

MATERIAL & METHODS

The authors collected the relevant articles published until 2023 and these are carefully selected from three scientific databases based on keywords.

KEY FINDINGS

It has been revealed that exercise might change the microparticle content in the body. The other factor which participates in obesity process is the oxidative stress which is increased in microparticles. Moreover, the obesity is implicated in metabolic conditions including diabetes and cardiovascular diseases.

SIGNIFICANCE

More than one-third of people on the planet today are known as overweight individuals. Microparticles (MPs) are small membrane-bound vesicles that are found in healthy people's blood and are elevated in patients with pathological conditions such as obesity. MPs mostly come from platelets, leukocytes, endothelial cells, and vascular smooth muscle cells. Considering the effect of obesity on microparticles, these small membrane-bound vesicles might play a crucial role in preventing or treatment of obesity.

Sonic hedgehog signalling pathway contributes in age-related disorders and Alzheimer's disease

Alzheimer's disease (AD) is caused by the aging process and manifested by cognitive deficits and progressive memory loss. During aging, several conditions, including hypertension, diabetes, and cholesterol, have been identified as potential causes of AD by affecting Sonic hedgehog (Shh) signalling. In addition to being essential for cell differentiation and proliferation, Shh signalling is involved in tissue repair and the prevention of neurodegeneration. Neurogenesis is dependent on Shh signalling; inhibition of this pathway results in neurodegeneration. Several protein-protein interactions that are involved in Shh signalling are implicated in the pathophysiology of AD like overexpression of the protein nexin-1 inhibits the Shh pathway in AD. A protein called Growth Arrest Specific-1 works with another protein called cysteine dioxygenase (CDO) to boost Shh signalling. CDO is involved in the development of the central nervous system (CNS). Shh signalling strengthened the blood brain barrier and therefore prevent the entry of amyloid beta and other toxins to the brain from periphery. Further, several traditional remedies used for AD and dementia, including Epigallocatechin gallate, yokukansan, Lycium barbarum polysaccharides, salvianolic acid, and baicalin, are known to stimulate the Shh pathway. In this review, we elaborated that the Shh signalling exerts a substantial influence on the pathogenesis of AD. In this article, we have tried to explore the various possible connections between the Shh signalling and various known pathologies of AD.

Extracellular Vesicles and Their Zeta Potential as Future Markers Associated with Nutrition and Molecular Biomarkers in Breast Cancer

A nutritional intervention promotes the loss of body and visceral fat while maintaining muscle mass in breast cancer patients. Extracellular vesicles (EVs) and their characteristics can be potential biomarkers of disease. Here, we explore the changes in the Zeta potential of EVs; the content of miRNA-30, miRNA-145, and miRNA-155; and their association with body composition and biomarkers of metabolic risk in breast cancer patients, before and 6 months after a nutritional intervention. Clinicopathological data (HER2neu, estrogen receptor, and Ki67), anthropometric and body composition data, and plasma samples were available from a previous study. Plasma EVs were isolated and characterized in 16 patients. The expression of miRNA-30, miRNA-145, and miRNA-155 was analyzed. The Zeta potential was associated with HER2neu (β = 2.1; p = 0.00), Ki67 (β = -1.39; p = 0.007), estrogen positive (β = 1.57; p = 0.01), weight (β = -0.09; p = 0.00), and visceral fat (β = 0.004; p = 0.00). miRNA-30 was associated with LDL (β = -0.012; p = 0.01) and HDL (β = -0.02; p = 0.05). miRNA-155 was associated with visceral fat (β = -0.0007; p = 0.05) and Ki67 (β = -0.47; p = 0.04). Our results reveal significant associations between the expression of miRNA-30 and miRNA-155 and the Zeta potential of the EVs with biomarkers of metabolic risk and disease prognosis in women with breast cancer; particularly, the Zeta potential of EVs can be a new biomarker sensitive to changes in the nutritional status and breast cancer progression.

The Pathophysiological Role of Platelet-Derived Extracellular Vesicles

Platelets are very abundant in the blood, where they play a role in hemostasis, inflammation, and immunity. When activated, platelets undergo a conformational change that allows the release of numerous effector molecules as well as the production of extracellular vesicles, which are circulating submicron vesicles (10 to 1,000 nm in diameter) released into the extracellular space. Extracellular vesicles are formed by the budding of platelet and they carry some of its contents, including nucleic acids, surface proteins, and organelles. While platelets cannot cross tissue barriers, platelet-derived extracellular vesicles can enter the lymph, bone marrow, and synovial fluid. This allows the transfer of diverse contents carried by these platelet-derived vesicles to cell recipients and organs inaccessible to platelets where they can perform many functions. This review highlights the importance of these platelet-derived extracellular vesicles under different physiological and pathophysiological conditions.

Kinetics of Circulating Extracellular Vesicles Over the 24-Hour Dosing Interval After Low-Dose Aspirin Administration in Patients at Cardiovascular Risk

Extracellular vesicles (EVs) are small vesicles deriving from all cell types during cell activation, involved in transcellular communication, and regarded as predictors of vascular damage and of cardiovascular events. We tested the hypothesis that, in patients on chronic low-dose aspirin treatment for cardiovascular prevention, aspirin may affect the release of EVs within the 24-hour interval. We enrolled 84 patients, mostly at high or very high cardiovascular risk, on chronic low-dose aspirin treatment. The numbers of circulating EVs (cEVs) and annexinV+ cEVs (total, platelet-derived, endothelial-derived, and leucocyte-derived) were assessed immediately before, and after 10 and 24 hours of a witnessed aspirin administration. Platelet cyclooxygenase 1 (COX-1) recovery was characterized by measuring serum thromboxane B₂ (sTXB₂ ) at the same timepoints. Nine healthy participants were also enrolled. In patients, daily aspirin administration acutely inhibited after 10 hours following aspirin administrations the release of cEVs (total and leukocyte-derived) and annexinV+ cEVs (total, platelet-derived, endothelial-derived, and leukocyte-derived), with a rapid recovery at 24 hours. The inhibition after 10 hours suggests a COX-1-dependent mechanism. Interestingly, the slope of platelet-derived and of annexinV+ platelet-derived cEVs were both directly related to sTXB₂ slope and COX-1 messenger RNA, raising the hypothesis that vice versa, cEVs may affect the rate of COX-1 recovery and the subsequent duration of aspirin effect. In healthy participants, no circadian difference was observed, except for leukocyte-derived cEVs. Our findings suggest a previously unappreciated effect of aspirin on the kinetics of a subset of cEVs possibly contributing to the cardioprotective effects of this drug.

Role of Circulating Exosomes in Cerebrovascular Diseases: A Comprehensive Review

Exosomes are lipid bilayer vesicles that contain multiple macromolecules secreted by the parent cells and play a vital role in intercellular communication. In recent years, the function of exosomes in cerebrovascular diseases (CVDs) has been intensively studied. Herein, we briefly review the current understanding of exosomes in CVDs. We discuss their role in the pathophysiology of the diseases and the value of the exosomes for clinical applications as biomarkers and potential therapies.

Copeptin, miRNA-208, and miRNA-499 as New Biomarkers for Early Detection of Acute Coronary Syndrome

cTn and CK-MB are gold standard biomarkers for acute coronary syndrome (ACS) but are less sensitive in the first 3 h after onset of symptoms. A need thus exists for novel biomarkers for early detection of ACS. We evaluated circulating copeptin, miRNA-208, and miRNA-499 as possible biomarkers for early detection of unstable angina (UA) and non-ST-segment elevation myocardial infarction (NSTEMI). Sixty-five patients with probable ACS that presented within 4 h of the onset of chest pain (23 UA and 42 NSTEMI) and 25 apparently healthy individuals were studied. Two sets of blood samples collected in the first 3 h and at 6 h after onset were analyzed for copeptin levels via ELISA and miRNA-208 and miRNA-499 expression via real-time PCR. Copeptin, miRNA-208, and miRNA-499 expression levels were significantly increased in UA and NSTEMI patients compared with controls (p < 0.001) and in NSTEMT compared with UA patients (p < 0.001). Levels were also significantly elevated in UA and NSTEMI patients with negative cardiac troponin in the first 3 h (p < 0.001). ROC curves displayed AUC for prediction of ACS of 0.96 for copeptin, 0.97 for miRNA-208, and 0.97 for miRNA-499. Their combination improved AUC to 0.98. Copeptin and miRNA-208 and miRNA-499 expression are promising biomarkers for UA and NSTEMI that present in the first 3 h of pain onset. A combination of these markers with cTn may increase the accuracy of diagnosis by avoiding the gray zone of cTn as a biomarker.

Malnutrition and Biomarkers: A Journey through Extracellular Vesicles

Extracellular vesicles (EVs) have been identified as active components in cellular communication, which are easily altered both morphologically and chemically by the cellular environment and metabolic state of the body. Due to this sensitivity to the conditions of the cellular microenvironment, EVs have been found to be associated with disease conditions, including those associated with obesity and undernutrition. The sensitivity that EVs show to changes in the cellular microenvironment could be a reflection of early cellular alterations related to conditions of malnutrition, which could eventually be used in the routine monitoring and control of diseases or complications associated with it. However, little is known about the influence of malnutrition alone; that is, without the influence of additional diseases on the heterogeneity and specific content of EVs. To date, studies in “apparently healthy” obese patients show that there are changes in the size, quantity, and content of EVs, as well as correlations with some metabolic parameters (glucose, insulin, and serum lipids) in comparison with non-obese individuals. In light of these changes, a direct participation of EVs in the development of metabolic and cardiovascular complications in obese subjects is thought to exist. However, the mechanisms through which this process might occur are not yet fully understood. The evidence on EVs in conditions of undernutrition is limited, but it suggests that EVs play a role in the maintenance of homeostasis and muscle repair. A better understanding of how EVs participate in or promote cellular signaling in malnutrition conditions could help in the development of new strategies to treat them and their comorbidities.

Exploring New Kingdoms: The Role of Extracellular Vesicles in Oxi-Inflamm-Aging Related to Cardiorenal Syndrome

The incidence of age associated chronic diseases has increased in recent years. Although several diverse causes produce these phenomena, abundant evidence shows that oxidative stress plays a central role. In recent years, numerous studies have focused on elucidating the role of oxidative stress in the development and progression of both aging and chronic diseases, opening the door to the discovery of new underlying mechanisms and signaling pathways. Among them, senolytics and senomorphics, and extracellular vesicles offer new therapeutic strategies to slow the development of aging and its associated chronic diseases by decreasing oxidative stress. In this review, we aim to discuss the role of extracellular vesicles in human cardiorenal syndrome development and their possible role as biomarkers, targets, or vehicles of drugs to treat this syndrome.

Targeting the microRNAs in exosome: A potential therapeutic strategy for alleviation of diabetes-related cardiovascular complication

Diabetes-related cardiovascular disease (CVD) is a global health issue that causes thousands of people's death around the world annually. Diabetes-related CVD is still prevailing despite the progression being made in its diagnosis and treatment. Therefore it is urgent to find therapeutic strategies.to prevent it. MicroRNA (miRNA) is a single-stranded non-coding RNA involved in the process of post-transcriptional control of gene expression in eukaryotes. A large number of literatures reveal that miRNAs are implicated in diabetes-related CVD. The increase of miRNAs in exosomes may promote the occurrence and development of diabetes-related cardiovascular complication. However, some other studies identify that miRNAs in exosomes are supposed to be involved in cardiac regeneration and confer cardiac protection effect. Therefore, targeting the miRNA in exosome is regarded as a potent therapeutic measure to alleviate diabetes-related CVD. In this article, we review current knowledge about the role of exosomal miRNAs in diabetes-related cardiovascular complication, such as coronary heart disease, Peripheral artery disease, stroke, diabetic cardiomyopathy, diabetic nephropathy and diabetic retinopathy. Exosomal miRNAs are considered to be central regulators of diabetes-Related CVD and provide a therapeutic tool for diagnosis and treatment of diabetes-related cardiovascular complication.

COVID-19 Infection and Circulating Microparticles-Reviewing Evidence as Microthrombogenic Risk Factor for Cerebral Small Vessel Disease

Severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) due to novel coronavirus disease 2019 (COVID-19) has affected the global society in numerous unprecedented ways, with considerable morbidity and mortality. Both direct and indirect consequences from COVID-19 infection are recognized to give rise to cardio- and cerebrovascular complications. Despite current limited knowledge on COVID-19 pathogenesis, inflammation, endothelial dysfunction, and coagulopathy appear to play critical roles in COVID-19-associated cerebrovascular disease (CVD). One of the major subtypes of CVD is cerebral small vessel disease (CSVD) which represents a spectrum of pathological processes of various etiologies affecting the brain microcirculation that can trigger subsequent neuroinflammation and neurodegeneration. Prevalent with aging, CSVD is a recognized risk factor for stroke, vascular dementia, and Alzheimer's disease. In the background of COVID-19 infection, the heightened cellular activations from inflammations and oxidative stress may result in elevated levels of microthrombogenic extracellular-derived circulating microparticles (MPs). Consequently, MPs could act as pro-coagulant risk factor that may serve as microthrombi for the vulnerable microcirculation in the brain leading to CSVD manifestations. This review aims to appraise the accumulating body of evidence on the plausible impact of COVID-19 infection on the formation of microthrombogenic MPs that could lead to microthrombosis in CSVD manifestations, including occult CSVD which may last well beyond the pandemic era.

Role of Stem Cell-Derived Microvesicles in Cardiovascular Disease

The role of stem cells in augmenting reparative processes in the heart after ischemic injury has been successfully demonstrated in small and large animal models. However, the outcomes of cell therapy in clinical trials have been somewhat variable, with overall effects of autologous stem cell therapies demonstrating a modest improvement in cardiac structure and function. How stem cells repair the heart after cardiac injury is still not well understood. Most recent studies suggest that adult derived stem cells act primarily through paracrine signaling to exert beneficial effects, including modulation of immune response, stimulation of new blood vessel formation, or by inducing mature myocytes to transiently reenter the cell cycle, rather than robust direct differentiation of the transplanted cells into myocytes. In addition, data from multiple laboratory results confirmed clearance of stem cells themselves within a few days still leading to functional benefits further confirming the role of paracrine signaling in augmenting cardiac reparative processes rather than direct differentiation of cells. These findings rapidly evolved the field of extracellular vesicles specifically microvesicles (MVs) as they are active hubs of autocrine, paracrine, and endocrine signaling targeting different biological processes. The beneficial effects seen after stem cell transplantation could be linked to the cardioprotective factors packaged in the MVs secreted from stem cells. Therefore, stem cell MVs provide a new avenue for the treatment of cardiovascular disease through a multitude of mechanisms including cellular communication within the stem cell niches, delivery of genetic information, regulation of the immune system in the heart, and stimulation of angiogenesis which will be discussed in this review.

The Role of the ATP-Binding Cassette A1 (ABCA1) in Human Disease

Cholesterol homeostasis is essential in normal physiology of all cells. One of several proteins involved in cholesterol homeostasis is the ATP-binding cassette transporter A1 (ABCA1), a transmembrane protein widely expressed in many tissues. One of its main functions is the efflux of intracellular free cholesterol and phospholipids across the plasma membrane to combine with apolipoproteins, mainly apolipoprotein A-I (Apo A-I), forming nascent high-density lipoprotein-cholesterol (HDL-C) particles, the first step of reverse cholesterol transport (RCT). In addition, ABCA1 regulates cholesterol and phospholipid content in the plasma membrane affecting lipid rafts, microparticle (MP) formation and cell signaling. Thus, it is not surprising that impaired ABCA1 function and altered cholesterol homeostasis may affect many different organs and is involved in the pathophysiology of a broad array of diseases. This review describes evidence obtained from animal models, human studies and genetic variation explaining how ABCA1 is involved in dyslipidemia, coronary heart disease (CHD), type 2 diabetes (T2D), thrombosis, neurological disorders, age-related macular degeneration (AMD), glaucoma, viral infections and in cancer progression.

Elevated Circulating Microparticle Subpopulations in Incidental Cerebral White Matter Hyperintensities: A Multimodal Study

Asymptomatic (or "silent") manifestations of cerebral small vessel disease (CSVD) are widely recognized through incidental findings of white matter hyperintensities (WMHs) as a result of magnetic resonance imaging (MRI). This study aims to examine the potential associations of surrogate markers for the evaluation of white matter integrity in CSVD among asymptomatic individuals through a battery of profiling involving QRISK2 cardiocerebrovascular risk prediction, neuroimaging, neurocognitive evaluation, and microparticles (MPs) titers. Sixty asymptomatic subjects (mean age: 39.83 ± 11.50 years) with low to moderate QRISK2 scores were recruited and underwent neurocognitive evaluation for memory and cognitive performance, peripheral venous blood collection for enumeration of selected MPs subpopulations, and 3T MRI brain scan with specific diffusion MRI (dMRI) sequences inclusive of diffusion tensor imaging (DTI). WMHs were detected in 20 subjects (33%). Older subjects (mean age: 46.00 ± 12.00 years) had higher WMHs prevalence, associated with higher QRISK2 score and reduced processing speed. They also had significantly higher mean percentage of platelet (CD62P)- and leukocyte (CD62L)-derived MPs. No association was found between reduced white matter integrity-especially at the left superior longitudinal fasciculus (LSLF)-with age and neurocognitive function; however, LSLF was associated with higher QRISK2 score, total MPs, and CD62L- and endothelial cell-derived MPs (CD146). Therefore, this study establishes these multimodal associations as potential surrogate markers for "silent" CSVD manifestations in the well-characterized cardiocerebrovascular demographic of relatively young, neurologically asymptomatic adults. Furthermore, to the best of our knowledge, this study is the first to exhibit elevated MP counts in asymptomatic CSVD (i.e., CD62P and CD62L), which warrants further delineation.

Exosomes: A Key Piece in Asthmatic Inflammation

Asthma is a chronic disease of the airways that has an important inflammatory component. Multiple cells are implicated in asthma pathogenesis (lymphocytes, eosinophils, mast cells, basophils, neutrophils), releasing a wide variety of cytokines. These cells can exert their inflammatory functions throughout extracellular vesicles (EVs), which are small vesicles released by donor cells into the extracellular microenvironment that can be taken up by recipient cells. Depending on their size, EVs can be classified as microvesicles, exosomes, or apoptotic bodies. EVs are heterogeneous spherical structures secreted by almost all cell types. One of their main functions is to act as transporters of a wide range of molecules, such as proteins, lipids, and microRNAs (miRNAs), which are single-stranded RNAs of approximately 22 nucleotides in length. Therefore, exosomes could influence several physiological and pathological processes, including those involved in asthma. They can be detected in multiple cell types and biofluids, providing a wealth of information about the processes that take account in a pathological scenario. This review thus summarizes the most recent insights concerning the role of exosomes from different sources (several cell populations and biofluids) in one of the most prevalent respiratory diseases, asthma.

Flow Cytometry Analysis of Circulating Extracellular Vesicle Subtypes from Fresh Peripheral Blood Samples

Extracellular vesicles (EVs) are released by shedding during different physiological processes and are increasingly thought to be new potential biomarkers. However, the impact of pre-analytical processing phases on the final measurement is not predictable and for this reason, the translation of basic research into clinical practice has been precluded. Here we have optimized a simple procedure in combination with polychromatic flow cytometry (PFC), to identify, classify, enumerate, and separate circulating EVs from different cell origins. This protocol takes advantage of a lipophilic cationic dye (LCD) able to probe EVs. Moreover, the application of the newly optimized PFC protocol here described allowed the obtainment of repeatable EVs counts. The translation of this PFC protocol to fluorescence-activated cell sorting allowed us to separate EVs from fresh peripheral blood samples. Sorted EVs preparations resulted particularly suitable for proteomic analyses, which we applied to study their protein cargo. Here we show that LCD staining allowed PFC detection and sorting of EVs from fresh body fluids, avoiding pre-analytical steps of enrichment that could impact final results. Therefore, LCD staining is an essential step towards the assessment of EVs clinical significance.

Extracellular Vesicles in Diagnosing Chronic Coronary Syndromes the Bumpy Road to Clinical Implementation

Coronary artery disease (CAD), comprising both acute coronary syndromes (ACS) and chronic coronary syndromes (CCS), remains one of the most important killers throughout the entire world. ACS is often quickly diagnosed by either deviation on an electrocardiogram or elevated levels of troponin, but CCS appears to be more complicated. The most used noninvasive strategies to diagnose CCS are coronary computed tomography and perfusion imaging. Although both show reasonable accuracy (80-90%), these modalities are becoming more and more subject of debate due to costs, radiation and increasing inappropriate use in low-risk patients. A reliable, blood-based biomarker is not available for CCS but would be of great clinical importance. Extracellular vesicles (EVs) are lipid-bilayer membrane vesicles containing bioactive contents e.g., proteins, lipids and nucleic acids. EVs are often referred to as the "liquid biopsy" since their contents reflect changes in the condition of the cell they originate from. Although EVs are studied extensively for their role as biomarkers in the cardiovascular field during the last decade, they are still not incorporated into clinical practice in this field. This review provides an overview on EV biomarkers in CCS and discusses the clinical and technological aspects important for successful clinical application of EVs.

Interplay between Endoplasmic Reticulum Stress and Large Extracellular Vesicles (Microparticles) in Endothelial Cell Dysfunction

Upon increased demand for protein synthesis, accumulation of misfolded and/or unfolded proteins within the endoplasmic reticulum (ER), a pro-survival response is activated termed unfolded protein response (UPR), aiming at restoring the proper function of the ER. Prolonged activation of the UPR leads, however, to ER stress, a cellular state that contributes to the pathogenesis of various chronic diseases including obesity and diabetes. ER stress response by itself can result in endothelial dysfunction, a hallmark of cardiovascular disease, through various cellular mechanisms including apoptosis, insulin resistance, inflammation and oxidative stress. Extracellular vesicles (EVs), particularly large EVs (lEVs) commonly referred to as microparticles (MPs), are membrane vesicles. They are considered as a fingerprint of their originating cells, carrying a variety of molecular components of their parent cells. lEVs are emerging as major contributors to endothelial cell dysfunction in various metabolic disease conditions. However, the mechanisms underpinning the role of lEVs in endothelial dysfunction are not fully elucidated. Recently, ER stress emerged as a bridging molecular link between lEVs and endothelial cell dysfunction. Therefore, in the current review, we summarized the roles of lEVs and ER stress in endothelial dysfunction and discussed the molecular crosstalk and relationship between ER stress and lEVs in endothelial dysfunction.

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 Vesicle cystatin c is associated with unstable angina in troponin negative patients with acute chest pain

Background

Despite the use of high-sensitive cardiac troponin there remains a group of high-sensitive cardiac troponin negative patients with unstable angina with a non-neglectable risk for future adverse cardiovascular events, emphasising the need for additional risk stratification. Plasma extracellular vesicles are small bilayer membrane vesicles known for their potential role as biomarker source. Their role in unstable angina remains unexplored. We investigate if extracellular vesicle proteins are associated with unstable angina in patients with chest pain and low high-sensitive cardiac troponin.

Methods

The MINERVA study included patients presenting with acute chest pain but no acute coronary syndrome. We performed an exploratory retrospective case-control analysis among 269 patients. Cases were defined as patients with low high-sensitive cardiac troponin and proven ischemia. Patients without ischemia were selected as controls. Blood samples were fractionated to analyse the EV proteins in three plasma-subfractions: TEX, HDL and LDL. Protein levels were quantified using electrochemiluminescence immunoassay.

Results

Lower levels of (adjusted) EV cystatin c in the TEX subfraction were associated with having unstable angina (OR 0.93 95% CI 0.88–0.99).

Conclusion

In patients with acute chest pain but low high-sensitive cardiac troponin, lower levels of plasma extracellular vesicle cystatin c are associated with having unstable angina. This finding is hypothesis generating only considering the small sample size and needs to be confirmed in larger cohort studies, but still identifies extracellular vesicle proteins as source for additional risk stratification.

Plasma extracellular vesicle proteins are associated with stress-induced myocardial ischemia in women presenting with chest pain

Diagnosing stable ischemic heart disease (IHD) is challenging, especially in females. Currently, no blood test is available. Plasma extracellular vesicles (EV) are emerging as potential biomarker source. We therefore aimed to identify stress induced ischemia due to stable IHD with plasma extracellular vesicle protein levels in chest pain patients. We analyzed 450 patients suspected for stable IHD who were referred for ⁸²Rb PET/CT in the outpatient clinic. Blood samples were collected before PET/CT and plasma EVs were isolated in 3 plasma subfractions named: TEX, HDL, LDL. In total 6 proteins were quantified in each of these subfractions using immuno-bead assays. CD14 and CystatinC protein levels were independent significant predictors of stress-induced ischemia in the LDL and the HDL subfraction and SerpinC1 and SerpinG1 protein levels in the HDL fraction. Subgroup-analysis on sex revealed that these associations were completely attributed to the associations in women. None of the significant EV proteins remained significant in men. Plasma EV proteins levels are associated with the presence of stable IHD in females presenting with chest pain. This finding, if confirmed in larger cohort studies could be a crucial step in improving diagnostic assessment of women with suspected IHD.

Platelet activation and prothrombotic mediators at the nexus of inflammation and atherosclerosis: Potential role of antiplatelet agents

Platelets are central to inflammation-related manifestations of cardiovascular diseases (CVD) such as atherosclerosis. Platelet-activating factor (PAF), thrombin, thromboxane A₂ (TxA₂), and adenosine diphosphate (ADP) are some of the key agonists of platelet activation that are at the intersection between a plethora of inflammatory pathways that modulate pro-inflammatory and coagulation processes. The aim of this article is to review the role of platelets and the relationship between their structure, function, and the interactions of their constituents in systemic inflammation and atherosclerosis. Antiplatelet therapies are discussed with a view to primary prevention of CVD by the clinical reduction of platelet reactivity and inflammation. Current antiplatelet therapies are effective in reducing cardiovascular risk but increase bleeding risk. Novel therapeutic antiplatelet approaches beyond current pharmacological modalities that do not increase the risk of bleeding require further investigation. There is potential for specifically designed nutraceuticals that may become safer alternatives to pharmacological antiplatelet agents for the primary prevention of CVD but there is serious concern over their efficacy and regulation, which requires considerably more research.

Electronic cigarettes containing nicotine increase endothelial and platelet derived extracellular vesicles in healthy volunteers

BACKGROUND AND AIMS

E-cigarette use is increasingly common. Whether e-cigarettes are harmful to human health is an intensely debated subject. In order to investigate whether e-cigarettes with and without nicotine cause different vascular responses, we obtained blood samples from healthy young volunteers who performed brief active e-cigarette inhalations. Extracellular vesicles (EVs) of endothelial and platelet origin were measured to determine vascular changes.

METHODS

Using a randomized, double-blind, crossover design, 17 healthy occasional smokers inhaled 30 puffs of e-cigarette vapor during 30 min. Blood samples were collected at baseline, as well as at 0, 2, 4 and 6 h post-exposure. EVs from platelets and endothelial cells were measured by flow cytometry.

RESULTS

Platelet and endothelial derived EVs were significantly increased with peak levels seen at 4 h following exposure to active inhalation of e-cigarette vapor with nicotine. Moreover, platelet derived EVs, expressing platelet activation marker P-selectin and the inflammation marker, CD40 ligand, were also significantly increased following inhalation of e-cigarette vapor with nicotine. In addition, platelet derived EVs expressing CD40 ligand was increased after inhalation of e-cigarette vapor without nicotine.

CONCLUSION

As few as 30 puffs of nicotine-containing e-cigarette vapor caused an increase in levels of circulating EVs of endothelial and platelet origin, which may signify underlying vascular changes. Although e-cigarette vapor without nicotine caused an increase in platelet EVs expressing CD40 ligand, nicotine, as a component in the vapor, seems to have a more compelling effect on extracellular vesicle formation and protein composition.

Cerebral Small Vessel Disease (CSVD) - Lessons From the Animal Models

Cerebral small vessel disease (CSVD) refers to a spectrum of clinical and imaging findings resulting from pathological processes of various etiologies affecting cerebral arterioles, perforating arteries, capillaries, and venules. Unlike large vessels, it is a challenge to visualize small vessels in vivo, hence the difficulty to directly monitor the natural progression of the disease. CSVD might progress for many years during the early stage of the disease as it remains asymptomatic. Prevalent among elderly individuals, CSVD has been alarmingly reported as an important precursor of full-blown stroke and vascular dementia. Growing evidence has also shown a significant association between CSVD's radiological manifestation with dementia and Alzheimer's disease (AD) pathology. Although it remains contentious as to whether CSVD is a cause or sequelae of AD, it is not far-fetched to posit that effective therapeutic measures of CSVD would mitigate the overall burden of dementia. Nevertheless, the unifying theory on the pathomechanism of the disease remains elusive, hence the lack of effective therapeutic approaches. Thus, this chapter consolidates the contemporary insights from numerous experimental animal models of CSVD, to date: from the available experimental animal models of CSVD and its translational research value; the pathomechanical aspects of the disease; relevant aspects on systems biology; opportunities for early disease biomarkers; and finally, converging approaches for future therapeutic directions of CSVD.

The effect of mild agonist stimulation on the platelet reactivity in patients with type 2 diabetes mellitus

BACKGROUND

Patients with type 2 diabetes mellitus (T2DM) have accelerated atherosclerosis as a pro thrombotic state that is associated with the platelet activation priming. Platelets, which undergo the continuous mild stimulation, may lose their sensitivity to react to a strong stimulation. The present study aimed to investigate activation responses of platelets to mild and subsequent strong stimulations in patients with T2DM and healthy individuals.

METHODS

Blood samples, which were taken from 40 patients with T2DM and 35 healthy individuals, were collected into the citrate containing tubes. The samples were subjected to the soft centrifugation to prepare the platelet rich plasma (PRP). Platelets in PRP samples were treated at a low (1 μM) concentration and then at a high (10 μM) concentration of ADP. Before and after stimulation with different doses of ADP, levels of CD62P expression and formation of platelet micro particles (PMPs) were measured using a flow cytometry method.

RESULTS

The platelets from patients with T2DM had higher levels of CD62P expression before any stimulation (P = 0.003) than control samples. Platelets, which underwent the mild stimulation, indicated lower responses to CD62P expression, but higher PMPs formation after stimulation with high dose of ADP. Patients with T2DM had higher platelet micro particles in all states with the ADP stimulation. (P = 0.004, SD: ±74.52).

CONCLUSIONS

The flow cytometry data indicated that platelets were pre-active and associated with metabolic conditions in patients with type 2 diabetes mellitus. The induction of desensitization state helped platelets to reduce the platelet activation and sensitivity to ADP in a diabetic environment. Furthermore, the production of platelets micro-particles was high in the patients; and desensitized platelets were more susceptible to shedding of micro-particles.

ERK-containing microparticles from a diabetic mouse induce endothelial dysfunction

Endothelial dysfunction is a hallmark of diabetic vascular complications. Microparticles (MPs) are small vesicles shed from the surface of blood and vascular cells that act as stimuli and during apoptosis. Circulating MPs of diabetic rats have been shown to induce endothelial dysfunction. However, the underlying mechanisms require further study. In this study, we investigated how MPs from diabetic mice affect endothelial function. MPs were collected from streptozotocin-induced diabetic mice and Institute of Cancer Research (ICR) mice as controls. The levels of MPs were assessed and characterized by flow cytometry, enzyme-linked immunosorbent assay and dot blotting. Normal mice aortas were incubated with MPs and expressions of enzymes and vascular relaxation were analyzed. We found that (1) circulating MPs level increased in diabetic mice; (2) MPs impaired endothelial-dependent relaxation in mice aorta, but diabetic mice-derived MPs (diabetes mellitus (DM) MPs) were easier to attach to the endothelial cells than were control MPs; (3) DM MPs had more extracellular signal-regulated kinase (ERK)1/2 than did control mice-derived MPs, and they induced ERK1/2 activation in mice aortas; (4) DM MPs decreased endothelial nitric oxide synthase (eNOS) in mice aortas, and eNOS was emitted from endothelial cells to blood in the shape of endothelial MPs. DM MPs significantly altered endothelial function by activation of ERK1/2, which might provide a therapeutic target for diabetic vascular complications.

Human vitreous in proliferative diabetic retinopathy: Characterization and translational implications

Diabetic retinopathy (DR) is one of the leading causes of visual impairment in the working-age population. DR is a progressive eye disease caused by long-term accumulation of hyperglycaemia-mediated pathological alterations in the retina of diabetic patients. DR begins with asymptomatic retinal abnormalities and may progress to advanced-stage proliferative diabetic retinopathy (PDR), characterized by neovascularization or preretinal/vitreous haemorrhages. The vitreous, a transparent gel that fills the posterior cavity of the eye, plays a vital role in maintaining ocular function. Structural and molecular alterations of the vitreous, observed during DR progression, are consequences of metabolic and functional modifications of the retinal tissue. Thus, vitreal alterations reflect the pathological events occurring at the vitreoretinal interface. These events are caused by hypoxic, oxidative, inflammatory, neurodegenerative, and leukostatic conditions that occur during diabetes. Conversely, PDR vitreous can exert pathological effects on the diabetic retina, resulting in activation of a vicious cycle that contributes to disease progression. In this review, we recapitulate the major pathological features of DR/PDR, and focus on the structural and molecular changes that characterize the vitreal structure and composition during DR and progression to PDR. In PDR, vitreous represents a reservoir of pathological signalling molecules. Therefore, in this review we discuss how studying the biological activity of the vitreous in different in vitro, ex vivo, and in vivo experimental models can provide insights into the pathogenesis of PDR. In addition, the vitreous from PDR patients can represent a novel tool to obtain preclinical experimental evidences for the development and characterization of new therapeutic drug candidates for PDR therapy.

Extracellular Vesicles: Mechanisms in Human Health and Disease

SIGNIFICANCE

Secreted extracellular vesicles (EVs) are now considered veritable entities for diagnosis, prognosis, and therapeutics. These structures are able to interact with target cells and modify their phenotype and function. Recent Advances: Since composition of EVs depends on the cell type of origin and the stimulation that leads to their release, the analysis of EV content remains an important input to understand the potential effects of EVs on target cells.

CRITICAL ISSUES

Here, we review recent data related to the mechanisms involved in the formation of EVs and the methods allowing specific EV isolation and identification. Also, we analyze the potential use of EVs as biomarkers in different pathologies such as diabetes, obesity, atherosclerosis, neurodegenerative diseases, and cancer. Besides, their role in these diseases is discussed. Finally, we consider EVs enriched in microRNA or drugs as potential therapeutic cargo able to deliver desirable information to target cells/tissues.

FUTURE DIRECTIONS

We underline the importance of the homogenization of the parameters of isolation of EVs and their characterization, which allow considering EVs as excellent biomarkers for diagnosis and prognosis.

Microparticle miRNAs as Biomarkers of Vascular Function and Inflammation Response to Aerobic Exercise in Obesity?

OBJECTIVE

This study aimed to explore the role of nine microRNAs (miRNAs) in microparticles (MPs) on the efficacy of aerobic exercise in the regulation of inflammation and vascular function in obesity.

METHODS

Sedentary women with normal weight (n = 6, BMI < 25 kg/m² ) and women with obesity (n = 9, BMI > 30 kg/m² ) were recruited at F. Hached Hospital (Sousse, Tunisia) and enrolled in an 8-week aerobic program. Vascular function was assessed using laser Doppler flowmetry/iontophoresis, circulating MPs by flow cytometry, miRNAs by real-time polymerase chain reaction, and inflammation by ELISA, before and after exercise.

RESULTS

Women with obesity presented with high prevalence of cardiovascular risk factors and a higher circulating MP level compared with healthy subjects. The MP miRNA profile was significantly different in the two groups. Exercise reduced BMI and inflammation in both groups and significantly improved endothelial-dependent response (acetylcholine cutaneous vascular conductance) for healthy subjects, with a trend for women with obesity. Circulating MP level was increased after exercise, and miRNA expression was differentially modulated in both populations. Pearson analysis revealed a correlation between MPs miR-124a and miR150 and adiponectin, TNFα, or IL-6 levels.

CONCLUSIONS

The relation between MPs and miRNA profile, inflammation, vascular function, and exercise is of particular interest for defining "miRNA biomarker signature" in patients with cardiovascular disease who are potentially susceptible to respond to exercise.

Extracellular Vesicles Derived from Hypoxic Human Mesenchymal Stem Cells Attenuate GSK3β Expression via miRNA-26a in an Ischemia-Reperfusion Injury Model

PURPOSE

Bioactive molecules critical to intracellular signaling are contained in extracellular vesicles (EVs) and have cardioprotective effects in ischemia/reperfusion (IR) injured hearts. This study investigated the mechanism of the cardioprotective effects of EVs derived from hypoxia-preconditioned human mesenchymal stem cells (MSCs).

MATERIALS AND METHODS

EV solutions (0.4 μg/μL) derived from normoxia-preconditioned MSCs (EV(NM)) and hypoxia-preconditioned MSCs (EV(HM)) were delivered in a rat IR injury model. Successful EV delivery was confirmed by the detection of PKH26 staining in hearts from EV-treated rats.

RESULTS

EV(HM) significantly reduced infarct size (24±2% vs. 8±1%, p<0.001), and diminished arrhythmias by recovering electrical conduction, I(Na) current, and Cx43 expression. EV(HM) also reversed reductions in Wnt1 and β-catenin levels and increases in GSK3β induced after IR injury. miRNA-26a was significantly increased in EV(HM), compared with EV(NM), in real-time PCR. Finally, in in vitro experiments, hypoxia-induced increases in GSK3β expression were significantly reduced by the overexpression of miRNA-26a.

CONCLUSION

EV(HM) reduced IR injury by suppressing GSK3β expression via miRNA-26a and increased Cx43 expression. These findings suggest that the beneficial effect of EVHM is related with Wnt signaling pathway.

Matrix Signaling Subsequent to a Myocardial Infarction: A Proteomic Profile of Tissue Factor Microparticles

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The occurrence of an MI activates production of TFMPs.

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We induced an MI in Yucatan miniswine and collected plasma samples over a 6-month period post-MI.

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Experimental groups consisted of infarcted but untreated animals and infarcted animals treated with CRT plus β-blocker.

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Using proteomic profiling, we confirm the heterogeneity of TFMP protein content with respect to physiological status of the host temporally.

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Spatially, the contents of the TFMPs provided information about multiple entities supplemental to what we obtained from assessing a set of 8 currently used cardiac biomarkers.

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The results from this study support recommending TFMP protein content profiling be used prospectively as a viable investigative methodology for chronic ischemic cardiomyopathy to help improve our understanding of β-adrenergic receptor signaling after an MI.

This study investigated the release and proteomic profile of tissue factor microparticles (TFMPs) prospectively (up to 6 months) following a myocardial infarction (MI) in a chronic porcine model to establish their utility in tracking cellular level activities that predict physiologic outcomes. Our animal groups (n = 6 to 8 each) consisted of control, noninfarcted (negative control); infarcted only (positive control); and infarcted animals treated with cardiac resynchronization therapy (CRT) and a β-blocker (BB) (metoprolol succinate). The authors found different protein profiles in TFMPs between the control, infarcted only group, and the CRT + BB treated group with predictive impact on the outward phenotype of pathological remodeling after an MI within and between groups. This novel approach of monitoring cellular level activities by profiling the content of TFMPs has the potential of addressing a shortfall of the current crop of cardiac biomarkers, which is the inability to capture composite molecular changes associated with chronic maladaptive signaling in a spatial and temporal manner.

Microvesicles as Emerging Biomarkers and Therapeutic Targets in Cardiometabolic Diseases

Microvesicles (MVs, also known as microparticles) are small vesicles that originate from plasma membrane of almost all eukaryotic cells during apoptosis or activation. MVs can serve as extracellular vehicles to transport bioactive molecules from their parental cells to recipient target cells, thereby serving as novel mediators for intercellular communication. Importantly, more and more evidence indicates that MVs could play important roles in early pathogenesis and subsequent progression of cardiovascular and metabolic diseases. Elevated plasma concentrations of MVs, originating from red blood cells, leukocytes, platelets, or other organs and tissues, have been reported in various cardiometabolic diseases. Circulating MVs could serve as potential biomarkers for disease diagnosis or therapeutic monitoring. In this review, we summarized recently-published studies in the field and discussed the role of MVs in the pathogenesis of cardiometabolic diseases. The emerging values of MVs that serve as biomarker for non-invasive diagnosis and prognosis, as well as their roles as novel therapeutic targets in cardiometabolic diseases, were also described.

MicroRNA-145-5p and microRNA-320a encapsulated in endothelial microparticles contribute to the progression of vasculitis in acute Kawasaki Disease

Kawasaki Disease (KD) is an acute inflammatory disease that takes the form of systemic vasculitis. Endothelial microparticles (EMPs) have been recognized as an important transcellular delivery system. We hypothesized whether EMPs are involved in vasculitis in acute KD. Fifty patients with acute KD were enrolled, divided into two subgroups: those with coronary artery lesions (CAL) (n = 5) and those without CAL (NCAL) (n = 45). EMPs were measured using flow cytometry, and microRNA (miR) expression profiling was performed by microRNA array. The percentage of EMPs in acute KD was significantly higher than in controls (P < 0.0001). EMPs in patients with CAL rapidly increased after the initial treatment, and was significantly higher than those in NCAL (P < 0.001). In patients with CAL, we identified 2 specific miRs encapsulated in EMPs, hsa-miR-145-5p and hsa-miR-320a, which are predicted to affect monocyte function using in silico analysis, and were demonstrated to upregulate inflammatory cytokine mRNAs in THP-1 monocytes. In situ hybridization confirmed that hsa-miR-145-5p was preferentially expressed in CAL. EMPs may serve as a sensitive marker for the severity of vasculitis in acute KD. Moreover, these 2 specific miRs encapsulated in EMPs might be involved in inflammatory cytokine regulation and the pathogenesis of vasculitis in acute KD.

[Vascular dysfunction in obstructive sleep apnoea: Implication of microparticules]

Obstructive sleep apnea (OSA) is associated with increased cardiovascular diseases, including myocardial infarction and stroke and promotes cardiovascular risk factors including diabetes and hypertension. OSA has also been proposed to have a direct proatherogenic effects. Recent studies have investigated the role of microparticles (MPs) in the atherogenic process. MPs are small plasma membrane vesicles that can be released by a variety of vascular or blood cells and that contain membrane and cytosolic elements. Case-control studies have suggested that OSA is associated with an increase in circulating platelet-, endothelial- and leukocyte-derived MPs. MPs from OSA patients injected to mice have also been shown to induce vascular inflammation and endothelial dysfunction. In this article, we provide an overview of the main characteristics of MPs expressed in OSA and their potential role in the atherogenic process.

Vitamin D suppresses oxidative stress-induced microparticle release by human umbilical vein endothelial cells

Endothelial microparticle (MP) release was increased in numerous cardiovascular diseases including preeclampsia. Oxidative stress is a potent inducer of endothelial dysfunction. In this study, we aimed to investigate if vitamin D could protect endothelial cells (ECs) from MP release induced by oxidative stress. Endothelial cell (from human umbilical vein) oxidative stress was induced by cultivation of cells under lowered oxygen condition (2%O2) for 48 h and cells cultured under standard condition (21%O2) served as control. 1,25(OH)2D3 was used as bioactive vitamin D. Using annexin-V as a marker of released MP assessed by flow cytometry and cytochrome c reduction assay to measure EC superoxide generation, we found that MP release and superoxide generation were significantly increased when cells were cultured under 2%O2, which could be significantly inhibited by 1,25(OH)2D3. To study the potential mechanisms of 1,25(OH)2D3 protective effects on ECs, EC expression of endothelial nitric oxide synthase (eNOS), p-eNOSSer1177, p-eNOSThr495, caveolin-1, extracellular signal-regulated kinase (ERK), p-ERK, Akt, p-AktSer473, Rho-associated coiled-coil protein kinase 1 (ROCK1), and vitamin D receptor were determined. Microparticle expression of eNOS and caveolin-1 were also determined. We found that under lowered oxygen condition, 1,25(OH)2D3 could upregulate EC eNOS, p-eNOSSer1177, and p-AktSer473 expression, but inhibit cleaved ROCK1 expression. The upregulatory and inhibitory effects induced by 1,25(OH)2D3 were dose dependent. Strikingly, we also found that oxidative stress-induced decrease in ratio of eNOS and caveolin-1 expression in MP could be attenuated when 1,25(OH)2D3 was present in culture. These results suggest that upregulation of eNOSSer1177 and AktSer473 phosphorylation and inhibition of ROCK1 cleavage in EC and modulation of eNOS and caveolin-1 expression in MP could be plausible mechanisms of vitamin D protective effects on ECs.

Vitamin D suppresses oxidative stress-induced microparticle release by human umbilical vein endothelial cells

Endothelial microparticle (MP) release was increased in numerous cardiovascular diseases including preeclampsia. Oxidative stress is a potent inducer of endothelial dysfunction. In this study, we aimed to investigate if vitamin D could protect endothelial cells (ECs) from MP release induced by oxidative stress. Endothelial cell (from human umbilical vein) oxidative stress was induced by cultivation of cells under lowered oxygen condition (2%O2) for 48 h and cells cultured under standard condition (21%O2) served as control. 1,25(OH)2D3 was used as bioactive vitamin D. Using annexin-V as a marker of released MP assessed by flow cytometry and cytochrome c reduction assay to measure EC superoxide generation, we found that MP release and superoxide generation were significantly increased when cells were cultured under 2%O2, which could be significantly inhibited by 1,25(OH)2D3. To study the potential mechanisms of 1,25(OH)2D3 protective effects on ECs, EC expression of endothelial nitric oxide synthase (eNOS), p-eNOSSer1177, p-eNOSThr495, caveolin-1, extracellular signal-regulated kinase (ERK), p-ERK, Akt, p-AktSer473, Rho-associated coiled-coil protein kinase 1 (ROCK1), and vitamin D receptor were determined. Microparticle expression of eNOS and caveolin-1 were also determined. We found that under lowered oxygen condition, 1,25(OH)2D3 could upregulate EC eNOS, p-eNOSSer1177, and p-AktSer473 expression, but inhibit cleaved ROCK1 expression. The upregulatory and inhibitory effects induced by 1,25(OH)2D3 were dose dependent. Strikingly, we also found that oxidative stress-induced decrease in ratio of eNOS and caveolin-1 expression in MP could be attenuated when 1,25(OH)2D3 was present in culture. These results suggest that upregulation of eNOSSer1177 and AktSer473 phosphorylation and inhibition of ROCK1 cleavage in EC and modulation of eNOS and caveolin-1 expression in MP could be plausible mechanisms of vitamin D protective effects on ECs.

Circulating levels and characterization of microparticles in patients with different degrees of glucose tolerance

Background

Microparticles (MPs) are vesicular structures shed from endothelial or circulating blood cells, after activation or apoptosis, and can be considered markers of vascular damage. We aimed to determine the levels of circulating MPs, their content of miRNA-126-3p and 5p, and their relationship with early endothelial activation/damage, in patients with different degree of glucose tolerance.

Methods

CD62E⁺, CD62P⁺, CD142⁺, CD45⁺ circulating MPs, their apoptotic (AnnexinV⁺) fractions, and miRNA-126 expression were determined in 39 prediabetic (PreDM), 68 type 2 diabetic (T2DM), and 53 control (NGT) subjects, along with main anthropometric and biochemical measurements. MPs were analysed by flow cytometry. miRNA-126 was measured by quantitative real-time PCR. Plasma antioxidant capacity was determined by electronic spin resonance; ICAM-1, and VCAM-1 by ELISA.

Results

Activated endothelial cell-derived MPs (CD62E⁺) were significantly increased in PreDM and T2DM in comparison to NGT (p < 0.0001). AnnexinV⁺/CD62E⁺ MPs and Annexin V⁺ MPs were significantly increased in T2DM compared to PreDM and NGT (p < 0.001); other MPs were not significantly different among groups. Plasma antioxidant capacity was significantly decreased in PreDM and T2DM compared to NGT (p = 0.001); VCAM-1 significantly increased in PreDM and T2DM in comparison to NGT (p = 0.001). miR-126-3p expression, but not miR-126-5p, in MPs, decreased significantly and progressively from NGT, to PreDM, and T2DM (p < 0.001). In PreDM and T2DM, CD62E⁺ MPs level was significantly and negatively associated with plasma glucose (p = 0.004).

Conclusion

We show for the first time that circulating CD62E⁺ MPs level and miR-126-3p content in MPs are abnormal in subjects with pre-diabetes; the content of miR-126-3p correlates with markers of endothelial inflammation, such as VCAM-1, plasma antioxidant capacity, and microparticles, well-accepted markers of endothelial dysfunction.

Brain-Heart Interaction: Cardiac Complications After Stroke

Neurocardiology is an emerging specialty that addresses the interaction between the brain and the heart, that is, the effects of cardiac injury on the brain and the effects of brain injury on the heart. This review article focuses on cardiac dysfunction in the setting of stroke such as ischemic stroke, brain hemorrhage, and subarachnoid hemorrhage. The majority of post-stroke deaths are attributed to neurological damage, and cardiovascular complications are the second leading cause of post-stroke mortality. Accumulating clinical and experimental evidence suggests a causal relationship between brain damage and heart dysfunction. Thus, it is important to determine whether cardiac dysfunction is triggered by stroke, is an unrelated complication, or is the underlying cause of stroke. Stroke-induced cardiac damage may lead to fatality or potentially lifelong cardiac problems (such as heart failure), or to mild and recoverable damage such as neurogenic stress cardiomyopathy and Takotsubo cardiomyopathy. The role of location and lateralization of brain lesions after stroke in brain-heart interaction; clinical biomarkers and manifestations of cardiac complications; and underlying mechanisms of brain-heart interaction after stroke, such as the hypothalamic-pituitary-adrenal axis; catecholamine surge; sympathetic and parasympathetic regulation; microvesicles; microRNAs; gut microbiome, immunoresponse, and systemic inflammation, are discussed.

Extracellular Vesicles in Metabolic Syndrome

Metabolic syndrome defines a cluster of interrelated risk factors for cardiovascular disease and diabetes mellitus. These factors include metabolic abnormalities, such as hyperglycemia, elevated triglyceride levels, low high-density lipoprotein cholesterol levels, high blood pressure, and obesity, mainly central adiposity. In this context, extracellular vesicles (EVs) may represent novel effectors that might help to elucidate disease-specific pathways in metabolic disease. Indeed, EVs (a terminology that encompasses microparticles, exosomes, and apoptotic bodies) are emerging as a novel mean of cell-to-cell communication in physiology and pathology because they represent a new way to convey fundamental information between cells. These microstructures contain proteins, lipids, and genetic information able to modify the phenotype and function of the target cells. EVs carry specific markers of the cell of origin that make possible monitoring their fluctuations in the circulation as potential biomarkers inasmuch their circulating levels are increased in metabolic syndrome patients. Because of the mixed components of EVs, the content or the number of EVs derived from distinct cells of origin, the mode of cell stimulation, and the ensuing mechanisms for their production, it is difficult to attribute specific functions as drivers or biomarkers of diseases. This review reports recent data of EVs from different origins, including endothelial, smooth muscle cells, macrophages, hepatocytes, adipocytes, skeletal muscle, and finally, those from microbiota as bioeffectors of message, leading to metabolic syndrome. Depicting the complexity of the mechanisms involved in their functions reinforce the hypothesis that EVs are valid biomarkers, and they represent targets that can be harnessed for innovative therapeutic approaches.

Deep Metaproteomics Approach for the Study of Human Microbiomes

Host-microbiome interactions have been shown to play important roles in human health and diseases. Most of the current studies of the microbiome have been performed by genomic approaches through next-generation sequencing. Technologies, such as metaproteomics, for functional analysis of the microbiome are needed to better understand the intricate host-microbiome interactions. However, significant efforts to improve the depth and resolution of gut metaproteomics are still required. In this study, we combined an efficient sample preparation technique, high resolution mass spectrometry, and metaproteomic bioinformatics tools to perform ultradeep metaproteomic analysis of human gut microbiome from stool. We reported the deepest analysis of the microbiome to date with an average of 20 558 protein groups identified per sample analysis. Moreover, strain resolution taxonomic and pathway analysis using deep metaproteomics revealed strain level variations, in particular for Faecalibacterium prausnitzii, in the microbiome from the different individuals. We also reported that the human proteins identified in stool samples are functionally enriched in extracellular region pathways and in particular those proteins involved in defense response against microbial organisms. Deep metaproteomics is a promising approach to perform in-depth microbiome analysis and simultaneously reveals both human and microbial changes that are not readily apparent using the standard genomic approaches.

Extracellular Vesicles in Lung Disease

Accumulating evidence suggests that extracellular vesicles (EVs) play a role in the pathogenesis of lung diseases. These vesicles include exosomes, ectosomes (ie, microparticles, extracellular vesicles, microvesicles, and shedding vesicles), and apoptotic bodies. Exosomes are generated by inward budding of the membrane (endocytosis), subsequent forming of multivesicular bodies, and release by exocytosis. Ectosomes are formed by outward blebbing from the plasma membrane and are then released by proteolytic cleavage from the cell surface. Apoptotic bodies are generated on apoptotic cell shrinkage and death. Extracellular vesicles are released when the cells are activated or undergo apoptosis under inflammatory conditions. The number and types of released EVs are different according to the pathophysiological status of the disease. Therefore, EVs can be novel biomarkers for various lung diseases. EVs contain several molecules, including proteins, mRNA, microRNA, and DNA; they transfer these molecules to distant recipient cells. Circulating EVs modify the targeted cells and influence the microenvironment of the lungs. For this unique capability, EVs are expected to be a new drug delivery system and a novel therapeutic target.

Endothelial Cell-derived Extracellular Vesicles Size-dependently Exert Procoagulant Activity Detected by Thromboelastometry

Endothelial cells (ECs) are major modulators of hemostasis by expressing and releasing pro- and anticoagulant mediators into the circulation. Previous studies showed that cultured ECs release procoagulant mediators into cell culture supernatants as evidenced by the reduction of viscoelastic clotting time. This effect was reversed with an anti-tissue factor antibody. Here, we aimed to investigate whether tissue factor (TF) was released by endothelial-derived extracellular vesicles (EVs) and which portion of the released vesicles displays the most prominent procoagulant properties. After stimulation of ECs with tumor-necrosis factor-α (TNF-α) the supernatants of EC cultures were subjected to differential centrifugation steps to collect larger and smaller EVs which were then characterised by nanoparticle tracking analysis (NTA) and flow cytometry. Mixed with fresh human blood and analysed by thromboelastometry EVs exerted a significant procoagulant stimulus, which could be partly reversed by addition of an anti-TF antibody. Moreover, TF activity was confirmed in the centrifuged fractions. In summary, our results provide evidence of the procoagulant potential of smaller and larger endothelial-derived EV fractions detected by thromboelastometry. The observed effect is most likely due to the release of TF-bearing EVs of different dimensions, which are released upon TNF-α stimulation of endothelial cell cultures.

ER stress dependent microparticles derived from smooth muscle cells promote endothelial dysfunction during thoracic aortic aneurysm and dissection

The degeneration of vascular smooth muscle cell(s) (SMC) is one of the key features of thoracic aortic aneurysm and dissection (TAAD). We and others have shown that elevated endoplasmic reticulum (ER) stress causes SMC loss and TAAD formation, however, the mechanism of how SMC dysfunction contributes to intimal damage, leading to TAAD, remains to be explored. In the present study, in vitro assay demonstrated that elevated mechanical stretch (18% elongation, 3600 cycles/h) stimulated the ER stress response and microparticle(s) (MP) production from both SMC and endothelial cell(s) (EC) in a time-dependent manner. Treatment of EC with isolated MP led to anoikis, which was determined by measuring the fluorescence of the ethidium homodimer (EthD-1) and Calcein AM cultured in hydrogel-coated plates and control plates. MP stimulation of EC also up-regulated the mRNA levels of inflammatory molecules (i.e. Vascular cellular adhesion molecular-1 (VCAM-1)), intercellular adhesion molecular-1 (ICAM-1), interleukin-1β (IL-1β), and interleukin-6 (IL-6)). Use of an ER stress inhibitor or knockout of CHOP decreased mechanical stretch-induced MP production in SMC. In vivo, administration of an ER stress inhibitor or knockout of CHOP suppressed both apoptosis of EC and the infiltration of inflammatory cells. Moreover, TAAD formation was also suppressed by the administration of an ER stress inhibitor. In conclusion, our study demonstrates that elevated mechanical stretch induces MP formation in SMC leading to endothelial dysfunction, which is ER stress dependent. The inhibition of ER stress suppressed EC apoptosis, inflammation in the aorta, and TAAD development.

Dissimilarity of increased phosphatidylserine-positive microparticles and associated coagulation activation in acute coronary syndromes

OBJECTIVE

We evaluated cellular origin, numbers, and procoagulant activity of phosphatidylserine-positive microparticles (MPs) among subgroups in acute coronary syndromes (ACS).

MATERIALS AND METHODS

Parameters were measured on admission, days 1 (within 24 h of admission), 2, 3, and 7. All ST-elevated myocardial infarction (STEMI) patients presented more than 3 h from symptom onset and received fibrinolysis treatment; controls included unstable angina and non-STEMI patients as well as healthy controls. Phosphatidylserine-positive MPs were detected by flow cytometry, whereas procoagulant activity was assessed by coagulation time, purified coagulation complex assays, and fibrin formation. MP-induced fibrins were visualized by confocal microscopy.

RESULTS

On admission, the total MP count was ∼2.5-fold higher in the ACS groups compared with the healthy controls (P<0.05), primarily originating from platelets and endothelial cells, and there were no significant differences among ACS subgroups. Specifically, leukocyte-derived and erythrocyte-derived MPs were higher in the STEMI group compared with unstable angina and non-STEMI groups (both P<0.05). Further, MPs from the ACS groups reduced coagulation time by 27.5% and induced intrinsic and extrinsic FXase, prothrombinase, and fibrin formation by 2.8-, 2.3-, 2.5-, and 1.7-fold, respectively (P<0.05 for all), whereas blocking phosphatidylserine with lactadherin inhibited ∼70% of procoagulant activity. MP number and concomitant coagulation decreased significantly by day 2 and continued to decrease gradually during the recovery period.

CONCLUSION

This study shows that MP characteristics from circulating blood may be used as prognostic indicators to reflect the origin cell of activation and thrombophilic states found in ACS subgroups.

Identification of CD4+ T-cell-derived CD161+ CD39+ and CD39+CD73+ microparticles as new biomarkers for rheumatoid arthritis

Aim: This study aimed to identify CD4+ T-cell-derived microparticles (MPs) and investigate their roles in rheumatoid arthritis (RA). Methods: Synovial fluids from 34 RA, 33 osteoarthritis patients and 42 healthy individuals were analyzed by flow cytometry. Human fibroblast-like synoviocytes and peripheral blood mononuclear cells were cultured with or without isolated MPs, chemokines and cytokines were measured by ELISA. Results: CD4+CD161+CD39+ and CD4+CD39+CD73+ MPs were abundantly present in RA patients, which were positively or negatively correlated with RA features, respectively. Chemokines CCL20, CCL17 and CCL22, and cytokines IL-17 and IL-10 were influenced by these MPs in human fibroblast-like synoviocytes (HFLS) or PMBCs. Conclusion: CD4+ T-cell-derived CD161+CD39+ and CD39+CD73+ MPs could serve as new reciprocal biomarkers for RA evaluation.