Endothelial Microparticles Research Articles

Circulating Endothelial Microparticles Reduce in Concentration Following an Exercise Programme in Women With Polycystic Ovary Syndrome.

Purpose: Endothelial dysfunction is a known comorbidity in women with polycystic ovary syndrome (PCOS). The aim was to assess if supervised, moderate intensity exercise could potentially impact markers of endothelial disruption; endothelial cell derived microparticles (EMP).Methods: The current study investigated the effects of a supervised 8-week moderate intensity exercise programme on EMP in women with PCOS (n = 11) and control women free from any known disease (n = 10). EMP were enumerated via specific antibody (CD105, CD106) labeling and flow cytometry.Results: CD105+MP significantly reduced in women with PCOS from pre to post-exercise programme, with CD105+ MP reducing from 2114 CD105+ MP per μl platelet free plasma (PFP) to 424 CD105+ MP per μl PFP (p = 0.025). Control women showed no significant change in CD105+ MP (p = 0.25) after completing the same exercise programme. CD106+ MP showed no change in either PCOS (p = 0.95) or control groups (p = 0.99). No significant correlations existed with the changes in EMP compared to body composition changes as a result of exercise.Conclusion: Supervised, moderate intensity exercise independent of substantial weight loss reduced circulating CD105+ MP, likely reflecting an improvement in endothelial function in women with PCOS compared to healthy control women. Additionally, EMP may be a useful marker for physical improvement in exercise programmes for clinical populations.

Microparticle Responses to Aerobic Exercise and Meal Consumption in Healthy Men.

Microparticles (MP) are shed extracellular vesicles that express the prothrombotic tissue factor (TF). Aerobic exercise may reduce MP count and TF expression. This study investigated the impact of acute running or rest followed by standardized meal consumption on MP phenotypes and TF expression. Fifteen males (age, 22.9 ± 3.3 yr; body mass, 81.9 ± 11.4 kg; V˙O2max, 54.9 ± 6.5 mL·kg·min; mean ± SD) completed 1 h of running (70% V˙O2max) or rest at 9:00 AM and consumed a standardized meal (1170 kcal, 43% CHO, 17% PRO, 40% fat) at 10:45 AM. Venous blood samples were taken at 9:00 AM, 10:00 AM, and 11:30 AM. The MP concentration, diameter, phenotypes, and TF expression were assessed using nanoparticle tracking analysis and flow cytometry. Nanoparticle tracking analysis identified no changes in MP concentration or diameter in response to time or trial. Flow cytometry revealed total MP count increased from 9:00 AM to 10:00 AM (1.62 ± 2.28 to 1.74 ± 2.61 × 10 L, P = 0.016, effect size (η) = 0.105), but was unaffected by trial. TF platelet-derived MP % reduced from 9:00 AM to 10:00 AM (44.0% ± 21.2% to 21.5% ± 9.3%, P = 0.001, η = 0.582) after exercise only (control, 36.8% ± 18.2% to 34.9% ± 11.9%; P = 0.972). TF neutrophil-derived MP percentage reduced from 9:00 AM to 11:30 AM (42.3% ± 17.2% to 25.1% ± 14.9%; P = 0.048, η = 0.801) in the exercise trial only (control, 28.5% ± 15.7% to 32.2% ± 9.6%; P = 0.508). Running induced a significant reduction in %TF platelet and neutrophil MP, suggesting a transient reduction in cardiovascular risk via reduced TF-stimulated thrombosis. This requires further investigation over longer periods in cardiovascular disease populations.

Circulating microparticles as biomarkers of stroke: A focus on the value of endothelial- and platelet-derived microparticles.

Stroke is one of the leading causes of mortality anddisability worldwide. Numerouspathophysiological mechanisms involving blood vessels, coagulation and inflammation contribute to the vascular occlusion. Perturbations in these pathways can be detected by numerous methods including changes in endoplasmic membrane remodeling and rearrangement leading to the shedding of microparticles (MPs) from various cellular origins in the blood. MPs are small membrane-derived vesicles that are shed from nearly all cells in the body in resting state or upon stimulation. MPs act as biological messengers to transfer information to adjacent and distant cells thus regulating various biological processes. MPs may be important biomarkers and tools for the identification of the risk and diagnosis of cerebrovascular diseases. Endothelial activation and dysfunction and altered thrombotic responses are two of the main features predisposing to stroke. Endothelial MPs (EMPs) have been recognized as both biomarkers and effectors of endothelial cell activation and injury while platelet-derived MPs (PMPs) carry a strong procoagulant potential and are activated in thrombotic states. Therefore, we reviewed here the role of EMPs and PMPs as biomarkers of stroke. Most studies reported high circulating levels of EMPs and PMPs in addition to other cell origins in stroke patients and have been linked to stroke severity, the size of infarction, and prognosis. The identification and quantification of EMPs and PMPs may thus be useful for the diagnosis and management of stroke.

LXA4 ameliorates cerebrovascular endothelial dysfunction by reducing acute inflammation after subarachnoid hemorrhage in rats

Lipoxin A4 (LXA4) has been reported to reduce inflammation in experimental subarachnoid hemorrhage (SAH), but the mechanism remains unclear. In this study, we investigated the role of LXA4 in inflammation-mediated cerebrovascular endothelial dysfunction and the potential mechanism after SAH. SAH was induced by endovascular perforation in male Sprague–Dawley rats, and recombinant LXA4 was injected intracerebroventricularly 1.5 h after the operation. The expression changes in the markers of endothelial dysfunction (endothelial microparticles and nitric oxide) were analyzed by flow cytometry or Nitric Oxide (NO) assay kit. Microflow in the cerebral cortex was assayed by laser speckle contrast imaging. Neutrophil infiltration was observed by a marker of leukocyte activity (myeloperoxidase, MPO) that colocalized with a specific marker of endothelial cells (von Willebrand factor, VWF). The expression of LXA4 and its downstream molecules, formyl peptide receptor 2 (FPR2), extracellular signal-regulated kinase (ERK1/2), nuclear factor-κB (NF-κB), matrix metalloproteinase-9 (MMP9), and the levels of pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), leukocyte adhesion molecule (intercellular adhesion molecule-1, ICAM-1) and MPO were measured either by Western blot or enzyme-linked immunosorbent assay (ELISA). SAH resulted in endothelial dysfunction and a reduction in microflow in the cerebral cortex. The expression of LXA4 was decreased, and the expression of pro-inflammatory factors (NF-κB, MMP9, ICAM-1, MPO) and cytokines (TNF-α, IL-1β, IL-6) was increased after SAH. The administration of LXA4 significantly ameliorated endothelial dysfunction, recovered microflow, and suppressed the inflammation and infiltration of neutrophils in SAH rats. The underlying mechanism of this outcome may involve the LXA4/FPR2/ERK1/2 pathway. LXA4 might be a promising candidate for acute SAH treatment.

Maraviroc Intensification Modulates Atherosclerotic Progression in HIV-Suppressed Patients at High Cardiovascular Risk. A Randomized, Crossover Pilot Study.

BackgroundExperimental CCR5 antagonism with maraviroc in atherosclerosis-prone mice and preliminary data in humans suggest an anti-atherosclerotic effect of the drug. We assessed the impact of maraviroc treatment in persons living with HIV on subclinical indicators of atherosclerosis.MethodsPersons living with HIV on effective antiretroviral therapy (ART) including only protease inhibitors were recruited if they had a Framingham risk score >20% and brachial flow-mediated dilation (bFMD) <4%, as indices of high cardiovascular risk. Maraviroc (300 mg per os for 24 weeks) was administered, in addition to ongoing ART, to all patients using a crossover design. Brachial FMD, carotid-femoral pulse wave velocity (cfPWV), and carotid intima-media thickness (cIMT) were measured as markers of atherosclerosis. Vascular competence—as expressed by the ratio of circulating endothelial microparticles (EMPs) to endothelial progenitor cells (EPCs)—and markers of systemic inflammation and monocyte and platelet activation were assessed.ResultsMaraviroc treatment significantly improved bFMD, cfPWV, and cIMT by 66%, 11%, and 13%, respectively (P = .002, P = .022, P = .038, respectively). We also found a beneficial effect of maraviroc on the EMP/EPC ratio (P < .001) and platelet/leucocyte aggregates (P = .013). No significant changes in markers of systemic inflammation, monocyte activation, and microbial translocation were observed.ConclusionsMaraviroc led to significant improvements in several markers for cardiovascular risk, endothelial dysfunction, arterial stiffness, and early carotid atherosclerosis, which was accompanied by an increase of vascular competence, without seeming to affect systemic inflammation. Our data support the need for larger studies to test for any effects of maraviroc on preventing atherosclerosis-driven pathologies.

Increased concentrations of platelet- and endothelial-derived microparticles in patients with myocardial infarction and reduced renal function- a descriptive study

BackgroundPatients with chronic kidney disease (CKD) have a high risk of recurring thrombotic events following acute myocardial infarction (AMI). Microparticles (MPs) are circulating small vesicles shed from various cells. Platelet microparticles (PMPs) reflect platelet activation and endothelial microparticles (EMPs) reflect endothelial activation or dysfunction. Both increase following AMI, and may mediate important biological effects. We hypothesized that AMI patients with CKD have further elevated PMPs and EMPs compared with non-CKD patients, despite concurrent antithrombotic treatment.MethodsWe performed a descriptive study of patients with AMI. Fasting blood samples were acquired from 47 patients on dual antiplatelet treatment. Patients were stratified by renal function: normal (H; n = 19) mean eGFR 88; moderate CKD (CKD3; n = 15) mean eGFR 47, and severe CKD (CKD4–5; n = 13) mean eGFR 20 mL/min/1.73 m2.MPs were measured by flow-cytometry and phenotyped according to size (< 1.0 μm) and expression of CD41 (GPIIb; PMPs) and CD62E (E-selectin; EMPs). In addition, expression of platelet activation markers P-selectin (CD62P) and CD40ligand (CD154) were also investigated.ResultsPMPs expressing CD40 ligand were higher in CKD4–5: 210 /μl (174–237); median and interquartile range; vs. group H; 101 /μl (71–134; p < 0.0001) and CKD 3: 142 /μl (125–187; p = 0.006). PMPs expressing P-selectin were higher in CKD4–5 compared with H, but not in CKD3. EMPs were higher in CKD4–5; 245 /μl (189–308) compared with H; 83 /μl (53–140; p < 0.0001) and CKD3; 197 /μl (120–245; p < 0.002).ConclusionsIn AMI patients, PMPs and EMPs from activated platelets and endothelial cell are further elevated in CKD patients. This indicate impaired endothelial function and higher platelet activation in CKD patients, despite concurrent antiplatelet treatment.

Short-Term Low-Carbohydrate High-Fat Diet in Healthy Young Males Renders the Endothelium Susceptible to Hyperglycemia-Induced Damage, An Exploratory Analysis.

Postprandial hyperglycemia has been linked to elevated risk of cardiovascular disease. Endothelial dysfunction and/or damage may be one of the mechanisms through which this occurs. In this exploratory study, we determined whether acute glucose ingestion would increase markers of endothelial damage/activation and impair endothelial function before and after a short-term low-carbohydrate high-fat diet (HFD) designed to induce relative glucose intolerance. Nine healthy young males (body mass index 23.2 ± 2 kg/m2) consumed a 75 g glucose drink before and <24 hours after consuming seven days of an iso-energetic HFD consisting of ~70% energy from fat, ~10% energy from carbohydrates, and ~20% energy from protein. CD31+/CD42b- and CD62E+ endothelial microparticles (EMPs) were enumerated at fasting, 1 hour (1 h), and 2 hours (2 h) post-consumption of the glucose drink. Flow-mediated dilation (FMD), arterial stiffness, and diameter, velocity, and flow of the common and internal carotid, and vertebral arteries were assessed in the fasting state and 1 h post glucose consumption. After the HFD, CD31+/CD42b- EMPs were elevated at 1 h compared to 2 h (p = 0.037), with a tendency for an increase above fasting (p = 0.06) only post-HFD. CD62E EMPs followed the same pattern with increased concentration at 1 h compared to 2 h (p = 0.005) post-HFD, with a tendency to be increased above fasting levels (p = 0.078). FMD was reduced at 1 h post glucose consumption both pre- (p = 0.01) and post-HFD (p = 0.005). There was also a reduction in FMD in the fasting state following the HFD (p = 0.02). In conclusion, one week of low-carbohydrate high-fat feeding that leads to a relative impairment in glucose homeostasis in healthy young adults may predispose the endothelium to hyperglycemia-induced damage.

Short-term exercise training reduces glycaemic variability and lowers circulating endothelial microparticles in overweight and obese women at elevated risk of type 2 diabetes

Exercise is recognized as a frontline therapy for the prevention and treatment of type 2 diabetes (T2D) but the optimal type of exercise is not yet determined. We compared the effects of high-intensity interval training (HIIT) with moderate-intensity continuous training (MICT) for improvement of continuous glucose monitoring (CGM)-derived markers of glycaemic variability, and biomarkers of endothelial cell damage (CD31+ and CD62+ endothelial microparticles (EMPs)) within a population at elevated risk of developing T2D. Fifteen inactive overweight or obese women were randomized to 2 weeks (10-sessions) of progressive HIIT (n = 8, 4–10X 1-min @ ∼90% peak heart rate, 1-min rest periods) or MICT (n = 7, 20–50 min of continuous activity at ∼65% peak heart rate). Prior and three days post-training, fasting blood samples were collected. Both HIIT and MICT improved glycaemic variability as measured by CGM standard deviation (HIIT: 0.82 ± 0.39 vs. 0.72 ± 0.33 mmol/L; MICT: 0.82 ± 0.19 vs. 0.62 ± 0.16 mmol/L, pre vs. post) and mean amplitude of glycaemic excursions (MAGE; HIIT: 1.98 ± 0.81 vs. 1.41 ± 0.90; MICT; 1.98 ± 0.43 vs. 1.65 ± 0.48, pre vs. post) with no difference between groups. CD62+ EMPs were lower following HIIT (187.7 ± 65 vs. 174.9 ± 55, pre vs. post) and MICT (170 ± 60 vs. 160.3 ± 59, pre vs. post) with no difference between groups. There was no change in 24-h mean glucose or CD31+ EMPs. Two weeks of both HIIT or MICT similarly decreased glycaemic variability and CD62+ EMPs in overweight/obese women at elevated risk of T2D.

Di-(2-Ethylhexyl) Phthalate Promotes Release of Tissue Factor-Bearing Microparticles From Macrophages via the TGFβ1/Smad/PAI-1 Signaling Pathway

BackgroundPlasminogen activator inhibitor type 1 promotes formation of endothelial microparticles with procoagulant activity. However, it remains unclear whether di-(2-ethylhexyl) phthalate, a peroxisome proliferator-activated receptor α agonist, influences microparticle formation. Materials and MethodsThe effect of di-(2-ethylhexyl) phthalate on release of tissue factor-bearing microparticles was investigated using human M1 macrophages. ResultsExposure of M1 macrophages to di-(2-ethylhexyl) phthalate significantly upregulated expression of plasminogen activator inhibitor type 1, whereas incubation of macrophages with small interfering RNA for peroxisome proliferator-activated receptor α attenuated it. Di-(2-ethylhexyl) phthalate significantly increased the tissue factor protein level in culture supernatants of M1 macrophages, but not M2 macrophages. After purification of proteins by centrifugal filtration, western blotting detected 2 high molecular weight bands of tissue factor-bearing microparticles in culture supernatants of M1 macrophages. The upper band showed binding to factor VIIa and tissue factor pathway inhibitor, unlike the lower band. This suggested heterogeneity of the procoagulant activity of tissue factor-bearing microparticles, presumably dependent upon encryption/decryption of tissue factor. Phosphatidylserine contributes to tissue factor decryption, and western blotting revealed that the density of phosphatidylserine was reduced in the upper tissue factor band compared with the lower band. Di-(2-ethylhexyl) phthalate also upregulated transforming growth factor-β1 protein production by M1 macrophages. Moreover, silencing of Smad2, Smad3 or Smad4 attenuated plasminogen activator inhibitor type 1 expression and tissue factor-release from macrophages after di-(2-ethylhexyl) phthalate stimulation. ConclusionsDi-(2-ethylhexyl) phthalate promotes formation of tissue factor-bearing microparticles in human M1 macrophages via the transforming growth factor-β1/Smad/ plasminogen activator inhibitor type 1 signaling pathway.

Microparticles in systemic sclerosis: Potential pro-inflammatory mediators and pulmonary hypertension biomarkers.

Endothelial microparticles (EMP) are submicron vesicles released from endothelial cells. We aimed to determine the utility of EMP as biomarkers of pulmonary arterial hypertension (PAH) in systemic sclerosis (SSc) patients and the pathogenic role of microparticles (MP) in vascular inflammation. Levels of EMP (CD144+, CD31+, CD62E+ and CD143+) were compared between three groups (10 SSc patients with PAH, 10 SSc patients without pulmonary hypertension (no-PH) and 10 healthy age- and sex-matched controls). Human pulmonary artery endothelial cells (HPAEC) were exposed in vitro to MP obtained from SSc patients or healthy controls, and levels of cytokines and inflammatory adhesion molecules were compared. CD144+ EMP were significantly higher in the SSc-PAH group compared to either the SSc-no PH or healthy controls (diagnostic accuracy 80%, P = 0.02). Compared to controls, SSc patients had higher CD31+/CD62E+ ratios, indicating larger contributions of apoptosis to EMP release (P = 0.04). Patients with limited SSc had significantly higher levels of CD143+ EMP compared to those with diffuse subtype (P = 0.008). When HPAEC were exposed to MP from SSc patients, there was a significant increase in inflammatory cytokines and adhesion molecules. Interestingly, exposure to healthy control MP caused a reduction in inflammatory markers. EMP (particularly CD144+) are promising biomarkers of PAH in SSc but require further study. MP isolated from SSc patients induced an increase in endothelial cell inflammation and may be an important pathogenic factor in SSc.

Microparticles from vascular endothelial growth factor pathway inhibitor-treated cancer patients mediate endothelial cell injury.

Vascular endothelial growth factor pathway inhibitors (VEGFi), used as anti-angiogenic drugs to treat cancer are associated with cardiovascular toxicities through unknown molecular mechanisms. Endothelial cell-derived microparticles (ECMPs) are biomarkers of endothelial injury and are also functionally active since they influence downstream target cell signalling and function. We questioned whether microparticle (MP) status is altered in cancer patients treated with VEGFi and whether they influence endothelial cell function associated with vascular dysfunction. Plasma MPs were isolated from cancer patients before and after treatment with VEGFi (pazopanib, sunitinib, or sorafenib). Human aortic endothelial cells (HAECs) were stimulated with isolated MPs (106 MPs/mL). Microparticle characterization was assessed by flow cytometry. Patients treated with VEGFi had significantly increased levels of plasma ECMP. Endothelial cells exposed to post-VEGFi treatment ECMPs induced an increase in pre-pro-ET-1 mRNA expression, corroborating the increase in endothelin-1 (ET-1) production in HAEC stimulated with vatalanib (VEGFi). Post-VEGFi treatment MPs increased generation of reactive oxygen species in HAEC, effects attenuated by ETA (BQ123) and ETB (BQ788) receptor blockers. VEGFi post-treatment MPs also increased phosphorylation of the inhibitory site of endothelial nitric oxide synthase (eNOS), decreased nitric oxide (NO), and increased ONOO− levels in HAEC, responses inhibited by ETB receptor blockade. Additionally, gene expression of proinflammatory mediators was increased in HAEC exposed to post-treatment MPs, effects inhibited by BQ123 and BQ788. Our findings define novel molecular mechanism involving interplay between microparticles, the ET-1 system and endothelial cell pro-inflammatory and redox signalling, which may be important in cardiovascular toxicity and hypertension associated with VEGFi anti-cancer treatment. New and noteworthy: our novel data identify MPs as biomarkers of VEGFi-induced endothelial injury and important mediators of ET-1-sensitive redox-regulated pro-inflammatory signalling in effector endothelial cells, processes that may contribute to cardiovascular toxicity in VEGFi-treated cancer patients.

Cardiovascular injury induced by tobacco products: assessment of risk factors and biomarkers of harm. A Tobacco Centers of Regulatory Science compilation.

Although substantial evidence shows that smoking is positively and robustly associated with cardiovascular disease (CVD), the CVD risk associated with the use of new and emerging tobacco products, such as electronic cigarettes, hookah, and heat-not-burn products, remains unclear. This uncertainty stems from lack of knowledge on how the use of these products affects cardiovascular health. Cardiovascular injury associated with the use of new tobacco products could be evaluated by measuring changes in biomarkers of cardiovascular harm that are sensitive to the use of combustible cigarettes. Such cardiovascular injury could be indexed at several levels. Preclinical changes contributing to the pathogenesis of disease could be monitored by measuring changes in systemic inflammation and oxidative stress, organ-specific dysfunctions could be gauged by measuring endothelial function (flow-mediated dilation), platelet aggregation, and arterial stiffness, and organ-specific injury could be evaluated by measuring endothelial microparticles and platelet-leukocyte aggregates. Classical risk factors, such as blood pressure, circulating lipoproteins, and insulin resistance, provide robust estimates of risk, and subclinical disease progression could be followed by measuring coronary artery Ca2+ and carotid intima-media thickness. Given that several of these biomarkers are well-established predictors of major cardiovascular events, the association of these biomarkers with the use of new and emerging tobacco products could be indicative of both individual and population-level CVD risk associated with the use of these products. Differential effects of tobacco products (conventional vs. new and emerging products) on different indexes of cardiovascular injury could also provide insights into mechanisms by which they induce cardiovascular harm.

Endothelial Microparticles and Vascular Endothelial Growth Factor in Patients With Head and Neck Cancer Undergoing Radiotherapy or Radiochemotherapy.

Endothelial microparticles (EMPs) released from activated or apoptotic endothelial cells may play a role in coagulation and thrombus formation. However, there is insufficient evidence regarding the impact of EMPs on angiogenesis in patients with cancer. Sixteen patients with head and neck cancer (HNC) undergoing radiotherapy/radiochemotherapy (RT/RCT) and 10 healthy controls were studied. Serum EMPs were counted by flow cytometry, and vascular endothelial growth factor (VEGF) was measured by enzyme-linked immunosorbent assay (ELISA). The mean EMP level was significantly higher in patients with HNC before RT/RCT (1,601±1,479 EMP/μl) compared to the control group (782±698 EMP/μl). The number of EMPs was not notably increased after RT/RCT (1,629±769 EMP/μl). There was no significant correlation between the plasma EMP number and concentration of VEGF before (r=0.131; p=0.625), 1 day after (r=-0.042, p=0.874), nor 3 months after RT/RCT (r=0.454, p=0.076). Released EMPs may not influence promotion of neovascularization in patients with HNC.

Endothelial Microparticles and Blood Coagulation Activation in Head and Neck Cancer Patients Undergoing Radiotherapy or Radiochemotherapy.

Endothelial microparticles (EMP) are small vesicles which are released from the endothelium and contribute to blood coagulation activation in various clinical settings. The aim of this study was to examine whether EMP influence blood coagulation activation in cancer patients during radiotherapy/radiochemotherapy (RT/RCT). Sixteen head and neck cancer (HNC) patients undergoing RT/RCT and 10 controls were examined. EMP and thrombin-antithrombin complex (TAT) were measured by flow cytometry and enzyme-linked immunosorbent assay (ELISA), respectively. Tissue factor-positive EMP (TF+EMP) were defined as CD31+/CD142+/CD42b- Results: TF+EMP were significantly elevated in HNC patients before RT/RCT (T0) (1299±1154/μl), one day after RT/RCT (T1d) (1257±603/μl) and 3 months after RT/RCT (T3m) (1289±372/μl) compared to controls (688±647/μl). TF+EMP levels at T0/T1d and T0, as well as at T1d and T3m were not significantly different. TAT levels at T0 and T1d did not differ significantly but at T3m were significantly lower compared to T0 and T1d TF+EMP and TAT concentrations were not significantly correlated at T0 (r=0.058; p=0.828), T1d (r=0.373, p=0.154) and T3m (r=-0.302, p=0.204). TF+EMP may not contribute to hemostatic abnormalities in HNC patients.

Immunophenotyping of Circulating Endothelial Cells and Endothelial Microparticles.

Flow-cytometric detection of circulating endothelial cells and endothelial microparticles is an essential tool in studies of vascular diseases. Here we describe the principles and detailed methods for human blood sample processing, storage, labeling, and gating of circulating endothelial elements.

Circulating microparticles and central blood pressure according to antihypertensive strategy

OBJECTIVES:This prospective, randomized, open-label study aimed to compare the effects of antihypertensive treatment based on amlodipine or hydrochlorothiazide on the circulating microparticles and central blood pressure values of hypertensive patients.METHODS:The effects of treatments on circulating microparticles were assessed during monotherapy and after the consecutive addition of valsartan and rosuvastatin followed by the withdrawal of rosuvastatin. Each treatment period lasted for 30 days. Central blood pressure and pulse wave velocity were measured at the end of each period. Endothelial, monocyte, and platelet circulating microparticles were determined by flow cytometry. Central blood pressure values and pulse wave velocity were recorded at the end of each treatment period.RESULTS:No differences in brachial blood pressure were observed between the treatment groups throughout the study. Although similar central blood pressure values were observed during monotherapy, lower systolic and diastolic central blood pressure values and early and late blood pressure peaks were observed in the amlodipine arm after the addition of valsartan alone or combined with rosuvastatin. Hydrochlorothiazide-based therapy was associated with a lower number of endothelial microparticles throughout the study, whereas a higher number of platelet microparticles was observed after rosuvastatin withdrawal in the amlodipine arm.CONCLUSIONS:Despite similar brachial blood pressure values between groups throughout the study, exposure to amlodipine was associated with lower central blood pressure values after combination with valsartan, indicating a beneficial interaction. Differences between circulating microparticles were modest and were mainly influenced by rosuvastatin withdrawal in the amlodipine arm.

Diagnostic and prognostic relevance of microparticles in peripheral and uterine blood of patients with endometrial cancer

Exosomes - microvesicles which are secreted by living cells - can be produced from different cell types and detected in various body fluids. They are the carriers of intercellular information which regulate tumor microenvironment and are considered to be involved in tumor progression and metastasis. Cancer cells can secrete more exosomes than healthy cells, and are expected to be potential tools for tumor diagnosis and treatment. In this report, we present the results of microparticle analysis in peripheral and uterine blood of patients with endometrial cancer. To the best of our knowledge, this study has been the first to report microvesicle status in peripheral and uterine blood samples. The aim of the study was to determine the amount of total (TF+), endothelial (CD144+) and monocytic (CD14+) microparticles. The counting of the selected microparticles in citrate plasma was performed using flow cytometry on the BD Canto II cytometer. We found that the total amount of microparticles in cancer patients was much higher than in healthy controls. Moreover, microparticle count in uterine blood was higher than in peripheral blood of patients with endometrial cancer. We also demonstrated that the amount of microparticles correlates with the histologic grade and clinical stage of the tumor. The most interesting finding in this work was the high level of TF, CD144 and CD14 MPs in uterine blood samples. Thus we can consider the monocyte-macrophage-derived MPs as a candidate marker of endometrial cancer and maybe very critical part of the endometrial carcinogenesis.

Acute effects of electronic and tobacco cigarettes on vascular and respiratory function in healthy volunteers: a cross-over study.

To assess the acute effects of nicotine-containing electronic cigarettes versus tobacco smoking on vascular and respiratory function and circulating microparticles, particularly platelet microparticles (PMPs, biomarker of haemostasis/thrombosis) and endothelial microparticles (EMPs, biomarker of endothelial function). Heart rate (HR), blood pressure, reactive hyperaemia index (RHI, microvascular reactivity), augmentation index (arterial stiffness) and respiratory function were assessed in 20 smokers immediately before and after electronic cigarettes use and tobacco smoking. The number of microparticles was determined by flow cytometry using counting beads as a reference. Labelling with Annexin-V was used to detect the total microparticle fraction. EMPs were characterized as CD31+CD42- and PMPs as CD31+CD42+. HR increased after electronic cigarettes use and tobacco smoking (P < 0.001), whereas blood pressure remained unchanged (P > 0.05). RHI (P = 0.006), augmentation index (P = 0.010) but not augmentation index standardized to HR 75 bpm (P > 0.05) increased with electronic cigarettes use but not with tobacco smoking. Following tobacco smoking, there was a significant increase in total microparticles (P < 0.001), EMPs (P < 0.001) and PMPs (P < 0.001). In contrast, electronic cigarettes were only associated with an increase in PMPs (P < 0.001), with no significant changes in the total microparticle fraction or EMPs (all P > 0.05). Peak expiratory flow significantly decreased following electronic cigarettes use (P = 0.019). Our results demonstrate that acute exposure to tobacco smoking as well as electronic cigarettes influences vascular and respiratory function. Where tobacco smoking significantly increased microparticle formation, indicative of possible endothelial injury, electronic cigarettes use induced vasoreactivity and decreased peak expiratory flow. These findings suggest that both electronic cigarettes and tobacco smoking negatively impact vascular function.

Microparticles from Endothelial Cells and Immune Cells in Patients with Takayasu Arteritis.

Aim: This study was designed to analyze microparticles (MPs) from endothelial cells (EMPs) and immune cells from healthy individuals and paitents with Takayasu arteritis (TA), and any possible relationships between MPs and TA acitivity.Methods: MPs derived from the plasma of 51 subjects were analyzed, including 32 patients with TA and 19 healthy individuals. Flow cytometry was performed with Annexin (Anx)-V and antibodies against surface markers of endothelial cells (CD144), T cells (CD3), B cells (CD19), and monocytes (CD14).Results: The concentrations of total EMPs, AnxV+ EMPs and AnxV− EMPs were significantly increased when comparing patients with TA and healthy controls (54 × 103 vs. 32 × 103 MPs /ml, P = 0.0004; 22 × 103 vs. 12 × 103 MPs /ml, P = 0.0006; and 31 × 103 vs. 19 × 103 MPs /ml, P = 0.0005), and comparing active TA patients with remission ones (85 × 103 vs. 45 × 103 MPs /ml, P = 0.016; 39 × 103 vs. 14 × 103 MPs /ml, P = 0.0092; and 47 × 103 vs. 29 × 103 MPs /ml, P = 0.0371). In addition, the concentrations of total EMPs (odds ratio [OR] = 1.024, 95% confidence interval [CI]: 1.001 to 1.048, P = 0.037), AnxV+ (OR = 1.089, 95%CI: 1.011 to 1.172, P = 0.024), and AnxV− EMPs (OR = 1.029, 95% CI: 1.002 to 1.056, P = 0.034) were positively related to TA activity. With multiple linear regression analysis, platelet was associated with both total and AnxV− EMP concentrations independently, while erythrocyte sedimentation rate was independently correlated with AnxV+ EMPs.Conclusion: Concentrations of endothelial microparticles are correlated with inflammation in Takayasu arteritis and may be useful markers to assess disease activity.

Effect of Endothelial Microparticles Induced by Hypoxia on Migration and Angiogenesis of Human Umbilical Vein Endothelial Cells by Delivering MicroRNA-19b.

Background:Microparticles (MPs) are small extracellular plasma membrane particles shed by activated and apoptotic cells, which are involved in the development of atherosclerosis. Our previous study found that microRNA (miR)-19b encapsulated within endothelial MPs (EMPs) may contribute to the upregulation of circulating miR-19b in unstable angina patients. Hypoxia is involved in atherosclerosis as a critical pathological stimulus. However, it still remains unclear whether the increase of miR-19b levels in EMPs is related to hypoxia and if the effect of miR-19b – wrapped within EMPs – stimulates hypoxia on vascular endothelial cells. This study aimed to explore the changes of miR-19b in EMPs induced by hypoxia as well as their effects on endothelial cells.Methods:Human umbilical vein endothelial cells (HUVECs) were cultured in vitro and arranged to harvest EMPs in two parts: the first part consisted of EMPcontrol and EMPhypoxia and the second part included EMPvehicle, EMPNC mimic, and EMPmiR-19b mimic. Cell migration was detected by scratch migration and transwell chamber migration. Angiogenesis was assessed by tube formation assays. Furthermore, we predicted the target gene of miR-19b by bioinformatics analysis, and luciferase assay was used to verify the targeted gene of miR-19b. Data were analyzed by one-way analysis of variance. Student's t-test was used when two groups were compared.Results:Compared with EMPcontrol- and EMPhypoxia-inhibited migration of cells by scratch migration assay (80.77 ± 1.10 vs. 28.37 ± 1.40, P < 0. 001) and transwell chamber migration assay (83.00 ± 3.46 vs. 235.00 ± 16.52, P < 0.01), the number of tube formations was markedly reduced by 70% in the EMPhypoxia group (P < 0.001) in vitro analysis of HUVECs. Meanwhile, a strong inhibition of migration and tube formation of HUVECs in the presence of miR-19b-enriched EMPmiR-19b mimic was observed. This effect might be due to the delivery of miR-19b in EMPs. Transforming growth factor-β2 (TGFβ2) was predicted to be one of the target genes of miR-19b, and we further confirmed that TGFβ2 was a direct target gene of miR-19b using the luciferase assay. The expression of TGFβ2 in HUVECs was inhibited by treatment with EMPhypoxia and EMPmiR-19b mimic.Conclusions:MiR-19b in EMPs induced by hypoxia could reduce endothelial cell migration and angiogenesis by downregulating TGFβ2 expression, which may have inhibited the progression of atherosclerosis.