Levels Of Endothelial Microparticles Research Articles

Effect of hemodialysis on extracellular vesicles and circulating submicron particles

BackgroundAlthough hemodialysis is a highly effective treatment for diffusive clearance of low molecular weight uremic toxins, its effect on circulating extracellular vesicles and submicron particles is less clear. The purpose of this study was to examine the impact of hemodialysis on circulating levels of submicron particles.MethodsPlasma samples from patients were collected immediately before and after the mid-week hemodialysis session. Total submicron particles were assessed by nanoparticle tracking analysis and levels of endothelial (CD144+), platelet (CD41+), leukocyte (CD45+), and total (Annexin V+) membrane microparticles (MPs) were assessed by flow cytometry.ResultsTotal submicron particle number was significantly lower post-dialysis with reductions in particles < 40 nm, 40–100 nm, and 100–1000 nm in size. Circulating annexin V+ MPs, platelet MPs, leukocyte MPs, and endothelial MPs were all reduced following dialysis. Assessment of protein markers suggested that extracellular vesicles were not present in the dialysate, but rather adsorbed to the dialysis membrane.ConclusionsIn summary, hemodialysis is associated with reductions in circulating submicron particles including membrane MPs. Accordingly, there may be significant interdialytic variation in circulating submicron particles. Investigators interested in measuring extracellular vesicles in patients undergoing hemodialysis should therefore carefully consider the timing of biosampling.

Endothelial Dysfunction in Patients with Severe Mitral Regurgitation.

Mitral valve prolapse (MVP) is the most common cause of severe mitral regurgitation. It has been reported that MVP patients—candidates for mitral valve repair (MVRep)—showed an alteration in the antioxidant defense systems as well as in the L-arginine metabolic pathway. In this study, we investigate if oxidative stress and endothelial dysfunction are an MVP consequence or driving factors. Forty-five patients undergoing MVRep were evaluated before and 6 months post surgery and compared to 29 controls. Oxidized (GSSG) and reduced (GSH) forms of glutathione, and L-arginine metabolic pathway were analyzed using liquid chromatography-tandem mass spectrometry methods while osteoprotegerin (OPG) through the ELISA kit and circulating endothelial microparticles (EMP) by flow cytometry. Six-month post surgery, in MVP patients, the GSSG/GSH ratio decreased while symmetric and asymmetric dimethylarginines levels remained comparable to the baseline. Conversely, OPG levels significantly increased when compared to their baseline. Finally, pre-MVRep EMP levels were significantly higher in patients than in controls and did not change post surgery. Overall, these results highlight that MVRep completely restores the increased oxidative stress levels, as evidenced in MVP patients. Conversely, no amelioration of endothelial dysfunction was evidenced after surgery. Thus, therapies aimed to restore a proper endothelial function before and after surgical repair could benefit MVP patients.

Anti-endothelial cell antibodies are associated with apoptotic endothelial microparticles, endothelial sloughing and decrease in angiogenic progenitors in systemic sclerosis.

IntroductionEvidence has accumulated for the role of endothelial damage in systemic sclerosis (SSc) and the anti-endothelial cell antibodies (AECAs) might underlie vascular injury.AimSince endothelial microparticles (EMPs) and circulating endothelial cells (CECs) reflect endothelial damage, we aimed to investigate their possible relationship with AECAs in SSc. We examined whether AECAs could affect endothelial repair based on the number of endothelial progenitor cells (EPCs).Material and methodsForty-seven SSc patients were screened. The AECAs were identified in serum by indirect immunofluorescence. EPCs and CECs were isolated from the peripheral blood using anti-CD34-based immunomagnetic separation, whereas EMPs were analyzed in plasma. Flow cytometry was used to quantify EMPs, CECs and EPCs.ResultsAECAs were found in 21 (44.7%) SSc patients and were significantly associated with higher levels of total as well as apoptotic (AnnV+ and CD51+) EMPs, whereas activated (CD62E+/AnnV–) EMPs did not differ between groups. Patients with AECAs had significantly elevated total CECs as well as activated CD105+ CECs. Total endothelial progenitors did not differ between patients with or without AECAs; however AECAs was negatively associated with the population of EPCs that express VEGFR2 or Tie2 receptors.ConclusionsWe found an association between AECAs and the severity of endothelial damage in SSc based on higher levels of total EMPs and CECs. In our study, AECAs were associated with apoptosis of ECs rather than their activation. We also identified a possible role of AECAs in the impairment of vascular repair in SSc as evidenced by significantly fewer angiogenic EPCs.

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.

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.

Loss of Renal Peritubular Capillaries in Hypertensive Patients Is Detectable by Urinary Endothelial Microparticle Levels.

Hypertension, an important cause of chronic kidney disease, is characterized by peritubular capillary (PTC) loss. Circulating levels of endothelial microparticles (EMPs) reflect systemic endothelial injury. We hypothesized that systemic and urinary PTC-EMPs levels would reflect renal microvascular injury in hypertensive patients. We prospectively measured by flow cytometry renal vein, inferior vena cava, and urinary levels of EMPs in essential (n=14) and renovascular (RVH; n=24) hypertensive patients and compared them with peripheral blood and urinary levels in healthy volunteers (n=14). PTC-EMPs were identified as urinary exosomes positive for the PTC marker plasmalemmal-vesicle-associated protein. In 7 RVH patients, PTC and fibrosis were also quantified in renal biopsy, and in 18 RVH patients, PTC-EMPs were measured again 3 months after continued medical therapy with or without stenting (n=9 each). Renal vein and systemic PTC-EMPs levels were not different among the groups, whereas their urinary levels were elevated in both RVH and essential hypertension versus healthy volunteers (56.8%±12.7% and 62.8%±10.7% versus 34.0%±17.8%; both P≤0.001). Urinary PTC-EMPs levels correlated directly with blood pressure and inversely with estimated glomerular filtration rate. Furthermore, in RVH, urinary PTC-EMPs levels correlated directly with stenotic kidney hypoxia, histological PTC count, and fibrosis and inversely with cortical perfusion. Three months after treatment, the change in urinary PTC-EMPs levels correlated inversely with a change in renal function ( r=-0.582; P=0.011). Therefore, urinary PTC-EMPs levels are increased in hypertensive patients and may reflect renal microcirculation injury, whereas systemic PTC-EMPs levels are unchanged. Urinary PTC-EMPs may be useful as novel biomarkers of intrarenal capillary loss.

Changes of microparticle levels before and after daunorubicin-based chemotherapy in patients with acute leukemia

Objective To observe the serum levels of endothelial microparticles (EMP) and tissue factor-bearing microparticles (TF+ MP) in patients with acute leukemia before and after daunorubicin-based chemotherapy. Methods From July 2012 to February 2013, 15 patients with newly diagnosed acute leukemia in Peking Union Medical College Hospital received DA (daunorubicin + cytarabine) regimen or VDCLP (vincristine + daunorubicin + cyclophosphamide + L-asparaginase + prednisone) regimen chemotherapy. There were 8 males and 7 females, and the median age of patients was 44 years old. Eleven patients were acute myeloid leukemia (M0 1 case, M1 1 case, M2 9 cases), and 4 were acute lymphocytic leukemia. The peripheral blood samples were taken before induction chemotherapy and after 3 days of daunorubicin. Levels of EMP and TF+ MP were assessed using flow cytometry. Results The serum EMP and TF+ MP levels were significantly higher after 3-day daunorubicin infusions than those before induction chemotherapy (28.94/μl vs. 10.74/μl, P = 0.001; 64.24/μl vs. 43.80/μl, P = 0.02). Conclusion Daunorubicin-based chemotherapy may cause increased numbers of EMP and TF+ MP in patients with acute leukemia. Key words: Leukemia, acute; Antineoplastic combined chemotherapy protocols; Daunorubicin; Endothelial particles; Tissue factor-bearing microparticles

The relationship between habitual dietary sodium intake and RAAS blockade on circulating microparticle levels in type two diabetes.

Low sodium intake is paradoxically associated with adverse cardiovascular outcomes in individuals with type 2 diabetes mellitus (T2D), possibly from renin-angiotensin-aldosterone system (RAAS) activation, leading to endothelial dysfunction. In the present study, we investigated the associations between habitual sodium intake and RAAS blockade on endothelial function by measuring circulating microparticles (MPs) in individuals with T2D. We conducted a prospective, cross-sectional study in 74 individuals with T2D. Habitual dietary sodium intake was estimated by using the mean of three corrected 24-h urine sodium excretion measurements (24hUNa). MP subtypes in platelet-free plasma were quantitated using flow cytometry. No associations between 24hUNa with levels of endothelial MPs were observed. Instead, a trend toward higher diabetes related CD36+/CD235a+ MP levels was associated with lower 24hUNa (rho = -0.23, P=0.05). When stratified according to tertiles of 24hUNa, platelet-derived CD42b+/CD41+ and CD42+/CD41+/Annexin V+ MPs were higher in the lowest tertile (24hUNa < 157 mmol/24 h) (P=0.02 respectively). Despite RAAS blockade being associated with lower levels of most MP subsets, it was not associated with lower MPs, in the setting of low sodium intake. Lower sodium intake is associated with higher circulating procoagulant MPs, but not with evidence of endothelial dysfunction in individuals with T2D.

Expression and significance of endothelial microparticles in children with Henoch-Schönlein purpura

To study the expression and significance of endothelial microparticles (EMPs) in children with Henoch-Schönlein purpura (HSP). A total of 100 previously untreated children with HSP were classified to Henoch-Schönlein purpura nephritis (HSPN) group (n=40) and non-nephritis group (n=60). Thirty healthy children who underwent physical examination were enrolled as control group. Serum levels of EMPs, T helper 17 cells (Th17), and interleukin-17 (IL-17) were compared between groups. The HSPN and non-nephritis groups had significantly higher levels of Th17 and IL-17 than the control group, and the HSPN group had the highest levels (P<0.05). The HSPN and non-nephritis groups had a significantly higher level of EMPs than the control group, and the HSPN group had the highest level (P<0.05). In the HSPN group, the levels of Th17 and IL-17 were positively correlated with the level of EMPs (r=0.830 and 0.644 respectively; P<0.05). EMPs play an important role in the pathogenesis of HSP. The increase in EMPs might be one of the reasons for renal involvement in children with HSP.

A11518 Hemodialysis reduces levels of circulating microparticles in individuals with hypertension

Objectives: Individuals with end stage kidney disease (ESKD) and hypertension are at increased risk of cardiovascular complications. Circulating microparticles (MPs) are putative biomarkers of vascular injury and circulating levels of MPs are increased in both hypertension and ESKD. The purpose of this study was to determine the effect of hemodialysis on circulating MPs in individuals with and without hypertension. Methods: 37 individuals with hypertension and 17 normotensive individuals on conventional 3 times weekly hemodialysis were studied (age 61 ± 2 years). Plasma samples from were collected in a non-fasting state immediately before and after hemodialysis at the mid-week hemodialysis session. An FX 800 hemodiafilter (Fresenius Medical Care) was used. Levels of endothelial (CD144 + ), platelet (CD41 + ), leukocyte (CD45 + ) and total (Annexin V + ) microparticles were assessed by flow cytometry. Results: Across all participants, significant reductions were seen in circulating annexin V + ve MPs (3x107vs1.6x107, P < 0.01), platelet MPs (1.8x107vs1.0x107, P < 0.001), leukocyte microparticles (2.4x106vs 1.8x106, P < 0.05), and endothelial MPs (8.4x105vs5.9x105, P < 0.01). There were no differences in pre-dialysis or post-dialysis MP levels (total, endothelial, leukocyte, or platelet) between hypertensive and non-hypertensive individuals and the inter-dialytic increases in MP levels were not significantly different between hypertensive and non-hypertensive individuals. Conclusion: Hemodialysis is associated with reductions in circulating platelet, leukocyte, and endothelial MPs. There may be significant interdialytic variation in MP levels and this should be an important consideration in studying MPs as biomarkers in ESKD. The presence of hypertension does not appear to alter inter-dialytic increases in circulating MPs.

Altered lung biology of healthy never smokers following acute inhalation of E-cigarettes

BackgroundLittle is known about health risks associated with electronic cigarette (EC) use although EC are rising in popularity and have been advocated as a means to quit smoking cigarettes.MethodsTen never-smokers, without exposure history to tobacco products or EC, were assessed at baseline with questionnaire, chest X-ray, lung function, plasma levels of endothelial microparticles (EMP), and bronchoscopy to obtain small airway epithelium (SAE) and alveolar macrophages (AM). One week later, subjects inhaled 10 puffs of “Blu” brand EC, waited 30 min, then another 10 puff; n = 7 were randomized to EC with nicotine and n = 3 to EC without nicotine to assess biological responses in healthy, naive individuals.ResultsTwo hr. post-EC exposure, subjects were again assessed as at baseline. No significant changes in clinical parameters were observed. Biological changes were observed compared to baseline, including altered transcriptomes of SAE and AM for all subjects and elevated plasma EMP levels following inhalation of EC with nicotine.ConclusionsThis study provides in vivo human data demonstrating that acute inhalation of EC aerosols dysregulates normal human lung homeostasis in a limited cohort of healthy naïve individuals. These observations have implications to new EC users, nonsmokers exposed to secondhand EC aerosols and cigarette smokers using EC to quit smoking.Trial registrationClinicalTrials.gov NCT01776398 (registered 10/12/12), NCT02188511 (registered 7/2/14).

Putative mechanisms Underlying Myocardial infarction onset and Emotions (PUME): a randomised controlled study protocol

IntroductionThe experience of negative emotions (eg, anger, anxiety and sadness) is associated with an increased short-term risk of incident cardiovascular disease (CVD) events, independent of traditional CVD risk factors. Impairment...

Association between vitamin D and vascular endothelial injury in hypertensive patients

Objective To evaluate the association between vitamin D (VD) and vascular endothelial injury in hypertensive patients. Methods Ninety nine patients with hypertension and 126 healthy subjects (control group) from the same community in Nanjing were recruited in the study. The serum levels of fasting blood glucose (GLU), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and triglycerides (TG) were measured. Serum 25-hydroxy vitamin D (25-OH-D) and nitric oxide (NO) levels were determined by enzyme-linked immunosorbent assay. The level of plasma endothelial microparticles was measured by flow cytometry. The data were statistically analyzed with SPSS version 19.0. Results The serum 25-(OH)-D[(55.22±11.92)nmol/L vs. (64.17±21.52) nmol/L, t=-3.71], vitamin D binding protein (VDBP)[(257.32±141.31) ng/ml vs. (314.21±124.13) ng/ml, t=-3.21], NO levels [(39.35±13.33) μmol/L vs. (43.42±11.83) μmol/L, t=-2.42]in hypertension group were significantly lower than those in control group. And the circulating endothelial cell particles(4.95±1.78 vs. 2.84±2.07, t=8.05)in hypertension group was significantly higher than that in control group. In hypertensive patients, the circulating endothelial cell particles in VD deficiency group was significantly higher than that in low VD group and normal VD group [(6.42±1.25)% vs. (4.6±1.68)%, (3.15±0.90)%, F=15.08]. And the serum NO level in VD deficiency group was significantly lower than that in other two groups[(36.57±10.52) μmol/L vs. (39.77±13.01) μmol/L, (46.26±25.90) mol/L, F=1.20]. Multiple linear regression analysis showed that low serum 25 (OH) D(B=-0.189, SE=0.033, β=0.509, t=-5.72)and gender (B=-0.682, SE=0.351, β=-0.182, t=-2.054)were the risk factors of vascular endothelial injury. Conclusion The serum vitamin D levels in hypertensive patients is decreased, and vitamin D deficiency may be a risk factor for endothelial injury in hypertension. Key words: Vitamin D; Hypertension; Vascular endothelial cells injury

Abstract 171: Endothelial Microparticle Levels and Silent Stroke in the Framingham Heart Study

Introduction: Endothelial microparticles (EMP) are membrane vesicles, with a characteristic diameter of 0.1-1.0μ, shed by endothelial cells during cellular activation or apoptosis. EMP are associated with cardiovascular disease and risk factors, but data are lacking on the relations of EMP with subclinical vascular brain injury. Methods: We studied 487 individuals (mean age 66.9±8.8 years, 55% women) from the Framingham Offspring Cohort, who were free from clinical stroke. CD31+/CD41- EMP were identified and quantified using flow cytometry. Silent cerebral infarcts (SCI) were quantified as parenchymal lesions on brain MRI &gt;3mm in size with characteristics of previous infarcts. Logistic regression models were used to investigate cross-sectional associations of EMP levels with prevalent SCI. We tested for interaction between EMP levels and statin use in their relationship with SCI. Results: SCI was observed in 49 (10%) participants. Figure 1 displays results of the logistic regression analysis. Circulating CD31+/CD41- EMP levels were inversely associated with SCI, adjusting for age, sex, and time interval between blood draw and brain MRI (OR 0.90 [0.82-0.98], p=0.016). Similar results were observed when adjusting for additional vascular risk factors. We observed an interaction between statin use and EMP levels in their association with SCI. There was an inverse association (OR 0.76 [0.64-0.89], p=0.001) among statin users and no association among non-statin users. Conclusions: In our analysis of the relationship of CD31+/CD41- EMP with SCI, in a well-defined community cohort, we observed an inverse association of higher EMP levels, primarily in participants on statins. Our data question whether constitutive or induced release of EMP, associated with a pleiotropic effect of statin medication, might mitigate vascular risk factor exposure and reduce risk of SCI. Further studies are needed to determine the associations of EMP with SCI and clinical stroke.

Bubbles Induce Endothelial Microparticle Formation via a Calcium-Dependent Pathway Involving Flippase Inactivation and Rho Kinase Activation

Background/Aims: Intravascular bubbles can exert pleiotropic detrimental effects, partly by inducing endothelial microparticles (EMPs) production, which play critical roles in cell communication and vascular inflammation cascades. However, the underlying mechanisms remain unclear. This study aimed to delineate the possible mechanisms involving bubble-induced EMPs formation. Methods: Human umbilical vein endothelial cells (HUVECs) were contacted by bubbles and EMPs level in supernatant were quantified by flow cytometry. Cytoplasmic calcium (Ca²⁺) was measured by the Ca²⁺ binding dyes Fluo-3 AM and flippase activity was assessed by translocation rate of fluorescent phosphatidylserine (PS) analogue NBD-PS. Protein levels of phospho-myosin light chain (MLC, a Rho kinase substrate) and phospho-extracellular signal-regulated kinase 1 or 2 (ERK1/2) were determined by western blotting. The score of actin colocalization was assessed by phalloidin-FITC using an immunofluorescent microscopy. Results: EMPs level markedly increased after bubble stimulus. Cytoplasmic calcium (Ca²⁺) significantly elevated (P< 0.05), flippase activity decreased (P< 0.05), protein levels of phospho- MLC and phospho- ERK1/2 significantly increased (P< 0.05, P < 0.05), and the score of actin colocalization markedly reduced (P< 0.05) in bubble-stimulated HUVECs. All the above changes except the increase in phospho-ERK1/2 can be reversed by Ca²⁺ channel blocker LaCl₃ (P< 0.05). Additionally, MLC phosphorylation was significantly inhibited and actin colocalization markedly increased by Rho kinase inhibitor pretreatment and more importantly, bubble-induced EMPs markedly decreased. Conclusions: These results demonstrate that bubble stimulates EMPs formation by cytoplasmic Ca²⁺ elevation and subsequently activating Rho kinase pathway and cytoskeleton reorganization. Simultaneously, cytoplasmic Ca²⁺ inhibits the flippase activity and subsequently increases phosphatidylserine exposure, which also contributes to EMPs formation.

Plasma microparticles in Alzheimer's disease: The role of vascular dysfunction.

Cerebrovascular lesions, a potent stimulus for endothelial cell activation, trigger cognitive and degenerative changes and contribute to pathology of Alzheimer's disease (AD). Circulating microparticles (MPs) are actively involved in the pathogenesis of AD and cerebrovascular diseases, which share common vascular risk factors. We examined the plasma changes of endothelial MPs (EMPs) and platelet MPs (PMPs) in AD patients with vascular risk factors. The plasma Annexin V+ CD 41a- CD144+ EMPs and Annexin V+ CD41a+ CD144- PMPs of 37 patients with AD, with or without vascular risk factors (hypertension, diabetes, dyslipidemia, stroke, coronary artery disease, and smoking), and 10 age-matched controls were quantified by flow cytometry. Pearson correlation analysis used to evaluate the linear relationship between variables. Significantly higher plasma levels of EMPs were observed in AD patients with vascular risk factors as compared to the patients without vascular risk factors [Mean Difference (MD): 2587.80, 95% confidence interval (CI) 770.30-4404.80], and control subjects (MD: 4990.60, 95% CI, 3054.40-6926.79). Significant correlations were found between circulating EMPs, total MPs, and PMPs. There were no significant correlations between plasma levels of EMPs/ PMPs, and cognitive decline indices. Circulating EMP levels are influenced by AD disease status, and plasma levels of MPs and PMPs are associated with vascular risk factors in patients with AD. EMP phenotyping, as cellular biomarkers of vascular injury/dysfunction, and their effects on cerebral perfusion, and cognitive decline should be further investigated. Graphical abstract Vascular endothelial cell activation results in release of endothelial-derived microparticles (EMPs), which contributing to vascular dysfunction and cognitive decline.

Endothelial Microparticles are Associated to Pathogenesis of Idiopathic Pulmonary Fibrosis.

Idiopathic pulmonary fibrosis (IPF) is a devastating disease characterized by obliteration of alveolar architecture, resulting in declining lung function and ultimately death. Pathogenic mechanisms remain unclear but involve a concomitant accumulation of scar tissue together with myofibroblasts activation. Microparticles (MPs) have been investigated in several human lung diseases as possible pathogenic elements, prognosis markers and therapeutic targets. We postulated that levels and cellular origins of circulating MPs might serve as biomarkers in IPF patients and/or as active players of fibrogenesis. Flow cytometry analysis showed a higher level of Annexin-V positive endothelial and platelet MPs in 41 IPF patients compared to 22 healthy volunteers. Moreover, in IPF patients with a low diffusing capacity of the lung for carbon monoxide (DLCO<40%), endothelial MPs (EMPs) were found significantly higher compared to those with DLCO>40% (p = 0.02). We then used EMPs isolated from endothelial progenitor cells (ECFCs) extracted from IPF patients or controls to modulate normal human lung fibroblast (NHLF) properties. We showed that EMPs did not modify proliferation, collagen deposition and myofibroblast transdifferentiation. However, EMPs from IPF patients stimulated migration capacity of NHLF. We hypothesized that this effect could result from EMPs fibrinolytic properties and found indeed higher plasminogen activation potential in total circulating MPs and ECFCs derived MPs issued from IPF patients compared to those isolated from healthy controls MPs. Our study showed that IPF is associated with an increased level of EMPs in the most severe patients, highlighting an active process of endothelial activation in the latter. Endothelial microparticles might contribute to the lung fibroblast invasion mediated, at least in part, by a fibrinolytic activity.

Systemic Toxicity of Smokeless Tobacco Products in Mice.

Smokeless tobacco products such as snuff and snus are used worldwide. However, little is known about the systemic and cardiovascular toxicity of smokeless tobacco exposure. Biomarkers of endothelial activation and injury, immune functions, platelet activation and insulin resistance were measured in 8-week old male C57BL/6 mice exposed to commercial snuff, CRP-2 reference snuff, commercial snus, CRP-1 reference snus, and nicotine in drinking water (100 µg/mL) for 4, 12, and 24 weeks. Twenty-four weeks of exposure to smokeless tobacco products or nicotine significantly decreased the levels of circulating Flk+/Sca+ endothelial progenitor cells. Twelve and 24 weeks of exposure to all the smokeless tobacco products and nicotine significantly decreased the levels of circulating CD19+ B cells, CD4+ T cells, CD8+ T cells, and CD11b+ monocytes, whereas 4 weeks of exposure to Camel snus and Copenhagen snuff significantly depleted the levels of peripheral blood CD19+ B cells and CD11b+ monocytes. Twenty-four weeks of exposure to smokeless tobacco products or nicotine significantly decreased plasma IFNγ levels. However, plasma TNFα levels were significantly increased in mice exposed to Copenhagen snuff or nicotine for 24 weeks. This was accompanied by a five to sevenfold increase in the hepatic expression of TNFα. Neither smokeless products nor nicotine affected plasma lipoproteins, platelet activation, or systemic insulin sensitivity. Chronic exposure to snuff and snus suppresses circulating levels of EPCs, endothelial microparticles and immune cells, but increases plasma TNF-α levels. These effects of smokeless tobacco products are attributable, at least in part, to nicotine. Exposure to smokeless tobacco products results in the depletion of endothelial progenitor cells, which may impair the endothelium repair. Suppression of the circulating levels of immune cells upon exposure to smokeless tobacco products may increase the susceptibility to secondary infection. Increased formation of proinflammatory cytokines such as TNFα by nicotine or Copenhagen snuff may lead to vascular inflammation and thereby exacerbate atherogenesis.

Endothelial dysfunction is associated with activation of the type I interferon system and platelets in patients with systemic lupus erythematosus

ObjectivesEndothelial dysfunction may be connected to cardiovascular disease (CVD) in systemic lupus erythematosus (SLE). Type I interferons (IFNs) are central in SLE pathogenesis and are suggested to induce both endothelial...

MicroRNAs Clustered within the 14q32 Locus Are Associated with Endothelial Damage and Microparticle Secretion in Bicuspid Aortic Valve Disease.

Background: We previously described that PECAM+ circulating endothelial microparticles (EMPs) are elevated in bicuspid aortic valve (BAV) disease as a manifestation of endothelial damage. In this study, we hypothesized that this endothelial damage, is functionally related to the secretion of a specific pattern of EMP-associated miRNAs.Methods: We used a bioinformatics approach to correlate the PECAM+ EMP levels with the miRNA expression profile in plasma in healthy individuals and BAV patients (n = 36). In addition, using the miRNAs that were significantly associated with PECAM+ EMP levels, we inferred a miRNA co-expression network using a Gaussian graphical modeling approach to identify highly co-expressed miRNAs or miRNA clusters whose expression could functionally regulate endothelial damage.Results: We identified a co-expression network composed of 131 miRNAs whose circulating expression was significantly associated with PECAM+ EMP levels. Using a topological analysis, we found that miR-494 was the most important hub within the co-expression network. Furthermore, through positional gene enrichment analysis, we identified a cluster of 19 highly co-expressed miRNAs, including miR-494, that was located in the 14q32 locus on chromosome 14 (p = 1.9 × 10−7). We evaluated the putative biological role of this miRNA cluster by determining the biological significance of the genes targeted by the cluster using functional enrichment analysis. We found that this cluster was involved in the regulation of genes with various functions, specifically the “cellular nitrogen compound metabolic process” (p = 2.34 × 10−145), “immune system process” (p = 2.57 × 10−6), and “extracellular matrix organization” (p = 8.14 × 10−5) gene ontology terms and the “TGF-β signaling pathway” KEGG term (p = 2.59 × 10−8).Conclusions: Using an integrative bioinformatics approach, we identified the circulating miRNA expression profile associated with secreted PECAM+ EMPs in BAV disease. Additionally, we identified a highly co-expressed miRNA cluster that could mediate crucial biological processes in BAV disease, including the nitrogen signaling pathway, cellular activation, and the transforming growth factor beta signaling pathway. In conclusion, EMP-associated and co-expressed miRNAs could act as molecular effectors of the intercellular communication carried out by EMPs in response to endothelial damage.