Periodontal disease and its association to endothelial dysfunction and clinical changes in limited systemic sclerosis: A case-control study.

OBJECTIVES: Periodontal disease occurs frequently in patients with limited cutaneous systemic sclerosis (lcSSc) while data about underlying pathways contributing to periodontal changes are scarce. The aim of this study was to evaluate periodontal disease and to investigate its association with endothelial dysfunction and clinical changes in patients with lcSSc. METHODS: In 38 lcSSc patients and 38 controls, periodontal status was evaluated by disease-specific questionnaire, dental examination including bleeding on probing (BOP), pocket depth, and plaque index, and dental panoramic radiograph. Periodontopathogen bacteria were collected subgingivally using paper points and interleukin-1 (IL-1) gene polymorphisms were evaluated using buccal swabs. Endothelial dysfunction was measured by flow-mediated dilatation, pulse-wave velocity and biochemical analysis, including arginine metabolites and endothelial microparticles. Additionally, lcSSc-specific clinical changes and parameters were recorded. RESULTS: Periodontitis was present in 31 patients with lcSSc (81.6%) and in 27 controls (71.1%) (p = .280). LcSSc patients had a lower teeth number (p = .039) and Eikenella corrodens was to a higher degree detectable in patients with lcSSc (p = .041) while the remaining periodontal parameters revealed no differences between both cohorts. Significant correlations between parameters of arterial stiffness, EUSTAR index, number of teeth and BOP were observed (all p < .05). Detection of Prevotella intermedia was associated with selected IL-1 gene polymorphisms (p = .032) and Porphyromonas gingivalis was associated with severe periodontitis (p = .041). CONCLUSION: Periodontal disease may occur frequently in patients with lcSSc and may be associated with arterial stiffness and with SSc activity.

Microparticles from Hyperphosphatemia-Stimulated Endothelial Cells Promote Vascular Calcification Through Astrocyte-Elevated Gene-1.

Endothelial microparticles (EMPs) can be released in chronic kidney disease (CKD). Plasma concentration of high inorganic phosphate (HP) is considered as a decisive determinant of vascular calcification in CKD. We therefore explored the role of HP-induced EMPs (HP-EMPs) in the vascular calcification and its potential mechanism. We observed the shape of HP-EMPs captured by vascular smooth muscle cells (VSMCs) dynamically changed from rare dots, rosettes, to semicircle or circle. Our results demonstrated that HP-EMPs could directly promote VSMC calcification, or accelerate HP-induced calcification through signal transducers and activators of transcription 3 (STAT3)/bone morphogenetic protein-2 (BMP2) signaling pathway. AEG-1 activity was increased through HP-EMPs-induced VSMC calcification, in arteries from uremic rats, or from uremic rats treated with HP-EMPs. AEG-1 deficiency blocked, whereas AEG-1 overexpression exacerbated, the calcium deposition of VSMCs. AEG-1, a target of miR-153-3p, could be suppressed by agomiR-153-3p. Notably, VSMC-specific enhance of miR-153-3p by tail vein injection of aptamer-agomiR-153-3p decreased calcium deposition in both uremia rats treated with HP-EMPs or not. HP-EMPs could directly induce VSMCs calcification and accelerate Pi-induced calcification, and AEG-1 may act as crucial regulator of HP-EMPs-induced vascular calcification. This study sheds light on the therapeutic agents that influence HP-EMPs production or AEG-1 activity, which may be of benefit to treat vascular calcification.

Human umbilical cord mesenchymal stem cells regulate CD54 and CD105 in vascular endothelial cells and suppress inflammation in Kawasaki disease.

OBJECTIVE: The objective was to evaluate the expression levels of CD31+CD54+ and CD31+CD105+ endothelial microparticles (EMPs) before and after intravenous immunoglobulin (IVIG) treatment of Kawasaki disease (KD). To explore the role of human umbilical cord mesenchymal stem cells (hucMSCs) in inhibiting endothelial inflammation in KD, the effects of hucMSCs on the expression of CD54 and CD105 in endothelial cells in KD were analyzed in vivo and in vitro. METHODS: The concentrations of IL-1ß and VEGF in the peripheral blood of KD or healthy children were detected, and the distributions of CD31+CD54+ and CD31+CD105+ EMPs in platelet-poor plasma (PPP) were analyzed by flow cytometry. Human umbilical vein endothelial cells (HUVECs) were first cocultured with the patients' peripheral blood mononuclear cells (PBMCs). Next, HUVECs were cocultured with hucMSCs after stimulation with inactivated serum from patients. Cell proliferation and migration activities were assessed, and the expression of CD54, CD105 and IL-1ß was analyzed. In an in vivo study, hucMSCs were transplanted into KD mice. The locations and expression levels of CD54, CD105 and IL-1ß in the heart tissues of mice were analyzed. RESULTS: The levels of IL-1ß and CD31+CD54+ EMPs were significantly higher before IVIG treatment and 2 weeks after treatment in KD patients (P < 0.01). However, the levels of VEGF and CD31+CD105+ EMPs increased significantly in KD only after IVIG treatment (P < 0.01). KD-inactivated serum stimulation combined with cocultivation of PBMCs can activate inflammation in HUVECs, leading to reduced cell proliferation and migration activities. Cocultivation also increased the expression of CD54 and decreased the expression of CD105 (P < 0.001). Cocultivation with hucMSCs can reverse these changes. Additionally, hucMSC transplantation downregulated the expression of IL-1ß and CD54 and significantly upregulated the expression of CD105 in KD mice. CONCLUSION: The expression levels of CD31+CD54+ and CD31+CD105+ EMPs showed inconsistent changes at different KD statuses, providing potential markers for clinical application. HucMSCs suppress inflammation and regulate the expression levels of CD54 and CD105 in vascular endothelial cells in KD, possibly providing a new basis for stem cell therapy for KD.

Endothelial microparticles induced by cyclic stretch activate Src and modulate cell apoptosis.

Endothelial microparticles (EMPs) are involved in various cardiovascular pathologies and play remarkable roles in communication between endothelial cells (ECs), which are constantly exposed to mechanical cyclic stretch (CS) following blood pressure. However, the roles of EMPs induced by CS in EC homeostasis are still unclear. Both fluorescence resonance energy transfer (FRET) and western blotting revealed the activation of Src in ECs was significantly increased by 5% CS-induced EMPs. Furthermore, proteomic analysis revealed that the contents were obvious different in the EMPs between 5%- and 15%-group. Based on the bioinformatic analysis, CD151 on EMPs was predicted to activate Src, which was further confirmed by both FRET and western blotting. Moreover, the expression of CD151 on EMPs was significantly increased by 5% CS and involved in the binding of EMPs to ECs. EC apoptosis, which was significantly decreased by 5% CS-derived EMPs, showed obvious increase after pretreatment with Src inhibitor in target ECs. Our present research suggests that mechanical stretch changes the components of EMPs, which in turn modulates EC apoptosis by Src activation. CD151 expressed on CS-induced EMPs may play important roles in EC communication and homeostasis.

Perfusion microvessel density in the cerebral cortex of septic rats is negatively correlated with endothelial microparticles in circulating plasma.

In sepsis, endothelial microparticles (EMPs) released from endothelial cells (ECs) participate in microcirculation dysfunction through pro-coagulant and pro-inflammatory effects, which can lead to sepsis-associated brain dysfunction. However, the relationship between EMPs and cerebral cortical perfusion microvessel density has not been explored. A closed cranial window was created in rats who were tended to until the cerebral cortex edema caused by preparation of the cranial window subsided, and the microvessel density was stable. A cecal ligation and puncture (CLP) sepsis procedure was then performed on day 6, post-surgery. At 12 and 24 h after the CLP, cerebral cortical perfusion microvessel density was measured with optical coherence tomography angiography (OCTA), followed by measurement of EMPs to evaluate the relationship between these factors. Microvessel density changed from 46.38 % ± 7.65 % on the day of surgery to 35.87 % ± 11.05 % on the second day and 36.71 % ± 11.38 % on the third day after surgery, and then increased daily. The microvessel density decreased to 27.20 % ± 8.50 % 24 h after CLP, which was significantly lower than that immediately and 12 h after CLP (P < 0.001). EMPs increased progressively at 12 and 24 h after CLP. Moreover, there was a negative correlation between EMPs and microvessel density (r=-0.56, P = 0.01). Edema and microvessel density decreased in the local cerebral cortex of the window and then gradually recovered after cranial window surgery. In sepsis, the perfusion microvessel density of the cerebral cortex negatively correlated with the EMPs. Therefore, the perfusion microvessel density can be indirectly evaluated by detecting the plasma EMP level.

ASSESSMENT OF ENDOTHELIAL DYSFUNCTION IN PREGNANT WOMEN WITH OBESITY AND PREECLAMPSIA.

OBJECTIVE: The aim: To assess the values of endothelial vascular growth factor (VEGF) in blood serum and circulating endothelial microparticles CD32+CD40+ in the peripheral blood of pregnant women depending on the severity of obesity and presence of preeclampsia. PATIENTS AND METHODS: Materials and methods: the study included 122 pregnant women divided into groups in accordance with their height and weight parameters and presence of preeclampsia. We studied the serum VEGF concentration by enzyme-linked immunosorbent assay, carried out the count of CD32+CD40+ circulating endothelial microparticles in the peripheral blood by using flow cytometry. RESULTS: Results: It has been found out the serum VEGF concentration in pregnant women with obesity decreases with rising level of obesity and the preeclampsia manifestation. In contrast to the decrease in this marker, there is an increase in the number of circulating endothelial microparticles CD32+CD40+ in the peripheral blood of pregnant women with obesity and preeclampsia. This pattern of these indicators points out the presence of endothelial dysfunction, which may contribute to occurrence of preeclampsia in pregnant women with concomitant obesity. CONCLUSION: Conclusions: The indicators of VEGF concentration and the count of circulating endothelial microparticles CD32+CD40+ in the blood serum can serve as reliable markers for evaluating the severity of endothelial dysfunction in pregnant women with concomitant obesity and preeclampsia.

Berberine reduces endothelial injury and arterial stiffness in spontaneously hypertensive rats.

Background: Changes in circulating endothelial microparticles (EMPs) and endothelial progenitor cells (EPCs) are considered as a new perspective reflection of the endothelial injury and repair status. Our previous studies have demonstrated that berberine improved endothelial function and arterial stiffness in healthy subjects. In this study, we further investigated the effects of berberine on regulating the circulating EMPs and EPCs, and preventing endothelial dysfunction and arterial stiffness in spontaneously hypertensive rats (SHRs). Methods: Twenty male SHRs were randomly divided into two groups: Berberine-treated SHR group and vehicle-treated SHR group. The SHR rats were intragastrically treated with physiologic saline, berberine 50 mg/kg.d or vehicle for 4 weeks, respectively. Ten male Wistar-Kyoto (WKY) rats treated with vehicle served as normotensive controls. Tail systolic blood pressure was monitored every 2 weeks. At the end of the study, aortic pulse wave velocity (aPWV) was measured in vivo, and aorta were collected for measurement of endothelium-dependent vasodilation and immunohistological staining of elastic fiber. Peripheral blood was collected for circulating EMP detection and EPC culture. Results: Compared to normotensive rats, hypertensive rats displayed significantly higher circulating CD31+/CD42- MPs, lower number and colony-forming units (CFUs) of EPCs, worse endothelium-dependent vasodilation, and faster aPWV. Berberine treatment in SHRs partly reduced the blood pressure and circulating EMPs, and augmented EPC numbers and CFUs. In addition, berberine preserved arterial elasticity by lowering aPWV and increasing the content of arterial media elastin fiber, and improved endothelial function by maintaining better endothelium-dependent vasodilation. Robust relationship was observed among circulating CD31+/CD42- MPs, EPC numbers and aPWV. Conclusions: Abnormal changes of circulating EMPs and EPCs in SHRs are associated with endothelial dysfunction and arterial stiffness. Berberine may be a novel therapeutic option for the hypertension-related vascular injury in SHRs.

[Circulating endothelial microparticles for prediction of therapeutic effect in advanced lung cancer].

Objective: To explore the correlation of endothelial microparticles and progression of advanced lung cancer, and its predictive value in therapeutic effect. Methods: The data of patients with advanced lung cancer in the Oncology Department of Frist Medical Center of Chinese PLA General Hospital from October 2018 to May 2019 were collected. Blood routine, lactate dehydrogenase (LDH), tumor markers, and circulating endothelial microparticles (CD105+ EMPs) were measured before treatment. Flow cytometry was used to detect the number of CD105+ EMPs, and multivariate regression analysis was used to study the predict factors of advanced lung cancer progression. Results: A total of 88 patients were recruited in the study, including 60 in the objective response (OR) group and 28 in the disease progression (PD) group. There were no significant differences in gender, age, basic diseases, tumor stage, cancer type and therapeutic intervention between two groups, while there were significant differences in tumor marker, LDH, total microparticles (MPs), and endothelial microparticles (CD105+ EMPs) between two groups (P<0.05). In the multivariate regression analysis, CD105+ EMPs ≥70 events/µl (OR=3.623, 95%CI=1.345~9.761, P=0.011) and LDH (OR=1.008, 95%CI=1.001~1.015, P=0.032) were able to predict the progression of advanced lung cancer. A predictive model of advanced lung cancer progression was established based on the multivariate regression results. The area under the receiver operating characteristic curve (AUC) was 0.729 (95%CI=0.620~0.837, P=0.001), the sensitivity was 32.1%, the specificity was 91.6%, the positive predictive value was 64.2%, and the negative predictive value was 74.3%. Conclusion: Circulating endothelial microparticles are associated with the progression of advanced lung cancer, it combined with LDH can predict the therapeutic effect of advanced lung cancer.

Endothelial Microparticle as an early Marker of Endothelial Dysfunction in Patients with Essential Hypertension: A Pilot Study.

Hypertension is a global health burden causing immense morbidity and mortality especially from the complications of end-organ damage. It is expected to affect 29% of the population by the year 2025. Hypertension is usually asymptomatic; it is diagnosed by a disease of exclusion. Numerous factors such as inflammation, oxidative stress, genetic predisposition etc. play roles in the pathogenesis of hypertension. Endothelial microparticles (EMPs) are released into the circulation with the onset of changes in endothelium, even before the release of other routine vascular endothelial markers. EMPs mediate inflammation, thrombosis and vasoconstriction of blood vessels in hypertensives. This pilot study was undertaken to assess whether EMPs are early markers of endothelial dysfunction in essential hypertensive patients. The study was conducted as a large case control study in which 525 individuals were involved. It consisted of three study groups: Group I: individuals with normal blood pressure (JNC8), group II: hypertensives without evidence of end-organ damage and group III: hypertensives with evidence of end-organ damage. Homocysteine, hsCRP, fibrinogen, eNOS, oxLDL and other markers were measured. For analysis of EMPs a subset of individuals are taken from each group. Control group of 10 individuals who had homocysteine level more than15µmol/L was taken as Group I. Another 10 individuals were taken randomly of five each from groups II and III. EMPs were analyzed by flow cytometry and were identified as CD31 +, CD42 - microparticles with diameters < 1.0 mm. There was significant increase in EMPs (p = 0.035) in hypertensive individuals with end organ damage. Measurement of EMPs in hypertensive individuals could help physicians in identifying and initiating therapeutic interventions at a very early stage of the disease, thus improving the quality of life.

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

INTRODUCTION: Evidence has accumulated for the role of endothelial damage in systemic sclerosis (SSc) and the anti-endothelial cell antibodies (AECAs) might underlie vascular injury. AIM: Since 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 METHODS: Forty-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. RESULTS: AECAs 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. CONCLUSIONS: We 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.

Dysfunctional endothelial-derived microparticles promote inflammatory macrophage formation via NF-кB and IL-1ß signal pathways.

BACKGROUND: Circulating endothelial-derived microparticles (EMPs) are reported to be increased in acute coronary syndrome (ACS). However, it remains unclear whether EMPs from dysfunctional endothelium participate in the initiation and progression of ACS and what the underlying mechanisms might be. METHODS: Plasma EMPs were measured in 22 patients with ACS and 20 control patients without coronary artery diseases. EMPs from dysfunctional human umbilical vein endothelial cells (HUVECs) stressed by serum-starvation or hypoxia were compared to the EMPs from healthy HUVECs. Confocal and fluorescent microscopy was used to visualize the incorporation of EMPs into monocytes and the translocation of NF-кB. Monocyte adhesion, cell proliferation, and phagocytosis were detected by PKH26 red fluorescent labelling, Ki67 immunostaining, and Sudan IV staining for uptake of oxidized low-density lipoprotein, respectively. RESULTS: Plasma EMPs was significantly increased in ACS patients compared to controls. EMPs were incorporated into monocytes and EMPs from stressed HUVECs produced more pro-inflammatory cytokines compared to vehicle control, which was depended on NF-кB and IL-1ß signal pathways. EMPs from dysfunctional endothelium promoted monocyte adherence via NF-кB and IL-1ß-mediated MCP-1 and CCR-5 signals, as well as proliferation via the NF-кB and IL-1ß-mediated Cyclin D1 signals. Finally, EMPs from dysfunctional endothelium showed greater promotion of macrophage phagocytosis forming foam cells to produce more pro-inflammatory cytokines. CONCLUSION: MPs might be involved in the inflammatory process in patients with ACS via NF-κB and IL-1ß-dependent signals. Targeting EMP-mediated inflammatory responses may be a promising therapeutic strategy to limit the progression of disease in ACS.

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 and disability worldwide. Numerous pathophysiological 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.

Effects of acute insulin-induced hypoglycaemia on endothelial microparticles in adults with and without type 2 diabetes.

AIMS: To assess whether endothelial microparticles (EMPs), novel surrogate markers of endothelial injury and dysfunction, are differentially produced in response to acute insulin-induced hypoglycaemia in adults with and without type 2 diabetes. MATERIALS AND METHODS: A prospective, parallel study was conducted in individuals with type 2 diabetes (n = 23) and controls (n = 22). Hypoglycaemia (<2.2 mmoL/L: <40 mg/dL) was achieved by intravenous infusion of soluble insulin. Blood samples were collected at baseline and at 0, 30, 60, 120, 240 minutes and 24 hours after hypoglycaemia and analysed for CD31+ (platelet endothelial cell adhesion molecule-1), CD54+ (intercellular adhesion molecule 1), CD62-E+ (E-selectin), CD105+ (endoglin), CD106+ (vascular cell adhesion molecule 1) and CD142+ (tissue factor) EMPs by flow cytometry. The peak elevations (% rise from 0 minutes after hypoglycaemia) in EMP within 240 minutes after insulin-induced hypoglycaemia were modelled using a regression model, with adjustment for relevant covariates. All EMPs were expressed as percentage from 0 minutes hypoglycaemia for each time point and total areas under the curve (AUC0min-24h ) were calculated. RESULTS: Following insulin-induced hypoglycaemia, levels of circulating EMPs were maximal at 240 minutes (P < 0.001) and returned to baseline values within 24 hours for both groups. The peak elevations (% rise from 0 minutes following hypoglycaemia) seen in CD31+ , CD54+ , CD62-E+ , CD105+ and CD142+ EMPs within 240 minutes were associated with diabetes status after adjustments for all relevant covariates. Individuals with type 2 diabetes showed increased CD31+ EMPs AUC0min-24h (P = 0.014) and CD105+ EMPs AUC0min-24h (P = 0.006) compared with controls, but there were no differences for CD54+ (P = 0.91), CD62-E+ (P = 0.14), CD106+ (P = 0.36) or CD142+ (P = 0.77) EMPs AUC0min-24h . CONCLUSIONS: The associations between peak elevations within 240 minutes after insulin-induced hypoglycaemia for CD31+ , CD54+ , CD62-E+ , CD105+ and CD142+ and diabetes status indicate that the assessment of a panel of EMPs within this timeframe would identify a hypoglycaemic event in this population. The greater overall responses over time (AUCs) for apoptosis-induced CD31+ and CD105+ EMPs suggest that hypoglycaemia exerts greater endothelial stress in type 2 diabetes.

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.

Deferiprone inhibits iron overload-induced tissue factor bearing endothelial microparticle generation by inhibition oxidative stress induced mitochondrial injury, and apoptosis.

Iron overload-induced cardiovascular toxicity is one of the most common causes of morbidity and mortality in beta-thalassemia major patients. We have previously shown that iron overload-induced systemic arterial changes characterized by endothelial dysfunction are associated with increased endothelial microparticle (EMP) release. In this study, we further demonstrate how EMP release is associated with iron-induced mitochondrial injury and apoptosis of endothelial cells. Iron increased the production of reactive oxygen species (ROS) and calcium influx into mitochondria [Ca2+]m. Iron also disturbed mitochondrial respiration function and eventually led to loss of mitochondrial membrane potential (ΔΨm). A significant increase in apoptotic cells and EMPs were found under iron treatment. EMPs contained tissue factor (TF), which has potential clinical impact on thromboembolic phenomenon. Then, we investigated the salvaging effect of deferiprone (L1) on endothelial cell damage and EMP release. We found that L1 could inhibit iron-induced ROS generation, and decrease mitochondrial damage with the resultant effect of less endothelial cell apoptosis and EMP release. L1 could protect endothelial cells from iron-induced toxic effects and minimize EMP release, which could be potentially helpful in a subgroup of thalassemia patients who have increased thromboembolic complications.

Intercellular transfer of miR-126-3p by endothelial microparticles reduces vascular smooth muscle cell proliferation and limits neointima formation by inhibiting LRP6.

BACKGROUND: Vascular smooth muscle cell (VSMC) proliferation is of importance in the pathogenesis of vascular diseases such as restenosis or atherosclerosis. Endothelial microparticles (EMPs) regulate function and phenotype of target endothelial cells (ECs), but their influence on VSMC biology is unknown. We aim to investigate the role of EMPs in the regulation of vascular smooth muscle cell (VSMC) proliferation and vascular remodeling. METHODS AND RESULTS: Systemic treatment of mice with EMPs after vascular injury reduced neointima formation in vivo. In vitro, EMP uptake in VSMCs diminished VSMC proliferation and migration, both pivotal steps in neointima formation. To explore the underlying mechanisms, Taqman microRNA-array was performed and miR-126-3p was identified as the predominantly expressed miR in EMPs. Confocal microscopy revealed an EMP-mediated miR-126 transfer into recipient VSMCs. Expression of miR-126 target protein LRP6, regulating VSMC proliferation, was reduced in VSMCs after EMP treatment. Importantly, genetic regulation of miR-126 in EMPs showed a miR-126-dependent inhibition of LRP6 expression, VSMC proliferation and neointima formation in vitro and in vivo, suggesting a crucial role of miR-126 in EMP-mediated neointima formation reduction. Finally, analysis of miR-126 expression in circulating MPs in 176 patients with coronary artery disease revealed a reduced PCI rate in patients with high miR-126 expression level, supporting a central role for MP-incorporated miR-126 in vascular remodelling. CONCLUSION: EMPs reduce VSMC proliferation, migration and subsequent neointima formation by delivering functional miR-126 into recipient VSMCs.

Endothelial microparticles act as novel diagnostic and therapeutic biomarkers of circulatory hypoxia-related diseases: a literature review.

Circulatory hypoxia-related diseases (CHRDs), including acute coronary syndromes, stroke and organ transplantation, attract increased attention due to high morbidity and mortality. Mounting evidence shows that hypoxia-induced oxidative stress, coagulation, inflammation and angiogenesis play extremely important roles in the physiological and pathological processes of CHRD-related vascular endothelial injury. Interestingly, hypoxia, even hypoxia-induced oxidative stress, coagulation and inflammation can all induce release of endothelial microparticles (EMPs). EMPs, shed from activated or apoptotic endothelial cells (ECs), reflect the degree of EC damage, and elevated EMP levels are found in several CHRDs. Furthermore, EMPs, which play an important role in cell-to-cell communication and function, have confirmed pro-coagulant, proinflammatory, angiogenic and other functions, affecting pathological processes. These findings suggest that EMPs and CHRDs have a very close relationship, and EMPs may help to identify CHRD phenotypes and stratify the severity of disease, to improve risk stratification for developing CHRDs, to better define prophylactic strategies and to ameliorate prognostic characterization of patients with CHRDs. This review summarizes the known and potential roles of EMPs in the diagnosis, staging, treatment and clinical prognosis of CHRDs.

Endothelial microparticles are increased in congenital heart diseases and contribute to endothelial dysfunction.

BACKGROUND: We previously demonstrated that endothelial microparticles (EMPs) are increased in mitral valve diseases and impair valvular endothelial cell function. Perioperative systemic inflammation is an important risk factor and complication of cardiac surgery. In this study, we investigate whether EMPs increase in congenital heart diseases to promote inflammation and endothelial dysfunction. METHODS: The level of plasma EMPs in 20 patients with atrial septal defect (ASD), 23 patients with ventricular septal defect (VSD), and 30 healthy subjects were analyzed by flow cytometry. EMPs generated from human umbilical vascular endothelial cells (HUVECs) were injected into C57BL6 mice, or cultured with HUVECs without or with siRNAs targeting P38 MAPK. The expression and/or phosphorylation of endothelial nitric oxide synthase (eNOS), P38 MAPK, and caveolin-1 in mouse heart and/or in cultured HUVECs were determined. We evaluated generation of nitric oxide (NO) in mouse hearts, and levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cultured HUVECs and in mice. RESULTS: EMPs were significantly elevated in patients with ASD and VSD, especially in those with pulmonary hypertension when compared with controls. EMPs increased caveolin-1 expression and P38 MAPK phosphorylation and decreased eNOS phosphorylation and NO production in mouse hearts. EMPs stimulated P38 MAPK expression, TNF-α and IL-6 production, which were all inhibited by siRNAs targeting P38 MAPK in cultured HUVECs. CONCLUSIONS: EMPs were increased in adult patients with congenital heart diseases and may contribute to increased inflammation leading to endothelial dysfunction via P38 MAPK-dependent pathways. This novel data provides a potential therapeutic target to address important complications of surgery of congenial heart disease.

Plasma endothelial microparticles reflect the extent of capillaroscopic alterations and correlate with the severity of skin involvement in systemic sclerosis.

INTRODUCTION AND AIM: Endothelial microparticles (EMPs) are membrane-coated vesicles shed from endothelial cells and are considered markers of the endothelial state. It has been shown that total numbers of circulating EMPs are increased in patients with systemic sclerosis (SSc), but their clinical correlations have not yet been investigated in detail. We aimed to assess possible relationships between circulating EMPs and clinical as well as laboratory features among SSc patients with special attention to possible association with alteration in microvascular morphology objectified on nailfold videocapillaroscopy and clinical signs of microvascular complications. MATERIALS AND METHODS: The study included 47 SSc patients and 27 age- and sex-matched healthy controls. EMPs were identified with flow cytometry after staining platelet-poor plasma with combinations of fluorescent cell-specific monoclonal antibodies (anti-CD31, -51, -42b, -62E and Annexin V). The following types of EMPs were evaluated: total EMPs (CD31+/CD42b-), activated EMPs (CD62E+/AnnV-,) and apoptotic EMPs (CD62E+/AnnV+ or CD51+). Clinical evaluation of patients was obtained, including nailfold videocapillaroscopy. RESULTS: All types of EMPs were significantly elevated in SSc patients as compared with healthy controls. We found significant inverse correlation between severity of skin involvement and values of total EMPs (r=-0.32; p=0.02) and their levels tended to be lower in SSc patients with digital ulcers when compared to those without ischaemic skin lesions (p=0.09). Total EMPs and activated EMPs showed correlations with the number of ramified capillaries (r=-0.40 and r=0.37, respectively, p<0.05 for both). Moreover, total EMPs inversely correlated with the severity of capillary loss (r=-0.35, p<0.05) and their levels were significantly lower in patients with late NVC pattern with respect to those with early microangiopathy (p<0.05). On the other hand, active NVC pattern was characterized by strongly elevated levels of activated EMPs when compared to an early vascular alteration (p<0.05). CONCLUSIONS: Our results suggest that quantity and phenotype of circulating EMPs might indicate on molecular vascular damage with endothelial dysfunction and to reflect progressive loss of capillaries consequencing in microvascular insufficiency in SSc patients.

Microparticles in patients undergoing transcatheter aortic valve implantation (TAVI).

Degenerative aortic stenosis (AS) is the most frequent form of acquired valvular heart disease. AS is known to entail endothelial dysfunction caused by increased mechanical shear stress leading to elevated circulatory levels of microparticles. Endothelial and platelet microparticles (EMP and PMP) are small vesicles that originate from activated cells and thrombocytes. We sought to evaluate whether transcatheter aortic valve implantation (TAVI) procedure would elicit effects on circulating EMP and PMP. 92 patients undergoing TAVI procedure for severe AS were included in this study. Samples were obtained at each visit before TAVI, 1 week post-procedure and at 1, 3 and after 6 months after TAVI and were evaluated using flow cytometry. A 12 month clinical follow-up was also performed. CD62E+ EMP concentration before TAVI was 21.11 % (±6.6 % SD) and declined to 20.99 % (±6.8 % SD) after 1 week, to 16.63 % (±5.4 % SD, p < 0.0001) after 1 month, to 17.08 % (±4.6 % SD, p < 0.0001) after 3 months and to 15.94 % (±5.4 % SD, p < 0.0001) after 6 months. CD31+/CD42b-, CD31+/Annexin+/- EMP remained unchanged. CD31+/CD41b+ PMP evidenced a slight, but statistically significant increase after TAVI and remained elevated during the entire follow-up. Apart from a procedure-related improvement in echocardiographic parameters, TAVI procedure led also to a decline in CD62E+ EMP. The reduction in pressure gradients with less hemodynamic shear stress seems also to have beneficially affected endothelial homeostasis.