Endothelial Microparticles Research Articles

Evaluation of endothelial microparticles as a prognostic marker in hemolytic disease of the newborn in China.

ObjectiveThis study aimed to evaluate endothelial microparticles (EMPs) as a potential prognostic marker in hemolytic disease of the Chinese neonate.MethodsWe compared 29 newborns with ABO hemolytic disease of the newborn (ABO HDN), 22 newborns with Rh HDN, and 21 healthy newborns with matched mother and infant blood groups (controls). Markers of hemolysis and von Willebrand factor antigen (vWF Ag) were analyzed. EMP (CD144+) levels were measured before and after therapy.ResultsvWF Ag and pretherapy EMP levels were higher in the ABO HDN and Rh HDN groups than in the control group. Additionally, vWF Ag and pretherapy EMP levels were significantly higher in the ABO HDN group than in the Rh HDN group. Posttherapy EMP levels were decreased compared with pretherapy levels in the ABO HDN and Rh HDN groups. Moreover, hemoglobin and indirect bilirubin levels were independently correlated with pretherapy EMP levels in the ABO HDN group.ConclusionOur findings indicate that EMP measurement in neonates with HDN may provide a novel method of monitoring possible severe vascular dysfunction in patients in China. An external validation in larger datasets is necessary for further study.

The CD105:CD106 microparticle ratio is CD106 dominant in polycystic ovary syndrome compared to type 2 diabetes and healthy subjects

BackgroundA retrospective analysis was carried out from patients and controls during the past 5 years from a series of studies investigating endothelial microparticles (MP).MethodsIn total, 319 samples from 207 individuals were included in this analysis, from patients with type 2 diabetes (T2D, n = 105), women with polycystic ovary syndrome (PCOS, n = 145) and healthy volunteers (n = 69). All data were generated via the same flow cytometry protocol with the same antibody clones. Endothelial markers CD105 (Endoglin) and CD106 (Vascular cell adhesion molecule-1) were used to enumerate MP in venous blood.ResultsThe ratio of CD105MP:CD106MP was significantly different between groups (F = 63.43, p < 0.0001). Women with PCOS were found to have a median CD105MP:CD106MP ratio of 0.40 (IQR 0.24–0.57), suggesting approximately two CD106MP were found per CD105MP. The T2D group showed a median ratio of 2.32 (1.51–3.69) whereas in healthy volunteers the ratio was 2.21 (1.63–3.55). Serum intercellular adhesion molecule-1 was also shown to be significantly increased in PCOS when compared with control or T2D groups (F = 14.5, p < 0.001).ConclusionThese data suggest that women with PCOS have an altered endothelial MP release in favour of CD106. Thus a potential activated endothelial state exists in women with PCOS with a shift towards a predominantly CD106MP profile.

Platelet activation in diabetic mice models: the role of vascular endothelial cell-derived protein disulfide isomerase-mediated GP IIb/IIIa receptor activation.

GP IIb/IIIa receptor activation plays an important role in thrombosis. The mechanism of early activation of GP IIb/IIIa receptors in diabetic conditions remains unknown. The purpose of this study was to investigate the release of Endothelial microparticle (EMP)-associated protein disulfide isomerase (PDI) after endothelial cell injury induced in diabetes and the changes in platelet activation. We produced an animal model of type 2 diabetes mellitus using ApoE−/− mice. Normal ApoE−/− and diabetic mice were allocated to four groups (n = 15): normal diet, normal diet plus rutin, diabetic, and diabetes plus rutin. The EMP-PDI content and GP IIb/IIIa expression of mice platelets were determined. In addition, EMPs obtained from the four groups were pretreated with the PDI inhibitor rutin; then, their effects on the platelets of normal C57 mice were characterized. Compared with the normal diet group, the diabetic group had significantly increased plasma EMP-PDI content and accelerated platelet activation by increased GP IIb/IIIa expression. In conclusion, EMP-PDI promotes early platelet activation through glycoprotein (GP) IIb/IIIa receptors present on platelet surface in the diabetic state. However, this process could be partially suppressed by the administration of rutin.

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.

Changes in microparticle profiles by vitamin D receptor activation in chronic kidney disease \u2013 a randomized trial

BackgroundMicroparticles (MPs) are biomarkers and mediators of disease through their expression of surface receptors, reflecting activation or stress in their parent cells. Endothelial markers, ICAM-1 and VCAM-1, are implicated in atherosclerosis and associated with cardiovascular risk. Chronic kidney disease (CKD) patients have endothelial dysfunction and high levels of endothelial derived MPs. Vitamin D treatment has been reported to ameliorate endothelial function in CKD patients. We aimed to examine cell specific MP profiles and concentrations of MPs expressing the atherosclerotic markers ICAM-1 and VCAM-1 after treatment with paricalcitol in patients with CKD stage 3–4.MethodsSub-study of the previously reported SOLID trial where 36 patients were randomly assigned to placebo, 1 or 2 μg paricalcitol, for 12 weeks. MPs were measured by flow cytometry after labelling with antibodies against endothelial (CD62E), platelet (CD62P, CD41, CD154) leukocyte (CD45) and vascular (CD54, CD106) markers.ResultsPatients had a mean age of 65 years with a mean eGFR of 40 mL/min/1.73m2. Concentrations of ICAM-1 positive MPs were significantly reduced by treatment (repeated measures ANOVA p = 0.04). Repeated measures MANOVA of concentrations of endothelial, platelet and leukocyte MPs showed sustained levels in the 2 μg treatment group (p = 0.85) but a decline in the 1 μg (p = 0.04) and placebo groups (p = 0.005).ConclusionsTreatment with paricalcitol reduces concentrations of ICAM-1 positive MPs. This is accompanied by sustained concentrations of all cell specific MPs in the 2 μg group, and decreasing concentrations in the other groups, possibly due to a more healthy and reactive endothelium with paricalcitol treatment.

Pseudoexfoliative Glaucoma, Endothelial Dysfunction, and Arterial Stiffness: The Role of Circulating Apoptotic Endothelial Microparticles.

PExG is characterized by the deposition of pseudoexfoliative material in several tissues and organs including in the cardiovascular system. This study aimed to evaluate the vascular endothelial function, arterial stiffness, inflammatory status, and circulating microparticle (MP) levels in PExG patients compared with those in primary open-angle glaucoma (POAG) patients and control subjects. Vascular endothelial function was evaluated by flow-mediated dilation. Pulse wave velocity and augmentation index were measured as indices of aortic stiffness and arterial wave reflections, respectively. Growth-differentiation factor-15 and intercellular adhesion molecule1 levels were measured to evaluate the systemic inflammatory status. Circulating MPs that constitute an emerging marker of vascular endothelial dysfunction and platelet activation were isolated and analyzed by flow cytometry. There was a stepwise impairment from the control to the POAG patients and PExG subjects in the flow-mediated dilation (8.21%±2.94% vs. 7.56%±3.12% vs. 5.79±3.13, P=0.005), pulse wave velocity (8.14±1.79 vs. 9.21±2.27 vs. 9.95±3.28 m/s, P=0.007), augmentation index (24.71%±7.84% vs. 26.78%±7.21% vs. 29.96%±7.58%, P=0.02), and growth-differentiation factor-15 (P=0.001) and intercellular adhesion molecule1 levels (P=0.08). PExG patients expressed greater levels of total circulating MPs (Annexin V+) (P=0.004) and endothelial-derived MPs (CD144+) (P<0.001) compared with POAG and control subjects. PExG patients with an accumulation of pseudoexfoliative microfibrillar material presented with vascular endothelial dysfunction and arterial wall impairment associated with the levels of circulating proinflammatory molecules and circulating apoptotic endothelial MPs. These findings highlight the underlying systemic pathophysiological mechanisms associated with the progress of the pseudoexfoliative syndrome.

Increase in circulating ACE-positive endothelial microparticles during acute lung injury.

Circulating endothelial microparticles (EMPs) are considered to be markers of endothelial injury, and lung microvascular endothelial cells express higher levels of angiotensin-converting enzyme (ACE). The aim of this study is to examine whether the number of ACE+ microvascular EMPs could be a prognostic marker for the development of acute respiratory distress syndrome (ARDS) in septic patients.The numbers of EMPs and ACE+ EMPs in the culture supernatant from human microvascular endothelial cells, as well as in the blood of mouse lung injury models and septic patients (n=82), were examined using flow cytometry.ACE+ EMPs in the culture supernatant from pulmonary microvascular endothelial cells increased after exposure to an inflammatory stimulus. In the mouse lung injury models, the circulating ACE+ EMPs and ACE+ EMP/EMP ratio were higher than in the controls (p<0.001). The ACE+ EMP/EMP ratio was correlated with the wet/dry lung ratio (rs=0.775, p<0.001). The circulating ACE+ EMPs and ACE+ EMP/EMP ratio on admission were significantly increased in septic patients who developed ARDS compared with septic patients who did not (p<0.001).Therefore, circulating ACE+ EMPs may be a prognostic marker for the development of ARDS in the septic patients.

Berberine reduces endothelial injury and arterial stiffness in spontaneously hypertensive rats

ABSTRACTBackground: 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.

PECULIARITIES OF SYSTEMIС INFLAMMATION OF LOW INTENSITY IN PATIENTS WITH STABLE CORONARY HEART DISEASE CONCURRENT WITH NON-ALCOHOLIC FATTY LIVER DISEASE

Nowadays, coronary heart disease and non-alchoholic fatty liver disease are significant problems in Ukraine and world. Functional liver disorders potentiate the development and progression of CHD. The initiation process of atherosclerosis is a chronic systemic inflammation of low intensity. This view on atherosclerosis development has been forming during the past two decades. The aim of the research was to study the features/characteristics of systemic inflammation of low intensity in patients with coronary heart disease in combination with non-alcoholic fatty liver disease. The research involved 135 people with CHD: stable angina, I-II functional class, 0-I heart failure in combination with non-alcoholic fatty liver disease and 30 healthy individuals. We examined patients in terms of blood levels of cytokines -TNFα and IL-10, the content of the acute phase reactant and the coagulation factor, the marker of endothelial dysfunction is the amount of circulating endothelial microparticles (CEM) CD32+ CD40+ and the expression level of IkBα gene NF-kB in mononuclear peripheral blood. We studied the level of expression of the mRNA gene of IkBα in mononuclear cells, which reflects the level of transcriptional activity of NF-kB in patients with stable coronary artery disease and CHD in combination with NAFLD showed a significant increase in the expression of the mRNA gene of IkBα by 88.5% compared to patients with stable stable coronary heart disease. The analysis of the functional state of the endothelium with help of CEM CD32+ CD40+ has shown the presence of endothelial dysfunction in the groups of patients with CHD and CHD in combination with of NAFLD. Comparison of the indicators of systemic inflammation of low intensity and marker of endothelial dysfunction in patients with CHD in combination with NAFLD revealed a significant increase of TNFα, acute phase reactant and coagulation fibrinogen factor and expression of the mRNA IkBα gene in patients with comorbidity, indicating an increase the level of systemic inflammation of low intensity in patients with CHD in combination with NAFLD as compared with the group of patients with CHD.

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.

Effects of Acute Moderate Exercise on Nitric Oxide and Endothelial Microparticles in Patients with Hypertension

Effects of Acute Moderate Exercise on Nitric Oxide and Endothelial Microparticles in Patients with Hypertension

ERK-containing microparticles from a diabetic mouse induce endothelial dysfunction.

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

The Role of Endothelial Microparticle in Coronary Heart Disease as The Complications of Diabetes Mellitus

Coronary heart disease (CHD) is caused by obstruction of coronary blood flow due to endothelial dysfunction triggered by various genetic and non-genetic risk factors such as hyperlipidemia, hypertension, hyperglycemia and obesity. Endothelial cell activation due to hyperglycaemia in diabetes mellitus induces production of pro-inflammatory factors that damage the cell membrane triggering the formation of membrane particles called microparticles. Endothe-lial microparticles contain proteins including endothelial nitric oxide synthase (eNOS) which plays a role in the production of nitric oxide (NO). To determine the role of microparticles in the occurrence of coro-nary heart disease in diabetes mellitus due to endothelial dysfunction, a study was conducted by comparing the levels of eNOS and NO in DM patients who had CHD with DM patients who had no CHD. Blood samples from 20 DM patients who had CHD and 20 DM patients who had no CHD of the outpatients in Cardiology Department and Inter-nal Medicine department of regional public hospital were included in this study. All patients were fulfilled inclusion and exclusion criteria and diagnosed by the appropriate specialist. The eNOS and NO lev-els were measured using the ELISA method. The results of this study show that eNOS levels in the group of DM patients who had CHD (21,292±12,415 ng/ml) were significantly lower (p &lt;0.05) than those in the group of DM patients who had no CHD (29,721±11,952 ng/ml). Nitric oxide levels in DM patients who had CHD (0,053±0,021 nmol/ μl) were not statistically different to the levels in DM patients who had no CHD (0,047±0,032 nmol/μl). From the results of this study we concluded that endothelial microparticle protein eNOS plays a role in the occurrence of CHD due to the complications of diabetes mellitus

Endothelial Microparticles in Uremia: Biomarkers and Potential Therapeutic Targets.

Endothelial microparticles (EMPs) are vesicles derived from cell membranes, which contain outsourced phosphatidylserine and express adhesion molecules, such as cadherin, intercellular cell adhesion molecule-1 (ICAM-1), E-selectin, and integrins. EMPs are expressed under physiological conditions and continue circulating in the plasma. However, in pathologic conditions their levels increase, and they assume a pro-inflammatory and pro-coagulant role via interactions with monocytes; these effects are related to the development of atherosclerosis. Chronic kidney dysfunction (CKD) characterizes this dysfunctional scenario through the accumulation of uremic solutes in the circulating plasma, whose toxicity is related to the development of cardiovascular diseases. Therefore, this review aims to discuss the formation of EMPs and their biological effects in the uremic environment. Data from previous research demonstrate that uremic toxins are closely associated with the activation of inflammatory biomarkers, cardiovascular dysfunction processes, and the release of EMPs. The impact of a decrease in circulating EMPs in clinical studies has not yet been evaluated. Thus, whether MPs are biochemical markers and/or therapeutic targets has yet to be established.

Tetramethylpyrazine alleviates LPS-induced inflammatory injury in HUVECs by inhibiting Rho/ROCK pathway

Endothelial dysfunction plays an important role in the pathogenesis of acute lung injury (ALI). Tetramethylpyrazine (TMP) has been reported to attenuate harmful changes in ALI rats. However, the effects of TMP on endothelial cell injury and its underlying mechanisms remain unknown. In this study, human umbilical vein endothelial cells (HUVECs) induced by lipopolysaccharide (LPS) was used as an inflammatory injury model, also served as LPS group. HUVECs pretreated with TMP for 2 h before induced by LPS was served as LPS + TMP group. Untreated HUVECs was served as control group. After incubation with LPS for 12 h, cell viability and morphology, cell apoptosis rate, CD31-positive endothelial microparticles (EMPs) release, proinflammatory cytokines secretion, and ROCK II expression were evaluated. Compared with LPS group, TMP pretreatment improved cell viability and morphology. Besides, cell apoptosis rate, CD31-positive EMPs amount, TNF-α and IL-1β concentrates, and ROCK II mRNA and protein levels in LPS + TMP group were significantly decreased when compared with LPS group. To further confirm the mechanism, HUVECs in all the above groups were pretreated with Y27632 (ROCK II inhibitor) for 30 min before grouping, then treated as above. No significant differences in cell apoptosis rate, CD31-positive EMPs amount, and ROCK II expression between Y27632 + LPS group and Y27632 + LPS + TMP group were found. To sum up, our study found that TMP alleviated LPS-induced inflammatory injury in HUVECs by inhibiting Rho/ROCK pathway.

Subclinical Atherosclerosis in Primary Sjögren's Syndrome: Does Inflammation Matter?

Sjögren's syndrome (SS) is a systemic autoimmune disease mainly characterized by inflammatory involvement of exocrine gland. Atherosclerosis is a complex process leading to plaque formation in arterial wall with subsequent cardiovascular (CV) events. Recently, numerous studies demonstrated that SS patients bear an increased CV risk. Since activation of immune system is a key element in atherosclerosis, it is interesting to analyze whether and how the autoimmune and inflammatory events characterizing SS pathogenesis directly or indirectly contribute to atherosclerosis risk in these patients. An increase in circulating endothelial microparticles and integrins, which may be a consequence of endothelial damage and impaired repair mechanisms, has been demonstrated in SS. Increased endothelial expression of adhesion molecules with subsequent infiltration of inflammatory cells into arterial wall is also a critical event in atherosclerosis. The early inflammatory events taking place in the atherosclerotic plaque cause an increase in alarmins, such as S100A8/A9, which seems to be associated with SS disease activity and, in turn, induce up-regulation of interleukin (IL)-1β and other pro-atherogenic cytokines. Interestingly, increased IL-1β levels were also detected in tertiary lymphoid structures developing in vessel adventitia adjacent to the atherosclerotic plaque, suggesting a direct role of IL-1β in this process. Similar to these structures, germinal center-like structures arising in SS exocrine glands are also tertiary lymphoid systems where T-helper (Th) cell subsets govern the adaptive immune response. Th1 cells are the most prevalent subtype and have been shown to be strongly involved in both SS pathogenesis and atherosclerosis. Th17 cells are attracting great interest and few studies showed its importance in SS development. Albeit in low amounts, a Th17 signature was also detected in atherosclerotic plaques and some animal models demonstrated a significant pro-atherogenic role and positive effects of IL-17A blockade. Despite the fact that T cells have a pivotal role in the inflammatory process that ultimately leads to atherosclerosis, B cells have also been detected in atherosclerotic plaques, although their exact role is still mostly unknown with studies showing contrasting results. In this scenario, the role of inflammation in atherosclerosis pathogenesis in patients with SS needs to be further explored.

Sirt6-induced autophagy restricted TREM-1-mediated pyroptosis in ox-LDL-treated endothelial cells: relevance to prognostication of patients with acute myocardial infarction

Inflammation mediated by myeloid cells trigger receptors 1 (TREM-1) is important for atherosclerosis development, while sirtuin 6 (Sirt6) levels decrease in atheroscleoritc plaque. Here we demonstrate that oxidatively modified low density lipoprotein (ox-LDL)-treated endothelial cells (ECs) exhibited increased TREM-1-mediated pyroptosis and decreased Sirt6-induced autophagy. We show that high sTREM-1 and low sSirt6 levels were independent predictors of boosted endothelial microparticles (EMPs) on admission, and were associated with increased risk for all-cause mortality and major adverse cardiovascular events (MACE) at median 24 months (interquartile range, 18–26) follow-up in acute myocardial infarction (AMI) patients. Additionally, blockage of Sirt6-induced autophagy led to augmented TREM-1-mediated pyroptosis, whereas Sirt6 overexpression attenuated ECs inflammation and pyroptosis following ox-LDL treatment. Our findings indicate that TREM-1 and in a reversed trend Sirt6 appeared to be markers of endothelial inflammation with potential for use in risk stratification.

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.

AT1R Blockade Inhibits Endothelial Dysfunction in Response to Mental Stress in Overweight/Obese Men

Acute exposure to mental stress (MS) leads to endothelial activation, microparticles release and, consequently, transient endothelial dysfunction in overweight/obesity grade 1 men. Considering that angiotensin II generates an oxidative imbalance mediated by angiotensin II type 1 receptors (AT1R), it is unknown whether this process is responsible for transient endothelial dysfunction present in MS in overweight/obesity grade 1. Therefore, the aim of this study was to determine endothelial responses to angiotensin II mediated by AT1R after MS in overweight/obesity grade I men. For this, fourteen overweight/obese men (27±7 years; 30.1±2.9 Kg/m2) participated in two randomized experimental sessions with oral administration of the AT1 receptor blocker (AT1R block) or placebo. Endothelial function was determined by flow‐mediated dilation (FMD) before (baseline), 30 (30MS) and 60 (60MS) minutes after a five minute session of acute MS (Stroop Color Word Test). Blood samples (n=11) were obtained at before (baseline), during (MS) and 60 minutes (60MS) after MS for measurement of: endothelial microparticle (EMP, flow cytometry); endothelial progenitor cells (EPC, flow cytometry); nitrite (chemoluminescence); and oxidative stress [lipid peroxidation (TBARS), protein oxidation (carbonylated proteins) and antioxidant enzyme (catalase) by colorimetry]. During MS, heart rate, systolic, diastolic and mean blood pressure increased similarly in both conditions (p=0.01 vs. baseline). At the placebo session, FMD decreased significantly in 30MS (p=0.04 vs. baseline) and returned to baseline levels in 60MS (p=0.03 vs. 30MS). There was a significant increase in EPC in 60MS (p=0.04 vs. baseline). Carbonylated proteins (p=0.01 vs. baseline) and catalase activity increased during MS (p=0.02 vs. baseline) and returned to baseline in 60MS (p=0.01 vs. MS). No differences were observed in nitrite levels at the placebo session. At AT1R block session, FMD increased in 30MS (p =0.01 vs. baseline) and 60MS (p=0.02 vs. baseline), while EPC levels were different from placebo only 60MS (p=0.04 vs. placebo). There was a significant increase in nitrite (p=0.01 vs. baseline) while no change was observed in carbonylated proteins in 30MS and 60MS. Carbonylated protein concentration was lower during AT1R blockade in MS (p=0.04 vs. placebo). Catalase increased only in 60EM (p=0.02 vs. placebo). There were no differences in the concentrations of EMP and TBARS. In conclusion, AT1R blockade appears to increase flow‐mediated dilatation and nitrite bioavailability in response to MS in addition to preventing the increase of protein oxidation after MS in overweight/obese men.Support or Funding InformationCoordination for the Improvement of Higher Education Personnel (CAPES)Foundation for Research Support of the State of Rio de Janeiro (FAPERJ)National Council for Scientific and Technological Development (CNPq)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Chemotherapy acutely impairs neurovascular and hemodynamic responses in patients with breast cancer

PurposeThe purpose of the present study was to test the hypothesis that doxorubicin (DX) and cyclophosphamide (CY) adjuvant chemotherapy (CHT) acutely impairs neurovascular and hemodynamic responses in patients with breast cancer.MethodsSixteen women (age: 47.0±2.0 years; body mass index: 24.2±1.5 Kg.m−2) with stage II–III breast cancer and indication for adjuvant CHT underwent two experimental sessions, saline (SL) and CHT. In the CHT session, DX (60 mg/m2) and CY (600mg/m2) were administered in 45 min. In the SL session, a matching SL volume was infused in 45 min. Muscle sympathetic nerve activity (MSNA, microneurography), calf blood flow (CBF, plethysmography) and calf vascular conductance (CVC), heart rate (HR, electrocardiography) and beat‐to‐beat blood pressure (BP) (Finger plethysmography) were measured before, during and after each session. Blood samples (5 mL) were collected before and after both sessions for assessment of circulating endothelial microparticles (EMPs, flow cytometry), a surrogate marker for endothelial damage.ResultsMSNA and BP responses were increased (P&lt;0.001), whereas CBF and CVC responses were decreased (P&lt;0.001), during and after CHT session when compared to SL session. Interestingly, the vascular alterations were also observed at the molecular level through an increased EMPs response to CHT (P=0.03 vs. SL session). No difference in HR response was observed (p&gt;0.05).ConclusionsAdjuvant CHT with DX and CY in patients treated for breast cancer leads to acute sympathetic hyperactivity and endothelial alterations, which results in reduced muscle vascular conductance and elevated systemic BP. These responses may anticipate susceptibility to CHT‐induced longterm cardiovascular alterations.Support or Funding InformationSão Paulo Research Foundation ‐ FAPESPThis abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.