Endothelial Progenitor Cells Levels Research Articles

Elevated Inflammatory Parameter Levels Negatively Impact Populations of Circulating Stem Cells (CD133+), Early Endothelial Progenitor Cells (CD133+/VEGFR2+), and Fibroblast Growth Factor in Stroke Patients.

Endothelial Progenitor Cells (EPCs) are important players in neovascularization, mobilized through signalling by Angiogenic Growth Factors (AGFs) such as Vascular Endothelial Growth Factor (VEGF) and fibroblast growth factor (FGF). In vitro, inflammatory parameters impair the function and influence of EPCs on AGFs. However, this connection is not clear in vivo. To understand the mechanisms of augmented arteriogenesis and angiogenesis in acute ischemic stroke (AIS) patients, we investigated whether circulating stem cells (CD133+), early endothelial progenitor cells (CD133+/VEGFR2+), and endothelial cells (ECs; CD34¯/CD133¯/VEGFR2+) were increasingly mobilized during AIS, and whether there were correlations between EPC levels, growth factor levels and inflammatory parameters. Data on demographics, classical vascular risk factors, neurological deficit information (assessed using the National Institutes of Health Stroke Scale), and treatment were collected from 43 consecutive AIS patients (group I). Risk factor control patients (group II) included 22 nonstroke subjects matched by age, gender, and traditional vascular risk factors. EPCs were measured by flow cytometry and the populations of circulating stem cells (CD133+), early EPCs (CD133+/VEGFR2+), and ECs (CD34¯/CD133¯/VEGFR2+) were analysed. Correlations between EPC levels and VEGF and FGF vascular growth factor levels as well as the influence of inflammatory parameters on EPCs and AGFs were assessed. Patient ages ranged from 54 to 92 years (mean age 75.2 ± 11.3 years). The number of circulating CD34¯/CD133¯/VEGF-R2+ cells was significantly higher in AIS patients than in control patients (p < 0.05). VEGF plasma levels were also significantly higher in AIS patients compared to control patients on day 7 (p < 0.05). FGF plasma levels in patients with AIS were significantly higher than those in the control group on day 3 (p < 0.05). There were no correlations between increased VEGF and FGF levels and the number of CD133+, CD133+/VEGFR2+, or CD34¯/CD133¯/VEGFR2+ cells. Leukocyte levels, FGF plasma levels, and the number of early EPCs were negatively correlated on day 3. High sensitivity C-reactive protein levels and the number of CD133+ and CD133+/VEGFR2+ cells were negatively correlated on day 7. In addition, there was a negative correlation between fibrinogen levels and FGF plasma levels as well as the number of early EPCs (CD133+/VEGFR2+). AIS patients exhibited increased numbers of early EPCs (CD133+/VEGFR2+) and AGF (VEGF and FGF) levels. A negative correlation between inflammatory parameters and AGFs and EPCs indicated the unfavourable influence of inflammatory factors on EPC differentiation and survival. Moreover, these correlations represented an important mechanism linking inflammation to vascular disease.

Concomitant overexpression of triple antioxidant enzymes selectively increases circulating endothelial progenitor cells in mice with limb ischaemia.

Endothelial progenitor cells (EPCs) are a group of heterogeneous cells in bone marrow (BM) and blood. Ischaemia increases reactive oxygen species (ROS) production that regulates EPC number and function. The present study was conducted to determine if ischaemia‐induced ROS differentially regulated individual EPC subpopulations using a mouse model concomitantly overexpressing superoxide dismutase (SOD)1, SOD3 and glutathione peroxidase. Limb ischaemia was induced by femoral artery ligation in male transgenic mice with their wild‐type littermate as control. BM and blood cells were collected for EPCs analysis and mononuclear cell intracellular ROS production, apoptosis and proliferation at baseline, day 3 and day 21 after ischaemia. Cells positive for c‐Kit+/CD31+ or Sca‐1+/Flk‐1+ or CD34+/CD133+ or CD34+/Flk‐1+ were identified as EPCs. ischaemia significantly increased ROS production and cell apoptosis and decreased proliferation of circulating and BM mononuclear cells and increased BM and circulating EPCs levels. Overexpression of triple antioxidant enzymes effectively prevented ischaemia‐induced ROS production with significantly decreased cell apoptosis and preserved proliferation and significantly increased circulating EPCs level without significant changes in BM EPC populations, associated with enhanced recovery of blood flow and function of the ischemic limb. These data suggested that ischaemia‐induced ROS was differentially involved in the regulation of circulating EPC population.

Effects of Extra Virgin Olive Oil and Apples Enriched-Dark Chocolate on Endothelial Progenitor Cells in Patients with Cardiovascular Risk Factors: A Randomized Cross-Over Trial.

Background: Endothelial dysfunction has been associated to cardiovascular outcomes in patients with cardiovascular risk factors. Circulating endothelial progenitor cells (EPCs) play an important physiological role for their reparative potential of vascular integrity, but are numerically reduced and functionally impaired in patients with cardiovascular risks. This study assesses the effects of Extra Virgin Olive Oil (EVOO) and apple-enriched dark chocolate intake on the blood levels of EPCs. Methods: Thirty volunteers with cardiovascular risk factors, enrolled in a randomised, crossover, four-weeks trial, received a solid dark chocolate bar (40 g/day) containing 10% EVOO or 2.5% dry apples. Urine samples were analyzed for endogenous metabolites. Circulating EPCs levels, clinical data and anthropometric examinations were collected. Results: 26 volunteers (M/F:14/12, 51 ± 9 years of age) completed the study. Comparison of pre-post intervention revealed a significant increase in EPCs levels associated with EVOO-dark chocolate consumption. Most biochemical parameters were not significantly modified by both chocolates. Conclusions: This study shows that a daily consumption of a non fattening dose of dark chocolate enriched with EVOO improves blood levels of EPCs, a well known surrogate biologic marker for endothelial function.

CD-34+ and VE-cadherin+ endothelial progenitor cells in preeclampsia and normotensive pregnancies.

The objective of our study was to determine levels of endothelial progenitor cells (EPCs) in preeclampsia and normotensive pregnant women. Prospective cohort study of women with preeclampsia and normotensive pregnancies. EPCs were estimated by flow cytometry. Multiple linear regression was used to assess the association of EPCs with preeclampsia adjusting for maternal age, body mass index (BMI), gestation and ethnicity. Levels of EPCs in preeclampsia and normotensive pregnancies, with CD-34 and vascular endothelial (VE)-cadherin as markers of EPCs. VE-cadherin is an endothelial cell adhesion molecule used to delineate endothelial lineage of EPCs. There were thirty women in the preeclampsia group and thirty-three in the normotensive group. The two groups were similar except for the BMI and blood pressures, which were higher in preeclampsia. On multiple linear regression, EPCs numbers were significantly higher by 29 (95% confidence interval 11.7-46.6, p = 0.001) in preeclampsia compared to the normotensive group. There was significant positive correlation between EPCs and systolic blood pressure in preeclampsia (Spearman correlation coefficient 0.39, p = 0.03). Although widely used in cardiovascular disease other than preeclampsia, this is the first study using VE-cadherin as a marker of endothelial lineage to define EPCs in preeclampsia. Our results suggest the higher number of EPCs in preeclampsia may be a response of the bone marrow to endothelial injury.

Red Blood Cell Distribution Width, Vascular Aging Biomarkers, and Endothelial Progenitor Cells for Predicting Vascular Aging and Diagnosing/Prognosing Age-Related Degenerative Arterial Diseases.

The emerging evidence emphasizes red blood cell distribution width (RDW) as optimal prognostic biomarker for cardiovascular diseases. However, several clinical biases impede its clinical application. Recent recommendations suggest combining RDW with other biomarkers. Accordingly, we propose evaluating the well-recognized biomarkers of vascular aging (i.e., the leukocyte telomere length and telomerase activity, and reduced levels of endothelial progenitor cells [EPCs]) with RDW, for predicting the risk for vascular aging and onset and prognosis of age-related degenerative arterial diseases, such as sporadic ascending aorta aneurysm (AAA), characterized to have an increased incidence in old people. Consequently, in this study (and for the first time), we simultaneously investigated the relationship between RDW values, systemic inflammatory molecules, mean values of leukocyte telomere length, telomerase activity and EPCs, and the risk for vascular aging and AAA onset and prognosis. To achieve this aim, we selected 80 old and 80 young healthy subjects and 80 AAA cases. Appropriate methodologies were used for assessing blood parameters, aorta alterations, genotyping, impairment of the leukocyte telomere length, and telomerase activity. The main findings obtained demonstrated that increased RDW values along with the augmented blood levels of high-sensitive C-reactive protein and the reduced mean values of both leukocyte telomere length, telomerase activity, and EPCs are independently associated with the high risk for both vascular aging and AAA onset and prognosis. They might be used as the best predictor biomarker profile for vascular aging, and for both diagnosis and outcome of sporadic AAA.

Atorvastatin Protects Against Cerebral Aneurysmal Degenerative Pathology by Promoting Endothelial Progenitor Cells (EPC) Mobilization and Attenuating Vascular Deterioration in a Rat Model.

BackgroundEndothelial injury is the early pathological change of cerebral aneurysm (CA) formation. In addition to its lipid-lowering activity, atorvastatin (ATR) also reportedly promotes vascular repair via mobilizing endothelial progenitor cells (EPC). Here, we investigated the influence of ATR on vascular worsening after CA induction in rats.Material/MethodsAdult male Sprague-Dawley rats were randomly assigned to 3 groups: a control (CTR) group, a CA group, and a CA+ATR treatment group. Circulating EPC level and hematological and lipid profiles were measured 3 months after CA induction. Verhoeff-Van Gieson staining and transmission electron microscopy were performed to assess pathological changes in the artery wall. RT-PCR was also performed to evaluate the expression of inflammation-related genes in the aneurysmal wall.ResultsATR significantly restored the impaired level of circulating EPC without changing hematological and lipid profiles 3 months after CA induction. ATR markedly inhibited endothelial injury, media thinning, and CA enlargement, accompanied by reduced vascular inflammation.ConclusionsOur preliminary results demonstrate that the mobilization of EPC and improvement of endothelial function by ATR contribute to the prevention of cerebral aneurysm. Further studies are warranted to investigate the detailed mechanism.

Circulating Endothelial Cells, Circulating Endothelial Progenitor Cells, and Circulating Microparticles in Type 1 Diabetes Mellitus.

Background and Aim:Hyperglycemia in type 1 diabetes (T1D) is accompanied by endothelial cell dysfunction which is known to contribute to the pathogenesis of cardiovascular disorders. The aim of the current study was to explore the profile of circulating endothelial progenitor cells (EPCs), circulating endothelial cells (CECs), endothelial and platelet derived micropaticles (EMPs, PMPs) and total microparticles (TMPs), in T1D children in relation to each other and to the metabolic disorders accompanying T1D.Patients and Methods:Thirty T1D patients and 20 age and sex matched healthy volunteers were assessed for HbA1c level and lipid profile. Quantification of CECs, EPCs, TMPs, EMPs and PMPs was done by flow cytometry.Results:The mean levels of EMPs, PMPs, TMPs and CECs were significantly higher in diabetic children compared to controls. Meanwhile, the levels of EPCs were significantly lower in diabetic children compared to controls. Both PMPs and CECs showed the highest significant differences between patients and controls and their levels were directly related to HbA1c, total cholesterol, LDL and triglycerides. A moderate correlation was observed between the frequency of PMPs and CECs. EPCs revealed negative correlations with both LDL and triglycerides. TMPs were only related to LDL, while EMPs were only related to HbA1c.Conclusion:Although there is disturbance in the levels of EMPs, PMPs, TMPs, CECs and EPCs in type 1 diabetic children compared to the controls, only the levels of PMPs and CECs were closely affected by the poor glycemic control and dyslipidemia occurring in T1D; thus may contribute to a higher risk of cardiovascular diseases.

High levels of endothelial progenitor cells and circulating endothelial cells in patients with Behcet’s disease and their relationship to disease activity

AbstractBackground: Behcet’s disease is a multisystemic vasculitis, associated with vascular endothelial dysfunction. Currently, the prognosis is unpredictable, because there is still no valid laboratory marker indicating the disease activity in Behcet’s disease. Endothelial progenitor cells and circulating endothelial cells are newly introduced hematological markers which are presumed to take part in the pathogenesis of vasculitis.Objectives: To evaluate the levels of endothelial progenitor cells and subtypes and circulating endothelial cells in patients with Behcet’s disease and to describe their relationship with the disease activity.Methods: A total of 45 patients with Behcet’s disease and 28 healthy controls were included in the study. Endothelial progenitor cells (CD34+CD133+KDR+ as early endothelial progenitor cells and CD34+KDR+ as late endothelial progenitor cells), and circulating endothelial cells (CD34+CD133+) were measured by flow cytometry.Results: The mean plasma level of endothelial progenitor cells and circulating endothelial cells, vascular endothelial growth factor, matrix metalloproteinase-9, C-reactive protein, and erythrocyte sedimentation rate were significantly higher in patients with Behcet’s disease. All of these parameters except circulating endothelial cells were also found to be higher in patients with active disease than in patients with inactive disease. Early endothelial progenitor cells showed significant correlations with C-reactive protein and circulating endothelial cells.Study limitations: The cross-sectional nature of the study and patient characteristics such as being under treatment, which can affect endothelial progenitor cells numbers.Conclusion: The increase in endothelial progenitor cells may play an essential role in the repair of endothelial injury in Behcet’s disease, especially in the active period of the disease. Thus, endothelial progenitor cells can indicate the disease activity. In addition, endothelial progenitor cells and circulating endothelial cells can be used as endothelial repair and injury markers for Behcet’s disease, respectively.

Circulating endothelial cells as biomarker for cardiovascular diseases

BackgroundEndothelial dysfunction is involved in several cardiovascular diseases. Elevated levels of circulating endothelial cells (CECs) and low levels of endothelial progenitor cells (EPCs) have been described in different cardiovascular conditions, suggesting their potential use as diagnostic biomarkers for endothelial dysfunction. Compared to typical peripheral blood leukocyte subsets, CECs and EPCs occur at very low frequency. The reliable identification and characterization of CECs and EPCs is a prerequisite for their clinical use, however, a validated method to this purpose is still missing but a key for rare cell events. ObjectivesTo establish a validated flow cytometric procedure in order to quantify CECs and EPCs in human whole blood. MethodsIn the establishment phase, the assay sensitivity, robustness, and the sample storage conditions were optimized as prerequisite for clinical use. In a second phase, CECs and EPCs were analyzed in heart failure with preserved (HFpEF) and reduced (HFrEF) ejection fraction, in arterial hypertension (aHT), and in diabetic nephropathy (DN) in comparison to age‐matched healthy controls. ResultsThe quantification procedure for CECs and EPCs showed high sensitivity and reproducibility. CEC values resulted significantly increased in patients with DN and HFpEF in comparison to healthy controls. CEC quantification showed a diagnostic sensitivity of 90% and a sensitivity of 68.0%, 70.4%, and 66.7% for DN, HFpEF, and aHT, respectively. ConclusionA robust and precise assay to quantify CECs and EPCs in pre‐clinical and clinical studies has been established. CEC counts resulted to be a good diagnostic biomarker for DN and HFpEF.

Oxidized HDL, Adipokines, and Endothelial Dysfunction: A Potential Biomarker Profile for Cardiovascular Risk in Women with Obesity.

High BMI predicts adverse cardiovascular outcomes and positively correlates with increased levels of adipokines. The relationship among BMI, IL-6, TNFα, adiponectin, and oxidized high-density lipoprotein (Ox-HDL) with circulating endothelial cells (CECs) and endothelial progenitor cells (EPCs) has not been well studied. Elevated CEC levels have been described in both humans and mice with obesity and diabetes. Ox-HDL has been shown to be a potent driver of adipogenesis in vivo and in vitro. In this study, elevated BMI was examined in 2 groups of women studied in Brooklyn, New York, and Huntington, West Virginia, respectively. Twenty-six females with obesity and five lean controls without overt cardiovascular disease were enrolled, 13 from Huntington and 13 from Brooklyn. Cytokine levels, EPCs, and CECs were determined. Females with obesity had elevated levels of leptin, IL-6, and Ox-HDL, increased CEC levels, and decreased EPC and adiponectin levels (all P<0.01). The Ox-HDL levels were higher in women from Brooklyn versus Huntington (P<0.01), possibly from higher TNFα levels in Brooklyn or higher adiponectin levels in Huntington. Seventy-five percent of the variance in Ox-HDL levels could be predicted in this population (P<0.01). This study reveals a unique inflammatory biomarker profile in females with obesity.

Hyperbaric Oxygen Therapy Enhanced Circulating Levels of Endothelial Progenitor Cells and Angiogenesis Biomarkers, Blood Flow, in Ischemic Areas in Patients with Peripheral Arterial Occlusive Disease.

Background: This study tested the hypothesis that hyperbaric oxygen (HBO) therapy enhanced the circulating levels of endothelial progenitor cells (EPCs), soluble angiogenesis factors, and blood flow in ischemic areas in patients with peripheral arterial occlusive disease (PAOD). Methods: In total, 57 consecutive patients with PAOD undergoing the HBO therapy (3 atmospheres (atm) for 2 h each time) were prospectively enrolled into the present study. Venous blood sampling was performed to assess the circulating levels of EPCs and soluble angiogenesis factors prior to and during five sessions of HBO therapy. Additionally, skin perfusion pressure (SPP), an indicator of blood flow in ischemic areas, was measured by moorVMS-PRES. Results: The results demonstrated that the circulating levels of EPCs (cluster of differentiation (CD)34+/CD133+/CD45dim, CD31+/CD133+/CD45dim, CD34+) and soluble angiogenesis factors—vascular endothelial growth factor/stromal cell-derived factor 1/hepatocyte growth factor/fibroblast growth factor (VEGF/SDF-1α/HGF/FGF) were significantly increased post-HBO therapy as compared to pre-HBO therapy (all p < 0.01). Additionally, Matrigel assay showed that the angiogenesis was significantly increased in post-HBO therapy as compared to prior to therapy (p < 0.001). Furthermore, SPP was significantly increased in the ischemic area (i.e., plantar foot and mean SPP of the ischemic foot) in post-HBO therapy as compared to pre-HBO therapy (all p < 0.01). Importantly, the HBO therapy did appear to result in complications, and all the patients were uneventfully discharged without amputation. Conclusions: HBO therapy augmented circulating levels of EPCs and angiogenesis factors, and improved the blood flow in the ischemic area.

Dysfunctional endothelial progenitor cells in patients with Hodgkin's lymphoma in complete remission.

BackgroundPatients with a history of Hodgkin's lymphoma (HL) are at increased long‐term risk of cardiovascular morbidity and mortality. Studies report an association between the pathophysiology of coronary artery disease (CAD) and levels of circulating endothelial progenitor cells (EPC), which play an essential role in vascular injury repair. The aim of the present study was to investigate the potential involvement of abnormal EPC level or function in the CAD risk of survivors of HL in remission.MethodsEPCs were isolated from peripheral blood samples drawn from 4 groups of patients aged 20‐50 years with no history of CAD: 17 patients with HL who had been in complete remission for at least 2 years, four newly diagnosed patients with HL before treatment, 28 patients with diabetes all attending a tertiary medical center, and 16 healthy individuals. Levels of EPC surface markers were measured by flow cytometry, and EPC function was evaluated by the number of colony‐forming units (CFUs) and MTT assay.ResultsLevels of circulating CD34(+)/VEGFR2(+) and CD133(+)/VEGFR2(+) were significantly higher in the newly diagnosed untreated patients with HL compared to the patients with HL in remission (P = 0.03 and P = 0.005, respectively), in the patients in remission compared to the patients with diabetes (P = 0.011 and P < 0.001, respectively), and in the patients in remission compared to the healthy individuals (P = 0.08 and P = 0.003, respectively). The analysis of cell viability and the number of colony‐forming units in the patients with HL in remission yielded significant differences from the healthy group (P = 0.005 and P < 0.001, respectively) but not from either the newly diagnosed patients with HL or the diabetic patients.ConclusionsThese results suggest that patients in complete remission of HL for at least 2 years have an abnormal EPC profile characterized by high circulating levels but attenuated function.

Endothelial Progenitor Cells as Mediators of the Crosstalk between Vascular Repair and Immunity: Lessons from Systemic Autoimmune Diseases.

From the discovery of Endothelial Progenitor Cells (EPC), these bone marrowderived precursors have been placed as crucial mediators of the endothelial repair. Accordingly, altered levels and function of EPC have been found in different scenarios of CV risk. Despite the fact that EPC exhibit important characteristics which support a link of this cell subset with a number of inflammatory and immune networks, little is known on the actual mediators involved and the clinical relevance of these features. Systemic diseases are generally hallmarked by a vascular repair failure and increased cardiovascular disease occurrence, EPC impairment having a pivotal role. Because of their immunemediated etiology, this group of conditions represents an invaluable scenario to unravel the connections between immune dysregulation and EPC dysfunction. In the present review, we summarize the current knowledge regarding the cutting-edge area of the modulation of EPC levels and function by inflammatory cytokines in systemic diseases. We also address the possibility of the available immunomodulatory drugs to counteract this situation. Finally, due to the emerging role of the vitamin D as a common mediator in the immune system and the cardiovascular axis, we cover the topic of the role of vitamin D as a potential player in the inflammatory-mediated EPC dysfunction in systemic diseases.

Predictors of strut coverage of drug eluting stent implantation in diabetic patients

BackgroundIncomplete re-endothelialization of drug eluting stent (DES) segments has been associated with the occurrence of major adverse cardiac events after DES implantation. It is unknown whether on-clopidogrel platelet reactivity (OPR) and/or circulating endothelial progenitor cells (EPC) levels may predict uncovered strut rate in diabetic patients treated by DES implantation. MethodsOne-hundred and five diabetic patients undergoing elective DES implantation were included into the study. EPC levels and OPR were assessed at 24 h (baseline) and 3 months. EPC were evaluated by flow cytometric analysis and defined by the co-expression of the markers CD34 and KDR. OPR was assessed using the impedance aggregometer. The degree of DES re-endothelialization was assessed at 3 months by optical coherence tomography. ResultsA direct correlation was observed between the uncovered strut rate and OPR both at baseline (r = 0.47: p < 0.001) and at the 3 months (r = 0.25: p = 0.015). On the contrary, we found no significant correlation between EPC level and uncovered strut rate either at baseline (r = −0.02; p = 0.85) or at 3 months (r = −0.06; p = 0.13). By multivariable regression analysis, independent predictors of uncovered strut rate > 5% were complex lesions (OR = 5.35; 95% confidence interval 1.32–17.57; p = 0.027) and OPR at baseline (OR = 4.73; 95% confidence interval 1.04–8.14; p = 0.039). ConclusionsIn diabetic patients treated with DES implantation OPR at baseline and complex lesions are independent predictors of uncovered strut rate at 3 months.

Intrinsic Vascular Repair by Endothelial Progenitor Cells in Acute Coronary Syndromes: an Update Overview.

Bone marrow-derived endothelial progenitor cells (EPCs) play a key role in the maintenance of endothelial homeostasis and endothelial repair at areas of vascular damage. The quantification of EPCs in peripheral blood by flow cytometry is a strategy to assess this reparative capacity. The number of circulating EPCs is inversely correlated with the number of cardiovascular risk factors and to the occurrence of cardiovascular events. Therefore, monitoring EPCs levels may provide an accurate assessment of susceptibility to cardiovascular injury, greatly improving risk stratification of patients with high cardiovascular risk, such as those with an acute myocardial infarction. However, there are many issues in the field of EPC identification and quantification that remain unsolved. In fact, there have been conflicting protocols used to the phenotypic identification of EPCs and there is still no consensual immunophenotypical profile that corresponds exactly to EPCs. In this paper we aim to give an overview on EPCs-mediated vascular repair with special focus on acute coronary syndromes and to discuss the different phenotypic profiles that have been used to identify and quantify circulating EPCs in several clinical studies. Finally, we will synthesize evidence on the prognostic role of EPCs in patients with high cardiovascular risk.

Moderate Exercise Enhances Endothelial Progenitor Cell Exosomes Release and Function.

Exercise has cardiovascular benefits which might be related to endothelial progenitor cells (EPC). Meanwhile, there is evidence suggesting that EPC-derived exosomes (EPC-EX) promote vascular repair and angiogenesis through their carried microRNA (miR)-126. In this study, we investigated whether exercise could increase the levels of circulating EPC-EX and their miR-126 cargo, and by which promote the protective function of EPC-EX on endothelial cells (EC). Plasma EPC-EX from sedentary, low, or moderate exercise mice, respectively, denoted as EPC-EX, EPC-EX, and EPC-EX, were isolated using microbead-based sorting techniques and characterized by nanoparticle tracking analysis, Western blot, and quantitative real-time polymerase chain reaction assessments of biomarkers and miR-126. High glucose (25 mM) with hypoxia (1% O2) was used for inducing an EC injury model. The injured EC were treated by coculturing with vehicle, EPC-EX, EPC-EX, EPC-EX, or EPC-EX + anti-miR-126. After that, EC were used for flow cytometry analysis of apoptosis, assessments of tube formation and migration, and measurements of miR-126 level and its downstream sprouty-related protein-1 (SPRED1) and vascular endothelial growth factor (VEGF). 1) Isolated EPC-EX positively expressed exosomal markers (CD63 and Tsg101) and EPC markers (CD34 and VEGFR2). 2) Exercise intensity dependently elevated plasma level of EPC, EPC-EX/EPC ratio, and miR-126 expression in EPC and EPC-EX. 3) Injured EC displayed apoptosis increment, angiogenic dysfunction and miR-126 reduction. 4) EPC-EX had better effects than EPC-EX and EPC-EX on alleviating those changes of injured EC, accompanied with SPRED1 downregulation and VEGF upregulation. 5) The effects of EPC-EX were abolished by miR-126 knockdown. Our data demonstrate that exercise can increase EPC-EX release and miR-126 level and enhance the effects of EPC-EX on protecting EC against injury through the SPRED1/VEGF pathway.

No Differences in Levels of Circulating Progenitor Endothelial Cells or Circulating Endothelial Cells Among Patients Treated With Ticagrelor Compared With Clopidogrel During Non- ST -Segment-Elevation Myocardial Infarction.

BackgroundTicagrelor use during acute coronary syndromes demonstrated a decrease in all‐cause mortality in the PLATO (Platelet Inhibition and Patient Outcomes) trial. This effect has been attributed to a non–platelet‐derived improvement in endothelial function. The aim of this study was to determine differences in the number of endothelial progenitor cells and/or circulating endothelial cells found in peripheral blood in patients treated with either ticagrelor or clopidogrel during non–ST‐segment–elevation myocardial infarction.Methods and ResultsIn this multicenter, randomized study (NCT02244710), patients were considered for inclusion after non–ST‐segment–elevation myocardial infarction whenever they were P2Y12‐inhibitor naïve. Ticagrelor and clopidogrel were allocated at a 1:1 ratio. Blood samples for determining endothelial progenitor cells and circulating endothelial cells were extracted before the antiplatelet loading dose, 48 hours after presentation of index symptoms, and 1 month after the event. A multichannel cytometer was used for optimal cell characterization. A total of 96 patients fulfilled the inclusion criteria. Circulating endothelial cell levels corrected by white blood cells were as follows at baseline, 48 hours, and 1 month: 44 (28–64), 50 (33–63), and 38 (23–62) cells/mL, respectively, for clopidogrel and 38 (29–60), 45 (32–85), and 35 (24–71) cells/mL, respectively, for ticagrelor (P=0.6). Endothelial progenitor cell levels were 29 (15–47), 27 (15–33), and 18 (10–25) cells/mL, respectively, for clopidogrel and 20 (11–33), 22 (12–32), and 18 (11–29) cells/mL, respectively, for ticagrelor (P=0.9). No differences in intraindividual changes were found.ConclusionsPatients treated with ticagrelor during non–ST‐segment–elevation myocardial infarction, in comparison to clopidogrel, showed similar levels of endothelial progenitor cells and circulating endothelial cells. These data suggest that the endothelial protective effect mediated by ticagrelor is not related to bone marrow physiology modulation.Clinical Trial RegistrationURL: https://www.clinicaltrials.gov. Unique identifier: NCT02244710.

Revascularization and endothelial progenitor cells in stroke.

Stroke is one of the leading causes of death and disability worldwide. Tremendous improvements have been achieved in the acute care of stroke patients with the implementation of stroke units, thrombolytic drugs, and endovascular trombectomies. However, stroke survivors with neurological deficits require long periods of neurorehabilitation, which is the only approved therapy for poststroke recovery. With this scenario, more treatments are urgently needed, and only the understanding of the mechanisms of brain recovery might contribute to identify new therapeutic agents. Fortunately, brain injury after stroke is counteracted by the birth and migration of several populations of progenitor cells towards the injured areas, where angiogenesis and vascular remodeling play a key role providing trophic support and guidance during neurorepair. Endothelial progenitor cells (EPCs) constitute a pool of circulating bone-marrow derived cells that mobilize after an ischemic injury with the potential to incorporate into the damaged endothelium, to form new vessels, or to secrete trophic factors stimulating vessel remodeling. The circulating levels of EPCs are altered after stroke, and several subpopulations have proved to boost brain neurorepair in preclinical models of cerebral ischemia. The goal of this review is to discuss the current state of the neuroreparative actions of EPCs, focusing on their paracrine signaling mechanisms thorough their secretome and released extracellular vesicles.

Circulating Angiogenic T Cells Are Increased in Lupus Nephritis Patients.

BackgroundPatients with systemic lupus erythematosus (SLE), especially with lupus nephritis (LN), undergo vascular damage and repair during the course of the disease. Since the recently identified angiogenic T cells (Tang) are involved in endothelial repair coupled with endothelial progenitor cells (EPCs), this study investigated the circulating Tang cells in LN patients and their potential correlations with disease features.Material/MethodsCirculating Tang cells and EPCs were assessed by flow cytometry in peripheral blood samples from 67 SLE patients; of these, 32 had LN and 30 were matched healthy controls (HCs). The plasma levels of interleukin IL-17, IL-8, and vascular endothelial growth factor (VEGF) were quantified by immunoassays.ResultsThe percentage of circulating Tang cells in LN patients was significantly increased as compared to the non-LN patients and HCs, and they were positively correlated with the level of EPC and VEGF. Additionally, circulating Tang cell percentages were positively correlated with the extent of proteinuria in LN patients.ConclusionsThe increased levels of circulating Tang cells in LN patients might play a role in the balance of endothelium dysfunction in these patients.

Effects of SGLT2 Inhibitors on Circulating Stem and Progenitor Cells in Patients With Type 2 Diabetes.

Reduction in the levels of circulating stem cells (CSCs) and endothelial progenitor cells (EPCs) predicts development or progression of microangiopathy and macroangiopathy in patients with type 2 diabetes (T2D). We tested whether treatment with sodium glucose cotransporter-2 (SGLT2) inhibitors affected the levels of CSCs and EPCs. A randomized trial of dapagliflozin vs placebo with open-label extension, and an open-label observational study of empagliflozin treatment. Tertiary referral diabetes outpatient clinic. Patients with T2D aged 18 to 75 years. Dapagliflozin at 10 mg vs placebo (n = 31); empagliflozin at 10 mg (n = 15). We measured CSCs (CD34+) and EPCs (CD34+KDR+) by flow cytometry at baseline, at 12 weeks, and after the extension period. After 12 weeks, CSCs declined nonsignificantly in the dapagliflozin group, remained stable in the placebo group, and the change from baseline was not significantly different between the two groups. EPCs declined nonsignificantly in the dapagliflozin group, increased nonsignificantly in the placebo group, and the change from baseline was significantly different between the two groups. After an open-label extension period of about 1.5 years, CSCs remained stable over time, whereas EPCs significantly increased in patients who received dapagliflozin. In all patients, irrespectively of treatment, EPCs increased significantly from baseline to the end of observation, concomitantly with improvement in HbA1c. In a cohort of 15 patients who received open-label empagliflozin for 12 weeks, CSCs declined nonsignificantly, whereas EPCs remained stable. SGLT2 inhibitors do not significantly increase CSCs or EPCs. Thus, cardiovascular protection by SGLT2 inhibitors may not directly involve stem/progenitor cells.