Endothelial Progenitor Cells Levels Research Articles

Abstract TP117: Endothelial Progenitor Cells in Acute Stage of Ischemic and Hemorrhagic Stroke

Introduction: Endothelial progenitor cells (EPC) play an important role in the regeneration of the nervous tissue, blood-brain barrier stabilization and in neovascularization of blood vessels damaged by stroke. The aim of the study was to assess the level of EPC in patients with acute cerebral stroke due to cerebral microangiopathy and the potential dependence with the clinical condition, radiological image and prognosis, both in the ischemic and the haemorrhagic stroke. Methods: 66 patients with lacunar ischemic stroke were included in the prospective study, 38 patients with the “loco typico” haemorrhagic stroke and 22 from the control group without acute/chronic cerebral circulatory disorders. The level of EPC was determined using flow cytometry and identified with the immune-phenotype CD45–, CD34+, CD133+ on the 1 st and 8 th day of stroke. Results: It has been shown a significantly higher level of EPC on the 1 st day of stroke (regardless of aetiology) compared to the control group (med. 17,75 cells/ul (0-488 cells/ul) vs 5,24 cells/ul (0-95 cells/ul); p=0.0006). The level of EPC on day 1 and 8 was correlated with the subgroup of patients with haemorrhagic stroke. A significant correlation was found between the volume of the haemorrhagic focus on the 1 st day and the level of EPC (R= -0.3378, p=0.0471) and the degree of regression of the haemorrhagic focus and the level of EPC (R=-0.3896, p=0.0367). Conclusions: The study showed that endothelial progenitor cells are an early marker of cerebral vascular damage, both in ischemic and haemorrhagic stroke. The research highlights, for the first time, the relationship between the level of EPC and the degree of regression of a haemorrhagic focus. However the prognostic value of EPC for clinical condition and prognosis of stroke patients was not found in the study.

Clinical significance of endothelial progenitor cells in patients with liver cirrhosis with or without hepatocellular carcinoma.

The role of endothelial progenitor cells in patients with cirrhosis has seldom been investigated. This study was conducted to assess the clinical significance of circulating endothelial progenitor cells in patients with liver cirrhosis with or without hepatocellular carcinoma. A blood sample was collected once from patients with cirrhosis alone (n = 34) or cirrhosis and hepatocellular carcinoma (n = 46) and healthy controls (n = 27) for assessing levels of endothelial progenitor cells and vascular endothelial growth factor. Blood cells staining positive for CD34/CD133/KDR using flow cytometry were characterized as endothelial progenitor cells. Plasma vascular endothelial growth factor was quantified by ELISA. The levels of CD34/KDR-positive endothelial progenitor cells, CD133/KDR-positive endothelial progenitor cells, and vascular endothelial growth factor were higher in patients with cirrhosis ± hepatocellular carcinoma than in healthy controls (P = 0.017, P < 0.001 and P < 0.001, respectively). The levels of endothelial progenitor cells and vascular endothelial growth factor did not show statistical difference according to Child-Turcotte-Pugh class. There was a moderately significant correlation between vascular endothelial growth factor levels and hepatocellular carcinoma stage (ρ = 0.464, P = 0.001). Smoking, ascites, and portal vein thrombosis were independently related to lower levels of circulating CD34/KDR-positive endothelial progenitor cells, higher levels of CD133/KDR-positive endothelial progenitor cells, and higher levels of vascular endothelial growth factor, respectively (P = 0.041, P = 0.023, and P < 0.001, respectively). Circulating endothelial progenitor cells and plasma vascular endothelial growth factor levels were higher in patients with liver cirrhosis ± hepatocellular carcinoma compared to healthy controls. The increase in endothelial progenitor cells and vascular endothelial growth factor may have a possible role in the development of complications, especially ascites and portal vein thrombosis, or in progression of hepatocellular carcinoma.

Cardiovascular risk in patients with plaque psoriasis and psoriatic arthritis without a clinically overt cardiovascular disease: the role of endothelial progenitor cells.

Psoriasis is an autoimmune, chronic disease determined by environmental and genetic factors. The occurrence of psoriasis is accompanied by metabolic diseases, cardiovascular diseases (CVD) and depression, disturbances on interpersonal interactions and a tendency towards social isolation. Regardless of the form of psoriasis and the severity of the disease, early arterial lesions are recorded in arterial vessels of patients. Nevertheless, the chance of CVD is higher in the population of patients with severe psoriasis than in patients with mild to moderate psoriasis. The correlation between the presence of atherosclerotic plaque and psoriatic plaque is partially explained by: (1) a similar inflammatory pathway – via the T helper cells, (2) impaired angiogenesis, and (3) endothelial dysfunction. In the considered tests, the diagnostic tools used showed a reduced level of endothelial progenitor cells in the circulation of patients with psoriasis. Endogenous angiopoietin stimulation in patients with psoriasis leads to deterioration of endothelial regeneration, atherosclerosis which secondarily contributes to the progression of heart failure. Clinical and experimental data confirm the potential of immunomodulatory methods to combat both autoimmune and cardiovascular diseases through the use of immunosuppressive drugs. Full understanding of the way in which CVD develops in patients with autoimmune diseases would enable the implementation of targeted cell therapy allowing the quality and life expectancy of patients to be improved. Modern cellular diagnostic tools allow the use of highly specific biomarkers, which in the near future will enable a reduction in morbidity and mortality due to CVD.

Low-Energy Shockwave Treatment Promotes Endothelial Progenitor Cell Homing to the Stenotic Pig Kidney

Endothelial progenitor cells (EPCs) patrols the circulation and contributes to endothelial cell regeneration. Atherosclerotic renal artery stenosis (ARAS) induces microvascular loss in the stenotic kidney (STK). Low-energy shockwave therapy (SW) can induce angiogenesis and restore the STK microcirculation, but the underlying mechanism remains unclear. We tested the hypothesis that SW increases EPC homing to the swine STK, associated with capillary regeneration. Normal pigs and pigs after 3 wk of renal artery stenosis were treated with six sessions of low-energy SW (biweekly for three consecutive weeks) or left untreated. Four weeks after completion of treatment, we assessed EPC (CD34+/KDR+) numbers and levels of the homing-factor stromal cell-derived factor (SDF)-1 in the inferior vena cava and the STK vein and artery, as well as urinary levels of vascular endothelial growth factor (VEGF) and integrin-1β. Subsequently, we assessed STK morphology, capillary count, and expression of the proangiogenic growth factors angiopoietin-1, VEGF, and endothelial nitric oxide synthase ex vivo. A 3-wk low-energy SW regimen improved STK structure, capillary count, and function in ARAS+SW, and EPC numbers and gradients across the STK decreased. Plasma SDF-1 and renal expression of angiogenic factors were increased in ARAS+SW, and urinary levels of VEGF and integrin-1β tended to rise during the SW regimen. In conclusion, SW improves ischemic kidney capillary density, which is associated with, and may be at least in part mediated by, promoting EPCs mobilization and homing to the stenotic kidney.

Circulating stem cells and cardiovascular outcomes: from basic science to the clinic.

The cardiovascular and haematopoietic systems have fundamental inter-relationships during development, as well as in health and disease of the adult organism. Although haematopoietic stem cells (HSCs) emerge from a specialized haemogenic endothelium in the embryo, persistence of haemangioblasts in adulthood is debated. Rather, the vast majority of circulating stem cells (CSCs) is composed of bone marrow-derived HSCs and the downstream haematopoietic stem/progenitors (HSPCs). A fraction of these cells, known as endothelial progenitor cells (EPCs), has endothelial specification and vascular tropism. In general, the levels of HSCs, HSPCs, and EPCs are considered indicative of the endogenous regenerative capacity of the organism as a whole and, particularly, of the cardiovascular system. In the last two decades, the research on CSCs has focused on their physiologic role in tissue/organ homoeostasis, their potential application in cell therapies, and their use as clinical biomarkers. In this review, we provide background information on the biology of CSCs and discuss in detail the clinical implications of changing CSC levels in patients with cardiovascular risk factors or established cardiovascular disease. Of particular interest is the mounting evidence available in the literature on the close relationships between reduced levels of CSCs and adverse cardiovascular outcomes in different cohorts of patients. We also discuss potential mechanisms that explain this association. Beyond CSCs' ability to participate in cardiovascular repair, levels of CSCs need to be interpreted in the context of the broader connections between haematopoiesis and cardiovascular function, including the role of clonal haematopoiesis and inflammatory myelopoiesis.

The relationship between endothelial progenitor cells and pulmonary arterial hypertension in children with congenital heart disease

BackgroundPulmonary arterial hypertension (PAH) caused by congenital heart disease (CHD) is very common in clinics. Some studies have shown that PAH is related to the number of endothelial progenitor cells (EPCs), but there is no report on the relationship between PAH and the number of EPCs in children with CHD.MethodsIn this study, a total of 173 cases with CHD (from 0 to 6 years old) were collected. According to the mean pulmonary arterial pressure (mPAP) measured by right heart catheterization, these cases were divided into PAH groups (including high PAH group, mPAP> 25 mmHg, n = 32, and the middle PAH group, 20 mmHg ≤ mPAP≤25 mmHg, n = 30) and non-PAH group (mPAP< 20 mmHg, n = 111). Peripheral blood was taken for flow cytometry, and the number of EPCs (CD133+/KDR+ cells) was counted. The number of EPCs /μL of peripheral blood was calculated using the following formula: EPCs /μL = WBC /L × lymphocytes % × EPCs % × 10− 6.ResultsThe median EPCs of the non-PAH group, middle PAH group and high PAH group is 1.86/μL, 1.30 /μL and 0.98/μL, respectively. The mPAP decreases steadily as the level of EPCs increases (P < 0.05). After adjustment of gender, age and BMI, the number of EPCs was significantly associated with a decreased risk of high PAH (OR = 0.37, 95% CI: 0.16–0.87, P < 0.05). However, EPCs was not significantly associated with middle PAH (P > 0.05).ConclusionThe findings revealed that the EPCs and high PAH in patients with CHD correlate significantly and EPCs may become an effective treatment for PAH in patients with CHD. EPCs may be a protective factor of high PAH for children with CHD.

Fluctuations in circulating endothelial progenitor cell levels and acute cardiac graft rejection.

Endothelial progenitor cells (EPCs) in nontransplant settings have reparative properties. However, their role in heart transplantation (HT) is not well defined. The aim of this study was to prospectively evaluate changes in EPC levels in relation to post‑HT rejection. EPC levels were measured in 27 HT recipients for 6 months after HT. Acute cellular rejection (ACR) or antibody‑mediated rejection (AMR) were assessed by right ventricular endomyocardial biopsy. ACR and AMR were observed in 7 (25.9%) and 6 (22.2%) patients, respectively. The ACR status at 1 month post‑HT did not differ with respect to EPC immediately post‑HT. At 1 month post‑HT in patients without ACR or AMR, EPC levels were significantly reduced compared with the measurements immediately post‑HT (P <0.001). On further follow‑up, EPC levels were similar regardless of the rejection events. Nonetheless, greater changes (coefficient of variation) in EPClog (logarithmic transformation) were associated with the risk of AMR or ACR compared with those without any rejection event (median [lower-upper quartile], 15 [13-18] vs 8 [5-13]; P = 0.02 and 22 [14-26] vs 8 [5-13]; P = 0.01, respectively). The receiver operating characteristic curve showed that the coefficient of variation of EPClog of 12 was the optimal cutoff value for the prediction of rejection (area under the curve = 0.85). Higher levels were associated with greater risk of ACR or AMR (P <0.005). Early reduction of EPC levels was related to a lower risk of ACR or AMR. Greater changes of EPC‑levels during follow‑up were associated with a significantly higher risk of rejection.

Patients with high levels of circulating endothelial progenitor cells (EPC) following at least three months of anticoagulation for unprovoked venous thromboembolism (VTE) are at low risk of recurrent VTE—Results from the ExACT randomised controlled trial.

BackgroundThere is clinical need for a laboratory biomarker to identify patients who, following an unprovoked venous thrombosis (VTE), are at low VTE recurrence risk and can discontinue anticoagulation after a limited treatment duration (3–6 m). This secondary analysis of the ExACT study aimed to evaluate whether quantitation of peripheral blood endothelial progenitor cells (EPCs) could improve prediction of VTE recurrence risk. MethodsThe ExACT study was a non-blinded, multicentre RCT comparing extended vs discontinued anticoagulation following a first unprovoked VTE. Adult patients were eligible if they had completed ≥3 months anticoagulation and remained anticoagulated. The primary outcome was time to first recurrent VTE from randomisation. Blood samples were taken at baseline and results correlated with clinical outcome over 2 years follow up. (Trial registration: ISRCTN:73819751 and EUDRACT:2101-022119-20) Findings281 patients were recruited, randomised (between July 2011 and February 2015) and followed up for 24 months (Male:Female 2:1, mean age 63). Of these, 273 patients were included in the final analysis. Blood samples were received at baseline for Full Blood Count(n = 216), d-dimers(n = 205) and endothelial progenitor cell (EPC) quantitation by flow cytometry(n = 193). VTE recurrence was lower in the extended vs discontinued anticoagulation arms (5% vs 23%, HR 0.20(95%CI:0.09–0.46,p < 0.001)). Level of EPCs were lower in patients who later developed VTE recurrence (43.41 ± 7.69 cells/ml vs 87.1 ± 7.15 cells/ml, p = 0.02). Survival free from VTE recurrence was significantly improved in patients with EPCs ≥ 100 cells/ml vs EPCs < 100 cells/ml (HR 0.10(95%CI:0.01–0.75,p = 0.025)). InterpretationIf confirmed, EPC quantitation may represent a novel biomarker that identifies patients at low VTE recurrence risk who are suitable for limited duration anticoagulation.

P750Role of circulating endothelial cells post-heart transplantation

Abstract Background The role of endothelial progenitor cells (EPC) in heart transplantation (HT) is not well defined. Thus, the aim of this study was to evaluate prospectively the dynamic changes of circulating EPC levels in relation to post-HT rejection risk. Methods There were 27 HT recipients who had EPC from peripheral blood quantified during 6 months follow-up after HT. Patients were monitored regularly, by right ventricular endomyocardial biopsy assessment, for cellular rejection (ACR) defined as grade ≥2 or an antibody-mediated rejection (AMR) characterized by histopathological changes recorded as AMR1H. The primary end-point was acute rejection, either AMR or ACR. Results ACR and AMR were observed in 7 (25.9%) and 6 (22.2%) subjects respectively. EPC levels, after logarithmic transformation, immediately post-HT were alike regardless of ACR status, however patients with lower EPC were at risk of AMR at 1 month (Table 1). On the other hand patients with a significant reduction of EPC at 1 month post-HT compared with HT were less likely to have either ACR or AMR (p=0.0003). During longer post-HT observation (12 months) patients had similar EPC levels regardless of the rejection events. Dynamic changes in EPC levels are presented in figure. Nonetheless, greater changes in EPC expressed by coefficient of variation were associated with the risk of either AMR or ACR compared to the participants without rejection (mean [lower–upper quartile]) 15 [13–18] vs 8 [5–13]; p=0.02) and (22 [14–26] vs 8 [5–13]; p=0.01) respectively. EPC by rejection – 1st month following HT ACR (+) AMR (+) ACR (−) and AMR (−) p^ p p N=3 (mean± SD) N=4 (mean± SD) N=20 (mean± SD) ACR (+) vs ACR (−) and AMR (−) AMR (+) vs ACR (−) and AMR (−) EPC log HT 5.14±1.55 3.81±1.01 5.30±0.88 0.0325 0.97 0.025 EPC log M1 4.97±0.59 3.69±1.33 4.15±1.29 0.4160 0.55 0.78 Delta EPC log M1-HT -0.17±1.98* −0.12±1.30* −1.15±1.18# 0.2195 0.44 0.32 ACR – acute cellular rejection; AMR or – acute antibody-mediated rejection; EPC log – endothelial progenitor cells after logarithmic transformation; HT – within 24 hours post-transplantation; M1 – at 1-month post-transplantation; Delta EPC log M1-HT – difference in EPC log between M1 and HT. #p=0.0003 for the difference between M1 vs HT; *p=ns for the difference between M1 vs HT; ^pP – for the difference among the groups. Changes in EPC level post-HT Conclusions Early reduction of EPC levels was predictive of a lower risk of ACR or AMR. Greater dynamic changes of EPC during 6 months of observation were associated with a higher risk of rejection suggesting an important role of EPC in the pathological processes post-HT. Thus our findings suggest significant role of EPC post-HT with respect to rejection status. Acknowledgement/Funding Intramural research grant from the Institute of Cardiology

P4712Hyperbaric oxygen therapy enhanced circulating levels of endothelial progenitor cells and angiogenesis biomarkers, blood flow in ischemic area in patients with peripheral arterial occlusive disease

Abstract Background Arterial atherosclerotic occlusive syndrome remains the leading cause of mortality and morbidity worldwide. Peripheral arterial occlusive disease (PAOD) is a manifestation of atherosclerosis in the lower extremities. In our previous preclinical study, hyperbaric oxygen (HBO) therapy improved ischemic PAOD mainly through an increase of vascular wall permeability and recruiting endothelial progenitor cells (EPCs) to enhance the angiogenesis and blood flow in the ischemic area. Purpose 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 area in patients with peripheral arterial occlusive disease (PAOD). Methods 57 consecutive patients with PAOD undergoing the HBO therapy (3 atm for 2h/each time) were prospectively enrolled into the present study. The venous blood sampling was drawn for assessing the circulating levels of EPCs and soluble angiogenesis factors prior to and during five times of HBO therapy. Additionally, skin perfusion pressure (SPP), an indicator of blood flow at ischemic area, was measured by moorVMS-PRES. Results The results demonstrated that the circulating levels of EPCs (CD34+/CD133+/CD45dim, CD31+/CD133+/CD45dim, CD34+) and soluble angiogenesis factors (VEGF/SDF-1α/HGF/FGF) were significantly increased in post-HBO therapy than in pre-HBO therapy (all p&lt;0.01). Additionally, Matrigel assay exhibited that the angiogenesis was significantly increased in post-HBO therapy than prior to the therapy (p&lt;0.001). Furthermore, the SPP was significantly increased in ischemic area (i.e., plantar foot and mean SPP of the ischemic foot) in post-HBO therapy than in pre-HBO therapy (all p&lt;0.01). Importantly, the HBO therapy did not show any complication and all the patients were uneventfully discharged without amputation. Conclusions HBO therapy augmented circulating levels of EPCs and angiogenesis factors as well as improved the blood flow in the ischemic area. Acknowledgement/Funding Kaohsiung Chang Gung Memorial Hospital, Taiwan Society of Stem Cell Research

P1960Endothelial progenitor cells are associated with cardiovascular outcome in patients with peripheral artery disease

Abstract Background and introduction Endothelial dysfunction and associated cells are an important cornerstone in the development and progression of peripheral artery disease (PAD). Endothelial progenitor cells (EPC) are released from the bone marrow and have exhibited the potential for cardiovascular repair. Higher EPC levels have been linked to longer event-free survival in coronary artery disease. Similar evaluation of EPC on mortality in PAD is lacking. Purpose The current study aimed to evaluate the possible association between EPC levels and mortality in PAD patients. Methods EPC were measured in 367 PAD patients (age 69.22±10.3, 66.5% male, Fontaine stage I-II) by flow cytometry using the cell surface marker CD34+ and CD309+. Patients were followed for seven years to assess all cause and cardiovascular mortality. Patients were categorized into quartiles according to EPC levels for further analyses. Statistics included Kaplan-Meier and Cox regression. Results 89 patients died over the observation period. ICD-codes indicated a cardiovascular cause in 58 patients. The group with the highest count of EPC showed a trend towards higher all-cause mortality (p=0.070) and a significant association with cardiovascular mortality (p=0.002). Multivariable adjustment for age, c-reactive protein, systolic blood pressure, renal function (creatinine and urinary albumin), low density lipoprotein cholesterol, HbA1c, and smoking status revealed the EPC quartile to be an independent risk factor for cardiovascular mortality (p=0.016). Conclusion Increased levels of CD34+CD309+ cells are independently associated with long-term cardiovascular mortality in PAD patients.

3045Role of osteogenic circulating endothelial progenitor cells in dissemination of large arterial calcification in rheumatoid arthritis

Abstract Background Rheumatoid arthritis is associated with both abnormal bone metabolism and atherogenesis but mechanistic links were missing. Aim This study aimed to investigate the role of osteocalcin (OCN)-expressing circulating endothelial progenitor cells (EPC)s in the severity and dissemination of systemic arterial calcifications in rheumatoid arthritis. Methods We performed flow cytometry studies in 145 consecutive patients with rheumatoid arthritis to determine osteogenic circulating levels of OCN-positive (OCN+) CD34+KDR+ and OCN+CD34+, versus conventional early EPC CD34+CD133+KDR+. Total calcium load of the thoracic aorta (ascending plus descending) and the carotid arteries were assessed by non-contrast computed tomography (CT) and contrast CT angiography. Results Osteogenic EPCs OCN+CD34+KDR+ (P=0.002) and OCN+CD34+ were strikingly associated with the clustered presence of aortic and carotid calcification (P=0.002 and 0.001 respectively, Figure). Multivariable analyses revealed that circulating OCN+CD34+KDR+ (B=14.4 [95% CI 4.0 to 24.8], P=0.007) and OCN+CD34+ (B=9.6 [95% CI 4.9 to 14.3], P&lt;0.001) remained independently associated with increased aortic calcium load. OCN+CD34+ EPC (B=0.8 [95% CI 0.1 to 1.5], P=0.023), but not OCN+CD34+KDR+ EPC (B=1.2 [95% CI −0.2 to 2.6], P=0.09) was further independently associated with carotid calcium load. In comparison, conventional early EPC CD34+CD133+KDR+ had no significant association with aortic or carotid calcium load (P=0.46 and 0.88, respectively). Conclusions Circulating level of osteogenic EPC is associated with promulgated aortic and carotid calcification in patients with rheumatoid arthritis, suggesting a potential mechanistic role of the bone-vascular axis in pro-atherogenicity of rheumatic diseases. Acknowledgement/Funding General Research Fund, Hong Kong Research Grants Council

Dexamethasone impairs neurofunctional recovery in rats following traumatic brain injury by reducing circulating endothelial progenitor cells and angiogenesis

The administration of glucocorticoids (GCs) after traumatic brain injury (TBI) is controversial. Clinical evidence reveals the deleterious effects of GCs, but the mechanism remains unclear. Previous studies indicate that GCs impair wound healing by affecting endothelial progenitor cell (EPC) function and inhibiting angiogenesis after skin injury. Thus, we hypothesize that the central deleterious effect of GCs is associated with reduced EPCs and angiogenesis after TBI. Using a controlled cortical impact model, we examined the dynamic changes in circulating EPCs and in the regional microcirculation within 14 days of TBI by flow cytometry analysis and contrast-enhanced ultrasound, respectively. The modified neurological severity score (mNSS) and Morris water maze assay were used to assess neurological recovery. Angiogenesis and hippocampal neuron counts were assessed using immunohistochemistry analysis and hematoxylin and eosin staining 14 days after TBI. Compared with the TBI control group, dexamethasone treatment significantly reduced the number of circulating EPCs on days 1, 3, 7 and 14 (P < 0.05); decreased the number of CD31+ cells, the peak intensity and the number of hippocampal neurons on day 14 (P < 0.05); increased the latency on days 12 and 13 (P < 0.05); and reduced the percentage of time spent in the goal quadrant (P < 0.05) on day 14. Similarly, dexamethasone increased the mNSS on days 7 and 14 (P < 0.05). A strong correlation was observed between these results at 14 days after TBI (r = 0.815–0.892, P < 0.05). These data indicate that DEX inhibits the mobilization of EPC levels and angiogenesis around the lesion after TBI, which may contribute to neuronal cell loss and impaired neurofunction.

Circulating hematopoietic stem cells, endothelial progenitor cells and cancer stem cells in hepatocellular carcinoma patients: contribution to diagnosis and prognosis

Background and aim: Circulating hematopoietic stem cells (HSCs), circulating endothelial progenitor cells (EPCs) and cancer stem cells (CSCs) contribute to tumor development and progression and can predict patient outcome. The aim of this study was to investigate the frequency of circulating HSCs, EPCs and CSCs in the peripheral blood of patients with hepatocellular carcinoma (HCC) and to explore their potential prognostic significance for HCC patients.Methods: The study included 30 HCC patients and 20 healthy controls. The HSCs and EPCs were enumerated with CD45, CD34, CD133, CD144 markers, while CSCs were enumerated with CD45, CD44, CD133 markers using flow cytometry.Results: The mean percentages of circulating HSCs were significantly lower in HCC patients than the controls (p = .001), whereas the mean percentages of EPCs within the HSCs subpopulation were significantly higher in the HCC patients than the controls (p = .002). The absolute count of CSCs within 100,000 peripheral blood mononuclear cells was 23.5 ± 3.4 in the HCC patients. Also, the mean percentages of circulating HSCs, EPCs and the number of CSCs were significantly increased in patients with multiple hepatic focal lesions than in patients with a single hepatic focal lesion. Both circulating HSCs and EPCs showed significant positive correlation with the level of AFP and with the numbers of CSCs. In the meantime, the numbers of CSCs revealed significant direct correlation with ALT, AST and AFP levels. The one-year overall survival (OS) of the patients was 77.5%. High levels of CSCs, HSCs and EPCs at diagnosis were all associated with worse outcome for the HCC patients.Conclusions: Significant changes in the levels of the circulating HSCs, EPCs and CSCs occur in HCC. These changes help the diagnosis and the prediction of HCC outcome, as higher levels of these cells are associated with worse OS.

Evaluation of related variables on endothelial progenitor cells in first transient ischemic attack

Background and aims: In a transient ischemic attack (TIA), the activation of the endothelial progenitor cells (EPCs) has a prominent role in the formation of collateral vessels. The aim of this study was to evaluate the role of effective variables (e.g., hypertension, diabetes, hyperlipidemia, cardiovascular diseases, a family history of cardiovascular diseases, and statin therapy on the level of EPCs in TIA. Methods: Thirty patients suffering from the first attack of TIA, without having a history of acute cerebral injury, surgery or trauma, and blood disorders were enrolled in this cross-sectional study. Then, flow cytometry was utilized to estimate the level of EPCs CD34 and CD309 and the results were evaluated based on the t test or the Mann-Whitney test. Finally, the Pearson or Spearman correlation was used to establish the relationship between the variables. The level of P&lt;0.05 was considered statistically significant in this study. Results: The mean±SD number of CD309 in patients with hyperlipidemia was less than those with no hyperlipidemia (3.35±2.77 vs. 5.59±3.85, P=0.02) and diabetic patients had a significantly higher number of CD309 compared to non-diabetics (6.14±4.89 vs, 3.5± 3.49, P=0.05). Conversely, the mean number of CD34 in groups with or without the studied variables was not statistically significant. The results further revealed that the average total of CD309 and CD34 was significantly lower in patients with hyperlipidemia as compared to those with no sign of hyperlipidemia (9.44± 3.05 vs. 6.67±4.6, P=0.02). Using logistic regression, the intended variables demonstrated no significant effects on endothelial cells, and the relationship between age and the number of progenitor cells was not significant. Conclusion: In our study, only hyperlipidemia acted as a factor influencing the numbers of EPCs. Therefore, more studies with larger sample sizes are required to discover the role of these variables on progenitor cells in TIA.

Vascular endothelium function among male carriers of BRCA 1&2 germline mutation.

Background: Breast cancer susceptibility genes 1&2 (BRCA1&2) mutations hinder DNA-repair. Germline mutations in these genes are known to cause cancer; however, they may have other consequences. In this study we evaluated for the first time, the effect of the BRCA mutations on the vascular endothelium of young healthy males. Results: The study included 82 participants (53 BRCA mutation positive-carriers and 29 negative-carriers). Subjects mean age was 40. There were no significant differences in the baseline characteristics of the two groups. BRCA-carriers had significantly higher levels of EPCs (fraction of CD34+/VEGF or CD133+/VEGF positive-cells) compared to non-carriers of the mutation (median 6.78[1.96,14.48]% vs. 1.46[0.65,6.18]%, p < 0.001, and median 7.17[1.70,16.69]% vs. 1.54[0.85,5.10]%, p < 0.001, respectively). This difference remained consistent after multivariate adjustment. We did not identify differences in endothelial function, endothelial damage markers and EPCs activity between the two groups.Methods: This was a prospective cohort study to test the association between BRCA status and possible endothelial alterations. The Study population included males, 18-50 years, with no cardiovascular morbidity, who were referred for BRCA screening. We tested the endothelial system by: Endothelial progenitor cells (EPC) production, endothelial function (EndoPAT2000), endothelial damage and related hormonal levels. We stratified the cohort by germline BRCA status and compared measurements between BRCA mutation positive- and negative-carriers. Conclusions: Male BRCA1&2 mutation positive-carriers had increased level of EPCs which may reflect a subclinical accumulative endothelial damage. These novel findings suggest that the effect of mutations in BRCA is not limited to increased cancer risk, but may affect the cardiovascular system.

Osteoprotegerin (OPG) Promotes Recruitment of Endothelial Progenitor Cells (EPCs) via CXCR4 Signaling Pathway to Improve Bone Defect Repair

BackgroundThe aim of this study was to investigate the effect of using osteoprotegerin (OPG) to treat bone defects mediated by endothelial progenitor cell (EPC) recruitment and migration through the CXCR4 signaling pathway.Material/MethodsThe EPCs extracted from human peripheral blood were cultured in vitro and the expression of CXCR4 and its downstream p-AKT was monitored by the Western blot analysis after OPG treatment. Using the scratch wound healing test and Transwell assay, we assessed the variables influencing the effect of OPG on EPCs after pre-treatment with CXCR4 blocker (AMD3100) and PI3K blocker (Ly294002). After 4 weeks, the bone defect repair condition was estimated via micro-CT and staining with HE and Masson trichrome. Then, immunofluorescence staining was performed to assess angiogenesis in bone defects, while the expression of EPC marker and vascular endothelial growth factor receptor 2 (VEGFR2) was detected by immunohistochemical staining.ResultsThe EPCs treated with OPG had increased levels of CXCR4 and p-AKT. Moreover, the difference in EPC levels among groups in the scratch wound healing experiment and migration experiment indicated that the OPG treatment promoted cell migration and AMD3100 and LY294002 inhibited the function of OPG. In addition, OPG promoted angiogenesis and repair of bone defect in rats, and these effects were abolished by AMD3100 and LY294002 administration.ConclusionsOPG enhanced the proliferation and migration of EPCs through the CXCR4 pathway and promoted angiogenesis and bone formation at bone defect sites.

Circulating endothelial and progenitor cells in age-related macular degeneration.

To evaluate circulating endothelial and circulating progenitor cells as biomarkers in age-related macular degeneration patients (both exudative and atrophic forms) in order to establish the possible clinical implication of their assessment. We have enrolled 44 age-related macular degeneration patients: 22 patients with a recently diagnosed exudative (neovascular) form (Group A) and 22 patients with an atrophic (dry) form (Group B). The control group consisted of 22 age and sex-matched healthy subjects (Group C). The number of circulating endothelial progenitor cells (CD34+/KDR+, CD133+/KDR+, and CD34+/KDR+/CD133+), circulating progenitor cells (CD34+, CD133+, and CD34+/CD133+), and circulating endothelial cells were determined in the peripheral venous blood samples by flow cytometry. Neovascular age-related macular degeneration patients were evaluated at baseline and 4 weeks after a loading phase of three consequent intravitreal injections of ranibizumab. Comparing age-related macular degeneration patients with the control group, endothelial progenitor cell and circulating progenitor cell levels were not significantly different, while age-related macular degeneration patients showed significantly higher levels of circulating endothelial cells (p = 0.001). Anti-vascular endothelial growth factor treatment with intravitreal ranibizumab was associated with a significant reduction of endothelial progenitor cell levels, with no significant influence on circulating progenitor cells and circulating endothelial cells. We reported higher levels of circulating endothelial cells in age-related macular degeneration patients in comparison with the control group, thereby supporting the hypothesis of an involvement of endothelial dysregulation in the age-related macular degeneration and a reduction of the endothelial progenitor cell level in neovascular age-related macular degeneration patients after three intravitreal injections of ranibizumab.

Effects of Sitagliptin on the Coronary Flow Reserve, Circulating Endothelial Progenitor Cells and Stromal Cell-derived Factor-1alpha.

Objective Circulating endothelial progenitor cells (EPCs) are regulated by stromal cell-derived factor-1alpha (SDF-1α) and are reduced in type 2 diabetes mellitus (DM). SDF-1α is a substrate of dipeptidyl-peptidase-4 (DPP-4), so we investigated whether or not DPP-4-inhibitors modulate EPC levels in type 2 DM patients with coronary artery disease (CAD). Methods Thirty patients with CAD and type 2 DM treated using an ordinary regimen were enrolled. EPC and SDF-1α levels were compared between those receiving additional 24-week treatment with a DPP-4-inhibitor (n=11) and no additional treatment (n=19). We determined the HbA1c, 1.5-Anhydro-D-glucitol (1,5-AG), coronary flow reserve (CFR), brain natriuretic peptide (BNP), E/e', and circulating EPC proportion and SDF-1α levels at baseline and the end of follow-up. The CFR was assessed using a dual-sensor-equipped guidewire. The primary endpoints were changes in the EPC count, SDF-1α levels, and CFR from baseline to the end of follow-up. The secondary endpoints were changes in the HbA1c and 1,5-AG, which are useful clinical markers of postprandial hyperglycemia, as well as the BNP and E/e'. Results After the 6-month follow-up, compared with ordinary regimen subjects, the patients receiving a DPP-4-inhibitor showed no significant increase in the EPC proportion (−0.01±0.50 vs. 0.02±0.77%, p=0.87), SDF-1α level (−600.4±653.6 vs. −283.2±543.1 pg/mL, p=0.18), or CFR (0.0±0.2 vs. 0.1±0.6, p=0.20), whereas both the 1.5-AG level (2.4±4.6 vs. −0.7±2.5 μg/dL, p=0.07) and HbA1c (−0.8±1.8 vs. 0.0±0.7%, p=0.02) were improved. There were no significant differences between the two groups in changes in the BNP and E/e'. Conclusion DPP-4 inhibition with sitagliptin did not increase or decrease the EPC proportion, SDF-1α level, or CFR, although the glycemic control was improved.

Dysfunctional stem and progenitor cells impair fracture healing with age.

Successful fracture healing requires the simultaneous regeneration of both the bone and vasculature; mesenchymal stem cells (MSCs) are directed to replace the bone tissue, while endothelial progenitor cells (EPCs) form the new vasculature that supplies blood to the fracture site. In the elderly, the healing process is slowed, partly due to decreased regenerative function of these stem and progenitor cells. MSCs from older individuals are impaired with regard to cell number, proliferative capacity, ability to migrate, and osteochondrogenic differentiation potential. The proliferation, migration and function of EPCs are also compromised with advanced age. Although the reasons for cellular dysfunction with age are complex and multidimensional, reduced expression of growth factors, accumulation of oxidative damage from reactive oxygen species, and altered signaling of the Sirtuin-1 pathway are contributing factors to aging at the cellular level of both MSCs and EPCs. Because of these geriatric-specific issues, effective treatment for fracture repair may require new therapeutic techniques to restore cellular function. Some suggested directions for potential treatments include cellular therapies, pharmacological agents, treatments targeting age-related molecular mechanisms, and physical therapeutics. Advanced age is the primary risk factor for a fracture, due to the low bone mass and inferior bone quality associated with aging; a better understanding of the dysfunctional behavior of the aging cell will provide a foundation for new treatments to decrease healing time and reduce the development of complications during the extended recovery from fracture healing in the elderly.