Percentage Of Endothelial Progenitor Cells Research Articles

Changes in endothelial microparticles and endothelial progenitor cells in obese patients in response to surgical stress.

Obese patients undergoing surgery are at increased risk of intraoperative and postoperative cardiovascular complications. The present study was designed to study the changes in endothelial microparticles, endothelial progenitor cells, and adipokines in obese patients in response to limb ischemia during knee surgery. This prospective study included seventy-four patients who underwent total knee arthroplasty. Patients were stratified in tertiles according to their body mass index. Flow cytometry was used for quantification and characterization of endothelial microparticles, endothelial progenitor cells, and adipokines. ELISA (enzyme-linked immunosorbent assay) was used to measure the adiponectin level. The number of endothelial microparticles was greater in obese compared with nonobese patients. The number of endothelial microparticles increased further immediately after surgery in all tertiles. Three days after surgery, endothelial microparticles returned to the basal preoperative level except in the most obese patients. The percentage of endothelial progenitor cells was lower in obese patients. Concentrations of adipokines increased after surgery, but the increase was more accentuated in obese patients. Obese patients present with a high number of endothelial microparticles, a low number of endothelial progenitor cells, and high levels of adipokines, with further increases in adipokines after surgery, suggesting an inflammatory condition that worsens after surgery and may affect endothelial repair.

Content of Endothelial Progenitor Cells in Autologous Stem Cell Grafts Predict Survival after Transplantation for Multiple Myeloma

Multiple myeloma (MM) is considered an incurable B cell malignancy, although many patients can benefit from high-dose therapy with autologous stem cell transplantation (ASCT) as a first-line treatment. In non-Hodgkin lymphoma (NHL), ASCT is usually performed after relapse with curative intent. Disease progression is often associated with increased angiogenesis, in which endothelial progenitor cells (EPC) may have a central role. Here, we investigated the clinical impact of EPC levels in peripheral blood stem cell (PBSC) autografts for MM and NHL patients who received ASCT. EPC were identified by flow cytometry as aldehyde dehydrogenasehi CD34+ vascular endothelial growth factor receptor 2+ CD133+ cells in both MM and NHL autografts. In MM, there was a positive correlation between EPC percentage and serum (s)-β2-microglobulin levels (r2 = .371, P = .002). Unlike for NHL patients, MM patients with high numbers of infused EPC (EPC cells per kilogram) during ASCT had significant shorter progression-free survival (PFS) (P = .035), overall survival (P = .044) and time to next treatment (P = .009). In multivariate analysis, EPC cells per kilogram was a significant independent negative prognostic indicator of PFS (P = .03). In conclusion, the presence of high number of EPC in PBSC grafts is associated with adverse prognosis after ASCT in MM.

Endothelial progenitor cells as cardiovascular surrogate markers in seropositive rheumatoid arthritis

Background Bone marrow-derived endothelial progenitor cells (EPCs) confer protection against atherosclerotic vascular damage, thereby reducing the cardiovascular (CV) risk. Hence, the depletion of EPCs in rheumatoid arthritis (RA) is associated with enhanced CV risk. Patients with seropositive RA have increased risk of CV morbidity and mortality. The aim of this study was to investigate the endothelial progenitor cell population in seropositive and seronegative RA patients and its potential relationships with disease variables and proinflammatory cytokines. Methods Forty adult RA patients were classified into seropositive (n = 20) and seronegative (n = 20) groups based on the presence of rheumatoid factor (RF). EPCs (CD34+/CD133+) quantified by flow cytometry and proinflammatory cytokines (TNF- α, IL-6 and IL-1) were measured using standard ELISA kits, and disease activity by DAS28, CRP, and ESR. Results EPCs were significantly reduced in total RA and seropositive patients compared to seronegative subjects (P <0.05). Levels of proinflammatory cytokines (TNF-α, IL-6, and IL-1) were significantly (P = 0.01) higher in seropositive patients as compared to seronegative but in total RA patients level of IL-6 and IL-1 were significantly (P <0.05) higher as compared to seronegative patients. Significant negative correlation was observed between percentage of EPCs and IL-1, TNF-α, and disease activity in seropositive patients, between RF and TNF-α in seropositive patients, and between EPCs and DAS 28 in total RA patients. Conclusion EPC depletion is inversely correlated with disease activity, RF, and proinflammatory cytokines in seropositive patients, suggesting the pivotal role of inflammation in depletion of EPCs. EPC may serve as a probable therapeutic target for preventing cardiovascular disease in seropositive RA.

Endothelial damage and vascular calcification in patients with chronic kidney disease.

Vascular calcification (VC) is a frequent complication of chronic kidney disease (CKD) and is a predictor of cardiovascular morbidity and mortality. In the present study, we investigated the potential involvement of endothelial microparticles (MPs) and endothelial progenitor cells (EPCs) in the generation of VC in CKD patients. The number of circulating EMPs is greater in patients with VC than without VC (307 ± 167 vs. 99 ± 75 EMPs/μl, P < 0.001). The percentage of EPCs is significantly lower in patient with VC than in patients without VC (0.14 ± 0.11% vs. 0.25 ± 0.18%, P = 0.002). The number of EPCs expressing osteocalcin (OCN) was higher in VC patients (349 ± 63 cells/100,000) than in non-VC patients (139 ± 75 cells/100,000, P < 0.01). In vitro, MPs obtained from CKD patients were able to induce OCN expression in EPCs from healthy donors; the increase in OCN expression was more accentuated if MPs were obtained from CKD patients with VC. MPs from CKD patients also induced OCN expression in vascular smooth muscle cells and fibroblasts. In CKD patients, the rise in endothelial MPs associated with a decrease in the number of EPCs, suggesting an imbalance in the processes of endothelial damage and repair in CKD patients, mainly those with VC. Our results suggest that EPCs, through OCN expression, may directly participate in the process of VC.

Compare of different pretreatment methods for early endothelial progenitor cells detection from peripheral blood of rabbit

Objective In order to find out the most convenient,economic,accurate pretreatment methods for early endothelial progenitor cells (EPCs) detection from peripheral blood,this article compared the detection result of density gradient centrifugation method and two kinds of red cells lysis methods.Methods Arterial blood of New Zealand rabbits stored in vacuum heparin containing tubes was pretreated by 3 kinds of method respectively.The first pretreated method used lymphocyte separation liquid density gradient centrifugation,the second method used flow cytometry cell hemolysin and the third method used red cells lysis solution.After that,Anti-Mouse CD3-allophycocyanin (APC),Anti-Mouse CD45-phycoerythrin (PE),Anti-Mouse CD133 (Prominin-1)-fluorescein isothiocyanate (FITC) were labeled to detect early EPCs.Results There was no significant different of percentage of early endothelial progenitor cells pretreated by 3 kinds of method (P ＞ 0.05).Of the three methods,flow cytometry cell hemolysin method was the most convenient method for using the least blood,processing liquid,vitro and Instrument,not easy to be effected and repeating easily.Conclusion Flow cytometry cell hemolysin method was the most convenient pretreatment method for test endothelial progenitor cells percentage from peripheral blood. Key words: Pretreatment ; Early endothelial progenitor cells ; Lysis ; Density gradient centrifugation

FRI0110 Epcs is A Determinant of Vascular Function and Atherosclerosis in As

BackgroundAnkylosing Spondylitis (AS) is an inflammatory disease associated with premature atherosclerosis.1 We hypothesized that depleted endothelial progenitor cells (EPCs), mediators of inflammation and Carotid intima media thickness (cIMT) are associated...

Decreased circulating endothelial progenitor cells as an early risk factor of subclinical atherosclerosis in systemic lupus erythematosus

Endothelial progenitor cells (EPCs) play an important role in vascular damage repair and it has been suggested that a decreased number of these cells is associated with increased subclinical atherosclerosis. Our study aim was to evaluate whether the number of circulating EPCs in patients with SLE is associated with subclinical atherosclerosis, the presence of cardiovascular (CV) risk factors and SLE-specific factors. Forty-six female SLE patients were included. At the time of each patient's appointment, CV risk factors, SLE-specific factors and EPCs were assessed in peripheral blood by flow cytometry. Simultaneously, atherosclerosis was assessed by measuring the carotid-femoral pulse wave velocity (PWV) by Doppler velocimetry, intima media thickness (IMT) and carotid plaque by B-mode US scanning. Patients were classificated according to PWV following the reference values adjusted by age and blood pressure published by the European Society of Cardiology. Patients with pathological values of PWV showed a significant decrease of circulating EPC percentage compared with normal PWV patients. Decreased EPC counts were also associated with certain risk factors, including hypertension, tobacco use, impaired glucose metabolism, and metabolic syndrome, and correlate with high levels of high-sensitivity CRP (hsCRP) or fibrinogen. The presence of carotid plaque and IMT measurement were unrelated with EPC quantification. Patients with a reduced percentage of EPCs showed pathological arterial stiffness and association with certain CV risk factors, suggesting that the measurement of circulating EPCs can be used as a biological marker to determine subclinical atherosclerosis in SLE.

Renal cell carcinoma-adjacent tissues enhance mobilization and recruitment of endothelial progenitor cells to promote the invasion of the neoplasm

AimsThe aim of this study was to detect the levels of CD34+/Flk-1+ endothelial progenitor cells (EPCs) in renal cell carcinoma (RCC)-adjacent tissues and explore the correlation of RCC-adjacent tissues EPCs and tumor invasion. MethodsAn orthotopic renal tumor model was successfully established. At days 7, 12, 17 and 21, eight mice were put to death respectively. Tumor diameters were measured and RCC-adjacent tissues were collected. The percentage of EPCs within the kidney mononuclear cell population was detected. The expression levels of Stromal cell-derived factor-1 (SDF-1), vascular endothelial growth factor (VEGF) and their receptors CXCR4, Flk-1 mRNA and protein were probed respectively. And then, mean microvascular density (MVD) was examined. ResultsEPC numbers in RCC-adjacent tissues were significantly higher than those in control groups. The ratios of EPCs were increased gradually, and so were tumor diameters. The levels of SDF-1 and VEGF were also increased gradually, but significantly reduced compared with control group at each time point. In addition, CXCR4 and Flk-1 expression were decreased gradually. ConclusionsOur investigation suggested that EPCs in RCC-adjacent tissues play an important role in early stage RCC invasion, involving the promotion on angiogenesis through releasing several angiogenic factors.

AB0130 Premature atherosclerosis of apoe-/-fasl-/- c57bl/6 mice was mediated by dysfunction of bone marrow derived endothelial progenitor cells

BackgroundSystemic lupus erythematosus (SLE) is an autoimmune disease with heterogeneous manifestations including severe organ damage and premature atherosclerosis. A mouse model of apolipoprotein E-deficient (apoE(-/-)) and Fas ligand-deficient (FasL(-/-)) showed...

Effect of Vitamin D Receptor Activator Therapy on Vitamin D Receptor and Osteocalcin Expression in Circulating Endothelial Progenitor Cells of Hemodialysis Patients

Background: The effects of vitamin D receptor (VDR) and osteocalcin (OC) expression as well as VDR agonist (VDRA) therapy on circulating endothelial progenitor cells (EPCs) has not been elucidated yet. Methods: We therefore analyzed EPCs in 30 healthy controls and 82 patients undergoing dialysis (no VDRA therapy: 28; oral calcitriol: 30, and intravenous paricalcitol, PCTA: 24). The percentage of EPCs (CD34+/CD133-/KDR+/CD45-) expressing VDR or OC, and VDR and OC expression defined by mean fluorescence intensity (MFI) were analyzed using flow cytometry. The in vitro effect of VDRAs was evaluated in EPCs isolated from each patient group. Results: The percentage of VDR+ EPCs correlated positively with VDRA therapy and 25(OH)D, and negatively with diabetes, C-reactive protein, hemoglobin and osteopontin. VDR-MFI correlated positively with VDRA therapy, parathyroid hormone (PTH) and 25(OH)D, and negatively with diabetes and osteopontin. The percentage of OC+ EPCs correlated positively with the calcium score, PTH and phosphate, and negatively with 25(OH)D. OC-MFI correlated positively with calcium score, PTH, phosphate and hemoglobin, and negatively with albumin, 25(OH)D and osteopontin. Cell cultures from patients without VDRA therapy had the highest levels of calcium deposition and OC expression, which both significantly decreased following in vitro VDRA administration: in particular extracellular calcium deposition was only reduced by adding PCTA. Conclusions: Our data suggest that 25(OH)D serum levels and VDRA therapy influence VDR and OC expression on circulating EPCs. Since OC expression may contribute to vascular calcification, we hypothesize a putative protective role of VDRA therapy.

Bone marrow mononuclear cells induce beneficial remodeling and reduce diastolic dysfunction in the left ventricle of hypertensive SS/MCWi rats

Bone marrow mononuclear cells (BMMNCs) increase capillary density and reduce fibrosis in rodents after myocardial infarction, resulting in an overall improvement in left ventricular function. Little is known about the effectiveness of BMMNC therapy in hypertensive heart disease. In the current study, we show that delivery of BMMNCs from hypertension protected SS-13(BN)/MCWi donor rats, but not BMMNC from hypertension susceptible SS/MCWi donor rats, resulted in 57.2 and 83.4% reductions in perivascular and interstitial fibrosis, respectively, as well as a 60% increase in capillary-to-myocyte count in the left ventricles (LV) of hypertensive SS/MCWi recipients. These histological changes were associated with improvements in LV compliance and relaxation (103 and 46.4% improvements, respectively). Furthermore, improved diastolic function in hypertensive SS/MCWi rats receiving SS-13(BN)/MCWi derived BMMNCs was associated with lower clinical indicators of heart failure, including reductions in end diastolic pressure (65%) and serum brain natriuretic peptide levels (49.9%) with no improvements observed in rats receiving SS/MCWi BMMNCs. SS/MCWi rats had a lower percentage of endothelial progenitor cells in their bone marrow relative to SS-13(BN)/MCWi rats. These results suggest that administration of BMMNCs can prevent or reverse pathological remodeling in hypertensive heart disease, which contributes to ameliorating diastolic dysfunction and associated symptomology. Furthermore, the health and hypertension susceptibility of the BMMNC donor are important factors influencing therapeutic efficacy, possibly via differences in the cellular composition of bone marrow.

Effect of preeclampsia and intrauterine growth restriction on endothelial progenitor cells in human umbilical cord blood

Objectives: Endothelial progenitor cells (EPCs) might play important roles in vascular homeostasis. This study evaluated the influence of prematurity, preeclampsia (PE) and intrauterine growth restriction (IUGR) on the EPC population in human umbilical cord blood (CB). Methods: CB was obtained from 19 preterm and 27 term deliveries. Mononuclear cells were isolated by gradient centrifugation and subjected to flow cytometry to obtain percentages of CD45(d) CD34+, CD45(d) CD133+, CD 45(d) CD34+ CD133+, and CD45(d) CD34+ CD133+ VEGFR-2+ cells. Clinical data were obtained using chart review. Results: Percentages of EPCs were comparable between preterm and term cord blood. CD45(d) CD34+ CD133+ cells were significantly decreased in CB samples obtained from women with PE (n = 14) [0.01, (0.00–2.6), [median, (range)], as compared to those without PE (n = 32) [1.74 (0.00–3.1)] (p = 0.005). CD45(d) CD133+ CD34− cells were significantly increased in presence of PE [0.43, (0.06–1.38)], (p = 0.002). CD45(d) CD34+ CD133+ cells were significantly decreased in presence of IUGR, with no change in CD45(d) CD133+ CD34− cells. Differences in EPC types associated with PE and IUGR were present only in term CB. Conclusions: Exposure to PE and IUGR is associated with significant changes in EPC population. Future studies are needed to explore the clinical impact of observed changes.

Polyphenol-rich cranberry juice has a neutral effect on endothelial function but decreases the fraction of osteocalcin-expressing endothelial progenitor cells

Cranberry juice (CJ) contains a remarkably high concentration of polyphenols, considered to be beneficial for cardiovascular and bone health. The current double-blind, randomized study was designed to test whether daily consumption of double-strength Ocean Spray light CJ (2 × 230 ml) over 4 months has beneficial effects on vascular function and on endothelial progenitor cells (EPCs) carrying the osteoblastic marker osteocalcin in particular. A total of 84 participants (49.5 ± 16.2 years) with peripheral endothelial dysfunction and cardiovascular risk factors were enrolled in this double-blind, randomized, controlled trial (69 completed the 4-month protocol-32 in the CJ group and 37 in the placebo group, respectively). Vascular responses to reactive hyperemia were measured non-invasively by peripheral arterial tonometry (EndoPAT). Peripheral blood mononuclear cells were stained for EPC markers, as well as osteocalcin, and counted by flow cytometry. Baseline characteristics were similar in both groups. The effect of CJ on peripheral endothelial function and on circulating EPC counts (CD34(+)/CD133(+)/KDR(+)) did not change during the study. A high percentage of EPCs expressed osteocalcin (59.4 ± 35.7%). CJ, as compared to placebo, induced a decrease in the fraction of EPCs expressing osteocalcin (-8.64 ± 48.98 and 19.13 ± 46.11%, respectively, p = 0.019). Systemic levels of the adhesion marker ICAM correlated significantly with the number of EPCs expressing osteocalcin. The study demonstrated that long-term supplementation of polyphenol-rich CJ did not improve peripheral endothelial function. However, the decrease in the fraction of osteocalcin+ EPCs suggests a potential beneficial effect of polyphenol-rich CJ.

Granulocyte Colony-Stimulating Factor Reduces Hyperoxia-Induced Alveolarization Inhibition by Increasing Angiogenic Factors

Background: Granulocyte colony-stimulating factor (G-CSF) is known to mobilize endothelial progenitor cells (EPCs) from bone marrow. EPCs reportedly promote neovascularization and participate in the repair of lung structure in adult animals. Objective: We tested the hypothesis that G-CSF contributes to alveolar growth by increasing the production of angiogenic growth factor in the lungs of hyperoxia-exposed neonatal mice. Methods: Neonatal mice were exposed to hyperoxia (80%) or room air (RA) for 7 days and treated with G-CSF (50 µg/kg/day) or vehicle for 5 days. Blood was subjected to flow cytometry to gate for CD45^dim/–/Sca-1⁺/CD133⁺/vascular endothelial growth factor (VEGF) receptor-2 (VEGFR2) to define the EPC population at day 7. Results: The percentage of EPCs in the peripheral blood and VEGF and VEGFR2 levels in the lungs of neonatal mice exposed to hyperoxia were significantly reduced compared to those of mice kept in RA. G-CSF significantly increased EPCs in the peripheral blood, and VEGF and VEGFR2 levels in the lungs of both mice exposed to hyperoxia and mice kept in RA. G-CSF restored alveolarization inhibited by hyperoxia without altering normal alveolarization under RA. Conclusion: G-CSF restored alveolarization inhibited by hyperoxia in the developing lungs and this alveolarization-enhancing effect of G-CSF is associated with mobilization of EPCs and upregulation of VEGF signaling.

Imbalance between endothelial progenitors cells and microparticles in HIV-infected patients naive for antiretroviral therapy

Cardiovascular events have been reported among HIV-infected patients following antiretroviral therapy. However, the role of HIV itself in determining vascular damage is less described. Chronic inflammatory state might impair some regulatory endothelium properties leading to its activation, apoptosis or erosion. To evaluate the balance between endothelial progenitor cells and microparticles in HIV-infected antiretroviral drug-naive patients. A case-control study comparing HIV-infected patients (n = 35) with sex-matched and age-matched healthy controls (n = 33). Endothelial progenitor cells populations expressing CD34, CD133 and KDR were quantified by flow cytometry. Endothelial-derived microparticles, expressing CD51, and platelet-derived microparticles, expressing CD31/CD42, were also measured. Endothelial function was estimated by flow-mediated dilation. Lower percentages of endothelial progenitor cells (CD34/KDR) were observed in HIV-infected individuals compared with controls (0.02 vs. 0.09%, P = 0.045). In addition, endothelial microparticles concentration was higher in HIV-infected individuals (1963 vs. 436 microparticles/μl platelet-poor plasma, P = 0.003), with similar number of platelet-derived microparticles among groups. Furthermore, flow-mediated dilation was lower among HIV-infected individuals compared with controls [mean (SEM): 10 (1) and 16% (2), respectively; P = 0.03]. Our findings suggest an imbalance between endothelial progenitor cells mobilization and endothelial apoptosis. The alteration in the turnover of endothelial cells may contribute to cardiovascular events in HIV-infected patients.

Circulating Angiopoietic Cells and Diabetic Retinopathy in Type 2 Diabetes Mellitus, with or without Macrovascular Disease

To investigate different types of circulating angiopoietic cells, such as vasculogenic circulating progenitor cells (CPCs), endothelial progenitor cells (EPCs), and mature EPCs (matEPCs) in patients with type 2 diabetes mellitus (T2DM), with or without diabetic retinopathy (DR) and with or without macrovascular disease (MVD). One hundred twenty-six patients with T2DM-66 with MVD and 60 without MVD-were enrolled in a case-control study. MVD comprised coronary heart disease, peripheral arterial disease, stroke, or various combinations of those conditions. By a modified Early Treatment of Diabetic Retinopathy Study (ETDRS) classification, 55 patients were classified without DR (CO), 19 with mild nonproliferative DR (mNPDR), 16 with moderate-severe NPDR (msNPDR), 19 with early proliferative diabetic retinopathy (ePDR), and 17 with high-risk PDR (hrPDR). CPCs (CD34/CD133), EPCs (CD34/CD133/CD30), and matEPCs (CD34/CD133/CD309/CD31) were enumerated by flow cytometry. Patients with MVD CPCs, EPCs, and matEPCs showed a significant, stepwise decline with advancing stages of retinopathy. In contrast, in the patients without MVD, EPCs and matEPCs reached up to 56% of CPCs and 37% of EPCs. On the other hand, the percentage of EPCs and matEPCs was reduced to 5% of CPCs and EPCs each in MVD patients. Thus, the percentage of EPCs and matEPCs in comparison with that of CPCs and EPCs represented an 11- and 7-fold difference. The circulating angiopoietic CPCs, EPCs, and matEPCs in T2DM patients with DR had a different regulations, with increasing relative differences occurring in proliferative DR, apparently depending on the macrovascular comorbidities. Patients with MVD showed a strong retinopathy-stage-dependent depletion of all angiopoietic cells.

Changes in the number and biological ability of endothelial progenitor cells from peripheral blood of patients with systemic lupus erythematosus (SLE)

Objective To analyze the changes in number and biological ability of endothelial progenitor cells (EPCs) from peripheral blood of SLE patients. Methods Mononuclear cells (MNCs) were isolated by Ficoll density gradient centrifugation from peripheral blood of 20 female SLE patients and 20 healthy female controls. EPCs were identified by double staining using antibodies to CD34 and CD133, or antibodies to CD133 and vascular endothelial growth factor receptor 2 (VEGFR2). Phycoerythrin (PE) conjugated antiCD34, fluorescein isothiocyanate (FITC) conjugated anti-CD133 and APC conjugated anti-VEGFR2 antibodies were used in a three color flow cytometric analysis to determine the percentage of EPCs in peripheral MNCs.The proliferation and migration ability of EPCs were measured by MTT assay and modified millicell chamber assay, respectively. The adhesion activity of EPCs was evaluated by counting the number of adherent cells.Results The percentage and proliferation rate of EPCs in peripheral MNCs from female SLE patients were significantly lower than those from the healthy controls(4.49% ± 1.66% vs 20.81% ± 4.14%, 23.11% ± 3.16%vs 35.65% ± 1.74%, both P ＜ 0.01 ). The migration and adhesion ability of EPCs from SLE patients was impaired compared with those from the healthy controls (12.00 ± 2.12 vs 23.60 ± 3.0 cells/field, 22.43 ± 4.43vs 36.43 ± 3.69 cells/filed, both P ＜ 0.01 ). Conclusion There is a decrease in the number and an impairment in biological ability of EPCs in SLE patients. Key words: Lupus erythematosus, systemic; Endothelium; Stem cells; Biology

Effect of Low-Density Lipoprotein Apheresis on Circulating Endothelial Progenitor Cells in Familial Hypercholesterolemia

Background: Long-term treatment with low-density lipoprotein (LDL) apheresis (LA) has been shown to reduce the incidence of cardiovascular events in patients affected by familial hypercholesterolemia (FH). Data from experimental studies suggest that circulating endothelial progenitor cells (EPCs) can repair the vascular lesions caused by atherosclerosis. Since a reduction of these cells has been demonstrated to predict atherosclerosis progression, the aim of this study was to verify whether LA can increase the percentage of EPCs. Methods: In 15 patients affected by FH periodically treated with LA, the percentage of EPCs was determined before and after performing LA, and compared with the values of 15 control subjects and 15 hypercholesterolemic patients treated with statins. Results: Significant differences were found in FH patients between the pre-apheresis percentages of CD34+/KDR+, defined as EPCs by a wide consensus of opinion, and the values found 24 h after the procedures (0.00868 ± 0.003 vs. 0.01009 ± 0.002%, p < 0.005). Instead, the percentages of CD34+/KDR+/CD133+, considered as an immature subset of EPCs, remained substantially unchanged. However, a significant reduction in the percentage of EPCs was observed in both patient groups as compared to the controls, at all the assessment times. Conclusion: In the short-term LA seems to stimulate mobilization of CD34+/KDR+ cells. Hypercholesterolemic patients show a lower percentage of EPCs than controls. There were no differences in the EPCs percentages between the 2 patients groups, despite the fact that LDL cholesterol levels were higher in the group undergoing LA.

Recovery from hind limb ischemia is less effective in type 2 than in type 1 diabetic mice: Roles of endothelial nitric oxide synthase and endothelial progenitor cells

We sought to directly compare the effects of type 1 and type 2 diabetes on postischemic neovascularization and evaluate the mechanisms underlying differences between these groups. We tested the hypothesis that type 2 diabetic mice have a greater reduction in endothelial nitric oxide synthase (eNOS) expression, a greater increase in oxidative stress, and reduced arteriogenesis and angiogenesis, resulting in less complete blood flow recovery than type 1 diabetic mice after induction of hind limb ischemia. Hind limb ischemia was generated by femoral artery excision in streptozotocin-treated mice (model of type 1 diabetes), in Lepr(db/db) mice (model of type 2 diabetes), and in control (C57BL/6) mice. Dependent variables included eNOS expression and markers of arteriogenesis, angiogenesis, and oxidative stress. Postischemia recovery of hind limb perfusion was significantly less in type 2 than in type 1 diabetic mice; however, neither group demonstrated a significant increase in collateral artery diameter or collateral artery angioscore in the ischemic hind limb. The capillary/myofiber ratio in the gastrocnemius muscle decreased in response to ischemia in control or type 1 diabetic mice but remained the same in type 2 diabetic mice. Gastrocnemius muscle eNOS expression was lower in type 1 and 2 diabetic mice than in control mice. This expression decreased after induction of ischemia in type 2 but not in type 1 diabetic mice. The percentage of endothelial progenitor cells (EPC) in the peripheral blood failed to increase in either diabetic group after induction of ischemia, whereas this variable significantly increased in the control group in response to ischemia. EPC eNOS expression decreased after induction of ischemia in type 1 but not in type 2 diabetic mice. EPC nitrotyrosine accumulation increased after induction of ischemia in type 2 but not in type 1 diabetic mice. EPC migration in response to vascular endothelial growth factor was reduced in type 1 and type 2 diabetic mice vs control mice. EPC incorporation into tubular structures was less effective in type 2 diabetic mice. Extensive fatty infiltration was present in ischemic muscle of type 2 but not in type 1 diabetic mice. Type 2 diabetic mice displayed a significantly less effective response to hind limb ischemia than type 1 diabetic mice.

SURROGATE MARKERS PREDICT ANGIOGENIC POTENTIAL AND SURVIVAL IN PATIENTS WITH GLIOBLASTOMA MULTIFORME

The neovascularization of malignant brain tumors is a poorly understood phenomenon. Radiographic and histological evidence of increased vascularity correlate with clinical grade of gliomas. However, a quantitative noninvasive assay to assess glioma vascularity and associated clinical aggressiveness has not been developed. Circulating endothelial progenitor cells are unique vascular precursors recruited from the bone marrow through the circulation to form new tumor blood vessels. These cells were measured in patients undergoing surgery for glioblastoma multiforme (GBM). We hypothesized that this might reflect the extent of tumor vascularity, predict prognosis, or be useful as an assay to assess response to antiangiogenesis therapies. In addition, we report on a novel in vitro assay to assess the proangiogenic activity within the plasma samples obtained from glioma patients. Fifty-six patients with various-grade gliomas had peripheral venous blood collected at the time of surgery and at subsequent visits during the follow-up period. The blood was separated into plasma and cellular fractions. The plasma was utilized in a human umbilical vein endothelial cell-based angiogenic assay. The cellular fraction containing endothelial progenitor cells was isolated, and specific cellular phenotypes were immunologically separated and counted using flow cytometry. Pathological samples were reviewed at the time of initial resection, and each patient's clinical course was monitored until the time of manuscript submission. Plasma derived from peripheral blood of patients with GBM scored significantly higher on the functional angiogenic scale compared with plasma derived from patients with low-grade gliomas and from controls. In addition, all patients with GBM had measurable numbers of bone marrow-derived endothelial precursor cells coexpressing CD133 and vascular endothelial growth factor receptor 2 in their peripheral circulation at the time of tumor resection. These cells range from less than 0.1% to 1.6% of the entire circulating mononuclear white blood cell population, or approximately 200,000 cells in some patients. A statistically significant relationship was observed between the percentage of endothelial progenitor cells in the peripheral blood at the time of initial GBM resection and survival. These studies suggest that plasma and circulating CD133+ vascular endothelial growth factor receptor 2+ proangiogenic cells are present in the peripheral blood of patients with glioma and can be used as a surrogate biomarker to measure tumor angiogenicity. These cells can be measured at the time of diagnosis and monitored in the postoperative period. These assays can be used to predict tumor aggressiveness. Also promising is their potential to identify patients with increased angiogenic activity who might respond maximally to antiangiogenesis therapies or to assess tumor response in patients using those therapies as the use of these adjuvant molecular modalities becomes more prevalent in neuro-oncology.