Circulating Endothelial Progenitor Cell Research Articles

Exploration of the influence of early rehabilitation training on circulating endothelial progenitor cell mobilization in patients with acute ischemic stroke and its related mechanism under a lightweight artificial intelligence algorithm.

This work aimed to explore the application of lightweight artificial intelligence algorithms in magnetic resonance imaging (MRI) image processing of patients with acute ischemic stroke (AIS) to clarify the effect and mechanism of early rehabilitation training on the mobilization of circulating endothelial progenitor cells (EPCs) in AIS. A total of 98 AIS patients undergoing MRI examination were selected as the research objects and were randomly divided into a rehabilitation group (early rehabilitation training, 50 cases) and a routine group (conventional treatment, 48 cases) by random number table method and lottery method. In this work, based on the convolutional neural network (CNN) algorithm, a low-rank decomposition algorithm was introduced to optimize it, and a lightweight MRI image computer intelligent segmentation model (LT-RCNN) was established. The LT-RCNN model was used in the MRI image processing of AIS patients, and the role of the model in AIS image segmentation and lesion localization was analyzed. Furthermore, flow cytometry was used to detect the number of peripheral circulating EPCs and CD34+KDR+ cells in the two groups of patients before and after treatment. The serum levels of vascular endothelial growth factor (VEGF), tumor necrosis factor-α (TNF-α), interleukin 10 (IL-10), and stromal cell-derived factor-1α (SDF-1α) content were detected by Enzyme-Linked Immunosorbent Assay (ELISA). In addition, the correlation between each factor and CD34+KDR+ was analyzed by Pearson linear correlation. The diffusion-weighted imaging (DWI) signal of MRI images of AIS patients under the LT-RCNN model was high. The location of the lesion could be accurately detected, and the contour of the lesion could be displayed and segmented, and the segmentation accuracy and sensitivity were significantly better than before optimization. The number of EPCs and CD34+KDR+ cells in the rehabilitation group was increased compared with the control group (p<0.01); the expression levels of VEGF, IL-10, and SDF-1α were higher than those of the control group (p<0.001), and TNF-α content was lower than the control group (p<0.001). The number of CD34+KDR+ cells was positively correlated with VEGF, IL-10, and TNF-α contents (p<0.01). The results showed that the computer-intelligent segmentation model LT-RCNN could accurately locate, and segment AIS lesions and the early rehabilitation training could change the expression level of inflammatory factors and further promote the mobilization of AIS circulation EPCs.

Neurotrophin-3 accelerates reendothelialization through inducing EPC mobilization and homing.

Rapid endothelialization is an effective way to treat intimal hyperplasia after intravascular stent implantation. Blood vessels and nerves coordinate with each other in function, while neurotrophin-3 (NT-3) is an important class of nerve growth factors. Our study found that NT-3 promoted endothelial progenitor cell (EPC) mobilization, and the proportion of EPCs in peripheral blood was increased by 1.774 times compared with the control group. Besides, NT-3 promoted the expression of stromal cell-derived factor-1α (SDF-1α), matrix metalloproteinase-9 (MMP9), and chemokine (C-X-C motif) receptor 4 (CXCR4) in EPCs, which increased by 59.89%, 74.46%, and 107.7%, respectively, compared with the control group. Transwell experiments showed that NT-3 enhanced the migration of EPCs by 1.31 times. Flow chamber experiments demonstrated that NT-3 captured more circulating EPCs. As shown by ELISA results, NT-3 can promote the paracrine of vascular endothelial growth factor, interleukin-8, MMP-9, and SDF-1 from EPCs. Such increased angiogenic growth factors further accelerated the closure of endothelial cell scratches. Additionally, EPC-conditioned medium in the NT-3 group significantly inhibited the proliferation of vascular smooth muscle cells. Then animal experiments also illustrated that NT-3 prominently accelerated the endothelialization of injured carotid artery. In short, NT-3 accelerated rapid reendothelialization of injured carotid artery through promoting EPC mobilization and homing.

Improved angiogenic activity of endothelial progenitor cell in diabetic patients treated with insulin plus metformin.

Type 2 diabetes (T2DM) is associated with an increased vascular disease. Moreover, endothelial progenitor cell (EPC) function is impaired in diabetic patients. Decreased EPC number plays a critical role in reduced endothelial repair and development of the vascular disorder. To determine the effect of metformin and insulin plus metformin on functional activity of EPCs, 130 participants were divided into three groups (group 1: healthy control; group 2: metformin; group 3: insulin plus metformin). The concentration of EPCs in the circulation was first quantified. Thereafter, circulating EPCs (cEPCs) were harvested and the biological features of these cells including proliferative, clonogenicity, tubulogenic, and migratory properties were analyzed after expansion. The serum protein levels of some proangiogenic factors were also measured. Our results showed greater numbers of cEPCs in control and in diabetic patients treated with insulin plus metformin than in metformin-treated patients. Insulin plus metformin therapy was associated with augmented proliferative, clonogenicity, migratory, and tubulogenic activity of cEPCs in patients with T2DM. Increased serum concentrations of angiogenic factors were also observed in patients treated with insulin plus metformin. Western blot analysis showed increased protein levels of pTie-2/Tie2 and Pakt/AKT in cEPCs harvested from T2DM, treated with insulin metformin plus. This study showed that treatment with insulin plus metformin in diabetic patients is associated with increased mobilization of EPCs into the circulation, with potential beneficial effect in vascular protection in diabetic patients.

Circulating osteogenic endothelial progenitor cell counts: new biomarker for the severity of coronary artery disease

BackgroundThere is increasing evidence implying that the early and functionally highly active circulating endothelial progenitor cell (CEPC) phenotype (CD34−/CD133+/KDR+) with osteogenic potential (OCN+) might link between vascular atherosclerotic calcification and mechanisms of bone metabolism. We sought to evaluate the early OCN+ CEPC counts as an independent biomarker for the severity of coronary artery disease (CAD). MethodsPeripheral blood samples were drawn from 593 patients undergoing clinically indicated coronary angiography. CAD severity was assessed by the presence of significant coronary artery stenosis (CAS) as well as an ordinal categorical variable. Subjects were followed for all-cause death over a median follow-up of 40months. ResultsOCN+ early CEPC counts (square-root transformed) were independently associated with the presence of significant CAS [odds ratio (OR) per standard deviation (SD) increment: 1.389, 95% confidence interval [CI]: 1.131 to 1.707, p=0.002). Similar association was observed with an increase in levels of CAS (OR: 1.353, 95% CI: 1.157 to 1.582, p<0.001). There was a weak tendency between OCN+ early CEPC counts and all-cause mortality (p=0.090), whereas the highest decile of OCN+ early CEPC counts had a 2.991-fold increased risk of all-cause death (p=0.047). ConclusionsWe demonstrate for the first time an independent, significant, and strong correlation between OCN+ early CEPC counts and CAD severity. Additionally, very high numbers of OCN+ early CEPC tend to be linked to the risk of all-cause mortality.

A vascular patch prepared from Thai silk fibroin and gelatin hydrogel incorporating simvastatin-micelles to recruit endothelial progenitor cells.

Delayed re-endothelialization is one of the major disadvantages in synthetic vascular grafts, especially in small-diameter grafts (inner diameter <6 mm), leading to thrombosis and stenosis of the grafts. Simvastatin, a serum cholesterol-lowering drug, has promotional effects on endothelial progenitor cell (EPC) mobilization from bone marrow and recruitment to sites of vascular injury exhibiting acceleration of re-endothelialization. In this study, we prepared double-layer vascular patches from Thai silk fibroin/gelatin with gelatin hydrogel incorporating simvastatin-micelles (SM) for sustained release of simvastatin to recruit circulation EPCs. To enhance simvastatin solubility, simvastatin was entrapped in micelles of l-lactic acid oligomer-grafted gelatin. The drug loading efficiency was at 4.1 ± 0.5 μg/mg micelles. SM had a chemoattractive effect on EPCs comparable to nonmodified simvastatin. Gelatin hydrogel incorporating SM at 100 μM of simvastatin (GSM100) could enhance in vitro EPC activities of adhesion and proliferation. In vitro results showed the initial cell adhesion of 86%, specific growth rate of 15.33×10(-3) h(-1), and population doubling time of 46.21 h. In vivo implantation of the patches incorporating SM significantly increased the recruitment of circulating EPCs. From the results of immunofluorescence staining, they demonstrated the complete re-endothelialization on the implanted patches containing SM at 2 weeks after implantation in rat carotid arteries. The gelatin hydrogel incorporating SM could be an effective inner layer of multifunctional vascular grafts to accelerate re-endothelialization in vascular tissue engineering.

Identification and significance of mobilized endothelial progenitor cells in tumor neovascularization of renal cell carcinoma.

Neovascularization is a key role of renal cell carcinoma (RCC) and the status of neovascularization in RCC is closely correlated with the tumor development and patient prognosis. Endothelial progenitor cells (EPCs) are considered as important building blocks for neovascularization. However, the role of mobilized EPCs in RCC remains unknown. In this study, the orthotopic RCC model was established to investigate the distribution, frequency, and significance of mobilized EPCs. We found that circulating endothelial progenitor cell (CEPC) levels and plasma angiogenic factors (vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1) were higher in peripheral blood (PB) of the RCC than those in the normal group and positively correlated with each other. EPC levels in adjacent nonmalignant kidney tissue (AT) were significantly higher than those in tumor tissue (TT) and normal kidney tissue (NT), which were positively correlated with CEPC levels. VEGF, VEGF receptor-2 (Flk), and SDF-1 and its SDF-1 receptor (CXCR4) expression in AT was significantly higher than that in TT and NT. Levels of these angiogenic factors in AT were positively correlated with those in PB. Mean microvessel density (MVD) was higher in AT than in TT, and that in TT was slightly lower than that in NT. Our findings propose that mobilized EPCs play an important role in RCC neovascularization. EPCs in PB and AT can be used as a biomarker for predicting RCC progression.

Markers of endothelial damage and repair in Takayasu arteritis: Are they associated with disease activity?

The current clinical and laboratory parameters of Takayasu arteritis (TA) are insufficient for proper assessment of disease activity. The aims of this study were to investigate the markers of endothelial injury and repair, including circulating endothelial cell (CEC), circulating endothelial progenitor cell (CEPC) and vascular endothelial growth factor (VEGF), and evaluate their associations with disease activity in patients with TA. Thirty-two patients with TA and 30 healthy age- and sex-matched controls were included in this study. Disease activity was assessed in TA patients using various tools, including Kerr's criteria, the Indian Takayasu's Arteritis Scoring (ITAS2010) and physician's global assessment (PGA). CECs and CEPCs were measured by flow cytometry, and VEGF was measured using an enzyme-linked immunosorbent assay. The CEC level was found to be higher in TA patients than in the healthy controls (HC) (p < 0.001). There was no significant difference in CEC level between the active and inactive patients, but its level was slightly correlated with C-reactive protein (CRP) level. CEPC and VEGF levels in TA patients with active disease were higher than those in the inactive patients and HC. CEPC and VEGF levels were positively correlated with ITAS-CRP and PGA scores. This study shows increased level of CEC in patients with TA. It also suggests that the CEPC and VEGF levels may be correlated with disease activity.

Phase II study of cixutumumab (IMC-A12) in thymic malignancies.

7033 Background: The IGF-1 receptor (IGF-IR) is expressed in thymoma (T) and thymic carcinoma (TC). Prolonged SD has been seen with anti-IGF-IR therapy in thymic tumors in phase I trials. Cixutumumab (C) is a fully human IgG1 monoclonal antibody (ab) that targets IGF-IR. Methods: Patients (pts) with recurrent T or TC, PS 0-2, measurable disease, and normal organ function received C at 20 mg/kg IV q3wks until progression or intolerable toxicity. Primary endpoint was response rate. Correlative studies included immune cell subset (central memory, effector memory, naïve and regulatory T cells), circulating endothelial progenitor (CEP) cell, serum IGF-1 and IGF-IR in PBMCs, anticytokine ab, and tumor mutational analysis. Results: Forty-five pts enrolled from two centers (20 female, T=33, med age 52 yrs, range, 26-86). Median number of prior systemic treatments: 3 (range, 1-11). Median number of cycles of C administered: 6 (range, 1-41). In 30 evaluable T pts there were 4 (13%) PR, 23 (77%) SD, and 3 (10%) PD. Corresponding numbers in 12 TC pts were 0, 5 (42%) and 7 (58%). Median PFS for T and TC was 40 and 9 wks respectively. C-related grade 3/4 AEs were hyperglycemia (8%), hyperuricemia, weight loss, lipase elevation, chest wall pain (5% each) and AST elevation (3%). Two pts died while on study: one due to respiratory insufficiency related to T after 5 cycles and one due to worsening myasthenia and an acute coronary event after 13 cycles. In 8 of 33 T pts autoimmune (AI) symptoms developed (4 new-onset) due to immune thrombocytopenic purpura, myositis, myocarditis, colitis, PRCA and food allergy. In the first 13 pts a trend towards increased numbers of central and effector memory T cells and a decrease in naïve T cells and CEPs was seen. High-titer anticytokine abs, including anti-IFNa, anti-IL-12, and anti-IL-17A, were found in 13/27 pts tested. No EGFR, KRAS or BRAF mutation, HER2 amplification or ALK translocations were detected in 11 tumors analyzed. Conclusions: C monotherapy is well tolerated and active in T. Accrual will continue until 37 T pts are enrolled. Activity in TC is unworthy of further investigation. CEP and immune cell subset analysis suggests therapy may impact angiogenesis and immune response. Development of AI symptoms during treatment needs further evaluation.

Effect of anticoagulation and thrombolysis on circulation endothelial cells and endothelial function after acute inferior vena cava thrombosis in rats

To explore the functions and adhesive properties of circulating endothelial cells after acute thrombosis in rats. The inferior caval venous thrombosis model were treated with heparin (n = 45), urokinase (n = 45) and a combination of heparin and urokinase (n = 45) respectively. The sham group was treated similarly (n = 30). The thrombosed caval veins were harvested at Days 1, 3, 7, 14 and 28 post-thrombosis. Structural integrity and intimal hyperplasia were observed by light microscope. Scanning electron microscopy was used to assess the damage of endothelial cells in inferior caval vein wall. The level of thrombotic adhesion was measured in different phases. At Day 28, endothelial cell layer was observed under scanning electron microscope. Measurements were taken for circulating endothelial cells count, CEPC (circulating endothelial progenitor cell) count and CEPC adhesive capacity. The adhesion to caval vein wall was lower in groups B and C than that in group A at Day 3 post-thrombosis (all P < 0.01). The endothelial damage in group A was more serious than groups B and C at Day 7 (P < 0.05). And the endothelial damage was less severe in group C at Day 28 (P < 0.05). For the rats in A, B, C, SH groups, the numbers of circulating endothelial cell [(6.3 ± 2.2)×10(6), (4.76 ± 3.1)×10(6), (1.9 ± 0.8)×10(6), (0.91 ± 0.3)×10(6)], CEPC count (18.9 ± 5.33, 37.4 ± 6.0, 55.4 ± 8.0, 64.1 ± 3.2) and CEPC adhesion (9.6 ± 2.9, 17.5 ± 3.2, 22.1 ± 4.4, 28.3 ± 2.0) increased successively. There was statistical significance. A combination of heparin and urokinase for the treatment of acute inferior caval venous thrombosis may effectively maintain the endothelial integrity of vein wall and decrease the fibroblast proliferation of thrombosed vein. Adhesion to caval vein wall is relatively lower during an early post-thrombotic period.

Circulating endothelial and endothelial progenitor cells in patients with severe sepsis

Elevated circulating endothelial cell (CEC) and circulating endothelial progenitor cell (CEPC) counts may indicate vascular damage and disease status, but data on these cell populations in patients with severe sepsis are limited. This study compared CEC and CEPC counts in patients with and without severe sepsis following intensive care unit (ICU) admission. Venous blood samples were collected within 24 h, 48–72 h, and 120–144 h. Baseline demographics, 28-day mortality, ICU and hospital days, and Sequential Organ Failure Assessment (SOFA) scores were recorded. Patients with ( n = 18) and without ( n = 28) severe sepsis were balanced for mean age (63.7 and 61.3 years, respectively) and gender. There were no differences in 28-day mortality, ICU days, or hospital days. Baseline SOFA scores were higher in the sepsis group. At 48–72 h, patients with severe sepsis had significantly higher median CEC counts (51.5 vs. 28.0 cells/4 ml of blood, P = 0.02). CEC values for all ICU patients were significantly ( P < 0.05) higher than in healthy volunteers. CEPC counts in both cohorts ranged from 0 to > 21 colonies/4 ml blood (mean = 1.13 ± 2.25; median = 0) without significant differences at any time point. This study demonstrates the ability to quantify CECs and CEPCs using consensus methodology. Understanding the relationship between CEC/CEPC counts and outcomes may provide insight into the mechanisms of endothelial cell changes in severe sepsis.

Different Biological Properties of Circulating and Bone Marrow Endothelial Progenitor Cells in Acute Myocardial Infarction Rats

Many studies have shown that endothelial progenitor cell (EPC) can enhance the neovascularization of the ischemic myocardium. Peripheral blood and bone marrow are the most convenient resources for EPC. The aim of the study was to investigate, in vitro and in vivo, the different biological properties between circulating EPC (CEPC) and bone marrow EPC (BM-EPC) of AMI rats. The proliferative, migrative, adherent and angiogenic properties were investigated in vitro. 1 x 10 (6) CEPCs, 1 x 10 (6) BM-EPCs and medium (EBM-2) were injected in the myocardium of AMI rats. Echocardiography, regional myocardial blood flow (RMBF), capillary density and Y chromosome fluorescence in situ hybridization (FISH) were performed at 4 weeks after transplantation. The CEPCs had higher proliferative, migrative, adherent capabilities and lower senescent ratio, could adhere more quickly to fibronectin than BM-EPCs. CEPCs could form capillary-like structures whereas BM-EPCs did not show similar structures on Matrigel. in vivo, transplanted CEPCs and BM-EPCs were found in cardiac tissue by FISH. CEPCs treatment led to a better cardiac function, RMBF and capillary density than BM-EPCs. Different biological properties were observed between CEPCs and BM-EPCs. Autologous CEPCs are more suitable for the AMI rat.

Effects of Resveratrol on Endothelial Progenitor Cells and Their Contributions to Reendothelialization in Intima-injured Rats

The aim of this study was to investigate the effects of resveratrol on endothelial progenitor cell (EPC) activities in vitro and on the mobilization of circulating EPCs, and reendothelialization in balloon-injured aorta of rats. After being isolated, cultured, and characterized, human EPCs were stimulated with resveratrol. We found that a low concentration of resveratrol (1 microM) led to significant enhanced activities of proliferation, migration, and adhesion, as well as promoting endothelial nitric acid synthetase (eNOS) expression in EPCs, whereas a high concentration (60 microM) inhibited the aforementioned functions and eNOS expression. In a rat model of injured aorta, a low dosage of resveratrol (10 mg/kg) increased the amount of EPCs in rat circulation as compared with placebo, whereas the result of a high dosage (50 mg/kg) did not reach statistical difference. In addition, 10 mg/kg of resveratrol both accelerated reendothelialization and inhibited neointimal formation; however, 50 mg/kg only reduced neointimal formation, which was not as effective as the previous one. eNOS expression in injured arteries was potently enhanced in the 10 mg/kg group, but not in the 50 mg/kg group. These findings suggest that a low dosage of resveratrol could markedly raise the proliferative, migrative, and adhesive activities of EPCs and upgrade eNOS expression in vitro as well as increase EPC mobilization, enhance eNOS expression, and accelerate the repair of injured artery; however, a high dosage cannot.