Serum from rats at different ages modulates the functional activities of rat bone marrow-derived endothelial progenitor cells

AIM: To investigate the effects of serum from rats at different ages on the functional activities of rat bone marrow-derived endothelial progenitor cells (EPCs). METHODS: Mononuclear cells were obtained from bone marrow of young (1 to 2 month-old) and aged (19 to 26 month-old) Sprague-Dawley rats by Ficoll density gradient centrifugation and cultured with medium DMEM/F12 (containing 10% fetal bovine serum, endothelial cell growth supplement ECGs 100 mg/L, 1×10⁵ U/L of penicillin and streptomycin, respectively), 48 h later, the suspending cells were translocated to be cultured in new flasks coated with fibronectin, the secondary attached cells were used to perform the further experiments. EPCs were characterized as double positive for Dil-ac-LDL uptake and lectin binding. The cells were further identified by CD31 and vWF expression. Serum from young (1 to 2 month-old) and aged (19 to 26 month-old) rats was collected and used to culture EPCs. The experiments were divided into four groups: A= aged rat EPCs + aged rat serum; B= aged rat EPCs + young rat serum; C= young rat EPCs +aged rat serum and D= young rat EPCs + young rat serum. After cultured in DMEM/F12 supplemented with 10% serum from rats at different age (no fetal bovine serum addition in this medium), the average fluorescence intensities of EPCs stained with Dil-ac-LDL were tested by laser scanning co-focal microscopy. Migration and proliferation were assayed by modified Boyden chamber and MTT, respectively. Cell adhesion was performed by replacing EPCs onto cultured DAPI-labeled confluent smooth muscle cell monolayer and the adherent cells were counted. RESULTS: Young rat serum significantly improved the ability of aged rat EPCs for uptake of Dil-ac-LDL (P<0.01), increased the migration (P<0.01), adhesion (P<0.05) and proliferation activity (P<0.01) of aged rat EPCs, whereas aged rat serum obviously decreased the migration (P<0.05) and adhesion (P<0.05) activity of the young rat EPCs. CONCLUSION: Young rat serum significantly improves the activity of aged rat EPCs. On the contrary, aged rat serum partially inhibits the activity of young rat EPCs.     

Protective effects of salidroside on endothelial progenitor cells damaged by radiation

AIM: To explore the protective effects of salidroside on endothelial progenitor cells (EPCs) damaged by radiation and its mechanisms.METHODS: EPCs from normal peripheral blood were cultured in fibronectin-coated flasks with endothelial progenitor medium. The effects of salidroside on the viability, migration, adhesion and apoptosis of radiation-damaged EPCs were detected. The viability, apoptosis and migration of the cells were assayed by CCK-8 assay, flow cytometry and Transwell chamber experiment, respectively. The cell adhesion assay was performed by re-plating the cells on fibronectin-coated dishes, and then the adherent cells were counted. The expression of Akt protein in the cells was assessed by Western blotting. RESULTS: Salidroside improved the viability, and migratory and adhesive capacities of the EPCs, and decreased the apoptosis after radiation. Salidroside also increased the protein level of phosphorylated Akt. However, the effects of salidroside on radiation-damaged EPCs were inhibited by phosphatidylinositol 3-kinase inhibitor LY294002. CONCLUSION: Salidroside protects EPCs from radiation damages and its mechanism is associated with enhancing phosphatidylinositol 3-kinase/Akt signaling pathway.     

Intravenous transfusion of endothelial progenitor cells reduces neointima formation

AIM: To investigate the feasibility of transplanting endothelial progenitor cells (EPCs) obtained from spleen in vascular endothelium repairmen after vascular injury. METHODS: EPCs were isolated by using a Ficoll density gradient centrifugation, and were cultured in plate. The endothelial characteristics of EPCs were identified by immunochemical staining and fluorescent labeling. Dil-Ac-LDL labeled spleen-derived EPCs were transplanted into the rats by intravenous injection directly after induction of arterial injury and again 24 hours later. Rats received FITC-labeled lectin intravenously before euthanasia. The distribution of fluorescent labeled EPCs was traced. The morphology of arterial intima and media was studied by optical microscopy and image analysing system. RESULTS: The adherent cells were considered EPCs that showed spindle shape and form blood-siland-like structures during development. The adherent cells had many endothelial characteristics. Fluorescent labeling showed that the intravenously injected EPCs specifically restricted to the vascular injury site, and lectin binding confirmed the endothelial phenotype. The ratio of neointimal/media area in EPCs transplantation group was obviously reduced than that in injury group and M199 group (0.82±0.09 vs 1.52±0.21, 1.48±0.19, P<0.01). The PCNA positive expression cells were evidently decreased compared with injury group and M199 group (19.25±3.96 vs 31.42±5.23, 29.37±3.16, P<0.05). CONCLUSION: EPCs incorporate into the process of injured carotid reendothelialization. EPCs transplantation induces an increase in the circulating EPCs, accelerates the process of endothelial repairmen and reduces neointima formation.     

Effects and possible mechanism of recombinant human erythropoietin on proliferation of endothelial progenitor cells

AIM: To observe the effects of recombinant human erythropoietin on proliferation of endothelial progenitor cells (EPCs) from healthy volunteers and patients with renal failure,and tried to elucidate the possible mechanism.METHODS: Various concentrations of rhEPO were added to the culture system of EPCs from 15 cases of patients with renal failure (RF group) and 15 cases of healthy volunteers (control group).MTT assays were used to detect proliferative rates.Annexin-V/PI stains were used to measure the apoptotic rates.Western blotting was used to determine the expression of Akt protein kinase.RESULTS: Numbers and proliferative ability of EPCs from control group and RF group were improved in dose-dependent manner when concentrations of rhEPO were 100 U/L,600 U/L and 1 200 U/L.However,compared to the control group,numbers and function of EPCs from RF group were remarkably decreased.The apoptosis rate of EPCs was decreased and the activity of Akt protein kinase was improved in the presence of 1 200 U/L rhEPO.Wortmannin was able to block the effects.CONCLUSION: rhEPO improves the number and function of EPCs from both healthy volunteer and patients with renal failure.PI3K/Akt might play an important role in it.     

Effects of erythropoietin on expression of SDF-1 and its receptor in peripheral blood endothelial progenitor cells from rats with chronic renal failure

AIM:To investigate the effects of erythropoietin (EPO) on the expression of homing factors in peripheral blood endothelial progenitor cells (EPCs) from rats with chronic renal failure (CRF). METHODS:The CRF model was established by a two-stage 5/6 nephrectomy procedure in rats. Experimental rats were randomly divided into three groups: sham operation group, CRF model group and EPO treatment group. From the third week after the second stage of 5/6 nephrectomy procedure, rats in EPO treatment group received subcutaneous injection of human recombinant EPO at 50 U/kg every time and three times a week for 6 weeks, and then all the rats were sacrificed. EPCs were isolated from rat peripheral blood and primarily cultured. The mobilization, angiogenesis and functional activity of EPCs in vitro were detected. The mRNA and protein expression of EPO, EPO receptor (EPOR), stromal cell-derived factor 1 (SDF-1) and CXC chemokine receptor 4 (CXCR4) in EPCs was also detected by the methods of real-time PCR and Western blotting. RESULTS:Compared with CRF model group, the expression of EPO and EPOR in EPCs in EPO treatment group was significantly up-regulated (P<0.05). Moreover, the expression of SDF-1 and its receptor CXCR4 in EPCs was also up-regulated by administration of EPO (P<0.05). CONCLUSION: EPO can mobilize EPCs from CRF rat peripheral blood, which may be associated with the increased expression of SDF-1 and its receptor CXCR4.     

Effects of Danggui Buxue decoction on endothelial progenitor cells,serum VEGF and SDF-1 in atherosclerotic rabbits

AIM: To investigate the effects of Danggui Buxue decoction (DBD) on serum vascular endothelial growth factor (VEGF) and stromal cell-derived factor 1 (SDF-1), as well as the activity of circulating endothelial progenitor cells (EPCs) in atherosclerotic rabbits. METHODS: The model of atherosclerosis was established using immune injury and fatty diet for 4 weeks in New Zealand rabbits (n=25). All modeled rabbits were randomized into 5 groups with 5 animals in each group. The rabbits in atherosclerosis group were intragastrically administered with distilled water. The rabbits in simvastatin group were treated with simvastatin at the dose of 1.7 mg/kg. The rabbits in DBD high-dose, middle-dose and low-dose treatment groups were given DBD at the doses of 6 g/kg, 3 g/kg and 1.5 g/kg, respectively. All drugs were given once a day for 2 weeks. After treatment, the levels of serum VEGF and SDF-1 were measured. The mononuclear cells isolated from the rabbit peripheral blood were cultured for 7 days in vitro, and then attached cells were cultured with both DiI-ac-LDL and FITC-UEA-1 for identification. The proliferation was detected by MTT method. The cell migration was observed using Transwell chambers. The adhesion determination and in vitro angiogenesis assay were also performed. RESULTS: Compared with atherosclerosis group, the levels of serum VEGF and SDF-1 were elevated (P<0.05), the proliferation, migration, adhesion and angiogenesis of EPCs were all improved in DBD high-dose, middle-dose treatment groups and simvastatin group (P<0.05). CONCLUSION: DBD elevates the levels of serum VEGF and SDF-1 to improve the activity of EPCs in the process of atherosclerosis.     

Effects of Chinese yellow wine on homocysteine-induced dysfunction in rat endothelial progenitor cells

AIM: To investigate whether Chinese yellow wine has influences on homocysteine (Hcy)-induced dysfunction in rat endothelial progenitor cells (EPCs). METHODS: Rat bone marrow was extracted to harvest mononuclear cells (MNCs) by density gradient centrifugation. The MNCs were plated on fibronectin-coated culture dishes, and were induced into EPCs by EGM-2 complete medium supplemented with cell growth factor. The adherent cells were collected 7 d later for all studies. EPCs were characterized as adherent cells double positive for DiI-ac-LDL uptaking and lectin binding by direct fluorescent staining under a laser scanning confocal microscope. The viability, migration, apoptosis and in vitro vasculogenic activity of the EPCs were determined by MTT assay, Transwell chamber assay, apoptosis kit and in vitro vasculogenesis kit, respectively. RESULTS: Compared with control group, the viability, migration and in vitro vasculogenic capacity of the EPCs in Hcy group were significantly decreased (P<0.01). Compared with Hcy group, yellow wine group and red wine group both significantly improved the viability, migration and in vitro vasculogenic capacity of Hcy-induced EPCs (P<0.01). Compared with control group, yellow wine group and red wine group both significantly improved the above-mentioned functions of EPCs (P<0.05). However, no significant difference of apoptosis in all groups was observed. CONCLUSION: Hcy may result in dysfuction of EPCs. Treatment with yellow wine improves Hcy-induced EPC functions.     

Effects of statin reloading before percutaneous coronary intervention on circulatory endothelial progenitor cells and inflammatory cytokines

AIM:To investigate the effects of atorvastatin reloading in pre-percutaneous coronary intervention (PCI) period on endothelial progenitor cell (EPC) count and inflammatory cytokine expression in the stable angina pectoris patients who had previously received long-term statin treatment. METHODS:The patients with stable angina pectoris that had received long-term statin therapy and planned to accept PCI were randomized into 3 groups: 80 mg atorvastatin 12 h and 40 mg 2 h before coronary angioplasty (80 mg reloading), pre-operatively with 40 mg/d atorvastatin for 7 d (40 mg reloading), and without atorvastatin reloading (no reloading). CD45-/CD133+/CD34+, CD45-/CD34+/KDR+ and CD45-/CD144+/KDR+ EPCs in 100 μL peripheral blood were determined by flow cytometry 1 h prior to PCI and 1 h, 6 h and 24 h after PCI. The serum concentrations of soluble intercellular adhesion molecule 1 (sICAM-1), C-reactive protein (CRP) and troponin I (TnI) were analyzed immediately prior to and 24 h after PCI. RESULTS: (1) In 80 mg reloading group, the numbers of circulating CD45-/CD133+/CD34+ and CD45-/CD34+/ KDR+ early differentiation stage EPCs 1 h and 6 h after coronary angioplasty was significantly elevated compared with those before PCI (P<0.05). (2) In control group, the serum concentrations of sICAM-1 and CRP 24 h after PCI were significantly elevated (P<0.05) compared with preoperative values. (3) The rise in serum TnI concentration from pre- to post-operation in 80 mg reloading group was lower than that in control group. CONCLUSION: The method of atorvastatin reload before PCI affects the number of EPCs in peri-operative period. High dose of atorvastatin application before PCI triggers early EPC circulation. The serum levels of post-operative inflammatory cytokine sICAM-1 as well as CRP are reduced by atorvastatin reloading before PCI.     

Insulin protects endothelial progenitor cells against functional damage caused by high glucose

AIM: To investigate the impact of various levels of glucose on endothelial progenitor cells (EPCs) proliferation, senescence, and nitric oxide (NO) secretion,and the effect of insulin under high glucose conditions.METHODS: Mononuclear cells were collected from rat bone marrow by density gradient centrifugation, cultured with medium 199, and identified to be EPCs at 7th day by flk-1 and AC133 double staining. EPCss were harvested and incubated with glucose (5, 10, 20, 40 mmol/L) or insulin (0.1, 1, 10, 100 nmol/L) under high glucose conditions for 24 h or 7 days. Proliferative capacity, senescence level and NO secretion (after 24 h of incubation) were subsequently determined.RESULTS: High glucose (40 mmol/L) markedly inhibited EPCs proliferation, accelerated EPCs senescence, and decreased NO production (all P<0.05). Compared with high glucose (40 mmol/L) group, insulin intervention promoted EPCs proliferation, inhibited EPCs senescence (prominent at 1 nmol/L, P<0.05), and enhanced NO secretion (prominent at 10 nmol/L, P<0.05).CONCLUSION: High glucose harms EPCs proliferation and function, while insulin alleviates this jeopardy, indicating the protective role of insulin for the cardiovascular system.     

Transforming growth factor α promotes the proliferation,migration and adhesion of human endothelial progenitor cells

AIM: To explore the effects of transforming growth factor-α (TGF-α) in the monoclonal formation, proliferation, migration and adhesiveness of human endothelial progenitor cells (EPCs). METHODS: The isolated and cultured EPCs were treated with various concentrations of TGF-α (final concentrations of 1, 5, 10 μg/L, respectively). At the same time, the PBS control and epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) group (10 μg/L TGF-α plus 1: 1 000 EGFR-TKI) were set. The effects of TGF-α on monoclonal formation, proliferation, migration and adhesiveness of EPCs were determined by clone formation experiment, thiazolyl blue tetrazolium bromide (MTT), EdU, Transwell and adhesion assays, respectively. The expression of epithelial growth receptor (EGFR) and vascular endothelial growth factor (VEGF) were measured by Western blotting. RESULTS: Different concentrations of TGF-α all significantly induced the monoclonal formation, proliferation, migration and adhesiveness of EPCs (P<0.01), which were inhibited by EGFR-TKI. The results of Western blotting showed that TGF-α also induced the expression of EGFR and VEGF with a certain concentration effect (P<0.01). CONCLUSION: By combining with EGFR induced the expression of VEGF, TGF-α significantly promotes the related cell function of monoclonal formation, proliferation, migration, adhesiveness in EPCs.     

Effects of high-glucose on proliferation and apoptosis in endothelial progenitor cells of type 2 diabetes mellitus

AIM: This study aimed to observe the effects of high-glucose on proliferation and apoptosis of endothelial progenitor cells (EPCs) in type 2 diabetes mellitus patients,and tried to elucidate their possible role.METHODS: Various concentrations of glucose were added to the culture system of EPCs from 25 cases of type 2 diabetes mellitus patients (DM group) and 25 cases of healthy volunteers (control group).MTT assays were used to detect the proliferative rates.Annexin-V/PI stains were used to detect the apoptotic rates,and RT-PCR to detect the expression level of bcl-2 and bax.RESULTS: Proliferative activity of EPCs in both control group and DM group were attenuated when concentration of glucose was 33 mmol/L,while apoptotic rates increased.No significant change of proliferative rate and apoptotic rate of EPCs in DM group and control group in the presence of 5 mmol/L glucose was observed.The expression level of bax of EPCs in both DM group and control group increased while expression level of bcl-2 did not change much in the presence of 33 mmol/L glucose.CONCLUSION: High-glucose attenuates proliferative activity of EPCs and increases the apoptotic rate.Upregulation of bax may be its possible role.     

BYHWD promotes endothelial progenitor cells to repair damaged vascular endothelium

AIM: To investigate the role of Buyanghuanwu decoction (BYHWD) in promoting endothelial progenitor cells (EPCs)-induced recovery of damaged vascular endothelium. METHODS: The endothelial damaged rats were lavaged with BYHWD and injected with EPCs through vena caudalis. The repaired situation of damaged endothelium was observed. RESULTS: Compared with EPCs group and BYHWD group, the endothelial thickness was reduced, the levels of calcium, triglycerides and total cholesterol were decreased, but the high density lipoprotein levels were increased. In addition, the protein expression of vascular endothelial nitric oxide synthase and vascular stromal cell-drived factor-1 was sig-nificantly increased, but the expression of CXC chemokine receptor-4 was significantly reduced in BYHWD+EPC group. CONCLUSION: BYHWD promotes EPCs repairing damaged endothelium, the mechanism may be related to improve the internal environment and promotes the EPCs homing.     

Effect of salidroside on activity of endothelial progenitor cells and phosphoinositide 3-kinase/Akt signaling pathway

AIM：To investigate whether salidroside has influence on the activities of endothelial progenitor cells (EPCs) and its mechanism. METHODS：Mononuclear cells from normal human peripheral blood were cultured in fibronectin coated flasks in endothelial progenitor medium. After 7 d, EPCs were characterized as adherent cells with acLDL-DiI uptaking and lectin binding by direct fluorescent staining. The proliferation and migration of EPCs were analyzed by MTT assay and Transwell chamber assay, respectively. The EPCs adhesion assay was performed by re-plating the cells on fibronectin-coated dishes, and then adherent cells were counted. NO and Akt protein were also detected. RESULTS：Salidroside promoted EPCs proliferative, migratory and adhesive capacities in a concentration dependent manner. Salidroside also increased NO secretion, and the level of phosphorylated Akt protein. However, the effects of salidroside on EPCs were inhibited by phosphoinositide 3-kinase inhibitor LY294002. CONCLUSION：Salidroside regulates the activity of EPCs by phosphoinositide 3-kinase/Akt signaling pathway.     

Gender differences in adult circulating endothelial progenitor cells (EPCs) and effect of estradiol on arousing of EPCs in vitro

AIM: To investigate the gender differences and influence of menstrual cycle on the number and activity of adult circulating endothelial progenitor cells (EPCs), and the effect of estradiol on EPCs. METHODS: Ten men and 10 women were enrolled in the study. Peripheral blood samples of the men were collected only once and peripheral blood samples of the women were collected at each menstrual cycle phase (menstrual, pre-ovulatory and mid-luteal phases). The number of CD34⁺/CD133⁺/kinase insert domain-containing receptor (KDR)⁺ EPCs was determined by flow cytometry analysis and the level of circulating estradiol was measured by radioimmunoassay. Mononuclear cells were isolated from the blood and cultured in vitro. After cultured for 7 days, the number and the adhesive capacity of EPCs were observed. The effect of estradiol on the EPCs were detected by transmembrane migration assay and proliferation assay. RESULTS: The number of circulating EPCs was significantly higher in women than that in men (P<0.01), and it was higher at the pre-ovulatory phase and the mid-luteal phase than that at the menstrual phase (P<0.05). After cultured in vitro, the activity of EPCs did not reveal gender difference. In the cells treated with estradiol at concentration of ≥1×10^-9 mol/L, the capacities of transmembrane migration and proliferation were significantly increased (P<0.05). CONCLUSION: There are the gender differences of adult circulating EPCs between men and women. The number and activity of adult circulating EPCs may be regulated by menstrual cycle. In addition, estrogen plays an important role in the arousing of EPCs.     

Influence of coadministration of β-mercaptoethanol and nitroglycerin on cell viability of peripheral blood-derived endothelial progenitor cells in patients with coronary heart disease

AIM: To observe the effects and mechanisms of nitroglycerin (NTG) on cell viability and β-mercaptoethanol (β-ME) on ameliorating nitrate tolerance of peripheral blood-derived endothelial progenitor cells (EPCs) in coronary heart disease (CAD) patients.METHODS: We studied 75 patients with diagnosis of coronary artery disease who were assigned to control group and NTG group. EPCs were evaluated by flow cytometry. Vascular endothelial growth factor-A (VEGF-A) and peroxynitrite anion (ONOO^-) production were measured by ELISA. EPCs were cultured in vitro with NTG and β-ME stimulation. The cell viability was determined by MTT assay. The levels of VEGF-A, ONOO^- and reactive oxygen species (ROS) were measured by ELISA and DCFH-DA assay. The protein levels of Akt,p-Akt,endothelial nitric oxide synthase (eNOS) and p-eNOS were determined by Western blot. RESULTS: Compared with the control group, the circulating EPCs levels were significantly lowered, plasma ONOO^- production was vitally increased, but there was a markedly decrease of VEGF-A production in the patients treated with excess NTG(P<0.05). Moderate dose of NTG increased the viability of EPCs, VEGF-A production, and phosphorylated protein levels of Akt and eNOS. Excess NTG was shown to reverse the effect of moderate dose of NTG, but β-ME improved the adverse effect of excess NTG. CONCLUSION: Moderate dose of NTG effectively promotes EPCs viability by PI3K/Akt/eNOS signaling pathway and β-ME improves NTG-induced tolerance by reducing oxidative stress and up-regulating the PI3K/Akt/eNOS signaling pathway.     

Bone marrow origin of endothelial progenitor cells responsible for postnatal vasculogenesis in physiological and pathological neovascularization

Endothelial progenitor cells (EPCs) exist in bone marrow, umbilical cord blood and peripheral blood of adult mammals, including humans. Furthermore, the discovery of EPCs has led to the notion of adult vasculogenesis, in which bone marrow (BM)-derived EPCs home to and incorporate into sites of new blood vessel formation, where they differentiate into endothelial cells, which is consistent with postnatal vasculogenesis. It has become apparent that circulating BM-derived EPCs are involved in promoting physiologic and pathologic neovascularization, such as wound healing and tumor growth. They are of great clinical importance in pro- or anti-angiogenic therapies.     

Effects of triptolide on changes of endothelial progenitor cells from peripheral blood

AIM: To investigate the effects of triptolide on endothelial progenitor cells from peripheral blood.METHODS: Total mononuclear cells (MNCs) were isolated from peripheral blood by density gradient centrifugation.The cells were plated on fibronectin-coated culture dishes.After 7 d of culture,adherent cells were characterized by demonstrating the expression of CD34,CD31 and vWF with immunohistochemistry.Adherent cells were stimulated with triptolide (2.5,5.0,10.0,20.0 μg/L) or vehicle control for 24 h.Activities of EPCs in terms of proliferation and migration were determined by MTT assay and modified Boyden chamber assay,respectively.EPCs adhesion assay was performed by replating MNCs on fibronectin-coated dishes,and then the adherent cells were counted.RESULTS: The proliferative,migratory and adhesive capacities of EPCs decreased significantly after 24 h incubation with triptolide,maximum at 20 μg/L (compared to that in control group).In patients with coronary heart disease,the biological function of EPCs was lower than that in patients without coronary heart disease in low dosage of triptolide but almost the same in high dosage group.CONCLUSION: Triptolide may inhibit functional activities of EPCs,the reendothelization and neovascularization of vessel.     

Overexpression of Jagged1 promotes aged rat-derived endothelial proge-nitor cells differentiating into mature endothelial cells

AIM: To investigate the effect of Jagged1 overexpression on endothelial cell-directional differentiation of aged rat-derived endothelial progenitor cells (EPC).METHODS: Mononuclear cells were obtained from bone marrow of young (1 to 2 months old) or aged (19 to 26 months old) Sprague-Dawley rats and cultured in DMEM/F12 medium supplemented with 10% FBS. EPC were characterized as double positive for DiI-ac-LDL uptake and lectin binding. The experiments were divided into control group, PIRES2-EGFP transfection group, PIRES2-EGFP-Jagged1 transfection group and young rat-derived EPC group in which transfection was not performed. The GFP expression positive cell number was acquired by fluorescence microscopy and the transfection efficiency was calculated. Immunofluorescence, RT-PCR and Western blotting were used to detect the mRNA and protein expression. In vitro vasculogenesis kit was used to test the tube formation ability of EPC.RESULTS: EGFP-Jagged1 transfection induced a significant increase in the expression of Jagged1 in aged rat-derived EPC (P<0.01). Compared with the control, Jagged1 overexpression markedly enhanced the mRNA expression of von Willebrand factor (vWF) and kinase insert domain receptor (KDR) of vascular endothelial grouth factor vWF in aged rat-derived EPC (P<0.01) and improved the EPC-related tube formation (P<0.01). No significant difference between Jagged1 transfection and young rat-derived EPC groups in vWF and KDR mRNA expression and the ability of tube formation was found. CONCLUSION: In endothelial cell-conditioning medium, Jagged1 overexpression significantly promotes aged rat-derived EPC differentiation into mature endothelial cells.