Transplantation of VEGF165-gene-transfected endothelial progenitor cells in the treatment of chronic venous thrombosis in rats / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The organization and recanalization of thrombi is a dynamic and complex process. The aim of this research was to study the cotherapeutic effect of stem cell transplantation and gene transfection on chronic venous thrombosis.</p><p><b>METHODS</b>We constructed a recombinant adenoviral vector carrying the vascular endothelial growth factor 165 (VEGF165) gene by using the pAdEasy system, which was subsequently identified and amplified. Simultaneously, endothelial progenitor cells (EPCs) were isolated from rat bone marrow using Ficoll, cultured in EBM-2MV medium, and identified. Then, the cells were transfected with the recombinant Ad-VEGF165. The EPCs were labeled with 1,1'-dioctadecyl-3,3,3',3'-tetramethylindocarbocyanine (Dil) before transplantation. A rat model of chronic vein thrombosis was developed by partial ligation of the inferior vena cava. The rats were randomly divided into 4 groups (n = 25, each): A, Ad-VEGF165/EPC-transplantation group received 1 ml (10(6)) of Ad-VEGF165/EPCs; B, EPC-transplantation group received 1 ml (10(6)) of EPCs; C, Ad/EPC-transplantation group received 1 ml (10(6)) of Ad/EPCs; D, control group received 1 ml of the transplantation medium. The thrombi and adjacent caval walls were harvested 28 days after transplantation; real-time quantitative polymerase chain reaction was used to detect the expression level of vascular endothelial growth factor (VEGF) mRNA; and western blotting was used to measure changes in VEGF protein expression. Hematoxylin-eosin staining and immunohistochemical staining were performed to detect recanalization. Neovascularization was detected by immunohistochemical staining using the antibody for von Willebrand factor (vWF), which is a component of endothelial cells. The capillary density was quantitatively determined by counting the capillaries under a high-power microscope.</p><p><b>RESULTS</b>The Ad-VEGF165 was constructed, and bone-marrow-derived EPCs were cultivated and successfully identified. We determined the optimum transfection ratio that promoted the growth of EPCs. After transfection, the EPCs secreted the VEGF protein. After transplantation, the in vivo survival of EPCs and their differentiation into endothelial cells were determined by detecting the fluorescence associated with the Dil stain. VEGF mRNA was expressed in groups A, B, C and D after transplantation, and the VEGF mRNA level in group A was significantly higher than those in groups B, C and D (P < 0.05); the VEGF mRNA levels in groups B and C were significantly higher than those in group D (P < 0.05), and there was no statistical significance between the VEGF mRNA levels in groups B and C. The recanalization capillary density in group A was significantly higher than those in groups B, C (P < 0.05) and D (P < 0.01); the recanalization capillary densities in groups B and C were significantly higher than that in group D (P < 0.05). Moreover, there was no statistical significant difference between the values for groups B and C.</p><p><b>CONCLUSIONS</b>The EPCs were successfully transfected by Ad-VEGF165. A suitable transfection ratio can improve the efficiency of EPCs and the possibility of promotion of angiogenesis after transplantation. Transfected EPCs caused accelerated organization and recanalization of vein thrombi.</p>

An in vitro study of PcDNA3.0-hVEGF165 transfection on endothelial progenitor cell derived from murine bone marrow / 中国普通外科杂志

Objective To investigate the eftect of VEGF gene transtection on endothelial progenitor cell derived from murine bone marrow.Methods Wistar rat's bone marrow was obtained, mononuclear cell isolated,and endothelial progenitor cells(EPS)were cultured in EGM-2MV.EPCs were identified by immunocytochemistry and electron microscope.EPCs were transfected by liposome mediated pcDNA3.0-hVEGF165.VEGF protein level was determined in the cultural medium supernatant after VEGF transfection by ELISA.Cultural medium supernatant was used to co-culture with ECV304,VEGF protein activity was evaluated by MTT.EPCs expression of vWF,VEGF,FLK-1 was detected by immunocytochemistry.Results EPCs were effectively enriched by EGM-2MV,and the EPCs obtained express the typical cell surface markers such as CD34,CD133,FLK-1.The concentration of VEGF protein in supernatant reaches 1280 pg/ml in the 7th day after pcDNA3.0-hVEGF transfection.No influence of EPCs proliferation could be found after transfeetion.The cell surface marker expression of VEGF,FLK-1, vWF became higher with time,and the ratios of positive cell were 88.52%,82.65% and 95.97% respectively.Conclusions pcDNA3.0-hVEGF165 transfeet EPCS mediated by liposome could excrete a high concentration of functional VEGF protein.It is helpful for EPC to maintain the characters of endothelial cell after VEGF gene transfection and differentiate to mature endothelial cell.