Transplantation of endothelial progenitor cells transferred by vascular endothelial growth factor gene for vascular regeneration of ischemic flaps.
BACKGROUND
Neovascularization occurs through two mechanisms: angiogenesis and vasculogenesis. Therefore, there are two strategies to promote neovascularization: therapeutic angiogenesis and therapeutic vasculogenesis (endothelial progenitor cells therapy).


METHODS
In this study, we examined whether or not endothelial progenitor cells combined with vascular endothelial growth factor (VEGF) gene therapy is useful for ischemia surgical flaps in vivo. At the same time, we quantitatively compared the neovascularization ability of transplanted endothelial progenitor cells (EPCs) transducted with VEGF165 gene and EPCs alone. EPCs were isolated from cord blood of healthy human volunteers, cultured in vitro for 7 days and identified by immunofluorescence. After transduced with VEGF165 gene in vitro, proliferative activity of EPCs was assessed using MTT assay. CM-DiI was used to trace EPCs in vivo 4 days after injection of 5 x 10(5) VEGF-transduced EPCs(VEGF-transduced EPCs group, n = 10), 5 x 10(5) EPCs (non-transduced EPCs group, n = 10) in 500 microL EBM-2 media, or 500 microL EBM-2 media (EBM-2 media group, n = 10) local, a cranially based flap was elevated on the back of nude mice. The percent flap survival, neovasculariztion and blood flow recovery of flaps was detected.


RESULTS
EPCs expressed cell markers CD34, KDR, and CD133. A statistically significant increase in percent flap survival was observed in mice of VEGF-transduced EPCs group as compared with that of non-transduced EPCs group: 67.99 +/- 6.64% versus 59.43 +/- 4.69% (P < 0.01), and 41.24 +/- 2.44% in EBM-2 media group (P < 0.01). The capillary density and blood flow recovery of flaps in VEGF-transduced EPCs group were both improved. CM-DiI-labeled VEGF-transduced EPCs were observed in vivo and the numbers of cells increased.


CONCLUSIONS
EPCs from human cord blood can increased neovascularization of ischemic flaps and augmented the survival areas, and VEGF-transduced EPCs have more powerful ability of promoting neovascularization in animal model of ischemic flaps.
Department of Plastic Surgery, Xijing Hospital Fourth Military Medical University, Xi'an, Shaanxi Province, China.
Chenggang
C
Yi
Wei
W
Xia
Yan
Y
Zheng
Lingxi
L
Zhang
Maoguo
M
Shu
Jie
J
Liang
Yan
Y
Han
Shuzhong
S
Guo
D000818:Animals; D002455:Cell Division; D036101:Cord Blood Stem Cell Transplantation; D042783:Endothelial Cells / Q000166:cytology; D005312:Fetal Blood / Q000166:cytology; D015316:Genetic Therapy / Q000379:methods*; D006085:Graft Survival / Q000502:physiology; D006801:Humans; D007511:Ischemia / Q000503:physiopathology / Q000628:therapy*; D051379:Mice; D008819:Mice, Nude; D018919:Neovascularization, Physiologic; D013234:Stem Cells / Q000166:cytology / Q000502:physiology; D013524:Surgical Flaps / Q000098:blood supply* / Q000502:physiology; D014161:Transduction, Genetic; D019076:Transgenes / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics*
C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A