Effect of recombinant adenovirus vector expressing human endostatin on endothelial cell proliferation / 中国组织工程研究

ABSTRACT

BACKGROUND: Scar hypertrophy is always followed by the wound healing in burn and trauma. Endothelial cells play a key role in scar hypertrophy, so inhibitory growth of endothelial cells can relieve scar hypertrophy to a certain degree. OBJECTIVE: To construct a recombinant adenovirus vector expressing human endostatin (Ad/hEnd), and to investigate the cooperative effect of Ad/hEnd and keratinocyte on endothelial cell proliferation. DESIGN, TIME AND SETTING: Observational study, which was performed in the State Key Laboratory of Trauma, Burn and Combined Injury, Institute of Burn Research, Southwest Hospital of the Third Military Medical University of Chinese PLA between September 2006 and May 2007. MATERIALS pAdTrack-CMV and pAdEasy-1 were obtained from Stratagene Company, USA; 293 cell and Ecoli.DH5α were stored in our laboratory. METHODS: The endostatin gene sequence was obtained by reverse transcription-polymerase chain reaction (RT-PCR) and polymerase chain reaction (PCR) based on mRNA of human fetal hepatic tissue and inserted into the adenovims shuttle plasmid pAdTrack-CMV to obtain recombinant plasmid pAdTrack-ES. After identification, positive recon was transformed into pAdeasy 1 recipient virus to screen positive clones. The adenovirus Ad/hEnd was generated from 293 cells and identified by PCR and fluorescence microscope. Then the keratinocytes were infected with Ad/hEnd, and co-cultured with endothelial cells by nest dish culture method. The content of endostatin was detected, and the non-transfection keratinocytes were used as the controls. MAIN OUTCOME MEASURES: Homologous recombination and identification of pAd/hEnd; generation and identification of Ad/hEnd; endostatin expression after 293 cell transfection; purification and titer measurement of Ad/hEnd; content of endostatin in culture solution; apoptotic percentage of endothelial cells; inhibitory ratio of endothelial cells. RESULTS: Ad/hEnd was constructed and the virus titer was generally up to 1.65×1012 PFU/L. Ad/hEnd-infected keratinocytes could effectively express and secrete endostatin of which the content reached 226 μg/L after 3 days of co-culture. The apoptotic percentage and inhibitory ratio of the endothelial cells co-cultured with Ad/hEnd-infected keratinocytes were significantly higher than those in control group (P<0.05). CONCLUSION: Ad/hEnd-infected keratinocytes co-cultured with endothelial cells can promote apoptosis and inhibit proliferation of endothelial cells through excretion of endostatin.