内皮抑素重组腺病毒表达载体构建及对内皮细胞增殖的影响(英文)

Effect of recombinant adenovirus vector expressing human endostatin on endothelial cell proliferation

背景:烧创伤后创面愈合多伴有瘢痕增生,内皮细胞在瘢痕增生中具有重要作用,抑制内皮细胞的生长可以在一定程度上减轻瘢痕增生。目的:构建含有人内皮抑素基因的重组腺病毒Ad/hEnd,并观察与感染该病毒的角朊细胞共培养时内皮细胞增殖特性的改变。设计、时间及地点:观察对照实验,于2006-09/2007-05在解放军第三军医大学西南医院烧伤研究所国家重点实验室完成。材料:pAdTrack-CMV及pAdEasy-1购自美国Stratagene公司;293细胞及大肠杆菌Ecoli.DH5α由本室保存。方法:以人胎肝组织mRNA为模板,通过反转录-聚合酶链反应及聚合酶链反应获得内皮抑素基因序列,插入到腺病毒穿梭质粒pAdTrack-CMV中,获得重组质粒pAdTrack-ES。经鉴定后将阳性重组子转化至pAdeasy1受体菌,筛选阳性克隆。脂质体介导转染293细胞,获取Ad/hEnd,经聚合酶链反应鉴定及上清中内皮抑素含量检测后,感染角朊细胞,采用套皿法与内皮细胞共培养。并与未转染的角朊细胞进行对照观察。主要观察指标:pAd/hEnd的同源重组及其鉴定,Ad/hEnd的产生与鉴定,转染293细胞后内皮抑素的表达,Ad/hEnd的纯化与滴度测定,培养液中内皮抑素含量,内皮细胞凋亡百分数及内皮细胞抑制率测定。结果:①成功获取了Ad/hEnd,病毒滴度可达1.65×1012PFU/L。②感染Ad/hEnd的角朊细胞可有效表达并分泌内皮抑素,连续培养3d后,培养液中内皮抑素含量可达226μg/L。③与转基因角朊细胞共培养的内皮细胞凋亡百分数与细胞抑制率均显著高于对照组(P<0.05)。结论:与内皮细胞共培养时,转Ad/hEnd角朊细胞可通过分泌内皮抑素促进内皮细胞凋亡,并抑制其增殖。

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 Bum 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.DH5 a 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 adenovirus 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 xl012 PFU/L. Ad/hEnd-infected keratinocytes could effectively express and secrete endostatin of which the content reached 226 la g/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.