门静脉注射超声微泡促进肝脏EGFP质粒表达

Enhancement of hepatic EGFP plasmid expression by introportal infusion of ultrasound microbubbles

目的探讨门静脉注射超声微泡对肝脏增强型绿色荧光蛋白(EGFP)质粒表达的影响。方法 48只健康SPF级雄性SD大鼠随机分为3组,每组16只。A组经尾静脉注射EGFP裸质粒,B、C组分别经尾静脉和门静脉导管注射微泡与EGFP质粒混悬液,同时按设定参数和时间超声辐照肝区。转染后第1、3、7、11天每组随机处死4只大鼠,肝组织冰冻切片,荧光显微镜观察EGFP表达。结果 3组大鼠转染后第1天发现少量荧光,第3天达高峰;A组于第7天荧光基本消失,B、C组第7天仍持续表达。第3、7天,B、C两组转染率较A组明显增加(P<0.05),第3天C组的转染率较B组也有增加(P<0.05)。结论门静脉注射超声微泡可显著提高肝脏EGFP质粒转染率,可作为一种安全、有效的靶向基因体内转运载体。

Objective To study the impact of introportal infusion of ultrasound microbubbles on enhanced green fluorescent protein （EGFP） plasmid expression in the liver. Methods Forty-eight healthy male SPF SD rats were randomly divided into 3 groups, each of 16 animals. Group A were injected with naked EGFP plasmid via tail vein. Group B and C were given with the mixture of EGFP plasmids and ultrasound microbubbles via tail vein and portal vein, respectively, followed by ultrasound wave irradiation over the hepatic region. Four rats in each group were randomly sacrificed on day 1, 3, 7 and 11 post-transfection. EGFP expression in frozen hepatic sections was observed by fluorescent microcopy. Results The fluorescence was weak on day 1, peaked on day 3, and almost disappeared in Group A. However, the fluorescence reached the peak on day 3, and continued to overexpress on day 7 in Group B and C. Transfection rate of EGFP plasmid was higher in Group B and C than that in Group A on day 3 and 7 （P〈0.05）. Also, transfection efficiency of EGFP plasmid in Group C was superior to that in Group B on day 3 （P〈0.05）. Conclusion Introportal infusion of ultrasound microbubbles can improve the hepatic transfection efficiency of EGFP plasmid, which might serve as an effective and safe in vivo transporter for target gene.