共聚物P85和微泡造影剂对小鼠骨骼肌超声介导基因转染的影响

目的 探讨共聚物P85、微泡造影剂和超声在质粒DNA对小鼠骨骼肌基因转染中的影响.方法 应用共聚物P85、微泡造影剂Optison与DNA混合后直接小鼠胫前肌(TA)注射,并辐照超声.1周后取出胫前肌并快速冰冻切片,荧光显微镜计数表达GFP转染的肌纤维数,HE染色评价肌肉损伤情况.结果 共聚物P85和微泡造影剂Optison均可促进质粒DNA的基因转染(P<0.01,P<0.05).辐照超声可使P85介导的基因转染效率显著提高(P<0.01),但对微泡造影剂介导的基因转染却无显著提高(P>0.05),并且P85所介导的基因转染效率高于微泡造影剂介导的基因转染效率(P<0.01).微泡造影剂和P85耦合并辐照超声可使质粒的基因转染效率显著提高,与所有各组的差异有统计学意义(P<0.01).同时辐照超声显著增加含微泡造影剂组骨骼肌的损伤面积(P<0.01).结论 共聚物P85和微泡造影剂可介导质粒DNA的基因转染,辐照超声对其有促进作用,三者联合应用具有协同作用.

Effects of P85 and microbubbles on the efficiency of ultrasound-induced gene transduction in skeletal muscle of mice in vivo

Objective To explore the effects of P85,microbubbles and ultrasound on plasmid DNA skeletal muscle gene transduction of mice in vivo. Methods Plasmid encoding green fluorescent protein (GFP) ,which conjugated with 0.05% P85 and/or microbubbles, 10% Optison,was injected into the tibialis anterior(TA) muscle of mice with or without ultrasound irradiation (1 MHz, 1 W/cm2 2 min,20% duty cycle). Mice were killed 1 week after injection. The TA muscles were removed and snap-frozen immediately in isopentane cooled by liquid nitrogen and sections 7 μm thick were cut at intervals. One set of sections mounted with DAPI were used to assess the transfection efficiency by counting the number of GFP-positive fibers under fluorescence microscopy,and the other set of sections were stained with haematoxylin and eosin to assess the tissue damage area. Results The P85 and Optison significantly enhanced the plasmid DNA skeletal muscle gene delivery in vivo separately (P<0.01, P<0.05).Ultrasound exposure could significantly enhance the efficiency of P85 induced gene delivery(P<0.01) but not of Option(P>0.05).The gene delivery efficiency induced by P85 was higher than that by Optison no matter with or without ultrasound irradiation(P<0.01). When the P85 conjugated with Optison, they could further significantly enhance gene delivery efficiency with ultrasound exposure (P<0.01). Meanwhile, ultrasound exposure could increase the muscle damage areas in the groups with microbubbles (P<0.01). Conclusions The P85,microbubbles and ultrasound exposure display synergistic effect to enhance plasmid DNA transduction in skeletal muscle of mice in vivo.