Schratzberger Peter, Krainin Joseph G, Schratzberger Gabriele, Silver Marcy, Ma Hong, Kearney Marianne, Zuk Robert F, Brisken Axel F, Losordo Douglas W, Isner Jeffrey M
Department of Cardiovascular Research, St. Elizabeth's Medical Center, Tufts University School of Medicine, Boston, Massachusetts 02135, USA.
Mol Ther. 2002 Nov;6(5):576-83.
This study was designed to test the hypothesis that transcutaneous ultrasound (US) exposure may augment the transfection efficiency and biological outcome associated with nonviral DNA gene transfer. Hindlimb muscles of New Zealand White rabbits were transfected with the reporter plasmid pCMV-beta, with or without US exposure. Optimization studies employed US exposure at various frequencies, mechanical indices, duty cycles, durations of exposure, and exposure time points. Based on these results, we explored the effect of US exposure on nonviral gene transfer of vascular endothelial growth factor (VEGF, phVEGF165) to promote neovascularization of ischemic hindlimbs. Ultrasound at 1 MHz, 100 W/cm(2), 6% duty cycle, and 5 minutes exposure time, applied immediately following DNA injection, was found to be the most effective among the settings tested, increasing beta-galactosidase expression approximately 20 fold. Compared with US exposure alone, or phVEGF165 only, phVEGF165 + US exposure yielded a statistically significant improvement in revascularization, as determined by calf blood pressure ratio, angiographic score, intravascular Doppler blood flow, and capillary/myocyte ratio. These data demonstrate that ultrasound, when applied directly after intramuscular gene transfer, significantly increases transfection efficiency in vivo. The biological significance of this finding was confirmed by augmented limb perfusion in response to US exposure and naked VEGF DNA.
经皮超声（US）照射可提高与非病毒DNA基因转移相关的转染效率及生物学效应。将报告质粒pCMV-β导入新西兰白兔的后肢肌肉，部分进行超声照射，部分不进行。优化研究采用不同频率、机械指数、占空比、照射时长及照射时间点的超声照射。基于这些结果，我们探讨了超声照射对血管内皮生长因子（VEGF，phVEGF165）非病毒基因转移的影响，以促进缺血后肢的血管新生。结果发现，在DNA注射后立即施加1MHz、100W/cm²、6%占空比及5分钟照射时间的超声，在所测试的条件中最为有效，可使β-半乳糖苷酶表达增加约20倍。通过小腿血压比值、血管造影评分、血管内多普勒血流及毛细血管/肌细胞比值测定，与单独超声照射或仅使用phVEGF165相比，phVEGF165 + 超声照射在血管再通方面有统计学显著改善。这些数据表明，肌肉内基因转移后立即施加超声，可显著提高体内转染效率。超声照射联合裸露的VEGF DNA可增加肢体灌注，证实了这一发现的生物学意义。
