Beebe Stephen J, White Jody, Blackmore Peter F, Deng Yuping, Somers Kenneth, Schoenbach Karl H
Eastern Virginia Medical School, Norfolk, Virginia 23510, USA.
DNA Cell Biol. 2003 Dec;22(12):785-96. doi: 10.1089/104454903322624993.
The application of pulsed electric fields to cells is extended to include nonthermal pulses with shorter durations (10-300 ns), higher electric fields (< or =350 kV/cm), higher power (gigawatts), and distinct effects (nsPEF) compared to classical electroporation. Here we define effects and explore potential application for nsPEF in biology and medicine. As the pulse duration is decreased below the plasma membrane charging time constant, plasma membrane effects decrease and intracellular effects predominate. NsPEFs induced apoptosis and caspase activation that was calcium-dependent (Jurkat cells) and calcium-independent (HL-60 and Jurkat cells). In mouse B10-2 fibrosarcoma tumors, nsPEFs induced caspase activation and DNA fragmentation ex vivo, and reduced tumor size in vivo. With conditions below thresholds for classical electroporation and apoptosis, nsPEF induced calcium release from intracellular stores and subsequent calcium influx through store-operated channels in the plasma membrane that mimicked purinergic receptor-mediated calcium mobilization. When nsPEF were applied after classical electroporation pulses, GFP reporter gene expression was enhanced above that observed for classical electroporation. These findings indicate that nsPEF extend classical electroporation to include events that primarily affect intracellular structures and functions. Potential applications for nsPEF include inducing apoptosis in cells and tumors, probing signal transduction mechanisms that determine cell fate, and enhancing gene expression.
脉冲电场对细胞的应用范围得以扩展，涵盖了持续时间更短（10 - 300纳秒）、电场更高（≤350千伏/厘米）、功率更高（千兆瓦）且与传统电穿孔相比具有独特效应（纳秒级脉冲电场，nsPEF）的非热脉冲。在此，我们定义了这些效应，并探索了nsPEF在生物学和医学中的潜在应用。随着脉冲持续时间降至质膜充电时间常数以下，质膜效应减弱，而细胞内效应占主导。纳秒级脉冲电场诱导了细胞凋亡和半胱天冬酶激活，其中在Jurkat细胞中是钙依赖性的，在HL - 60和Jurkat细胞中是钙非依赖性的。在小鼠B10 - 2纤维肉瘤肿瘤中，纳秒级脉冲电场在体外诱导了半胱天冬酶激活和DNA片段化，并在体内减小了肿瘤大小。在低于传统电穿孔和细胞凋亡阈值的条件下，纳秒级脉冲电场诱导细胞内钙库释放钙，随后钙通过质膜上的储存-操作性通道内流，这模拟了嘌呤能受体介导的钙动员。当在传统电穿孔脉冲后施加纳秒级脉冲电场时，绿色荧光蛋白报告基因的表达比传统电穿孔时增强。这些发现表明，纳秒级脉冲电场扩展了传统电穿孔，使其包括主要影响细胞内结构和功能的事件。纳秒级脉冲电场的潜在应用包括诱导细胞和肿瘤凋亡、探究决定细胞命运的信号转导机制以及增强基因表达。
