Vernier P Thomas, Sun Yinghua, Marcu Laura, Salemi Sarah, Craft Cheryl M, Gundersen Martin A
Department of Electrical Engineering-Electrophysics, School of Engineering, University of Southern California, Los Angeles, CA 90089-0271, USA.
Biochem Biophys Res Commun. 2003 Oct 17;310(2):286-95. doi: 10.1016/j.bbrc.2003.08.140.
We report here real-time imaging of calcium bursts in human lymphocytes exposed to nanosecond, megavolt-per-meter pulsed electric fields. Ultra-short (less than 30 ns), high-field (greater than 1 MV/m), electric pulses induce increases in cytosolic calcium concentration and translocation of phosphatidylserine (PS) to the outer layer of the plasma membrane in Jurkat T lymphoblasts. Pulse-induced calcium bursts occur within milliseconds and PS externalization within minutes. Caspase activation and other indicators of apoptosis follow these initial symptoms of nanosecond pulse exposure. Pulse-induced PS translocation is observed even in the presence of caspase inhibitors. Ultra-short, high-field, electroperturbative pulse effects differ substantially from those associated with electroporation, where pulses of a few tens of kilovolts-per-meter lasting a few tens of microseconds open pores in the cytoplasmic membrane. Nanosecond pulsed electric fields, because their duration is less than the plasma membrane charging time, develop voltages across intracellular structures without porating the cell.
我们在此报告了对暴露于纳秒级、兆伏每米脉冲电场的人类淋巴细胞中钙爆发的实时成像。超短（小于30纳秒）、高场（大于1兆伏/米）的电脉冲会导致Jurkat T淋巴母细胞胞质钙浓度升高以及磷脂酰丝氨酸（PS）转位至质膜外层。脉冲诱导的钙爆发在数毫秒内发生，而PS外化在数分钟内发生。半胱天冬酶激活和其他凋亡指标在纳秒脉冲暴露的这些初始症状之后出现。即使在存在半胱天冬酶抑制剂的情况下，也能观察到脉冲诱导的PS转位。超短、高场的电扰动脉冲效应与电穿孔相关的效应有很大不同，在电穿孔中，几十千伏每米持续几十微秒的脉冲会在细胞质膜上开孔。纳秒脉冲电场由于其持续时间小于质膜充电时间，会在不使细胞穿孔的情况下在细胞内结构上产生电压。
