Bioelectrics Research Center, Kumamoto University, Kumamoto 860-8555, Japan.
Biochem Biophys Res Commun. 2012 Nov 23;428(3):371-5. doi: 10.1016/j.bbrc.2012.10.061. Epub 2012 Oct 24.
Nanosecond pulsed electric fields (nsPEFs) are increasingly being recognized as a potential tool for use in the life sciences. Exposure of human cells to nsPEFs elicits the formation of small membrane pores, intracellular Ca(2+) mobilization, signaling pathway activation, and apoptosis. Here we report the activation of AMP-activated protein kinase (AMPK) by nsPEFs. AMPK activation is generally achieved by the phosphorylation of AMPK in response to changes in cellular energy status and is mediated by two protein kinases, LKB1 and CaMKK. Exposure to nsPEFs rapidly induced phosphorylation of AMPK and its downstream target ACC in both LKB1-proficient and LKB1-deficient cells. In LKB1-deficient cells, AMPK activation by nsPEFs was mediated by CaMKK and required extracellular Ca(2+), which suggested the occurrence of Ca(2+) mobilization and its participation in AMPK activation by nsPEFs. Our results provide experimental evidence for a direct link between activated cellular signaling and Ca(2+) mobilization in nsPEF-exposed cells.
纳秒级脉冲电场（nsPEFs）正日益被认为是生命科学中一种有潜力的工具。将人类细胞暴露于 nsPEFs 中会引起小膜孔的形成、细胞内 Ca(2+)动员、信号通路激活和细胞凋亡。在这里，我们报告了 nsPEFs 对 AMP 激活蛋白激酶（AMPK）的激活。AMPK 的激活通常是通过 AMPK 在细胞能量状态变化时的磷酸化来实现的，并且由两种蛋白激酶，LKB1 和 CaMKK 介导。nsPEFs 的暴露会迅速诱导 LKB1 有效和 LKB1 缺陷细胞中 AMPK 的磷酸化及其下游靶标 ACC。在 LKB1 缺陷细胞中，nsPEFs 通过 CaMKK 诱导 AMPK 的激活，需要细胞外 Ca(2+)，这表明 Ca(2+)动员的发生及其参与 nsPEFs 对 AMPK 的激活。我们的结果为细胞信号转导的激活与 nsPEF 暴露细胞中 Ca(2+)动员之间的直接联系提供了实验证据。
