Investigation about effects on endoplasmic reticulum stress responses by applying nanosecond pulsed electric fields

The application area of pulsed power technology has been expanding into biological and medical fields. In particular, nanosecond pulsed electric fields (nsPEFs) could directly act on intercellular components without destruction of cell membrane. Clarification of biological effect of endoplasmic reticulum (ER) stress response by nsPEFs would suggest new methods of prevention or therapy of disorders, such as diabetes and obesity. Activation of ER stress response with nsPEFs was investigated in vitro and in vivo experiments. Skeletal muscle of mice was exposed to nsPEFs in vivo experiment. The cell solutions of HEK293, HeLa and C2C12 were exposed to nsPEFs in vitro experiments. Blumlein-type pulse forming network (B-PFN) was used to apply nsPEFs, whose pulse-width was 80 ns, on them. Phosphorylation of eIF2α was investigated by western blot analysis and RT-quantitative PCR analysis to confirm activation of ER stress response. In vivo experiment, Phosphorylation of eIF2α was confirmed, but it was not strong. In vitro experiment, activation of HeLa cell was confirmed by applying nsPEFs. Therefore it is considered that activation of ER stress response by nsPEFs depends on the type of cells.