Dose Dependent Translocations of Fluorescent Probes of PIP_2 Hydrolysis in Cells Exposed to Nanosecond Pulsed Electric Fields

摘要

Previously, it was demonstrated that small nanometer-sized pores (nanopores) are preferentially formed after exposure to nanosecond pulsed electric fields (nsPEF). We have reported that nanoporation of the plasma membrane directly affects the phospholipids of the cell membrane, ultimately culminating in phosphatidylinositol_(4.5)-bisphosphate (PIP_2) intracellular signaling. PIP_2, located within the internal layer of the plasma membrane, plays a critical role as a regulator of ion transport proteins, a source of second messenger compounds, and an anchor for cytoskeletal elements. In this proceeding, we present data that demonstrates that nsPEFs initiate electric field dose-dependent PIP_2 hydrolysis and/or depletion from the plasma membrane through the observation of the accumulation of inositol_(1,4,5)-trisphosphate (IP_3) in the cytoplasm and the increase of diacylglycerol (DAG) on the inner surface of the plasma membrane. The phosphoinositide signaling cascade presented here involves activation of phospholipase C (PLC) and protein kinase C (PKC), which are responsible for a multitude of biological effects after nsPEF exposure. These results expand our current knowledge of nsPEF induced physiological effects, and serve as a basis for development of novel tools for drug independent stimulation or modulation of different cellular functions.