Nanosecond electric pulses penetrate the nucleus and enhance speckle formation

Abstract

Nanosecond electric pulses generate nanopores in the interior membranes of cells and modulate cellular functions. Here, we used confocal microscopy and flow cytometry to observe Smith antigen antibody (Y12) binding to nuclear speckles, known as small nuclear ribonucleoprotein particles (snRNPs) or intrachromatin granule clusters (IGCs), in Jurkat cells following one or five 10 ns, 150 kV/cm pulses. Using confocal microscopy and flow cytometry, we observed changes in nuclear speckle labeling that suggested a disruption of pre-messenger RNA splicing mechanisms. Pulse exposure increased the nuclear speckled substructures by 2.5-fold above basal levels while the propidium iodide (PI) uptake in pulsed cells was unchanged. The resulting nuclear speckle changes were also cell cycle dependent. These findings suggest that 10 ns pulses directly influenced nuclear processes, such as the changes in the nuclear RNA-protein complexes. Published by Elsevier Inc.Keywords: Nucleus; Nuclear speckles; Small nuclear ribonucleoprotein particles/intrachromatin granule clusters; Intracellular electromanipulation; Nanosecond electric pulsesWe have been exploring a new nanosecond (ns) time domain in cell biology. When cells are exposed to intense (50-300 kV/cm) pulsed electric fields (PEFs) with rise times faster than the time it takes for charges on the plasma membrane to redistribute, the electric field can penetrate into the interior of the cell and organelles. If these fields exceed the breakdown threshold of these membranes, nanopores will form in the organelle membranes [1,2]. To better understand the mechanism involved, mathematical models for the cellular electropermeabilization due to nsPEFs have been developed [3,4]. The resulting changes in cellular structures and functions differ significantly from traditional electroporation [microseconod to millisecond pulsed electric fields (PEFs)] [1,5,6]. Increased permeabilization of the plasma membrane, typically demonstrated by measuring propidium iodide (PI) uptake, due to nsPEFs was delayed compared to traditional electroporation [5,6], indicating that it was an indirect effect. These nsPEFs 0006-291X/$ -see front matter Published by Elsevier Inc.

Induction of cell growth arrest by atmospheric non-thermal plasma in colorectal cancer cells

“…The effects of cold atmospheric plasma were shown to be due not to heat, but to active species, mainly oxygen/hydroxyl radicals and nitric oxide, generated in the plasma or in the tissue brought into contact with the plasma (Chen et al, 2007). Plasma treatment offers the possibility of modifying tissues at the cellular level and removing affected sections without inflammation and damage, as well as suppressing infections (Kieft et al, 2004;Stoffels et al, 2006).…”

Cell responses without receptors and ligands, using nanosecond pulsed electric fields (nsPEFs)

“…36 By unknown mechanisms, nsPEFs also increase the substructures of small nuclear ribonucleoprotein particles or intrachromatin granule clusters, suggesting the modification of pre−messenger RNA-splicing mechanisms. 37 However, it should be considered that some nsPEF effects are secondary to or require plasma membrane pore formation. NsPEF effects can be considered "supranatural."…”

Effects of atmospheric nonthermal plasma on invasion of colorectal cancer cells

“…10 The effects of nonthermal, atmospheric plasmas are due to active species, mainly oxygen/hydroxyl radicals and nitric oxide, generated in the plasma or in the tissue brought into contact with the plasma. 11 In fibroblast cells, plasmas affect migration. At a mild level of plasma exposures, the migration of fibroblasts is decreased, whereas at a medium level exposure, cells are detached from the extracellular matrix.…”