Nanoelectropulse-driven membrane perturbation and small molecule permeabilization

<p>Abstract</p> <p>Background</p> <p>Nanosecond, megavolt-per-meter pulsed electric fields scramble membrane phospholipids, release intracellular calcium, and induce apoptosis. Flow cytometric and fluorescence microscopy evidence has associated phospholipid rearrangemen...

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Main Authors: Sun Yinghua, Vernier P Thomas, Gundersen Martin A
Format: Article
Language:English
Published: BMC 2006-10-01
Series:BMC Cell Biology
Online Access:http://www.biomedcentral.com/1471-2121/7/37
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author Sun Yinghua
Vernier P Thomas
Gundersen Martin A
author_facet Sun Yinghua
Vernier P Thomas
Gundersen Martin A
author_sort Sun Yinghua
collection DOAJ
description <p>Abstract</p> <p>Background</p> <p>Nanosecond, megavolt-per-meter pulsed electric fields scramble membrane phospholipids, release intracellular calcium, and induce apoptosis. Flow cytometric and fluorescence microscopy evidence has associated phospholipid rearrangement directly with nanoelectropulse exposure and supports the hypothesis that the potential that develops across the lipid bilayer during an electric pulse drives phosphatidylserine (PS) externalization.</p> <p>Results</p> <p>In this work we extend observations of cells exposed to electric pulses with 30 ns and 7 ns durations to still narrower pulse widths, and we find that even 3 ns pulses are sufficient to produce responses similar to those reported previously. We show here that in contrast to unipolar pulses, which perturb membrane phospholipid order, tracked with FM1-43 fluorescence, only at the anode side of the cell, bipolar pulses redistribute phospholipids at both the anode and cathode poles, consistent with migration of the anionic PS head group in the transmembrane field. In addition, we demonstrate that, as predicted by the membrane charging hypothesis, a train of shorter pulses requires higher fields to produce phospholipid scrambling comparable to that produced by a time-equivalent train of longer pulses (for a given applied field, 30, 4 ns pulses produce a weaker response than 4, 30 ns pulses). Finally, we show that influx of YO-PRO-1, a fluorescent dye used to detect early apoptosis and activation of the purinergic P2X<sub>7 </sub>receptor channels, is observed after exposure of Jurkat T lymphoblasts to sufficiently large numbers of pulses, suggesting that membrane poration occurs even with nanosecond pulses when the electric field is high enough. Propidium iodide entry, a traditional indicator of electroporation, occurs with even higher pulse counts.</p> <p>Conclusion</p> <p>Megavolt-per-meter electric pulses as short as 3 ns alter the structure of the plasma membrane and permeabilize the cell to small molecules. The dose responses of cells to unipolar and bipolar pulses ranging from 3 ns to 30 ns duration support the hypothesis that a field-driven charging of the membrane dielectric causes the formation of pores on a nanosecond time scale, and that the anionic phospholipid PS migrates electrophoretically along the wall of these pores to the external face of the membrane.</p>
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spelling doaj.art-9983b719085c4526b754b927fb6a97e52022-12-22T02:59:42ZengBMCBMC Cell Biology1471-21212006-10-01713710.1186/1471-2121-7-37Nanoelectropulse-driven membrane perturbation and small molecule permeabilizationSun YinghuaVernier P ThomasGundersen Martin A<p>Abstract</p> <p>Background</p> <p>Nanosecond, megavolt-per-meter pulsed electric fields scramble membrane phospholipids, release intracellular calcium, and induce apoptosis. Flow cytometric and fluorescence microscopy evidence has associated phospholipid rearrangement directly with nanoelectropulse exposure and supports the hypothesis that the potential that develops across the lipid bilayer during an electric pulse drives phosphatidylserine (PS) externalization.</p> <p>Results</p> <p>In this work we extend observations of cells exposed to electric pulses with 30 ns and 7 ns durations to still narrower pulse widths, and we find that even 3 ns pulses are sufficient to produce responses similar to those reported previously. We show here that in contrast to unipolar pulses, which perturb membrane phospholipid order, tracked with FM1-43 fluorescence, only at the anode side of the cell, bipolar pulses redistribute phospholipids at both the anode and cathode poles, consistent with migration of the anionic PS head group in the transmembrane field. In addition, we demonstrate that, as predicted by the membrane charging hypothesis, a train of shorter pulses requires higher fields to produce phospholipid scrambling comparable to that produced by a time-equivalent train of longer pulses (for a given applied field, 30, 4 ns pulses produce a weaker response than 4, 30 ns pulses). Finally, we show that influx of YO-PRO-1, a fluorescent dye used to detect early apoptosis and activation of the purinergic P2X<sub>7 </sub>receptor channels, is observed after exposure of Jurkat T lymphoblasts to sufficiently large numbers of pulses, suggesting that membrane poration occurs even with nanosecond pulses when the electric field is high enough. Propidium iodide entry, a traditional indicator of electroporation, occurs with even higher pulse counts.</p> <p>Conclusion</p> <p>Megavolt-per-meter electric pulses as short as 3 ns alter the structure of the plasma membrane and permeabilize the cell to small molecules. The dose responses of cells to unipolar and bipolar pulses ranging from 3 ns to 30 ns duration support the hypothesis that a field-driven charging of the membrane dielectric causes the formation of pores on a nanosecond time scale, and that the anionic phospholipid PS migrates electrophoretically along the wall of these pores to the external face of the membrane.</p>http://www.biomedcentral.com/1471-2121/7/37
spellingShingle Sun Yinghua
Vernier P Thomas
Gundersen Martin A
Nanoelectropulse-driven membrane perturbation and small molecule permeabilization
BMC Cell Biology
title Nanoelectropulse-driven membrane perturbation and small molecule permeabilization
title_full Nanoelectropulse-driven membrane perturbation and small molecule permeabilization
title_fullStr Nanoelectropulse-driven membrane perturbation and small molecule permeabilization
title_full_unstemmed Nanoelectropulse-driven membrane perturbation and small molecule permeabilization
title_short Nanoelectropulse-driven membrane perturbation and small molecule permeabilization
title_sort nanoelectropulse driven membrane perturbation and small molecule permeabilization
url http://www.biomedcentral.com/1471-2121/7/37
work_keys_str_mv AT sunyinghua nanoelectropulsedrivenmembraneperturbationandsmallmoleculepermeabilization
AT vernierpthomas nanoelectropulsedrivenmembraneperturbationandsmallmoleculepermeabilization
AT gundersenmartina nanoelectropulsedrivenmembraneperturbationandsmallmoleculepermeabilization