Nanoelectropulse-induced phosphatidylserine translocation

Area of Science:

• Cellular biology
• Biophysics
• Electrobiology

Background:

• Nanosecond pulsed electric fields (nsPEFs) are known to induce cellular responses.
• The precise mechanisms by which nsPEFs trigger intracellular events remain under investigation.
• Understanding these mechanisms is crucial for applications in cell manipulation and therapy.

Purpose of the Study:

• To investigate the membrane phospholipid rearrangement following nanosecond pulsed electric field exposure.
• To characterize the minimum field strength and pulse parameters required for phosphatidylserine (PS) externalization.
• To elucidate the role of extracellular calcium and temperature in nsPEF-induced cellular effects.

Main Methods:

• Exposure of Jurkat T-lymphoblasts to nanosecond pulsed electric fields (nsPEFs) with varying parameters (field strength, pulse width, repetition rate).
• Assessment of phosphatidylserine (PS) externalization using flow cytometry.
• Monitoring of intracellular calcium levels and membrane integrity.
• Analysis of caspase activation and mitochondrial membrane potential.

Main Results:

• nsPEFs induce PS externalization, calcium redistribution, and apoptosis in Jurkat cells without immediate membrane damage.
• PS externalization occurs within minutes, while apoptosis indicators appear later.
• Microsecond pulse widths, compared to nanosecond, require lower field strengths for PS externalization.
• Pulse repetition rates (2-2000 Hz) and absence of external calcium do not significantly alter PS externalization.
• Joule heating was found to be negligible.

Conclusions:

• Nanosecond pulsed electric fields trigger specific cellular responses, including membrane phospholipid rearrangement and apoptosis, in T-lymphoblasts.
• The study identifies key parameters influencing these effects, such as pulse width and field strength.
• The findings contribute to understanding the fundamental mechanisms of nsPEF-cell interactions.