Electrophilic Modification of PKM2 by 4-Hydroxynonenal and 4-Oxononenal Results in Protein Cross-Linking and Kinase Inhibition.

Rapidly proliferating cells require an increased rate of metabolism to allow for the production of nucleic acids, amino acids, and lipids. Pyruvate kinase catalyzes the final step in the glycolysis pathway, and different isoforms display vastly different catalytic efficiencies. The M2 isoform of pyruvate kinase (PKM2) is strongly expressed in cancer cells and contributes to aerobic glycolysis in what is commonly termed the Warburg effect.

Activation of autophagy in response to nanosecond pulsed electric field exposure.

Previous work demonstrated significant changes in cellular membranes following exposure of cells to nanosecond pulsed electric fields (nsPEF), including nanoporation and increases in intracellular calcium concentration. While it is known that nsPEF exposure can cause cell death, how cells repair and survive nsPEF-induced cellular damage is not well understood. In this paper, we investigated whether autophagy is stimulated following nsPEF exposure to repair damaged membranes, proteins, and/or organelles in a pro-survival response.

Cancellation of cellular responses to nanoelectroporation by reversing the stimulus polarity.

Nanoelectroporation of biomembranes is an effect of high-voltage, nanosecond-duration electric pulses (nsEP). It occurs both in the plasma membrane and inside the cell, and nanoporated membranes are distinguished by ion-selective and potential-sensitive permeability. Here we report a novel phenomenon of bioeffects cancellation that puts nsEP cardinally apart from the conventional electroporation and electrostimulation by milli- and microsecond pulses.

Alkylation damage by lipid electrophiles targets functional protein systems.

Protein alkylation by reactive electrophiles contributes to chemical toxicities and oxidative stress, but the functional impact of alkylation damage across proteomes is poorly understood. We used Click chemistry and shotgun proteomics to profile the accumulation of proteome damage in human cells treated with lipid electrophile probes. Protein target profiles revealed three damage susceptibility classes, as well as proteins that were highly resistant to alkylation.

Bipolar nanosecond electric pulses are less efficient at electropermeabilization and killing cells than monopolar pulses.

Multiple studies have shown that bipolar (BP) electric pulses in the microsecond range are more effective at permeabilizing cells while maintaining similar cell survival rates as compared to monopolar (MP) pulse equivalents. In this paper, we investigated whether the same advantage existed for BP nanosecond-pulsed electric fields (nsPEF) as compared to MP nsPEF. To study permeabilization effectiveness, MP or BP pulses were delivered to single Chinese hamster ovary (CHO) cells and the response of three dyes, Calcium Green-1, propidium iodide (PI), and FM1-43, was measured by confocal microscopy.