The group of researchers has developed a novel approach to map plasma membrane tension changes in living cells, shedding light on the mechanical dynamics of neutrophil extracellular trap (NET) formation. Using the mechanosensitive probe Flipper-TR and fluorescence lifetime imaging microscopy (FLIM), the team observed dynamic tension changes during NETosis, a vital immune process.
The study, validated in HeLa and dHL-60 cells under osmotic perturbation, was applied to primary human neutrophils undergoing NETosis. The findings revealed a transient increase in membrane tension during chromatin decondensation and nuclear swelling within the first 60 minutes, followed by a marked decrease after membrane rupture. Notably, the tension was spatially heterogeneous before rupture, indicating localized nanoscale mechanical regulation.
Cholesterol depletion was found to abolish the transient increase in tension and reduce heterogeneity without affecting the kinetics of NETosis. These results establish the plasma membrane as a dynamic nanoscale reporter of intracellular mechanical stress during NETosis, offering a deeper understanding of the mechanical forces at play in cellular processes.
This research opens new avenues for exploring the mechanical dynamics of various cellular processes and could have significant implications for understanding disease mechanisms and developing targeted therapies.
The study was published in the latest issue of the journal “Nano Letters”.