Mechanical Strain Induces and Increases Vesicular Release Monitored by Microfabricated Stretchable Electrodes

Area of Science:

• Cell biology
• Biophysics
• Neuroscience

Background:

• Exocytosis, the fusion of intracellular vesicles with the cell membrane, is crucial for cellular communication.
• The influence of mechanical cues on exocytosis is not well understood.
• Single-cell electrochemistry offers a method to study exocytotic events but has limitations in exploring mechanical force effects.

Purpose of the Study:

• To investigate the impact of mechanical force on vesicular exocytosis at the single-cell level.
• To develop a novel microelectrode for real-time measurement of strain-induced exocytosis.
• To elucidate the mechanisms by which mechanical strain modulates catecholamine release.

Main Methods:

• Fabrication of a stretchable microelectrode using functionalized poly(3,4-ethylenedioxythiophene) conductive ink.
• Real-time quantitation of strain-induced vesicular exocytosis from single cells using the developed microelectrode.
• Investigation of calcium influx and Piezo1 channel activation under mechanical strain.

Main Results:

• Developed a stretchable microelectrode with stable electrochemical performance under deformation.
• Achieved the first real-time quantitation of strain-induced vesicular exocytosis from a single cell.
• Demonstrated that mechanical strain induces calcium influx via Piezo1 channel activation in chromaffin cells.
• Showed that mechanical strain increases catecholamine release by altering fusion pore dynamics (accelerated opening, prolonged closing).

Conclusions:

• Mechanical stimuli significantly regulate vesicular exocytosis.
• The developed stretchable microelectrode is a valuable tool for studying mechanotransduction in exocytosis.
• Findings provide insights into how mechanical forces in the microenvironment control cellular release processes.