Visualizing Spatiotemporal Dynamics of Intercellular Mechanotransmission upon Wounding

Area of Science:

• Cell Biology
• Biophysics
• Molecular Imaging

Background:

• Intercellular communication relies on physical and biochemical cues, crucial for multicellular organism function.
• Visualizing dynamic intercellular signaling in single live cells remains a significant challenge.
• Understanding the interplay between physical contact and biochemical signaling is vital.

Purpose of the Study:

• To develop a photonic approach for visualizing intercellular signaling dynamics in live cells.
• To investigate the role of physical cues in triggering biochemical signaling cascades.
• To study the molecular mechanisms underlying cell-cell contact loss and subsequent signaling events.

Main Methods:

• Development of a highly sensitive Förster resonance energy transfer (FRET)-based biosensor (SCAGE) for Src kinase.
• Utilized femtosecond laser pulses ('laser microscissors') to precisely sever physical intercellular connections.
• Employed FRET microscopy to visualize real-time Src kinase activation in response to physical perturbations.

Main Results:

• The novel SCAGE biosensor demonstrated over 40-fold sensitivity enhancement in live mammalian cells.
• Severing cell-cell contacts induced a transient Src kinase activation in neighboring cells.
• This Src activation was dependent on passive cytoskeletal support, independent of active actomyosin contractility.

Conclusions:

• The integrated photonic approach enables precise physical perturbation and visualization of intercellular signaling.
• This method provides a unique system for studying the physical-biochemical basis of intercellular coupling and wounding.
• Findings elucidate the role of the cytoskeleton in mediating signaling responses to mechanical stress.