Infrared Laser Effects on Cell Projection Depend on Irradiation Intermittence and Cell Activity

Area of Science:

• Cell Biology
• Biophysics
• Laser-Induced Cellular Responses

Background:

• Near-infrared (NIR) lasers enable optical guidance of cell protrusions.
• Biochemical and biophysical effects of NIR laser stimulation on cells are not well understood.
• Optimal protocols for NIR laser stimulation of cell protrusions are not established.

Purpose of the Study:

• To analyze the effects of intermittent NIR laser radiation on cell protrusion direction and velocity.
• To investigate the biochemical and biophysical mechanisms underlying NIR laser-induced cell protrusions.
• To determine optimal conditions for enhancing cell protrusion speed and distance using NIR lasers.

Main Methods:

• Utilized multivariate time series analysis of cell leading edge movement.
• Employed intermittent near-infrared laser radiation for cell stimulation.
• Observed actin dynamics using time-lapse imaging of actin-GFP.

Main Results:

• Cell protrusion orientation and advance persisted after NIR laser cessation.
• Increased protrusion velocity ceased immediately upon termination of NIR radiation.
• NIR irradiation accelerated actin recruitment and filament formation in advancing cell protrusions.
• NIR laser stimulation did not induce state switching between retracting and advancing cell edges.

Conclusions:

• NIR laser irradiation influences cell protrusion dynamics and actin polymerization.
• Cell protrusion speed enhancement by NIR lasers requires a pre-advancing leading edge.
• Understanding these mechanisms is crucial for advancing optical guidance techniques in cell biology.