Cells in Slow Motion: Apparent Undercooling Increases Glassy Behavior at Physiological Temperatures.

Area of Science:

• Biophysics
• Cell Biology
• Biochemistry

Background:

• Protein-solvent interactions are crucial for cellular function.
• Cellular dynamics are typically rapid and non-equilibrium processes.
• Understanding factors that modulate cellular dynamics is important for various biological applications.

Purpose of the Study:

• To investigate the effect of heavy water (D2O) on cellular dynamics.
• To explore the molecular mechanisms behind D2O-induced cellular slowdown.
• To assess the reversibility and potential applications of these observed changes.

Main Methods:

• In vitro experiments with living cells.
• Addition of heavy water (D2O) to cell medium.
• Analysis of protein-solvent interactions and intracellular viscosity.
• Observation of cell morphology, phenotype, proliferation, and migration.

Main Results:

• Heavy water (D2O) significantly increases intracellular viscosity and causes reversible cytoplasm gelation.
• Cellular dynamics, including proliferation and migration, are drastically slowed down.
• Actin networks transition from viscoelastic to elastic behavior, impairing cell movement.
• D2O-induced changes are fully reversible and independent of cellular signaling or expression.

Conclusions:

• Solvent conditions, specifically heavy water (D2O), can reversibly control cellular dynamics.
• Increased intracellular viscosity and altered actin network behavior underlie the observed slowdown.
• This reversible modulation of cellular time offers potential for biological material preservation, such as organ transport.