The nucleus acts as a ruler tailoring cell responses to spatial constraints

Area of Science:

• Cell biology
• Biophysics
• Mechanobiology

Background:

• Metazoan organisms present a crowded cellular environment.
• How cells adapt to spatial confinement is not fully understood.

Purpose of the Study:

• To investigate how cells measure and respond to spatial confinement.
• To identify the mechanisms cells use to navigate restrictive environments.

Main Methods:

• Studied cell behavior under varying degrees of spatial confinement.
• Utilized microscopy and biophysical techniques to analyze nuclear deformation and cell contractility.
• Investigated signaling pathways involving the nuclear envelope and actomyosin cortex.

Main Results:

• Cells measure confinement using their nucleus, their largest and stiffest organelle.
• Confinement below nuclear size deforms the nucleus, stretching its envelope.
• This deformation activates actomyosin cortex contractility via stretch-sensitive proteins.
• A nuclear ruler-based signaling pathway was identified, modulating cell contractility.

Conclusions:

• Cells employ a nuclear ruler mechanism to gauge spatial confinement.
• This pathway regulates cell contractility for migration through 3D environments.
• The findings are relevant to cancer invasion, immune responses, and embryonic development.