Volume regulation and shape bifurcation in the cell nucleus

Area of Science:

• Cell biology
• Biophysics
• Mechanobiology

Background:

• Nuclear morphology is crucial for cell functions like motility and polarization.
• Abnormal nuclear shape is linked to diseases including cancer, muscular dystrophy, dilated cardiomyopathy, and progeria.
• The physical forces governing nuclear shape are not fully understood.

Purpose of the Study:

• To investigate the mechanical forces that shape the cell nucleus.
• To understand how cell detachment from the extracellular matrix affects nuclear morphology.
• To explore the relationship between the extracellular microenvironment and nuclear structure.

Main Methods:

• Observational studies of adherent cells upon detachment.
• Development of a mathematical model to analyze nuclear shape and volume dynamics.
• Analysis of the role of pressure differences across the nuclear envelope.

Main Results:

• Cell detachment induces significant nuclear volume reduction and surface folding.
• Mathematical modeling indicates pressure difference across the nuclear envelope is a key determinant of nuclear morphology.
• Microtubules and actin filaments play a role in regulating nuclear shape by influencing pressure.

Conclusions:

• Extracellular microenvironment properties directly impact nuclear morphology.
• Nuclear shape is dynamically regulated by physical forces and cellular components.
• A direct link exists between the cellular environment and gene regulation via nuclear structure.