Nuclear apoptotic volume decrease in individual cells: Confocal microscopy imaging and kinetic modeling.

Area of Science:

• Cell Biology
• Molecular Biology
• Biophysics

Background:

• Apoptosis, or programmed cell death, involves significant cellular restructuring.
• Nuclear morphological changes during early apoptosis are not well understood.
• Investigating these changes offers insights into cell death mechanisms.

Purpose of the Study:

• To investigate the dynamics of nuclear morphological changes in early apoptosis.
• To quantitatively model the observed changes using a molecular kinetic approach.
• To elucidate the molecular mechanisms driving nuclear alterations during apoptosis.

Main Methods:

• Utilized 3D time-lapse confocal microscopy on living HepG2 cells.
• Induced early-stage apoptosis using etoposide.
• Developed and applied a general molecular kinetic model to experimental data.

Main Results:

• Observed simultaneous apoptotic volume decrease (AVD) and peripheral chromatin condensation ('apoptotic ring').
• The developed molecular kinetic model accurately fits the experimental data.
• Provided quantitative evidence for the dynamics of nuclear morphological changes.

Conclusions:

• Nuclear volume decrease and chromatin condensation are concurrent events in early apoptosis.
• The proposed molecular kinetic model successfully describes these dynamic changes.
• Findings contribute to understanding the molecular basis of nuclear apoptosis morphology.