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Strategies for Tracking Anastasis, A Cell Survival Phenomenon that Reverses Apoptosis
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Strategies for Tracking Anastasis, A Cell Survival Phenomenon that Reverses Apoptosis

Published on: February 16, 2015

Protease inhibitors block apoptosis at intermediate stages: a compared analysis of DNA fragmentation and apoptotic

L Ghibelli1, V Maresca, S Coppola

  • 1Dipartimento di Biologia, Università di Roma Tor Vergata, Italy.

FEBS Letters
|December 11, 1995
PubMed

Insights

This study reveals how DNA digestion correlates with nuclear changes during apoptosis. Protease inhibitors block DNA fragmentation, offering insights into intermediate stages of programmed cell death.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Apoptosis, or programmed cell death, involves characteristic DNA fragmentation and nuclear morphological changes.
  • Understanding the precise correlation between DNA digestion and nuclear morphology is crucial for deciphering cell death pathways.

Purpose of the Study:

  • To investigate the correlation between DNA digestion and nuclear morphology during apoptosis.
  • To identify intermediate stages of apoptosis by blocking the process using protease inhibitors.
  • To compare the effects of different apoptogenic drugs and protease inhibitors on U937 cells.

Main Methods:

  • Blocking apoptosis at intermediate stages using protease inhibitors.
  • Treating U937 cells with apoptogenic drugs (etoposide, puromycin, tributyltin) and protease inhibitors.
  • Analyzing nuclear morphology and DNA digestion patterns using DNA analysis.
  • Comparing DNA fragment sizes with observed nuclear morphologies.

Main Results:

  • Protease inhibitors prevented the development of typical apoptotic features without causing necrosis.
  • Abnormal nuclear morphologies were observed, representing intermediate stages of apoptosis.
  • DNA analysis demonstrated an inhibitor-dependent blockade of apoptotic DNA digestion.
  • Specific correlations were found: loss of nuclear shape with >2 Mb DNA band, chromatin condensation with 50 kb DNA fragments, and nuclear fragmentation with DNA laddering.
  • Protease inhibitors blocked the formation of 700-300 kb fragments in etoposide-treated cells, suggesting a cell-mediated origin.

Conclusions:

  • The study establishes clear correlations between specific DNA digestion patterns and nuclear morphological changes during apoptosis.
  • Protease inhibitors are effective tools for dissecting intermediate stages of apoptosis and understanding DNA fragmentation.
  • The findings suggest that certain DNA fragments (700-300 kb) may result from cell-mediated effects during etoposide-induced apoptosis.

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