Related Experiment Videos
[Effect of mitochondrial energetic state on radiation-induced DNA internucleosomal fragmentation in irradiated
V E Galitovskiĭ1, V G Gogvadze
1Institute of Theoretical and Experimental Biophysics, Russian Academy of Science, Pushchino, 142290 Russia.
Abstract:
One of the earliest features of apoptosis is a decrease of mitochondrial membrane potential. Here we show that when apoptosis is induced in thymocytes by ionizing radiation, inhibitors of mitochondrial energy production suppress DNA internucleosomal fragmentation. The suppression of fragmentation by inhibitors does not correlate with their effect on mitochondrial membrane potential, as it was observed when membrane potential was decreased (in the presence of inhibitors of respiratory chain, uncouplers of oxidative phosphorylation) or non affected (in the presence of oligomycin, inhibitor of mitochondrial ATPase).
Insights
Inhibitors of mitochondrial energy production can prevent DNA fragmentation during apoptosis induced by radiation. This effect occurs regardless of changes to the mitochondrial membrane potential.
Area of Science:
- Biochemistry
- Cell Biology
- Molecular Biology
Context:
- Apoptosis, or programmed cell death, is a fundamental biological process.
- A decrease in mitochondrial membrane potential is an early indicator of apoptosis.
- Ionizing radiation is a known inducer of apoptosis in thymocytes.
Purpose:
- To investigate the role of mitochondrial energy production in DNA fragmentation during radiation-induced apoptosis.
- To determine if the suppression of DNA fragmentation by mitochondrial inhibitors correlates with changes in mitochondrial membrane potential.
Summary:
- Ionizing radiation induces apoptosis in thymocytes, characterized by DNA internucleosomal fragmentation.
- Inhibitors of mitochondrial energy production were found to suppress this DNA fragmentation.
- Crucially, the suppression of DNA fragmentation did not correlate with the inhibitors' effects on mitochondrial membrane potential, observed with various inhibitors targeting different aspects of mitochondrial function.
Impact:
- This finding suggests that the inhibition of DNA fragmentation during apoptosis by mitochondrial energy production inhibitors is independent of direct effects on mitochondrial membrane potential.
- Highlights a complex interplay between mitochondrial energy metabolism and the execution phase of apoptosis.
- Provides new insights into the mechanisms regulating DNA fragmentation in programmed cell death.