Telomere Length Dynamics and DNA Damage Responses Associated with Long-Duration Spaceflight

Area of Science:

• Space biology
• Genomics
• Cellular biology

Background:

• Telomeres protect chromosome ends and shorten with age.
• Spaceflight exposes astronauts to unique stressors like oxidative damage.
• Understanding telomere dynamics is crucial for astronaut health.

Purpose of the Study:

• To investigate telomere length dynamics and DNA damage responses in astronauts.
• To compare astronaut telomere status with ground controls.
• To explore the relationship between oxidative stress and telomere changes during spaceflight.

Main Methods:

• Assessed telomere length and telomerase activity before, during, and after space missions.
• Compared astronauts (n=11) with age- and sex-matched ground controls.
• Monitored oxidative stress markers and chromosomal aberrations.

Main Results:

• Astronauts had shorter telomeres and lower telomerase activity than controls.
• Telomeres were longer during spaceflight but shortened rapidly upon return.
• Oxidative stress correlated with telomere length dynamics; chromosomal inversions increased.

Conclusions:

• Spaceflight induces telomere shortening and increased DNA damage.
• A telomerase-independent Alternative Lengthening of Telomeres (ALT) pathway may activate.
• This suggests a telomeric adaptive response to chronic oxidative stress in extreme environments.