Simulated microgravity accelerates aging in Saccharomyces cerevisiae.

Area of Science:

• Cellular Biology
• Aging Research
• Space Biology

Background:

• Microgravity induces physiological changes mimicking aging, posing risks for space missions.
• Previous studies used model organisms like worms, flies, and mice to investigate microgravity's effects on aging.

Purpose of the Study:

• To investigate the impact of simulated microgravity on the lifespan of Saccharomyces cerevisiae (budding yeast).
• To explore potential mechanisms and interventions related to microgravity-induced aging in yeast.

Main Methods:

• Utilized a clinostat to simulate microgravity conditions for yeast cultures.
• Assessed replicative lifespan (RLS) and tolerance to heat shock and oxidative stress.
• Investigated the role of FOB1, SIR2 genes, calorie restriction, and extrachromosomal rDNA circles.

Main Results:

• Simulated microgravity significantly decreased yeast replicative lifespan (RLS).
• This lifespan reduction was independent of heat shock or oxidative stress tolerance.
• Deletion of FOB1 or calorie restriction extended yeast RLS under simulated microgravity.
• SIR2 deletion exacerbated the microgravity effect, suggesting increased extrachromosomal rDNA circle formation.

Conclusions:

• Simulated microgravity accelerates aging in yeast, conserved across yeast, worms, and flies.
• Findings suggest microgravity augments aging pathways, potentially via rDNA circles.
• Implications for crewed space missions and using microgravity as a model for human aging.