Mimic microgravity effect on muscle transcriptome under ionizing radiation

Area of Science:

• Space biology
• Muscle physiology
• Molecular biology

Background:

• Spaceflight poses risks to astronaut skeletal muscle, primarily due to microgravity and cosmic radiation.
• Understanding spaceflight-induced muscle atrophy is crucial for astronaut health and mission success.

Purpose of the Study:

• To investigate transcriptional changes in rat soleus muscle using ground-based models simulating spaceflight conditions.
• To identify common differentially expressed genes (DEGs) between denervation and tail suspension models.

Main Methods:

• Utilized tail suspension and denervation models to simulate microgravity in rats.
• Exposed rats to a low-dose radiation environment.
• Analyzed transcriptional changes in soleus muscle using microarrays.

Main Results:

• Identified 144 common DEGs between the two microgravity models.
• Observed transcriptional suppression of genes involved in energy metabolism, including fatty acid oxidation and oxidative phosphorylation.
• Found down-regulation of slow-twitch contractile protein genes and up-regulation of fast-twitch type genes.

Conclusions:

• Ground-based models effectively simulate spaceflight-induced muscle atrophy effects.
• Identified key genes related to energy metabolism and muscle fiber type changes.
• These findings provide candidate genes for future research into countermeasures for astronaut muscle atrophy.