New insights into how microgravity affects muscle function have emerged from a study involving live human muscle cells sent to the International Space Station (ISS).
The research by a team at Stanford University in the US utilised muscle chips — bioengineered structures containing oriented muscle cells — to investigate the effects of space travel on muscle health and to test potential treatments.
The study, published in Stem Cell Reports, found that muscle cells exposed to microgravity exhibited metabolic changes indicative of impaired muscle regeneration and gene activities similar to those seen in age-related muscle loss, or sarcopenia.
“Space is a unique environment that accelerates ageing processes and impairs healthy functions. Astronauts often experience muscle atrophy due to the lack of gravity, which prevents active muscle use,” explained Ngan Huang, an associate professor at Stanford.
The researchers discovered that muscles grown in microgravity had reduced muscle fibre formation and altered gene activity. Notably, genes associated with mitochondrial function were compromised, while those related to fat formation were upregulated. This suggests that microgravity can lead to dysfunctions in muscle regeneration.
In a proof-of-concept experiment, astronauts treated the muscle chips with drugs aimed at countering sarcopenia or promoting muscle regeneration. The treatment partially mitigated the adverse effects of microgravity, preventing a shift towards fat formation and aligning gene activity more closely with Earth-based samples.
The study highlights the potential of engineered tissue chip platforms in microgravity for studying various diseases and drug screening, bypassing the need for animal or human subjects.
The team plans to continue this research, with another space mission scheduled for 2025 to further explore treatments for microgravity-induced muscle impairment.