Microgravity Accelerates Skeletal Muscle Degeneration: Functional and Transcriptomic Insights from a Muscle...

Area of Science:

• Space biology
• Muscle physiology
• Aging research

Background:

• Microgravity accelerates skeletal muscle degeneration, mirroring aging processes.
• Human muscle cell function and signaling in microgravity are not fully understood.
• Aging and microgravity both induce skeletal muscle atrophy.

Purpose of the Study:

• To investigate microgravity's effects on human muscle cell function and age-related changes.
• To compare responses of young and old muscle cells to microgravity and electrical stimulation.
• To identify molecular signatures of muscle aging in microgravity.

Main Methods:

• Utilized a 3D bioengineered muscle lab-on-chip model on the International Space Station.
• Cultured myobundles from young and older individuals for 21 days, including 12 days in microgravity.
• Applied electrical stimulation and analyzed global transcriptomics and gene expression related to aging.

Main Results:

• Microgravity reduced muscle contraction magnitude.
• Younger, stimulated muscle cells showed increased mitochondrial gene expression in microgravity.
• Microgravity induced age-related gene expression changes in younger cells, but not older cells.

Conclusions:

• Microgravity uniquely alters molecular signatures in muscle cells, with age-dependent responses.
• Electrical stimulation shows potential as a countermeasure against microgravity-induced muscle degeneration.
• Findings advance understanding of muscle aging and space-induced degeneration for terrestrial and extraterrestrial applications.