Overview

• The study in Stem Cell Reports reveals that 3D-bioengineered skeletal muscle myobundles lose strength in microgravity at rates analogous to age-related sarcopenia within two weeks.
• Young donor myobundles aboard the ISS experienced strength declines and protein content reductions that matched levels seen in tissues from older donors.
• Transcriptomic profiling identified 86 muscle-specific genes with altered expression in microgravity, highlighting pathways linked to inflammation, mitochondrial dysfunction, and cellular stress.
• Intermittent electrical stimulation applied via the onboard mini-lab countered molecular and functional deterioration, boosting mitochondrial-related gene activity in younger tissues.
• Researchers say these findings could guide strategies to preserve astronaut muscle health on long-duration missions and inform novel treatments for sarcopenia on Earth.