Microgravity Accelerates Skeletal Muscle Degeneration: Functional and Transcriptomic Insights from a Muscle Lab-on-Chip Model Onboard the ISS.

Global transcriptomic analysis revealed increased gene expression and particularly mitochondrial-related gene expression in microgravity for the electrically stimulated younger myobundles, while the older myobundles were less responsive. Young- and old-derived skeletal muscle myobundles were exposed to microgravity for 12 days and matching ground control group. CD56 myoblasts-derived from young active and old sedentary muscle biopsies, differentiated into functional myobundles, that exhibited classic skeletal muscle bio-functions, were subjected to microgravity. We report on the differences in gene expression profiling between the flight young- vs old-derived electrically stimulated myobundles and ground young- vs old-derived myobundles. A minimum of three biological replicates was used for RNA seq.