Yang, J.-H.; Izydore, E. K.; Mazan-Mamczarz, K.; Tsitsipatis, D.; Mattison, J. A.; Romero, B.; Shi, C.; Yang, X.; Munk, R.; Martindale, J. L.; Anerillas, C.; Salamini-Montemurri, M.; Rossi, M.; Piao, Y.; Fan, J.; Chen, Y.-C.; Cedeno-Veloz, B. A.; Ferrero, R.; Montes, M.; Martinez-Velilla, N.; Chu, T.-H.; Abdelmohsen, K.; Cui, C.-Y.; Batish, M.; De, S.; Sen, P.; Ferrucci, L.; de Cabo, R.; Gorospe, M.

Regeneration of skeletal muscle preserves muscle mass and function, which decline with age. Here, we sought to identify long noncoding (lnc)RNAs involved in skeletal muscle myogenesis and potentially relevant to muscle aging. Cross-sectional analysis of skeletal muscle transcriptomes from healthy 22-through 89-year-old individuals revealed lncRNA LANCL1-AS1 among the top declining transcripts. Conversely, LANCL1-AS1 increased robustly during skeletal myogenesis and promoted myogenic differentiation in culture. Affinity pulldown by ChIRP followed by mass spectrometry revealed that LANCL1-AS1 associated with the mitochondrial protein LRPPRC, enhancing the formation of the chaperone complex LRPPRC-SLIRP, which maintains longer poly(A) tails of mitochondrial (mt-)mRNAs and stabilizes mt-mRNAs. Importantly, while myoblasts from old rhesus monkey muscle expressed lower levels of LANCL1-AS1 and mt-mRNAs, and displayed lower mitochondrial activity than young monkey myoblasts, overexpressing LANCL1-AS1 in old myoblasts restored mitochondrial activity and myogenesis. We propose that the age-associated reduction in LANCL1-AS1 contributes to impaired mitochondrial function and reduced myogenic capacity in aging skeletal muscle.