Betaine delays age-related muscle loss by mitigating Mss51-induced impairment in mitochondrial respiration via Yin Yang1.

Altogether, betaine transcriptionally represses Mss51 via Yy1, improving age-related mitochondrial respiration in skeletal muscle. These findings suggest betaine holds promise as a dietary supplement to delay skeletal muscle degeneration and improve age-related mitochondrial diseases.