MFN2 and sarcopenia: In addition, Huang et al. [61] identified that mitochondrial fusion-related factors (Mfn1, Mfn2 and Opa1) and mitochondrial fission-related factor (Drp1) were decreased in old Nrf-2 KO mice with sarcopenia, suggesting that loss of Nrf-2 can aggravate sarcopenia by disrupting balanced mitochondrial dynamics and that mitochondrial biogenesis and dynamics may be associated with each other.