Mitochondria

Mitochondria are the double-membrane organelles responsible for the bulk of cellular ATP production via oxidative phosphorylation, plus a long list of secondary roles: calcium buffering, apoptosis initiation, iron-sulfur cluster biogenesis, and several biosynthetic pathways.

Mitochondrial dysfunction is one of the recognized hallmarks of aging. Declines in membrane potential, mtDNA integrity, and electron-transport-chain efficiency accumulate with age and contribute to the broader phenotypes of frailty, sarcopenia, and metabolic disease.

Two peptides in current research are directly mitochondrially targeted: SS-31 (elamipretide) localizes to the inner mitochondrial membrane and stabilizes cardiolipin to protect ETC function, and MOTS-c is a mitochondrially-encoded peptide that signals to the nucleus and modulates AMPK and metabolic homeostasis.