Mitochondria
Organelles within cells responsible for generating the majority of cellular energy in the form of ATP through oxidative phosphorylation. Mitochondrial dysfunction is implicated in many diseases. Elamipretide is a mitochondria-targeted peptide approved for Barth syndrome, a condition of mitochondrial membrane dysfunction.
Technical Context
Mitochondria are double-membrane organelles (1-10μm, hundreds to thousands per cell depending on energy demand) with their own circular DNA (mtDNA, 16,569bp encoding 13 ETC subunits, 22 tRNAs, 2 rRNAs) inherited maternally. The inner membrane is extensively folded into cristae, creating a large surface area for ETC complexes. Mitochondrial functions beyond ATP production: calcium buffering, apoptosis regulation (cytochrome c release triggers caspase cascade), ROS signalling, haem synthesis, steroid synthesis, and ketogenesis. Mitochondrial dysfunction is implicated in: ageing (mitochondrial theory of ageing — accumulated mtDNA mutations + oxidative damage), neurodegenerative diseases, metabolic diseases, cardiomyopathy, and rare mitochondrial diseases like Barth syndrome. Elamipretide targets the inner mitochondrial membrane specifically, representing a novel therapeutic approach to mitochondrial dysfunction distinct from antioxidant supplementation (which has shown limited clinical benefit in most trials).