Mitochondrial Extracellular Vesicles Enhance Aortic Valve Calcification Via Carnitine O-Octanoyltransferase

BACKGROUND: Calcific aortic valve disease, commonly manifesting as aortic stenosis, is a leading cause of mortality with no effective therapy. We previously identified CROT (carnitine O-octanoyltransferase) as a mediator of mitochondrial dysfunction and vascular calcification; however, its role in calcific aortic valve disease is unknown. We investigated whether CROT promotes calcific aortic valve disease progression through the release of procalcific mitochondria-derived extracellular vesicles (mitoEVs). METHODS: (aortic valve wire injury, n=23) mice. Disease progression was monitored by echocardiography, and calcification was visualized using OsteoSense680EX imaging. RESULTS: <0.05). Proteomics revealed alterations in mitochondria-associated proteins following siCROT. Osteogenic medium-induced mitochondrial fragmentation and increased mitoEV release were attenuated by CROT silencing. Immunofluorescence revealed mitoEVs localized to calcified extracellular regions. In vivo, CROT deficiency reduced valvular calcification and attenuated aortic stenosis progression. CONCLUSIONS: Osteogenic stress drives mitochondrial fragmentation and procalcific mitoEV release. CROT inhibition restores mitochondrial homeostasis, reduces mitoEV release and calcification, identifying CROT as a potential therapeutic strategy for calcific aortic valve disease.