Heart HealthNAD Decline Triggers Lysosomal Failure That Destroys Heart Cell Mitochondria With Age
As we age, NAD levels in heart cells fall. This study shows that drop weakens a critical enzyme interaction needed to keep lysosomes acidic. When lysosomes lose their acid environment, a destructive enzyme called cathepsin B leaks into mitochondria and destroys cardiolipin — a lipid essential for mitochondrial energy production. Without cardiolipin, mitochondria become stressed and die, accelerating cardiac dysfunction. The researchers confirmed this chain of events using multiple mouse models and genetic tools. Most importantly, restoring NAD levels rescued lysosomal function, preserved cardiolipin, and protected heart function in both aging rodents and elderly humans. The findings identify v-ATPase and cardiolipin synthesis as promising targets for treating age-related heart failure.
