Senescence-Activated NAD+ Depletion Rescue

**Molecular Mechanism and Rationale** The senescence-activated NAD+ depletion hypothesis centers on the enzymatic activity of CD38, a multifunctional ectoenzyme that functions as the primary NAD+ glycohydrolase in mammalian tissues. CD38 exhibits dual enzymatic activities: it catalyzes the hydrolysis of NAD+ to adenosine diphosphoribose (ADPR) and nicotinamide, while also synthesizing cyclic ADPR (cADP-ribose), a potent calcium-mobilizing second messenger. In the context of neurodegeneration, s...