Longevity & AgingFOXO1-NMNAT3 Axis Drives Chemo Heart Damage — NAD+ May Be the Fix
Doxorubicin (DOX), a widely used chemotherapy drug, causes serious heart damage partly by depleting NAD+, a critical cellular energy and redox molecule. Researchers identified that DOX activates the transcription factor FOXO1, which suppresses NMNAT3, a mitochondrial enzyme essential for NAD+ synthesis in the heart. This depletion triggers oxidative stress and cardiomyocyte death. Crucially, restoring NAD+ levels—either by direct supplementation, by giving the NAD+ precursor NMN, or by overexpressing NMNAT3—significantly reduced heart damage in both cell and mouse models. Blocking CD38, another NAD+-consuming enzyme, did not rescue NAD+ levels, pointing specifically to the FOXO1-NMNAT3 axis as the critical vulnerability. These findings open a new therapeutic avenue for protecting cancer patients' hearts during chemotherapy.
