PARP1 and Parkinson disease: In summary, this study demonstrates that NAD+ supplementation enhances the neuroprotective efficacy of the PARP1 inhibitor PJ34 in a 6-OHDA-induced PD model by mitigating oxidative stress, preserving mitochondrial integrity, suppressing senescence, promoting autophagy, and reducing neuroinflammation across SH-SY5Y cells, C. elegans, and mice (Fig. S9).