s NAD⁺ Consuming Enzymes: Involvement in Therapies and Prevention of Human Diseases

Neuroprotection is one of the hot topics in medicine. Alzheimer’s disease, amyotrophic lateral sclerosis, retinal pigment epithelial (RPE) degeneration, and axonal degeneration have been studied for the involvement of NAD depletion. Localized NAD⁺ depletion could lead to overactivation and crowding of local NAD⁺ salvage pathways. It has been stated that NAD⁺ depletion caused by PARPs and PAR cycling has been related to metabolic diseases and cancer. Additionally, it is now acknowledged that SARM1 dependent NAD⁺ depletion causes axon degeneration. New targeted therapeutics, such as SARM1 inhibitors, and NAD⁺ salvage drugs will help alleviate the dysfunctions affecting cell life and death in neurodegeneration as well as in metabolic diseases and cancer.