Loss of REST associated with Alzheimer's disease pathology is ameliorated by NAD

Downregulation and inactivation of the Repressor Element 1-Silencing Transcription factor (REST) is shown in Alzheimer's disease (AD) and likely contributes to its progression, but the exact molecular mechanism linking REST reduction to AD remains unclear. We examined changes in REST expression in the entorhinal cortex and hippocampus across different Braak stages of tauopathy. We show that alterations in REST expression and sub-cellular localization are partially responsible for AD pathology, as REST overexpression improves cognition, reduces amyloid-β and phosphorylated Tau deposition, and restores mitochondrial and synaptic homeostasis. Mechanistically, the NAD+/SIRT1 axis modulates REST expression through chromatin remodelling in the promoter region of REST, leading to changes in the expression of REST target genes involved in mitophagy and synaptic function. These findings reveal a new mechanism of action for NAD+ and highlight REST as a promising therapeutic target for AD therapy.