ABSTRACT Dysregulation of histone acetylation in the brain has emerged as a major contributor to human Alzheimer’s disease (AD). The mechanisms by which these protective or risk-conferring epigenetic marks are established and maintained are under intense investigation. ACSS2 (Acetyl-CoA Synthetase 2) is a key metabolic enzyme that is chromatin-associated in neurons. ACSS2 is recruited to specific promoters and generates a local pool of acetyl-CoA from acetate, thereby fueling histone acetylation and driving the expression of neuronal genes that regulate learning and memory. Here, we examine the contribution of ACSS2-mediated histone acetylation to AD-related molecular and behavioral outcomes. Using a mouse model of human pathological AD-Tau injection, we show that loss of ACSS2 exacerbates Tau-related memory impairments, while dietary supplementation of acetate rescues learning in an ACSS2-dependent manner. Combining state-of-the-art proteomic and genomic approaches, we demonstrate that this effect is accompanied by ACSS2-dependent incorporation of acetate into hippocampal histone acetylation, which facilitates gene expression programs related to learning. Further, we identify Cajal-Retzius neurons as a critical hippocampal neuronal population affected, exhibiting the largest epigenetic and transcriptional dysregulation. Overall, these results reveal ACSS2 as a key neuroprotective metabolic enzyme, dysregulation of which might play an important role in the etiology of human AD, and guide the development of future therapies for AD and related dementia.

ACSS2 contributes to transcriptional regulation in Cajal-Retzius cells in a mouse model of Alzheimer’s disease