Reducing histone acetylation rescues cognitive deficits in mouse model of fragile X syndrome

Fragile X syndrome(FXS) is the most prevalent inherited intellectual disability, resulting from a loss of fragile X mental retardation protein(FMRP). Patients with FXS suffer lifelong cognitive disabilities, but the function of FMRP in the adult brain and the mechanism underlying age-related cognitive decline in FXS is not fully understood. Here, we report that a loss of FMRP results in increased protein synthesis of histone acetyltransferase EP300 and ubiquitinationmediated degradation of histone deacetylase HDAC1 in adult hippocampal neural stem cells(NSCs). Consequently, FMRPdeficient NSCs exhibit elevated histone acetylation and age-related NSC depletion, leading to cognitive impairment in mature adult mice. Reducing histone acetylation rescues both neurogenesis and cognitive deficits in mature adult FMRPdeficient mice. Our work reveals a role for FMRP and histone acetylation in cognition and presents a potential novel therapeutic strategy for treating adult FXS patients.