Amyloid β-induced elevation of O-GlcNAcylated c-Fos promotes neuronal cell death.

Alzheimer's disease (AD) is an age-related neurodegenerative disease characterized by progressive memory loss resulting from cumulative neuronal cell death. O-linked -N-acetyl glucosamine (O-GlcNAc) modification of the proteins reflecting glucose metabolism is altered in the brains of patients with AD. However, the link between altered O-GlcNAc modification and neuronal cell death in AD is poorly understood. Here, we examined the regulation of O-GlcNAcylation of c-Fos and the effects of O-GlcNAcylated c-Fos on neuronal cell death during AD pathogenesis. We found that amyloid beta (A)-induced O-GlcNAcylation on serine-56 and 57 of c-Fos was resulted from decreased interaction between c-Fos and O-GlcNAcase and promoted neuronal cell death. O-GlcNAcylated c-Fos increased its stability and potentiated the transcriptional activity through higher interaction with c-Jun, resulting in induction of Bim expression leading to neuronal cell death. Taken together, A-induced O-GlcNAcylation of c-Fos plays an important role in neuronal cell death during the pathogenesis of AD.