Discussion
Our results indicate that cycles of DNA methylation contribute to the regulation of BMAL1 rhythms in the brain. Hence, aberrant epigenetic patterns may be linked to circadian alterations in AD.
Methods
We investigated DNA methylation, transcription, and expression of BMAL1, a positive regulator of the circadian clock, in cultured fibroblasts and brain samples from two independent cohorts of aging and AD.
Results
DNA methylation modulated rhythmic expression of clock genes in cultured fibroblasts. Moreover, rhythmic methylation of BMAL1 was altered in AD brains and fibroblasts and correlated with transcription cycles.