Integrative Epigenomic and Transcriptomic Analysis Reveals Robust Metabolic Switching in the Brain During Intermittent Fasting

Intermittent fasting (IF) is a lifestyle intervention comprising a dietary regimen in which energy intake is restricted via alternating periods of fasting and ad libitum food consumption, without compromising nutritional composition. While epigenetic modifications can mediate effects of environmental factors on gene expression, no information is yet available on potential effects of IF on the epigenome. In this study, we found that IF causes modulation of histone H3 lysine 9 trimethylation (H3K9me3) epigenetic mark in the cerebellum of male C57/BL6 mice, which in turn orchestrates a plethora of transcriptomic changes involved in the robust metabolic switching processes commonly observed during IF. Interestingly, both epigenomic and transcriptomic modulation continued to be observed after refeeding, suggesting that memory of the IF-induced epigenetic change is maintained at the locus. Notably though, we found that termination of IF results in a loss of H3K9me3 regulation of the transcriptome. Collectively, our study characterizes a novel mechanism of IF in the epigenetic-transcriptomic axis, which controls myriad metabolic process changes. In addition to providing a valuable and innovative resource, our systemic analyses reveal molecular framework for understanding how IF impacts the metaboloepigenetics axis of the brain.