NADH Inhibition of SIRT1 Links Energy State to Transcription During Time-Restricted Feeding
In mammals, circadian rhythms are entrained to the light cycle and drive daily oscillations in levels of NAD+ a co-substrate of the class III histone deacetylase SIRT1 that associates with clock transcription factors. While NAD+ also participates in redox reactions, the extent to which NAD(H) couples nutrient state with circadian transcriptional cycles remains unknown. Here we show that nocturnal animals subjected to time-restricted feeding of a calorie-restricted diet (TRF-CR) only during nighttime display reduced body temperature and elevated hepatic NADH during daytime. Genetic uncoupling of nutrient state from NADH redox state through transduction of the water-forming NADH oxidase from Lactobacillus brevis (LbNOX) increases daytime body temperature and blood and liver acyl-carnitines. LbNOX expression in TRF-CR mice induces oxidative gene networks controlled by BMAL1 and PPARa and suppresses amino acid catabolic pathways. Enzymatic analyses reveal that NADH inhibits SIRT1 in vitro, corresponding with reduced deacetylation of SIRT1 substrates during TRF-CR in vivo. Remarkably, Sirt1 liver nullizygous animals subjected to TRF-CR display persistent hypothermia even when NADH is oxidized by LbNOX. Our findings reveal that the hepatic NADH cycle links nutrient state to whole-body energetics through the rhythmic regulation of SIRT1. Overall design: 87 libraries were generated in this study. They include ChIP-Seq and RNA-Seq experiments to determine the effect of NADH and SIRT1 on transcription during time-restricted calorie restriction (CR). Replicates are indicated in the final position of the title of each library. Inputs for ChIP-Seq experiments consist of equimolar pools of replicates within each group. RNA-seq controls for PPARaKO are GSM3347582-5 within GSE118787.