Impaired function of the suprachiasmatic nucleus rescues the loss of body temperature homeostasis caused by time-restricted feeding

The suprachiasmatic nucleus (SCN) is the master circadian pacemaker that drives body temperature rhythm. Time-restricted feeding (TRF) has potential as a preventative or therapeutic approach against many diseases. The potential side effects of TRF remain unknown. Here we show that daily 4-h TRF treatment in mice can severely impair body temperature homeostasis and can result in lethality. Nearly half of the mice died at 21 degrees C, and all mice died at 18 degrees C during 4-h TRF. This effect was modulated by the circadian clock and was associated with severe hypothermia due to loss of body temperature homeostasis. Remarkably, disrupting the circadian clock by SCN lesions or constant light rescued lethality during TRF. Analysis of circadian gene expression in the dorsomedial hypothalamus (DMH) demonstrated that TRF reprograms rhythmic transcriptome in DMH and suppresses expression of genes, such as Ccr5 and Calcrl, which are involved in thermoregulation. Together, our results demonstrated a potent effect of TRF on body temperature homeostasis and the role of SCN function in this process. Our results further suggested that circadian arrhythmicity can have potential beneficial effects under certain stress conditions. (C) 2020 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.