Frozen? Let it go to reset circadian rhythms

Abstract

The molecular events in response to severe hyperthermia are not fully under- stood, and research has focused mainly on the effects of cooling at temperatures between 28°C and 35°C. In a new study, Fischl et al have analysed human cardiomyocytes at lower temperatures (8°C, 18°C and 28°C) and identified a novel mechanism by which hypothermia synchronises the circadian clock: cooling induces nuclear accumulation of tran- scripts that encode negative regulators of the circadian clock, which are released into the cytoplasm upon rewarming allowing synthesis of specific clock proteins.