Rhythms of Mammalian Body Temperature Can Sustain Peripheral Circadian Clocks

Article Article scientifique Article Rhythms of Mammalian Body Temperature Can Sustain Peripheral Circadian Clocks eng 2002 author Brown Steven 506722 author Zumbrunn Gottlieb 25749 author Fleury Olela Fabienne 22087 author Preitner Nicolas 86440 author Schibler Ulrich 22687 1574-1583 10.1016/S0960-9822(02)01145-4 0960-9822 https://linkinghub.elsevier.com/retrieve/pii/S0960982202011454 Background: Low-amplitude temperature oscillations can entrain the phase of circadian rhythms in several unicellular and multicellular organisms, including Neurospora and Drosophila. Because mammalian body temperature is subject to circadian variations of 1°C–4°C, we wished to determine whether these temperature cycles could serve as a Zeitgeber for circadian gene expression in peripheral cell types. Results: In RAT1 fibroblasts cultured in vitro, circadian gene expression could be established by a square wave temperature rhythm with a ΔT of 4°C (12 hr 37°C/12 hr 33°C). To examine whether natural body temperature rhythms can also affect circadian gene expression, we first measured core body temperature cycles in the peritoneal cavities of mice by radiotelemetry. We then reproduced these rhythms with high precision in the liquid medium of cultured fibroblasts for several days by means of a homemade computer-driven incubator. While these “in vivo” temperature rhythms were incapable of establishing circadian gene expression de novo, they could maintain previously induced rhythms for multiple days; by contrast, the rhythms of control cells kept at constant temperature rapidly dampened. Moreover, circadian oscillations of environmental temperature could reentrain circadian clocks in the livers of mice, probably via the changes they imposed upon both body temperature and feeding behavior. Interestingly, these changes in ambient temperature did not affect the phase of the central circadian pacemaker in the suprachiasmatic nucleus (SCN) of the hypothalamus. Conclusions: We postulate that both endogenous and environmental temperature cycles can participate in the synchronization of peripheral clocks in mammals. Dewey 570 43 Département de biologie moléculaire 161 false Current Biology 12 18 333e2a11-52b8-4f08-bea7-5be7b49beeeb Article (Published version) Restricted 1-s2.0-S0960982202011454-main.pdf 584743 application/pdf restrictedAccess Faculté des sciences / Section de biologie / Département de biologie moléculaire

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Rhythms of Mammalian Body Temperature Can Sustain Peripheral Circadian Clocks	Current Biology			2002	382	0

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