Liver and muscle circadian clocks cooperate to support glucose tolerance in mice

Physiology is regulated by interconnected cell and tissue circadian clocks. Disruption of the rhythms generated by the concerted activity of these clocks is associated with metabolic disease. Here we tested the interactions between clocks in two critical components of organismal metabolism, liver and skeletal muscle, by rescuing clock function either in each organ separately or in both organs simultaneously in otherwise clock-less mice. Experiments showed that individual clocks are partially sufficient for tissue glucose metabolism, yet the connections between both tissue clocks coupled to daily feeding rhythms support systemic glucose tolerance. This synergy relies in part on local transcriptional control of the glucose machinery, feeding-responsive signals such as insulin, and metabolic cycles that connect the muscle and liver. We posit that spatiotemporal mechanisms of muscle and liver play an essential role in the maintenance of systemic glucose homeostasis and that disrupting this diurnal coordination can contribute to metabolic disease. ; This paper is dedicated to Paolo Sassone-Corsi, a hugely inspiring scientist and mentor who remains an important influence on our work. We also thank P.S.C. Lab animal technician S. Sato and laboratory manager W. Orquiz for their valued contributions, as well as Aintzane Rueda and Alfonso Saera-Vila at Sequentia Biotech (Barcelona) for their work on RNA sequencing read alignment and differential gene expression analysis. J.G.S. was supported by Zymo-CEM Postdoctoral Fellowship (Zymo Research) awarded at the University of California, Irvine. K.B.K. was supported by NIH, NIDDK F32 Fellowship – DK121425. T.S. was supported by a Japan Society for the Promotion of Science (JSPS) fellowship. C.M.G. was supported by the National Cancer Institute of the National Institutes of Health under award T32CA009054 and by the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement 749869. P.P. was funded by The Wenner-Gren ...