Franck Delaunay

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Recent evidence has emerged that peroxisome proliferator-activated receptor alpha (PPARalpha), which is largely involved in lipid metabolism, can play an important role in connecting circadian biology and metabolism. In the present study, we investigated the mechanisms by which PPARalpha influences the pacemakers acting in the central clock located in the(More)
Most living organisms show circadian (approximately 24 h) rhythms in physiology and behavior. These oscillations are generated by endogenous circadian clocks, present in virtually all cells where they control key biological processes. Although circadian gating of mitosis has been reported for many years in some peripheral tissues, the underlying molecular(More)
Daily synchronous rhythms of cell division at the tissue or organism level are observed in many species and suggest that the circadian clock and cell cycle oscillators are coupled. For mammals, despite known mechanistic interactions, the effect of such coupling on clock and cell cycle progression, and hence its biological relevance, is not understood. In(More)
Nuclear receptors form a superfamily of ligand-activated transcription factors that regulate various physiological functions, from development to homeostasis, in metazoans. The superfamily contains not only receptors for known ligands but also a large number of so-called orphan receptors for which ligands do not exist or have not been identified. The(More)
Circadian clocks are time-keeping systems found in most organisms. In zebrafish, expression of the clock gene Period3 (Per3) oscillates throughout embryogenesis in the central nervous system and the retina. Per3 rhythmic expression was free-running and was reset by light but not by the developmental delays caused by low temperature. The time of(More)
Frequent transmeridian flights or predominant work at night can increase cancer risk. Altered circadian rhythms also predict for poor survival in cancer patients, whereas physical destruction of the suprachiasmatic nuclei (SCN), the hypothalamic circadian pacemaker, accelerates tumor growth in mice. Here we tested the effect of functional disruption of(More)
Circadian (∼24 h) rhythms in physiology and behaviour are observed in all mammals, including humans. These rhythms are generated by circadian clocks located in the hypothalamus and also in most peripheral tissues. Clock genes are essential components of circadian clocks, and mutations or polymorphisms within several of them have been associated with(More)
The circadian timing system coordinates many aspects of mammalian physiology and behavior in synchrony with the external light/dark cycle. These rhythms are driven by endogenous molecular clocks present in most body cells. Many clock outputs are transcriptional regulators, suggesting that clock genes primarily control physiology through indirect pathways.(More)
Central and peripheral mammalian circadian clocks regulate a variety of behavioral and physiological processes through the rhythmic transcription of hundreds of clock-controlled genes. The circadian expression of many transcriptional regulators suggests that a major part of this circadian gene network is indirectly regulated by clock genes. Here we show(More)
Rev-erbalpha is a ubiquitously expressed orphan nuclear receptor which functions as a constitutive transcriptional repressor and is expressed in vertebrates according to a robust circadian rhythm. We report here that two Rev-erbalpha mRNA isoforms, namely Rev-erbalpha1 and Rev-erbalpha 2, are generated through alternative promoter usage and that both show a(More)