Université de Fribourg

The role of clock genes and rhythmicity in the liver

Schmutz, Isabelle ; Albrecht, Urs ; Ripperger, Jürgen A.

In: Molecular and Cellular Endocrinology, 2011, p. -

The liver is the important organ to maintain energy homeostasis of an organism. To achieve this, many biochemical reactions run in this organ in a rhythmic fashion. An elegant way to coordinate the temporal expression of genes for metabolic enzymes relies in the link to the circadian timing system. In this fashion not only a maximum of synchronization is achieved, but also anticipation of daily...

Université de Fribourg

Effects of the circadian rhythm gene period 1 (Per1) on psychosocial stress-Induced alcohol drinking

Dong, Li ; Bilbao, Ainhoa ; Laucht, Manfred ; Henriksson, Richard ; Yakovleva, Tatjana ; Ridinger, Monika ; Desrivieres, Sylvane ; Clarke, Toni-Kim ; Lourdusamy, Anbarasu ; Smolka, Michael N. ; Cichon, Sven ; Blomeyer, Dorothea ; Treutlein, Jens ; Perreau-Lenz, Stephanie ; Witt, Stephanie ; Leonardi-Essmann, Fernando ; Wodarz, Norbert ; Zill, Peter ; Soyka, Michael ; Albrecht, Urs ; Rietschel, Marcella ; Lathrop, Mark ; Bakalkin, Georgy ; Spanagel, Rainer ; Schumann, Gunter

In: American Journal of Psychiatry, 2011, vol. 168, no. 10, p. 1090-1098

Objective: Circadian and stress-response systems mediate environmental changes that affect alcohol drinking. Psychosocial stress is an environmental risk factor for alcohol abuse. Circadian rhythm gene period 1 (Per1) is targeted by stress hormones and is transcriptionally activated in corticotropin releasing factor-expressing cells. The authors hypothesized that Per1 is involved in ...

Université de Fribourg

Circadian rhythms and sleep—the metabolic connection

Albrecht, Urs

In: Pflügers Archiv European Journal of Physiology, 2011, p. -

The circadian system coordinates mammalian physiology and behavior with the environmental light–dark cycle. It allocates sleep to the inactivity phase using various mechanisms involving neurotransmitters, nuclear receptors, and protein kinases. These pathways are related to metabolism, indicating that the circadian system and sleep are connected via metabolic parameters. This suggests that...

Université de Fribourg

Protein phosphatase 1 (pp1) is a post-translational regulator of the mammalian circadian clock

Schmutz, Isabelle ; Wendt, Sabrina ; Schnell, Anna ; Kramer, Achim ; Mansuy, Isabelle M. ; Albrecht, Urs

In: PLoS ONE, 2011, vol. 6, no. 6, p. e21325

Circadian clocks coordinate the timing of important biological processes. Interconnected transcriptional and post-translational feedback loops based on a set of clock genes generate and maintain these rhythms with a period of about 24 hours. Many clock proteins undergo circadian cycles of post-translational modifications. Among these modifications, protein phosphorylation plays an important role...

Université de Fribourg

The daily rhythm of mice

Ripperger, Jürgen A. ; Jud, Corinne ; Albrecht, Urs

In: FEBS Letters, 2011, p. -

The house mouse Mus musculus represents a valuable tool for the analysis and the understanding of the mammalian circadian oscillator. Forward and reverse genetics allowed the identification of clock components and the verification of their function within the circadian clockwork. In many cases unforeseen links were discovered between a particular circadian regulatory protein and various diseases...

Université de Fribourg

High amplitude phase resetting in Rev-Erba/Per1 double mutant mice

Jud, Corinne ; Hayoz, Antoinette ; Albrecht, Urs

In: PLoS ONE, 2010, vol. 5, no. 9, p. e12540

Over time, organisms developed various strategies to adapt to their environment. Circadian clocks are thought to have evolved to adjust to the predictable rhythms of the light-dark cycle caused by the rotation of the Earth around its own axis. The rhythms these clocks generate persist even in the absence of environmental cues with a period of about 24 hours. To tick in time, they continuously...

Université de Fribourg

PERsuading nuclear receptors to dance the circadian rhythm

Ripperger, Jürgen A. ; Schmutz, Isabelle ; Albrecht, Urs

In: Cell Cycle, 2010, vol. 9, no. 13, p. 2515-2521

The recurring light/dark cycle that has a period length of about 24 hours has been internalized in various organisms in the form of a circadian clock. This clock allows a precise orchestration of biochemical and physiological processes in the body thus improving performance. Recently, we found that the clock component PERIOD2 (PER2) can coordinate transcriptional regulation of metabolic,...

Université de Fribourg

Cones are required for normal temporal responses to light of phase shifts and clock gene expression

Dollet, Anna ; Albrecht, Urs ; Cooper, Howard M. ; Dkhissi-Benyahya, Ouria

In: Chronobiology International, 2010, vol. 27, no. 4, p. 768-781

In mammals, non-visual responses to light involve intrinsically photosensitive melanopsin-expressing retinal ganglion cells (ipRGCs) that receive synaptic inputs from rod and cone photoreceptors. Several studies have shown that cones also play a role in light entrainment, photic responses of the suprachiasmatic nucleus (SCN), pupil constriction, and sleep induction. These studies suggest that...

Université de Fribourg

the clock genes Period 2 and Cryptochrome 2 differentially balance bone formation

Maronde, Erik ; Schilling, Arndt F. ; Seitz, Sebastian ; Schinke, Thorsten ; Schmutz, Isabelle ; Horst, Gijsbertus van der ; Amling, Michael ; Albrecht, Urs

In: PLoS One, 2010, vol. 5, no. 7, p. e11527

Background: Clock genes and their protein products regulate circadian rhythms in mammals but have also been implicated in various physiological processes, including bone formation. Osteoblasts build new mineralized bone whereas osteoclasts degrade it thereby balancing bone formation. To evaluate the contribution of clock components in this process, we investigated mice mutant in clock genes for a...

Université de Fribourg

Circadian clocks in mood-related behaviors

Albrecht, Urs

In: Annals of Medicine, 2010, p. -

The circadian clock organizes biochemical and physiological processes of an organism in a temporal fashion. This temporal organization is crucial to avoid interference of processes that have adverse effects on each other. Thus, disruption of temporal organization can lead to health problems and behavioral disorders related to mood alterations. To alleviate the consequences of a disrupted...