Université de Fribourg

Disturbed processing of contextual information in HCN3 channel deficient mice

Stieglitz, Marc S. ; Fenske, Stefanie ; Hammelmann, Verena ; Becirovic, Elvir ; Schöttle, Verena ; Delorme, James E. ; Schöll-Weidinger, Martha ; Mader, Robert ; Deussing, Jan ; Wolfer, David P. ; Seeliger, Mathias W. ; Albrecht, Urs ; Wotjak, Carsten T. ; Biel, Martin ; Michalakis, Stylianos ; Wahl-Schott, Christian

In: Frontiers in Molecular Neuroscience, 2018, vol. 10, p. -

Hyperpolarization-activated cyclic nucleotide-gated channels (HCNs) in the nervous system are implicated in a variety of neuronal functions including learning and memory, regulation of vigilance states and pain. Dysfunctions or genetic loss of these channels have been shown to cause human diseases such as epilepsy, depression, schizophrenia, and Parkinson's disease. The physiological...

Université de Fribourg

Β-Klotho deficiency protects against obesity through a crosstalk between liver, microbiota, and brown adipose tissue

Somm, Emmanuel ; Henry, Hugues ; Bruce, Stephen J. ; Aeby, Sébastien ; Rosikiewicz, Marta ; Sykiotis, Gerasimos P. ; Asrih, Mohammed ; Jornayvaz, François R. ; Denechaud, Pierre Damien ; Albrecht, Urs ; Mohammadi, Moosa ; Dwyer, Andrew ; Jr., James S. Acierno ; Schoonjans, Kristina ; Fajas, Lluis ; Greub, Gilbert ; Pitteloud, Nelly

In: JCI Insight, 2017, vol. 2, no. 8, p. -

β-Klotho (encoded by Klb) is the obligate coreceptor mediating FGF21 and FGF15/19 signaling. Klb–/– mice are refractory to beneficial action of pharmacological FGF21 treatment including stimulation of glucose utilization and thermogenesis. Here, we investigated the energy homeostasis in Klb–/– mice on high-fat diet in order to better understand the consequences of abrogating both...

Université de Fribourg

Liver-derived ketone bodies are necessary for food anticipation

Chavan, Rohit ; Feillet, Céline ; Costa, Sara S. Fonseca ; Delorme, James E. ; Okabe, Takashi ; Ripperger, Jürgen A. ; Albrecht, Urs

In: Nature Communications, 2016, vol. 7, p. 10580

The circadian system has endowed animals with the ability to anticipate recurring food availability at particular times of day. As daily food anticipation (FA) is independent of the suprachiasmatic nuclei, the central pacemaker of the circadian system, questions arise of where FA signals originate and what role components of the circadian clock might play. Here we show that liver-specific...

Université de Fribourg

Nucleotide excision repair efficiency in quiescent human fibroblasts is modulated by circadian clock

Bee, Leonardo ; Marini, Selena ; Pontarin, Giovanna ; Ferraro, Paola ; Costa, Rodolfo ; Albrecht, Urs ; Celotti, Lucia

In: Nucleic Acids Research, 2015, vol. 43, no. 4, p. 2126–2137

The efficiency of Nucleotide Excision Repair (NER)process is crucial for maintaining genomic integrity because in many organisms, including humans, it represents the only system able to repair a wide range of DNA damage. The aim of the work was to investigate whether the efficiency of the repair of photoproducts induced by UV-light is affected by the circadian phase at which irradiation occurred....

Université de Fribourg

Circadian rhythms govern cardiac repolarization and arrhythmogenesis

Jeyaraj, Darwin ; Haldar, Saptarsi M. ; Wan, Xiaoping ; McCauley, Mark D. ; Ripperger, Juergen A. ; Hu, Kun ; Lu, Yuan ; Eapen, Betty L. ; Sharma, Nikunj ; Ficker, Eckhard ; Cutler, Michael J. ; Gulick, James ; Sanbe, Atsushi ; Robbins, Jeffrey ; Demolombe, Sophie ; Kondratov, Roman V. ; Shea, Steven A. ; Albrecht, Urs ; Wehrens, Xander H. T. ; Rosenbaum, David S. ; Jain, Mukesh K.

In: Nature, 2012, vol. 483, p. 96–99

Sudden cardiac death exhibits diurnal variation in both acquired and hereditary forms of heart disease, but the molecular basis of this variation is unknown. A common mechanism that underlies susceptibility to ventricular arrhythmias is abnormalities in the duration (for example, short or long QT syndromes and heart failure) or pattern (for example, Brugada’s syndrome)6 of myocardial...

Université de Fribourg

Lab mice in the field: unorthodox daily activity and effects of a dysfunctional circadian clock allele

Spoelstra, Kamiel ; Albrecht, Urs ; Schmutz, Isabelle ; Daan, Moritz ; Daan, Berte ; Rienks, Froukje ; Poletaeva, Inga ; Dell'Omo, Giacomo ; Vyssotski, Alexei ; Lipp, Hans-Peter

In: Journal of Biological Rhytms, 2011, vol. 26, no. 2, p. 118-129

Daily patterns of animal behavior are potentially of vast functional importance. Fitness benefits have been identified in nature by the association between individual timing and survival or by the fate of individuals after experimental deletion of their circadian pacemaker. The recent advances in unraveling the molecular basis of circadian timing enable new approaches to natural selection on...

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

Role of mutation of the circadian clock gene Per2 in cardiovascular circadian rhythms

Vukolic, Ana ; Antic, Vladan ; Vliet, Bruce N. Van ; Yang, Zhihong ; Albrecht, Urs ; Montani, Jean-Pierre

In: American Journal of Physiology Regulatory, Integrative and Comparative Physiolology, 2010, p. -

Alterations in the circadian blood pressure pattern are frequently observed in hypertension and lead to increased cardiovascular morbidity. However, there are no studies that have investigated a possible implication of the Period2 gene, a key component of the molecular circadian clock, on the circadian rhythms of blood pressure and heart rate. To address this question, we monitored blood...

Université de Fribourg

Age-dependent alterations in human PER2 levels after early morning blue light exposure

Jud, Corinne ; Chappuis, Sylvie ; Revell, Victoria L. ; Sletten, Tracey L. ; Saaltink, Dirk-Jan ; Cajochen, Christian ; Skene, Debra J. ; Albrecht, Urs

In: Chronobiology International, 2009, vol. 26, no. 7, p. 1462-1469

In our modern society, we are exposed to different artificial light sources that could potentially lead to disturbances of circadian rhythms and, hence, represent a risk for health and welfare. Investigating the acute impact of light on clock-gene expression may thus help us to better understand the mechanisms underlying disorders rooted in the circadian system. Here, we show an overall...

Université de Fribourg

Mutation of the circadian clock gene Per2 alters vascular endothelial function

Viswambharan, Hema ; Carvas, João Miguel ; Antic, Vladan ; Marecic, Ana ; Jud, Corinne ; Zaugg, Christian E. ; Ming, Xiu-Fen ; Montani, Jean-Pierre ; Albrecht, Urs ; Yang, Zhihong

In: Circulation, 2007, vol. 115, p. 2188-2195

Background— The circadian clock regulates biological processes including cardiovascular function and metabolism. In the present study, we investigated the role of the circadian clock gene Period2 (Per2) in endothelial function in a mouse model. Methods and Results— Compared with the wild-type littermates, mice with Per2 mutation exhibited impaired...