Without consciously checking your watch, your body knows the time by maintaining its own internal clock that tracks the day–night cycle through so-called circadian rhythms. Accordingly, disruption of these cycles, whether due to transient effects of jet-lag or disorders such as familial advanced sleep-phase syndrome, can profoundly affect an individual’s ability to maintain a normal pattern of sleeping and waking.
Circadian rhythms also affect a number of other physiological activities, including manifestations of disease and the body’s response to therapeutics. “Interestingly, some cancer growth is under circadian clock control,” says Yoichi Minami of the RIKEN Center for Developmental Biology in Kobe. “This suggests that if we take drugs with precise timing, we can reduce unwanted effects.”
Inspired by the work of 18th Century botanist Karl Linné, who assembled a literal circadian clock composed of flower species that open and close their petals at specific times of day, Minami and colleagues Takeya Kasukawa, Yuji Kakazu, Tomoyoshi Soga and Hiroki Ueda recently set about constructing an analogous ‘body clock’ for mammals.
To achieve this, they applied sophisticated analytical chemistry techniques to characterize time-of-day-specific fluctuations in the levels of a broad variety of small molecules circulating in the mouse bloodstream1. They performed their analysis with mice that were maintained either in fixed light–dark cycles, or in constant darkness, to distinguish variability resulting from external environmental time cues versus purely internal circadian timetables.
Depending on the analytical method applied, the researchers were able to detect between 150 and 300 compounds that appeared to show circadian regulation under both conditions. Once the oscillations of these various metabolites had been characterized, they were able to apply these patterns to determine the body-time at which a blood sample was collected. Importantly, the accuracy of these measurements was not affected by differences in age, sex or food consumption, and the team was even able to directly observe relative shifts in the circadian clock resulting from simulated jet-lag.
These findings now clear the way for constructing an equivalent internal timetable for people. “One of our main goals is translation of circadian clock research from lab to clinic,” says Kasukawa. “If we can show the validity of our method in human beings … our method will contribute to the diagnosis of disease caused by circadian clock dysfunction [and] speed up development of circadian clock-conditioning drugs.”
1. Minami, Y., Kasukawa, T., Kakazu, Y., Iigo, M., Sugimoto, M., Ikeda, S., Yasui, A., van der Horst, G.T.J., Soga, T. & Ueda, H.R. Measurement of internal body time by blood metabolomics. Proceedings of the National Academy of Sciences USA 106, 9890–9895 (2009).
The corresponding author for this highlight is based at the RIKEN Laboratory for Systems Biology
The irresistible fragrance of dying vinegar flies
16.08.2017 | Max-Planck-Institut für chemische Ökologie
How protein islands form
15.08.2017 | Albert-Ludwigs-Universität Freiburg im Breisgau
Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.
Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...
For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.
While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...
An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.
The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...
A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.
Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...
Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).
The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...
16.08.2017 | Event News
04.08.2017 | Event News
26.07.2017 | Event News
16.08.2017 | Physics and Astronomy
16.08.2017 | Materials Sciences
16.08.2017 | Interdisciplinary Research