bims-ciryme Biomed News
on Circadian rhythms and metabolism
Issue of 2019‒03‒03
two papers selected by
Gabriela Da Silva Xavier
University of Birmingham

  1. Genes Dev. 2019 Mar 01. 33(5-6): 255-257
      The circadian clock in the suprachiasmatic nucleus (SCN) of mammals drives 24-h rhythms of sleep/wake cycles. Peripheral clocks present in other organs coordinate local and global physiology according to rhythmic signals from the SCN and via metabolic cues. The core circadian clockwork is identical in all cells. However, there is only a small amount of overlap of the circadian transcriptomes in different organs and tissues. A novel study by Beytebiere and colleagues (pp. 294-309) indicates that the regulation of tissue-specific rhythmic gene expression involves the cooperation of the circadian transcription factor (TF) BMAL1:CLOCK with tissue-specific TFs (ts-TFs) and correlates with the potential of BMAL1:CLOCK to facilitate rhythmic enhancer-enhancer interactions.
    Keywords:  circadian clock; enhancer–enhancer interactions; tissue-specific cistromes; transcription
  2. Trends Endocrinol Metab. 2019 Feb 21. pii: S1043-2760(19)30023-2. [Epub ahead of print]
      Hormone rhythms are ubiquitous and essential to sustain normal physiological functions. Combined mathematical modelling and experimental approaches have shown that these rhythms result from regulatory processes occurring at multiple levels of organisation and require continuous dynamic equilibration, particularly in response to stimuli. We review how such an interdisciplinary approach has been successfully applied to unravel complex regulatory mechanisms in the metabolic, stress, and reproductive axes. We discuss how this strategy is likely to be instrumental for making progress in emerging areas such as chronobiology and network physiology. Ultimately, we envisage that the insight provided by mathematical models could lead to novel experimental tools able to continuously adapt parameters to gradual physiological changes and the design of clinical interventions to restore normal endocrine function.
    Keywords:  chronotherapy; circadian rhythms; hormone dynamics; hybrid systems; regulatory networks; ultradian oscillations