In vivo single-cell detection of metabolic oscillations in stem cells

Cell Rep. 2015 Jan 6;10(1):1-7. doi: 10.1016/j.celrep.2014.12.007. Epub 2014 Dec 24.

Abstract

Through the use of bulk measurements in metabolic organs, the circadian clock was shown to play roles in organismal energy homeostasis. However, the relationship between metabolic and circadian oscillations has not been studied in vivo at a single-cell level. Also, it is unknown whether the circadian clock controls metabolism in stem cells. We used a sensitive, noninvasive method to detect metabolic oscillations and circadian phase within epidermal stem cells in live mice at the single-cell level. We observe a higher NADH/NAD+ ratio, reflecting an increased glycolysis/oxidative phosphorylation ratio during the night compared to the day. Furthermore, we demonstrate that single-cell metabolic heterogeneity within the basal cell layer correlates with the circadian clock and that diurnal fluctuations in NADH/NAD+ ratio are Bmal1 dependent. Our data show that, in proliferating stem cells, the circadian clock coordinates activities of oxidative phosphorylation and glycolysis with DNA synthesis, perhaps as a protective mechanism against genotoxicity.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • ARNTL Transcription Factors / genetics
  • Animals
  • Cell Proliferation / genetics*
  • Circadian Clocks / genetics*
  • DNA Damage / genetics
  • Glycolysis
  • Homeostasis
  • Humans
  • Mice
  • Oxidative Phosphorylation
  • Period Circadian Proteins / genetics
  • Single-Cell Analysis*
  • Stem Cells / cytology
  • Stem Cells / metabolism*

Substances

  • ARNTL Transcription Factors
  • Arntl protein, mouse
  • Period Circadian Proteins