Format

Send to

Choose Destination
See comment in PubMed Commons below
J Invest Dermatol. 2011 Feb;131(2):338-48. doi: 10.1038/jid.2010.315. Epub 2010 Oct 21.

A circadian clock in HaCaT keratinocytes.

Author information

1
Research and Development, Beiersdorf AG, Hamburg, Germany.

Abstract

To anticipate daily environmental changes, most organisms developed endogenous timing systems, the so-called circadian (∼24 hours) clocks. Circadian clocks exist in most peripheral tissues and govern a huge variety of cellular, metabolic, and physiological processes. Recent studies have suggested daytime-dependent variations in epidermal functions such as barrier recovery and pH homeostasis. However, a local circadian clock in epidermal keratinocytes has not been reported yet, and as such the molecular link between the circadian system and epidermal physiology remains elusive. In this study we describe a functional cell autonomous circadian clock in human adult low calcium temperature (HaCaT) keratinocytes. Using live-cell bioluminescence imaging and mRNA expression time series, we show robust circadian transcription of canonical clock genes in synchronized HaCaT keratinocytes. Genetic and pharmacological perturbation experiments as well as the phase relations between clock gene rhythms confirm that the molecular makeup of the HaCaT keratinocyte clock is very similar to that of other peripheral clocks. Furthermore, temperature was identified to be a potent time cue (Zeitgeber) for the epidermal oscillator. Temperature cycles entrain HaCaT keratinocytes, leading to the identification of rhythmic expression of several genes involved in epidermal physiology such as cholesterol homeostasis and differentiation. Thus, we present HaCaT keratinocytes as an excellent model to study the regulation of keratinocyte physiology by the circadian clock in a simple yet robust in vitro system.

PMID:
20962856
DOI:
10.1038/jid.2010.315
[Indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Support Center