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In Vitro Bioluminescence Assay to Characterize Circadian Rhythm in Mammary Epithelial Cells
Published on: September 28, 2017
Evening exposure to blue light stimulates the expression of the clock gene PER2 in humans
Christian Cajochen1, Corinne Jud, Mirjam Münch
1Centre for Chronobiology, Psychiatric University Clinics, University of Basel, CH-4025 Basel, Switzerland. christian.cajochen@unibas.ch
Abstract:
We developed a non-invasive method to measure and quantify human circadian PER2 gene expression in oral mucosa samples and show that this gene oscillates in a circadian (= about a day) fashion. We also have the first evidence that induction of human PER2 expression is stimulated by exposing subjects to 2 h of light in the evening. This increase in PER2 expression was statistically significant in comparison to a non-light control condition only after light at 460 nm (blue) but not after light exposure at 550 nm (green). Our results indicate that the non-image-forming visual system is involved in human circadian gene expression. The demonstration of a functional circadian machinery in human buccal samples and its response to light opens the door for investigation of human circadian rhythms at the gene level and their associated disorders.
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