[Circadian clock gene expression in human peripheral blood mononuclear cells]

Circadian clock genes have been identified in humans but information regarding their expression has remained very limited. However from a basic point as well as in a diagnostic and therapeutic perspective, it is important to evaluate molecular clock gene expression. Peripheral blood mononuclear cells represent an ideal material to investigate non-invasively the human clock at the molecular level. Several studies including ours reported rhythmic expression of clock genes in these cells, with significant intersubject variability of expression. In addition, our results reveal the existence of different chronotypes of clock gene expression patterns and suggest specific regulatory mechanisms in these human cells as compared to other peripheral tissues.