Biography
Biography: Telma Quintela
Abstract
The suprachiasmatic nucleus (SCN) of the mammalian hypothalamus is considered the master circadian pacemaker. The SCN clockwork is a cell autonomous mechanism consisting of a series of interlocked transcriptional/ post-translational feedback loops. However, the SCN is not the only structure in the brain displaying daily rhythms. Recently it was demonstrated that choroid plexus (CP) expresses core clock genes that are subjected to circadian regulation in a gender dependent manner, suggesting that hormones can regulate circadian rhythmicity in CP. Moreover, using CP explants cultured from mice carrying the Period-luciferase transgene, we report that CP exhibits endogenous circadian rhythms of PERIOD2::LUCIFERASE expression. We also observed that estrogen depletion following ovariectomy affects the CP circadian rhythmicity and that Period 1 and 2 mRNA expression are up-regulated by estradiol (E2) in rat CP epithelial cell cultures. In addition, the mechanism underlying these responses was investigated, and we provide evidence that the estrogen receptor is involved. Therefore, our study reinforces the importance of estrogens on circadian oscillators and supports the hypothesis that E2 directly controls the molecular clock machinery present in the CP.