STUDY ON MECHANISM AND TREATMENT OF JET LAG CAUSED BY DISSOCIATION OF TWO OSILLATORS.

点击翻译按钮获取中文摘要

A. Dichotomy of the circadian center is associated with jet lag syndromeIn both 10 hour delay and 6 hour advance of light-dark cycle, we found that there appeared the dissociation of the suprachiasmatic into two oscillators. The ventrolateral region of the SCN (VLSCN) shifted rapidly whereas the dorsomedial regions of the SCN (DMSCN) shifted very slowly, spent more than a week to regain synchronization of the VLSCN and VLSCN. The sluggish shift of the DMSCN corresponds to the suppressed locomotors activity, which suggests that jet lag is caused by the slow shift of the DMSCN after LD cycle shift.B. Transgene of mammalian Per2 genes to Per2-null Drosophila mutants recovered the circadian rhythmicity.We introduced transgene to Per2-null Drosophila of which activity is arrhythmic. In the Drosophila expressing mouse Per21 or Per22 gene, we found the recovery of locomotor rhythms. The finding suggests that Pa-21 and Per22 have similar roles of clock genes even in the mammalian species.C. A Transcription Factor Response Element for Gene Eypressinn During Circadian NightWe profiled suprachiasmatic nuclei (SCN) and liver genome-wide expression patterns under light/dark (LD) cycles and constant darkness (DD). We extensively determined transcription start sites (TSS) of human orthologues for newly identified cycling genes and then Per2 formed bioinformatical searches for relationships between time-of-day specific expression and transcription factor response elements around TSS. We demonstrate the role of the Rev-ErbA/ROR response element in gene expression of nocturnally expressed genes in SCN and liver.D. Phosphodiesterase type,4 (PDE4) specifically degradg cAMPTo enhance Per21 transcription by the inhibition of cAMP degradation, we used Rolipram, a specific inhibitor of phosphodiesterase type 4 which degrades the cAMP. We found that the Per21 transcript increased transiently but the Per2iod length of Per21 increase was not extended.