Urlep Ziga, Rozman Damjana
Center for Functional Genomics and Bio-Chips, Institute for Biochemistry, Faculty of Medicine, University of Ljubljana , Ljubljana , Slovenia.
Front Endocrinol (Lausanne). 2013 Sep 2;4:111. doi: 10.3389/fendo.2013.00111.
Circadian aspect of reproduction has gained much attention in recent years. In mammals, it is very important that the timing of greatest sexual motivation is in line with the highest fertility. Peripheral clocks have been found to reside also in reproductive organs, such as the uterus and ovary. The timing signal from the suprachiasmatic nucleus is suggested to be transmitted via hormonal and neural mechanisms, and could thus mediate circadian expression of target genes in these organs. In turn, estrogens from the ovary have been found to signal back to the hypothalamus, completing the feedback loop. In this review we will focus on the interplay between clock and estrogens. Estradiol has been directly linked with expression of Per1 and Per2 in the uterus. CLOCK, on the other hand, has been shown to alter estradiol signaling. We also present the idea that cholesterol could play a vital role in the regulation of reproduction. Cholesterol synthesis itself is circadially regulated and has been found to interfere with steroidogenesis in the ovary on the molecular level. This review presents a systems view on how the interplay between circadian clock, steroidogenesis, and cholesterol synthesis affect various aspects of mammalian reproduction.
近年来，生殖的昼夜节律方面备受关注。在哺乳动物中，最大性动机的时间与最高生育力保持一致非常重要。已发现外周生物钟也存在于生殖器官中，如子宫和卵巢。来自视交叉上核的定时信号被认为是通过激素和神经机制传递的，因此可以介导这些器官中靶基因的昼夜节律表达。反过来，已发现来自卵巢的雌激素会向丘脑下部发出信号，从而完成反馈回路。在这篇综述中，我们将重点关注生物钟与雌激素之间的相互作用。雌二醇已与子宫中Per1和Per2的表达直接相关。另一方面，生物钟蛋白已被证明会改变雌二醇信号传导。我们还提出胆固醇可能在生殖调节中发挥至关重要的作用这一观点。胆固醇合成本身受昼夜节律调节，并且已发现在分子水平上它会干扰卵巢中的类固醇生成。这篇综述从系统角度阐述了昼夜节律钟、类固醇生成和胆固醇合成之间的相互作用如何影响哺乳动物生殖的各个方面。
