近日，国际学术刊物《公共科学图书馆—综合》（PLoS ONE）发表的一项研究结果首次阐明了SepSecS在鸡脑硒稳态调控中发挥着关键作用。该研究由华南农业大学兽医学院和东北农业大学的研究人员合作完成。
O-磷酸丝氨酰-tRNA:硒氨酰-tRNA合成酶(SepSecS)在硒氨酸的合成与转化中发挥至关重要的作用，并通过硒蛋白合成调控在硒（Se）生物学功能中扮演重要角色。过去的研究证实硒和硒蛋白对大脑功能起关键性作用。然而对于微量元素硒摄取如何影响基因表达，以及大脑中硒代谢的调控机制却并不清楚。
研究人员以鸡脑和鸡胚神经元细胞为实验对象，测定了不同硒水平饲料饲喂鸡的不同脑区硒含量及SepSecS mRNA表达水平，同时检测了不同硒浓度条件下鸡胚神经元细胞中SepSecS mRNA稳定性及其表达水平，结果表明在过量硒供给鸡不同脑区中存在程度不同的硒稳态，硒能够改变神经元细胞内SepSecS mRNA稳定性及表达水平，揭示硒摄入过量时机体能够优先确保不同脑区中的硒稳态，其与硒对SepSecS转录调控作用密切相关。
这项成果首次阐明了SepSecS在鸡脑硒稳态调控中发挥着关键作用，从新的视角阐明硒及硒蛋白在禽类脑中生物学功能，并为比较医学提供了借鉴。
华南农业大学兽医学院的唐兆新教授和东北农业大学徐世文教授为这篇文章的共同通讯作者，华南农业大学兽医学院临床兽医学专业博士生李金龙为这篇文章的第一作者。（生物谷Bioon.com）
doi:10.1371/journal.pone.0035761
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Priority in Selenium Homeostasis Involves Regulation of SepSecS Transcription in the Chicken Brain
Jin-Long Li, Hui-Xin Li, Xue-Jiao Gao, Jiu-Li Zhang, Shu Li, Shi-Wen Xu, Zhao-Xin Tang
O-Phosphoseryl-tRNA:selenocysteinyl-tRNA synthase (SepSecS) is critical for the biosynthesis and transformation of selenocysteine (Sec) and plays an important role in the biological function of Se through the regulation of selenoprotein synthesis. Selenium (Se) and Selenoprotein play a pivotal role in brain function. However, how intake of the micronutrient Se affects gene expression and how genetic factors influence Se metabolism in the brain is unknown. To investigate the regulation of SepSecS transcription induced by Se in the chicken brain, we determined the Se content of brain tissue, SepSecS gene expression levels and mRNA stability in the chicken brain and primary cultured chicken embryos neurons receiving Se supplements. These results showed that Se content in the brain remains remarkably stable during Se supplementation. A significant increase in SepSecS mRNA levels was observed in all of the brain tissues of chickens fed diets containing 1–5 mg/kg sodium selenite. Most strikingly, significant changes in SepSecS mRNA levels were not observed in neurons treated with Se. However, Se altered the SepSecS mRNA half-life in cells. These data suggest that Se could regulate SepSecS mRNA stability in the avian brain and that SepSecS plays an important role in Se homeostasis regulation.
