近日,，國際學(xué)術(shù)刊物《公共科學(xué)圖書館—綜合》（PLoS ONE）發(fā)表的一項(xiàng)研究結(jié)果首次闡明了SepSecS在雞腦硒穩(wěn)態(tài)調(diào)控中發(fā)揮著關(guān)鍵作用,。該研究由華南農(nóng)業(yè)大學(xué)獸醫(yī)學(xué)院和東北農(nóng)業(yè)大學(xué)的研究人員合作完成,。
O-磷酸絲氨酰-tRNA:硒氨酰-tRNA合成酶(SepSecS)在硒氨酸的合成與轉(zhuǎn)化中發(fā)揮至關(guān)重要的作用，并通過硒蛋白合成調(diào)控在硒（Se）生物學(xué)功能中扮演重要角色,。過去的研究證實(shí)硒和硒蛋白對(duì)大腦功能起關(guān)鍵性作用,。然而對(duì)于微量元素硒攝取如何影響基因表達(dá)，以及大腦中硒代謝的調(diào)控機(jī)制卻并不清楚,。
研究人員以雞腦和雞胚神經(jīng)元細(xì)胞為實(shí)驗(yàn)對(duì)象,，測(cè)定了不同硒水平飼料飼喂雞的不同腦區(qū)硒含量及SepSecS mRNA表達(dá)水平，同時(shí)檢測(cè)了不同硒濃度條件下雞胚神經(jīng)元細(xì)胞中SepSecS mRNA穩(wěn)定性及其表達(dá)水平,，結(jié)果表明在過量硒供給雞不同腦區(qū)中存在程度不同的硒穩(wěn)態(tài),，硒能夠改變神經(jīng)元細(xì)胞內(nèi)SepSecS mRNA穩(wěn)定性及表達(dá)水平，揭示硒攝入過量時(shí)機(jī)體能夠優(yōu)先確保不同腦區(qū)中的硒穩(wěn)態(tài),，其與硒對(duì)SepSecS轉(zhuǎn)錄調(diào)控作用密切相關(guān),。
這項(xiàng)成果首次闡明了SepSecS在雞腦硒穩(wěn)態(tài)調(diào)控中發(fā)揮著關(guān)鍵作用，從新的視角闡明硒及硒蛋白在禽類腦中生物學(xué)功能,，并為比較醫(yī)學(xué)提供了借鑒,。
華南農(nóng)業(yè)大學(xué)獸醫(yī)學(xué)院的唐兆新教授和東北農(nóng)業(yè)大學(xué)徐世文教授為這篇文章的共同通訊作者，華南農(nóng)業(yè)大學(xué)獸醫(yī)學(xué)院臨床獸醫(yī)學(xué)專業(yè)博士生李金龍為這篇文章的第一作者,。（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.
