Maciel-Dominguez Anabel, Swan Daniel, Ford Dianne, Hesketh John
Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK; Human Nutrition Research Centre, Newcastle University, Newcastle upon Tyne, UK.
Mol Nutr Food Res. 2013 Dec;57(12):2195-205. doi: 10.1002/mnfr.201300168. Epub 2013 Aug 12.
Intake of the essential micronutrient selenium (Se) has health implications. This work addressed whether some effects of Se on gene expression are exerted through microRNAs (miRNA).
Human colon adenocarcinoma cells (Caco-2) were grown in Se-deficient or Se-adequate medium for 72 h. RNA was extracted and subjected to analysis of 737 miRNA using microarray technology. One hundred and forty-five miRNA were found to be expressed in Caco-2 cells. Twelve miRNA showed altered expression after Se depletion: miR-625, miR-492, miR-373*, miR-22, miR-532-5p, miR-106b, miR-30b, miR-185, miR-203, miR1308, miR-28-5p, miR-10b. These changes were validated by quantitative real-time PCR (RT-qPCR). Transcriptomic analysis showed that Se depletion altered expression of 50 genes including selenoproteins GPX1, SELW, GPX3, SEPN1, SELK, SEPSH2 and GPX4. Pathway analysis identified arachidonic acid metabolism, glutathione metabolism, oxidative stress, positive acute phase response proteins and respiration of mitochondria as Se-sensitive pathways. Bioinformatic analysis identified 13 transcripts as targets for the Se-sensitive miRNA; three were predicted to be recognised by miR-185. Silencing of miR-185 increased GPX2 and SEPSH2 expression.
We propose that miR-185 plays a role in up-regulation of GPX2 and SEPHS2 expression. In the case of SEPHS2 this may contribute to maintaining selenoprotein synthesis. The data indicate that micronutrient supply can regulate the cell miRNA expression profile.
必需微量营养素硒（Se）的摄入对健康有影响。本研究探讨了硒对基因表达的某些影响是否通过微小RNA（miRNA）发挥作用。
将人结肠腺癌细胞（Caco-2）在缺硒或富硒培养基中培养72小时。提取RNA并使用微阵列技术分析737种miRNA。发现145种miRNA在Caco-2细胞中表达。缺硒后12种miRNA表达发生改变：miR-625、miR-492、miR-373*、miR-22、miR-532-5p、miR-106b、miR-30b、miR-185、miR-203、miR1308、miR-28-5p、miR-10b。这些变化通过定量实时PCR（RT-qPCR）得到验证。转录组分析表明，缺硒改变了50个基因的表达，包括硒蛋白GPX1、SELW、GPX3、SEPN1、SELK、SEPSH2和GPX4。通路分析确定花生四烯酸代谢、谷胱甘肽代谢、氧化应激、正急性期反应蛋白和线粒体呼吸为对硒敏感的通路。生物信息学分析确定13个转录本为对硒敏感的miRNA的靶标；预测其中3个可被miR-185识别。miR-185沉默增加了GPX2和SEPSH2的表达。
我们提出miR-185在GPX2和SEPHS2表达上调中起作用。就SEPHS2而言，这可能有助于维持硒蛋白的合成。数据表明微量营养素供应可调节细胞miRNA表达谱。
