低硒大鼠microRNA表达谱的变化

Changes of MicroRNA expression profiles in rats with selenium deficiency

目的探讨低硒大鼠microRNA表达谱的变化。方法将30只SD大鼠随机分为对照组、低硒组及补硒组,每组各10只,对照组喂养标准饲料,低硒组喂养低硒饲料,补硒组喂养低硒饲料14周后再给予亚硒酸钠补硒3周。各组喂养17周后,检测大鼠的血硒水平。提取各组大鼠心肌组织RNA进行microRNA基因芯片检测,寻找低硒大鼠与正常大鼠microRNA的表达差异。采用GO分析等生物学方法对差异性表达的microRNA基因进行深度的分析,并通过RT-q PCR进行验证。结果成功构建了SD大鼠低硒模型(血硒含量0.026 ng/L),低硒组大鼠血硒水平与对照组相比明显降低(P<0.05),补硒后又明显增加(P<0.05)。通过microRNA基因芯片检测低硒组筛选出显著差异性表达基因共30个,上调基因中表达最显著的为:miR-374,miR-16,miR-199a-5p,miR-195和miR-30e*,下调基因中表达最显著的为:miR-3571,miR-675和miR-450a*。其中miR-374表达量最高,与低硒密切相关。结论低硒大鼠中miR-374,miR-16,miR-199a-5p,miR-195,miR-30e*,miR-3571,miR-675,miR-450a*表达显著异常,其中miR-374与低硒关系最为密切。为MicroRNA在克山病的诊断及治疗方面研究提供实验依据。

AIM To investigate changes of microRNA expression profiles in rats with selenium deficiency. METHODS Thirty SD rats were randomly divided into a control group, low selenium group, and selenium supplement group, with 10 in each group. Rats in the control group were fed with standard diet, rats in the low selenium group were fed with a low selenium diet, and rats in the selenium supplement group were fed first with a low selenium diet for 14 weeks and then were given sodium selenite for 3 weeks. Seventeen weeks later, blood selenium in all groups was detected. RNA was extracted from myocardial tissue of rats for microRNA microarray detection, identifying differential microRNA of low selenium rats and normal rats. Then, these differential microRNAs were deeply analyzed by GO analysis and were verified through RT-qPCR. RESULTS The model of SD rats with selenium deficiency was successfully constructed （the concentration of selenium was 0.026 ng/L）. The levels of blood selenium in the low selenium group decreased significantly compared with those in the control group （P〈0.05）, but after selenium supplement, they increased significantly （P〈0.05）. Through microRNA microarray detection, 30 microRNAs with differential expression in the low selenium group were screened. In up-regulated gene expression and the most significant microRNAs were miR-374, miR-16, miR-199a-5p, miR-195 and miR-30e＊. In down-regulated gene expression, the most significant microRNAs were miR-3571, miR-675 and miR-450a＊. Among these, the expression of miR-374 was the highest, which may be of significant importance in rats with selenium deficiency. CONCLUSION Expressions of miR-374, miR-16, miR-199a-5p, miR-195, miR-30e＊, miR-3571, miR-675 and miR-450a＊ were significnatly abnormal in rats with selenium deficiency, among which miR-374 is most closely related to selenium deficiency, providing an experimental basis for the diagnosis and treatment of Keshan disease with microRNA.