锌α_2糖蛋白真核表达载体的构建和体外表达鉴定

Construction of Zinc-α2-glycoprotein Expression Plasmid and Its Expression in 3T3-L1 Preadipocytes

目的构建小鼠锌α2糖蛋白(mZAG)真核表达载体,在体外培养细胞中鉴定其mRNA和蛋白水平表达。方法提取小鼠肝组织总RNA,采用RT-PCR法扩增mZAG全基因表达序列,酶切法将mZAGcDNA全序列插入表达质粒载体pcDNA3.1(-)中构建pcDNA3.1(-)-mZAG真核表达质粒。采用阳离子脂质体转染法将不同浓度mZAG表达质粒(0、0.4、0.8、1.6μg)pcDNA3.1(-)-mZAG和4对mZAG小干扰RNA(siRNA)序列转染到3T3-L1前脂肪细胞中,实时荧光定量RT-PCR测定mZAGmRNA表达水平,Western blot检测mZAG蛋白表达情况。结果测序鉴定证实成功构建mZAG真核表达质粒pcDNA3.1(-)-mZAG。实时荧光定量RT-PCR检测结果显示,0.4、0.8、1.6μg mZAG转染组3T3-L1细胞中的mZAGmRNA表达水平分别是0μg mZAG转染组的2.58(P=0.002)、3.67(P=0.000)、5.19倍(P=0.001);mZAG-siRNA1组和mZAG-siRNA4组小鼠3T3-L1细胞中的mZAGmRNA表达水平显著减少,分别是不转染mZAGsiRNA干扰序列对照组的49%(P=0.002)和41%(P=0.000)。Western blot检测结果显示,0.8μg mZAG质粒转染组的体外mZAG蛋白表达水平是不转染mZAG质粒对照组的2.75倍(P=0.017);mZAG-siRNA1和mZAG-siR-NA4干扰序列转染组的体外mZAG蛋白表达水平仅为对照组的55%(P=0.004)和62%(P=0.025)。结论成功构建mZAG真核表达载体,该载体能够在体外细胞中良好表达。筛选出能够显著抑制mZAG表达的siRNA1和siRNA4,为今后进一步深入研究ZAG提供了有用工具。

Objective To construct mouse Zinc-α2-glycoprotein(mZAG) eucaryotic expression plasmid and identify its expression in 3T3-L1 preadipocytes.Methods The total RNA from mouse liver tissue was extracted.The reverse-transcript(RT)-PCR method was used to amplify the complete domain sequence of mZAG,and the confirmed PCR products was inserted into expression plasmid by DNA ligation.The mZAG expression plasmids with various concentrations(0,0.4,0.8,and 1.6 μg) were transfectd into 3T3-L1preadipocytes,and ZAG express...