镉诱导人外周血淋巴细胞金属硫蛋白-1基因亚型的表达

Metallothionein isoforms gene expression induced by cadmium in human peripheral blood lymphocytes

目的 研究金属硫蛋白- 1(MT- 1)基因在人外周血淋巴细胞 (HPBLs)中的基础表达和镉诱导表达水平。方法 应用RT- PCR方法检测HPBLs中 7种有功能的MT -1基因亚型的mRNA基础表达水平和不同时间、不同浓度镉诱导的表达水平。结果 HPBLsMT-1各亚型中 ,mRNAs的基础转录水平从高到低依次为MT -1X、MT- 1A、MT- 1H、MT- 1F、MT- 1E、MT- 1G ,而MT 1B没有表达 ,其中男性MT 1E的基础表达明显高于女性(P <0 . 0 5 )。在未引起细胞损伤时 ,80 μmol /LCdCl2 诱导 12小时可使MT- 1A ,MT- 1E ,MT 1XmRNA的转录水平开始显著增加 (P <0 . 0 5 ) ,4 0 μmol LCdCl2 诱导 4小时出现MT- 1FmRNA ,2 0 μmol/ LCdCl2 诱导 4小时出现MT- 1GmRNA ,80 μmol- LCdCl2 诱导 4小时出现MT -1HmRNA的转录水平开始显著增加 (P <0. 0 5 ) ,MT 1BmRNA表达无明显变化。结论 镉可诱导人外周血淋巴细胞MT-1F、MT -1G、MT- 1H、MT- 1XmRNA表达增加 ,并表现出剂量 -时间 -效应关系 ,可作为潜在的镉接触生物标志物。

Objective\ To explore gene expression of metallothion 1 (MT-1) isforms in human peripheral blood lymphocytes. Methods mRNA of expressi on representing t he seven active subtypes of MT-1 gene was determined in cultured human peripher a l blood lymphocytes (HPBLs) before and after exposure to cadmium by quantitative RT-PCR. Results Basal expression of MT-1X, MT-1A in HPBLs w as similar to expres sion of the housekeeping gene glyceraldehydes 3-phosphate dehydrognase. In cont r ast, the basal gene expression of MT-1H,MT-1F,MT-1E, MT-1G was a little t rans cript in HPBLs. No signal was detected for the MT-1B. There was a sex differenc e (P<0.05) in basal gene expression of MT-1E. The level of gene expression o f MT-1A,MT-1E,MT-1F,MT-1G,MT-1H and MT-1X was significantly increased( P<0.05), but not the level of MT -1B after exposure to cadmium. Conclusion It was suggested th at gene expression of MT-1F,MT-1G ,MT-1H and 1X in HPBLs could be used as potential exposure biomarker.