硫酸镉诱导大鼠肝组织及L02细胞热应激蛋白70基因表达的研究

Gene Expression of Heat Shock Protein 70 Induced by Cadmium in Rats

目的研究重金属镉诱导热应激蛋白70(HSP70)基因表达的变化,探讨以HSP70基因表达作为环境污染及暴露人群监控的敏感性指标。方法将Wistar大鼠随机分成25.0、8.0及3.0 mg/kg硫酸镉染毒组及正常对照共4组,每组16只,雌雄各半,连续染毒28 d;运用RT-PCR扩增技术观察肝组织HSP70 mRNA表达的变化,并用原子吸收光谱法检测大鼠肝脏镉含量。以0.5,1.0,2.0μmol/L硫酸镉染毒胚胎肝细胞株L02细胞,运用RT-PCR扩增技术观察HSP70 mRNA表达的变化。结果大鼠肝组织HSP70mRNA表达呈剂量-效应关系,8.0及25.0 mg/kg剂量组HSP70 mRNA表达明显增加,与阴性对照组比较,差异有统计学意义(P<0.05),而3.0 mg/kg剂量组与阴性对照组比较,差异没有统计学意义(P>0.05);在L02细胞未出现明显细胞毒作用的1μmol/L剂量组,HSP70基因表达明显上调。染毒组大鼠肝脏镉含量增加(P<0.05)。结论硫酸镉能够诱导Wistar大鼠肝组织及L02细胞HSP70 mRNA表达明显增强。

Abstract：Objective To understand the sensitivity of the gene expression of heat shock protein70 （HSP70） induced by cadmium and whether it can be taken as a biomarker in cadmium exposure assessment. Methods L02 cells were exposed to 0.5,1.0 and 2.0μmol/L of CdS04 for 4 h,then the expression of HSP70 mRNA was observed by polymerase chain reaction （PCR）. Wistar rats aged 6 weeks were divided into 4 groups, experimental groups were treated with CdSO4 by garage once 16 in each, including 8 male and 8 female. The rats in the a day at the doses of 25.0 mg/kg, 8.0 mg/kg and 3.0 mg/kg respectively for 28 consecutive days, one group was the negative control. After the exposure, the liver tissue was sampled to examine the expression of HSP70 mRNA in the liver tissue by PCR. Results In the CdSO4-treated groups （25.0 mg/kg, 8.0 mg/kg）, the expression of HSP70 mRNA in the liver tissue was significantly up-regulated （P〈0.05） with a dose-dependent manner compared with the negative control group. Conclusion CdSO4 may induce an up-regulated expression of HSP70mRNA in the hepatic tissue and in L02 cells in rats.