母鼠围产期铅暴露对仔鼠不同脑区POU域蛋白表达的影响

Effect of prenatal lead exposure on the expression of POU-domain proteins in different brain regions of rat offsprings

目的探讨POU域蛋白在铅的神经毒性机制中的作用。方法受孕雌性大鼠从妊娠第15天开始经饮水染铅(对照饮蒸馏水,试验组醋酸铅低0.5g L、中1.0g L、高2.0g L),至仔鼠出生后21日断乳为止。分别取21日龄仔鼠大脑皮层、海马、小脑部位组织制作冰冻切片,采用免疫组织化学方法测定不同脑区的Oct2和Brn3a蛋白表达水平。结果显微图像分析表明,染铅组脑组织皮层、海马及小脑的Oct2和Brn3a蛋白表达的阳性面积比[Aa(%)]、平均灰度与对照组相比其差异有不同程度的显著性(P<0.05或P<0.01),并呈剂量依赖性的变化。染铅组Oct2表达高于对照组,而Brn3a表达低于对照组。结论POU域蛋白作为转录调节因子参与了铅对学习记忆损害的神经毒性过程。

Objective To study the role of POU-domain proteins in the neurotoxic mechanism of lead. Methods The pregnant rats were randomly divided into 4 groups, which were provided with distilled water, 0.5g/L, 1.0g/L and 2.0g/L lead actate solution via drinking water, respectively, the lead-exposure period for exposure groups was limited from the 15th day after pregnancy to the 21st day when the offspring began to weaned, the expression of Oct-2 and Brn-3a proteins in neural cells from cerebral cortex, hippocampus and cerebellum were measured by immunohistochemistry methods. Results The immunohistochemistry results showed that Oct-2 increased significantly and Brn-3a decreased significantly in lead poisoning groups compared with that of the control group （ P 〈 0.05 or P 〈 0.01 ）. Conclusion The results indicateded that POU-domain proteins, as a transcription regular factor, may participate in the neurological toxicity damaging the learning and memory ability induced by lead. The study provided experimental basis for revealing the molecular neurotoxic mechanism of lead.