铅对体外培养大鼠海马神经细胞生长和Oct-2蛋白表达的影响

目的　探讨铅对海马神经细胞生长发育和对Ⅱ型POU域蛋白Oct 2表达的影响。方法　采用大鼠海马神经细胞体外培养建立细胞模型 ,醋酸铅的染毒浓度分别为 10 -1、10 0 、10 1、10 2 、10 3μmol/L ,对照组给予等量培养液。染毒后 2 4h用免疫组织化学法检测神经细胞和神经胶质细胞的标志物神经丝 (NF)和神经胶质原纤维酸性蛋白质 (GFAP)以及Oct 2蛋白的表达。结果 10 μmol/L及 以上浓度醋酸铅组海马神经细胞胞体减小、轴突突起长度和细胞间连接减少。GFAP免疫组化结果发现1μmol/L醋酸铅即可使GFAP阳性细胞数明显增加 ,与对照组相比差异具有统计学意义。此外 ,1μmol/L的醋酸铅可导致神经元和神经胶质细胞Oct 2表达阳性面积比与对照组相比差异具有统计学意义 ,10 μmol/L以上浓度醋酸铅作用下 ,Oct 2表达阳性面积比和吸光度均高于对照组 ,差异具有统计学意义。结论　醋酸铅在抑制神经元生长和分化的同时可刺激神经胶质细胞增生 ,铅对中枢神经系统的部分毒作用至少与其导致的Oct 2表达增加有关

Studies on the effects of lead on the growth and differentiation of hippocampal neural cells as well as the expression of Oct-2

OBJECTIVE: In order to explore the effects of lead on the growth and development of cultured hippocampal neural cells and on the expression of Oct-2, the II subtype POU domain protein. METHODS: Experiment cell model was established using primary culture of hippocampal neural cells from SD rat embryos. Target cells were exposed to lead acetate in the different concentrations, i.e. 10(-1), 10(0), 10(1), 10(2), 10(3) micromol/L, while the control group was given the same quantity of the culture medium. The immunohistochemistry method was utilized to detect the expressions of Neurofilament (NF) and Glial Fibrillary Acidic Protein (GFAP), the markers for neuron and astrocyte, respectively, and the expression of Oct-2 as well. RESULTS: The results showed that 10 micromol/L lead acetate treatment caused diminishing of neuronal cell body and the decreases of both axon lengths and inter-cellular connections. In addition, 1 micromol/L lead acetate significantly increased the number of GFAP-positive cells compared with the control group (P < 0.05). By image analysis system, 1 micromol/L lead acetate treatment was found to induce a statistically significant increase of the positive area rate concerning Oct-2 expression in hippocampal neurons and astrocytes, while both positive area rate and integral density of light of Oct-2 expression were found to increase markedly in the groups treated by 10 micromol/L lead acetate (P < 0.01). CONCLUSIONS: Lead acetate treatment may contribute to the inhibitions of both growth and differentiation of hippocampus neurons, and to the stimulation of glial cell hyperplasia simultaneously. In addition, the CNS impairments caused by lead is partly correlated with the enhancement of Oct-2 expression.