铅对培养大鼠海马神经元mGluR5 mRNA和蛋白表达水平的影响

目的 研究铅暴露对海马神经元代谢性谷氨酸受体5亚型（mGluR5）mRNA和蛋白水平表达的影响。方法 对原代培养3d的胎鼠海马神经元分为4组,分别为加入氯化铅溶液终浓度为10^-8 mol／L、10^-6 mol／L、10^-4mol／L的各铅暴露组和空白对照组。用实时荧光定量RT—PCR和Westernblot方法检测每组神经元mGluR5 mRNA和蛋白水平的表达。结果 铅暴露组海马神经元mGluR5mRNA表达较正常对照组下调,且随铅暴露浓度升高下调越明显。10^-8mol／LPb^2＋ 组、10^-6 mol／LPb^2＋组、10^-4 mol／LPb^2＋组mGluR5 mRNA表达量与正常对照组比值分别为0．724、0．421、0．321。Westernblot结果显示铅暴露组mGluR5蛋白表达量低于正常对照组,同样呈剂量效应关系,差异有统计学意义（F=77．966,P〈0．001）。结论 铅暴露导致培养的大鼠海马神经元mGluR5基因mRNA和蛋白表达下降,且铅暴露剂量与下降幅度有一定相关性。

Effects of lead exposure on expression of mGluR5 in mRNA and protein levels of the cultured hippocampal neurons

OBJECTIVE: To study the effects on the expression of mGluR5 mRNA and protein levels in primarily cultured hippocampal neurons after lead exposure. METHODS: Primary embryonic rat hippocampal neuronal culture was prepared. On the 3(rd) day of incubation, lead chloride solution was added into medium to produce four different lead exposure levels: 0, 1 x 10(-8) mol/L, 1 x 10(-6) mol/L, 1 x 10(-4) mol/L Pb(2+). After 10 days of incubation, the neurons were collected to measure the alteration of mGluR5 mRNA expression by real-time fluorescent quantity PCR and the expression of mGluR5 in protein level by Westernblot. RESULTS: The studies revealed that mGluR5 mRNA expression was down-regulated after lead exposure in a dose-dependent manner. The mGluR5 mRNA expression of the lower lead-exposed neurons (Pb(2+) 10(-8) mol/L), the medium lead-exposed neurons(Pb(2+) 10(-6) mol/L), the higher lead-exposed neurons(Pb(2+) 10(-4) mol/L) were 0.724, 0.421, 0.321 times less than that of the controls, respectively. The Westernblot demonstrated that mGluR5 expression in protein level should be decreased after lead exposure. CONCLUSION: The expression of mGluR5 in mRNA and protein levels should be down-regulated after lead exposure at different lead levels in a dose-dependent manner.