锌对体外应激海马神经元MTs亚型表达的影响

目的:观察不同锌水平对体外应激海马神经元金属硫蛋白(MTs)亚型表达的影响。方法:取新生1dWis-tar大鼠海马组织进行体外神经元培养,无血清培养24h后,分别向培养液中加入皮质酮、Zn2+特异鳌合剂TPEN,使二者的最终浓度均为1×10-5mol/L,然后加入不同浓度的ZnSO4溶液,使Zn2+的最终浓度分别为1×10-5mol/L、1×10-4mol/L和2×10-4mol/L,作用24h后检测培养液中IL-6和NO含量,以蛋白印迹法检测细胞MTs含量,以RT-PCR检测细胞MT-1mRNA和MT-3mRNA的表达水平。结果:在海马神经元培养液中加入TPEN后,MTs的表达出现明显降低,皮质酮刺激也未见其表达升高。在补锌组,MTs的含量均明显增加,其中以10-4mol/LZn2+组的表达量最高。海马神经元MT-1mRNA和MT-3mRNA的表达水平在皮质酮应激组和补锌组均出现明显升高。另外,锌缺乏和皮质酮刺激可使海马神经元培养上清中的IL-6和NO水平均出现明显升高。结论:不同锌水平对应激海马神经元金属硫蛋白及其亚型mRNA的表达具有调控作用,缺锌可降低金属硫蛋白的表达,而补锌可增加金属硫蛋白的表达。

Effects of zinc on the expression of metallothionein isoforms in stressed hippocampal neurons in vitro

Aim: To evaluate the effects of different doses of zinc on the expression of metallothionein isoforms in stressed hippocampal neurons in vitro. Methods: The cell stress model was developed by corticosterone. The cultured hippocampal neurons were assigned to seven groups as follows: control group, zinc deficiency group, and their corresponding stressed groups, as well as three different levels of zinc complementarity groups. Results: In zinc deficiency group, the expressions of metallothionein and MT-1 mRNA , MT-3 mRNA were downregulated. On the other hand, inductions of metallothionein and it's mRNAs in stressed zinc complementarity group were increased. In addition, the levels of supernatant IL-6 and NO were increased clearly in zinc deficiency group and corticosterone stressed groups. Conclusion: Our results suggest that zinc deficiency may decrease while zinc complementarety increase the expressions of metallothioneins and MT-1 mRNA, MT-3 mRNA in stressed hippocampal neurons in vitro.