硝酸钇对小鼠胚胎干细胞神经发育的影响及机制研究

Effects of yttrium nitrate on the neural development of mouse embryonic stem cells and the related mechanism

目的研究硝酸钇对小鼠胚胎干细胞神经发育的影响及可能作用机制。方法建立以胰岛素-转铁蛋白-硒-纤维连接蛋白(ITSFn)培养法为基础的胚胎干细胞神经发育毒性评价模型,通过MTT试验、彗星试验、流式细胞试验、RT-PCR和免疫印迹试验,检测不同浓度硝酸钇溶液对胚胎干细胞神经发育的影响。结果彗星试验和流式细胞仪检测结果显示,低剂量硝酸钇降低了神经元细胞凋亡率,而高剂量组神经元细胞凋亡率上升,各剂量组细胞凋亡率随着浓度增加呈现先降后升的趋势。RT-PCR和免疫印迹结果表明,低剂量硝酸钇可上调抗凋亡基因Bcl-2的表达,高剂量组则上调Bax的表达,抑制Bcl-2的表达。结论硝酸钇可通过调节凋亡相关基因Bcl-2和Bax表达影响小鼠胚胎干细胞的神经发育,但这种影响因剂量高低而具有两面性。

Objective To study the effects of yttrium nitrate on developmental neurotoxicity of mouse embryonic stem(ES） cells and the mechanisms involved. Methods Based on the established ITSFn neural developmental toxicity evaluation in vitro model,MTT method,comet assay,flow cytometry,RT-PCR and Western blot method were used to assess the neural developmental effects of ES cells exposed to yttrium nitrate of different concentrations. Result Both comet assay and flow cytometry results showed yttrium nitrate could inhibit the rate of apoptosis at a low concentration,while increase the rate at a high dose. The rate of apoptosis ascended first then decreased. RT-PCR and Western blot results demonstrated that yttrium nitrate could up-regulate the expression of Bcl-2 at low concentrations,but down-regulate the expression of Bcl-2 and up-regulate the expression of Bax at high concentrations. Conclusion As regulating and control genes of apoptosis,both Bcl-2 and Bax genes took part in the neural developmental process of ES cells