【摘要】 目的研究慢性铅暴露对原代培养的大鼠脑星形胶质细胞增殖、形态、细胞周期以及葡萄糖调节蛋白78(glucose regulated proteins,GRP78)、生长抑制DNA损伤诱导因子(growth arrest and DNA damage inducible gene,GADD153)和细胞周期蛋白D1(CyclinD1)表达的影响,探讨脑星形胶质细胞中铅所诱导的内质网应激反应。方法出生1～4d Wistar大鼠脑星形胶质细胞原代培养并传代,分为对照组和染毒组。分别应用四甲基偶氮唑蓝(methyl thiazolyl tetrazolium,MTT)、流式细胞术、倒置显微镜观察1.0μmol/L乙酸铅染毒细胞增殖率、细胞周期和形态的变化。利用Western blotting检测乙酸铅对星形胶质细胞GRP78、GADD153和CylcinD1表达的影响。结果染铅30d后细胞增殖率下降50.8%。染铅8、12、15和30d后,停留在G1期的细胞数由(58.64±1.75)%分别增加至(69.81±1.56)%、(70.80±1.27)%、(90.59±1.25)%和(80.9±1.11%)。1.0μmol/L乙酸铅呈时间依赖性促进GRP78表达,抑制CyclinD1表达,差异有统计学意义(P<0.05),而GADD153的表达无显著性改变。结论铅可使原代培养的大鼠脑星形胶质细胞发生增殖抑制、细胞周期停滞、GRP78表达上调、CyclinD1表达下调等一系列应激反应。更多还原

【Abstract】 Objective To evaluate the effects of lead on the cell proliferation, morphological changes, cell-cycle and the expression of glucose -regulated protein of 78 kDa (GRP78), growth arrest and DNA damage inducible gene (GADD153) and CyclinD1 in astrocytes. Methods The astrocyte cells in primary culture of Wistar rats 1-4 days old were treated with lead acetate at 1.0 μmol/L, the cell proliferation rate, cell-cycle and morphological changes were determined respectively by MTT, FACS analysis and inverted microscope. The expression of GRP78, GADD153 and CyclinD1 were detected by Western blotting. Results Compared with the control, after lead treatment, the morphological changes were found expressly. A significant reduction for 26.5% was observed following exposure to 1.0 μmol/L lead acetate for 8 d, and 50.8% of astrocyte cells were lost at 30 d. The proportion of cells treated with 1.0 μmol/L lead acetate for 8 d, 12 d or 15 d in G1 phase gradually increased [(58.64±1.75)%, (69.81±1.56)%, (70.80±1.27)%,(90.59±1.25)%]and then little resumed in the group treated by lead acetate for 30 d (80.9 ±1.11)%. In a time- dependent manner, lead exposure induced the expression of GRP78 and inhibited CyclinD1, and no notable alter with GADD153. Conclusion Lead exposure may result in the unfolded protein response (UPR) including proliferation inhibition, cell-cycle stagnation, up-regulate the expression of GRP78 and down-regulate the level of cyclinD1 in the astrocytes.更多还原