亚硒酸钠对谷氨酸所致神经细胞损伤的影响及机制

Effect of sodium selenite on glutamic acid-induced neuronal injury

目的观察亚硒酸钠对谷氨酸(Glu)所致神经细胞损伤的影响,并探讨其机制。方法将HT22神经细胞分成3组,对照组加入细胞培养液培养,Glu组加入6 mmol/L Glu和细胞培养液共同培养,亚硒酸钠组加入100nmol/L亚硒酸钠、6 mmol/L Glu和细胞培养液共同培养。MTT法检测各组6、10、24 h的细胞增殖抑制率;倒置显微镜观察细胞大体形态,透射电镜观察细胞超微结构;采用氧自由基(ROS)特异性标记探针DHE对各组细胞进行标记,用荧光电子显微镜观察DHE表达。结果 Glu组培养6 h时的细胞增殖抑制率为8.71%±0.009%,10、24h时细胞增殖抑制率较6 h时升高,24 h时最高;亚硒酸钠组各时点细胞增殖抑制率均较Glu组降低(P均<0.05)。倒置显微镜下可见Glu组细胞数量较对照组减少,细胞皱缩、形态不规则,亚硒酸钠组细胞数量较Glu组数量增多;透射电镜下可见Glu组细胞凋亡数目较对照组增加,线粒体、内质网损伤加重,亚硒酸钠组细胞凋亡数量较Glu组减少。荧光电子显微镜观察显示,Glu组较对照组DHE染色的平均光密度增加,亚硒酸钠组DHE染色较Glu减轻(P均<0.01)。结论硒能够减轻Glu对神经细胞的损伤作用,其机制可能与减少ROS产生有关。

Objective To investigate the effect of sodium selenite on glutamic acid（Glu）-induced neuronal injury and its mechanism.Methods The HT22 cells were divided into three groups.The control group was cultured in cell culture fluid.The Glu group was co-cultured with Glu（6 mmol/L） and cell culture fluid.The sodium selenite group was cocultured with Glu（6 mmol/L）,cell culture fluid,and 100 nmol/L sodium selenite.MTT method was used to detect the cell inhibition rates in each group at 6,10,and 24 h after cultivation.Inverted microscope was used to observe the changes of cell morphology.Transmission electron microscope（TEM） was used to observe the changes of cell micro-structure.The cells were labeled with oxygen free radical ROS-specific labeling probe DHE.The expression of DHE was observed with fluorescent electron microscope.Results The cell inhibition rate of the Glu group was 8.71%±0.009% at 6 h,the inhibition rate increased at 10 and 24 h,and at 24 h it reached the peak.But the cell inhibition rate dropped significantly after that common incubation with sodium selenite（P0.05）.The results of the inverted microscope showed the number of cells in the Glu group was lower than that of the control group,and with cell shrinkage and irregular shapes.The number of cells in the sodium selenite group was increased than that of the the Glu group.The results of TEM showed the number of apoptosis in the Glu group was higher than that of the control group,and with severer mitochondria and endoplasmic reticulum damage.The number of apoptosis in the sodium selenite group was lower than that of the Glu group.Fluorescent electronic microscope showed the average optical density of DHE dyeing in the Glu group was higher than that of the control group,and the average optical density of DHE dyeing in the sodium selenite group was lower than that of the Glu group.Conclusion Selenium（Sodium selenite） can alleviate the damage of nerve cells from Glu by reducing the ROS production.