论文部分内容阅读
目的探讨孕期亚硝酸盐暴露对海马损伤的作用。方法利用C57BL/6J小鼠建立孕期亚硝酸盐暴露模型,分为对照组(生理盐水)、低剂量亚硝酸盐组(60mg/kg)和高剂量亚硝酸盐组(120mg/kg)。收集出生当日(P0)、P7、P14及P30各年龄点仔鼠大脑,用于免疫荧光染色、彗星实验、Western blotting蛋白半定量分析,对海马损伤进行研究。结果不论是亚硝酸盐暴露组还是对照组,仔鼠齿状回增殖的神经干细胞数目均随着年龄的增长逐渐减少;在P0、P7、P14和P30年龄点,暴露组仔鼠增殖的神经干细胞的数量明显比对照组少,且具有剂量依赖性(P<0.05,n=96)。为了鉴别这种抑制作用是否具有选择性,我们对P0仔鼠室管膜下区神经干细胞的增殖情况进行了观察。结果发现,亚硝酸盐暴露组室管膜下区的神经干细胞增殖较对照组也减少,同样具有剂量依赖性(P<0.05);亚硝酸盐暴露组仔鼠门区炎症损伤细胞和凋亡细胞的数目比对照组多,具有剂量依赖性(P<0.05);彗星实验结果显示,亚硝酸盐暴露组P0仔鼠海马细胞的彗尾比对照组长,具有剂量依赖性(P<0.01);与对照组P0仔鼠相比,亚硝酸盐暴露组仔鼠海马组织内Caspase-8和核因子κB(NF-κB)蛋白的表达量较高(P<0.05)。结论孕期亚硝酸盐暴露可通过抑制神经干细胞增殖,促进细胞损伤和凋亡而对仔鼠海马造成损伤。
Objective To investigate the effect of nitrite exposure during pregnancy on hippocampal lesion. Methods C57BL / 6J mice were used to establish the model of nitrite exposure during pregnancy. The models were divided into control group (saline), low dose nitrite group (60mg / kg) and high dose nitrite group (120mg / kg). The brain of offspring rats were collected on the day of birth (P0), P7, P14 and P30, and used for immunofluorescence staining, comet assay and Western blotting protein semiquantitative analysis. Results The number of neural stem cells proliferated in the dentate gyrus in both exposed and untreated groups decreased with age. At the age of P0, P7, P14 and P30, the number of neural stem cells (P <0.05, n = 96) were significantly lower than those in the control group. In order to identify whether this inhibitory effect is selective, we observed the proliferation of neural stem cells in the subventricular zone of the rat offspring. The results showed that the proliferation of neural stem cells in the subependymal zone of nitrite exposure group was also decreased compared with that in the control group (P <0.05). In the nitrite exposure group, inflammatory injury cells and apoptotic cells (P <0.05). The comet assay showed that the tail of hippocampal cells in the offspring of nitrite exposure group was longer than that of the control group (P <0.01). Compared with the control group, the expression of Caspase-8 and NF-κB in the hippocampus was higher in the nitrite exposed group (P <0.05). Conclusion Nitrite exposure during pregnancy can damage the hippocampus of offspring rats by inhibiting the proliferation of neural stem cells, promoting cell injury and apoptosis.