亚慢性砷暴露对小鼠海马神经元凋亡调控基因Bcl-2和Bax表达的影响

发布时间：2018-03-20 07:33

本文选题：三氧化二砷　切入点：凋亡　出处：《大连医科大学》2012年硕士论文　论文类型：学位论文

【摘要】：目的：探讨砷诱导小鼠海马神经元凋亡与Bcl-2和Bax表达之间的关联性，为阐明砷的神经毒作用机制以及预防神经毒性危害提供依据。方法：SPF级小鼠40只，雌雄各半，按体重将小鼠随机分为4组，分别为对照组、1ppm As2O3染毒组、2ppm As2O3染毒组、4ppm As2O3染毒组。通过自然饮用含不同浓度As2O3蒸馏水的方式使小鼠染毒，连续染毒60天后取出海马组织。用TUNEL染色法和电镜技术检测染砷小鼠海马神经元的凋亡情况，用Real-timePCR，Western blot技术检测Bcl-2和Bax的基因、蛋白表达。采用SPSS11.5统计软件，用单因素方差分析（ANOVA），比较各染砷组与对照组间的统计学差异，两组间比较用LSD法分析，以P0.05表示统计学差异显著。结果：TUNEL凋亡染色结果显示，对照组小鼠海马组织CA1区未见阳性染色细胞，而染砷组小鼠海马组织CA1区可见阳性染色细胞，且随着染砷剂量的增加其阳性染色细胞数也增加，尤其2ppm染砷组4ppm染砷组小鼠海马组织阳性细胞数量显著多于对照组。电镜检测结果显示，，染砷组小鼠海马组织在视野中可见较多数量的凋亡细胞，细胞皱缩，染色质凝聚分布于核周，与TUNEL凋亡染色结果基本一致。Real Time PCR定量检测结果显示，染砷组小鼠海马组织中Bcl-2基因表达显著低于对照组，而Bax基因表达显著高于对照组(P0.05)。Western blot检测结果显示，染砷组的小鼠海马组织中Bcl-2基因表达显著低于对照组，而Bax基因表达显著高于对照组(P0.05)，与Real-time PCR结果一致。结论：亚慢性砷暴露诱导小鼠海马神经元凋亡，下调小鼠海马组织Bcl-2基因、蛋白表达和上调小鼠海马组织Bax基因、蛋白表达。亚慢性砷暴露小鼠海马神经元出现凋亡可能与砷导致的Bcl-2表达下调和Bax表达上调有关。
[Abstract]:Aim: to investigate the relationship between arsenic induced apoptosis of hippocampal neurons and the expression of Bcl-2 and Bax in mice, and to provide evidence for elucidating the neurotoxic mechanism of arsenic and preventing neurotoxicity. Methods Forty SPF mice, half male and half female, were randomly divided into 4 groups according to their body weight. The mice were exposed to 4 ppm As2O3 in the control group treated with 1 ppm As2O3 and 2 ppm As2O3. The mice were poisoned by drinking distilled water containing different concentrations of As2O3 naturally. The hippocampal tissue was taken out after 60 days of continuous exposure. Apoptosis of hippocampal neurons in arsenic exposed mice was detected by TUNEL staining and electron microscopy. The gene and protein expression of Bcl-2 and Bax were detected by Real-time PCR Western blot technique, and the expression of Bcl-2 and Bax were detected by SPSS11.5 statistical software. Single factor ANOVAX was used to compare the statistical difference between the arsenic exposed group and the control group, and the LSD method was used to analyze the difference between the two groups. Results the results of apoptosis staining showed that there were no positive staining cells in the CA1 region of hippocampal tissue in the control group, but there were positive staining cells in the CA1 area of the hippocampal tissue in the arsenic exposed group, and the number of positive staining cells increased with the increase of arsenic exposure dose. In particular, the number of positive cells in the hippocampus of 4ppm arsenic exposed mice in 2 ppm arsenic group was significantly higher than that in the control group. The results of electron microscopy showed that a large number of apoptotic cells were found in the hippocampal tissues of arsenic exposed mice, and the cells shrank. Chromatin condensed around the nucleus and was consistent with the results of TUNEL apoptosis staining. Real Time PCR quantitative analysis showed that the expression of Bcl-2 gene in the hippocampus of arsenic exposed mice was significantly lower than that of the control group. However, the expression of Bax gene was significantly higher than that of control group (P 0.05). Western blot analysis showed that the expression of Bcl-2 gene in hippocampus of arsenic exposed mice was significantly lower than that of control group, while the expression of Bax gene was significantly higher than that of control group (P 0.05), which was consistent with the result of Real-time PCR. Conclusion: subchronic arsenic exposure induces apoptosis of hippocampal neurons in mice, down-regulates Bcl-2 gene expression and up-regulates Bax gene expression in hippocampal tissues of mice. The apoptosis of hippocampal neurons in mice exposed to subchronic arsenic may be related to the down-regulation of Bcl-2 expression and the up-regulation of Bax expression induced by arsenic.
【学位授予单位】：大连医科大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R114

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