慢性铅暴露损伤大鼠学习记忆的组蛋白甲基化机制

发布时间：2018-03-13 17:34

本文选题：铅　切入点：学习记忆损伤　出处：《合肥工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：铅是一种广泛存在的环境污染物,许多研究表明慢性铅暴露会损伤发育期儿童学习记忆能力,并且其损伤机制涉及方方面面,表观遗传作为联系环境因素和遗传因素的桥梁在铅暴露损伤学习记忆能力的过程中发挥什么样的作用尚不清楚。目的1.阐明EZH2在铅暴露损伤发育期大鼠学习记忆能力过程中的中心调控作用;2.探究慢性铅暴露损伤发育期大鼠学习记忆能力过程中H3K27me3发挥的作用;3.阐明慢性铅暴露降低海马区神经元中H3K27me3水平的机制;4.初步探究铅暴露通过H3K27me3影响Wnt信号通路的机制。方法1.以PC12为神经元模式细胞,研究EZH2对细胞突起生长的影响;2.通过染色质免疫共沉淀实验研究EZH2在铅的神经毒性过程中发挥的作用;3.通过免疫共沉淀等实验探究慢性铅暴露是否通过EZH2影响神经元内H3K27me3水平;4.通过高尔基染色实验和行为学实验验证慢性铅暴露通过H3K27me3损伤发育期大鼠学习记忆能力;5.通过染色质免疫共沉淀和基因芯片技术初步探讨H3K27me3损伤发育期大鼠学习记忆能力的机制。结果1.铅暴露降低细胞内EZH2表达,影响NGF诱导的细胞突起的长度、数量;2.慢性铅暴露影响EZH2与NGFR、EGR2和CaMKK2等基因的结合水平,改变EZH2对其表达调控作用;3.慢性铅暴露降低了EZH2与PRC2复合体中其他组分的结合,进而降低海马区神经元内H3K27me3水平;4.慢性铅暴露会降低发育期大鼠海马区神经元树突棘密度,影响大鼠空间记忆能力,海马区注射过表达EZH2慢病毒后,该损伤有一定程度的修复;4.慢性铅暴露改变了H3K27me3对Wnt信号通路中关键蛋白表达的调控作用。结论1.H3K27me3对相关基因表达调控的改变是铅暴露损伤大鼠学习记忆功能的主要原因;2.慢性铅暴露通过抑制EZH2表达降低海马区神经元中H3K27me3水平;3.铅暴露后H3K27me3对众多基因的表达调控发生改变,其对Wnt信号通路关键蛋白表达的影响可能是铅损伤学习记忆功能的重要原因。
[Abstract]:Lead is a widespread environmental pollutant, many studies show that chronic lead exposure can damage the development of children's ability of learning and memory, and the mechanism of injury involving all aspects of epigenetics as a bridge between genetic and environmental factors in the process of learning and memory ability of lead exposure injury plays what role is not clear 1.. To clarify the EZH2 exposure center role during the development of injury of learning and memory abilities of rats in the lead; 2. to explore the chronic lead exposure rats during development process of H3K27me3 damage the ability of learning and memory in the role of the 3. states; chronic lead exposure mechanism to reduce H3K27me3 levels of hippocampal neurons in 4. lead exposure through the preliminary inquiry; the mechanism of H3K27me3 effect of Wnt pathway. Methods 1. PC12 patterns of neuronal cells, the effects of EZH2 on the growth of cell processes; 2. through chromatinimmune Co Experimental study on precipitation of EZH2 play in the lead role in the process of neurotoxicity; 3. by CO immunoprecipitation experiments to explore whether chronic lead exposure through the level of H3K27me3 in neurons of EZH2; 4. by Golgi staining experiments and behavioral experiments by H3K27me3 damage during the development of learning and memory abilities of rats with chronic lead exposure; 5. through chromatinimmune co precipitation and microarray technology to investigate mechanisms of learning and memory ability of rats during H3K27me3 damage development. Results of the 1. lead exposure reduced the expression of EZH2 in cells, the length of the influence of the number of cell processes induced by NGF; 2. chronic lead exposure effects of EZH2 and NGFR, combined with the level of EGR2 and CaMKK2 genes, the expression change of EZH2 gene regulation on the 3.; chronic lead exposure reduced with other components of the EZH2 and PRC2 complex, and then reduce the level of H3K27me3 in hippocampus neurons; 4. chronic lead exposure Will reduce the development period of hippocampal neuronal dendritic spines, affecting the spatial memory ability of rats hippocampus injected lentiviral EZH2 expression after repair to a certain extent of the damage; 4. chronic lead exposure alters the regulation role of H3K27me3 on the expression of key proteins in Wnt signaling pathway. Conclusion 1.H3K27me3 regulates the expression of related genes the main reason is the change of lead exposure damage the function of learning and memory in rats; 2. chronic lead exposure through inhibiting the expression of EZH2 decreased the level of H3K27me3 in hippocampal neurons; change regulation of H3K27me3 on expression of many genes occurred in 3. after lead exposure, the effect of Wnt signaling pathway key protein expression may be an important cause of lead damage the function of learning and memory.

【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：R114

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