放射治疗论文大鼠全脑照射后早期表观遗传学变化特征的研究.doc

放射治疗论文:大鼠全脑照射后早期表观遗传学变化特征的研究【中文摘要】实验:观察大鼠全脑照射条件下海马组织内组蛋白 H3乙酰化和DNA甲基化在不同剂量和不同时间表达的变化，探讨表观 遗传学在放射性脑损伤早期表达的变化特征材料和方法:体重150-200g,年龄约4-5周的雄性SD大鼠，应用4MeV电子线以单次剂量 2Gy、30Gy照射全脑,制备大鼠的脑放射诱导损伤模型随机分为空 白对照(OGy) 2Gy, 30 Gy三个剂量组,分别于照射后7天和30天提取 海马组织蛋白进彳亍western blot,应用莱卡冰冻切片机切取30 u m冰 冻切片进行免疫组织化学染色，观察海马区组蛋口 H3乙酰化及DNA甲 基转移酶(DNMTs)变化结果:2Gy,30Gy电子线照射导致了大鼠海马 脑区组蛋白H3乙酰化明显降低实验发现2Gy电子线金脑照射后7 天和30天，海马脑区组蛋白H3乙酰化分别降低了 25%(P<0. 05)和 5%(P<0. 05) o 30Gy电子线全脑照射后7天和30天，海马脑区组蛋白 H3乙酰化分别降低了 5%(P〈0・05)和13%(P<0. 05)低剂量照射在照 射后早期对组蛋白H3乙酰化水平影响更为明显。

2Gy, 30Gy电子线全 脑照射也影响了 DNA甲基转移酶的表达变化,DNA甲基转移酶 (DNMTs) DNMT1表达明显升高(P〈0・05), DNMT3b在照射后则明显降低 (P<0. 05), DNMT3a没有明显改变结论:照射引起的组蛋白H3乙酰化 降低以及DNMTs的变化反映了全脑照射后海马区表观遗传学信号的 变化这些结果都提示染色体结构等表观遗传学的改变可能是照射引 起的神经损伤的重要的分子机制英文摘耍】Purpose To investigate the rol e of epi genetic in the irradiation-induced memory deficiency by observing the changes of histon H3 acetylation and DNA methylation in the hippocampus of rat brain radiation injury model.Materials and methods Young adult, male Sprague-Dawley rats (150 - 200 g, 4-5 weeks) were divided into groups of 2Gy, 30Gy, and controL After whole brain irradiation, the total protein was extracted from irradiated hippocampus and whole brain 30 u m cryosections were cut coronally through the center of the impact using a Leica cryostat at 7 days and 30 days・ Western blot was performed and the brain sections were immunohistocheniiea stained. The alterations of histon H3 acetylation and DNMTs was observed and analyzed. Results We show that both 2Gy and 30 Gy 4MV nominal photon energy 1ead to significent deacrease in histon H3 acetylation in the hippocampus・ We found a 25% reduction in histon H3 acetylation at 7 days (P < 0.05) and 5% reduction at 30 days (P < 0.05) after 2Gy irradiation. Campared to control, 30Gy induced 13% reduction at 30 day but 5% reduction at 7 day. Tn the early stage, 1ow-dose induced more significant epigenetic alterations・ 2Gy and 30 Gy irradiation induced the increase of DNMT 1 (P < 0. 05) and decrease of DNMT3b (P < 0. 05),DNMT3a was not impaired・ Conclusion Decreased histone H3 acetylation and the alterations of DNMTs suggest altered hippocampal epigenetic signaling after whole brain irradiation. This result indicate that alterations in chromatin structure may be a new possible molecular correlate of irradiation-induced memory deficiency・【关键词】放射治疗 学习记忆 表观遗传学 组蛋白乙酰化DNA 甲基化【备注】索购全文加好友:1.3.9.9.3 ^8848同时提供论文写作一对一指导和论文发表委托服务learning and【英文关键词】irradiation treatmentmemory epigenetics histon acetylation DNA methylation【目录】大鼠全脑照射后早期表观遗传学变化特征的研究 中文摘要4-5Abstract 5引言7-10材料和方法10-14结果14-16讨论16-19结论19-20参考文献20-23附录23-28综述28-36参考文献33-36中英文对照缩略词表36-37致谢37-39。