【作者】 叶侃；

【导师】 古桂雄；

【作者基本信息】 苏州大学 ， 放射医学， 2011， 博士

【摘要】 目的:建立秀丽线虫的60Coγ射线辐射损伤模型,研究辐射对秀丽线虫的生长损伤及其机制,利用此模型研究白藜芦醇辐射防护作用及其机制。方法:(1)采用不同剂量(50Gy,100Gy,200Gy)60Coγ射线照射L1阶段野生型秀丽线虫(N2),观察辐射后秀丽线虫的寿命,运动能力,生殖能力,记忆能力的改变。(2)采用不同浓度(10μM,100μM,1000μM)白藜芦醇干预野生型秀丽线虫(N2),观察其对秀丽线虫寿命影响和有效的实验干预浓度。(3)采用有效浓度的白藜芦醇干预,观察60Coγ射线照射后对秀丽线虫的寿命,运动能力,生殖能力,记忆能力,评价其保护作用。(4)应用DCF荧光染色法及SOD3-GFP荧光reporter突变株CF1553 [muIs84 [pAD76 (sod-3::GFP)]],检测秀丽线虫的氧化应激水平。(5)应用实时定量PCR,检测秀丽线虫的线粒体拷贝数(mtDNA)。(6)采用秀丽线虫突变株VC199 [sir-2.1(ok434)]观察其寿命变化,探讨白藜芦醇辐射防护的有关机制。结果:(1)随着放射剂量增加,照射后的野生型秀丽线虫(N2)寿命显著缩短;受60Coγ射线照射后运动能力明显受损;记忆能力随着辐射剂量增加而显著下降;辐射后成虫期的产卵量明显减少,当剂量增加至200Gy时,可导致所有线虫不育。(2)不同浓度白藜芦醇均能延长野生型秀丽线虫(N2)的寿命,100μM与更高浓度之间无显著性差异,后续实验采用100μM为干预浓度。(3)白藜芦醇干预后,经60Coγ射线照射的秀丽线虫寿命显著延长;运动能力明显增强;记忆能力得到有效改善;产卵能力增加、卵存活率增加。(4)白藜芦醇干预可以显著改善60Coγ射线照射后秀丽线虫体内的氧化应激状态。(5)白藜芦醇干预后, 60Coγ射线照射后秀丽线虫的线粒体DNA拷贝数(mtDNA)有所增加。(6)白藜芦醇干预能延长经60Coγ射线照射的sir-2.1突变株的寿命。结论:(1)秀丽线虫是一个理想的辐射损伤研究的工具, 60Coγ射线照射对秀丽线虫造成生长损伤。(2)白藜芦醇具有良好的辐射防护作用:能够延长60Coγ射线照射后的秀丽线虫寿命;增强其运动能力;改善记忆能力;有效的保护生殖系统。(3)白藜芦醇辐射防护作用与其强有力的抗氧化作用以及对线粒体保护作用有关。(4)白藜芦醇辐射防护作用是通过非sir-2相关的途径。更多还原

【Abstract】 Objective: To establish the model of radiation damage by 60Coγ-ray in Caenorhabditis elegan; investigate the radiation damage of growth and its mechanism in Caenorhabditis Elegans; investigate radiation protective effect of resveratrol and its mechanism in Caenorhabditis elegans.Methods: (1) Wild-type C. elegans at L1 stage were irradiated by 60Coγ-irradiation with 50Gy, 100Gy and 200Gy respectively, and detected the lifespan, locomotion, reproduction and the memory of irradiated C. elegans. (2) Wild-type C. elegans treated with the different concentration (10μM,100μM,1000μM) of resveratrol, the lifespan of C. elegans and its experimental intervention concentration were detected effective. (3) With the effective concentration of resveratrol on wild-type C. elegans, the lifespan, locomotion, reproduction and the memory of irradiated C. elegans were detected, and assessed the protective effect of resveratrol on the radiation. (4) The level of oxidative stress were detected in C. elegans with CF1553 [muIs84 [pAD76 (sod-3::GFP)]] and DCF. (5) The mtDNA copy number of C. elegans was determined with the quantitative PCR. (6) The changes of lifespan were observed with VC199 [sir-2.1(ok434)], to investigate its some activity mechanism of the protective effect of resveratrol in Caenorhabditis elegans on radiation.Result: (1) Life span of irradiated wild-type C. elegans were shortened along with the increased radiation dose; the locomotion suffered injury obviously and memory deficits were caused with 60Coγ-irradiation exposure; the amount of offspring was obvious reduced along with the increased radiation dose, and when the dosage increased to 200Gy, all maternal worms became sterile. (2)Dietary resveratrol with the different density extended life span of wild-type C. elegans. As there was no significant difference between 100μM and the higher density, all other experiments were performed with 100μM resveratrol. (3) The lifespan was extended, the locomotion was enhanced, the memory was improved, laying-egg was increased, and the egg survival percentage was increased with resvertrol pre-treatment. (4) The oxidative stress was significantly attenuated with resvertrol pre-treatment in 60Coγ-irradiated C. elegans. (5) The mtDNA copy number was increased with resvertrol pre-treatment in 60Coγ-irradiated C. elegans. (6) Resveratrol pre-treatment also extended life span 60Coγ-irradiated sir-2.1 mutants.Conclusion: (1) Caenorhabditis elegans is a useful model of animal on irradiation-related damage, which can be examined the damage of growth caused by 60Coγ-irradiation. (2) Resveratrol has the good protective function to the 60Coγ-irradiated, such as extended the lifespan of wild-type C. elegans, enhanced its locomotion, improved the memory and protected the reproductive system. (3) The protective effect of resveratrol on radiation is the strong ability to protect from oxidative stress and protective effects to mitochondria. (4) The sir-2 independent mechanisms play an important role in the protective action of resveratrol.更多还原