【作者】 李翔；

【导师】 王汉东；

【作者基本信息】 南京大学 ， 外科学（神经外科）， 2017， 硕士

【摘要】 研究背景随着经济、社会的发展,创伤性脑损伤(traumatic brain injury,TBI)成为生活中致死率和致残率较高的疾病之一[1,2]。其对患者的身心健康造成了一定程度的不利影响,也给社会带来了严重负担。TBI后脑组织代谢加速而此时受伤脑组织中的线粒体的形态、功能发生改变致其无法进行正常的能量代谢从而使细胞的正常生理功能发生故障,最终导致后期更为严重的继发性损伤[3]。而在此过程中,大量线粒体形态和结构遭到破坏,导致线粒体无法正常供应能量,引起神经元细胞的死亡。所以,增强线粒体自身的生物合成以改善线粒体的能量代谢,可大大减少细胞的损伤,起到保护神经元的作用。第一部分槲皮素可在TBi后激活Nrf2通路并保护线粒体损伤目的探讨槲皮素通过Nrf2途径对TBI后线粒体损伤的保护作用。方法选取雄性成年ICR小鼠,采用自由落体模型,分为四组:假手术组(sham组)、外伤组(TBI组)、外伤+溶剂组(TBI+vehicle组)、外伤+槲皮素组(TBI+quercetin组)。在伤后24h取伤灶周围大脑皮层组织,使用Western blot检测细胞核及胞浆的中Nrf2蛋白的表达情况;检测线粒体及胞浆中Bax及CytC的浓度。使用免疫组化检测Nrf2蛋白由胞浆向胞核转移情况;用酶标仪检测线粒体SOD及MDA浓度。结果与假手术组相比,外伤组和溶剂组Nrf2表达增强且向核内转移明显增多。线粒体Cyt C及SOD含量减少,而Bax与MDA含量增多。槲皮素干预后不但促进了 Nrf2的入核和表达,而且使创伤性脑损伤后线粒体的氧化应激相关蛋白表达减少。。结论槲皮素可进一步激活TBI后Nrf2信号通路,减轻TBI后线粒体的破坏。第二部分Nrf2通路在槲皮素减轻TBI后线粒体破坏中的作用目的应用Nrf2基因敲除小鼠来验证Nrf2通路在TBI后槲皮素对线粒体保护过程中的作用。方法选取野生型[Nrf(+/+)]小鼠与Nrf2基因敲除型[Nrf(-/-)]小鼠,采用相同的自由落体颅脑损伤模型。并在伤后30min给予腹腔注射槲皮素。在伤后24h取伤灶周围大脑皮层组织使用Western blot检测线粒体及胞浆中Bax及Cyt C的浓度。用酶标仪检测线粒体SOD及MDA浓度。结果与野生型小鼠相比,Nrf2基因敲除小鼠TBI后线粒体保护作用明显减弱。结论Nrf2通路在槲皮素在TBI后线粒体保护中起重要作用。更多还原

【Abstract】 BackgroudTraumatic brain injury(TBI)is a high lethality and disability disease.After TBI,there was something wrong with metabolism of mitochondrial which would lead to short of energy supportion to normal neuron cells.Except that,large number of mitochondria morphology and structure would be destroyed,and led to the death of neuron cells.So,enhancing mitochondrial function adaptation after TBI can greatly reduce the damage of neuron cells.Part I Quercetin active the Nrf2 pathway and protect mitochondrial founctionObjective The present study was carried out to explore the protective effect of quercetin on mitochondrial function adaptation after TBI in the activation of the nuclear factor erythroid 2-related factor 2(Nrf2).Methods All of ICR mice were divided into four groups(n=20 for each group):sham group,TBI group,TBI + vehicle group,and TBI + quercetin group.The tissue was obtained 24h after TBI,exactly on the center of injury site,including contused and penumbra.Bax,cyt c of mitochondrial and Nrf2 of nuclear and cytosolic proteins were detected by western blotting.The transaction of Nrf2 was detected by immunohistochemical staining.Results The administration of quercetin following TBI significantly ameliorated the effects of the mitochondrial injury,such as the change of cyt c,MDA and so on.Quercetin markly promoted the translocation of Nrf2 from the cytoplasm to the nucleus,and increased the expression of Nrf2,and prevented the decline of antioxidant enzyme activities,including superoxide dismutase(SOD).Conclusion Quercetin administration may attenuate mitochondrial injury in experiment TBI,potentially via the mediation of the Nrf2 pathway.Part II The role of the Nrf2 pathway in quercetin’s alleviating mitochondrial injury following traumatic brain injuryObjective The goal of study was to evaluate the role of the Nrf2 pathway in quercetin alleviating mitochondrial destruction in an experiment model of TBI.Methods Wild-type[Nrf2(+/+)]group and Nrf2 knock out[Nrf2(-/-)]group received TBI insult followed by quercetin administration at the corresponding time-points.Results Knock out of Nrf2 also declined the protection of mitochondrial Function after TBI.Conclusion Quercetin administration attenuate mitochondrial destruction via the mediation of the Nrf2 pathway.更多还原