氚对神经细胞迁移相关因子表达及空间学习记忆能力的影响  

Expression of neuronal migration-related factors and the spatial learning and memory of rats prenatally exposed to tritiated water

作　　者：王永生 王明明 Wang Yongsheng;Wang Mingming(Department of Nuclear Medicine,Zhongda Hospital,Southeast University,Nanjing 210009,China;Department of Radiation Hygiene,Affiliated Hospital of Anhui Medical College,Hefei 230001,China)

机构地区：[1]东南大学附属中大医院核医学科,南京210000 [2]安徽医学高等专科学校附属医院放射卫生科,合肥230001

出　　处：《中华放射医学与防护杂志》2019年第12期887-892,共6页Chinese Journal of Radiological Medicine and Protection

基　　金：安徽省自然科学基金(1208085MH162)。

摘　　要：目的探讨氚水(HTO)对大鼠海马神经细胞迁移相关因子表达及空间学习记忆能力的影响。方法取24 h内新生鼠脑海马细胞培养,培养第7天以0、3.7×10^2、3.7×10^3、3.7×10^4、3.7×10^5、3.7×10^6 Bq/ml终浓度氚水培养细胞24 h;Western blot法、RT-PCR法分别检测各浓度氚水处理后的神经细胞骨架蛋白(F-肌动蛋白、α-微管蛋白、tau蛋白及MAP2蛋白)、脑源性神经细胞营养因子(BDNF)及Reelin mRNA的表达情况。取妊娠14 d孕鼠16只,采用随机数表法分两组,每组8只,实验组单次注射3.7×10^6 Bq/g(体重)氚水,对照组注射等量体积生理盐水,Morris水迷宫法观察出生后两组大鼠的空间学习能力。结果3.7×10^2、3.7×10^3、3.7×10^4、3.7×10^5、3.7×10^6 Bq/ml终浓度氚水处理后的神经细胞中,F-肌动蛋白(t=8.898~25.749,P<0.05)、α-微管蛋白(t=3.261~7.900,P<0.05)、tau(t=2.274~5.003,P<0.05)、MAP2(t=2.274~5.003,P<0.05)、BDNF mRNA(t=3.580~19.792,P<0.05)、Reelin mRNA(t=3.240~39.692,P<0.05)表达水平均低于0 Bq/ml浓度并随氚水浓度的升高表达量呈递减趋势。Morris水迷宫结果显示,与对照组相比,实验组大鼠逃避潜伏期延长(t=-2.563,P<0.05),目标象限穿行次数减少、停留时间缩短(t=3.214、3.874,P<0.05)。结论HTO辐射对大鼠神经元迁移相关因子表达和空间学习有影响,这可能有助于了解放射性脑损伤的机制。Objective To study the expression of neuronal migration-related factors and spatial learning and memory of rats exposed to tritiated water(HTO).Methods Hippocampal neural cells from newborn Sprague-Dawley(SD)rats at postnatal 24 h were primarily cultured in DMEM/F12 medium with 20%of fetal bovine serum for 6 days,followed by subjection to tritiated water(HTO)at concentrations of 3.7×10^2,3.7×10^3,3.7×10^4,3.7×10^5,3.7×10^6 Bq/ml for 24 h,respectively.Western blot and RT-qPCR were used to determine the expression levels of F-actin,α-tubulin,tau,AP2,BDNF mRNA and Reelin mRNA.16 pregnant SD rats at embryonic(E)day 14 were randomly divided into the tested and control groups(8 rats/each group).The tested rats were injected with body fluid of HTO(3.7×10^6 Bq/g)intraperitoneally,while the saline as the control.Morris water maze(MWM)was employed for the spatial learning and memory of rats.Results Compared to the control cells,HTO caused a significant downregulation of expressions of cytoskeletal proteins[F-actin(t=8.898-19.896,P<0.05),α-tubulin(t=3.261-7.900,P<0.05),tau(t=2.274-5.003,P<0.05),and MAP2(t=2.274-5.003,P<0.05)]and mRNA of BDNF(t=3.580-19.792,P<0.05)and Reelin(t=3.240-39.692,P<0.05)in the tested neural cells in a dose-dependent manner.In addition,the escape latency of irradiated offsprings was significantly prolonged(t=-2.563,P<0.05),the time for offsprings to cross through target quadrant was markedly reduced(t=3.214,P<0.05),and the swimming time in the platform quadrant of irradiated offsprings were obviously shortened(t=3.874,P<0.05)in the MWM trial.Conclusions The results indicate that HTO irradiation in utero downregulates the expressions of neuron migration-related factors and induces brain dysfunction,which may shed a light on a mechanism of the radiation-induced brain impairment.

关 键 词：神经细胞 氚水 神经元迁移相关因子 空间学习与记忆能力 

分 类 号：R74[医药卫生—神经病学与精神病学]