Nam Sung Min, Chang Byung-Joon, Kim Ji-Hye, Nahm Sang-Soep, Lee Jong-Hwan
Department of Anatomy, College of Veterinary Medicine, Konkuk University, Seoul 05030, Republic of Korea.
Department of Rehabilitation Psychology, Seoul Rehabilitation Hospital, Seoul 03428, Republic of Korea.
Brain Res. 2018 May 1;1686:10-18. doi: 10.1016/j.brainres.2018.02.014. Epub 2018 Feb 17.
We investigated the effects of the gestational administration of lead (Pb) and ascorbic acid on cerebellar development. Pregnant female rats were randomly assigned to the control, Pb, or Pb plus ascorbic acid (PA) groups; six offspring per cage were randomly selected for analysis. Compared to the control group, fewer Purkinje cells were observed in the Pb-exposed pups at postnatal day 21. However, co-administrating Pb and ascorbic acid inhibited the Pb-induced reduction in Purkinje cells. Terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL) staining, which detected DNA fragmentation in the dying cells, showed more TUNEL-positive cells in the Pb group, while co-treatment with Pb and ascorbic acid mitigated the Pb-induced cellular degeneration. Using immunohistochemistry and immunoblotting, we additionally found that Pb exposure induced a rise in the apoptotic factor Bax in the cerebellum, while Pb plus ascorbic acid treatment ameliorated this Bax induction. Since, Pb competes with the iron in the cell and the accumulation of free iron triggers oxidative stress, we performed iron staining, which revealed that ascorbic acid prevented the Pb-induced rises in iron-reactive cells and iron-reactivity. The anti-oxidant enzyme manganese-dependent superoxide dismutase showed change patterns that were similar to those of iron in the cerebellum. Finally, the pups' blood Pb levels were highest in the Pb group but were reduced in the PA group. Our findings suggest that ascorbic acid effectively ameliorates Pb-induced apoptosis and oxidative stress in the cerebellum. The present results imply that ascorbic acid treatment during pregnancy may protect against Pb-mediated developmental impairments in the cerebellum.
我们研究了孕期给予铅（Pb）和抗坏血酸对小脑发育的影响。将怀孕的雌性大鼠随机分为对照组、铅组或铅加抗坏血酸（PA）组；每个笼子随机选取6只后代进行分析。与对照组相比，出生后第21天暴露于铅的幼崽中观察到的浦肯野细胞较少。然而，同时给予铅和抗坏血酸可抑制铅诱导的浦肯野细胞减少。末端脱氧核苷酸转移酶介导的dUTP缺口末端标记（TUNEL）染色用于检测死亡细胞中的DNA片段化，结果显示铅组中有更多TUNEL阳性细胞，而铅与抗坏血酸联合处理可减轻铅诱导的细胞变性。通过免疫组织化学和免疫印迹，我们还发现铅暴露会导致小脑中凋亡因子Bax升高，而铅加抗坏血酸处理可改善这种Bax的诱导。由于铅与细胞中的铁竞争，游离铁的积累会引发氧化应激，我们进行了铁染色，结果显示抗坏血酸可防止铅诱导的铁反应性细胞增加和铁反应性升高。抗氧化酶锰依赖性超氧化物歧化酶在小脑中的变化模式与铁相似。最后，铅组幼崽的血铅水平最高，而PA组则降低。我们的研究结果表明，抗坏血酸可有效改善铅诱导的小脑细胞凋亡和氧化应激。目前的结果表明，孕期给予抗坏血酸治疗可能预防铅介导的小脑发育损伤。
