College of Life Sciences, Shanxi Agricultural University, Taigu, 030801, Shanxi, China.
Shanxi Key Laboratory of Ecological Animal Sciences and Environmental Veterinary Medicine, College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, 030801, Shanxi, China.
Biol Trace Elem Res. 2020 Nov;198(1):216-223. doi: 10.1007/s12011-020-02053-7. Epub 2020 Feb 3.
Fluoride exposure is associated with lowered cognitive function ability, intelligence quotient, and mental decline, especially in children. The brain insulin receptor (IR) signaling system is related to neuronal plasticity and consequent cognitive ability. In our previous study, NaF exposure decreased IR expressions in olfactory bulb (OB) and hippocampus after Y-maze test in male mice. In order to further explore whether the Y-maze test affected IR gene and protein expression levels in the OB and hippocampus under the NaF exposure, healthy male mice were randomly allotted into four groups and challenged with 0, 50, 100, and 150 mg/L NaF for three continuous months. The results showed that femur fluorine content of the NaF-exposed groups increased significantly in a dose-dependent manner. NaF significantly decreased brain protein content and organ coefficient of the treated male mice. The protein and mRNA expression levels of the IR were significantly decreased in the OB and hippocampus of the NaF-treated mice. Interestingly, indicators (brain protein content and organ coefficient) measured in the present study were significantly lower than our previous study indicators (mice tested Y-maze test), especially the expression levels of IR protein and mRNA in the same concentration groups. Taken together, these results indicated that Y-maze test could promote the expression levels of IR protein and mRNA in the OB and hippocampus, while NaF had a stronger inhibitory effect, which resulted in adverse effects on the expression levels of IR in the OB and hippocampus of male mice.
氟化物暴露与认知功能能力、智商和智力下降有关，尤其是在儿童中。脑胰岛素受体 (IR) 信号系统与神经元可塑性和随后的认知能力有关。在我们之前的研究中，NaF 暴露会降低雄性小鼠 Y 迷宫测试后嗅球 (OB) 和海马体中的 IR 表达。为了进一步探讨 NaF 暴露下 Y 迷宫测试是否会影响 OB 和海马体中的 IR 基因和蛋白表达水平，将健康雄性小鼠随机分为四组，连续三个月分别用 0、50、100 和 150 mg/L NaF 处理。结果表明，NaF 暴露组的股骨氟含量呈剂量依赖性显著增加。NaF 显著降低了雄性小鼠的大脑蛋白含量和器官系数。IR 的蛋白和 mRNA 表达水平在 NaF 处理的小鼠的 OB 和海马体中显著降低。有趣的是，本研究中测量的指标（大脑蛋白含量和器官系数）明显低于我们之前的研究指标（测试 Y 迷宫的小鼠），尤其是相同浓度组中 IR 蛋白和 mRNA 的表达水平。总之，这些结果表明 Y 迷宫测试可以促进 OB 和海马体中 IR 蛋白和 mRNA 的表达水平，而 NaF 具有更强的抑制作用，导致雄性小鼠 OB 和海马体中 IR 的表达水平受到不良影响。
