Wang Zeming, Zhang Xueyan, Shi Fan, Yan Licheng, Wang Weixuan, Zhang Yanshu
School of Public Health, North China University of Science and Technology, Tangshan 063210, China.
School of Public Health, North China University of Science and Technology, Tangshan 063210, China Laboratory Animal Center, North China University of Science and Technology, Tangshan 063210, China.
Wei Sheng Yan Jiu. 2025 Jul;54(4):663-672. doi: 10.19813/j.cnki.weishengyanjiu.2025.04.019.
To investigate the mechanism of neurological damage in mice induced by Pb exposure combined with high glucose.
SPF C57 mice were randomly divided into a control group, a Pb group, a high-glucose diet group, and a Pb + high-glucose diet group. Mice in the control group and the Pb group were given basic feed, while those in the high-glucose diet group and the Pb + high-glucose diet group were given a high-glucose diet(50.26% carbohydrates, 21.44% fat, 17.45% protein, 4.21% minerals, and 3.64% fiber). The control group and the high-glucose diet group had free access to pure water, while the Pb group and the Pb + high-glucose diet group were given free access to 250 mg/L Pb acetate water for 12 weeks. The sucrose water preference test and elevated plus maze test were used to assess anxiety and depression-like behaviors in mice. The murine microglial cell line BV-2 was randomly divided into a control group, a Pb group, a high-glucose environment group, and a Pb + high-glucose environment group. The control group received no treatment, the Pb group was given 10 μmol/L Pb acetate, the high-glucose environment group was given 40 mmol/L glucose, and the Pb + high-glucose environment group was given 10 μmol/L Pb acetate and 40 mmol/L glucose for 24 hours. siRNA transfection in BV-2 cells was used to establish a synthesis of cytochrome C oxidase 1(SCO1) knockdown cell model(siSCO1 cells), which were exposed to 10 μmol/L Pb acetate and 40 mmol/L glucose for 24 hours. ICP-MS, immunofluorescence, and kit method were applied to detect copper and Pb content in mice cortex and BV-2 cells. Kits were used to detect superoxide dismutase(SOD) and catalase(CAT) in mice cortex and BV-2 cells. Western blot was used to measure the protein expression of SCO1, ionized calcium binding adaptor molecule 1(Iba-1), interleukin-1β(IL-1β) and interleukin-6(IL-6) in mice cortex and BV-2 cells.
The sucrose water preference test result showed that the sucrose water preference rate of mice in the Pb + high-glucose diet group was 31.00%, which was significantly lower than that in the Pb group and the high-glucose diet group(P<0.05). The elevated plus maze result showed that the percentage of entries into the open arms(27.20%) and the percentage of time spent in the open arms(24.20%) of mice in the Pb + high-glucose diet group were significantly lower than those in the Pb group and the high-glucose diet group(P<0.05). The content of SOD in the cerebral cortex of mice in the Pb + high-glucose diet group was 210.96 U/mg prot and the content of CAT was 108.94 U/mg prot, which were significantly lower than those in the Pb group and the high-glucose diet group(P<0.05). The total copper content in the cerebral cortex of mice in the Pb + high-glucose diet group was 4.41 μg/g, which was significantly higher than that in the Pb or high-glucose diet groups alone(P<0.05). Additionally, the expression of SCO1 protein in the cerebral cortex of mice in the Pb + high-glucose diet group was 1.86 times that of the control group, 1.23 times that of the Pb group, and 1.21 times that of the high-glucose diet group(P<0.05). The expression of Iba1, IL-1β, and IL-6 proteins in the cerebral cortex of mice in the Pb + high-glucose diet group was significantly higher than that in the Pb group and the high-glucose diet group(P<0.05). After knocking down SCO1, the average fluorescence density of total Pb in BV-2 cells exposed to Pb and high-glucose combined showed no change, but the copper content in the mitochondria of BV-2 cells was 0.07 nmol/10~6 cells, which was lower than that in the non-knockdown BV-2 cells(P<0.05). Moreover, knocking down SCO1 led to an increase in the content of SOD and CAT in the mitochondria of BV-2 cells exposed to Pb and high-glucose combined, and a decrease in the expression of Iba1 and IL-1β proteins(P<0.05).
High-glucose can exacerbate anxiety and depression-like behaviors in mice with Pb exposure, which may be related to the mitochondrial SCO1 increase, which result ing in elevated mitochondrial copper content in microglial cells, thereby causing inflammatory activation of microglial cells.
探讨铅暴露联合高糖诱导小鼠神经损伤的机制。
将SPF级C57小鼠随机分为对照组、铅组、高糖饮食组和铅+高糖饮食组。对照组和铅组给予基础饲料，高糖饮食组和铅+高糖饮食组给予高糖饮食（碳水化合物50.26%、脂肪21.44%、蛋白质17.45%、矿物质4.21%、纤维3.64%）。对照组和高糖饮食组自由饮用纯净水，铅组和铅+高糖饮食组自由饮用250mg/L醋酸铅水12周。采用蔗糖水偏好试验和高架十字迷宫试验评估小鼠的焦虑和抑郁样行为。将小鼠小胶质细胞系BV-2随机分为对照组、铅组、高糖环境组和铅+高糖环境组。对照组不做处理，铅组给予10μmol/L醋酸铅，高糖环境组给予40mmol/L葡萄糖，铅+高糖环境组给予10μmol/L醋酸铅和40mmol/L葡萄糖处理24小时。通过BV-2细胞的siRNA转染建立细胞色素C氧化酶1（SCO1）敲低细胞模型（siSCO1细胞），并将其暴露于10μmol/L醋酸铅和40mmol/L葡萄糖中24小时。采用电感耦合等离子体质谱法（ICP-MS）、免疫荧光法和试剂盒法检测小鼠皮质和BV-2细胞中的铜和铅含量。试剂盒法检测小鼠皮质和BV-2细胞中的超氧化物歧化酶（SOD）和过氧化氢酶（CAT）。采用蛋白质免疫印迹法检测小鼠皮质和BV-2细胞中SCO1、离子钙结合衔接分子1（Iba-1）、白细胞介素-1β（IL-1β）和白细胞介素-6（IL-6）的蛋白表达。
蔗糖水偏好试验结果显示，铅+高糖饮食组小鼠的蔗糖水偏好率为31.00%，显著低于铅组和高糖饮食组（P<0.05）。高架十字迷宫试验结果显示，铅+高糖饮食组小鼠进入开放臂的百分比（27.20%）和在开放臂停留的时间百分比（24.20%）均显著低于铅组和高糖饮食组（P<0.05）。铅+高糖饮食组小鼠大脑皮质中SOD含量为210.96U/mg prot,CAT含量为108.94U/mg prot，均显著低于铅组和高糖饮食组（P<0.05）。铅+高糖饮食组小鼠大脑皮质中总铜含量为4.41μg/g，显著高于单独的铅组或高糖饮食组（P<0.05）。此外，铅+高糖饮食组小鼠大脑皮质中SCO1蛋白表达是对照组的1.86倍、铅组的1.23倍、高糖饮食组的1.21倍（P<0.05）。铅+高糖饮食组小鼠大脑皮质中Iba1、IL-1β和IL-6蛋白表达显著高于铅组和高糖饮食组（P<0.05）。敲低SCO1后，铅与高糖联合暴露的BV-2细胞中总铅的平均荧光密度无变化，但BV-2细胞线粒体中的铜含量为0.07nmol/10⁶细胞，低于未敲低的BV-2细胞（P<0.05）。此外，敲低SCO1导致铅与高糖联合暴露的BV-2细胞线粒体中SOD和CAT含量增加，Iba1和IL-1β蛋白表达降低（P<0.05）。
高糖可加重铅暴露小鼠的焦虑和抑郁样行为，这可能与线粒体SCO1增加有关，导致小胶质细胞线粒体铜含量升高，从而引起小胶质细胞炎症激活。
