铅暴露通过线粒体钙单向转运体介导的线粒体钙蓄积加重Aβ1-42处理的小胶质细胞活化

doi:10.12122/j.issn.1673-4254.2026.10.08

南方医科大学学报 ›› 2026, Vol. 46 ›› Issue (10): 2384-2392.doi: 10.12122/j.issn.1673-4254.2026.10.08

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铅暴露通过线粒体钙单向转运体介导的线粒体钙蓄积加重Aβ_1-42处理的小胶质细胞活化

陈丽旋¹(), 龙谚培¹, 黄定帮¹, 郑刚², 孟晓静¹()

^1.南方医科大学公共卫生学院职业卫生与职业医学系，广东广州 510515
^2.空军军医大学军事预防医学系，特殊作业环境危害评估与防治教育部重点实验室，陕西西安 710032

收稿日期:2026-02-06 出版日期:2026-10-20 发布日期:2026-10-26
通讯作者: 孟晓静 E-mail:923585950@qq.com;xiaojingmeng@smu.edu.cn
作者简介:陈丽旋，在读硕士研究生，E-mail: 923585950@qq.com
基金资助:
国家自然科学基金(82473665);广东省自然科学基金(2024A1515012722)

Lead exposure aggravates Aβ_1-42-induced microglial activation through mitochondrial calcium uniporter-mediated mitochondrial calcium accumulation

Lixuan CHEN¹(), Yanpei LONG¹, Dingbang HUANG¹, Gang ZHENG², Xiaojing MENG¹()

^1.Department of Occupational Health and Occupational Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China
^2.Department of Military Preventive Medicine, Air Force Medical University, Ministry of Education Key Laboratory of Hazard Assessment and Control in Special Operational Environment, Xi'an 710032, China

Received:2026-02-06 Online:2026-10-20 Published:2026-10-26
Contact: Xiaojing MENG E-mail:923585950@qq.com;xiaojingmeng@smu.edu.cn
Supported by:
National NaturalScience Foundation of China(82473665)

摘要/Abstract

摘要：

目的探讨线粒体钙单向转运体（MCU）在铅（Pb）暴露加重β淀粉样蛋白1-42（Aβ_1-42）处理的小胶质细胞活化的作用，以揭示铅加重阿尔兹海默症（AD）样变的调控机制。方法将BV2细胞分为Control组（不予任何处理）、Aβ_1-42组（10 μmol/L的Aβ_1-42处理12 h）、Pb组（10 μmol/L铅处理细胞12 h）、Aβ_1-42+Pb组（10 μmol/L的Aβ_1-42处理1 h后加入10 μmol/L铅处理12 h）。ICP-MS检测BV2细胞的钙含量，相差显微镜观察BV2细胞的形态变化，细胞免疫荧光检测iNOS释放与氧化应激情况，Western blotting检测MCU蛋白表达量，CCK-8检测细胞活力。结果相比于Aβ_1-42组，Aβ_1-42+Pb组的细胞线粒体钙含量显著升高（P<0.001），MCU蛋白表达增多（P<0.05）。当下调MCU表达后，Pb与Aβ_1-42联合处理的BV2细胞上清液对HT22细胞生长活力的损伤得到缓解（P>0.05）。铅与Aβ_1-42联合处理可使BV2细胞活化，表现为胞体增大、突起增多，且Iba1与iNOS荧光信号均升高。下调MCU表达后，siMCU+Aβ_1-42+Pb组的BV2细胞活化程度降低，显著缓解了氧化应激水平、线粒体钙超载及膜电位水平。结论铅暴露通过上调Aβ_1-42处理的BV2细胞的MCU表达增加，使钙离子蓄积，引发氧化应激，加重了Aβ_1-42处理的小胶质细胞活化引起的神经元损伤。

关键词: 铅, 线粒体钙单向转运体, 线粒体钙, β淀粉样蛋白1-42, 小胶质细胞活化

Abstract:

Objective To investigate the role of mitochondrial calcium uniporter (MCU) in lead (Pb)‑potentiated microglial activation induced by amyloid β‑protein (1-42) (Aβ1-42) and the regulatory mechanism by which Pb exacerbates Alzheimer disease (AD)-like pathology. Methods Cultured BV2 cells treated with 10 μmol/L Aβ_1-42 for 12 h (Aβ_1-42 group), 10 μmol/L Pb for 12 h (Pb group), or 10 μmol/L Aβ_1-42 for 1 h followed by 10 μmol/L Pb for 12 h (Aβ_1-42+Pb group) were examined for changes in intracellular calcium levels using ICP-MS. Morphological changes of the treated cells were observed, and iNOS release and oxidative stress were assessed with immunofluorescence staining. The changes in cellular MCU protein expression was determined with Western blotting, and cell viability was evaluated using CCK-8 assay. Results Compared with Aβ_1-42-treated cells, the cells with the combined treatment showed significantly elevated mitochondrial Ca²⁺ content and increased MCU protein expression. Downregulation of MCU expression obviously alleviated the reduction of viability of HT22 cells treated with the supernatant from BV2 cells co-treated with Pb and Aβ_1-42. The combined treatment with lead and Aβ_1-42 caused activation of BV2 cells, manifested by increased cell volume and number of protrusions and intensified fluorescence signals of both Iba1 and iNOS. Downregulation of MCU expression significantly suppressed activation of BV2 cells in the siMCU+Aβ_1-42+Pb group, and obviously lowered oxidative stress level, mitochondrial calcium overload, and membrane potential level in the cells. Conclusion Pb exposure exacerbates neuronal injury mediated by Aβ_1-42-activated microglia through upregulation of MCU expression, which causes mitochondrial calcium accumulation to trigger oxidative stress.

Key words: lead (Pb), mitochondrial calcium uniporter, mitochondrial calcium, Aβ_1-42, microglial activation

陈丽旋, 龙谚培, 黄定帮, 郑刚, 孟晓静. 铅暴露通过线粒体钙单向转运体介导的线粒体钙蓄积加重Aβ_1-42处理的小胶质细胞活化[J]. 南方医科大学学报, 2026, 46(10): 2384-2392.

Lixuan CHEN, Yanpei LONG, Dingbang HUANG, Gang ZHENG, Xiaojing MENG. Lead exposure aggravates Aβ_1-42-induced microglial activation through mitochondrial calcium uniporter-mediated mitochondrial calcium accumulation[J]. Journal of Southern Medical University, 2026, 46(10): 2384-2392.

图/表 6

表1 MCU siRNA干扰序列

Tab.1 MCU siRNA interference sequences

Name	Sequence
siRNA-1 sense	5' GGAGAAGGUACGAAUUGAAdTdT
siRNA-l antisense	5' UUCAAUUCGUACCUUCUCCdTdT
siRNA-2 sense	5' CCUUCCGGAACAAUAAAUAdTdT
siRNA-2 antisense	5' UAUUUAUUGUUCCGGAAGGdTdT
siRNA-3 sense	5' GAUUACCGGUGAUAUCUGUdTdT
siRNA-3 antisense	5' ACAGAUAUCACCGGUAAUCdTdT

图1 铅对Aβ1-42处理的BV2细胞线粒体钙蓄积及MCU蛋白表达的影响

Fig.1 Effects of lead on mitochondrial calcium accumulation and MCU protein expression in Aβ1 42 treated BV2 cells. A: ICP-MS detection of mitochondrial calcium concentration in BV2 cells. B: Rhod-2 AM fluorescence staining for detecting mitochondrial calcium ion concentration in BV2 cells. C: Western blotting for detecting MCU expression in BV2 cells (n=3). *P<0.05, ***P<0.05 vs control group; #P<0.05, ###P<0.001.

图2 敲低MCU缓解铅与Aβ1-42联合处理的BV2细胞介导的HT22神经元损伤

Fig.2 Downregulation of MCU alleviates HT22 neuronal damage caused by BV2 cells with combined treatment with lead and Aβ1-42. A: Western blotting for analyzing efficiency for siRNA-mediated MCU silencing. B: CCK-8 assay for detecting the effect of conditioned medium from BV2 cells with combine treatment with Aβ1-42 and lead on viability of HT22 cells before and after MCU silencing (n=3). *P<0.01, **P<0.01, ***P<0.001 vs NC group.

图3 敲低MCU可缓解铅与Aβ1-42联合处理的BV2细胞活化

Fig.3 Downregulation of MCU alleviates activation of BV2 cells treated with both lead and Aβ1-42. A: Morphological changes of BV2 cells before and after MCU interference. B: Immunofluorescence labeling of Iba1 for observing activation of microglial cells before and after MCU interference. C: Immunofluorescence staining for observing expression of iNOS in cells before and after MCU interference.

图4 干扰MCU可缓解铅与Aβ1-42联合处理的BV2细胞氧化应激

Fig.4 Downregulation of MCU alleviates oxidative stress in BV2 cells treated with both lead and Aβ1-42, shown by lowered by ROS level detected using DCFH-DA fluorescence labeling.

图5 敲低MCU缓解铅与Aβ1-42联合处理的BV2细胞线粒体钙蓄积增加及膜电位下降

Fig.5 Downregulation of MCU alleviates mitochondrial calcium accumulation and mitochondrial membrane potential reduction in BV2 cells treated with both lead and Aβ1-42. A: Rhod-2 AM fluorescence staining for detecting mitochondrial calcium ion concentration of BV2 cells. B: JC-1 fluorescence labeling for detecting mitochondrial membrane potential.

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铅暴露通过线粒体钙单向转运体介导的线粒体钙蓄积加重Aβ_1-42处理的小胶质细胞活化

Lead exposure aggravates Aβ_1-42-induced microglial activation through mitochondrial calcium uniporter-mediated mitochondrial calcium accumulation

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