Synergistic suppression of BDNF via epigenetic mechanism deteriorating learning and memory impairment caused by Mn and Pb co-exposure

作者：Lancheng Wei, Hongjian He, Shuting Yang, Qianqian Shi, Xinhang Wang, Liyuan Huang, Jianyong Lu, Yinghui Shen, Kaikai Zhi, Junni Xiang, Chengying Chen, Jiao Mo, Zhijian Zheng, Yunfeng Zou, Xiaobo Yang, Shen Tang, Xiyi Li, Cailing Lu · 发表于：Ecotoxicology and Environmental Safety · 年份：2024 · DOI：10.1016/j.ecoenv.2024.116365 · 被引用次数：14 · 研究领域：Neuroinflammation and Neurodegeneration Mechanisms、Alzheimer's disease research and treatments、Neurogenesis and neuroplasticity mechanisms

Microglia, the resident immune cells of the central nervous system (CNS), play a dual role in neurotoxicity by releasing the NLR Family Pyrin Domain Containing 3 (NLRP3) inflammasome and brain-derived neurotrophic factor (BDNF) in response to environmental stress. Suppression of BDNF is implicated in learning and memory impairment induced by exposure to manganese (Mn) or lead (Pb) individually. Methyl CpG Binding Protein 2 (MeCp2) and its phosphorylation status are related to BDNF suppression. Protein phosphatase2A (PP2A), a member of the serine/threonine phosphatases family, dephosphorylates substrates based on the methylation state of its catalytic C subunit (PP2Ac). However, the specific impairment patterns and molecular mechanisms resulting from co-exposure to Mn and Pb remain unclear. Therefore, the purpose of this study was to explore the effects of Mn and Pb exposure, alone and in combination, on inducing neurotoxicity in the hippocampus of mice and BV2 cells, and to determine whether simultaneous exposure to both metals exacerbate their toxicity. Our findings reveal that co-exposure to Mn and Pb leads to severe learning and memory impairment in mice, which correlates with the accumulation of metals in the hippocampus and synergistic suppression of BDNF. This suppression is accompanied by up-regulation of the epigenetic repressor MeCp2 and its phosphorylation status, as well as demethylation of PP2Ac. Furthermore, inhibition of PP2Ac demethylation using ABL127, an inhi...