Department of Occupational Health and Occupational Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou 510515, China.
Department of Neurobiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou 510515, China.
Environ Int. 2024 Feb;184:108479. doi: 10.1016/j.envint.2024.108479. Epub 2024 Feb 7.
Lead is an environmentally widespread neurotoxic pollutant. Although the neurotoxicity of lead has been found to be closely associated with metabolic disorders, the effects of short-chain fatty acids on the neurotoxicity of lead and its mechanisms have not yet been explored. In this study, the results of open field tests and Morris water maze tests demonstrated that chronic lead exposure caused learning and memory deficits and anxiety-like symptoms in mice. The serum butyric acid content of lead-treated mice decreased in a dose-dependent manner, and oral administration of butyrate significantly improved cognitive memory impairment and anxiety symptoms in lead-exposed mice. Moreover, butyrate alleviated neuroinflammation caused by lead exposure by inhibiting the STAT3 signaling in microglia. Butyrate also promoted the expression of acetyl-CoA synthetase ACSS2 in hippocampal neurons, thereby increasing the content of acetyl-CoA and restoring the expression of both histone H3K9ac and the downstream BDNF. We also found that the median butyric acid concentration in high-lead exposure humans was remarkably lower than that in the low-lead exposure humans (45.16 μg/L vs. 60.92 μg/L, P < 0.01), and that butyric acid significantly mediated the relationship of lead exposure with the Montreal cognitive assessment scores, with a contribution rate of 27.57 %. In conclusion, our results suggest that butyrate supplementation is a possible therapeutic strategy for lead-induced neurotoxicity.
铅是一种环境中广泛存在的神经毒性污染物。尽管已经发现铅的神经毒性与代谢紊乱密切相关,但短链脂肪酸对铅的神经毒性及其机制的影响尚未得到探索。在这项研究中,旷场试验和 Morris 水迷宫试验的结果表明,慢性铅暴露导致小鼠学习和记忆能力下降以及焦虑样症状。铅处理小鼠的血清丁酸含量呈剂量依赖性下降,丁酸盐口服给药可显著改善铅暴露小鼠的认知记忆障碍和焦虑症状。此外,丁酸盐通过抑制小胶质细胞中的 STAT3 信号通路缓解铅暴露引起的神经炎症。丁酸盐还促进了海马神经元中乙酰辅酶 A 合成酶 ACSS2 的表达,从而增加了乙酰辅酶 A 的含量,并恢复了组蛋白 H3K9ac 和下游 BDNF 的表达。我们还发现,高铅暴露人群的中位数丁酸浓度明显低于低铅暴露人群(45.16μg/L 比 60.92μg/L,P<0.01),丁酸显著介导了铅暴露与蒙特利尔认知评估评分之间的关系,贡献率为 27.57%。总之,我们的结果表明,丁酸补充可能是铅诱导的神经毒性的一种治疗策略。