Activation of NLRP3 in microglia exacerbates diesel exhaust particles-induced impairment in learning and memory in mice. (March 2020)

• Record Type: Journal Article
• Authors: Li, Xiaobo; Zhang, Yanshu; Li, Bin; Yang, Hongbao; Cui, Jian; Li, Xiaoyan; Zhang, Xinwei; Sun, Hao; Meng, Qingtao; Wu, Shenshen; Li, Shuang; Wang, Jianbo; Aschner, Michael; Chen, Rui
• Is Part Of: Environment international. Volume 136(2020)
• Publication Date: 2020-03
• Subjects: Diesel exhaust particles (DEPs) -- NLRP3 -- Inflammasome -- Microglia -- Taurine; DEP diesel exhaust particle -- UFP airborne ultrafine particle -- CNS central nervous system -- PAH polycyclic aromatic hydrocarbons -- NLRP3 NLR family, pyrin domain containing 3 -- H&E hematoxylin and eosin -- Iba-1 ionized calcium binding adapter molecule 1 -- ROS reactive oxygen species -- PBS phosphate buffered saline -- DCFH-DA dichloro-dihydro-fluorescein diacetate -- MWM Morris water maze; Environmental protection -- Periodicals; Environmental health -- Periodicals; Environmental monitoring -- Periodicals; Environmental Monitoring -- Periodicals; Environnement -- Protection -- Périodiques; Hygiène du milieu -- Périodiques; Environnement -- Surveillance -- Périodiques; Environmental health; Environmental monitoring; Environmental protection; Periodicals; 333.705
• DOI: 10.1016/j.envint.2020.105487
• Languages: English
• ISSNs: 0160-4120

Abstract

Highlights: DEPs-induced neural disorders are triggered by sustained activation of microglia. Inhibition of NLRP3 inflammasome activation ameliorates the neural disorders. Taurine protects mice from DEPs-induced neural disorders. Abstract: Background: The major components of traffic pollution particulate matter, diesel exhaust particles (DEPs), are airborne ultrafine particles (UFPs). DEPs can enter the central nervous system (CNS), where they may cause neurotoxicity. Methods: We established murine models with intranasal DEPs instillation in male C57BL/6 and Nlrp3 knock-out ( Nlrp3 −/− ) mice to investigate the effects of DEPs exposure on murine neurobehaviors and related mechanisms. Morris water maze (MWM) tests were performed to evaluate the learning and memory behaviors of mice following DEPs instillation. Metabolomics were assessed using an gas chromatography system coupled to a mass spectrometer. Real-time PCR and immunohistochemistry assays were used to analyze the mRNA and protein expression levels of target genes. Murine microglia, BV2 cells were employed to assay the effects of DEPs exposure in vitro . Results: Intranasal administration of DEPs in mice led to impairment in hippocampal-dependent learning and memory. Moreover, this phenotype was linked to increased number of Iba-1 + microglia and NLRP3 inflammasome, as well as suppression of mitochondrial gene expression in the hippocampus of mice exposed to DEPs. Nlrp3 −/− mice were resistant to DEPs-induced learning and memory impairment, concomitant with protection against the suppression of mitochondrial gene expression. Murine microglia cells (BV2) were exposed to DEPs in vitro and taurine was identified as one of the significantly suppressed metabolites in DEPs-treated microglia by metabolomics analysis. Supplementation with taurine efficiently rescued learning, memory and mitochondrial gene expression levels in the hippocampus of DEPs-exposed mice. Conclusions: Mechanistically, our study revealed that microglia-mediated NLRP3 inflammasome activation plays a deleterious role in DEPs-induced neurotoxicity by inhibiting mitochondrial gene expression. These results shed novel light on the potential value of nutritional supplementation against DEPs-induced neurotoxicity in individuals exposed to severe airborne traffic-related air pollutions.