Paraquat exposure induces Parkinsonism by altering lipid profile and evoking neuroinflammation in the midbrain

• Published in: Environment international 2022-11, Vol.169, p.107512, Article 107512
• Main Authors: Tong, Tong, Duan, Weixia, Xu, Yudong, Hong, Huihui, Xu, Jia, Fu, Guanyan, Wang, Xue, Yang, Lingling, Deng, Ping, Zhang, Jingjing, He, Haotian, Mao, Gaofeng, Lu, Yuanqiang, Lin, Xiqin, Yu, Zhengping, Pi, Huifeng, Cheng, Yong, Xu, Shangcheng, Zhou, Zhou
• Format: Article
• Language: English
• Subjects: alpha-Synuclein - pharmacology; Animals; biosynthesis; blood serum; brain; ceramides; Ceramides - pharmacology; Cytokines; environment; Environmental Pollutants - toxicity; Glycerides - pharmacology; glycerophospholipids; Glycerophospholipids - pharmacology; Herbicides - toxicity; Humans; inflammation; Inflammatory cytokines; lipid composition; lipid metabolism; Lipidome; Lipopolysaccharides - pharmacology; Mesencephalon; Mice; Mice, Inbred C57BL; muscle strength; Neuroinflammation; Neuroinflammatory Diseases; neurons; neurotoxicity; Neurotoxicity Syndromes - etiology; Neurotoxins; Paraquat; Paraquat - toxicity; Parkinson disease; Parkinson Disease - etiology; Parkinsonian Disorders - chemically induced; Parkinsonian Disorders - complications; Parkinsonism; pathogenesis; risk; RNA, Messenger; Sphingolipids - pharmacology
• ISSN: 0160-4120; 1873-6750
• DOI: 10.1016/j.envint.2022.107512

•PQ exposure perturbs lipid metabolism and elevates pro-inflammatory lipids in the midbrain;•PQ exposure provokes neuroinflammation in the midbrain and induces an intense systemic inflammation in humans;•Elevated pro-inflammatory lipids and cytokines correlate with motor deficits after PQ exposure. Paraquat (PQ) is the most widely used herbicide in the world and a well-known potent neurotoxin for humans. PQ exposure has been linked to increase the risk of Parkinson's disease (PD). However, the mechanism underlying its neurotoxic effects in PD pathogenesis is unclear. In our present study, C57BL/6J mice treated with PQ manifested severe motor deficits indicated by the significant reductions in suspension score, latency to fall from rotarod, and grip strength at 8 weeks after PQ exposure. Pathological hallmarks of Parkinsonism in the midbrain such as dopaminergic neuron loss, increased α-synuclein protein, and dysregulated PD-related genes were observed. Non-targeted lipidome analysis demonstrated that PQ exposure alters lipid profile and abundance, increases pro-inflammatory lipids.27 significantly altered subclasses of lipids belonged to 6 different lipid categories. Glycerophospholipids, sphingolipids, and glycerides were the most abundant lipids. Abundance of pro-inflammatory lipids such as Cer, LPC, LPS, and LPI was significantly increased in the midbrain. mRNA expressions of genes regulating ceramide biosynthesis in the midbrain were markedly up-regulated. Moreover, PQ exposure increased serum pro-inflammatory cytokines and provoked neuroinflammation in the midbrain. Pro-inflammatory lipids and cytokines in the midbrain were positively correlated with motor deficits. PQ poisoning in humans significantly also elevated serum pro-inflammatory cytokines and induced an intense systemic inflammation. In summary, we presented initial investigations of PQ induced molecular events related to the PD pathogenesis, capturing aspects of disturbed lipid metabolism, neuroinflammation, impairment of dopaminergic neurons in the midbrain, and an intense systemic inflammation. These neurotoxic effects of PQ exposure may mechanistically contribute to the pathogenesis of PQ induced Parkinsonism. Results of this study also strongly support the hypothesis that ever-increasing prevalence of Parkinson’s disease is etiologically linked to the health risk of exposure to neurotoxic environmental pollutants.