Metabolomics analysis of urine from healthy wild type mice exposed to ambient PM2.5

Ambient fine particulate matter (PM2.5) exposure has been linked with various adverse health outcomes. However, the urine metabolomics changes impacted by PM2.5 have not been well elucidated. The normal healthy C57BL/6 mice were exposed to concentrated ambient PM2.5 (PM) or filtered air (FA) for four weeks using “Shanghai-METAS”. The urinary metabolome was quantified using liquid/gas chromatography coupled with mass spectrometry. There were 2213 metabolites identified in total and 163 of them were significantly different between FA- and PM-exposed mice. The KEGG pathway analysis suggested that there were nine perturbed metabolic pathways related to amino acid metabolism. The amino acid metabolism what mainly impacted by PM2.5 were beta-alanine, arginine, proline, alanine, aspartate, glutamate, phenylalanine, glycine, serine, threonine and tyrosine metabolism. Meanwhile, nineteen differential metabolites related to lipid metabolism and seven differential metabolites related to glucose homeostasis were different between FA and PM mice. Furthermore, the glucose and its metabolites were significantly increased in the PM mice compared with the FA mice. The current study provided a critical information on evaluating the systemic toxicity of PM2.5. The results demonstrated that there were significant alterations in urine metabolome by short-term exposure to PM, including amino acid metabolism, lipid metabolism and glucose metabolism. The metabolomics approach might be an effective tool to evaluate the potential mechanism of PM2.5 in inducing adverse health outcomes.