Nuclear magnetic resonance-based metabolomic investigation reveals metabolic perturbations in PM 2.5 -treated A549 cells

Exposure to PM is associated with an increased risk of lung diseases, and oxidative damage is the main reason for PM -mediated lung injuries. However, little is known about the early molecular events in PM -induced lung toxicity. In the present study, the metabolites in PM -treated A549 cells were examined via a robust and nondestructive nuclear magnetic resonance (NMR)-based metabolic approach to clarify the molecular mechanism of PM -induced toxicity. NMR analysis revealed that 12 metabolites were significantly altered in PM -treated A549 cells, including up-regulation of alanine, valine, lactate, ω-6 fatty acids, and citrate and decreased levels of gamma-aminobutyric acid, acetate, leucine, isoleucine, D-glucose, lysine, and dimethylglycine. Pathway analysis demonstrated that seven metabolic pathways which included alanine, aspartate and glutamate metabolism, aminoacyl-tRNA biosynthesis, taurine and hypotaurine metabolism, arginine and proline metabolism, starch and sucrose metabolism, valine, leucine and isoleucine biosynthesis, and tricarboxylic acid cycle were mostly influenced. Our results indicate that NMR technique turns out to be a simple and reliable method for exploring the toxicity mechanism of air pollutant.