High-throughput single-cell metabolomics to reveal the hepatotoxicity of 77PDQ exposure in mice

Elucidating the effects of pollutants at the level of primary single cells is of great significance for an in-depth understanding of their health risks and toxicological mechanisms. N,N'-bis (1,4-dimethylpentyl)-p-phenylenediamine quinone (77PDQ) is an emerging environmental contaminant with multiple biological toxicities; however, its toxic effects at the primary single-cell level remain unexplored. In this study, we established a high-throughput single-cell metabolomics platform based on label-free CyESI-MS and applied it to the analysis of freshly isolated primary mouse liver cells for toxicological assessment of 77PDQ exposure at single-cell resolution. This strategy enabled us to capture cell-to-cell metabolic heterogeneity that was lost in conventional bulk measurements. Analysis of primary mouse liver cells revealed 181 significantly altered metabolites (|Log₂FC|>1, p < 0.05) following 77PDQ exposure. Pathway analysis demonstrated substantial disruptions in glycerophospholipid, arginine-proline, and beta-alanine metabolism. Eight lipid biomarkers (PC (41:6), PS (31:4), Cer (d41:1), TAG (53:2), LPG (18:1), SM (d42:3), FA (23:0), PA (36:2)) showed excellent diagnostic capacity (AUC>0.9). Our study provides the single-cell metabolomics evidence of 77PDQ hepatotoxicity and offers new mechanistic insights into this emerging environmental contaminant.