Feiyan Lin, Congcong Wen, Junliang Lin, Ruyi Jin, Chuanfeng Shao, Ningxia Xu, Yuqing Miao, Jianxin Wang, Lianguo Chen, Xianqing Wang, Jianshe Ma, Guangliang Hong, Lufeng Hu
The early pathogenic mechanisms underlying human diquat (DQ) poisoning remain incompletely understood. This study integrated retrospective clinical analysis, exploratory serum metabolomics, and in vitro experiments to characterize early metabolic disturbances and investigate potential cell-death mechanisms associated with acute DQ poisoning. Clinical data from 95 patients with acute DQ poisoning were retrospectively analyzed to identify clinical variables associated with outcome. Guided by these findings, exploratory pretreatment serum metabolomics was performed in eight patients with acute DQ poisoning and eight age- and sex-matched healthy controls. Cellular experiments were subsequently conducted in DQ-exposed HepG2 cellsto examine oxidative stress, lipid peroxidation, and ferroptosis-related features using biochemical, molecular, morphological, and inhibitor-based approaches. DQ concentration and markers of multi-organ injury were among the variables most strongly associated with clinical outcome in the random-forest analysis. Serum metabolomic analysis revealed alterations in polyunsaturated fatty acid metabolism, including perturbations in linoleic acid- and α-linolenic acid-related pathways and increased levels of several ω-6 polyunsaturated fatty acids and their oxidation derivatives. Correlation analysis demonstrated associations between these lipid-related metabolites and clinical markers of renal, hepatic, and muscular injury. In HepG2 cells, DQ exposure was associated with ROS accumulation, GSH depletion, lipid peroxidation, increased intracellular Fe²⁺, time-dependent alterations in GPX4 and SLC7A11 expression, and mitochondrial ultrastructural injury, a combination of changes consistent with ferroptosis-related cellular injury. Ferrostatin-1 significantly improved cell viability, whereas Necrostatin-1 showed no comparable protective effect and Z-DEVD-FMK provided less protection than Ferrostatin-1 under the conditions tested. In conclusion, acute DQ poisoning is associated with distinct clinical and metabolic disturbances involving PUFA metabolism. The HepG2 experiments further suggested that ferroptosis-related lipid peroxidation may contribute to DQ-induced cellular injury. These findings support further investigation of lipid peroxidation and ferroptosis-related pathways as potential therapeutic targets in DQ poisoning.