Spatial multi-omics reveals region-specific redox dysregulation in chronic aristolochic acid I-induced nephrotoxicity

Aristolochic acid I (AAI) is a potent nephrotoxin responsible for aristolochic acid nephropathy (AAN); however, the spatial relationship between toxicant accumulation and region-specific metabolic dysfunction during chronic exposure remains incompletely understood. Here, we established a 12-week chronic AAN rat model using repeated oral administration of AAI (1 and 10 mg/kg/day) and integrated spatial metabolomics, spatial transcriptomics, and regional LC-MS/MS quantification to elucidate the underlying mechanisms. Quantitative analysis revealed dose-dependent accumulation of aristolactam I (ALI), the major Phase I metabolite, predominantly in cortical regions. Airflow-assisted desorption electrospray ionization (AFADESI)-MSI uncovered extensive, region-specific metabolic reprogramming, with the inner cortex exhibiting the greatest perturbation. Integrated analyses demonstrated coordinated disruption of arginine-nitric oxide signaling, mitochondrial oxidative phosphorylation, fatty acid β-oxidation, arachidonic acid-mediated inflammation, purine metabolism, antioxidant defense, and osmolyte homeostasis. Spatial transcriptomics further revealed suppression of redox-regulating enzymes, fatty acid oxidation pathways, and transporters, alongside activation of oxidative stress and inflammatory responses. Mechanistically, chronic AAI exposure induced mitochondrial dysfunction, glutathione depletion, lipid peroxidation, and energy insufficiency, establishing spatially localized redox stress microdomains. The strong spatial concordance between ALI accumulation and metabolic collapse supports a toxicokinetic-toxicodynamic coupling in AAN pathogenesis. Collectively, this study provides a spatially resolved multi-omics framework that advances mechanistic understanding of AAI-induced nephrotoxicity and identifies potential targets for intervention.