Spatial lipidomics and metabolomics reveal brain region-specific metabolic dysregulation in mice exposed to the emerging persistent organic pollutant methoxychlor

Methoxychlor (MXC), an organochlorine pesticide, is an emerging persistent organic pollutant of significant environmental concern due to its notable persistence and bioaccumulation. While compelling evidence supports its neurotoxic effects, the underlying molecular mechanisms remain unclear and warrant systematic investigation. This study establishes an integrated spatial molecular platform combining matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) with lipidomics and metabolomics to investigate region-specific neurotoxic mechanisms in mouse brain tissues. Following 90-day exposure, quantitative analysis revealed preferential MXC bioaccumulation in the midbrain (0.069 ng/mg tissue), 4-fold higher than in the striatum. MALDI-MSI identified significant dysregulation of sulfatides and glycerophospholipids in midbrain and striatal regions, with lipidomic analysis revealing region-specific regulatory patterns between the two brain areas. Mechanistic investigation demonstrated that MXC exerts neurotoxicity through mitochondrial complex I inhibition, triggering region-specific stress responses. Specifically, the striatum exhibited robust antioxidant defense activation while the midbrain showed inadequate compensation and excessive neuroinflammation. Untargeted metabolomic analysis revealed disrupted energy metabolism, glycerophospholipid metabolism, and aromatic amino acid biosynthesis pathways. Targeted analysis confirmed impaired dopamine synthesis and metabolism in both brain regions, with dopamine levels significantly decreased despite opposing metabolic patterns. These findings provide spatial molecular evidence that MXC induces region-specific neurotoxicity through mitochondrial targeting, revealing differential brain vulnerability patterns. This novel analytical framework offers a valuable platform for environmental neurotoxicant assessment and supports enhanced regulatory strategies for persistent organic pollutants.