Abstract
With the increasing global burden of major depressive disorder (MDD), identifying modifiable environmental risk factors has become a critical priority. Per- and polyfluoroalkyl substances (PFASs), characterized by environmental persistence and bioaccumulation, have been linked to elevated mental health risks. However, the potential neurotoxicity of GenX-a novel PFAS developed to replace perfluorooctanoic acid (PFOA)-and its molecular association with MDD remain unclear. In this study, peripheral blood serum transcriptomic data from the Gene Expression Omnibus (GEO) were integrated with multidimensional bioinformatics analyses to elucidate molecular mechanisms connecting GenX exposure with MDD. Four hub genes (UCP2, AKR1B1, TP53, and F5) were identified, showing strong combined diagnostic performance (AUC = 0.925). Functional enrichment and immune infiltration analyses revealed their involvement in energy metabolism, oxidative stress, and immune-coagulation regulation. Molecular docking and dynamics simulations further confirmed stable interactions between GenX and these proteins, providing structural support for their mechanistic roles. Although classical dopaminergic markers (TH, SLC6A3, DRD1-5) were not detected in the serum-derived transcriptomes, the identified hub genes may still affect dopaminergic function indirectly by modulating metabolic, oxidative stress, and inflammatory/coagulation pathways, thereby influencing MDD susceptibility. This study provides the first integrated transcriptomic and structural evidence linking GenX to psychiatric risk, proposing a novel "GenX-dopamine-MDD" framework for understanding pollutant-mediated neuropsychiatric mechanisms.