Exploring the mechanisms of diethyl phthalate-induced diabetic nephropathy through integrated network toxicology, machine learning, and experimental validation

Phthalate plasticizers, especially diethyl phthalate (DEP), are linked to metabolic disorders, while their precise role and mechanism in diabetic nephropathy (DN) pathogenesis remain unclear. Here, we integrated transcriptomic bioinformatics, machine learning, molecular docking, and in vitro validation to decipher the nephrotoxic effect of DEP and its primary metabolite monoethyl phthalate (MEP) on DN. We found that common phthalate targets were significantly enriched in unsaturated fatty acid metabolism, prostaglandin synthesis, and prolactin signaling pathways. Fourteen core genes were screened, among which lymphocyte-specific protein tyrosine kinase (LCK) and hematopoietic prostaglandin D synthase (HPGDS) showed robust diagnostic potential for DN. Molecular docking revealed stable binding of phthalates to signal transducer and activator of transcription 3 (STAT3). In HK-2 renal tubular epithelial cells, DEP/MEP exposure reduced cell viability in a dose-dependent manner, activated the STAT3/transforming growth factor-beta 1 (TGF-β1) axis, and induced apoptosis, which were partially reversed by STAT3 inhibition. Collectively, environmental phthalate exposure exacerbates DN progression via disrupting lipid metabolism, activating inflammatory signaling, and promoting renal cell apoptosis, with LCK and HPGDS as promising diagnostic biomarkers for DN.