Gestational and Lactational Atrazine Exposure Potentially Mediates Behavioral and Dopaminergic Alterations in Rat...

This study aimed to investigate the molecular mechanisms underlying dopaminergic injury induced by gestational and lactational atrazine (ATR) exposure in rat offspring, with a particular focus on non-coding RNA-mediated regulation. Pregnant rats were exposed to ATR during gestation and lactation. Offspring underwent behavioral testing at postnatal day 21 (PND21) and were sacrificed for midbrain tissue collection at PND28. Behavioral alterations, histopathological changes in the substantia nigra, and dopaminergic marker expression were assessed to evaluate ATR-induced neurotoxicity. Whole-transcriptome sequencing was then performed to identify differentially expressed mRNAs, miRNAs, and lncRNAs, followed by co-expression, protein-protein interaction, and competing endogenous RNA (ceRNA) network analyses. Key targets were validated by qRT-PCR. Candidate molecules identified from transcriptomic and ceRNA analyses were further examined in an ATR-induced neurotoxicity model established in RA-differentiated SK-N-SH cells. Dual-luciferase reporter, Ago2-RNA immunoprecipitation, and biotin-labeled RNA pull-down assays were used to examine putative binding relationships and molecular interactions. In addition, lentivirus-mediated Elavl4 overexpression was performed to further evaluate the role of this candidate regulator in ATR-induced Nurr1 downregulation. Gestational and lactational ATR exposure induced significant behavioral abnormalities in rat offspring. These changes were accompanied by histopathological alterations in the substantia nigra, including reduced TH immunoreactivity, as well as abnormal expression of dopaminergic markers, characterized by decreased TH and Nurr1 levels and increased α-syn expression. Together, these findings indicate the presence of dopaminergic injury. Whole-transcriptome analysis further revealed widespread dysregulation of mRNAs, miRNAs, and lncRNAs in ATR-exposed offspring. Subsequent integrative analysis suggested a potential ceRNA regulatory relationship among Elavl4, miR-301a-5p, and Nurr1, which was further supported by qRT-PCR. Dual-luciferase reporter, RIP, and RNA pull-down assays supported direct interactions between miR-301a-5p and both Elavl4 and Nurr1, as well as their association with the Ago2-containing silencing complex. Moreover, Elavl4 overexpression partially reversed ATR-induced Nurr1 downregulation in vitro. Gestational and lactational ATR exposure induced behavioral abnormalities and dopaminergic injury in rat offspring. Whole-transcriptome analysis combined with experimental validation suggests a potential association between the Elavl4/miR-301a-5p/Nurr1 ceRNA axis and ATR-induced dopaminergic injury, providing insight into the post-transcriptional mechanisms underlying developmental neurotoxicity.