Abstract

The hypothalamic–pituitary–gonadal (HPG) axis is a major target of endocrine-disrupting chemicals (EDCs) and a central regulator of sexual maturation and reproduction in humans and vertebrates. The gonadotropin-releasing hormone (GnRH) neuron-gonadotrope axis (GG axis) is a core component within the HPG system, linking upstream and downstream hormonal cascades. In this study, we developed a two-cell assay system using independently cultured GT1–7 and LβT2 cell lines to simulate GG axis hormonal regulation and evaluate the disruptive effects of 50 environmental chemicals on the expression of key hormones and receptors genes, including GnRH, G protein-coupled receptor 54 (GPR54), GnRH receptor (GnRHR), chorionic gonadotropin α (CGα), luteinizing hormone β (LHβ), and follicle-stimulating hormone β (FSHβ). Using the Toxicological Priority Index (ToxPi) tool, we quantified and weighted alterations in these six target genes, ranking the chemicals according to their GG axis disruption potential and identifying high-risk EDCs. We further validated this integrated high-throughput screening system by assessing the in vivo effects of hexafluoropropylene oxide trimer acid (HFPO-TA), the third-ranked compound and a widely used perfluorooctanoic acid (PFOA) substitute, on pubertal onset timing in female mice, confirming the system’s effectiveness and accuracy. This comprehensive strategy provides a reliable framework for efficient identification of GG axis disruptors and offers a novel, streamlined approach to chemical risk assessment.