Bisphenol S disrupts human sertoli cell function through NR1H3 degradation: Mechanistic insights from integrated bulk and single-cell transcriptomics.

Male infertility, often linked to impaired spermatogenesis, is increasingly associated with environmental pollutants such as bisphenol S (BPS), a common bisphenol A substitute, yet its molecular mechanisms in human Sertoli cells remain unclear. In this study, immortalized human Sertoli cells were exposed to BPS, and cell viability, proliferation, and transcriptomic changes were assessed, with bulk RNA sequencing integrated with single-cell transcriptomic profiles from non-obstructive azoospermia (NOA) testes to identify key regulatory factors. Potential BPS targets were predicted via pharmacophore mapping and confirmed through molecular docking, molecular dynamics simulations, and MM/GBSA binding free energy calculations, while functional validation was performed using NR1H3 knockdown and overexpression assays with luciferase reporter and Western blot analyses. BPS significantly inhibited cell viability and proliferation at concentrations ≥ 20 μM, inducing transcriptomic dysregulation involving cell cycle suppression, metabolic pathway alterations, and steroid biosynthesis disruption. Integration of computational and transcriptomic analyses identified NR1H3 as a direct BPS target, with docking and dynamics simulations demonstrating stable binding (-20.64 ± 2.26 kcal/mol), and experimental data showing that BPS reduced NR1H3 protein levels and transcriptional activity, while NR1H3 knockdown impaired cell survival and overexpression partially rescued BPS-induced cytotoxicity. These findings provide the first evidence that BPS impairs human Sertoli cell function by targeting NR1H3, revealing a critical role of NR1H3 in Sertoli cell survival and suggesting that BPS exposure may contribute to male infertility through NR1H3-mediated pathways.