Prenatal dexamethasone exposure programs male offspring subfertility via GR/HDAC6/CTSL-mediated spermatogonial autophagic flux blockade.

BACKGROUND: Male infertility is significant, and part of it is associated with prenatal drug exposure. While prenatal glucocorticoid treatment is widely used, its long-term effects on male offspring fertility and the underlying programming mechanisms remain unclear. METHODS: Based on a clinical-based PDE rat model (0.4 mg/kg dexamethasone, b.i.d.) during late pregnancy (gestational day 18-19), the fertility of male offspring was evaluated. Transcriptome sequencing was employed to identify potential targets. The epigenetic regulation of lysosomal protease Cathepsin L (CTSL) was analyzed using chromatin immunoprecipitation (Ch-IP) and co-immunoprecipitation (co-IP). Rescue experiments were performed using the TRPML1 agonist ML-SA1 and genetic CTSL overexpression to validate the signaling pathway. Multiple prenatal exposure models were used to verify the generalizability of this mechanism. RESULTS: The subfertility of PDE male offspring originated in the fetal period. Then, a specific autophagic flux blockade in spermatogonia was identified, and was driven by the persistent downregulation of CTSL. Mechanistically, the activated Glucocorticoid Receptor (GR) recruited Histone Deacetylase 6 (HDAC6) to the Ctsl promoter, leading to reduced H3K27 acetylation and subsequent transcriptional silencing. Importantly, reactivating lysosomal signaling via ML-SA1 or genetically restoring CTSL expression reversed the autophagic flux blockade and rescued fertility outcomes. Furthermore, this GR/HDAC6/CTSL axis might be a shared pathway underlying a subset of other glucocorticoid-related prenatal exposures. CONCLUSIONS: These findings provide potential intervention targets for the early prevention and treatment of fetal-origin male subfertility and offer a theoretical basis for guiding rational drug use and healthy lifestyles during pregnancy.