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.