Down-regulation of TET2 inhibits testosterone synthesis in offspring mice exposed to DBP during pregnancy through LH/cAMP/PKA/StAR signaling mediated by LHR

Exposure to di-n-butyl phthalate (DBP) during embryo development or lactation has been linked to reproductive toxicity. The ten-eleven translocation (TET) protein family plays a role in various pathological processes; however, its involvement in reproductive dysfunction in offspring mice exposed to DBP during gestation remains sparsely reported. In this study, SPF C57BL/6 pregnant mice were intragastrically administered DBP at doses of 0.5, 5, and 75 mg/kg body weight, or corn oil as a control, from gestational days 5-19. Following weaning, the offspring mice were maintained on a standard diet for 5 weeks. Additionally, mono-n-butyl phthalate (MBP)-induced TM3 cells were utilized to explore the underlying mechanisms in vitro. The results showed that in utero exposure to DBP resulted in diminished sperm quality, testicular damage, decreased reproductive hormone levels, and reduced expression of testosterone synthesis proteins in male offspring mice. Moreover, DBP exposure influenced the expression of steroidogenic acute regulatory protein (StAR) via the cAMP/PKA signaling pathway, associated with luteinizing hormone receptor (LHR)-mediated suppression of testosterone synthesis. Notably, DBP exposure led to decreased expression of TET methylcytosine dioxygenase 2 (TET2) in the progeny, and overexpression or silencing of TET2 affected the levels of proteins involved in the LHR-mediated testosterone synthesis pathway. Further investigations revealed that TET2 downregulation inhibits testosterone synthesis through the LHR-mediated LH/cAMP/PKA/StAR signaling pathway, ultimately impairing reproductive function in DBP-exposed offspring mice during gestation. This study provides a novel perspective for identifying molecular markers that may be more sensitive indicators of male reproductive damage from an epigenetic standpoint.