Gender difference in adrenal developmental toxicity induced by dexamethasone and its intrauterine programming mechanism

Background: and Purpose: Dexamethasone is widely used in preterm labor and related diseases. However, prenatal dexamethasone exposure (PDE) can cause multi-organ developmental toxicities in offspring. Our previous study found the occurrence of fetal-originated diseases were associated with adrenal developmental programming alteration in offspring. Here, we investigated the effects of PDE on the adrenal function in offspring and its intrauterine programming mechanism. Experimental Approach: A rat model of PDE was established to observe the alteration of adrenal steroidogenesis in offspring. Further, we confirmed the gender difference of adrenal steroidogenesis and its molecular mechanism combined with in vivo and in vitro experiment. Key Results: PDE caused a decrease in adrenal steroidogenic function in fetal rats, but decreased in males and increased in females after birth. Meanwhile, the adrenal H3K14ac level and expression of 11β-hydroxysteroid dehydrogenase 2 (11β-HSD2) in PDE offspring were decreased in males and increased in females, suggesting 11β-HSD2 might mediate gender difference of adrenal function. We further confirmed dexamethasone inhibited the H3K14ac level and expression of 11β-HSD2 through GR/SP1/p300 pathway. After bilateral testectomy or ovariectomy in adult PDE offspring rats, adrenal 11β-HSD2 expression and steroidogenic function were both reduced. Using rat primary fetal adrenal cells, the differential expression in AR and ERβ were proved to involve in regulating the gender difference of 11β-HSD2 expression. Conclusion and Implications: This study demonstrated the gender difference in adrenal steroidogenic function of PDE offspring after birth, and elucidates a sex hormone receptor-dependent epigenetically regulating mechanism for adrenal 11β-HSD2 programming alteration.