Critical Role of Histone Acetylation by p300 in Human Placental 11β-HSD2 Expression

Context: Fetal overexposure to glucocorticoids leads to growth restriction. Optimal fetal glucocorticoid level is ensured by the expression of cortisol-inactivating enzyme 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) in placental syncytiotrophoblasts. The transcription factor selective promoter factor 1 (Sp1) is known to up-regulate 11β-HSD2 expression in the presence of enhanced histone acetylation in syncytiotrophoblasts, but the mechanisms underlying histone acetylation remain unknown. Objectives: The role of p300 in histone acetylation associated with 11β-HSD2 expression in syncytiotrophoblasts was investigated. Design: Distribution of p300 in human placenta was studied with immunohistochemistry. The role of p300 in histone-3 (H3) acetylation in association with 11β-HSD2 expression was investigated in cultured primary human placental trophoblasts in the presence of small interfering RNA (siRNA)-mediated knockdown of p300, p300 inhibitor C646, or p300 overexpression. The interaction of Sp1 and p3...