title: DNA-binding ability of NF-kappaB is affected differently by ERalpha and ERbeta and its activation results in inhibition of estrogen responsiveness.
abstract: Estrogenic effects involve interactions between estrogen receptors (ERs), response elements, and nuclear proteins. It is hypothesized that interaction between ER and NF-kappa B may affect the regulation of responsive genes. Electrophoretic mobility shift assay (EMSA) was performed to assess if the interaction of ERs and NF- kappaB affect their respective DNA-binding activities, and alkaline phosphatase assay was done to evaluate estrogenic activity. EMSA revealed that ERs inhibit DNA-binding of p50 and p65, whereas p50 did not impair ER alpha binding. Stimulation with estradiol inhibited DNA binding of NF-kappaB in ERalpha-transfected endometrial stromal cells (ESCs). Moreover, activation of NF-kappaB significantly decreased estrogen responsiveness of Ishikawa cells and ERalpha-transfected ESC. Our results suggest that ERs downregulate NF-kappaB-dependent gene activation by directly preventing DNA binding. However, NF-kappaB-mediated inhibition of ER-dependent gene activation may be carried out indirectly rather than through a direct inhibition of ER-DNA binding. These findings offer new insight into the specific role of ERalpha and could eventually help in developing therapeutics for endometriosis.
authors.affiliation: Division of Reproductive Endocrinology, Department of Obstetrics, Gynecology and Reproductive Sciences, Yale University School of Medicine, New Haven, Connecticut 06520-8063, USA.
authors.forename: Ozlem
authors.initials: O
authors.lastname: Guzeloglu-Kayisli
authors.forename: Gulden
authors.initials: G
authors.lastname: Halis
authors.forename: Sarper
authors.initials: S
authors.lastname: Taskiran
authors.forename: Umit A
authors.initials: UA
authors.lastname: Kayisli
authors.forename: Aydin
authors.initials: A
authors.lastname: Arici
mesh_terms: D000328:Adult; D001667:Binding, Competitive; D002460:Cell Line; D004247:DNA / Q000378:metabolism*; D004715:Endometriosis / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology*; D047628:Estrogen Receptor alpha / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000378:metabolism*; D005260:Female; D006801:Humans; D019169:Jurkat Cells; D016328:NF-kappa B / Q000378:metabolism*; D020298:U937 Cells
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D016328:NF-kappa B; D004958:Estradiol; D004247:DNA