title: Modulation of response to estrogens in cultured human female bone cells by a non-calcemic Vitamin D analog: changes in nuclear and membranal binding.
abstract: Estradiol17beta (E2) and the phytoestrogens genistein (G), and daidzein (D) increase creatine kinase (CK) specific activity in primary cell cultures of human female to a greater extent in cells from pre-menopausal than post-menopausal women. Pretreatment with the non-calcemic analog of Vitamin D, JK 1624 F2-2 (JKF), upregulated this estrogenic response at all ages. In contrast, biochainin A (BA) and quercertin (Qu) increased CK with no age dependence or modulation by JKF pretreatment. Both ERalpha and ERbeta present in the cells were upregulated by pretreatment with JKF, as measured by Western blot analysis. Real time PCR showed no significant change in ERalpha mRNA but a marked decrease in ERbeta mRNA in both age groups after JKF treatment. Cells from both age groups had surface binding sites for E2, shown by assays using cell impermeable Europium labeled ovalbumin-E2 conjugate (Eu-Ov-E2). Binding of [3H]-E2 to intracellular E2 receptors (ERs) was similar in both age groups with differences in phytoestrogenic competition. JKF pretreatment increased nuclear but decreased membranal binding in both age groups. These results provide evidence for membranal, in addition to nuclear estrogen receptors which are differentially modulated by a Vitamin D analog.
authors.affiliation: Institute of Endocrinology, Metabolism and Hypertension, Tel-Aviv Sourasky Medical Center, 6 Weizman St., Tel-Aviv 64239, Israel. dalias@tasmc.health.gov.il
authors.forename: Dalia
authors.initials: D
authors.lastname: Somjen
authors.forename: Sara
authors.initials: S
authors.lastname: Katzburg
authors.forename: Orly
authors.initials: O
authors.lastname: Sharon
authors.forename: Alvin M
authors.initials: AM
authors.lastname: Kaye
authors.forename: Batya
authors.initials: B
authors.lastname: Gayer
authors.forename: Fortune
authors.initials: F
authors.lastname: Kohen
authors.forename: David
authors.initials: D
authors.lastname: Hendel
authors.forename: Gary H
authors.initials: GH
authors.lastname: Posner
mesh_terms: D015153:Blotting, Western; D001842:Bone and Bones / Q000166:cytology / Q000502:physiology*; D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens / Q000378:metabolism / Q000502:physiology*; D005260:Female; D006801:Humans; D011485:Protein Binding; D011960:Receptors, Estrogen / Q000378:metabolism
chemical_list: D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; D011960:Receptors, Estrogen