The tissue-specific effects of different 17 beta-estradiol doses reveal the key sensitizing role of AF1 domain in ER alpha activity

• 17 beta-Estradiol (E2) action can be mediated by the full-length estrogen receptor alpha (ER alpha 66), and also by the AF1 domain-deficient ER alpha (ER alpha 46) isoform, but their respective sensitivity to E2 is essentially unknown. We first performed a dose response study using subcutaneous home-made pellets mimicking either metestrus, proestrus or a pharmacological doses of E2, which resulted in plasma concentrations around 3, 30 and 600 pM, respectively. Analysis of the uterus, vagina and bone after chronic exposure to E2 demonstrated dose-dependent effects, with a maximal response reached at the proestrus-dose in wild type mice expressing mainly ER alpha 66. In contrast, in transgenic mice harbouring only an ER alpha deleted in AF1, these effects of E2 were either strongly shifted rightward (10-100-fold) and/or attenuated, depending on the tissue studied. Finally, experiments in different cell lines transfected with ER alpha 66 or ER alpha 46 also delineated varying profiles of ER alpha AF1 sensitivity to E2. Altogether, this work emphasizes the importance of dose in the tissue-specific actions of E2 and demonstrates the key sensitizing role of AF1 in ER alpha activity.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Endokrinologi och diabetes (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Endocrinology and Diabetes (hsv//eng)

Nyckelord

Estrogen receptor alpha (ER alpha)

Activation function (AF)

Dose

response

Tissue-specificity

estrogen-receptor-alpha

in-vitro

phosphorylation

activation

af-1

sex

estradiol

sufficient

complexes

isoform

Cell Biology

Endocrinology & Metabolism

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)