A novel role for an endothelial adrenergic receptor system in mediating catecholestradiol-induced proliferation of uterine artery endothelial cells.
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ABSTRACT: Sequential conversion of estradiol-17? to its biologically active catecholestradiols, 2-hydroxyestradiol (OHE(2)) and 4-OHE(2), contributes importantly to its angiogenic effects on uterine artery endothelial cells (UAECs) derived from pregnant, but not nonpregnant ewes via an estrogen receptor-independent mechanism. Because catecholestradiols and catecholamines exhibit structural similarities and have high affinity for ?- and ?-adrenergic receptors (ARs), we investigated whether the endothelial ?- or ?-ARs mediate catecholestradiol-induced proliferation of P-UAECs and whether catecholamines alter these responses. Western analyses revealed expression of specific AR subtypes in nonpregnant UAECs and P-UAECs, including ?(2)-, ?(2)-, and ?(3)-ARs but not ?(1)- and ?(1)-ARs. Levels of ?(2)-ARs and ?(3)-ARs were unaltered by pregnancy, whereas ?(2)-ARs were decreased. Norepinephrine and epinephrine increased P-UAEC, but not nonpregnant UAEC proliferation, and these effects were suppressed by propranolol (?-AR blocker) but not phentolamine (?-AR blocker). Catecholamines combinations with 2-OHE(2) or 4-OHE(2) enhanced P-UAEC mitogenesis. Catecholestradiol-induced P-UAEC proliferation was also inhibited by propranolol but not phentolamine. ?(2)-AR and ?(3)-AR antagonists (ICI 118 551and SR 59230A, respectively) abrogated the mitogenic effects of both 2-OHE(2) and 4-OHE(2). Stimulation of ?(2)-ARs and ?(3)-ARs using formoterol and BRL 37344 dose-dependently stimulated P-UAEC proliferation, which was abrogated by ICI 118 551 and SR 59230A, respectively. Proliferation effects of both catecholamines and catecholestradiols were only observed in P-UAECs (not nonpregnant UAECs) and were mediated via ?(2)-ARs and ?(3)-ARs. We demonstrate for the first time convergence of the endothelial AR and estrogenic systems in regulating endothelial proliferation, thus providing a distinct evolutionary advantage for modulating uterine perfusion during stressful pregnancies.
SUBMITTER: Jobe SO
PROVIDER: S-EPMC3199972 | biostudies-literature | 2011 Nov
REPOSITORIES: biostudies-literature
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