title: 17β-Estradiol upregulates ecto-5'-nucleotidase (CD73) in hippocampal synaptosomes of female rats through action mediated by estrogen receptor-α and -β.
abstract: 17β-Estradiol (E2) crucially affects several processes in the hippocampus of both sexes. E2 acts upon estradiol receptors ERα and ERβ, influencing target gene expression and/or modulates intracellular signaling cascades. Another potent modulator of hippocampal function is nucleoside adenosine, the final product of ectonucleotidase cascade, enzymes which hydrolyze extracellular ATP to adenosine. The last and rate-limiting step of the hydrolysis is catalyzed by membrane-bound ecto-5'-nucleotidase (eN). Previous findings obtained on adenosine metabolism in brain suggest that eN may be modulated by ovarian steroids. Therefore, the present study reports that the activity and protein abundance of membrane-bound eN fluctuates across the estrus cycle in the hippocampal synaptosomes of female rats. Further, we analyzed the role of E2 and its intracellular receptors on the expression of eN in ovariectomized females. We found that E2 upregulated eN activity and protein abundance in the hippocampal synaptosomes. Application of nonspecific ER antagonist, ICI 182,780 and selective ERα and ERβ agonists, PPT and DPN, respectively, demonstrated the involvement of both receptor subtypes in observed actions. Selective ERα receptor agonist, PPT, induced upregulation of both the protein level and activity of eN, while application of selective ERβ receptor agonist, DPN, increased only the activity of eN. In both cases, E2 entered into the intracellular compartment and activated ER(s), which was demonstrated by membrane impermeable E2-BSA conjugate. Together these results imply that E2-induced effects on connectivity and functional properties of the hippocampal synapses may be in part mediated through observed effect on eN.
authors.affiliation: Department of Molecular Biology and Endocrinology, VINČA Institute of Nuclear Sciences, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia.
authors.forename: N
authors.initials: N
authors.lastname: Mitrović
authors.affiliation: Department of Molecular Biology and Endocrinology, VINČA Institute of Nuclear Sciences, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia.
authors.forename: M
authors.initials: M
authors.lastname: Zarić
authors.affiliation: Department of Molecular Biology and Endocrinology, VINČA Institute of Nuclear Sciences, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia.
authors.forename: D
authors.initials: D
authors.lastname: Drakulić
authors.affiliation: Department of Molecular Biology and Endocrinology, VINČA Institute of Nuclear Sciences, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia.
authors.forename: J
authors.initials: J
authors.lastname: Martinović
authors.affiliation: Department of Molecular Biology and Endocrinology, VINČA Institute of Nuclear Sciences, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia.
authors.forename: M
authors.initials: M
authors.lastname: Stanojlović
authors.affiliation: Département de microbiologie-infectiologie et d'immunologie, Faculté de Médecine, Université Laval, Québec G1V 0A6, QC, Canada; Centre de recherche du CHU de Québec - Université Laval, G1V 4G2 QC, Canada.
authors.forename: J
authors.initials: J
authors.lastname: Sévigny
authors.affiliation: Department of Molecular Biology and Endocrinology, VINČA Institute of Nuclear Sciences, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia.
authors.forename: A
authors.initials: A
authors.lastname: Horvat
authors.affiliation: Institute for Physiology and Biochemistry, Faculty of Biology, University of Belgrade, Studentski trg 3, 11000 Belgrade, Serbia.
authors.forename: N
authors.initials: N
authors.lastname: Nedeljković
authors.affiliation: Department of Molecular Biology and Endocrinology, VINČA Institute of Nuclear Sciences, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade, Serbia. Electronic address: istanojevic@vinca.rs.
authors.forename: I
authors.initials: I
authors.lastname: Grković
mesh_terms: D015720:5'-Nucleotidase / Q000378:metabolism*; D000818:Animals; D004958:Estradiol / Q000031:analogs & derivatives / Q000494:pharmacology*; D065171:Estrogen Receptor Antagonists / Q000494:pharmacology; D047628:Estrogen Receptor alpha / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D047629:Estrogen Receptor beta / Q000819:agonists / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004967:Estrogens / Q000494:pharmacology*; D030762:Estrous Cycle / Q000187:drug effects / Q000502:physiology; D005260:Female; D000077267:Fulvestrant; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D042541:Intracellular Space / Q000378:metabolism; D009570:Nitriles / Q000494:pharmacology; D010636:Phenols / Q000494:pharmacology; D011720:Pyrazoles / Q000494:pharmacology; D011897:Random Allocation; D017208:Rats, Wistar; D013569:Synapses / Q000187:drug effects / Q000378:metabolism; D013574:Synaptosomes / Q000187:drug effects / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D011422:Propionates
chemical_list: D015720:5'-Nucleotidase; D004958:Estradiol; D065171:Estrogen Receptor Antagonists; D047628:Estrogen Receptor alpha; D047629:Estrogen Receptor beta; D004967:Estrogens; D000077267:Fulvestrant; D009570:Nitriles; D010636:Phenols; D011720:Pyrazoles; C486182:2,3-bis(4-hydroxyphenyl)-propionitrile; D011422:Propionates; C486184:4,4',4''-(4-propyl-((1)H)-pyrazole-1,3,5-triyl) tris-phenol
keywords: 17β-estradiol; ecto-5′-nucleotidase (CD73); estradiol receptors α and β; hippocampus; synaptosomes