title: Estradiol and GPER Activation Differentially Affect Cell Proliferation but Not GPER Expression in the Hippocampus of Adult Female Rats.
abstract: Estradiol increases cell proliferation in the dentate gyrus of the female rodent but it is not known whether the G protein-coupled estrogen receptor (GPER), a membrane receptor, is involved in this process, nor whether there are regional differences in estradiol's effects on cell proliferation. Thus, we investigated whether estradiol exerts its effects on cell proliferation in the dorsal and ventral dentate gyrus through GPER, using the GPER agonist, G1, and antagonist, G15. Ovariectomized adult female rats received a single injection of either: 17β-estradiol (10 μg), G1 (0.1, 5, 10 μg), G15 (40 μg), G15 and estradiol, or vehicle (oil, DMSO, or oil+DMSO). After 30 min, animals received an injection of bromodeoxyuridine (BrdU) and were perfused 24 h later. Acute treatment with estradiol increased, while the GPER agonist G1 (5 μg) decreased, the number of BrdU+ cells in the dentate gyrus relative to controls. The GPER antagonist, G15 increased the number of BrdU+ cells relative to control in the dorsal region and decreased the number of BrdU+ cells in the ventral region. However, G15 treatment in conjunction with estradiol partially eliminated the estradiol-induced increase in cell proliferation in the dorsal dentate gyrus. Furthermore, G1 decreased the expression of GPER in the dentate gyrus but not the CA1 and CA3 regions of the hippocampus. In summary, we found that activation of GPER decreased cell proliferation and GPER expression in the dentate gyrus of young female rats, presenting a potential and novel estrogen-independent role for this receptor in the adult hippocampus.
authors.affiliation: Department of Psychology, Program in Neuroscience, Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Paula
authors.initials: P
authors.lastname: Duarte-Guterman
authors.affiliation: Department of Psychology, Program in Neuroscience, Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Stephanie E
authors.initials: SE
authors.lastname: Lieblich
authors.affiliation: Department of Psychology, Program in Neuroscience, Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Carmen
authors.initials: C
authors.lastname: Chow
authors.affiliation: Department of Psychology, Program in Neuroscience, Centre for Brain Health, University of British Columbia, Vancouver, British Columbia, Canada.
authors.forename: Liisa A M
authors.initials: LA
authors.lastname: Galea
mesh_terms: D000818:Animals; D052117:Benzodioxoles / Q000494:pharmacology; D001835:Body Weight; D049109:Cell Proliferation / Q000187:drug effects; D003517:Cyclopentanes / Q000494:pharmacology; D018891:Dentate Gyrus / Q000033:anatomy & histology / Q000187:drug effects / Q000378:metabolism; D004958:Estradiol / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects; D006624:Hippocampus / Q000033:anatomy & histology / Q000187:drug effects* / Q000378:metabolism*; D019394:Ki-67 Antigen / Q000235:genetics / Q000378:metabolism; D009929:Organ Size; D011804:Quinolines / Q000494:pharmacology; D051381:Rats; D043562:Receptors, G-Protein-Coupled / Q000819:agonists* / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism
chemical_list: C517943:1-(4-(6-bromobenzo(1,3)dioxol-5-yl)-3a,4,5,9b-tetrahydro-3H-cyclopenta(c)quinolin-8-yl)ethanone; C568862:4-(6-bromo-1,3-benzodioxol-5-yl)-3a,4,5,9b-3H-cyclopenta(c)quinoline; D052117:Benzodioxoles; D003517:Cyclopentanes; C520305:Gper1 protein, rat; D019394:Ki-67 Antigen; D011804:Quinolines; D043562:Receptors, G-Protein-Coupled; D004958:Estradiol