Estradiol stimulates progenitor cell division in the ventricular and subventricular zones of the embryonic neocortex.
Two distinct populations of cerebral cortical progenitor cells that generate neurons during embryogenesis have been identified: radial glial cells and intermediate progenitor cells. Despite advances in our understanding of progenitor cell populations, we know relatively little about factors that regulate their proliferative behaviour. 17-beta-Estradiol (E2) is present in the adult and developing mammalian brain, and plays an important role in central nervous system processes such as neuronal differentiation, survival and plasticity. E2 also stimulates neurogenesis in the adult dentate gyrus. We examined the role of E2 during embryonic cortical neurogenesis through immunohistochemistry, in situ hybridization, functional enzyme assay, organotypic culture and in utero administration of estradiol-blocking agents in mice. We show that aromatase, the E2 synthesizing enzyme, is present in the embryonic neocortex, that estrogen receptor-alpha is present in progenitor cells during cortical neurogenesis, that in vitro E2 administration rapidly promotes proliferation, and that in utero blockade of estrogen receptors decreases proliferation of embryonic cortical progenitor cells. Furthermore, the E2 inhibitor alpha-fetoprotein is expressed at high levels by radial glial cells but at lower levels by intermediate progenitor cells, suggesting that E2 differentially influences the proliferation of these cortical progenitor cell types. These findings demonstrate a new functional role for E2 as a proliferative agent during critical stages of cerebral cortex development.
Martínez-Cerdeño
Verónica
V
Department of Neurology and Program in Developmental and Stem Cell Biology, 513 Parnassus Avenue, HSW 1201, Box 0525, University of California San Francisco, San Francisco, California 94143, USA. vmc@ventricular.org
Noctor
Stephen C
SC
Kriegstein
Arnold R
AR
D000735:Androstenedione / Q000494:pharmacology; D000818:Animals; D000831:Animals, Newborn; D001141:Aromatase / Q000378:metabolism; D015153:Blotting, Western / Q000379:methods; D002455:Cell Division / Q000187:drug effects*; D002552:Cerebral Ventricles / Q000166:cytology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D004622:Embryo, Mammalian; D004958:Estradiol / Q000494:pharmacology*; D004965:Estrogen Antagonists / Q000008:administration & dosage; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D019579:Neocortex / Q000196:embryology*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D013234:Stem Cells / Q000187:drug effects*; D013629:Tamoxifen / Q000008:administration & dosage; D013997:Time Factors
D004965:Estrogen Antagonists; D013629:Tamoxifen; D000735:Androstenedione; D004958:Estradiol; D001141:Aromatase