title: Calcitropic gene expression suggests a role for the intraplacental yolk sac in maternal-fetal calcium exchange.
abstract: The expression of calcitropic genes and proteins was localized within murine placenta during late gestation (the time frame of active calcium transfer) with an analysis of several gene-deletion mouse models by immunohistochemistry and in situ hybridization. Parathyroid hormone-related protein (PTHrP), the PTH/PTHrP receptor, calcium receptor, calbindin-D(9k), Ca(2+)-ATPase, and vitamin D receptor were all highly expressed in a localized structure of the murine placenta, the intraplacental yolk sac, compared with trophoblasts. In the PTHrP gene-deleted or Pthrp-null placenta in which placental calcium transfer is decreased, calbindin-D(9k) expression was downregulated in the intraplacental yolk sac but not in the trophoblasts. These observations indicated that the intraplacental yolk sac contains calcium transfer and calcium-sensing capability and that it is a probable route of maternal-fetal calcium exchange in the mouse.
authors.affiliation: Faculty of Medicine-Endocrinology, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3V6, Canada.
authors.forename: Christopher S
authors.initials: CS
authors.lastname: Kovacs
authors.forename: Linda L
authors.initials: LL
authors.lastname: Chafe
authors.forename: Mandy L
authors.initials: ML
authors.lastname: Woodland
authors.forename: Kirsten R
authors.initials: KR
authors.lastname: McDonald
authors.forename: Neva J
authors.initials: NJ
authors.lastname: Fudge
authors.forename: Peter J
authors.initials: PJ
authors.lastname: Wookey
mesh_terms: D000818:Animals; D001692:Biological Transport; D064026:Calbindins; D002116:Calcitonin / Q000235:genetics; D002118:Calcium / Q000378:metabolism*; D002135:Calcium-Binding Proteins / Q000235:genetics; D000252:Calcium-Transporting ATPases / Q000235:genetics; D005260:Female; D015870:Gene Expression; D005865:Gestational Age; D006023:Glycoproteins / Q000235:genetics; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D036341:Intercellular Signaling Peptides and Proteins; D008431:Maternal-Fetal Exchange; D051379:Mice; D018345:Mice, Knockout; D044162:Parathyroid Hormone-Related Protein; D010920:Placenta / Q000737:chemistry / Q000378:metabolism*; D010928:Placental Lactogen / Q000235:genetics; D011247:Pregnancy; D011388:Prolactin; D011506:Proteins / Q000235:genetics; D044168:Receptor, Parathyroid Hormone, Type 1; D018167:Receptors, Calcitriol / Q000235:genetics; D018016:Receptors, Parathyroid Hormone / Q000235:genetics; D064030:S100 Calcium Binding Protein G / Q000235:genetics; D015017:Yolk Sac / Q000502:physiology*; D000509:alpha-Fetoproteins / Q000235:genetics
chemical_list: D064026:Calbindins; D002135:Calcium-Binding Proteins; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D044162:Parathyroid Hormone-Related Protein; C000634106:Prl2c2 protein, mouse; D011506:Proteins; D044168:Receptor, Parathyroid Hormone, Type 1; D018167:Receptors, Calcitriol; D018016:Receptors, Parathyroid Hormone; D064030:S100 Calcium Binding Protein G; D000509:alpha-Fetoproteins; D011388:Prolactin; D002116:Calcitonin; D010928:Placental Lactogen; D000252:Calcium-Transporting ATPases; D002118:Calcium