Calcitropic gene expression suggests a role for the intraplacental yolk sac in maternal-fetal calcium exchange.
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.
Kovacs
Christopher S
CS
Faculty of Medicine-Endocrinology, Memorial University of Newfoundland, St. John's, Newfoundland A1B 3V6, Canada.
Chafe
Linda L
LL
Woodland
Mandy L
ML
McDonald
Kirsten R
KR
Fudge
Neva J
NJ
Wookey
Peter J
PJ
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
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