Regulation of Murine Fetal-placental Calcium Metabolism by the Calcium-sensing Receptor
Overview
Affiliations
The calcium-sensing receptor (CaSR) regulates PTH secretion to control the extracellular calcium concentration in adults, but its role in fetal life is unknown. We used CaSR gene knockout mice to investigate the role of the CaSR in regulating fetal calcium metabolism. The normal calcium concentration in fetal blood is raised above the maternal level, an increase that depends upon PTH-related peptide (PTHrP). Heterozygous (+/-) and homozygous (-/-) disruption of the CaSR caused a further increase in the fetal calcium level. This increase was modestly blunted by concomitant disruption of the PTHrP gene and completely reversed by disruption of the PTH/ PTHrP receptor gene. Serum levels of PTH and 1, 25-dihydroxyvitamin D were substantially increased above the normal low fetal levels by disruption of the CaSR. The free deoxypyridinoline level was increased in the amniotic fluid (urine) of CaSR-/- fetuses; this result suggests that fetal bone resorption is increased. Placental calcium transfer was reduced, and renal calcium excretion was increased, by disruption of the CaSR. These studies indicate that the CaSR normally suppresses PTH secretion in the presence of the normal raised (and PTHrP-dependent) fetal calcium level. Disruption of the CaSR causes fetal hyperparathyroidism and hypercalcemia, with additional effects on placental calcium transfer.
The Molecular Biology of Placental Transport of Calcium to the Human Foetus.
Walker V Int J Mol Sci. 2025; 26(1.
PMID: 39796238 PMC: 11720126. DOI: 10.3390/ijms26010383.
Bennin D, Hartery S, Kirby B, Maekawa A, St-Arnaud R, Kovacs C JBMR Plus. 2024; 8(5):ziae012.
PMID: 38577520 PMC: 10993470. DOI: 10.1093/jbmrpl/ziae012.
Maternal Mineral Nutrition Regulates Fetal Genomic Programming in Cattle: A Review.
Anas M, Diniz W, Menezes A, Reynolds L, Caton J, Dahlen C Metabolites. 2023; 13(5).
PMID: 37233634 PMC: 10223334. DOI: 10.3390/metabo13050593.
The role of biomineralization in disorders of skeletal development and tooth formation.
Kovacs C, Chaussain C, Osdoby P, Brandi M, Clarke B, Thakker R Nat Rev Endocrinol. 2021; 17(6):336-349.
PMID: 33948016 DOI: 10.1038/s41574-021-00488-z.
Parathyroid Disease in Pregnancy and Lactation: A Narrative Review of the Literature.
Tsourdi E, Anastasilakis A Biomedicines. 2021; 9(5).
PMID: 33925967 PMC: 8145477. DOI: 10.3390/biomedicines9050475.