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Ohata Y, Ozono K, Michigami T. Current concepts in perinatal mineral metabolism. Clin Pediatr Endocrinol 2016; 25:9-17. [PMID: 26865750 PMCID: PMC4738188 DOI: 10.1297/cpe.25.9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 09/26/2015] [Indexed: 12/03/2022] Open
Abstract
The serum levels of calcium (Ca) and phosphate are maintained higher in the fetus than in
the pregnant mother, especially in late gestation, to meet the demands of fetal bone
development. In order to maintain this fetal stage-specific mineral homeostasis, the
placenta plays a critical role through active transcellular mineral transport. Although
the molecular mechanism of transplacental Ca transport has been well studied, little is
known about the transport mechanism of phosphate and magnesium. Maternal mineral
homeostasis is also altered during pregnancy to supply minerals to the fetus. In the
lactating mother, osteocytic osteolysis is suggested to be involved in the supply of
minerals to the baby. The levels of some calcitropic and phosphotropic (Ca- and
phosphate-regulating, respectively) hormones in the fetus are also different from those in
the adult. The PTH level in the fetus is lower than that in the mother and nonpregnant
adult. It is suggested, however, that low fetal PTH plays an important role in fetal
mineral metabolism. The concentration of PTHrP in the fetus is much higher than that of
PTH and plays a critical role in perinatal Ca homeostasis. Uncovering the molecular
mechanisms for fetal stage-specific mineral metabolism will lead to better management of
perinatal patients with mineral abnormalities.
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Affiliation(s)
- Yasuhisa Ohata
- Department of Bone and Mineral Research, Osaka Medical Center and Research Institute for Maternal and Child Health, Izumi, Japan; Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Keiichi Ozono
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Toshimi Michigami
- Department of Bone and Mineral Research, Osaka Medical Center and Research Institute for Maternal and Child Health, Izumi, Japan
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Kovacs CS. Bone development and mineral homeostasis in the fetus and neonate: roles of the calciotropic and phosphotropic hormones. Physiol Rev 2014; 94:1143-218. [PMID: 25287862 DOI: 10.1152/physrev.00014.2014] [Citation(s) in RCA: 129] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mineral and bone metabolism are regulated differently in utero compared with the adult. The fetal kidneys, intestines, and skeleton are not dominant sources of mineral supply for the fetus. Instead, the placenta meets the fetal need for mineral by actively transporting calcium, phosphorus, and magnesium from the maternal circulation. These minerals are maintained in the fetal circulation at higher concentrations than in the mother and normal adult, and such high levels appear necessary for the developing skeleton to accrete a normal amount of mineral by term. Parathyroid hormone (PTH) and calcitriol circulate at low concentrations in the fetal circulation. Fetal bone development and the regulation of serum minerals are critically dependent on PTH and PTH-related protein, but not vitamin D/calcitriol, fibroblast growth factor-23, calcitonin, or the sex steroids. After birth, the serum calcium falls and phosphorus rises before gradually reaching adult values over the subsequent 24-48 h. The intestines are the main source of mineral for the neonate, while the kidneys reabsorb mineral, and bone turnover contributes mineral to the circulation. This switch in the regulation of mineral homeostasis is triggered by loss of the placenta and a postnatal fall in serum calcium, and is followed in sequence by a rise in PTH and then an increase in calcitriol. Intestinal calcium absorption is initially a passive process facilitated by lactose, but later becomes active and calcitriol-dependent. However, calcitriol's role can be bypassed by increasing the calcium content of the diet, or by parenteral administration of calcium.
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Affiliation(s)
- Christopher S Kovacs
- Faculty of Medicine-Endocrinology, Memorial University of Newfoundland, St. John's, Newfoundland, Canada
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Surowiak P, Dziegiel P, Matkowski R, Sopel M, Wojnar A, Kornafel J, Zabel M. Prognostic value of immunocytochemical determination of parathyroid hormone-related peptide expression in cells of mammary ductal carcinoma. Analysis of 7 years of the disease course. Virchows Arch 2003; 442:245-51. [PMID: 12647214 DOI: 10.1007/s00428-002-0743-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2002] [Accepted: 11/01/2002] [Indexed: 10/25/2022]
Abstract
Parathyroid hormone-related peptide (PTHrP) participates in the development of humoral hypercalcaemia of malignancy. The peptide is thought to affect growth and differentiation of normal and neoplastic cells. The present study aimed at evaluation of the relationship between survival time and development of distant metastases in patients with ductal mammary carcinoma on the one hand and PTHrP expression on the other. Immunocytochemical reactions using mouse monoclonal (clone 212-10.7) anti-PTHrP (38-64) antibodies were performed in paraffin sections originating from 47 patients with ductal mammary carcinoma. Expression of the protein was quantified employing a scale, considering the number of positive cells and intensity of the reaction (immunoreactive score, IRS). Survival time of the patients, determined during the course of a 7-year observation was also analysed. The obtained results demonstrated a relationship between intensity of PTHrP expression and the survival time. Patients with high expression of PTHrP (IRS>6) manifested longer survival than patients with lower PTHrP expression (IRS< or =6; Cox'es F test, P<0.05). Moreover, in the group with the lower PTHrP expression, a negative relationship was detected between expression of the protein and the survival time (Cox'es model, P<0.05). No relationship was detected between PTHrP expression and the development of distant metastases.
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Affiliation(s)
- Paweł Surowiak
- Department of Histology and Embryology, University School of Medicine, ul.Chałubińskiego 6a, 50-356, Wrocław, Poland.
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Maioli E, Fortino V, Torricelli C, Arezzini B, Gardi C. Effect of parathyroid hormone-related protein on fibroblast proliferation and collagen metabolism in human skin. Exp Dermatol 2002; 11:302-10. [PMID: 12190938 DOI: 10.1034/j.1600-0625.2002.110403.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The parathyroid hormone-related protein (PTHrp), structurally similar to the parathyroid hormone (PTH) in its NH(2)-terminal part, was first identified as a tumour-derived peptide responsible for a paraneoplastic syndrome known as humoral hypercalcemia of malignancy. The PTHrp gene is expressed not only in cancer but also in normal tissues during adult and/or fetal life, where it plays predominantly paracrine and/or autocrine roles. In the skin PTHrp produced by keratinocytes acts on fibroblasts by complex cooperative circuits involving cytokines and growth factors. In this report, we studied the direct effects of synthetic PTHrp 1-40 on proliferation and collagen synthesis and matrix metalloproteinase-2 (MMP-2) activity in cultures of fibroblasts isolated from normal human skin. Fibroblasts exposure to varying doses of PTHrp for 48 h, significantly and dose-dependently inhibited proliferation evaluated by [(3)H]-thymidine incorporation into DNA. A dose-dependent stimulation of cAMP released into the medium was concomitantly observed. In contrast, PTHrp had no effect on collagen synthesis evaluated either by [(3)H]-proline incorporation or by radioimmunoassay (RIA) of the carboxyterminal fragment of type I procollagen (PICP). MMP-2 activity, evaluated by quantitative zymographic analysis, was significantly increased by PTHrp treatment at doses of 160 and 320 nM. These findings indicate that PTHrp may play a role in normal dermal physiology by controlling both fibroblast proliferation and extracellular matrix degradation.
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Affiliation(s)
- Emanuela Maioli
- Institute of General Physiology, University of Siena, Siena, Italy.
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Clemens TL, Cormier S, Eichinger A, Endlich K, Fiaschi-Taesch N, Fischer E, Friedman PA, Karaplis AC, Massfelder T, Rossert J, Schlüter KD, Silve C, Stewart AF, Takane K, Helwig JJ. Parathyroid hormone-related protein and its receptors: nuclear functions and roles in the renal and cardiovascular systems, the placental trophoblasts and the pancreatic islets. Br J Pharmacol 2001; 134:1113-36. [PMID: 11704631 PMCID: PMC1573066 DOI: 10.1038/sj.bjp.0704378] [Citation(s) in RCA: 141] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2001] [Accepted: 09/10/2001] [Indexed: 11/09/2022] Open
Abstract
The cloning of the so-called 'parathyroid hormone-related protein' (PTHrP) in 1987 was the result of a long quest for the factor which, by mimicking the actions of PTH in bone and kidney, is responsible for the hypercalcemic paraneoplastic syndrome, humoral calcemia of malignancy. PTHrP is distinct from PTH in a number of ways. First, PTHrP is the product of a separate gene. Second, with the exception of a short N-terminal region, the structure of PTHrP is not closely related to that of PTH. Third, in contrast to PTH, PTHrP is a paracrine factor expressed throughout the body. Finally, most of the functions of PTHrP have nothing in common with those of PTH. PTHrP is a poly-hormone which comprises a family of distinct peptide hormones arising from post-translational endoproteolytic cleavage of the initial PTHrP translation products. Mature N-terminal, mid-region and C-terminal secretory forms of PTHrP are thus generated, each of them having their own physiologic functions and probably their own receptors. The type 1 PTHrP receptor, binding both PTH(1-34) and PTHrP(1-36), is the only cloned receptor so far. PTHrP is a PTH-like calciotropic hormone, a myorelaxant, a growth factor and a developmental regulatory molecule. The present review reports recent aspects of PTHrP pharmacology and physiology, including: (a) the identification of new peptides and receptors of the PTH/PTHrP system; (b) the recently discovered nuclear functions of PTHrP and the role of PTHrP as an intracrine regulator of cell growth and cell death; (c) the physiological and developmental actions of PTHrP in the cardiovascular and the renal glomerulo-vascular systems; (d) the role of PTHrP as a regulator of pancreatic beta cell growth and functions, and, (e) the interactions of PTHrP and calcium-sensing receptors for the control of the growth of placental trophoblasts. These new advances have contributed to a better understanding of the pathophysiological role of PTHrP, and will help to identify its therapeutic potential in a number of diseases.
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Affiliation(s)
- Thomas L Clemens
- Department of Medicine, University of Cincinnati, Cincinnati, Ohio, U.S.A
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio, U.S.A
| | - Sarah Cormier
- INSERM U 426 and Institut Federatif de Recherche ‘Cellules Epitheliales', Faculte de Medecine Xavier Bichat, Paris, France
| | - Anne Eichinger
- Section of Renovascular Pharmacology and Physiology, INSERM E0015-ULP, University Louis Pasteur School of Medicine, Strasbourg, France
| | - Karlhans Endlich
- Institut für Anatomie und Zellbiologie 1, Universität Heidelberg, Heidelberg, Germany
| | - Nathalie Fiaschi-Taesch
- Section of Renovascular Pharmacology and Physiology, INSERM E0015-ULP, University Louis Pasteur School of Medicine, Strasbourg, France
- Division of Endocrinology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, PA 15213, U.S.A
| | - Evelyne Fischer
- Department of Nephrology, University Hospital of Strasbourg, Strasbourg, France
| | - Peter A Friedman
- Department of Pharmacology, University of Pittsburgh School of Medicine, Pittsburgh, U.S.A
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, U.S.A
| | | | - Thierry Massfelder
- Section of Renovascular Pharmacology and Physiology, INSERM E0015-ULP, University Louis Pasteur School of Medicine, Strasbourg, France
| | - Jérôme Rossert
- INSERM U489 and Departments of Nephrology and Pathology, Paris VI University, France
| | | | - Caroline Silve
- INSERM U 426 and Institut Federatif de Recherche ‘Cellules Epitheliales', Faculte de Medecine Xavier Bichat, Paris, France
| | - Andrew F Stewart
- Division of Endocrinology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, PA 15213, U.S.A
| | - Karen Takane
- Division of Endocrinology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, PA 15213, U.S.A
| | - Jean-Jacques Helwig
- Section of Renovascular Pharmacology and Physiology, INSERM E0015-ULP, University Louis Pasteur School of Medicine, Strasbourg, France
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Wysolmerski JJ, Stewart AF. The physiology of parathyroid hormone-related protein: an emerging role as a developmental factor. Annu Rev Physiol 1998; 60:431-60. [PMID: 9558472 DOI: 10.1146/annurev.physiol.60.1.431] [Citation(s) in RCA: 206] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Parathyroid hormone-related protein (PTHrP) is the agent responsible for humoral hypercalcemia of malignancy. Its pathogenic role in this syndrome is well established and attention has focused in recent years on the elucidation of the roles played by PTHrP in normal developmental and adult physiology. This review focuses on studies of the past two years: (a) elucidation of the posttranslational processing pattern of PTHrP, the mechanisms of action of the various secretory forms of PTHrP, the role of PTHrP as an intracrine regulator of cell growth and cell death; (b) the emergence of PTHrP as a critical developmental factor in the mammary gland, epidermis, and the skeleton; and (c) the advances in understanding of the roles of PTHrP in the regulation of pancreatic islet mass, vascular smooth muscle tone and proliferation, and materno-fetal calcium transfer across the placenta.
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Affiliation(s)
- J J Wysolmerski
- Division of Endocrinology, Yale University School of Medicine, New Haven, Connecticut 06520, USA
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