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Sandovici I, Knee O, Lopez-Tello J, Shreeve N, Fowden AL, Sferruzzi-Perri AN, Constância M. A genetically small fetus impairs placental adaptations near term. Dis Model Mech 2024; 17:dmm050719. [PMID: 39207227 PMCID: PMC11381921 DOI: 10.1242/dmm.050719] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Accepted: 07/18/2024] [Indexed: 09/04/2024] Open
Abstract
The placenta is a gatekeeper between the mother and fetus, adapting its structure and functions to support optimal fetal growth. Studies exploring adaptations of placentae that support the development of genetically small fetuses are lacking. Here, using a mouse model of impaired fetal growth, achieved by deleting insulin-like growth factor 2 (Igf2) in the epiblast, we assessed placental nutrient transfer and umbilical artery (UA) blood flow during late gestation. At embryonic day (E) 15.5, we observed a decline in the trans-placental flux of glucose and system A amino acids (by using 3H-MeG and 14C-MeAIB), proportionate to the diminished fetal size, whereas UA blood flow was normal. However, at E18.5, the trans-placental flux of both tracers was disproportionately decreased and accompanied by blunted UA blood flow. Feto-placental growth and nutrient transfer were more impaired in female conceptuses. Thus, reducing the fetal genetic demand for growth impairs the adaptations in placental blood flow and nutrient transport that normally support the fast fetal growth during late gestation. These findings have important implications for our understanding of the pathophysiology of pregnancies afflicted by fetal growth restriction.
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Affiliation(s)
- Ionel Sandovici
- Department of Obstetrics and Gynaecology and National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge CB2 0SW, UK
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
| | - Olatejumoye Knee
- Department of Obstetrics and Gynaecology and National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge CB2 0SW, UK
| | - Jorge Lopez-Tello
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
- Department of Physiology, Faculty of Medicine, Universidad Autónoma de Madrid, Madrid 28029, Spain
| | - Norman Shreeve
- Department of Obstetrics and Gynaecology and National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge CB2 0SW, UK
| | - Abigail L Fowden
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
| | - Amanda N Sferruzzi-Perri
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
| | - Miguel Constância
- Department of Obstetrics and Gynaecology and National Institute for Health Research Cambridge Biomedical Research Centre, Cambridge CB2 0SW, UK
- Metabolic Research Laboratories and MRC Metabolic Diseases Unit, Wellcome Trust-MRC Institute of Metabolic Science, University of Cambridge, Cambridge CB2 0QQ, UK
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
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2
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Shimada H, Powell TL, Jansson T. Regulation of placental amino acid transport in health and disease. Acta Physiol (Oxf) 2024; 240:e14157. [PMID: 38711335 PMCID: PMC11162343 DOI: 10.1111/apha.14157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 04/19/2024] [Accepted: 04/23/2024] [Indexed: 05/08/2024]
Abstract
Abnormal fetal growth, i.e., intrauterine growth restriction (IUGR) or fetal growth restriction (FGR) and fetal overgrowth, is associated with increased perinatal morbidity and mortality and is strongly linked to the development of metabolic and cardiovascular disease in childhood and later in life. Emerging evidence suggests that changes in placental amino acid transport may contribute to abnormal fetal growth. This review is focused on amino acid transport in the human placenta, however, relevant animal models will be discussed to add mechanistic insights. At least 25 distinct amino acid transporters with different characteristics and substrate preferences have been identified in the human placenta. Of these, System A, transporting neutral nonessential amino acids, and System L, mediating the transport of essential amino acids, have been studied in some detail. Importantly, decreased placental Systems A and L transporter activity is strongly associated with IUGR and increased placental activity of these two amino acid transporters has been linked to fetal overgrowth in human pregnancy. An array of factors in the maternal circulation, including insulin, IGF-1, and adiponectin, and placental signaling pathways such as mTOR, have been identified as key regulators of placental Systems A and L. Studies using trophoblast-specific gene targeting in mice have provided compelling evidence that changes in placental Systems A and L are mechanistically linked to altered fetal growth. It is possible that targeting specific placental amino acid transporters or their upstream regulators represents a novel intervention to alleviate the short- and long-term consequences of abnormal fetal growth in the future.
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Affiliation(s)
- Hiroshi Shimada
- Department of Obstetrics and Gynecology University of Colorado, Anschutz Medical Campus, Aurora, CO, US
- Departments of Obstetrics & Gynecology, Sapporo Medical University, Sapporo, Japan
| | - Theresa L Powell
- Department of Obstetrics and Gynecology University of Colorado, Anschutz Medical Campus, Aurora, CO, US
- Department of Pediatrics, University of Colorado, Anschutz Medical Campus, Aurora, CO, US
| | - Thomas Jansson
- Department of Obstetrics and Gynecology University of Colorado, Anschutz Medical Campus, Aurora, CO, US
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3
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Portillo R, Abad C, Synova T, Kastner P, Heblik D, Kucera R, Karahoda R, Staud F. Cannabidiol disrupts tryptophan metabolism in the human term placenta. Toxicology 2024; 505:153813. [PMID: 38663822 DOI: 10.1016/j.tox.2024.153813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Revised: 04/08/2024] [Accepted: 04/22/2024] [Indexed: 04/30/2024]
Abstract
The increasing use of cannabis during pregnancy raises concerns about its impact on fetal development. While cannabidiol (CBD) shows therapeutic promise, its effects during pregnancy remain uncertain. We investigated CBD's influence on tryptophan (TRP) metabolism in the human placenta. TRP is an essential amino acid that is metabolized via the serotonin and kynurenine (KYN) pathways, which are critical for fetal neurodevelopment. We used human term villous placental explants, an advanced ex vivo model, to study CBD's impact on key TRP metabolic enzymes. In addition, vesicles isolated from the microvillous membrane (MVM) of the human placenta were used to assess CBD's effect on placental serotonin uptake. Explants were exposed to CBD at therapeutic (0.1, 1, 2.5 μg/ml) and non-therapeutic (20 and 40 μg/ml) concentrations to determine its effects on the gene and protein expression of key enzymes in TRP metabolism and metabolite release. CBD upregulated TRP hydroxylase (TPH) and downregulated monoamine oxidase (MAO-A), resulting in reduced levels of 5-hydroxyindoleacetic acid (HIAA). It also downregulated serotonin transporter expression and inhibited serotonin transport across the MVM by up to 60% while simultaneously enhancing TRP metabolism via the kynurenine pathway by upregulating indoleamine-pyrrole 2,3-dioxygenase (IDO-1). Among kynurenine pathway enzymes, kynurenine 3 monooxygenase (KMO) was upregulated while kynurenine aminotransferase 1 (KAT-1) was downregulated; the former is associated with neurotoxic metabolite production, while the latter is linked to reduced neuroprotective metabolite levels. Overall, these results indicate that CBD modulates TRP catabolism in the human placenta, potentially disrupting the tightly regulated homeostasis of the serotonin and KYN pathways.
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Affiliation(s)
- Ramon Portillo
- Department of Pharmacology and Toxicology, Charles University, Faculty of Pharmacy in Hradec Kralove, Czech Republic
| | - Cilia Abad
- Department of Pharmacology and Toxicology, Charles University, Faculty of Pharmacy in Hradec Kralove, Czech Republic
| | - Tetiana Synova
- Department of Pharmacology and Toxicology, Charles University, Faculty of Pharmacy in Hradec Kralove, Czech Republic
| | - Petr Kastner
- Department of Pharmaceutical Chemistry and Pharmaceutical Analysis, Charles University, Faculty of Pharmacy in Hradec Kralove, Czech Republic
| | - Daniel Heblik
- Department of Pharmaceutical Chemistry and Pharmaceutical Analysis, Charles University, Faculty of Pharmacy in Hradec Kralove, Czech Republic
| | - Radim Kucera
- Department of Pharmaceutical Chemistry and Pharmaceutical Analysis, Charles University, Faculty of Pharmacy in Hradec Kralove, Czech Republic
| | - Rona Karahoda
- Department of Pharmacology and Toxicology, Charles University, Faculty of Pharmacy in Hradec Kralove, Czech Republic
| | - Frantisek Staud
- Department of Pharmacology and Toxicology, Charles University, Faculty of Pharmacy in Hradec Kralove, Czech Republic.
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4
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Brown ER, Giussani DA. Cause of fetal growth restriction during high-altitude pregnancy. iScience 2024; 27:109702. [PMID: 38694168 PMCID: PMC11061758 DOI: 10.1016/j.isci.2024.109702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 02/23/2024] [Accepted: 04/05/2024] [Indexed: 05/04/2024] Open
Abstract
High-altitude pregnancy increases the incidence of fetal growth restriction and reduces birth weight. This poses a significant clinical challenge as both are linked to adverse health outcomes, including raised infant mortality and the development of the metabolic syndrome in later life. While this reduction in birth weight is mostly understood to be driven by the hypobaric hypoxia of high altitude, the causative mechanism is unclear. Moreover, it is now recognized that highland ancestry confers protection against this reduction in birth weight. Here, we analyze the evidence that pregnancy at high altitude reduces birth weight and that highland ancestry confers protection, discussing mechanisms contributing to both effects.
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Affiliation(s)
- Emily R. Brown
- Department of Physiology, Development & Neuroscience, University of Cambridge, Cambridge, UK
| | - Dino A. Giussani
- Department of Physiology, Development & Neuroscience, University of Cambridge, Cambridge, UK
- Centre for Trophoblast Research, University of Cambridge, Cambridge, UK
- Cambridge Strategic Research Initiative in Reproduction
- Cambridge Cardiovascular Centre for Research Excellence
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5
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White MR, Yates DT. Dousing the flame: reviewing the mechanisms of inflammatory programming during stress-induced intrauterine growth restriction and the potential for ω-3 polyunsaturated fatty acid intervention. Front Physiol 2023; 14:1250134. [PMID: 37727657 PMCID: PMC10505810 DOI: 10.3389/fphys.2023.1250134] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 08/14/2023] [Indexed: 09/21/2023] Open
Abstract
Intrauterine growth restriction (IUGR) arises when maternal stressors coincide with peak placental development, leading to placental insufficiency. When the expanding nutrient demands of the growing fetus subsequently exceed the capacity of the stunted placenta, fetal hypoxemia and hypoglycemia result. Poor fetal nutrient status stimulates greater release of inflammatory cytokines and catecholamines, which in turn lead to thrifty growth and metabolic programming that benefits fetal survival but is maladaptive after birth. Specifically, some IUGR fetal tissues develop enriched expression of inflammatory cytokine receptors and other signaling cascade components, which increases inflammatory sensitivity even when circulating inflammatory cytokines are no longer elevated after birth. Recent evidence indicates that greater inflammatory tone contributes to deficits in skeletal muscle growth and metabolism that are characteristic of IUGR offspring. These deficits underlie the metabolic dysfunction that markedly increases risk for metabolic diseases in IUGR-born individuals. The same programming mechanisms yield reduced metabolic efficiency, poor body composition, and inferior carcass quality in IUGR-born livestock. The ω-3 polyunsaturated fatty acids (PUFA) are diet-derived nutraceuticals with anti-inflammatory effects that have been used to improve conditions of chronic systemic inflammation, including intrauterine stress. In this review, we highlight the role of sustained systemic inflammation in the development of IUGR pathologies. We then discuss the potential for ω-3 PUFA supplementation to improve inflammation-mediated growth and metabolic deficits in IUGR offspring, along with potential barriers that must be considered when developing a supplementation strategy.
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Affiliation(s)
| | - Dustin T. Yates
- Stress Physiology Laboratory, Department of Animal Science, University of Nebraska-Lincoln, Lincoln, NE, United States
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6
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Yong HEJ, Maksym K, Yusoff MAB, Salazar-Petres E, Nazarenko T, Zaikin A, David AL, Hillman SL, Sferruzzi-Perri AN. Integrated Placental Modelling of Histology with Gene Expression to Identify Functional Impact on Fetal Growth. Cells 2023; 12:1093. [PMID: 37048166 PMCID: PMC10093760 DOI: 10.3390/cells12071093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/31/2023] [Accepted: 04/03/2023] [Indexed: 04/14/2023] Open
Abstract
Fetal growth restriction (FGR) is a leading cause of perinatal morbidity and mortality. Altered placental formation and functional capacity are major contributors to FGR pathogenesis. Relating placental structure to function across the placenta in healthy and FGR pregnancies remains largely unexplored but could improve understanding of placental diseases. We investigated integration of these parameters spatially in the term human placenta using predictive modelling. Systematic sampling was able to overcome heterogeneity in placental morphological and molecular features. Defects in villous development, elevated fibrosis, and reduced expression of growth and functional marker genes (IGF2, VEGA, SLC38A1, and SLC2A3) were seen in age-matched term FGR versus healthy control placentas. Characteristic histopathological changes with specific accompanying molecular signatures could be integrated through computational modelling to predict if the placenta came from a healthy or FGR pregnancy. Our findings yield new insights into the spatial relationship between placental structure and function and the etiology of FGR.
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Affiliation(s)
- Hannah Ee Juen Yong
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience University of Cambridge, Cambridge CB2 3EG, UK
- Singapore Institute for Clinical Sciences (SICS), Agency for Science, Technology and Research (A*STAR), 30 Medical Drive, Brenner Centre for Molecular Medicine, Singapore 117609, Singapore
| | - Katarzyna Maksym
- Elizabeth Gareth Anderson Institute for Women’s Health, University College London, 84-86 Chenies Mews, London WC1E 6HU, UK
- Fetal Medicine Unit Elizabeth Gareth Anderson Wing, University College Hospitals NHS Trust, 25 Grafton Way, London WC1E 6DB, UK
| | - Muhammad Ashraf Bin Yusoff
- Elizabeth Gareth Anderson Institute for Women’s Health, University College London, 84-86 Chenies Mews, London WC1E 6HU, UK
| | - Esteban Salazar-Petres
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience University of Cambridge, Cambridge CB2 3EG, UK
| | - Tatiana Nazarenko
- Elizabeth Gareth Anderson Institute for Women’s Health, University College London, 84-86 Chenies Mews, London WC1E 6HU, UK
- Department of Mathematics, University College London, London WC1E 6AE, UK
| | - Alexey Zaikin
- Elizabeth Gareth Anderson Institute for Women’s Health, University College London, 84-86 Chenies Mews, London WC1E 6HU, UK
- Department of Mathematics, University College London, London WC1E 6AE, UK
| | - Anna L. David
- Elizabeth Gareth Anderson Institute for Women’s Health, University College London, 84-86 Chenies Mews, London WC1E 6HU, UK
- Fetal Medicine Unit Elizabeth Gareth Anderson Wing, University College Hospitals NHS Trust, 25 Grafton Way, London WC1E 6DB, UK
- National Institute for Health Research University College London Hospitals Biomedical Research Centre, 149 Tottenham Court Road, London W1T 7DN, UK
| | - Sara L. Hillman
- Elizabeth Gareth Anderson Institute for Women’s Health, University College London, 84-86 Chenies Mews, London WC1E 6HU, UK
- Fetal Medicine Unit Elizabeth Gareth Anderson Wing, University College Hospitals NHS Trust, 25 Grafton Way, London WC1E 6DB, UK
| | - Amanda N. Sferruzzi-Perri
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience University of Cambridge, Cambridge CB2 3EG, UK
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7
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Sferruzzi‐Perri AN, Lopez‐Tello J, Salazar‐Petres E. Placental adaptations supporting fetal growth during normal and adverse gestational environments. Exp Physiol 2023; 108:371-397. [PMID: 36484327 PMCID: PMC10103877 DOI: 10.1113/ep090442] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 11/15/2022] [Indexed: 12/13/2022]
Abstract
NEW FINDINGS What is the topic of this review? How the placenta, which transports nutrients and oxygen to the fetus, may alter its support of fetal growth developmentally and with adverse gestational conditions. What advances does it highlight? Placental formation and function alter with the needs of the fetus for substrates for growth during normal gestation and when there is enhanced competition for substrates in species with multiple gestations or adverse gestational environments, and this is mediated by imprinted genes, signalling pathways, mitochondria and fetal sexomes. ABSTRACT The placenta is vital for mammalian development and a key determinant of life-long health. It is the interface between the mother and fetus and is responsible for transporting the nutrients and oxygen a fetus needs to develop and grow. Alterations in placental formation and function, therefore, have consequences for fetal growth and birthweight, which in turn determine perinatal survival and risk of non-communicable diseases for the offspring in later postnatal life. However, the placenta is not a static organ. As this review summarizes, research from multiple species has demonstrated that placental formation and function alter developmentally to the needs of the fetus for substrates for growth during normal gestation, as well as when there is greater competition for substrates in polytocous species and monotocous species with multiple gestations. The placenta also adapts in response to the gestational environment, integrating information about the ability of the mother to provide nutrients and oxygen with the needs of the fetus in that prevailing environment. In particular, placental structure (e.g. vascularity, surface area, blood flow, diffusion distance) and transport capacity (e.g. nutrient transporter levels and activity) respond to suboptimal gestational environments, namely malnutrition, obesity, hypoxia and maternal ageing. Mechanisms mediating developmentally and environmentally induced homeostatic responses of the placenta that help support normal fetal growth include imprinted genes, signalling pathways, subcellular constituents and fetal sexomes. Identification of these placental strategies may inform the development of therapies for complicated human pregnancies and advance understanding of the pathways underlying poor fetal outcomes and their consequences for health and disease risk.
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Affiliation(s)
- Amanda Nancy Sferruzzi‐Perri
- Centre for Trophoblast Research, Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUK
| | - Jorge Lopez‐Tello
- Centre for Trophoblast Research, Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUK
| | - Esteban Salazar‐Petres
- Centre for Trophoblast Research, Department of Physiology, Development and NeuroscienceUniversity of CambridgeCambridgeUK
- Facultad de CienciasDepartamento de Ciencias Básicas, Universidad Santo TomásValdiviaChile
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SLC38A4 Amino Acid Transporter Expression Is Significantly Lower in Early Preterm Intrauterine Growth Restriction Complicated Placentas. Int J Mol Sci 2022; 24:ijms24010403. [PMID: 36613847 PMCID: PMC9820794 DOI: 10.3390/ijms24010403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/14/2022] [Accepted: 12/17/2022] [Indexed: 12/28/2022] Open
Abstract
Intrauterine growth restriction (IUGR), predominantly caused by placental insufficiency, affects partitioning of nutrients to the fetus. The system A sodium-coupled transporters (SNAT or SLC38), of types A1, A2, and A4, control non-essential amino acid uptake and supply. Here, we aimed to investigate the expression of these transporters across different placental disease cohorts and cells. To determine disease impact, transporter expressions at the gene (qPCR) and protein (western blots) level were assessed in gestationally matched placental tissues. Early (<34 weeks), and late (34−36 weeks) onset IUGR cases with/out preeclampsia were compared to preterm controls. We also investigated level of transporter expression in primary trophoblasts under glucose deprivation (n = 6) and hypoxia conditions (n = 7). SLC38A4 protein was significantly downregulated in early preterm pregnancies complicated with IUGR with/out preeclampsia. There were no differences in late preterm IUGR cohorts. Furthermore, we demonstrate for the first time in primary trophoblast cells, that gene expression of the transporters was sensitive to and induced by glucose starvation. SLC38A4 mRNA expression was also significantly upregulated in response to hypoxia. Thus, SLC38A4 expression was persistently low in early preterm IUGR pregnancies, regardless of disease aetiology. This suggests that gestational age at delivery, and consequently IUGR severity, may influence loss of its expression.
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9
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Cindrova-Davies T, Sferruzzi-Perri AN. Human placental development and function. Semin Cell Dev Biol 2022; 131:66-77. [PMID: 35393235 DOI: 10.1016/j.semcdb.2022.03.039] [Citation(s) in RCA: 67] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/30/2022] [Accepted: 03/30/2022] [Indexed: 12/14/2022]
Abstract
The placenta is a transient fetal organ that plays a critical role in the health and wellbeing of both the fetus and its mother. Functionally, the placenta sustains the growth of the fetus as it facilitates delivery of oxygen and nutrients and removal of waste products. Not surprisingly, defective early placental development is the primary cause of common disorders of pregnancy, including recurrent miscarriage, fetal growth restriction, pre-eclampsia and stillbirth. Adverse pregnancy conditions will also affect the life-long health of the fetus via developmental programming[1]. Despite its critical importance in reproductive success and life-long health, our understanding of placental development is not extensive, largely due to ethical limitations to studying early or chronological placental development, lack of long-term in vitro models, or comparative animal models. In this review, we examine current knowledge of early human placental development, discuss the critical role of the maternal endometrium and of the fetal-maternal dialogue in pregnancy success, and we explore the latest models of trophoblast and endometrial stem cells. In addition, we discuss the role of oxygen in placental formation and function, how nutrient delivery is mediated during the periods of histotrophic nutrition (uptake of uterine secretions) and haemotrophic nutrition (exchange between the maternal and fetal circulations), and how placental endocrine function facilitates fetal growth and development.
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Affiliation(s)
- Tereza Cindrova-Davies
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK
| | - Amanda N Sferruzzi-Perri
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3EG, UK.
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10
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Garcia-Santillan JA, Lazo-de-la-Vega-Monroy ML, Rodriguez-Saldaña GC, Solis-Barbosa MA, Corona-Figueroa MA, Gonzalez-Dominguez MI, Gomez-Zapata HM, Malacara JM, Barbosa-Sabanero G. Placental Nutrient Transporters and Maternal Fatty Acids in SGA, AGA, and LGA Newborns From Mothers With and Without Obesity. Front Cell Dev Biol 2022; 10:822527. [PMID: 35399516 PMCID: PMC8990844 DOI: 10.3389/fcell.2022.822527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Accepted: 02/25/2022] [Indexed: 12/01/2022] Open
Abstract
Adverse environmental factors in early life result in fetal metabolic programming and increased risk of adult diseases. Birth weight is an indirect marker of the intrauterine environment, modulated by nutrient availability and placental transport capacity. However, studies of placental transporters in idiopathic birth weight alterations and in maternal obesity in relation to neonatal metabolic outcomes are scarce. We aimed to analyze the placental nutrient transporter protein expression in small (SGA, n = 14), adequate (AGA, n = 18), and large (LGA n = 10) gestational age term for newborns from healthy or obese mothers (LGA-OB, n = 9) and their association with maternal fatty acids, metabolic status, placental triglycerides, and neonatal outcomes. The transporter expression was determined by Western blot. The fatty acid profile was evaluated by gas chromatography, and placental triglycerides were quantified by an enzymatic colorimetric method. GLUT1 was higher in LGA and lower in SGA and positively correlated with maternal HbA1c and placental weight (PW). SNAT2 was lower in SGA, while SNAT4 was lower in LGA-OB. FATP1 was lower in SGA and higher in LGA. SNAT4 correlated negatively and FATP1 correlated positively with the PW and birth anthropometry (BA). Placental triglycerides were higher in LGA and LGA-OB and correlated with pregestational BMI, maternal insulin, and BA. Maternal docosahexaenoic acid (DHA) was higher in SGA, specifically in male placentas, correlating negatively with maternal triglycerides, PW, cord glucose, and abdominal perimeter. Palmitic acid (PA) correlated positively with FATP4 and cord insulin, linoleic acid correlated negatively with PA and maternal cholesterol, and arachidonic acid correlated inversely with maternal TG and directly with FATP4. Our study highlights the importance of placental programming in birth weight both in healthy and obese pregnancies.
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Affiliation(s)
| | | | | | - Miguel-Angel Solis-Barbosa
- Medical Sciences Department, Health Sciences Division, University of Guanajuato, Campus Leon, Guanajuato, Mexico
| | | | | | | | - Juan-Manuel Malacara
- Medical Sciences Department, Health Sciences Division, University of Guanajuato, Campus Leon, Guanajuato, Mexico
| | - Gloria Barbosa-Sabanero
- Medical Sciences Department, Health Sciences Division, University of Guanajuato, Campus Leon, Guanajuato, Mexico
- *Correspondence: Gloria Barbosa-Sabanero,
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11
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Jia X, Cao Y, Ye L, Liu X, Huang Y, Yuan X, Lu C, Xu J, Zhu H. Vitamin D stimulates placental L-type amino acid transporter 1 (LAT1) in preeclampsia. Sci Rep 2022; 12:4651. [PMID: 35301401 PMCID: PMC8931068 DOI: 10.1038/s41598-022-08641-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Accepted: 03/09/2022] [Indexed: 11/09/2022] Open
Abstract
Vitamin D insufficiency/deficiency has been linked to an increased risk of preeclampsia. Impaired placental amino acid transport is suggested to contribute to abnormal fetal intrauterine growth in pregnancies complicated by preeclampsia. However, if vitamin D-regulated amino acid transporter is involved in the pathophysiologic mechanism of preeclampsia has not been clarified yet. The aberrant expression of key isoform of L-type amino acid transporter LAT1 was determined by western blot and immunohistochemistry in the placenta from normotensive and preeclamptic pregnancies. The role for vitamin D on placental LAT1 expression was investigated through the exposure of HTR-8/SVneo human trophoblast cells to the biologically active 1,25(OH)2D3 and the oxidative stress-inducer cobalt chloride (CoCl2). Our results showed that placental LAT1 expression was reduced in women with preeclampsia compared to normotensive pregnancies, which was associated with decreased expression of vitamin D receptor (VDR). 1,25(OH)2D3 significantly upregulated LAT1 expression in placental trophoblasts, and also prevented the decrease of mTOR activity under CoCl2-induced oxidative stress. siRNA targeting VDR significantly attenuated 1,25(OH)2D3-stimulated LAT1 expression and mTOR signaling activity. Moreover, treatment of rapamycin specifically inhibited the activity of mTOR signaling and resulted in decrease of LAT1 expression. In conclusion, LAT1 expression was downregulated in the placenta from women with preeclampsia. 1,25(OH)2D3/VDR could stimulate LAT1 expression, which was likely mediated by mTOR signaling in placental trophoblasts. Regulation on placental amino acid transport may be one of the mechanisms by which vitamin D affects fetal growth in preeclampsia.
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Affiliation(s)
- Xiaotong Jia
- Department of Physiology, Harbin Medical University, Harbin, 150081, China
| | - Yang Cao
- Department of Physiology, Harbin Medical University, Harbin, 150081, China
| | - Lingyu Ye
- Department of Physiology, Harbin Medical University, Harbin, 150081, China
| | - Xueqing Liu
- Department of Physiology, Harbin Medical University, Harbin, 150081, China
| | - Yujia Huang
- Department of Physiology, Harbin Medical University, Harbin, 150081, China
| | - Xiaolei Yuan
- Department of Obstetrics and Gynecology, Second Affiliated Hospital of Harbin Medical University, Harbin, 150081, China
| | - Chunmei Lu
- Department of Physiology, Harbin Medical University, Harbin, 150081, China
| | - Jie Xu
- Department of Physiology, Harbin Medical University, Harbin, 150081, China.
| | - Hui Zhu
- Department of Physiology, Harbin Medical University, Harbin, 150081, China.
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12
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Reduction of In Vivo Placental Amino Acid Transport Precedes the Development of Intrauterine Growth Restriction in the Non-Human Primate. Nutrients 2021; 13:nu13082892. [PMID: 34445051 PMCID: PMC8401823 DOI: 10.3390/nu13082892] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 08/12/2021] [Accepted: 08/19/2021] [Indexed: 11/17/2022] Open
Abstract
Intrauterine growth restriction (IUGR) is associated with reduced placental amino acid transport (AAT). However, it remains to be established if changes in AAT contribute to restricted fetal growth. We hypothesized that reduced in vivo placental AAT precedes the development of IUGR in baboons with maternal nutrient restriction (MNR). Baboons were fed either a control (ad libitum) or MNR diet (70% of control diet) from gestational day (GD) 30. At GD 140, in vivo transplacental AA transport was measured by infusing nine (13)C- or (2)H-labeled essential amino acids (EAAs) as a bolus into the maternal circulation at cesarean section. A fetal vein-to-maternal artery mole percent excess ratio for each EAA was measured. Microvillous plasma membrane (MVM) system A and system L transport activity were determined. Fetal and placental weights were not significantly different between MNR and control. In vivo, the fetal vein-to-maternal artery mole percent excess ratio was significantly decreased for tryptophan in MNR. MVM system A and system L activity was markedly reduced in MNR. Reduction of in vivo placental amino acid transport precedes fetal growth restriction in the non-human primate, suggesting that reduced placental amino acid transfer may contribute to IUGR.
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Abstract
Almost 2 billion adults in the world are overweight, and more than half of them are classified as obese, while nearly one-third of children globally experience poor growth and development. Given the vast amount of knowledge that has been gleaned from decades of research on growth and development, a number of questions remain as to why the world is now in the midst of a global epidemic of obesity accompanied by the "double burden of malnutrition," where overweight coexists with underweight and micronutrient deficiencies. This challenge to the human condition can be attributed to nutritional and environmental exposures during pregnancy that may program a fetus to have a higher risk of chronic diseases in adulthood. To explore this concept, frequently called the developmental origins of health and disease (DOHaD), this review considers a host of factors and physiological mechanisms that drive a fetus or child toward a higher risk of obesity, fatty liver disease, hypertension, and/or type 2 diabetes (T2D). To that end, this review explores the epidemiology of DOHaD with discussions focused on adaptations to human energetics, placental development, dysmetabolism, and key environmental exposures that act to promote chronic diseases in adulthood. These areas are complementary and additive in understanding how providing the best conditions for optimal growth can create the best possible conditions for lifelong health. Moreover, understanding both physiological as well as epigenetic and molecular mechanisms for DOHaD is vital to most fully address the global issues of obesity and other chronic diseases.
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Affiliation(s)
- Daniel J Hoffman
- Department of Nutritional Sciences, Program in International Nutrition, and Center for Childhood Nutrition Research, New Jersey Institute for Food, Nutrition, and Health, Rutgers, the State University of New Jersey, New Brunswick, New Jersey
| | - Theresa L Powell
- Department of Pediatrics and Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Emily S Barrett
- Department of Biostatistics and Epidemiology, School of Public Health and Division of Exposure Science and Epidemiology, Rutgers Environmental and Occupational Health Sciences Institute, Rutgers, the State University of New Jersey, New Brunswick, New Jersey
| | - Daniel B Hardy
- Department of Biostatistics and Epidemiology, School of Public Health and Division of Exposure Science and Epidemiology, Rutgers Environmental and Occupational Health Sciences Institute, Rutgers, the State University of New Jersey, New Brunswick, New Jersey
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Interaction between Metformin, Folate and Vitamin B 12 and the Potential Impact on Fetal Growth and Long-Term Metabolic Health in Diabetic Pregnancies. Int J Mol Sci 2021; 22:ijms22115759. [PMID: 34071182 PMCID: PMC8198407 DOI: 10.3390/ijms22115759] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2021] [Revised: 05/24/2021] [Accepted: 05/25/2021] [Indexed: 12/15/2022] Open
Abstract
Metformin is the first-line treatment for many people with type 2 diabetes mellitus (T2DM) and gestational diabetes mellitus (GDM) to maintain glycaemic control. Recent evidence suggests metformin can cross the placenta during pregnancy, thereby exposing the fetus to high concentrations of metformin and potentially restricting placental and fetal growth. Offspring exposed to metformin during gestation are at increased risk of being born small for gestational age (SGA) and show signs of ‘catch up’ growth and obesity during childhood which increases their risk of future cardiometabolic diseases. The mechanisms by which metformin impacts on the fetal growth and long-term health of the offspring remain to be established. Metformin is associated with maternal vitamin B12 deficiency and antifolate like activity. Vitamin B12 and folate balance is vital for one carbon metabolism, which is essential for DNA methylation and purine/pyrimidine synthesis of nucleic acids. Folate:vitamin B12 imbalance induced by metformin may lead to genomic instability and aberrant gene expression, thus promoting fetal programming. Mitochondrial aerobic respiration may also be affected, thereby inhibiting placental and fetal growth, and suppressing mammalian target of rapamycin (mTOR) activity for cellular nutrient transport. Vitamin supplementation, before or during metformin treatment in pregnancy, could be a promising strategy to improve maternal vitamin B12 and folate levels and reduce the incidence of SGA births and childhood obesity. Heterogeneous diagnostic and screening criteria for GDM and the transient nature of nutrient biomarkers have led to inconsistencies in clinical study designs to investigate the effects of metformin on folate:vitamin B12 balance and child development. As rates of diabetes in pregnancy continue to escalate, more women are likely to be prescribed metformin; thus, it is of paramount importance to improve our understanding of metformin’s transgenerational effects to develop prophylactic strategies for the prevention of adverse fetal outcomes.
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Colson A, Sonveaux P, Debiève F, Sferruzzi-Perri AN. Adaptations of the human placenta to hypoxia: opportunities for interventions in fetal growth restriction. Hum Reprod Update 2020; 27:531-569. [PMID: 33377492 DOI: 10.1093/humupd/dmaa053] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 10/15/2020] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND The placenta is the functional interface between the mother and the fetus during pregnancy, and a critical determinant of fetal growth and life-long health. In the first trimester, it develops under a low-oxygen environment, which is essential for the conceptus who has little defense against reactive oxygen species produced during oxidative metabolism. However, failure of invasive trophoblasts to sufficiently remodel uterine arteries toward dilated vessels by the end of the first trimester can lead to reduced/intermittent blood flow, persistent hypoxia and oxidative stress in the placenta with consequences for fetal growth. Fetal growth restriction (FGR) is observed in ∼10% of pregnancies and is frequently seen in association with other pregnancy complications, such as preeclampsia (PE). FGR is one of the main challenges for obstetricians and pediatricians, as smaller fetuses have greater perinatal risks of morbidity and mortality and postnatal risks of neurodevelopmental and cardio-metabolic disorders. OBJECTIVE AND RATIONALE The aim of this review was to examine the importance of placental responses to changing oxygen environments during abnormal pregnancy in terms of cellular, molecular and functional changes in order to highlight new therapeutic pathways, and to pinpoint approaches aimed at enhancing oxygen supply and/or mitigating oxidative stress in the placenta as a mean of optimizing fetal growth. SEARCH METHODS An extensive online search of peer-reviewed articles using PubMed was performed with combinations of search terms including pregnancy, placenta, trophoblast, oxygen, hypoxia, high altitude, FGR and PE (last updated in May 2020). OUTCOMES Trophoblast differentiation and placental establishment are governed by oxygen availability/hypoxia in early pregnancy. The placental response to late gestational hypoxia includes changes in syncytialization, mitochondrial functions, endoplasmic reticulum stress, hormone production, nutrient handling and angiogenic factor secretion. The nature of these changes depends on the extent of hypoxia, with some responses appearing adaptive and others appearing detrimental to the placental support of fetal growth. Emerging approaches that aim to increase placental oxygen supply and/or reduce the impacts of excessive oxidative stress are promising for their potential to prevent/treat FGR. WIDER IMPLICATIONS There are many risks and challenges of intervening during pregnancy that must be considered. The establishment of human trophoblast stem cell lines and organoids will allow further mechanistic studies of the effects of hypoxia and may lead to advanced screening of drugs for use in pregnancies complicated by placental insufficiency/hypoxia. Since no treatments are currently available, a better understanding of placental adaptations to hypoxia would help to develop therapies or repurpose drugs to optimize placental function and fetal growth, with life-long benefits to human health.
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Affiliation(s)
- Arthur Colson
- Pole of Obstetrics, Institute of Experimental and Clinical Research (IREC), Université catholique de Louvain, Brussels, Belgium.,Pole of Pharmacology & Therapeutics, Institute of Experimental and Clinical Research (IREC), Université catholique de Louvain, Brussels, Belgium.,Department of Obstetrics, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Pierre Sonveaux
- Pole of Pharmacology & Therapeutics, Institute of Experimental and Clinical Research (IREC), Université catholique de Louvain, Brussels, Belgium
| | - Frédéric Debiève
- Pole of Obstetrics, Institute of Experimental and Clinical Research (IREC), Université catholique de Louvain, Brussels, Belgium.,Department of Obstetrics, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Amanda N Sferruzzi-Perri
- Department of Physiology, Development and Neuroscience, Centre for Trophoblast Research, University of Cambridge, Cambridge, UK
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16
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Coats LE, Bamrick-Fernandez DR, Ariatti AM, Bakrania BA, Rawls AZ, Ojeda NB, Alexander BT. Stimulation of soluble guanylate cyclase diminishes intrauterine growth restriction in a rat model of placental ischemia. Am J Physiol Regul Integr Comp Physiol 2020; 320:R149-R161. [PMID: 33175587 DOI: 10.1152/ajpregu.00234.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Placental ischemia in preeclampsia (PE) results in hypertension and intrauterine growth restriction (IUGR). Stimulation of soluble guanylate cyclase (sGC) reduces blood pressure in the clinically relevant reduced uterine perfusion pressure (RUPP) rat model of PE, implicating involvement in RUPP-induced hypertension. However, the contribution of sGC in the development of IUGR in PE is not known. Thus, this study demonstrated the efficacy of Riociguat, an sGC stimulator, in IUGR reversion in the RUPP rat model of PE, and tested the hypothesis that improvement in fetal weight occurs in association with improvement in placental perfusion, placental morphology, and placental nutrient transport protein expression. Sham or RUPP surgery was performed at gestational day 14 (G14) with administration of vehicle (Sham or RUPP) or the sGC stimulator (Riociguat, 10 mg/kg/day sc; sGC-treated) until G20. Fetal weight was reduced (P = 0.004) at G20 in RUPP but not in sGC-treated RUPP compared with Sham, the control group. At G20, uterine artery resistance index (UARI) was increased (P = 0.010) in RUPP, indicating poor placental perfusion; proportional junctional zone surface area was elevated (P = 0.035), indicating impaired placental development. These effects were ameliorated in sGC-treated RUPP. Placental protein expression of nutrient transporter heart fatty acid-binding protein (hFABP) was increased (P = 0.008) in RUPP but not in sGC-treated RUPP, suggesting a compensatory mechanism to maintain normal neurodevelopment. Yet, UARI (P < 0.001), proportional junctional zone surface area (P = 0.013), and placental hFABP protein expression (P = 0.008) were increased in sGC-treated Sham, suggesting a potential adverse effect of Riociguat. Collectively, these results suggest sGC contributes to IUGR in PE.
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Affiliation(s)
- Laura E Coats
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
| | | | - Allison M Ariatti
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
| | - Bhavisha A Bakrania
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
| | - Adam Z Rawls
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
| | - Norma B Ojeda
- Department of Pediatrics, University of Mississippi Medical Center, Jackson, Mississippi
| | - Barbara T Alexander
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, Mississippi
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17
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McIntyre KR, Vincent KMM, Hayward CE, Li X, Sibley CP, Desforges M, Greenwood SL, Dilworth MR. Human placental uptake of glutamine and glutamate is reduced in fetal growth restriction. Sci Rep 2020; 10:16197. [PMID: 33004923 PMCID: PMC7530652 DOI: 10.1038/s41598-020-72930-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Accepted: 09/02/2020] [Indexed: 12/21/2022] Open
Abstract
Fetal growth restriction (FGR) is a significant risk factor for stillbirth, neonatal complications and adulthood morbidity. Compared with those of appropriate weight for gestational age (AGA), FGR babies have smaller placentas with reduced activity of amino acid transporter systems A and L, thought to contribute to poor fetal growth. The amino acids glutamine and glutamate are essential for normal placental function and fetal development; whether transport of these is altered in FGR is unknown. We hypothesised that FGR is associated with reduced placental glutamine and glutamate transporter activity and expression, and propose the mammalian target of rapamycin (mTOR) signaling pathway as a candidate mechanism. FGR infants [individualised birth weight ratio (IBR) < 5th centile] had lighter placentas, reduced initial rate uptake of 14C-glutamine and 14C-glutamate (per mg placental protein) but higher expression of key transporter proteins (glutamine: LAT1, LAT2, SNAT5, glutamate: EAAT1) versus AGA [IBR 20th-80th]. In further experiments, in vitro exposure to rapamycin inhibited placental glutamine and glutamate uptake (24 h, uncomplicated pregnancies) indicating a role of mTOR in regulating placental transport of these amino acids. These data support our hypothesis and suggest that abnormal glutamine and glutamate transporter activity is part of the spectrum of placental dysfunction in FGR.
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Affiliation(s)
- Kirsty R McIntyre
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK. .,Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK. .,School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, University of Glasgow, Wolfson Medical School Building, University Avenue, Glasgow, G12 8QQ, UK.
| | - Kirsty M M Vincent
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.,Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Christina E Hayward
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.,Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Xiaojia Li
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.,Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Colin P Sibley
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.,Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Michelle Desforges
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.,Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Susan L Greenwood
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.,Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
| | - Mark R Dilworth
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK.,Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, UK
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18
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Bourdon A, Hannigsberg J, Misbert E, Tran TN, Amarger V, Ferchaud-Roucher V, Winer N, Darmaun D. Maternal supplementation with citrulline or arginine during gestation impacts fetal amino acid availability in a model of intrauterine growth restriction (IUGR). Clin Nutr 2020; 39:3736-3743. [PMID: 32336525 DOI: 10.1016/j.clnu.2020.03.036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 03/09/2020] [Accepted: 03/30/2020] [Indexed: 01/16/2023]
Abstract
BACKGROUND Supplementing maternal diet with citrulline or arginine during gestation was shown to enhance fetal growth in a model of IUGR induced by maternal dietary protein restriction in the rat. OBJECTIVE The aims of this study were to determine in the same model whether maternal supplementation with citrulline or arginine would increase 1) citrulline and arginine concentration in fetal circulation; 2) the expression of placental amino acid transporters, and 3) the fetal availability of essential amino acids. METHODS Pregnant rats (n = 8 per group) were fed either an isocaloric control (20% protein, NP) or a low protein (LP, 4% protein) diet, either alone or supplemented with 2 g/kg/d of l-citrulline (LP + CIT) or isonitrogenous Arginine (LP + ARG) in drinking water throughout gestation. Fetuses were extracted by C-section on the 21st day of gestation. The gene expression of system A (Slc38a1, Slc38a2, and Slc38a4) and L (Slc7a2, Slc7a5, Slc7a8) amino acid transporters was measured in placenta and amino acid concentrations determined in maternal and fetal plasma. RESULTS Maternal LP diet decreased fetal (4.01 ± 0.03 vs. 5.45 ± 0.07 g, p < 0.0001) and placental weight (0.617 ± 0.01 vs. 0.392 ± 0.04 g, p < 0.001), by 26 and 36% respectively, compared with NP diet. Supplementation with either CIT or ARG increased fetal birth weight by ≈ 5 or 11%, respectively (4.21 ± 0.05 and 4.48 ± 0.05 g vs. 4.01 ± 0.03 g, p < 0.05). CIT supplementation produced a 5- and 2-fold increase in fetal plasma citrulline and arginine, respectively, whereas ARG supplementation only increased fetal arginine concentration. LP diet led to lower placental SNAT 4 mRNA, and higher LAT2 and SNAT1 expression, compared with NP. SNAT4, 4hFC, LAT2 mRNA were up-regulated in LP + CIT and LP + ARG group compared with the un-supplemented LP group. Higher level of LAT1 mRNA was also observed in the LP + CIT group than in the LP group (p < 0.01). SNAT2 expression was unchanged in response to CIT or ARG supplementation. Fetal amino acid concentrations were decreased by LP diet, and were not restored by CIT or ARG supplementation. CONCLUSIONS The current findings confirm supplementation with citrulline or arginine enhances fetal growth in a rat model of IUGR. They further suggest that: 1) citrulline and arginine administered orally to the pregnant mother may reach fetal circulation; 2) citrulline effectively raises fetal arginine availability; and 3) although it failed to increase the concentrations of essential amino acids in fetal plasma, citrulline or arginine supplementation upregulates the gene expression of several placental amino acid transporters.
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Affiliation(s)
- Aurélie Bourdon
- INRAE, UMR 1280, Physiology of Nutritional Adaptations, University of Nantes, IMAD, CRNH-Ouest, Nantes, France
| | - Jacob Hannigsberg
- INRAE, UMR 1280, Physiology of Nutritional Adaptations, University of Nantes, IMAD, CRNH-Ouest, Nantes, France
| | - Emilie Misbert
- INRAE, UMR 1280, Physiology of Nutritional Adaptations, University of Nantes, IMAD, CRNH-Ouest, Nantes, France; Department of Gynecology and Obstetrics, Centre Hospitalier Universitaire Hotel-Dieu, Nantes, France
| | - Thang Nhat Tran
- INRAE, UMR 1280, Physiology of Nutritional Adaptations, University of Nantes, IMAD, CRNH-Ouest, Nantes, France
| | - Valérie Amarger
- INRAE, UMR 1280, Physiology of Nutritional Adaptations, University of Nantes, IMAD, CRNH-Ouest, Nantes, France
| | - Véronique Ferchaud-Roucher
- INRAE, UMR 1280, Physiology of Nutritional Adaptations, University of Nantes, IMAD, CRNH-Ouest, Nantes, France
| | - Norbert Winer
- INRAE, UMR 1280, Physiology of Nutritional Adaptations, University of Nantes, IMAD, CRNH-Ouest, Nantes, France; Department of Gynecology and Obstetrics, Centre Hospitalier Universitaire Hotel-Dieu, Nantes, France
| | - Dominique Darmaun
- INRAE, UMR 1280, Physiology of Nutritional Adaptations, University of Nantes, IMAD, CRNH-Ouest, Nantes, France; Nutrition Support Team, IMAD, University Medical Center of Nantes, France.
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19
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Vaughan OR, Thompson F, Lorca RA, Julian CG, Powell TL, Moore LG, Jansson T. Effect of high altitude on human placental amino acid transport. J Appl Physiol (1985) 2019; 128:127-133. [PMID: 31804891 DOI: 10.1152/japplphysiol.00691.2019] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Women residing at high altitudes deliver infants of lower birth weight than at sea level. Birth weight correlates with placental system A-mediated amino acid transport capacity, and severe environmental hypoxia reduces system A activity in isolated trophoblast and the mouse placenta. However, the effect of high altitude on human placental amino acid transport remains unknown. We hypothesized that microvillous membrane (MVM) system A and system L amino acid transporter activity is lower in placentas of women living at high altitude compared with low-altitude controls. Placentas were collected at term from healthy pregnant women residing at high altitude (HA; >2,500 m; n = 14) or low altitude (LA; <1,700 m; n = 14) following planned, unlabored cesarean section. Birth weight, but not placenta weight, was 13% lower in HA pregnancies (2.88 ± 0.11 kg) compared with LA (3.30 ± 0.07 kg, P < 0.01). MVM erythropoietin receptor abundance, determined by immunoblot, was greater in HA than in LA placentas, consistent with lower placental oxygen levels at HA. However, there was no effect of altitude on MVM system A or L activity, determined by Na+-dependent [14C]methylaminoisobutyric acid uptake and [3H]leucine uptake, respectively. MVM abundance of glucose transporters (GLUTs) 1 and 4 and basal membrane GLUT4 were also similar in LA and HA placentas. Low birth weights in the neonates of women residing at high altitude are not a consequence of reduced placental amino acid transport capacity. These observations are in general agreement with studies of IUGR babies at low altitude, in which MVM system A activity is downregulated only in growth-restricted babies with significant compromise.NEW & NOTEWORTHY Babies born at high altitude are smaller than at sea level. Birth weight is dependent on growth in utero and, in turn, placental nutrient transport. We determined amino acid transport capacity in placentas collected from women resident at low and high altitude. Altitude did not affect system A amino acid transport across the syncytiotrophoblast microvillous membrane, suggesting that impaired placental amino acid transport does not contribute to reduced birth weight in this high-altitude population.
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Affiliation(s)
- Owen R Vaughan
- Department of Ob/Gyn, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Fredrick Thompson
- Department of Ob/Gyn, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Ramón A Lorca
- Department of Ob/Gyn, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Colleen G Julian
- Department of Medicine University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Theresa L Powell
- Department of Ob/Gyn, University of Colorado Anschutz Medical Campus, Aurora, Colorado.,Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Lorna G Moore
- Department of Ob/Gyn, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Thomas Jansson
- Department of Ob/Gyn, University of Colorado Anschutz Medical Campus, Aurora, Colorado
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20
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Vaughan OR, Powell TL, Jansson T. Glucocorticoid regulation of amino acid transport in primary human trophoblast cells. J Mol Endocrinol 2019; 63:239-248. [PMID: 31505460 PMCID: PMC6872941 DOI: 10.1530/jme-19-0183] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 09/10/2019] [Indexed: 12/20/2022]
Abstract
Excess maternal glucocorticoids reduce placental amino acid transport and fetal growth, but whether these effects are mediated directly on the syncytiotrophoblast remains unknown. We hypothesised that glucocorticoids inhibit mechanistic target of rapamycin (mTOR) signaling and insulin-stimulated System A amino acid transport activity in primary human trophoblast (PHT) cells. Syncytialised PHTs, isolated from term placentas (n = 15), were treated with either cortisol (1 μM) or dexamethasone (1 μM), ± insulin (1 nM) for 24 h. Compared to vehicle, dexamethasone increased mRNA expression, but not protein abundance of the mTOR suppressor, regulated in development and DNA damage response 1 (REDD1). Dexamethasone enhanced insulin receptor abundance, activated mTOR complex 1 and 2 signaling and stimulated System A activity, measured by Na+-dependent 14C-methylaminoisobutyric acid uptake. Cortisol also activated mTORC1 without significantly altering insulin receptor or mTORC2 read-outs or System A activity. Both glucocorticoids downregulated expression of the glucocorticoid receptor and the System A transporter genes SLC38A1, SLC38A2 and SLC38A4, without altering SNAT1 or SNAT4 protein abundance. Neither cortisol nor dexamethasone affected System L amino acid transport. Insulin further enhanced mTOR and System A activity, irrespective of glucocorticoid treatment and despite downregulating its own receptor. Contrary to our hypothesis, glucocorticoids do not inhibit mTOR signaling or cause insulin resistance in cultured PHT cells. We speculate that glucocorticoids stimulate System A activity in PHT cells by activating mTOR signaling, which regulates amino acid transporters post-translationally. We conclude that downregulation of placental nutrient transport in vivo following excess maternal glucocorticoids is not mediated by a direct effect on the placenta.
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Affiliation(s)
- O R Vaughan
- Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - T L Powell
- Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - T Jansson
- Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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21
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Renshall LJ, Morgan HL, Moens H, Cansfield D, Finn-Sell SL, Tropea T, Cottrell EC, Greenwood S, Sibley CP, Wareing M, Dilworth MR. Melatonin Increases Fetal Weight in Wild-Type Mice but Not in Mouse Models of Fetal Growth Restriction. Front Physiol 2018; 9:1141. [PMID: 30158878 PMCID: PMC6104307 DOI: 10.3389/fphys.2018.01141] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 07/30/2018] [Indexed: 01/08/2023] Open
Abstract
Fetal growth restriction (FGR) presents with an increased risk of stillbirth and childhood and adulthood morbidity. Melatonin, a neurohormone and antioxidant, has been suggested as having therapeutic benefit in FGR. We tested the hypothesis that melatonin would increase fetal growth in two mouse models of FGR which together represent a spectrum of the placental phenotypes in this complication: namely the endothelial nitric oxide synthase knockout mouse (eNOS-/-) which presents with abnormal uteroplacental blood flow, and the placental specific Igf2 knockout mouse (P0+/-) which demonstrates aberrant placental morphology akin to human FGR. Melatonin (5 μg/ml) was administered via drinking water from embryonic day (E)12.5 in C57Bl/6J wild-type (WT), eNOS-/-, and P0+/- mice. Melatonin supplementation significantly increased fetal weight in WT, but not eNOS-/- or P0+/- mice at E18.5. Melatonin did, however, significantly increase abdominal circumference in P0+/- mice. Melatonin had no effect on placental weight in any group. Uterine arteries from eNOS-/- mice demonstrated aberrant function compared with WT but melatonin treatment did not affect uterine artery vascular reactivity in either of these genotypes. Umbilical arteries from melatonin treated P0+/- mice demonstrated increased relaxation in response to the nitric oxide donor SNP compared with control. The increased fetal weight in WT mice and abdominal circumference in P0+/-, together with the lack of any effect in eNOS-/-, suggest that the presence of eNOS is required for the growth promoting effects of melatonin. This study supports further work on the possibility of melatonin as a treatment for FGR.
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Affiliation(s)
- Lewis J Renshall
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, St. Mary's Hospital, Manchester, United Kingdom
| | - Hannah L Morgan
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, St. Mary's Hospital, Manchester, United Kingdom
| | - Hymke Moens
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, St. Mary's Hospital, Manchester, United Kingdom
| | - David Cansfield
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, St. Mary's Hospital, Manchester, United Kingdom
| | - Sarah L Finn-Sell
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, St. Mary's Hospital, Manchester, United Kingdom
| | - Teresa Tropea
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, St. Mary's Hospital, Manchester, United Kingdom
| | - Elizabeth C Cottrell
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, St. Mary's Hospital, Manchester, United Kingdom
| | - Susan Greenwood
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, St. Mary's Hospital, Manchester, United Kingdom
| | - Colin P Sibley
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, St. Mary's Hospital, Manchester, United Kingdom
| | - Mark Wareing
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, St. Mary's Hospital, Manchester, United Kingdom
| | - Mark R Dilworth
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom.,Manchester Academic Health Science Centre, Manchester University NHS Foundation Trust, St. Mary's Hospital, Manchester, United Kingdom
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22
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Myatt L, Thornburg KL. Effects of Prenatal Nutrition and the Role of the Placenta in Health and Disease. Methods Mol Biol 2018; 1735:19-46. [PMID: 29380305 DOI: 10.1007/978-1-4939-7614-0_2] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Epidemiologic studies identified the linkage between exposures to stresses, including the type and plane of nutrition in utero with development of disease in later life. Given the critical roles of the placenta in mediating transport of nutrients between the mother and fetus and regulation of maternal metabolism, recent attention has focused on the role of the placenta in mediating the effect of altered nutritional exposures on the development of disease in later life. In this chapter we describe the mechanisms of nutrient transport in the placenta, the influence of placental metabolism on this, and how placental energetics influence placental function in response to a variety of stressors. Further the recent "recognition" that the placenta itself has a sex which affects its function may begin to help elucidate the mechanisms underlying the well-known dimorphism in development of disease in adult life.
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Affiliation(s)
- Leslie Myatt
- Department of Obstetrics & Gynecology, Oregon Health & Science University, Portland, OR, USA. .,Bob and Charlee Moore Institute for Nutrition & Wellness, Oregon Health & Science University, Portland, OR, USA.
| | - Kent L Thornburg
- Bob and Charlee Moore Institute for Nutrition & Wellness, Oregon Health & Science University, Portland, OR, USA.,Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, USA
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23
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Hayward CE, McIntyre KR, Sibley CP, Greenwood SL, Dilworth MR. Mechanisms Underpinning Adaptations in Placental Calcium Transport in Normal Mice and Those With Fetal Growth Restriction. Front Endocrinol (Lausanne) 2018; 9:671. [PMID: 30515131 PMCID: PMC6255882 DOI: 10.3389/fendo.2018.00671] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2018] [Accepted: 10/29/2018] [Indexed: 12/25/2022] Open
Abstract
Fetal delivery of calcium, via the placenta, is crucial for appropriate skeletal mineralization. We have previously demonstrated that maternofetal calcium transport, per gram placenta, is increased in the placental specific insulin-like growth factor 2 knockout mouse (P0) model of fetal growth restriction (FGR) compared to wild type littermates (WTL). This effect was mirrored in wild-type (WT) mice comparing lightest vs. heaviest (LvH) placentas in a litter. In both models increased placental calcium transport was associated with normalization of fetal calcium content. Despite this adaptation being observed in small normal (WT), and small dysfunctional (P0) placentas, mechanisms underpinning these changes remain unknown. Parathyroid hormone-related protein (PTHrP), elevated in cord blood in FGR and known to stimulate plasma membrane calcium ATPase, might be important. We hypothesized that PTHrP expression would be increased in LvH WT placentas, and in P0 vs. WTL. We used calcium pathway-focused PCR arrays to assess whether mechanisms underpinning these adaptations in LvH WT placentas, and in P0 vs. WTL, were similar. PTHrP protein expression was not different between LvH WT placentas at E18.5 but trended toward increased expression (139%; P = 0.06) in P0 vs. WTL. PCR arrays demonstrated that four genes were differentially expressed in LvH WT placentas including increased expression of the calcium-binding protein calmodulin 1 (1.6-fold; P < 0.05). Twenty-four genes were differentially expressed in placentas of P0 vs. WTL; significant reductions were observed in expression of S100 calcium binding protein G (2-fold; P < 0.01), parathyroid hormone 1 receptor (1.7-fold; P < 0.01) and PTHrP (2-fold; P < 0.05), whilst serum/glucocorticoid-regulated kinase 1 (SGK1), a regulator of nutrient transporters, was increased (1.4 fold; P < 0.05). Tartrate resistant acid phosphatase 5 (TRAP5 encoded by Acp5) was reduced in placentas of both LvH WT and P0 vs. WTL (1.6- and 1.7-fold, respectively; P < 0.05). Signaling events underpinning adaptations in calcium transport are distinct between LvH placentas of WT mice and those in P0 vs. WTL. Calcium binding proteins appear important in functional adaptations in the former whilst PTHrP and SGK1 are also implicated in the latter. These data facilitate understanding of mechanisms underpinning placental calcium transport adaptation in normal and growth restricted fetuses.
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Affiliation(s)
- Christina E. Hayward
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
- Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Kirsty R. McIntyre
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
- Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Colin P. Sibley
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
- Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Susan L. Greenwood
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
- Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
| | - Mark R. Dilworth
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, Faculty of Biology, Medicine and Health, School of Medical Sciences, University of Manchester, Manchester, United Kingdom
- Manchester Academic Health Science Centre, St. Mary's Hospital, Manchester University NHS Foundation Trust, Manchester, United Kingdom
- *Correspondence: Mark R. Dilworth
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24
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Hayward CE, Renshall LJ, Sibley CP, Greenwood SL, Dilworth MR. Adaptations in Maternofetal Calcium Transport in Relation to Placental Size and Fetal Sex in Mice. Front Physiol 2017; 8:1050. [PMID: 29311979 PMCID: PMC5732954 DOI: 10.3389/fphys.2017.01050] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Accepted: 11/30/2017] [Indexed: 01/21/2023] Open
Abstract
Appropriate placental transport of calcium is essential for normal fetal skeletal mineralization. In fetal growth restriction (FGR), the failure of a fetus to achieve its growth potential, a number of placental nutrient transport systems show reduced activity but, in the case of calcium, placental transport is increased. In a genetic mouse model of FGR this increase, or adaptation, maintains appropriate fetal calcium content, relative to the size of the fetus, despite a small, dysfunctional placenta. It is unknown whether such an adaptation is also apparent in small, but normally functioning placentas. We tested the hypothesis that calcium transfer would be up-regulated in the lightest vs. heaviest placentas in the same C57Bl/6J wild-type (WT) mouse litter. Since lightest placentas are often from females, we also assessed whether fetal sex influenced placental calcium transfer. Placentas and fetuses were collected at embryonic day (E)16.5 and 18.5; the lightest and heaviest placentas, and female and male fetuses, were identified. Unidirectional maternofetal calcium clearance (CaKmf) was assessed following 45Ca administration to the dam and subsequent radiolabel counts within the fetuses. Placental expression of calcium pathway components was measured by Western blot. Data (median) are lightest placenta expressed as percentage of the heaviest within a litter and analyzed by Wilcoxon signed-rank test. In WT mice having normally grown fetuses, CaKmf, per gram placenta near term, in the lightest placentas was increased (126%; P < 0.05) in association with reduced fetal calcium accretion earlier in gestation (92%; P < 0.05), that was subsequently normalized near term. Increased placental expression of calbindin-D9K, an important calcium binding protein, was observed in the lightest placentas near term (122%; P < 0.01). There was no difference in fetal calcium accretion between male and female littermates but a trend toward higher CaKmf in females (P = 0.055). These data suggest a small, normal placenta adapts calcium transfer according to its size, as previously demonstrated in a mouse model of FGR. Fetal sex had limited influence on this adaptive increase. These adaptations are potentially driven by fetal nutrient demand, as evidenced by the normalization of fetal calcium content. Understanding the regulatory mechanisms involved may provide novel avenues for treating placental dysfunction.
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Affiliation(s)
- Christina E Hayward
- Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
| | - Lewis J Renshall
- Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
| | - Colin P Sibley
- Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
| | - Susan L Greenwood
- Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
| | - Mark R Dilworth
- Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.,Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester, United Kingdom
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25
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Murthi P, Wallace EM, Walker DW. Altered placental tryptophan metabolic pathway in human fetal growth restriction. Placenta 2017; 52:62-70. [DOI: 10.1016/j.placenta.2017.02.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 01/24/2017] [Accepted: 02/10/2017] [Indexed: 01/19/2023]
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26
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Cottrell E, Tropea T, Ormesher L, Greenwood S, Wareing M, Johnstone E, Myers J, Sibley C. Dietary interventions for fetal growth restriction - therapeutic potential of dietary nitrate supplementation in pregnancy. J Physiol 2017; 595:5095-5102. [PMID: 28090634 DOI: 10.1113/jp273331] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 01/03/2017] [Indexed: 11/08/2022] Open
Abstract
Fetal growth restriction (FGR) affects around 5% of pregnancies and is associated with significant short- and long-term adverse outcomes. A number of factors can increase the risk of FGR, one of which is poor maternal diet. In terms of pathology, both clinically and in many experimental models of FGR, impaired uteroplacental vascular function is implicated, leading to a reduction in the delivery of oxygen and nutrients to the developing fetus. Whilst mechanisms underpinning impaired uteroplacental vascular function are not fully understood, interventions aimed at enhancing nitric oxide (NO) bioavailability remain a key area of interest in obstetric research. In addition to endogenous NO production from the amino acid l-arginine, via nitric oxide synthase (NOS) enzymes, research in recent years has established that significant NO can be derived from dietary nitrate, via the 'alternative NO pathway'. Dietary nitrate, abundant in green leafy vegetables and beetroot, can increase NO bioactivity, conferring beneficial effects on cardiovascular function and blood flow. Given the beneficial effects of dietary nitrate supplementation to date in non-pregnant humans and animals, current investigations aim to assess the therapeutic potential of this approach in pregnancy to enhance NO bioactivity, improve uteroplacental vascular function and increase fetal growth.
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Affiliation(s)
- Elizabeth Cottrell
- School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, St Mary's Hospital, M13 9WL, UK
| | - Teresa Tropea
- School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, St Mary's Hospital, M13 9WL, UK
| | - Laura Ormesher
- School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, St Mary's Hospital, M13 9WL, UK
| | - Susan Greenwood
- School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, St Mary's Hospital, M13 9WL, UK
| | - Mark Wareing
- School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, St Mary's Hospital, M13 9WL, UK
| | - Edward Johnstone
- School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, St Mary's Hospital, M13 9WL, UK
| | - Jenny Myers
- School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, St Mary's Hospital, M13 9WL, UK
| | - Colin Sibley
- School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, St Mary's Hospital, M13 9WL, UK
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27
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Vaughan O, Rosario F, Powell T, Jansson T. Regulation of Placental Amino Acid Transport and Fetal Growth. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2017; 145:217-251. [DOI: 10.1016/bs.pmbts.2016.12.008] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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28
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Gaccioli F, Lager S. Placental Nutrient Transport and Intrauterine Growth Restriction. Front Physiol 2016; 7:40. [PMID: 26909042 PMCID: PMC4754577 DOI: 10.3389/fphys.2016.00040] [Citation(s) in RCA: 79] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Accepted: 01/28/2016] [Indexed: 01/30/2023] Open
Abstract
Intrauterine growth restriction refers to the inability of the fetus to reach its genetically determined potential size. Fetal growth restriction affects approximately 5–15% of all pregnancies in the United States and Europe. In developing countries the occurrence varies widely between 10 and 55%, impacting about 30 million newborns per year. Besides having high perinatal mortality rates these infants are at greater risk for severe adverse outcomes, such as hypoxic ischemic encephalopathy and cerebral palsy. Moreover, reduced fetal growth has lifelong health consequences, including higher risks of developing metabolic and cardiovascular diseases in adulthood. Numerous reports indicate placental insufficiency as one of the underlying causes leading to altered fetal growth and impaired placental capacity of delivering nutrients to the fetus has been shown to contribute to the etiology of intrauterine growth restriction. Indeed, reduced expression and/or activity of placental nutrient transporters have been demonstrated in several conditions associated with an increased risk of delivering a small or growth restricted infant. This review focuses on human pregnancies and summarizes the changes in placental amino acid, fatty acid, and glucose transport reported in conditions associated with intrauterine growth restriction, such as maternal undernutrition, pre-eclampsia, young maternal age, high altitude and infection.
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Affiliation(s)
- Francesca Gaccioli
- Department of Obstetrics and Gynaecology, University of Cambridge Cambridge, UK
| | - Susanne Lager
- Department of Obstetrics and Gynaecology, University of Cambridge Cambridge, UK
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29
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Hayward CE, Lean S, Sibley CP, Jones RL, Wareing M, Greenwood SL, Dilworth MR. Placental Adaptation: What Can We Learn from Birthweight:Placental Weight Ratio? Front Physiol 2016; 7:28. [PMID: 26903878 PMCID: PMC4742558 DOI: 10.3389/fphys.2016.00028] [Citation(s) in RCA: 170] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Accepted: 01/18/2016] [Indexed: 11/17/2022] Open
Abstract
Appropriate fetal growth relies upon adequate placental nutrient transfer. Birthweight:placental weight ratio (BW:PW ratio) is often used as a proxy for placental efficiency, defined as the grams of fetus produced per gram placenta. An elevated BW:PW ratio in an appropriately grown fetus (small placenta) is assumed to be due to up-regulated placental nutrient transfer capacity i.e., a higher nutrient net flux per gram placenta. In fetal growth restriction (FGR), where a fetus fails to achieve its genetically pre-determined growth potential, placental weight and BW:PW ratio are often reduced which may indicate a placenta that fails to adapt its nutrient transfer capacity to compensate for its small size. This review considers the literature on BW:PW ratio in both large cohort studies of normal pregnancies and those studies offering insight into the relationship between BW:PW ratio and outcome measures including stillbirth, FGR, and subsequent postnatal consequences. The core of this review is the question of whether BW:PW ratio is truly indicative of altered placental efficiency, and whether changes in BW:PW ratio reflect those placentas which adapt their nutrient transfer according to their size. We consider this question using data from mice and humans, focusing upon studies that have measured the activity of the well characterized placental system A amino acid transporter, both in uncomplicated pregnancies and in FGR. Evidence suggests that BW:PW ratio is reduced both in FGR and in pregnancies resulting in a small for gestational age (SGA, birthweight < 10th centile) infant but this effect is more pronounced earlier in gestation (<28 weeks). In mice, there is a clear association between increased BW:PW ratio and increased placental system A activity. Additionally, there is good evidence in wild-type mice that small placentas upregulate placental nutrient transfer to prevent fetal undergrowth. In humans, this association between BW:PW ratio and placental system A activity is less clear and is worthy of further consideration, both in terms of system A and other placental nutrient transfer processes. This knowledge would help decide the value of measuring BW:PW ratio in terms of determining the risk of poor health outcomes, both in the neonatal period and long term.
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Affiliation(s)
- Christina E Hayward
- Maternal and Fetal Health Research Centre, Institute of Human Development, University of ManchesterManchester, UK; Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester, UK
| | - Samantha Lean
- Maternal and Fetal Health Research Centre, Institute of Human Development, University of ManchesterManchester, UK; Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester, UK
| | - Colin P Sibley
- Maternal and Fetal Health Research Centre, Institute of Human Development, University of ManchesterManchester, UK; Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester, UK
| | - Rebecca L Jones
- Maternal and Fetal Health Research Centre, Institute of Human Development, University of ManchesterManchester, UK; Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester, UK
| | - Mark Wareing
- Maternal and Fetal Health Research Centre, Institute of Human Development, University of ManchesterManchester, UK; Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester, UK
| | - Susan L Greenwood
- Maternal and Fetal Health Research Centre, Institute of Human Development, University of ManchesterManchester, UK; Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester, UK
| | - Mark R Dilworth
- Maternal and Fetal Health Research Centre, Institute of Human Development, University of ManchesterManchester, UK; Maternal and Fetal Health Research Centre, Manchester Academic Health Science Centre, St. Mary's Hospital, Central Manchester University Hospitals NHS Foundation TrustManchester, UK
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30
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Day PE, Ntani G, Crozier SR, Mahon PA, Inskip HM, Cooper C, Harvey NC, Godfrey KM, Hanson MA, Lewis RM, Cleal JK. Maternal Factors Are Associated with the Expression of Placental Genes Involved in Amino Acid Metabolism and Transport. PLoS One 2015; 10:e0143653. [PMID: 26657885 PMCID: PMC4682815 DOI: 10.1371/journal.pone.0143653] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 11/07/2015] [Indexed: 12/22/2022] Open
Abstract
Introduction Maternal environment and lifestyle factors may modify placental function to match the mother’s capacity to support the demands of fetal growth. Much remains to be understood about maternal influences on placental metabolic and amino acid transporter gene expression. We investigated the influences of maternal lifestyle and body composition (e.g. fat and muscle content) on a selection of metabolic and amino acid transporter genes and their associations with fetal growth. Methods RNA was extracted from 102 term Southampton Women’s Survey placental samples. Expression of nine metabolic, seven exchange, eight accumulative and three facilitated transporter genes was analyzed using quantitative real-time PCR. Results Increased placental LAT2 (p = 0.01), y+LAT2 (p = 0.03), aspartate aminotransferase 2 (p = 0.02) and decreased aspartate aminotransferase 1 (p = 0.04) mRNA expression associated with pre-pregnancy maternal smoking. Placental mRNA expression of TAT1 (p = 0.01), ASCT1 (p = 0.03), mitochondrial branched chain aminotransferase (p = 0.02) and glutamine synthetase (p = 0.05) was positively associated with maternal strenuous exercise. Increased glutamine synthetase mRNA expression (r = 0.20, p = 0.05) associated with higher maternal diet quality (prudent dietary pattern) pre-pregnancy. Lower LAT4 (r = -0.25, p = 0.05) and aspartate aminotransferase 2 mRNA expression (r = -0.28, p = 0.01) associated with higher early pregnancy diet quality. Lower placental ASCT1 mRNA expression associated with measures of increased maternal fat mass, including pre-pregnancy BMI (r = -0.26, p = 0.01). Lower placental mRNA expression of alanine aminotransferase 2 associated with greater neonatal adiposity, for example neonatal subscapular skinfold thickness (r = -0.33, p = 0.001). Conclusion A number of maternal influences have been linked with outcomes in childhood, independently of neonatal size; our finding of associations between placental expression of transporter and metabolic genes and maternal smoking, physical activity and diet raises the possibility that their effects are mediated in part through alterations in placental function. The observed changes in placental gene expression in relation to modifiable maternal factors are important as they could form part of interventions aimed at maintaining a healthy lifestyle for the mother and for optimal fetal development.
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Affiliation(s)
- Pricilla E. Day
- Institute of Developmental Sciences, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Georgia Ntani
- MRC Lifecourse Epidemiology Unit, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Sarah R. Crozier
- MRC Lifecourse Epidemiology Unit, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Pam A. Mahon
- MRC Lifecourse Epidemiology Unit, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Hazel M. Inskip
- MRC Lifecourse Epidemiology Unit, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Cyrus Cooper
- MRC Lifecourse Epidemiology Unit, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom
- NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, SO16 6YD, United Kingdom
- NIHR Musculoskeletal Biomedical Research Unit, University of Oxford, Nuffield Orthopedic Centre, Headington, Oxford, OX3 7HE, United Kingdom
| | - Nicholas C. Harvey
- MRC Lifecourse Epidemiology Unit, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom
- NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Keith M. Godfrey
- Institute of Developmental Sciences, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom
- MRC Lifecourse Epidemiology Unit, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom
- NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Mark A. Hanson
- Institute of Developmental Sciences, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom
- NIHR Southampton Biomedical Research Centre, University of Southampton and University Hospital Southampton NHS Foundation Trust, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Rohan M. Lewis
- Institute of Developmental Sciences, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
| | - Jane K. Cleal
- Institute of Developmental Sciences, University of Southampton, Tremona Road, Southampton, SO16 6YD, United Kingdom
- Institute for Life Sciences, University of Southampton, Southampton, SO17 1BJ, United Kingdom
- * E-mail:
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31
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Lin G, Wang X, Wu G, Feng C, Zhou H, Li D, Wang J. Improving amino acid nutrition to prevent intrauterine growth restriction in mammals. Amino Acids 2015; 46:1605-23. [PMID: 24658999 DOI: 10.1007/s00726-014-1725-z] [Citation(s) in RCA: 66] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2014] [Accepted: 03/06/2014] [Indexed: 12/18/2022]
Abstract
Intrauterine growth restriction (IUGR) is one of the most common concerns in human obstetrics and domestic animal production. It is usually caused by placental insufficiency, which decreases fetal uptake of nutrients (especially amino acids) from the placenta. Amino acids are not only building blocks for protein but also key regulators of metabolic pathways in fetoplacental development. The enhanced demands of amino acids by the developing conceptus must be met via active transport systems across the placenta as normal pregnancy advances. Growing evidence indicates that IUGR is associated with a reduction in placental amino acid transport capacity and metabolic pathways within the embryonic/fetal development. The positive relationships between amino acid concentrations in circulating maternal blood and placental amino acid transport into fetus encourage designing new therapies to prevent or treat IUGR by enhancing amino acid availability in maternal diets or maternal circulation. Despite the positive effects of available dietary interventions, nutritional therapy for IUGR is still in its infancy. Based on understanding of the underlying mechanisms whereby amino acids promote fetal growth and of their dietary requirements by IUGR, supplementation with functional amino acids (e.g., arginine and glutamine) hold great promise for preventing fetal growth restriction and improving health and growth of IUGR offspring.
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32
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Li F, Teng HY, Liu J, Wang HW, Zeng L, Zhao LF. Antenatal taurine supplementation increases taurine content in intrauterine growth restricted fetal rat brain tissue. Metab Brain Dis 2014; 29:867-71. [PMID: 24676564 DOI: 10.1007/s11011-014-9532-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Accepted: 03/17/2014] [Indexed: 02/05/2023]
Abstract
This study aimed to determine the influence of antenatal taurine supplementation on taurine content in the brains of fetal rats with intrauterine growth restriction (IUGR). Experiments were performed at the Central Laboratory of Bayi Children's Hospital Affiliated to Beijing Military General Hospital in China from January to June 2013. Fifteen pregnant rats were randomly divided into three groups: normal controls, an IUGR group and an IUGR + antenatal taurine supplement group (Taurine group) (n = 5). The IUGR model was induced using a low-protein diet throughout gestation. Rats in the taurine group were fed a diet supplemented with 300 mg/kg/day taurine for 12 days after conception until natural delivery. Two fetal rats were randomly selected in every litter, and taurine levels in the brains of rats were detected using high-performance liquid chromatography-mass spectrometry. Results showed that (1) the mean body weight of the fetal rats in the normal control, IUGR and IUGR + antenatal taurine supplement groups was 6.619 ± 0.4132, 4.509 ± 0.454, and 5.176 ± 0.436 g (F = 429.818, P < 0.01), respectively, and (2) that taurine levels in the brains of the fetal rats in the normal control, IUGR and taurine groups were (2.399 ± 0.134) × 10(5), (1.881 ± 0.166) × 10(5) and (2.170 ± 0.191) × 10(5) μg/g (F = 24.828, P < 0.01), respectively. Overall, our results indicated that taurine levels in IUGR fetal rat brains were lower than in the control animals, and that antenatal taurine supplementation could significantly increase taurine levels in the brains of fetal rats with IUGR.
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Affiliation(s)
- Fang Li
- Department of Pediatrics, The Second Artillery General Hospital of Chinese People's Liberation Army, Beijing, 100088, China
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Kleppa MJ, Erlenwein SV, Darashchonak N, von Kaisenberg CS, von Versen-Höynck F. Hypoxia and the anticoagulants dalteparin and acetylsalicylic acid affect human placental amino acid transport. PLoS One 2014; 9:e99217. [PMID: 24901243 PMCID: PMC4047053 DOI: 10.1371/journal.pone.0099217] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 05/12/2014] [Indexed: 01/12/2023] Open
Abstract
Background Anticoagulants, e.g. low-molecular weight heparins (LMWHs) and acetylsalicylic acid (ASA) are prescribed to women at risk for pregnancy complications that are associated with impaired placentation and placental hypoxia. Beyond their role as anticoagulants these compounds exhibit direct effects on trophoblast but their impact on placental function is unknown. The amino acid transport systems A and L, which preferably transfer essential amino acids, are well-described models to study placental nutrient transport. We aimed to examine the effect of hypoxia, LMWHs and ASA on the activity of the placental amino acid transport systems A and L and associated signalling mechanisms. Methods The uptake of C14-MeAIB (system A) or H3-leucin (system L) was investigated after incubation of primary villous fragments isolated from term placentas. Villous tissue was incubated at 2% O2 (hypoxia), 8% O2 and standard culture conditions (21% O2) or at 2% O2 and 21% O2 with dalteparin or ASA. Activation of the JAK/STAT or mTOR signalling pathways was determined by Western analysis of total and phosphorylated STAT3 or Raptor. Results Hypoxia decreased system A mediated MeAIB uptake and increased system L mediated leucine uptake compared to standard culture conditions (21% O2). This was accompanied by an impairment of STAT3 and a stimulation of Raptor signalling. System L activity increased at 8% O2. Dalteparin treatment reduced system A and system L activity under normoxic conditions and ASA (1 mM) decreased system A and L transporter activity under normoxic and hypoxic conditions. Conclusions Our data underline the dependency of placental function on oxygen supply. LMWHs and ASA are not able to reverse the effects of hypoxia on placental amino acid transport. These findings and the uncovering of the signalling mechanisms in more detail will help to understand the impact of LMWHs and ASA on placental function and fetal growth.
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Affiliation(s)
- Marc-Jens Kleppa
- Department of Obstetrics and Gynecology, Hannover Medical School, Hannover, Germany
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Aiko Y, Askew DJ, Aramaki S, Myoga M, Tomonaga C, Hachisuga T, Suga R, Kawamoto T, Tsuji M, Shibata E. Differential levels of amino acid transporters System L and ASCT2, and the mTOR protein in placenta of preeclampsia and IUGR. BMC Pregnancy Childbirth 2014; 14:181. [PMID: 24886642 PMCID: PMC4060848 DOI: 10.1186/1471-2393-14-181] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Accepted: 05/22/2014] [Indexed: 12/14/2022] Open
Abstract
Background Sufficient amino acid transport activity (AAT) is indispensable for appropriate fetal growth. Studies suggest that placental nutrient uptake activity is responsive to both maternal and fetal nutrient demands. We hypothesize that under conditions of limited nutrient availability to the fetus, as often present in preeclampsia, intrauterine growth restriction (IUGR), and insufficient weight-gain during pregnancy, a general adaptive response aimed to increase amino acid transport activity may be observed in the placenta. Method A total of 40 placentas from full-term (n = 10) and pre-term (average gestational period = 34.8 weeks, n = 10) normal pregnancies, IUGR (n = 10), and preeclampsia (n = 10) associated pregnancies were looked at by immunohistochemistry followed by relative qualitative scoring to compare expression levels and localization of System L, ASCT2, and mTOR proteins. Result Microvillous syncytiotrophoblast (ST) in placenta of pregnancies complicated by IUGR or preeclampsia (PE) showed significant increases in the levels of System L amino acid transport proteins 4F2hc and LAT1 compared to both full-term control and pre-term (early gestation control) pregnancies seperately (p < 0.05). Elevated mTOR protein was uniquely higher in IUGR placentas compared to full-term controls (P = 0.0026). Total cellular ASCT2 transporter protein levels were similar in all groups, however, levels of ASCT2 protein localized to the ST microvillous membrane (MVM) were significantly lower in IUGR compared to both full-term and pre-term pregnancies (P = 0.0006, 0.03, respectively). Additionally, ASCT2 and mTOR protein levels were positively associated with maternal pre-pregnancy BMI (P = 0.046, 0.048, respectively). Conclusion There are three important findings based upon the present study. First, in conditions of limited nutrient availability, such as PE or IUGR, there is an overall increase in the level of System L and mTOR protein expression in the ST, suggestive of an adaptive response. Second, a decrease in ASCT2 protein at the ST MVM suggests a post-translational event that may decrease AAT activity in IUGR placentas. Third, a physiological link between transporter expression and pre-pregnancy BMI is suggested based upon a positive association observed with ASCT2 and mTOR expression values.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - Eiji Shibata
- Department of Obstetrics and Gynecology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan.
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Sildenafil citrate increases fetal weight in a mouse model of fetal growth restriction with a normal vascular phenotype. PLoS One 2013; 8:e77748. [PMID: 24204949 PMCID: PMC3813774 DOI: 10.1371/journal.pone.0077748] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Accepted: 09/06/2013] [Indexed: 11/19/2022] Open
Abstract
Fetal growth restriction (FGR) is defined as the inability of a fetus to achieve its genetic growth potential and is associated with a significantly increased risk of morbidity and mortality. Clinically, FGR is diagnosed as a fetus falling below the 5(th) centile of customised growth charts. Sildenafil citrate (SC, Viagra™), a potent and selective phosphodiesterase-5 inhibitor, corrects ex vivo placental vascular dysfunction in FGR, demonstrating potential as a therapy for this condition. However, many FGR cases present without an abnormal vascular phenotype, as assessed by Doppler measures of uterine/umbilical artery blood flow velocity. Thus, we hypothesized that SC would not increase fetal growth in a mouse model of FGR, the placental-specific Igf2 knockout mouse, which has altered placental exchange capacity but normal placental blood flow. Fetal weights were increased (by 8%) in P0 mice following maternal SC treatment (0.4 mg/ml) via drinking water. There was also a trend towards increased placental weight in treated P0 mice (P = 0.056). Additionally, 75% of the P0 fetal weights were below the 5(th) centile, the criterion used to define human FGR, of the non-treated WT fetal weights; this was reduced to 51% when dams were treated with SC. Umbilical artery and vein blood flow velocity measures confirmed the lack of an abnormal vascular phenotype in the P0 mouse; and were unaffected by SC treatment. (14)C-methylaminoisobutyric acid transfer (measured to assess effects on placental nutrient transporter activity) per g placenta was unaffected by SC, versus untreated, though total transfer was increased, commensurate with the trend towards larger placentas in this group. These data suggest that SC may improve fetal growth even in the absence of an abnormal placental blood flow, potentially affording use in multiple sub-populations of individuals presenting with FGR.
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Gaccioli F, Lager S, Powell TL, Jansson T. Placental transport in response to altered maternal nutrition. J Dev Orig Health Dis 2013; 4:101-15. [PMID: 25054676 PMCID: PMC4237017 DOI: 10.1017/s2040174412000529] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The mechanisms linking maternal nutrition to fetal growth and programming of adult disease remain to be fully established. We review data on changes in placental transport in response to altered maternal nutrition, including compromized utero-placental blood flow. In human intrauterine growth restriction and in most animal models involving maternal undernutrition or restricted placental blood flow, the activity of placental transporters, in particular for amino acids, is decreased in late pregnancy. The effect of maternal overnutrition on placental transport remains largely unexplored. However, some, but not all, studies in women with diabetes giving birth to large babies indicate an upregulation of placental transporters for amino acids, glucose and fatty acids. These data support the concept that the placenta responds to maternal nutritional cues by altering placental function to match fetal growth to the ability of the maternal supply line to allocate resources to the fetus. On the other hand, some findings in humans and mice suggest that placental transporters are regulated in response to fetal demand signals. These observations are consistent with the idea that fetal signals regulate placental function to compensate for changes in nutrient availability. We propose that the placenta integrates maternal and fetal nutritional cues with information from intrinsic nutrient sensors. Together, these signals regulate placental growth and nutrient transport to balance fetal demand with the ability of the mother to support pregnancy. Thus, the placenta plays a critical role in modulating maternal-fetal resource allocation, thereby affecting fetal growth and the long-term health of the offspring.
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Affiliation(s)
- F Gaccioli
- Department of Obstetrics and Gynecology, Center for Pregnancy and Newborn Research, University of Texas Health Science Center, San Antonio, TX, USA
| | - S Lager
- Department of Obstetrics and Gynecology, Center for Pregnancy and Newborn Research, University of Texas Health Science Center, San Antonio, TX, USA
| | - T L Powell
- Department of Obstetrics and Gynecology, Center for Pregnancy and Newborn Research, University of Texas Health Science Center, San Antonio, TX, USA
| | - T Jansson
- Department of Obstetrics and Gynecology, Center for Pregnancy and Newborn Research, University of Texas Health Science Center, San Antonio, TX, USA
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Vaughan OR, Sferruzzi-Perri AN, Fowden AL. Maternal corticosterone regulates nutrient allocation to fetal growth in mice. J Physiol 2012; 590:5529-40. [PMID: 22930269 DOI: 10.1113/jphysiol.2012.239426] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Stresses during pregnancy that increase maternal glucocorticoids reduce birth weight in several species. However, the role of natural glucocorticoids in the mother in fetal acquisition of nutrients for growth remains unknown. This study aimed to determine whether fetal growth was reduced as a consequence of altered amino acid supply when mice were given corticosterone in their drinking water for 5 day periods in mid to late pregnancy (day, D, 11-16 or D14-19). Compared to controls drinking tap water, fetal weight was always reduced by corticosterone. At D16, corticosterone had no effect on materno-fetal transfer of [(14)C]methylaminoisobutyric acid (MeAIB), although placental MeAIB accumulation and expression of the Slc38a1 and Slc38a2 transporters were increased. However, at D19, 3 days after treatment ended, materno-fetal transfer of MeAIB was increased by 37% (P < 0.04). During treatment at D19, placental accumulation and materno-fetal transfer of MeAIB were reduced by 40% (P < 0.01), although expression of Slc38a1 was again elevated. Permanent reductions in placental vascularity occurred during the earlier but not the later period of treatment. Placental Hsd11b2 expression, which regulates feto-placental glucocorticoid bioavailability, was also affected by treatment at D19 only. Maternal corticosterone concentrations inversely correlated with materno-fetal MeAIB clearance and fetal weight at D19 but not D16. On D19, weight gain of the maternal carcass was normal during corticosterone treatment but reduced in those mice treated from D11 to D16, in which corticosterone levels were lowest. Maternal corticosterone is, therefore, a physiological regulator of the amino acid supply for fetal growth via actions on placental phenotype.
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Affiliation(s)
- Owen R Vaughan
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, Downing Street, Cambridge CB2 3EG, UK.
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Hayward CE, Greenwood SL, Sibley CP, Baker PN, Challis JRG, Jones RL. Effect of maternal age and growth on placental nutrient transport: potential mechanisms for teenagers' predisposition to small-for-gestational-age birth? Am J Physiol Endocrinol Metab 2012; 302:E233-42. [PMID: 22028413 PMCID: PMC3340900 DOI: 10.1152/ajpendo.00192.2011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Teenagers have an increased risk of delivering small-for-gestational-age (SGA) infants. Young maternal age and continued skeletal growth have been implicated as causal factors. In growing adolescent sheep, impaired placental development and nutrient transfer cause reduced birth weight. In human pregnancies, SGA is associated with reduced placental amino acid transport. Maternal growth has no effect on placental morphology or cell turnover, but growing teenagers have higher birth weight:placental weight ratios than nongrowing teenagers. We hypothesized that placental nutrient transporter activity would be affected by maternal age and/or growth status. Placentas from teenagers and adults were collected. Teenagers were defined as growing or nongrowing based on knee height measurements. System A amino acid transporter activity was quantified as sodium-dependent uptake of [(14)C]methylaminoisobutyric acid into placental fragments. Teenagers had lower placental system A activity than adults (P < 0.05). In adults, placental system A activity was lower in SGA infants than appropriate-for-gestational-age (AGA) infants (P < 0.05). In teenagers, AGA and SGA infants had lower placental system A activity than AGA infants born to adults (P < 0.05). Placental system A activity was higher in growing teenagers than in nongrowing teenagers (P < 0.001). Placental mRNA expression of system A transporter isoforms SLC38A1 and -2 was lower in teenagers than in adults (P < 0.05) but did not differ between growing and nongrowing teenagers. There was no difference in transporter protein expression/localization between cohorts. Teenagers have inherently reduced placental transport, which may underlie their susceptibility to delivering SGA infants. Growing teenagers appear to overcome this susceptibility by stimulating the activity, but not expression, of system A transporters.
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Affiliation(s)
- Christina E Hayward
- Maternal and Fetal Health Research Centre, St Mary's Hospital, Oxford Road, Manchester, UK.
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Liu J, Liu L, Chen H. Antenatal taurine supplementation for improving brain ultrastructure in fetal rats with intrauterine growth restriction. Neuroscience 2011; 181:265-70. [PMID: 21376105 DOI: 10.1016/j.neuroscience.2011.02.056] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2011] [Revised: 02/24/2011] [Accepted: 02/25/2011] [Indexed: 02/05/2023]
Abstract
Changes in brain ultrastructure of fetal rats with intrauterine growth restriction (IUGR) were explored and the effects of antenatal taurine supplementation on their brain ultrastructure were determined. Fifteen pregnant rats were randomly divided into three groups: control group, IUGR model group and IUGR group given antenatal taurine supplements. Taurine was added to the diet of the taurine group at a dose of 300 mg/kg/d from 12 days after conception until natural delivery. Transmission electron microscopy was used to observe ultrastructural changes in the brains of the newborn rats. At the same time, brain cellular apoptosis was detected using TUNEL, and the changes in protein expression of neuron specific enolase and glial fibrillary acidic protein were analyzed using immunohistochemistry. The results showed that: 1) The average body weight and cerebral weight were significantly lower in the IUGR group than in the control group (p<0.01) and both of them were less so after taurine was supplemented (p<0.01). 2) Transmission electron microscopy revealed that brain cortex structures were sparse IUGR rats, showing many scattered apoptotic cells, decreased numbers of synapses, lower glial cell proliferation, and fewer neurons, more sparsely arranged, while these factors were significantly improved with taurine supplementation. 3) The results of TUNEL showed that the counts of apoptotic brain cells in IUGR groups were significantly increased from those in control groups and that taurine could significantly decrease brain cell apoptosis (p<0.001). 4) The results of immunohistochemistry showed that antenatal taurine-supplementation could significantly increase the counts of neuron specific enolase and glial fibrillary acidic protein immunoreactive cells in fetal rats with IUGR (p<0.001). It can be concluded that it IUGR has a significant detrimental influence on the development of fetal rat brains, and antenatal supplement of taurine can significantly improve the IUGR fetal brain development.
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Affiliation(s)
- J Liu
- Department of Neonatology and NICU, Bayi Children's Hospital Affiliated with General Hospital of Beijing Military Command, Beijing 100700, China.
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Cleal JK, Glazier JD, Ntani G, Crozier SR, Day PE, Harvey NC, Robinson SM, Cooper C, Godfrey KM, Hanson MA, Lewis RM. Facilitated transporters mediate net efflux of amino acids to the fetus across the basal membrane of the placental syncytiotrophoblast. J Physiol 2011; 589:987-97. [PMID: 21224231 DOI: 10.1113/jphysiol.2010.198549] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Fetal growth depends on placental transfer of amino acids from maternal to fetal blood. The mechanisms of net amino acid efflux across the basal membrane (BM) of the placental syncytiotrophoblast to the fetus, although vital for amino acid transport, are poorly understood. We examined the hypothesis that facilitated diffusion by the amino acid transporters TAT1, LAT3 and LAT4 plays an important role in this process, with possible effects on fetal growth. Amino acid transfer was measured in isolated perfused human placental cotyledons (n = 5 per experiment) using techniques which distinguish between different transport processes. Placental TAT1, LAT3 and LAT4 proteins were measured, and mRNA expression levels (measured using real-time quantitative-PCR) were related to fetal and neonatal anthropometry and dual-energy X-ray absorptiometry measurements of neonatal lean mass in 102 Southampton Women's Survey (SWS) infants. Under conditions preventing transport by amino acid exchangers, all amino acids appearing in the fetal circulation were substrates of TAT1, LAT3 or LAT4. Western blots demonstrated the presence of TAT1, LAT3 and LAT4 in placental BM preparations. Placental TAT1 and LAT3 mRNA expression were positively associated with measures of fetal growth in SWS infants (P < 0.05). We provide evidence that the efflux transporters TAT1, LAT3 and LAT4 are present in the human placental BM, and may play an important role in the net efflux of amino acids to the fetus. Unlike other transporters they can increase fetal amino acid concentrations. Consistent with a role in placental amino acid transfer capacity and fetal growth TAT1 and LAT3 mRNA expression showed positive associations with infant size at birth.
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Affiliation(s)
- J K Cleal
- Institute of Developmental Sciences, University of Southampton, Mail point 887, Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK.
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Gourvas V, Sifakis S, Dalpa E, Soulitzis N, Koukoura O, Spandidos DA. Reduced placental prolyl hydroxylase 3 mRNA expression in pregnancies affected by fetal growth restriction. BJOG 2010; 117:1635-42. [PMID: 21040392 DOI: 10.1111/j.1471-0528.2010.02735.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To investigate the role of the hypoxia-inducible factor (HIF) pathway in fetal growth restriction (FGR). DESIGN A case-control study. SETTING Research laboratory and gynaecology clinic. SAMPLE Twenty placentas from normal pregnancies and 20 from FGR pregnancies. METHODS RNA extraction, cDNA synthesis, quantitative real-time polymerase chain reaction (qRT-PCR) assay, statistical analysis. MAIN OUTCOME MEASURES mRNA expression of HIF-1α, HIF-2α and HIF-β (ARNT), along with prolyl hydroxylase domain 3 (PHD3), which leads to proteasomal degradation of HIF-α subunits. RESULTS No statistically significant differences in the transcription levels of ARNT and HIF-2α were found between FGR and normal placentas. By contrast, PHD3 and HIF-1α mRNA were downregulated in FGR placentas. PHD3 mRNA expression was associated with gestational age at delivery (P = 0.008), birthweight centile (P = 0.029) and abnormal umbilical artery (UA) Doppler measurements (P = 0.034). CONCLUSIONS As PHD3 regulates the HIF-mediated hypoxic response in FGR, we deduce that fetal adaptation to hypoxia ranges from impaired to adequate, as observed by the gradient of PHD3 downregulation in relation to the severity of FGR.
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Affiliation(s)
- V Gourvas
- Laboratory of Clinical Virology, Medical School, University of Crete, Heraklion, Crete, Greece
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James JL, Whitley GS, Cartwright JE. Pre-eclampsia: fitting together the placental, immune and cardiovascular pieces. J Pathol 2010; 221:363-78. [PMID: 20593492 DOI: 10.1002/path.2719] [Citation(s) in RCA: 145] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The success of pregnancy is a result of countless ongoing interactions between the placenta and the maternal immune and cardiovascular systems. Pre-eclampsia is a serious pregnancy complication that arises from multiple potential aberrations in these systems. The pathophysiology of pre-eclampsia is established in the first trimester of pregnancy, when a range of deficiencies in placentation affect the key process of spiral artery remodelling. As pregnancy progresses to the third trimester, inadequate spiral artery remodelling along with multiple haemodynamic, placental and maternal factors converge to activate the maternal immune and cardiovascular systems, events which may in part result from increased shedding of placental debris. As we understand more about the pathophysiology of pre-eclampsia, it is becoming clear that the development of early- and late-onset pre-eclampsia, as well as intrauterine growth restriction (IUGR), does not necessarily arise from the same underlying pathology.
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Affiliation(s)
- Joanna L James
- Division of Basic Medical Sciences, St George's University of London, London, UK.
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Brand A, Greenwood S, Glazier J, Bennett E, Godfrey K, Sibley C, Hanson M, Lewis R. Comparison of l-serine uptake by human placental microvillous membrane vesicles and placental villous fragments. Placenta 2010; 31:456-9. [DOI: 10.1016/j.placenta.2010.01.016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2009] [Revised: 01/27/2010] [Accepted: 01/28/2010] [Indexed: 12/18/2022]
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Huisman MA, Timmer B, Stegehuis J, Swart B, Aarnoudse JG, Erwich JH. Vascularization in first-trimester chorionic villi in complicated and uncomplicated pregnancies. Am J Obstet Gynecol 2010; 202:88.e1-7. [PMID: 19846051 DOI: 10.1016/j.ajog.2009.08.036] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 06/14/2009] [Accepted: 08/20/2009] [Indexed: 01/22/2023]
Abstract
OBJECTIVE The purpose of this study was to investigate possible altered chorionic vascularization patterns that are seen already in the first trimester of pregnancies that are complicated by hypertensive disorders or intrauterine growth restriction (IUGR) in the third trimester of pregnancy. STUDY DESIGN After chorionic villous sampling, surplus of villi were stored, and a selection was made of pregnancies that were complicated further by hypertensive disorders (n = 26), normotensive IUGR (n = 13), and matched control subjects (n = 60). Vascular parameters of these villi were analyzed with a video-image-analysis system. RESULTS In pregnancies that are complicated by early-onset hypertensive disorders and IUGR, the mean distance of the peripheral vessels to the intervillous space and the total of the distances (central and peripheral) are significantly smaller, compared with control subjects (9.3% and 13.8% for hypertensive disorders and 12.2% and 16.1% for IUGR, respectively). CONCLUSION Differences in vascularization patterns in the placenta already in the first trimester of pregnancies that are complicated later by hypertensive disorders or IUGR confirm the hypothesis of early changes by means of more vessels and more peripheral vessels that are located in chorionic villi.
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von Versen-Höynck F, Rajakumar A, Bainbridge SA, Gallaher MJ, Roberts JM, Powers RW. Human placental adenosine receptor expression is elevated in preeclampsia and hypoxia increases expression of the A2A receptor. Placenta 2009; 30:434-42. [PMID: 19303140 DOI: 10.1016/j.placenta.2009.02.004] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Revised: 02/22/2009] [Accepted: 02/23/2009] [Indexed: 10/21/2022]
Abstract
Placental hypoxia as a result of impaired trophoblast invasion is suggested to be involved in the pathophysiology of preeclampsia. Hypoxia is a potent stimulus for the release of adenosine, and the actions of adenosine are mediated through four adenosine receptors, A(1), A(2A), A(2B) and A(3). We investigated the presence, distribution and expression of adenosine receptor subtypes in the human placenta, the expression of the adenosine receptors in placentas from pregnancies complicated by preeclampsia, small for gestational age (SGA) infants and uncomplicated pregnancies, and the effect of hypoxia on placental adenosine receptor expression. Immunofluorescent microscopy localized A(1), A(2A), A(2B) and A(3) adenosine receptors to the syncytiotrophoblast, endothelial cells and myofibroblasts within the human placenta. Adenosine receptor protein and message expression levels were significantly higher in placentas from preeclamptic pregnancies with or without SGA infants, but not different in pregnancies with SGA infants alone. In vitro exposure of placental villous explants to hypoxia (2% oxygen) increased the expression of A(2A) adenosine receptor 50%. These data indicate that all four known adenosine receptors are expressed in the human placenta and adenosine receptor expression is significantly higher in pregnancies complicated by preeclampsia. These data are consistent with the hypothesis that differences in placental adenosine receptors may contribute to alterations in placental function in preeclampsia.
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Affiliation(s)
- F von Versen-Höynck
- Magee-Womens Research Institute, University of Pittsburgh, Pittsburgh, PA 15213, USA
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Roberts JM, Hubel CA. The two stage model of preeclampsia: variations on the theme. Placenta 2008; 30 Suppl A:S32-7. [PMID: 19070896 DOI: 10.1016/j.placenta.2008.11.009] [Citation(s) in RCA: 572] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Revised: 11/14/2008] [Accepted: 11/14/2008] [Indexed: 01/29/2023]
Abstract
The Two Stage Model of preeclampsia proposes that a poorly perfused placenta (Stage 1) produces factor(s) leading to the clinical manifestations of preeclampsia (Stage 2). Stage 1 is not sufficient to cause the maternal syndrome but interacts with maternal constitutional factors (genetic, behavioral or environmental) to result in Stage 2. Recent information indicates the necessity for modifications of this model. It is apparent that changes relevant to preeclampsia and other implantation disorders can be detected in the first trimester, long before the failed vascular remodeling necessary to reduce placental perfusion is completed. In addition, although the factor(s) released from the placenta has usually been considered a toxin, we suggest that what is released may also be an appropriate signal from the fetal/placental unit to overcome reduced nutrient availability that cannot be tolerated by some women who develop preeclampsia. Further, it is evident that linkage is not likely to be one factor but several, different for different women. Also although the initial model limited the role of maternal constitutional factors to the genesis of Stage 2, this does not appear to be the case. It is evident that the factors increasing risk for preeclampsia are also associated with abnormal implantation. These several modifications have important implications. An earlier origin for Stage 1, which appears to be recognizable by altered concentrations of placental products, could allow earlier intervention. The possibility of a fetal placental factor increasing nutrient availability could provide novel therapeutic options. Different linkages and preeclampsia subtypes could direct specific preventive treatments for different women while the role of maternal constitutional factors to affect placentation provides targets for prepregnancy therapy. The modified Two Stage Model provides a useful guide towards investigating pathophysiology and guiding therapy.
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Affiliation(s)
- J M Roberts
- Magee-Womens Research Institute, University of Pittsburgh, Pittsburgh, PA, USA.
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Burton GJ, Yung HW, Cindrova-Davies T, Charnock-Jones DS. Placental endoplasmic reticulum stress and oxidative stress in the pathophysiology of unexplained intrauterine growth restriction and early onset preeclampsia. Placenta 2008; 30 Suppl A:S43-8. [PMID: 19081132 PMCID: PMC2684656 DOI: 10.1016/j.placenta.2008.11.003] [Citation(s) in RCA: 358] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2008] [Revised: 11/06/2008] [Accepted: 11/06/2008] [Indexed: 12/16/2022]
Abstract
The pregnancy complications of unexplained intrauterine growth restriction and early onset preeclampsia are thought to share a common aetiology in placental malperfusion secondary to deficient maternal spiral artery conversion. A key question is whether the contrasting clinical manifestations reflect different placental pathologies, or whether they are due to altered maternal responses to a common factor derived from the placenta. Recently, molecular evidence of protein synthesis inhibition secondary to endoplasmic reticulum stress has provided an explanation for the small placental phenotype in both conditions. However, other pathways activated by more severe endoplasmic reticulum stress are only observed in placentas from pregnancies associated with early onset preeclampsia. Here, we review the literature and conclude that there is evidence of greater maternal vascular compromise of the placenta in these cases. We speculate that in cases of normotensive intrauterine growth restriction the placental pathology is centred predominantly around endoplasmic reticulum stress, whereas in cases complicated by preeclampsia oxidative stress is further superimposed. This causes the release of a potent mix of pro-inflammatory cytokines, anti-angiogenic factors and trophoblastic aponecrotic debris into the maternal circulation that causes the peripheral syndrome. Maternal and fetal constitutional factors may modulate how the placenta responds to the maternal vascular insult, and how the mother is affected by the placental factors released. However, the principal conclusion is that the difference between these two conditions lies in the severity of the initiating deficit in spiral arterial conversion, and the relative degrees of endoplasmic reticulum stress and oxidative stress induced in the placenta as a result.
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Affiliation(s)
- G J Burton
- Department of Physiology, Development and Neuroscience, University of Cambridge, UK.
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