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Sferruzzi-Perri AN, Vaughan OR, Coan PM, Suciu MC, Darbyshire R, Constancia M, Burton GJ, Fowden AL. Placental-specific Igf2 deficiency alters developmental adaptations to undernutrition in mice. Endocrinology 2011; 152:3202-12. [PMID: 21673101 DOI: 10.1210/en.2011-0240] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The pattern of fetal growth is a major determinant of the subsequent health of the infant. We recently showed in undernourished (UN) mice that fetal growth is maintained until late pregnancy, despite reduced placental weight, through adaptive up-regulation of placental nutrient transfer. Here, we determine the role of the placental-specific transcript of IGF-II (Igf2P0), a major regulator of placental transport capacity in mice, in adapting placental phenotype to UN. We compared the morphological and functional responses of the wild-type (WT) and Igf2P0-deficient placenta in WT mice fed ad libitium or 80% of the ad libitium intake. We observed that deletion of Igf2P0 prevented up-regulation of amino acid transfer normally seen in UN WT placenta. This was associated with a reduction in the proportion of the placenta dedicated to nutrient transport, the labyrinthine zone, and its constituent volume of trophoblast in Igf2P0-deficient placentas exposed to UN on d 16 of pregnancy. Additionally, Igf2P0-deficient placentas failed to up-regulate their expression of the amino acid transporter gene, Slc38a2, and down-regulate phosphoinositide 3-kinase-protein kinase B signaling in response to nutrient restriction on d 19. Furthermore, deleting Igf2P0 altered maternal concentrations of hormones (insulin and corticosterone) and metabolites (glucose) in both nutritional states. Therefore, Igf2P0 plays important roles in adapting placental nutrient transfer capacity during UN, via actions directly on the placenta and/or indirectly through the mother.
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Affiliation(s)
- A N Sferruzzi-Perri
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, United Kingdom.
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Abstract
Angiogenesis is a characteristic feature of solid tumors, which depend on the newly formed vasculature to prevent hypoxia and to sustain uncontrolled tumor cell proliferation. In this study, we investigated the blood supply system in 10 gestational choriocarcinomas on the basis of histopathological and immunohistochemical features. In all examined cases, morphological analysis demonstrated that blood channels within the center of choriocarcinomas were surrounded by neoplastic trophoblastic cells rather than by endothelial cells. Similarly, there was a lack of CD31 and CD34-positive endothelial cells within choriocarcinomas. In the periphery of choriocarcinomas, tumor cells invaded uterine stroma-derived blood vessels where trophoblastic cells replaced endothelial cells, forming anastomoses between endothelium-lined blood vessels and trophoblast-lined pseudovascular channels. Masson's trichrome staining revealed minimal amounts of connective tissue within choriocarcinomas. In contrast, CD31 and CD34-positive blood vessels were present in other types of gestational trophoblastic neoplasms including 8 placental site trophoblastic tumors and 12 epithelioid trophoblastic tumors. These findings provide cogent evidence that choriocarcinoma represents one of a few human tumor types that utilizes vasculogenic mimicry by tumor cell in supporting tumor development.
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Tsitsiou E, Sibley CP, D’Souza SW, Catanescu O, Jacobsen DW, Glazier JD. Homocysteine is transported by the microvillous plasma membrane of human placenta. J Inherit Metab Dis 2011; 34:57-65. [PMID: 20567909 PMCID: PMC2966547 DOI: 10.1007/s10545-010-9141-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2010] [Revised: 04/01/2010] [Accepted: 05/31/2010] [Indexed: 12/18/2022]
Abstract
Elevated maternal plasma concentrations of homocysteine (Hcy) are associated with pregnancy complications and adverse neonatal outcomes. The postulate that we wish to advance here is that placental transport of Hcy, by competing with endogenous amino acids for transporter activity, may account for some of the damaging impacts of Hcy on placental metabolism and function as well as fetal development. In this article, we provide an overview of some recent studies characterising the transport mechanisms for Hcy across the microvillous plasma membrane (MVM) of the syncytiotrophoblast, the transporting epithelium of human placenta. Three Hcy transport systems have been identified, systems L, A and y(+)L. This was accomplished using a strategy of competitive inhibition to investigate the effects of Hcy on the uptake of well-characterised radiolabelled substrates for each transport system into isolated MVM vesicles. The reverse experiments were also performed, examining the effects of model substrates on [³⁵S]L-Hcy uptake. This article describes the evidence for systems L, A and y(+)L involvement in placental Hcy transport and discusses the physiological implications of these findings with respect to placental function and fetal development.
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Affiliation(s)
- Eleni Tsitsiou
- Maternal and Fetal Health Research Group, School of Biomedicine, University of Manchester, Manchester Academic Health Science Centre, St Mary’s Hospital, Oxford Road, Manchester M13 9WL, UK
| | - Colin P. Sibley
- Maternal and Fetal Health Research Group, School of Biomedicine, University of Manchester, Manchester Academic Health Science Centre, St Mary’s Hospital, Oxford Road, Manchester M13 9WL, UK
| | - Stephen W. D’Souza
- Maternal and Fetal Health Research Group, School of Biomedicine, University of Manchester, Manchester Academic Health Science Centre, St Mary’s Hospital, Oxford Road, Manchester M13 9WL, UK
| | - Otilia Catanescu
- Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Donald W. Jacobsen
- Department of Cell Biology, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
- Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Jocelyn D. Glazier
- Maternal and Fetal Health Research Group, School of Biomedicine, University of Manchester, Manchester Academic Health Science Centre, St Mary’s Hospital, Oxford Road, Manchester M13 9WL, UK.
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Kulvietis V, Zalgeviciene V, Didziapetriene J, Rotomskis R. Transport of Nanoparticles through the Placental Barrier. TOHOKU J EXP MED 2011; 225:225-34. [DOI: 10.1620/tjem.225.225] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Vytautas Kulvietis
- Biomedical Physics Laboratory, Institute of Oncology, Vilnius University
- Biophotonics group of Laser Research Center, Faculty of Physics, Vilnius University
| | | | - Janina Didziapetriene
- Biomedical Physics Laboratory, Institute of Oncology, Vilnius University
- Faculty of Medicine, Vilnius University
| | - Ricardas Rotomskis
- Biomedical Physics Laboratory, Institute of Oncology, Vilnius University
- Biophotonics group of Laser Research Center, Faculty of Physics, Vilnius University
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Sonographic Maturation of the Placenta at 30 to 34 Weeks Is Not Associated With Second Trimester Markers of Placental Insufficiency in Low-risk Pregnancies. JOURNAL OF OBSTETRICS AND GYNAECOLOGY CANADA 2010; 32:1134-1139. [DOI: 10.1016/s1701-2163(16)34736-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Identifying placental dysfunction in women with reduced fetal movements can be used to predict patients at increased risk of pregnancy complications. Med Hypotheses 2010; 76:17-20. [PMID: 20826059 DOI: 10.1016/j.mehy.2010.08.020] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2010] [Revised: 08/12/2010] [Accepted: 08/13/2010] [Indexed: 12/25/2022]
Abstract
Maternal perception of fetal movements has historically been used to indicate fetal wellbeing, and has been used with varying success in recent years to identify those pregnancies at increased risk of stillbirth, and other placental pathologies. We present a hypothesis that links reduced fetal movements (RFM) to fetal growth restriction (FGR) and stillbirth through placental dysfunction, and suggests the possibility that this can allow development of a reliable method to identify those women experiencing RFM who are at increased risk of adverse outcome. Reduced fetal movement is thought to represent fetal compensation in a chronic hypoxic environment due to inadequacies in the placental supply of oxygen and nutrients. Placental analysis in FGR and in stillbirth has revealed a number of structural abnormalities and an imbalance in cell turnover, and in terms of function, FGR is also associated with reduced nutrient transport. Both FGR and stillbirth are linked to changes in maternal levels of placental hormones. However, no such studies have been performed in samples from pregnancies affected by RFM. Currently, there are no formal guidelines to direct the management of such women, although it is recommended they undergo measurement of symphysis-fundal height and cardiotocography, and possibly Doppler ultrasound and biophysical profiling. Novel tests could involve the measurement of placental-derived hormones in maternal serum. To address this hypothesis, macroscopic and microscopic analysis of placental samples from both normal pregnancies and those affected by RFM is needed to detect any changes in structure. Placental function could be evaluated by levels of placental hormones in maternal blood. If placental dysfunction can be linked to RFM, and a robust method of identifying those women with placental insufficiency can be developed; screening patients with RFM could lead to a reduction in perinatal morbidity and mortality.
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Sengers BG, Please CP, Lewis RM. Computational modelling of amino acid transfer interactions in the placenta. Exp Physiol 2010; 95:829-40. [DOI: 10.1113/expphysiol.2010.052902] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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Lewis RM, Greenwood SL, Cleal JK, Crozier SR, Verrall L, Inskip HM, Cameron IT, Cooper C, Sibley CP, Hanson MA, Godfrey KM. Maternal muscle mass may influence system A activity in human placenta. Placenta 2010; 31:418-22. [PMID: 20206993 DOI: 10.1016/j.placenta.2010.02.001] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 01/28/2010] [Accepted: 02/01/2010] [Indexed: 11/28/2022]
Abstract
During pregnancy, nutrient partitioning between the mother and fetus must balance promoting fetal survival and maintaining nutritional status of the mother for her health and future fertility. The nutritional status of the pregnant woman, reflected in her body composition, may affect placental function with consequences for fetal development. We investigated the relationship between maternal body composition and placental system A amino acid transporter activity in 103 term placentas from Southampton Women's Survey pregnancies. Placental system A activity was measured as Na(+)-dependent uptake of 10 mumol/L (14)C-methylaminoisobutyric acid (a system A specific amino acid analogue) in placental villous fragments. Maternal body composition was measured at enrollment pre-pregnancy; in 45 infants neonatal body composition was measured using dual-energy x-ray absorptiometry. Term placental system A activity was lower in women with smaller pre-pregnancy upper arm muscle area (r = 0.27, P = 0.007), but was not related to maternal fat mass. System A activity was lower in mothers who reported undertaking strenuous exercise (24.6 vs 29.7 pmol/mg/15 min in sedentary women, P = 0.03), but was not associated with other maternal lifestyle factors. Lower placental system A activity in women who reported strenuous exercise and had a lower arm muscle area may reflect an adaptation in placental function which protects maternal resources in those with lower nutrient reserves. This alteration may affect fetal development, altering fetal body composition, with long-term consequences.
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Affiliation(s)
- R M Lewis
- Institute of Developmental Sciences, School of Medicine, University of Southampton, UK.
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Placental-specific Igf2 knockout mice exhibit hypocalcemia and adaptive changes in placental calcium transport. Proc Natl Acad Sci U S A 2010; 107:3894-9. [PMID: 20133672 DOI: 10.1073/pnas.0911710107] [Citation(s) in RCA: 74] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Evidence is emerging that the ability of the placenta to supply nutrients to the developing fetus adapts according to fetal demand. To examine this adaptation further, we tested the hypothesis that placental maternofetal transport of calcium adapts according to fetal calcium requirements. We used a mouse model of fetal growth restriction, the placental-specific Igf2 knockout (P0) mouse, shown previously to transiently adapt placental System-A amino acid transporter activity relative to fetal growth. Fetal and placental weights in P0 mice were reduced when compared with WT at both embryonic day 17 (E17) and E19. Ionized calcium concentration [Ca(2+)] was significantly lower in P0 fetal blood compared with both WT and maternal blood at E17 and E19, reflecting a reversal of the fetomaternal [Ca(2+)] gradient. Fetal calcium content was reduced in P0 mice at E17 but not at E19. Unidirectional maternofetal calcium clearance ((Ca) K (mf)) was not different between WT and P0 at E17 but increased in P0 at E19. Expression of the intracellular calcium-binding protein calbindin-D(9K), previously shown to be rate-limiting for calcium transport, was increased in P0 relative to WT placentas between E17 and E19. These data show an increased placental transport of calcium from E17 to E19 in P0 compared to WT. We suggest that this is an adaptation in response to the reduced fetal calcium accumulation earlier in gestation and speculate that the ability of the placenta to adapt its supply capacity according to fetal demand may stretch across other essential nutrients.
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Fowden AL, Sferruzzi-Perri AN, Coan PM, Constancia M, Burton GJ. Placental efficiency and adaptation: endocrine regulation. J Physiol 2009; 587:3459-72. [PMID: 19451204 PMCID: PMC2742275 DOI: 10.1113/jphysiol.2009.173013] [Citation(s) in RCA: 203] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2009] [Accepted: 05/06/2009] [Indexed: 12/23/2022] Open
Abstract
Size at birth is critical in determining life expectancy and is dependent primarily on the placental supply of nutrients. However, the fetus is not just a passive recipient of nutrients from the placenta. It exerts a significant acquisitive drive for nutrients, which acts through morphological and functional adaptations in the placenta, particularly when the genetically determined drive for fetal growth is compromised by adverse intrauterine conditions. These adaptations alter the efficiency with which the placenta supports fetal growth, which results in optimal growth for prevailing conditions in utero. This review examines placental efficiency as a means of altering fetal growth, the morphological and functional adaptations that influence placental efficiency and the endocrine regulation of these processes.
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Affiliation(s)
- A L Fowden
- Department of Physiology, Development and Neuroscience, University of Cambridge, Physiology Building, Downing Street, Cambridge CB2 3EG, UK.
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