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Darby JRT, Saini BS, Holman SL, Hammond SJ, Perumal SR, Macgowan CK, Seed M, Morrison JL. Acute-on-chronic: using magnetic resonance imaging to disentangle the haemodynamic responses to acute and chronic fetal hypoxaemia. Front Med (Lausanne) 2024; 11:1340012. [PMID: 38933113 PMCID: PMC11199546 DOI: 10.3389/fmed.2024.1340012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Accepted: 06/04/2024] [Indexed: 06/28/2024] Open
Abstract
Introduction The fetal haemodynamic response to acute episodes of hypoxaemia are well characterised. However, how these responses change when the hypoxaemia becomes more chronic in nature such as that associated with fetal growth restriction (FGR), is less well understood. Herein, we utilised a combination of clinically relevant MRI techniques to comprehensively characterize and differentiate the haemodynamic responses occurring during acute and chronic periods of fetal hypoxaemia. Methods Prior to conception, carunclectomy surgery was performed on non-pregnant ewes to induce FGR. At 108-110 days (d) gestational age (GA), pregnant ewes bearing control (n = 12) and FGR (n = 9) fetuses underwent fetal catheterisation surgery. At 117-119 days GA, ewes underwent MRI sessions where phase-contrast (PC) and T2 oximetry were used to measure blood flow and oxygenation, respectively, throughout the fetal circulation during a normoxia and then an acute hypoxia state. Results Fetal oxygen delivery (DO2) was lower in FGR fetuses than controls during the normoxia state but cerebral DO2 remained similar between fetal groups. Acute hypoxia reduced both overall fetal and cerebral DO2. FGR increased ductus venosus (DV) and foramen ovale (FO) blood flow during both the normoxia and acute hypoxia states. Pulmonary blood flow (PBF) was lower in FGR fetuses during the normoxia state but similar to controls during the acute hypoxia state when PBF in controls was decreased. Conclusion Despite a prevailing level of chronic hypoxaemia, the FGR fetus upregulates the preferential streaming of oxygen-rich blood via the DV-FO pathway to maintain cerebral DO2. However, this upregulation is unable to maintain cerebral DO2 during further exposure to an acute episode of hypoxaemia. The haemodynamic alterations required at the level of the liver and lung to allow the DV-FO pathway to maintain cerebral DO2, may have lasting consequences on hepatic function and pulmonary vascular regulation after birth.
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Affiliation(s)
- Jack R. T. Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Brahmdeep S. Saini
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Research Institute, Toronto, ON, Canada
| | - Stacey L. Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Sarah J. Hammond
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Sunthara Rajan Perumal
- Preclinical, Imaging & Research Laboratories, South Australian Health & Medical Research Institute, Adelaide, SA, Australia
| | - Christopher K. Macgowan
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Research Institute, Toronto, ON, Canada
| | - Mike Seed
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Research Institute, Toronto, ON, Canada
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Janna L. Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
- Peter Gilgan Centre for Research and Learning, The Hospital for Sick Children, Research Institute, Toronto, ON, Canada
- Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada
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Darby JRT, Williams GK, Cho SKS, Meakin AS, Holman SL, Quinn M, Wiese MD, Macgowan CK, Seed M, Morrison JL. Acute resveratrol exposure does not impact hemodynamics of the fetal sheep. Physiol Rep 2023; 11:e15749. [PMID: 37332034 PMCID: PMC10277215 DOI: 10.14814/phy2.15749] [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: 04/29/2023] [Revised: 05/29/2023] [Accepted: 05/29/2023] [Indexed: 06/20/2023] Open
Abstract
Babies born growth restricted are at an increased risk of both poor short-and long-term outcomes. Current interventions to improve fetal growth are ineffective and do not lower the lifetime risk of poor health status. Maternal resveratrol (RSV) treatment increases uterine artery blood flow, fetal oxygenation, and fetal weight. However, studies suggest that diets high in polyphenols such as RSV may impair fetal hemodynamics. We aimed to characterize the effect of RSV on fetal hemodynamics to further assess its safety as an intervention strategy. Pregnant ewes underwent magnetic resonance imaging (MRI) scans to measure blood flow and oxygenation within the fetal circulation using phase contrast-MRI and T2 oximetry. Blood flow and oxygenation measures were performed in a basal state and then repeated while the fetus was exposed to RSV. Fetal blood pressure and heart rate were not different between states. RSV did not impact fetal oxygen delivery (DO2 ) or consumption (VO2 ). Blood flow and oxygen delivery throughout the major vessels of the fetal circulation were not different between basal and RSV states. As such, acute exposure of the fetus to RSV does not directly impact fetal hemodynamics. This strengthens the rationale for the use of RSV as an intervention strategy against fetal growth restriction.
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Affiliation(s)
- Jack R. T. Darby
- Early Origins of Adult Health Research GroupUniSA: Clinical and Health SciencesUniversity of South AustraliaSouth AustraliaAdelaideAustralia
| | - Georgia K. Williams
- Preclinical, Imaging and Research LaboratoriesSouth Australian Health and Medical Research InstituteAdelaideSouth AustraliaAustralia
| | - Steven K. S. Cho
- Early Origins of Adult Health Research GroupUniSA: Clinical and Health SciencesUniversity of South AustraliaSouth AustraliaAdelaideAustralia
- Univeristy of Toronto and The Hospital for Sick ChildrenTorontoOntarioCanada
| | - Ashley S. Meakin
- Early Origins of Adult Health Research GroupUniSA: Clinical and Health SciencesUniversity of South AustraliaSouth AustraliaAdelaideAustralia
| | - Stacey L. Holman
- Early Origins of Adult Health Research GroupUniSA: Clinical and Health SciencesUniversity of South AustraliaSouth AustraliaAdelaideAustralia
| | - Megan Quinn
- Early Origins of Adult Health Research GroupUniSA: Clinical and Health SciencesUniversity of South AustraliaSouth AustraliaAdelaideAustralia
| | - Michael D. Wiese
- Centre for Pharmaceutical Innovation, UniSA: Clinical and Health SciencesUniversity of South AustraliaSouth AustraliaAdelaideAustralia
| | | | - Mike Seed
- Univeristy of Toronto and The Hospital for Sick ChildrenTorontoOntarioCanada
| | - Janna L. Morrison
- Early Origins of Adult Health Research GroupUniSA: Clinical and Health SciencesUniversity of South AustraliaSouth AustraliaAdelaideAustralia
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Flouri D, Darby JRT, Holman SL, Cho SKS, Dimasi CG, Perumal SR, Ourselin S, Aughwane R, Mufti N, Macgowan CK, Seed M, David AL, Melbourne A, Morrison JL. Placental MRI Predicts Fetal Oxygenation and Growth Rates in Sheep and Human Pregnancy. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2022; 9:e2203738. [PMID: 36031385 PMCID: PMC9596844 DOI: 10.1002/advs.202203738] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 08/05/2022] [Indexed: 06/09/2023]
Abstract
Magnetic resonance imaging (MRI) assessment of fetal blood oxygen saturation (SO2 ) can transform the clinical management of high-risk pregnancies affected by fetal growth restriction (FGR). Here, a novel MRI method assesses the feasibility of identifying normally grown and FGR fetuses in sheep and is then applied to humans. MRI scans are performed in pregnant ewes at 110 and 140 days (term = 150d) gestation and in pregnant women at 28+3 ± 2+5 weeks to measure feto-placental SO2 . Birth weight is collected and, in sheep, fetal blood SO2 is measured with a blood gas analyzer (BGA). Fetal arterial SO2 measured by BGA predicts fetal birth weight in sheep and distinguishes between fetuses that are normally grown, small for gestational age, and FGR. MRI feto-placental SO2 in late gestation is related to fetal blood SO2 measured by BGA and body weight. In sheep, MRI feto-placental SO2 in mid-gestation is related to fetal SO2 later in gestation. MRI feto-placental SO2 distinguishes between normally grown and FGR fetuses, as well as distinguishing FGR fetuses with and without normal Doppler in humans. Thus, a multi-compartment placental MRI model detects low placental SO2 and distinguishes between small hypoxemic fetuses and normally grown fetuses.
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Affiliation(s)
- Dimitra Flouri
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonSE1 7EUUK
- Department of Medical Physics and Biomedical EngineeringUniversity College LondonLondonWC1E 6BTUK
| | - Jack R. T. Darby
- Early Origins of Adult Health Research GroupHealth and Biomedical InnovationUniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSA 5001Australia
| | - Stacey L. Holman
- Early Origins of Adult Health Research GroupHealth and Biomedical InnovationUniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSA 5001Australia
| | - Steven K. S. Cho
- Early Origins of Adult Health Research GroupHealth and Biomedical InnovationUniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSA 5001Australia
- Department of PhysiologyThe Hospital for Sick ChildrenUniversity of TorontoTorontoON M5G 1X8Canada
| | - Catherine G. Dimasi
- Early Origins of Adult Health Research GroupHealth and Biomedical InnovationUniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSA 5001Australia
| | - Sunthara R. Perumal
- South Australian Health & Medical Research InstitutePreclinicalImaging & Research LaboratoriesAdelaideSA 5001Australia
| | - Sebastien Ourselin
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonSE1 7EUUK
| | - Rosalind Aughwane
- Department of Medical Physics and Biomedical EngineeringUniversity College LondonLondonWC1E 6BTUK
- Elizabeth Garrett Anderson Institute for Women's HealthUniversity College LondonLondonWC1E 6AUUK
| | - Nada Mufti
- Department of Medical Physics and Biomedical EngineeringUniversity College LondonLondonWC1E 6BTUK
- Elizabeth Garrett Anderson Institute for Women's HealthUniversity College LondonLondonWC1E 6AUUK
| | - Christopher K. Macgowan
- Division of Translational MedicineThe Hospital for Sick ChildrenUniversity of TorontoTorontoON M5G 1X8Canada
- Department of Medical BiophysicsUniversity of TorontoTorontoON M5S 1A1Canada
| | - Mike Seed
- Department of PaediatricsDivision of CardiologyThe Hospital for Sick ChildrenUniversity of TorontoTorontoON M5G 1X8Canada
- Department of Diagnostic ImagingThe Hospital for Sick ChildrenUniversity of TorontoTorontoON M5G 1X8Canada
| | - Anna L. David
- Elizabeth Garrett Anderson Institute for Women's HealthUniversity College LondonLondonWC1E 6AUUK
- NIHR Biomedical Research CentreUniversity College London HospitalsLondonW1T 7DNUK
| | - Andrew Melbourne
- School of Biomedical Engineering and Imaging SciencesKing's College LondonLondonSE1 7EUUK
- Department of Medical Physics and Biomedical EngineeringUniversity College LondonLondonWC1E 6BTUK
- Early Origins of Adult Health Research GroupHealth and Biomedical InnovationUniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSA 5001Australia
| | - Janna L. Morrison
- Early Origins of Adult Health Research GroupHealth and Biomedical InnovationUniSA Clinical and Health SciencesUniversity of South AustraliaAdelaideSA 5001Australia
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4
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Dimasi CG, Lazniewska J, Plush SE, Saini BS, Holman SL, Cho SKS, Wiese MD, Sorvina A, Macgowan CK, Seed M, Brooks DA, Morrison JL, Darby JRT. Redox ratio in the left ventricle of the growth restricted fetus is positively correlated with cardiac output. JOURNAL OF BIOPHOTONICS 2021; 14:e202100157. [PMID: 34499415 DOI: 10.1002/jbio.202100157] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 09/01/2021] [Accepted: 09/03/2021] [Indexed: 06/13/2023]
Abstract
Intrauterine growth restriction (IUGR) is a result of limited substrate supply to the developing fetus in utero, and can be caused by either placental, genetic or environmental factors. Babies born IUGR can have poor long-term health outcomes, including being at higher risk of developing cardiovascular disease. Limited substrate supply in the IUGR fetus not only changes the structure of the heart but may also affect metabolism and function of the developing heart. We have utilised two imaging modalities, two-photon microscopy and phase-contrast MRI (PC-MRI), to assess alterations in cardiac metabolism and function using a sheep model of IUGR. Two-photon imaging revealed that the left ventricle of IUGR fetuses (at 140-141 d GA) had a reduced optical redox ratio, suggesting a reliance on glycolysis for ATP production. Concurrently, the use of PC-MRI to measure foetal left ventricular cardiac output (LVCO) revealed a positive correlation between LVCO and redox ratio in IUGR, but not control fetuses. These data suggest that altered heart metabolism in IUGR fetuses is indicative of reduced cardiac output, which may contribute to poor cardiac outcomes in adulthood.
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Affiliation(s)
- Catherine G Dimasi
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Joanna Lazniewska
- Mechanisms in Cell Biology and Disease Research Group, UniSA Cancer Research Institute, University of South Australia, Adelaide, South Australia, Australia
| | - Sally E Plush
- Future Industries Institute, University of South Australia, Adelaide, South Australia, Australia
- Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Brahmdeep S Saini
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Steven K S Cho
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Michael D Wiese
- Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Alexandra Sorvina
- Mechanisms in Cell Biology and Disease Research Group, UniSA Cancer Research Institute, University of South Australia, Adelaide, South Australia, Australia
| | - Christopher K Macgowan
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Mike Seed
- Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Doug A Brooks
- Mechanisms in Cell Biology and Disease Research Group, UniSA Cancer Research Institute, University of South Australia, Adelaide, South Australia, Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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5
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Lazniewska J, Darby JRT, Holman SL, Sorvina A, Plush SE, Massi M, Brooks DA, Morrison JL. In utero substrate restriction by placental insufficiency or maternal undernutrition decreases optical redox ratio in foetal perirenal fat. JOURNAL OF BIOPHOTONICS 2021; 14:e202000322. [PMID: 33389813 DOI: 10.1002/jbio.202000322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Revised: 12/04/2020] [Accepted: 12/30/2020] [Indexed: 06/12/2023]
Abstract
Intrauterine growth restriction (IUGR) can result from reduced delivery of substrates, including oxygen and glucose, during pregnancy and may be caused by either placental insufficiency or maternal undernutrition. As a consequence of IUGR, there is altered programming of adipose tissue and this can be associated with metabolic diseases later in life. We have utilised two sheep models of IUGR, placental restriction and late gestation undernutrition, to determine the metabolic effects of growth restriction on foetal perirenal adipose tissue (PAT). Two-photon microscopy was employed to obtain an optical redox ratio, which gives an indication of cell metabolism. PAT of IUGR foetuses exhibited higher metabolic activity, altered lipid droplet morphology, upregulation of cytochrome c oxidase subunit genes and decreased expression of genes involved in growth and differentiation. Our results indicate that there are adaptations in PAT of IUGR foetuses that might be protective and ensure survival in response to an IUGR insult.
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Affiliation(s)
- Joanna Lazniewska
- Mechanisms in Cell Biology and Disease Research Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Alexandra Sorvina
- Mechanisms in Cell Biology and Disease Research Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Sally E Plush
- Future Industries Institute, University of South Australia, Adelaide, South Australia, Australia
| | - Massimiliano Massi
- Department of Chemistry, Curtin University, Perth, Western Australia, Australia
| | - Doug A Brooks
- Mechanisms in Cell Biology and Disease Research Group, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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6
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Aujla T, Darby JRT, Saini BS, Lock MC, Holman SL, Bradshaw EL, Perumal SR, McInnes SJP, Voelcker NH, Wiese MD, Macgowan CK, Seed M, Morrison JL. Impact of resveratrol-mediated increase in uterine artery blood flow on fetal haemodynamics, blood pressure and oxygenation in sheep. Exp Physiol 2021; 106:1166-1180. [PMID: 33600040 DOI: 10.1113/ep089237] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 02/15/2021] [Indexed: 11/08/2022]
Abstract
NEW FINDINGS What is the central question of this study? Uterine artery blood flow helps to maintain fetal oxygen and nutrient delivery. We investigated the effects of increased uterine artery blood flow mediated by resveratrol on fetal growth, haemodynamics, blood pressure regulation and oxygenation in pregnant sheep. What is the main finding and its importance? Fetuses from resveratrol-treated ewes were significantly larger and exhibited a haemodynamic profile that might promote peripheral growth. Absolute uterine artery blood flow was positively correlated with umbilical vein oxygen saturation, absolute fetal oxygen delivery and fetal growth. Increasing uterine artery blood flow with compounds such as resveratrol might have clinical significance for pregnancy conditions in which fetal growth and oxygenation are compromised. ABSTRACT High placental vascular resistance hinders uterine artery (UtA) blood flow and fetal substrate delivery. In the same group of animals as the present study, we have previously shown that resveratrol (RSV) increases UtA blood flow, fetal weight and oxygenation in an ovine model of human pregnancy. However, the mechanisms behind changes in growth and the effects of increases in UtA blood flow on fetal circulatory physiology have yet to be investigated. Twin-bearing ewes received s.c. vehicle (VEH, n = 5) or RSV (n = 6) delivery systems at 113 days of gestation (term = 150 days). Magnetic resonance imaging was performed at 123-124 days to quantify fetal volume, blood flow and oxygen saturation of major fetal vessels. At 128 days, i.v. infusions of sodium nitroprusside and phenylephrine were administered to study the vascular tone of the fetal descending aorta. Maternal RSV increased fetal body volume (P = 0.0075) and weight (P = 0.0358), with no change in brain volume or brain weight. There was a positive relationship between absolute UtA blood flow and umbilical vein oxygen saturation, absolute fetal oxygen delivery and combined fetal twin volume (all P ≤ 0.05). There were no differences between groups in fetal haemodynamics or blood pressure regulation except for higher blood flow to the lower body in RSV fetuses (P = 0.0170). The observed increase in fetal weight might be helpful in pregnancy conditions in which fetal growth and oxygen delivery are compromised. Further preclinical investigations on the mechanism(s) accounting for these changes and the potential to improve growth in complicated pregnancies are warranted.
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Affiliation(s)
- Tanroop Aujla
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada.,Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Brahmdeep S Saini
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada.,Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Emma L Bradshaw
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Sunthara R Perumal
- Preclinical Imaging and Research Laboratories, South Australian Health & Medical Research Institute, Adelaide, South Australia, Australia
| | - Steven J P McInnes
- UniSA STEM, University of South Australia, Adelaide, South Australia, Australia
| | - Nicolas H Voelcker
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Clayton, Victoria, Australia.,Department of Materials Science and Engineering, Monash University, Clayton, Victoria, Australia
| | - Michael D Wiese
- Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
| | - Christopher K Macgowan
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Mike Seed
- Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada.,Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia.,Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, Australia
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Darby JRT, Varcoe TJ, Holman SL, McMillen IC, Morrison JL. The reliance on α-adrenergic receptor stimuli for blood pressure regulation in the chronically hypoxaemic fetus is not dependent on post-ganglionic activation. J Physiol 2020; 599:1307-1318. [PMID: 33347615 DOI: 10.1113/jp280693] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 11/30/2020] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS Chronic hypoxaemia is associated with intrauterine growth restriction (IUGR) and a predisposition to the development of hypertension in adult life. IUGR fetuses exhibit a greater reliance on α-adrenergic activation for blood pressure regulation. The fetal blood pressure response to post-ganglionic blockade is not different between control and IUGR fetuses. The decrease in mean arterial pressure is greater in the IUGR sheep fetus after α-adrenergic receptor blockade at the level of the vasculature and this is inversely related to fetal P O 2 . The increased reliance that the IUGR fetus has on α-adrenergic activation for maintenance of mean arterial pressure is not a result of increased post-ganglionic sympathetic activation. ABSTRACT Intrauterine growth restriction (IUGR) is associated with an increased risk of cardiovascular disease in adult life. Placental restriction (PR) in sheep results in chronic hypoxaemia and early onset IUGR with increased circulating plasma noradrenaline concentrations. These IUGR fetuses exhibit a greater decrease in mean arterial pressure (MAP) during α-adrenergic blockade. We aimed to determine the role of post-ganglionic sympathetic activation with respect to regulating MAP in IUGR fetal sheep. PR was induced by carunclectomy surgery prior to conception. Fetal vascular catheterization was performed at 110-126 days gestational age (GA) (term, 150 days) in nine control and seven PR-IUGR fetuses. The fetal blood pressure response to both a post-ganglionic and an α-adrenergic receptor blocker was assessed at 116-120 days GA and/or 129-131 days GA. The effect of both post ganglionic and α-adrenergic blockade on fetal blood pressure was then compared between control and IUGR fetuses at both GAs. There was no difference in the effect of post-ganglionic blockade on MAP in control and IUGR fetal sheep at either 116-120 days GA or 129-131 days GA. α-adrenergic receptor blockade decreased MAP to the same extent in both control and IUGR fetuses at 116-120 days GA. At 129-131 days GA, the drop in MAP in response to α-adrenergic receptor blockade was greater in IUGR fetuses than controls. There was a significant inverse relationship between the drop in MAP in response to α-adrenergic receptor blockade at both GAs with fetal P O 2 . Thus, the increased dependence on α-adrenergic activation for blood pressure regulation in the chronically hypoxaemic IUGR fetus is not a result of increased post-ganglionic sympathetic activation.
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Affiliation(s)
- Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Tamara J Varcoe
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - I Caroline McMillen
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
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8
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Schrauben EM, Darby JRT, Saini BS, Holman SL, Lock MC, Perumal SR, Seed M, Morrison JL, Macgowan CK. Technique for comprehensive fetal hepatic blood flow assessment in sheep using 4D flow MRI. J Physiol 2020; 598:3555-3567. [PMID: 32533704 DOI: 10.1113/jp279631] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 06/04/2020] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS The comprehensive visualization and quantification of in vivo fetal hepatic haemodynamics, particularly the shunting of ductus venosus blood, has been elusive and is not yet fully understood. We introduce the combination of chronically instrumented fetal sheep and 4D flow MRI of the whole fetal liver, which allows retrospective blood flow measurement in all visible vessels as well as qualitative assessment. The applicability and usefulness of this technique is exhibited in normally grown fetal Merino sheep in mid- and late-gestation with detailed dynamic distribution of hepatic blood flow presented. The feasibility of this approach in clinical pathology is demonstrated in two growth-restricted fetuses at mid-gestation. Further exemplification of blood flow quantification is performed over major hepatic vessels. ABSTRACT Although the fetal vasculature has been demarcated and well understood for several decades, the corresponding haemodynamics permitting oxygen- and nutrient-rich blood delivery to the fetal organs has been comparatively difficult to study. We married two well-established methods: 4D flow MRI, a volumetric and dynamic blood-flow measurement technique, and chronically instrumented sheep to broadly assess fetal hepatic circulation. We performed this technique in mid- and late-gestation fetal Merino sheep under normoxemic conditions and major hepatic vasculature was segmented to quantify blood flow and related parameters. Dynamic blood flow was visualized, exhibiting an acceleration of umbilical vein blood through the ductus venosus as well as spiralling into the inferior vena cava where its stream remained separate from that of the hepatic veins and lower body. Ductus venosus changes from mid- to late-gestation included larger diameter (mid: 5.8 ± 0.9 vs. late: 7.1 ± 1.1 mm; P = 0.003) and cross-sectional area (mid: 27.1 ± 8.6 vs. late: 40.4 ± 11.8 mm2 ; P = 0.003), and lower velocity averaged over the cardiac cycle (mid: 15.7 ± 5.4 vs. late: 9.8 ± 7.0 cm s-1 ; P = 0.020). This resulted in higher magnitude blood flow (indexed to umbilical vein input) at mid-gestation in the ductus venosus (mid: 0.73 ± 0.21; late: 0.46 ± 0.21; P = 0.008). The visualization and quantification results support the further use of this technique to better understand regional blood flow changes during normal or abnormal fetal growth, as well as to observe acute haemodynamic responses to physiological challenges or drug interventions.
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Affiliation(s)
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia
| | - Brahmdeep S Saini
- Heart Centre, Hospital for Sick Children, Faculty of Medicine, Institute of Medical Science, University of Toronto
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia
| | - Sunthara R Perumal
- Preclinical Imaging and Research Laboratories, South Australian Health and Medical Research Institute
| | - Mike Seed
- Division of Cardiology, Hospital for Sick Children, Department of Paediatrics, University of Toronto
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia
| | - Christopher K Macgowan
- Translational Medicine, Hospital for Sick Children, Department of Medical Biophysics, University of Toronto
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9
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Fetal Growth Restriction and Hypertension in the Offspring: Mechanistic Links and Therapeutic Directions. J Pediatr 2020; 224:115-123.e2. [PMID: 32450071 PMCID: PMC8086836 DOI: 10.1016/j.jpeds.2020.05.028] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 05/14/2020] [Accepted: 05/14/2020] [Indexed: 12/24/2022]
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10
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Darby JRT, Schrauben EM, Saini BS, Holman SL, Perumal SR, Seed M, Macgowan CK, Morrison JL. Umbilical vein infusion of prostaglandin I 2 increases ductus venosus shunting of oxygen-rich blood but does not increase cerebral oxygen delivery in the fetal sheep. J Physiol 2020; 598:4957-4967. [PMID: 32776527 DOI: 10.1113/jp280019] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 07/27/2020] [Indexed: 01/01/2023] Open
Abstract
KEY POINTS The ductus venosus (DV) is a dynamic fetal shunt that allows substrate-rich blood from the umbilical vein to bypass the hepatic circulation. In vitro studies suggest a direct role of prostaglandin I2 (PGI2 ) in the regulation of DV tone; however, the extent of this regulation has not been determined in utero. 4D flow and T2 oximetry magnetic resonance imaging can be combined to determine blood flow and oxygen delivery within the fetal circulation. PGI2 increases DV shunting of substrate-rich blood but this does not increase cerebral oxygen delivery. ABSTRACT During fetal development, the maintenance of adequate oxygen and nutrient supply to vital organs is regulated through specialized fetal shunts. One of these shunts, the ductus venosus (DV), allows oxygen-rich blood to preferentially stream from the placenta toward the heart and brain. Herein, we combine magnetic resonance imaging (MRI) techniques that measure blood flow (4D flow) and oxygen saturation (T2 oximetry) in the fetal circuit to determine whether umbilical vein infusion of prostaglandin I2 (PGI2 , regulator of DV tone ex utero) directly dilates the DV and thus increases the preferential streaming of oxygen-rich blood toward the brain. At 114-115 days gestational age (dGA; term = 150 days), fetal sheep (n = 6) underwent surgery to implant vascular catheters in the fetal femoral artery, femoral vein, amniotic cavity and umbilical vein. Fetal MRI scans were performed at 119-124 dGA. 4D flow and T2 oximetry were performed to measure blood flow and oxygen saturation across the fetal circulation in both a basal state and whilst the fetus was receiving a continuous infusion of PGI2 . The proportion of oxygenated blood that passed through the DV from the umbilical vein was increased by PGI2 . Cerebral oxygen delivery was unchanged in the PGI2 state. This may be a result of decreased flow from the right to left side of the heart as blood flow through the foramen ovale was decreased by PGI2 . We have shown that although PGI2 acts on the DV to increase the proportion of oxygen-rich blood that bypasses the liver, this does not increase cerebral oxygen delivery in the fetal sheep.
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Affiliation(s)
- Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5001, Australia
| | - Eric M Schrauben
- Univeristy of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Brahmdeep S Saini
- Univeristy of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5001, Australia
| | - Sunthara Rajan Perumal
- Preclinical, Imaging & Research Laboratories, South Australian Health & Medical Research Institute, Adelaide, Australia
| | - Mike Seed
- Univeristy of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada
| | | | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5001, Australia
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11
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Botting KJ, Skeffington KL, Niu Y, Allison BJ, Brain KL, Itani N, Beck C, Logan A, Murray AJ, Murphy MP, Giussani DA. Translatable mitochondria-targeted protection against programmed cardiovascular dysfunction. SCIENCE ADVANCES 2020; 6:eabb1929. [PMID: 32875110 PMCID: PMC7438086 DOI: 10.1126/sciadv.abb1929] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Accepted: 07/08/2020] [Indexed: 06/11/2023]
Abstract
The prenatal origins of heart disease in offspring have been established. However, research in species with developmental milestones comparable to humans is lacking, preventing translation of this knowledge to clinical contexts. Using sheep and chickens, two species with similar cardiovascular developmental milestones to humans, we combined in vivo experiments with in vitro studies at organ, cellular, mitochondrial, and molecular levels. We tested mitochondria-targeted antioxidant intervention with MitoQ against cardiovascular dysfunction programmed by developmental hypoxia, a common complication in human pregnancy. Experiments in sheep determined in vivo fetal and adult cardiovascular function through surgical techniques not possible in humans, while those in chicken embryos isolated effects independent of maternal or placental influences. We show that hypoxia generates mitochondria-derived oxidative stress during cardiovascular development, programming endothelial dysfunction and hypertension in adult offspring. MitoQ treatment during hypoxic development protects against this cardiovascular risk via enhanced nitric oxide signaling, offering a plausible intervention strategy.
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Affiliation(s)
- K. J. Botting
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
- Cambridge Cardiovascular Strategic Research Initiative, Cambridge, UK
- Barcroft Centre, University of Cambridge, Cambridge, UK
| | - K. L. Skeffington
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
- Barcroft Centre, University of Cambridge, Cambridge, UK
| | - Y. Niu
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
- Cambridge Cardiovascular Strategic Research Initiative, Cambridge, UK
- Barcroft Centre, University of Cambridge, Cambridge, UK
| | - B. J. Allison
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
- Barcroft Centre, University of Cambridge, Cambridge, UK
| | - K. L. Brain
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
- Barcroft Centre, University of Cambridge, Cambridge, UK
| | - N. Itani
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
- Barcroft Centre, University of Cambridge, Cambridge, UK
| | - C. Beck
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
- Barcroft Centre, University of Cambridge, Cambridge, UK
| | - A. Logan
- MRC-Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - A. J. Murray
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
| | - M. P. Murphy
- MRC-Mitochondrial Biology Unit, University of Cambridge, Hills Road, Cambridge CB2 0XY, UK
| | - D. A. Giussani
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3EG, UK
- Cambridge Cardiovascular Strategic Research Initiative, Cambridge, UK
- Barcroft Centre, University of Cambridge, Cambridge, UK
- Cambridge Strategic Research Initiative in Reproduction, Cambridge, UK
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12
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Skeffington KL, Beck C, Itani N, Niu Y, Shaw CJ, Giussani DA. Hypertension Programmed in Adult Hens by Isolated Effects of Developmental Hypoxia In Ovo. Hypertension 2020; 76:533-544. [PMID: 32536277 PMCID: PMC7340221 DOI: 10.1161/hypertensionaha.120.15045] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
In mammals, pregnancy complicated by chronic hypoxia can program hypertension in the adult offspring. However, mechanisms remain uncertain because the partial contributions of the challenge on the placenta, mother, and fetus are difficult to disentangle. Here, we used chronic hypoxia in the chicken embryo-an established model system that permits isolation of the direct effects of developmental hypoxia on the cardiovascular system of the offspring, independent of additional effects on the mother or the placenta. Fertilized chicken eggs were exposed to normoxia (N; 21% O2) or hypoxia (H; 13.5%-14% O2) from the start of incubation (day 0) until day 19 (hatching, ≈day 21). Following hatching, all birds were maintained under normoxic conditions until ≈6 months of adulthood. Hypoxic incubation increased hematocrit (+27%) in the chicken embryo and induced asymmetrical growth restriction (body weight, -8.6%; biparietal diameter/body weight ratio, +7.5%) in the hatchlings (all P<0.05). At adulthood (181±4 days), chickens from hypoxic incubations remained smaller (body weight, -7.5%) and showed reduced basal and stimulated in vivo NO bioavailability (pressor response to NG-nitro-L-arginine methyl ester, -43%; phenylephrine pressor response during NO blockade, -61%) with significant hypertension (mean arterial blood pressure, +18%), increased cardiac work (ejection fraction, +12%; fractional shortening, +25%; enhanced baroreflex gain, +456%), and left ventricular wall thickening (left ventricular wall volume, +36%; all P<0.05). Therefore, we show that chronic hypoxia can act directly on a developing embryo to program hypertension, cardiovascular dysfunction, and cardiac wall remodeling in adulthood in the absence of any maternal or placental effects.
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Affiliation(s)
- Katie L. Skeffington
- From the Department of Physiology, Development and Neuroscience, University of Cambridge, United Kingdom (K.L.S., C.B., N.I., Y.N., C.J.S., D.A.G.)
| | - Christian Beck
- From the Department of Physiology, Development and Neuroscience, University of Cambridge, United Kingdom (K.L.S., C.B., N.I., Y.N., C.J.S., D.A.G.)
| | - Nozomi Itani
- From the Department of Physiology, Development and Neuroscience, University of Cambridge, United Kingdom (K.L.S., C.B., N.I., Y.N., C.J.S., D.A.G.)
| | - Youguo Niu
- From the Department of Physiology, Development and Neuroscience, University of Cambridge, United Kingdom (K.L.S., C.B., N.I., Y.N., C.J.S., D.A.G.)
| | - Caroline J. Shaw
- From the Department of Physiology, Development and Neuroscience, University of Cambridge, United Kingdom (K.L.S., C.B., N.I., Y.N., C.J.S., D.A.G.),Department of Metabolism, Digestion and Reproduction, Institute of Reproductive and Developmental Biology, Imperial College London, United Kingdom (C.J.S.)
| | - Dino A. Giussani
- From the Department of Physiology, Development and Neuroscience, University of Cambridge, United Kingdom (K.L.S., C.B., N.I., Y.N., C.J.S., D.A.G.)
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13
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Saini BS, Darby JRT, Portnoy S, Sun L, van Amerom J, Lock MC, Soo JY, Holman SL, Perumal SR, Kingdom JC, Sled JG, Macgowan CK, Morrison JL, Seed M. Normal human and sheep fetal vessel oxygen saturations by T2 magnetic resonance imaging. J Physiol 2020; 598:3259-3281. [PMID: 32372463 DOI: 10.1113/jp279725] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Accepted: 04/30/2020] [Indexed: 12/21/2022] Open
Abstract
KEY POINTS Human fetal Doppler ultrasound and invasive blood gas measurements obtained by cordocentesis or at the time of delivery reveal similarities with sheep (an extensively used model for human fetal cardiovascular physiology). Oxygen saturation (SO2 ) measurements in human fetuses have been limited to the umbilical and scalp vessels, providing little information about normal regional SO2 differences in the fetus. Blood T2 MRI relaxometry presents a non-invasive measure of SO2 in the major fetal vessels. This study presents the first in vivo validation of fetal vessel T2 oximetry against the in vitro T2-SO2 relationship using catheterized sheep fetuses and compares the normal SO2 in the major vessels between the human and sheep fetal circulations. Human fetal vessel SO2 by T2 MRI confirms many similarities with the sheep fetal circulation and is able to demonstrate regional differences in SO2 ; in particular the significantly higher SO2 in the left versus right heart. ABSTRACT Blood T2 magnetic resonance imaging (MRI) relaxometry non-invasively measures oxygen saturation (SO2 ) in major vessels but has not been validated in fetuses in vivo. We compared the blood T2-SO2 relationship in vitro (tubes) and in vivo (vessels) in sheep, and measured SO2 across the normal human and sheep fetal circulations by T2. Singleton pregnant ewes underwent surgery to implant vascular catheters. In vitro and in vivo sheep blood T2 measurements were related to corresponding SO2 measured using a blood gas analyser, as well as relating T2 and SO2 of human fetal blood in vitro. MRI oximetry was performed in the major vessels of 30 human fetuses at 36 weeks (term, 40 weeks) and 10 fetal sheep (125 days; term, 150 days). The fidelity of in vivo fetal T2 oximetry was confirmed through comparison of in vitro and in vivo sheep blood T2-SO2 relationships (P = 0.1). SO2 was similar between human and sheep fetuses, as was the fetal oxygen extraction fraction (human, 33 ± 11%; sheep, 34 ± 7%; P = 0.798). The presence of streaming in the human fetal circulation was demonstrated by the SO2 gradient between the ascending aorta (68 ± 10%) and the main pulmonary artery (49 ± 9%; P < 0.001). Human and sheep fetal vessel MRI oximetry based on T2 is a validated approach that confirms the presence of streaming of umbilical venous blood towards the heart and brain. Streaming is important in ensuring oxygen delivery to these organs and its disruption may have important implications for organ development, especially in conditions such as congenital heart disease and fetal growth restriction.
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Affiliation(s)
- Brahmdeep S Saini
- Institute of Medical Science, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Sharon Portnoy
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada
| | - Liqun Sun
- Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Joshua van Amerom
- Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Jia Yin Soo
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Sunthara R Perumal
- Preclinical Imaging and Research Laboratories, South Australian Health and Medical Research Institute, Adelaide, South Australia, 5086, Australia
| | - John C Kingdom
- Department of Obstetrics and Gynaecology, Maternal-Fetal Medicine, Mount Sinai Hospital, Toronto, Ontario, M5G 1X5, Canada.,Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario, M5G 1E2, Canada
| | - John G Sled
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
| | - Christopher K Macgowan
- Translational Medicine, The Hospital for Sick Children, Toronto, Ontario, M5G 0A4, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, M5G 1L7, Canada
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Health and Biomedical Innovation, UniSA: Clinical and Health Sciences, University of South Australia, Adelaide, South Australia, 5000, Australia
| | - Mike Seed
- Institute of Medical Science, University of Toronto, Toronto, Ontario, M5S 1A8, Canada.,Division of Cardiology, The Hospital for Sick Children, Toronto, Ontario, M5G 1X8, Canada.,Department of Obstetrics and Gynaecology, University of Toronto, Toronto, Ontario, M5G 1E2, Canada
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14
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Darby JRT, Varcoe TJ, Orgeig S, Morrison JL. Cardiorespiratory consequences of intrauterine growth restriction: Influence of timing, severity and duration of hypoxaemia. Theriogenology 2020; 150:84-95. [PMID: 32088029 DOI: 10.1016/j.theriogenology.2020.01.080] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 01/31/2020] [Indexed: 12/28/2022]
Abstract
At birth, weight of the neonate is used as a marker of the 9-month journey as a fetus. Those neonates born less than the 10th centile for their gestational age are at risk of being intrauterine growth restricted. However, this depends on their genetic potential for growth and the intrauterine environment in which they grew. Alterations in the supply of oxygen and nutrients to the fetus will decrease fetal growth, but these alterations occur due to a range of causes that are maternal, placental or fetal in nature. Consequently, IUGR neonates are a heterogeneous population. For this reason, it is likely that these neonates will respond differently to interventions compared not only to normally grown fetuses, but also to other neonates that are IUGR but have travelled a different path to get there. Thus, a range of models of IUGR should be studied to determine the effects of IUGR on the development and function of the heart and lung and subsequently the impact of interventions to improve development of these organs. Here we focus on a range of models of IUGR caused by manipulation of the maternal, placental or fetal environment on cardiorespiratory outcomes.
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Affiliation(s)
- Jack R T Darby
- Early Origins of Adult Health Research Group, Australia; School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia
| | - Tamara J Varcoe
- Early Origins of Adult Health Research Group, Australia; School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia
| | - Sandra Orgeig
- School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Australia; School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, Australia.
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15
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Darby JRT, Saini BS, Soo JY, Lock MC, Holman SL, Bradshaw EL, McInnes SJP, Voelcker NH, Macgowan CK, Seed M, Wiese MD, Morrison JL. Subcutaneous maternal resveratrol treatment increases uterine artery blood flow in the pregnant ewe and increases fetal but not cardiac growth. J Physiol 2019; 597:5063-5077. [PMID: 31483497 DOI: 10.1113/jp278110] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Accepted: 08/28/2019] [Indexed: 12/27/2022] Open
Abstract
KEY POINTS Substrate restriction during critical developmental windows of gestation programmes offspring for a predisposition towards cardiovascular disease in adult life. This study aimed to determine the effect of maternal resveratrol (RSV) treatment in an animal model in which chronic fetal catheterisation is possible and the timing of organ maturation reflects that of the human. Maternal RSV treatment increased uterine artery blood flow, fetal oxygenation and fetal weight. RSV was not detectable in the fetal circulation, indicating that it may not cross the sheep placenta. This study highlights RSV as a possible intervention to restore fetal substrate supply in pregnancies affected by placental insufficiency. ABSTRACT Suboptimal in utero environments with reduced substrate supply during critical developmental windows of gestation predispose offspring to non-communicable diseases such as cardiovascular disease (CVD). Improving fetal substrate supply in these pregnancies may ameliorate the predisposition these offspring have toward adult-onset CVD. This study aimed to determine the effect of maternal resveratrol (RSV) supplementation on uterine artery blood flow and the direct effects of RSV on the fetal heart in a chronically catheterised sheep model of human pregnancy. Maternal RSV treatment significantly increased uterine artery blood flow as measured by phase contrast magnetic resonance imaging, mean gestational fetal P a O 2 and S a O 2 as well as fetal weight. RSV was not detectable in the fetal circulation, and mRNA and protein expression of the histone/protein deacetylase SIRT1 did not differ between treatment groups. No effect of maternal RSV supplementation on AKT/mTOR or CAMKII signalling in the fetal left ventricle was observed. Maternal RSV supplementation is capable of increasing fetal oxygenation and growth in an animal model in which cardiac development parallels that of the human.
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Affiliation(s)
- Jack R T Darby
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia, 5001.,School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, Australia, 5001
| | - Brahmdeep S Saini
- Univeristy of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jia Yin Soo
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia, 5001.,School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, Australia, 5001
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia, 5001.,School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, Australia, 5001
| | - Stacey L Holman
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia, 5001.,School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, Australia, 5001
| | - Emma L Bradshaw
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia, 5001.,School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, Australia, 5001
| | - Steven J P McInnes
- Future Industries Institute, University of South Australia, Adelaide, SA, Australia.,School of Engineering, Division of Information Technology, Engineering and the Environment, University of South Australia, Adelaide, SA, Australia, 5095
| | - Nicolas H Voelcker
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical Sciences, Monash University, Victoria, Australia.,Department of Materials Science and Engineering, Monash University, Clayton, Victoria, 3800, Australia
| | | | - Mike Seed
- Univeristy of Toronto and The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Michael D Wiese
- School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, Australia, 5001
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, University of South Australia, Adelaide, SA, Australia, 5001.,School of Pharmacy & Medical Sciences, University of South Australia, Adelaide, SA, Australia, 5001
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16
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Mechanical characterization of arteries affected by fetal growth restriction in guinea pigs (Cavia porcellus). J Mech Behav Biomed Mater 2018; 88:92-101. [PMID: 30142566 DOI: 10.1016/j.jmbbm.2018.08.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 08/09/2018] [Accepted: 08/10/2018] [Indexed: 12/11/2022]
Abstract
Fetal growth restriction (FGR) is a perinatal condition associated with a low birth weight that results mainly from maternal and placental constrains. Newborns affected by this condition are more likely to develop in the long term cardiovascular diseases whose origins would be in an altered vascular structure and function defined during fetal development. Thus, this study presents the modeling and numerical simulation of systemic vessels from guinea pig fetuses affected by FGR. We aimed to characterize the biomechanical properties of the arterial wall of FGR-derived the aorta, carotid, and femoral arteries by performing ring tensile and ring opening tests and, based on these data, to simulate the biomechanical behavior of FGR vessels under physiological conditions. The material parameters were first obtained from the experimental data of the ring tensile test. Then, the residual stresses were determined from the ring opening test and taken as initial stresses in the simulation of the ring tensile test. These two coupled steps are iteratively considered in a nonlinear least-squares algorithm to obtain the final material parameters. Then, the stress distribution changes along the arterial wall under physiological pressure were quantified using the adjusted material parameters. Overall, the obtained results provide a realistic approximation of the residual stresses and the changes in the mechanical behavior under physiological conditions.
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17
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Camm EJ, Botting KJ, Sferruzzi-Perri AN. Near to One's Heart: The Intimate Relationship Between the Placenta and Fetal Heart. Front Physiol 2018; 9:629. [PMID: 29997513 PMCID: PMC6029139 DOI: 10.3389/fphys.2018.00629] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 05/09/2018] [Indexed: 01/19/2023] Open
Abstract
The development of the fetal heart is exquisitely controlled by a multitude of factors, ranging from humoral to mechanical forces. The gatekeeper regulating many of these factors is the placenta, an external fetal organ. As such, resistance within the placental vascular bed has a direct influence on the fetal circulation and therefore, the developing heart. In addition, the placenta serves as the interface between the mother and fetus, controlling substrate exchange and release of hormones into both circulations. The intricate relationship between the placenta and fetal heart is appreciated in instances of clinical placental pathology. Abnormal umbilical cord insertion is associated with congenital heart defects. Likewise, twin-to-twin transfusion syndrome, where monochorionic twins have unequal sharing of their placenta due to inter-twin vascular anastomoses, can result in cardiac remodeling and dysfunction in both fetuses. Moreover, epidemiological studies have suggested a link between placental phenotypic traits and increased risk of cardiovascular disease in adult life. To date, the mechanistic basis of the relationships between the placenta, fetal heart development and later risk of cardiac dysfunction have not been fully elucidated. However, studies using environmental exposures and gene manipulations in experimental animals are providing insights into the pathways involved. Likewise, surgical instrumentation of the maternal and fetal circulations in large animal species has enabled the manipulation of specific humoral and mechanical factors to investigate their roles in fetal cardiac development. This review will focus on such studies and what is known to date about the link between the placenta and heart development.
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Affiliation(s)
- Emily J Camm
- Department of Physiology, Development and Neuroscience and Centre for Trophoblast Research, University of Cambridge, Cambridge, United Kingdom
| | - Kimberley J Botting
- Department of Physiology, Development and Neuroscience and Centre for Trophoblast Research, University of Cambridge, Cambridge, United Kingdom
| | - Amanda N Sferruzzi-Perri
- Department of Physiology, Development and Neuroscience and Centre for Trophoblast Research, University of Cambridge, Cambridge, United Kingdom
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18
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Soo JY, Wiese MD, Berry MJ, McMillen IC, Morrison JL. Intrauterine growth restriction may reduce hepatic drug metabolism in the early neonatal period. Pharmacol Res 2018; 134:68-78. [PMID: 29890254 DOI: 10.1016/j.phrs.2018.06.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 05/23/2018] [Accepted: 06/04/2018] [Indexed: 11/26/2022]
Abstract
The effects of intrauterine growth restriction (IUGR) extend well into postnatal life. IUGR is associated with an increased risk of adverse health outcomes, which often leads to greater medication usage. Many medications require hepatic metabolism for activation or clearance, but hepatic function may be altered in IUGR fetuses. Using a sheep model of IUGR, we determined the impact of IUGR on hepatic drug metabolism and drug transporter expression, both important mediators of fetal drug exposure, in late gestation and in neonatal life. In the late gestation fetus, IUGR decreased the gene expression of uptake drug transporter OATPC and increased P-glycoprotein protein expression in the liver, but there was no change in the activity of the drug metabolising enzymes CYP3A4 or CYP2D6. In contrast, at 3 weeks of age, CYP3A4 activity was reduced in the livers of lambs born with low birth weight (LBW), indicating that LBW results in changes to drug metabolising capacity in neonatal life. Together, these results suggest that IUGR may reduce hepatic drug metabolism in fetal and neonatal life through different mechanisms.
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Affiliation(s)
- Jia Yin Soo
- Early Origins of Adult Health Research Group, Adelaide, SA, 5001, Australia; School of Pharmacy & Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, 5001, Australia
| | - Michael D Wiese
- School of Pharmacy & Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, 5001, Australia
| | - Mary J Berry
- Centre for Translational Physiology, Wellington, New Zealand; Department of Paediatrics and Child Health, University of Otago, Wellington, New Zealand
| | | | - Janna L Morrison
- Early Origins of Adult Health Research Group, Adelaide, SA, 5001, Australia; School of Pharmacy & Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, 5001, Australia.
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19
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Zhang S, Barker P, Botting KJ, Roberts CT, McMillan CM, McMillen IC, Morrison JL. Early restriction of placental growth results in placental structural and gene expression changes in late gestation independent of fetal hypoxemia. Physiol Rep 2018; 4:4/23/e13049. [PMID: 27923976 PMCID: PMC5357827 DOI: 10.14814/phy2.13049] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 11/02/2016] [Accepted: 10/31/2016] [Indexed: 01/12/2023] Open
Abstract
Placental restriction and insufficiency are associated with altered patterns of placental growth, morphology, substrate transport capacity, growth factor expression, and glucocorticoid exposure. We have used a pregnant sheep model in which the intrauterine environment has been perturbed by uterine carunclectomy (Cx). This procedure results in early restriction of placental growth and either the development of chronic fetal hypoxemia (PaO2≤17 mmHg) in late gestation or in compensatory placental growth and the maintenance of fetal normoxemia (PaO2>17 mmHg). Based on fetal PaO2, Cx, and Control ewes were assigned to either a normoxemic fetal group (Nx) or a hypoxemic fetal group (Hx) in late gestation, resulting in 4 groups. Cx resulted in a decrease in the volumes of fetal and maternal connective tissues in the placenta and increased placental mRNA expression of IGF2, vascular endothelial growth factor (VEGF), VEGFR‐2,ANGPT2, and TIE2. There were reduced volumes of trophoblast, maternal epithelium, and maternal connective tissues in the placenta and a decrease in placental GLUT1 and 11βHSD2 mRNA expression in the Hx compared to Nx groups. Our data show that early restriction of placental growth has effects on morphological and functional characteristics of the placenta in late gestation, independent of whether the fetus becomes hypoxemic. Similarly, there is a distinct set of placental changes that are only present in fetuses that were hypoxemic in late gestation, independent of whether Cx occurred. Thus, we provide further understanding of the different placental cellular and molecular mechanisms that are present in early placental restriction and in the emergence of later placental insufficiency.
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Affiliation(s)
- Song Zhang
- Early Origins of Adult Health Research Group, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
| | - Paige Barker
- Early Origins of Adult Health Research Group, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
| | - Kimberley J Botting
- Early Origins of Adult Health Research Group, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
| | - Claire T Roberts
- The Robinson Research Institute and Adelaide Medical School, University of Adelaide, Adelaide, South Australia, Australia
| | - Christine M McMillan
- Early Origins of Adult Health Research Group, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
| | - Isabella Caroline McMillen
- Early Origins of Adult Health Research Group, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
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20
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Duan AQ, Darby JRT, Soo JY, Lock MC, Zhu MY, Flynn LV, Perumal SR, Macgowan CK, Selvanayagam JB, Morrison JL, Seed M. Feasibility of phase-contrast cine magnetic resonance imaging for measuring blood flow in the sheep fetus. Am J Physiol Regul Integr Comp Physiol 2017; 317:R780-R792. [PMID: 29351431 DOI: 10.1152/ajpregu.00273.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Phase-contrast cine MRI (PC-MRI) is the gold-standard noninvasive technique for measuring vessel blood flow and has previously been applied in the human fetal circulation. We aimed to assess the feasibility of using PC-MRI to define the distribution of the fetal circulation in sheep. Fetuses were catheterized at 119-120 days of gestation (term, 150 days) and underwent MRI at ∼123 days of gestation under isoflurane anesthesia, ventilated at a FIO2 of 1.0. PC-MRI was performed using a fetal arterial blood pressure catheter signal for cardiac triggering. Blood flows were measured in the major fetal vessels, including the main pulmonary artery, ascending and descending aorta, superior vena cava, ductus arteriosus, left and right pulmonary arteries, umbilical vein, ductus venosus, and common carotid artery and were indexed to estimated fetal weight. The combined ventricular output, pulmonary blood flow, and flow across the foramen ovale were calculated from vessel flows. Intraobserver and interobserver agreement and reproducibility was assessed. Blood flow measurements were successfully obtained in 61 out of 74 vessels (82.4%) interrogated in 9 fetuses. There was good intraobserver [R = 0.998, P < 0.0001; intraclass correlation (ICC) = 0.997] and interobserver agreement (R = 0.996, P < 0.0001; ICC = 0.996). Repeated MRI measurements showed good reproducibility (R = 0.989, P = 0.0002; ICC = 0.990). We conclude that PC-MRI using fetal catheters for gating triggers is feasible in the major vessels of late gestation fetal sheep. This approach may provide a useful new tool for assessing the circulatory characteristics of fetal sheep models of human disease, including fetal growth restriction and congenital heart disease.
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Affiliation(s)
- An Qi Duan
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.,Division of Cardiology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Jack R T Darby
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Jia Yin Soo
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Mitchell C Lock
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Meng Yuan Zhu
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.,Division of Cardiology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Lucy V Flynn
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Sunthara Rajan Perumal
- Preclinical, Imaging, and Research Laboratories, South Australian Health and Medical Research Institute, Gilles Plains, Adelaide, Australia
| | - Christopher K Macgowan
- Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada.,Division of Translational Medicine, Hospital for Sick Children, Toronto, Ontario, Canada
| | | | - Janna L Morrison
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Mike Seed
- Institute of Medical Science, University of Toronto, Toronto, Ontario, Canada.,Division of Cardiology, Hospital for Sick Children, Toronto, Ontario, Canada
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21
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Soo JY, Orgeig S, McGillick EV, Zhang S, McMillen IC, Morrison JL. Normalisation of surfactant protein -A and -B expression in the lungs of low birth weight lambs by 21 days old. PLoS One 2017; 12:e0181185. [PMID: 28949968 PMCID: PMC5614422 DOI: 10.1371/journal.pone.0181185] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2017] [Accepted: 06/27/2017] [Indexed: 11/18/2022] Open
Abstract
Intrauterine growth restriction (IUGR) induced by placental restriction (PR) in the sheep negatively impacts lung and pulmonary surfactant development during fetal life. Using a sheep model of low birth weight (LBW), we found that there was an increase in mRNA expression of surfactant protein (SP)-A, -B and -C in the lung of LBW lambs but no difference in the protein expression of SP-A or -B. LBW also resulted in increased lysosome-associated membrane glycoprotein (LAMP)-3 mRNA expression, which may indicate an increase in either the density of type II Alveolar epithelial cells (AEC) or maturity of type II AECs. Although there was an increase in glucocorticoid receptor (GR) and 11β-hydroxysteroid dehydrogenase (11βHSD)-1 mRNA expression in the lung of LBW lambs, we found no change in the protein expression of these factors, suggesting that the increase in SP mRNA expression is not mediated by increased GC signalling in the lung. The increase in SP mRNA expression may, in part, be mediated by persistent alterations in hypoxia signalling as there was an increase in lung HIF-2α mRNA expression in the LBW lamb. The changes in the hypoxia signalling pathway that persist within the lung after birth may be involved in maintaining SP production in the LBW lamb.
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Affiliation(s)
- Jia Yin Soo
- Early Origins of Adult Health Research Group, School of Pharmacy & Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - Sandra Orgeig
- Molecular & Evolutionary Physiology of the Lung Laboratory, School of Pharmacy & Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - Erin Victoria McGillick
- Early Origins of Adult Health Research Group, School of Pharmacy & Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
- Molecular & Evolutionary Physiology of the Lung Laboratory, School of Pharmacy & Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - Song Zhang
- Early Origins of Adult Health Research Group, School of Pharmacy & Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - I Caroline McMillen
- Early Origins of Adult Health Research Group, School of Pharmacy & Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - Janna L. Morrison
- Early Origins of Adult Health Research Group, School of Pharmacy & Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
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22
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Reduced fetal vitamin D status by maternal undernutrition during discrete gestational windows in sheep. J Dev Orig Health Dis 2017; 8:370-381. [PMID: 28327211 DOI: 10.1017/s2040174417000149] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Placental transport of vitamin D and other nutrients (e.g. amino acids, fats and glucose) to the fetus is sensitive to maternal and fetal nutritional cues. We studied the effect of maternal calorific restriction on fetal vitamin D status and the placental expression of genes for nutrient transport [aromatic T-type amino acid transporter-1 (TAT-1); triglyceride hydrolase/lipoprotein uptake facilitator lipoprotein lipase (LPL)] and vitamin D homeostasis [CYP27B1; vitamin D receptor (VDR)], and their association with markers of fetal cardiovascular function and skeletal muscle growth. Pregnant sheep received 100% total metabolizable energy (ME) requirements (control), 40% total ME requirements peri-implantation [PI40, 1-31 days of gestation (dGA)] or 50% total ME requirements in late gestation (L, 104-127 dGA). Fetal, but not maternal, plasma 25-hydroxy-vitamin D (25OHD) concentration was lower in PI40 and L maternal undernutrition groups (P<0.01) compared with the control group at 0.86 gestation. PI40 group placental CYP27B1 messenger RNA (mRNA) levels were increased (P<0.05) compared with the control group. Across all groups, higher fetal plasma 25OHD concentration was associated with higher skeletal muscle myofibre and capillary density (P<0.05). In the placenta, higher VDR mRNA levels were associated with higher TAT-1 (P<0.05) and LPL (P<0.01) mRNA levels. In the PI40 maternal undernutrition group only, reduced fetal plasma 25OHD concentration may be mediated in part by altered placental CYP27B1. The association between placental mRNA levels of VDR and nutrient transport genes suggests a way in which the placenta may integrate nutritional cues in the face of maternal dietary challenges and alter fetal physiology.
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23
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Allison BJ, Brain KL, Niu Y, Kane AD, Herrera EA, Thakor AS, Botting KJ, Cross CM, Itani N, Skeffington KL, Beck C, Giussani DA. Fetal in vivo continuous cardiovascular function during chronic hypoxia. J Physiol 2016; 594:1247-64. [PMID: 26926316 PMCID: PMC4771786 DOI: 10.1113/jp271091] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 09/10/2015] [Indexed: 12/31/2022] Open
Abstract
Although the fetal cardiovascular defence to acute hypoxia and the physiology underlying it have been established for decades, how the fetal cardiovascular system responds to chronic hypoxia has been comparatively understudied. We designed and created isobaric hypoxic chambers able to maintain pregnant sheep for prolonged periods of gestation under controlled significant (10% O2) hypoxia, yielding fetal mean P(aO2) levels (11.5 ± 0.6 mmHg) similar to those measured in human fetuses of hypoxic pregnancy. We also created a wireless data acquisition system able to record fetal blood flow signals in addition to fetal blood pressure and heart rate from free moving ewes as the hypoxic pregnancy is developing. We determined in vivo longitudinal changes in fetal cardiovascular function including parallel measurement of fetal carotid and femoral blood flow and oxygen and glucose delivery during the last third of gestation. The ratio of oxygen (from 2.7 ± 0.2 to 3.8 ± 0.8; P < 0.05) and of glucose (from 2.3 ± 0.1 to 3.3 ± 0.6; P < 0.05) delivery to the fetal carotid, relative to the fetal femoral circulation, increased during and shortly after the period of chronic hypoxia. In contrast, oxygen and glucose delivery remained unchanged from baseline in normoxic fetuses. Fetal plasma urate concentration increased significantly during chronic hypoxia but not during normoxia (Δ: 4.8 ± 1.6 vs. 0.5 ± 1.4 μmol l(-1), P<0.05). The data support the hypotheses tested and show persisting redistribution of substrate delivery away from peripheral and towards essential circulations in the chronically hypoxic fetus, associated with increases in xanthine oxidase-derived reactive oxygen species.
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Affiliation(s)
- B J Allison
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - K L Brain
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - Y Niu
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - A D Kane
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - E A Herrera
- Laboratorio de Función y Reactividad Vascular, Programa de Fisiopatología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - A S Thakor
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK.,Department of Radiology, Stanford University Medical Centre, Palo Alto, CA, 94305, USA
| | - K J Botting
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - C M Cross
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - N Itani
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - K L Skeffington
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - C Beck
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
| | - D A Giussani
- Department of Physiology, Development & Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3EG, UK
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24
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Affiliation(s)
- Lucy R. Green
- Centre for Fetal Origins of Adult Disease, Universiy of Southampton, 887(F) Princess Anne Hospital, Coxford Road, Southanmpton SO16 5YA United Kingdom
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25
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McGillick EV, Orgeig S, Morrison JL. Regulation of lung maturation by prolyl hydroxylase domain inhibition in the lung of the normally grown and placentally restricted fetus in late gestation. Am J Physiol Regul Integr Comp Physiol 2016; 310:R1226-43. [PMID: 26936783 DOI: 10.1152/ajpregu.00469.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Accepted: 02/23/2016] [Indexed: 12/28/2022]
Abstract
Intrauterine growth restriction induced by placental restriction (PR) in sheep leads to chronic hypoxemia and reduced surfactant maturation. The underlying molecular mechanism involves altered regulation of hypoxia signaling by increased prolyl hydroxylase domain (PHD) expression. Here, we evaluated the effect of intratracheal administration of the PHD inhibitor dimethyloxalylglycine (DMOG) on functional, molecular, and structural determinants of lung maturation in the control and PR sheep fetus. There was no effect of DMOG on fetal blood pressure or fetal breathing movements. DMOG reduced lung expression of genes regulating hypoxia signaling (HIF-3α, ACE1), antioxidant defense (CAT), lung liquid reabsorption (SCNN1-A, ATP1-A1, AQP-1, AQP-5), and surfactant maturation (SFTP-A, SFTP-B, SFTP-C, PCYT1A, LPCAT, ABCA3, LAMP3) in control fetuses. There were very few effects of DMOG on gene expression in the PR fetal lung (reduced lung expression of angiogenic factor ADM, water channel AQP-5, and increased expression of glucose transporter SLC2A1). DMOG administration in controls reduced total lung lavage phosphatidylcholine to the same degree as in PR fetuses. These changes appear to be regulated at the molecular level as there was no effect of DMOG on the percent tissue, air space, or numerical density of SFTP-B positive cells in the control and PR lung. Hence, DMOG administration mimics the effects of PR in reducing surfactant maturation in the lung of control fetuses. The limited responsiveness of the PR fetal lung suggests a potential biochemical limit or reduced plasticity to respond to changes in regulation of hypoxia signaling following exposure to chronic hypoxemia in utero.
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Affiliation(s)
- Erin V McGillick
- Early Origins of Adult Health Research Group and Molecular and Evolutionary Physiology of the Lung Laboratory, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
| | - Sandra Orgeig
- Molecular and Evolutionary Physiology of the Lung Laboratory, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, Australia
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26
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Burns P, Liu HL, Kuthiala S, Fecteau G, Desrochers A, Durosier LD, Cao M, Frasch MG. Instrumentation of Near-term Fetal Sheep for Multivariate Chronic Non-anesthetized Recordings. J Vis Exp 2015:e52581. [PMID: 26555084 DOI: 10.3791/52581] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
The chronically instrumented pregnant sheep has been used as a model of human fetal development and responses to pathophysiologic stimuli such as endotoxins, bacteria, umbilical cord occlusions, hypoxia and various pharmacological treatments. The life-saving clinical practices of glucocorticoid treatment in fetuses at risk of premature birth and the therapeutic hypothermia have been developed in this model. This is due to the unique amenability of the non-anesthetized fetal sheep to the surgical placement and maintenance of catheters and electrodes, allowing repetitive blood sampling, substance injection, recording of bioelectrical activity, application of electric stimulation and in vivo organ imaging. Here we describe the surgical instrumentation procedure required to achieve a stable chronically instrumented non-anesthetized fetal sheep model including characterization of the post-operative recovery from blood gas, metabolic and inflammation standpoints.
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Affiliation(s)
- Patrick Burns
- Département de sciences cliniques, CHUV, Université de Montréal, St-Hyacinthe, QC
| | - Hai Lun Liu
- Département d'obstetriques et de gynécologie, CHU Ste-Justine Research Centre, Université de Montréal
| | - Shikha Kuthiala
- Département d'obstetriques et de gynécologie, CHU Ste-Justine Research Centre, Université de Montréal
| | - Gilles Fecteau
- Département de sciences cliniques, CHUV, Université de Montréal, St-Hyacinthe, QC
| | - André Desrochers
- Département de sciences cliniques, CHUV, Université de Montréal, St-Hyacinthe, QC
| | - Lucien Daniel Durosier
- Département d'obstetriques et de gynécologie, CHU Ste-Justine Research Centre, Université de Montréal
| | - Mingju Cao
- Département d'obstetriques et de gynécologie, CHU Ste-Justine Research Centre, Université de Montréal
| | - Martin G Frasch
- Département d'obstetriques et de gynécologie, CHU Ste-Justine Research Centre, Université de Montréal; Département de neurosciences, CHU Ste-Justine Centre de recherche, Université de Montréal; Centre de recherche en reproduction animale (CRRA), Université de Montréal, St-Hyacinthe, QC;
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27
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Orgeig S, McGillick EV, Botting KJ, Zhang S, McMillen IC, Morrison JL. Increased lung prolyl hydroxylase and decreased glucocorticoid receptor are related to decreased surfactant protein in the growth-restricted sheep fetus. Am J Physiol Lung Cell Mol Physiol 2015; 309:L84-97. [PMID: 25934670 DOI: 10.1152/ajplung.00275.2014] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2014] [Accepted: 04/24/2015] [Indexed: 11/22/2022] Open
Abstract
Experimental placental restriction (PR) by carunclectomy in fetal sheep results in intrauterine growth restriction (IUGR), chronic hypoxemia, increased plasma cortisol, and decreased lung surfactant protein (SP) expression. The mechanisms responsible for decreased SP expression are unknown but may involve decreased glucocorticoid (GC) action or changes in hypoxia signaling. Endometrial caruncles were removed from nonpregnant ewes to induce PR. Lungs were collected from control and PR fetuses at 130-135 (n = 19) and 139-145 (n = 28) days of gestation. qRT-PCR and Western blotting were used to quantify lung mRNA and protein expression, respectively, of molecular regulators and downstream targets of the GC and hypoxia-signaling pathways. We confirmed a decrease in SP-A, -B, and -C, but not SP-D, mRNA expression in PR fetuses at both ages. There was a net downregulation of GC signaling with a reduction in GC receptor (GR)-α and -β protein expression and a decrease in the cofactor, GATA-6. GC-responsive genes including transforming growth factor-β1, IL-1β, and β2-adrenergic receptor were not stimulated. Prolyl hydroxylase domain (PHD)2 mRNA and protein and PHD3 mRNA expression increased with a concomitant increase in hypoxia-inducible factor-1α (HIF-1α) and HIF-1β mRNA expression. There was an increase in mRNA expression of several, but not all, hypoxia-responsive genes. Hence, both GC and hypoxia signaling may contribute to reduced SP expression. Although acute hypoxia normally inactivates PHDs, chronic hypoxemia in the PR fetus increased PHD abundance, which normally prevents HIF signaling. This may represent a mechanism by which chronic hypoxemia contributes to the decrease in SP production in the IUGR fetal lung.
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Affiliation(s)
- Sandra Orgeig
- Molecular and Evolutionary Physiology of the Lung Laboratory, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
| | - Erin V McGillick
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia; Molecular and Evolutionary Physiology of the Lung Laboratory, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
| | - Kimberley J Botting
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
| | - Song Zhang
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
| | - I Caroline McMillen
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia;
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28
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Wang KCW, Brooks DA, Summers-Pearce B, Bobrovskaya L, Tosh DN, Duffield JA, Botting KJ, Zhang S, Caroline McMillen I, Morrison JL. Low birth weight activates the renin-angiotensin system, but limits cardiac angiogenesis in early postnatal life. Physiol Rep 2015; 3:3/2/e12270. [PMID: 25649246 PMCID: PMC4393187 DOI: 10.14814/phy2.12270] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Low birth weight (LBW) is associated with increased risk of adult cardiovascular disease and this association may be partly a consequence of early programming of the renin-angiotensin system (RAS). We investigated the effects of LBW on expression of molecules in the RAS and cardiac tissue remodeling. Left ventricular samples were collected from the hearts of 21 days old lambs that were born average birth weight (ABW) and LBW. Cardiac mRNA expression was quantified using real-time RT-PCR and protein expression was quantified using Western blotting. DNA methylation and histone acetylation were assessed by combined bisulfite restriction analysis and chromatin immunoprecipitation, respectively. There were increased plasma renin activity, angiotensin I (ANGI), and ANGII concentrations in LBW compared to ABW lambs at day 20. In LBW lambs, there was increased expression of cardiac ACE2 mRNA, decreased ANGII receptor type 1 (AT1R) protein, and acetylation of histone H3K9 of the AT1R promoter but no changes in AT1R mRNA expression and AT1R promoter DNA methylation. There was no difference in the abundance of proteins involved in autophagy or fibrosis. BIRC5 and VEGF mRNA expression was increased; however, the total length of the capillaries was decreased in the hearts of LBW lambs. Activation of the circulating and local cardiac RAS in neonatal LBW lambs may be expected to increase cardiac fibrosis, autophagy, and capillary length. However, we observed only a decrease in total capillary length, suggesting a dysregulation of the RAS in the heart of LBW lambs and this may have significant implications for heart health in later life.
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Affiliation(s)
- Kimberley C W Wang
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - Doug A Brooks
- Mechanisms in Cell Biology and Disease Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - Brooke Summers-Pearce
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - Larisa Bobrovskaya
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - Darran N Tosh
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - Jaime A Duffield
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - Kimberley J Botting
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - Song Zhang
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - I Caroline McMillen
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, SA, Australia
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29
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Poudel R, McMillen IC, Dunn SL, Zhang S, Morrison JL. Impact of chronic hypoxemia on blood flow to the brain, heart, and adrenal gland in the late-gestation IUGR sheep fetus. Am J Physiol Regul Integr Comp Physiol 2015; 308:R151-62. [DOI: 10.1152/ajpregu.00036.2014] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
In the fetus, there is a redistribution of cardiac output in response to acute hypoxemia, to maintain perfusion of key organs, including the brain, heart, and adrenal glands. There may be a similar redistribution of cardiac output in the chronically hypoxemic, intrauterine growth-restricted fetus. Surgical removal of uterine caruncles in nonpregnant ewe results in the restriction of placental growth (PR) and intrauterine growth. Vascular catheters were implanted in seven control and six PR fetal sheep, and blood flow to organs was determined using microspheres. Placental and fetal weight was significantly reduced in the PR group. Despite an increase in the relative brain weight in the PR group, there was no difference in blood flow to the brain between the groups, although PR fetuses had higher blood flow to the temporal lobe. Adrenal blood flow was significantly higher in PR fetuses, and there was a direct relationship between mean gestational PaO2 and blood flow to the adrenal gland. There was no change in blood flow, but a decrease in oxygen and glucose delivery to the heart in the PR fetuses. In another group, there was a decrease in femoral artery blood flow in the PR compared with the Control group, and this may support blood flow changes to the adrenal and temporal lobe. In contrast to the response to acute hypoxemia, these data show that there is a redistribution of blood flow to the adrenals and temporal lobe, but not the heart or whole brain, in chronically hypoxemic PR fetuses in late gestation.
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Affiliation(s)
- Rajan Poudel
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
| | - I. Caroline McMillen
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
| | - Stacey L. Dunn
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
| | - Song Zhang
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
| | - Janna L. Morrison
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
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Orgeig S, Morrison JL. Does the intrauterine growth-restricted fetus benefit from antenatal glucocorticoids? ACTA ACUST UNITED AC 2014. [DOI: 10.1586/eog.10.4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Mueller CA, Burggren WW, Crossley DA. ANG II and baroreflex control of heart rate in embryonic chickens (Gallus gallus domesticus). Am J Physiol Regul Integr Comp Physiol 2013; 305:R855-63. [DOI: 10.1152/ajpregu.00298.2013] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
ANG II alters the short-term blood pressure buffering capacity of the baroreflex in many adult animals. In embryonic chickens, high plasma ANG II levels contribute to baseline mean arterial pressure (MAP, kPa) without changing heart rate (ƒH, beats/min). We hypothesized, on the basis of these features, that an ANG II-induced reduction in baroreflex sensitivity is present in embryonic chickens as in adults. We examined baroreflex function in day 19 embryonic chickens ( Gallus gallus domesticus) after chronic depletion of endogenous ANG II via angiotensin-converting enzyme (ACE) inhibition with captopril (5 mg/kg) from days 5–18 of incubation. The correlation between MAP and ƒH was assessed using increasing doses of sodium nitroprusside, a vasodilator, and phenylephrine, a vasoconstrictor. We used two analytical methods to evaluate baroreflex function: a conventional “static” method, in which maximal MAP and ƒH responses were examined, and a “dynamic” method that assessed beat-to-beat changes during the response to pharmacological manipulation. Captopril-treated embryos were hypotensive by 19% with baroreflex slopes ∼40% steeper and normalized gains ∼50% higher than controls, and differences across treatments were similar using either analytical method. Furthermore, reintroduction of ANG II via infusion raised MAP back to control levels and decreased the baroreflex gain in captopril-treated embryos. Therefore, during typical chicken development, ANG II dampens the baroreflex regulatory capacity and chicken embryos can be used as a natural model of elevated ANG II for studying developmental cardiovascular function. This study is the first to demonstrate that reduction of embryonic ANG II alters normal baroreflex function.
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Affiliation(s)
- Casey A. Mueller
- Developmental Integrative Biology, Department of Biological Sciences, University of North Texas, Denton, Texas
| | - Warren W. Burggren
- Developmental Integrative Biology, Department of Biological Sciences, University of North Texas, Denton, Texas
| | - Dane A. Crossley
- Developmental Integrative Biology, Department of Biological Sciences, University of North Texas, Denton, Texas
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Lie S, Duffield JA, McMillen IC, Morrison JL, Ozanne SE, Pilgrim C, Muhlhausler BS. The effect of placental restriction on insulin signaling and lipogenic pathways in omental adipose tissue in the postnatal lamb. J Dev Orig Health Dis 2013; 4:421-9. [PMID: 24970733 DOI: 10.1017/s2040174413000202] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Intrauterine growth restriction (IUGR) followed by accelerated growth after birth is associated with an increased risk of abdominal (visceral) obesity and insulin resistance in adult life. The aim of the present study was to determine the impact of IUGR on mRNA expression and protein abundance of insulin signaling molecules in one of the major visceral fat depots, the omental adipose depot. IUGR was induced by placental restriction, and samples of omental adipose tissue were collected from IUGR (n = 9, 5 males, 4 females) and Control (n = 14, 8 males, 6 females) neonatal lambs at 21 days of age. The mRNA expression of the insulin signaling molecules, AMP-kinase (AMPK) and adipogenic/lipogenic genes was determined by qRT-PCR, and protein abundance by Western Blotting. AMPKα2 mRNA expression was increased in male IUGR lambs (0.015 ± 0.002 v. 0.0075 ± 0.0009, P < 0.001). The proportion of the AMPK pool that was phosphorylated (%P-AMPK) was lower in IUGR lambs compared with Controls independent of sex (39 ± 9% v. 100 ± 18%, P < 0.001). The mRNA expression and protein abundance of insulin signaling proteins and adipogenic/lipogenic genes was not different between groups. Thus, IUGR is associated with sex-specific alterations in the mRNA expression of AMPKα2 and a reduction in the percentage of the total AMPK pool that is phosphorylated in the omental adipose tissue of neonatal lambs, before the onset of visceral obesity. These molecular changes would be expected to promote lipid accumulation in the omental adipose depot and may therefore contribute to the onset of visceral adiposity in IUGR animals later in life.
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Affiliation(s)
- S Lie
- 1 Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, The University of South Australia, Adelaide, Australia
| | - J A Duffield
- 1 Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, The University of South Australia, Adelaide, Australia
| | - I C McMillen
- 1 Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, The University of South Australia, Adelaide, Australia
| | - J L Morrison
- 1 Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, The University of South Australia, Adelaide, Australia
| | - S E Ozanne
- 2 Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - C Pilgrim
- 2 Metabolic Research Laboratories, Institute of Metabolic Science, University of Cambridge, Cambridge, UK
| | - B S Muhlhausler
- 1 Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, The University of South Australia, Adelaide, Australia
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Maternal undernutrition during the first week after conception results in decreased expression of glucocorticoid receptor mRNA in the absence of GR exon 17 hypermethylation in the fetal pituitary in late gestation. J Dev Orig Health Dis 2013; 4:391-401. [DOI: 10.1017/s2040174413000378] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Exposure to maternal undernutrition during the periconceptional period results in an earlier prepartum activation of the fetal hypothalamo–pituitary–adrenal (HPA) axis and altered stress responsiveness in the offspring. It is not known whether such changes are a consequence of exposure of the oocyte and/or the early embryo to maternal undernutrition in the periconceptional period. We have compared the effects of ‘periconceptional’ undernutrition (PCUN: maternal undernutrition imposed from at least 45 days before until 6 days after conception), and ‘early preimplantation’ undernutrition (PIUN: maternal undernutrition imposed for only 6 days after conception) on the expression of genes in the fetal anterior pituitary that regulate adrenal growth and steroidogenesis, proopiomelanorcortin (POMC), prohormone convertase 1 (PC1), 11β-hydroxysteroid dehydrogenase type 1 and 2 (11βHSD1 and 2) and the glucocorticoid receptor (GR) in fetal sheep at 136–138 days of gestation. Pituitary GR mRNA expression was significantly lower in the PCUN and PIUN groups in both singletons and twins compared with controls, although this suppression of GR expression was not associated with hypermethylation of the exon 17 region of the GR gene. In twin fetuses, the pituitary 11βHSD1 mRNA expression was significantly higher in the PIUN group compared with the PCUN but not the control group. Thus, exposure of the single or twin embryo to maternal undernutrition for only 1 week after conception is sufficient to cause a suppression of the pituitary GR expression in late gestation. These changes may contribute to the increased stress responsiveness of the HPA axis in the offspring after exposure to poor nutrition during the periconceptional period.
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Antenatal steroids and the IUGR fetus: are exposure and physiological effects on the lung and cardiovascular system the same as in normally grown fetuses? J Pregnancy 2012; 2012:839656. [PMID: 23227338 PMCID: PMC3512319 DOI: 10.1155/2012/839656] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Accepted: 09/06/2012] [Indexed: 02/06/2023] Open
Abstract
Glucocorticoids are administered to pregnant women at risk of preterm labour to promote fetal lung surfactant maturation. Intrauterine growth restriction (IUGR) is associated with an increased risk of preterm labour. Hence, IUGR babies may be exposed to antenatal glucocorticoids. The ability of the placenta or blood brain barrier to remove glucocorticoids from the fetal compartment or the brain is compromised in the IUGR fetus, which may have implications for lung, brain, and heart development. There is conflicting evidence on the effect of exogenous glucocorticoids on surfactant protein expression in different animal models of IUGR. Furthermore, the IUGR fetus undergoes significant cardiovascular adaptations, including altered blood pressure regulation, which is in conflict with glucocorticoid-induced alterations in blood pressure and flow. Hence, antenatal glucocorticoid therapy in the IUGR fetus may compromise regulation of cardiovascular development. The role of cortisol in cardiomyocyte development is not clear with conflicting evidence in different species and models of IUGR. Further studies are required to study the effects of antenatal glucocorticoids on lung, brain, and heart development in the IUGR fetus. Of specific interest are the aetiology of IUGR and the resultant degree, duration, and severity of hypoxemia.
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Wang KCW, Botting KJ, Padhee M, Zhang S, McMillen IC, Suter CM, Brooks DA, Morrison JL. Early origins of heart disease: Low birth weight and the role of the insulin-like growth factor system in cardiac hypertrophy. Clin Exp Pharmacol Physiol 2012; 39:958-64. [DOI: 10.1111/j.1440-1681.2012.05743.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Kimberley CW Wang
- Early Origins of Adult Health Research Group; Sansom Institute for Health Research; School of Pharmacy and Medical Sciences; University of Adelaide; Adelaide; South Australia; Australia
| | | | - Monalisa Padhee
- Early Origins of Adult Health Research Group; Sansom Institute for Health Research; School of Pharmacy and Medical Sciences; University of Adelaide; Adelaide; South Australia; Australia
| | - Song Zhang
- Early Origins of Adult Health Research Group; Sansom Institute for Health Research; School of Pharmacy and Medical Sciences; University of Adelaide; Adelaide; South Australia; Australia
| | - I Caroline McMillen
- Early Origins of Adult Health Research Group; Sansom Institute for Health Research; School of Pharmacy and Medical Sciences; University of Adelaide; Adelaide; South Australia; Australia
| | - Catherine M Suter
- Victor Chang Cardiac Research Institute; Darlinghurst; New South Wales; Australia
| | - Doug A Brooks
- Cell Biology of Diseases Research Group; Sansom Institute for Health Research; School of Pharmacy and Medical Sciences; University of Adelaide; Adelaide; South Australia; Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group; Sansom Institute for Health Research; School of Pharmacy and Medical Sciences; University of Adelaide; Adelaide; South Australia; Australia
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Wang KCW, Brooks DA, Thornburg KL, Morrison JL. Activation of IGF-2R stimulates cardiomyocyte hypertrophy in the late gestation sheep fetus. J Physiol 2012; 590:5425-37. [PMID: 22930271 DOI: 10.1113/jphysiol.2012.238410] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
In vitro studies using rat and fetal sheep cardiomyocytes indicate that, in addition to its role as a clearance receptor, the insulin-like growth factor 2 receptor (IGF-2R) can induce cardiomyocyte hypertrophy. In the present study, we have determined the effect of specific activation of the IGF-2R in the heart of the late gestation fetus on cardiomyocyte development. Leu(27)IGF-2, an IGF-2R agonist, was infused into the fetal left circumflex coronary artery for 4 days beginning at 128.1 ± 0.4 days gestation. Ewes were humanely killed at 132.2 ± 1.2 days gestation (term, 150 days). Fetuses were delivered and hearts dissected to isolate the cardiomyocytes and to collect and snap-freeze tissue. Leu(27)IGF-2 infusion into the left circumflex coronary artery of fetal sheep increased the area of binucleated cardiomyocytes in the left, but not the right, ventricle. However, this infusion of Leu(27)IGF-2 did not change fetal weight, heart weight, blood pressure, blood gases or cardiomyocyte proliferation/binucleation. The increase in cardiomyocyte size in the Leu(27)IGF-2-infused group was associated with increased expression of proteins in the Gαs, but not the Gαq, signalling pathway. We concluded that infusion of Leu(27)IGF-2 into the left circumflex coronary artery causes cardiac IGF-2R activation in the left ventricle of the heart, and this stimulates cardiomyocyte hypertrophy in a Gαs-dependent manner.
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Affiliation(s)
- Kimberley C W Wang
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, SA, Australia 5001
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van der Hout-van der Jagt MB, Oei SG, Bovendeerd PH. A mathematical model for simulation of early decelerations in the cardiotocogram during labor. Med Eng Phys 2012; 34:579-89. [DOI: 10.1016/j.medengphy.2011.09.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 08/29/2011] [Accepted: 09/04/2011] [Indexed: 10/15/2022]
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38
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Wang KCW, Zhang L, McMillen IC, Botting KJ, Duffield JA, Zhang S, Suter CM, Brooks DA, Morrison JL. Fetal growth restriction and the programming of heart growth and cardiac insulin-like growth factor 2 expression in the lamb. J Physiol 2011; 589:4709-22. [PMID: 21807611 DOI: 10.1113/jphysiol.2011.211185] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Reduced growth in fetal life together with accelerated growth in childhood, results in a ~50% greater risk of coronary heart disease in adult life. It is unclear why changes in patterns of body and heart growth in early life can lead to an increased risk of cardiovascular disease in adulthood. We aimed to investigate the role of the insulin-like growth factors in heart growth in the growth-restricted fetus and lamb. Hearts were collected from control and placentally restricted (PR) fetuses at 137-144 days gestation and from average (ABW) and low (LBW) birth weight lambs at 21 days of age. We quantified cardiac mRNA expression of IGF-1, IGF-2 and their receptors, IGF-1R and IGF-2R, using real-time RT-PCR and protein expression of IGF-1R and IGF-2R using Western blotting. Combined bisulphite restriction analysis was used to assess DNA methylation in the differentially methylated region (DMR) of the IGF-2/H19 locus and of the IGF-2R gene. In PR fetal sheep, IGF-2, IGF-1R and IGF-2R mRNA expression was increased in the heart compared to controls. LBW lambs had a greater left ventricle weight relative to body weight as well as increased IGF-2 and IGF-2R mRNA expression in the heart, when compared to ABW lambs. No changes in the percentage of methylation of the DMRs of IGF-2/H19 or IGF-2R were found between PR and LBW when compared to their respective controls. In conclusion, a programmed increased in cardiac gene expression of IGF-2 and IGF-2R may represent an adaptive response to reduced substrate supply (e.g. glucose and/or oxygen) in order to maintain heart growth and may be the underlying cause for increased ventricular hypertrophy and the associated susceptibility of cardiomyocytes to ischaemic damage later in life.
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Affiliation(s)
- Kimberley C W Wang
- Heart Foundation and NHMRC Career Development Research Fellow, Sansom Institute for Health Research, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA 5001, Australia.
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Posterino GS, Dunn SL, Botting KJ, Wang W, Gentili S, Morrison JL. Changes in cardiac troponins with gestational age explain changes in cardiac muscle contractility in the sheep fetus. J Appl Physiol (1985) 2011; 111:236-43. [PMID: 21493721 DOI: 10.1152/japplphysiol.00067.2011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The development of the adult cardiac troponin complex in conjunction with changes in cardiac function and cardiomyocyte binucleation has not been systematically characterized during fetal life in a species where maturation of the cardiomyocytes occurs prenatally as it does in the human. The aim of this study was to correlate the expression of each of the major adult troponin isoforms (T, I, and C) during late gestation (term of 150 days) to changes in both Ca(2+) sensitivity and maximum Ca(2+)-activated force of the contractile apparatus and the maturation of cardiomyocytes. The percentage of mononucleated cardiomyocytes in the right ventricle decreased with gestational age to 46% by 137-142 days of gestation. The length of binucleated cardiomyocytes did not change with gestational age, but the length of binucleated cardiomyocytes relative to heart weight decreased with gestational age. There was no change in the expression of adult cardiac troponin T with increasing gestation. The contractile apparatus was significantly more sensitive to Ca(2+) at 90 days compared with either 132 or 139 days of gestation, consistent with an ∼30% increase in the expression of adult cardiac troponin I between 90 and 110 days of gestation. Maximum Ca(2+)-activated force significantly increased from 90 days compared with 130 days consistent with an increase of ∼40% in cardiac troponin C protein expression. These data show that increased adult cardiac troponin I and C protein expression across late gestation is consistent with reduced Ca(2+) sensitivity and increased maximum Ca(2+)-activated force. Furthermore, changes in cardiac troponin C, not I, protein expression track with the timing of cardiomyocyte binucleation.
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Affiliation(s)
- Giuseppe Saverio Posterino
- Department of Zoology, School of Life Sciences, Faculty of Science and Technology, LaTrobe University, Melbourne, VIC, Australia.
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Loizzo S, Vella S, Loizzo A, Fortuna A, Di Biase A, Salvati S, Frajese GV, Agrapart V, Ramirez Morales R, Spampinato S, Campana G, Capasso A, Galietta G, Guarino I, Carta S, Carru C, Zinellu A, Ghirlanda G, Seghieri G, Renzi P, Franconi F. Sexual dimorphic evolution of metabolic programming in non-genetic non-alimentary mild metabolic syndrome model in mice depends on feed-back mechanisms integrity for pro-opiomelanocortin-derived endogenous substances. Peptides 2010; 31:1598-605. [PMID: 20493223 DOI: 10.1016/j.peptides.2010.05.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2009] [Revised: 05/12/2010] [Accepted: 05/12/2010] [Indexed: 01/05/2023]
Abstract
Previously, we showed that our post-natal handling model induces pro-opiomelanocortin-derived (POMC) endogenous systems alterations in male mice at weaning. These alterations last up to adult age, and are at the basis of adult hormonal and metabolic conditions similar to mild metabolic syndrome/type-2 diabetes. Here, we evaluate how sex influences post-natal programming in these metabolic conditions. Subjects are adult control (non-handled) female (NHF) and male (NHM) CD-1 mice; adult post-natal handled female (HF) and male (HM) mice. Handling consists of daily maternal separation (10 min) plus sham injection, from birth to weaning (21 days). In adult handled males (90-days old) we find not only POMC-derived hormones alterations (enhanced basal plasma corticosterone (+91%) and ACTH (+109%)) but also overweight (+5.4%), fasting hyperglycemia (+40%), hypertriglyceridemia (+21%), enhanced brain mRNA expression of hydroxysteroid(11-beta)dehydrogenase type-1 (HSD11B1) (+49%), and decreased mRNA-HSD11B2 (-39%). Conversely, uric acid, creatinine, HDL(C), total cholesterol, glucose and insulin incremental area under-the-curve are not affected. In females, post-natal handling does not produce both hormonal and dysmetabolic diabetes-like changes; but handling enhances n3- and n6-poly-unsaturated, and decreases saturated fatty acids content in erythrocyte membrane composition in HF versus NHF. In conclusion, for the first time we show that female sex in mice exerts effective protection against the hypothalamus-pituitary-adrenal homeostasis disruption induced by our post-natal handling model on POMC cleavage products; endocrine disruption is in turn responsible for altered metabolic programming in male mice. The role of sex hormones is still to be elucidated.
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MESH Headings
- 11-beta-Hydroxysteroid Dehydrogenase Type 1/genetics
- 11-beta-Hydroxysteroid Dehydrogenase Type 1/metabolism
- 11-beta-Hydroxysteroid Dehydrogenase Type 2/genetics
- 11-beta-Hydroxysteroid Dehydrogenase Type 2/metabolism
- Adrenocorticotropic Hormone/blood
- Animals
- Animals, Newborn
- Brain/metabolism
- Corticosterone/blood
- Diabetes Mellitus, Type 2/blood
- Diabetes Mellitus, Type 2/etiology
- Diabetes Mellitus, Type 2/metabolism
- Feedback, Physiological
- Female
- Gene Expression Regulation, Enzymologic
- Handling, Psychological
- Hypothalamo-Hypophyseal System/metabolism
- Hypothalamo-Hypophyseal System/physiopathology
- Lipid Metabolism/physiology
- Male
- Metabolic Syndrome/blood
- Metabolic Syndrome/etiology
- Metabolic Syndrome/metabolism
- Metabolic Syndrome/physiopathology
- Mice
- Pain Threshold/physiology
- Pituitary-Adrenal System/metabolism
- Pituitary-Adrenal System/physiopathology
- Pro-Opiomelanocortin/metabolism
- RNA, Messenger/metabolism
- Random Allocation
- Sex Characteristics
- Stress, Psychological/complications
- Stress, Psychological/physiopathology
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Affiliation(s)
- Stefano Loizzo
- Department of Therapeutic Research and Medicines Evaluation, Istituto Superiore di Sanità, via Regina Elena 299, 00161 Roma, Italy.
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Morrison JL, Duffield JA, Muhlhausler BS, Gentili S, McMillen IC. Fetal growth restriction, catch-up growth and the early origins of insulin resistance and visceral obesity. Pediatr Nephrol 2010; 25:669-77. [PMID: 20033220 DOI: 10.1007/s00467-009-1407-3] [Citation(s) in RCA: 131] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2009] [Revised: 11/15/2009] [Accepted: 11/18/2009] [Indexed: 12/15/2022]
Abstract
There is an association between growing slowly before birth, accelerated growth in early postnatal life and the emergence of insulin resistance, visceral obesity and glucose intolerance in adult life. In this review we consider the pathway through which intrauterine growth restriction (IUGR) leads to the initial increase in insulin sensitivity and to catch-up growth. We also discuss the importance of the early insulin environment in determining later visceral adiposity and the intrahepatic mechanisms that may result in the emergence of glucose intolerance in a subset of IUGR infants. We present evidence that a key fetal adaptation to poor fetal nutrition is an upregulation of the abundance of the insulin receptor in the absence of an upregulation of insulin signalling in fetal skeletal muscle. After birth, however, there is an upregulation in the abundance of the insulin receptor and the insulin signalling pathway in the IUGR offspring. Thus, the origins of the accelerated postnatal growth rate experienced by IUGR infants lie in the fetal adaptations to a poor nutrient supply. We also discuss how the intracellular availability of free fatty acids and glucose within the visceral adipocyte and hepatocyte in fetal and neonatal life are critical in determining the subsequent metabolic phenotype of the IUGR offspring. It is clear that a better understanding of the relative contributions of the fetal and neonatal nutrient environment to the regulation of key insulin signalling pathways in muscle, visceral adipose tissue and the liver is required to support the development of evidence-based intervention strategies and better outcomes for the IUGR infant.
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Affiliation(s)
- Janna L Morrison
- Sansom Institute of Health Research, School of Pharmacy and Medical Sciences, University of South Australia, Adelaide, SA 5001, Australia
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42
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Orgeig S, Crittenden TA, Marchant C, McMillen IC, Morrison JL. Intrauterine growth restriction delays surfactant protein maturation in the sheep fetus. Am J Physiol Lung Cell Mol Physiol 2010; 298:L575-83. [PMID: 20097737 DOI: 10.1152/ajplung.00226.2009] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Pulmonary surfactant is synthesized by type II alveolar epithelial cells to regulate the surface tension at the air-liquid interface of the air-breathing lung. Developmental maturation of the surfactant system is controlled by many factors including oxygen, glucose, catecholamines, and cortisol. The intrauterine growth-restricted (IUGR) fetus is hypoxemic and hypoglycemic, with elevated plasma catecholamine and cortisol concentrations. The impact of IUGR on surfactant maturation is unclear. Here we investigate the expression of surfactant protein (SP) A, B, and C in lung tissue of fetal sheep at 133 and 141 days of gestation (term 150 +/- 3 days) from control and carunclectomized Merino ewes. Placentally restricted (PR) fetuses had a body weight <2 SD from the mean of control fetuses and a mean gestational Pa(O(2)) <17 mmHg. PR fetuses had reduced absolute, but not relative, lung weight, decreased plasma glucose concentration, and increased plasma cortisol concentration. Lung SP-A, -B, and -C protein and mRNA expression was reduced in PR compared with control fetuses at both ages. SP-B and -C but not SP-A mRNA expression and SP-A but not SP-B or -C protein expression increased with gestational age. Mean gestational Pa(O(2)) was positively correlated with SP-A, -B, and -C protein and SP-B and -C mRNA expression in the younger cohort. SP-A and -B gene expression was inversely related to plasma cortisol concentration. Placental restriction, leading to chronic hypoxemia and hypercortisolemia in the carunclectomy model, results in significant inhibition of surfactant maturation. These data suggest that IUGR fetuses are at significant risk of lung complications, especially if born prematurely.
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Affiliation(s)
- Sandra Orgeig
- Early Origins of Adult Health Research Group, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia
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43
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Gheorghe CP, Goyal R, Mittal A, Longo LD. Gene expression in the placenta: maternal stress and epigenetic responses. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 2010; 54:507-23. [PMID: 19876832 PMCID: PMC2830734 DOI: 10.1387/ijdb.082770cg] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Successful placental development is crucial for optimal growth, development, maturation and survival of the embryo/fetus into adulthood. Numerous epidemiologic and experimental studies have demonstrated the profound influence of intrauterine environment on life, and the diseases to which one is subject as an adult. For the most part, these invidious influences, whether maternal hypoxia, protein or caloric deficiency or excess, and others, represent types of maternal stress. In the present review, we examine certain aspects of gene expression in the placenta as a consequence of maternal stressors. To examine these issues in a controlled manner, and in a species in which the genome has been sequenced, most of these reported studies have been performed in the mouse. Although each individual maternal stress is characterized by up- or down-regulation of specific genes in the placenta, functional analysis reveals some patterns of gene expression common to the several forms of stress. Of critical importance, these genes include those involved in DNA methylation and histone modification, cell cycle regulation, and related global pathways of great relevance to epigenesis and the developmental origins of adult health and disease.
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Affiliation(s)
- Ciprian P Gheorghe
- Center for Perinatal Biology, Department of Physiology, Loma Linda University School of Medicine, Loma Linda, CA, USA
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Muhlhausler BS, Morrison JL, McMillen IC. Rosiglitazone increases the expression of peroxisome proliferator-activated receptor-gamma target genes in adipose tissue, liver, and skeletal muscle in the sheep fetus in late gestation. Endocrinology 2009; 150:4287-94. [PMID: 19520784 DOI: 10.1210/en.2009-0462] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Exposure to maternal overnutrition increases the expression of peroxisome proliferator-activated receptor-gamma (PPARgamma) in adipose tissue before birth, and it has been proposed that the precocial activation of PPARgamma target genes may lead to increased fat deposition in postnatal life. In this study, we determined the effect of intrafetal administration of a PPARgamma agonist, rosiglitazone, on PPARgamma target gene expression in fetal adipose tissue as well indirect actions of rosiglitazone on fetal liver and skeletal muscle. Osmotic pumps containing rosiglitazone (n = 7) or vehicle (15% ethanol, n = 7) were implanted into fetuses at 123-126 d gestation (term = 150 +/- 3 d gestation). At 137-141 d gestation, tissues were collected and mRNA expression of PPARgamma, lipoprotein lipase (LPL), adiponectin, and glycerol-3-phosphate dehydrogenase (G3PDH) in adipose tissue, PPARalpha and PPARgamma-coactivator 1alpha (PGC1alpha) in liver and muscle and phosphoenolpyruvate carboxykinase (PEPCK) in liver determined by quantitative real-time RT-PCR. Plasma insulin concentrations were lower in rosiglitazone-treated fetuses (P < 0.02). Rosiglitazone treatment resulted in increased expression of LPL and adiponectin mRNA (P < 0.01) in fetal adipose tissue. The expression of PPARalpha mRNA in liver (P < 0.05) and PGC1alpha mRNA (P < 0.02) in skeletal muscle were also increased by rosiglitazone treatment. Rosiglitazone treatment increased expression of PPARgamma target genes within fetal adipose tissue and also had direct or indirect actions on the fetal liver and muscle. The effects of activating PPARgamma in fetal adipose tissue mimic those induced by prenatal overnutrition, and it is therefore possible that activation of PPARgamma may be the initiating mechanism in the pathway from prenatal overnutrition to postnatal obesity.
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Affiliation(s)
- B S Muhlhausler
- Sansom Research Institute, University of South Australia, Adelaide 5000, Australia.
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Muhlhausler BS, Duffield JA, Ozanne SE, Pilgrim C, Turner N, Morrison JL, McMillen IC. The transition from fetal growth restriction to accelerated postnatal growth: a potential role for insulin signalling in skeletal muscle. J Physiol 2009; 587:4199-211. [PMID: 19622603 DOI: 10.1113/jphysiol.2009.173161] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
A world-wide series of epidemiological and experimental studies have demonstrated that there is an association between being small at birth, accelerated growth in early postnatal life and the emergence of insulin resistance in adult life. The aim of this study was to investigate why accelerated growth occurs in postnatal life after in utero growth restriction. Samples of quadriceps muscle were collected at approximately 140 days gestation (term approximately 150 days gestation) from normally grown fetal lambs (Control, n = 7) and from growth restricted fetal lambs (placentally restricted: PR, n = 8) and from Control (n = 14) and PR (n = 9) lambs at 21 days after birth. The abundance of the insulin and IGF1 receptor protein was higher in the quadriceps muscle of the PR fetus, but there was a lower abundance of the insulin signalling molecule PKC, and GLUT4 protein in the PR group. At 21 days of postnatal age, insulin receptor abundance remained higher in the muscle of the PR lamb, and there was also an up-regulation of the insulin signalling molecules, PI3Kinase p85, Akt1 and Akt2 and of the GLUT4 protein in the PR group. Fetal growth restriction therefore results in an increased abundance of the insulin receptor in skeletal muscle, which persists after birth when it is associated with an upregulation of insulin signalling molecules and the glucose transporter, GLUT4. These data provide evidence that the origins of the accelerated growth experienced by the small baby after birth lie in the adaptive response of the growth restricted fetus to its low placental substrate supply.
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Affiliation(s)
- B S Muhlhausler
- Early Origins of Adult Health Research Group, Sansom Research Institute, University of South Australia, Adelaide 5001, Australia
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Dyer JL, McMillen IC, Warnes KE, Morrison JL. No evidence for an enhanced role of endothelial nitric oxide in the maintenance of arterial blood pressure in the IUGR sheep fetus. Placenta 2009; 30:705-10. [PMID: 19515421 DOI: 10.1016/j.placenta.2009.05.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2009] [Revised: 04/15/2009] [Accepted: 05/07/2009] [Indexed: 01/21/2023]
Abstract
The fetus makes a number of physiological adaptations to a restriction of placental substrate supply, including a decrease in body growth and an increase in peripheral vasoconstriction which maintains mean arterial pressure (MAP) and supports a redistribution of cardiac output to key fetal organs. It is not known, however, whether chronic restriction of placental substrate supply results in an enhanced or diminished role for vasodilators such as endothelial nitric oxide in the regulation of MAP. We hypothesised that there is an increased contribution of NO to blood pressure regulation in growth restricted fetuses and that a 2h infusion of a nitric oxide synthase inhibitor, N(omega)-nitro-l-arginine methyl ester (l-NAME) would result in an augmented rise in MAP in chronically hypoxemic, placentally restricted (PR, n=8) fetuses compared to controls (n=6) in late gestation. There was no difference in the increase in fetal MAP and decrease in HR during l-NAME infusion between Control and PR fetuses. In the PR group, fetuses with lower mean gestational PaO(2) had a lower increase in MAP during l-NAME infusion. Thus we have found no evidence for an enhanced role of NO in the maintenance of MAP in the chronically hypoxemic IUGR fetus.
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Affiliation(s)
- J L Dyer
- Discipline of Physiology, University of Adelaide, Adelaide, SA 5005, Australia
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Gheorghe CP, Goyal R, Holweger JD, Longo LD. Placental gene expression responses to maternal protein restriction in the mouse. Placenta 2009; 30:411-7. [PMID: 19362366 DOI: 10.1016/j.placenta.2009.03.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2008] [Revised: 03/04/2009] [Accepted: 03/05/2009] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Maternal protein restriction has been shown to have deleterious effects on placental development, and has long-term consequences for the progeny. We tested the hypothesis that, by the use of microarray technology, we could identify specific genes and cellular pathways in the developing placenta that are responsive to maternal protein deprivation, and propose a potential mechanism for observed gene expression changes. METHODS We fed pregnant FVB/NJ mice from day post-coitum 10.5 (DPC10.5) to DPC17.5, an isocaloric diet containing 50% less protein than normal chow. We used the Affymetrix Mouse 430A_2.0 array to measure gene expression changes in the placenta. We functionally annotated the regulated genes, and examined over-represented functional categories and performed pathway analysis. For selected genes, we confirmed the microarray results by use of qPCR. RESULTS We observed 244 probe sets, corresponding to 235 genes, regulated by protein restriction (p<0.001), with ninety-one genes being up-regulated, and 153 down-regulated. Up-regulated genes included those involved in the p53 pathway, apoptosis, negative regulators of cell growth, negative regulators of cell metabolism and genes related to epigenetic control. Down-regulated genes included those involved in nucleotide metabolism. CONCLUSIONS Microarray analysis has allowed us to describe the genetic response to maternal protein deprivation in the mouse placenta. We observed that negative regulators of cell growth and metabolism in conjunction with genes involved in epigenesis were up-regulated, suggesting that protein deprivation may contribute to growth restriction and long-term epigenetic changes in stressed tissues and organs. The challenge will be to understand the cellular and molecular mechanisms of these gene expression responses.
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Affiliation(s)
- C P Gheorghe
- Department of Physiology, Loma Linda University, School of Medicine, Loma Linda, CA 92350, USA
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Morrison JL, Orgeig S. Review: Antenatal Glucocorticoid Treatment of The Growth-restricted Fetus: Benefit or Cost? Reprod Sci 2009; 16:527-38. [DOI: 10.1177/1933719109332821] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Janna L. Morrison
- Sansom Institute, University of South Australia, Adelaide, South Australia, Australia, , Early Origins of Adult Health Research Group, University of South Australia, Adelaide, South Australia, Australia
| | - Sandra Orgeig
- Sansom Institute, University of South Australia, Adelaide, South Australia, Australia
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Gentili S, Morrison JL, McMillen IC. Intrauterine growth restriction and differential patterns of hepatic growth and expression of IGF1, PCK2, and HSDL1 mRNA in the sheep fetus in late gestation. Biol Reprod 2009; 80:1121-7. [PMID: 19208549 DOI: 10.1095/biolreprod.108.073569] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Fetal adaptations to periods of substrate deprivation can result in the programming of glucose intolerance, insulin resistance, and metabolic dysfunction in later life. Placental insufficiency can be associated with either sparing or sacrifice of fetal liver growth, and these different responses may have different metabolic consequences. It is unclear what intrahepatic mechanisms determine the differential responses of the fetal liver to substrate restriction. We investigated the effects of placental restriction (PR) on liver growth and the hepatic expression of SLC2A1, IGF1, IGF2, IGF1R, IGF2R, PPARGC1A, PPARA, PRKAA1, PRKAA2, PCK2, and HSDL1 mRNA in fetal sheep at 140-145 days of gestation. A mean gestational arterial partial pressure of oxygen less than 17 mmHg was defined as hypoxic, and a relative liver of weight more than 2 SD below the mean liver weight of controls was defined as reduced liver growth. Fetuses therefore were defined as control-normoxic (C-N; n = 9), PR-normoxic (PR-N; n = 7), PR-hypoxic (PR-H; n = 8), or PR-hypoxic reduced liver growth (PR-H RLG; n = 4). Hepatic SLC2A1 mRNA expression was highest (P < 0.05) in the PR-H fetuses, in which liver growth was maintained. Expression of IGF1 mRNA was decreased (P < 0.05) only in the PR-H RLG group. Hepatic expression of HSDL1, PPARGC1A, and PCK2 mRNA also were increased (P < 0.05) in the PR-H RLG fetuses. The present study highlights that intrahepatic responses to fetal substrate restriction may exist that protect the liver from decreased growth and, potentially, from a decreased responsiveness to the actions of insulin in postnatal life.
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Affiliation(s)
- Sheridan Gentili
- Early Origins of Adult Health Research Group, Sansom Institute, School of Pharmacy and Medical Sciences, University of South Australia, South Australia, Australia.
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Left ventricular isovolumic relaxation and renin-angiotensin system in the growth restricted fetus. Eur J Obstet Gynecol Reprod Biol 2008; 140:33-7. [PMID: 18722896 DOI: 10.1016/j.ejogrb.2008.02.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2007] [Revised: 02/12/2008] [Accepted: 02/18/2008] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To determine left ventricular isovolumic relaxation time (LV IRT) in normally developing and growth restricted fetuses (FGR) as an indicator of fetal cardiac afterload and neonatal systolic blood pressure. STUDY DESIGN A prospective longitudinal study in 124 normally developing and 47 growth restricted fetuses (FGR). LV IRT, fetal heart rate (FHR) and umbilical artery pulsatility index (PI) were determined at 2-3 week intervals starting at 22-26 weeks of gestation until delivery. Renin and angiotensin I levels were measured by radioimmunoassay in umbilical venous blood after delivery. Systolic blood pressure was measured at day 1 and day 5 of postnatal life. To evaluate the association between LV IRT, gestational age and FHR, bivariate regression analyses were performed. RESULTS Mean LV IRT (62+/-8 ms) was 29 percent longer in FGR as compared to the normal subset (47+/-6 ms) at all gestational ages (p<0.001). Mean postnatal active plasma renin level (7.78+/-S.D. 1.03 ng/ml) and postnatal angiotensin I level (4.21+/-0.70 ng/ml) in the FGR subset were significantly higher (p<0.001) than in the normal subset (4.81+/-1.04 ng/ml, renin and 2.69+/-0.44 ng/ml, angiotensin I). There was a significant difference (p<0.01) in systolic blood pressure between the two subsets on postnatal day 1 (FGR 52+/-6 mmHg vs. normal 46+/-4 mmHg) and day 5 (FGR 76+/-5 mmHg vs. normal 60+/-6 mmHg). CONCLUSION Left ventricular isovolumic relaxation time may act as a sensitive index of increased arterial afterload in the growth retarded fetus and may herald raised systolic blood pressure in the early neonatal period.
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