1
|
Yong HEJ, Maksym K, Yusoff MAB, Salazar-Petres E, Nazarenko T, Zaikin A, David AL, Hillman SL, Sferruzzi-Perri AN. Integrated Placental Modelling of Histology with Gene Expression to Identify Functional Impact on Fetal Growth. Cells 2023; 12:1093. [PMID: 37048166 PMCID: PMC10093760 DOI: 10.3390/cells12071093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/31/2023] [Accepted: 04/03/2023] [Indexed: 04/14/2023] Open
Abstract
Fetal growth restriction (FGR) is a leading cause of perinatal morbidity and mortality. Altered placental formation and functional capacity are major contributors to FGR pathogenesis. Relating placental structure to function across the placenta in healthy and FGR pregnancies remains largely unexplored but could improve understanding of placental diseases. We investigated integration of these parameters spatially in the term human placenta using predictive modelling. Systematic sampling was able to overcome heterogeneity in placental morphological and molecular features. Defects in villous development, elevated fibrosis, and reduced expression of growth and functional marker genes (IGF2, VEGA, SLC38A1, and SLC2A3) were seen in age-matched term FGR versus healthy control placentas. Characteristic histopathological changes with specific accompanying molecular signatures could be integrated through computational modelling to predict if the placenta came from a healthy or FGR pregnancy. Our findings yield new insights into the spatial relationship between placental structure and function and the etiology of FGR.
Collapse
Affiliation(s)
- Hannah Ee Juen Yong
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience University of Cambridge, Cambridge CB2 3EG, UK
- Singapore Institute for Clinical Sciences (SICS), Agency for Science, Technology and Research (A*STAR), 30 Medical Drive, Brenner Centre for Molecular Medicine, Singapore 117609, Singapore
| | - Katarzyna Maksym
- Elizabeth Gareth Anderson Institute for Women’s Health, University College London, 84-86 Chenies Mews, London WC1E 6HU, UK
- Fetal Medicine Unit Elizabeth Gareth Anderson Wing, University College Hospitals NHS Trust, 25 Grafton Way, London WC1E 6DB, UK
| | - Muhammad Ashraf Bin Yusoff
- Elizabeth Gareth Anderson Institute for Women’s Health, University College London, 84-86 Chenies Mews, London WC1E 6HU, UK
| | - Esteban Salazar-Petres
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience University of Cambridge, Cambridge CB2 3EG, UK
| | - Tatiana Nazarenko
- Elizabeth Gareth Anderson Institute for Women’s Health, University College London, 84-86 Chenies Mews, London WC1E 6HU, UK
- Department of Mathematics, University College London, London WC1E 6AE, UK
| | - Alexey Zaikin
- Elizabeth Gareth Anderson Institute for Women’s Health, University College London, 84-86 Chenies Mews, London WC1E 6HU, UK
- Department of Mathematics, University College London, London WC1E 6AE, UK
| | - Anna L. David
- Elizabeth Gareth Anderson Institute for Women’s Health, University College London, 84-86 Chenies Mews, London WC1E 6HU, UK
- Fetal Medicine Unit Elizabeth Gareth Anderson Wing, University College Hospitals NHS Trust, 25 Grafton Way, London WC1E 6DB, UK
- National Institute for Health Research University College London Hospitals Biomedical Research Centre, 149 Tottenham Court Road, London W1T 7DN, UK
| | - Sara L. Hillman
- Elizabeth Gareth Anderson Institute for Women’s Health, University College London, 84-86 Chenies Mews, London WC1E 6HU, UK
- Fetal Medicine Unit Elizabeth Gareth Anderson Wing, University College Hospitals NHS Trust, 25 Grafton Way, London WC1E 6DB, UK
| | - Amanda N. Sferruzzi-Perri
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience University of Cambridge, Cambridge CB2 3EG, UK
| |
Collapse
|
2
|
Wang JJ, Wang X, Li Q, Huang H, Zheng QL, Yao Q, Zhang J. Feto-placental endothelial dysfunction in Gestational Diabetes Mellitus under dietary or insulin therapy. BMC Endocr Disord 2023; 23:48. [PMID: 36814227 PMCID: PMC9948408 DOI: 10.1186/s12902-023-01305-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 02/16/2023] [Indexed: 02/24/2023] Open
Abstract
OBJECTIVE Gestational diabetes mellitus (GDM) is a serious complication in pregnancy. Despite controlling the plasma glucose levels with dietary intervention (GDM-D) or insulin therapy (GDM-I), children born of diabetic mothers suffer more long-term complications from childhood to early adulthood. Placental circulation and nutrient exchange play a vital role in fetal development. Additionally, placental endothelial function is an indicator of vascular health, and plays an important role in maintaining placental circulation for nutrient exchange. This study was conducted to assess changes in fetal endothelial dysfunction in GDM under different interventions during pregnancy. METHODS The primary human umbilical vein endothelial cells (HUVECs) were obtained from normal pregnant women (n = 11), GDM-D (n = 14), and GDM-I (n = 12) patients. LC-MS/MS was used to identify differentially expressed proteins in primary HUVECs among the three groups, after which Bioinformatics analysis was performed. Glucose uptake, ATP level, apoptosis, and differentially expressed proteins were assessed to investigate changes in energy metabolism. RESULTS A total of 8174 quantifiable proteins were detected, and 142 differentially expressed proteins were identified after comparing patients with GDM-D/GDM-I and healthy controls. Of the 142, 64 proteins were upregulated while 77 were downregulated. Bioinformatics analysis revealed that the differentially expressed proteins were involved in multiple biological processes and signaling pathways related to cellular processes, biological regulation, and metabolic processes. According to the results from KEGG analysis, there were changes in the PI3K/AKT signaling pathway after comparing the three groups. In addition, there was a decrease in glucose uptake in the GDM-I (P < 0.01) group. In GDM-I, there was a significant decrease in the levels of glucose transporter 1 (GLUT1) and glucose transporter 3 (GLUT3). Moreover, glucose uptake was significantly decreased in GDM-I, although in GDM-D, there was only a decrease in the levels of GLUT1. ATP levels decreased in GDM-I (P < 0.05) and apoptosis occurred in both the GDM-D and GDM-I groups. Compared to the normal controls, the levels of phosphate AKT and phosphate AMPK over total AKT and AMPK were reduced in the GDM-I group. CONCLUSION In summary, endothelial dysfunction occurred in pregnancies with GDM even though the plasma glucose levels were controlled, and this dysfunction might be related to the degree of glucose tolerance. The energy dysfunction might be related to the regulation of the AKT/AMPK/mTOR signaling pathway.
Collapse
Affiliation(s)
- Jing-Jing Wang
- Department of Clinical pharmacy, First Affiliated hospital of Kunming Medical University, Yunnan, China
| | - Xi Wang
- Department of Clinical pharmacy, First Affiliated hospital of Kunming Medical University, Yunnan, China
| | - Qian Li
- Department of Clinical pharmacy, First Affiliated hospital of Kunming Medical University, Yunnan, China
| | - Hua Huang
- Department of Clinical pharmacy, First Affiliated hospital of Kunming Medical University, Yunnan, China
| | - Qiao-Ling Zheng
- Department of Clinical pharmacy, First Affiliated hospital of Kunming Medical University, Yunnan, China
| | - Qin Yao
- Department of Clinical pharmacy, First Affiliated hospital of Kunming Medical University, Yunnan, China
| | - Jun Zhang
- Department of Clinical pharmacy, First Affiliated hospital of Kunming Medical University, Yunnan, China.
| |
Collapse
|
3
|
Fujita A, Noguchi S, Hamada R, Inoue S, Shimada T, Katakura S, Maruyama T, Sai Y, Nishimura T, Tomi M. Limited Impact of Murine Placental MDR1 on Fetal Exposure of Certain Drugs Explained by Bypass Transfer Between Adjacent Syncytiotrophoblast Layers. Pharm Res 2022; 39:1645-1658. [PMID: 35083640 PMCID: PMC9246986 DOI: 10.1007/s11095-022-03165-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 01/03/2022] [Indexed: 11/30/2022]
Abstract
Purpose Multidrug resistance protein 1 (MDR1) is located at the interface between two syncytiotrophoblast layers in rodent placenta, and may influence fetal drug distribution. Here, we quantitatively compare the functional impact per single MDR1 molecule of MDR1 at the placental barrier and blood-brain barrier in mice. Methods MDR1A and MDR1B proteins were quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Paclitaxel or digoxin was continuously administered to pregnant Mdr1a−/−/Mdr1b−/− or wild-type mice, and the drug concentrations in the maternal and fetal plasma and maternal brain were quantified by LC-MS/MS. Results MDR1A and MDR1B proteins are expressed in the membrane of mouse placental labyrinth, and total MDR1 at the placental barrier amounts to about 30% of that at the blood-brain barrier. The fetal-to-maternal plasma concentration ratio of digoxin was only marginally affected in Mdr1a−/−/Mdr1b−/− mice, while that of paclitaxel showed a several-fold increase. No such difference between the two drugs was found in the maternal brain distribution. The impact per single MDR1 molecule on the fetal distribution of digoxin was calculated to be much lower than that on the brain distribution, but this was not the case for paclitaxel. Our pharmacokinetic model indicates that the impact of placental MDR1 is inversely correlated to the ratio of permeability through gap junctions connecting the two syncytiotrophoblast layers to passive diffusion permeability. Conclusion Our findings indicate that murine placental MDR1 has a minimal influence on the fetal concentration of certain substrates, such as digoxin, due to bypass transfer, probably via connexin26 gap junctions. Supplementary Information The online version contains supplementary material available at 10.1007/s11095-022-03165-6.
Collapse
Affiliation(s)
- Arimi Fujita
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan.,Department of Clinical Pharmacokinetics, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, 920-8641, Japan.,Department of Hospital Pharmacy, University Hospital, Kanazawa University, Kanazawa, Ishikawa, 920-8641, Japan
| | - Saki Noguchi
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan
| | - Rika Hamada
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan
| | - Satoko Inoue
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan
| | - Tsutomu Shimada
- Department of Clinical Pharmacokinetics, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, 920-8641, Japan.,Department of Hospital Pharmacy, University Hospital, Kanazawa University, Kanazawa, Ishikawa, 920-8641, Japan
| | - Satomi Katakura
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Tetsuo Maruyama
- Department of Obstetrics and Gynecology, Keio University School of Medicine, Shinjuku-ku, Tokyo, 160-8582, Japan
| | - Yoshimichi Sai
- Department of Clinical Pharmacokinetics, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Ishikawa, 920-8641, Japan.,Department of Hospital Pharmacy, University Hospital, Kanazawa University, Kanazawa, Ishikawa, 920-8641, Japan
| | - Tomohiro Nishimura
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan
| | - Masatoshi Tomi
- Division of Pharmaceutics, Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan.
| |
Collapse
|
4
|
He M, Mirzakhani H, Chen L, Wu R, Litonjua AA, Bacharier L, Weiss ST, Nelson DM. Vitamin D Sufficiency Has a Limited Effect on Placental Structure and Pathology: Placental Phenotypes in the VDAART Trial. Endocrinology 2020; 161:5818078. [PMID: 32270179 PMCID: PMC7528633 DOI: 10.1210/endocr/bqaa057] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 04/06/2020] [Indexed: 11/19/2022]
Abstract
Vitamin D insufficiency during pregnancy is widespread. The effects of active vitamin D on the human placenta in vivo are unknown. We test the hypotheses that 25(OH)D sufficiency (arbitrarily defined as 25(OH)D ≥32 ng/mL) modulates placental structure and function in vivo in a population of women whose offspring are at risk for childhood asthma, and that placental pathology is more common in offspring that evolve asthma at age 3. Pregnant volunteers in the St. Louis, MO, cohort of the Vitamin D Antenatal Asthma Reduction Trial (VDAART, NIH grant #HL091528) participated in a nested case-control study and consented for the study of placentas after delivery. Maternal concentrations of 25(OH)D were measured at trial entry and in the third trimester. The histopathology of the placentas from women with sufficient 25(OH)D, versus insufficient, showed no clinically significant differences, but morphometry revealed villi of women with sufficient third-trimester 25(OH)D had a higher villous surface density. Notably, analyses of transcripts, extracted from formalin-fixed paraffin-embedded specimens, revealed higher expression of INTS9, vWF, MACC1, and ARMS2, and diminished expression of the CNTN5 genes in the insufficient group. A larger proportion of placentas showed chronic chorioamnionitis in offspring with versus without asthma at age 3. These findings suggest that maternal 25(OH)D insufficiency has a limited effect on human placental villous histopathology and morphometry, but attenuates a small number of placental gene expression profiles in this selected population. The association of placental chronic chorioamnionitis and offspring asthma is worthy of further study.
Collapse
Affiliation(s)
- Mai He
- Department of Pathology & Immunology, Washington University School of Medicine in St. Louis, St. Louis, Missouri
- Correspondence: Mai He, MD, PhD, Department of Pathology & Immunology, 660 South Euclid, Campus Box 8118, Washington University School of Medicine in St. Louis, St. Louis, MO 63110.
| | - Hooman Mirzakhani
- Channing Division of Network Medicine, Department of Medicine, Harvard Medical School and Brigham and Women’s Hospital, Boston, Massachusetts
| | - Ling Chen
- Division of Biostatistics, Washington University School of Medicine in St. Louis, St. Louis, Missouri
| | - Robert Wu
- Penn State College of Medicine, Hershey, Pennsylvania
| | - Augusto A Litonjua
- Division of Pulmonary Medicine, Department of Pediatrics, University of Rochester, School of Medicine, Rochester, New York
| | - Leonard Bacharier
- Division of Allergy, Immunology and Pulmonary Medicine, Department of Pediatrics, Washington University School of Medicine in St. Louis, St. Louis, Missouri
| | - Scott T Weiss
- Channing Division of Network Medicine, Department of Medicine, Harvard Medical School and Brigham and Women’s Hospital, Boston, Massachusetts
| | - D Michael Nelson
- Department of Obstetrics & Gynecology, Washington University School of Medicine in St. Louis, St. Louis, Missouri
| |
Collapse
|
5
|
Kazemian A, Hooshmandabbasi R, Schraner EM, Boos A, Klisch K. Evolutionary implications of fetal and maternal microvillous surfaces in epitheliochorial placentae. J Morphol 2019; 280:615-622. [PMID: 30805975 DOI: 10.1002/jmor.20970] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Revised: 01/29/2019] [Accepted: 02/02/2019] [Indexed: 12/19/2022]
Abstract
According to the "parent-offspring conflict hypothesis" the rapid evolution and diversification of the mammalian placenta is driven by divergent optima of resource allocation between fetus and mother. The fetus has an interest to maximize its resource intake, while the mother has an interest to restrict the transfer of resources, and thus retain resources for subsequent pregnancies. In the epitheliochorial placenta, the contacting fetal and maternal surfaces at the feto-maternal interface are covered with microvilli, which leads to an increase of membrane surfaces available for transport processes. Because membranes are the site of active transport, the conflict hypothesis predicts that the fetal surfaces at the feto-maternal interfaces are larger than the maternal ones. We use transmission electron microscopy and a stereological method to estimate the factors by which the apical fetal and maternal membranes are enlarged by the microvilli. Ten species with an epitheliochorial placenta were studied. Focused ion beam-scanning electron microscopy (FIB-SEM) was used to create three-dimensional models of the interdigitating microvilli of the bovine and porcine placenta. In all species, the fetal surface was larger than the maternal. This was due to a higher number of fetal microvilli and to the presence of membrane folds at the base of the fetal, but not of maternal microvilli. Our results suggest that the ultrastructural morphology of the feto-maternal interface in the epitheliochorial placenta is shaped by conflicting interests between fetus and mother and thus represent a so far neglected arena of the parent-offspring conflict.
Collapse
Affiliation(s)
- Ali Kazemian
- Institute of Veterinary Anatomy, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.,Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Reyhaneh Hooshmandabbasi
- Institute of Veterinary Anatomy, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.,Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran
| | - Elisabeth M Schraner
- Institute of Veterinary Anatomy, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.,Institute of Virology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Alois Boos
- Institute of Veterinary Anatomy, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Karl Klisch
- Institute of Veterinary Anatomy, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| |
Collapse
|
6
|
Illsley NP, Baumann MU. Human placental glucose transport in fetoplacental growth and metabolism. Biochim Biophys Acta Mol Basis Dis 2018; 1866:165359. [PMID: 30593896 DOI: 10.1016/j.bbadis.2018.12.010] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Revised: 11/13/2018] [Accepted: 12/06/2018] [Indexed: 02/07/2023]
Abstract
While efficient glucose transport is essential for all cells, in the case of the human placenta, glucose transport requirements are two-fold; provision of glucose for the growing fetus in addition to the supply of glucose required the changing metabolic needs of the placenta itself. The rapidly evolving environment of placental cells over gestation has significant consequences for the development of glucose transport systems. The two-fold transport requirement of the placenta means also that changes in expression will have effects not only for the placenta but also for fetal growth and metabolism. This review will examine the localization, function and evolution of placental glucose transport systems as they are altered with fetal development and the transport and metabolic changes observed in pregnancy pathologies.
Collapse
Affiliation(s)
- Nicholas P Illsley
- Center for Abnormal Placentation, Department of Obstetrics and Gynecology, Hackensack University Medical Center, Hackensack, NJ, USA.
| | - Marc U Baumann
- Department of Obstetrics and Gynaecology, Inselspital, Bern University Hospital, University of Bern, Bern, Switzerland
| |
Collapse
|
7
|
First-trimester placental thickness and the risk of preeclampsia or SGA. Placenta 2017; 57:123-128. [DOI: 10.1016/j.placenta.2017.06.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Revised: 06/13/2017] [Accepted: 06/17/2017] [Indexed: 01/02/2023]
|
8
|
Richardson BS, Ruttinger S, Brown HK, Regnault TRH, de Vrijer B. Maternal body mass index impacts fetal-placental size at birth and umbilical cord oxygen values with implications for regulatory mechanisms. Early Hum Dev 2017; 112:42-47. [PMID: 28688997 DOI: 10.1016/j.earlhumdev.2017.06.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 06/22/2017] [Accepted: 06/27/2017] [Indexed: 11/17/2022]
Abstract
BACKGROUND Maternal under- and over-nutrition are known to effect fetal growth with altered placental development and nutrient transport, but whether fetal oxygenation is also altered remains unknown. AIMS To examine linkages between maternal BMI and birth weights, placental weights, and umbilical vein and artery PO2, with implications for signaling mechanisms. STUDY DESIGN Population-based cohort study. SUBJECTS Analysis of hospital database information on all patients with pre-pregnant BMI values delivering viable, singleton infants between Jan 1, 1999 and Dec 31, 2010 (N=29,212). BMI was categorized into underweight, normal weight, overweight, and obese, with birth weights categorized into small (SGA), appropriate (AGA), and large for gestational age (LGA). OUTCOME MEASURES Maternal BMI, birth and placental weights, umbilical vein and artery PO2. RESULTS Underweight mothers with smaller infants and overweight/obese mothers with larger infants had disproportionately large placentas, suggesting compensatory and/or enhanced placental growth in these pregnancies. All SGA infants had lower umbilical vein and artery PO2, consistent with aberrant placental development leading to diffusional impairment of oxygen. Both maternal overweight/obese BMI and LGA resulted in lower artery PO2, likely due to increased growth rates with the larger size in these infants. CONCLUSIONS These findings support fetal hypoxemia as a common determinant of growth restriction, whether in underweight mothers and due to under-nutrition or in overweight/obese mothers and due to placental insufficiency. However, oxygen is unlikely to be the primary promotor for fetal growth in overweight/obese mothers and LGA infants, with other substrates of more importance as nutritional cues in these pregnancies.
Collapse
Affiliation(s)
- Bryan S Richardson
- Department of Obstetrics and Gynecology; Department of Physiology and Pharmacology; Department of Pediatrics; Children's Health Research Institute; Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada.
| | - Stephanie Ruttinger
- Department of Physiology and Pharmacology; Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Hilary K Brown
- Department of Obstetrics and Gynecology; Department of Epidemiology & Biostatistics; Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Timothy R H Regnault
- Department of Obstetrics and Gynecology; Department of Physiology and Pharmacology; Children's Health Research Institute; Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Barbra de Vrijer
- Department of Obstetrics and Gynecology; Children's Health Research Institute; Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| |
Collapse
|
9
|
Pantham P, Rosario FJ, Weintraub ST, Nathanielsz PW, Powell TL, Li C, Jansson T. Down-Regulation of Placental Transport of Amino Acids Precedes the Development of Intrauterine Growth Restriction in Maternal Nutrient Restricted Baboons. Biol Reprod 2016; 95:98. [PMID: 27605346 PMCID: PMC5178152 DOI: 10.1095/biolreprod.116.141085] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 08/24/2016] [Indexed: 12/17/2022] Open
Abstract
Intrauterine growth restriction (IUGR) is an important risk factor for perinatal complications and adult disease. IUGR is associated with down-regulation of placental amino acid transporter expression and activity at birth. It is unknown whether these changes are a cause or a consequence of human IUGR. We hypothesized that placental amino acid transport capacity is reduced prior to onset of reduced fetal growth in baboons with maternal nutrient restriction (MNR). Pregnant baboons were fed either a control (n = 8) or MNR diet (70% of control diet, n = 9) from Gestational Day 30. At Gestational Day 120 (0.65 of gestation), fetuses and placentas were collected. Microvillous (MVM) and basal (BM) plasma membrane vesicles were isolated. System A and system L transport activity was determined in MVM, and leucine transporter activity was assessed in BM using radiolabeled substrates. MVM amino acid transporter isoform expression (SNAT1, SNAT2, and SNAT4 and LAT1 and LAT2) was measured using Western blots. LAT1 and LAT2 expression were also determined in BM. Maternal and fetal plasma amino acids concentrations were determined using mass spectrometry. Fetal and placental weights were unaffected by MNR. MVM system A activity was decreased by 37% in MNR baboon placentas (P = 0.03); however MVM system A amino acid transporter protein expression was unchanged. MVM system L activity and BM leucine transporter activity were not altered by MNR. Fetal plasma concentrations of essential amino acids isoleucine and leucine were reduced, while citrulline increased (P < 0.05) in MNR fetuses compared to controls. In this primate model of IUGR, placental MVM system A amino acid transporter activity is decreased prior to the onset of reduction in the fetal growth trajectory. The reduction in plasma leucine and isoleucine in MNR fetuses may be caused by reduced activity of MVM system A, which is strongly coupled with system L essential amino acid uptake. Our findings indicate that reduced placental amino acid transport may be a cause rather than a consequence of IUGR due to inadequate maternal nutrition.
Collapse
Affiliation(s)
- Priyadarshini Pantham
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Fredrick J Rosario
- Department of Obstetrics & Gynecology, Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Susan T Weintraub
- Department of Biochemistry, University of Texas Health Science Center San Antonio, San Antonio, Texas
| | - Peter W Nathanielsz
- Department of Animal Science, University of Wyoming, Laramie, Wyoming.,Southwest National Primate Research Center, San Antonio, Texas
| | - Theresa L Powell
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| | - Cun Li
- Department of Animal Science, University of Wyoming, Laramie, Wyoming.,Southwest National Primate Research Center, San Antonio, Texas
| | - Thomas Jansson
- Department of Obstetrics & Gynecology, Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, Colorado
| |
Collapse
|
10
|
Yallapragada SG, Mestan KK, Palac H, Porta N, Gotteiner N, Hamvas A, Grobman W, Ernst LM. Placental Villous Vascularity Is Decreased in Premature Infants with Bronchopulmonary Dysplasia-Associated Pulmonary Hypertension. Pediatr Dev Pathol 2016; 19:101-7. [PMID: 26366786 DOI: 10.2350/15-05-1646-oa.1] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The development of pulmonary hypertension (PH) is a serious complication of bronchopulmonary dysplasia (BPD) among infants born at extremely low gestational ages. Bronchopulmonary dysplasia-associated PH is characterized by persistent pulmonary vasoconstriction, progressive right heart dysfunction, and an increased risk of death. We have shown previously that certain placental vascular lesions are associated with BPD-associated PH. Further evaluation of the villous and vascular morphometry of these placentas is warranted. Using digital image analysis (DIA), we compared villous and vascular morphometric parameters of placentas from infants with and without BPD-associated PH. We conducted a case-control study of placentas from 14 infants born at ≤28 weeks' gestational age (GA). Cases with PH (N=7) and non-PH controls (N=7) were identified using echocardiogram screening at 36 weeks' corrected GA. Central parenchymal sections from each placenta were stained for CD31. Digital image analysis was used to measure vessel and villous capillary number, perimeter, diameter, and area. Mean villous vascularity (number of vessels per villus) was calculated for each patient. Mean vessel and villous number as well as area were similar between the two groups. Villous vascularity was decreased in placentas from infants who ultimately had PH disease compared to non-PH controls (5.5±1.0 vs 7.1±1.6; P<0.05). Placental villous vascularity is decreased in infants with BPD-associated PH. Further studies should assess whether placental morphometric markers may allow clinicians to better predict BPD and provide earlier and more targeted management.
Collapse
Affiliation(s)
- Sushmita G Yallapragada
- 1 Department of Pediatrics, Division of Neonatology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Karen K Mestan
- 1 Department of Pediatrics, Division of Neonatology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Hannah Palac
- 2 Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Nicolas Porta
- 1 Department of Pediatrics, Division of Neonatology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Nina Gotteiner
- 3 Department of Pediatrics, Division of Cardiology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Aaron Hamvas
- 1 Department of Pediatrics, Division of Neonatology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - William Grobman
- 4 Departments of Obstetrics & Gynecology and Maternal-Fetal Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Linda M Ernst
- 5 Department of Pathology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| |
Collapse
|
11
|
Elias AA, Ghaly A, Matushewski B, Regnault TRH, Richardson BS. Maternal Nutrient Restriction in Guinea Pigs as an Animal Model for Inducing Fetal Growth Restriction. Reprod Sci 2015; 23:219-27. [DOI: 10.1177/1933719115602773] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Alexander A. Elias
- Departments of Obstetrics and Gynecology, Physiology and Pharmacology, and Pediatrics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Andrew Ghaly
- Departments of Obstetrics and Gynecology, Physiology and Pharmacology, and Pediatrics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Brad Matushewski
- Departments of Obstetrics and Gynecology, Physiology and Pharmacology, and Pediatrics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Timothy R. H. Regnault
- Departments of Obstetrics and Gynecology, Physiology and Pharmacology, and Pediatrics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| | - Bryan S. Richardson
- Departments of Obstetrics and Gynecology, Physiology and Pharmacology, and Pediatrics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Canada
| |
Collapse
|
12
|
Clark AR, Lin M, Tawhai M, Saghian R, James JL. Multiscale modelling of the feto-placental vasculature. Interface Focus 2015; 5:20140078. [PMID: 25844150 DOI: 10.1098/rsfs.2014.0078] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The placenta provides all the nutrients required for the fetus through pregnancy. It develops dynamically, and, to avoid rejection of the fetus, there is no mixing of fetal and maternal blood; rather, the branched placental villi 'bathe' in blood supplied from the uterine arteries. Within the villi, the feto-placental vasculature also develops a complex branching structure in order to maximize exchange between the placental and maternal circulations. To understand the development of the placenta, we must translate functional information across spatial scales including the interaction between macro- and micro-scale haemodynamics and account for the effects of a dynamically and rapidly changing structure through the time course of pregnancy. Here, we present steps towards an anatomically based and multiscale approach to modelling the feto-placental circulation. We assess the effect of the location of cord insertion on feto-placental blood flow resistance and flow heterogeneity and show that, although cord insertion does not appear to directly influence feto-placental resistance, the heterogeneity of flow in the placenta is predicted to increase from a 19.4% coefficient of variation with central cord insertion to 23.3% when the cord is inserted 2 cm from the edge of the placenta. Model geometries with spheroidal and ellipsoidal shapes, but the same volume, showed no significant differences in flow resistance or heterogeneity, implying that normal asymmetry in shape does not affect placental efficiency. However, the size and number of small capillary vessels is predicted to have a large effect on feto-placental resistance and flow heterogeneity. Using this new model as an example, we highlight the importance of taking an integrated multi-disciplinary and multiscale approach to understand development of the placenta.
Collapse
Affiliation(s)
- A R Clark
- Auckland Bioengineering Institute , University of Auckland , Auckland , New Zealand
| | - M Lin
- Auckland Bioengineering Institute , University of Auckland , Auckland , New Zealand
| | - M Tawhai
- Auckland Bioengineering Institute , University of Auckland , Auckland , New Zealand
| | - R Saghian
- Auckland Bioengineering Institute , University of Auckland , Auckland , New Zealand
| | - J L James
- Obstetrics and Gynaecology , University of Auckland , Auckland , New Zealand
| |
Collapse
|
13
|
UNDERSTANDING THE PLACENTAL AETIOLOGY OF FETAL GROWTH RESTRICTION; COULD THIS LEAD TO PERSONALIZED MANAGEMENT STRATEGIES? ACTA ACUST UNITED AC 2014. [DOI: 10.1017/s0965539514000114] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Fetal growth restriction (FGR) is defined as the failure of a fetus to attain its full genetic growth potential. It is a leading cause of stillbirth, prematurity, cerebral palsy and perinatal mortality. Small size at birth increases surviving infants’ lifelong risk of adverse health outcomes associated with the metabolic syndrome. The pathophysiology of abnormal fetal growth is extremely complex and incompletely understood, with a plethora of genetic, signalling and metabolic candidates under investigation, many of which may result in abnormal structure and function of the placenta. In contrast to, or maybe because of, the underlying complexities of FGR, the strategies clinicians have for identifying and managing this outcome are conspicuously limited. Current clinical practice is restricted to identifying pregnancies at risk of FGR, and when FGR is detected, using intensive monitoring to guide the timing of delivery to optimise fetal outcomes. Abnormal Doppler indices in the umbilical artery are strongly associated with poor perinatal outcomes and are currently the “gold standard” for clinical surveillance of the growth-restricted fetus.
Collapse
|
14
|
Karadeniz O, Mendilcioglu I, Ozdem S, Ozekinci M, Sanhal CY, Uzun G, Sakinci M, Simsek M. The association between ischaemia-modified albumin levels in umbilical vein and intrauterine growth restriction. J OBSTET GYNAECOL 2014; 35:9-12. [PMID: 24999531 DOI: 10.3109/01443615.2014.930101] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Intrauterine growth restriction (IUGR) is one of the most common problems in obstetrics. Ischaemia-modified albumin (IMA), a product deriving from albumin as a result of the modification by oxidative free radicals in response to hypoxia, was previously used as a marker of ischaemia in acute coronary syndrome. We performed this study to determine whether umbilical venous IMA levels are associated with IUGR. A total of 40 pregnancies with IUGR were compared with 40 of normal fetal development. Blood samples were obtained from the umbilical vein after delivery. IMA levels in the IUGR group were higher than in the control group (78.74 ± 6.87 vs 74.43 ± 7.84 U/ml, respectively, p = 0.011). An elevated IMA level was associated with IUGR (OR: 1.079, 95% CI: 1.000-1.163, p = 0.049). We suggest that IMA, which was formerly proved to arise in ischaemic conditions, may also be a valuable marker in perinatal hypoxia and IUGR detection.
Collapse
Affiliation(s)
- O Karadeniz
- Department of Obstetrics and Gynecology, Akdeniz University , Antalya , Turkey
| | | | | | | | | | | | | | | |
Collapse
|
15
|
Murthi P, Abumaree M, Kalionis B. Analysis of homeobox gene action may reveal novel angiogenic pathways in normal placental vasculature and in clinical pregnancy disorders associated with abnormal placental angiogenesis. Front Pharmacol 2014; 5:133. [PMID: 24926269 PMCID: PMC4045154 DOI: 10.3389/fphar.2014.00133] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 05/14/2014] [Indexed: 11/13/2022] Open
Abstract
Homeobox genes are essential for both the development of the blood and lymphatic vascular systems, as well as for their maintenance in the adult. Homeobox genes comprise an important family of transcription factors, which are characterized by a well conserved DNA binding motif; the homeodomain. The specificity of the homeodomain allows the transcription factor to bind to the promoter regions of batteries of target genes and thereby regulates their expression. Target genes identified for homeodomain proteins have been shown to control fundamental cell processes such as proliferation, differentiation, and apoptosis. We and others have reported that homeobox genes are expressed in the placental vasculature, but our knowledge of their downstream target genes is limited. This review highlights the importance of studying the cellular and molecular mechanisms by which homeobox genes and their downstream targets may regulate important vascular cellular processes such as proliferation, migration, and endothelial tube formation, which are essential for placental vasculogenesis and angiogenesis. A better understanding of the molecular targets of homeobox genes may lead to new therapies for aberrant angiogenesis associated with clinically important pregnancy pathologies, including fetal growth restriction and preeclampsia.
Collapse
Affiliation(s)
- Padma Murthi
- Department of Perinatal Medicine, Pregnancy Research Centre, The Royal Women's Hospital Parkville, VIC, Australia ; Department of Obstetrics and Gynaecology, The University of Melbourne Parkville, VIC, Australia ; NorthWest Academic Centre, The University of Melbourne St. Albans, VIC, Australia
| | - Mohamed Abumaree
- College of Science and Health Professions, King Abdullah International Medical Research Center, King Saud bin Abdulaziz University for Health Sciences Riyadh, Saudi Arabia
| | - Bill Kalionis
- Department of Perinatal Medicine, Pregnancy Research Centre, The Royal Women's Hospital Parkville, VIC, Australia ; Department of Obstetrics and Gynaecology, The University of Melbourne Parkville, VIC, Australia
| |
Collapse
|
16
|
Matsubara S, Minakami H, Sato I. Placenta of discordant twins: lack of change in histochemically detectable enzyme activities. ACTA ACUST UNITED AC 2012. [DOI: 10.1375/twin.3.3.123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractWe localised three important enzymes histochemically in placental trophoblasts from women who gave birth to dichorionic discordant twins, in which the co-twin was affected by foetal growth restriction (FGR). The enzymes studied were adenosine diphosphate-degrading enzyme (ADPdegrading enzyme, plasma membrane enzyme), cytochrome c oxidase (mitochondrial enzyme), and glucose-6-phosphatase (endoplasmic reticular enzyme). We compared these enzyme activities and their distribution patterns among placentas of the smaller (FGR) co-twin, larger co-twin, preeclamptic singleton with FGR, and normal singletons with birth weight of appropriate for their gestational ages. In FGR co-twin placentas, the intensity and localisation pattern of these three enzymes did not differ from those seen in the larger co-twin and normal singleton placentas. Decreased ADP-degrading activity and cytochrome c oxidase negative mitochondria, which were characteristic features of pre-eclamptic trophoblasts, were not observed in FGR co-twin placentas. These observations indicated that, in the FGR co-twin, enzyme-histochemically detectable trophoblastic cell dysfunction may be absent, or if present, less prominent, compared with preeclamptic FGR. We previously reported that placental trophoblasts from singleton idiopathic FGR also showed no reduction in these enzyme activities. In mechanism and pathophysiology, FGR in dichorionic discordant twins may be quite different from pre-eclamptic FGR, but somewhat resembles idiopathic FGR, though all three disorders lead to placental insufficiency, resulting in limited foetal growth. Twin Research (2000) 3, 123–128.
Collapse
|
17
|
Effects of Labor on Placental Expression of Superoxide Dismutases in Preeclampsia. Placenta 2010; 31:392-400. [DOI: 10.1016/j.placenta.2010.02.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 02/08/2010] [Accepted: 02/09/2010] [Indexed: 11/22/2022]
|
18
|
Farley D, Tejero ME, Comuzzie AG, Higgins PB, Cox L, Werner SL, Jenkins SL, Li C, Choi J, Dick EJ, Hubbard GB, Frost P, Dudley DJ, Ballesteros B, Wu G, Nathanielsz PW, Schlabritz-Loutsevitch NE. Feto-placental adaptations to maternal obesity in the baboon. Placenta 2009; 30:752-60. [PMID: 19632719 PMCID: PMC3011231 DOI: 10.1016/j.placenta.2009.06.007] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2009] [Revised: 06/24/2009] [Accepted: 06/25/2009] [Indexed: 12/28/2022]
Abstract
Maternal obesity is present in 20-34% of pregnant women and has been associated with both intrauterine growth restriction and large-for-gestational age fetuses. While fetal and placental functions have been extensively studied in the baboon, no data are available on the effect of maternal obesity on placental structure and function in this species. We hypothesize that maternal obesity in the baboon is associated with a maternal inflammatory state and induces structural and functional changes in the placenta. The major findings of this study were: 1) decreased placental syncytiotrophoblast amplification factor, intact syncytiotrophoblast endoplasmic reticulum structure and decreased system A placental amino acid transport in obese animals; 2) fetal serum amino acid composition and mononuclear cells (PBMC) transcriptome were different in fetuses from obese compared with non-obese animals; and 3) maternal obesity in humans and baboons is similar in regard to increased placental and adipose tissue macrophage infiltration, increased CD14 expression in maternal PBMC and maternal hyperleptinemia. In summary, these data demonstrate that in obese baboons in the absence of increased fetal weight, placental and fetal phenotype are consistent with those described for large-for-gestational age human fetuses.
Collapse
Affiliation(s)
- D Farley
- Center of Pregnancy-related and Newborn Research, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Abstract
Successful outcome of human pregnancy not only impacts the quality of infant life and well-being, but considerable evidence now suggests that what happens during fetal development may well impact health and well-being into adulthood. Consequently, a thorough understanding of the developmental events that occur between conception and delivery is needed. For obvious ethical reasons, many of the questions remaining about the progression of human pregnancy cannot be answered directly, necessitating the use of appropriate animal models. A variety of animal models exist for the study of both normal and compromised pregnancies, including laboratory rodents, non-human primates and domestic ruminants. While all of these animal models have merit, most suffer from the inability to repetitively sample from both the maternal and fetal side of the placenta, limiting their usefulness in the study of placental or fetal physiology under non-stressed in vivo conditions. No animal model truly recapitulates human pregnancy, yet the pregnant sheep has been used extensively to investigate maternal-fetal interactions. This is due in part to the ability to surgically place and maintain catheters in both the maternal and fetal vasculature, allowing repeated sampling from non-anesthetized pregnancies. Considerable insight has been gained on placental oxygen and nutrient transfer and utilization from use of pregnant sheep. These findings were often confirmed in human pregnancies once appropriate technologies became available. The purpose of this review is to provide an overview of human and sheep pregnancy, with emphasis placed on placental development and function as an organ of nutrient transfer.
Collapse
Affiliation(s)
- J S Barry
- Perinatal Research Facility, Department of Pediatrics, University of Colorado Health Sciences Center, Aurora, CO 80045-0508, USA
| | | |
Collapse
|
20
|
Regnault TRH, Friedman JE, Wilkening RB, Anthony RV, Hay WW. Fetoplacental transport and utilization of amino acids in IUGR — a review. Placenta 2005; 26 Suppl A:S52-62. [PMID: 15837069 DOI: 10.1016/j.placenta.2005.01.003] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 01/06/2005] [Indexed: 11/16/2022]
Abstract
Amino acids have multiple functions in fetoplacental development. The supply of amino acids to the fetus involves active transport across and metabolism within the trophoblast. Transport occurs through various amino acid transport systems located on both the maternal and fetal facing membranes, many of which have now been documented to be present in rat, sheep and human placentas. The capacity of the placenta to supply amino acids to the fetus develops during pregnancy through alterations in such factors as surface area and specific time-dependent transport system expression. In intrauterine growth restriction (IUGR), placental surface area and amino acid uptakes are decreased in human and experimental animal models. In an ovine model of IUGR, produced by hyperthermia-induced placental insufficiency (PI-IUGR), umbilical oxygen and essential amino acid uptake rates are significantly reduced in the most severe cases in concert with decreased fetal growth. These changes indicate that severe IUGR is likely associated with a shift in amino acid transport capacity and metabolic pathways within the fetoplacental unit. After transport across the trophoblast in normal conditions, amino acids are actively incorporated into tissue proteins or oxidized. In the sheep IUGR fetus, however, which is hypoxic, hypoglycemic and hypoinsulinemic, there appear to be net effluxes of amino acids from the liver and skeletal muscle, suggesting changes in amino acid metabolism. Potential changes may be occurring in the insulin/IGF-I signaling pathway that includes decreased production and/or activation of specific signaling proteins leading to a reduced protein synthesis in fetal tissues. Such observations in the placental insufficiency model of IUGR indicate that the combination of decreased fetoplacental amino acid uptake and disrupted insulin/IGF signaling in liver and muscle account for decreased fetal growth in IUGR.
Collapse
Affiliation(s)
- T R H Regnault
- Perinatal Research Center, Department of Pediatrics, Division of Perinatal Medicine, University of Colorado Health Sciences Center, F441, Aurora, CO 80045, USA.
| | | | | | | | | |
Collapse
|
21
|
Fuchs R, Ellinger I. Endocytic and Transcytotic Processes in Villous Syncytiotrophoblast: Role in Nutrient Transport to the Human Fetus. Traffic 2004; 5:725-38. [PMID: 15355509 DOI: 10.1111/j.1600-0854.2004.00221.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The supply of nutrients to the developing fetus is a major function of the human hemochorial placenta, a placenta type in which the fetal chorion is in direct contact with the maternal blood. At term, nutrients have to be transported across two cell layers in chorionic villi, the syncytiotrophoblast (STB) and fetal endothelial cells. The STB is a continuous syncytium covering the entire surface of chorionic villi. This polarized epithelium is specialized in exchange processes and membrane trafficking between the apical membrane facing the maternal blood and the basal membrane facing the fetal endothelium. To meet placental and fetal requirements, the STB selectively takes up and transports a variety of nutrients, hormones, growth factors and cytokines and also transfers passive immunity to the fetus by receptor-mediated transcytosis. In this review in vivo and in vitro systems currently used to study STB functions are discussed and the potential mechanisms of transplacental IgG, iron, lipoprotein and glucose transport are presented. As revealed in this article, the placenta is a tissue where intensive cell biological research is required to unravel endocytic trafficking pathways in a highly specialized cell such as the STB.
Collapse
Affiliation(s)
- Renate Fuchs
- Center for Physiology and Pathophysiology, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
| | | |
Collapse
|
22
|
Battistelli M, Burattini S, Pomini F, Scavo M, Caruso A, Falcieri E. Ultrastructural study on human placenta from intrauterine growth retardation cases. Microsc Res Tech 2004; 65:150-8. [PMID: 15605416 DOI: 10.1002/jemt.20120] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
A morphological study was performed on 27 human placentas from normal gestations (Group 1) and compared with those from eight cases of intrauterine growth restriction (IUGR) (Group 2). Semithin section light microscopy, transmission, and scanning electron microscopy were carried out on trophoblastic terminal villi, carefully identified under the stereomicroscope. In growth retardation cases, villi appear longer, thinner, and less vascularized, compared to the normal condition. Fibrinoid, an extracellular material of hematic origin, frequently fills villar stroma. The density of apical microvilli appears considerably reduced and occasional microvilli-free areas are observed in growth retardation cases. Moreover, the underlying basal membrane appears significantly thicker than that of normal syncytiotrophoblast. Recently, particular attention has been paid to apoptosis as a possible cell deletion mechanism in growth restriction. In our study, a majority of typical apoptotic features appear indifferently in both IUGR and normal pregnancy. Our data hints that growth retardation might be correlated with a complex of structural changes, suggestive of maternofetal traffic downregulation, but further studies are required to understand the underlying functional mechanisms.
Collapse
|
23
|
Schneider H, Reiber W, Sager R, Malek A. Asymmetrical transport of glucose across the in vitro perfused human placenta. Placenta 2003; 24:27-33. [PMID: 12495656 DOI: 10.1053/plac.2002.0869] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The transplacental flux of glucose together with the consumption by the tissue was studied in human term placenta using the dual in vitro perfusion of an isolated cotyledon. The effect of different transplacental glucose gradients going either from the maternal to the foetal side or in the opposite direction was tested. A linear correlation between uptake from the donor circuit as well as transplacental flux and concentration difference of glucose between the two sides was found in both directions. At comparable gradients both uptake and flux were significantly higher with the gradient going from the maternal to the foetal side as compared to the other direction. For the non-metabolizable 2-deoxy-analog of D -glucose no asymmetry of flux was seen. The large fraction of glucose uptake, which is metabolized by placental tissue together with the difference in membrane transport capacity across the microvillous as compared to the basal membrane of the syncytiotrophoblast could be an explanation for the asymmetry in transplacental glucose flux.
Collapse
Affiliation(s)
- H Schneider
- Universitäts-Frauenklinik Inselspital, Bern, Switzerland
| | | | | | | |
Collapse
|
24
|
Roberts CT, Sohlstrom A, Kind KL, Earl RA, Khong TY, Robinson JS, Owens PC, Owens JA. Maternal food restriction reduces the exchange surface area and increases the barrier thickness of the placenta in the guinea-pig. Placenta 2001; 22:177-85. [PMID: 11170822 DOI: 10.1053/plac.2000.0602] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The extent to which maternal nutrition influences fetal growth through effects on placental functional development is unclear. Poor maternal nutrition is a major cause of poor fetal growth which increases neonatal morbidity and mortality, and may also increase the risk of several adult-onset diseases. We have therefore characterized the ontogeny of structural determinants of function in the placenta in guinea-pigs fed ad libitum or food restricted from before and during pregnancy. Guinea-pigs were killed at days 30 and 60 (term=67 days) of pregnancy. In ad libitum fed animals, the surface density (surface area/g placental labyrinth), which is a measure of the convolution of the exchange surface, doubled, while total surface area increased 18-fold between mid and late gestation. Concomitantly, the arithmetic mean barrier thickness to diffusion across trophoblast decreased by 68 per cent. Late in gestation, food restriction reduced the proportion of the placenta devoted to exchange (labyrinth) by 70 per cent (P< 0.04) and the weight of the placental labyrinth by 45 per cent (P=0.001). Maternal food restriction also reduced the total placental surface area for exchange by 36 per cent at day 30 (P=0.02) and 60 per cent at day 60 (P< 0.0005) of gestation, and the surface density of trophoblast by 36 per cent at day 30 (P=0.01) and 29 per cent at day 60 (P=0.005) of gestation. The arithmetic mean barrier thickness for diffusion was increased by maternal food restriction at both gestational ages (day 30, +37 per cent, P=0.008, and day 60, +40 per cent, P=0.01). These findings suggest that maternal food restriction not only reduces fetal and placental weights, but also induces structural alterations in the placenta that indicate functional impairment beyond what would be expected for the reduction in its weight.
Collapse
Affiliation(s)
- C T Roberts
- Department of Obstetrics and Gynaecology, Adelaide University, Adelaide, South Australia, 5005.
| | | | | | | | | | | | | | | |
Collapse
|
25
|
Abstract
Amino acid transport across the human placenta is active, mediated by specific transporters in syncytiotrophoblast plasma membranes. Using functional criteria such as substrate specificity and sodium dependence, approximately 15 transport systems have been identified in the human placenta. Recently, the area of molecular biology of amino acid transporters has evolved rapidly and at least 25 cDNA clones coding for mammalian amino acid transporters or transporter subunits have been identified. The primary objective of this review is to integrate the available functional data on placental amino acid transport systems with recent molecular information on mammalian amino acid transporters. Furthermore, models for the mechanisms for net materno-fetal transfer of amino acids are discussed. Finally, the evidence to suggest that alterations in placental amino acid transport systems may play a crucial role in the regulation of fetal growth are presented briefly.
Collapse
Affiliation(s)
- T Jansson
- Perinatal Center, Department of Physiology and Pharmacology, Göteborg University, s-405 30 Göteborg, Sweden
| |
Collapse
|
26
|
Holcberg G, Huleihel M, Sapir O, Katz M, Tsadkin M, Furman B, Mazor M, Myatt L. Increased production of tumor necrosis factor-alpha TNF-alpha by IUGR human placentae. Eur J Obstet Gynecol Reprod Biol 2001; 94:69-72. [PMID: 11134828 DOI: 10.1016/s0301-2115(00)00321-3] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE To evaluate the effect of pathological placental conditions such as intrauterine growth restriction (IUGR) or exposure to angiotensin II (AII) on TNF-alpha secretion in the vasculature of isolated human placental cotyledons. STUDY DESIGN Isolated placental cotyledons from 10 normal and four intrauterine growth restricted fetuses were dually perfused. Perfusate samples from the fetal circulation were collected every 30 min during 120 min. TNF-alpha levels in the fetal-placental perfusate were evaluated using specific commercial ELISA kits. In three additional normal placentae, bolus injections of angiotensin II (10(-9)-10(-4) mol/l) were given into the fetal-placental circulation and perfusate samples were collected. Statistical significance of difference TNF-alpha levels between different conditions was determined by analysis of variance (ANOVA) and paired t-test. RESULTS TNF-alpha levels were significantly higher in the perfusate of IUGR placentae as compared with normal placentae after 120 min of perfusion (mean 410+/-121 vs. 39+/-14 pg/ml, P=0.005). There was a significant dose-dependent increase in TNF-alpha levels in the placental perfusate after a bolus injection of AII 66 pg/ml with AII 10(-9) mol/l vs. 97 pg/ml with AII 10(-5) mol/l (P=0.004), respectively. CONCLUSIONS Placental pathology related to condition IUGR might induce the secretion of proinflammatory cytokines such as TNF-alpha, which may enhance the vasoconstriction of the fetal placental vascular bed.
Collapse
Affiliation(s)
- G Holcberg
- Division of Obstetrics and Gynecology, Soroka University Medical Center, Faculty of Health Sciences, Ben-Gurion University of the Negev, PO Box 151, 84101, Beer Sheva, Israel.
| | | | | | | | | | | | | | | |
Collapse
|
27
|
Affiliation(s)
- N P Illsley
- Department of Obstetrics, Gynecology, and Women's Health, UMD-New Jersey Medical School, Newark 07103-2714, USA
| |
Collapse
|
28
|
Matsubara S, Sato I. Placenta of idiopathic fetal growth restriction: cytochemically detectable enzyme activities do not change at a subcellular level. Placenta 2000; 21:257-62. [PMID: 10736250 DOI: 10.1053/plac.1999.0474] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The present study was designed to localize some important enzymes, such as adenosine diphospate-degrading enzyme (ADP-degrading enzyme) (plasma membrane enzyme), cytochrome c oxidase (mitochondrial enzyme) and glucose-6-phosphatase (endoplasmic reticulum enzyme), in placentae from patients with idiopathic fetal growth restriction (FGR) associated with absent end-diastolic flow velocity in the fetal umbilical artery. We compared these enzyme activities and their localization patterns to those in placentae both from pre-eclampsia with FGR and normal pregnancy with appropriate for their gestational age infants. In idiopathic FGR placentae, the intensity and localization patterns of these three enzymes did not differ from those seen in the placentae from normal pregnancy. Decreased ADP-degrading enzyme activity and cytochrome c oxidase negative mitochondria, which were characteristic features of pre-eclamptic trophoblasts, were absent from trophoblasts of the idiopathic FGR placentae. These observations indicated that enzyme-cytochemically detectable trophoblastic cell dysfunction may be absent in idiopathic FGR, or if present, there is less functional impairment of each trophoblast in this disease than in pre-eclampsia. Though both idiopathic FGR and pre-eclampsia lead to placental insufficiency, and finally to restricted fetal growth, a different mechanism and pathophysiology may work at the cellular and subcellular levels in these two diseases.
Collapse
Affiliation(s)
- S Matsubara
- Department of Obstetrics and Gynecology, Jichi Medical School, Tochigi, Japan.
| | | |
Collapse
|
29
|
Abstract
The availability of antibodies and cDNA probes specific for the various members of the facilitated-diffusion glucose transporter (GLUT) family has enabled researchers to obtain a much clearer picture of the mechanisms for placental uptake and transplacental transport of glucose. This review examines studies of human placental glucose transport with the aim of providing a model which describes the transporter isoforms present in the placenta, their cellular localization and functional significance. The GLUT1 glucose transporter, present on both the microvillous and basal membranes of the syncytial barrier, is the primary isoform involved in the transplacental movement of glucose. Although GLUT3 mRNA is widely distributed, GLUT3 protein is localized to the arterial component of the vascular endothelium, where it may play a role in enhancing transplacental glucose transport. This data is in contrast to the situation in other mammalian species, such as the mouse, rat and sheep, where GLUT3 protein is not only present in those epithelial cells which carry out transplacental transport but becomes an increasingly prominent isoform as gestation progresses. The asymmetric distribution of GLUT1 in the human syncytiotrophoblast (microvillous>basal) means that basal GLUT1 acts as the rate limiting step in transplacental transfer. Changes in basal GLUT1 therefore have the potential to cause alterations in transplacental transport of glucose. Although there appear to be no changes in syncytial GLUT1 expression in intrauterine growth retardation, in diabetic pregnancies increases in basal GLUT1 expression and activity have been observed, with significant consequences for the maternal-fetal flux of glucose. Little is known of glucose transporter regulation in the placenta save for the effects of hyper- and hypoglycemia. GLUT1 expression and activity appear to be inversely related to extracellular glucose concentration, however within the physiological range, GLUT1 expression is relatively refractory to glucose concentration. Information is still needed on gestational development, on the expression and activity in well-defined conditions of intrauterine growth retardation, on the mechanisms and consequences of the changes observed in diabetic pregnancy and on the role of external agents other than glucose in regulating placental glucose transport.
Collapse
Affiliation(s)
- N P Illsley
- Department of Obstetrics, Gynecology and Women's Health, UMD-New Jersey Medical School, Newark, NJ 07103-2714, USA.
| |
Collapse
|
30
|
Powell TL, Jansson T, Illsley NP, Wennergren M, Korotkova M, Strandvik B. Composition and permeability of syncytiotrophoblast plasma membranes in pregnancies complicated by intrauterine growth restriction. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1420:86-94. [PMID: 10446293 DOI: 10.1016/s0005-2736(99)00096-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The objective of this study was to determine placental membrane permeabilities to water, urea and mannitol in intrauterine growth restriction (IUGR) and compare them to normal gestational age matched controls. Further, we wished to investigate whether potential changes in permeability were related to changes in membrane fluidity, cholesterol or phospholipid fatty acid content of the membranes. Syncytiotrophoblast microvillous (MVM) and basal membranes (BM) were isolated from normal and IUGR placentas at term. Passive permeability to water, urea, and mannitol showed no significant alterations in IUGR compared to controls. Cholesterol content in BM, but not in MVM, was lower in placentas from pregnancies complicated by IUGR. However, membrane fluidity did not change in these pregnancies. The phospholipid fatty acid composition of the plasma membranes isolated from all placentas showed a predominance of unsaturated fatty acid species in the BM and saturated species in the MVM. In the MVM from IUGR, mead acid (20:3), behenic acid (22:0) and nervonic acid (24:1) constituted higher percentages of the total when compared to normally grown controls. In the BM from IUGR, mead acid (20:3) was increased relative to the total phospholipid fatty acid content. In conclusion, the syncytiotrophoblast membranes exhibit only minor changes in passive permeability and composition when the pregnancy is complicated by IUGR.
Collapse
Affiliation(s)
- T L Powell
- Perinatal Center, Department of Physiology and Pharmacology, Göteborg University, Box 432, S-405 30, Göteborg, Sweden.
| | | | | | | | | | | |
Collapse
|
31
|
Jansson T, Scholtbach V, Powell TL. Placental transport of leucine and lysine is reduced in intrauterine growth restriction. Pediatr Res 1998; 44:532-7. [PMID: 9773842 DOI: 10.1203/00006450-199810000-00011] [Citation(s) in RCA: 151] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Intrauterine growth restriction (IUGR) is characterized by a reduction in fetal plasma concentrations of a number of essential amino acids. Whether this is caused by impaired placental transport is unknown. We studied transport of leucine and lysine in syncytiotrophoblast microvillous (MVM) and basal membrane (BM) vesicles isolated from uncomplicated (control) and IUGR pregnancies. In addition, we investigated the possibility that leucine uptake is stimulated by an outwardly directed glycine gradient. Uptake of 3H-L-lysine (0.1 microM) and 3H-L-leucine (0.25 microM) was studied at 37 degrees C using rapid filtration techniques. In IUGR, mediated uptake of lysine was reduced by 44% (p < 0.05) in BM and uptake of leucine was lower in both MVM (-46%, p < 0.05) and BM (-38%, p < 0.05) compared with control vesicles. Intravesicular glycine (2 mM) increased the uptake of leucine by 98% in MVM (p < 0.05). These data suggest that the activity of placental transporters for cationic and neutral amino acids is reduced in IUGR. We speculate that a reduced glycine gradient in the placenta in IUGR, due to reduction in system A activity, will impair leucine transport to the fetus, providing an additional mechanism for reduced placental transport of leucine in IUGR.
Collapse
Affiliation(s)
- T Jansson
- Perinatal Center, Department of Physiology and Pharmacology, Göteborg University, Sweden
| | | | | |
Collapse
|
32
|
Powell TL, Lundquist C, Doughty IM, Glazier JD, Jansson T. Mechanisms of chloride transport across the syncytiotrophoblast basal membrane in the human placenta. Placenta 1998; 19:315-21. [PMID: 9639328 DOI: 10.1016/s0143-4004(98)90064-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Chloride transport mechanisms in isolated plasma membrane vesicles were studied to characterize pathways for transcellular transport of chloride. Microvillous membrane (MVM) and basal membranes (BM) vesicles were isolated from term placentae. Western blot analysis of the anion exchanger isoform 1 (AE1) demonstrated that the density of AE1 was 12-fold higher on the MVM compared to the BM. At 30 sec, the Cl- uptake in the absence of a potential difference (p.d.) was 457.3 +/- 69.7 and 111.0 +/- 29.1 pmol/mg protein in MVM and BM, respectively (mean +/- SEM, n=6). Chloride transport pathways were characterized using diisothiocyano-2'2-disulphonic stilbene. (DIDS, 0.1 mM) and diphenylamine-2-carboxylate (DPC, 0.5 mM) in the absence or presence of inside positive membrane potentials. Anion exchange (DIDS-sensitive uptake at zero mV) was found in the MVM only. Both MVM and BM showed increased chloride uptake in the presence of inside positive potentials, suggesting the presence of chloride conductance pathways. The chloride uptake with a 25-mV inside positive p.d. could be inhibited by both DIDS and DPC in MVM and BM. However greater potentials (50 mV) showed no significant inhibition by DIDS or DPC in BM. In conclusion, the anion exchanger is unlikely to contribute significantly to chloride fluxes across BM. The data also suggest the presence of Cl- conductance pathways in both the MVM and BM which are sensitive to both DIDS and DPC.
Collapse
Affiliation(s)
- T L Powell
- Department of Physiology and Pharmacology, Göteborg University, Sweden.
| | | | | | | | | |
Collapse
|
33
|
Abstract
The extensive role played by protein kinase C (PKC) in signal transduction prompted this study of the expression and localization of PKC isoforms in human placental syncytiotrophoblast. Membranes prepared from these cells and samples of villous tissue were analysed by immunoblotting and immunocytochemistry using isoform-specific antibodies. PKC beta 2, gamma, epsilon and zeta were found to be present in both microvillous and basal membranes from term placenta. The alpha isoform was observed only on the basal membrane while the beta 1 isoform was confined to the microvillous membrane. The basal microvillous ratios for beta 2, gamma, epsilon and zeta ranged between 0.3 and 0.5, demonstrating a substantial asymmetry in plasma membrane localization. Immunocytochemistry supported the isoform identification and localization observed in the immunoblotting experiments. Moreover the cellular distribution showed that the majority of syncytical PKC was bound to the plasma membranes, in contrast to the other villous cell types. Immunoblotting experiments demonstrated significant increases in PKC beta 2 and epsilon on the microvillous membrane and PKC gamma and epsilon on the basal membrane between 16 and 40 of weeks gestation. This is the first detailed mapping of PKC isoform distribution in an epithelial cell type and demonstrates the potential for selectivity in signal transduction through phosphorylation of isoform specific and spatially-separated substrates.
Collapse
Affiliation(s)
- A L Ruzycky
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, USA
| | | | | |
Collapse
|
34
|
Jansson T, Powell TL, Illsley NP. Non-electrolyte solute permeabilities of human placental microvillous and basal membranes. J Physiol 1993; 468:261-74. [PMID: 8254509 PMCID: PMC1143825 DOI: 10.1113/jphysiol.1993.sp019770] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
1. Permeability to non-electrolytes of isolated microvillous and basal membranes from human term placenta was measured using stopped-flow light-scattering techniques. The studied solutes were urea, ethylene glycol, glycerol, creatinine, erythritol, arabitol and mannitol. 2. At 37 degrees C, permeability of the microvillous membrane to mannitol and urea was 0.30 +/- 0.02 x 10(-6) cm/s (mean +/- S.E.M.) and 3.2 +/- 0.2 x 10(-6) cm/s, respectively. The corresponding permeabilities for the basal membrane were 1.2 +/- 0.1 x 10(-6) cm/s (mannitol) and 4.4 +/- 0.3 x 10(-6) cm/s (urea). The basal membrane was substantially more permeable to hydrophilic solutes than the microvillous membrane. This is probably due to differences in lipid composition, as illustrated by membrane cholesterol content, which was found to be approximately 50% lower in the basal as compared to the microvillous membrane. 3. Similarities between permeabilities in placental membranes and lipid bilayers and the linear relationship noted between solute hydrophobicity and placental permeability suggested that solutes permeate both human syncytiotrophoblast membranes by a solubility/diffusion mechanism. In the microvillous membrane this was supported by data obtained for activation energies (> 10 kcal/mol) and reflection coefficients (close to 1). In the basal membrane, low activation energies for glycerol and urea and a low reflection coefficient for urea indicated that these solutes may, in part, share a common pathway with water. 4. It was estimated that the placental permeability to molecules with a molecular weight under 200 observed in vivo can, to a great extent, be accounted for by transcellular permeation.
Collapse
Affiliation(s)
- T Jansson
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco 94143
| | | | | |
Collapse
|
35
|
Jansson T, Illsley NP. Osmotic water permeabilities of human placental microvillous and basal membranes. J Membr Biol 1993; 132:147-55. [PMID: 8496946 DOI: 10.1007/bf00239004] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Literature data suggest that water accumulation by the human fetus is driven by osmotic gradients of small solutes. However, the existence of such gradients has not been supported by prior measurements. Attempts to estimate the size of the gradient necessary to drive net water movement have been seriously hampered by the lack of permeability data for the syncytiotrophoblast membranes. Stopped-flow light scattering techniques were employed to measure the osmotic water permeability (Pf) of microvillous (MVM) and basal membrane (BM) vesicles isolated from human term placenta. At 37 degrees C, the Pf was determined to be 1.9 +/- 0.06 x 10(-3) cm/sec for MVM and 3.1 +/- 0.20 x 10(-3) cm/sec for BM (mean +/- SD, n = 6). At 23 degrees C, Pf was reduced to 0.7 +/- 0.04 x 10(-3) cm/sec in MVM and 1.6 +/- 0.05 x 10(-3) cm/sec in BM. These Pf values are comparable to those observed in membranes where water has been shown to permeate via a lipid diffusive mechanism. Arrhenius plots of Pf over the range 20-40 degrees C were linear, with activation energies of 13.6 +/- 0.6 kcal/mol for MVM and 12.9 +/- 1.0 kcal/mol for BM. Water permeation was not affected by mercurial sulfhydryl agents and glucose transport inhibitors. These data clearly suggest that water movement across human syncytiotrophoblast membranes occurs by a lipid diffusion pathway. As noted in several other epithelial tissues, the basal membrane has a higher water permeability than the microvillous membrane.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
Affiliation(s)
- T Jansson
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco 94143
| | | |
Collapse
|
36
|
Pardi G, Cetin I, Marconi AM, Bozzetti P, Buscaglia M, Makowski EL, Battaglia FC. Venous drainage of the human uterus: respiratory gas studies in normal and fetal growth-retarded pregnancies. Am J Obstet Gynecol 1992; 166:699-706. [PMID: 1536255 DOI: 10.1016/0002-9378(92)91700-k] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVE To determine respiratory gas relationships between the uterine veins and umbilical vein in normal and pregnancies complicated by intrauterine growth retardation. STUDY DESIGN Respiratory gases were measured in both uterine veins and the umbilical vein in eight normal and 13 pregnancies with intrauterine growth retardation. RESULTS No significant differences were found in the placental versus nonplacental uterine veins. There was a significant correlation for umbilical and uterine venous values of PO2 (p less than 0.002) and PCO2 (p less than 0.004) in appropriate-for-gestational-age pregnancies, umbilical venous PO2 was always less than uterine venous PO2, and PCO2 always greater than uterine. The transplacental gradient was significantly higher in intrauterine growth retarded than appropriate-for-gestational-age pregnancies for both POC2 and PCO2. There was a lower uterine oxygen extraction in intrauterine growth retarded pregnancies (p less than 0.05). CONCLUSION There is no consistent relationship between placental venous drainage in each uterine vein and placental location. The human placenta simulates a relatively inefficient venous equilibrator and the larger transplacental gradients in intrauterine growth retarded pregnancies may reflect differences in both perfusion pattern and placental structure.
Collapse
Affiliation(s)
- G Pardi
- Department of Obstetrics and Gynecology, San Paolo Institute of Biomedical Sciences, University of Milan, Italy
| | | | | | | | | | | | | |
Collapse
|
37
|
Feneley MR, Burton GJ. Villous composition and membrane thickness in the human placenta at term: a stereological study using unbiased estimators and optimal fixation techniques. Placenta 1991; 12:131-42. [PMID: 1871071 DOI: 10.1016/0143-4004(91)90017-a] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The aim of this study was to obtain unbiased estimates of in vivo villous composition and membrane thickness in the human placenta at term. By taking biopsies of the placenta 1 min after separation during caesarean section, and at regular intervals thereafter, it was possible to extrapolate back to the time zero values. It was estimated that at term intermediate and terminal villi are composed of 25.3 per cent trophoblast, 36.2 per cent stromal core and 37.1 per cent fetal capillaries. The villous membrane, defined as the outer surface of the syncytiotrophoblast (excluding the microvilli) to the inner surface of the capillary endothelium, was estimated to have an arithmetic mean thickness of 4.53 microns and a harmonic mean thickness of 3.65 microns. Villous composition and membrane thickness were found to change rapidly after delivery, despite the umbilical cord remaining clamped, and these changes were believed to be predominantly due to leakage of fetal blood or plasma from sites of damage to the villous tree caused at the time of delivery. These estimates do not, and indeed cannot, take into account the fact that the villi sampled have been removed from their uterine environment, and thus from the influences of the maternal and fetal blood pressures. However, they are free from methodological errors that have detracted from previous studies, and thus allow the morphometric diffusing capacity of the placenta at term to be calculated more accurately. They also provide baseline data against which measurements obtained from pathological pregnancies can be compared.
Collapse
Affiliation(s)
- M R Feneley
- Department of Anatomy, University of Cambridge, UK
| | | |
Collapse
|
38
|
Mayhew TM, Burton GJ. Methodological problems in placental morphometry: apologia for the use of stereology based on sound sampling practice. Placenta 1988; 9:565-81. [PMID: 3070535 DOI: 10.1016/0143-4004(88)90001-x] [Citation(s) in RCA: 88] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Several problem areas in morphometry of human and animal placentae are reviewed. Attention is given to methods of tissue processing (handling, mode of fixation, embedding, shrinkage) and sampling (of organs, tissue blocks, sections, micrographs). Principal sources of bias and sampling variability are identified and the crucial importance of randomized sampling is emphasized. Methods for obtaining structural quantities from sections are compared. The case is made for estimating absolute values (volumes, surface areas, lengths, numbers, thicknesses) using stereological principles rather than relying on planar data (profile areas, perimeter lengths, numbers, apparent thicknesses). Absolute values may be obtained simply and efficiently without resort to expensive measuring devices. Finally, morphological descriptors suitable for correlating with functional data or for comparing normal and diseased organs are surveyed.
Collapse
Affiliation(s)
- T M Mayhew
- Department of Anatomy, Marischal College, University of Aberdeen, UK
| | | |
Collapse
|