1
|
Joshi N, Sahay A, Mane A, Sundrani D, Randhir K, Wagh G, Thornburg K, Powell T, Yajnik C, Joshi S. Altered expression of nutrient transporters in syncytiotrophoblast membranes in preeclampsia placentae. Placenta 2023; 139:181-189. [PMID: 37421872 DOI: 10.1016/j.placenta.2023.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Revised: 05/29/2023] [Accepted: 07/03/2023] [Indexed: 07/10/2023]
Abstract
INTRODUCTION Expression of nutrient transporters in the placenta affects fetal growth. This study reports the protein expression of nutrient transporters in the syncytial membranes [microvillous membrane (MVM) and basal membrane (BM)] of normotensive control and preeclampsia placentae. METHODS Placentae were collected from fourteen normotensive control women and fourteen women with preeclampsia. The syncytiotrophoblast MVM and BM membranes were isolated. The protein expression of glucose transporter (GLUT1), vitamin B12 transporter (CD320) and fatty acid transporters (FATP2, FATP4) was assessed in both the membranes. RESULTS Comparison between membranes demonstrates similar CD320 protein expression in normotensive group whereas, in preeclampsia placentae it was higher in the BM as compared to MVM (p < 0.05). FATP2&4 protein expression was higher in the BM as compared to their respective MVM fraction in both the groups (p < 0.01 for both). Comparison between groups demonstrates higher GLUT1 expression in the MVM (p < 0.05) and BM (p < 0.05) whereas lower CD320 expression in the MVM (p < 0.05) of preeclampsia placentae as compared to their respective membranes in normotensive control. Furthermore, GLUT1 protein expression was positively associated and CD320 protein expression was negatively associated with maternal body mass index (BMI) (p < 0.05 for both). No difference was observed in the FATP2&4 protein expression. However, FATP4 protein expression was negatively associated with maternal blood pressure (p < 0.05 for MVM; p = 0.060 for BM) and birth weight (p < 0.05 for both membranes). DISCUSSION The current study for the first time demonstrates differential expression of various transporters in the syncytiotrophoblast membranes of the preeclampsia placentae which may influence fetal growth.
Collapse
Affiliation(s)
- Nikita Joshi
- Mother and Child Health, Interactive Research School for Health Affairs, Bharati Vidyapeeth University, Pune, India
| | - Akriti Sahay
- Mother and Child Health, Interactive Research School for Health Affairs, Bharati Vidyapeeth University, Pune, India
| | - Aditi Mane
- Mother and Child Health, Interactive Research School for Health Affairs, Bharati Vidyapeeth University, Pune, India
| | - Deepali Sundrani
- Mother and Child Health, Interactive Research School for Health Affairs, Bharati Vidyapeeth University, Pune, India
| | - Karuna Randhir
- Mother and Child Health, Interactive Research School for Health Affairs, Bharati Vidyapeeth University, Pune, India
| | - Girija Wagh
- Department of Obstetrics and Gynecology, Bharati Medical College and Hospital, Bharati Vidyapeeth University, Pune, India
| | - Kent Thornburg
- Department of Medicine, Center for Developmental Health, Knight Cardiovascular Institute, Bob and Charlee Moore Institute for Nutrition and Wellness, Oregon Health and Science University, Portland, OR, United States
| | - Theresa Powell
- Department of Pediatrics, Section of Neonatology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States; Division of Reproductive Sciences, Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | | | - Sadhana Joshi
- Mother and Child Health, Interactive Research School for Health Affairs, Bharati Vidyapeeth University, Pune, India.
| |
Collapse
|
2
|
Elser BA, Hing B, Stevens HE. A narrative review of converging evidence addressing developmental toxicity of pyrethroid insecticides. Crit Rev Toxicol 2022; 52:371-388. [PMID: 36345971 PMCID: PMC9930199 DOI: 10.1080/10408444.2022.2122769] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 09/01/2022] [Accepted: 09/05/2022] [Indexed: 11/11/2022]
Abstract
Pyrethroid insecticides are broadly used in agriculture and household products throughout the world. Exposure to this class of insecticides is widespread, and while generally believed to be safe for use, there is increasing concern regarding their effects on neurodevelopment. Due to the critical roles that molecular targets of pyrethroids play in the regulation of neurodevelopment, particular focus has been placed on evaluating the effects of in utero and childhood pyrethroid exposure on child cognition and behavior. As such, this narrative review synthesizes an assessment of converging study types; we review reports of neonatal pyrethroid levels together with current epidemiological literature that convergently address the risk for developmental toxicity linked to exposure to pyrethroid insecticides. We first address studies that assess the degree of direct fetal exposure to pyrethroids in utero through measurements in cord blood, meconium, and amniotic fluid. We then focus on the links between prenatal exposure to these insecticides and child neurodevelopment, fetal growth, and other adverse birth outcomes. Furthermore, we assess the effects of postnatal exposure on child neurodevelopment through a review of the data on pediatric exposures and child cognitive and behavioral outcomes. Study quality was evaluated individually, and the weight of evidence was assessed broadly to characterize these effects. Overall, while definitive conclusions cannot be reached from the currently available literature, the available data suggest that the potential links between pyrethroid exposure and child neurodevelopmental effects deserve further investigation.
Collapse
Affiliation(s)
- Benjamin A Elser
- Interdisciplinary Graduate Program in Human Toxicology, Graduate College, The University of Iowa, Iowa City, IA, USA
- Department of Psychiatry, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| | - Benjamin Hing
- Department of Psychiatry, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| | - Hanna E Stevens
- Interdisciplinary Graduate Program in Human Toxicology, Graduate College, The University of Iowa, Iowa City, IA, USA
- Department of Psychiatry, Carver College of Medicine, The University of Iowa, Iowa City, IA, USA
| |
Collapse
|
3
|
António T, Cosme D, Igreja B, Fraga S, Serrão MP, Pires NM, Soares-da-Silva P. The role of salt-inducible kinases on the modulation of renal and intestinal Na +,K +-ATPase activity during short- and long-term high-salt intake. Eur J Pharmacol 2021; 904:174153. [PMID: 33989615 DOI: 10.1016/j.ejphar.2021.174153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 04/24/2021] [Accepted: 04/30/2021] [Indexed: 11/29/2022]
Abstract
Type 1 salt-inducible kinases (SIK1) has been shown to act as a mediator during the cellular adaptation to variations in intracellular sodium in a variety of cell types. Type 2 SIK (SIK2) modulates various biological functions and acts as a signal transmitter in various pathways. To evaluate the role of both SIK isoforms in renal and intestinal Na+,K+-ATPase (NKA) activity, we made use of constitutive sik1-/- (SIK1-KO), sik2-/- (SIK2-KO), double sik1-/-sik2-/- (double SIK1*2-KO) knockout and wild-type (WT) mice challenged to a standard (0.3% NaCl) or chronic high-salt (HS, 8% NaCl) diet intake for 48 h or 12 weeks. Long-term HS intake in WT was accompanied by 2-fold increase in jejunal NKA activity and slight (~30% reduction) decreases in NKA in the ileum and cecum; none of these changes was accompanied by changes in the expression of α1-NKA. The ablation of SIK1 and SIK2 prevented the marked increase in jejunal NKA activity following the long-term HS intake. The ablation of SIK1 and SIK2 in mice on a long-term HS intake impacted differently in the ileum and cecum. The most interesting finding is that in SIK2-KO mice marked reductions in NKA activity were observed in the ileum and cecum when compared to WT mice, both on normal and long-term HS intake. In summary, SIK1 or SIK2 ablation on chronic high-salt intake is accompanied by modulation of NKA along the intestinal tract, which differ from those after an acute high-salt intake, and this may represent an absorptive compensatory mechanism to keep electrolyte homeostasis.
Collapse
Affiliation(s)
- Tatiana António
- Unit of Pharmacology and Therapeutics, Department of Biomedicine, Faculty of Medicine, University of Porto, 4200-319, Porto, Portugal; MedInUp - Center for Drug Discovery and Innovative Medicines, University of Porto, 4200-319, Porto, Portugal
| | - Dina Cosme
- Unit of Pharmacology and Therapeutics, Department of Biomedicine, Faculty of Medicine, University of Porto, 4200-319, Porto, Portugal; MedInUp - Center for Drug Discovery and Innovative Medicines, University of Porto, 4200-319, Porto, Portugal
| | - Bruno Igreja
- Division of Research and Development, BIAL-Portela & C(a), S.A, 4745-457, Coronado, Portugal
| | - Sónia Fraga
- Unit of Pharmacology and Therapeutics, Department of Biomedicine, Faculty of Medicine, University of Porto, 4200-319, Porto, Portugal; MedInUp - Center for Drug Discovery and Innovative Medicines, University of Porto, 4200-319, Porto, Portugal
| | - Maria Paula Serrão
- Unit of Pharmacology and Therapeutics, Department of Biomedicine, Faculty of Medicine, University of Porto, 4200-319, Porto, Portugal; MedInUp - Center for Drug Discovery and Innovative Medicines, University of Porto, 4200-319, Porto, Portugal
| | - Nuno M Pires
- Division of Research and Development, BIAL-Portela & C(a), S.A, 4745-457, Coronado, Portugal
| | - Patrício Soares-da-Silva
- Unit of Pharmacology and Therapeutics, Department of Biomedicine, Faculty of Medicine, University of Porto, 4200-319, Porto, Portugal; MedInUp - Center for Drug Discovery and Innovative Medicines, University of Porto, 4200-319, Porto, Portugal; Division of Research and Development, BIAL-Portela & C(a), S.A, 4745-457, Coronado, Portugal.
| |
Collapse
|
4
|
Powell TL, Barner K, Madi L, Armstrong M, Manke J, Uhlson C, Jansson T, Ferchaud-Roucher V. Sex-specific responses in placental fatty acid oxidation, esterification and transfer capacity to maternal obesity. Biochim Biophys Acta Mol Cell Biol Lipids 2021; 1866:158861. [PMID: 33321178 PMCID: PMC11247378 DOI: 10.1016/j.bbalip.2020.158861] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 12/06/2020] [Accepted: 12/08/2020] [Indexed: 12/20/2022]
Abstract
Fatty acid metabolism and oxidation capacity in the placenta, which likely affects the rate and composition of lipid delivered to the fetus remains poorly understood. Long chain polyunsaturated fatty acids, such as docosahexaenoic acid (DHA), are critical for fetal growth and brain development. We determined the impact of maternal obesity on placental fatty acid oxidation, esterification and transport capacity by measuring PhosphatidylCholine (PC) and LysoPhosphatidylCholine (LPC) containing DHA by mass spectrometry in mother-placenta-baby triads as well as placental free carnitine and acylcarnitine metabolites in women with normal and obese pre-pregnancy BMI. Placental protein expression of enzymes involved in beta-oxidation and esterification pathways, MFSD2a (lysophosphatidylcholine transporter) and OCTN2 (carnitine transporter) expression in syncytiotrophoblast microvillous (MVM) and basal (BM) membranes were determined by Western Blot. Maternal obesity was associated with decreased umbilical cord plasma DHA in LPC and PC fractions in male, but not female, fetuses. Basal membrane MFSD2a protein expression was increased in placenta of males of obese mothers. In female placentas, despite an increased MVM OCTN2 expression, maternal obesity was associated with a reduced MUFA-carnitine levels and increased esterification enzymes. We speculate that lower DHA-PL in fetal circulation of male offspring of obese mothers, despite a significant increase in transporter expression for LPC-DHA, may lead to low DHA needed for brain development contributing to neurological consequences that are more prevalent in male children. Female placentas likely have reduced beta-oxidation capacity and appear to store FA through greater placental esterification, suggesting impaired placenta function and lipid transfer in female placentas of obese mothers.
Collapse
Affiliation(s)
- Theresa L Powell
- Department of Obstetrics & Gynecology, Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; Department of Pediatrics, Section of Neonatology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Kelsey Barner
- Department of Obstetrics & Gynecology, Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Lana Madi
- Department of Obstetrics & Gynecology, Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Michael Armstrong
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Jonathan Manke
- Department of Pharmaceutical Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Charis Uhlson
- Department of Pediatrics, Section of Neonatology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Thomas Jansson
- Department of Obstetrics & Gynecology, Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Véronique Ferchaud-Roucher
- Department of Obstetrics & Gynecology, Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA; University of Nantes, INRAe UMR1280 PhAN, Physiopathology of Nutritional Adaptations, CHU Nantes University Hospital, CRNH Ouest, 44000 Nantes, France.
| |
Collapse
|
5
|
Watkins OC, Yong HEJ, Sharma N, Chan SY. A review of the role of inositols in conditions of insulin dysregulation and in uncomplicated and pathological pregnancy. Crit Rev Food Sci Nutr 2020; 62:1626-1673. [PMID: 33280430 DOI: 10.1080/10408398.2020.1845604] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Inositols, a group of 6-carbon polyols, are highly bioactive molecules derived from diet and endogenous synthesis. Inositols and their derivatives are involved in glucose and lipid metabolism and participate in insulin-signaling, with perturbations in inositol processing being associated with conditions involving insulin resistance, dysglycemia and dyslipidemia such as polycystic ovary syndrome and diabetes. Pregnancy is similarly characterized by substantial and complex changes in glycemic and lipidomic regulation as part of maternal adaptation and is also associated with physiological alterations in inositol processing. Disruptions in maternal adaptation are postulated to have a critical pathophysiological role in pregnancy complications such as gestational diabetes and pre-eclampsia. Inositol supplementation has shown promise as an intervention for the alleviation of symptoms in conditions of insulin resistance and for gestational diabetes prevention. However, the mechanisms behind these affects are not fully understood. In this review, we explore the role of inositols in conditions of insulin dysregulation and in pregnancy, and identify priority areas for research. We particularly examine the role and function of inositols within the maternal-placental-fetal axis in both uncomplicated and pathological pregnancies. We also discuss how inositols may mediate maternal-placental-fetal cross-talk, and regulate fetal growth and development, and suggest that inositols play a vital role in promoting healthy pregnancy.
Collapse
Affiliation(s)
- Oliver C Watkins
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Hannah E J Yong
- Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore, Singapore
| | - Neha Sharma
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
| | - Shiao-Yng Chan
- Department of Obstetrics and Gynaecology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.,Singapore Institute for Clinical Sciences, Agency for Science, Technology and Research, Singapore, Singapore
| |
Collapse
|
6
|
Chassen SS, Ferchaud-Roucher V, Palmer C, Li C, Jansson T, Nathanielsz PW, Powell TL. Placental fatty acid transport across late gestation in a baboon model of intrauterine growth restriction. J Physiol 2020; 598:2469-2489. [PMID: 32338384 PMCID: PMC7384518 DOI: 10.1113/jp279398] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 04/14/2020] [Indexed: 12/13/2022] Open
Abstract
KEY POINTS Intrauterine growth restriction (IUGR) is associated with perinatal morbidity and increased risk of lifelong disease, including neurodevelopmental impairment. Fatty acids (FA) are critical for normal brain development, although their transport across the placenta in IUGR pregnancies is poorly understood. The present study used a baboon model of IUGR (maternal nutrient restriction, MNR) to investigate placental expression of FA transport and binding proteins, and to determine gestational age-related changes in maternal and fetal plasma FA concentrations. We found MNR to be associated with increased placental expression of FA binding and transport proteins in late gestation, with fetal plasma FA concentrations that were similar to those of control animals. The present study is the first to report a profile of fetal and maternal plasma FA concentrations in a baboon model of growth restriction with data that suggest adaptation of placental transport to maintain delivery of critically needed FA. ABSTRACT Intrauterine growth restriction (IUGR) is associated with specific changes in placental transport of amino acids, folate and ions. However, little is known about placental fatty acid (FA) transport in IUGR. We hypothesized that placental FA transport proteins (FATP) and FA binding proteins (FABP) are up-regulated and fetal plasma FA concentrations are decreased at term in a baboon model of IUGR. Pregnant baboons were fed control or maternal nutrient restricted (MNR) diet (70% of control calories) from gestation day (GD) 30 (term 184 days). Plasma and placental samples were collected at GD120 (control n = 8, MNR n = 9), GD140 (control n = 6, MNR n = 7) and GD170 (control n = 6, MNR n = 6). Placentas were homogenized, and syncytiotrophoblast microvillous plasma membrane (MVM) and basal plasma membranes (BM) were isolated. Protein expression of FABP1, 3, 4 and 5 (homogenate) and FATP2, 4, and 6 (MVM, BM) was determined by Western blotting. FA content in maternal and umbilical vein plasma was measured by gas chromatography-mass spectrometry. Placental FABP1 and FABP5 expression was increased in MNR compared to controls at GD170, as was MVM FATP2 and FATP6 expression at GD140 and FATP2 expression at GD170. BM FATP4 and FATP6 expression was increased in MNR at GD140. Fetal plasma FA concentrations were similar in controls and MNR. These data suggest the adaptation of placental transport when aiming to maintain delivery of critically needed FAs for fetal growth and brain development.
Collapse
Affiliation(s)
- Stephanie S Chassen
- Department of Pediatrics, Section of Neonatology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Veronique Ferchaud-Roucher
- University of Nantes, CHU Nantes, INRA, UMR 1280 Physiology of Nutritional Adaptations, Nantes, France
- Department of Obstetrics & Gynecology, Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Claire Palmer
- Department of Pediatrics, Section of Neonatology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Cun Li
- Department of Animal Science, University of Wyoming, Laramie, WY, USA
- Southwest National Primate Research Center, San Antonio, TX, USA
| | - Thomas Jansson
- Department of Obstetrics & Gynecology, Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Peter W Nathanielsz
- Department of Animal Science, University of Wyoming, Laramie, WY, USA
- Southwest National Primate Research Center, San Antonio, TX, USA
| | - Theresa L Powell
- Department of Pediatrics, Section of Neonatology, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
- Department of Obstetrics & Gynecology, Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| |
Collapse
|
7
|
Chassen S, Jansson T. Complex, coordinated and highly regulated changes in placental signaling and nutrient transport capacity in IUGR. Biochim Biophys Acta Mol Basis Dis 2020; 1866:165373. [PMID: 30684642 PMCID: PMC6650384 DOI: 10.1016/j.bbadis.2018.12.024] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Revised: 12/20/2018] [Accepted: 12/26/2018] [Indexed: 01/01/2023]
Abstract
The most common cause of intrauterine growth restriction (IUGR) in the developed world is placental insufficiency, a concept often used synonymously with reduced utero-placental and umbilical blood flows. However, placental insufficiency and IUGR are associated with complex, coordinated and highly regulated changes in placental signaling and nutrient transport including inhibition of insulin and mTOR signaling and down-regulation of specific amino acid transporters, Na+/K+-ATPase, the Na+/H+-exchanger, folate and lactate transporters. In contrast, placental glucose transport capacity is unaltered and Ca2+-ATPase activity and the expression of proteins involved in placental lipid transport are increased in IUGR. These findings are not entirely consistent with the traditional view that the placenta is dysfunctional in IUGR, but rather suggest that the placenta adapts to reduce fetal growth in response to an inability of the mother to allocate resources to the fetus. This new model has implications for the understanding of the mechanisms underpinning IUGR and for the development of intervention strategies.
Collapse
Affiliation(s)
- Stephanie Chassen
- Department of Pediatrics, Division of Neonatology, University of Colorado, Anschutz Medical Campus, Aurora, USA
| | - Thomas Jansson
- Department of Obstetrics and Gynecology, Division of Reproductive Sciences, University of Colorado, Anschutz Medical Campus, Aurora, USA.
| |
Collapse
|
8
|
Chen YY, Gupta MB, Grattton R, Powell TL, Jansson T. Down-regulation of placental folate transporters in intrauterine growth restriction. J Nutr Biochem 2018; 59:136-141. [PMID: 29986308 PMCID: PMC6129407 DOI: 10.1016/j.jnutbio.2018.06.003] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 05/13/2018] [Accepted: 06/06/2018] [Indexed: 11/21/2022]
Abstract
Folate deficiency in pregnancy is associated with neural tube defects, restricted fetal growth and fetal programming of diseases later in life. Fetal folate availability is dependent on maternal folate levels and placental folate transport capacity, mediated by two key transporters, Folate Receptor-α and Reduced Folate Carrier (RFC). We tested the hypothesis that intrauterine growth restriction (IUGR) is associated with decreased folate transporter expression and activity in isolated syncytiotrophoblast microvillous plasma membranes (MVM). Women with pregnancies complicated by IUGR (birth weight <3rd percentile, mean birth weight 1804±110 g, gestational age 35.7±0.61 weeks, n=25) and women delivering an appropriately-for gestational age infant (control group, birth weight 25th-75th centile, mean birth weight 2493±216 g, gestational age 33.9±0.95 weeks, n=19) were recruited and placentas were collected at delivery. MVM was isolated and folate transporter protein expression was measured using Western blot and transporter activity was determined using radiolabelled methyltetrahydrofolic acid and rapid filtration. Whereas the expression of FR-α was unaffected, MVM RFC protein expression was significantly decreased in the IUGR group (-34%, P<.05). IUGR MVM had a significantly lower folate uptake compared to the control group (-38%, P<.05). In conclusion, placental folate transport capacity is decreased in IUGR, which may contribute to the restricted fetal growth and intrauterine programming of childhood and adult disease. These findings suggest that continuation of folate supplementation in the second and third trimester is of particular importance in pregnancies complicated by IUGR.
Collapse
Affiliation(s)
- Yi-Yung Chen
- Department of Obstetrics & Gynecology, University of Colorado Anschutz Medical Campus Aurora, CO, USA; Division of High-risk Pregnancy, Department of Obstetrics & Gynecology, Mackay Memorial Hospital, Taipei, Taiwan.
| | - Madhulika B Gupta
- Children's Health Research Institute, University of Western Ontario, London, ON, Canada; Department of Pediatrics and Biochemistry, University of Western Ontario, London, ON, Canada.
| | - Rob Grattton
- Department of Obstetrics and Gynecology, University of Western Ontario, London, ON, Canada.
| | - Theresa L Powell
- Department of Obstetrics & Gynecology, University of Colorado Anschutz Medical Campus Aurora, CO, USA; Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
| | - Thomas Jansson
- Department of Obstetrics & Gynecology, University of Colorado Anschutz Medical Campus Aurora, CO, USA.
| |
Collapse
|
9
|
Sibley CP, Brownbill P, Glazier JD, Greenwood SL. Knowledge needed about the exchange physiology of the placenta. Placenta 2018; 64 Suppl 1:S9-S15. [PMID: 29370939 DOI: 10.1016/j.placenta.2018.01.006] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 01/09/2018] [Accepted: 01/10/2018] [Indexed: 01/30/2023]
Abstract
There is now a basic understanding of the driving forces and mechanisms underlying rates of solute exchange across the placenta but there are still major gaps in knowledge. Here we summarise this basic understanding, whilst highlighting gaps in knowledge. We then focus on two particular areas where more knowledge is needed: (1) the electrical potential difference (PD) across the placenta and (2) the paracellular permeability of the placenta to hydrophilic solutes. In many species a PD has been recorded between a catheter in a maternal blood vessel and one in a fetal vessel. However, the key question is whether this PD is the same as that across the placental exchange barrier. We addressed this in the human placenta using microelectrodes to measure the PD in isolated villi in vitro; the transtrophoblast PD so measured had a median value of -3 mV (range 0-15 mV). There have been no subsequent studies to validate this measurement. The syncytiotrophoblast of haemochorial placentas lacks any obvious extracellular water filled paracellular space between the syncytial nuclei. However, in mouse, rat, guinea pig and human there is an inverse relationship between the rate of diffusion of inert hydrophilic solutes across the placenta and their molecular size. The simplest explanation is that a paracellular route exists but its morphological identity is still uncertain. Areas of syncytial denudation could provide a paracellular route but this has not been proven. Answers to these and similar questions are required to fully understand the exchange physiology of the normal placenta and how this is affected in pathology.
Collapse
Affiliation(s)
- Colin P Sibley
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK; St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, M13 9WL, UK.
| | - Paul Brownbill
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK; St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, M13 9WL, UK
| | - Jocelyn D Glazier
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK; St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, M13 9WL, UK
| | - Susan L Greenwood
- Maternal and Fetal Health Research Centre, Division of Developmental Biology and Medicine, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, UK; St Mary's Hospital, Central Manchester University Hospitals NHS Foundation Trust, Manchester Academic Health Science Centre, Manchester, M13 9WL, UK
| |
Collapse
|
10
|
Zatloukalová M, Nazaruk E, Novák D, Vacek J, Bilewicz R. Lipidic liquid crystalline cubic phases for preparation of ATP-hydrolysing enzyme electrodes. Biosens Bioelectron 2017; 100:437-444. [PMID: 28961546 DOI: 10.1016/j.bios.2017.09.036] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 09/17/2017] [Accepted: 09/18/2017] [Indexed: 11/26/2022]
Abstract
The lipidic liquid-crystalline cubic phase (LCP) is a membrane-mimetic material useful for the stabilization and structural analysis of membrane proteins. Here, we focused on the incorporation of the membrane ATP-hydrolysing sodium/potassium transporter Na+/K+-ATPase (NKA) into a monoolein-derived LCP. Small-angle X-ray scattering was employed for the determination of the LCP structure, which was of Pn3m symmetry for all the formulations studied. The fully characterized NKA-LCP material was immobilized onto a glassy carbon electrode, forming a highly stable enzyme electrode and a novel sensing platform. A typical NKA voltammetric signature was monitored via the anodic reaction of tyrosine and tryptophan residues. The in situ enzyme activity evaluation was based on the ability of NKA to transform ATP to ADP and free phosphate, the latter reacting with ammonium molybdate to form the ammonium phosphomolybdate complex under acidic conditions. The square-wave voltammetric detection of phosphomolybdate was performed and complemented with spectrophotometric measurement at 710nm. The anodic voltammetric response, corresponding to the catalytic ATP-hydrolysing function of NKA incorporated into the LCP, was monitored at around + 0.2V vs. Ag/AgCl in the presence or absence of ouabain, a specific NKA inhibitor. NKA incorporated into the LCP retained its ATP-hydrolysing activity for 7 days, while the solubilized protein became practically inactive. The novelty of this work is the first incorporation of NKA into a lipidic cubic phase with consequent enzyme functionality and stability evaluation using voltammetric detection. The application of LCPs could also be important in the further development of new membrane protein electrochemical sensors and enzyme electrodes.
Collapse
Affiliation(s)
- Martina Zatloukalová
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland; Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, 775 15 Olomouc, Czech Republic
| | - Ewa Nazaruk
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland
| | - David Novák
- Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, 775 15 Olomouc, Czech Republic
| | - Jan Vacek
- Department of Medical Chemistry and Biochemistry, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 3, 775 15 Olomouc, Czech Republic.
| | - Renata Bilewicz
- Faculty of Chemistry, University of Warsaw, Pasteura 1, 02-093 Warsaw, Poland.
| |
Collapse
|
11
|
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
|
12
|
Protein expression of fatty acid transporter 2 is polarized to the trophoblast basal plasma membrane and increased in placentas from overweight/obese women. Placenta 2016; 40:60-6. [PMID: 27016784 DOI: 10.1016/j.placenta.2016.02.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2015] [Revised: 02/12/2016] [Accepted: 02/18/2016] [Indexed: 11/20/2022]
Abstract
BACKGROUND Obese and overweight women are more likely to deliver a large infant or an infant with increased adiposity, however the underlying mechanisms are not well established. We tested the hypothesis that placental capacity to transport fatty acid is increased in overweight/obese women. METHODS Pregnant women with body mass index (BMI) ranging from 18.4 to 54.3 kg/m(2) and with uncomplicated term pregnancies were recruited for collection of blood samples and placental tissue. Maternal and fetal levels of non-esterified fatty acids (NEFAs) were measured in plasma. The expression and localization of CD36/fatty acid translocase (FAT), fatty acid transport protein (FATP)2, and FATP4 was determined in fixed placental tissue and in isolated syncytiotrophoblast plasma membranes from normal and high BMI mothers. RESULTS Maternal and fetal plasma NEFA levels did not correlate (n = 42). FATP2 and FATP4 expressions were higher in the basal plasma membrane (BPM) compared to the microvillous membrane (P < 0.001; n = 7) per unit membrane protein. BPM expression of FATP2 correlated with maternal BMI (P < 0.01; n = 30); there was no association between CD36/FAT or FATP4 expression and maternal BMI. CONCLUSION The polarization of FATPs to the BPM will facilitate fatty acid transfer across the placenta. In overweight/obese pregnancies, the increased FATP2 expression could contribute to increased fatty acid delivery to the fetus and while we have no direct data we speculate that this could lead accelerated fetal growth or increased fat deposition.
Collapse
|
13
|
Increased ubiquitination and reduced plasma membrane trafficking of placental amino acid transporter SNAT-2 in human IUGR. Clin Sci (Lond) 2015; 129:1131-41. [PMID: 26374858 PMCID: PMC4614027 DOI: 10.1042/cs20150511] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 09/14/2015] [Indexed: 02/07/2023]
Abstract
Inhibition of placental mechanistic target of rapamycin (mTOR) signalling, which activates NEDD4-2 (neural precursor cell expressed developmentally down-regulated protein 4-2) ubiquitin ligase leading to increased sodium-coupled neutral amino acid transporter 2 (SNAT-2) ubiquitination and removal from the syncytiotrophoblast plasma membrane may constitute a key mechanism underlying decreased placental amino acid transport in human IUGR. Placental amino acid transport is decreased in intrauterine growth restriction (IUGR); however, the underlying mechanisms remain largely unknown. We have shown that mechanistic target of rapamycin (mTOR) signalling regulates system A amino acid transport by modulating the ubiquitination and plasma membrane trafficking of sodium-coupled neutral amino acid transporter 2 (SNAT-2) in cultured primary human trophoblast cells. We hypothesize that IUGR is associated with (1) inhibition of placental mTORC1 and mTORC2 signalling pathways, (2) increased amino acid transporter ubiquitination in placental homogenates and (3) decreased protein expression of SNAT-2 in the syncytiotrophoblast microvillous plasma membrane (MVM). To test this hypothesis, we collected placental tissue and isolated MVM from women with pregnancies complicated by IUGR (n=25) and gestational age-matched women with appropriately grown control infants (n=19, birth weights between the twenty-fifth to seventy-fifth percentiles). The activity of mTORC1 and mTORC2 was decreased whereas the protein expression of the ubiquitin ligase NEDD4-2 (neural precursor cell expressed developmentally down-regulated protein 4-2; +72%, P<0.0001) and the ubiquitination of SNAT-2 (+180%, P<0.05) were increased in homogenates of IUGR placentas. Furthermore, IUGR was associated with decreased system A amino acid transport activity (–72%, P<0.0001) and SNAT-1 (–42%, P<0.05) and SNAT-2 (–31%, P<0.05) protein expression in MVM. In summary, these findings are consistent with the possibility that decreased placental mTOR activity causes down-regulation of placental system A activity by shifting SNAT-2 trafficking towards proteasomal degradation, thereby contributing to decreased fetal amino acid availability and restricted fetal growth in IUGR.
Collapse
|
14
|
Boyd C. Review: Epithelial aspects of human placental trophoblast. Placenta 2013; 34 Suppl:S24-6. [DOI: 10.1016/j.placenta.2012.11.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 11/13/2012] [Accepted: 11/15/2012] [Indexed: 11/25/2022]
|
15
|
Fetal serum folate concentrations and placental folate transport in obese women. Am J Obstet Gynecol 2011; 205:83.e17-25. [PMID: 21514551 DOI: 10.1016/j.ajog.2011.02.053] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2010] [Revised: 02/05/2011] [Accepted: 02/14/2011] [Indexed: 11/21/2022]
Abstract
OBJECTIVE We hypothesized that fetal folate serum concentrations are lower and placental folate transport is impaired in pregnancies of obese women. STUDY DESIGN Umbilical vein serum and placental tissue were collected from normal weight and obese pregnant women at term. Cellular localization (immunohistochemistry) of folate receptor-α (FR-α), proton coupled folate transporter (PCFT), and reduced folate carrier (RFC) was established. Protein expression (Western blot) and transporter activity (isotope labeled methyltetrahydrofolate) were determined in syncytiotrophoblast microvillus membranes (MVM). RESULTS Fetal folate concentrations were similar in obese women as compared with normal weight women. Protein expression of FR-α in microvillus membranes was increased (+173%), in RFC was decreased (-41%), and in PCFT was unchanged. However, activity of FR-α, PCFT, and RFC was unaltered in obesity. CONCLUSION Fetal serum folate concentrations and placental folate transport activity are not altered in obesity at term, which suggests that limited availability of folate does not contribute to abnormal gene methylation and developmental programming.
Collapse
|
16
|
Zhang Q, Schulenborg T, Tan T, Lang B, Friauf E, Fecher-Trost C. Proteome analysis of a plasma membrane-enriched fraction at the placental feto-maternal barrier. Proteomics Clin Appl 2010; 4:538-49. [DOI: 10.1002/prca.200900048] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Revised: 12/17/2009] [Accepted: 12/18/2009] [Indexed: 12/15/2022]
|
17
|
Irani RA, Zhang Y, Blackwell SC, Zhou CC, Ramin SM, Kellems RE, Xia Y. The detrimental role of angiotensin receptor agonistic autoantibodies in intrauterine growth restriction seen in preeclampsia. ACTA ACUST UNITED AC 2009; 206:2809-22. [PMID: 19887397 PMCID: PMC2806612 DOI: 10.1084/jem.20090872] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Growth-restricted fetuses are at risk for a variety of lifelong medical conditions. Preeclampsia, a life-threatening hypertensive disorder of pregnancy, is associated with fetuses who suffer from intrauterine growth restriction (IUGR). Recently, emerging evidence indicates that preeclamptic women harbor AT1 receptor agonistic autoantibodies (AT1-AAs) that contribute to the disease features. However, the exact role of AT1-AAs in IUGR and the underlying mechanisms have not been identified. We report that these autoantibodies are present in the cord blood of women with preeclampsia and retain the ability to activate AT1 receptors. Using an autoantibody-induced animal model of preeclampsia, we show that AT1-AAs cross the mouse placenta, enter fetal circulation, and lead to small fetuses with organ growth retardation. AT1-AAs also induce apoptosis in the placentas of pregnant mice, human villous explants, and human trophoblast cells. Finally, autoantibody-induced IUGR and placental apoptosis are diminished by either losartan or an autoantibody-neutralizing peptide. Thus, these studies identify AT1-AA as a novel causative factor of preeclampsia-associated IUGR and offer two possible underlying mechanisms: a direct detrimental effect on fetal development by crossing the placenta and entering fetal circulation, and indirectly through AT1-AA–induced placental damage. Our findings highlight AT1-AAs as important therapeutic targets.
Collapse
Affiliation(s)
- Roxanna A Irani
- Department of Biochemistry and Molecular Biology, University of Texas Medical School at Houston, Houston, TX, 77030, USA
| | | | | | | | | | | | | |
Collapse
|
18
|
Sibley CP. Understanding placental nutrient transfer--why bother? New biomarkers of fetal growth. J Physiol 2009; 587:3431-40. [PMID: 19417095 PMCID: PMC2742272 DOI: 10.1113/jphysiol.2009.172403] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2009] [Accepted: 04/30/2009] [Indexed: 12/13/2022] Open
Abstract
The placenta, in general and the physiology of maternofetal nutrient transfer is under-researched compared to other organs with epithelial transport function, as evidenced, for example, by publication numbers. This report provides reasons why more researchers should become involved in this topic. First, the syncytiotrophoblast, the transporting epithelium of the placenta, though having many basic cell physiology properties similar to those of other transporting epithelia, has several properties which are markedly different. Better information on these might help fundamental understanding of how epithelia in general function as well as improving knowledge of how the syncytiotrophoblast operates. Second, the synctiotrophoblast has a key role in controlling fetal growth, not only by transporting nutrients and waste products of metabolism but also because it increasingly appears to be one site, perhaps even the dominant site, in which integration of, sometimes conflicting, signals between mother and fetus takes place. Finally, better understanding of placental nutrient transfer and especially of how it is regulated by maternal and fetal signals could provide better information on the placental phenotype in fetal growth disorders--information which might contribute to providing better biomarkers which the obstetrician could use to improve early diagnosis of these disorders.
Collapse
Affiliation(s)
- C P Sibley
- Maternal and Fetal Health Research Centre, Research School of Clinical and Laboratory Sciences, University of Manchester, Research Floor, St Mary's Hospital, Manchester M13 OJH, UK.
| |
Collapse
|
19
|
Abstract
The human placental syncytiotrophoblast (hSTB) is a polarized epithelial structure, that forms the main barrier to materno-fetal exchange. The chloride (Cl(-)) channels in other epithelial tissues contribute to several functions, such as maintenance of the membrane potential, volume regulation, absorption and secretion. Additionally, the contributions of Cl(-) channels to these functions are demonstrated by certain diseases and knock-out animal models. There are multiple lines of evidence for the presence of Cl(-) channels in the hSTB, which could contribute to different placental functions. However, both the mechanism by which these channels are involved in the physiology of the placenta, and their molecular identities are still unclear. Furthermore, a correlation between altered Cl(-) channels functions and pathological pregnancies is beginning to emerge. This review summarizes recent developments on conductive placental chloride transport, and discusses its potential implications for placental physiology.
Collapse
|
20
|
Roos S, Jansson N, Palmberg I, Säljö K, Powell TL, Jansson T. Mammalian target of rapamycin in the human placenta regulates leucine transport and is down-regulated in restricted fetal growth. J Physiol 2007; 582:449-59. [PMID: 17463046 PMCID: PMC2075295 DOI: 10.1113/jphysiol.2007.129676] [Citation(s) in RCA: 200] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Pathological fetal growth is associated with perinatal morbidity and the development of diabetes and cardiovascular disease later in life. Placental nutrient transport is a primary determinant of fetal growth. In human intrauterine growth restriction (IUGR) the activity of key placental amino acid transporters, such as systems A and L, is decreased. However the mechanisms regulating placental nutrient transporters are poorly understood. We tested the hypothesis that the mammalian target of rapamycin (mTOR) signalling pathway regulates amino acid transport in the human placenta and that the activity of the placental mTOR pathway is reduced in IUGR. Using immunohistochemistry and culture of trophoblast cells, we show for the first time that the mTOR protein is expressed in the transporting epithelium of the human placenta. We further demonstrate that placental mTOR regulates activity of the l-amino acid transporter, but not system A or taurine transporters, by determining the mediated uptake of isotope-labelled leucine, methylaminoisobutyric acid and taurine in primary villous fragments after inhibition of mTOR using rapamycin. The protein expression of placental phospho-S6K1 (Thr-389), a measure of the activity of the mTOR signalling pathway, was markedly reduced in placentas obtained from pregnancies complicated by IUGR. These data identify mTOR as an important regulator of placental amino acid transport, and provide a mechanism for the changes in placental leucine transport in IUGR previously demonstrated in humans. We propose that mTOR functions as a placental nutrient sensor, matching fetal growth with maternal nutrient availability by regulating placental nutrient transport.
Collapse
Affiliation(s)
- Sara Roos
- Perinatal Center, Department of Physiology, Institute of Neuroscience and Physiology, University of Gothenburg, PO Box 432, SE-405 30 Gothenburg, Sweden.
| | | | | | | | | | | |
Collapse
|
21
|
Ericsson A, Säljö K, Sjöstrand E, Jansson N, Prasad PD, Powell TL, Jansson T. Brief hyperglycaemia in the early pregnant rat increases fetal weight at term by stimulating placental growth and affecting placental nutrient transport. J Physiol 2007; 581:1323-32. [PMID: 17430988 PMCID: PMC2170823 DOI: 10.1113/jphysiol.2007.131185] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
In pregnant women with type 1 diabetes, suboptimal glucose control in the first trimester is a strong predictor for giving birth to a large fetus. However, the mechanisms underlying this association are unknown. We hypothesized that transient hyperglycaemia in early pregnancy results in (1) increased placental growth and (2) an up-regulation of placental nutrient transport capacity, which leads to fetal overgrowth at term. In order to test this hypothesis, pregnant rats were given intraperitoneal injections of glucose (2 g kg(-1), resulting in a 50-100% increase in blood glucose level during 90 min) or saline (control) in either early or late gestation using four different protocols: one single injection on gestational day (GD) 10 (n=5), three injections on GD 10 (n=8-9), six injections on GD 10 and 11 (n=9-11) or three injections on GD 19 (n=7-8). Multiple injections were given approximately 4 h apart. Subsequently, animals were studied on GD 21. Three glucose injections in early pregnancy significantly increased placental weight by 10%, whereas fetal weight was found to be increased at term in response to both three (9% increase in fetal weight, P<0.05) and six glucose injections (7%, P=0.05) in early gestation. A single glucose injection on GD 10 or three injections of glucose on GD 19 had no effect on placental or fetal growth. In groups where a change in feto-placental growth was observed, we measured placental system A and glucose transport activity in the awake animals on GD 21 and placental expression of the glucose and amino acid transporters GLUT1, GLUT3, SNAT2 (system A), LAT1 and LAT 2 (system L). Placental system A transport at term was down-regulated by six glucose injections in early pregnancy (by -33%, P<0.05), whereas placental mRNA and protein levels were unchanged. No long-term alterations in maternal metabolic status were detected. In conclusion, we demonstrate that transient hyperglycaemia in early pregnancy is sufficient to increase fetal weight close to term. In contrast, brief hyperglycaemia in late pregnancy did not stimulate fetal growth. Increased fetal growth may be explained by a larger placenta, which would allow for more nutrients to be transferred to the fetus. These data suggest that maternal metabolic control in early pregnancy is an important determinant for feto-placental growth and placental function throughout the remainder of gestation. We speculate that maternal metabolism in early pregnancy represents a key environmental cue to which the placenta responds in order to match fetal growth rate with the available resources of the mother.
Collapse
MESH Headings
- Amino Acid Transport System A
- Amino Acid Transport System y+/metabolism
- Amino Acid Transport Systems/metabolism
- Amino Acid Transport Systems, Neutral/genetics
- Amino Acid Transport Systems, Neutral/metabolism
- Animals
- Blood Glucose/metabolism
- Diabetes, Gestational/blood
- Diabetes, Gestational/chemically induced
- Diabetes, Gestational/metabolism
- Diabetes, Gestational/pathology
- Disease Models, Animal
- Female
- Fetal Nutrition Disorders/blood
- Fetal Nutrition Disorders/etiology
- Fetal Nutrition Disorders/metabolism
- Fetal Nutrition Disorders/pathology
- Fetal Weight
- Fusion Regulatory Protein 1, Light Chains/metabolism
- Gestational Age
- Glucose
- Glucose Transport Proteins, Facilitative/genetics
- Glucose Transport Proteins, Facilitative/metabolism
- Glucose Transporter Type 1/metabolism
- Glucose Transporter Type 3/metabolism
- Hyperglycemia/blood
- Hyperglycemia/chemically induced
- Hyperglycemia/complications
- Hyperglycemia/metabolism
- Hyperglycemia/pathology
- Insulin/blood
- Large Neutral Amino Acid-Transporter 1/metabolism
- Maternal-Fetal Exchange
- Organ Size
- Placenta/metabolism
- Placenta/pathology
- Pregnancy
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
Collapse
Affiliation(s)
- Anette Ericsson
- Perinatal Center, Institute of Neuroscience and Physiology, Gothenburg University, Box 432, s-405 30 Gothenburg, Sweden.
| | | | | | | | | | | | | |
Collapse
|
22
|
Meyer zu Schwabedissen HE, Dreisbach A, Hammer E, Fusch C, Hecker M, Völker U, Kroemer HK. Direct mass spectrometric identification of ABCB1 (P-glycoprotein/MDR1) from the apical membrane fraction of human placenta using fourier transform ion cyclotron mass spectrometry. Pharmacogenet Genomics 2006; 16:385-9. [PMID: 16708047 DOI: 10.1097/01.fpc.0000215064.83599.47] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Identification and quantification of proteins from human tissue by electrophoresis and subsequent mass spectrometry (MS) has been mainly restricted to high abundance, non-membrane-bound molecules. Pharmacologically relevant structures such as cytochrome P450 enzyme, drug transporters and receptors were not accessible by this technology. We developed a method to identify an integral membrane-bound protein (ABCB1) from human placenta using Fourier transform ion cyclotron (FTICR)-MS. Apical and basal membrane fractions were enriched from term human placenta using differential centrifugation. Following SDS-page these fractions were cleaved with trypsin, separated by nano-HPLC and subjected to FTICR-MS. We identified a total of 70 and 89 proteins in the apical and basal membranes, respectively. Among these proteins, and restricted to the apical membrane, was the transport protein ABCB1, with 10 peptides identified by MS, covering a total of 10% of the entire protein. The study describes a method suitable for direct monitoring of membrane-bound proteins from human tissue using FTICR-MS.
Collapse
Affiliation(s)
- Henriette E Meyer zu Schwabedissen
- Department of Pharmacology, Peter-Holtz Research Center of Pharmacology and Experimental Therapeutics, Ernst-Moritz-Arndt-University, Greifswald, Germany
| | | | | | | | | | | | | |
Collapse
|
23
|
Shibata E, Powers RW, Rajakumar A, von Versen-Höynck F, Gallaher MJ, Lykins DL, Roberts JM, Hubel CA. Angiotensin II decreases system A amino acid transporter activity in human placental villous fragments through AT1 receptor activation. Am J Physiol Endocrinol Metab 2006; 291:E1009-16. [PMID: 16787961 DOI: 10.1152/ajpendo.00134.2006] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Reduced transport of amino acids from mother to fetus can lead to fetal intrauterine growth restriction (IUGR). The activities of several amino acid transport systems, including system A, are decreased in placental syncytiotrophoblast of IUGR pregnancies. Na(+)-K(+)-ATPase activity provides an essential driving force for Na(+)-coupled system A transport, is decreased in the placenta of IUGR pregnancies, and is decreased by angiotensin II in several tissues. Several reports have shown activation of the fetoplacental renin-angiotensin system (RAS) in IUGR. We investigated the effect of angiotensin II on placental system A transport and Na(+)-K(+)-ATPase activity in placental villi. Placental system A activity in single primary villous fragments was measured as the Na(+)-dependent uptake of alpha-(methylamino)isobutyric acid, and Na(+)/K(+) ATPase activity was measured as ouabain-sensitive uptake of (86)rubidium. Angiotensin II decreased system A activity in a concentration-dependent fashion (10-500 nmol/l). Angiotensin II type 1 receptor (AT1-R) antagonists losartan and AT1-R anti-peptide blocked the angiotensin II effect, but the angiotensin II type 2 receptor antagonist PD-123319 was without effect. System A activity was not altered by preincubation with AT1-R-independent vasoconstrictors, and antioxidants did not prevent the decrease in activity mediated by angiotensin II. Angiotensin II decreased Na(+)-K(+)-ATPase activity by an AT1-R dependent mechanism, and inhibition of Na(+)-K(+)-ATPase activity decreased system A activity in a dose-response fashion. These data suggest that angiotensin II, via AT1-R signaling, decreases system A activity by suppressing Na(+)-K(+)-ATPase in human placental villi, consistent with possible adverse effects of enhanced placental RAS on fetal growth.
Collapse
Affiliation(s)
- Eiji Shibata
- Magee-Womens Research Institute, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15213, USA
| | | | | | | | | | | | | | | |
Collapse
|
24
|
Beijar ECE, Mallard C, Powell TL. Expression and Subcellular Localization of TLR-4 in Term and First Trimester Human Placenta. Placenta 2006; 27:322-6. [PMID: 16338476 DOI: 10.1016/j.placenta.2004.12.012] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2004] [Revised: 12/16/2004] [Accepted: 12/20/2004] [Indexed: 02/07/2023]
Abstract
Toll-like receptor 4 (TLR-4) mediates Gram-negative bacterial-induced inflammatory responses, including production of pro-inflammatory cytokines. Maternal infection and inflammation play an important role in preterm birth and neonatal brain damage. The localization of placental TLR-4 as well as changes during normal gestation are critical issues in understanding the role of toll-like receptors in defending the placento-fetal unit from maternal infection. We therefore investigated, by immunohistochemistry (IHC) and Western blot, the subcellular localization of TLR-4 in first trimester and term human placenta. In both term placenta (n=4) and first trimester placenta villous samples (n=5), immunoreactivity for TLR-4 was found in the cytoplasm of the syncytiotrophoblast, with darker staining in some areas of the maternal facing plasma membrane (MVM). In addition, TLR-4 was found to be expressed in the first trimester cytotrophoblast cells. Using Western blot analysis, TLR-4 was identified in both placental homogenates and isolated MVM and the fetal facing basal membrane (BM). TLR-4 expression in MVM was significantly higher in term (n=9) as compared to first trimester (n=2) samples. We have shown for the first time that the subcellular localization of TLR-4 in term placenta is preferentially in the MVM compared to BM. The MVM is continuously bathed in maternal blood, suggesting that from this vantage point TLR-4 can initiate a rapid response to maternal bacterial infection.
Collapse
Affiliation(s)
- E C E Beijar
- Perinatal Center, Department of Physiology, Göteborg University, 405 30 Göteborg, Sweden
| | | | | |
Collapse
|
25
|
Bosco C, Buffet C, Bello MA, Rodrigo R, Gutierrez M, García G. Placentation in the degu (Octodon degus): analogies with extrasubplacental trophoblast and human extravillous trophoblast. Comp Biochem Physiol A Mol Integr Physiol 2006; 146:475-85. [PMID: 16448832 DOI: 10.1016/j.cbpa.2005.12.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2005] [Revised: 12/06/2005] [Accepted: 12/09/2005] [Indexed: 10/25/2022]
Abstract
This study examined the placentation in the degu, the origin of the extrasubplacental trophoblast (EST) (extravillous trophoblast in human), and the activity of Na+/K+ ATPase in the placental barrier during different gestational ages, as part of a wider effort to understand the reproductive biology of this species. Fifteen degus at the first stage of gestation, midgestation and at term of pregnancy were studied. At day 27 of gestation, the subplacenta is formed under the wall of the central excavation. Simultaneously, the outermost trophoblast of the ectoplacental cone differentiated into secondary trophoblast giant cells that lie on the outside of the placenta, forming an interface with the maternal cells in the decidua. These giant cells immunostained positive for cytokeratin (CK) and placental lactogen (hPL) until term. During this period, the EST merged from the subplacenta to the decidua and immunostained negative for CK, but at term, immunostained for CK and hPL in the maternal vessels. The vascular mesenchyme of the central excavation invaded the chorioallantoic placenta during this period, forming two fetal lobules of labyrinthine-fine syncytium, the zone of the placental barrier. The activity of Na+/K+ ATPase in the placental barrier was constant during the gestational period. The residual syncytium at the periphery of the placental disc and between the lobules was not invaded by fetal mesenchyme and formed the marginal and interlobular labyrinthine syncytium that immunostained first for CK, and later for hPL, as in the labyrinthine fine syncytium. The presence of intracytoplasmic electron-dense material in the interlobular labyrinthine syncytium suggested a secretory process in these cells that are bathed in maternal blood. Placentas obtained from vaginal births presented a large, single lobe, absence of the subplacenta, and a reduced interlobular labyrinthine syncytium. At day 27, the inverted visceral yolk sac is observed and its columnar epithelium immunostained for CK and hPL. This suggests that the yolk sac is an early secretory organ. The epithelium of the parietal yolk sac covers the placenta. The origin of the EST in the degu placenta and its migration to maternal vessels allows us to present this animal model for the study of pregnancy pathologies related to alterations in the migration of the extravillous trophoblast.
Collapse
Affiliation(s)
- Cleofina Bosco
- Programas de Anatomía y Biología del Desarrollo, ICBM, Facultad de Medicina, Universidad de Chile, Chile.
| | | | | | | | | | | |
Collapse
|
26
|
Ericsson A, Hamark B, Powell TL, Jansson T. Glucose transporter isoform 4 is expressed in the syncytiotrophoblast of first trimester human placenta. Hum Reprod 2005; 20:521-30. [PMID: 15528266 DOI: 10.1093/humrep/deh596] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
BACKGROUND Placental glucose transport mechanisms in early pregnancy are poorly understood. The aims of this study were to investigate the expression of glucose transporter (GLUT) isoforms 1, 3 and 4 in first trimester villous tissue, to assess the effects of insulin on glucose uptake and compare them with term. METHODS The expression of GLUT isoforms was investigated using immunohistochemistry, Western blot and reverse transcription (RT)-PCR in trophoblast tissue from terminations at 6-13 weeks gestation and term. The effects of insulin (300 ng/ml, 1 h) on glucose uptake were studied in villous fragments. RESULTS In the first trimester, GLUT1 and GLUT3 were present in the microvillous membrane and the cytotrophoblast, and GLUT4 in perinuclear membranes in the cytosol of the syncytiotrophoblast (ST). GLUT4 protein (48 kDa) and mRNA were identified in trophoblast homogenates. Whereas GLUT1 was expressed abundantly in term placenta, the expression of GLUT3 and 4 was markedly lower at term compared with first trimester. Insulin increased glucose uptake by 182% (n=6, P<0.05) in first trimester fragments, but not in term fragments. CONCLUSIONS The insulin-regulatable GLUT4 is expressed in the cytosol of first trimester ST compatible with a role for GLUT4 in placental glucose transport in early pregnancy. The placental expression pattern of GLUT isoforms in early pregnancy is distinct from that later in pregnancy.
Collapse
Affiliation(s)
- A Ericsson
- Department of Physiology and Pharmacology, Perinatal Center, Göteborg University, 405 30 Göteborg, Sweden.
| | | | | | | |
Collapse
|
27
|
Roos S, Powell TL, Jansson T. Human placental taurine transporter in uncomplicated and IUGR pregnancies: cellular localization, protein expression, and regulation. Am J Physiol Regul Integr Comp Physiol 2004; 287:R886-93. [PMID: 15166008 DOI: 10.1152/ajpregu.00232.2004] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Transplacental transfer is the fetus' primary source of taurine, an essential amino acid during fetal life. In intrauterine growth restriction (IUGR), placental transport capacity of taurine is reduced and fetal taurine levels are decreased. We characterized the protein expression of the taurine transporter (TAUT) in human placenta using immunocytochemistry and Western blotting, tested the hypothesis that placental protein expression of TAUT is reduced in IUGR, and investigated TAUT regulation by measuring the Na(+)-dependent taurine uptake in primary villous fragments after 1 h of incubation with different effectors. TAUT was primarily localized in the syncytiotrophoblast microvillous plasma membrane (MVM). TAUT was detected as a single 70-kDa band, and MVM TAUT expression was unaltered in IUGR. The PKC activator PMA and the nitric oxide (NO) donor 3-morpholinosydnonimine decreased TAUT activity (P < 0.05, n = 7-15). However, none of the tested hormones, e.g., leptin and growth hormone, altered TAUT activity significantly. PKC activity measured in MVM from control and IUGR placentas was not different. In conclusion, syncytiotrophoblast TAUT is strongly polarized to the maternal-facing plasma membrane. MVM TAUT expression is unaltered in IUGR, suggesting that the reduced MVM taurine transport in IUGR is due to changes in transporter activity. NO release downregulates placental TAUT activity, and it has previously been shown that IUGR is associated with increased fetoplacental NO levels. NO may therefore play an important role in downregulating MVM TAUT activity in IUGR.
Collapse
Affiliation(s)
- S Roos
- Perinatal Center, Dept. of Physiology and Pharmacology, Göteborg Univ., PO Box 432, S-405 30 Göteborg, Sweden.
| | | | | |
Collapse
|
28
|
Jimenez V, Henriquez M, Llanos P, Riquelme G. Isolation and Purification of Human Placental Plasma Membranes from Normal and Pre-eclamptic Pregnancies. A Comparative Study. Placenta 2004; 25:422-37. [PMID: 15081637 DOI: 10.1016/j.placenta.2003.10.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2003] [Revised: 10/15/2003] [Accepted: 10/28/2003] [Indexed: 11/20/2022]
Abstract
Human placental syncytiotrophoblast is the main barrier for materno-fetal exchange. Analysis of transplacental transport involves the study of ion channels in both the maternal-facing microvillous membrane (MVM) and the fetal-facing basal membrane (BM). Difficulties in having access to intact placenta with conventional electrophysiological methods favour alternative methodologies, such as isolation and reconstitution of membranes in artificial lipid systems. Pre-eclampsia is a major health problem of human pregnancy. The search for altered physiological processes in pre-eclamptic placentae requires the investigation of events at both the microvillous and basal surfaces. The aim of this study was to obtain reliable syncytiotrophoblast plasma membranes from human normal (N) and pre-eclamptic (PE) pregnancies. We describe a protocol which allows for the simultaneous isolation of MVM and BM. The purity of the membranes isolated was evaluated using enzymatic assays, binding studies, Western blotting and immunohistochemistry. Enrichment of alkaline phosphatase activity for MVM was 17 to 21-fold, with 13-16 per cent protein recovery, for both N and PE. Enrichment of adenylate cyclase activity for BM was 9-fold for N, and enrichment of dihydroalprenolol binding to beta-adrenergic receptors was 12-fold for N and 6-fold for PE, with 14 per cent protein recovery for both N and PE. Cross contamination was low and mitochondrial membrane contamination was negligible. We conclude that MVM and BM isolated from placentae of pre-eclamptic women are similar in enrichment and purity to those of healthy women, thus allowing their use in comparative electrophysiological studies.
Collapse
Affiliation(s)
- V Jimenez
- Programa de Fisiología y Biofísica, Instituto de Ciencias Biomédicas (ICBM), Facultad de Medicina, Universidad de Chile, Casilla 70005, Santiago 7, Chile
| | | | | | | |
Collapse
|
29
|
Lecuit M, Nelson DM, Smith SD, Khun H, Huerre M, Vacher-Lavenu MC, Gordon JI, Cossart P. Targeting and crossing of the human maternofetal barrier by Listeria monocytogenes: role of internalin interaction with trophoblast E-cadherin. Proc Natl Acad Sci U S A 2004; 101:6152-7. [PMID: 15073336 PMCID: PMC395938 DOI: 10.1073/pnas.0401434101] [Citation(s) in RCA: 173] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2003] [Indexed: 11/18/2022] Open
Abstract
Listeria monocytogenes produces severe fetoplacental infections in humans. How it targets and crosses the maternofetal barrier is unknown. We used immunohistochemistry to examine the location of L. monocytogenes in placental and amniotic tissue samples obtained from women with fetoplacental listeriosis. The results raised the possibility that L. monocytogenes crosses the maternofetal barrier through the villous syncytiotrophoblast, with secondary infection occurring via the amniotic epithelium. Because epidemiological studies indicate that the bacterial surface protein, internalin (InlA), may play a role in human fetoplacental listeriosis, we investigated the cellular patterns of expression of its host receptor, E-cadherin, at the maternofetal interface. E-cadherin was found on the basal and apical plasma membranes of syncytiotrophoblasts and in villous cytotrophoblasts. Established trophoblastic cell lines, primary trophoblast cultures, and placental villous explants were each exposed to isogenic InlA+ or InlA- strains of L. monocytogenes, and to L. innocua expressing or not InlA. Quantitative assays of cellular invasion demonstrated that bacterial entry into syncytiotrophoblasts occurs via the apical membrane in an InlA-E-cadherin dependent manner. In human placental villous explants, bacterial invasion of the syncytiotrophoblast barrier and underlying villous tissue and subsequent replication produces histopathological lesions that mimic those seen in placentas of women with listeriosis. Thus, the InlA-E-cadherin interaction that plays a key role in the crossing of the intestinal barrier in humans is also exploited by L. monocytogenes to target and cross the placental barrier. Such a ligand-receptor interaction allowing a pathogen to specifically cross the placental villous trophoblast barrier has not been reported previously.
Collapse
Affiliation(s)
- Marc Lecuit
- Unité des Interactions Bactéries-Cellules and Unité d'Histotechnologie et Pathologie, Institut Pasteur, Paris 75015, France.
| | | | | | | | | | | | | | | |
Collapse
|
30
|
Magnusson AL, Powell T, Wennergren M, Jansson T. Glucose Metabolism in the Human Preterm and Term Placenta of IUGR Fetuses. Placenta 2004; 25:337-46. [PMID: 15028426 DOI: 10.1016/j.placenta.2003.08.021] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2003] [Revised: 08/13/2003] [Accepted: 08/14/2003] [Indexed: 11/16/2022]
Abstract
Many fetuses suffering from intrauterine growth restriction (IUGR) are hypoglycaemic. However, the underlying mechanisms are not well established. An increased placental glucose consumption in IUGR could impair glucose transfer across the placenta. In this study we used two different approaches to investigate glucose metabolism in preterm and term placentae of IUGR fetuses. We determined activity and protein expression of the three rate-limiting glycolytic enzymes phosphofructo kinase (PFK), pyruvate kinase (PK) and hexokinase (HXK) in a cytoplasmic fraction of homogenates of placentae obtained from IUGR and appropriate for gestational age (AGA) pregnancies. Protein expression was assessed using Western blot and enzyme activities were determined in a spectrophotometer by measuring the rate of NADH oxidation (PFK and PK) or NADP reduction (HXK) in enzyme reactions coupled to the respective enzyme. To determine the distribution of the glycolytic enzymes immunocytochemistry was performed. We also measured glucose consumption and lactate production in fresh placental villous tissue using a perifusion system. The expression of PFK, PK and HXK as well as the activity of PK and HXK was unaltered in IUGR placentae. The activity of PFK on the other hand was 32 per cent lower in IUGR placentae (n=24, P<0.05). Immunocytochemistry confirmed the distribution of the enzymes to the cytoplasm of the syncytiotrophoblast. Placental glucose consumption in IUGR [0.06+/-0.01 micromol/(min*g), n=5] was not different from AGA [0.06+/-0.005 micromol/(min*g), n=12], whereas lactate production was decreased by 28 per cent in IUGR. These results do not support the hypothesis of increased placental glucose consumption but suggest an altered glycolytic pathway in the IUGR placenta.
Collapse
Affiliation(s)
- A L Magnusson
- Department of Physiology and Pharmacology, Perinatal Center, Göteborg University, Medicinaregatan 11, Box 432, s-405 30 Göteborg, Sweden.
| | | | | | | |
Collapse
|
31
|
Wester K, Asplund A, Bäckvall H, Micke P, Derveniece A, Hartmane I, Malmström PU, Pontén F. Zinc-based fixative improves preservation of genomic DNA and proteins in histoprocessing of human tissues. J Transl Med 2003; 83:889-99. [PMID: 12808124 DOI: 10.1097/01.lab.0000074892.53211.a5] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
Advantageous preservation of histology and detailed cellular morphology has rendered neutral buffered formalin (NBF) the most widely used fixative in clinical pathology. Despite excellent morphology for routine diagnostics, a major drawback of NBF fixation is its detrimental effect on DNA and RNA quality. In addition to complicating analysis of genes and transcripts in complex tissues, NBF denatures proteins and thereby hampers immunohistochemical visualization of certain antigens. In the present study, we evaluated a zinc-based fixative (ZBF) regarding its effects on tissue morphology, quality of genomic DNA, and preservation of protein immunoreactivity in a broad spectrum of tissues. Four different modes of fixation were analyzed: ZBF-paraffin embedding, NBF-paraffin embedding, ZBF-fixation prior to snap-freezing, and immediate snap-freezing. Laser-assisted microdissection, allowing retrieval of a defined number of cells for PCR, was used to study DNA quality. Genomic DNA was analyzed using primers for beta2-microglobulin and the transferrin receptor. Immunohistochemistry was performed using nine antibodies. Tissue microarray blocks were used for analysis of morphology and immunoreactivity. Only slight impairment of morphologic qualities was found after ZBF-paraffin embedding, whereas ZBF prior to freezing resulted in a more crisp morphology compared with routine cryosections. A significantly higher DNA yield was observed in samples isolated from ZBF-paraffin-embedded tissues compared with NBF-paraffin-embedded tissues. Both yield and quality of DNA was comparable in frozen tissues irrespective to prior ZBF fixation. Immunoreactivity in paraffin-embedded tissue was superior in ZBF-fixated tissue compared with NBF-fixated for a majority of tested antibodies. Furthermore, for seven out of nine antibodies, antigen retrieval pretreatment proved unnecessary in ZBF-fixated tissue. Thus, despite a slight impairment of morphology, ZBF preserves protein structures well. We conclude that ZBF is superior to NBF for analysis of DNA and protein expression. Fixation of tissues in ZBF may also be an alternative strategy to freeze storage of tissue specimens, eg, in future bio-banks.
Collapse
Affiliation(s)
- Kenneth Wester
- Department of Genetics and Pathology, Uppsala University, Uppsala, Sweden.
| | | | | | | | | | | | | | | |
Collapse
|
32
|
Page KR, Ashworth CJ, McArdle HJ, Finch AM, Nwagwu MO. Sodium transport across the chorioallantoic membrane of porcine placenta involves the epithelial sodium channel (ENaC). J Physiol 2003; 547:849-57. [PMID: 12562966 PMCID: PMC2342719 DOI: 10.1113/jphysiol.2002.031153] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2002] [Accepted: 01/02/2003] [Indexed: 11/08/2022] Open
Abstract
The properties of chorioallantoic membrane derived from Large White Landrace sows at 45, 65 and 100 days gestation are examined. Under short circuit conditions positive charge flows from fetal to maternal sides of the tissue. Na+ is shown to be the sole charge carrier as the short circuit current is inhibited reversibly by fetal applications of amiloride and replacement of Na+ by choline in the Ringer solution, and irreversibly by both fetal and maternal applications of ouabain. The initial short circuit current is smaller at day 100 compared to days 45 and 65. The dose responses to amiloride indicate that the epithelial sodium channel (ENaC) is involved in the movement of Na+ and that it is accessible on the fetal side of the tissue only. Immunostaining shows that the ENaC-alpha subunit is present in both the allantoic membrane and the trophoblast. Uptake studies using microvillous (apical) membrane vesicles suggest it is either inactive or only weakly active at this site. The trophoblast at day 100 has a higher content of ENaC than at days 45 and 65. This is the first report of the presence of ENaC in placental tissues. The effects of ouabain indicate the presence of a Na+ pump that is more readily inhibited by applications of the drug on the maternal aspect of the tissue than on the fetal side. Differential mechanisms may be present that would allow net movement of Na+ in either direction across the chorioallantoic membrane according to the changing demands of the developing fetus.
Collapse
Affiliation(s)
- K R Page
- Department of Biomedical Sciences, Aberdeen University, Scottish Agricultural College, Craibstone and Rowett Research Institute, Aberdeen, UK.
| | | | | | | | | |
Collapse
|
33
|
Granger JP. Maternal and fetal adaptations during pregnancy: lessons in regulatory and integrative physiology. Am J Physiol Regul Integr Comp Physiol 2002; 283:R1289-92. [PMID: 12429557 DOI: 10.1152/ajpregu.00562.2002] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Affiliation(s)
- Joey P Granger
- Department of Physiology and Biophysics, University of Mississippi, Jackson, Mississippi 39216, USA.
| |
Collapse
|
34
|
Jansson T, Ekstrand Y, Björn C, Wennergren M, Powell TL. Alterations in the activity of placental amino acid transporters in pregnancies complicated by diabetes. Diabetes 2002; 51:2214-9. [PMID: 12086952 DOI: 10.2337/diabetes.51.7.2214] [Citation(s) in RCA: 159] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Alterations in placental transport may contribute to accelerated fetal growth in pregnancies complicated by diabetes. We studied the activity of the syncytiotrophoblast amino acid transporter system A and the transport of the essential amino acids leucine, lysine, and taurine. Syncytiotrophoblast microvillous plasma membranes (MVMs) and basal plasma membranes (BMs) were isolated from placentas obtained from normal pregnancies and pregnancies complicated by gestational diabetes mellitus (GDM) and type 1 diabetes, with and without large-for-gestational-age (LGA) fetuses. Amino acid transport was assessed using radio-labeled substrates and rapid filtration techniques. System A activity in MVM was increased (65-80%, P < 0.05) in all groups with diabetes independent of fetal overgrowth. However, MVM system A activity was unaffected in placentas of normal pregnancies with LGA fetuses. MVM leucine transport was increased in the GDM/LGA group. In BMs, amino acid transport was unaffected by diabetes. In conclusion, diabetes in pregnancy is associated with an increased system A activity in MVM, and MVM leucine transport is increased in the GDM/LGA group. We suggest that these changes result in an increased uptake of neutral amino acids across MVM, which may be used in placental metabolism or be delivered to the fetus. The increased MVM leucine uptake in the GDM/LGA group may contribute to accelerated fetal growth in these patients.
Collapse
Affiliation(s)
- Thomas Jansson
- Department of Physiology and Pharmacology, the Perinatal Center, Göteborg University, Box 432, S-405 30 Göteborg, Sweden.
| | | | | | | | | |
Collapse
|
35
|
Persson A, Johansson M, Jansson T, Powell TL. Na(+)/K(+)-ATPase activity and expression in syncytiotrophoblast plasma membranes in pregnancies complicated by diabetes. Placenta 2002; 23:386-91. [PMID: 12061854 DOI: 10.1053/plac.2002.0807] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Many of the transport processes across the syncytiotrophoblast (ST), such as amino acid transport, are Na(+)-coupled. The maintenance of a low intracellular Na(+) concentration by Na(+)/K(+)-ATPase is therefore crucial for placental transport of nutrients and consequently, foetal growth. In pregnancies complicated by diabetes foetal growth is often accelerated despite rigorous glycemic control of the mother, however the underlying mechanisms are not fully understood. We tested the hypothesis that Na(+)/K(+)-ATPase in ST plasma membranes is up-regulated in diabetic pregnancies associated with accelerated growth. ST microvillous (MVM) and basal (BM) plasma membranes were purified from term placentas of normal pregnancies (control, n=13) and pregnancies complicated by insulin-dependent diabetes mellitus (n=7) or gestational diabetes (n=6). All mothers with diabetes gave birth to large for gestational age babies. The Na(+)/K(+)-ATPase alpha(1)-subunit protein expression (Western blot) in MVM and BM was unaltered by diabetes. Na(+)/K(+)-ATPase activity (K(+)-stimulated, ouabain-sensitive phosphatase activity) in ST plasma membranes was not affected by diabetes. This is the first study of Na(+)/K(+)-ATPase in ST membranes of the human placenta in diabetes. Our data show that accelerated foetal growth in diabetic pregnancies is not associated with elevated ST Na(+)/K(+)-ATPase protein expression or activity.
Collapse
Affiliation(s)
- A Persson
- Perinatal Center, Department of Physiology and Pharmacology, Göteborg University, Sweden
| | | | | | | |
Collapse
|
36
|
Clarson LH, Roberts VHJ, Greenwood SL, Elliott AC. ATP-stimulated Ca(2+)-activated K(+) efflux pathway and differentiation of human placental cytotrophoblast cells. Am J Physiol Regul Integr Comp Physiol 2002; 282:R1077-85. [PMID: 11893612 DOI: 10.1152/ajpregu.00564.2001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The aim of this study was to determine whether extracellular ATP ([ATP](o)) stimulated a Ca(2+)-activated K(+) efflux in trophoblast cells that was dependent on extracellular Ca(2+) ([Ca(2+)](o)). Cytotrophoblast cells, isolated from human placenta, were examined following 18 h (relatively undifferentiated) and 66 h (multinucleate cells) of culture. Potassium efflux was measured using (86)Rb as a trace marker. Intracellular Ca(2+) ([Ca(2+)](i)) was examined by microfluorometry using fura 2. [ATP](o) significantly increased (86)Rb efflux to a peak that declined to control (18-h cells) or an elevated plateau (66-h cells) and was inhibited by 100 nM charybdotoxin. Removing [Ca(2+)](o) significantly reduced (86)Rb efflux in both groups as did application of 150 microM GdCl(3). [ATP](o) significantly increased [Ca(2+)](i) in both groups of cells. The response was reduced by removing [Ca(2+)](o) and applying 150 microM GdCl(3). For both (86)Rb efflux and microfluorometry experiments, the response to [ATP](o) was more dependent on [Ca(2+)](o) in 66-h cells compared with 18-h cells (approximately 70% greater). Cytotrophoblast cells exhibit an [ATP](o)-stimulated Ca(2+)-activated K(+) efflux. The dependency of this pathway on [Ca(2+)](o) is greater in the 66-h multinucleate syncytiotrophoblast-like cells, suggesting that the mechanism for Ca(2+) entry may be altered during differentiation of trophoblast cells.
Collapse
Affiliation(s)
- L H Clarson
- Academic Unit of Child Health, University of Manchester, St. Mary's Hospital, Manchester M13 0JH, United Kingdom.
| | | | | | | |
Collapse
|
37
|
Scheidl SJ, Nilsson S, Kalén M, Hellström M, Takemoto M, Håkansson J, Lindahl P. mRNA expression profiling of laser microbeam microdissected cells from slender embryonic structures. THE AMERICAN JOURNAL OF PATHOLOGY 2002; 160:801-13. [PMID: 11891179 PMCID: PMC1867164 DOI: 10.1016/s0002-9440(10)64903-6] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Microarray hybridization has rapidly evolved as an important tool for genomic studies and studies of gene regulation at the transcriptome level. Expression profiles from homogenous samples such as yeast and mammalian cell cultures are currently extending our understanding of biology, whereas analyses of multicellular organisms are more difficult because of tissue complexity. The combination of laser microdissection, RNA amplification, and microarray hybridization has the potential to provide expression profiles from selected populations of cells in vivo. In this article, we present and evaluate an experimental procedure for global gene expression analysis of slender embryonic structures using laser microbeam microdissection and laser pressure catapulting. As a proof of principle, expression profiles from 1000 cells in the mouse embryonic (E9.5) dorsal aorta were generated and compared with profiles for captured mesenchymal cells located one cell diameter further away from the aortic lumen. A number of genes were overexpressed in the aorta, including 11 previously known markers for blood vessels. Among the blood vessel markers were endoglin, tie-2, PDGFB, and integrin-beta1, that are important regulators of blood vessel formation. This demonstrates that microarray analysis of laser microbeam micro-dissected cells is sufficiently sensitive for identifying genes with regulative functions.
Collapse
Affiliation(s)
- Stefan J. Scheidl
- From the Department of Medical Biochemistry,* Göteborg University; and AngiogeneticsAB,† Göteborg, Sweden
| | - Sven Nilsson
- From the Department of Medical Biochemistry,* Göteborg University; and AngiogeneticsAB,† Göteborg, Sweden
| | - Mattias Kalén
- From the Department of Medical Biochemistry,* Göteborg University; and AngiogeneticsAB,† Göteborg, Sweden
| | - Mats Hellström
- From the Department of Medical Biochemistry,* Göteborg University; and AngiogeneticsAB,† Göteborg, Sweden
| | - Minoru Takemoto
- From the Department of Medical Biochemistry,* Göteborg University; and AngiogeneticsAB,† Göteborg, Sweden
| | - Joakim Håkansson
- From the Department of Medical Biochemistry,* Göteborg University; and AngiogeneticsAB,† Göteborg, Sweden
| | - Per Lindahl
- From the Department of Medical Biochemistry,* Göteborg University; and AngiogeneticsAB,† Göteborg, Sweden
| |
Collapse
|