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Huang Y, Qiu F, Dziegielewska KM, Koehn LM, Habgood MD, Saunders NR. Effects of paracetamol/acetaminophen on the expression of solute carriers (SLCs) in late-gestation fetal rat brain, choroid plexus and the placenta. Exp Physiol 2024; 109:427-444. [PMID: 38059686 PMCID: PMC10988763 DOI: 10.1113/ep091442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 11/21/2023] [Indexed: 12/08/2023]
Abstract
Solute carriers (SLCs) regulate transfer of a wide range of molecules across cell membranes using facilitative or secondary active transport. In pregnancy, these transporters, expressed at the placental barrier, are important for delivery of nutrients to the fetus, whilst also limiting entry of potentially harmful substances, such as drugs. In the present study, RNA-sequencing analysis was used to investigate expression of SLCs in the fetal (embryonic day 19) rat brain, choroid plexus and placenta in untreated control animals and following maternal paracetamol treatment. In the treated group, paracetamol (15 mg/kg) was administered to dams twice daily for 5 days (from embryonic day 15 to 19). In untreated animals, overall expression of SLCs was highest in the placenta. In the paracetamol treatment group, expression of several SLCs was significantly different compared with control animals, with ion, amino acid, neurotransmitter and sugar transporters most affected. The number of SLC transcripts that changed significantly following treatment was the highest in the choroid plexus and lowest in the brain. All SLC transcripts that changed in the placenta following paracetamol treatment were downregulated. These results suggest that administration of paracetamol during pregnancy could potentially disrupt fetal nutrient homeostasis and affect brain development, resulting in major consequences for the neonate and extending into childhood.
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Affiliation(s)
- Yifan Huang
- Department of NeuroscienceMonash UniversityMelbourneVictoriaAustralia
| | - Fiona Qiu
- Department of NeuroscienceMonash UniversityMelbourneVictoriaAustralia
| | | | - Liam M. Koehn
- Drug Delivery, Disposition and Dynamics, Monash Institute of Pharmaceutical SciencesMonash UniversityParkvilleVictoriaAustralia
| | - Mark D. Habgood
- Department of NeuroscienceMonash UniversityMelbourneVictoriaAustralia
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2
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Ornoy A, Miller RK. Yolk sac development, function and role in rodent pregnancy. Birth Defects Res 2023; 115:1243-1254. [PMID: 36949669 DOI: 10.1002/bdr2.2172] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 03/01/2023] [Accepted: 03/03/2023] [Indexed: 03/24/2023]
Abstract
During the early phases of embryonic development, the yolk sac serves as an initial placenta in many animal species. While in some, this role subsides around the end of active organogenesis, it continues to have important functions in rodents, alongside the chorio-allantoic placenta. The yolk sac is the initial site of hematopoiesis in many animal species including primates. Cells of epiblastic origin form blood islands that are the forerunners of hematopoietic cells and of the primitive endothelial cells that form the vitelline circulation. The yolk sac is also a major route of embryonic and fetal nutrition apparently as long as it functions. In mammals and especially rodents, macro and micronutrients are absorbed by active pinocytosis into the visceral yolk sac, degraded and the degradation products (i.e., amino acids) are then transferred to the embryo. Interference with the yolk sac function may directly reflect on embryonic growth and development, inducing congenital malformations or in extreme damage, causing embryonic and fetal death. In rodents, many agents were found to damage the yolk sac (i.e., anti-yolk sac antibodies or toxic substances interfering with yolk sac pinocytosis) subsequently affecting the embryo/fetus. Often, the damage to the yolk sac is transient while embryonic damage persists. In humans, decreased yolk sac diameter was associated with diabetic pregnancies and increased diameter was associated with pregnancy loss. In addition, culture of rat yolk sacs in serum obtained from pregnant diabetic women or from women with autoimmune diseases induced severe damage to the visceral yolk sac epithelium and embryonic malformations. It can be concluded that as a result of the crucial role of the yolk sac in the well-being of the early embryo, any damage to its normal function may severely and irreversibly affect further development of the embryo/fetus.
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Affiliation(s)
- Asher Ornoy
- Department of Morphological Sciences and Teratology, Adelson School of Medicine, Ariel University and Hebrew University Hadassah Medical School, Jerusalem, Israel
| | - Richard K Miller
- School of Medicine and Dentistry, Departments of Obstetrics/Gynecology, of Pediatrics, of Pathology and of Environmental Medicine, University of Rochester, Rochester, New York, 14642, USA
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3
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Burton GJ, Jauniaux E. The human placenta: new perspectives on its formation and function during early pregnancy. Proc Biol Sci 2023; 290:20230191. [PMID: 37072047 PMCID: PMC10113033 DOI: 10.1098/rspb.2023.0191] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2023] Open
Abstract
The placenta has evolved to support the development of the embryo and fetus during the different intrauterine periods of life. By necessity, its development must precede that of the embryo. There is now evidence that during embryogenesis and organogenesis, the development of the human placenta is supported by histotrophic nutrition secreted from endometrial glands rather than maternal blood. These secretions provide a plentiful supply of glucose, lipids, glycoproteins and growth factors that stimulate rapid proliferation and differentiation of the villous trophoblast. Furthermore, evidence from endometrial gland organoids indicates that expression and secretion of these products are upregulated following sequential exposure to oestrogen, progesterone and trophoblastic and decidual hormones, in particular prolactin. Hence, a feed-forward signalling dialogue is proposed among the trophoblast, decidua and glands that enables the placenta to stimulate its own development, independent of that of the embryo. Many common complications of pregnancy represent a spectrum of disorders associated with deficient trophoblast proliferation. Increasing evidence suggests that this spectrum is mirrored by one of impaired decidualization, potentially compromising histotroph secretion through diminished prolactin secretion and reduced gland function. Optimizing endometrial wellbeing prior to conception may therefore help to prevent common pregnancy complications, such as miscarriage, growth restriction and pre-eclampsia.
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Affiliation(s)
- Graham J Burton
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | - Eric Jauniaux
- EGA Institute for Women's Health, Faculty of Population Health Sciences, University College London, London, UK
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Pereira VM, Pinto PAF, Motta LCB, Almeida MF, de Andrade AFC, Pavaneli APP, Ambrósio CE. Initial Characterization of 3D Culture of Yolk Sac Tissue. Animals (Basel) 2023; 13:ani13091435. [PMID: 37174472 PMCID: PMC10177165 DOI: 10.3390/ani13091435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 04/07/2023] [Accepted: 04/17/2023] [Indexed: 05/15/2023] Open
Abstract
The role of the yolk sac (YS) in miscarriage is not yet clear, largely due to ethical reasons that make in vivo studies difficult to conduct. However, 3D cultures could provide a solution to this problem by enabling cells to be arranged in a way that more closely mimics the structure of the YS as it exists in vivo. In this study, three domestic species (porcine, canine, and bovine) were chosen as models to standardize 3D culture techniques for the YS. Two techniques of 3D culture were chosen: the Matrigel® and Hanging-Drop techniques, and the 2D culture technique was used as a standardized method. The formed structures were initially characterized using scanning electron microscopy (SEM), immunohistochemistry (IHC), and quantitative real-time PCR (RT-qPCR). In general, the 3D culture samples showed better organization of the YS cells compared to 2D cultures. The formed structures from both 3D methods assemble the mesothelial layer of YS tissue. Regarding the IHC assay, all in vitro models were able to express zinc and cholesterol transport markers, although only 3D culture techniques were able to generate structures with different markers pattern, indicating a cell differentiation process when compared to 2D cultures. Regarding mRNA expression, the 3D models had a greater gene expression pattern on the Hemoglobin subunit zeta-like (HBZ) gene related to the YS tissue, although no significant expression was found in Alpha-fetoprotein (AFP), indicating a lack of endodermal differentiation in our 3D model. With the initial technique and characterization established, the next step is to maintain the cultures and characterize the diversity of cell populations, stemness, functions, and genetic stability of each 3D in vitro model.
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Affiliation(s)
- Vitória Mattos Pereira
- Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of São Paulo (USP), Pirassununga 13635-900, SP, Brazil
- School of Pharmacy, University of Wyoming, Laramie, WY 82072, USA
| | - Priscila Avelino Ferreira Pinto
- Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of São Paulo (USP), Pirassununga 13635-900, SP, Brazil
| | - Lina Castelo Branco Motta
- Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of São Paulo (USP), Pirassununga 13635-900, SP, Brazil
| | - Matheus F Almeida
- Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of São Paulo (USP), Pirassununga 13635-900, SP, Brazil
| | - André Furugen Cesar de Andrade
- Department of Animal Reproduction, School of Veterinary Medicine and Animal Science (FMVZ), University of São Paulo USP, Pirassununga 13635-900, SP, Brazil
| | - Ana Paula Pinoti Pavaneli
- Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of São Paulo (USP), Pirassununga 13635-900, SP, Brazil
| | - Carlos Eduardo Ambrósio
- Department of Veterinary Medicine, Faculty of Animal Science and Food Engineering (FZEA), University of São Paulo (USP), Pirassununga 13635-900, SP, Brazil
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Translational Comparison of the Human and Mouse Yolk Sac Development and Function. Reprod Sci 2023; 30:41-53. [PMID: 35137348 DOI: 10.1007/s43032-022-00872-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Accepted: 01/29/2022] [Indexed: 01/06/2023]
Abstract
The yolk sac (YS) is the oldest of the extraembryonic membranes in vertebrates. Considered a transitory structure in the human species, the importance of the YS for a successful pregnancy is often overlooked. Due to the general inaccessibility of healthy human YS tissue for research, the use of experimental animal models is of great value. In order to better understand whether the mouse could be used as a translational model for the study of the human YS under normal and pathological conditions, this review comprehensively describes key developmental aspects of the human and mouse YS, detailing their development and function. YS major similarities in both species comprise the following: (1) histological composition (both being composed of endoderm, mesoderm, and mesothelium layers); (2) endoderm endocytosis, synthesis, secretion, and transport capabilities; and (3) mesoderm onset of haematopoiesis and angiogenesis. Examples of main dissimilarities include (1) persistence across pregnancy (i.e. early pregnancy in humans vs term pregnancy in mice); (2) the existence of a secondary YS in humans; (3) the presence of proliferative primordial germ cells (PGCs) in the human versus their absence in mice; and (4) eversion of histological layers in the mouse. Although these differences should be considered when interpreting data from mouse-based studies, the overall morphofunctional similarities in the YS between these species indicate that the mouse can be potentially used as a translational model for the study of the human YS.
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Burton GJ, Jauniaux E. Placentation in the Human and Higher Primates. ADVANCES IN ANATOMY, EMBRYOLOGY, AND CELL BIOLOGY 2021; 234:223-254. [PMID: 34694484 DOI: 10.1007/978-3-030-77360-1_11] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Placentation in humans is precocious and highly invasive compared to other mammals. Implantation is interstitial, with the conceptus becoming completely embedded within the endometrium towards the end of the second week post-fertilization. Villi initially form over the entire surface of the chorionic sac, stimulated by histotrophic secretions from the endometrial glands. The secondary yolk sac never makes contact with the chorion, and a choriovitelline placenta is never established. However, recent morphological and transcriptomic analyses suggest that the yolk sac plays an important role in the uptake of nutrients from the coelomic fluid. Measurements performed in vivo demonstrate that early development takes place in a physiological, low-oxygen environment that protects against teratogenic free radicals and maintains stem cells in a multipotent state. The maternal arterial circulation to the placenta is only fully established around 10-12 weeks of gestation. By then, villi have regressed over the superficial, abembryonic pole, leaving the definitive discoid placenta, which is of the villous, hemochorial type. Remodeling of the maternal spiral arteries is essential to ensure a high-volume but low-velocity inflow into the mature placenta. Extravillous trophoblast cells migrate from anchoring villi and surround the arteries. Their interactions with maternal immune cells release cytokines and proteases that are key to remodeling, and a successful pregnancy.
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Affiliation(s)
- Graham J Burton
- Centre for Trophoblast Research, Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
| | - Eric Jauniaux
- Faculty of Population Health Sciences, EGA Institute for Women's Health, University College London, London, UK
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Protection of Lycopene against Embryonic Anomalies and Yolk Sac Placental Vasculogenic Disorders Induced by Nicotine Exposure. BIOMED RESEARCH INTERNATIONAL 2020; 2020:7957045. [PMID: 32596374 PMCID: PMC7298257 DOI: 10.1155/2020/7957045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Accepted: 05/13/2020] [Indexed: 11/18/2022]
Abstract
Identification of a new agent from natural products for the protection of embryonic anomalies is potentially valuable. To investigate the protective effect exerted by lycopene against nicotine-induced malformations, mouse embryos in embryonic day 8.5 with yolk sac placentas were cocultured with 1 mM nicotine and/or lycopene (1 × 10-6, 1 × 10-5 μM) for 48 h. The morphological defects and apoptotic cell deaths in the embryo and yolk sac placenta of the nicotine group were significantly increased. Exposure to nicotine resulted in reduced superoxide dismutase (SOD) activity and cytoplasmic SOD and cytoplasmic glutathione peroxidase mRNA levels, but increased lipid peroxidation level in embryos. Moreover, treatment with nicotine resulted in aggravated expressions of the mRNA or protein level of antiapoptotic (BCL2-associated X protein, B-cell lymphoma-extralarge, and caspase 3), anti-inflammatory (nuclear factor kappa-light-chain-enhancer of activated B cells and tumor necrosis factor-alpha), and vasculogenic (vascular endothelial growth factor-alpha, insulin-like growth factor-1, alpha smooth muscle actin, transforming growth factor-beta 1, and hypoxia inducible factor-1 alpha) factors in the embryo and yolk sac placenta. However, all the parameters were significantly improved by treatment with lycopene, as compared to the nicotine group. These findings indicate the potential of lycopene as a protective agent against embryonic anomalies and yolk sac vasculogenic and placenta-forming defects induced by nicotine through modulations of oxidative, apoptotic, vasculogenic, and inflammatory activities.
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8
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The John Hughes Memorial Lecture: Stimulation of Early Placental Development Through a Trophoblast-Endometrial Dialog. J Equine Vet Sci 2018. [DOI: 10.1016/j.jevs.2018.03.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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9
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RNA-seq reveals conservation of function among the yolk sacs of human, mouse, and chicken. Proc Natl Acad Sci U S A 2017; 114:E4753-E4761. [PMID: 28559354 DOI: 10.1073/pnas.1702560114] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The yolk sac is phylogenetically the oldest of the extraembryonic membranes. The human embryo retains a yolk sac, which goes through primary and secondary phases of development, but its importance is controversial. Although it is known to synthesize proteins, its transport functions are widely considered vestigial. Here, we report RNA-sequencing (RNA-seq) data for the human and murine yolk sacs and compare those data with data for the chicken. We also relate the human RNA-seq data to proteomic data for the coelomic fluid bathing the yolk sac. Conservation of transcriptomes across the species indicates that the human secondary yolk sac likely performs key functions early in development, particularly uptake and processing of macro- and micronutrients, many of which are found in coelomic fluid. More generally, our findings shed light on evolutionary mechanisms that give rise to complex structures such as the placenta. We identify genetic modules that are conserved across mammals and birds, suggesting these modules are part of the core amniote genetic repertoire and are the building blocks for both oviparous and viviparous reproductive modes. We propose that although a choriovitelline placenta is never established physically in the human, the placental villi, the exocoelomic cavity, and the secondary yolk sac function together as a physiological equivalent.
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10
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Abstract
Epidemiological evidence links an individual's susceptibility to chronic disease in adult life to events during their intrauterine phase of development. Biologically this should not be unexpected, for organ systems are at their most plastic when progenitor cells are proliferating and differentiating. Influences operating at this time can permanently affect their structure and functional capacity, and the activity of enzyme systems and endocrine axes. It is now appreciated that such effects lay the foundations for a diverse array of diseases that become manifest many years later, often in response to secondary environmental stressors. Fetal development is underpinned by the placenta, the organ that forms the interface between the fetus and its mother. All nutrients and oxygen reaching the fetus must pass through this organ. The placenta also has major endocrine functions, orchestrating maternal adaptations to pregnancy and mobilizing resources for fetal use. In addition, it acts as a selective barrier, creating a protective milieu by minimizing exposure of the fetus to maternal hormones, such as glucocorticoids, xenobiotics, pathogens, and parasites. The placenta shows a remarkable capacity to adapt to adverse environmental cues and lessen their impact on the fetus. However, if placental function is impaired, or its capacity to adapt is exceeded, then fetal development may be compromised. Here, we explore the complex relationships between the placental phenotype and developmental programming of chronic disease in the offspring. Ensuring optimal placentation offers a new approach to the prevention of disorders such as cardiovascular disease, diabetes, and obesity, which are reaching epidemic proportions.
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Affiliation(s)
- Graham J Burton
- Centre for Trophoblast Research and Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom; and Department of Medicine, Knight Cardiovascular Institute, and Moore Institute for Nutrition and Wellness, Oregon Health and Science University, Portland, Oregon
| | - Abigail L Fowden
- Centre for Trophoblast Research and Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom; and Department of Medicine, Knight Cardiovascular Institute, and Moore Institute for Nutrition and Wellness, Oregon Health and Science University, Portland, Oregon
| | - Kent L Thornburg
- Centre for Trophoblast Research and Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom; and Department of Medicine, Knight Cardiovascular Institute, and Moore Institute for Nutrition and Wellness, Oregon Health and Science University, Portland, Oregon
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Amino acid starvation induced by protease inhibition produces differential alterations in redox status and the thiol proteome in organogenesis-stage rat embryos and visceral yolk sacs. J Nutr Biochem 2015; 26:1589-98. [PMID: 26365578 DOI: 10.1016/j.jnutbio.2015.07.026] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Revised: 07/23/2015] [Accepted: 07/29/2015] [Indexed: 12/21/2022]
Abstract
The process of embryonic nutrition in rodent conceptuses during organogenesis has been shown to involve a dominant histiotrophic mechanism where essential developmental substrates and micronutrients are supplied as whole maternal proteins or cargoes associated with proteins. The histiotrophic nutrition pathways (HNP) responsible for uptake and initial processing of proteins across maternal-conceptal interfaces involve uptake via receptor mediated endocytosis and protein degradation via lysosomal proteolysis. Chemical inhibition of either process can lead to growth deficits and malformation in the embryo (EMB), but selective inhibition of either HNP component will elicit a different subset of developmental perturbations. In vitro, whole embryo culture exposure of GD10 or GD11 rat conceptuses to the natural protease inhibitor, leupeptin, leads to significant reductions in all measured embryonic growth parameters as well as a myriad of other effects. Leupeptin doses of 10 μM or 20 μM over a 26-h period (GD10-GD11) and 50 μM over a 3 h pulse period produced significant decreases in the clearance of FITC-albumin from culture media. The near complete loss of acid soluble fluorescence and increased total visceral yolk sac (VYS) protein content confirmed the selective inhibition of proteolysis. Inhibition of lysosomal proteolysis thus deprives the developing EMB of essential nutrient amino acids producing conditions akin to amino acid starvation, but may also cause direct effects on pathways critical for normal growth and differentiation. Following leupeptin exposure for 26 or 6 h, total glutathione (GSH) concentrations dropped significantly in the VYS, but only slightly in yolk sac (YSF) and amniotic (AF) fluids. Cys concentrations increased in VYS and EMB, but dropped in YSF and AF fluids. Redox potentials (Eh) for the glutathione disulfide (GSSG)/glutathione (GSH) redox couple trended significantly toward the positive, confirming the net oxidation of conceptual tissues following leupeptin treatment. Analysis of the thiol proteome showed few alterations to specific pathways mapped to the Kyoto Encyclopedia of Genes and Genomes Pathway database, but did reveal significant increases in concentrations of proteins associated with glycolysis/gluconeogenesis in the VYS and decreased concentrations proteins associated with ribosome biogenesis and function in the EMB. A subset of proteins elevated by >2-23-fold in the VYS were identified as serum (blood) proteins and represent the maternal-side proteins captured by the VYS and which are not degraded in the lysosomes as a result of leupeptin's inhibitory action. The observed constellation of proteins decreased in the EMB by leupeptin represent proteins from several adaptive pathways that are commonly altered in responses to amino acid starvation. These studies show clear differential responses to protease inhibition in VYS and EMB during organogenesis and suggest the possibility for additional roles of redox regulation, cellular adaptations and metabolic insufficiency caused by protease inhibition.
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Jilek JL, Sant KE, Cho KH, Reed MS, Pohl J, Hansen JM, Harris C. Ethanol Attenuates Histiotrophic Nutrition Pathways and Alters the Intracellular Redox Environment and Thiol Proteome during Rat Organogenesis. Toxicol Sci 2015; 147:475-89. [PMID: 26185205 DOI: 10.1093/toxsci/kfv145] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Ethanol (EtOH) is a reactive oxygen-generating teratogen involved in the etiology of structural and functional developmental defects. Embryonic nutrition, redox environment, and changes in the thiol proteome following EtOH exposures (1.56.0 mg/ml) were studied in rat whole embryo culture. Glutathione (GSH) and cysteine (Cys) concentrations with their respective intracellular redox potentials (Eh) were determined using high-performance liquid chromatography. EtOH reduced GSH and Cys concentrations in embryo (EMB) and visceral yolk sac (VYS) tissues, and also in yolk sac and amniotic fluids. These changes produced greater oxidation as indicated by increasingly positive Eh values. EtOH reduced histiotrophic nutrition pathway activities as measured by the clearance of fluorescin isothiocyanate (FITC)-albumin from culture media. A significant decrease in total FITC clearance was observed at all concentrations, reaching approximately 50% at the highest dose. EtOH-induced changes to the thiol proteome were measured in EMBs and VYSs using isotope-coded affinity tags. Decreased concentrations for specific proteins from cytoskeletal dynamics and endocytosis pathways (α-actinin, α-tubulin, cubilin, and actin-related protein 2); nuclear translocation (Ran and RanBP1); and maintenance of receptor-mediated endocytosis (cubilin) were observed. Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis also identified a decrease in ribosomal proteins in both EMB and VYS. Results show that EtOH interferes with nutrient uptake to reduce availability of amino acids and micronutrients required by the conceptus. Intracellular antioxidants such as GSH and Cys are depleted following EtOH and Eh values increase. Thiol proteome analysis in the EMB and VYS show selectively altered actin/cytoskeleton, endocytosis, ribosome biogenesis and function, nuclear transport, and stress-related responses.
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Affiliation(s)
- Joseph L Jilek
- *Department of Environmental Health Sciences, University of Michigan, Ann Arbor, Michigan 48109
| | - Karilyn E Sant
- *Department of Environmental Health Sciences, University of Michigan, Ann Arbor, Michigan 48109
| | - Katherine H Cho
- *Department of Environmental Health Sciences, University of Michigan, Ann Arbor, Michigan 48109
| | - Matthew S Reed
- Biotechnology Core Facility Branch, Centers for Disease Control, Atlanta, Georgia 30333; and
| | - Jan Pohl
- Biotechnology Core Facility Branch, Centers for Disease Control, Atlanta, Georgia 30333; and
| | - Jason M Hansen
- Department of Physiology and Developmental Biology, College of Life Sciences, Brigham Young University, Provo, Utah 84602
| | - Craig Harris
- *Department of Environmental Health Sciences, University of Michigan, Ann Arbor, Michigan 48109;
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13
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Marshall VA, Johnson KJ, Moore NP, Rasoulpour RJ, Tornesi B, Carney EW. Comparative Response of Rat and Rabbit Conceptuses In Vitro to Inhibitors of Histiotrophic Nutrition. ACTA ACUST UNITED AC 2015; 104:1-10. [DOI: 10.1002/bdrb.21134] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2014] [Accepted: 11/18/2014] [Indexed: 12/18/2022]
Affiliation(s)
- Valerie A. Marshall
- Toxicology and Environmental Research and Consulting; The Dow Chemical Company; Midland Michigan
| | - Kamin J. Johnson
- Toxicology and Environmental Research and Consulting; The Dow Chemical Company; Midland Michigan
| | | | - Reza J. Rasoulpour
- Toxicology and Environmental Research and Consulting; The Dow Chemical Company; Midland Michigan
| | - Belen Tornesi
- Toxicology and Environmental Research and Consulting; The Dow Chemical Company; Midland Michigan
| | - Edward W. Carney
- Toxicology and Environmental Research and Consulting; The Dow Chemical Company; Midland Michigan
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14
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Zohn IE, Sarkar AA. The visceral yolk sac endoderm provides for absorption of nutrients to the embryo during neurulation. ACTA ACUST UNITED AC 2010; 88:593-600. [DOI: 10.1002/bdra.20705] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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15
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Yoshidome K, Kobae H, Yamamoto K, Sameshima K, Miyata K, Kawano Y. Effects of supplemental L-methionine on E-64 [trans-epoxysuccinyl-1-leucyl-amido (4-guanido) butane]-induced dysmorphology in rat embryos cultured in vitro. Clin Genet 2008. [DOI: 10.1111/j.1399-0004.2003.tb02324.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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16
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Zabihi S, Wentzel P, Eriksson UJ. Maternal blood glucose levels determine the severity of diabetic embryopathy in mice with different expression of copper-zinc superoxide dismutase (CuZnSOD). Toxicol Sci 2008; 105:166-72. [PMID: 18502742 DOI: 10.1093/toxsci/kfn101] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Excess oxygen radical formation is suggested to be involved in the etiology of diabetic embryopathy. We aimed to investigate the effects of altered maternal antioxidative status in conjunction with a varied severity of the maternal diabetic state on embryonic development by using mice with different gene expression of CuZn superoxide dismutase (CuZnSOD). The mice were wild-type (WT), transgenic (TG), or knockout (KO) with regard to CuZnSOD. Alloxan was used to induce diabetes (DWT, DTG, DKO) in female mice before pregnancy and, noninjected mice served as controls (NWT, NTG, NKO). The minimum alloxan dose required to induce diabetes was 80 mg/kg for WT, 100 mg/kg for TG, and 65 mg/kg for KO mice. When KO mice were made diabetic with 80 mg/kg alloxan, they produced no living offspring. The pregnancies were interrupted on gestational day 18, when maternal diabetic state, that is, blood glucose concentration, as well as fetal outcome, genotype and hepatic isoprostane levels were assessed. The mean maternal blood glucose levels were positively associated with the alloxan dose, that is, the DWT and DTG groups had higher blood glucose concentration than the DKO group, and the DWT and DTG fetuses increased their hepatic isoprostane levels, whereas the DKO fetuses did not. However, in all diabetic groups, increased maternal blood glucose concentration was associated with higher resorption and malformation rates as well as lowered fetal and placental weight. Furthermore, diabetes increased the fraction of WT offspring in the TG and KO groups. We conclude that both fetal antioxidative capacity and maternal diabetic state affect the development of the offspring. However, the maternal diabetic state is the major teratogenic factor and overrides the influence of fetal antioxidative capacity.
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Affiliation(s)
- Sheller Zabihi
- Department of Medical Cell Biology, Uppsala University, Biomedical Center, SE-75123 Uppsala, Sweden.
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Kultima K, Fernández EL, Scholz B, Gustafson AL, Dencker L, Stigson M. Cadmium-induced gene expression changes in the mouse embryo, and the influence of pretreatment with zinc. Reprod Toxicol 2006; 22:636-46. [PMID: 16842966 DOI: 10.1016/j.reprotox.2006.05.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2005] [Revised: 05/10/2006] [Accepted: 05/17/2006] [Indexed: 10/24/2022]
Abstract
Cadmium (Cd) administered to female C57BL/6 mice on gestation day 8 induces a high incidence of anterior neural tube defects (exencephaly). This adverse effect can be attenuated by maternal pretreatment with zinc (Zn). In this study we used replicated microarray analysis and real-time PCR to investigate gene expression changes induced in the embryo 5 and 10h after maternal Cd exposure in the absence or presence of Zn pretreatment. We report nine genes with a transcriptional response induced by Cd, none of which was influenced by Zn pretreatment, and two genes induced only by combined maternal Cd exposure and Zn pretreatment. We discuss the results in relation to the possibility that Cd is largely excluded from the embryo, that the teratogenic effects of Cd may be secondary to toxicity in extraembryonic tissues, and that the primary protective role of Zn may not be to reverse Cd-induced transcription in the embryo.
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Affiliation(s)
- Kim Kultima
- Department of Pharmaceutical Biosciences, Division of Toxicology, Uppsala University, BMC, Uppsala, Sweden
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Mu J, Adamson SL. Developmental changes in hemodynamics of uterine artery, utero- and umbilicoplacental, and vitelline circulations in mouse throughout gestation. Am J Physiol Heart Circ Physiol 2006; 291:H1421-8. [PMID: 16603699 DOI: 10.1152/ajpheart.00031.2006] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In human pregnancy, abnormal placental hemodynamics likely contribute to the etiology of early-onset preeclampsia and fetal intrauterine growth restriction. The mouse is increasingly being deployed to study normal and abnormal mammalian placental development, yet the placental hemodynamics in normal pregnancy in mice is currently unknown. We used ultrasound biomicroscopy to noninvasively image and record Doppler blood velocity waveforms from the maternal and embryonic placental circulations in mice throughout gestation. In the uterine artery, peak systolic velocity (PSV) increased significantly from 23 ± 2 (SE) to 59 ± 3 cm/s, and end-diastolic velocity (EDV) increased from 7 ± 1 to 28 ± 2 cm/s in nonpregnant versus full-term females so that the uterine arterial resistance index (RI) decreased from 0.70 ± 0.02 to 0.53 ± 0.02. Velocities in the maternal arterial canal in the placenta were low and nearly steady and increased from 0.9 ± 0.03 cm/s at embryonic day 10.5 (E10.5) to 2.4 ± 0.07 cm/s at E18.5. PSV in the umbilical artery increased steadily from 0.8 ± 0.1 cm/s at E8.5 to 15 ± 0.6 cm/s at E18.5, whereas PSV in the vitelline artery increased from 0.6 ± 0.1 cm/s at E8.5 to 4 ± 0.2 cm/s at E13.5 and then remained stable to term. In the umbilical artery, the EDV detection rate was 0% at ≤E14.5 and 94% at E18.5, and the RI decreased from 1 to 0.82 ± 0.01 during this interval. We conclude that ultrasound biomicroscopy can be used to monitor placental hemodynamics during pregnancy in mice. These results provide novel information concerning the development of the vitelline and placental circulations in mice and reveal strong similarities in placental hemodynamics between mice and humans.
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Affiliation(s)
- Junwu Mu
- Samuel Lunenfeld Research Institute, Mount Sinai Hospital, and Department of Obstetrics and Gynecology, University of Toronto, ON, Canada M5G 1X5
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Ishida T, Hatae T, Nishi N, Araki N, Hamasaki M. Immunocytochemical analysis of cubilin-mediated endocytosis of high density lipoproteins (HDL) in epithelial cells of the rat visceral yolk sac. Cell Tissue Res 2004; 318:533-43. [PMID: 15578272 DOI: 10.1007/s00441-004-0962-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2004] [Accepted: 07/31/2004] [Indexed: 11/24/2022]
Abstract
Cubilin was recently shown to function as an endocytic receptor for high density lipoprotein (HDL) holoparticles and apolipoprotein A-I (apo A-I), the main protein constituent of HDL. In the present study, we analyzed the distribution and intracellular trafficking of cubilin and HDL in rat visceral yolk sac epithelial cells. After epithelial cells were loaded with apolipoprotein E-free HDL for 30 min in vitro, double immunofluorescence showed that the apical cytoplasm of the cells was strongly stained with anti-cubilin antibodies and anti-apo A-I/HDL. Furthermore, double immunogold electron-microscopic observations revealed the distinct localization of cubilin and HDL in endocytic vacuoles. In early endosomes, both were colocalized on the membrane. Although, in late endosomes, cubilin was also localized on the membrane, HDL was mainly located in the matrix. Both were found in the matrix in lysosomes. In addition, cubilin was markedly localized in apical tubules (ATs), which are generally accepted as being receptor recycling compartments. Thus, HDL is internalized through cubilin-mediated endocytosis and is finally transported to lysosomes. By contrast, cubilin is mainly translocated to ATs for recycling, although some of the cubilin is degraded in lysosomes. Quantitative analysis further revealed that cubilin was not concentrated on the membranes of ATs, although it accumulated in the AT area. Some HDL were also observed in the AT area. These findings suggest that the translocation of cubilin and HDL to ATs from early endosomes occurs through a simple sorting mechanism based on the geometry of these compartments and the bulk membrane and volume flow.
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Affiliation(s)
- Tetsuya Ishida
- Department of Histology and Cell Biology, School of Medicine, Kagawa University, Miki, 761-0793, Kagawa, Japan.
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Strope S, Rivi R, Metzger T, Manova K, Lacy E. Mouse amnionless, which is required for primitive streak assembly,mediates cell-surface localization and endocytic function of cubilin on visceral endoderm and kidney proximal tubules. Development 2004; 131:4787-95. [PMID: 15342463 DOI: 10.1242/dev.01341] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Impaired primitive streak assembly in the mouse amnionless(amn) mutant results in the absence of non-axial trunk mesoderm, a derivative of the middle region of the primitive streak. In addition, the epiblast of amn mutants fails to increase significantly in size after E7.0, indicating that middle primitive streak assembly is mechanistically tied to the growth of the embryo during gastrulation. Amn, a novel transmembrane protein, is expressed exclusively in an extra-embryonic tissue, visceral endoderm (VE), during the early post-implantation stages. We show that Amn is also expressed in kidney proximal tubules (KPT) and intestinal epithelium,which, like the VE, are polarized epithelia specialized for resorption and secretion. To explore whether Amn participates in the development or function of KPT and intestinal epithelia and to gain insight into the function of Amn during gastrulation, we constructed Amn-/- ES cell↔+/+blastocyst chimeras. While chimeras form anatomically normal kidneys and intestine, they exhibit variable, selective proteinuria, a sign of KPT malfunction. In humans, AMN has been genetically connected to Cubilin(CUBN), a multi-ligand scavenger receptor expressed by KPT, intestine and yolk sac. Loss of CUBN, the intestinal intrinsic factor (IF)-vitamin B12 receptor, results in hereditary megaloblastic anemia (MGA1), owing to vitamin B12 malabsorption. The recent report of MGA1 families with mutations in AMN suggests that AMN functions in the same pathway as CUBN. We demonstrate that Cubn is not properly localized to the cell surface in Amn-/- tissues in the embryo and adult mouse, and that adult chimeras exhibit selective proteinuria of Cubn ligands. This study demonstrates that Amn is an essential component of the Cubn receptor complex in vivo and suggests that Amn/Cubn is required for endocytosis/transcytosis of one or more ligands in the VE during gastrulation to coordinate growth and patterning of the embryo. Furthermore, as AMN is apparently not required for gastrulation in humans, the developmental requirements for Amn/Cubn function may not be evolutionarily conserved, possibly reflecting differences between species in the role and organization of extra-embryonic tissues.
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Affiliation(s)
- Sharon Strope
- Molecular Biology Graduate Program, Weill Graduate School of Medical Sciences of Cornell University, New York, NY 10021, USA
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21
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Yoshidome K, Kobae H, Yamamoto K, Sameshima K, Miyata K, Kawano Y. Effects of supplemental L-methionine on E-64 [trans-epoxysuccinyl-1-leucyl-amido (4-guanido) butane]-induced dysmorphology in rat embryos cultured in vitro. Congenit Anom (Kyoto) 2003; 43:280-5. [PMID: 15041779 DOI: 10.1111/j.1741-4520.2003.tb01014.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
E-64 [trans-epoxysuccinyl-1-leucyl-amido (4-guanido) butane] is teratogenic, inducing a spec-trum of malformations in vivo and producing similar effects in vitro. Numerous studies support the concept that E-64-induced malformations result from embryonic nutritionaldeficiency, without affecting the maternal nutritional status. This has provided a useful model with which to investigate the nutritional requirements of the early embryo, as well as the role of various nutrients in the etiology of congenital defects. In the current investigation, we examined effects of L-methionine on E-64-induced embryotoxicity in vitro. For these experiments, we cultured rat embryos 9.5 days postconception (p.c.) for 48 hours with E-64 and/or L-methionine. We found that the addition of L-methionine to E-64-exposed cultures reduced optic abnormality and increased embryo protein. These results suggest that embryopathy largely results from a deficiency of L-methionine although E-64 limits the supply of all amino acids to the embryo. Furthermore, although endocytosis and degradation of proteins by the visceral yolk sac (VYS) supply most amino acids to the embryo, free amino acids may be compensatory when this source is reduced. These results support those of previous investigations that suggest L-methionine is a limiting nutrient for embryonic development.
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Affiliation(s)
- Kouichi Yoshidome
- Department of Pediatrics, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
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Tomboc M, Witchel SF. Frequencies of the D85 and Y85 variants of UGT2B15 in children and adolescent girls with hyperandrogenism. J Pediatr Endocrinol Metab 2003; 16:719-26. [PMID: 12880121 DOI: 10.1515/jpem.2003.16.5.719] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Premature pubarche (PP) appears to be a risk factor for the subsequent development of polycystic ovary syndrome (PCOS) during or after puberty. The clinical manifestations due to hyperandrogenism are influenced by androgen production, androgen metabolism, and androgen receptor activity. Glucuronidation by the UDP-glucuronyltransferase 2B (UGT2B) family of enzymes is one mechanism through which androgens are inactivated. Two variants differing by the amino acid at codon 85 have been described for UGT2B15, a member of this family. Both variants show similar substrate specificities. However, for the substrates alpha-androstanediol (alpha-diol) and dihydrotestosterone (DHT), the D85 variant has a lower Vmax than the Y85 variant. We compared the frequencies of these variants in 69 patients with PP, 46 adolescent girls with hyperandrogenism (HA), and 88 healthy controls to determine whether the frequency of the D85 variant was increased among patients with hyperandrogenism. Allele frequencies were comparable in children with PP, adolescent girls with HA, and healthy control subjects. Although D85 and Y85 appear to be common variants, we cannot exclude the possibility that the UGT2B15 gene represents a minor modifying locus.
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Affiliation(s)
- Marlah Tomboc
- Division of Pediatric Endocrinology, Children's Hospital of Pittsburgh, University of Pittsburgh, Pittsburgh, PA 15213, USA
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Gruñeiro de Papendieck L, Chiesa A, Bastida MG, Alonso G, Finkielstain G, Heinrich JJ. Thyroid dysfunction and high thyroid stimulating hormone levels in children with Down's syndrome. J Pediatr Endocrinol Metab 2002; 15:1543-8. [PMID: 12503863 DOI: 10.1515/jpem.2002.15.9.1543] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
UNLABELLED In order to delineate the spectrum of thyroid abnormalities in children with Down's syndrome (DS), first visit height data (SDS) and serum TSH, T4 and antiperoxidase antibodies concentrations were retrospectively evaluated in 137 children (71 girls) with DS (0.04-16 years). RESULTS Congenital hypothyroidism was detected in 2.9% of patients. Thyroid disease occurred in 9%: four hyperthyroidism and eight hypothyroidism. Overt thyroid disease was always related to thyroid autoimmunity. The remaining 121 patients had normal T4 levels but increased mean TSH compared with controls (4.7 +/- 2.8 vs 2.3 +/- 1.3 mU/l). According to TSH levels, they were divided into two groups: G1 (n = 68) with normal TSH (<5 mU/l), and G2 (n = 53) with high TSH (> 5 mU/l). T4 levels were significantly lower in G2 (p < 0.01 vs G1 and controls). Height SDS was not different. CONCLUSIONS Thyroid disorders are frequent in children with DS. Subtle thyroid abnormalities found in patients with DS with no evidence of clinical dysfunction need further investigation to demonstrate whether there is a need for therapeutic intervention.
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Abstract
OBJECTIVE To review the process of blood-cell formation in the murine and human yolk sac. DATA SOURCES Most articles were selected from the PubMed database. DATA SYNTHESIS The yolk sac is the first site of blood-cell production during murine and human ontogeny. Primitive erythroid cells originate in the yolk sac and complete their maturation, including enucleation, in the bloodstream. Though species differences exist, the pattern of hematopoietic progenitor cell emergence in the yolk sac is similar in mouse and man. In both species, there is a stage of development where both primitive red blood cells and definitive erythroid progenitors are produced in the yolk sac. An "embryonic" hematopoietic stem cell that engrafts in myeloablated newborn but not adult mice can be detected in the murine yolk sac and embryo. Stem-cell activity in the human yolk sac has not been reported. CONCLUSIONS The yolk sac is the sole site of embryonic erythropoiesis. However, definitive erythroid, myeloid, and multipotential progenitors also originate in the yolk sac. The relationship between these progenitors and the "embryonic" hematopoietic stem cell has not been elucidated. Yolk sac-derived progenitor cells may seed the developing liver via the circulation and serve as the immediate source of the mature blood cells that are required to meet the metabolic needs of the rapidly growing fetus.
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Affiliation(s)
- J Palis
- University of Rochester, Department of Pediatrics and Cancer Center, Rochester, NY 14642, USA.
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25
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Abstract
The yolk sac plays an important role in fetal nutrition. Transport of amino acids by the rodent visceral yolk sac has been shown previously. We have demonstrated the presence of several amino acid transport proteins capable of the Na(+)-dependent transport of anionic amino acids within late gestation mouse visceral yolk sac and uterine epithelium. We speculate that these proteins may be involved in the efflux of glutamate from the fetal to the maternal circulations.
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Affiliation(s)
- D A Novak
- Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610-0296, USA
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Fawcett LB, Pugarelli JE, Brent RL. Effects of supplemental methionine on antiserum-induced dysmorphology in rat embryos cultured in vitro. TERATOLOGY 2000; 61:332-41. [PMID: 10777828 DOI: 10.1002/(sici)1096-9926(200005)61:5<332::aid-tera4>3.0.co;2-d] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND Heterologous antiserum to the visceral yolk sac (AVYS) is teratogenic, inducing a spectrum of malformations in vivo and producing similar effects in vitro. Numerous studies support the concept that AVYS-induced malformations result from embryonic nutritional deficiency, without affecting the maternal nutritional status. This has provided a useful model with which to investigate the nutritional requirements of the early embryo, as well as the role of various nutrients in the etiology of congenital defects. METHODS In the current investigation, we examined the effects of methionine and other nutrients on AVYS-induced embryotoxicity in vitro. For these experiments, we cultured rat embryos (9.5 p.c) for 48 hr with AVYS and/or methionine at several concentration levels. RESULTS The addition of L-methionine to AVYS-exposed cultures reduced dysmorphology and open neural tube; this effect was concentration dependent. AVYS-induced dysmorphology was completely prevented at a concentration of L-methionine corresponding to 50-fold the basal serum concentration. Utilization of D-methionine, L-leucine, or folic acid (5-methyltetrahydrofolate, MTHF) instead of L-methionine had no protective effects. CONCLUSIONS These results suggest that, although AVYS limits the supply of all amino acids to the embryo, embryopathy largely results from a deficiency of methionine. Furthermore, although endocytosis and degradation of proteins by the VYS supplies most amino acids to the embryo, free amino acids may be compensatory when this source is reduced. These results support those of previous investigations that suggest methionine is required for normal NT closure and that methionine is a limiting nutrient for embryonic development.
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Affiliation(s)
- L B Fawcett
- Department of Pediatrics, Jefferson Medical College, Philadelphia, Pennsylvania 19107, USA.
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Knepper PA, Mayanil CS, Hayes E, Goossens W, Byrne RW, McLone DG. The presence of transcription factors in chicken albumin, yolk and blastoderm. In Vitro Cell Dev Biol Anim 1999; 35:357-63. [PMID: 10476924 DOI: 10.1007/s11626-999-0087-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Embryonic development is determined by preset intrinsic programs and extrinsic signals. To explore the possibility that transcription factors are present at the onset of development, preparations of yolk, albumin, and blastoderm from unfertilized and fertilized white Leghorn chicken eggs were screened by a panel of 16 transcription factor antibodies with Western blot techniques. Yolk was positive for 13 transcription factors, whereas blastoderm was positive for 10, and albumin was positive for 5. In yolk, several transcription factors, GATA-2, E2F-1, MyoD, and TFIID, were developmentally regulated. These results indicate that intracellular yolk and extracellular albumin contain transcription factors which presumably influence early chick embryonic development from prefertilization to the late blastoderm stage. Thus, the utility of preset maternal transcription factors within yolk and albumin complement maternally derived mRNA to determine the early development of the zygote.
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Affiliation(s)
- P A Knepper
- Division of Neurosurgery, Children's Memorial Medical Center and Northwestern University Medical School, Chicago, Illinois 60614, USA
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