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Glycosylation patterns of proteins in trophoblast and decidua of the cat placenta
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Abstracts / Placenta 36 (2015) 469e521
K4. GLYCOSYLATION PATTERNS OF PROTEINS IN TROPHOBLAST AND DECIDUA OF THE CAT PLACENTA
K6. IMPACT OF HIGH DENSITY LIPOPROTEIN METABOLISM IN MOUSE EMBRYO PHYSIOLOGY
nica 1, Ortega Barbeito Claudio 1, Fern andez Patricia 1, Diessler Mo Hugo 2, Gimeno Eduardo 1, Portiansky Enrique 1. 1 School of Veterinary Science UNLP, CONICET. La Plata, Bs As, Argentina; 2 Faculty of Veterinary Sciences UNL, Esperanza, Santa F e, Argentina
Nicol as Santander 1, Attilio Rigotti 1, 2, Dolores Busso 1. 1 Departamento de n, Diabetes y Metabolismo, Escuela de Medicina, Pontificia Nutricio n Molecular y lica, Santiago, Chile; 2 Centro de Nutricio Universidad Cato nicas, Escuela de Medicina, Pontificia Universidad Enfermedades Cro lica, Santiago, Chile Cato
The aim of this study was to characterize glycoconjugates of syncytiotrophoblast, cytotrophoblast and decidual cells of mature feline placenta. Samples from 12 normal pregnant female cats, after 45±5 days of gestation were obtained by hysterectomy. Sections were processed for routine observation. Lectinhistochemistry was performed using biotinylated lectins to characterize the expression of saccharides. Trophoblast expressed a varied composition of glycans, highly exposing terminal N-Acetylglucosamine residues and non-sialylated galactose and N-Acetyl galactosamine oligomers. Phaseolus vulgaris erythroagglutinin lectin, which recognized highly branched N-linked residues, was restricted to the syncytiotrophoblast. Unlike results reported in humans, mice and rats on lectin affinity of decidual cells, sialic acids and complex N-linked oligosaccharides were not demonstrated in cats. Glycosylation of proteins determines many of their final properties, thus becoming essential for the embryo-maternal relation during implantation and placentation. Knowledge about the glycosylation profile of the normal cat placenta may lead to a better understanding of both normal and pathological reproductive events.
K5. ADIPONECTIN e CROSS TALK BETWEEN MATERNAL ADIPOSE TISSUE AND PLACENTA Theresa L. Powell, Irving Aye, Fredrick Rosario, Thomas Jansson. Departments of Pediatrics and Obstetrics and Gynecology, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA Adiponectin is a multimeric protein secreted from adipose tissue. Secretion decreases as adipose tissue expands during weight gain. Low circulating levels of adiponectin are associated with decreased insulin sensitivity in skeletal muscle and liver. In contrast, our studies demonstrate that trophoblast cells respond by increasing insulin sensitivity with low maternal adiponectin. This establishes adiponectin as an endocrine link between maternal adipose tissue and the placenta, which promotes nutrient flux to the fetus when supplies are high and limits nutrient delivery to the fetus and preserves maternal tissues when nutrients are in low abundance. With low nutrient status maternal fasting insulin is low and adiponectin levels are high. During the postprandial period, insulin stimulated nutrient transport in the placenta is blunted by the high maternal adiponectin, therefore limiting fetal growth when maternal supplies are reduced. In maternal obesity, low adiponectin and chronically high insulin (due to maternal insulin resistance) will lead to maximal insulin stimulation of placental nutrient transport, contributing to fetal overgrowth. We have demonstrated in cultured trophoblast cells that increasing adiponectin concentrations caused a loss of insulin sensitivity at the level of IRS-1 and blunts insulin stimulated nutrient uptake. We also studied responses to infused adiponectin in normal lean pregnant mice using mini-osmotic pumps to increase maternal adiponectin levels 4-fold (within the normal physiological range) between E14-18. This treatment caused a significant reduction (-18%, p<0.05) in pup weight. Placental studies in the lean dams supported our hypothesis that increasing adiponectin inhibits placental nutrient transport by decreasing insulin sensitivity. Currently, we are studying diet-induced maternal obesity in mice and adiponectin replacement therapy. Infusion of adiponectin in obese dams corrected placental insulin signaling and nutrient transport capacity, reversing fetal overgrowth. These studies suggest that therapeutic adiponectin supplementation may improve birth outcomes in obese and diabetic mothers with low levels of adiponectin.
Lipoproteins transport in plasma lipophilic molecules such as cholesterol, triglycerides, vitamins, bioactive lipids, etc. High-density lipoproteins (HDL) have a central role in the regulation of plasma cholesterol levels, mainly by mediating the transport of this lipid from peripheral tissues to the liver, where it is taken up by Scavenger Receptor class B type I (SR-BI) and secreted into bile. HDL also transport and supply different tissues with vitamin E. The generation of a SR-BI-deficient mouse led researchers to hypothesize that this HDL receptor could play a role in embryonic development, as heterozygous SR-BI +/ intercrosses yielded only half of the SRBI -/- expected by the Mendelian ratio, suggestive of embryonic lethality due to the lack of SR-BI. Recently, we demonstrated that around half of the SR-BI-/- embryos showed a lethal developmental abnormality known as exencephaly. This defect is analogous to human anencephaly and is produced by a defect in neural tube closure. SR-BI-/- embryos also show eyelid closure defects and an impaired architecture of tongue myogenic fibers. In addition, some knockout fetuses with well-closed neural tubes show intrauterine growth restriction, as they weigh less than their wild-type littermates at birth. During development, SR-BI is localized in cells from extra-embryonic tissues that mediate maternal-fetal transport of nutrients, i.e. trophoblast giant cells during early gestation and syncytiotrophoblasts from mid- to late pregnancy. In our laboratory, we are currently studying the role of the HDL receptor SR-BI in the maternal-fetal transport of different lipid classes and the impact of the SR-BI-mediated HDL metabolism on neural tube closure and fetal growth. FONDECYT 1141236 (D.B.) and 1110712 (A.R.), Doctoral Fellowship CONICYT 21130444 (N.S.).
K7. INTRAUTERINE PROGRAMMING OF BETA CELL DEFECTS Edith Arany. Lawson Health Research Institute, University of Western Ontario, Schulich School of Medicine and Dentistry, Department of Pathology, London, Ontario, Canada Maternal inflammatory environment (type 1 diabetes) or nutritional deficiencies directly influence fetal and neonatal pancreas development. We have shown that protein restriction (LP) or maternal deficiencies (such as lack of specific AA or certain free fatty acids) at specific windows of endocrine pancreas differentiation (in utero and /or after birth) result in impaired glucose homeostasis with distinct mechanisms in males and females. Moreover, LP diets given during gestation or late gestation only, had offspring with life-long reduction of ®-cell mass and impaired ®-cell function by reducing ®-cell transcriptional machinery at the level of PDX-1 and downstream targets genes (insulin, Glut-2 and GK) and impairing glucose homeostasis in young adult males. Additionally, LP offspring failed to regenerate ®-cells following streptozotocin (STZ) depletion early after birth. At 30 days of age, REG1 pathway was programmed to limit the ability to increase ®-cell mass during metabolic stress. LP during gestation and lactation developed a similar but milder phenotype with clear alterations in insulin signaling and secretion. Our studies showed that changes in intra islet cellular mechanisms were due to alterations in expression of GABAA receptors with implications in glucagon secretion. Also, the LP diet altered the balance of islet cell replication and apoptosis in the neonate and was associated with reduced pancreatic expression of IGF-II. We found that feeding pregnant NOD (non-obese diabetic) mice with LP selectively decreased the levels of cytotoxic cytokines, reduced insulitis,
Abstracts / Placenta 36 (2015) 469e521
K4. GLYCOSYLATION PATTERNS OF PROTEINS IN TROPHOBLAST AND DECIDUA OF THE CAT PLACENTA
K6. IMPACT OF HIGH DENSITY LIPOPROTEIN METABOLISM IN MOUSE EMBRYO PHYSIOLOGY
nica 1, Ortega Barbeito Claudio 1, Fern andez Patricia 1, Diessler Mo Hugo 2, Gimeno Eduardo 1, Portiansky Enrique 1. 1 School of Veterinary Science UNLP, CONICET. La Plata, Bs As, Argentina; 2 Faculty of Veterinary Sciences UNL, Esperanza, Santa F e, Argentina
Nicol as Santander 1, Attilio Rigotti 1, 2, Dolores Busso 1. 1 Departamento de n, Diabetes y Metabolismo, Escuela de Medicina, Pontificia Nutricio n Molecular y lica, Santiago, Chile; 2 Centro de Nutricio Universidad Cato nicas, Escuela de Medicina, Pontificia Universidad Enfermedades Cro lica, Santiago, Chile Cato
The aim of this study was to characterize glycoconjugates of syncytiotrophoblast, cytotrophoblast and decidual cells of mature feline placenta. Samples from 12 normal pregnant female cats, after 45±5 days of gestation were obtained by hysterectomy. Sections were processed for routine observation. Lectinhistochemistry was performed using biotinylated lectins to characterize the expression of saccharides. Trophoblast expressed a varied composition of glycans, highly exposing terminal N-Acetylglucosamine residues and non-sialylated galactose and N-Acetyl galactosamine oligomers. Phaseolus vulgaris erythroagglutinin lectin, which recognized highly branched N-linked residues, was restricted to the syncytiotrophoblast. Unlike results reported in humans, mice and rats on lectin affinity of decidual cells, sialic acids and complex N-linked oligosaccharides were not demonstrated in cats. Glycosylation of proteins determines many of their final properties, thus becoming essential for the embryo-maternal relation during implantation and placentation. Knowledge about the glycosylation profile of the normal cat placenta may lead to a better understanding of both normal and pathological reproductive events.
K5. ADIPONECTIN e CROSS TALK BETWEEN MATERNAL ADIPOSE TISSUE AND PLACENTA Theresa L. Powell, Irving Aye, Fredrick Rosario, Thomas Jansson. Departments of Pediatrics and Obstetrics and Gynecology, University of Colorado, Anschutz Medical Campus, Aurora, CO, USA Adiponectin is a multimeric protein secreted from adipose tissue. Secretion decreases as adipose tissue expands during weight gain. Low circulating levels of adiponectin are associated with decreased insulin sensitivity in skeletal muscle and liver. In contrast, our studies demonstrate that trophoblast cells respond by increasing insulin sensitivity with low maternal adiponectin. This establishes adiponectin as an endocrine link between maternal adipose tissue and the placenta, which promotes nutrient flux to the fetus when supplies are high and limits nutrient delivery to the fetus and preserves maternal tissues when nutrients are in low abundance. With low nutrient status maternal fasting insulin is low and adiponectin levels are high. During the postprandial period, insulin stimulated nutrient transport in the placenta is blunted by the high maternal adiponectin, therefore limiting fetal growth when maternal supplies are reduced. In maternal obesity, low adiponectin and chronically high insulin (due to maternal insulin resistance) will lead to maximal insulin stimulation of placental nutrient transport, contributing to fetal overgrowth. We have demonstrated in cultured trophoblast cells that increasing adiponectin concentrations caused a loss of insulin sensitivity at the level of IRS-1 and blunts insulin stimulated nutrient uptake. We also studied responses to infused adiponectin in normal lean pregnant mice using mini-osmotic pumps to increase maternal adiponectin levels 4-fold (within the normal physiological range) between E14-18. This treatment caused a significant reduction (-18%, p<0.05) in pup weight. Placental studies in the lean dams supported our hypothesis that increasing adiponectin inhibits placental nutrient transport by decreasing insulin sensitivity. Currently, we are studying diet-induced maternal obesity in mice and adiponectin replacement therapy. Infusion of adiponectin in obese dams corrected placental insulin signaling and nutrient transport capacity, reversing fetal overgrowth. These studies suggest that therapeutic adiponectin supplementation may improve birth outcomes in obese and diabetic mothers with low levels of adiponectin.
Lipoproteins transport in plasma lipophilic molecules such as cholesterol, triglycerides, vitamins, bioactive lipids, etc. High-density lipoproteins (HDL) have a central role in the regulation of plasma cholesterol levels, mainly by mediating the transport of this lipid from peripheral tissues to the liver, where it is taken up by Scavenger Receptor class B type I (SR-BI) and secreted into bile. HDL also transport and supply different tissues with vitamin E. The generation of a SR-BI-deficient mouse led researchers to hypothesize that this HDL receptor could play a role in embryonic development, as heterozygous SR-BI +/ intercrosses yielded only half of the SRBI -/- expected by the Mendelian ratio, suggestive of embryonic lethality due to the lack of SR-BI. Recently, we demonstrated that around half of the SR-BI-/- embryos showed a lethal developmental abnormality known as exencephaly. This defect is analogous to human anencephaly and is produced by a defect in neural tube closure. SR-BI-/- embryos also show eyelid closure defects and an impaired architecture of tongue myogenic fibers. In addition, some knockout fetuses with well-closed neural tubes show intrauterine growth restriction, as they weigh less than their wild-type littermates at birth. During development, SR-BI is localized in cells from extra-embryonic tissues that mediate maternal-fetal transport of nutrients, i.e. trophoblast giant cells during early gestation and syncytiotrophoblasts from mid- to late pregnancy. In our laboratory, we are currently studying the role of the HDL receptor SR-BI in the maternal-fetal transport of different lipid classes and the impact of the SR-BI-mediated HDL metabolism on neural tube closure and fetal growth. FONDECYT 1141236 (D.B.) and 1110712 (A.R.), Doctoral Fellowship CONICYT 21130444 (N.S.).
K7. INTRAUTERINE PROGRAMMING OF BETA CELL DEFECTS Edith Arany. Lawson Health Research Institute, University of Western Ontario, Schulich School of Medicine and Dentistry, Department of Pathology, London, Ontario, Canada Maternal inflammatory environment (type 1 diabetes) or nutritional deficiencies directly influence fetal and neonatal pancreas development. We have shown that protein restriction (LP) or maternal deficiencies (such as lack of specific AA or certain free fatty acids) at specific windows of endocrine pancreas differentiation (in utero and /or after birth) result in impaired glucose homeostasis with distinct mechanisms in males and females. Moreover, LP diets given during gestation or late gestation only, had offspring with life-long reduction of ®-cell mass and impaired ®-cell function by reducing ®-cell transcriptional machinery at the level of PDX-1 and downstream targets genes (insulin, Glut-2 and GK) and impairing glucose homeostasis in young adult males. Additionally, LP offspring failed to regenerate ®-cells following streptozotocin (STZ) depletion early after birth. At 30 days of age, REG1 pathway was programmed to limit the ability to increase ®-cell mass during metabolic stress. LP during gestation and lactation developed a similar but milder phenotype with clear alterations in insulin signaling and secretion. Our studies showed that changes in intra islet cellular mechanisms were due to alterations in expression of GABAA receptors with implications in glucagon secretion. Also, the LP diet altered the balance of islet cell replication and apoptosis in the neonate and was associated with reduced pancreatic expression of IGF-II. We found that feeding pregnant NOD (non-obese diabetic) mice with LP selectively decreased the levels of cytotoxic cytokines, reduced insulitis,