Sp1 transcription factor is involved in the regulation of placental leptin expression

Sp1 transcription factor is involved in the regulation of placental leptin expression

492 Abstracts / Placenta 36 (2015) 469e521 Methods: Rats were randomly assigned into four groups (n¼12/group): Sedentary non-diabetic (Control¼C, gl...

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492

Abstracts / Placenta 36 (2015) 469e521

Methods: Rats were randomly assigned into four groups (n¼12/group): Sedentary non-diabetic (Control¼C, glycemia<120 mg/dL); Sedentary mild diabetic (MD - Streptozotocin - 100 mg/kg b.w., sc., at birth); Exercised non-diabetic (Cex) and Exercised mild diabetic (MDex). Cex and MDex rats were subjected to a swimming program supporting a load of 4% of body weight from day 7 to 18.5 of pregnancy. On day 18.5 of pregnancy, the different experimental groups were killed for exposure of the uterine corns for the analysis of the reproductive outcomes. P<0.05 was considered as a significant statistical limit. Results: MD rats presented glucose intolerance and the area under the curve analysis showed a significant negative correlation between maternal glycemia and a decrease in the number of live fetuses. MD rats showed a lower number of live fetuses and litter weight than C rats. MDex dams presented reduced maternal weight gain, implantation number and litter weight, and increased number of live fetuses as compared with Cex. Both MD groups presented increased fetal and placental weights, and percentage of fetuses classified as large for pregnancy age in relation to control groups. Conclusion: The mild diabetic rats subjected to the swimming program presented no alterations in glucose intolerance, but the number of live fetuses and fetal weight of these rats were consistent with those in the control group, confirming beneficial effects of swimming with an appropriate intensity for the parameters analyzed. Acknowledgement: FAPESP/Brazil (Process number: 2013/23478-3).

PA.13. MATERNAL SATURATED FAT-ENRICHED DIET DETERMINES LEPTIN RESISTANCE IN THE FETAL LIVER AND PROGRAMS LIPID HOMEOSTASIS IMPAIRMENT IN THE OFFSPRING n Mazzucco, Daiana Fornes, Alicia Jawerbaum, Vero  nica María Bele White. Centre from Pharmacology and Botanical Studies (CEFyBO) CONICET UBA, Buenos Aires, Argentina Maternal obesity leads to impaired metabolic programming. In a rat model of saturated fat overload in the maternal diet, we have previously found increased fetal liver lipid content. Lipid catabolism in the liver assures proper lipid homeostasis. Leptin regulates lipid catabolism in several tissues. Objective: To investigate whether an overload of saturated fat on the maternal diet impairs leptin effects on hepatic lipid catabolism in rat fetuses at term gestation and whether these anomalies are sustained in the offspring of these rats. Methods: Female Wistar rats were fed with a standard (5% fat) or with a saturated fat diet (28% fat) from 6 weeks of age (SFD rats). After 8 weeks of diet, they were mated with control males. Control and SFD rats were euthanized at 21 days of gestation and fetal livers obtained for further culture of explants (3h) with or without leptin (100 ng/ml). Another group of control and SFD rats were allowed to deliver, and their offspring euthanized at 21 or 130 days of age. Livers were analyzed for lipid accumulation (TLC) and acylCoA oxidase (ACO) expression (PCR). Results: Leptin induced a decrease in triglycerides (49%), free fatty acids (75%) and cholesteryl esters (42%) concentrations in fetal livers from control rats (p<0.05), but no changes but no changes in fetal livers from SFD rats, which showed. Leptin induced an increased ACO expression (50%, p<0.05) in control fetal livers. Fetal livers from SFD rats showed a decrease in ACO expression (25% p<0.05) and no changes with leptin additions. A decrease in ACO expression were also observed in the livers of 21- and 130day-old offspring from SFD rats (20%, p<0.05). Conclusions: Saturated fat in maternal diet induces hepatic lipid metabolism impairment in fetuses and offspring. Liver leptin resistance on lipid catabolism begins in utero and maybe responsible for the alterations on the offspring lipid metabolism.

PA.14. METABOLIC ABNORMALITIES IN THE FETAL LIVER OF RATS WITH GESTATIONAL DIABETES INDUCED BY INTRAUTERINE PROGRAMMING Daiana Fornes, Romina Higa, Ivana Linenberg, Evangelina Capobianco, Alicia Jawerbaum. Laboratory of Reproduction and Metabolism, CEFYBO-CONICET, School of Medicine, University of Buenos Aires, Buenos Aires, Argentina Gestational diabetes (GDM) is a prevalent disease with adverse consequences to both mothers and offspring. We have recently described a new GDM model obtained through adverse intrauterine programming in the offspring of diabetic rats. This model allows analyzing the regulation of lipid metabolism in the fetal liver of GDM mothers. Peroxisome proliferator activated receptors (PPARs) are nuclear receptors involved in lipid metabolic pathways, being PPARa a major regulator of lipid catabolism, while PPARg is highly involved in lipid synthesis and deposition in different tissues. Objective: To evaluate whether lipid concentrations are altered and related to impaired PPAR protein expression in the fetal liver of GDM rats. Methods: Control and GDM rats (obtained from intrauterine programming (F1) in the offspring of streptozotocin-induced diabetic rats (F0)) were evaluated on day 21 of pregnancy. Glucose and insulin concentrations were measured in maternal and fetal serum. Lipid concentrations were measured by TLC and PPARa and PPARg protein expression were evaluated through immunohistochemistry. Results: GDM rats showed increased glycemia and insulinemia only in pregnancy (p<0.01). Male and female fetuses had increased glycemia and insulinemia (p<0.01). Male fetuses from GDM rats showed increased triglycerides (33%) and cholesterol (30%) concentrations in the liver when compared to controls (p<0.05). In these GDM fetal tissues, PPARg protein expression was increased (p<0.001) whereas PPARa protein expression showed no changes compared to controls. Differently, female fetuses from GDM rats showed reduced triglycerides (34%), cholesterol (26%), phospholipids (29%) and free fatty acids (25%) in the liver, p<0.02, compared to controls. Also, in these GDM fetal tissues, both PPARg and PPARa levels were reduced (p<0.01). Conclusion: In a GDM model induced by intrauterine programming, the altered lipid deposition in the fetal liver is gender-dependent and possibly related to changes in the concentrations of the different PPAR isotypes in this fetal tissue.

PA.15. SP1 TRANSCRIPTION FACTOR IS INVOLVED IN THE REGULATION OF PLACENTAL LEPTIN EXPRESSION n Toro 1, Julieta Maymo  1, A. Pe rez-Pe rez 2, Ye sica Malena Schanton 1, Ayele nchez Margalet 2, Cecilia Gambino 1, Bernardo Maskin 3, Victor Sa gica, FCEN, UBA, IQUIBICEN, Varone 1. 1 Departamento de Química Biolo edica y CONICET, Buenos Aires, Argentina; 2 Departamento de Bioquímica M Biología Molecular, Universidad de Sevilla, Sevilla, Spain; 3 Hospital Nacional Profesor Alejandro Posadas, Buenos Aires, Argentina Objectives: Leptin is a key hormone in placental physiology. It regulates trophoblast proliferation, inhibits apoptosis, stimulates protein synthesis, and regulates fetal growth and development. The mechanisms involved in the regulation of placental leptin expression are not fully understood. Previous results from our lab demonstrated that estradiol (E2) regulates leptin expression involving genomic and non-genomic effects. Sp1 is a ubiquitous transcription factor. Several potential binding sites for Sp1 have been found in the leptin promoter. One of them is present in the region identified as PLE (enhancer of the placental leptin) involved in E2 effect. In the present study, we analyzed the effect of Sp1 in the induction of leptin expression by E2 in human placental cells.

Abstracts / Placenta 36 (2015) 469e521

Methods: BeWo cells were cultured under standard conditions. BeWo cells were transiently transfected with different reporter vectors and expression vectors for Sp1 or ERa. Results: We observed that Sp1 overexpression increased basal leptin promoter activity (p < 0.0070). This effect was enhanced by E2 (p < 0.01). On the other hand, Sp1 increased leptin promoter activity of the reporter, which contains the promoter region of the leptin gene between -1951 and -1847 bp (p < 0.05), but not when the Sp1 element is mutated in this region. Sp1 effect was ERa-dependent as it had no activity in cells that had been knocked down with an ERa siRNA. We observed that there is a joint interaction between Sp1 and ERa regulating the expression of placental leptin. Conclusions: All these findings suggest that leptin expression is tightly regulated and improve the understanding of the mechanisms whereby E2 regulates leptin expression involving Sp1 transcription factor.

PA.16. ADIPONECTIN RECEPTOR 1 EXPRESSION IN HUMAN UMBILICAL ARTERY ENDOTHELIAL CELLS (HUAEC) FROM LARGE FETUSES (LGA) OF OBESE WOMEN IS RELATED TO eNOS ACTIVATION ~ oz-Mun ~ oz 1, B. Krause 2, 3, R. Uauy 2, P. Casanello 2, 3. 1 PhD Program E.C. Mun in Nutrition and Food, Universidad de Chile, Santiago, Chile; 2 Division of lica de Chile, Pediatrics, Faculty of Medicine, Pontificia Universidad Cato Santiago, Chile; 3 Division of Obstetrics and Gynecology, Faculty of lica de Chile, Santiago, Chile Medicine, Pontificia Universidad Cato Objectives: We aimed to determine whether Adiponectin Receptor 1 (AdipoR1) expression is related to eNOS activation in HUAEC. Additionally we studied the differential expression of AdipoR1 and eNOS activation in large for gestational age (LGA) fetuses of obese pregnant women compared to appropriate-for-gestational-age (AGA) fetuses of normal weight pregnant women. Methods: Primary cultures of HUAEC were obtained from the umbilical cord of term single pregnancies of AGA babies from normal weight women (A/N) and LGA babies from obese women (L/O). AdipoR1 and eNOS mRNA was measured by qPCR (Sybr Green). AdipoR1 and eNOS protein expression was measured by Western blot and total and phospho-eNOS (p-eNOS) by ELISA. Results: HUAEC expressed the mRNA and protein for AdipoR1. In basal conditions, mRNA and protein expression of AdipoR1 and eNOS were increased in HUAEC from the L/O compared to the A/N group. P-eNOS and the p-eNOS/eNOS ratio were decreased in the L/O group. Conclusions: AdipoR1 is overexpressed in HUAEC from L/O and a negative association to eNOS activation could be associated with further vascular compromise. The participation of the classical AdipoR1 signaling pathway is currently being studied. Funded by Fondecyt N 1120928, Fondecyt Nº1130277, Conicyt Nº21120534.

PA.17. MELATONIN INCREASES OFFSPRING SURVIVAL IN A MURINE MODEL OF PRETERM LABOR INDUCED BY LPS A.P. Domínguez Rubio, J. Aisemberg, J. Blanco, M.V. Bariani, M.A. Zorrilla Zubilete, A.M. Franchi. Laboratory of Physiopathology of Pregnancy and Labor, CEFyBO (CONICET-UBA), Buenos Aires, Argentina Preterm birth (PTB) is the leading cause of neonatal mortality and promotes delayed physical and cognitive development in children. Intraamniotic infections are one of the main causes of PTB. In a model of inflammation-associated PTB (induced by LPS), melatonin was administered on gestational day 14, preventing PTB in 50% of the cases and conferring fetal protection. Objectives: a) To determine the consequences of melatonin and LPS treatment on the fetal brain. b) To evaluate whether maternal treatment with melatonin+LPS affects weight, physical landmarks in newborn mice and behavior in adulthood.

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Methods: Histological studies were performed and IL-1b mRNA expression was determined in fetal brains on day 15 of pregnancy. At birth, pups were weighed and observed for physical landmarks. As adults, open-field, elevated plus maze and passive avoidance behavioral tests were also assessed. Results: LPS induced IL-1b release and triggered neurovascular unit injury and cell damage in the fetal brain parenchyma. Melatonin blocked LPSinduced IL-1b expression, reduced cell infiltration and prevented the deleterious effects in brain parenchyma. No differences were observed in body weight or physical landmarks: pinna detachment, incisor eruption, and eye opening. Maternal treatment with melatonin+LPS did not affect the offspring’s horizontal and vertical locomotor activity following exposure to an open field test when compared to control or melatonin-treated mice. In repeated exposure to open field, all treated mice showed the same habituation memory. No differences were found in the anxiety-like behavior evaluated in the elevated plus maze. There were no effects of melatonin+LPS on associative memory in the passive avoidance test when compared to control or melatonin-treated mice. Conclusions: We concluded that exposure to LPS is extremely detrimental to the fetal brain, but that a treatment with melatonin prevents brain injury. These results suggest a potential therapeutic use of melatonin as a tocolytic agent in order to prevent PTB and increase offspring survival.

PA.18. INTRAUTERINE GROWTH RESTRICTED RATS PREGNANCY: MATERNAL-FETAL REPERCUSSIONS

EXERCISED

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A.O. Netto 1, S.B. Corvino 1, Y.K. Sinzato 1, K.E. Campos 1, 2, I.M.P. Calderon 1, M.V.C. Rudge 1, G.T. Volpato 1, 2, E. Zambrano 3, D.C. Damasceno 1. 1 Laboratory of Experimental Research on Gynecology and Obstetrics, Graduate Program on Gynecology, Obstetrics and Mastology, ~o Botucatu Medical School, Univ. Estadual Paulista_Unesp, Botucatu, Sa Paulo, Brazil; 2 Institute of Biological and Health Sciences, University Center of Araguaia, Mato Grosso Federal University (UFMT), Barra do Garças, Mato Grosso, Brazil; 3 Department of Reproductive Biology, Instituto n, Mexico n, Salvador, Zubira Nacional de Ciencias M edicas y Nutricio Background: There is evidence that the nature of fetal programming is such that it is involved in many disease phenotypes, including those of successive generations. Laboratory animal models have been developed as an attempt to understand the pathophysiological mechanisms involved in an unfavorable intrauterine environment. We hypothesized that the swimming program may lead to an adequate maternal environment, improving embryofetal development. Objective: To evaluate the effect of swimming in pregnant rats born with intrauterine growth restriction (IUGR) and their offspring. Methods: IUGR rats were obtained using streptozotocin-induced severe diabetic (SD) rats. The nondiabetic and SD pregnant rats generated offspring with appropriate (APA) and small (IUGR) weight for pregnancy age, respectively. At adult life, the APA group was maintained sedentary (nonexercised) and classified as control group and IUGR rats were distributed into two subgroups: non-exercised (IUGR) and exercised (IUGRex). Results: The rate of mated rats in the IUGR group was reduced compared to the control group. During pregnancy, the IUGR rats presented hyperinsulinemia, impaired reproductive outcomes, decreased body weight, hypertriglyceridemia and hyperlactacidemia. The IUGRex rats presented reduced insulin and triglyceride levels. There was a reduced percentage of appropriate weight for pregnancy age (APA) fetuses in the IUGR and IUGRex groups in relation to the control group, and an increase in the proportion of small weight for pregnancy age (SPA) fetuses in the IUGRex rats compared with the control group. Conclusion: Swimming improved lipid metabolism and increased insulin sensitivity. However, the offspring showed retarded growth, reinforcing the need to stimulate the exercise practice in women under supervision with different professional expertise to promote appropriate gestational conditions and to improve perinatal outcomes. Acknowledgement: CAPES/Brazil.