Browsing by Author "Casanello, Paola"

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    D-Glucose stimulation of L-arginine transport and nitric oxicle synthesis results from activation of mitogen-activated protein kinases p42/44 and smad2 requiring functional type II TGF-beta receptors in human umbilical vein endothelium
    (WILEY, 2007) Vasquez, Rodrigo; Farias, Marcelo; Vega, Jost Luis; Martin, Rody San; Vecchiola, Andrea; Casanello, Paola; Sobrevia, Luis
    Elevated extracellular D-glucose increases transforming growth factor P I (TGF-P 1) release from human umbilical vein endothelium (HUVEC). TGF-P 1, via TGF-P receptors I (T beta RI) and T beta RII, activates Smad2 and mitogen -activated protein kinases p44 and p42 (p42/44 (mapk)). We studied whether D-glucose-stimulation Of L-arginine transport and nitric oxide synthesis involves TGF-beta 1 in primary cultures of HUVEC. TGF-P I release was higher (similar to 1.6-fold) in 25 mM (high) compared with 5 mM (normal) D-glucose. TGF-P I increases L-arginine transport (half maximal effect similar to 1.6 ng/ml) in normal D-glucose, but did not alter high D-glucose-increased L-arginine transport. TGF-P I and high D-glucose increased hCAT- I mRNA expression (similar to 8-fold) and maximal transport velocity (V-max), L- [(3) H]citrulline formation from L- [3 H]arginine (index of NO synthesis) and endothelial NO synthase (eNOS) protein abundance, but did not alter eNOS phosphorylation. TGF-beta 1 I and high D-gludose increased p42/44 mapk and Smad2 phosphorylation, an effect blocked by PD-98059 (MEK 1 /2 inhibitor). However, TGF-P I and high D-glucose were ineffective in cells expressing a truncated, negative dominant T beta RII High D-glucose increases L-arginine transport and eNOS expression following T beta RII activation by TGF-P I involving p42/44 (mapk) and Smad2 in HUVEC. Thus, TGF-P I could play a crucial role under conditions of hyperglycemia, such as gestational diabetes mellitus, which is
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    DHA Supplementation during Pregnancy in Women with Obesity Normalizes IGF2R Levels in the Placenta of Male Newborns
    (2023) Castro, Juan Jose; Umana-Perez, Adriana; Castano-Moreno, Erika; Casanello, Paola; Ronco, Ana Maria
    Introduction. Insulin-like growth factor receptor 2 (IGF2R) regulates placental nutrient transport, and its soluble form is related to obesity in adults. If the placental expression of IGF2R is altered in women with obesity is unknown. Whether maternal supplementation with docosahexaenoic acid (DHA), a polyunsaturated fatty acid with anti-inflammatory properties, has a modulatory role in IGF2R's function has not been elucidated. We hypothesized that maternal obesity (Ob) would be associated with alterations in placental IGF2R expression, which may be prevented with DHA supplementation during pregnancy. Methods. At delivery, we obtained placentas from women with Ob (BMI & GE; 30 kg/m(2), n = 17), Ob supplemented with 800 mg/day of DHA during pregnancy (Ob + DHA, n = 13), and normal-weight women (Nw, BMI & GE; 18.5 & LE; 24.9 kg/m(2), n = 14). The IGF2R mRNA and protein were determined by RT-PCR and western blotting, respectively. Moreover, we quantified the gene expression of molecules that modulate the IGF2R function in the extracellular domain, such as TACE/ADAM17, PLAU, and IGF2. Mann-Whitney and Kruskal-Wallis nonparametric tests were used to compare results between two or three groups accordingly. Results. The IGF2R levels in the Ob placentas of the male offspring were higher than in the Nw group. The DHA supplementation prevented this effect, suggesting an unknown relationship between IGF2R-Ob-DHA in placental tissues. Conclusion. We report, for the first time, that DHA supplementation during pregnancy in women with obesity normalizes the increased IGF2R levels in male placentas, reducing the risk of adverse outcomes related to the IGF2/IGF2R system in male newborns.
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    Epigenetics: New Concepts of Old Phenomena in Vascular Physiology
    (BENTHAM SCIENCE PUBL LTD, 2009) Krause, Bernardo; Sobrevia, Luis; Casanello, Paola
    The hypothesis of 'Developmental Origins of Health and Disease' (DOHaD) relies on the presence of mechanisms sensing and signalling a diversity of stimuli during fetal development. The mechanisms that have been broadly suggested to be involved in these processes are the epigenetic modifications that could 'record' perinatal stimuli. Since the definition of epigenetic and the associated mechanisms are conflictive, in this review epigenetic was defined as 'chromosome-based mechanisms that can change the phenotypic plasticity in a cell or organism'. The most understood epigenetic mechanisms (i.e. DNA methylation, histone post-translational modifications (PTM), ATP-dependent chromatin modifications and non-coding RNAs) and reported evidence for their role in fetal programming were briefly reviewed.
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    FOETAL AND UMBILICAL VASCULAR REACTIVITY IN A MODEL OF IUGR THROUGH GRADUAL UTERINE ARTERY OCCLUSION IN GUINEA PIGS
    (W B SAUNDERS CO LTD, 2014) Scheneider, Daniela; Alegria, Rene; Herrera, Emilio; Farias, Marcelo; Casanello, Paola; Krause, Bernardo
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    Functional consequences of SARS-CoV-2 infection in pregnant women, fetoplacental unit, and neonate
    (ELSEVIER, 2023) Carvajal, Jorge; Casanello, Paola; Toso, Alberto; Farias, Marcelo; Carrasco-Negue, Karina; Araujo, Kenny; Valero, Paola; Fuenzalida, Javiera; Solari, Caterina; Sobrevia, Luis
    The SARS-CoV-2 infection causes COVID-19 disease, characterized by acute respiratory distress syndrome, bilateral pneumonia, and organ failure. The consequences of maternal SARS-CoV-2 infection for the pregnant woman, fetus, and neonate are controversial. Thus, it is required to determine whether there is viral and non -viral vertical transmission in COVID-19. The disease caused by SARS-CoV-2 leads to functional alterations in asymptomatic and symptomatic pregnant women, the fetoplacental unit and the neonate. Several diseases of pregnancy, including COVID-19, affect the fetoplacental function, which causes in utero programming for young and adult diseases. A generalized inflammatory state and a higher risk of infection are seen in pregnant women with COVID-19. Obesity, diabetes mellitus, and hypertension may increase the vulnerability of pregnant women to infection by SARS-CoV-2. Alpha, Delta, and Omicron variants of SARS-CoV-2 show specific mutations that seem to increase the capacity of the virus to infect the pregnant woman, likely due to increasing its interaction via the virus S protein and angiotensin-converting enzyme 2 receptors. This review shows the literature addressing to what extent COVID-19 in pregnancy affects the pregnant woman, fetoplacental unit, and neonate. Prospective studies that are key in managing SARS-CoV-2 infection in pregnancy are discussed.
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    Functional Link Between Adenosine and Insulin: A Hypothesis for Fetoplacental Vascular Endothelial Dysfunction in Gestational Diabetes
    (BENTHAM SCIENCE PUBL LTD, 2011) Guzman Gutierrez, Enrique; Abarzua, Fernando; Belmar, Cristian; Nien, Jyh K.; Ramirez, Marco A.; Arroyo, Pablo; Salomon, Carlos; Westermeier, Francisco; Puebla, Carlos; Leiva, Andrea; Casanello, Paola; Sobrevia, Luis
    Gestational diabetes mellitus (GDM) is a syndrome compromising the health of the mother and the fetus. Endothelial damage and reduced metabolism of the vasodilator adenosine occur and fetal hyperinsulinemia associated with deficient insulin response and a metabolic rather than mitogenic phenotype is characteristic of this pathology. These phenomena lead to endothelial dysfunction of the fetoplacental unit. Major databases were searched for the relevant literature in the field. Special attention was placed on publications related with diabetes and hormone/metabolic disorders. We aimed to summarize the information regarding insulin sensitivity changes in GDM and the role of adenosine in this phenomenon. Evidence supporting the possibility that fetal endothelial dysfunction involves a functional link between adenosine and insulin signaling in the fetal endothelium from GDM pregnancies is summarized. Since insulin acts via membrane receptors type A (preferentially associated with mitogenic responses) or type B (preferentially associated with metabolic responses), a differential activation of these receptors in this syndrome is proposed.
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    Gestational Diabetes Reduces Adenosine Transport in Human Placental Microvascular Endothelium, an Effect Reversed by Insulin
    (PUBLIC LIBRARY SCIENCE, 2012) Salomon, Carlos; Westermeier, Francisco; Puebla, Carlos; Arroyo, Pablo; Guzman Gutierrez, Enrique; Pardo, Fabian; Leiva, Andrea; Casanello, Paola; Sobrevia, Luis
    Gestational diabetes mellitus (GDM) courses with increased fetal plasma adenosine concentration and reduced adenosine transport in placental macrovascular endothelium. Since insulin modulates human equilibrative nucleoside transporters (hENTs) expression/activity, we hypothesize that GDM will alter hENT2-mediated transport in human placental microvascular endothelium (hPMEC), and that insulin will restore GDM to a normal phenotype involving insulin receptors A (IR-A) and B (IR-B). GDM effect on hENTs expression and transport activity, and IR-A/IR-B expression and associated cell signalling cascades (p42/44 mitogen-activated protein kinases (p42/44(mapk)) and Akt) role in hPMEC primary cultures was assayed. GDM associates with elevated umbilical whole and vein, but not arteries blood adenosine, and reduced hENTs adenosine transport and expression. IR-A/IR-B mRNA expression and p42/44(mapk)/Akt ratios ('metabolic phenotype') were lower in GDM. Insulin reversed GDM-reduced hENT2 expression/activity, IR-A/IR-B mRNA expression and p42/44(mapk)/Akt ratios to normal pregnancies ('mitogenic phenotype'). It is suggested that insulin effects required IR-A and IR-B expression leading to differential modulation of signalling pathways restoring GDM-metabolic to a normal-mitogenic like phenotype. Insulin could be acting as protecting factor for placental microvascular endothelial dysfunction in GDM.
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    High D-Glucose reduces SLC29A1 promoter activity and adenosine transport involving specific protein 1 in human umbilical vein endothelium
    (WILEY, 2008) Puebla, Carlos; Farias, Marcelo; Gonzalez, Marcelo; Vecchiola, Andrea; Aguayo, Claudio; Krause, Bernardo; Pastor Anglada, Marcal; Casanello, Paola; Sobrevia, Luis
    High D-glucose reduces human equilibrative nucleoside transporter 1 (hENT1)-mediated adenosine uptake involving endothelial nitric oxide synthase (eNOS), mitogen-activated protein (MAP) kinase kinases 1 and 2/MAP kinases p42/44 (MEK/ERKs), and protein kinase C (PKC) activation in human umbilical vein endothelium (HUVEC). Since NO represses SLC29A1 gene (hENT1) promoter activity we studied whether D-glucose-reduced hENT1-adenosine transport results from lower SLC29A1 expression in HUVEC primary cultures. HUVEC incubation (24 h) with high D-glucose (25 mM) reduced hENT1-adenosine transport and pGL3-hENT1(-1114) construct SLC29A1 reporter activity compared with normal D-glucose (5 mM). High D-glucose also reduced pGL3-hENT1(-1114) reporter activity compared with cells transfected with pGL3-hENT1(-795) Construct. N-G-nitro-L-arginine methyl ester (L-NAME, NOS inhibitor), PD-98059 (MEK1/2 inhibitor), and/or calphostin C (PKC inhibitor) blocked D-glucose effects. Insulin(1 nM) and phorbol 12-myristate 13-acetate (PMA, 100 nM, PKC activator), but not 4 alpha-phorbol 12,13-didecanoate (4 alpha PDD, 100 nM, PMA less active analogue) reduced hENT1-adenosine transport. L-NAME and PD-98059 blocked insulin effects. L-NAME, PD-98059, and calphostin C increased hENT1 expression without altering protein or mRNA stability. High D-glucose increased Sp1 transcription factor protein abundance and binding to SLC29A1 promoter, phenomena blocked by L-NAME, PD-98059, and calphostin C. Sp1 overexpression reduced SLC29A1 promoter activity in normal D-glucose, an effect reversed by L-NAME and further reduced by S-nitroso-N-acetyl-L,D-penicillamine (SNAP, NO donor) in high D-glucose. Thus, reduced hENT1 -mediated adenosine transport in high D-glucose may result from increased Sp1 binding to SLC29A1 promoter down-regulating hENT1 expression. This phenomenon depends on eNOS, MEK/ERKs, and PKC activity, suggesting potential roles for these molecules in hyperglycemia-associated endothelial dysfunction.
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    Higher levels of insulin‐like growth factor‐1 in cord blood associate with risk of asthma at age 3
    (2023) Castro‐Rodríguez, José Antonio; Padilla, Oslando; Casanello, Paola; Forno, Erick
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    Increased expression of the multidrug resistance-associated protein 1 (MRP1) in kidney glomeruli of streptozotocin-induced diabetic rats
    (WALTER DE GRUYTER GMBH, 2011) Quezada, Claudia; Alarcon, Sebastian; Carcamo, Juan G.; Yanez, Alejandro; Casanello, Paola; Sobrevia, Luis; San Martin, Rody
    Oxidative stress has been linked to the podocytopathy, mesangial expansion and progression of diabetic nephropathy. The major cell defence mechanism against oxidative stress is reduced glutathione (GSH). Some ABC transporters have been shown to extrude GSH, oxidised glutathione or their conjugates out of the cell, thus implying a role for these transporters in GSH homeostasis. We found a remarkable expression of mRNA for multidrug resistance-associated proteins (MRP/ABCC) 1, 3, 4 and 5 in rat glomeruli. Three weeks after induction of diabetes in glomeruli of streptozotocin-treated rats, we observed a decline in reduced GSH levels and an increase in the expression and activity of MRP1 (ABCC1). These lower GSH levels were improved by ex vivo treatment with pharmacological inhibitors of MRP1 activity (MK571). We conclude that increased activity of MRP1 in diabetic glomeruli is correlated with an inadequate adaptive response to oxidative stress.
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    Insulin Restores Gestational Diabetes Mellitus Reduced Adenosine Transport Involving Differential Expression of Insulin Receptor Isoforms in Human Umbilical Vein Endothelium
    (AMER DIABETES ASSOC, 2011) Westermeier, Francisco; Salomon, Carlos; Gonzalez, Marcelo; Puebla, Carlos; Guzman Gutierrez, Enrique; Cifuentes, Fredi; Leiva, Andrea; Casanello, Paola; Sobrevia, Luis
    OBJECTIVE-To determine whether insulin reverses gestational diabetes mellitus (GDM)-reduced expression and activity of human equilibrative nucleoside transporters 1 (hENT1) in human umbilical vein endothelium cells (HUVECs).
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    Insulin restores glucose inhibition of adenosine transport by increasing the expression and activity of the equilibrative nucleoside transporter 2 in human umbilical vein endothelium
    (WILEY, 2006) Munoz, Gonzalo; San Martin, Rody; Farias, Marcelo; Cea, Luis; Vecchiola, Andrea; Casanello, Paola; Sobrevia, Luis
    L-Arginine transport and nitric oxide (NO) synthesis (L-arginine/NO pathway) are stimulated by insulin, adenosine or elevated extracellular D-glucose in human umbilical vein endothelial cells (HUVEC). Adenosine uptake via the human equilibrative nucleoside transporters 1 (hENT1) and 2 (hENT2) has been proposed as a mechanism regulating adenosine plasma concentration, and therefore its vascular effects in human umbilical veins. Thus, altered expression and/or activity of hENT1 or hENT2 could lead to abnormal physiological plasma adenosine level. We have characterized insulin effect on adenosine transport in HUVEC cultured in normal (5 mM) or high (25, mM) D-glucose. Insulin (1 nM) increased overall adenosine transport associated with higher hENT2-, but lower hENT1-mediated transport in normal D-glucose. insulin increased hENT2 protein abundance in normal or high D-glucose, but reduced hENT1 protein abundance in normal D-glucose. Insulin did not alter the reduced hENT1 protein abundance, but blocked the reduced hENT1 and hENT2 mRNA expression induced by high D-glucose. Insulin effect on hENT1 mRNA expression in normal D-glucose was blocked by N-G-nitro-L-arginine methyl ester (L-NAME, NO synthase inhibitor) and mimicked by S-nitroso-N-acetyl-L,D-penicillamine (SNAP, NO donor). L-NAME did not block insulin effect on hENT2 expression. In conclusion, insulin stimulation of overall adenosine transport results from increased hENT2 expression and activity via a NO-independent mechanism. These findings could be important in hyperglycemia-associated pathological pregnancies, such as gestational diabetes, where plasma adenosine removal by the endothelium is reduced, a condition that could alter the blood flow from the placenta to the fetus affecting fetus growth and development. J. Cell. Physiol. 209: 826-835, 2006. (c) 2006 Wiley-Liss, Inc.
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    Insulin-Stimulated L-Arginine Transport Requires SLC7A1 Gene Expression and Is Associated With Human Umbilical Vein Relaxation
    (WILEY, 2011) Gonzalez, Marcelo; Gallardo, Victoria; Rodriguez, Natalia; Salomon, Carlos; Westermeier, Francisco; Guzman Gutierrez, Enrique; Abarzua, Fernando; Leiva, Andrea; Casanello, Paola; Sobrevia, Luis
    Insulin causes endothelium-derived nitric oxide (NO)-dependent vascular relaxation, and increases L-arginine transport via cationic amino acid transporter 1 (hCAT-1) and endothelialNOsynthase (eNOS) expression and activity in human umbilical vein endothelium (HUVEC). We studied insulin effect on SLC7A1 gene (hCAT-1) expression and hCAT-transport activity role in insulin-modulated human fetal vascular reactivity. HUVEC were used for L-arginine transport and L-[H-3] citrulline formation (NOS activity) assays in absence or presence of N-ethylmaleimide (NEM) or L-lysine (L-arginine transport inhibitors). hCAT-1 protein abundance was estimated by Western blot, mRNA quantification by real time PCR, and SLC7A1 promoter activity by Luciferase activity (-1,606 and -650 bp promoter fragments from ATG). Specific protein 1 (Sp1), and total or phosphorylatedeNOSprotein was determined by Western blot. Sp1 activity (at four sites between -177 and -105 bp from ATG) was assayed by chromatin immunoprecipitation (ChIP) and vascular reactivity in umbilical vein rings. Insulin increased hCATs-L-arginine transport, maximal transport capacity (V-max/K-m), and hCAT-1 expression. NEM and L-lysine blocked L-arginine transport. In addition, it was trans-stimulated (similar to 7.8-fold) by L-lysine in absence of insulin, but unaltered (similar to 1.4-fold) in presence of insulin. Sp1 nuclear protein abundance and binding to DNA, and SLC7A1 promoter activity was increased by insulin. Insulin increasedNOsynthesis and caused endothelium-dependent vessel relaxation and reduced U46619-induced contraction, effects blocked by NEM and L-lysine, and dependent on extracellular L-arginine. We suggest that insulin induces human umbilical vein relaxation by increasing HUVEC L-arginine transport via hCATs (likely hCAT-1) most likely requiring Sp1-activated SLC7A1 expression. J. Cell. Physiol. 226: 2916-2924, 2011. (C) 2011 Wiley-Liss, Inc.
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    Interactions between a polygenic risk score for plasma docosahexaenoic fatty acid concentration, eating behaviour, and body composition in children
    (2022) Jaramillo-Ospina, Angela; Casanello, Paola; Garmendia, Maria Luisa; Andersen, Ross; Levitan, Robert D.; Meaney, Michael J.; Silveira, Patricia Pelufo
    Background The relationship between eating behaviour and current body weight has been described. However little is known about the effect of polyunsaturated fatty acids (PUFA) in this relationship. Genetic contribution to a certain condition is derived from a combination of small effects from many genetic variants, and polygenic risk scores (PRS) summarize these effects. A PRS based on a GWAS for plasma docosahexaenoic fatty acid (DHA) has been created, based on SNPs from 9 genes. Objective To analyze the interaction between the PRS for plasma DHA concentration, body composition and eating behaviour (using the Children Eating Behaviour Questionnaire) in childhood. Subjects/Methods We analyzed a subsample of children from the Maternal, Adversity, Vulnerability and Neurodevelopment (MAVAN) cohort with PRS and measurements of eating behaviour performed at 4 years of age (n = 210), 6 y (n = 177), and body fat determined by bioelectric impedance at 4 y and 6 y or by air displacement plethysmography and dual-energy X-ray absorptiometry at 8 y (n = 42 and n = 37). PRS was based on the GWAS from Lemaitre et al. 2011 (p threshold = p < 5*10(-6)), and a median split created low and high PRS groups (high PRS = higher DHA level). Results In ALSPAC children, we observed an association between PRS and plasma DHA concentration (beta = 0.100, p < 0.01) and proportion (beta = 0.107, p < 0.01). In MAVAN, there were interactions between PRS and body fat on pro-intake scores in childhood, in which low PRS and higher body fat were linked to altered behaviour. There were also interactions between PRS and pro-intake scores early in childhood on body fat later in childhood, suggesting that the genetic profile and eating behaviour influence the development of adiposity at later ages. Conclusions A lower PRS (lower plasma PUFA) can be a risk factor for developing higher body fat associated with non-adaptive eating behaviour in childhood; it is possible that the higher PRS (higher plasma PUFA) is a protective feature.
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    INTRAUTERINE GROWTH RESTRICTION IN GUINEA PIG IMPAIRS UMBILICAL AND SYSTEMIC VASCULAR FUNCTION
    (W B SAUNDERS CO LTD, 2015) Herrera, Emilio A.; Schneider, Daniela; Alegria, Rene; Figueroa, Esteban; Villanueva, Cristian; Farias, Marcelo; Casanello, Paola; Krause, Bernardo J.
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    Maternal obesity is associated with a higher number of regulatory-T-cells in newborns without affecting suppression
    (2023) Arroyo-Jousse, Viviana; Borzutzky, Arturo; Rosa Bono, Maria; Casanello, Paola
    BackgroundMaternal obesity (MO) is associated with a higher risk of immune-mediated diseases in the offspring and higher leptin levels in cord blood (CB). This study evaluates the number and function of lymphocyte subtypes in CB related to MO and its relationship with leptin concentration and leptin receptor expression. MethodsPregnant women with (n = 32) or without obesity (n = 41) were enrolled at delivery. Cord blood mononuclear cells were separated with Ficoll-Hypaque. B and CD4+, regulatory and effector T cells were quantified by Flow Cytometry. Cord blood leptin concentration was measured by ELISA, and the leptin receptor (sLepR) on Treg cells was determined by Flow Cytometry. ResultsMO was associated with higher numbers of CD4+, Treg and effector T cells in the CB of their offspring, without differences in the suppressive function of Tregs. Female offspring had a higher number of these cells and a higher cord leptin concentration. Tregs expressed higher levels of sLepR than effector T cells, without differences between groups. ConclusionsMO is associated with changes in the newborn's immune profile, more evident in female newborns with higher leptin concentrations. More studies are needed to identify the mechanisms by which the high levels of cord leptin in the newborn of women with obesity could affect the offspring's immune system.
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    Maternal obesity is associated with a sex-specific epigenetic programming in human neonatal monocytes
    (2020) Vega-Tapia, Fabian; Artigas, Rocio; Hernandez, Cherie; Uauy, Ricardo; Casanello, Paola; Krause, Bernardo J.; Castro-Rodriguez, Jose A.
    Aim: To determine changes in global DNA methylation in monocytes from neonates of women with obesity, as markers of an immune programming resulting from maternal obesity. Materials & methods: Cord blood monocytes were obtained from neonates born to women with obesity and normal weight, genome-wide differentially methylated CpGs were determined using an Infinium MethylationEPIC-BeadChip (850K). Results: No clustering of samples according to maternal BMI was observed, but sex-specific analysis revealed 71,728 differentially methylated CpGs in female neonates from women with obesity (p < 0.01). DAVID analysis showed increased methylation levels within genes involved in the innate immune response and inflammation. Conclusion: Maternal obesity induces, in a sex-specific manner, an epigenetic programming of monocytes that could contribute to disease later in life.
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    Nitric oxide reduces SLC29A1 promoter activity and adenosine transport involving transcription factor complex hCHOP-C/EBPα in human umbilical vein endothelial cells from gestational diabetes
    (2010) Farias, Marcelo; Puebla, Carlos; Westermeier, Francisco; Jo, Miguel J.; Pastor-Anglada, Marcal; Casanello, Paola; Sobrevia, Luis
    Reduced expression of human equilibrative nucleoside transporter 1 (hENT1) results from nitric oxide (NO)-dependent reduced SLC29A1 transcriptional activity in human umbilical vein endothelial cells (HUVECs) from gestational diabetes. As expression of the transcription factor C/EBP homologous protein 10 (hCHOP, which forms heterodimers with C/EBP alpha transcription factor) is activated by NO and induced in diabetes mellitus, we hypothesize that hCHOP plays a role in the gestational diabetes-reduced hENT1 expression in HUVECs.
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    Nitric oxide reduces adenosine transporter ENT1 gene (SLC29A1) promoter activity in human fetal endotheliurn from gestational diabetes
    (WILEY, 2006) Farias, Marcelo; Martin, Rody San; Puebla, Carlos; Pearson, Jeremy D.; Casado, Javier F.; Pastor Anglada, Marcal; Casanello, Paola; Sobrevia, Luis
    Human umbilical vein endothelial cells (HUVEC) from gestational diabetes exhibit reduced adenosine uptake and increased nitric oxide (NO) synthesis. Adenosine transport via human equilibrative nucleoside transporters 1 (hENT1) is reduced by NO by unknown mechanisms in HUVEC. We examined whether gestational diabetes-reduced adenosine transport results from lower hENT1 gene (SLC29A1) expression. HUVEC from gestational diabetes exhibit reduced SLC29A1 promoter activity when transfected with pGL3-hENT1(-2154) compared with pGL3-hENT1(-1114) constructs, an effect blocked by N-G-nitro-L-arginine methyl ester (L-NAME, NOS inhibitor), but unaltered by S-nitroso-N-acetyl-L,D-penicillamine (SNAP, NO donor). In cells from gestational diabetes transfected with pGL3-hENT1(-2114), L-NAME increased, but SNAP did not alter promoter activity and hENT1 expression. However, in cells from normal pregnancies L-NAME increased, but SNAP reduced promoter activity and hENT1 expression. Adenovirus-silenced eNOS expression increased hENT1 expression and activity in cells from normal or gestational diabetic pregnancies. Thus, reduced adenosine transport may result from downregulation of SLC29A1 expression by NO in HUVEC from gestational diabetes. These findings explain the accumulation of extracellular adenosine detected in cultures of HUVEC from gestational diabetes. In addition, fetal endothelial dysfunction could be involved in the abnormal fetal development and growth seen in gestational diabetes.