Role of heme oxygenase 1 and human chorionic gonadotropin in pregnancy associated diseases.

Heme oxygenase (HO) is the enzyme that catalyses heme breakdown to biliverdin, carbon monoxide, and ferrous ion. Biliverdin is rapidly converted to bilirubin by biliverdin reductase. HO-1, the inducible HO isoenzyme, is involved in placental development. HO-1 decreases the oxidative stress and promotes an immune tolerant microenvironment at the foetomaternal interface. This isozyme also regulates angiogenesis and vasculogenesis, and trophoblasts proliferation, migration and invasion, thus contributing to the adaptive changes in the uterine circulation to pregnancy. HO-1 expression is induced by several stimuli, including physical, chemical and biological agents. The reduced HO-1 expression and activity associated with adverse pregnancy outcomes in both humans and animal models. The human chorionic gonadotropin (hCG) is the first hormonal signal of pregnancy whose effects in pregnancy are mediated by HO-1. In this review, we summarise the current evidence showing the beneficial actions of HO-1 and hCG in early pregnancy. It is proposed that the biological effect of hCG in pregnancy is mediated by HO-1 upregulation. Noteworthy, humans quantitatively differ in their ability to up-regulate HO-1 due to the presence of an HMOX1 polymorphism in their proximal promoter region affecting its transcriptional activity. Consequently, a deficiency in HO-1 expression due to HMOX1 polymorphism may be considered as an underlying cause of human pregnancy disorders, particularly those related to placental dysfunction.

Insulin Induces Relaxation and Decreases Hydrogen Peroxide-Induced Vasoconstriction in Human Placental Vascular Bed in a Mechanism Mediated by Calcium-Activated Potassium Channels and L-Arginine/Nitric Oxide Pathways.

HIGHLIGHTS Short-term incubation with insulin increases the L-arginine transport in HUVECs.Short-term incubation with insulin increases the NO synthesis in HUVECs.Insulin induces relaxation in human placental vascular bed.Insulin attenuates the constriction induced by hydrogen peroxide in human placenta.The relaxation induced by insulin is dependent on BKCa channels activity in human placenta. Insulin induces relaxation in umbilical veins, increasing the expression of human amino acid transporter 1 (hCAT-1) and nitric oxide synthesis (NO) in human umbilical vein endothelial cells (HUVECs). Short-term effects of insulin on vasculature have been reported in healthy subjects and cell cultures; however, its mechanisms remain unknown. The aim of this study was to characterize the effect of acute incubation with insulin on the regulation of vascular tone of placental vasculature. HUVECs and chorionic vein rings were isolated from normal pregnancies. The effect of insulin on NO synthesis, L-arginine transport, and hCAT-1 abundance was measured in HUVECs. Isometric tension induced by U46619 (thromboxane A2 analog) or hydrogen peroxide (H2O2) were measured in vessels previously incubated 30 min with insulin and/or the following pharmacological inhibitors: tetraethylammonium (KCa channels), iberiotoxin (BKCa channels), genistein (tyrosine kinases), and wortmannin (phosphatidylinositol 3-kinase). Insulin increases L-arginine transport and NO synthesis in HUVECs. In the placenta, this hormone caused relaxation of the chorionic vein, and reduced perfusion pressure in placental cotyledons. In vessels pre-incubated with insulin, the constriction evoked by H2O2 and U46619 was attenuated and the effect on H2O2-induced constriction was blocked with tetraethylammonium and iberiotoxin, but not with genistein, or wortmannin. Insulin rapidly dilates the placental vasculature through a mechanism involving activity of BKCa channels and L-arginine/NO pathway in endothelial cells. This phenomenon is related to quick increases of hCAT-1 abundance and higher capacity of endothelial cells to take up L-arginine and generate NO.

Insulin reverses D-glucose-increased nitric oxide and reactive oxygen species generation in human umbilical vein endothelial cells.

Vascular tone is controlled by the L-arginine/nitric oxide (NO) pathway, and NO bioavailability is strongly affected by hyperglycaemia-induced oxidative stress. Insulin leads to high expression and activity of human cationic amino acid transporter 1 (hCAT-1), NO synthesis and vasodilation; thus, a protective role of insulin on high D-glucose-alterations in endothelial function is likely. Vascular reactivity to U46619 (thromboxane A2 mimetic) and calcitonin gene related peptide (CGRP) was measured in KCl preconstricted human umbilical vein rings (wire myography) incubated in normal (5 mmol/L) or high (25 mmol/L) D-glucose. hCAT-1, endothelial NO synthase (eNOS), 42 and 44 kDa mitogen-activated protein kinases (p42/44mapk), protein kinase B/Akt (Akt) expression and activity were determined by western blotting and qRT-PCR, tetrahydrobiopterin (BH4) level was determined by HPLC, and L-arginine transport (0-1000 µmol/L) was measured in response to 5-25 mmol/L D-glucose (0-36 hours) in passage 2 human umbilical vein endothelial cells (HUVECs). Assays were in the absence or presence of insulin and/or apocynin (nicotinamide adenine dinucleotide phosphate-oxidase [NADPH oxidase] inhibitor), tempol or Mn(III)TMPyP (SOD mimetics). High D-glucose increased hCAT-1 expression and activity, which was biphasic (peaks: 6 and 24 hours of incubation). High D-glucose-increased maximal transport velocity was blocked by insulin and correlated with lower hCAT-1 expression and SLC7A1 gene promoter activity. High D-glucose-increased transport parallels higher reactive oxygen species (ROS) and superoxide anion (O2•-) generation, and increased U46619-contraction and reduced CGRP-dilation of vein rings. Insulin and apocynin attenuate ROS and O2•- generation, and restored vascular reactivity to U46619 and CGRP. Insulin, but not apocynin or tempol reversed high D-glucose-increased NO synthesis; however, tempol and Mn(III)TMPyP reversed the high D-glucose-reduced BH4 level. Insulin and tempol blocked the high D-glucose-increased p42/44mapk phosphorylation. Vascular dysfunction caused by high D-glucose is likely attenuated by insulin through the L-arginine/NO and O2•-/NADPH oxidase pathways. These findings are of interest for better understanding vascular dysfunction in states of foetal insulin resistance and hyperglycaemia.

Frecuencia de trastornos respiratorios del sueño en pacientes con enfermedad difusa del parénquima pulmonar / Frecuency of sleep related disorders in patients with diffuse lung diseases

Introducción: Los pacientes con enfermedad pulmonar difusa (EPD) a menudo presentan fragmentación del sueño con microdespertares frecuentes. En este grupo de pacientes, la desaturación nocturna de oxígeno es frecuente con una prevalencia de 50- 80%. Se agrava en el sueño REM y se asocia con una menor calidad de vida, pudiendo contribuir al daño vascular a largo plazo. La presencia de apneas obstructivas del sueño (AOS) se presenta en el 20% de la población adulta general. Objetivos: Describir las características de los parámetros respiratorios clínicos y fisiológicos y la frecuencia de los trastornos respiratorios del sueño (TRS), especialmente de AOS, en pacientes con EPD. Materiales y métodos: Se incluyeron prospectivamente pacientes con diagnóstico establecido de EPD que consultaron en un hospital especializado en enfermedades respiratorias entre julio de 2010 y enero de 2012. Se les realizó polisomnografía (PSG) y estudio de función pulmonar (CVF y DLCO). Resultados: Se estudiaron 41 pacientes con edad promedio de 61.5 ± 12.6 años. El 54% eran hombres (n = 22). Los diagnósticos de EPD fueron neumonía intersticial usual (NIU) en el 70.7%, neumonía intersticial no específica (NINE) en el 14.6%, neumonitis por hipersensibilidad (NHS) en el 9.8% y proteinosis alveolar pulmonar (PAP) en el 4.8%. El índice de masa corporal (IMC) medio fue 29.4 ± 4.4 kg/m². En el 80% fue = 25 y en el 41% = 30. La CVF media fue de 2.18 ± 0.7 l y 64.8 ± 16.8 del porcentaje del predictivo. La DLCO ajustada a la Hb media fue de 10.3±3.6 ml/mmHg/min y 46.9 ± 14 del porcentaje del valor predictivo. Con respecto a la PSG, la SpO2 basal media fue de 93.9 ±3.4%, la saturación media durante el sueño fue 89.8 ±7% y en el 39% de los casos la SpO2 media era < 90%. En el 90% de los casos la SpO>2 mínima durante el sueño fue menor de 90%. El 34% de los casos presentaba CT 90 (tiempo con SpO2 < 90%) > 50%. De los 13 pacientes con SpO2 basal despierto > 95%, 3 presentaron un CT90 = 20% yv de los 27 pacientes con SpO2 basal > 92%, 10 cursaban con un CT90 = 20%.v Del total de los pacientes, el 48.8% presentaba AOS. El índice de apneas-hipoapneasv (IAH) medio fue 11.4 y el 20% de los pacientes presentó IAH = 15. Con respecto a la escala de somnolencia de Epworth (ESE), el 45% de los pacientes conv AOS presentaba una ESE = 10, que resultó significativamente mayor en comparación conv el grupo sin AOS. Del grupo de pacientes con IAH = 15, el 62.5% presentaban ESE < 10. Conclusiones: Un número importante de pacientes sin hipoxemia en reposo presentan desaturación durante el sueño. En este estudio, la frecuencia de AOS fue del 48.8%. Además, el grupo de pacientes con EPD con AOS presentó mayor compromiso oximétrico medido a través de CT90. Globalmente, el grupo de pacientes con AOS presentaba mayores valores de FVC (71.25% vs 58.67 p = 0.019).(AU)

Background: Patients with interstitial lung disease (ILD) often have sleep fragmentation with frequent arousals. In this group of patients, nocturnal oxygen desaturation is common, with a prevalence of 50-80%. It is worse in Rapid Eye Movement (REM) sleep, is associated with reduced quality of life and can contribute to long-term vascular damage. The presence of obstructive sleep apnea (OSA) occurs in 20% of the general adult population. Aims: To describe the characteristics of clinical and physiological respiratory parameters and frequency of respiratory sleep disorders (RSD), especially OSA, in patients with ILD. Materials and Methods: We prospectively included ILD patients who attended a specialized hospital between July 2010 and January 2012. Polysomnography (PSG) and study of pulmonary function: Forced Vital Capacity (FVC) and Diffusing Lung Capacity for Carbon Monoxide (DLCO) were performed. Results: We studied 41 patients with a mean age of 61.5 ± 12.6 years. 54% were male (n = 22). ILD diagnoses were usual interstitial pneumonia (UIP) in 70.7%, nonspecific interstitial pneumonia (NSIP) in 14.6%, hypersensitivity pneumonitis (HP) in 9.8% and pulmonary alveolar proteinosis (PAP) in 4.8%. The body mass index (BMI) was 29.4 ± 4.4 kg/m²; it was = 25 in 80% of patients and = 30 in 41%. The mean FVC was 2.18 ± 0.7 l and 64.8 ± 16.8 in the percentage of predictive value. The DLCO adjusted to Hb mean was 10.3 ± 3.6 ml/mmHg/min and 46.9 ± 14 in the percentage of predictive value. Regarding the PSG, the mean baseline SpO2 was 93.9 ± 3.4%, the mean saturation during sleep was 89.8 ± 7%, and the mean SpO2 was < 90% in 39% of cases. In 90% of cases the minimum SpO2 during sleep was less than 90%; 34% of patients had CT 90 (time with SpO2 < 90%) > 50%. In 13 patients with baseline SpO2 > 95%, 3 had CT90 = 20% and 10 of the 27 patients with basal SpO2 > 92%, had CT90 = 20%. Of all patients, 48.8% had OSA. The mean apnea-hypopnea index ...(AU)

Frecuencia de trastornos respiratorios del sueño en pacientes con enfermedad difusa del parénquima pulmonar / Frecuency of sleep related disorders in patients with diffuse lung diseases

Introducción: Los pacientes con enfermedad pulmonar difusa (EPD) a menudo presentan fragmentación del sueño con microdespertares frecuentes. En este grupo de pacientes, la desaturación nocturna de oxígeno es frecuente con una prevalencia de 50- 80%. Se agrava en el sueño REM y se asocia con una menor calidad de vida, pudiendo contribuir al daño vascular a largo plazo. La presencia de apneas obstructivas del sueño (AOS) se presenta en el 20% de la población adulta general. Objetivos: Describir las características de los parámetros respiratorios clínicos y fisiológicos y la frecuencia de los trastornos respiratorios del sueño (TRS), especialmente de AOS, en pacientes con EPD. Materiales y métodos: Se incluyeron prospectivamente pacientes con diagnóstico establecido de EPD que consultaron en un hospital especializado en enfermedades respiratorias entre julio de 2010 y enero de 2012. Se les realizó polisomnografía (PSG) y estudio de función pulmonar (CVF y DLCO). Resultados: Se estudiaron 41 pacientes con edad promedio de 61.5 ± 12.6 años. El 54% eran hombres (n = 22). Los diagnósticos de EPD fueron neumonía intersticial usual (NIU) en el 70.7%, neumonía intersticial no específica (NINE) en el 14.6%, neumonitis por hipersensibilidad (NHS) en el 9.8% y proteinosis alveolar pulmonar (PAP) en el 4.8%. El índice de masa corporal (IMC) medio fue 29.4 ± 4.4 kg/m². En el 80% fue = 25 y en el 41% = 30. La CVF media fue de 2.18 ± 0.7 l y 64.8 ± 16.8 del porcentaje del predictivo. La DLCO ajustada a la Hb media fue de 10.3±3.6 ml/mmHg/min y 46.9 ± 14 del porcentaje del valor predictivo. Con respecto a la PSG, la SpO2 basal media fue de 93.9 ±3.4%, la saturación media durante el sueño fue 89.8 ±7% y en el 39% de los casos la SpO2 media era < 90%. En el 90% de los casos la SpO>2 mínima durante el sueño fue menor de 90%. El 34% de los casos presentaba CT 90 (tiempo con SpO2 < 90%) > 50%. De los 13 pacientes con SpO2 basal despierto > 95%, 3 presentaron un CT90 = 20% yv de los 27 pacientes con SpO2 basal > 92%, 10 cursaban con un CT90 = 20%.v Del total de los pacientes, el 48.8% presentaba AOS. El índice de apneas-hipoapneasv (IAH) medio fue 11.4 y el 20% de los pacientes presentó IAH = 15. Con respecto a la escala de somnolencia de Epworth (ESE), el 45% de los pacientes conv AOS presentaba una ESE = 10, que resultó significativamente mayor en comparación conv el grupo sin AOS. Del grupo de pacientes con IAH = 15, el 62.5% presentaban ESE < 10. Conclusiones: Un número importante de pacientes sin hipoxemia en reposo presentan desaturación durante el sueño. En este estudio, la frecuencia de AOS fue del 48.8%. Además, el grupo de pacientes con EPD con AOS presentó mayor compromiso oximétrico medido a través de CT90. Globalmente, el grupo de pacientes con AOS presentaba mayores valores de FVC (71.25% vs 58.67 p = 0.019).

Background: Patients with interstitial lung disease (ILD) often have sleep fragmentation with frequent arousals. In this group of patients, nocturnal oxygen desaturation is common, with a prevalence of 50-80%. It is worse in Rapid Eye Movement (REM) sleep, is associated with reduced quality of life and can contribute to long-term vascular damage. The presence of obstructive sleep apnea (OSA) occurs in 20% of the general adult population. Aims: To describe the characteristics of clinical and physiological respiratory parameters and frequency of respiratory sleep disorders (RSD), especially OSA, in patients with ILD. Materials and Methods: We prospectively included ILD patients who attended a specialized hospital between July 2010 and January 2012. Polysomnography (PSG) and study of pulmonary function: Forced Vital Capacity (FVC) and Diffusing Lung Capacity for Carbon Monoxide (DLCO) were performed. Results: We studied 41 patients with a mean age of 61.5 ± 12.6 years. 54% were male (n = 22). ILD diagnoses were usual interstitial pneumonia (UIP) in 70.7%, nonspecific interstitial pneumonia (NSIP) in 14.6%, hypersensitivity pneumonitis (HP) in 9.8% and pulmonary alveolar proteinosis (PAP) in 4.8%. The body mass index (BMI) was 29.4 ± 4.4 kg/m²; it was = 25 in 80% of patients and = 30 in 41%. The mean FVC was 2.18 ± 0.7 l and 64.8 ± 16.8 in the percentage of predictive value. The DLCO adjusted to Hb mean was 10.3 ± 3.6 ml/mmHg/min and 46.9 ± 14 in the percentage of predictive value. Regarding the PSG, the mean baseline SpO2 was 93.9 ± 3.4%, the mean saturation during sleep was 89.8 ± 7%, and the mean SpO2 was < 90% in 39% of cases. In 90% of cases the minimum SpO2 during sleep was less than 90%; 34% of patients had CT 90 (time with SpO2 < 90%) > 50%. In 13 patients with baseline SpO2 > 95%, 3 had CT90 = 20% and 10 of the 27 patients with basal SpO2 > 92%, had CT90 = 20%. Of all patients, 48.8% had OSA. The mean apnea-hypopnea index ...

Fetal endothelium dysfunction is associated with circulating maternal levels of sE-selectin, sVCAM1, and sFlt-1 during pre-eclampsia.

OBJECTIVES: To evaluate the association between endothelial activation markers in the maternal circulation with nitric oxide (NO) synthesis in human umbilical endothelial cells. STUDY DESIGN: This is a case-control study of normal and pre-eclamptic pregnancies. The levels of sE-selectin, soluble vascular cell adhesion molecule 1 (sVCAM-1), and soluble fms-like tyrosine kinase 1 (sFlt-1) were measured by enzyme-linked immunosorbent assay, and histamine-induced NO synthesis was detected by fluorometric examination of the human umbilical vein endothelial cells (HUVECs) isolated from normal and pathological pregnancies. RESULTS: Mothers with severe pre-eclamptic pregnancies have premature and smaller babies than mothers with normal pregnancies (P < 0.05); they also have high maternal plasma levels of sVCAM-1 (∼2-fold), sFlt-1 (∼2.5-fold), and lower (∼70%) histamine-stimulated NO synthesis in HUVECs. A positive relationship between systolic blood pressure (SBP) and plasma levels of sE-selectin, sVCAM-1, and sFlt-1 was demonstrated. Moreover, levels of sE-selectin, sVCAM-1, and sFlt-1 were negatively associated with newborn weight (NBW), gestational age at delivery, and NO synthesis. Women with high E-selectin (>63 ng/ml), VCAM-1 (>752 ng/ml), and sFlt-1 (>15204 pg/ml) showed high risk (∼2-fold) for preterm delivery and very preterm delivery, or fetal weight <1500 g (∼1.5-fold) compared with women with low levels. CONCLUSIONS: High circulating levels of maternal endothelial dysfunction markers present in pre-eclampsia are associated with decreased NO synthesis in fetal endothelium.

Insulin-stimulated L-arginine transport requires SLC7A1 gene expression and is associated with human umbilical vein relaxation.

Insulin causes endothelium-derived nitric oxide (NO)-dependent vascular relaxation, and increases L-arginine transport via cationic amino acid transporter 1 (hCAT-1) and endothelial NO synthase (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-[(3) H]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 phosphorylated eNOS protein 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 (∼7.8-fold) by L-lysine in absence of insulin, but unaltered (~1.4-fold) in presence of insulin. Sp1 nuclear protein abundance and binding to DNA, and SLC7A1 promoter activity was increased by insulin. Insulin increased NO synthesis 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.

Hybrid catalytic-DBD plasma reactor for the production of hydrogen and preferential CO oxidation (CO-PROX) at reduced temperatures.

Dielectric Barrier Discharges (DBD) operated at atmospheric pressure and working at reduced temperatures (T < 115 degrees C) and a copper-manganese oxide catalyst are combined for the direct decomposition and the steam reforming of methanol (SRM) for hydrogen production and for the preferential oxidation of CO (CO-PROX).

Vitamin C is an essential antioxidant that enhances survival of oxidatively stressed human vascular endothelial cells in the presence of a vast molar excess of glutathione.

Cellular glutathione levels may exceed vitamin C levels by 10-fold, generating the question about the real antioxidant role that low intracellular concentrations of vitamin C can play in the presence of a vast molar excess of glutathione. We characterized the metabolism of vitamin C and its relationship with glutathione in primary cultures of human endothelial cells oxidatively challenged by treatment with hydrogen peroxide or with activated cells undergoing the respiratory burst, and analyzed the manner in which vitamin C interacts with glutathione to increase the antioxidant capacity of cells. Our data indicate that: (i) endothelial cells express transporters for reduced and oxidized vitamin C and accumulate ascorbic acid with participation of glutathione-dependent dehydroascorbic acid reductases, (ii) although increased intracellular levels of vitamin C or glutathione caused augmented resistance to oxidative stress, 10-times more glutathione than vitamin C was required, (iii) full antioxidant protection required the simultaneous presence of intracellular and extracellular vitamin C at concentrations normally found in vivo, and (iv) intracellular vitamin C cooperated in enhancing glutathione recovery after oxidative challenge thus providing cells with enhanced survival potential, while extracellular vitamin C was recycled through a mechanism involving the simultaneous neutralization of oxidant species. Therefore, in endothelial cells under oxidative challenge, vitamin C functions as an essential cellular antioxidant even in the presence of a vast molar excess of glutathione.

Equilibrative nucleoside transporter 1 expression is downregulated by hypoxia in human umbilical vein endothelium.

Reduced oxygen level (hypoxia) induces endothelial dysfunction and release of the endogenous nucleoside adenosine. Human umbilical vein endothelium (HUVEC) function in an environment with 3% to 5% O2 and exhibit efficient adenosine membrane transport via human equilibrative nucleoside transporters 1 (hENT1). We studied whether adenosine transport and hENT1 expression are altered by hypoxia in HUVEC. Hypoxia (0 to 24 hours, 2% and 1% O2) reduced maximal hENT1-adenosine transport velocity (V(max)) and maximal nitrobenzylthionosine (NBMPR, a high-affinity hENT1 protein ligand) binding, but increased extracellular adenosine concentration. Hypoxia also reduced hENT1 protein and mRNA levels, effects unaltered by N(omega)-nitro-l-arginine methyl ester (l-NAME, nitric oxide synthase [NOS] inhibitor) or PD-98059 (inhibitor of mitogen-activated protein kinase kinase 1 and 2 [MEK1/2]). Hypoxia reduced endothelial NOS (eNOS) activity and eNOS phosphorylation at Ser(1177), but increased eNOS protein level. Hypoxia increased (1 to 3 hours), but reduced (24 hours) p42/44(mapk) phosphorylation. Thus, hypoxia-increased extracellular adenosine may result from reduced hENT1-adenosine transport in HUVEC. Hypoxia effect seems not to involve NO, but p42/44(mapk) may be required for the relatively rapid effect (1 to 3 hours) of hypoxia. These results could be important in diseases where the fetus is exposed to intrauterine environments poor in oxygen, such as intrauterine growth restriction, or where adenosine transport is altered, such as gestational diabetes.