Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 147
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Br J Nutr ; 122(s1): S59-S67, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-28587705

RESUMO

Cultural background is an important variable influencing neuropsychological performance. Multinational projects usually involve gathering data from participants from different countries and/or different cultures. Little is known about the influence of culture on neuropsychological testing results in children and especially in European children. The objectives of this study were to compare neuropsychological performance of children from six European countries (Belgium, Germany, Italy, The Netherlands, Poland and Spain) using a comprehensive neuropsychological battery and to apply a statistical procedure to reduce the influence of country/cultural differences in neuropsychological performance. As expected, the results demonstrated differences in neuropsychological performance among children of the six countries involved. Cultural differences remained after adjusting for other confounders related to neuropsychological execution, such as sex, type of delivery, maternal age, gestational age and maternal educational level. Differences between countries disappeared and influence of culture was considerably reduced when standardised scores by country and sex were used. These results highlight the need for developing specific procedures to compare neuropsychological performance among children from different cultures to be used in multicentre studies.


Assuntos
Cultura , Testes Neuropsicológicos/estatística & dados numéricos , Bélgica , Criança , Fenômenos Fisiológicos da Nutrição Infantil , Bases de Dados Factuais , Feminino , Alemanha , Humanos , Itália , Masculino , Processos Mentais/fisiologia , Países Baixos , Polônia , Espanha
2.
Ann Nutr Metab ; 70(3): 161-169, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28683464

RESUMO

The Power of Programming conference 2016 at Ludwig-Maximilians-Universität Munich brought together about 600 researchers and other stakeholders from around the world who reviewed the recent evidence on the lasting health impact of environment and nutrition during early life, from pre-pregnancy to early childhood. The conference was hosted by the Early Nutrition Project, a multidisciplinary research collaboration funded by the European Commission with collaborating researchers from 35 institutions in 15 countries in Europe, the United States and Australia. The project explores the early origins of obesity, adiposity and associated non-communicable diseases, underlying mechanisms and opportunities for prevention. The project also proactively supports translational application of research findings. In fact, some existing evidence has already been rapidly adopted into policy, regulatory standards and practice. Further, broad dissemination of findings is achieved through the established digital eLearning platform of the Early Nutrition eAcademy, video clip-based learning and graphically supported messaging to consumers. The project demonstrated powerful effects of early metabolic programming on later health. Compared to other common prevention strategies, modifying risk trajectories in early life can achieve a much larger risk reduction and be more cost-effective. While some effective prevention strategies have been promptly implemented in policy and guidelines, legislation and practice, in other areas, the uptake is limited by a paucity of quality human intervention trials and insufficient evaluation of the feasibility of implementation and econometric impact. This needs to be strengthened by future collaborative research work.


Assuntos
Fenômenos Fisiológicos da Nutrição do Lactente , Fenômenos Fisiológicos da Nutrição Materna , Obesidade/prevenção & controle , Efeitos Tardios da Exposição Pré-Natal/prevenção & controle , Pesquisa Translacional Biomédica/normas , Austrália , Pré-Escolar , Meio Ambiente , Europa (Continente) , Feminino , Política de Saúde , Humanos , Lactente , Recém-Nascido , Cooperação Internacional , Masculino , Obesidade/etiologia , Gravidez , Efeitos Tardios da Exposição Pré-Natal/etiologia , Estados Unidos
3.
BMC Public Health ; 17(1): 595, 2017 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-28645324

RESUMO

BACKGROUND: Physical activity (PA) and its health benefits are a continuous point of discussion. Recommendations for children's daily PA vary between guidelines. To better define the amount of PA necessary to prevent overweight and obesity in children, further research is needed. The present study investigates children's compliance to physical activity guidelines (PAGs) and the association between objectively measured PA and body mass index (BMI). METHODS: Participating children were 11 years old (n = 419) and part of the European CHOP trial, which was conducted in Germany, Belgium, Poland, Spain, Italy. At least 2 days of PA measurements were collected from each child using a SenseWear™ armband. BMI was calculated from children's height and weight. Thresholds of min·day-1 in PA needed to differentiate between normal and excess weight (overweight/obesity) were determined with Receiver Operator Characteristics (ROC) analysis. Additionally, adjusted linear and logistic regressions models were calculated for group differences and effects of a 5, 15 and 60 min·day-1 increases in PA on BMI. RESULTS: Median time spent in total PA was 462 min·day-1 (25th percentile; 75th percentile: 389; 534) and 75 min·day-1 (41; 115) in moderate to vigorous PA (MVPA). Girls spent 36 min·day-1 less in MVPA than boys and overweight/obese children 24 min·day-1 less than normal weight children (linear regression, p < 0.001). 63.2% of the children met PAGs of 60 min·day-1 in MVPA. The optimal threshold for min·day-1 in MVPA determined with ROC analysis was 46 min·day-1. Comparing 5, 15 and 60 min·day-1 increases in PA revealed that an additional 15 min·day-1 of vigorous PA had the same effect as 60 min·day-1 of MVPA. Sedentary time and light PA showed contrary associations to one another, with light PA being negatively and sedentary time being positively associated with excessive weight. CONCLUSIONS: Current PAGs are met by 2/3 of children and seem appropriate to prevent excess weight in children. An official recommendation of daily 15-20 min of vigorous PA and further reduction of sedentary time could help to fight youth overweight and thus be of potential public health importance. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT00338689 . Registered: June 19, 2006 (retrospectively registered).


Assuntos
Índice de Massa Corporal , Comportamento Infantil , Exercício Físico , Obesidade Infantil , Esforço Físico , Bélgica , Peso Corporal , Criança , Feminino , Alemanha , Humanos , Itália , Modelos Logísticos , Masculino , Sobrepeso/etiologia , Sobrepeso/prevenção & controle , Obesidade Infantil/etiologia , Obesidade Infantil/prevenção & controle , Polônia , Curva ROC , Comportamento Sedentário , Fatores Sexuais , Espanha
4.
Pflege Z ; 75(11): 16-17, 2022.
Artigo em Alemão | MEDLINE | ID: mdl-36267105
5.
Ann Nutr Metab ; 66(1): 51-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25572773

RESUMO

BACKGROUND: Nutrition in childhood has an influence on the cardiovascular function later on in life. European Childhood Obesity Project is a multicenter, randomized clinical intervention trial examining the effect of early protein intake on later health outcomes, particularly adiposity and related disorders. The aim of the study was to examine the effect of nutritional intervention--different protein intake in infancy on carotid intima-media thickness (cIMT) at 5 years. The association of cardiovascular risk factors with cIMT was also assessed. METHODS: Healthy term formula-fed infants in five European countries were enrolled either to the higher (HP) or to the lower (LP) protein group. Observational group consisted of breastfed infants. Plasma insulin, glucose, lipid profile, IGF-1, apolipoprotein A1 and B were measured as well as anthropometric parameters of parents and a child, blood pressure and physical activity. RESULTS: No difference in cIMT between HP and LP group was observed. Insulin, HOMA-IR index and total IGF-1 were positively associated with cIMT but after adjustment for confounders only an inverse association between ApoA1 and positive between ApoB/ApoA1 and cIMT were significant. CONCLUSION: High versus low protein intake in infancy does not influence cIMT at 5 years. cIMT in healthy children at 5 years is associated with their apolipoprotein profile.


Assuntos
Aleitamento Materno , Espessura Intima-Media Carotídea , Proteínas Alimentares/administração & dosagem , Fórmulas Infantis/administração & dosagem , Fenômenos Fisiológicos da Nutrição do Lactente , Apolipoproteína A-I/sangue , Apolipoproteína B-100/sangue , Glicemia , Pressão Sanguínea , Índice de Massa Corporal , Doenças Cardiovasculares/patologia , Doenças Cardiovasculares/prevenção & controle , Espessura Intima-Media Carotídea/estatística & dados numéricos , Pré-Escolar , Europa (Continente) , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Insulina/sangue , Fator de Crescimento Insulin-Like I/análise , Lipídeos/sangue , Masculino , Atividade Motora , Fatores de Risco
6.
Physiol Genomics ; 46(22): 833-40, 2014 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-25315114

RESUMO

MicroRNAs (miRNAs) encapsulated within microparticles (MPs) are likely to have a role in cell-to-cell signaling in a variety of diseases, including atherosclerosis. However, little is known about the mechanisms by which different cell types release and transfer miRNAs. Here, we examined TNF-α-induced release of MP-encapsulated miR-126, miR-21, and miR-155 from human aortic endothelial cells (ECs) and their transfer to recipient cells. ECs were treated with TNF-α (100 ng/ml) in the presence or absence of inhibitors that target different MP production pathways. MPs released in response to TNF-α were characterized by: 1) 70-80% decrease in miRNA/MP levels for miR-126 and -21 but a significant increase in pre-miR-155 and miR-155 (P < 0.05), 2) 50% reduction in uptake by recipient cells (P < 0.05), and 3) diminished ability to transfer miRNA to recipient cells. Cotreatment of donor ECs with TNF-α and caspase inhibitor (Q-VD-OPH, 10 µM) produced MPs that had: 1) 1.5- to 2-fold increase in miRNA/MP loading, 2) enhanced uptake by recipient cells (2-fold), and 3) increased ability to transfer miR-155. Cotreatment of ECs with TNF-α and Rho-associated kinase (ROCK) inhibitor (10 µM) produced MPs with features similar to those produced by TNF-α treatment alone. Our data indicate that TNF-α induced the production of distinct MP populations: ROCK-dependent, miRNA-rich MPs that effectively transferred their cargo and were antiapoptotic, and caspase-dependent, miRNA-poor MPs that were proapoptotic. These data provide insight into the relationship between MP production and extracellular release of miRNA, as well as the potential of encapsulated miRNA for cell-to-cell communication.


Assuntos
Micropartículas Derivadas de Células/metabolismo , Células Endoteliais/metabolismo , MicroRNAs/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Aorta/citologia , Inibidores de Caspase/farmacologia , Caspases/metabolismo , Micropartículas Derivadas de Células/efeitos dos fármacos , Micropartículas Derivadas de Células/enzimologia , Células Endoteliais/efeitos dos fármacos , Células Endoteliais/enzimologia , Humanos , MicroRNAs/genética , Fenótipo , Quinases Associadas a rho/antagonistas & inibidores , Quinases Associadas a rho/metabolismo
7.
Am J Physiol Heart Circ Physiol ; 306(8): H1192-203, 2014 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-24486510

RESUMO

Previously, we identified a microRNA (miRNA) signature for endothelial cells (ECs) subjected to unidirectional shear stress (USS). MiR-155, a multifunctional miRNA that has been implicated in atherosclerosis, was among the shear stress-responsive miRNAs. Here, we examined the role of miR-155 in modulating EC phenotype and function. In vitro, increased miR-155 levels in human ECs induced changes in morphology and filamentous (F)-actin organization. In addition, ECs transfected with miR-155 mimic were less migratory and less proliferative and had less apoptosis compared with control ECs. In mouse aorta, miR-155 expression was increased in the intima of thoracic aorta, where blood flow produces steady and unidirectional shear stress, compared with the intima of the lower curvature of the aortic arch, which is associated with oscillatory and low shear stress. These differences in miR-155 expression were associated with distinct changes in EC morphology and F-actin. The effects of miR-155 in vitro were mediated through suppression of two key regulators of the EC cytoskeleton organization: RhoA and myosin light chain kinase (MYLK). A novel direct interaction between miR-155 and the MYLK 3'UTR was verified by luciferase-MYLK 3'UTR reporter assays. Furthermore, the intensity of immunofluorescence staining for RhoA and MYLK in mouse aorta correlated inversely with miR-155 expression. In conclusion, a prominent effect of the multifunctional miR-155 in ECs is modulation of phenotype through alterations in RhoA, MYLK expression, and actin cytoskeleton organization.


Assuntos
Citoesqueleto de Actina/ultraestrutura , Células Endoteliais/enzimologia , Células Endoteliais/ultraestrutura , MicroRNAs/fisiologia , Quinase de Cadeia Leve de Miosina/metabolismo , Animais , Aorta/química , Aorta/metabolismo , Aterosclerose , Imunofluorescência , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/genética , Quinase de Cadeia Leve de Miosina/análise , Fenótipo , Transfecção , Proteína rhoA de Ligação ao GTP/análise
8.
Ann Nutr Metab ; 65(2-3): 101-9, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25413647

RESUMO

Growth and development are central characteristics of childhood. Deviations from normal growth can indicate serious health challenges. The adverse impact of early growth faltering and malnutrition on later health has long been known. In contrast, the impact of rapid early weight and body fat gain on programming of later disease risk have only recently received increased attention. Numerous observational studies related diet in early childhood and rapid early growth to the risk of later obesity and associated disorders. Causality was confirmed in a large, double-blind randomised trial testing the 'Early Protein Hypothesis'. In this trial we found that attenuation of protein supply in infancy normalized early growth and markedly reduced obesity prevalence in early school age. These results indicate the need to describe and analyse growth patterns and their regulation through diet in more detail and to characterize the underlying metabolic and epigenetic mechanisms, given the potential major relevance for public health and policy. Better understanding of growth patterns and their regulation could have major benefits for the promotion of public health, consumer-orientated nutrition recommendations, and the development of improved food products for specific target populations.


Assuntos
Fenômenos Fisiológicos da Nutrição do Lactente , Obesidade/epidemiologia , Obesidade/prevenção & controle , Peso Corporal , Aleitamento Materno , Dieta , Proteínas Alimentares/administração & dosagem , Epigênese Genética , Humanos , Lactente , Fórmulas Infantis/química , Estado Nutricional , Prevalência , Saúde Pública , Ensaios Clínicos Controlados Aleatórios como Assunto , Fatores de Risco
9.
Ann Nutr Metab ; 64(3-4): 187-96, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25300259

RESUMO

At The Power of Programming 2014 Conference, researchers from multiple disciplines presented and discussed the effects of early nutrition and other environmental cues during the first thousand days of life and beyond on the lifelong risk of noncommunicable diseases. This paper aims to summarize the concepts and some of the first achievements of the EarlyNutrition research project that initiated the conference. The EarlyNutrition consortium is a multinational, multidisciplinary research collaboration of researchers from Europe, the USA, and Australia. A focus is placed on exploration of the developmental origins of obesity, adiposity, and related health outcomes. Here we report on the first findings of experimental approaches, cohort studies, randomized clinical trials, and systematic reviews of current information, as well as position papers, which have all been developed with the involvement of project partners. We conclude that the EarlyNutrition project has successfully established itself during the first 2 project years as a very strong platform for collaborative research on early programming effects. The first results, available already at this early stage of the project, point to great opportunities for health prevention strategies via the implementation of dietary and lifestyle modifications, with large effect sizes. Further results are expected which should support improved recommendations and related policies for optimized nutrition and lifestyle choices before and during pregnancy, in infancy, and in early childhood.


Assuntos
Desenvolvimento Infantil , Desenvolvimento Fetal , Promoção da Saúde , Fenômenos Fisiológicos da Nutrição do Lactente , Fenômenos Fisiológicos da Nutrição Materna , Política Nutricional , Obesidade/prevenção & controle , Adiposidade , Austrália/epidemiologia , Congressos como Assunto , Dieta/efeitos adversos , Europa (Continente)/epidemiologia , Feminino , Humanos , Lactente , Recém-Nascido , Estilo de Vida , Masculino , Obesidade/epidemiologia , Obesidade/etiologia , Gravidez , Fatores de Risco , Estados Unidos/epidemiologia
10.
Ann Nutr Metab ; 64(3-4): 294-303, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25300273

RESUMO

BACKGROUND: Despite the growing interest in the early-origins-of-later-disease hypothesis, little is known about the metabolic underpinnings linking infant weight gain and childhood obesity. OBJECTIVE: To discover biomarkers reflective of weight change in the first 6 months and overweight/obesity at age 6 years via a targeted metabolomics approach. DESIGN: This analysis comprised 726 infants from a European multicenter randomized trial (Childhood Obesity Programme, CHOP) for whom plasma blood samples at age 6 months and anthropometric data up to the age of 6 years were available. 'Rapid growth' was defined as a positive difference in weight within the first 6 months of life standardized to WHO growth standards. Weight change was regressed on each of 168 metabolites (acylcarnitines, lysophosphatidylcholines, sphingomyelins, and amino acids). Metabolites significant after Bonferroni's correction were tested as predictors of later overweight/obesity. RESULTS: Among the overall 19 significant metabolites, 4 were associated with rapid growth and 15 were associated with a less-than-ideal weight change. After adjusting for feeding group, only the lysophosphatidylcholine LPCaC14:0 remained significantly associated with rapid weight gain (ß = 0.18). Only LPCaC14:0 at age 6 months was predictive of overweight/obesity at age 6 years (OR 1.33; 95% CI 1.04-1.69). CONCLUSION: LPCa14:0 is strongly related to rapid growth in infancy and childhood overweight/obesity. This suggests that LPCaC14:0 levels may represent a metabolically programmed effect of infant weight gain on the later obesity risk. However, these results require confirmation by independent cohorts.


Assuntos
Desenvolvimento Infantil , Fenômenos Fisiológicos da Nutrição Infantil , Dieta/efeitos adversos , Fenômenos Fisiológicos da Nutrição do Lactente , Lisofosfatidilcolinas/sangue , Obesidade/etiologia , Sobrepeso/etiologia , Biomarcadores/sangue , Índice de Massa Corporal , Criança , Estudos de Coortes , Diagnóstico Precoce , Europa (Continente)/epidemiologia , Feminino , Humanos , Lactente , Masculino , Obesidade/sangue , Obesidade/diagnóstico , Obesidade/epidemiologia , Sobrepeso/sangue , Sobrepeso/diagnóstico , Sobrepeso/epidemiologia , Valor Preditivo dos Testes , Fatores de Risco , Aumento de Peso
11.
Plants (Basel) ; 13(8)2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38674523

RESUMO

Orchidaceae display enormous diversity in their flower morphology, which is particularly evident in their pollen dispersal units (pollinia, pollinaria). The packaging of pollen by elastoviscin leads to a great diversity of these morphologically and structurally complex pollen units. Despite being one of the most diverse angiosperm families, the available palynological data on orchids remain limited and sometimes contradicting. This study provides new insights into the pollen morphology and ultrastructure of five orchid species from the subfamily Epidendroideae, using combined light, scanning electron, and transmission electron microscopy. The aim was to compare the morphology and ultrastructure of pollen dispersal units and to elucidate the chemical nature of the pollen wall layers and of elastoviscin. Our combined light and electron microscopy investigation demonstrated the presence of six tetrad types even within a single pollinium, which is unique for orchids. The application of different staining methods confirmed the assumed lipidic nature of elastoviscin and the differences in its contrast and ultrastructure suggest a mixture of sticky materials with dissimilar chemical compositions. This study affirmed that sporopollenin is mostly restricted to the outer pollen grains of peripheral tetrads in compact and sectile pollinia, while inner tetrads exhibit highly reduced non-sporopollenin pollen walls.

12.
FASEB J ; 26(6): 2424-36, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22415311

RESUMO

Community-acquired pneumonia presents a spectrum of clinical phenotypes, from lobar pneumonia to septic shock, while mechanisms underlying progression are incompletely understood. In a transcriptomic and metabolomic study across tissues, we examined serotype-specific regulation of signaling and metabolic pathways in C57BL/6 mice intratracheally instilled with either serotype 19F Streptococcus pneumoniae (S19; causing lobar pneumonia), or serotype 2 S. pneumoniae (S2; causing septic pneumococcal disease,) or vehicle (Todd-Hewitt broth). Samples of lung, liver, and blood were collected at 6 and 24 h postinfection and subjected to microarray analysis and mass spectrometry. Results comprise a preferential induction of cholesterol biosynthesis in lobar pneumonia at low-infection doses (10(5) colony forming units/mouse) leading to increased plasma cholesterol (vehicle: 1.8±0.12 mM, S2: 2.3±0.10 mM, S19: 2.9±0.15 mM; P<0.05, comparing S19 to vehicle and S2). This induction was pneumolysin dependent, as a pneumolysin-deficient strain of serotype 19F failed to induce cholesterol biosynthesis (S19ΔPLY: 1.9±0.03 mM). Preincubation of pneumolysin with purified cholesterol or plasma from hypercholesterolemic mice prior to intratracheal instillation protected against lung barrier dysfunction and alveolar macrophage necrosis. Cholesterol may attenuate disease severity by neutralizing pneumolysin in the alveolar compartment and thus prevent septic disease progression.


Assuntos
Colesterol/biossíntese , Fígado/metabolismo , Pneumonia Pneumocócica/fisiopatologia , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/farmacologia , Colesterol/farmacologia , Feminino , Macrófagos Alveolares/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Análise Serial de Proteínas , Estreptolisinas/genética , Estreptolisinas/farmacologia
13.
Taxon ; 62(4): 701-712, 2013 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-25821249

RESUMO

Almost all systematic treatments agree that Calla is a puzzling case, being a highly autapomorphic taxon with obscure relationships. In molecular-based classifications the variable placements of Calla within Aroideae conflict strongly with those in morphologically and anatomically based systematic classifications, which treat the genus as a subfamily (Calloideae) of its own. We studied the pollen morphology and ultrastructure of Calla by light and electron microscopy, and mapped the relevant pollen characters as well as some flower characters to the proposed placements of Calla within the Araceae as indicated in the various molecular phylogenies. Calla pollen is extraordinary within the entire Araceae. Pollen grains are small, and basically disulcate or with a ring-like aperture. The ornamentation is psilate to perforate, and the pollen wall consists of a sporopolleninous tectate-columellate exine. These pollen characters are shared with those of several earlier-diverging aroid taxa, especially with those of subfamily Zamioculcadoideae, whereas pollen characters in members of subfamily Aroideae deviate significantly. These findings are in accordance with other floral characters. Therefore, we propose that Calla is best placed in a transition zone between either subfamily Zamioculcadoideae (Stylochaeton clade) and subfamily Aroideae (Aroideae clade) or between subfamily Zamioculcadoideae (Stylochaeton clade) and subfamily Lasioideae.

14.
Anal Chem ; 84(3): 1483-90, 2012 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-22224852

RESUMO

Despite their central importance for lipid metabolism, straightforward quantitative methods for determination of nonesterified fatty acid (NEFA) species are still missing. The protocol presented here provides unbiased quantitation of plasma NEFA species by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Simple deproteination of plasma in organic solvent solution yields high accuracy, including both the unbound and initially protein-bound fractions, while avoiding interferences from hydrolysis of esterified fatty acids from other lipid classes. Sample preparation is fast and nonexpensive, hence well suited for automation and high-throughput applications. Separation of isotopologic NEFA is achieved using ultrahigh-performance liquid chromatography (UPLC) coupled to triple quadrupole LC-MS/MS detection. In combination with automated liquid handling, total assay time per sample is less than 15 min. The analytical spectrum extends beyond readily available NEFA standard compounds by a regression model predicting all the relevant analytical parameters (retention time, ion path settings, and response factor) of NEFA species based on chain length and number of double bonds. Detection of 50 NEFA species and accurate quantification of 36 NEFA species in human plasma is described, the highest numbers ever reported for a LC-MS application. Accuracy and precision are within widely accepted limits. The use of qualifier ions supports unequivocal analyte verification.


Assuntos
Cromatografia Líquida de Alta Pressão , Ácidos Graxos não Esterificados/análise , Espectrometria de Massas em Tandem , Ácidos Graxos não Esterificados/sangue , Humanos , Água/química
19.
Basic Res Cardiol ; 106(4): 539-49, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21298436

RESUMO

In isolated cells, soluble guanylyl cyclase (sGC) activity is regulated by exogenous nitric oxide (NO) via downregulation of expression and posttranslational S-nitrosylation. The aim of this study was to investigate whether such regulatory mechanism impact on endothelium-dependent vasodilation in a newly developed mouse strain carrying an endothelial-specific overexpression of eNOS (eNOS(++)). When compared with transgene negative controls (eNOS(n)), eNOS(++)-mice showed a 3.3-fold higher endothelial-specific aortic eNOS expression, increased vascular cGMP and VASP phosphorylation, a L-nitroarginine (L-NA)-inhibitable decrease in systolic blood pressure, but normal levels of peroxynitrite and nitrotyrosine formation, endothelium-dependent aortic vasodilation and vasodilation to NO donors. Western blot analysis for sGC showed similar protein levels of sGC-α1 and sGC-ß1 subunits in eNOS(n) and eNOS(++). In striking contrast, the activity of isolated sGC was strongly decreased in lungs of eNOS(++). Semiquantitative evaluation of sGC-ß1-S-nitrosylation demonstrated that this loss of sGC activity is associated with increased nitrosylation of the enzyme in eNOS(++), a difference that disappeared after L-NA-treatment. Our data suggest the existence of a physiologic NO-dependent posttranslational regulation of vascular sGC in mammals involving S-nitrosylation as a key mechanism. Because this mechanism can compensate for reduction in vascular NO bioavailability, it may mask the development of endothelial dysfunction.


Assuntos
Aorta/enzimologia , Guanilato Ciclase/metabolismo , Óxido Nítrico Sintase Tipo III/fisiologia , Processamento de Proteína Pós-Traducional , Animais , Moléculas de Adesão Celular/metabolismo , GMP Cíclico/fisiologia , Hidrazinas/farmacologia , Pulmão/enzimologia , Camundongos , Camundongos Endogâmicos C57BL , Proteínas dos Microfilamentos/metabolismo , Óxido Nítrico/fisiologia , Fosfoproteínas/metabolismo
20.
Arterioscler Thromb Vasc Biol ; 30(3): 561-7, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20167666

RESUMO

OBJECTIVE: In endothelial cells exposed to unidirectional laminar shear stress, endothelial nitric oxide synthase transcription (eNOS), mRNA stability, and protein levels are enhanced. We have previously demonstrated that these changes are associated with increased 3' polyadenylation of eNOS mRNA. Here, we investigated the effect of laminar shear stress on the phosphorylation and localization of RNA polymerase (Pol) II, the enzyme primarily responsible for coordinating transcription and posttranscriptional processing. METHODS AND RESULTS: Using Western and chromatin immunoprecipitation analyses, Pol II phosphorylation and localization on the eNOS gene were assessed in bovine aortic endothelial cells exposed to laminar shear stress. Total Pol II (phosphorylated and unphosphorylated) levels were increased 65% in response to laminar shear stress. This was associated with an increase in Pol II phosphoserine 2, but no change in levels of the unphosphorylated or phosphoserine 5 isoforms. Quantitative chromatin immunoprecipitation analysis showed that laminar shear stress enhanced binding of Pol II phosphoserine 2 to the 3' end of the eNOS gene, particularly exon 26, which encodes the 3'UTR. Treatment of cells with DRB attenuated laminar shear stress-induced Pol II phosphorylation, eNOS 3' polyadenylation, and eNOS expression. CONCLUSIONS: These data suggest that laminar shear stress enhances eNOS mRNA 3' polyadenylation by modulating phosphorylation and localization of Pol II.


Assuntos
Endotélio Vascular/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , RNA Polimerase II/metabolismo , Estresse Mecânico , Animais , Aorta/citologia , Aorta/efeitos dos fármacos , Aorta/metabolismo , Bovinos , Células Cultivadas , Citocalasina D/farmacologia , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Técnicas In Vitro , Mecanotransdução Celular , Modelos Animais , Inibidores da Síntese de Ácido Nucleico/farmacologia , Fosforilação , Fosfosserina/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA