Arylesterase activity is associated with antioxidant intake and paraoxonase-1 (PON1) gene methylation in metabolic syndrome patients following an energy restricted diet

The arylesterase (ARE) activity linked to the paraoxonase-1 (PON1) gene is known to protect lipoproteins from oxidation and provide defense against metabolic syndrome (MetS) and cardiovascular diseases. The epigenetic regulation of enzymatic activities is gaining importance nowadays. This research aimed to assess the potential relationships between the ARE activity with the methylation levels of the PON1 gene transcriptional regulatory region, anthropometrics, biochemical markers and antioxidant dietary components. Forty-seven subjects (47 ± 10 y.o; BMI 36.2 ± 3.8 kg/m² 46.8 % female) with MetS features, who followed a six-month energy-restricted dietary weight-loss intervention, were included in this study (www.clinicaltrials.gov; NCT01087086). Anthropometric, biochemical, enzymatic and dietary data were assessed using validated procedures. PON1 transcriptional regulatory region methylation was analyzed by a microarray technical approach. Volunteers reduced ARE activity in parallel with body weight (p = 0.005), BMI (p = 0.006), total fat mass (p = 0.020), diastolic blood pressure (p = 0.018), mean blood pressure (p = 0.022) and triglycerides (p = 0.014). Methylation levels of some CpG sites of the PON1 gene correlated negatively with ARE activity (p < 0.05). Interestingly, dietary vitamin C (p = 0.001), tocopherols (p = 0.009) and lycopene (p = 0.038) were positively associated with ARE activity and showed an inverse correlation (p = 0.004, p = 0.029 and p = 0.021, respectively) with the methylation of some selected CpG sites of the PON1 gene. In conclusion, ARE activity decreased in parallel with MetS-related markers associated to the energy restriction, while dietary antioxidants might enhance the ARE activity by lowering the PON1 gene methylation in patients with MetS features

The nutrigenetic influence of the interaction between dietary vitamin E and TXN and COMT gene polymorphisms on waist circumference: a case control study

Journal Article; Research Support, Non-U.S. Gov't;BACKGROUND Abdominal obesity (AO) is a common modifiable risk factor for certain non-communicable diseases associated with enhanced oxidative stress (OS). The objective of this work was to investigate whether the interaction between antioxidant vitamin intake and OS-related polymorphisms modulates gene-associated anthropometry in a Spanish population. METHODS A total of 246 subjects with AO, and 492 age and gender matched non-AO subjects were included in the study. Anthropometric, biochemical, and OS parameters, and antioxidant dietary intake data were assessed using validated procedures. DNA from white blood cells was isolated and the genotype of seven polymorphisms from genes involved in OS (pro-oxidant and antioxidant) were analyzed using the SNPlex system. The effects of the c.-793T > C polymorphism on promoter activity and thus thioredoxin (TXN) activity were examined using reporter assays. RESULTS The AO group had higher 8-Oxo-2'-deoxyguanosine levels and took in less vitamin A and vitamin E compared to the non-AO group. Logistic regression analysis revealed that the rs2301241 polymorphism in TXN and rs740603 in catechol-O-methyltransferase (COMT) were associated with waist circumference (WC) and AO. Moreover, these polymorphisms were more strongly associated with variations in WC in subjects with low vitamin E intakes. A promoter assay revealed that the T to C conversion at c.-793 (rs2301241) induced a more than two fold increase in reporter gene expression. CONCLUSIONS WC is associated both with dietary vitamin E intake and genetic variants of TXN and COMT suggesting that existence of a complex nutrigenetic pathway that involves regulation of AO.This work was co-funded with European Funds for Regional Development (FEDER), the Spanish Science and Technology Ministry [SAF2005-02883]; the health research fund from the Carlos III Health Institute [PI070497], CIBER Fisiopatología Obesidad y Nutrición (CIBERobn) [CB06/03], and CIBER de Diabetes y Enfermedades Metabólicas Relacionadas (CIBERDEM). CIBEROB and CIBERDEM are initiatives by the Carlos III Health Institute in Madrid and the Spanish Health Ministry. Funding also came from GRUPOS 03/101, PROMETEO/2009/029 and 2005/027, AMP07/075, and ACOMP/2009/201 from the Valencian Government and European Network of Excellence InGenious HyperCare (EPSS-037093) from the European Commission.Ye

Ghrelin attenuates hepatocellular injury and liver fibrogenesis in rodents and influences fibrosis progression in humans

El pdf del artículo es la versión pre-print.-- et al-There are no effective antifibrotic therapies for patients with liver diseases. We performed an experimental and translational study to investigate whether ghrelin, an orexigenic hormone with pleiotropic properties, modulates liver fibrogenesis. Recombinant ghrelin was administered to rats with chronic (bile duct ligation) and acute (carbon tetrachloride) liver injury. Hepatic gene expression was analyzed by way of microarray analysis and quantitative polymerase chain reaction. The hepatic response to chronic injury was also evaluated in wild-type and ghrelin-deficient mice. Primary human hepatic stellate cells were used to study the effects of ghrelin in vitro. Ghrelin hepatic gene expression and serum levels were assessed in patients with chronic liver diseases. Ghrelin gene polymorphisms were analyzed in patients with chronic hepatitis C. Recombinant ghrelin treatment reduced the fibrogenic response, decreased liver injury and myofibroblast accumulation, and attenuated the altered gene expression profile in bile duct-ligated rats. Moreover, ghrelin reduced the fibrogenic properties of hepatic stellate cells. Ghrelin also protected rats from acute liver injury and reduced the extent of oxidative stress and inflammation. Ghrelin-deficient mice developed exacerbated hepatic fibrosis and liver damage after chronic injury. In patients with chronic liver diseases, ghrelin serum levels decreased in those with advanced fibrosis, and ghrelin gene hepatic expression correlated with expression of fibrogenic genes. In patients with chronic hepatitis C, polymorphisms of the ghrelin gene (994CT and 604GA) influenced the progression of liver fibrosis. Conclusion: Ghrelin exerts antifibrotic effects in the liver and may represent a novel antifibrotic therapy. Copyright © 2010 by the American Association for the Study of Liver Diseases.Supported by grants from the Ministerio de Ciencia e Investigación (SAF2005-06245), from the Instituto de Salud Carlos III (FIS2005-050567, FIS 2008-PI08/0237 and PI070497), and from the European Community FP6 (LSHB-CT-2007-036644 - DIALOK) and by fellowships from Institut d’Investigacions Biomèdiques August Pi i Sunyer (to M. M. and M. D.), the Fundación Bilbao Vizcaya Argentaria (to M. D.) and the Fundació Clínic (to P. S. B.).Peer Reviewe

Estudio de factores genéticos de los sistemas relacionados con estrés oxidativo

RESUMEN El riesgo de desarrollar una enfermedad cardiovascular en pacientes con hipertensión (HTA) se incrementa en más de 3 veces con respecto a otras enfermedades de elevado riesgo cardiovascular (diabetes, hipercolesterolemias, etc.), siendo además la HTA la mayor causa de mortalidad y morbilidad cardiovascular. La HTA se representa como una patología compleja que a menudo se asocia a otras alteraciones como microalbuminuria, disfunción endotelial, etc. Bajo estas condiciones fisiopatológicas se ha demostrado que se produce un aumento en la generación de especies oxidantes en el organismo, superando la capacidad de protección de los sistemas celulares de defensas antioxidantes, lo que provoca estrés oxidativo (EO). En la presente tesis doctoral se ha caracterizado el EO a nivel bioquímico y genético, mediante el análisis de los productos finales de EO, niveles de ARN mensajero y polimorfismos de genes implicados en la producción y defensa de EO y que pudieran afectar a la presión arterial y el daño orgánico. En este estudio se han analizado parámetros de EO como los glutatión reducido y oxidado, malondialdehido y 8-hidroxi 2-desoxiguanosina tanto en células mononucleares circulantes como en plasma de pacientes hipertensos (con y sin tratamientos) y en normotensos. Además, se han cuantificado los niveles de ARNm de los principales genes de estos sistemas, en linfocitos de hipertensos y controles (NADPHoxidasa, catalasa, superóxidos dismutasas y enzimas del sistema glutatión y tiorredoxina). Por otra parte, se ha realizado el estudio de variantes genéticas de genes de los sistemas implicados en EO, localizados en regiones que podrían afectar en la homeostasis oxidativa, lo que da lugar a alterarse la función de las proteínas y promotor región polimorfismos que alteran los niveles de EO como consecuencia de la regulación de genes. Esta parte del estudio se ha llevado a cabo en una población de hipertensos, controles y una población general. Los resultados obtenidos nos muestran que en la HTA esencial: 1. Exite un aumento en los niveles de estrés oxidativo tanto en plasma como en células monolinfocitarias y a su vez este aumento se ve correlacionado con los niveles de presión arterial (PA) de los sujetos. Además, el EO se relaciona con el aumento los niveles de excreción urinaria de albúmina (EUA) independientemente de los valores de PA. 2. Se produce un aumento de los niveles de ARNm de genes que codifican las distintas subunidades de NAD(P)H oxidasa y una disminución de los niveles de ARNm de las enzimas antioxidantes en monolinfocitos. Además, estos cambios se relacionan con el estado crónico de EO presente en la HTA, a pesar de la activación del sistema tiorredoxina y la enzima Manganeso Superóxido Dismutasa. Por tanto, los pacientes hipertensos tanto en presencia o en ausencia de microalbuminuria se encuentran peor protegidos frente a EO que los sujetos control. 3. Independientemente del tratamiento antihipertensivo utilizado, los niveles de los marcadores bioquímicos de EO se reducen, y también los niveles de ARNm de todas las enzimas implicadas. 4. Los análisis de asociación han mostrado que ciertas variantes, y sus haplotipos, se encuentran asociadas a niveles de EO, PA, EUA y riesgo de microalbuminuria en sujetos hipertensos. Hay que destacar que estos datos se han replicado en otra población de hipertensos y en la población general, donde se han mantenido dos de estas asociaciones. 5. En el análisis de asociación entre los polimorfismos de distintos genes observamos la interacción entre el gen de la XDH y GPX1 en la población hipertensa. Estas interacciones nos confirman la naturaleza compleja de esta patología y de la necesidad de enfocar las nuevas investigaciones hacia el estudio de las interacciones entre distintos genes y estos con los factores ambientales. __________________________________________________________________________________________________Hypertension is a complex disease that is often associated with other disorders such as microalbuminuria, endothelial dysfunction, etc. Under this pathophysiological condition has been shown that there is an increase in the generation of oxidizing species in the body, without being able to avoid the protection capacity of cellular antioxidant defense systems, leading to oxidative stress (OS). In this thesis OS status has been characterized by biochemical and genetic level of OS byproducts, messenger RNA levels and polymorphisms of oxidant and antioxidant system genes. The results have shown increased levels of oxidative stress in blood and peripheral mononuclear cells and this increase is correlated with levels of blood pressure (BP) in essential hypertension. Furthermore OS seems to be a determinant of urinary albumin excretion (UAE) independent of BP levels even in hypertensive subjects. The increase in mRNA levels of genes encoding different subunits of NAD(P)H oxidase complex and decreased mRNA levels of antioxidant enzymes in peripheral mononuclear cells, has been related to the chronic state of OS in the hypertension, despite the action of thioredoxin system and manganese superoxide dismutase enzyme. Thus, hypertensive patients in presence or absence of microalbuminuria are less protected from OS compared to control subjects. Furthermore, any type of antihypertensive treatment reduced the levels of OS, and therefore also the mRNA levels of all enzymes involved. The association analysis have confirmed that certain genetic variants, their haplotypes and their interactions, are associated with levels of OS, BP, UAE and microalbuminuria risk in hypertensive subjects. It should be noted that these results have been replicated in another hypertensive population and in spanish general population some associations have remained

Dietary factors, epigenetic modifications and obesity outcomes: Progresses and perspectives

Nutritional factors play a life-long role in human health. Indeed, there is growing evidence that one of the mechanisms by which nutrients and bioactive compounds affect metabolic traits is epigenetics. Complex interactions among food components and histone modifications, DNA methylation, non-coding RNA expression and chromatin remodeling factors lead to a dynamic regulation of gene expression that controls the cellular phenotype. Although perinatal period is the time of highest phenotypic plasticity, contributing largely to developmental programming, also during adulthood there is evidence about a nutritional influence on epigenetic regulation. Similarly to type 2 diabetes, hypertension, atherosclerosis and other metabolic disorders, obesity predisposition and weight loss outcomes have been repeatedly associated to changes in epigenetic patterns. Different non-nutritional risk factors that usually accompany obesity seem also to be involved in these epigenetic modifications, especially hyperglycemia, inflammation, hypoxia and oxidative stress. There are currently three major objectives in epigenetic research in relation to obesity: to search for epigenetic biomarkers to predict future health problems or detect the individuals at most risk, to understand the obesity-related environmental factors that could modulate gene expression by affecting epigenetic mechanisms, and to study novel therapeutic strategies based on nutritional or pharmacological agents that can modify epigenetic marks. At this level, the major tasks are: development of robust epigenetic biomarkers of weight regulation, description of those epigenetic marks more susceptible to be modified by dietary exposures, identification of the active ingredients (and the doses) that alter the epigenome, assessment of the real importance of other obesity-related factors on epigenetic regulation, determination of the period of life in which best results are obtained, and understanding the importance of the inheritance of these epigenetic marks

Estudio de asociación epigenómica en la pérdida de peso tras una intervención nutricional: Estudio RESMENA.

Through anepigenomics approach, the possible association between baseline levels in DNA methylation and a better weight loss response after a multidisciplinary intervention program were analyzedin obese population from RESMENA-S study. Three DNA regions that are differentially methylated (RGS6, A2BP1 and RASGRF1 genes) showed differential methylation levels at baseline between high and low responders to the multidisciplinary weight loss intervention. Moreover, these genes were implicated in the same metabolic pathway and have been previously significantly associated with obesity.Mediante una aproximación epigenómica, se analizaron las posibles asociaciones entre los niveles basales en la metilación del ADN y una mejor respuesta a la pérdida de peso después de un programa de intervención nutricional en la población obesa del estudio RESMENA. Esta investigación ha identificado 3 regiones de ADN (genes RGS6, A2BP1 y RASGRF1) que se encuentran diferencialmente metiladas entre sujetos con alta y baja respuesta a la pérdida de peso. Además, estos genes están implicados en la misma ruta metabólica y habían sido previamente significativamente asociados con la obesidad

Different Impacts of Cardiovascular Risk Factors on Oxidative Stress

The objective of the study was to evaluate oxidative stress (OS) status in subjects with different cardiovascular risk factors. With this in mind, we have studied three models of high cardiovascular risk: hypertension (HT) with and without metabolic syndrome, familial hypercholesterolemia (FH) and familial combined hyperlipidemia (FCH) with and without insulin resistance. Oxidative stress markers (oxidized/reduced glutathione ratio, 8-oxo-deoxyguanosine and malondialdehide) together with the activity of antioxidant enzyme triad (superoxide dismutase, catalase, glutathione peroxidase) and activation of both pro-oxidant enzyme (NAPDH oxidase components) and AGTR1 genes, as well as antioxidant enzyme genes (CuZn-SOD, CAT, GPX1, GSR, GSS and TXN) were measured in mononuclear cells of controls (n = 20) and patients (n = 90) by assessing mRNA levels. Activity of some of these antioxidant enzymes was also tested. An increase in OS and pro-oxidant gene mRNA values was observed in patients compared to controls. The hypertensive group showed not only the highest OS values, but also the highest pro-oxidant activation compared to those observed in the other groups. In addition, in HT a significantly reduced antioxidant activity and mRNA induction of antioxidant genes were found when compared to controls and the other groups. In FH and FCH, the activation of pro-oxidant enzymes was also higher and antioxidant ones lower than in the control group, although it did not reach the values obtained in hypertensives. The thioredoxin system was more activated in patients as compared to controls, and the highest levels were in hypertensives. The increased oxidative status in the presence of cardiovascular risk factors is a consequence of both the activation of pro-oxidant mechanisms and the reduction of the antioxidant ones. The altered response of the main cytoplasmic antioxidant systems largely contributes to OS despite the apparent attempt of the thioredoxin system to control it

DNA methylation in genes of longevity‐regulating pathways: association with obesity and metabolic complications

Aging is the main risk factor for most chronic diseases. Epigenetic mechanisms, such as DNA methylation (DNAm) plays a pivotal role in the regulation of physiological responses that can vary along lifespan. The aim of this research was to analyze the association between leukocyte DNAm in genes involved in longevity and the occurrence of obesity and related metabolic alterations in an adult population. Subjects from the MENA cohort (n=474) were categorized according to age () and the presence of metabolic alterations: increased waist circumference, hypercholesterolemia, insulin resistance, and metabolic syndrome. The methylation levels of 58 CpG sites located at genes involved in longevity‐regulating pathways were strongly correlated (FDR‐ adjusted< 0.0001) with BMI. Fifteen of them were differentially methylated (p<0.05) between younger and older subjects that exhibited at least one metabolic alteration. Six of these CpG sites, located at MTOR (cg08862778), ULK1 (cg07199894), ADCY6 (cg11658986), IGF1R (cg01284192), CREB5 (cg11301281), and RELA (cg08128650), were common to the metabolic traits, and CREB5, RELA, and ULK1 were statistically associated with age. In summary, leukocyte DNAm levels of several CpG sites located at genes involved in longevity‐ regulating pathways were associated with obesity and metabolic syndrome traits, suggesting a role of DNAm in aging‐related metabolic alterations

Association between genetic variants in oxidative stress-related genes and osteoporotic bone fracture. The Hortega follow-up study

The most widely accepted etiopathogenesis hypothesis of the origin of osteoporosis and its complications is that they are a consequence of bone aging and other environmental factors, together with a genetic predisposition. Evidence suggests that oxidative stress is crucial in bone pathologies associated with aging. The aim of this study was to determine whether genetic variants in oxidative stress-related genes modified the risk of osteoporotic fracture. We analysed 221 patients and 354 controls from the HORTEGA sample after 12-14 years of follow up. We studied the genotypic and allelic distribution of 53 SNPs in 24 genes involved in oxidative stress. The results showed that being a carrier of the variant allele of the SNP rs4077561 within TXNRD1 was the principal genetic risk factor associated with osteoporotic fracture and that variant allele of the rs1805754 M6PR, rs4964779 TXNRD1, rs406113 GPX6, rs2281082 TXN2 and rs974334 GPX6 polymorphisms are important genetic risk factors for fracture. This study provides information on the genetic factors associated with oxidative stress which are involved in the risk of osteoporotic fracture and reinforces the hypothesis that genetic factors are crucial in the etiopathogenesis of osteoporosis and its complications