Epicatechin induces NF-kappa B, activator rotein-1 (AP-1) and nuclear transcription factor erythroid 2p45-related factor-2 (Nrf2) via phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) and extracellular regulated kinase (ERK) signalling in HepG2 cells

The dietary flavonoid epicatechin has been reported to exhibit a wide range of biological activities. The objective of the present study was to investigate the time-dependent regulation by epicatechin on the activity of the main transcription factors (NF-kappa B, activator protein-1 (AP-1) and nuclear transcription factor erythroid 2p45-related factor (Nrf2)) related to antioxidant defence and survival and proliferation pathways in HepG2 cells. Treatment of cells with 10 mu M-epicatechin induced the NF-kappa B pathway in a time-dependent manner characterised by increased levels Of I kappa B kinase (IKK) and phosphorylated inhibitor Of kappa B subunit-a (p-I kappa B alpha) and proteolytic degradation Of I kappa B, which was consistent with an up-regulation of the NF-kappa B-binding activity. Time-dependent activation of the AP-1 pathway, in concert with enhanced c-Jun nuclear levels and induction of Nrf2 translocation and phosphorylation were also demonstrated. Additionally, epicatechin-induced NF-kappa B and Nrf2 were connected to reactive oxygen species intracellular levels and to the activation of cell survival and proliferation pathways, being phosphatidylinositol-3-kinase/protein kinase B (PI3K/AKT) and extracellular regulated kinase (ERK) associated to Nrf2 modulation and ERK to NF-kappa B induction. These data suggest that the epicatechin-induced survival effect occurs by the induction of redox-sensitive transcription factors through a tight regulation of survival and proliferation pathways

Uso de Redes Sociales como estrategia de enseñanza-aprendizaje colaborativo en los estudiantes del tercer año de bachillerato, especialidad de informática

Usar las redes sociales como estrategia de enseñanza-aprendizaje colaborativo, para los estudiantes del Tercer Año de Bachillerato, especialidad de Informática, de la Unidad Educativa La Concordia, ubicada en el cantón La Concordia, provincia de Santo Domingo de los Tsáchilas, del módulo de Programación y Bases de Datos, período 2021-2022.La utilización de un modelo de instrucción académica genera un cambio radical en los procesos educativos de forma colaborativa en las unidades educativas. Existe una posición de incertidumbre en los docentes; buscar una estrategia pedagógica que indague sobre el trabajo en equipo con sus estudiantes; evolucionar positivamente los procesos de enseñanza escolar en sus instituciones. Este estudio se realizó con el objetivo de usar las redes sociales como estrategia de enseñanza en un marco de cooperación mutua dentro de las tareas académicas. Para cumplir con este fin se aplicó una metodología de tipo no experimental con un alcance descriptivo-exploratorio a fin obtener un acercamiento hacia los conceptos y adeptos de las redes sociales con la elaboración de un referente teórico. Se empleó un cuestionario validado por dos expertos, con 20 preguntas clasificadas en 5 dimensiones; Información, Comunicación, Creación de contenido, Seguridad, Resolución de problemas y Trabajo colaborativo y marcadas con escala tipo Likert. La fiabilidad del instrumento quedó establecida con un coeficiente de alfa Cronbach de 0,930. Con los resultados y análisis estadísticos, utilizando IBM SPPS statistics, se detectó a Facebook como red social con más popularidad, de la cual nos servimos para el desarrollo de una propuesta que aplique el trabajo colaborativo, la misma que evaluó la experiencia de los docentes y estudiantes en la practicidad de la herramienta innovando la forma de enseñar colaborativamente al que finalmente se evaluó con una encuesta aplicada por García & Díaz, (2020), donde la mayoría de los participantes expresaron su satisfacción en la practicidad. En conclusión, las redes sociales poseen características y métodos prácticos de enseñanza para el trabajo grupal; construyendo y evolucionando el conocimiento. Esta investigación aportó con un mecanismo de aprendizaje colaborativo con redes sociales para que los profesores y estudiantes innoven positivamente nuevas formas de aprender y enseñar.Maestrí

Descomposición y mineralización de la hojarasca foliar en plantaciones de <i>Eucalyptus grandis</i> en tres tipos diferentes de suelos en Entre Ríos, Argentina

The decay of organic matter returned to the soil via litter fall is an important source of nutrients for vegetation uptake. The rate of decomposition of organic matter, release, and immobilization of nitrogen, phosphorus, potassium, calcium, magnesium, manganese, iron and aluminum of fresh leaf litter of Eucalyptus grandis were measured using litter bags in three trial plots located on an Oxic Quartzipsamment (red sandy), a Fluventic Haplumbrept (dark sandy), and an Argiudolic Pelludert soil (black clay soils). The annual rate of decay of dry matter (k) was faster in clay soil (0.44) than in both sandy soils (0.30). Temporal patterns of changes in nutrient concentration in leaf litter were similar at both sandy soil sites compared to the clay soil. Nitrogen and phosphorus increased over time at all sites, but their immobilization was greater at the clay soil site. Calcium, magnesium and manganese fluctuated with a different pattern in each soil type. Iron and aluminum showed a similar pattern of increasing concentration at each site. A higher rate of dry mass loss, together with an increase in nitrogen and phosphorus immobilization, was observed at the more fertile clay soil site.La descomposición de la materia orgánica que ingresa al suelo a través de la caída a la hojarasca es una fuente importante de nutrientes para la vegetación. Se estimaron la tasa de descomposición de la materia orgánica, la liberación/inmovilización de nitrógeno, fósforo, potasio, calcio, magnesio, manganeso, hierro y aluminio de hojas recién caídas de Eucalyptus grandis utilizando bolsas de descomposición en parcelas de ensayo situadas en tres tipos de suelos: Oxic Quartzipsamment (arenoso), Fluventic Haplumbrept (mestizo) y Argiudolic Pelludert (arcilloso). La tasa anual de descomposición de la materia seca (k) fue más rápida en el suelo arcilloso (0,44) que en los suelos arenoso y mestizo (0,30). El patrón temporal de cambios de las concentraciones de nutrientes en la hojarasca fue similar entre los suelos arenoso y mestizo, comparados con el arcilloso. La concentración de nitrógeno y fósforo aumentó con el tiempo en los tres sitios, pero su inmovilización fue mayor en el sitio arcilloso. Las concentraciones de calcio, magnesio y manganeso fluctuaron de forma diferente en cada tipo de suelo. En cada sitio, las concentraciones de hierro y aluminio aumentaron de manera similar. Una mayor tasa de pérdida de masa seca, junto con un aumento de inmovilización de nitrógeno y fósforo se observó en el suelo arcilloso, relativamente más rico en nutrientes.Laboratorio de Investigación de Sistemas Ecológicos y Ambientale

Descomposición y mineralización de la hojarasca foliar en plantaciones de <i>Eucalyptus grandis</i> en tres tipos diferentes de suelos en Entre Ríos, Argentina

The decay of organic matter returned to the soil via litter fall is an important source of nutrients for vegetation uptake. The rate of decomposition of organic matter, release, and immobilization of nitrogen, phosphorus, potassium, calcium, magnesium, manganese, iron and aluminum of fresh leaf litter of Eucalyptus grandis were measured using litter bags in three trial plots located on an Oxic Quartzipsamment (red sandy), a Fluventic Haplumbrept (dark sandy), and an Argiudolic Pelludert soil (black clay soils). The annual rate of decay of dry matter (k) was faster in clay soil (0.44) than in both sandy soils (0.30). Temporal patterns of changes in nutrient concentration in leaf litter were similar at both sandy soil sites compared to the clay soil. Nitrogen and phosphorus increased over time at all sites, but their immobilization was greater at the clay soil site. Calcium, magnesium and manganese fluctuated with a different pattern in each soil type. Iron and aluminum showed a similar pattern of increasing concentration at each site. A higher rate of dry mass loss, together with an increase in nitrogen and phosphorus immobilization, was observed at the more fertile clay soil site.La descomposición de la materia orgánica que ingresa al suelo a través de la caída a la hojarasca es una fuente importante de nutrientes para la vegetación. Se estimaron la tasa de descomposición de la materia orgánica, la liberación/inmovilización de nitrógeno, fósforo, potasio, calcio, magnesio, manganeso, hierro y aluminio de hojas recién caídas de Eucalyptus grandis utilizando bolsas de descomposición en parcelas de ensayo situadas en tres tipos de suelos: Oxic Quartzipsamment (arenoso), Fluventic Haplumbrept (mestizo) y Argiudolic Pelludert (arcilloso). La tasa anual de descomposición de la materia seca (k) fue más rápida en el suelo arcilloso (0,44) que en los suelos arenoso y mestizo (0,30). El patrón temporal de cambios de las concentraciones de nutrientes en la hojarasca fue similar entre los suelos arenoso y mestizo, comparados con el arcilloso. La concentración de nitrógeno y fósforo aumentó con el tiempo en los tres sitios, pero su inmovilización fue mayor en el sitio arcilloso. Las concentraciones de calcio, magnesio y manganeso fluctuaron de forma diferente en cada tipo de suelo. En cada sitio, las concentraciones de hierro y aluminio aumentaron de manera similar. Una mayor tasa de pérdida de masa seca, junto con un aumento de inmovilización de nitrógeno y fósforo se observó en el suelo arcilloso, relativamente más rico en nutrientes.Laboratorio de Investigación de Sistemas Ecológicos y Ambientale

A diet rich in cocoa attenuates N-nitrosodiethylamine-induced liver injury in rats

The effects of cocoa feeding against N-nitrosodiethylamine (DEN)-induced liver injury were studied in rats. Animals were divided into five groups. Groups 1 and 2 were fed with standard and cocoa-diet, respectively. Groups 3 and 4 were injected with DEN at 2 and 4 weeks, and fed with standard and cocoa-diet, respectively. Group 5 was treated with DEN, received the standard diet for 4 weeks and then it was replaced by the cocoa-diet. DEN-induced hepatic damage caused a significant increase in damage markers, as well as a decrease in the hepatic glutathione, diminished levels of p-ERK and enhanced protein carbonyl content, caspase-3 activity and values of p-AKT and p-JNK. The cocoa-rich diet prevented the reduction of hepatic glutathione concentration and catalase and GPx activities in DEN-injected rats, as well as diminished protein carbonyl content, caspase-3 activity, p-AKT and p-JNK levels, and increased GST activity. However, cocoa administration did not abrogate the DEN-induced body weight loss and the increased levels of hepatic-specific enzymes and LDH. These results suggested that cocoa-rich diet attenuates the DEN-induced liver injury. © 2009 Elsevier Ltd. All rights reserved.This work was supported by the grants 200870I198, AGL2004-302, AGL2007-64042 and CSD2007-00063 from the Spanish Ministry of Science and Innovation. A.B. Granado-Serrano is a predoctoral fellow of the Spanish Ministry of Science and Education.Peer Reviewe

Insulin-like growth factor-I gene delivery to astrocytes reduces their inflammatory response to lipopolysaccharide

<p>Abstract</p> <p>Background</p> <p>Insulin-like growth factor-I (IGF-I) exerts neuroprotective actions in the central nervous system that are mediated at least in part by control of activation of astrocytes. In this study we have assessed the efficacy of exogenous IGF-I and IGF-I gene therapy in reducing the inflammatory response of astrocytes from cerebral cortex.</p> <p>Methods</p> <p>An adenoviral vector harboring the rat IGF-I gene and a control adenoviral vector harboring a hybrid gene encoding the herpes simplex virus type 1 thymidine kinase fused to <it>Aequorea victoria </it>enhanced green fluorescent protein were used in this study. Primary astrocytes from mice cerebral cortex were incubated for 24 h or 72 h with vehicle, IGF-I, the IGF-I adenoviral vector, or control vector; and exposed to bacterial lipopolysaccharide to induce an inflammatory response. IGF-I levels were measured by radioimmunoassay. Levels of interleukin 6, tumor necrosis factor-α, interleukin-1β and toll-like receptor 4 mRNA were assessed by quantitative real-time polymerase chain reaction. Levels of IGF-I receptor and IGF binding proteins 2 and 3 were assessed by western blotting. The subcellular distribution of nuclear factor κB (p65) was assessed by immunocytochemistry. Statistical significance was assessed by one way analysis of variance followed by the Bonferroni pot hoc test.</p> <p>Results</p> <p>IGF-I gene therapy increased IGF-I levels without affecting IGF-I receptors or IGF binding proteins. Exogenous IGF-I, and IGF-I gene therapy, decreased expression of toll-like receptor 4 and counteracted the lipopolysaccharide-induced inflammatory response of astrocytes. In addition, IGF-I gene therapy decreased lipopolysaccharide-induced translocation of nuclear factor κB (p65) to the cell nucleus.</p> <p>Conclusion</p> <p>These findings demonstrate efficacy of exogenous IGF-I and of IGF-I gene therapy in reducing the inflammatory response of astrocytes. IGF-I gene therapy may represent a new approach to reduce inflammatory reactions in glial cells.</p

Oxidative and Inflammatory Imbalance in Placenta and Kidney of sFlt1-Induced Early-Onset Preeclampsia Rat Model

Preeclampsia (PE) is a pregnancy-specific disorder characterized by the new onset of hypertension plus proteinuria and/or end-organ dysfunction. Here, we investigate the role of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase system as a major component of reactive oxygen species generation, in a rodent model of early-onset preeclampsia induced by excess sFlt1 (soluble fms-like tyrosine kinase 1). Placenta and kidney samples were obtained from normal pregnant and PE rats to measure the sFlt1/PlGF (placental growth factor) ratio in addition to oxidative stress-related parameters, including the activities and expressions of NADPH oxidase isoforms (NOX1, NOX2, and NOX4), components of nitric oxide (NO) metabolism, and antioxidant enzymes. Peroxisome proliferator-activated receptors (PPARα, PPARγ) and cytokines IL1β, IL3, IL6, IL10, and IL18 were also measured to evaluate the inflammation status in our experimental setting. Excessive O2●− production was found in rats that were treated with sFlt1; interestingly, this alteration appears to be mediated mainly by NOX2 in the placenta and by NOX4 in the kidney. Altered NO metabolism and antioxidant defense systems, together with mitochondrial dysfunction, were observed in this model of PE. Preeclamptic animals also exhibited overexpression of proinflammatory biomarkers as well as increased collagen deposition. Our results highlight the role of NADPH oxidase in mediating oxidative stress and possibly inflammatory processes in the placenta and kidney of an sFlt1-based model of early-onset preeclampsia

Effects of regularly consuming dietary fibre rich soluble cocoa products on bowel habits in healthy subjects: a free-living, two-stage, randomized, crossover, single-blind intervention

Abstract Background Dietary fibre is both preventive and therapeutic for bowel functional diseases. Soluble cocoa products are good sources of dietary fibre that may be supplemented with this dietary component. This study assessed the effects of regularly consuming two soluble cocoa products (A and B) with different non-starch polysaccharides levels (NSP, 15.1 and 22.0% w/w, respectively) on bowel habits using subjective intestinal function and symptom questionnaires, a daily diary and a faecal marker in healthy individuals. Methods A free-living, two-stage, randomized, crossover, single-blind intervention was carried out in 44 healthy men and women, between 18-55 y old, who had not taken dietary supplements, laxatives, or antibiotics six months before the start of the study. In the four-week-long intervention stages, separated by a three-week-wash-out stage, two servings of A and B, that provided 2.26 vs. 6.60 g/day of NSP respectively, were taken. In each stage, volunteers' diet was recorded using a 72-h food intake report. Results Regularly consuming cocoa A and B increased fibre intake, although only cocoa B significantly increased fibre intake (p < 0.001) with respect to the non-cocoa stage. No changes in body weight were observed in either of the 4 week interventions. With cocoa product B, the number of daily bowel movements increased (p = 0.002), the frequency of having a bowel movement once a day increased (p = 0.009), the time to have a bowel movement was lower (p = 0.016) as well as the feeling of constipation (p = 0.046) without inducing adverse gastrointestinal symptoms, only flatulence increased (p = 0.019). Conclusions Regular consumption of the cocoa products increases dietary fibre intake to recommended levels and product B improves bowel habits. The use of both objective and subjective assessments to evaluate the effects of food on bowel habits is recommended.Projects AGL2007-64042 and Consolider-Ingenio (CSD2007-00063) from the Spanish Ministry of Science and Innovation also acknowledged. S.M.-L. is a JAE-Predoc fellow of CSIC Programme "Junta para la Ampliación de Estudios" co-funded by the European Social Fund (ESF). M.G.-J. is a predoctoral fellow of the Spanish Ministry of Science and Innovation. A.F.-E. was a FINNOVA fellow also cofinanced by CSIC and the ESF.Peer Reviewe

Relationship among aboveground biomass, leaf area and soil types in Eucalyptus grandis plantations from NE Entre Ríos, Argentina

El objetivo de este trabajo consistió en constatar si existen diferencias en la biomasa aérea y área foliar y, consecuentemente, en la producción y el rendimiento de la masa de madera de plantaciones de Eucalyptus grandis ubicadas en los tres tipos de suelos con aptitud forestal de Concordia (31° 23' S; 58° 02' W). El estudio se realizó en tres rodales experimentales de 0,207 ha con E. grandis de procedencia sudafricana y 14 años de edad, con un distanciamiento original de 3 x 3m, localizados, respectivamente, sobre suelos Quartzipsamment Oxico (localmente arenoso), Haplumbrept Fluvéntico (localmente mestizo) y Argiacuol Vértico (localmente arcilloso). En cada rodal se determinaron los parámetros estructurales densidad, área basal y volumen . Se apearon 22 árboles en el rango diamétrico y de altura presentes en los rodales; y se les midió el peso fresco y seco de los compartimientos fuste > 5cm de diámetro, ramas 1cm de diámetro, ramas pequeñas 5 cm diameter, branches 1cm diameter, small branches < 1cm diameter, twigs, leaves and fruits. Dimensional analysis procedures were applied. Biomass (total and by compartment) for each plot was calculated using the regression equations obtained and DBH-height measures of all trees in the plot. The Leaf Area Index (LAI) of each plot was obtained multiplying it specific leaf area (SLA) and leaf biomass. To calculate SLA, 15 groups of 20 leaves of each plot were measured with an optical planimeter and dried to constant weight. A unique model for each tree compartment dry weight estimation was used because there were not significant differences among site models. Significant stand structural differences were observed. The mestizo site showed trees with diameters 20-10 % and height 35-29% more length, 31-33% more basal area and 73% higher volume and Mean Annual Increment (MAI) than the arenoso and arcilloso sites, respectively. The LAI was also higher in the mestizo site. In mestizo site stem biomass and MAI were 351 Mg.ha-1 and 25 Mg.ha-1.yr-1, respectively, and the LAI attained 4.5. For the arenoso and arcilloso sites the correspondent stem biomass, MAI and LAI were, respectively, 200-201 Mg.ha-1, 14-13 Mg.ha-1.yr-1 and 3.3-3.0. We conclude that wood mass and volume yield are strongly influenced by the soil type because texture is probably limiting water availability in both textural soil extremes. Differences in MAI indicate that maximum sustained yield differ among sites. E. grandis  wood mass yields in NE Entre Ríos are similar to the higher figures reported for sites in the southern hemisphere.Facultad de Ciencias Agrarias y Forestale