An Extract from the Plant Deschampsia antarctica

The Antarctic plant Deschampsia antarctica (DA) is able to survive in extreme conditions thanks to its special mechanism of protection against environmental aggressions. In this work, we investigated whether an aqueous extract of the plant (EDA) retains some of its defensive properties and is able to protect our skin against common external oxidants. We evaluated EDA over young human fibroblasts and exposed to H2O2, and we measured cell proliferation, viability, and senescence-associated β-galactosidase (SA-β-Gal). We also tested the expression of several senescence-associated proteins including sirtuin1, lamin A/C, the replicative protein PCNA, and the redox protein thioredoxin 2. We found that EDA promoted per se cell proliferation and viability and increased the expression of anti-senescence-related markers. Then, we selected a dose of H2O2 as an inductor of senescence in human fibroblasts, and we found that an EDA treatment 24 h prior H2O2 exposure increased fibroblast proliferation. EDA significantly inhibited the increase in SA-β-Gal levels induced by H2O2 and promoted the expression of sirtuin 1 and lamin A/C proteins. Altogether, these results suggest that EDA protects human fibroblasts from cellular senescence induced by H2O2, pointing to this compound as a potential therapeutic agent to treat or prevent skin senescence

Thioredoxin dependent changes in the redox states of FurA from Anabaena sp. PCC7120

FurA is a multifunctional regulator in cyanobacteria that contains five cysteines, four of them arranged into two CXXC motifs. Lack of a structural zinc ion enables FurA to develop disulfide reductase activity. In vivo, FurA displays several redox isoforms, and the oxidation state of its cysteines determines its activity as regulator and its ability to bind different metabolites. Because of the relationship between FurA and the control of genes involved in oxidative stress defense and photosynthetic metabolism, we sought to investigate the role of type m thioredoxin TrxA as a potential redox partner mediating dithiol-disulfide exchange reactions necessary to facilitate the interaction of FurA with its different ligands. Both in vitro cross-linking assays and in vivo two-hybrid studies confirmed the interaction between FurA and TrxA. Light to dark transitions resulted in reversible oxidation of a fraction of the regulator present in Anabaena sp. PCC7120. Reconstitution of an electron transport chain using E. coli NADPH-thioredoxin-reductase followed by alkylation of FurA reduced cysteines evidenced the ability of TrxA to reduce FurA. Furthermore, the use of site-directed mutants allowed us to propose a plausible mechanism for FurA reduction. These results point to TrxA as one of the redox partners that modulates FurA performance

Glutathionylation of Pea Chloroplast 2-Cys Prx and Mitochondrial Prx IIF Affects Their Structure and Peroxidase Activity and Sulfiredoxin Deglutathionylates Only the 2-Cys Prx

Together with thioredoxins (Trxs), plant peroxiredoxins (Prxs), and sulfiredoxins (Srxs) are involved in antioxidant defense and redox signaling, while their regulation by post-translational modifications (PTMs) is increasingly regarded as a key component for the transduction of the bioactivity of reactive oxygen and nitrogen species. Among these PTMs, S-glutathionylation is considered a protective mechanism against overoxidation, it also modulates protein activity and allows signaling. This study explores the glutathionylation of recombinant chloroplastic 2-Cys Prx and mitochondrial Prx IIF from Pisum sativum. Glutathionylation of the decameric form of 2-Cys Prx produced a change in the elution volume after FPLC chromatography and converted it to its dimeric glutathionylated form, while Prx IIF in its reduced dimeric form was glutathionylated without changing its oligomeric state. Mass spectrometry demonstrated that oxidized glutathione (GSSG) can glutathionylate resolving cysteine (Cys174), but not the peroxidatic equivalent (Cys52), in 2-Cys Prx. In contrast, GSSG was able to glutathionylate both peroxidatic (Cys59) and resolving (Cys84) cysteine in Prx IIF. Glutathionylation was seen to be dependent on the GSH/GSSG ratio, although the exact effect on the 2-Cys Prx and Prx IIF proteins differed. However, the glutathionylation provoked a similar decrease in the peroxidase activity of both peroxiredoxins. Despite growing evidence of the importance of post-translational modifications, little is known about the enzymatic systems that specifically regulate the reversal of this modification. In the present work, sulfiredoxin from P. sativum was seen to be able to deglutathionylate pea 2-Cys Prx but not pea Prx IIF. Redox changes during plant development and the response to stress influence glutathionylation/deglutathionylation processes, which may represent an important event through the modulation of peroxiredoxin and sulfiredoxin proteins.This research was supported by MICINN, Spain (BFU2014-52452-P co-financed by FEDER) and Seneca Foundation, Murcia, Spain (Excellence Group 19876/GERM/15).Peer reviewedPeer Reviewe

Alteraciones Refractivas que Causan Disminución de la A.V en Niños de primaria de las escuelas públicas en la zona urbana del municipio de Nandaime-Granada durante los meses de Abril-Mayo del 2019

La disminución de la visión es una pérdida parcial de visión transitoria o permanente” (Americana Academia de Oftalmología [AAO],2015:1) y su detección precoz en un escolar permitirá la corrección visual necesaria para que no altere su aprendizaje ni su desarrollo físico, social y cultural, por tal razón nos planteamos como objetivo determinar las alteraciones refractivas que causan disminución de la A.V en niños de primaria de las escuelas públicas en la zona urbana del municipio de Nandaime-Granada durante los meses de Abril-Mayo del 2019. El tipo de estudio es Observacional, descriptivo, correlacional, prospectivo, analítico y según el período y secuencia del estudio es transversal. El universo lo constituyen 631 niños de primaria quienes fueron los que cumplieron con los criterios de inclusión, se realizó la agudeza visual con cartilla de Snellen, Símbolos LEA y se utilizó para conocer su estado refractivo la retinoscopía estática, utilizando reglas esquiascopicas y lentes sueltas de la caja de prueba. Los principales resultados fueron: Prevaleció el sexo femenino 54%, el cual destaca la participación de la escuela Carmela Noguera 51%; se descubrió una afectación visual en el 54% de los niños cuya AV más frecuente fue el 20/25 de los cuales el 9.4% presentaron AV 20/25 en VL y el 8.4% una AV 20/25 en VC, la alteración refractiva más predominante fue hipermetropía en un 14%. En conclusión, se dedujo que el 47% de los niños presentaban una alteración refractiva que causaron disminución de la agudeza visual y que el 18% de estos niños deberían portar una corrección óptic

Distribución del sonido en sangre, plasma y eritrocitos en doce agrupaciones caprinas autóctonas españolas

[ES] Distribución del sonido en sangre, plasma y eritrocitos en doce agrupaciones caprinas autóctonas española

Distribución del sonido en sangre, plasma y eritrocitos, en seis razas bovinas españolas

[ES] Distribución del sonido en sangre, plasma y eritrocitos, en seis razas bovinas española

Papel de los reguladores transcripcionales Fur (Ferric Uptake Regulator) en la síntesis de exopolisacáridos y formación de biofilms en Anabaena sp. PCC7120

Las cianobacterias presentan un gran potencial como biofertilizantes debido a sus numerosas estrategias de adaptación, entre las que destaca la producción de biofilms. La matriz del biofilm protege a la cianobacteria y le permite crecer en condiciones hostiles, como deficiencia de nutrientes o altos niveles de salinidad, por lo que puede proliferar en suelos erosionados por la sobrecarga de actividades agrícolas y proveer un soporte para el crecimiento de otros microorganismos beneficiosos. Además, algunas cianobacterias como Anabaena contribuyen a la fertilización con el proceso de fijación biológica de nitrógeno. Trabajos preliminares llevados a cabo por el grupo de investigación en Regulación Génica y Fisiología de Cianobacterias de la Universidad de Zaragoza, sugieren que las tres proteínas de la familia de reguladores transcripcionales FUR (FurA, FurB y FurC) presentes en Anababena sp. PCC7120, pueden controlar algunos de los factores que influyen en la producción de biofilms en esta cianobacteria. En este trabajo se ha analizado el impacto de la desregulación de las proteínas FUR de Anabaena en la producción de biofilms en diferentes condiciones de estrés. Para ello se ha estudiado cómo afecta la deficiencia de nitrógeno y altos niveles de salinidad a la producción de exopolisacáridos presentes en los sobrenadantes de cultivos de Anabaena y como se ven afectadas otras características como su metabolismo, crecimiento y morfología. Además, se han seleccionado un conjunto de genes relacionados con la síntesis de exopolisacáridos y se ha evaluado su posible regulación por FurA y FurC mediante ensayos de cambio en la migración electroforética (EMSA). Estos genes fueron escogidos con base en resultados previos de q-RT-PCR en los que se observó un alto nivel de expresión en condiciones de deficiencia de nitrógeno. Un total de seis glicosiltransferasas fueron evaluadas como dianas potenciales de FUR, la presencia de Fur boxes para FurA y FurC confirmó estos resultados. Adicionalmente, se cuantificó en sobrenadante la cantidad de exopolisacárido producido por la estirpe silvestre de Anabaena sp. PCC7120 y sus variantes de sobreexpresión AG2770FurA, VCS2770FurB y EB2770FurC en deficiencia de nitrógeno y en 300 mM de NaCl. Así mismo se evaluó la capacidad de estas cepas para producir biofilms. Finalmente, se estudió la capacidad protectora de los exopolisacáridos obtenidos del sobrenadante de Anabaena sp. PCC7120 en la germinación de semillas de arroz (Oryza sativa) de la variedad Ariete, sometiendo las semillas durante su germinación en placas de Petri a condiciones de estrés salino (100 mM de NaCl). Los resultados sugieren que FurA y FurC están relacionados con el control de la expresión de genes implicados en la formación de biofilms en Anabaena. <br /

Decreased levels of Thioredoxin o1 influences stomatal development and aperture but not Photosynthesis under non-stress and saline conditions

Salinity has a negative impact on plant growth, with photosynthesis being downregulated partially due to osmotic effect and enhanced cellular oxidation. Redox signaling contributes to the plant response playing thioredoxins (TRXs) a central role. In this work we explore the potential contribution of Arabidopsis TRXo1 to the photosynthetic response under salinity analyzing Arabidopsis wild-type (WT) and two Attrxo1 mutant lines in their growth under short photoperiod and higher light intensity than previous reported works. Stomatal development and apertures and the antioxidant, hormonal and metabolic acclimation are also analyzed. In control conditions mutant plants displayed less and larger developed stomata and higher pore size which could underlie their higher stomatal conductance, without being affected in other photosynthetic parameters. Under salinity, all genotypes displayed a general decrease in photosynthesis and the oxidative status in the Attrxo1 mutant lines was altered, with higher levels of H2O2 and NO but also higher ascorbate/glutathione (ASC/GSH) redox states than WT plants. Finally, sugar changes and increases in abscisic acid (ABA) and NO may be involved in the observed higher stomatal response of the TRXo1-altered plants. Therefore, the lack of AtTRXo1 affected stomata development and opening and the mutants modulate their antioxidant, metabolic and hormonal responses to optimize their adaptation to salinity.info:eu-repo/semantics/publishedVersio

The role of EZH2 in overall survival of colorectal cancer: a meta-analysis

[EN] Enhancer of zeste homolog 2 (EZH2) is the catalitic subunit of polycomb repressive complex 2 and mediates gene silencing. EZH2 is overexpressed in many cancers and correlates with poor prognosis. The role of the gene EZH2 in colorectal cancer survival is uncertainly, the aim of this study is clear this relationship. Relevant literaure was searched from electronic databases. A meta-analysis was performed with elegible studies which quantitatively evaluated the relationship between EZH2 overexpression and survival of patients with colorectal cancer. Survival data were aggregated and quantitatively analyzed. We performed a meta-analysis of 8 studies (n = 1059 patients) that evaluated the correlation between EZH2 overexpression and survival in patients with colorectal cancer. Combined hazard ratios suggested that EZH2 overexpression was associated with better prognosis of overall survival (OS) HR(hazard ratio) = 0.61 95% CI (0.38–0.84) We performed bias analysis according Egger and Begg,s test and we did not find publication bias. EZH2 overexpression indicates a better prognosis for colorectal cancerS