Antioxidant and Anti-Inflammatory Strategies Based on the Potentiation of Glutathione Peroxidase Activity Prevent Endothelial Dysfunction in Chronic Kidney Disease

BACKGROUND/AIMS: Accelerated atherosclerosis in chronic kidney disease (CKD) is preceded by endothelial dysfunction (ED), which exhibits a proinflammatory and prothrombotic phenotype and enhanced oxidative stress. In this study, the effect of several compounds with anti-inflammatory and/or antioxidant properties on uremia-induced endothelial dysfunction has been evaluated in an in vitro model. METHODS: Endothelial cells (ECs) were exposed to sera from uremic patients in the absence and presence of the flavonoids apigenin, genistein and quercetin, the antioxidant enzyme mimetics (AEM) ebselen (glutathione peroxidase mimetic), EUK-134 and EUK-118 (both superoxide dismutase mimetics), and the pharmacological drug N-acetylcysteine (NAC). We explored changes in the expression of adhesion receptors on the cell surface, by immunofluorescence, the production of radical oxygen species (ROS), by fluorescence detection, and the activation of signaling proteins related to inflammation, by both a phosphospecific antibody cell-based ELISA and immunoblotting techniques. RESULTS: Uremic media induced a significantly increased expression of ICAM-1, overproduction of radical oxygen species (ROS) and activation of p38 mitogen activated protein kinase (p38MAPK) and Nuclear Factor kB (NFkB) in ECs. Quercetin, the AEM and NAC showed a significant inhibitory effect on both ICAM-1 expression and ROS generation (p<0.05). All the compounds reduced p38MAPK activation, but only the AEM, especially ebselen, and NAC, both potentiating the glutathione peroxidase pathway, also inhibited NFkB activation. These two compounds were capable of increasing endothelial glutathione levels, especially in response to uremia. CONCLUSION: Our results indicate that the potentiation of the antioxidant pathways can be an effective strategy to improve endothelial dysfunction in uremia and a potential target to reduce the cardiovascular risk in this population

Antioxidant and Anti-Inflammatory Strategies Based on the Potentiation of Glutathione Peroxidase Activity Prevent Endothelial Dysfunction in Chronic Kidney Disease

Background/Aims: Accelerated atherosclerosis in chronic kidney disease (CKD) is preceded by endothelial dysfunction (ED), which exhibits a proinflammatory and prothrombotic phenotype and enhanced oxidative stress. In this study, the effect of several compounds with anti-inflammatory and/or antioxidant properties on uremia-induced endothelial dysfunction has been evaluated in an in vitro model. Methods: Endothelial cells (ECs) were exposed to sera from uremic patients in the absence and presence of the flavonoids apigenin, genistein and quercetin, the antioxidant enzyme mimetics (AEM) ebselen (glutathione peroxidase mimetic), EUK-134 and EUK-118 (both superoxide dismutase mimetics), and the pharmacological drug N-acetylcysteine (NAC). We explored changes in the expression of adhesion receptors on the cell surface, by immunofluorescence, the production of radical oxygen species (ROS), by fluorescence detection, and the activation of signaling proteins related to inflammation, by both a phosphospecific antibody cell-based ELISA and immunoblotting techniques. Results: Uremic media induced a significantly increased expression of ICAM-1, overproduction of radical oxygen species (ROS) and activation of p38 mitogen activated protein kinase (p38MAPK) and Nuclear Factor kB (NFkB) in ECs. Quercetin, the AEM and NAC showed a significant inhibitory effect on both ICAM-1 expression and ROS generation (p&#x3c;0.05). All the compounds reduced p38MAPK activation, but only the AEM, especially ebselen, and NAC, both potentiating the glutathione peroxidase pathway, also inhibited NFkB activation. These two compounds were capable of increasing endothelial glutathione levels, especially in response to uremia. Conclusion: Our results indicate that the potentiation of the antioxidant pathways can be an effective strategy to improve endothelial dysfunction in uremia and a potential target to reduce the cardiovascular risk in this population

Metodologías alternativas y colaborativas en el uso de la fotografía analógica en períodos de crisis

El objetivo principal del proyecto Metodologías alternativas y colaborativas en el uso de la fotografía analógica en períodos de crisis era: “redescubrir un saber y una técnica que se encuentra olvidada y establecer una metodología colaborativa y nueva para su aprendizaje. Esto conlleva de forma física la recuperación de unas instalaciones de la Facultad de CC.INF. que se encontraban en estado de desuso” (memoria del proyecto de innovación docente 2016-2017, núm. 139)

The katG mRNA of Mycobacterium tuberculosis and Mycobacterium smegmatis is processed at its 5' end and is stabilized by both a polypurine sequence and translation initiation

<p>Abstract</p> <p>Background</p> <p>In <it>Mycobacterium tuberculosis </it>and in <it>Mycobacterium smegmatis </it>the <it>furA</it>-<it>katG </it>loci, encoding the FurA regulatory protein and the KatG catalase-peroxidase, are highly conserved. In <it>M. tuberculosis furA-katG </it>constitute a single operon, whereas in <it>M. smegmatis </it>a single mRNA covering both genes could not be found. In both species, specific 5' ends have been identified: the first one, located upstream of the <it>furA </it>gene, corresponds to transcription initiation from the <it>furA </it>promoter; the second one is the <it>katG </it>mRNA 5' end, located in the terminal part of <it>furA</it>.</p> <p>Results</p> <p>In this work we demonstrate by in vitro transcription and by RNA polymerase Chromatin immunoprecipitation that no promoter is present in the <it>M. smegmatis </it>region covering the latter 5' end, suggesting that it is produced by specific processing of longer transcripts. Several DNA fragments of <it>M. tuberculosis </it>and <it>M. smegmatis </it>were inserted in a plasmid between the <it>sigA </it>promoter and the <it>lacZ </it>reporter gene, and expression of the reporter gene was measured. A polypurine sequence, located four bp upstream of the <it>katG </it>translation start codon, increased beta-galactosidase activity and stabilized the <it>lacZ </it>transcript. Mutagenesis of this sequence led to destabilization of the mRNA. Analysis of constructs, in which the polypurine sequence of <it>M. smegmatis </it>was followed by an increasing number of <it>katG </it>codons, demonstrated that mRNA stability requires translation of at least 20 amino acids. In order to define the requirements for the 5' processing of the <it>katG </it>transcript, we created several mutations in this region and analyzed the 5' ends of the transcripts: the distance from the polypurine sequence does not seem to influence the processing, neither the sequence around the cutting point. Only mutations which create a double stranded region around the processing site prevented RNA processing.</p> <p>Conclusion</p> <p>This is the first reported case in mycobacteria, in which both a polypurine sequence and translation initiation are shown to contribute to mRNA stability. The <it>furA-katG </it>mRNA is transcribed from the <it>furA </it>promoter and immediately processed; this processing is prevented by a double stranded RNA at the cutting site, suggesting that the endoribonuclease responsible for the cleavage cuts single stranded RNA.</p

Redox homeostasis and age-related deficits in neuromuscular integrity and function

Skeletal muscle is a major site of metabolic activity and is the most abundant tissue in the human body. Age-related muscleatrophy (sarcopenia) and weakness, characterized by progressive loss of lean muscle mass and function, is a major contributorto morbidity and has a profound effect on the quality of life of older people. With a continuously growing older population(estimated 2 billion of people aged >60 by 2050), demand for medical and social care due to functional deficits, associatedwith neuromuscular ageing, will inevitably increase. Desp ite the importance of this ‘epidemic’ problem, the primarybiochemical and molecular mechanisms underlying age-related deficits in neuromuscular integrity and function have not beenfully determined. Skeleta l muscle generates reactive oxygen and nitrogen species (RONS) from a variety of subcellular sources,and age-associated oxidative damage has been suggested to be a major fac tor contributing to the initiation and progression ofmuscle atrophy inherent with ageing. RONS can modulate a variety of intracellular signal transduction processes, anddisruption of these events over time due to altered redox control has been proposed as an underlying mechanis m of ageing.The role of oxidants in ageing has been extensively examined in different model organisms that have undergone geneticmanipulations with inconsistent findings. Transgenic and knockout rodent studies have provided insight into the function ofRONS regulatory systems in neuromuscular ageing. This review summarizes almost 30 years of research in the field of redoxhomeostasis and muscle ageing, providing a detailed discussion of the experimental approaches that have been undertaken inmurine models to examine the role of redox regulation in age-related muscle atrophy and weakness

Trends in socioeconomic inequalities in general mortality in the city of Cadiz, Spain (1992-2007)

Objective: To analyze trends in socioeconomic inequality in mortality in the city of Cadiz (Spain) from 1992 to 2007. Methods: An ecological study was performed of trends over 3 cross-sections, with the census tract as the unit of analysis. Deaths were grouped into three periods: 1992-1996, 1997-2001 and 2002-2007 and were then classified according to a deprivation index of the census tract. We calculated adjusted rates by the direct method and three measures of health inequality. Results: Of 18,586 deaths, 96.7% was geocoded to a census tract. The population-attributable risk decreased in men and women, respectively, from 15.4% and 12.2% in 1992-1996 to 9.3% and 5.6% in 2002-2007. The other measures, slope index and the relative index also showed a decline in inequality but only among women. Conclusions: Despite a decreasing trend, social inequalities are a substantial component in the distribution of overall mortality in the city of Cadiz. Titel på spanska: Evolución de las desigualdades sociales en la mortalidad general de la ciudad de Cádiz (1992–2007)</p