Protein Tyrosine Nitration during Development and Abiotic Stress Response in Plants

In recent years, the study of nitric oxide (NO) in plant systems has attracted the attention of many researchers. A growing number of investigations have shown the significance of NO as a signal molecule or as a molecule involved in the response against (a)biotic processes. NO can be responsible of the post-translational modifications (NO-PTM) of target proteins by mechanisms such as the nitration of tyrosine residues. The study of protein tyrosine nitration during development and under biotic and adverse environmental conditions has increased in the last decade; nevertheless, there is also an endogenous nitration which seems to have regulatory functions. Moreover, the advance in proteome techniques has enabled the identification of new nitrated proteins, showing the high variability among plant organs, development stage and species. Finally, it may be important to discern between a widespread protein nitration because of greater RNS content, and the specific nitration of key targets which could affect cell-signaling processes. In view of the above point, we present a mini-review that offers an update about the endogenous protein tyrosine nitration, during plant development and under several abiotic stress conditions.This study was supported by an ERDF grant co-financed by the Ministry of Economy and Competitiveness (project BIO2015-66390-P) and Junta de Andalucía (groups BIO286 and BIO192). Research in FJC laboratory is supported by an ERDF grant co-financed by the Ministry of Economy and Competitiveness (AGL2015-65104-P).Peer reviewedPeer Reviewe

Diseño de simuladores usando planilla de cálculo por alumnos ingresantes de Ingeniería

Esta publicación informa sobre la experiencia acumulada en el diseño y la construcción de simuladores usando Planilla de Cálculo por ingresantes de la Facultad de Ingeniería Química de la UNL durante el cursado de la asignatura Informática. El alumno debe hallar un procedimiento de resolución de un problema sin la computadora –introduciendo el concepto de algoritmo- para luego volcarlo a la Planilla de Cálculo y obtener un simulador eficiente y de fácil construcción. De los sistemas físicos evaluados seleccionamos el tema gases porque es básico, común a todas las carreras, exige el uso de un sistema de unidades y es anterior al desarrollo de Planilla de Cálculo. Se muestran algunas variantes de estos simuladores con distintos niveles de complejidad; el más completo realiza cálculos para diez gases ideales y reales usando la ecuación de Van der Waals. Se aplican comandos, herramientas y procedimientos -incluido el grabador de macros- sin acceder al código de programación. Aun con poco tiempo disponible, es posible la enseñanza del diseño y la construcción de estos simuladores en el inicio de las carreras de grado en ingenierías y en el pregrado de escuelas técnicas, dotando al alumno de una herramienta versátil y poderosa.Red de Universidades con Carreras en Informática (RedUNCI

Global environmental effects versus galaxy interactions

We explore properties of close galaxy pairs and merging systems selected from the Sloan Digital Sky Survey Data Release 4 in different environments with the aim to assess the relative importance of the role of interactions over global environmental processes. For this purpose, we perform a comparative study of galaxies with and without close companions as a function of local density and host halo mass, carefully removing sources of possible biases. We find that at low- and high-local-density environments, colours and concentration indices of close galaxy pairs are very similar to those of isolated galaxies. At intermediate densities, we detect significant differences, indicating that close pairs could have experienced a more rapid transition on to the red sequence than isolated galaxies. The presence of a correlation between concentration index and colours indicates that the physical mechanism responsible for the colour transformation also operates in the transformation of the luminous matter distribution. At fixed local densities, we find a dependence of the red galaxy fraction on dark matter halo mass for galaxies with or without a close companion. This suggests the action of host halo mass related effects. Regardless of dark matter halo mass, we show that the percentage of red galaxies in close pairs and in the control sample are comparable at low- and high-local-density environments. However, at intermediate local densities, the gap in the red fraction between close pairs and the control galaxies increases from ∼10 per cent in low-mass haloes up to ∼50 per cent in the most massive ones. Interestingly, we also detect that 50 per cent of merging systems populate the intermediate local environments, with a large fraction of them being extremely red and bulge dominated. Our findings suggest that in intermediate-density environments galaxies are efficiently pre-processed by close encounters and mergers before entering higher local density regions.Facultad de Ciencias Astronómicas y Geofísica

Diseño de simuladores usando planilla de cálculo por alumnos ingresantes de Ingeniería

Esta publicación informa sobre la experiencia acumulada en el diseño y la construcción de simuladores usando Planilla de Cálculo por ingresantes de la Facultad de Ingeniería Química de la UNL durante el cursado de la asignatura Informática. El alumno debe hallar un procedimiento de resolución de un problema sin la computadora –introduciendo el concepto de algoritmo- para luego volcarlo a la Planilla de Cálculo y obtener un simulador eficiente y de fácil construcción. De los sistemas físicos evaluados seleccionamos el tema gases porque es básico, común a todas las carreras, exige el uso de un sistema de unidades y es anterior al desarrollo de Planilla de Cálculo. Se muestran algunas variantes de estos simuladores con distintos niveles de complejidad; el más completo realiza cálculos para diez gases ideales y reales usando la ecuación de Van der Waals. Se aplican comandos, herramientas y procedimientos -incluido el grabador de macros- sin acceder al código de programación. Aun con poco tiempo disponible, es posible la enseñanza del diseño y la construcción de estos simuladores en el inicio de las carreras de grado en ingenierías y en el pregrado de escuelas técnicas, dotando al alumno de una herramienta versátil y poderosa.Red de Universidades con Carreras en Informática (RedUNCI

Dual regulation of cytosolic ascorbate peroxidase (APX) by tyrosine nitration and S-nitrosylation

JBM acknowledges a PhD fellowship (F.P.U.) from the Ministry of Science and Innovation. This work was supported by an ERDF-co-financed grant from the Ministry of Science and Innovation (BIO2009-12003-C02-01, BIO2009-12003-C02-02, and BIO2012-33904) and Junta de Andalucia (group BIO286 and BIO192), Spain. LC/MS/MS analyses were carried out at the Laboratorio de Proteomica LP-CSIC/UAB, a member of the ProteoRed network. Technical and human support provided by CICT of Universidad de Jaen (UJA, MINECO, Junta de Andalucia, FEDER) is gratefully acknowledged. We acknowledge Mr Carmelo Ruiz-Torres for his excellent technical support.Post-translational modifications (PTMs) mediated by nitric oxide (NO)-derived molecules have become a new area of research, as they can modulate the function of target proteins. Proteomic data have shown that ascorbate peroxidase (APX) is one of the potential targets of PTMs mediated by NO-derived molecules. Using recombinant pea cytosolic APX, the impact of peroxynitrite (ONOO–) and S-nitrosoglutathione (GSNO), which are known to mediate protein nitration and S-nitrosylation processes, respectively, was analysed. While peroxynitrite inhibits APX activity, GSNO enhances its enzymatic activity. Mass spectrometric analysis of the nitrated APX enabled the determination that Tyr5 and Tyr235 were exclusively nitrated to 3-nitrotyrosine by peroxynitrite. Residue Cys32 was identified by the biotin switch method as S-nitrosylated. The location of these residues on the structure of pea APX reveals that Tyr235 is found at the bottom of the pocket where the haem group is enclosed, whereas Cys32 is at the ascorbate binding site. Pea plants grown under saline (150mM NaCl) stress showed an enhancement of both APX activity and S-nitrosylated APX, as well as an increase of H2O2, NO, and S-nitrosothiol (SNO) content that can justify the induction of the APX activity. The results provide new insight into the molecular mechanism of the regulation of APX which can be both inactivated by irreversible nitration and activated by reversible S-nitrosylation.Spanish GovernmentERDF from the Ministry of Science and Innovation BIO2009-12003-C02-01 BIO2009-12003-C02-02 BIO2012-33904Junta de Andalucia BIO286 BIO192CICT of Universidad de Jaen (UJA, MINECO, Junta de Andalucia, FEDER

Nitro-fatty acids in plant signaling: Nitro-linolenic acid induces the molecular chaperone network in Arabidopsis

Nitro-fatty acids (NO-FAs) are the product of the reaction between reactive nitrogen species derived of nitric oxide (NO) and unsaturated fatty acids. In animal systems, NO-FAs are considered novel signaling mediators of cell function based on a proven antiinflammatory response. Nevertheless, the interaction of NO with fatty acids in plant systems has scarcely been studied. Here, we examine the endogenous occurrence of nitro-linolenic acid (NO-Ln) in Arabidopsis and the modulation of NO-Ln levels throughout this plant’s development by mass spectrometry. The observed levels of this NO-FA at picomolar concentrations suggested its role as a signaling effector of cell function. In fact, a transcriptomic analysis by RNA-seq technology established a clear signaling role for this molecule, demonstrating that NO-Ln was involved in plant defense response against different abiotic-stress conditions, mainly by inducing heat shock proteins and supporting a conserved mechanism of action in both animal and plant defense processes. Bioinformatics analysis revealed that NO-Ln was also involved in the response to oxidative stress conditions, mainly depicted by HO, reactive oxygen species, and oxygen-containing compound responses, with a high induction of ascorbate peroxidase expression. Closely related to these results, NO-Ln levels significantly rose under several abiotic-stress conditions such as wounding or exposure to salinity, cadmium, and low temperature, thus validating the outcomes found by RNA-seq technology. Jointly, to our knowledge, these are the first results showing the endogenous presence of NO-Ln in Arabidopsis (Arabidopsis thaliana) and supporting the strong signaling role of these molecules in the defense mechanism against different abiotic-stress situations.C.M.-P. thanks the University of Jaén for funding the Ph.D. fellowship. LC-MS/MS analyses were carried out at the Technical Services Department of the University of Granada, Spain. ACSCs were kindly provided by Dr. Juan Bautista Arellano from the Institute of Natural Resources and Agrobiology (IRNASA-CSIC, Salamanca, Spain).Peer Reviewe

The economic impact of machine perfusion technology in liver transplantation

Introduction: Several clinical studies have demonstrated the safety, feasibility, and efficacy of machine perfusion in liver transplantation, although its economic outcomes are still underexplored. This review aimed to examine the costs related to machine perfusion and its associated outcomes.Methods: Expert opinion of several groups representing different machine perfusion modalities. Critical analysis of the published literature reporting the economic outcomes of the most used techniques of machine perfusion in liver transplantation (normothermic and hypothermic ex situ machine perfusion and in situ normothermic regional perfusion).Results: Machine perfusion costs include disposable components of the perfusion device, perfusate components, personnel and facility fees, and depreciation of the perfusion device or device lease fee. The limited current literature suggests that although this upfront cost varies between perfusion modalities, its use is highly likely to be cost-effective. Optimization of the donor liver utilization rate, local conditions of transplant programs (long waiting list times and higher MELD scores), a decreased rate of complications, changes in logistics, and length of hospital stay are potential cost savings points that must highlight the expected benefits of this intervention. An additional unaccounted factor is that machine perfusion optimizing donor organ utilization allows patients to be transplanted earlier, avoiding clinical deterioration while on the waiting list and the costs associated with hospital admissions and other required procedures.Conclusion: So far, the clinical benefits have guided machine perfusion implementation in liver transplantation. Albeit there is data suggesting the economic benefit of the technique, further investigation of its costs to healthcare systems and society and associated outcomes is needed.</p

Differential molecular response of monodehydroascorbate reductase and glutathione reductase by nitration and S-nitrosylation

The ascorbate–glutathione cycle is a metabolic pathway that detoxifies hydrogen peroxide and involves enzymatic and non-enzymatic antioxidants. Proteomic studies have shown that some enzymes in this cycle such as ascorbate peroxidase (APX), monodehydroascorbate reductase (MDAR), and glutathione reductase (GR) are potential targets for post-translational modifications (PMTs) mediated by nitric oxide-derived molecules. Using purified recombinant pea peroxisomal MDAR and cytosolic and chloroplastic GR enzymes produced in Escherichia coli, the effects of peroxynitrite (ONOO–) and S-nitrosoglutathione (GSNO) which are known to mediate protein nitration and S-nitrosylation processes, respectively, were analysed. Although ONOO– and GSNO inhibit peroxisomal MDAR activity, chloroplastic and cytosolic GR were not affected by these molecules. Mass spectrometric analysis of the nitrated MDAR revealed that Tyr213, Try292, and Tyr345 were exclusively nitrated to 3-nitrotyrosine by ONOO–. The location of these residues in the structure of pea peroxisomal MDAR reveals that Tyr345 is found at 3.3 Å of His313 which is involved in the NADPbinding site. Site-directed mutagenesis confirmed Tyr345 as the primary site of nitration responsible for the inhibition of MDAR activity by ONOO–. These results provide new insights into the molecular regulation of MDAR which is deactivated by nitration and S-nitrosylation. However, GR was not affected by ONOO– or GSNO, suggesting the existence of a mechanism to conserve redox status by maintaining the level of reduced GSH. Under a nitro-oxidative stress induced by salinity (150 mM NaCl), MDAR expression (mRNA, protein, and enzyme activity levels) was increased, probably to compensate the inhibitory effects of S-nitrosylation and nitration on the enzyme. The present data show the modulation of the antioxidative response of key enzymes in the ascorbate–glutathione cycle by nitric oxide (NO)- PTMs, thus indicating the close involvement of NO and reactive oxygen species metabolism in antioxidant defence against nitro-oxidative stress situations in plants.Spanish GovernmentERDF - Ministry of Economy and Competitiveness BIO2012-33904Junta de Andalucía BIO286 BIO19

Metodología del estudio Guadix sobre los efectos de un desayuno de tipo mediterráneo sobre los parámetros lipídicos y postprandiales en preadolescentes con sobrepeso y obesidad

El exceso de peso corporal de la población ha llevado a la Organización Mundial de la Salud a calificarlo como epidemia global. La prevalencia de sobrepeso y obesidad infantil en España se sitúa entre las más elevadas del continente europeo, y es aún superior en Andalucía. Las consecuencias para la salud de los niños no son tan evidentes como en los adultos, pero la obesidad infantil se está asociando con patologías que se creían eran sólo padecidas por los adultos, tales como el síndrome metabólico. La resistencia a la insulina es el factor de riesgo más importante en sujetos con obesidad severa, que junto con la obesidad visceral, exacerban la trigliceridemia postprandial, lo que incrementa el riesgo cardiovascular. Sin embargo y a nuestro entender, este fenómeno no ha sido debidamente estudiado por el momento en la población infantil. Las propiedades cardiosaludables del aceite de oliva, el ingrediente principal de la Dieta Mediterránea, han sido sobradamente puestas de manifiesto, que incluyen un mejor patrón lipídico postprandial. En este contexto, el objetivo de este estudio es determinar los efectos de un desayuno de tipo mediterráneo sobre parámetros lipídicos postprandiales en preadolescentes con sobrepeso y obesidad. Para ello, se ha llevado a cabo un estudio cuasi experimental prospectivo multicéntrico, que compara los beneficios de una intervención dietética en una sola comida de tipo mediterráneo en el metabolismo lipídico postprandial en sujetos en edades preadolescentes (10-14 años) afectados por obesidad o sobrepeso (grupo estudio), con respecto a los sujetos normopeso (grupo control). Los resultados permiten ampliar el conocimiento sobre la fisiopatología de la obesidad de los niños y contribuir a las recomendaciones dietéticas para el mantenimiento de la población infantil. Más aún, aportan información sobre el desarrollo de aterogénesis durante el periodo postprandial, que puede comenzar a edades tan tempranas.The excess weight that characterizes much of the population of the world today has led the World Health Organization to declare a obesity pandemic. The number of overweight and obese children in Spain is among the highest in Europe, and this number is even higher in Andalusia. The health consequences of excess weight for children are not as evident as for adults. However, child obesity is now being associated with pathologies, such as the metabolic syndrome, which were previously believed to be only found in adults. Resistance to insulin is an important risk factor in subjects with severe obesity, which along with visceral obesity, make postprandial triglyceridemia more severe. This increases cardiovascular risk. However, in our opinion, this phenomenon has not been adequately studied in children. The hearthealthy properties of olive oil, the main ingredient of the Mediterranean diet, have been clearly highlighted in various studies. These properties include an improved postprandial lipid pattern. In this context, the objective of this study was to determine the effects of a Mediterranean-diet breakfast on the postprandial lipid parameters in a study group of overweight and obese preadolescents (age 10-14) in comparison to a control group of subjects with no weight problems. The results obtained provide greater knowledge of the physiopathology of child obesity and contribute to the elaboration of dietary recommendations for the maintenance of child health. Additionally, our results give information regarding the development of atherogenesis during the postprandial period, which can begin at a very early age

Breast feeding: an effective method to prevent breast cancer

Introducción: El cáncer de mama constituye el tumor ginecológico más frecuente entre las mujeres jóvenes de los países occidentales. Sus graves consecuencias para la salud y una cada vez más temprana edad de diagnóstico han llevado a analizar cuidadosamente sus causas y posibles medidas preventivas, convirtiéndose su estudio en un objetivo primario de la investigación epidemiológica. Muestra y métodos: se revisaron 504 historias clínicas pertenecientes a pacientes de sexo femenino con edades comprendidas entre los 19 y los 91 años. Todos ellas diagnosticadas y tratadas de cáncer de mama entre los años 2003 a 2008 en el Hospital Universitario "San Cecilio" de Granada (España). Resultados: se encontró una correlación significativa (p = 0,001) entre la edad de diagnóstico del cáncer, el tiempo de lactancia materna, y la existencia de antecedentes familiares y personales para cáncer. Por el contrario, no se encontraron diferencias estadísticamente significativas test (t-Student) entre la edad media de diagnóstico del cáncer y el hecho de haber tenido o no descendencia (t = 0,559, p = 0,576). Conclusiones: la lactancia materna por períodos de tiempo superiores a seis meses, no sólo proporciona a los niños numerosos beneficios para su salud, sino que también puede proteger a la madre de enfermedades graves, como lo es el cáncer de mama.Introduction: Breast cancer is the most common gynecological tumor in young women in Western countries. Its profound implications for health and an increasingly early age of diagnosis have been carefully analyzed its causes and possible preventive measures, making their study in a primary goal of epidemiological research. Sample and methods: We reviewed medical records pertaining to 504 female patients aged 19 to 91 years. All of them were diagnosed and treated for breast cancer between 2003-2008 at the Hospital Universitario "San Cecilio" of Granada (Spain). Results: We found a significant correlation (p = 0.001) between the age of cancer diagnosis, length of breastfeeding, and the existence of personal and family history for cancer. By contrast, there were no statistically significant differences test (t-test) between the average age of diagnosis of cancer and having had offspring or not (t = 0.559, p = 0.576). Conclusions: Breastfeeding for periods of longer than six months, not only provides children with many health benefits, but may also protect the mother from serious diseases, such as breast cancer