The Senegalese Sole Mx gene promoter contains a variable microsatellite region involved in the transcriptional

Interferons (IFNs) play a key role against viral infections by stimulating the expression of IFN stimulated genes, such as Mx. The transcriptional regulation of these genes in fish are poorly understood. The sequencing of the Senegalese sole (Solea senegalensis) Mx gene promoter revealed the presence of a guanosine-citosine rich region that contains a microsatellite, sited close to the translation start codon. The aim of the current study has been to determine the functional role of this region and to study its variability.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Microtubules regulate cardiomyocyte transversal Young's modulus.

The field of cardiomyocyte mechanobiology is gaining significant attention, due to accumulating evidence concerning the significant role of cellular mechanical effects on the integrated function of the heart. To date, the protein titin has been demonstrated as a major contributor to the cardiomyocytes Young's modulus (YM). The microtubular network represents another potential regulator of cardiac mechanics. However, the contribution of microtubules (MTs) to the membrane YM is still understudied and has not been interrogated in the context of myocardial infarction (MI) or mechanical loading and unloading. Using nanoscale mechanoscanning ion conductance microscopy, we demonstrate that MTs contribute to cardiomyocyte transverse YM in healthy and pathological states with different mechanical loading. Specifically, we show that posttranslational modifications of MTs have differing effects on cardiomyocyte YM: Acetylation provides flexibility, whereas detyrosination imparts rigidity. Further studies demonstrate that there is no correlation between the total protein amount of acetylated and detyrosinated MT. Yet, in the polymerized-only populations, an increased level of acetylation results in a decline of detyrosinated MTs in an MI model

Short-term angiotensin II treatment regulates cardiac nanomechanics via microtubule modifications.

Mechanical properties of single myocytes contribute to the whole heart performance, but the measurement of mechanics in living cells at high resolution with minimal force interaction remains challenging. Angiotensin II (AngII) is a peptide hormone that regulates a number of physiological functions, including heart performance. It has also been shown to contribute to cell mechanics by inducing cell stiffening. Using non-contact high-resolution Scanning Ion Conductance Microscopy (SICM), we determine simultaneously cell topography and membrane transverse Young's modulus (YM) by a constant pressure application through a nanopipette. While applying pressure, the vertical position is recorded and a deformation map is generated from which YM can be calculated and corrected for the uneven geometry. High resolution of this method also allows studying specific membrane subdomains, such as Z-grooves and crests. We found that short-term AngII treatment reduces the transversal YM in isolated adult rat cardiomyocytes acting via an AT1 receptor. Blocking either a TGF-β1 receptor or Rho kinase abolishes this effect. Analysis of the cytoskeleton showed that AngII depletes microtubules by decreasing long-lived detyrosinated and acetylated microtubule populations. Interestingly, in the failing cardiomyocytes, which are stiffer than controls, the short-term AngII treatment also reduces the YM, thus normalizing the mechanical state of cells. This suggests that the short-term softening effect of AngII on cardiac cells is opposite to the well-characterized long-term hypertrophic effect. In conclusion, we generate a precise nanoscale indication map of location-specific transverse cortical YM within the cell and this can substantially advance our understanding of cellular mechanics in a physiological environment, for example in isolated cardiac myocytes

Short-term angiotensin II treatment regulates cardiac nanomechanics: Via microtubule modifications

Mechanical properties of single myocytes contribute to the whole heart performance, but the measurement of mechanics in living cells at high resolution with minimal force interaction remains challenging. Angiotensin II (AngII) is a peptide hormone that regulates a number of physiological functions, including heart performance. It has also been shown to contribute to cell mechanics by inducing cell stiffening. Using non-contact high-resolution Scanning Ion Conductance Microscopy (SICM), we determine simultaneously cell topography and membrane transverse Young's modulus (YM) by a constant pressure application through a nanopipette. While applying pressure, the vertical position is recorded and a deformation map is generated from which YM can be calculated and corrected for the uneven geometry. High resolution of this method also allows studying specific membrane subdomains, such as Z-grooves and crests. We found that short-term AngII treatment reduces the transversal YM in isolated adult rat cardiomyocytes acting via an AT1 receptor. Blocking either a TGF-β1 receptor or Rho kinase abolishes this effect. Analysis of the cytoskeleton showed that AngII depletes microtubules by decreasing long-lived detyrosinated and acetylated microtubule populations. Interestingly, in the failing cardiomyocytes, which are stiffer than controls, the short-term AngII treatment also reduces the YM, thus normalizing the mechanical state of cells. This suggests that the short-term softening effect of AngII on cardiac cells is opposite to the well-characterized long-term hypertrophic effect. In conclusion, we generate a precise nanoscale indication map of location-specific transverse cortical YM within the cell and this can substantially advance our understanding of cellular mechanics in a physiological environment, for example in isolated cardiac myocytes

Aprendizaje basado en proyectos: aplicación a la asignatura “Proyecto de Embarcaciones Rápidas y a Vela”

En este artículo se presenta la metodología de aprendizaje aplicada a la asignatura “Proyecto de Embarcaciones Rápidas y a Vela”, optativa del grado de Arquitectura Naval de la UPM. Proponemos un enfoque amplio basado en proyectos (PBL), con tres objetivos: que los alumnos realicen un ante-proyecto de embarcación rápida o a vela; que conecten con la realidad industrial del sector; y, por último, estimular su curiosidad y motivación hacia el contenido del curso. La asignatura se divide en dos bloques temáticos y tres módulos de trabajo, dos teóricos y uno práctico. Para evaluar el cumplimento de los objetivos propuestos se ha realizado una encuesta a los alumnos y se analizan algunos de los proyectos entregados por ellos. El artículo se cierra con conclusiones y propuestas de trabajo futuro

Potenciar la experiencia y habilidades frente a problemas prácticos en las clases de laboratorio de “Flotabilidad y Estabilidad”

En este trabajo se presentan las medidas adoptadas en las prácticas de la asignatura “Flotabilidad y Estabilidad”, del grado de “Arquitectura Naval” de la UPM, para potenciar la capacidad de los alumnos de enfrentarse a problemas prácticos y para entender la casuística que ellos involucran (necesidad de planificación, manejo de herramientas, etc.). En concreto, se describen: a) Una actividad complementaria, introducida en el curso 2019/2020, que involucra la realización de un experimento con un barco real; b) La adaptación de las prácticas a formato no presencial en el curso 2020/2021. Este cambio de formato, consecuencia de la situación de pandemia, tiene en principio un efecto negativo en cuanto al objetivo que se persigue. Para tratar de minimizarlo, se introdujo un nuevo concepto de práctica en la que los alumnos realizaron un experimento casero, devolviendo así el aspecto práctico a la actividad, a pesar de la no presencialidad. En este artículo se evalúa la efectividad de las medidas implementadas en cuanto al cumplimento del objetivo de mejorar la capacidad de los alumnos de enfrentar problemas prácticos, así como de otros objetivos que se buscan con las prácticas. El artículo se cierra con conclusiones y propuestas de trabajo futuro

Junctophilin-2 tethers T-tubules and recruits functional L-type calcium channels to lipid rafts in adult cardiomyocytes

Aim: In cardiomyocytes, transverse tubules (T-tubules) associate with the sarcoplasmic reticulum (SR), forming junctional membrane complexes (JMCs) where L-type calcium channels (LTCCs) are juxtaposed to Ryanodine receptors (RyR). Junctophilin-2 (JPH2) supports the assembly of JMCs by tethering T-tubules to the SR membrane. T-tubule remodeling in cardiac diseases is associated with down-regulation of JPH2 expression suggesting that JPH2 plays a crucial role in T-tubule stability. Furthermore, increasing evidence indicate that JPH2 might additionally act as a modulator of calcium signaling by directly regulating RyR and LTCCs. This study aimed at determining whether JPH2 overexpression restores normal T-tubule structure and LTCC function in cultured cardiomyocytes. Methods and results: Rat ventricular myocytes kept in culture for 4 days showed extensive T-tubule remodeling with impaired JPH2 localization and relocation of the scaffolding protein Caveolin3 (Cav3) from the T-tubules to the outer membrane. Overexpression of JPH2 restored T-tubule structure and Cav3 relocation. Depletion of membrane cholesterol by chronic treatment with Methyl-β-cyclodextrin (MβCD) countered the stabilizing effect of JPH2 overexpression on T-tubules and Cav3. Super-resolution scanning patch-clamp showed that JPH2 overexpression greatly increased the number of functional LTCCs at the plasma membrane. Treatment with MβCD reduced LTCC open probability and activity. Proximity ligation assays showed that MβCD did not affect JPH2 interaction with RyR and the pore-forming LTCC subunit Cav1.2, but strongly impaired JPH2 association with Cav3 and the accessory LTCC subunit Cavβ2. Conclusions: JPH2 promotes T-tubule structural stability and recruits functional LTCCs to the membrane, most likely by directly binding to the channel. Cholesterol is involved in the binding of JPH2 to T-tubules as well as in the modulation of LTCC activity. We propose a model where cholesterol and Cav3 support the assembly of lipid rafts which provide an anchor for JPH2 to form JMCs and a platform for signaling complexes to regulate LTCC activity

Desarrollo de un servicio experimental de teledetección en los riegos del Porma (León) para el cálculo ajustado de necesidades hídricas y mejora en la gestión del regadío

El proyecto de innovación tecnológica OPTIREG Eficiencia Hídrica, impulsado por el Grupo Tragsa, tiene entre sus objetivos principales introducir el uso de la teledetección, como tecnología de apoyo a la gestión hídrica. Para ello se está desarrollando un servicio web gis experimental que servirá de repositorio único de imágenes y de sus productos derivados y que facilitará, tanto a los regantes, como a los gestores del riego, el seguimiento de los cultivos y de sus necesidades hídricas. Diversos estudios científicos han demostrado la buena relación lineal existente entre el índice de vegetación normalizado (NDVI), derivado de las imágenes de satélite, y el coeficiente de cultivo, Kc (Torres, 2010), utilizado en el cálculo de la evapotranspiración y las necesidades hídricas. Una primera evaluación de los resultados obtenidos en la campaña 2015 para los principales cultivos en regadío en la zona de estudio del Porma (León), indica que el Kc calculado a partir del NDVI, se ajusta mejor que el de FAO. Por ello, se considera un sistema muy válido como referencia para ajustar no sólo la cantidad de agua, sino también para determinar el momento más adecuado de riego, que redundará en una mayor eficiencia hídrica

Bacillus subtilis polynucleotide phosphorylase 3′-to-5′ DNase activity is involved in DNA repair

In the presence of Mn2+, an activity in a preparation of purified Bacillus subtilis RecN degrades single-stranded (ss) DNA with a 3′ → 5′ polarity. This activity is not associated with RecN itself, because RecN purified from cells lacking polynucleotide phosphorylase (PNPase) does not show the exonuclease activity. We show here that, in the presence of Mn2+ and low-level inorganic phosphate (Pi), PNPase degrades ssDNA. The limited end-processing of DNA is regulated by ATP and is inactive in the presence of Mg2+ or high-level Pi. In contrast, the RNase activity of PNPase requires Mg2+ and Pi, suggesting that PNPase degradation of RNA and ssDNA occur by mutually exclusive mechanisms. A null pnpA mutation (ΔpnpA) is not epistatic with ΔrecA, but is epistatic with ΔrecN and Δku, which by themselves are non-epistatic. The addA5, ΔrecO, ΔrecQ (ΔrecJ), ΔrecU and ΔrecG mutations (representative of different epistatic groups), in the context of ΔpnpA, demonstrate gain- or loss-of-function by inactivation of repair-by-recombination, depending on acute or chronic exposure to the damaging agent and the nature of the DNA lesion. Our data suggest that PNPase is involved in various nucleic acid metabolic pathways, and its limited ssDNA exonuclease activity plays an important role in RecA-dependent and RecA-independent repair pathways