Regulación de la expresión y actividad de IF1, el inhibidor fisiológico de la H+-ATP sintasa de la mitocondria

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 27-11-2015The mitochondrial H+-ATP synthase synthesizes most of cellular ATP requirements by oxidative phosphorylation (OXPHOS). The ATPase Inhibitory Factor 1 (IF1) is a nuclear-encoded mitochondrial protein known to inhibit the ATP hydrolytic activity of the H+-ATP synthase to preserve the proton electrochemical gradient in situations that compromise respiration. Recent findings in colon cancer cells indicate that inhibition of the H+-ATP synthase by IF1 also affects ATP synthetic activity thus promoting aerobic glycolysis and a reactive oxygen species (ROS)- mediated signal that enhances proliferation and cell survival. Herein we have studied the mechanisms that govern the regulation of the expression and activity of IF1 and show the tight regulation exerted by IF1 on the H+-ATP synthase. We illustrate that the overexpression of isoform 1 of IF1observed in human colon, lung, breast and ovarian carcinomas is exerted posttranscripcionally. We demonstrate that IF1 is a short-lived protein (t1/2 = 4 h) whose degradation depends on the activity of mitochondrial serine-proteases and on the inner mitochondrial membrane metalloprotease YME1L. In addition, we describe mechanisms that regulate translation of IF1 mRNA mediated by mitochondrial ROS and microRNA 24-3p. Moreover, this study also unveils a novel regulatory mechanism of IF1 activity: the phosphorylation of serine 39 of human IF1 by mitochondrial protein kinase A (PKA). Phosphorylation of IF1 abolishes its capacity to bind the H+- ATP synthase and hence to exert its biological activity on the enzyme. Only dephosphorylated IF1 binds and inhibits both the hydrolase and synthase activities of the enzyme. The phosphorylation status of IF1 regulates the flux of aerobic glycolysis and ATP production through OXPHOS in several cellular situations such as hypoxia or during cell cycle progression. Moreover, dephosphorylated IF1 is present in human carcinomas suggesting the importance of active IF1 for the tumorigenic phenotype. Remarkably, mouse heart contains a large fraction of dephosphorylated IF1 that becomes phosphorylated and inactivated upon in vivo β-adrenergic stimulation. Dephosphorylated IF1 is also less prone to its turnover than phosphorylated IF1. Overall, our results demonstrate the wide range of mechanisms that post-transcriptionally regulate IF1 expression and activity and stress the essential function of IF1 in regulating ATP output and energy metabolismLa H+-ATP sintasa es el complejo enzimático que se encarga de sintetizar la mayor parte de los requerimientos celulares de ATP a través de la fosforilación oxidativa (OXPHOS). El factor inhibidor de la ATPasa (IF1) es una proteína mitocondrial codificada en el núcleo cuya función descrita es la de inhibir la actividad ATP hidrolítica de la H+-ATP sintasa con el fin de preservar el ATP celular en situaciones que comprometen el funcionamiento de la cadena de transporte electrónico y la OXPHOS. Estudios recientes en diferentes tipos celulares implican que la inhibición de la H+-ATP sintasa por IF1 afecta además a la actividad ATP sintética produciendo un aumento de la glucolisis aeróbica y una señal mediada por especies reactivas de oxígeno (ROS) que aumenta la proliferación y supervivencia celular. En este trabajo estudiamos los mecanismos que controlan la expresión y actividad de IF1 demostrando la relevancia de la acción inhibidora mediada por IF1 sobre la H+-ATP sintasa. La sobreexpresión de la proteína observada en carcinomas humanos de colon, pulmón, mama y ovario se debe a cambios en la regulación post-transcripcional de la expresión de la isoforma 1 de IF1. Demostramos que IF1 es una proteína de vida media corta (t1/2 = 4 h) cuya degradación depende de serín-proteasas mitocondriales y de la metaloproteasa de membrana interna mitocondrial YME1L. También describimos mecanismos de regulación traduccional del mRNA de IF1 mediada por ROS mitocondriales y el microRNA 24-3p. En este trabajo se desvela un nuevo mecanismo regulador de la actividad de IF1: la fosforilación de la serina 39 del IF1 humano por una protein quinasa A (PKA) mitocondrial. La fosforilación de IF1 anula su capacidad para unirse a la H+-ATP sintasa. Solo el IF1 defosforilado se une e inhibe tanto la actividad hidrolasa como la sintasa del enzima. El estado de fosforilación de IF1 regula el flujo de la glucolisis aeróbica y la producción de ATP mediante OXPHOS en distintas situaciones celulares tales como la hipoxia o la progresión por el ciclo celular. Además, IF1 está en su estado defosforilado en carcinomas humanos sugiriendo la importancia del mismo para explicar el fenotipo tumoral. Es de destacar que el corazón de ratón contiene una fracción de IF1 defosforilado que se fosforila e inactiva ante una estimulación β-adrenérgica in vivo. IF1 defosforilado es también menos propenso a degradarse que el IF1 fosforilado. En conjunto los resultados de este estudio demuestran la amplitud de mecanismos que regulan de manera post-transcripcional la expresión de IF1 y su actividad, poniendo de manifiesto la función esencial de IF1 y de su forma defosforilada activa en la regulación de la producción de ATP y el metabolismo energéticoEl autor ha disfrutado de una Beca/contrato predoctoral del Programa Nacional de Formación de Personal Investigador (FPI-MICINN) asociada al proyecto BFU2010-1890

Evaluation of Enzyme Additives on the Nutritional Use of Feeds with a High Content of Plant Ingredients for Mugil cephalus

The Mugilidae are a group of fish with a great interest for aquaculture due to their omnivorous profile, rapid growth, and resistance to environmental variations. The selection of feed ingredients for these species is currently focused on an extensive use of plant by-products, with this being limited by their content in anti-nutritive factors (mainly phytate and non-starch polysaccharides; NSPs). Nevertheless, specific enzymes can be used to counteract some of those negative effects. In the present study, the effect of pretreating two high-plant feeds with a mixture of enzymes (glucanases + phytase) on the digestive use of protein and phosphorus by juvenile mullets (Mugil cephalus) was assessed using both in vitro and in vivo assays. The enzymatic treatment significantly modified the potential bioavailability of some nutrients, such as a reduction of sugars, pentoses, and phytic phosphorus. Also, it increased the digestibility of protein in one of the feeds but reduced that of phosphorus in both of them. The potential usefulness of enzyme treatment and the information provided by the two types of assays are discusse

Dicyanamide-Perovskites at the Edge of Dense Hybrid Organic–Inorganic Materials

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] Hybrid organic–inorganic ABX3 perovskites with dicyanamide-ligands (dca: [N(CN)2]−) on the X-site are emerging as a distinct group of materials courtesy of their multifunctional properties. Here we present an in-depth analysis of the members of this dicyanamide perovskite family, where the presence of the 5 atom-long dca ligand gives rise to relatively open crystal structures - especially when compared with other dense hybrids such as perovskite formates, and which has a profound influence on their chemistry and properties. We compile the synthetic procedures used to obtain these compounds, along with their chemical and structural properties. In terms of their functional properties, dicyanamide-perovskites have already shown an enormous potential for future applications, such as dielectric or magnetic switches, eco-friendly barocaloric refrigerants at low-pressure and room-temperature, or precursors for oil-recovery nanomaterials and thermoelectric glasses, as reviewed here. Additionally, we highlight several emerging phenomena in this family, and anticipate areas with room for development in the field.This work was financially supported by the Ministerio de Economía y Competitividad (MINECO) and EU-FEDER under the project MAT2017-86453-R, and funding for open access charge was covered by Universidade da Coruña/CISUG J. G.-B. and J. M. B.-G. acknowledges Xunta de Galicia for a Predoctoral and Postdoctoral Fellowships, respectivetly. T.D.B. thanks the Royal Society for a University Research Fellowship (UF150021) and the University of Canterbury Te Whare Wānanga o Waitaha, New Zealand, for a University of Cambridge Visiting Canterbury Fellowship. He would also like to acknowledge, alongside L.N.M, the Leverhulme Trust for a Philip Leverhulme PrizeReino Unido. Royal Society; UF15002

Simple and Low-Cost Footstep Energy-Recover Barocaloric Heating and Cooling Device

[Abstract] In this work, we design, build, and test one of the very first barocaloric devices. The here presented device can recover the energy generated by an individual’s footstep and transform it into barocaloric heating and/or cooling. Accordingly, we present an innovative device that can provide eco-friendly and gas-free heating/cooling. Moreover, we test the device by measuring a new barocaloric organic polymer that exhibits a large adiabatic temperature change of ~2.9 K under the application of 380 bar. These results pave the way towards novel and more advanced barocaloric technologies and provide a simple and low-cost device to explore new barocaloric materials.This research was funded by Ministerio de Economía y Competitividad MINECO and EU-FEDER (project MAT2017-86453-R), and Xunta de Galici

Continuación del programa en habilidades blandas con el taller de comunicación eficaz y documentación de descripciones de puesto para actualizar su estructura organizacional

En el PAP Gestión del Cambio, del Talento Humano y la Efectividad Organizacional realizamos un taller de Comunicación Efectiva, el cual surge como una necesidad prioritaria de la organización, a partir del PAP de verano 2022, en el que se realizó el diagnóstico de la NOM 035, concluyendo como una recomendación para atender la comunicación efectiva dentro de organización. Así mismo, se identificaron la falta de información actualizada en ciertas descripciones de puesto en algunas áreas, lo que generaba diversos problemas, que detectamos junto con la organización, tale como; ambigüedad del puesto, falta de claridad de las tareas asignadas, así como el personal a su cargo o al que reporta y sobre todo la falta de indicadores para la evaluación del desempeño del ocupante de dicho puesto. Igualmente, al integrarse dos nuevas áreas a la estructura de la organización de la empresa, se realizaron dos descripciones y perfiles de puesto.ITESO, A.C

Erythroderma and Chronic Lichenification Due to Metformin

We present the case of a 62-year-old man with a 4-year history of pruritus and erythroderma. The patient had been taking metformin for 5 years, so after contact allergies, contact with toxic products, and autoimmune diseases were ruled out, the condition was treated as erythroderma secondary to metformin. A skin biopsy subsequently confirmed the diagnosis and lichenification of some areas of the patient's skin

PARP inhibition promotes endothelial-like traits in melanoma cells and modulates pericyte coverage dynamics during vasculogenic mimicry

Vasculogenic mimicry (VM) describes the ability of highly aggressive tumor cells to develop pseudovascular structures without the participation of endothelial cells. PARP1 is implicated in the activation of hypoxia-inducible factors, which are crucial in tumor neovascularization. We have explored the role of hypoxia and PARP inhibition in VM. In uveal melanoma xenografts, the PARP inhibitor olaparib improved in vivo pericyte coverage specifically of VM channels. This was concomitant with reduced metastasis in olaparib-treated VM+ tumors. PARP inhibition and hypoxia modulated melanoma tube formation in vitro, inducing a more sparse and regular tubular architecture. Wholetranscriptome profiling revealed that olaparib treatment under hypoxic conditions modulated the expression of genes implicated in vasculogenesis during tube formation, enhancing the endothelial-like phenotype of VM+ uveal melanoma cells. PARP inhibition, especially during hypoxia, upregulated PDGFβ, which is essential for pericyte recruitment. Our study indicates that PARP inhibitors may enhance the endothelial characteristics of VM+ cells, modulate pericyte coverage, and reduce metastatic spread in VM+ melanoma.Spanish Government Ministry of Science and Innovation, Spain (MICINN) Spanish Government SAF2015-70520-R RTI2018-098968-B-I00 RTICC RD12/0036/0026CIBER Cancer ISCIII CB16/12/00421Junta de Andalucia PY20_01179Fundacion Domingo Martine

Development of procedures to assess problem-solving competence in computing engineering

In the context of higher education, a competence may be understood as the combination of skills, knowledge, attitudes, values, and abilities that underpin effective and/or superior performance in a professional area. The aim of the work reported here was to design a set of procedures to assess a transferable competence, i.e., problem solving, that is basic for learning, in both academic and professional life, and crucial for engineering. The study involved a total of 71 students enrolled at three universities at two different stages of their studies. The development phases of the assessment device included an analysis of the competence and its facets, the design of the assessment task, the development of criteria to rate student performance, and the analysis of the basic psychometric properties for assessment methods in the area of education. The conclusion was drawn that the training process and the elaboration of scoring criteria are costly but necessary if objectivity in the interpretation of results is to be guaranteed. The main achievement of this project was the development of a procedure that measures learning outcomes and, more specifically, problem solvin

Degradation of IF1 controls energy metabolism during osteogenic differentiation of stem cells

Differentiation of human mesenchymal stem cells (hMSCs) requires the rewiring of energy metabolism. Herein, we demonstrate that the ATPase inhibitory factor 1 (IF1) is expressed in hMSCs and in prostate and colon stem cells but is not expressed in the differentiated cells. IF1 inhibits oxidative phosphorylation and regulates the activity of aerobic glycolysis in hMSCs. Silencing of IF1 in hMSCs mimics the metabolic changes observed in osteocytes and accelerates cellular differentiation. Activation of IF1 degradation acts as the switch that regulates energy metabolism during differentiation. We conclude that IF1 is a stemness marker important for maintaining the quiescence stateThis work was supported by grants from the Ministerio de Educación y Ciencia (BFU2010-18903), the Centro de Investigación Biomédica en Red de Enfermedades Raras (CIBERER), ISCIII, and Comunidad de Madrid (S2011/BMD-2402), Spai

Plan de Mejoramiento en los Procesos de Compra e Implementación de Herramientas que Muestren el Grado de Satisfacción del Cliente en Empresas de Transporte.

23 (14) h.Establecer los procedimientos que se deben efectuar en el proceso de compras de una empresa de servicios de transportes, para que se optimice y haya un mejoramiento en la prestación de servicios, además de tener nuevas herramientas que permitan evaluar la opinión que tienen los clientes sobre el funcionamiento que tiene la organización. Identificar la importancia de llevar un mapa de procesos en una empresa de servicios. Determinar quiénes son los responsables en el cumplimento de los procedimientos estipulados en el mapa de procesos. Considerar el valor que debe tener la opinión del cliente de la organización para realizar una alimentación y mejora continua.Resultado para optar el título de Administrador Financiero, Seminario (Administración Financiera). Universidad de los Llanos Convenio Universidad del Tolima. Administración Financiera. Ceres - Acacias (Meta). 2016.PregradoEspecializaciones en Finanza