Stay Fit, Stay Young: Mitochondria in Movement: The Role of Exercise in the New Mitochondrial Paradigm

Skeletal muscles require the proper production and distribution of energy to sustain their work. To ensure this requirement is met, mitochondria form large networks within skeletal muscle cells, and during exercise, they can enhance their functions. In the present review, we discuss recent findings on exercise-induced mitochondrial adaptations. We emphasize the importance of mitochondrial biogenesis, morphological changes, and increases in respiratory supercomplex formation as mechanisms triggered by exercise that may increase the function of skeletal muscles. Finally, we highlight the possible effects of nutraceutical compounds on mitochondrial performance during exercise and outline the use of exercise as a therapeutic tool in noncommunicable disease prevention. The resulting picture shows that the modulation of mitochondrial activity by exercise is not only fundamental for physical performance but also a key point for whole-organism well-being.The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia, Innovación y Universidades (MCNU), and the Pro CNIC Foundation and is a Severo Ochoa Center of Excellence (SEV-2015-0505)

Overcoming the solid solubility limit of Te in Ge by ion implantation and pulsed laser melting recrystallization

Germanium hyperdoped with deep level donors, such as tellurium, would lead to dopant-mediated sub-band gap mid-infrared photoresponse at room temperature. We use a combination of non-equilibrium techniques to supersaturate Ge with Te via ion implantation followed by pulsed laser melting (PLM). Typically, liquid N2 (77K) temperatures are used to avoid implantation-induced Ge surface porosity. In this work, alternatively, we report on the use of slightly higher implantation temperatures (143 K) together with an amorphous Si (a-Si) capping layer. We demonstrate that the solid solubility limit of Te in Ge is overcome upon recovering the crystallinity of the material after laser processing

γ-Linolenic acid in maternal milk drives cardiac metabolic maturation.

Birth presents a metabolic challenge to cardiomyocytes as they reshape fuel preference from glucose to fatty acids for postnatal energy production1,2. This adaptation is triggered in part by post-partum environmental changes3, but the molecules orchestrating cardiomyocyte maturation remain unknown. Here we show that this transition is coordinated by maternally supplied γ-linolenic acid (GLA), an 18:3 omega-6 fatty acid enriched in the maternal milk. GLA binds and activates retinoid X receptors4 (RXRs), ligand-regulated transcription factors that are expressed in cardiomyocytes from embryonic stages. Multifaceted genome-wide analysis revealed that the lack of RXR in embryonic cardiomyocytes caused an aberrant chromatin landscape that prevented the induction of an RXR-dependent gene expression signature controlling mitochondrial fatty acid homeostasis. The ensuing defective metabolic transition featured blunted mitochondrial lipid-derived energy production and enhanced glucose consumption, leading to perinatal cardiac dysfunction and death. Finally, GLA supplementation induced RXR-dependent expression of the mitochondrial fatty acid homeostasis signature in cardiomyocytes, both in vitro and in vivo. Thus, our study identifies the GLA-RXR axis as a key transcriptional regulatory mechanism underlying the maternal control of perinatal cardiac metabolism.S

Aula Virtual de Electrónica

El proyecto ha consistido en la creación de un espacio virtual en Moodle para publicar contenidos complementarios para las asignaturas relacionadas con el área de la Electrónica

High Pressure Sputtering of materials for selective contacts in emerging photovoltaic cells

In this work we have explored the growth by high pressure sputtering (HPS) of materials intended for novel selective contacts for photovoltaic cells. This technique shows promise for the low-damage low-temperature deposition of PV materials. We studied the deposition of ITO, MoOx and TiOx using pure Ar and mixed Ar/O2 atmospheres as well as ceramic or metallic targets. We show that HPS deposition of these materials is feasible. The growth rate is greatly reduced when oxygen is added to the argon sputtering atmosphere. The best sputtering RF power was 20-45 W for the pressure range studied. Finally, as-deposited films present high surface recombination, but a mild hot plate anneal at 200ºC recovers long effective lifetimes

On the Optoelectronic Mechanisms Ruling Ti-hyperdoped Si Photodiodes

This work deepens the understanding of the optoelectronic mechanisms ruling hyperdoped-based photodevices and shows the potential of Ti hyperdoped-Si as a fully complementary metal-oxide semiconductor compatible material for room-temperature infrared photodetection technologies. By the combination of ion implantation and laser-based methods, approximate to 20 nm thin hyperdoped single-crystal Si layers with a Ti concentration as high as 10(20) cm(-3) are obtained. The Ti hyperdoped Si/p-Si photodiode shows a room temperature rectification factor at +/- 1 V of 509. Analysis of the temperature-dependent current-voltage characteristics shows that the transport is dominated by two mechanisms: a tunnel mechanism at low bias and a recombination process in the space charge region at high bias. A room-temperature sub-bandgap external quantum efficiency (EQE) extending to 2.5 mu m wavelength is obtained. Temperature-dependent spectral photoresponse behavior reveals an increase of the EQE as the temperature decreases, showing a low-energy photoresponse edge at 0.45 eV and a high-energy photoresponse edge at 0.67 eV. Temperature behavior of the open-circuit voltage correlates with the high-energy photoresponse edge. A model is proposed to relate the optoelectronic mechanisms to sub-bandgap optical transitions involving an impurity band. This model is supported by numerical semiconductor device simulations using the SCAPS software

Risk of ischaemic heart disease and acute myocardial infarction in a Spanish population: observational prospective study in a primary-care setting

BACKGROUND: Ischaemic heart disease is a global priority of health-care policy, because of its social repercussions and its impact on the health-care system. Yet there is little information on coronary morbidity in Spain and on the effect of the principal risk factors on risk of coronary heart disease. The objective of this study is to describe the epidemiology of coronary disease (incidence, mortality and its association with cardiovascular risk factors) using the information gathered by primary care practitioners on cardiovascular health of their population. METHODS: A prospective study was designed. Eight primary-care centres participated, each contributing to the constitution of the cohort with the entire population covered by the centre. A total of 6124 men and women aged over 25 years and free of cardiovascular disease agreed to participate and were thus enrolled and followed-up, with all fatal and non-fatal coronary disease episodes being registered during a 5-year period. Repeated measurements were collected on smoking, blood pressure, weight and height, serum total cholesterol, high-density and low-density lipoproteins and fasting glucose. Rates were calculated for acute myocardial infarction and ischaemic heart disease. Associations between cardiovascular risk factors and coronary disease-free survival were evaluated using Kaplan-Meier and Cox regression analyses. RESULTS: Mean age at recruitment was 51.6 ± 15, with 24% of patients being over 65. At baseline, 74% of patients were overweight, serum cholesterol over 240 was present in 35% of patients, arterial hypertension in 37%, and basal glucose over 126 in 11%. Thirty-four percent of men and 13% of women were current smokers. During follow-up, 155 first episodes of coronary disease were detected, which yielded age-adjusted rates of 362 and 191 per 100,000 person-years in men and women respectively. Disease-free survival was associated with all risk factors in univariate analyses. After multivariate adjustments, age, male gender, smoking, high total cholesterol, high HDL/LDL ratio, diabetes and overweight remained strongly associated with risk. Relative risks for hypertension in women and for diabetes in men did not reach statistical significance. CONCLUSION: Despite high prevalence of vascular risk factors, incidence rates were lower than those reported for other countries and other periods, but similar to those reported in the few population-based studies in Spain. Effect measures of vascular risk factors were mainly as reported worldwide and support the hypothesis that protective factors not considered in this study must exist as to explain low rates. This study shows the feasibility of conducting epidemiological cohort studies in primary-care settings

Acute hypoxia produces a superoxide burst in cells

et al.Oxygen is a key molecule for cell metabolism. Eukaryotic cells sense the reduction in oxygen availability (hypoxia) and trigger a series of cellular and systemic responses to adapt to hypoxia, including the optimization of oxygen consumption. Many of these responses are mediated by a genetic program induced by the hypoxia-inducible transcription factors (HIFs), regulated by a family of prolyl hydroxylases (PHD or EGLN) that use oxygen as a substrate producing HIF hydroxylation. In parallel to these oxygen sensors modulating gene expression within hours, acute modulation of protein function in response to hypoxia is known to occur within minutes. Free radicals acting as second messengers, and oxidative posttranslational modifications, have been implied in both groups of responses. Localization and speciation of the paradoxical increase in reactive oxygen species production in hypoxia remain debatable. We have observed that several cell types respond to acute hypoxia with a transient increase in superoxide production for about 10 min, probably originating in the mitochondria. This may explain in part the apparently divergent results found by various groups that have not taken into account the time frame of hypoxic ROS production. We propose that this acute and transient hypoxia-induced superoxide burst may be translated into oxidative signals contributing to hypoxic adaptation and preconditioning.This research has been financed by the Spanish government Grants CSD2007-00020 (RosasNet, Consolider-Ingenio 2010 program; to S.L. and A.M.-R.), CP07/00143 (Miguel Servet program), PS09/00101 and PI12/00875 (to A.M.-R), and SAF2009-7520, SAF 2012-31338, and the “New Indigo” Partnership Program “Nitroxdiab” (PIM2010ENI-00631) (to S.L.); by Swiss National Science Foundation Grant 310030_124970/1 to A.B., by a travel grant from the Instituto de Investigación Sanitaria Princesa (to P.H.-A.); and by the COST actions TD0901 (HypoxiaNet) BM1005 (ENOG–European Network on Gasotransmitters) and BM1203 (EU-ROS). P.H.-A. is the recipient of an FPU fellowship from the Spanish government, and A.M.-R. is supported by the I3SNS program (ISCIII, Spanish government).Peer Reviewe

Acute hypoxia produces a superoxide burst in cells

Resumen del trabajo presentado al X Meeting of the Spanish Group for Research on Free Radicals: "Symposium on Oxidative Stress and Redox Signaling in Biology and Medicine", celebrado en la Facultad de Medicina de la Universidad de Valencia (España) del 2 al 4 de junio de 2014.-- et al.Oxygen is a key molecule for cell metabolism. Eukaryotic cells sense the reduction in oxygen availability (hypoxia) and trigger a series of cellular and systemic responses in order to adapt to hypoxia, including the optimization of oxygen consumption. Many of these responses are mediated by a genetic programme induced by the hypoxia-inducible transcription factors (HIFs), regulated by a family of prolyl hydroxylases (PHD or EGLN) that use oxygen as a substrate producing HIF hydroxylation. In parallel to these oxygen sensors modulating gene expression within hours, acute modulation of protein function in response to hypoxia is known to occur within minutes. Free radicals acting as second messengers and oxidative post-translational modifications have been implied in both groups of responses. Localization and speciation of the paradoxical increase in reactive oxygen species (ROS) production in hypoxia remains debatable. We have developed a series of techniques for measuring superoxide in short times of hypoxia in cells. We have observed that several cell types respond to acute hypoxia with a transient increase in superoxide production for about 10 minutes, probably originated in the mitochondria. This may explain in part the apparently divergent results found by different groups that have not taken into account the time frame of hypoxic ROS production. We propose that cells subjected to hypoxia produce an initial burst of superoxide anion which may be translated in later times into oxidative signals contributing to hypoxic adaptation and preconditioning.Peer Reviewe

Prevención secundaria de cardiopatía isquémica a nivel lipídico en atención primaria Aragón: estudio PRECIAR 1

Background: Despite the existing evidence of the effectiveness of secondary prevention by modifying lifestyles or using the different drugs which have shown themselves to be clinically beneficial for heart patients, there is little, not highly accurate information available regarding the handling of the treatment of these patients within the scope of primary care in our country. The purpose of this study is that of ascertaining the current status of secondary prevention of heart disease as far as lipid control is concerned. Methods: A review was made of the clinical records of all of the patients diagnosed at some point in time of their life as having ischemic heart disease, including those under the heading of acute myocardial infarction and angina pectoris within the 11 groups of patients assigned to three urban Health Care Centers in Area II in Zaragoza. The population in question totaled 19,692 patients, 388 cases of ischemic heart disease having been found in the record files data. Results: Based on a study of the lipid control data, 60.8% of the cases analyzed in this study showed a complete lipid profile for the last year. Solely 4.7% of these patients had LDL < 100, the control objective having to be limited to c- LDL<130 to find a 31.3% of patients with a lower than optimum control of this parameter. Conclusions: The results of our study reveal that the diagnosis of dyslipemias as well as the control of all other heart disease risk factors in secondary care have not been in keeping, for the most part, with the quality criteria of this health care procedure and therefore reveal the existence of a major degree of room for improvement.Fundamento: A pesar de la evidencia existente sobre la eficacia de la prevención secundaria, modificando los estilos de vida o utilizando los diversos fármacos que han mostrado su beneficio clínico en pacientes coronarios, la información disponible sobre el manejo terapéutico de estos pacientes en el ámbito de la atención primaria en nuestro país es escasa y poco precisa. El objetivo de este estudio es conocer el estado de la prevención secundaria de la enfermedad coronaria desde el punto de vista del control de los lípidos. Métodos: Se revisaron las historias clínicas de todas las personas diagnosticadas en algún momento de su vida de patología cardiovascular isquémica; incluyéndose en este apartado el infarto agudo de miocardio y el ángor, dentro de 11 cupos de 3 Centros de Salud urbanos del área II de Zaragoza. La población global era de 19.692 pacientes, encontrándose 388 casos de cardiopatía isquémica, de los datos recogidos de las historias. Resultados: Estudiando los datos sobre el control lipídico, el 60.8% de los casos analizados en este estudio presentaba un perfil lipídico completo en el último año. De estos 236 pacientes solamente el 4,7% tenía el LDL < 100, teniendo que limitar a un c-LDL < 130 el objetivo de control para encontrar un 31,3% de pacientes con un control subóptimo de este parámetro. Conclusiones: Los resultados de nuestro estudio revelan que el diagnóstico de las dislipemias, así como el control del resto de factores de riesgo cardiovascular en prevención secundaria no se han adecuado en gran medida a los criterios de calidad de este proceso asistencial y señalan, en consecuencia, la existencia de un amplio margen de mejora