Adenovirus-mediated suppression of hypothalamic glucokinase affects feeding behavior

Glucokinase (GK), the hexokinase involved in glucosensing in pancreatic β-cells, is also expressed in arcuate nucleus (AN) neurons and hypothalamic tanycytes, the cells that surround the basal third ventricle (3V). Several lines of evidence suggest that tanycytes may be involved in the regulation of energy homeostasis. Tanycytes have extended cell processes that contact the feeding-regulating neurons in the AN, particularly, agouti-related protein (AgRP), neuropeptide Y (NPY), cocaine- and amphetamine-regulated transcript (CART) and proopiomelanocortin (POMC) neurons. In this study, we developed an adenovirus expressing GK shRNA to inhibit GK expression in vivo. When injected into the 3V of rats, this adenovirus preferentially transduced tanycytes. qRT-PCR and Western blot assays confirmed GK mRNA and protein levels were lower in GK knockdown animals compared to the controls. In response to an intracerebroventricular glucose injection, the mRNA levels of anorexigenic POMC and CART and orexigenic AgRP and NPY neuropeptides were altered in GK knockdown animals. Similarly, food intake, meal duration, frequency of eating events and the cumulative eating time were increased, whereas the intervals between meals were decreased in GK knockdown rats, suggesting a decrease in satiety. Thus, GK expression in the ventricular cells appears to play an important role in feeding behavior.Fil: Uranga, Romina Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Investigaciones Bioquímicas de Bahía Blanca. Universidad Nacional del Sur. Instituto de Investigaciones Bioquímicas de Bahía Blanca; Argentina. Universidad de Concepción; ChileFil: Millán, Carola. Universidad de Concepción; Chile. Universidad Adolfo Ibañez; ChileFil: Barahona, María José. Universidad de Concepción; ChileFil: Recabal, Antonia. Universidad de Concepción; ChileFil: Salgado, Magdiel. Universidad de Concepción; ChileFil: Martinez, Fernando. Universidad de Concepción; ChileFil: Ordenes, Patricio. Universidad de Concepción; ChileFil: Elizondo Vega, Roberto. Universidad de Concepción; ChileFil: Sepúlveda, Fernando. Universidad de Concepción; ChileFil: Uribe, Elena. Universidad de Concepción; ChileFil: García Robles, María de los Ángeles. Universidad de Concepción; Chil

Localizing SDGs through Development Education. The Experience of the Valencian City Strategy

[ES] Este artículo presenta la propuesta de Educación para el Desarrollo que se recoge en la Estrategia para la Educación no formal de la ciudad de Valencia y su relación con los Objetivos de Desarrollo Sostenible (ODS). El contenido de la Estrategia se basa en tres ejes fundamentales: 1) un enfoque territorial en el barrio o distrito; 2) la importancia de la coordinación entre actores municipales y las ONGD para desarrollar las propuestas educativas y 3) una serie de temáticas y metodologías prioritarias. La correspondencia de la Estrategia con los ODS ha sido interpretada empleando un marco de análisis pensado para la innovación transformadora. Esta interpretación distingue entre ODS que definen los sistemas sociotécnicos o áreas de aplicación, los que definen la direccionalidad y los que indican las condiciones de contexto. Esta interpretación puede contribuir a aumentar la reflexión sobre los objetivos de transformación de las acciones educativas de una manera sinérgica, evitando perspectivas compartimentadas. Por otro lado, pone de manifiesto la importancia de las redes y coordinación entre actores y la ciudad y sus barrios. Estos son los espacios que necesitan ser transformados y a partir de los cuales pueden partir las transformaciones[EN] This article presents the relationship between the Strategy of Non-Formal Development Education of the city of Valencia and the Sustainable Development Goals (SDG). The content of the Strategy is based on three fundamental axes: 1) a territorial approach in the neighbourhood or district; 2) the importance of coordination between municipal actors and NGDOS to develop educational proposals and 3) a series of priority themes and methodologies. The correspondence of the Strategy with the SDGS has been interpreted using an analytical framework designed for transformative innovation. This interpretation distinguishes between SDGS that define socio-technical systems or areas of application; those that define directionality and those that indicate context conditions. This interpretation can contribute to increase the reflection on the transformatory potential of educational actions in a synergic way, avoiding compartmentalized perspectives. On the other hand, it highlights the importance of networks and coordination between actors in the city and its neighbourhoods. These are the spaces that need to be transformed and from which transformations can startBoni Aristizábal, A.; Belda-Miquel, S.; Calabuig Tormo, C.; Millán-Franco, MA.; Talón-Villacañas, A. (2019). Adaptando los ODS a lo Local mediante la Educación para el Desarrollo. La Experiencia de la Estrategia de la Ciudad de Valencia. Revista Internacional de Educación para la Justicia Social. 8(1):117-134. https://doi.org/10.15366/riejs2019.8.1.00711713481Argibay, M. y Celorio, G. (2005). Educación para el desarrollo. Recuperdo de http://www.dhl.hegoa.ehu.es/ficheros/0000/0023/La_educacion_para_el_desarrollo.pdfAsamblea General de NNUU. (2015). Transformar nuestro mundo: La agenda 2030 para el desarrollo sostenible. Recuperdo de http://www.un.org/es/comun/docs/?symbol=A/RES/70/1Boni, A. (2011). Educación para la ciudadanía global. Significados y espacios para un cosmopolitismo transformador. Revista Española de Educación Comparada, 17, 65-85.Boni, A. y León, R. (2013). Educación para una ciudadanía global: Una estrategia imprescindible para la justicia social. En Intermon Oxfam (Ed.), La realidad de la ayuda 2012 (pp. 214-239). Barcelona: Oxfam.Boni, A., Lopez-Fogues, A. y Walker, M. (2016). Higher education and the post-2015 agenda: A contribution from the human development approach. Journal of Global Ethics, 12(1), 17-28.Boni, A., Belda, S., Calabuig, C., Millán, M. A. y Talón, A. (2018). Estrategia de educación para el desarrollo en el ámbito no formal de la ciudad de Valencia.Valencia: Ingenio.Boni, A, Arias, B., López-Fogués, A., Calabuig, C., Belda, S. y C. Monge (2016). Estrategia de educación para el desarrollo en el ámbito formal de la Comunitat Valenciana. Recuperado de http://www.transparencia.gva.es/web/cooperacion/estrategia-de-epdCONGDE. (2011). La educación para el desarrollo en las coordinadoras autonómicas de ONGD. Recuperado de http://coordinadoraongd.org/publicaciones/la-educacion-para-el-desarrollo-en-las-coordinadoras-autonomicas-de-ongd/CONGDE. (2014). Posicionamiento sobre la importancia de la educación para el desarrollo y el rol de las ONGD en la construcción de la ciudadanía global. Recuperado de http://aragonparticipa.aragon.es/sites/default/files/taller_2_epd_ciudadania_global_2014.pdfFreire, P. (1993). Pedagogía de la esperanza. Ciudad de México: Siglo XXI Editores.Gómez, C. (2010). Una visión panorámica de la cooperación descentralizada de las entidades locales. Vitoria-Gasteiz: Ayuntamiento de Vitoria-Gasteiz.HEGOA. (2014). Cambiar la educación para cambiar el mundo. Recuperado de http://publicaciones.hegoa.ehu.es/publications/330INCYDE. (2016). Diagnóstico para la estrategia de educación para la transformación social. Bilbao: Agencia Vasca de Cooperación para el Desarrollo.Mesa, M. (2000). La educación para el desarrollo: Entre la caridad y la ciudadanía global. Papeles de Cuestiones Internacionales, 70, 11-26.Ortega-Carpio, M. L., Cordón, R. y Sianes, A. (2013). Educar para la ciudadanía global en el espacio universitario. Buenas prácticas de colaboración entre ONGD y universidad. Madrid: Fundación ETEA.Schot, J., Boni, A., Ramirez, M. y Steward, E. (2018). Addressing SDGs through transformative innovation policy. TIPC research briefing. Recuperado de http://www.tipconsortium.net/wp-content/uploads/2018/06/4198_TIPC_research_brief_web-FINAL.pd

Glial glucokinase expression in adult and post-natal development of the hypothalamic region

It has recently been proposed that hypothalamic glial cells sense glucose levels and release lactate as a signal to activate adjacent neurons. GK (glucokinase), the hexokinase involved in glucose sensing in pancreatic β-cells, is also expressed in the hypothalamus. However, it has not been clearly determined if glial and/or neuronal cells express this protein. Interestingly, tanycytes, the glia that cover the ventricular walls of the hypothalamus, are in contact with CSF (cerebrospinal fluid), the capillaries of the arcuate nucleus and adjacent neurons; this would be expected for a system that can detect and communicate changes in glucose concentration. Here, we demonstrated by Western-blot analysis, QRT–PCR [quantitative RT–PCR (reverse transcription–PCR)] and in situ hybridization that GK is expressed in tanycytes. Confocal microscopy and immunoultrastructural analysis revealed that GK is localized in the nucleus and cytoplasm of β1-tanycytes. Furthermore, GK expression increased in these cells during the second week of post-natal development. Based on this evidence, we propose that tanycytes mediate, at least in part, the mechanism by which the hypothalamus detects changes in glucose concentrations

Inter- and intra-annual variations of macroinvertebrate assemblages are related to the hydroperiod in Mediterranean temporary ponds

17 pages, 6 figures, 3 tables.-- Printed version published Nov 2009.-- Issue title: "Pond Conservation: From Science to Practice. 3rd Conference of the European Pond Conservation Network" (Valencia, Spain, May 14–16, 2008).Macroinvertebrate assemblages of 22 temporary ponds with different hydroperiod were sampled monthly during a dry year (2005–2006) and a wet year (2006–2007). Coleopteran and Heteropteran adults were most abundant at the end of the hydroperiod, while Coleopteran larvae, mainly Dytiscidae, were mostly recorded in spring. Macroinvertebrate assemblages differed between study years. The shorter hydroperiod of ponds in the dry year constrained the length of the aquatic period for macroinvertebrates, and three distinct wet phases of community composition could be distinguished: filling phase, aquatic phase and drying phase. In the wet year, with a longer pond hydroperiod, five phases could be identified, with the aquatic phase differentiated into winter, early spring and late spring phases. Dispersers such as Anisops sardeus, Berosus guttalis or Anacaena lutescens were typical during the filling phase and Corixa affinis or Enochrus fuscipennis during the drying phase. The ponds with intermediate hydroperiod showed a similar composition (mainly dispersers) at the beginning and end of their wet period; this is not being seen in early drying or long hydroperiod ponds. A general pattern was detected, with similar variation between both years, which may be associated with the life histories of the macroinvertebrate taxa recorded.We wish to thank the Spanish Ministry of Science and Innovation and EU Feder Funds (CGL2006-04458/BOS and Fellowship grants CSIC-I3P to M.F. and AP-2001-3475 to C.G.-R.) and Junta de Andalucía (Excellence Research Project 932). The fellowship grant to M.F. was funded by European Union Social Fund.Peer reviewe

BMAL1 Regulates Glucokinase Expression Through E-Box Elements In Vitro

The organization of a circadian system includes an endogenous pacemaker system, input pathways for environmental synchronizing (entraining) stimuli, and output pathways through which the clock regulates physiological and behavioral processes, for example, the glucose-sensing mechanism in the liver. The liver is the central regulator of metabolism and one of our peripherals clocks. In mammals, central to this pacemaker are the transcription factors Circadian Locomotor Output Cycles Kaput (CLOCK) and BMAL1 (Brain and Muscle ARNT-Like 1). BMAL1 dimerizes with CLOCK, and this heterodimer then binds to the E-box promoter elements (CACGTG) present in clock and clock-controlled genes (CCGs). However, we are just beginning to understand how output pathways and regulatory mechanisms of CCGs are involved in rhythmic physiological processes. Glucokinase (GCK) is a fundamental enzyme in glucose homeostasis, catalyzing the high Km phosphorylation of glucose and allowing its storage. Moreover, gck is a dependent circadian gene. This study aims to determine the contribution of clock genes to hepatic gck expression and to define the specific role of E-box sequences on the circadian regulation of hepatic gck. Results showed that gck expression follows a circadian rhythm in rat hepatocytes in vitro. Accordingly, bmal1 expression induces the glucokinase circadian rhythmic expression in hepatocytes and the analysis of human and rat gck promoters, indicating the presence of E-box regions. Moreover, the basal activity of gck promoter was increased by clock/bmal1 co-transfection but inhibited by Period1/Period2 (per1/per2) co-transfection. Thus, the data suggest that the clock proteins tightly regulate the transcriptional activity of the gck promoter

Evidence of Hydroperiod Shortening in a Preserved System of Temporary Ponds

Based on field data simultaneous with Landsat overpasses from six different dates, we developed a robust linear model to predict subpixel fractions of water cover. The model was applied to a time series of 174 Landsat TM and ETM+ images to reconstruct the flooding regime of a system of small temporary ponds and to study their spatio-temporal changes in a 23-year period. We tried to differentiate natural fluctuations from trends in hydrologic variables (i.e., hydroperiod shortening) that may threaten the preservation of the system. Although medium-resolution remote sensing data have rarely been applied to the monitoring of small-sized wetlands, this study evidences its utility to understand the hydrology of temporary ponds at a local scale. We show that the temporary ponds in Doñana National Park constitute a large and heterogeneous system with high intra and inter-annual variability. We also evidence that the conservation value of this ecosystem is threatened by the observed tendency to shorter annual hydroperiods in recent years, probably due to aquifer exploitation. This system of temporary ponds deserves special attention for the high density and heterogeneity of natural ponds, not common in Europe. For this reason, management decisions to avoid its destruction or degradation are critical.Peer reviewe

Effect of Gelatin Coating and GO Incorporation on the Properties and Degradability of Electrospun PCL Scaffolds for Bone Tissue Regeneration

Polymer-based nanocomposites such as polycaprolactone/graphene oxide (PCL/GO) have emerged as alternatives for bone tissue engineering (BTE) applications. The objective of this research was to investigate the impact of a gelatin (Gt) coating on the degradability and different properties of PCL nanofibrous scaffolds fabricated by an electrospinning technique with 1 and 2 wt% GO. Uniform PCL/GO fibers were obtained with a beadless structure and rough surface. PCL/GO scaffolds exhibited an increase in their crystallization temperature (Tc), attributed to GO, which acted as a nucleation agent. Young’s modulus increased by 32 and 63% for the incorporation of 1 and 2 wt% GO, respectively, in comparison with neat PCL. A homogeneous Gt coating was further applied to these fibers, with incorporations as high as 24.7 wt%. The introduction of the Gt coating improved the hydrophilicity and degradability of the scaffolds. Bioactivity analysis revealed that the hydroxyapatite crystals were deposited on the Gt-coated scaffolds, which made them different from their uncoated counterparts. Our results showed the synergic effect of Gt and GO in enhancing the multifunctionality of the PCL, in particular the degradability rate, bioactivity, and cell adhesion and proliferation of hGMSC cells, making it an interesting biomaterial for BTE

Central and peripheral clocks are coupled by a neuropeptide pathway in Drosophila

Animal circadian clocks consist of central and peripheral pacemakers, which are coordinated to produce daily rhythms in physiology and behaviour. Despite its importance for optimal performance and health, the mechanism of clock coordination is poorly understood. Here we dissect the pathway through which the circadian clock of Drosophila imposes daily rhythmicity to the pattern of adult emergence. Rhythmicity depends on the coupling between the brain clock and a peripheral clock in the prothoracic gland (PG), which produces the steroid hormone, ecdysone. Time information from the central clock is transmitted via the neuropeptide, sNPF, to non-clock neurons that produce the neuropeptide, PTTH. These secretory neurons then forward time information to the PG clock. We also show that the central clock exerts a dominant role on the peripheral clock. This use of two coupled clocks could serve as a paradigm to understand how daily steroid hormone rhythms are generated in animals

Dynamic Localization of Glucokinase and Its Regulatory Protein in Hypothalamic Tanycytes

<div><p>Glucokinase (GK), the hexokinase involved in glucose sensing in pancreatic β cells, is also expressed in hypothalamic tanycytes, which cover the ventricular walls of the basal hypothalamus and are implicated in an indirect control of neuronal activity by glucose. Previously, we demonstrated that GK was preferentially localized in tanycyte nuclei in euglycemic rats, which has been reported in hepatocytes and is suggestive of the presence of the GK regulatory protein, GKRP. In the present study, GK intracellular localization in hypothalamic and hepatic tissues of the same rats under several glycemic conditions was compared using confocal microscopy and Western blot analysis. In the hypothalamus, increased GK nuclear localization was observed in hyperglycemic conditions; however, it was primarily localized in the cytoplasm in hepatic tissue under the same conditions. Both GK and GKRP were next cloned from primary cultures of tanycytes. Expression of GK by <i>Escherichia coli</i> revealed a functional cooperative protein with a S_0.5 of 10 mM. GKRP, expressed in <i>Saccharomyces cerevisiae</i>, inhibited GK activity <i>in vitro</i> with a K_i 0.2 µM. We also demonstrated increased nuclear reactivity of both GK and GKRP in response to high glucose concentrations in tanycyte cultures. These data were confirmed using Western blot analysis of nuclear extracts. Results indicate that GK undergoes short-term regulation by nuclear compartmentalization. Thus, in tanycytes, GK can act as a molecular switch to arrest cellular responses to increased glucose.</p></div