Vitronectin regulates Sonic hedgehog activity during cerebellum development through CREB phosphorylation

12 páginas, 7 figuras.During development of the cerebellum, Sonic hedgehog (SHH) is expressed in migrating and settled Purkinje neurons and is directly responsible for proliferation of granule cell precursors in the external germinal layer. We have previously demonstrated that SHH interacts with vitronectin in the differentiation of spinal motor neurons. Here, we analysed whether similar interactions between SHH and extracellular matrix glycoproteins regulate subsequent steps of granule cell development. Laminins and their integrin receptor subunit alpha6 accumulate in the outer most external germinal layer where proliferation of granule cell precursors is maximal. Consistent with this expression pattern, laminin significantly increases SHH-induced proliferation in primary cultures of cerebellar granule cells. Vitronectin and its integrin receptor subunits alpha(v) are expressed in the inner part of the external germinal layer where granule cell precursors exit the cell cycle and commence differentiation. In cultures, vitronectin is able to overcome SHH-induced proliferation, thus allowing granule cell differentiation. Our studies indicate that the pathway in granule cell precursors responsible for the conversion of a proliferative SHH-mediated response to a differentiation signal depends on CREB. Vitronectin stimulates phosphorylation of cyclic-AMP responsive element-binding protein (CREB), and over-expression of CREB is sufficient to induce granule cell differentiation in the presence of SHH. Taken together, these data suggest that granule neuron differentiation is regulated by the vitronectin-induced phosphorylation of CREB, a critical event that terminates SHH-mediated proliferation and permits the differentiation program to proceed in these cells.This research was supported by grant PM97-0018 to Dr Ignacio Torres Alemán and by grants PM97-0019 and BIO4-CT98-0399 to Dr Paola Bovolenta, in whose laboratories this research was carried out.Peer reviewe

Artisanal trawl fisheries as a sentinel of marine litter pollution

Systematic seafloor surveys are a highly desirable method of marine litter monitoring, but the high costs involved in seafloor sampling are not a trivial handicap. In the present work, we explore the opportunity provided by the artisanal trawling fisheries to obtain systematic data on marine litter in the Gulf of Cadiz between 2019 and 2021. We find that plastic was the most frequent material, with a prevalence of single-use and fishing-related items. Litter densities decreased with increasing distance to shore with a seasonal migration of the main litter hotspots. During pre-lockdown and post-lockdown stages derived from COVID-19, marine litter density decreased by 65 %, likely related to the decline in tourism and outdoor recreational activities. A continuous collaboration of 33 % of the local fleet would imply a removal of hundreds of thousands of items each year. The artisanal trawl fishing sector can play a unique role of monitoring marine litter on the seabe

White Paper 5: Brain, Mind & Behaviour

© CSICThe study of the brain will tell us what makes us humans and how our social behavior generates. Increasing our understanding of how the brain functions and interacts with the ecosystem to interpret the world will not only help to find effective means to treat and/or cure neurological and psychiatric disorders but will also change our vision on questions pertaining to philosophy and humanities and transform other fields such as economy and law. Neurosciences research at the CSIC is already valuable and should be intensified mainly focused on the eight major challenges described in this volume

Libro Blanco Volumen 5: Cerebro, mente y comportamiento

Llegar a entender cómo funciona el cerebro y cómo este interacciona con el ecosistema para interpretar el mundo que nos rodea sin duda facilitará el desarrollo de estrategias más eficaces para tratar o curar los trastornos neurológicos y psiquiátricos. Además, la comprensión de los principios fundamentales que controlan el funcionamiento del sistema nervioso transformará nuestra visión sobre muchas cuestiones que han sido tradicionalmente enmarcadas en el campo de la filosofía, repercutiendo en áreas como la economía o el derecho. Las neurociencias nos ayudarán, en definitiva, a entender qué nos hace humanos. Este es un campo en el que los investigadores del CSIC destacan internacionalmente y así debe seguir siendo en los próximos años. Para lograrlo, deberíamos potenciar y reforzar nuestras investigaciones en los ocho desafíos que describimos en este volumen.Peer reviewe

Multicentre, randomised, single-blind, parallel group trial to compare the effectiveness of a Holter for Parkinson's symptoms against other clinical monitoring methods: study protocol

Introduction In recent years, multiple studies have aimed to develop and validate portable technological devices capable of monitoring the motor complications of Parkinson's disease patients (Parkinson's Holter). The effectiveness of these monitoring devices for improving clinical control is not known. Methods and analysis This is a single-blind, cluster-randomised controlled clinical trial. Neurologists from Spanish health centres will be randomly assigned to one of three study arms (1:1:1): (a) therapeutic adjustment using information from a Parkinson?s Holter that will be worn by their patients for 7 days, (b) therapeutic adjustment using information from a diary of motor fluctuations that will be completed by their patients for 7 days and (c) therapeutic adjustment using clinical information collected during consultation. It is expected that 162 consecutive patients will be included over a period of 6 months. The primary outcome is the efficiency of the Parkinson?s Holter compared with traditional clinical practice in terms of Off time reduction with respect to the baseline (recorded through a diary of motor fluctuations, which will be completed by all patients). As secondary outcomes, changes in variables related to other motor complications (dyskinesia and freezing of gait), quality of life, autonomy in activities of daily living, adherence to the monitoring system and number of doctor?patient contacts will be analysed. The noninferiority of the Parkinson's Holter against the diary of motor fluctuations in terms of Off time reduction will be studied as the exploratory objective. Ethics and dissemination approval for this study has been obtained from the Hospital Universitari de Bellvitge Ethics Committee. The results of this study will inform the practical utility of the objective information provided by a Parkinson's Holter and, therefore, the convenience of adopting this technology in clinical practice and in future clinical trials. We expect public dissemination of the results in 2022.Funding This work is supported by AbbVie S.L.U, the Instituto de Salud Carlos III [DTS17/00195] and the European Fund for Regional Development, 'A way to make Europe'

Vitronectin is expressed in the ventral region of the neural tube and promotes the differentiation of motor neurons

9 páginas, 7 figuras.The extracellular matrix protein vitronectin and its mRNA are present in the embryonic chick notochord, floor plate and in the ventral neural tube at the time position of motor neuron generation. When added to cultures of neural tube explants of developmental stage 9, vitronectin promotes the generation of motor neurons in the absence of either notochord or exogenously added Sonic hedgehog. Conversely, the neutralisation of endogenous vitronectin with antibodies inhibits over 90% motor neuron differentiation in co-cultured neural tube/notochord explants, neural tube explants cultured in the presence of Sonic hedgehog, and in committed (stage 13) neural tube explants. Furthermore, treatment of embryos with anti-vitronectin antibodies results in a substantial and specific reduction in the number of motor neurons generated in vivo. These results demonstrate that vitronectin stimulates the differentiation of motor neurons in vitro and in vivo. Since the treatment of stage 9 neural tube explants with Sonic hedgehog resulted in induction of vitronectin mRNA expression before the expression of floor plate markers, we conclude that vitronectin may act either as a downstream effector in the signalling cascade induced by Sonic hedgehog, or as a synergistic factor that increases Shh-induced motor neuron differentiation.This research was financed by grants from the DGCYT (Ministry of Science of Spain, no. PB95-0025 and PB94-0102), Regional Governments of Madrid and Canary Islands, Spain, and European Union, Programme Biotech (no. 960024).Peer reviewe

Developmentally regulated vitronectin influences cell differentiation, neuron survival and process outgrowth in the developing chicken retina

9 páginas, 7 figuras.Vitronectin is a multifunctional protein involved in the regulation of the immune system and blood coagulation. Here we report that the expression of vitronectin is developmentally regulated in the embryonic retina of the chicken. Vitronectin immunoreactivity was detected in chicken retinas from embryonic day 5, encompassing the cell bodies of most neuroepithelial cells. At this developmental stage, αv integrin subunit expression was distributed across the retina, suggesting a ligand/receptor interaction. Expression of both vitronectin and αv increased during development and reached a maximum at embryonic day 9, a time when most differentiated neurons grow processes and initiate synapse formation. At this age, vitronectin immunoreactivity appeared to be located predominantly in the fiber and inner plexiform layers of the differentiated stratified retina. αv immunoreactivity and mRNA expression was seen associated with all layers formed by differentiated neurons, being most abundant in the ganglion cell and inner nuclear layers. Later in development, levels of vitronectin decreased and immunoreactivity appeared exclusively associated with the fiber layer. In accordance with this pattern of expression, vitronectin as a substrate sustained both proliferation and differentiation of cultured neuroepithelial cells from embryonic day 5 retinas. At later stages, vitronectin supported survival and neurite outgrowth of most differentiated neurons. Our data suggest that vitronectin is a ubiquitous component of the retinal extracellular matrix, serving as a substrate for developmental processes such as proliferation, differentiation of neuron progenitors, cell survival, and axonal and dendritic growth of differentiated neurons.This research was financed by grants from the DGCYT (Ministry of Science of Spain nº PB93-0124), Regional Governments of Madrid and Canary Islands, Spain, and European Union, Programme Science (nº SCC-CT90-0021). J. R. Martínez-Morales is holding a fellowship from the Government of the Canary Islands.Peer reviewe

Developmentally regulated vitronectin influences cell differentiation, neuron survival and process outgrowth in the developing chicken retina

9 páginas, 7 figuras.Vitronectin is a multifunctional protein involved in the regulation of the immune system and blood coagulation. Here we report that the expression of vitronectin is developmentally regulated in the embryonic retina of the chicken. Vitronectin immunoreactivity was detected in chicken retinas from embryonic day 5, encompassing the cell bodies of most neuroepithelial cells. At this developmental stage, αv integrin subunit expression was distributed across the retina, suggesting a ligand/receptor interaction. Expression of both vitronectin and αv increased during development and reached a maximum at embryonic day 9, a time when most differentiated neurons grow processes and initiate synapse formation. At this age, vitronectin immunoreactivity appeared to be located predominantly in the fiber and inner plexiform layers of the differentiated stratified retina. αv immunoreactivity and mRNA expression was seen associated with all layers formed by differentiated neurons, being most abundant in the ganglion cell and inner nuclear layers. Later in development, levels of vitronectin decreased and immunoreactivity appeared exclusively associated with the fiber layer. In accordance with this pattern of expression, vitronectin as a substrate sustained both proliferation and differentiation of cultured neuroepithelial cells from embryonic day 5 retinas. At later stages, vitronectin supported survival and neurite outgrowth of most differentiated neurons. Our data suggest that vitronectin is a ubiquitous component of the retinal extracellular matrix, serving as a substrate for developmental processes such as proliferation, differentiation of neuron progenitors, cell survival, and axonal and dendritic growth of differentiated neurons.This research was financed by grants from the DGCYT (Ministry of Science of Spain nº PB93-0124), Regional Governments of Madrid and Canary Islands, Spain, and European Union, Programme Science (nº SCC-CT90-0021). J. R. Martínez-Morales is holding a fellowship from the Government of the Canary Islands.Peer reviewe

Enhanced High-Temperature Thermoelectric Performance of Yb_{14–<i>x</i>}Ca_<i>x</i>MnSb₁₁

The high temperature <i>p</i>-type thermoelectric material Yb₁₄MnSb₁₁ has been of increasing research interest since its high temperature thermoelectric properties were first measured in 2006. Subsequent substitutions of Zn, Al, and La into the structure have shown that this material can be further optimized by altering the carrier concentration or by reduction of spin-disorder scattering. Here the properties of the Yb_{14–<i>x</i>}Ca_<i>x</i>MnSb₁₁ solid solution series where isovalent Ca²⁺ is substituted for Yb²⁺ will be presented. Crystals of the Yb_{14–<i>x</i>}Ca_<i>x</i>MnSb₁₁ solid solution series were made by Sn-flux (<i>x</i> = 2, 4, 6, 8) with the following ratio of elements: (14–<i>x</i>)­Yb: <i>x</i>Ca: 6 Mn: 11Sb: 86Sn, and their structures determined by single crystal X-ray diffraction. The density of the material significantly decreases by over 2 g/cm³ as more Ca is added (from <i>x</i> = 1 to 8), because of the lighter mass of Ca. The resulting lower density is beneficial from a device manufacturing perspective where there is often a trade-off with the specific power per kilogram. The compounds crystallize in the Ca₁₄AlSb₁₁ structure type. The Ca substitution contributes to systematic lengthening the Mn–Sb bond while shortening the Sb–Sb bond in the 3 atom linear unit with increasing amounts of Ca. Temperature dependent thermoelectric properties, Seebeck, electrical resistivity, and thermal conductivity were measured from room temperature to 1273 K. Substitution of Yb with Ca improves the Seebeck coefficient while decreasing the thermal conductivity, along with decreasing the carrier concentration in this p-type material resulting in an enhanced thermoelectric figure of merit, zT, compared to Yb₁₄MnSb₁₁

Module interconnection for the three-terminal heterojunction bipolar transistor solar cell

In common multijunction solar cells the subcells are connected in series. In this way, achieving a high voltage at module level is straightforward. However, calculations have proven that the annual energy efficiency limit is higher for independently connected subcells, because they are more tolerant to spectral variations throughout the year. We have recently proposed a three-terminal heterojunction bipolar transistor solar cell (HBTSC) with the maximum limiting efficiency of a dual-junction solar cell, but without the need for a tunnel junction and with only three crucial semiconductor layers. In this work, we present the implementation of a two-terminal module prototype including five HBTSCs which provides a high-voltage power output