Genetic Evidence for p75NTR-Dependent Tetraploidy in Cortical Projection Neurons from Adult Mice

A subpopulation of chick retinal projection neurons becomes tetraploid during development, an event prevented by blocking antibodies against p75 neurotrophin receptor (p75(NTR)). We have used an optimized flow cytometric assay, based on the analysis of unfixed brain cell nuclei, to study whether p75(NTR)-dependent neuronal tetraploidization takes place in the cerebral cortex, giving rise to projection neurons as well. We show that 3% of neurons in both murine neocortex and chick telencephalic derivatives are tetraploid, and that in the mouse ~85% of these neurons express the immediate early genes Erg-1 and c-Fos, indicating that they are functionally active. Tetraploid cortical neurons (65-80%) express CTIP2, a transcription factor specific for subcortical projection neurons in the mouse neocortex. During the period in which these neurons are born, p75(NTR) is detected in differentiating neurons undergoing DNA replication. Accordingly, p75(NTR)-deficient mice contain a reduced proportion of both NeuN and CTIP2-positive neocortical tetraploid neurons, thus providing genetic evidence for the participation of p75(NTR) in the induction of neuronal tetraploidy in the mouse neocortex. In the striatum tetraploidy is mainly associated with long-range projection neurons as well since ~80% of tetraploid neurons in this structure express calbindin, a marker of neostriatal-matrix spiny neurons, known to establish long-range projections to the substantia nigra and globus pallidus. In contrast, only 20% of tetraploid cortical neurons express calbindin, which is mainly expressed in layers II-III, where CTIP2 is absent. We conclude that tetraploidy mainly affects long-range projection neurons, being facilitated by p75(NTR) in the neocortex.Peer Reviewe

The Use of ICTs in Internal Communication of the University: The Case of Universidad Europea Miguel de Cervantes

El estudio de caso que se presenta tiene por objetivo el análisis del uso y la opinión de los directivos, profesores y alumnos de la Universidad Europea Miguel de Cervantes sobre las herramientas tecnológicas existentes. Mediante la encuesta se pone de manifiesto los altos niveles de conocimiento en las dos herramientas evaluadas: campus virtual y webmail (con un bajo nivel de uso efectivo, especialmente en el colectivo de estudiantes). En conclusión, si bien las TICs son positivamente valoradas, su uso efectivo presenta ciertas deficiencias que podrían subsanarse si se mejora el contenido de estos espacios y son usadas como canales esenciales de información entre los públicos implicados.The case study presented aims to use analysis and the opinion of management, professors and students of the Universidad Europea Miguel de Cervantes on existing technological tools. Through the survey it shows high levels of knowledge assessed in the two tools: a virtual campus and webmail (with a low level of use, especially in the student group). In conclusion, while ICTs are positively valued, their actual use has certain shortcomings which could be remedied by improving the content of these spaces are used as key channels of information between the public involve

Análisis del imprinting genómico en neuronas tetraploides

En las células diploides, la mayoría de genes tienen dos copias, localizadas en el cromosoma materno y el cromosoma paterno. El imprinting es una de las excepciones a esta regla. En humanos, aproximadamente 100 genes se encuentran sujetos a imprinting, de forma que sólo el alelo paterno o el materno de un gen está activo. A día de hoy, se piensa que el silenciamiento de genes con imprinting ocurre en la línea germinal, y que este estado se mantiene en los tejidos somáticos después de la fertilización. El descubrimiento en el sistema nervioso de vertebrados de neuronas tetraploides, con el doble de contenido de DNA debido a la realización de una fase S sin mitosis posterior, y el interés por su caracterización morfológica y fisiológica, nos llevó a realizar este estudio para comprobar si el imprinting genómico se ve alterado en este tipo de neuronas. Tras aislar núcleos de neuronas 2C y 4C mediante citometría de flujo, y realizar una modificación del DNA con bisulfito sódico, se analizó mediante secuenciación la región cromosómica en la que se encuentra el gen Snrpn, por ser una de las regiones con imprinting más estudiadas. La existencia de enfermedades relacionadas con el imprinting, como el síndrome de Prader-Willi o el síndrome de Angelman, hacen de especial interés, además, la búsqueda de las consecuencias fisiológicas y/o patológicas del aumento de la dosis de un gen con esta característica en la tetraploidía neurona

Autoperception of teachers and direct team in the development of creativity: A case study analyzed with VADECRIE

El objetivo primordial de este trabajo es constatar la autopercepción que tiene el profesorado y equipo directivo de la creatividad en escuela. Valorar hasta qué punto existe un desarrollo creativo de la institución educativa a partir de un estudio de caso. Para ello aplicamos varios parámetros del instrumento “Valoración del desarrollo creativo de instituciones educativas” (VADECRIE) referidos a la dimensión humana: profesorado, equipo directivo y estudiantes. Intentamos conocer sus opiniones y autopercepciones. De ese modo triangularemos la información proveniente de dichas fuentes. La investigación se plantea desde un enfoque o paradigma de la complejidad y se utiliza como metodología el estudio de caso, centrando en el Colegio concertado Santo Ángel de la Guarda (Albacete. España). Este estudio se realizó con 348 participantes, de los cuales 14 fueron docentes de enseñanza básica, 7 miembros del equipo directivo y 327 alumnos. Los resultados ponen de manifiesto que existe una autopercepción positiva de la creatividad en el CentroThe main objective of this work is to verify the self-perception of the faculty and management team of creativity in school. Evaluate the extent to which there is a creative development of the educational institution from a case study. To do this we apply several parameters of the instrument "Valuing the creative development of educational institutions" (VADECRIE) referring to the human dimension: teaching staff, management team and students. We try to know their opinions and self-perceptions. In this way, we will triangulate and contrast the information coming from these sources. The research is based on an approach or paradigm of complexity and is used as a case study methodology, focusing on the Colegio Santo Ángel de la Guarda (Albacete, Spain). This study was carried out with 348 participants, of which 14 were teachers of basic education, 7 members of the management team and 327 students. The results show that there is a positive self-perception of creativity in the Cente

Control of early cell death by BDNF in the chick retina

8 páginas, 6 figuras, 1 tabla.The developing chick retina undergoes at least two discrete periods of programmed cell death. The earlier period coincides with the main onset of neuron birth and migration (embryonic day 5-7), whereas the latter one corresponds to the well-documented process of retinal ganglion cell death following tectal innervation (embryonic day 10-14; Rager, G. H. (1980) Adv. Anat. Embryol. Cell Biol. 63, 1-92). In the early period, apoptosis is induced by nerve growth factor (NGF) acting via its p75 receptor (Frade, J. M., Rodríguez-Tébar, A. and Barde, Y.-A. (1996) Nature 383, 166-168). Here, we show that the application of brain-derived neurotrophic factor (BDNF) to chick embryos in ovo prevented retinal cell death in the early period, whereas exogenously applied NGF and neurotrophin-3 had no such effect. The addition of BDNF to embryos resulted in about 70% increase in the number of retinal ganglion cells in both E6 and E9 retinas relative to controls. BDNF is first expressed in both the pigment epithelium and neural retina of embryonic day 4 embryos, and at the same stage of development, its TrkB receptor is expressed in the neural retina. Our data indicate that early cell death is an important process in the neurogenesis of retinal ganglion cells and is regulated by locally produced BDNF.This research was financed by grants from the DGCYT (Ministery of Science of Spain, no. PB95-0025 and PB94-0102-B), Regional Governments of Madrid and Canary Islands, Spain, and European Union, Programme Biotech (no. 960024).Peer reviewe

The Unfolded Protein Response and the Phosphorylations of Activating Transcription Factor 2 in the trans-Activation of il23a Promoter Produced by β-Glucans

Producción CientíficaCurrent views on the control of IL-23 production focus on theregulation ofil23a, the gene encoding IL-23 p19, by NF- Bincombination with other transcription factors. C/EBP homolo-gous protein (CHOP), X2-Box-binding protein 1 (XBP1), acti-vator protein 1 (AP1), SMAD, CCAAT/enhancer-binding pro-tein (C/EBP ), and cAMP-response element-binding protein(CREB) have been involved in response to LPS, but no data areavailable regarding the mechanism triggered by the fungalmimic and -glucan-containing stimulus zymosan, which pro-duces IL-23 and to a low extent the related cytokine IL-12 p70.Zymosan induced the mobilization of CHOP from the nuclearfractions to phagocytic vesicles. Hypha-formingCandidaalsoinduced the nuclear disappearance of CHOP. Assay of tran-scription factor binding to theil23apromoter showed anincrease of Thr(P)-71–Thr(P)-69-activating transcription fac-tor 2 (ATF2) binding in response to zymosan. PKC and PKA/mitogen- and stress-activated kinase inhibitors down-regulatedThr(P)-71–ATF2 binding to theil23apromoter andil23amRNA expression. Consistent with the current concept ofcomplementary phosphorylations on N-terminal Thr-71 andThr-69 of ATF2 by ERK and p38 MAPK, MEK, and p38 MAPKinhibitors blunted Thr(P)-69–ATF2 binding. Knockdown ofatf2mRNA with siRNA correlated with inhibition ofil23amRNA, but it did not affect the expression ofil12/23bandil10mRNA. These data indicate the following: (i) zymosan decreasesnuclear proapoptotic CHOP, most likely by promoting its accu-mulation in phagocytic vesicles; (ii) zymosan-inducedil23amRNA expression is best explained through coordinated B-and ATF2-dependent transcription; and (iii)il23aexpressionrelies on complementary phosphorylation of ATF2 on Thr-69and Thr-71 dependent on PKC and MAPK activities

Neuronal and astrocytic tetraploidy is increased in drug-resistant epilepsy

Aims: Epilepsy is one of the most prevalent neurological diseases. A third of patients with epilepsy remain drug-resistant. The exact aetiology of drug-resistant epilepsy (DRE) is still unknown. Neuronal tetraploidy has been associated with neuropathology. The aim of this study was to assess the presence of tetraploid neurons and astrocytes in DRE. Methods. For that purpose, cortex, hippocampus and amygdala samples were obtained from patients subjected to surgical resection of the epileptogenic zone. Post-mortem brain tissue of subjects without previous records of neurological, neurodegenerative or psychiatric diseases was used as control. Results: The percentage of tetraploid cells was measured by immunostaining of neurons (NeuN) or astrocytes (S100β) followed by flow cytometry analysis. The results were confirmed by image cytometry (ImageStream X Amnis System Cytometer) and with an alternative astrocyte biomarker (NDRG2). Statistical comparison was performed using univariate tests. A total of 22 patients and 10 controls were included. Tetraploid neurons and astrocytes were found both in healthy individuals and DRE patients in the three brain areas analysed: cortex, hippocampus and amygdala. DRE patients presented a higher number of tetraploid neurons (p = 0.020) and astrocytes (p = 0.002) in the hippocampus than controls. These results were validated by image cytometry. Conclusions: We demonstrated the presence of both tetraploid neurons and astrocytes in healthy subjects as well as increased levels of both cell populations in DRE patients. Herein, we describe for the first time the presence of tetraploid astrocytes in healthy subjects. Furthermore, these results provide new insights into epilepsy, opening new avenues for future treatment

Seven microaneurysms: Description of an experimental rodent model for neurovascular training

AIM: To demonstrate the microsurgical procedures, and to evaluate the feasibility of living models of experimental neurovascular training by developing new complex vascular exercises mimicking the most common intracranial aneurysms. MATERIAL and METHODS: The procedures were performed under a Zeiss (OPMI pico f170) microscope using basic microsurgery instruments, 10/0 Nylon and blue Polypropylene micro-sutures. We selected adult albino Wistar rats weighing between 258 and 471g each. Seven different aneurysm types were created using carotid, jugular, cava, aorta and femoral vessels. RESULTS: Seven types of aneurysm were designed and created in the rat with a high-medium successful rate. There are differences in terms of realism and the difficulty of performance, according to the different types: lateral wall, bifurcation, top of the basilar, fusiform, fusiform + involved branch, Anterior Communicating Artery (ACoA) and giant. The steps and technical issues to produce these exercises are described. CONCLUSION: We show the feasibility of creating several types of aneurysm using different vessels in a rodent model. Training on these models help to improve microsurgical skills, allowing safe practice for neurosurgeons in all stages of their caree

Innovación en procedimientos de evaluación de resultados de aprendizaje con soporte tecnológico y atención a criterios de inclusión (E-RA-INCLUYE)

Memoria ID2022-232 Ayudas de la Universidad de Salamanca para la innovación docente, curso 2022-2023

Polymorphisms in receptors involved in opsonic and nonopsonic phagocytosis, and correlation with risk of infection in oncohematology patients

Producción CientíficaHigh-risk hematological malignancies are a privileged setting for infection by opportunistic microbes, with invasive mycosis being one of the most serious complications. Recently, genetic background has emerged as an unanticipated risk factor. For this reason, polymorphisms for genes encoding archetypal receptors involved in the opsonic and nonopsonic clearance of microbes, pentraxin-3 (PTX3) and Dectin-1, respectively, were studied and correlated with the risk of infection. Fungal, bacterial, and viral infections were registered for a group of 198 patients with highrisk hematological malignancies. Polymorphisms for the pentraxin-3 gene (PTX3) showed a significant association with the risk of fungal infection by Candida spp. and, especially, by Aspergillus spp. This link remained even for patients undergoing antifungal prophylaxis, thus demonstrating the clinical relevance of PTX3 in the defense against fungi. CLEC7A polymorphisms did not show any definite correlation with the risk of invasive mycosis, nor did they influence the expression of Dectin-1 isoforms generated by alternative splicing. The PTX3 mRNA expression level was significantly lower in samples from healthy volunteers who showed these polymorphisms, although no differences were observed in the extents of induction elicited by bacterial lipopolysaccharide and heat-killed Candida albicans, thus suggesting that the expression of PTX3 at the start of infection may influence the clinical outcome. PTX3 mRNA expression can be a good biomarker to establish proper antifungal prophylaxis in immunodepressed patients