Functional Phenotypic Rescue of Caenorhabditis elegans Neuroligin-Deficient Mutants by the Human and Rat NLGN1 Genes

Neuroligins are cell adhesion proteins that interact with neurexins at the synapse. This interaction may contribute to differentiation, plasticity and specificity of synapses. In humans, single mutations in neuroligin encoding genes lead to autism spectrum disorder and/or mental retardation. Caenorhabditis elegans mutants deficient in nlg-1, an orthologue of human neuroligin genes, have defects in different behaviors. Here we show that the expression of human NLGN1 or rat Nlgn1 cDNAs in C. elegans nlg-1 mutants rescues the fructose osmotic strength avoidance and gentle touch response phenotypes. Two specific point mutations in NLGN3 and NLGN4 genes, involved in autistic spectrum disorder, were further characterized in this experimental system. The R451C allele described in NLGN3, was analyzed with both human NLGN1 (R453C) and worm NLG-1 (R437C) proteins, and both were not functional in rescuing the osmotic avoidance behavior and the gentle touch response phenotype. The D396X allele described in NLGN4, which produces a truncated protein, was studied with human NLGN1 (D432X) and they did not rescue any of the behavioral phenotypes analyzed. In addition, RNAi feeding experiments measuring gentle touch response in wild type strain and worms expressing SID-1 in neurons (which increases the response to dsRNA), both fed with bacteria expressing dsRNA for nlg-1, provided evidence for a postsynaptic in vivo function of neuroligins both in muscle cells and neurons, equivalent to that proposed in mammals. This finding was further confirmed generating transgenic nlg-1 deficient mutants expressing NLG-1 under pan-neuronal (nrx-1) or pan-muscular (myo-3) specific promoters. All these results suggest that the nematode could be used as an in vivo model for studying particular synaptic mechanisms with proteins orthologues of humans involved in pervasive developmental disorders

Actividad física y acelerometría: orientaciones metodológicas, recomendaciones y patrones de movimiento en escolares

Introducción: En los últimos años, ha cobrado especial importancia el empleo de acelerómetros para valorar la actividad física de niños y jóvenes. La metodología utilizada en el uso de la acelerometría determina los resultados obtenidos y condiciona la posibilidad de comparar diferentes estudios. Objetivo: El objetivo de esta revisión, se centra en aspectos metodológicos relacionados con la evaluación de la actividad física en escolares utilizando la acelerometría. Metodología: Se realizó una revisión de la literatura de los artículos incluidos en las bases de datos Medline/ Pubmed y Scielo que utilizaran acelerómetros con participantes en edad escolar entre Enero de 2002 y Agosto de 2013, seleccionándose 133 artículos científicos. Resultados: Parece existir un cierto consenso respecto a la elección del lugar de colocación, el tiempo de registro y el empleo de epochs cada vez más reducidos; sin embargo, se encuentra una gran variabilidad respecto al modelo de acelerómetro empleado y los puntos de corte seleccionados. Discusión y Conclusiones: Los diferentes criterios empleados, dificultan la comparación en la metodología empleada entre estudios a pesar de que existan ciertos puntos en común entre ellos. Introduction: Over the last years, the use of accelerometers has become relevant to quantify physical activity among youth. Methods used with accelerometers might modify the results and the possibility to compare different papers. These devices have been proved to be effective and valid quantifying long periods of physical activity compared to other methods. Objective: To show methodological criteria regarding physical activity assessed by accelerometry with schoolars. Methodology: It was conducted a review of the literature related to accelerometers and scholar-aged subjects at PubMed from January 2002 to August 2013, selecting 133 papers. Results: As far as it is shown, it appears to be some tendencies related to the choice of attachment of the device, wearing time and a shorter epoch-length; however, it has been found a wide variability regarding the model of accelerometer and cutoff points used. Discussion and Conclusions: The different criterion used makes it difficult to compare methodological aspects among studies in spite of some papers carried out similar methods

A Potassium Metal-Organic Framework based on Perylene- 3,4,9,10-tetracarboxylate as Sensing Layer for Humidity Actuators

We have synthesized a novel three-dimensional metal-organic-framework (MOF) based on the perylene-3,4,9,10-tetracarboxylate linker and potassium as metallic centre. We report the formation of this K-based MOF using conventional routes with water as solvent. This material displays intense green photoluminescence at room temperature, and displays an aggregation dependent quenching. Correlation of the optical properties with the crystalline packing was confirmed by DFT calculations. We also demonstrate its potential to build humidity actuators with a reversible and reproducible response, with a change of 5 orders of magnitudes in its impedance at about 40% relative humidity (RH). This 3D-MOF is based on an interesting perylene derivative octadentate ligand, a moiety with interesting fluorescent properties and known component in organic semiconductors. To the best of our knowledge, this is the first time to build such a printed and flexible actuator towards humidity with a reversible response, enabling precise humidity threshold monitoring.This work was supported by the Junta de Andalucía (FQM-1484, and FQM-195). Red Guipuzcoana de Ciencia, Tecnología e Innovación (OF188/2017) and University of the Basque Country (GIU14/01, EHUA16/32). BB acknowledges funding by RyC-2012–10381 contract and computational resources provided by the RES and Alhambra supercomputing facilities. This work was also supported by the German Research Foundation (DFG) and the Technical University of Munich within the Open Access Publishing Funding Programme

Using C. elegans to decipher the cellular and molecular mechanisms underlying neurodevelopmental disorders

Prova tipográfica (uncorrected proof)Neurodevelopmental disorders such as epilepsy, intellectual disability (ID), and autism spectrum disorders (ASDs) occur in over 2 % of the population, as the result of genetic mutations, environmental factors, or combination of both. In the last years, use of large-scale genomic techniques allowed important advances in the identification of genes/loci associated with these disorders. Nevertheless, following association of novel genes with a given disease, interpretation of findings is often difficult due to lack of information on gene function and effect of a given mutation in the corresponding protein. This brings the need to validate genetic associations from a functional perspective in model systems in a relatively fast but effective manner. In this context, the small nematode, Caenorhabditis elegans, presents a good compromise between the simplicity of cell models and the complexity of rodent nervous systems. In this article, we review the features that make C. elegans a good model for the study of neurodevelopmental diseases. We discuss its nervous system architecture and function as well as the molecular basis of behaviors that seem important in the context of different neurodevelopmental disorders. We review methodologies used to assess memory, learning, and social behavior as well as susceptibility to seizures in this organism. We will also discuss technological progresses applied in C. elegans neurobiology research, such as use of microfluidics and optogenetic tools. Finally, we will present some interesting examples of the functional analysis of genes associated with human neurodevelopmental disorders and how we can move from genes to therapies using this simple model organism.The authors would like to acknowledge Fundação para a Ciência e Tecnologia (FCT) (PTDC/SAU-GMG/112577/2009). AJR and CB are recipients of FCT fellowships: SFRH/BPD/33611/2009 and SFRH/BPD/74452/2010, respectively

Human alpha- and beta-NRXN1 isoforms rescue behavioral impairments of caenorhabditis elegans neurexin-deficient mutants

Neurexins are cell adhesion proteins that interact with neuroligin and other ligands at the synapse. In humans, mutations in neurexin or neuroligin genes have been associated with autism and other mental disorders. The human neurexin and neuroligin genes are orthologous to the Caenorhabditis elegans genes nrx-1 and nlg-1, respectively. Here we show that nrx-1-deficient mutants are defective in exploratory capacity, sinusoidal postural movements and gentle touch response. Interestingly, the exploratory behavioral phenotype observed in nrx-1 mutants was markedly different to nlg-1-deficient mutants; thus, while the former had a 'hyper-reversal' phenotype increasing the number of changes of direction with respect to the wild-type strain, the nlg-1 mutants presented a 'hypo-reversal' phenotype. On the other hand, the nrx-1- and nlg-1-defective mutants showed similar abnormal sinusoidal postural movement phenotypes. The response of these mutant strains to aldicarb (acetylcholinesterase inhibitor), levamisole (ACh agonist) and pentylenetetrazole [gamma-aminobutyric (GABA) receptor antagonist], suggested that the varying behavioral phenotypes were caused by defects in ACh and/or GABA inputs. The defective behavioral phenotypes of nrx-1-deficient mutants were rescued in transgenic strains expressing either human alpha- or beta-NRXN-1 isoforms under the worm nrx-1 promoter. A previous report had shown that human and rat neuroligins were functional in C. elegans. Together, these results suggest that the functional mechanism underpinning both neuroligin and neurexin in the nematode are comparable to human. In this sense the nematode might constitute a simple in vivo model for understanding basic mechanisms involved in neurological diseases for which neuroligin and neurexin are implicated in having a rol

Apple extract induces increased epithelial resistance and claudin 4 expression in Caco-2 cells

BACKGROUND: The small intestinal epithelium functions both to absorb nutrients, and to provide a barrier between the outside, luminal, world and the human body. One of the passageways across the intestinal epithelium is paracellular diffusion, which is controlled by the properties of tight junction complexes. We used a differentiated Caco-2 monolayer as a model for small intestinal epithelium to study the effect of crude apple extracts on paracellular permeability. RESULTS: Exposure of crude apple homogenate to the differentiated Caco-2 cells increased the paracellular resistance, determined as trans-epithelial electrical resistance (TEER). This increase was linearly related to the concentration of apple present. The TEER-enhancing effect of apple extract was due to factors mainly present in the cortex, and the induction was not inhibited by protein kinase inhibitors. Apple-induced resistance was accompanied by increased expression of several tight junction related genes, including claudin 4 (CLDN4). CONCLUSION: Crude apple extract induces a higher paracellular resistance in differentiated Caco-2 cells. Future research will determine whether these results can be extrapolated to human small intestinal epitheli

Effects of a soccer training program on physical fitness in young players

El objetivo de este estudio es analizar los efectos de un programa de entrenamiento de fútbol sobre la condición física en jugadores jóvenes. La muestra estuvo compuesta por 44 sujetos, dividido en dos grupos: Grupo Experimental (GE) de 25 jugadores de fútbol (14,44±1,19 años; 53,88±10,81 kg de masa; 163,60±8,15 cm de talla; 5,08±1,18 años de experiencia) y un Grupo Control (GC) de 19 alumnos sin actividad física dirigida, aparte de las sesiones de EF (16,89±0,45 años; 66,83±10,62 kg de masa; 171,36±7,01 cm de talla). Se realizaron dos valoraciones, antes y después del programa de entrenamiento de una duración de 8 semanas, las cuales siguieron el mismo protocolo de pruebas: velocidad de 30 m, flexibilidad isquiosural, fuerza explosiva del tren inferior, dinamometría manual y consumo máximo de oxígeno. Los resultados muestran que las cargas son acordes a estas edades, provocando una mejora de la condición física con los entrenamientos. No obstante, no se reflejan diferencias sustanciales entre ambos grupos, existiendo la necesidad de planificar más concretamente las capacidades a mejorar en una especialidad como el fútbol en estas edades.The objective of this paper is to analyze the effects of a soccer training program on physical fitness among young soccer players. The sample was composed of 44 subjects, who were divided into two groups: Experimental Group (EG) of 25 football players (14.44 ± 1.19 years old, 53.88 ± 10.81 kg mass; 163.60 ± 8, 15 cm of height, 5.08 ± 1.18 years of experience) and a control group (CG) of 19 students who did not perform physical activity, apart from physical education during school classes (16.89 ± 0.45 years old 66.83 ± 10.62 kg mass, 171, 36 ± 7.01 cm of height). There was carried out two assessments, before and after the training program, which lasts 8 weeks, and both of them where done by the same protocol testing: speed of 30 m, hamstring flexibility, explosive lower body strength, hand grip test and maximal oxygen consumption. The results show that the load of training is according to these ages, improving fitness with the training. However, there are not important differences between groups, so there might be interesting to develop a detailed planning on physical fitness in order to improve in a specific sport such as soccer.Sin financiaciónNo data 201