182 research outputs found

    Novel galanin receptors in teleost fish: identification, expression and regulation by sex steroids

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    In fish, the onset of puberty, the transition from juvenile to sexually reproductive adult animals, is triggered by the activation of pituitary gonadotrophin secretion and its timing is influenced by external and internal factors that include the growth/adiposity status of the animal. Kisseptins have been implicated in the activation of puberty but peripheral signals coming from the immature gonad or associated to the metabolic/nutritional status are also thought to be involved. Additionally, there is evidence that the galaninergic system in the brain and testis of pre-pubertal male sea bass is a possible mediator involved in the translation of somatic signals leading to gonadal maturation. Here, the transcripts for four galanin receptors (GALR), named GALR1a, 1b, 2a and 2b, were isolated from European sea bass, Dicentrarchus labrax. Phylogenetic analysis confirmed the previously reported duplication of GALR1 in teleost fish, and unravelled the duplication of GALR2 in teleost fish and in some tetrapod species. Comparison with human showed that the key amino acids involved in ligand binding are present in the corresponding GALR1 and GALR2 orthologues. Transcripts for all four receptors are expressed in brain and testes of adult fish with GALR1a and GALR1b abundant in testes 15 and hardly detected in ovaries. In order to investigate whether GALR1 dimorphic expression was dependent on steroid context we evaluated the effect of 11-ketotestosterone and 17β-estradiol treatments on the receptor expression in brain and testes of pre-pubertal males. Interestingly, steroid treatments had no effect on the expression of GALRs in the brain while in the testes, GALR1a and GALR1b were significantly up regulated by 11KT. Altogether, these results support a role for the galaninergic system, in particular the GALR1 paralog in fish reproductive function

    Effects of artificial day length on early sexual maturation, reproductive performance, and egg quality in female European sea bass Dicentrarchus labrax (Linnaeus, 1758)

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    Juvenile sea bass, Dicentrarchus labrax (Linnaeus, 1758), (4-5 months old) were kept during four (experiment I) or three (experiment II) consecutive years under artificial photoperiod conditions. Compared with the control group, in experiment I, during the first reproductive cycle, the EX and LO groups showed a statistically significant advance and delay of 53 and 58 days, respectively, in mean spawning time. In Experiment II, the SLmar and CO groups presented a significant advance in spawning time, of 1 and 2 months, respectively, compared with the controls. From these results, it can be concluded that long-term application of artificial photoperiods can advance or delay the time of first spawning in D. labrax, as well as altering their rates of relative fecundity, and the quality of eggs and larvae.Se estudió la influencia del fotoperiodo en juveniles de lubina Dicentrarchus labrax (Linnaeus, 1758), de 4-5 meses de edad, mantenidos en cautividad durante 4 y 3 años consecutivos (experimentos I y II, respectivamente). En el experimento I, durante el primer ciclo reproductor, se observó que los grupos EX (fotoperiodo expandido) y LO (fotoperiodo largo constante) adelantaron y retrasaron el periodo medio de puesta en 53 y 58 días, respectivamente, en comparación con el grupo control. En el siguiente ciclo reproductor, estos grupos retrasaron el periodo medio de puesta en 21 y 31 días, respectivamente, con respecto al control. En general, las fecundidades relativas y las tasas de viabilidad de huevos y larvas de los grupos experimentales fueron un 50 % más bajas que las observadas en el grupo control. En el experimento II, los grupos SLmar y CO adelantaron en 1 o 2 meses el periodo medio de puesta en comparación con el grupo control (NP). En conclusión, el fotoperiodo puede alterar la aparición de la primera madurez sexual en las hembras, el periodo de puesta, la fecundidad y las tasas de viabilidad de huevos y larvas.Instituto Español de Oceanografí

    Cannabidiol antidepressant-like effect in the lipopolysaccharide model in mice: Modulation of inflammatory pathways

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    Major Depression is a severe psychiatric condition with a still poorly understood etiology. In the last years, evidence supporting the neuroinflammatory hypothesis of depression has increased. In the current clinical scenario, in which the available treatments for depression is far from optimal, there is an urgent need to develop fast-acting drugs with fewer side effects. In this regard, recent pieces of evidence suggest that cannabidiol (CBD), the major non-psychotropic component of Cannabis sativa with anti-inflammatory properties, appears as a drug with antidepressant properties. In this work, CBD 30 mg/kg was administered systemically to mice 30 min before lipopolysaccharide (LPS; 0.83 mg/kg) administration as a neuroinflammatory model, and behavioral tests for depressive-, anhedonic- and anxious-like behavior were performed. NF-?B, I?B? and PPAR? levels were analyzed by western blot in nuclear and cytosolic fractions of cortical samples. IL-6 and TNF? levels were determined in plasma and prefrontal cortex using ELISA and qPCR techniques, respectively. The precursor tryptophan (TRP), and its metabolites kynurenine (KYN) and serotonin (5-HT) were measured in hippocampus and cortex by HPLC. The ratios KYN/TRP and KYN/5-HT were used to estimate indoleamine 2,3-dioxygenase (IDO) activity and the balance of both metabolic pathways, respectively. CBD reduced the immobility time in the tail suspension test and increased sucrose preference in the LPS model, without affecting locomotion and central activity in the open-field test. CBD diminished cortical NF-?B activation, IL-6 levels in plasma and brain, and the increased KYN/TRP and KYN/5-HT ratios in hippocampus and cortex in the LPS model. Our results demonstrate that CBD produced antidepressant-like effects in the LPS neuroinflammatory model, associated to a reduction in the kynurenine pathway activation, IL-6 levels and NF-?B activation. As CBD stands out as a promising antidepressant drug, more research is needed to completely understand its mechanisms of action in depression linked to inflammation.FUNDING AND ACKNOWLEDGMENTS: This research was supported by the Ministerio de Economía y Competitividad (SAF2015-67457-R MINECO/FEDER), the Ministerio de Ciencia, Innovación y Universidades (RTI2018-097534-B-I00), the Instituto de Salud Carlos III (PI19/00170), and Centro de Investigación Biomédica en Red de Salud Mental (CIBERSAM). E F-Z was supported by a predoctoral fellowship from the Universidad de Cantabria (Spain). We acknowledge the technical assistance of Annamaria Architravo and Deborah Vasturzo, and Dr Rebeca Vidal for her scientific advice

    An overview of digital speech watermarking

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    Digital speech watermarking is a robust way to hide and thus secure data like audio and video from any intentional or unintentional manipulation through transmission. In terms of some signal characteristics including bandwidth, voice/non-voice and production model, digital speech signal is different from audio, music and other signals. Although, various review articles on image, audio and video watermarking are available, there are still few review papers on digital speech watermarking. Therefore this article presents an overview of digital speech watermarking including issues of robustness, capacity and imperceptibility. Other issues discussed are types of digital speech watermarking, application, models and masking methods. This article further highlights the related challenges in the real world, research opportunities and future works in this area, yet to be explored fully

    Configurational entropy calculation of poly(α-alkyl β,L-aspartate)s amorphous and crystalline films using gas permeation

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    The permeability and diffusion coefficient of gases such as N-2, O-2 and CO2 through two polymeric membranes of poly(alpha-alkyl beta,L-aspartate)s (PAALA-n) were determined by the "time-lag" method. One of these membranes was crystalline (PAALA-1) and the other one was amorphous (PAALA-6). The comparison of the obtained result for both membranes is addressed by the calculation of the so called configurational entropy. The study has been done in the range of temperatures 20 degrees C to 70 degrees C.This work was supported by the Direccion General de Investigacion Cientifica y Tecnica (DGICYT), Grant ENE-2011-Ref.24761 and also DGAPA-UNAM Proyecto IN 102512, and SEP-CONACYT 154626.Del Castillo, LF.; Andrio Balado, A.; Nava, JA.; Mollá Romano, S.; Muñoz-Guerra, S.; Compañ Moreno, V. (2014). Configurational entropy calculation of poly(α-alkyl β,L-aspartate)s amorphous and crystalline films using gas permeation. European Polymer Journal. 59:254-261. https://doi.org/10.1016/j.eurpolymj.2014.07.024S2542615

    Photoperiodic Modulation of Circadian Clock and Reproductive Axis Gene Expression in the Pre-Pubertal European Sea Bass Brain

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    The acquisition of reproductive competence requires the activation of the brain-pituitary-gonad (BPG) axis, which in most vertebrates, including fishes, is initiated by changes in photoperiod. In the European sea bass long-term exposure to continuous light (LL) alters the rhythm of reproductive hormones, delays spermatogenesis and reduces the incidence of precocious males. In contrast, an early shift from long to short photoperiod (AP) accelerates spermatogenesis. However, how photoperiod affects key genes in the brain to trigger the onset of puberty is still largely unknown. Here, we investigated if the integration of the light stimulus by clock proteins is sufficient to activate key genes that trigger the BPG axis in the European sea bass. We found that the clock genes clock, npas2, bmal1 and the BPG genes gnrh, kiss and kissr share conserved transcription factor frameworks in their promoters, suggesting co-regulation. Other gene promoters of the BGP axis were also predicted to be co-regulated by the same frameworks. Co-regulation was confirmed through gene expression analysis of brains from males exposed to LL or AP photoperiod compared to natural conditions: LL fish had suppressed gnrh1, kiss2, galr1b and esr1, while AP fish had stimulated npas2, gnrh1, gnrh2, kiss2, kiss1rb and galr1b compared to NP. It is concluded that fish exposed to different photoperiods present significant expression differences in some clock and reproductive axis related genes well before the first detectable endocrine and morphological responses of the BPG axis.European Community [222719 - LIFECYCLE]; Foundation for Science and Technology of Portugal (FCT) [SFRH/BPD/66742/2009, PEst-C/MAR/LA0015/2011]; Valencian Regional Goverment [Prometeo II/2014/051]; Spanish Ministry of Science and Innovation (MICINN) [CSD 2007-0002]info:eu-repo/semantics/publishedVersio

    Responsiveness of pituitary to galanin throughout the reproductive cycle of male European sea bass (Dicentrarchus labrax)

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    The neuropeptide galanin (Gal) is a putative factor regulating puberty onset and reproduction through its actions on the pituitary. The present study investigated the pituitary responsiveness to galanin and the patterns of galanin receptors (Galrs) expression throughout the reproductive cycle of two years old male European sea bass (Dicentrarchus labrax), an important aquaculture species. Quantitative analysis of pituitary and hypothalamus transcript expression of four galr subtypes revealed differential regulation according to the testicular developmental stage, with an overall decrease in expression from the immature stage to the mid-recrudescence stage. Incubation of pituitary cells with mammalian 1-29 Gal peptide induced significant changes in cAMP concentration, with sensitivities that varied according to the testicular development stages. Furthermore 1-29 Gal was able to stimulate both follicle stimulating hormone (Fsh) and luteinizing hormone (Lh) release from pituitary cell suspensions. The magnitude of the effects and effective concentrations varied according to reproductive stage, with generalized induction of Fsh and Lh release in animals sampled in January (full spermiation). The differential expression of galrs in pituitary and hypothalamus across the reproductive season, together with the differential effects of Gal on gonadotropins release in vitro strongly suggests the involvement of the galaninergic system in the regulation the hypothalamus-pituitary-gonad axis of male sea bass. This is to our knowledge the first clear evidence for the involvement of galanin in the regulation of reproduction in non-mammalian vertebrates. (C) 2017 Elsevier Inc. All rights reserved.European Union Seventh Framework Programme [262336]Spanish Ministry of Science and Innovation (MICINN)Spanish Ministry of the Economy and Competitiveness (MINECO) [AGL2009-11086]Spanish Ministry of the Economy and CompetitivenessRegional Government of Valencia [PROME-TEOH/2014/051]info:eu-repo/semantics/acceptedVersio

    Polyglutamine Induced Misfolding of Huntingtin Exon1 is Modulated by the Flanking Sequences

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    Polyglutamine (polyQ) expansion in exon1 (XN1) of the huntingtin protein is linked to Huntington's disease. When the number of glutamines exceeds a threshold of approximately 36–40 repeats, XN1 can readily form amyloid aggregates similar to those associated with disease. Many experiments suggest that misfolding of monomeric XN1 plays an important role in the length-dependent aggregation. Elucidating the misfolding of a XN1 monomer can help determine the molecular mechanism of XN1 aggregation and potentially help develop strategies to inhibit XN1 aggregation. The flanking sequences surrounding the polyQ region can play a critical role in determining the structural rearrangement and aggregation mechanism of XN1. Few experiments have studied XN1 in its entirety, with all flanking regions. To obtain structural insights into the misfolding of XN1 toward amyloid aggregation, we perform molecular dynamics simulations on monomeric XN1 with full flanking regions, a variant missing the polyproline regions, which are hypothesized to prevent aggregation, and an isolated polyQ peptide (Qn). For each of these three constructs, we study glutamine repeat lengths of 23, 36, 40 and 47. We find that polyQ peptides have a positive correlation between their probability to form a β-rich misfolded state and their expansion length. We also find that the flanking regions of XN1 affect its probability to^x_page_count=28 form a β-rich state compared to the isolated polyQ. Particularly, the polyproline regions form polyproline type II helices and decrease the probability of the polyQ region to form a β-rich state. Additionally, by lengthening polyQ, the first N-terminal 17 residues are more likely to adopt a β-sheet conformation rather than an α-helix conformation. Therefore, our molecular dynamics study provides a structural insight of XN1 misfolding and elucidates the possible role of the flanking sequences in XN1 aggregation
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