Publication

• The nervous and prenervous roles of serotonin in Echinococcus spp

  F Camicia , M Herz, L C Prada, L Kamenetzky, S H Simonetta, M A Cucher, J I Bianchi, C Fernández, K Brehm, M C Rosenzvit

  (System: ONE, Model organism: Echinococcus spp)

  PMID: 23639266 DOI: 10.1016/j.ijpara.2013.03.006
  2013 Jul;43(8):647-59. doi: 10.1016/j.ijpara.2013.03.006. Epub 2013 Apr 29.

  ABSTRACT:Serotonin (5-hydroxytryptamine, 5-HT) is an important neuroactive and morphogenetic molecule in several metazoan phyla, including flatworms. Serotoninergic nervous system studies are incomplete and 5-HT function/s are unknown in Echinococcus spp.the flatworm parasites that cause hydatid disease. In the present work, we searched for genes of the serotoninergic pathway and performed immunocytochemical and functional analyses of 5-HT in Echinococcus spp. Bioinformatic analysis using the recently available Echinococcus multilocularis and Echinococcus granulosus genomes suggests the presence of genes encoding enzymes, receptors and transporters participating in 5-HT synthesis, sensing and transport in these parasites.

  
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• An automated tracking system for Caenorhabditis elegans locomotor behavior and circadian studies application

  ergio H Simonetta, Diego A Golombek

  (System: ONE, Model organism: C. Elegans)

  PMID: 17207862 DOI: 10.1016/j.jneumeth.2006.11.015
  2007 Apr 15;161(2):273-80. doi: 10.1016/j.jneumeth.2006.11.015.

  ABSTRACT:Automation of simple behavioral patterns, such as locomotor activity, is fundamental for pharmacological and genetic screening studies. Recently, circadian behaviors in locomotor activity and stress responses were reported in the nematode Caenorhabditis elegans, a well-known model in genetics and developmental studies. Here we present a new method for long-term recordings of C. elegans (as well as other similar-sized animals) locomotor activity based on an infrared microbeam scattering. Individual nematodes were cultured in a 96-well microtiter plate; we tested L15, CeMM and E. coli liquid cultures in long-term activity tracking experiments, and found CeMM to be the optimal medium. Treatment with 0.2% azide caused an immediate decrease in locomotor activity as recorded with our system. In addition to the validation of the method (including hardware and software details), we report its application in chronobiological studies. Circadian rhythms in animals entrained to light-dark and constant dark conditions (n=48 and 96 worms, respectively) at 16 degrees C, were analyzed by LS periodograms. We obtained a 24.2+/-0.44 h period (52% of significantly rhythmic animals) in LD, and a 23.1+/-0.40 h period (37.5% of significantly rhythmic animals) under DD. The system is automateable using microcontrollers, of low-cost construction and highly reproducible.

  
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• Neurodegeneration in C. elegans models of ALS requires TIR-1/Sarm1 immune pathway activation in neurons

  Julie Vérièpe, Lucresse Fossouo, J Alex Parker

  (System: ONE, Model organism: C. Elegans)

  PMID: 26059317 DOI: 10.1038/ncomms8319 Free article
  2015 Jun 10;6:7319. doi: 10.1038/ncomms8319.

  ABSTRACT:Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease thought to employ cell non-autonomous mechanisms where neuronal injury engages immune responses to influence disease progression. Here we show that the expression of mutant proteins causative for ALS in Caenorhabditis elegans motor neurons induces an innate immune response via TIR-1/Sarm1. Loss of function mutations in tir-1, associated downstream kinases, and the transcription factor atf-7 all suppress motor neuron degeneration. The neurosecretory proteins UNC-13 and UNC-31 are required for induction of the immune response as well as the degeneration of motor neurons. The human orthologue of UNC-13, UNC13A, has been identified as a genetic modifier of survival in ALS, and we provide functional evidence of UNC-13/UNC13A in regulating motor neuron degeneration. We propose that the innate immune system reacts to the presence of mutant proteins as a contagion, recruiting a pathogen resistance response that is ultimately harmful and drives progressive neurodegeneration.

  
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• Reliable Screening of Dye Phototoxicity by Using a Caenorhabditis elegans Fast Bioassay.

  Javier Ignacio Bianchi, Juan Carlos Stockert, Lucila Ines Buzzi, Alfonso Blázquez-Castro, Sergio Hernán Simonetta

  (System: ONE ,Model organism: C. Elegans)

  PMID: 26039060 PMCID: PMC4454604 DOI: 10.1371/journal.pone.0128898 Free PMC article
  2015 Jun 3;10(6):e0128898. doi: 10.1371/journal.pone.0128898. eCollection 2015.

  ABSTRACT:Phototoxicity consists in the capability of certain innocuous molecules to become toxic when subjected to suitable illumination. In order to discover new photoactive drugs or characterize phototoxic pollutants, it would be advantageous to use simple biological tests of phototoxicy. In this work, we present a pilot screening of 37 dyes to test for phototoxic effects in the roundworm Caenorhabditis elegans. Populations of this nematode were treated with different dyes, and subsequently exposed to 30 min of white light. Behavioral outcomes were quantified by recording the global motility using an infrared tracking device (WMicrotracker). Of the tested compounds, 17 dyes were classified as photoactive, being phloxine B, primuline, eosin Y, acridine orange and rose Bengal the most phototoxic. To assess photoactivity after uptake, compounds were retested after washing them out of the medium before light irradiation. Dye uptake into the worms was also analyzed by staining or fluorescence. All the positive drugs were incorporated by animals and produced phototoxic effects after washing. We also tested the stress response being triggered by the treatments through reporter strains. Endoplasmic reticulum stress response (hsp-4::GFP strain) was activated by 22% of phototoxic dyes, and mitochondrial stress response (hsp-6::GFP strain) was induced by 16% of phototoxic dyes. These results point to a phototoxic perturbation of the protein functionality and an oxidative stress similar to that reported in cell cultures. Our work shows for the first time the feasibility of C. elegans for running phototoxic screenings and underscores its application on photoactive drugs and environmental pollutants assessment.

  
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• Optimization of a locomotion-based zebrafish seizure model

  Philip Anthony Gilbert Shaw, Sujogya Kumar Panda, Alexandru Stanca, Walter Luyten

  (System: ONE, Model organism: Zebrafish)

  ABSTRACT:Background: Locomotor assays in zebrafish have emerged as a screening test in early drug discovery for antiseizure compounds. However, parameters differ considerably between published studies, which may explain some discrepant results with (candidate) antiseizure medications. New method: We optimized a locomotor-based seizure assay in zebrafish with pentylenetetrazol (PTZ) as the pharmacological proconvulsant to generate a therapeutic window in which proconvulsant-treated zebrafish larvae could be discriminated from a non-treated control. To generate a reliable control, exposure time and concentration of valproate (VPA, anticonvulsant) was optimized.
  Results: Wells with one or three larvae show a similar PTZ dose-dependent increase in locomotion with less variability in motility for the latter. Zebrafish immersed in 10 mM PTZ showed a significant increase in movement with a sustained effect, without any indication of toxicity. Animals treated with 3 mM VPA showed the strongest reduction of PTZ-induced movement without toxicity. The decrease in PTZ-induced locomotion was greater after 18 h versus 2 h.
  Comparison with existing method(s): For the larval zebrafish PTZ-induced seizure model, varying experimental parameters have been reported in literature. Our results show that PTZ is often used at toxic concentrations and we provide instead reliable conditions to quantify convulsant behaviour using an infrared-beam motility assay.
  Conclusions: We recommend using three zebrafish larvae per well to quantify locomotion in 96-multiwell plates.
  Larvae should preferably be exposed to 10 mM PTZ for 1 h, consisting of 30 min acclimation and 30 min subsequent recording. As positive control for anticonvulsant activity, we recommend exposure to 3 mM VPA for 18 h before administration of PTZ.

  
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• Nutraceutical emulsion containing valproic acid (NE-VPA): a drug delivery system for reversion of seizures in zebrafish larvae epilepsy model

  Daniela Agustina Feas· Daniela Edith Igartúa· María Natalia Calienni·
  Carolina Soledad Martinez· Marina Pifano· Nadia Silvia Chiaramoni·
  Silvia del Valle Alonso · María Jimena Prieto

  (System: ONE, Model organism: Zebrafish)

  Published: 27 February 2017

  ABSTRACT: Valproic acid (VPA) is an antiepileptic drug which is currently used in neurodegenerative diseases. However a high dose is required to obtain a therapeutic effect. Long-chain polyunsaturated fatty acids (PUFAs) such as omega 3 and omega 6, are efficient complements in treatments for neurological diseases. Previous studies have reported that a dietary supplement containing PUFAs together with the administration of antiepileptic drugs significantlyreduces the frequency of seizures. Based on this the main goal of this work was to obtain a complex based on VPA encapsulation in an oil/water (o/w) nutraceutical emulsion (NE) enriched with PUFAs for oral administration.Besides, encapsulation of VPA might reduce its dose and increase its therapeutic effect. In order to study its effect, we used a zebrafish larvae model of induced epileptiform behavior with the proconvulsant drug pentylenetetrazol (PTZ). Results have shown that when 100 μM VPA and fatty acids were combined in the NE (NE-VPA), the epileptiform behavior of PTZ-treated zebrafish larvae decreased significantly. Additionally, morphological changes hepatotoxicity,lethality and heart rate were studied. Despite the fact that a high dose of VPA exerted a cardiotoxic effect this was no longer detected after addition of this drug in the NE. This treatment exerted a significant antiepileptic effectand did not result in highly toxic or lethal effects. In order

  Nutraceutical emulsion containing valproic acid (NE-VPA): a drug delivery system for reversion of seizures in zebrafish larvae epilepsy model

• Set-up of an infrared fast behavioral assay using zebrafish (Danio rerio) larvae, and its application in compound biotoxicity screening

  Darío Bicharaa,b, Nora B. Calcaterrab, Silvia Arranzb, Pablo Armasb and
  Sergio H. Simonettaa

  (System: ONE, Model organism: Zebrafish)

  PMID: 23401233 DOI: 10.1002/jat.2856
  2014 Feb;34(2):214-9. doi: 10.1002/jat.2856. Epub 2013 Feb 11.

  ABSTRACT:Zebrafish (Danio rerio) is increasingly employed for evaluating toxicity and drug discovery assays. Commonly experimental approaches for biotoxicity assessment are based on visual inspection or video recording. However, these techniques are limited for large-scale assays, as they demand either a time-consuming detailed inspection of the animals or intensive computing resources in order to analyze a considerable amount of screenshots. Recently, we have developed a simple methodology for tracking the locomotor activity of small animals cultured in microtiter plates. In this work, we implemented this automatic methodology, based on infrared (IR) microbeam scattering, for measuring behavioral activity in zebrafish larvae. We determined the appropriate culture conditions, number of animals and stage of development to get robust results.

  
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