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15 p.-7 fig. Faria, Melissa et al. ; Terrorist use of organophosphorus-based nerve agents and toxic industrial chemicals against civilian populations constitutes a real threat, as demonstrated by the terrorist attacks in Japan in the 1990 s or, even more recently, in the Syrian civil war. Thus, development of more effective countermeasures against acute organophosphorus poisoning is urgently needed. Here, we have generated and validated zebrafish models for mild, moderate and severe acute organophosphorus poisoning by exposing zebrafish larvae to different concentrations of the prototypic organophosphorus compound chlorpyrifos-oxon. Our results show that zebrafish models mimic most of the pathophysiological mechanisms behind this toxidrome in humans, including acetylcholinesterase inhibition, N-methyl-D-aspartate receptor activation, and calcium dysregulation as well as inflammatory and immune responses. The suitability of the zebrafish larvae to in vivo high-throughput screenings of small molecule libraries makes these models a valuable tool for identifying new drugs for multifunctional drug therapy against acute organophosphorus poisoning. ; This work was supported in part by the US Army ERDC-IRO (W912HZ-13-BAA-01; D.R., N.G.R., and P.J.B.) and Environmental Quality Research Program (N.G.R.), the NATO SfP project MD.SFPP 984777 (D.R., N.G.R., and P.J.B.), the National Science Foundation EPSCOR Grant EPS-0903787 (N.G.R.), the Portuguese Foundation for Science and Technology Grant SFRH/BPD/78342/2011 (Programme POPH – QREN through the Portuguese Ministry of Education and Science and the European Social Fund; M.F.), the Advanced Grant ERC-2012-AdG-320737 (D.R.) and the Spanish Government (CTM2014-51985-R; D.R.). ; Peer reviewed

Hyperthermia is a common confounding factor for assessing the neurotoxic effects of methamphetamine (METH) in mammalian models. The development of new models of methamphetamine neurotoxicity using vertebrate poikilothermic animals should allow to overcome this problem. The aim of the present study was to develop a zebrafish model of neurotoxicity by binge-like methamphetamine exposure. After an initial testing at 20 and 40 mg/L for 48 h, the later METH concentration was selected for developing the model and the effects on the brain monoaminergic profile, locomotor, anxiety-like and social behaviors as well as on the expression of key genes of the catecholaminergic system were determined. A concentration- and time-dependent decrease in the brain levels of dopamine (DA), norepinephrine (NE) and serotonin (5-HT) was found in METH-exposed fish. A significant hyperactivity was found during the first hour of exposure, followed 3 h after by a positive geotaxis and negative scototaxis in the novel tank and in the light/dark paradigm, respectively. Moreover, the behavioral phenotype in the treated fish was consistent with social isolation. At transcriptional level, th1 and slc18a2 (vmat2) exhibited a significant increase after 3 h of exposure, whereas the expression of gfap, a marker of astroglial response to neuronal injury, was strongly increased after 48 h exposure. However, no evidences of oxidative stress were found in the brain of the treated fish. Altogether, this study demonstrates the suitability of the adult zebrafish as a model of METH-induced neurotoxicity and provides more information about the biochemical and behavioral consequences of METH abuse. ; This work was supported by Grants PID2020-113371RB-C21 and PID2019-109390RB-I00 funded by MCIN/AEI/ 10.13039/501100011033 and by ERDF A way of making Europe, as well as by Grant CEX2018-000794-S funded by MCIN/AEI/ 10.13039/501100011033. Moreover, J.B. was supported by Grant PRE2018-083513 funded by MCIN/AEI/10.13039/501100011033 and by ESF Investing in your future. The work was also partially supported by the Catalan Government through the network of recognized research groups (2017 SGR_902 (DR, EP) and 2017SGR979 (RL-A, EE)). ; Peer reviewed

The accumulation and aggregation of α-synuclein (α-SYN) is a common characteristic of synucleinopathies, such as Parkinson's Disease (PD), Dementia with Lewy Bodies (DLB) or Multiple System Atrophy (MSA). Multiplications of the wildtype gene of α-SYN (SNCA) and most point mutations make α-SYN more aggregate-prone, and are associated with mitochondrial defects, trafficking obstruction, and impaired proteostasis, which contribute to elevated neuronal death. Here, we present new zebrafish models expressing either human wildtype (wt), or A53T mutant, α-SYN that recapitulate the above-mentioned hallmarks of synucleinopathies. The appropriate clearance of toxic α-SYN has been previously shown to play a key role in maintaining cell homeostasis and survival. However, the paucity of models to investigate α-SYN degradation in vivo limits our understanding of this process. Based on our recently described imaging method for measuring tau protein clearance in neurons in living zebrafish, we fused human SNCA to the photoconvertible protein Dendra2 which enabled analyses of wt and A53T α-SYN clearance kinetics in vivo. Moreover, these zebrafish models can be used to investigate the kinetics of α-SYN aggregation and to study the mechanisms, and potential new targets, controlling the clearance of both soluble and aggregated α-SYN. ; Funding for this study was obtained from Servier and the UK Dementia Research Institute (funded by the MRC, Alzheimer's Research UK and the Alzheimer's Society). European Union's Horizon 2020 Framework research and innovation program under the Marie Skłodowska-Curie Grant Number 746509 and Guarantors of Brain Non-Clinical Post - Doctoral Fellowship (to S.D.T).

The accumulation and aggregation of α-synuclein (α-SYN) is a common characteristic of synucleinopathies, such as Parkinson's Disease (PD), Dementia with Lewy Bodies (DLB) or Multiple System Atrophy (MSA). Multiplications of the wildtype gene of α-SYN (SNCA) and most point mutations make α-SYN more aggregate-prone, and are associated with mitochondrial defects, trafficking obstruction, and impaired proteostasis, which contribute to elevated neuronal death. Here, we present new zebrafish models expressing either human wildtype (wt), or A53T mutant, α-SYN that recapitulate the above-mentioned hallmarks of synucleinopathies. The appropriate clearance of toxic α-SYN has been previously shown to play a key role in maintaining cell homeostasis and survival. However, the paucity of models to investigate α-SYN degradation in vivo limits our understanding of this process. Based on our recently described imaging method for measuring tau protein clearance in neurons in living zebrafish, we fused human SNCA to the photoconvertible protein Dendra2 which enabled analyses of wt and A53T α-SYN clearance kinetics in vivo. Moreover, these zebrafish models can be used to investigate the kinetics of α-SYN aggregation and to study the mechanisms, and potential new targets, controlling the clearance of both soluble and aggregated α-SYN. ; Funding for this study was obtained from Servier and the UK Dementia Research Institute (funded by the MRC, Alzheimer's Research UK and the Alzheimer's Society). European Union's Horizon 2020 Framework research and innovation program under the Marie Skłodowska-Curie Grant Number 746509 and Guarantors of Brain Non-Clinical Post - Doctoral Fellowship (to S.D.T).

Organophosphorus compounds are acetylcholinesterase inhibitors used as pesticides and chemical warfare nerve agents. Acute organophosphorus poisoning (acute OPP) affects 3 million people, with 300 000 deaths annually worldwide. Severe acute OPP effects include overstimulation of cholinergic neurons, seizures, status epilepticus, and finally, brain damage. In a previous study, we developed 3 different chemical models of acute OPP in zebrafish larvae. To elucidate the complex pathophysiological pathways related to acute OPP, we used integrative omics (proteomic, transcriptomics, and metabolomics) on these 3 animal models. Our results show that these stochastic, apparently disparate morphological phenotypes can result from almost linear concentration-response variations in molecular levels. Results from the multiomics analysis strongly suggest that endoplasmic reticulum stress might play a central role in the pathophysiology of severe acute OPP, emphasizing the urgent need of further research on this molecular pathway. Endoplasmic reticulum stress could be an important therapeutic target to be included in the treatment of patients with severe acute OPP. ; NATO SfP project MD.SFPP 984777 (D.R.); the European Research Council under European Union's Seven Framework Programme (FP/2007–2013)/ERC Grant Agreement No. 320737; the Spanish Government (CTM2017-83242-R and CTM2015-65691-R). M.F. acknowledges the financial support from the Government of Catalonia through a Beatriu de Pinos fellowship (2016 BP-B 00233) ; Peer reviewed

Funding Information: Funding: This work was supported by Sociedade Portuguesa de Nefrologia, iNOVA4Health-UID/Multi/04462/2013 (a program financially supported by Fundação para a Ciência e Tecnolo-gia (FCT)/Ministério da Educação e Ciência, through national funds and co-funded by FEDER under the PT2020 Partnership Agreement) and FCT-ANR/BEX-BID/0153/2012 and PTDC/BEX-BID/1411/2014 research grants. M.R.R. was supported by national funds through FCT, first with an iNOVA post-doctoral fellowship and, more recently, with a contract in the context of the celebration of the program contract foreseen in the numbers 4, 5, and 6 of article 23.◦ of D.L. no. 57/2016 of 29 August, as amended by Law no. 57/2017 of 19 July. S.S.L. had a FCT-Investigator contract, followed by NOVA NMS contracts and, at the moment, a FCT CEEC (Concurso Estímulo ao Emprego Científico) contract, as principal investigator. This article is supported by the LYSOCIL project. This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 811087. Zebrafish used as an animal model were reproduced and maintained in the CEDOC Fish Facility, with the support from the research infrastructure Congento, co-financed by Lisboa Regional Operational Programme (Lisboa2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and FCT under the project LISBOA-01-0145-FEDER-022170. Funding Information: This work was supported by Sociedade Portuguesa de Nefrologia, iNOVA4Health-UID/Multi/04462/2013 (a program financially supported by Funda??o para a Ci?ncia e Tecnolo-gia (FCT)/Minist?rio da Educa??o e Ci?ncia, through national funds and co-funded by FEDER under the PT2020 Partnership Agreement) and FCT-ANR/BEX-BID/0153/2012 and PTDC/BEX-BID/1411/2014 research grants. M.R.R. was supported by national funds through FCT, first with an iNOVA post-doctoral fellowship and, more recently, with a contract in the context of the celebration of the program contract foreseen in the numbers 4, 5, and 6 of article 23.? of D.L. no. 57/2016 of 29 August, as amended by Law no. 57/2017 of 19 July. S.S.L. had a FCT-Investigator contract, followed by NOVA NMS contracts and, at the moment, a FCT CEEC (Concurso Est?mulo ao Emprego Cient?fico) contract, as principal investigator. This article is supported by the LYSOCIL project. This project has received funding from the European Union?s Horizon 2020 research and innovation programme under grant agreement No 811087. Zebrafish used as an animal model were reproduced and maintained in the CEDOC Fish Facility, with the support from the research infrastructure Congento, co-financed by Lisboa Regional Operational Programme (Lisboa2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and FCT under the project LISBOA-01-0145-FEDER-022170. Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. ; In autosomal dominant polycystic kidney disease (ADPKD), kidney cyst growth requires the recruitment of CFTR (cystic fibrosis transmembrane conductance regulator), the chloride channel that is defective in cystic fibrosis. We have been studying cyst inflation using the zebrafish Kupffer's vesicle (KV) as model system because we previously demonstrated that knocking down polycystin 2 (PC2) induced a CFTR-mediated enlargement of the organ. We have now quantified the PC2 knock-down by showing that it causes a 73% reduction in the number of KV cilia expressing PC2. According to the literature, this is an essential event in kidney cystogenesis in ADPKD mice. Additionally, we demonstrated that the PC2 knockdown leads to a significant accumulation of CFTR-GFP at the apical region of the KV cells. Furthermore, we determined that KV enlargement is rescued by the injection of Xenopus pkd2 mRNA and by 100 µM tolvaptan treatment, the unique and approved pharmacologic approach for ADPKD management. We expected vasopressin V2 receptor antagonist to lower the cAMP levels of KV-lining cells and, thus, to inactivate CFTR. These findings further support the use of the KV as an in vivo model for screening compounds that may prevent cyst enlargement in this ciliopathy, through CFTR inhibition. ; publishersversion ; published

Occupational, accidental, or suicidal exposure to acrylamide (ACR) may result in a neurotoxic syndrome. Development of animal models of acrylamide neurotoxicity is necessary for increasing our mechanistic understanding of this syndrome and developing more effective therapies. A new model for acute ACR neurotoxicity has been recently developed in adult zebrafish. Whereas the results of the initial characterization were really promising, a further characterization is needed for testing the construct validity of the model. In this study, the presence of gait abnormalities has been investigated by using ZebraGait, software specifically designed to analyze the kinematics of fish swimming in a water tunnel. The results of the kinematic analyses demonstrated that the model exhibits mild-to-moderate gait abnormalities. Moreover, the model exhibited negative scototaxis, a result confirming a phenotype of anxiety comorbid with depression phenotype. Interestingly, depletion of the reduced glutathione levels was found in the brain without a concomitant increase in oxidative stress. Finally, hypolocomotion and positive geotaxis exhibited by this model were fully recovered 5 days after transferring the fish to clean fish-water. All this data support the validity of the ACR acute neurotoxicity model developed in adult zebrafish. ; We thank Dr. Caio Maximino, from the Universidade Federal do Sul e Sudeste do Pará (Marabá, Brazil), for his comments and suggestions on the DLT. The IRI Lab technical staff members are gratefully thanked for their valuable assistance in the design of the experimental setup for video-recording the fish swimming. This work was supported by the NATO SfP project MD. SFPP 984777 (D.R.) and the Spanish Government (CTM2017-83242-R; D.R. and J.M.P.). M.F. acknowledges financial support from the Beatriu de Pinós programme (Grant No. 2016 BP 00233) provided by the Secretariat of Universities and Research department of the Ministry for Business and Knowledge, Catalonia Government. ; Peer reviewed

Glioblastoma (GBM) is the most common of all brain malignant tumors; it displays a median survival of 14.6 months with current complete standard treatment. High heterogeneity, aggressive and invasive behavior, the impossibility of completing tumor resection, limitations for drug administration and therapeutic resistance to current treatments are the main problems presented by this pathology. In recent years, our knowledge of GBM physiopathology has advanced significantly, generating relevant information on the cellular heterogeneity of GBM tumors, including cancer and immune cells such as macrophages/microglia, genetic, epigenetic and metabolic alterations, comprising changes in miRNA expression. In this scenario, the zebrafish has arisen as a promising animal model to progress further due to its unique characteristics, such as transparency, ease of genetic manipulation, ethical and economic advantages and also conservation of the major brain regions and blood–brain–barrier (BBB) which are similar to a human structure. A few papers described in this review, using genetic and xenotransplantation zebrafish models have been used to study GBM as well as to test the anti-tumoral efficacy of new drugs, their ability to interact with target cells, modulate the tumor microenvironment, cross the BBB and/or their toxicity. Prospective studies following these lines of research may lead to a better diagnosis, prognosis and treatment of patients with GBM ; F.T.A. has been supported by the AECC ("Asociación Española Contra el Cáncer", Spain). We would also like to thank the following: the Talento Program from Madrid Government, Spain (2017-T1/BMD-5333); Convocatoria 2018 de proyectos de I+D+i «RETOS INVESTIGACIÓN» (RTI2018-095061-B-I00) (to C.M.R.); "Convocatoria de ayudas para la contratación de ayudantes de investigación" (PEJ-2018-AI/BMD-9724) (to M.T.-P.); the Xunta de Galicia Pre-doctoral Fellowship (ED481A-2018/095) (to A.P.L.) ; SI

Mutations in the gene encoding tau (MAPT) cause frontotemporal dementia spectrum disorders. A rare tau variant p.A152T was reported as a risk factor for frontotemporal dementia spectrum and Alzheimer's disease in an initial case-control study. Such findings need replication in an independent cohort. We analysed an independent multinational cohort comprising 3100 patients with neurodegenerative disease and 4351 healthy control subjects and found p.A152T associated with significantly higher risk for clinically defined frontotemporal dementia and progressive supranuclear palsy syndrome. To assess the functional and biochemical consequences of this variant, we generated transgenic zebrafish models expressing wild-type or A152T-tau, where A152T caused neurodegeneration and proteasome compromise. Impaired proteasome activity may also enhance accumulation of other proteins associated with this variant. We increased A152T clearance kinetics by both pharmacological and genetic upregulation of autophagy and ameliorated the disease pathology observed in A152T-tau fish. Thus, autophagy-upregulating therapies may be a strategy for the treatment for tauopathies. ; We thank the Tau consortium (SEL, ALB, GC, BLM, DCR), P50 AG02350, P01 AG019724, R01AG038791, U54NS092089, F31 NS084556, Alzheimer's Research UK (DCR) Wellcome Trust (Principal Research Fellowship to 095317/Z/11/Z), a Wellcome Trust Strategic Grant to Cambridge Institute for Medical Research (100140/Z/12/Z), NIHR Biomedical Research Unit in Dementia at Addenbrooke's Hospital, the John Douglas French Alzheimer's Foundation for funding. L.S. is funded by a DFG fellowship, N.V.O. is funded by BBSRC project grant BB/L000830/1. Samples from the National Cell Repository for Alzheimer's Disease (NCRAD), which receives government support under a cooperative agreement grant (U24 AG21886) awarded by the National Institute on Aging (NIA), were used in this study.

Acrylamide (ACR), a type-2 alkene, may lead to a synaptopathy characterized by ataxia, skeletal muscles weakness and numbness of the extremities in exposed human and laboratory animals. Currently, only the mildly affected patients undergo complete recovery, and identification of new molecules with therapeutic bioactivity against ACR acute neurotoxicity is urgently needed. Here, we have generated a zebrafish model for ACR neurotoxicity by exposing 5 days post-fertilization zebrafish larvae to 1 mM ACR for 3 days. Our results show that zebrafish mimics most of the pathophysiological processes described in humans and mammalian models. Motor function was altered, and specific effects were found on the presynaptic nerve terminals at the neuromuscular junction level, but not on the axonal tracts or myelin sheath integrity. Transcriptional markers of proteins involved in synaptic vesicle cycle were selectively altered, and the proteomic analysis showed that ACR-adducts were formed on cysteine residues of some synaptic proteins. Finally, analysis of neurotransmitters profile showed a significant effect on cholinergic and dopaminergic systems. These data support the suitability of the developed zebrafish model for screening of molecules with therapeutic value against this toxic neuropathy. © 2017 The Author(s). ; We thank Dr. Harold A. Burgess for providing Flote software and advice with the kinematic analysis. The 3A10 antibody, developed by Jessell, T.M./Dodd, J./Brenner-Morton, S. (DSHB Hybridoma Product 3A10), was obtained from the Developmental Studies Hybridoma Bank, created by the NICHD of the NIH and maintained at The University of Iowa, Department of Biology, Iowa City, IA 52242. This work was supported in part by the NATO SfP project MD.SFPP 984777 (D.R., A.A. and N.G.R.), the US Army Environmental Quality and Installations Research Program (N.G.R.), the Advanced Grant ERC-2012-AdG-320737 (D.R., C.G-C, R.T.), the Spanish Government (CTM2014-51985-R; D.R.) and the I-CORE Program of the Planning and Budgeting Committee and The Israel Science Foundation (grant No. 1775/12 to A.A.) for the purchase of the mass spectrometer. ; Peer reviewed