Mouse Model Of Machado-Joseph Disease Research Articles

Profiling Microglia in a Mouse Model of Machado-Joseph Disease.

Microglia have been increasingly implicated in neurodegenerative diseases (NDs), and specific disease associated microglia (DAM) profiles have been defined for several of these NDs. Yet, the microglial profile in Machado–Joseph disease (MJD) remains unexplored. Here, we characterized the profile of microglia in the CMVMJD135 mouse model of MJD. This characterization was performed using primary microglial cultures and microglial cells obtained from disease-relevant brain regions of neonatal and adult CMVMJD135 mice, respectively. Machine learning models were implemented to identify potential clusters of microglia based on their morphological features, and an RNA-sequencing analysis was performed to identify molecular perturbations and potential therapeutic targets. Our findings reveal morphological alterations that point to an increased activation state of microglia in CMVMJD135 mice and a disease-specific transcriptional profile of MJD microglia, encompassing a total of 101 differentially expressed genes, with enrichment in molecular pathways related to oxidative stress, immune response, cell proliferation, cell death, and lipid metabolism. Overall, these results allowed us to define the cellular and molecular profile of MJD-associated microglia and to identify genes and pathways that might represent potential therapeutic targets for this disorder.

Mesenchymal stem cell-derived exosomes improve motor function and attenuate neuropathology in a mouse model of Machado-Joseph disease

BackgroundMachado-Joseph disease is the most common autosomal dominant hereditary ataxia worldwide without effective treatment. Mesenchymal stem cells (MSCs) could slow the disease progression, but side effects limited their clinical application. Besides, MSC-derived exosomes exerted similar efficacy and have many advantages over MSCs. The aim of this study was to examine the efficacy of MSC-derived exosomes in YACMJD84.2 mice.MethodsRotarod performance was evaluated every 2 weeks after a presymptomatic administration of intravenous MSC-derived exosomes twice in YACMJD84.2 mice. Loss of Purkinje cells, relative expression level of Bcl-2/Bax, cerebellar myelin loss, and neuroinflammation were assessed 8 weeks following treatment.ResultsMSC-derived exosomes were isolated and purified through anion exchange chromatography. Better coordination in rotarod performance was maintained for 6 weeks in YACMJD84.2 mice with exosomal treatment, compared with those without exosomal treatment. Neuropathological changes including loss of Purkinje cells, cerebellar myelin loss, and neuroinflammation were also attenuated 8 weeks after exosomal treatment. The higher relative ratio of Bcl-2/Bax was consistent with the attenuation of loss of Purkinje cells.ConclusionsMSC-derived exosomes could promote rotarod performance and attenuate neuropathology, including loss of Purkinje cells, cerebellar myelin loss, and neuroinflammation. Therefore, MSC-derived exosomes have a great potential in the treatment of Machado-Joseph disease.

Pre-Clinical Assessment of Mesenchymal Stem Cell-Based Therapies in Spinocerebellar Ataxia Type 3

Motor uncoordination is one of the symptoms of spinocerebellar ataxia type 3/ Machado-Joseph disease (MJD), for which there is no effective treatment. In recent years, stem-cell related therapies begun to be explored for the treatment of neurodegenerative diseases. Beyond their potential for cell replacement therapies, stem cells also act as immunomodulators and neuroprotectors. Despite the evidence of beneficial outcomes in this context, the short duration of the pre and clinical trials and the fact that most patients regressed to the disease stage prior to treatment, highlights the urgency to assess therapeutic efficacy in a chronic fashion. The purpose of this study was to compare the therapeutic efficacy of hMSC transplantation versus administration of their secretome in different disease-relevant regions of the CNS, using a mouse model of MJD. We observed a more marked and sustained therapeutic benefit with hMSC transplantation into the cerebellum when compared to substantia nigra/ striatum or the spinal cord, or to administration of MSC secretome. Funding Statement: This work has been funded the National Ataxia Foundation (NAF), by FEDER, through the Competitiveness Factors Operational Programme (COMPETE), project NORTE-01-0145-FEDER-000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, and by National funds through the Foundation for Science and Technology (FCT) under the scope of the project UID/Multi/50026/2019 and fellowships to A.N-C., B. M-P., J. S. C., F. G. T., N. S., R. L., and S. D-S. (SFRH/BPD/118779/2016, SFRH/BD/120124/2016, SFRH/BD/140624/2018, SFRH/BPD/118408/2016, CEECIND/04794/2017, PD/BDE/127836/2016 and PTDC/NEUNMC/3648/2014). Declaration of Interests: The authors have no conflict of interests to report. Ethics Approval Statement: All procedures were conducted in accordance with European regulations (European Union Directive 86/609/EEC). Animal facilities and the people directly involved in animal experiments (A.N.C, B.M.P, J.S.C., S.D.S, S.M., F.G.T, F.L., R.L., N.A.S) as well as the principal investigators (A.J.S. and P.M.) were certified by the Portuguese regulatory entity Direcao Geral de Alimentacao e Veterinaria. All the protocols performed were approved by the Animal Ethics Committee of the Life and Health Sciences Research Institute, University of Minho (Braga, Portugal) and by the national regulatory agency, Direcao Geral de Alimentacao e Veterinaria (DGAV 020317).

Citalopram Reduces Aggregation of ATXN3 in a YAC Transgenic Mouse Model of Machado-Joseph Disease.

Machado-Joseph disease, also known as spinocerebellar ataxia type 3, is a fatal polyglutamine disease with no disease-modifying treatment. The selective serotonin reuptake inhibitor citalopram was shown in nematode and mouse models to be a compelling repurposing candidate for Machado-Joseph disease therapeutics. We sought to confirm the efficacy of citalopram to decrease ATXN3 aggregation in an unrelated mouse model of Machado-Joseph disease. Four-week-old YACMJD84.2 mice and non-transgenic littermates were given citalopram 8mg/kg in drinking water or water for 10weeks. At the end of treatment, brains were collected for biochemical and pathological analyses. Brains of citalopram-treated YACMJD84.2 mice showed an approximate 50% decrease in the percentage of cells containing ATXN3-positive inclusions in the substantia nigra and three examined brainstem nuclei compared to controls. No differences in ATXN3 inclusion load were observed in deep cerebellar nuclei of mice. Citalopram effect on ATXN3 aggregate burden was corroborated by immunoblotting analysis. While lysates from the brainstem and cervical spinal cord of citalopram-treated mice showed a decrease in all soluble forms of ATXN3 and a trend toward reduction of insoluble ATXN3, no differences in ATXN3 levels were found between cerebella of citalopram-treated and vehicle-treated mice. Citalopram treatment altered levels of select components of the cellular protein homeostatic machinery that may be expected to enhance the capacity to refold and/or degrade mutant ATXN3. The results here obtained in a second independent mouse model of Machado-Joseph disease further support citalopram as a potential drug to be repurposed for this fatal disorder.

Limited Effect of Chronic Valproic Acid Treatment in a Mouse Model of Machado-Joseph Disease.

Machado-Joseph disease (MJD) is an inherited neurodegenerative disease, caused by a CAG repeat expansion within the coding region of ATXN3 gene, and which currently lacks effective treatment. In this work we tested the therapeutic efficacy of chronic treatment with valproic acid (VPA) (200mg/kg), a compound with known neuroprotection activity, and previously shown to be effective in cell, fly and nematode models of MJD. We show that chronic VPA treatment in the CMVMJD135 mouse model had limited effects in the motor deficits of these mice, seen mostly at late stages in the motor swimming, beam walk, rotarod and spontaneous locomotor activity tests, and did not modify the ATXN3 inclusion load and astrogliosis in affected brain regions. However, VPA chronic treatment was able to increase GRP78 protein levels at 30 weeks of age, one of its known neuroprotective effects, confirming target engagement. In spite of limited results, the use of another dosage of VPA or of VPA in a combined therapy with molecules targeting other pathways, cannot be excluded as potential strategies for MJD therapeutics.

Re-establishing ataxin-2 downregulates translation of mutant ataxin-3 and alleviates Machado-Joseph disease.

Machado-Joseph disease is a progressive neurodegenerative disorder associated with the polyQ-expanded ataxin-3 (encoded by ATXN3), for which no therapy is available. With the aim of clarifying the mechanism of neurodegeneration, we hypothesized that the abnormally long polyQ tract would interact aberrantly with ataxin-2 (encoded by ATXN2), another polyQ protein whose function has recently been linked to translational regulation. Using patient's samples and cellular and animal's models we found that in Machado-Joseph disease: (i) ataxin-2 levels are reduced; and (ii) its subcellular localization is changed towards the nucleus. Restoring ataxin-2 levels by lentiviral-mediated overexpression: (i) reduced mutant ataxin-3 levels; and (ii) rescued behaviour defects and neuropathology in a transgenic mouse model of Machado-Joseph disease. Conversely (i) mutating the ataxin-2 motif that enables binding to its natural interactor and translation activator poly(A)-binding protein; or (ii) overexpressing poly(A)-binding protein, had opposite effects, increasing mutant ataxin-3 translation and aggregation. This work suggests that in Machado-Joseph disease, mutant ataxin-3 drives an abnormal reduction of ataxin-2 levels, which overactivates poly(A)-binding protein, increases translation of mutant ataxin-3 and other proteins and aggravates Machado-Joseph disease. Re-establishment of ataxin-2 levels reduces mutant ataxin-3 and alleviates Machado-Joseph disease pathogenesis opening a new avenue for therapeutic intervention in this and potentially other polyQ disorders.

RNA interference mitigates motor and neuropathological deficits in a cerebellar mouse model of Machado-Joseph disease.

Machado-Joseph disease or Spinocerebellar ataxia type 3 is a progressive fatal neurodegenerative disorder caused by the polyglutamine-expanded protein ataxin-3. Recent studies demonstrate that RNA interference is a promising approach for the treatment of Machado-Joseph disease. However, whether gene silencing at an early time-point is able to prevent the appearance of motor behavior deficits typical of the disease when initiated before onset of the disease had not been explored. Here, using a lentiviral-mediated allele-specific silencing of mutant ataxin-3 in an early pre-symptomatic cerebellar mouse model of Machado-Joseph disease we show that this strategy hampers the development of the motor and neuropathological phenotypic characteristics of the disease. At the histological level, the RNA-specific silencing of mutant ataxin-3 decreased formation of mutant ataxin-3 aggregates, preserved Purkinje cell morphology and expression of neuronal markers while reducing cell death. Importantly, gene silencing prevented the development of impairments in balance, motor coordination, gait and hyperactivity observed in control mice. These data support the therapeutic potential of RNA interference for Machado-Joseph disease and constitute a proof of principle of the beneficial effects of early allele-specific silencing for therapy of this disease.

Lithium chloride therapy fails to improve motor function in a transgenic mouse model of Machado-Joseph disease.

The accumulation of misfolded proteins in neurons, leading to the formation of cytoplasmic and nuclear aggregates, is a common theme in age-related neurodegenerative diseases, possibly due to disturbances of the proteostasis and insufficient activity of cellular protein clearance pathways. Lithium is a well-known autophagy inducer that exerts neuroprotective effects in different conditions and has been proposed as a promising therapeutic agent for several neurodegenerative diseases. We tested the efficacy of chronic lithium (10.4 mg/kg) treatment in a transgenic mouse model of Machado-Joseph disease, an inherited neurodegenerative disease, caused by an expansion of a polyglutamine tract within the protein ataxin-3. A battery of behavioral tests was used to assess disease progression. In spite of activating autophagy, as suggested by the increased levels of Beclin-1, Atg7, and LC3-II, and a reduction in the p62 protein levels, lithium administration showed no overall beneficial effects in this model concerning motor performance, showing a positive impact only in the reduction of tremors at 24 weeks of age. Our results do not support lithium chronic treatment as a promising strategy for the treatment of Machado-Joseph disease (MJD).

Chronic treatment with 17-DMAG improves balance and coordination in a new mouse model of Machado-Joseph disease.

Machado-Joseph disease (MJD) or spinocerebellar ataxia type 3 (SCA3) is a neurodegenerative disease currently with no treatment. We describe a novel mouse model of MJD which expresses mutant human ataxin-3 at near endogenous levels and manifests MJD-like motor symptoms that appear gradually and progress over time. CMVMJD135 mice show ataxin-3 intranuclear inclusions in the CNS and neurodegenerative changes in key disease regions, such as the pontine and dentate nuclei. Hsp90 inhibition has shown promising outcomes in some neurodegenerative diseases, but nothing is known about its effects in MJD. Chronic treatment of CMVMJD mice with Hsp90 inhibitor 17-DMAG resulted in a delay in the progression of their motor coordination deficits and, at 22 and 24 weeks of age, was able to rescue the uncoordination phenotype to wild-type levels; in parallel, a reduction in neuropathology was observed in treated animals. We observed limited induction of heat-shock proteins with treatment, but found evidence that 17-DMAG may be acting through autophagy, as LC3-II (both at mRNA and protein levels) and beclin-1 were induced in the brain of treated animals. This resulted in decreased levels of the mutant ataxin-3 and reduced intranuclear aggregation of this protein. Our data validate this novel mouse model as a relevant tool for the study of MJD pathogenesis and for pre-clinical studies, and show that Hsp90 inhibition is a promising therapeutic strategy for MJD.

Patterns of Mitochondrial DNA Damage in Blood and Brain Tissues of a Transgenic Mouse Model of Machado-Joseph Disease

Background: Machado-Joseph disease (MJD) is an autosomal dominant spinocerebellar ataxia caused by a CAG tract expansions in the ATXN3 gene. Patterns of mitochondrial damage associated with pathological findings of brain tissues could provide molecular biomarkers of this disorder. Objective: The potential of mitochondrial DNA (mtDNA) damage as a biomarker of MJD progression was investigated using a transgenic mouse model. Methods: DNA was obtained from affected (pontine nuclei) and nonaffected tissues (hippocampus and blood) of transgenic animals of three distinct age groups: 8 weeks, before onset of the phenotype; 16 weeks, at onset, and 24 weeks, at well-established phenotype. Wild-type littermate mice, serving as controls, were analyzed for the same tissues and age groups. mtDNA damage was studied by fluorescence-based quantitative PCR in 84 transgenic and 93 wild-type samples. Results: A clear pattern of decrease in mtDNA copy number with age and accumulation of 3,867-bp deletions at the initial stages (both being more pronounced in transgenic mice) was observed. Pontine nuclei, the affected tissue in transgenic mice, displayed 1.5 times less copies of mtDNA than nonaffected brain tissue hippocampus (odds ratio = 1.21). Pontine nuclei displayed the highest percentage of mtDNA deletions (6.05% more in transgenic mice). Conclusion: These results suggest that mtDNA damage is related to the initiation of the phenotype in transgenic mice; mtDNA 3,867-bp deletions may be a biomarker of the initial stages of the disease.

Inhibition of Mutant Ataxin-3 Proteolysis by Calpains in a Lentiviral Mouse Model of Machado-Joseph Disease

Event Abstract Back to Event Inhibition of Mutant Ataxin-3 Proteolysis by Calpains in a Lentiviral Mouse Model of Machado-Joseph Disease A. T. Simões1, 2, N. Goncalves1, 2, C. Nóbrega1, N. Déglon3, C. Bandeira Duarte1, S. Kügler4 and L. Pereira De Almeida1, 2* 1 University of Coimbra, Faculty of Pharmacy, Portugal 2 University of Coimbra, Center for Neuroscience and Cell Biology, Portugal 3 Institute of Biomedical Imaging and MIRCen, CEA, France 4 University of Gottingen, Department of Neurology, Vector Laboratory, Germany Machado-Joseph Disease (MJD), also known as Spinocerebellar ataxia type 3 (SCA3), is caused by polyglutamine repeat expansions of more than 55 CAGs within the coding region of the causative gene-MJD1. Originally described in people of Portuguese descent, MJD is the most frequent form among the autosomal dominantly inherited cerebellar ataxias. Neuronal loss in MJD has been proposed to be associated with a toxic cleavage fragment of mutant ataxin-3, which may aggregate, recruit other proteins including normal ataxin-3, and seed the formation of intranuclear inclusions.In this study, we aimed at overexpressing mutant ataxin-3 in the mouse brain using lentiviral vectors (LV), to generate an in vivo MJD genetic model and to investigate a role of the calcium-dependent proteases, calpains, in the generation of toxic ataxin-3 fragments.Co-injection of adeno-associated viral vectors (AAV) encoding the endogenous calpain inhibitor protein, calpastatin, with LV-mutant ataxin-3 (72Q) reduced the number of mutant ataxin-3 intranuclear inclusions and significantly decreased neuronal dysfunction and neurodegeneration evaluated by DARPP-32 immunoreactivity and number of pycnotic nuclei, respectively. Furthermore, overexpression of calpastatin altered the subcellular localization of mutant ataxin-3 in a dose dependent manner, restraining the protein in the cytoplasm, and overcoming calpastatin depletion observed upon mutant ataxin-3 expression. These data suggest that mutant ataxin-3 proteolysis by calpains is essential for its aggregation, translocation to the nucleus and consequent toxicity. Therefore, these results are an in vivo proof of principle that inhibition of this mechanism may provide a new therapeutic approach for MJD.Supported by the Portuguese Foundation for Science and Technology, grant PTDC/SAU-FCF/70384/2006 and fellowship SFRH/BD/38636/2007 Conference: 11th Meeting of the Portuguese Society for Neuroscience, Braga, Portugal, 4 Jun - 6 Jun, 2009. Presentation Type: Poster Presentation Topic: Neurodegenerative Disorders Citation: Simões AT, Goncalves N, Nóbrega C, Déglon N, Bandeira Duarte C, Kügler S and Pereira De Almeida L (2009). Inhibition of Mutant Ataxin-3 Proteolysis by Calpains in a Lentiviral Mouse Model of Machado-Joseph Disease. Front. Neurosci. Conference Abstract: 11th Meeting of the Portuguese Society for Neuroscience. doi: 10.3389/conf.neuro.01.2009.11.100 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 10 Aug 2009; Published Online: 10 Aug 2009. * Correspondence: L. Pereira De Almeida, University of Coimbra, Faculty of Pharmacy, Coimbra, Portugal, luispa@ci.uc.pt Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers A. T Simões N. Goncalves C. Nóbrega N. Déglon C. Bandeira Duarte S. Kügler L. Pereira De Almeida Google A. T Simões N. Goncalves C. Nóbrega N. Déglon C. Bandeira Duarte S. Kügler L. Pereira De Almeida Google Scholar A. T Simões N. Goncalves C. Nóbrega N. Déglon C. Bandeira Duarte S. Kügler L. Pereira De Almeida PubMed A. T Simões N. Goncalves C. Nóbrega N. Déglon C. Bandeira Duarte S. Kügler L. Pereira De Almeida Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Blockade of Adenosine Receptors by Caffeine Provides Neuroprotection in a Lentiviral Mouse Model of Machado-Joseph Disease

Event Abstract Back to Event Blockade of Adenosine Receptors by Caffeine Provides Neuroprotection in a Lentiviral Mouse Model of Machado-Joseph Disease Nelio Goncalves1, 2, 3*, Ana T. Simoes2, 3, Rodrigo A. Cunha2, 4 and Luis Pereira-de-Almeida2, 3 1 University of Coimbra, PhD Programme in Experimental Biology and Biomedicine, Center for Neuroscience and Cell Biology, Portugal 2 University of Coimbra, Center for Neuroscience and Cell Biology, Portugal 3 University of Coimbra, Faculty of Pharmacy, Portugal 4 University of Coimbra, Institute of Biochemistry, Faculty of Medicine, Portugal Machado Joseph Disease (MJD) or spinocerebellar ataxia type 3, a devastating brain disease, is one of the nine dominantly-inherited polyglutamine neurodegenerative disorders presently known, and it is considered to result from a toxic gain of function of mutant ataxin-3, a polyubiquitin-binding protein. The mechanisms accounting for neuronal degeneration are still largely unknown and there is currently no treatment available. One candidate strategy to manage MJD neurodegeneration might be the antagonism of adenosine A2A receptors (A2ARs). In fact, A2AR blockade has been shown to afford robust neuroprotection in different neurodegenerative disorders based on the key role of A2ARs to control glutamatergic transmission, apoptotic neuronal death, astrocytic function and neuroinflammation. This prompts the hypothesis that the manipulation of A2AR function might also be beneficial in MJD.A non-selective antagonism of the A2AR function promoted by the chronic consumption of caffeine (applied through the drinking water – 1g/L) was carried out in a lentiviral mouse model of MJD (Alves et al, 2008). Preliminary data suggest that caffeine led to an increase in the number of mutant ataxin-3 intranuclear inclusions in the striatum, a reduction in the loss of immunoreactivity for the dopaminergic marker DARPP-32, a decrease in the number of pycnotic nuclei and a reduction of the MJD-associated astrogliosis over time, when compared to the control group that only drank water. Further studies are necessary to confirm if blockade of A2ARs is indeed able to control striatal pathology associated with MJD. Conference: 11th Meeting of the Portuguese Society for Neuroscience, Braga, Portugal, 4 Jun - 6 Jun, 2009. Presentation Type: Poster Presentation Topic: Neurodegenerative Disorders Citation: Goncalves N, Simoes AT, Cunha RA and Pereira-de-Almeida L (2009). Blockade of Adenosine Receptors by Caffeine Provides Neuroprotection in a Lentiviral Mouse Model of Machado-Joseph Disease. Front. Neurosci. Conference Abstract: 11th Meeting of the Portuguese Society for Neuroscience. doi: 10.3389/conf.neuro.01.2009.11.105 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 10 Aug 2009; Published Online: 10 Aug 2009. * Correspondence: Nelio Goncalves, University of Coimbra, PhD Programme in Experimental Biology and Biomedicine, Center for Neuroscience and Cell Biology, Coimbra, Portugal, neliomotag@gmail.com Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Nelio Goncalves Ana T Simoes Rodrigo A Cunha Luis Pereira-de-Almeida Google Nelio Goncalves Ana T Simoes Rodrigo A Cunha Luis Pereira-de-Almeida Google Scholar Nelio Goncalves Ana T Simoes Rodrigo A Cunha Luis Pereira-de-Almeida PubMed Nelio Goncalves Ana T Simoes Rodrigo A Cunha Luis Pereira-de-Almeida Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Aging, Genetic Background and Parental Gender Modulate the CAG Repeat Instability Pattern in a Transgenic Mouse Model of Machado-Joseph Disease

Frontiers Events is a rapidly growing calendar management system dedicated to the scheduling of academic events. This includes announcements and invitations, participant listings and search functionality, abstract handling and publication, related events and post-event exchanges. Whether an organizer or participant, make your event a Frontiers Event!