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Grønbæk-Thygesen M, Hartmann-Petersen R. Cellular and molecular mechanisms of aspartoacylase and its role in Canavan disease. Cell Biosci 2024; 14:45. [PMID: 38582917 PMCID: PMC10998430 DOI: 10.1186/s13578-024-01224-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 03/24/2024] [Indexed: 04/08/2024] Open
Abstract
Canavan disease is an autosomal recessive and lethal neurological disorder, characterized by the spongy degeneration of the white matter in the brain. The disease is caused by a deficiency of the cytosolic aspartoacylase (ASPA) enzyme, which catalyzes the hydrolysis of N-acetyl-aspartate (NAA), an abundant brain metabolite, into aspartate and acetate. On the physiological level, the mechanism of pathogenicity remains somewhat obscure, with multiple, not mutually exclusive, suggested hypotheses. At the molecular level, recent studies have shown that most disease linked ASPA gene variants lead to a structural destabilization and subsequent proteasomal degradation of the ASPA protein variants, and accordingly Canavan disease should in general be considered a protein misfolding disorder. Here, we comprehensively summarize the molecular and cell biology of ASPA, with a particular focus on disease-linked gene variants and the pathophysiology of Canavan disease. We highlight the importance of high-throughput technologies and computational prediction tools for making genotype-phenotype predictions as we await the results of ongoing trials with gene therapy for Canavan disease.
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Affiliation(s)
- Martin Grønbæk-Thygesen
- The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200N, Copenhagen, Denmark.
| | - Rasmus Hartmann-Petersen
- The Linderstrøm-Lang Centre for Protein Science, Department of Biology, University of Copenhagen, Ole Maaløes Vej 5, 2200N, Copenhagen, Denmark.
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Hull VL, Wang Y, McDonough J, Zhu M, Burns T, Al Ramel N, Dehghani A, Guo F, Pleasure D. Astroglial conditional Slc13a3 knockout is therapeutic in murine Canavan leukodystrophy. Ann Clin Transl Neurol 2024; 11:1059-1062. [PMID: 38282243 PMCID: PMC11021635 DOI: 10.1002/acn3.52010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 12/22/2023] [Accepted: 01/19/2024] [Indexed: 01/30/2024] Open
Abstract
Canavan disease is a leukodystrophy caused by ASPA mutations that diminish oligodendroglial aspartoacylase activity, and is characterized by markedly elevated brain concentrations of the aspartoacylase substrate N-acetyl-l-aspartate (NAA) and by astroglial and intramyelinic vacuolation. Astroglia express NaDC3 (encoded by SLC13A3), a sodium-coupled transporter for NAA and other dicarboxylates. Astroglial conditional Slc13a3 deletion in aspartoacylase-deficient Canavan disease model mice ("CD mice") reversed brain NAA elevation and improved motor function. These results demonstrate that astroglial NaDC3 contributes to brain NAA elevation in CD mice, and suggest that suppressing astroglial NaDC3 activity would ameliorate human Canavan disease.
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Affiliation(s)
- Vanessa L. Hull
- Department of NeurologyUC Davis School of MedicineSacramentoCaliforniaUSA
- Shriners Hospital for ChildrenSacramentoCaliforniaUSA
- Department of PhysiologyDavid Geffen School of Medicine, UCLALos AngelesCaliforniaUSA
| | - Yan Wang
- Department of NeurologyUC Davis School of MedicineSacramentoCaliforniaUSA
- Shriners Hospital for ChildrenSacramentoCaliforniaUSA
| | | | - Meina Zhu
- Department of NeurologyUC Davis School of MedicineSacramentoCaliforniaUSA
- Shriners Hospital for ChildrenSacramentoCaliforniaUSA
| | - Travis Burns
- Department of NeurologyUC Davis School of MedicineSacramentoCaliforniaUSA
- Shriners Hospital for ChildrenSacramentoCaliforniaUSA
| | - Najmah Al Ramel
- Department of Biological SciencesKent State UniversityKentOhioUSA
| | - Ali Dehghani
- Department of NeurologyUC Davis School of MedicineSacramentoCaliforniaUSA
- Shriners Hospital for ChildrenSacramentoCaliforniaUSA
| | - Fuzheng Guo
- Department of NeurologyUC Davis School of MedicineSacramentoCaliforniaUSA
- Shriners Hospital for ChildrenSacramentoCaliforniaUSA
| | - David Pleasure
- Department of NeurologyUC Davis School of MedicineSacramentoCaliforniaUSA
- Shriners Hospital for ChildrenSacramentoCaliforniaUSA
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Becker I, Wang-Eckhardt L, Eckhardt M. NAAG synthetase deficiency has only low influence on pathogenesis in a Canavan disease mouse model. J Inherit Metab Dis 2024; 47:230-243. [PMID: 38011891 DOI: 10.1002/jimd.12693] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 11/14/2023] [Accepted: 11/15/2023] [Indexed: 11/29/2023]
Abstract
Canavan disease (CD) is a leukodystrophy caused by mutations in the N-acetylaspartate (NAA) hydrolase aspartoacylase (ASPA). Inability to degrade NAA and its accumulation in the brain results in spongiform myelin degeneration. NAA is mainly synthesized by neurons, where it is also a precursor of the neuropeptide N-acetylaspartylglutamate (NAAG). Hydrolysis of this peptide by glutamate carboxypeptidases is an additional source of extracellular NAA besides the instant neuronal release of NAA. This study examines to what extent NAA released from NAAG contributes to NAA accumulation and pathogenesis in the brain of Aspanur7/nur7 mutant mice, an established model of CD. Towards this aim, Aspanur7/nur7 mice with additional deficiencies in NAAG synthetase genes Rimklb and/or Rimkla were generated. Loss of myelin in Aspanur7/nur7 mice was not significantly affected by Rimkla and Rimklb deficiency and there was also no obvious change in the extent of brain vacuolation. Astrogliosis was slightly reduced in the forebrain of Rimkla and Rimklb double deficient Aspanur7/nur7 mice. However, only minor improvements at the behavioral level were found. The brain NAA accumulation in CD mice was, however, not significantly reduced in the absence of NAAG synthesis. In summary, there was only a weak tendency towards reduced pathogenic symptoms in Aspanur7/nur7 mice deficient in NAAG synthesis. Therefore, we conclude that NAAG metabolism has little influence on NAA accumulation in Aspanur7/nur7 mice and development of pathological symptoms in CD.
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Affiliation(s)
- Ivonne Becker
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Lihua Wang-Eckhardt
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Matthias Eckhardt
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn, Germany
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Feng L, Chao J, Zhang M, Pacquing E, Hu W, Shi Y. Developing a human iPSC-derived three-dimensional myelin spheroid platform for modeling myelin diseases. iScience 2023; 26:108037. [PMID: 37867939 PMCID: PMC10589867 DOI: 10.1016/j.isci.2023.108037] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 08/11/2023] [Accepted: 09/21/2023] [Indexed: 10/24/2023] Open
Abstract
Myelin defects cause a collection of myelin disorders in the brain. The lack of human models has limited us from better understanding pathological mechanisms of myelin diseases. While human induced pluripotent stem cell (hiPSC)-derived spheroids or organoids have been used to study brain development and disorders, it has been difficult to recapitulate mature myelination in these structures. Here, we have developed a method to generate three-dimensional (3D) myelin spheroids from hiPSCs in a robust and reproducible manner. Using this method, we generated myelin spheroids from patient iPSCs to model Canavan disease (CD), a demyelinating disorder. By using CD patient iPSC-derived myelin spheroids treated with N-acetyl-aspartate (NAA), we were able to recapitulate key pathological features of the disease and show that high-level NAA is sufficient to induce toxicity on myelin sheaths. Our study has established a 3D human cellular platform to model human myelin diseases for mechanistic studies and drug discovery.
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Affiliation(s)
- Lizhao Feng
- Department of Neurodegenerative Diseases, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
- Oujiang Laboratory, Zhejiang Lab for Regenerative Medicine, Vision and Brain Health, Wenzhou, Zhejiang 325000, China
| | - Jianfei Chao
- Department of Neurodegenerative Diseases, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - Mingzi Zhang
- Department of Neurodegenerative Diseases, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - Elizabeth Pacquing
- Department of Neurodegenerative Diseases, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - Weidong Hu
- Department of Molecular Imaging and Therapy, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - Yanhong Shi
- Department of Neurodegenerative Diseases, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
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Becker I, Eckhardt M. An enzymatic fluorimetric assay for determination of N-acetylaspartate. Anal Biochem 2023; 667:115083. [PMID: 36804395 DOI: 10.1016/j.ab.2023.115083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 01/27/2023] [Accepted: 02/11/2023] [Indexed: 02/17/2023]
Abstract
N-acetylaspartate (NAA) is an abundant metabolite in the mammalian brain and a precursor of the neuropeptide N-acetylaspartylglutamate (NAAG). The physiological role of NAA is not fully understood and requires further studies. We here describe the development of a coupled enzymatic fluorimetric assay for the determination of NAA in biological samples. Deproteinized tissue extracts are first passed through a strong cation exchange column to remove aspartate. NAA in the sample is hydrolysed by aspartoacylase and released aspartate oxidized using l-aspartate oxidase. Generated H2O2 is measured with peroxidase in a fluorimetric assay using Ampliflu Red. The limit of detection and the lower limit of quantification are 1.0 μM (10 pmol/well) and 3.3 μM (33 pmol/well), respectively, with a linear range to 100 μM. Specificity of the assay was confirmed using samples from mice deficient in NAA synthase Nat8l that were spiked with NAA. Analysis of samples from aspartoacylase-deficient mice showed a 2 to 3-fold increase in brain NAA concentration, in line with previous reports. Mice lacking NAAG synthetases had a slightly reduced (-10%) brain NAA level. Thus, the new fluorimetric enzymatic assay is useful to perform sensitive and large scale quantification of NAA in biological samples without the need for expensive equipment.
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Affiliation(s)
- Ivonne Becker
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Nussallee 11, 53115, Bonn, Germany
| | - Matthias Eckhardt
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Nussallee 11, 53115, Bonn, Germany.
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Wang Y, Zhang S, Lan Z, Doan V, Kim B, Liu S, Zhu M, Hull VL, Rihani S, Zhang CL, Gray JA, Guo F. SOX2 is essential for astrocyte maturation and its deletion leads to hyperactive behavior in mice. Cell Rep 2022; 41:111842. [PMID: 36543123 PMCID: PMC9875714 DOI: 10.1016/j.celrep.2022.111842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2021] [Revised: 09/23/2022] [Accepted: 11/24/2022] [Indexed: 12/24/2022] Open
Abstract
Children with SOX2 deficiency develop ocular disorders and extra-ocular CNS anomalies. Animal data show that SOX2 is essential for retinal and neural stem cell development. In the CNS parenchyma, SOX2 is primarily expressed in astroglial and oligodendroglial cells. Here, we report a crucial role of astroglial SOX2 in postnatal brain development. Astroglial Sox2-deficient mice develop hyperactivity in locomotion and increased neuronal excitability in the corticostriatal circuit. Sox2 deficiency inhibits postnatal astrocyte maturation molecularly, morphologically, and electrophysiologically without affecting astroglia proliferation. Mechanistically, SOX2 directly binds to a cohort of astrocytic signature and functional genes, the expression of which is significantly reduced in Sox2-deficient CNS and astrocytes. Consistently, Sox2 deficiency remarkably reduces glutamate transporter expression and compromised astrocyte function of glutamate uptake. Our study provides insights into the cellular mechanisms underlying brain defects in children with SOX2 mutations and suggests a link of astrocyte SOX2 with extra-ocular abnormalities in SOX2-mutant subjects.
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Affiliation(s)
- Yan Wang
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA
| | - Sheng Zhang
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA
| | - Zhaohui Lan
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA
| | - Vui Doan
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA
| | - Bokyung Kim
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA
| | - Sihan Liu
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA
| | - Meina Zhu
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA
| | - Vanessa L Hull
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA
| | - Sami Rihani
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA
| | - Chun-Li Zhang
- Department of Molecular Biology and Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - John A Gray
- Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA; Center for Neuroscience, University of California, Davis, Davis, CA 95618, USA
| | - Fuzheng Guo
- Institute for Pediatric Regenerative Medicine, Shriners Hospitals for Children Northern California, Sacramento, CA 95817, USA; Department of Neurology, School of Medicine, University of California, Davis, Davis, CA 95817, USA.
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7
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Fröhlich D, Kalotay E, von Jonquieres G, Bongers A, Lee B, Suchowerska AK, Housley GD, Klugmann M. Dual-function AAV gene therapy reverses late-stage Canavan disease pathology in mice. Front Mol Neurosci 2022; 15:1061257. [PMID: 36568275 PMCID: PMC9772617 DOI: 10.3389/fnmol.2022.1061257] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 11/18/2022] [Indexed: 12/13/2022] Open
Abstract
The leukodystrophy Canavan disease is a fatal white matter disorder caused by loss-of-function mutations of the aspartoacylase-encoding ASPA gene. There are no effective treatments available and experimental gene therapy trials have failed to provide sufficient amelioration from Canavan disease symptoms. Preclinical studies suggest that Canavan disease-like pathology can be addressed by either ASPA gene replacement therapy or by lowering the expression of the N-acetyl-L-aspartate synthesizing enzyme NAT8L. Both approaches individually prevent or even reverse pathological aspects in Canavan disease mice. Here, we combined both strategies and assessed whether intracranial adeno-associated virus-mediated gene delivery to a Canavan disease mouse model at 12 weeks allows for reversal of existing pathology. This was enabled by a single vector dual-function approach. In vitro and in vivo biopotency assessment revealed significant knockdown of neuronal Nat8l paired with robust ectopic aspartoacylase expression. Following nomination of the most efficient cassette designs, we performed proof-of-concept studies in post-symptomatic Aspa-null mice. Late-stage gene therapy resulted in a decrease of brain vacuoles and long-term reversal of all pathological hallmarks, including loss of body weight, locomotor impairments, elevated N-acetyl-L-aspartate levels, astrogliosis, and demyelination. These data suggest feasibility of a dual-function vector combination therapy, directed at replacing aspartoacylase with concomitantly suppressing N-acetyl-L-aspartate production, which holds potential to permanently alleviate Canavan disease symptoms and expands the therapeutic window towards a treatment option for adult subjects.
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Affiliation(s)
- Dominik Fröhlich
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia,*Correspondence: Dominik Fröhlich,
| | - Elizabeth Kalotay
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Georg von Jonquieres
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Andre Bongers
- Biological Resources Imaging Laboratory, University of New South Wales, Sydney, NSW, Australia
| | - Brendan Lee
- Biological Resources Imaging Laboratory, University of New South Wales, Sydney, NSW, Australia
| | - Alexandra K. Suchowerska
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Gary D. Housley
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility and Department of Physiology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia,Research Beyond Borders, Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany,Matthias Klugmann,
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Chao J, Feng L, Ye P, Chen X, Cui Q, Sun G, Zhou T, Tian E, Li W, Hu W, Riggs AD, Matalon R, Shi Y. Therapeutic development for Canavan disease using patient iPSCs introduced with the wild-type ASPA gene. iScience 2022; 25:104391. [PMID: 35637731 PMCID: PMC9142666 DOI: 10.1016/j.isci.2022.104391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Revised: 03/03/2022] [Accepted: 05/06/2022] [Indexed: 12/04/2022] Open
Abstract
Canavan disease (CD) is a devastating neurological disease that lacks effective therapy. Because CD is caused by mutations of the aspartoacylase (ASPA) gene, we introduced the wild-type (WT) ASPA gene into patient iPSCs through lentiviral transduction or CRISPR/Cas9-mediated gene editing. We then differentiated the WT ASPA-expressing patient iPSCs (ASPA-CD iPSCs) into NPCs and showed that the resultant ASPA-CD NPCs exhibited potent ASPA enzymatic activity. The ASPA-CD NPCs were able to survive in brains of transplanted CD mice. The engrafted ASPA-CD NPCs reconstituted ASPA activity in CD mouse brains, reduced the abnormally elevated level of NAA in both brain tissues and cerebrospinal fluid (CSF), and rescued hallmark pathological phenotypes of the disease, including spongy degeneration, myelination defects, and motor function impairment in transplanted CD mice. These genetically modified patient iPSC-derived NPCs represent a promising cell therapy candidate for CD, a disease that has neither a cure nor a standard treatment. The wild-type ASPA gene was introduced into CD patient iPSCs to make ASPA-CD iPSCs ASPA-CD iPSCs were differentiated into ASPA-CD NPCs with potent ASPA activity Engrafted ASPA-CD NPCs could rescue major disease phenotypes in CD mice CSF NAA level can be used as a biomarker to monitor the treatment outcome for CD
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Affiliation(s)
- Jianfei Chao
- Division of Stem Cell Biology Research, Department of Stem Cell Biology and Regenerative Medicine, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - Lizhao Feng
- Division of Stem Cell Biology Research, Department of Stem Cell Biology and Regenerative Medicine, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - Peng Ye
- Division of Stem Cell Biology Research, Department of Stem Cell Biology and Regenerative Medicine, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - Xianwei Chen
- Division of Stem Cell Biology Research, Department of Stem Cell Biology and Regenerative Medicine, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - Qi Cui
- Division of Stem Cell Biology Research, Department of Stem Cell Biology and Regenerative Medicine, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - Guihua Sun
- Division of Stem Cell Biology Research, Department of Stem Cell Biology and Regenerative Medicine, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA.,Diabetes and Metabolism Research Institute, City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - Tao Zhou
- Division of Stem Cell Biology Research, Department of Stem Cell Biology and Regenerative Medicine, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - E Tian
- Division of Stem Cell Biology Research, Department of Stem Cell Biology and Regenerative Medicine, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - Wendong Li
- Division of Stem Cell Biology Research, Department of Stem Cell Biology and Regenerative Medicine, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - Weidong Hu
- Department of Molecular Imaging and Therapy, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - Arthur D Riggs
- Diabetes and Metabolism Research Institute, City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
| | - Reuben Matalon
- Department of Pediatrics, The University of Texas Medical Branch at Galveston, 301 University Boulevard, Galveston, TX 77555-0359, USA
| | - Yanhong Shi
- Division of Stem Cell Biology Research, Department of Stem Cell Biology and Regenerative Medicine, Beckman Research Institute of City of Hope, 1500 E. Duarte Road, Duarte, CA 91010, USA
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Wei H, Moffett JR, Amanat M, Fatemi A, Tsukamoto T, Namboodiri AM, Slusher BS. The pathogenesis of, and pharmacological treatment for, Canavan disease. Drug Discov Today 2022; 27:2467-2483. [DOI: 10.1016/j.drudis.2022.05.019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Revised: 05/05/2022] [Accepted: 05/24/2022] [Indexed: 12/12/2022]
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Pardo B, Herrada-Soler E, Satrústegui J, Contreras L, del Arco A. AGC1 Deficiency: Pathology and Molecular and Cellular Mechanisms of the Disease. Int J Mol Sci 2022; 23:528. [PMID: 35008954 PMCID: PMC8745132 DOI: 10.3390/ijms23010528] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Revised: 12/23/2021] [Accepted: 12/24/2021] [Indexed: 02/01/2023] Open
Abstract
AGC1/Aralar/Slc25a12 is the mitochondrial carrier of aspartate-glutamate, the regulatory component of the NADH malate-aspartate shuttle (MAS) that transfers cytosolic redox power to neuronal mitochondria. The deficiency in AGC1/Aralar leads to the human rare disease named "early infantile epileptic encephalopathy 39" (EIEE 39, OMIM # 612949) characterized by epilepsy, hypotonia, arrested psychomotor neurodevelopment, hypo myelination and a drastic drop in brain aspartate (Asp) and N-acetylaspartate (NAA). Current evidence suggest that neurons are the main brain cell type expressing Aralar. However, paradoxically, glial functions such as myelin and Glutamine (Gln) synthesis are markedly impaired in AGC1 deficiency. Herein, we discuss the role of the AGC1/Aralar-MAS pathway in neuronal functions such as Asp and NAA synthesis, lactate use, respiration on glucose, glutamate (Glu) oxidation and other neurometabolic aspects. The possible mechanism triggering the pathophysiological findings in AGC1 deficiency, such as epilepsy and postnatal hypomyelination observed in humans and mice, are also included. Many of these mechanisms arise from findings in the aralar-KO mice model that extensively recapitulate the human disease including the astroglial failure to synthesize Gln and the dopamine (DA) mishandling in the nigrostriatal system. Epilepsy and DA mishandling are a direct consequence of the metabolic defect in neurons due to AGC1/Aralar deficiency. However, the deficits in myelin and Gln synthesis may be a consequence of neuronal affectation or a direct effect of AGC1/Aralar deficiency in glial cells. Further research is needed to clarify this question and delineate the transcellular metabolic fluxes that control brain functions. Finally, we discuss therapeutic approaches successfully used in AGC1-deficient patients and mice.
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Affiliation(s)
- Beatriz Pardo
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain; (E.H.-S.); (J.S.); (L.C.)
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid (UAM)-Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain;
- Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Eduardo Herrada-Soler
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain; (E.H.-S.); (J.S.); (L.C.)
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid (UAM)-Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain;
- Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Jorgina Satrústegui
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain; (E.H.-S.); (J.S.); (L.C.)
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid (UAM)-Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain;
- Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Laura Contreras
- Departamento de Biología Molecular, Universidad Autónoma de Madrid, 28049 Madrid, Spain; (E.H.-S.); (J.S.); (L.C.)
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid (UAM)-Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain;
- Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Araceli del Arco
- Centro de Biología Molecular Severo Ochoa, Universidad Autónoma de Madrid (UAM)-Consejo Superior de Investigaciones Científicas (CSIC), 28049 Madrid, Spain;
- Instituto de Investigaciones Sanitarias Fundación Jiménez Díaz (IIS-FJD), Universidad Autónoma de Madrid, 28049 Madrid, Spain
- Centro Regional de Investigaciones Biomédicas, Facultad de Ciencias Ambientales y Bioquímica, Universidad de Castilla La Mancha, 45071 Toledo, Spain
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11
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Nešuta O, Thomas AG, Alt J, Hin N, Neužilová A, Long S, Tsukamoto T, Rojas C, Wei H, Slusher BS. High Throughput Screening Cascade To Identify Human Aspartate N-Acetyltransferase (ANAT) Inhibitors for Canavan Disease. ACS Chem Neurosci 2021; 12:3445-3455. [PMID: 34477360 DOI: 10.1021/acschemneuro.1c00455] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Canavan disease (CD) is a progressive, fatal neurological disorder that begins in infancy resulting from a mutation in aspartoacyclase (ASPA), an enzyme that catalyzes the deacetylation of N-acetyl aspartate (NAA) into acetate and aspartate. Increased NAA levels in the brains of affected children are one of the hallmarks of CD. Interestingly, genetic deletion of N-acetyltransferase-8-like (NAT8L), which encodes aspartate N-aceyltransferase (ANAT), an enzyme responsible for the synthesis of NAA from l-aspartate and acetyl-CoA, leads to normalization of NAA levels and improvement of symptoms in several genetically engineered mouse models of CD. Therefore, pharmacological inhibition of ANAT presents a promising therapeutic strategy for treating CD. Currently, however, there are no clinically viable ANAT inhibitors. Herein we describe the development of fluorescence-based high throughput screening (HTS) and radioactive-based orthogonal assays using recombinant human ANAT expressed in E. coli. In the fluorescence-based assay, ANAT activity was linear with respect to time of incubation up to 30 min and protein concentration up to 97.5 ng/μL with Km values for l-aspartate and acetyl-CoA of 237 μM and 11 μM, respectively. Using this optimized assay, we conducted a pilot screening of a 10 000-compound library. Hits from the fluorescence-based assay were subjected to an orthogonal radioactive-based assay using L-[U-14C] aspartate as a substrate. Two compounds were confirmed to have dose-dependent inhibition in both assays. Inhibitory kinetics studies of the most potent compound revealed an uncompetitive inhibitory mechanism with respect to l-aspartate and a noncompetitive inhibitory mechanism against acetyl-CoA. The screening cascade developed herein will enable large-scale compound library screening to identify novel ANAT inhibitors as leads for further medicinal chemistry optimization.
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Affiliation(s)
- Ondřej Nešuta
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Ajit G. Thomas
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Jesse Alt
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Niyada Hin
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Anna Neužilová
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Shunyou Long
- ChemBioCORE, High Throughput Screening Facility, Johns Hopkins University, 733 N. Broadway, Baltimore, Maryland 21205, United States
| | - Takashi Tsukamoto
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland 21205, United States
| | - Camilo Rojas
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
| | - Huijun Wei
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland 21205, United States
| | - Barbara S. Slusher
- Johns Hopkins Drug Discovery, Johns Hopkins School of Medicine, 855 N. Wolfe Street, Baltimore, Maryland 21205, United States
- Department of Neurology, Johns Hopkins University, Baltimore, Maryland 21205, United States
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12
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Wang Y, Hull V, Sternbach S, Popovich B, Burns T, McDonough J, Guo F, Pleasure D. Ablating the Transporter Sodium-Dependent Dicarboxylate Transporter 3 Prevents Leukodystrophy in Canavan Disease Mice. Ann Neurol 2021; 90:845-850. [PMID: 34498299 DOI: 10.1002/ana.26211] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 09/06/2021] [Accepted: 09/07/2021] [Indexed: 12/11/2022]
Abstract
Canavan disease is caused by ASPA mutations that diminish brain aspartoacylase activity, and it is characterized by excessive brain storage of the aspartoacylase substrate, N-acetyl-l-aspartate (NAA), and by astroglial and intramyelinic vacuolation. Astroglia and the arachnoid mater express sodium-dependent dicarboxylate transporter (NaDC3), encoded by SLC13A3, a sodium-coupled transporter for NAA and other dicarboxylates. Constitutive Slc13a3 deletion in aspartoacylase-deficient Canavan disease mice prevents brain NAA overaccumulation, ataxia, and brain vacuolation. ANN NEUROL 2021;90:845-850.
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Affiliation(s)
- Yan Wang
- Institute for Pediatric Regenerative Medicine, UC Davis, c/o Shriners Hospital, Sacramento, CA
| | - Vanessa Hull
- Institute for Pediatric Regenerative Medicine, UC Davis, c/o Shriners Hospital, Sacramento, CA
| | - Sarah Sternbach
- Department of Biological Sciences and School of Biomedical Sciences, Kent State University, Kent, OH
| | - Brad Popovich
- Department of Chemistry and Biochemistry, Kent State University, Kent, OH
| | - Travis Burns
- Institute for Pediatric Regenerative Medicine, UC Davis, c/o Shriners Hospital, Sacramento, CA
| | - Jennifer McDonough
- Department of Biological Sciences and School of Biomedical Sciences, Kent State University, Kent, OH
| | - Fuzheng Guo
- Institute for Pediatric Regenerative Medicine, UC Davis, c/o Shriners Hospital, Sacramento, CA
| | - David Pleasure
- Institute for Pediatric Regenerative Medicine, UC Davis, c/o Shriners Hospital, Sacramento, CA
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13
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von Jonquieres G, Rae CD, Housley GD. Emerging Concepts in Vector Development for Glial Gene Therapy: Implications for Leukodystrophies. Front Cell Neurosci 2021; 15:661857. [PMID: 34239416 PMCID: PMC8258421 DOI: 10.3389/fncel.2021.661857] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 05/12/2021] [Indexed: 12/12/2022] Open
Abstract
Central Nervous System (CNS) homeostasis and function rely on intercellular synchronization of metabolic pathways. Developmental and neurochemical imbalances arising from mutations are frequently associated with devastating and often intractable neurological dysfunction. In the absence of pharmacological treatment options, but with knowledge of the genetic cause underlying the pathophysiology, gene therapy holds promise for disease control. Consideration of leukodystrophies provide a case in point; we review cell type – specific expression pattern of the disease – causing genes and reflect on genetic and cellular treatment approaches including ex vivo hematopoietic stem cell gene therapies and in vivo approaches using adeno-associated virus (AAV) vectors. We link recent advances in vectorology to glial targeting directed towards gene therapies for specific leukodystrophies and related developmental or neurometabolic disorders affecting the CNS white matter and frame strategies for therapy development in future.
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Affiliation(s)
- Georg von Jonquieres
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, UNSW Sydney, Sydney, NSW, Australia
| | - Caroline D Rae
- Neuroscience Research Australia, Randwick, NSW, Australia
| | - Gary D Housley
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, UNSW Sydney, Sydney, NSW, Australia
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14
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Lotun A, Gessler DJ, Gao G. Canavan Disease as a Model for Gene Therapy-Mediated Myelin Repair. Front Cell Neurosci 2021; 15:661928. [PMID: 33967698 PMCID: PMC8102781 DOI: 10.3389/fncel.2021.661928] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 03/23/2021] [Indexed: 11/13/2022] Open
Abstract
In recent years, the scientific and therapeutic fields for rare, genetic central nervous system (CNS) diseases such as leukodystrophies, or white matter disorders, have expanded significantly in part due to technological advancements in cellular and clinical screenings as well as remedial therapies using novel techniques such as gene therapy. However, treatments aimed at normalizing the pathological changes associated with leukodystrophies have especially been complicated due to the innate and variable effects of glial abnormalities, which can cause large-scale functional deficits in developmental myelination and thus lead to downstream neuronal impairment. Emerging research in the past two decades have depicted glial cells, particularly oligodendrocytes and astrocytes, as key, regulatory modulators in constructing and maintaining myelin function and neuronal viability. Given the significance of myelin formation in the developing brain, myelin repair in a time-dependent fashion is critical in restoring homeostatic functionality to the CNS of patients diagnosed with white matter disorders. Using Canavan Disease (CD) as a leukodystrophy model, here we review the hypothetical roles of N-acetylaspartate (NAA), one of the brain's most abundant amino acid derivatives, in Canavan disease's CNS myelinating pathology, as well as discuss the possible functions astrocytes serve in both CD and other leukodystrophies' time-sensitive disease correction. Through this analysis, we also highlight the potential remyelinating benefits of gene therapy for other leukodystrophies in which alternative CNS cell targeting for white matter disorders may be an applicable path for reparative treatment.
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Affiliation(s)
- Anoushka Lotun
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA, United States.,Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, United States
| | - Dominic J Gessler
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA, United States.,Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, United States.,Department of Neurosurgery, University of Minnesota, Minneapolis, MN, United States
| | - Guangping Gao
- Horae Gene Therapy Center, University of Massachusetts Medical School, Worcester, MA, United States.,Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, United States.,Li Weibo Institute for Rare Diseases Research, University of Massachusetts Medical School, Worcester, MA, United States
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15
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Becker I, Wang-Eckhardt L, Lodder-Gadaczek J, Wang Y, Grünewald A, Eckhardt M. Mice deficient in the NAAG synthetase II gene Rimkla are impaired in a novel object recognition task. J Neurochem 2021; 157:2008-2023. [PMID: 33638175 DOI: 10.1111/jnc.15333] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 02/11/2021] [Accepted: 02/21/2021] [Indexed: 12/27/2022]
Abstract
N-acetylaspartylglutamate (NAAG) is an abundant neuropeptide in the mammalian nervous system, synthesized by two related NAAG synthetases I and II (NAAGS-I and -II) encoded by the genes Rimklb and Rimkla, respectively. NAAG plays a role in cognition and memory, according to studies using inhibitors of the NAAG hydrolase glutamate carboxypeptidase II that increase NAAG concentration. To examine consequences of reduced NAAG concentration, Rimkla-deficient (Rimkla-/- ) mice were generated. These mice exhibit normal NAAG level at birth, likely because of the intact Rimklb gene, but have significantly reduced NAAG levels in all brain regions in adulthood. In wild type mice NAAGS-II was most abundant in brainstem and spinal cord, as demonstrated using a new NAAGS-II antiserum. In the hippocampus, NAAGS-II was only detectable in neurons expressing parvalbumin, a marker of GABAergic interneurons. Apart from reduced open field activity, general behavior of adult (6 months old) Rimkla-/- mice examined in different tests (dark-light transition, optokinetic behavior, rotarod, and alternating T-maze) was not significantly altered. However, Rimkla-/- mice were impaired in a short-term novel object recognition test. This was also the case for mice lacking NAA synthase Nat8l, which are devoid of NAAG. Together with results from previous studies showing that inhibition of the NAAG degrading enzyme glutamate carboxypeptidase II is associated with a significant improvement in object recognition, these results suggest a direct involvement of NAAG synthesized by NAAGS-II in the memory consolidation underlying the novel object recognition task.
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Affiliation(s)
- Ivonne Becker
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Lihua Wang-Eckhardt
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Julia Lodder-Gadaczek
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Yong Wang
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Agathe Grünewald
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Matthias Eckhardt
- Institute of Biochemistry and Molecular Biology, Medical Faculty, University of Bonn, Bonn, Germany
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16
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Francis JS, Markov V, Wojtas ID, Gray S, McCown T, Samulski RJ, Figueroa M, Leone P. Preclinical biodistribution, tropism, and efficacy of oligotropic AAV/Olig001 in a mouse model of congenital white matter disease. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2021; 20:520-534. [PMID: 33614826 PMCID: PMC7878967 DOI: 10.1016/j.omtm.2021.01.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 01/16/2021] [Indexed: 11/28/2022]
Abstract
Recent advances in adeno-associated viral (AAV) capsid variants with novel oligotropism require validation in models of disease in order to be viable candidates for white matter disease gene therapy. We present here an assessment of the biodistribution, tropism, and efficacy of a novel AAV capsid variant (AAV/ Olig001) in a model of Canavan disease. We first define a combination of dose and route of administration of an AAV/Olig001-GFP reporter conducive to widespread CNS oligodendrocyte transduction in acutely symptomatic animals that model the Canavan brain at time of diagnosis. Administration of AAV/Olig001-GFP resulted in >70% oligotropism in all regions of interest except the cerebellum without the need for lineage-specific expression elements. Intracerebroventricular infusion into the cerebrospinal fluid (CSF) was identified as the most appropriate route of administration and employed for delivery of an AAV/Olig001 vector to reconstitute oligodendroglial aspartoacylase (ASPA) in adult Canavan mice, which resulted in a dose-dependent rescue of ASPA activity, motor function, and a near-total reduction in vacuolation. A head-to-head efficacy comparison with astrogliotropic AAV9 highlighted a significant advantage conferred by oligotropic AAV/Olig001 that was independent of overall transduction efficiency. These results support the continued development of AAV/Olig001 for advancement to clinical application to white matter disease.
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Affiliation(s)
- Jeremy S Francis
- Cell and Gene Therapy Center, Department of Cell Biology & Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA
| | - Vladimir Markov
- Cell and Gene Therapy Center, Department of Cell Biology & Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA
| | - Irenuez D Wojtas
- Cell and Gene Therapy Center, Department of Cell Biology & Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA
| | - Steve Gray
- Department of Pediatrics, The University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Thomas McCown
- Gene Therapy Center, Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | - R Jude Samulski
- Asklepios BioPharmaceutical, Research Triangle Park, NC, USA
| | - Marciano Figueroa
- Cell and Gene Therapy Center, Department of Cell Biology & Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA
| | - Paola Leone
- Cell and Gene Therapy Center, Department of Cell Biology & Neuroscience, Rowan University School of Osteopathic Medicine, Stratford, NJ, USA
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17
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Polyakov IV, Kniga AE, Grigorenko BL, Nemukhin AV. Structure of the Brain N-Acetylaspartate Biosynthetic Enzyme NAT8L Revealed by Computer Modeling. ACS Chem Neurosci 2020; 11:2296-2302. [PMID: 32639720 DOI: 10.1021/acschemneuro.0c00250] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
We report the results of computational modeling of a three-dimensional all-atom structure of the membrane-associated protein encoded by the NAT8L gene, aspartate N-acetyltransferase, which is essential for brain synthesis of N-acetyl-l-aspartate (NAA). The lack of experimentally derived three-dimensional structures of NAT8L poses one of the obstacles in studies of the mechanism of NAA formation and understanding the precise role of NAA in neurological disorders. We apply a computational protocol employing the contact map prediction, ab initio folding, homology modeling, and refinement to obtain a structure of NAT8L with the aspartate and acetyl coenzyme A cofactors in the protein molecule. To verify the computational protocol, we check its predictive power by reproducing the crystal structure of a related N-acetyltransferase domain, specifically, that from the bacterial N-acetylglutamate synthase. We show that the constructed NAT8L model correlates with structural features of the protein revealed in rare experimental studies. The obtained structure of the enzyme active site with the trapped reactants suggests a mechanism of the acetyl transfer upon NAA formation.
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Affiliation(s)
- Igor V. Polyakov
- Department of Chemistry, Lomonosov Moscow State University, Moscow, 119991, Russian Federation
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, 119334, Russian Federation
| | - Artem E. Kniga
- Department of Chemistry, Lomonosov Moscow State University, Moscow, 119991, Russian Federation
| | - Bella L. Grigorenko
- Department of Chemistry, Lomonosov Moscow State University, Moscow, 119991, Russian Federation
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, 119334, Russian Federation
| | - Alexander V. Nemukhin
- Department of Chemistry, Lomonosov Moscow State University, Moscow, 119991, Russian Federation
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, Moscow, 119334, Russian Federation
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18
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Stecula A, Hussain MS, Viola RE. Discovery of Novel Inhibitors of a Critical Brain Enzyme Using a Homology Model and a Deep Convolutional Neural Network. J Med Chem 2020; 63:8867-8875. [DOI: 10.1021/acs.jmedchem.0c00473] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Affiliation(s)
- Adrian Stecula
- Atomwise Inc., San Francisco, California 94103, United States
| | - Muhammad S. Hussain
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
| | - Ronald E. Viola
- Department of Chemistry and Biochemistry, University of Toledo, Toledo, Ohio 43606, United States
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19
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Pleasure D, Guo F, Chechneva O, Bannerman P, McDonough J, Burns T, Wang Y, Hull V. Pathophysiology and Treatment of Canavan Disease. Neurochem Res 2020; 45:561-565. [PMID: 30535831 PMCID: PMC11131954 DOI: 10.1007/s11064-018-2693-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Revised: 11/27/2018] [Accepted: 11/29/2018] [Indexed: 01/28/2023]
Affiliation(s)
- David Pleasure
- Institute for Pediatric Regenerative Research, Shriners Hospitals for Children Northern California and UC Davis School of Medicine, 2425 Stockton Blvd, 95817, Sacramento, CA, USA.
- , C/o Shriners Hospital, 2425 Stockton Blvd, Sacramento, CA, 95817, USA.
| | - Fuzheng Guo
- Institute for Pediatric Regenerative Research, Shriners Hospitals for Children Northern California and UC Davis School of Medicine, 2425 Stockton Blvd, 95817, Sacramento, CA, USA
| | - Olga Chechneva
- Institute for Pediatric Regenerative Research, Shriners Hospitals for Children Northern California and UC Davis School of Medicine, 2425 Stockton Blvd, 95817, Sacramento, CA, USA
| | - Peter Bannerman
- Institute for Pediatric Regenerative Research, Shriners Hospitals for Children Northern California and UC Davis School of Medicine, 2425 Stockton Blvd, 95817, Sacramento, CA, USA
| | - Jennifer McDonough
- Department of Biological Sciences, School of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA
| | - Travis Burns
- Institute for Pediatric Regenerative Research, Shriners Hospitals for Children Northern California and UC Davis School of Medicine, 2425 Stockton Blvd, 95817, Sacramento, CA, USA
| | - Yan Wang
- Institute for Pediatric Regenerative Research, Shriners Hospitals for Children Northern California and UC Davis School of Medicine, 2425 Stockton Blvd, 95817, Sacramento, CA, USA
| | - Vanessa Hull
- Institute for Pediatric Regenerative Research, Shriners Hospitals for Children Northern California and UC Davis School of Medicine, 2425 Stockton Blvd, 95817, Sacramento, CA, USA
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20
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Hull V, Wang Y, Burns T, Zhang S, Sternbach S, McDonough J, Guo F, Pleasure D. Antisense Oligonucleotide Reverses Leukodystrophy in Canavan Disease Mice. Ann Neurol 2020; 87:480-485. [PMID: 31925837 DOI: 10.1002/ana.25674] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 01/06/2020] [Accepted: 01/06/2020] [Indexed: 11/09/2022]
Abstract
Marked elevation in the brain concentration of N-acetyl-L-aspartate (NAA) is a characteristic feature of Canavan disease, a vacuolar leukodystrophy resulting from deficiency of the oligodendroglial NAA-cleaving enzyme aspartoacylase. We now demonstrate that inhibiting NAA synthesis by intracisternal administration of a locked nucleic acid antisense oligonucleotide to young-adult aspartoacylase-deficient mice reverses their pre-existing ataxia and diminishes cerebellar and thalamic vacuolation and Purkinje cell dendritic atrophy. Ann Neurol 2020;87:480-485.
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Affiliation(s)
- Vanessa Hull
- Institute for Pediatric Regenerative Medicine, University of California Davis School of Medicine and Shriners Hospitals for Children, Sacramento, CA
| | - Yan Wang
- Institute for Pediatric Regenerative Medicine, University of California Davis School of Medicine and Shriners Hospitals for Children, Sacramento, CA
| | - Travis Burns
- Institute for Pediatric Regenerative Medicine, University of California Davis School of Medicine and Shriners Hospitals for Children, Sacramento, CA
| | - Sheng Zhang
- Institute for Pediatric Regenerative Medicine, University of California Davis School of Medicine and Shriners Hospitals for Children, Sacramento, CA
| | - Sarah Sternbach
- Department of Biological Sciences, Kent State University, Kent, OH
| | | | - Fuzheng Guo
- Institute for Pediatric Regenerative Medicine, University of California Davis School of Medicine and Shriners Hospitals for Children, Sacramento, CA
| | - David Pleasure
- Institute for Pediatric Regenerative Medicine, University of California Davis School of Medicine and Shriners Hospitals for Children, Sacramento, CA
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21
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Mutthamsetty V, Dahal GP, Wang Q, Viola RE. Development of bisubstrate analog inhibitors of aspartate
N
‐acetyltransferase, a critical brain enzyme. Chem Biol Drug Des 2019; 95:48-57. [DOI: 10.1111/cbdd.13586] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 05/31/2019] [Accepted: 06/17/2019] [Indexed: 11/25/2022]
Affiliation(s)
- Vinay Mutthamsetty
- Department of Chemistry and Biochemistry University of Toledo Toledo OH USA
| | - Gopal P. Dahal
- Department of Chemistry and Biochemistry University of Toledo Toledo OH USA
| | - Qinzhe Wang
- Department of Chemistry and Biochemistry University of Toledo Toledo OH USA
| | - Ronald E. Viola
- Department of Chemistry and Biochemistry University of Toledo Toledo OH USA
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22
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23
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Sox2 Is Essential for Oligodendroglial Proliferation and Differentiation during Postnatal Brain Myelination and CNS Remyelination. J Neurosci 2018; 38:1802-1820. [PMID: 29335358 DOI: 10.1523/jneurosci.1291-17.2018] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 12/11/2017] [Accepted: 01/08/2018] [Indexed: 11/21/2022] Open
Abstract
In the CNS, myelination and remyelination depend on the successful progression and maturation of oligodendroglial lineage cells, including proliferation and differentiation of oligodendroglial progenitor cells (OPCs). Previous studies have reported that Sox2 transiently regulates oligodendrocyte (OL) differentiation in the embryonic and perinatal spinal cord and appears dispensable for myelination in the postnatal spinal cord. However, the role of Sox2 in OL development in the brain has yet to be defined. We now report that Sox2 is an essential positive regulator of developmental myelination in the postnatal murine brain of both sexes. Stage-specific paradigms of genetic disruption demonstrated that Sox2 regulated brain myelination by coordinating upstream OPC population supply and downstream OL differentiation. Transcriptomic analyses further supported a crucial role of Sox2 in brain developmental myelination. Consistently, oligodendroglial Sox2-deficient mice developed severe tremors and ataxia, typical phenotypes indicative of hypomyelination, and displayed severe impairment of motor function and prominent deficits of brain OL differentiation and myelination persisting into the later CNS developmental stages. We also found that Sox2 was required for efficient OPC proliferation and expansion and OL regeneration during remyelination in the adult brain and spinal cord. Together, our genetic evidence reveals an essential role of Sox2 in brain myelination and CNS remyelination, and suggests that manipulation of Sox2 and/or Sox2-mediated downstream pathways may be therapeutic in promoting CNS myelin repair.SIGNIFICANCE STATEMENT Promoting myelin formation and repair has translational significance in treating myelin-related neurological disorders, such as periventricular leukomalacia and multiple sclerosis in which brain developmental myelin formation and myelin repair are severely affected, respectively. In this report, analyses of a series of genetic conditional knock-out systems targeting different oligodendrocyte stages reveal a previously unappreciated role of Sox2 in coordinating upstream proliferation and downstream differentiation of oligodendroglial lineage cells in the mouse brain during developmental myelination and CNS remyelination. Our study points to the potential of manipulating Sox2 and its downstream pathways to promote oligodendrocyte regeneration and CNS myelin repair.
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24
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Bannerman P, Guo F, Chechneva O, Burns T, Zhu X, Wang Y, Kim B, Singhal NK, McDonough JA, Pleasure D. Brain Nat8l Knockdown Suppresses Spongiform Leukodystrophy in an Aspartoacylase-Deficient Canavan Disease Mouse Model. Mol Ther 2018; 26:793-800. [PMID: 29456021 DOI: 10.1016/j.ymthe.2018.01.002] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 01/02/2018] [Accepted: 01/06/2018] [Indexed: 10/18/2022] Open
Abstract
Canavan disease, a leukodystrophy caused by loss-of-function ASPA mutations, is characterized by brain dysmyelination, vacuolation, and astrogliosis ("spongiform leukodystrophy"). ASPA encodes aspartoacylase, an oligodendroglial enzyme that cleaves the abundant brain amino acid N-acetyl-L-aspartate (NAA) to L-aspartate and acetate. Aspartoacylase deficiency results in a 50% or greater elevation in brain NAA concentration ([NAAB]). Prior studies showed that homozygous constitutive knockout of Nat8l, the gene encoding the neuronal NAA synthesizing enzyme N-acetyltransferase 8-like, prevents aspartoacylase-deficient mice from developing spongiform leukodystrophy. We now report that brain Nat8l knockdown elicited by intracerebroventricular/intracisternal administration of an adeno-associated viral vector carrying a short hairpin Nat8l inhibitory RNA to neonatal aspartoacylase-deficient AspaNur7/Nur7 mice lowers [NAAB] and suppresses development of spongiform leukodystrophy.
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Affiliation(s)
- Peter Bannerman
- Institute for Pediatric Regenerative Medicine, University of California, Davis, Sacramento, CA 95817, USA
| | - Fuzheng Guo
- Institute for Pediatric Regenerative Medicine, University of California, Davis, Sacramento, CA 95817, USA
| | - Olga Chechneva
- Institute for Pediatric Regenerative Medicine, University of California, Davis, Sacramento, CA 95817, USA
| | - Travis Burns
- Institute for Pediatric Regenerative Medicine, University of California, Davis, Sacramento, CA 95817, USA
| | - Xiaoqing Zhu
- Cancer Institute, The Affiliated Hospital of Qingdao University, Qingdao, Shandong 266-61, China
| | - Yan Wang
- Institute for Pediatric Regenerative Medicine, University of California, Davis, Sacramento, CA 95817, USA
| | - Bokyung Kim
- Institute for Pediatric Regenerative Medicine, University of California, Davis, Sacramento, CA 95817, USA
| | - Naveen K Singhal
- Department of Biological Sciences and School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA
| | - Jennifer A McDonough
- Department of Biological Sciences and School of Biomedical Sciences, Kent State University, Kent, OH 44242, USA
| | - David Pleasure
- Institute for Pediatric Regenerative Medicine, University of California, Davis, Sacramento, CA 95817, USA.
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Uncoupling N-acetylaspartate from brain pathology: implications for Canavan disease gene therapy. Acta Neuropathol 2018; 135:95-113. [PMID: 29116375 PMCID: PMC5756261 DOI: 10.1007/s00401-017-1784-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2017] [Revised: 10/31/2017] [Accepted: 11/01/2017] [Indexed: 11/25/2022]
Abstract
N-Acetylaspartate (NAA) is the second most abundant organic metabolite in the brain, but its physiological significance remains enigmatic. Toxic NAA accumulation appears to be the key factor for neurological decline in Canavan disease—a fatal neurometabolic disorder caused by deficiency in the NAA-degrading enzyme aspartoacylase. To date clinical outcome of gene replacement therapy for this spongiform leukodystrophy has not met expectations. To identify the target tissue and cells for maximum anticipated treatment benefit, we employed comprehensive phenotyping of novel mouse models to assess cell type-specific consequences of NAA depletion or elevation. We show that NAA-deficiency causes neurological deficits affecting unconscious defensive reactions aimed at protecting the body from external threat. This finding suggests, while NAA reduction is pivotal to treat Canavan disease, abrogating NAA synthesis should be avoided. At the other end of the spectrum, while predicting pathological severity in Canavan disease mice, increased brain NAA levels are not neurotoxic per se. In fact, in transgenic mice overexpressing the NAA synthesising enzyme Nat8l in neurons, supra-physiological NAA levels were uncoupled from neurological deficits. In contrast, elimination of aspartoacylase expression exclusively in oligodendrocytes elicited Canavan disease like pathology. Although conditional aspartoacylase deletion in oligodendrocytes abolished expression in the entire CNS, the remaining aspartoacylase in peripheral organs was sufficient to lower NAA levels, delay disease onset and ameliorate histopathology. However, comparable endpoints of the conditional and complete aspartoacylase knockout indicate that optimal Canavan disease gene replacement therapies should restore aspartoacylase expression in oligodendrocytes. On the basis of these findings we executed an ASPA gene replacement therapy targeting oligodendrocytes in Canavan disease mice resulting in reversal of pre-existing CNS pathology and lasting neurological benefits. This finding signifies the first successful post-symptomatic treatment of a white matter disorder using an adeno-associated virus vector tailored towards oligodendroglial-restricted transgene expression.
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Behavioral impairment in SHATI/NAT8L knockout mice via dysfunction of myelination development. Sci Rep 2017; 7:16872. [PMID: 29203794 PMCID: PMC5715020 DOI: 10.1038/s41598-017-17151-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 11/21/2017] [Indexed: 11/28/2022] Open
Abstract
We have identified SHATI/NAT8L in the brain of mice treated with methamphetamine. Recently, it has been reported that SHATI is N-acetyltransferase 8-like protein (NAT8L) that produces N-acetylaspatate (NAA) from aspartate and acetyl-CoA. We have generated SHATI/NAT8L knockout (Shati−/−) mouse which demonstrates behavioral deficits that are not rescued by single NAA supplementation, although the reason for which is still not clarified. It is possible that the developmental impairment results from deletion of SHATI/NAT8L in the mouse brain, because NAA is involved in myelination through lipid synthesis in oligodendrocytes. However, it remains unclear whether SHATI/NAT8L is involved in brain development. In this study, we found that the expression of Shati/Nat8l mRNA was increased with brain development in mice, while there was a reduction in the myelin basic protein (MBP) level in the prefrontal cortex of juvenile, but not adult, Shati−/− mice. Next, we found that deletion of SHATI/NAT8L induces several behavioral deficits in mice, and that glyceryltriacetate (GTA) treatment ameliorates the behavioral impairments and normalizes the reduced protein level of MBP in juvenile Shati−/− mice. These findings suggest that SHATI/NAT8L is involved in myelination in the juvenile mouse brain via supplementation of acetate derived from NAA. Thus, reduction of SHATI/NAT8L induces developmental neuronal dysfunction.
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Bogner-Strauss JG. N-Acetylaspartate Metabolism Outside the Brain: Lipogenesis, Histone Acetylation, and Cancer. Front Endocrinol (Lausanne) 2017; 8:240. [PMID: 28979238 PMCID: PMC5611401 DOI: 10.3389/fendo.2017.00240] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 08/30/2017] [Indexed: 01/18/2023] Open
Abstract
N-acetylaspartate (NAA) is a highly abundant brain metabolite. Aberrant NAA concentrations have been detected in many pathological conditions and although the function of NAA has been extensively investigated in the brain it is still controversial. Only recently, a role of NAA has been reported outside the brain. In brown adipocytes, which show high expression of the NAA-producing and the NAA-cleaving enzyme, the metabolism of NAA has been implicated in lipid synthesis and histone acetylation. Increased expression of N-acetyltransferase 8-like (Nat8l, the gene encoding the NAA synthesizing enzyme) induces de novo lipogenesis and the brown adipocyte phenotype. Accordingly silencing of aspartoacylase, the NAA-cleaving enzyme, reduced brown adipocyte differentiation mechanistically by decreasing histone acetylation and gene transcription. Notably, the expression of Nat8l and the amount of NAA were also shown to be increased in several tumors and inversely correlate with patients' survival. Additionally, Nat8l silencing reduced cell proliferation in tumor and non-tumor cells, while NAA supplementation could rescue it. However, the mechanism behind has not yet been clarified. It remains to be addressed whether NAA per se and/or its catabolism to acetate and aspartate, metabolites that have both been implicated in tumor growth, are valuable targets for future therapies.
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Affiliation(s)
- Juliane G. Bogner-Strauss
- Institute of Biochemistry, Graz University of Technology, Graz, Austria
- BioTechMed-Graz, Graz, Austria
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Suppressing N-Acetyl-l-Aspartate Synthesis Prevents Loss of Neurons in a Murine Model of Canavan Leukodystrophy. J Neurosci 2017; 37:413-421. [PMID: 28077719 DOI: 10.1523/jneurosci.2013-16.2016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Revised: 11/07/2016] [Accepted: 11/29/2016] [Indexed: 11/21/2022] Open
Abstract
Canavan disease is a leukodystrophy caused by aspartoacylase (ASPA) deficiency. The lack of functional ASPA, an enzyme enriched in oligodendroglia that cleaves N-acetyl-l-aspartate (NAA) to acetate and l-aspartic acid, elevates brain NAA and causes "spongiform" vacuolation of superficial brain white matter and neighboring gray matter. In children with Canavan disease, neuroimaging shows early-onset dysmyelination and progressive brain atrophy. Neuron loss has been documented at autopsy in some cases. Prior studies have shown that mice homozygous for the Aspa nonsense mutation Nur7 also develop brain vacuolation. We now report that numbers of cerebral cortical and cerebellar neurons are decreased and that cerebral cortex progressively thins in AspaNur7/Nur7 mice. This neuronal pathology is prevented by constitutive disruption of Nat8l, which encodes the neuronal NAA-synthetic enzyme N-acetyltransferase-8-like. SIGNIFICANCE STATEMENT This is the first demonstration of cortical and cerebellar neuron depletion and progressive cerebral cortical thinning in an animal model of Canavan disease. Genetic suppression of N-acetyl-l-aspartate (NAA) synthesis, previously shown to block brain vacuolation in aspartoacylase-deficient mice, also prevents neuron loss and cerebral cortical atrophy in these mice. These results suggest that lowering the concentration of NAA in the brains of children with Canavan disease would prevent or slow progression of neurological deficits.
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Appu AP, Moffett JR, Arun P, Moran S, Nambiar V, Krishnan JKS, Puthillathu N, Namboodiri AMA. Increasing N-acetylaspartate in the Brain during Postnatal Myelination Does Not Cause the CNS Pathologies of Canavan Disease. Front Mol Neurosci 2017; 10:161. [PMID: 28626388 PMCID: PMC5454052 DOI: 10.3389/fnmol.2017.00161] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 05/09/2017] [Indexed: 01/03/2023] Open
Abstract
Canavan disease is caused by mutations in the gene encoding aspartoacylase (ASPA), a deacetylase that catabolizes N-acetylaspartate (NAA). The precise involvement of elevated NAA in the pathogenesis of Canavan disease is an ongoing debate. In the present study, we tested the effects of elevated NAA in the brain during postnatal development. Mice were administered high doses of the hydrophobic methyl ester of NAA (M-NAA) twice daily starting on day 7 after birth. This treatment increased NAA levels in the brain to those observed in the brains of Nur7 mice, an established model of Canavan disease. We evaluated various serological parameters, oxidative stress, inflammatory and neurodegeneration markers and the results showed that there were no pathological alterations in any measure with increased brain NAA levels. We examined oxidative stress markers, malondialdehyde content (indicator of lipid peroxidation), expression of NADPH oxidase and nuclear translocation of the stress-responsive transcription factor nuclear factor (erythroid-derived 2)-like 2 (NRF-2) in brain. We also examined additional pathological markers by immunohistochemistry and the expression of activated caspase-3 and interleukin-6 by Western blot. None of the markers were increased in the brains of M-NAA treated mice, and no vacuoles were observed in any brain region. These results show that ASPA expression prevents the pathologies associated with excessive NAA concentrations in the brain during postnatal myelination. We hypothesize that the pathogenesis of Canavan disease involves not only disrupted NAA metabolism, but also excessive NAA related signaling processes in oligodendrocytes that have not been fully determined and we discuss some of the potential mechanisms.
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Affiliation(s)
- Abhilash P. Appu
- Department of Anatomy, Physiology and Genetics and Neuroscience Program, Uniformed Services University of the Health SciencesBethesda, MD, United States
| | - John R. Moffett
- Department of Anatomy, Physiology and Genetics and Neuroscience Program, Uniformed Services University of the Health SciencesBethesda, MD, United States
| | - Peethambaran Arun
- Department of Anatomy, Physiology and Genetics and Neuroscience Program, Uniformed Services University of the Health SciencesBethesda, MD, United States
| | - Sean Moran
- Department of Anatomy, Physiology and Genetics and Neuroscience Program, Uniformed Services University of the Health SciencesBethesda, MD, United States
| | - Vikram Nambiar
- Department of Anatomy, Physiology and Genetics and Neuroscience Program, Uniformed Services University of the Health SciencesBethesda, MD, United States
| | - Jishnu K. S. Krishnan
- Department of Anatomy, Physiology and Genetics and Neuroscience Program, Uniformed Services University of the Health SciencesBethesda, MD, United States
| | - Narayanan Puthillathu
- Department of Anatomy, Physiology and Genetics and Neuroscience Program, Uniformed Services University of the Health SciencesBethesda, MD, United States
| | - Aryan M. A. Namboodiri
- Department of Anatomy, Physiology and Genetics and Neuroscience Program, Uniformed Services University of the Health SciencesBethesda, MD, United States
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Gessler DJ, Li D, Xu H, Su Q, Sanmiguel J, Tuncer S, Moore C, King J, Matalon R, Gao G. Redirecting N-acetylaspartate metabolism in the central nervous system normalizes myelination and rescues Canavan disease. JCI Insight 2017; 2:e90807. [PMID: 28194442 PMCID: PMC5291725 DOI: 10.1172/jci.insight.90807] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 12/21/2016] [Indexed: 02/05/2023] Open
Abstract
Canavan disease (CD) is a debilitating and lethal leukodystrophy caused by mutations in the aspartoacylase (ASPA) gene and the resulting defect in N-acetylaspartate (NAA) metabolism in the CNS and peripheral tissues. Recombinant adeno-associated virus (rAAV) has the ability to cross the blood-brain barrier and widely transduce the CNS. We developed a rAAV-based and optimized gene replacement therapy, which achieves early, complete, and sustained rescue of the lethal disease phenotype in CD mice. Our treatment results in a super-mouse phenotype, increasing motor performance of treated CD mice beyond that of WT control mice. We demonstrate that this rescue is oligodendrocyte independent, and that gene correction in astrocytes is sufficient, suggesting that the establishment of an astrocyte-based alternative metabolic sink for NAA is a key mechanism for efficacious disease rescue and the super-mouse phenotype. Importantly, the use of clinically translatable high-field imaging tools enables the noninvasive monitoring and prediction of therapeutic outcomes for CD and might enable further investigation of NAA-related cognitive function.
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Affiliation(s)
- Dominic J. Gessler
- Department of Microbiology and Physiological Systems
- Horae Gene Therapy Center, University of Massachusetts, Worcester, Massachusetts, USA
- University Hospital Heidelberg, Centre for Child and Adolescent Medicine, Division of Child Neurology and Metabolic Medicine
- Ruprecht-Karls University, Medical School, Heidelberg, Germany
| | - Danning Li
- Horae Gene Therapy Center, University of Massachusetts, Worcester, Massachusetts, USA
| | - Hongxia Xu
- Horae Gene Therapy Center, University of Massachusetts, Worcester, Massachusetts, USA
- University of Science and Technology of Kunming, China
| | - Qin Su
- Horae Gene Therapy Center, University of Massachusetts, Worcester, Massachusetts, USA
| | - Julio Sanmiguel
- Horae Gene Therapy Center, University of Massachusetts, Worcester, Massachusetts, USA
| | | | - Constance Moore
- Center for Comparative Neuroimaging, Department of Psychiatry, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | - Jean King
- Center for Comparative Neuroimaging, Department of Psychiatry, University of Massachusetts Medical School, Worcester, Massachusetts, USA
| | | | - Guangping Gao
- Department of Microbiology and Physiological Systems
- Horae Gene Therapy Center, University of Massachusetts, Worcester, Massachusetts, USA
- State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu, China
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Design and optimization of aspartate N -acetyltransferase inhibitors for the potential treatment of Canavan disease. Bioorg Med Chem 2017; 25:870-885. [DOI: 10.1016/j.bmc.2016.11.060] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2016] [Revised: 11/27/2016] [Accepted: 11/29/2016] [Indexed: 11/19/2022]
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Merrill ST, Nelson GR, Longo N, Bonkowsky JL. Cytotoxic edema and diffusion restriction as an early pathoradiologic marker in canavan disease: case report and review of the literature. Orphanet J Rare Dis 2016; 11:169. [PMID: 27927234 PMCID: PMC5142413 DOI: 10.1186/s13023-016-0549-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2016] [Accepted: 11/29/2016] [Indexed: 12/27/2022] Open
Abstract
Background Canavan disease is a devastating autosomal recessive leukodystrophy leading to spongiform degeneration of the white matter. There is no cure or treatment for Canavan disease, and disease progression is poorly understood. Results We report a new presentation of a patient found to have Canavan disease; brain magnetic resonance imaging (MRI) revealed white matter cytotoxic edema, indicative of an acute active destructive process. We performed a comprehensive review of published cases of Canavan disease reporting brain MRI findings, and found that cytotoxic brain edema is frequently reported in early Canavan disease. Conclusions Our results and the literature review support the notion of an acute phase in Canavan disease progression. These findings suggest that there is a window available for therapeutic intervention and support the need for early identification of patients with Canavan disease.
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Affiliation(s)
- Steven T Merrill
- College of Osteopathic Medicine, Touro University Nevada, Henderson, NV, USA
| | - Gary R Nelson
- Division of Pediatric Neurology, University of Utah School of Medicine, Salt Lake City, UT, USA
| | - Nicola Longo
- Division of Medical Genetics, Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, USA.,Department of Pediatrics, University of Utah School of Medicine, 295 Chipeta Way/Williams Building, 84108, Salt Lake City, UT, USA
| | - Joshua L Bonkowsky
- Division of Pediatric Neurology, University of Utah School of Medicine, Salt Lake City, UT, USA. .,Department of Pediatrics, University of Utah School of Medicine, 295 Chipeta Way/Williams Building, 84108, Salt Lake City, UT, USA.
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Singhal NK, Huang H, Li S, Clements R, Gadd J, Daniels A, Kooijman EE, Bannerman P, Burns T, Guo F, Pleasure D, Freeman E, Shriver L, McDonough J. The neuronal metabolite NAA regulates histone H3 methylation in oligodendrocytes and myelin lipid composition. Exp Brain Res 2016; 235:279-292. [PMID: 27709268 DOI: 10.1007/s00221-016-4789-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 09/27/2016] [Indexed: 01/01/2023]
Abstract
The neuronal mitochondrial metabolite N-acetylaspartate (NAA) is decreased in the multiple sclerosis (MS) brain. NAA is synthesized in neurons by the enzyme N-acetyltransferase-8-like (NAT8L) and broken down in oligodendrocytes by aspartoacylase (ASPA) into acetate and aspartate. We have hypothesized that NAA links the metabolism of axons with oligodendrocytes to support myelination. To test this hypothesis, we performed lipidomic analyses using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and high-performance thin-layer chromatography (HPTLC) to identify changes in myelin lipid composition in postmortem MS brains and in NAT8L knockout (NAT8L-/-) mice which do not synthesize NAA. We found reduced levels of sphingomyelin in MS normal appearing white matter that mirrored decreased levels of NAA. We also discovered decreases in the amounts of sphingomyelin and sulfatide lipids in the brains of NAT8L-/- mice compared to controls. Metabolomic analysis of primary cultures of oligodendrocytes treated with NAA revealed increased levels of α-ketoglutarate, which has been reported to regulate histone demethylase activity. Consistent with this, NAA treatment resulted in alterations in the levels of histone H3 methylation, including H3K4me3, H3K9me2, and H3K9me3. The H3K4me3 histone mark regulates cellular energetics, metabolism, and growth, while H3K9me3 has been linked to alterations in transcriptional repression in developing oligodendrocytes. We also noted the NAA treatment was associated with increases in the expression of genes involved in sulfatide and sphingomyelin synthesis in cultured oligodendrocytes. This is the first report demonstrating that neuronal-derived NAA can signal to the oligodendrocyte nucleus. These data suggest that neuronal-derived NAA signals through epigenetic mechanisms in oligodendrocytes to support or maintain myelination.
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Affiliation(s)
- N K Singhal
- Department of Biological Sciences and School of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA
| | - H Huang
- Department of Chemistry and Biology, University of Akron, Akron, OH, 44325, USA
| | - S Li
- Department of Biological Sciences and School of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA
| | - R Clements
- Department of Biological Sciences and School of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA
| | - J Gadd
- Department of Biological Sciences and School of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA
| | - A Daniels
- Department of Biological Sciences and School of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA
| | - E E Kooijman
- Department of Biological Sciences and School of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA
| | - P Bannerman
- Department of Cell Biology and Human Anatomy, UC Davis School of Medicine, Sacramento, CA, 95817, USA
| | - T Burns
- Department of Neurology, UC Davis School of Medicine, Sacramento, CA, 95817, USA
| | - F Guo
- Department of Neurology, UC Davis School of Medicine, Sacramento, CA, 95817, USA
| | - D Pleasure
- Department of Neurology, UC Davis School of Medicine, Sacramento, CA, 95817, USA
| | - E Freeman
- Department of Biological Sciences and School of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA
| | - L Shriver
- Department of Chemistry and Biology, University of Akron, Akron, OH, 44325, USA
| | - J McDonough
- Department of Biological Sciences and School of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA.
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Francis JS, Wojtas I, Markov V, Gray SJ, McCown TJ, Samulski RJ, Bilaniuk LT, Wang DJ, De Vivo DC, Janson CG, Leone P. N-acetylaspartate supports the energetic demands of developmental myelination via oligodendroglial aspartoacylase. Neurobiol Dis 2016; 96:323-334. [PMID: 27717881 DOI: 10.1016/j.nbd.2016.10.001] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 09/27/2016] [Accepted: 10/01/2016] [Indexed: 12/13/2022] Open
Abstract
Breakdown of neuro-glial N-acetyl-aspartate (NAA) metabolism results in the failure of developmental myelination, manifest in the congenital pediatric leukodystrophy Canavan disease caused by mutations to the sole NAA catabolizing enzyme aspartoacylase. Canavan disease is a major point of focus for efforts to define NAA function, with available evidence suggesting NAA serves as an acetyl donor for fatty acid synthesis during myelination. Elevated NAA is a diagnostic hallmark of Canavan disease, which contrasts with a broad spectrum of alternative neurodegenerative contexts in which levels of NAA are inversely proportional to pathological progression. Recently generated data in the nur7 mouse model of Canavan disease suggests loss of aspartoacylase function results in compromised energetic integrity prior to oligodendrocyte death, abnormalities in myelin content, spongiform degeneration, and motor deficit. The present study utilized a next-generation "oligotropic" adeno-associated virus vector (AAV-Olig001) to quantitatively assess the impact of aspartoacylase reconstitution on developmental myelination. AAV-Olig001-aspartoacylase promoted normalization of NAA, increased bioavailable acetyl-CoA, and restored energetic balance within a window of postnatal development preceding gross histopathology and deteriorating motor function. Long-term effects included increased oligodendrocyte numbers, a global increase in myelination, reversal of vacuolation, and rescue of motor function. Effects on brain energy observed following AAV-Olig001-aspartoacylase gene therapy are shown to be consistent with a metabolic profile observed in mild cases of Canavan disease, implicating NAA in the maintenance of energetic integrity during myelination via oligodendroglial aspartoacylase.
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Affiliation(s)
- Jeremy S Francis
- Department of Cell Biology, Cell & Gene Therapy Center, Rowan School of Osteopathic Medicine, Stratford, NJ, USA
| | - Ireneusz Wojtas
- Department of Cell Biology, Cell & Gene Therapy Center, Rowan School of Osteopathic Medicine, Stratford, NJ, USA
| | - Vladimir Markov
- Department of Cell Biology, Cell & Gene Therapy Center, Rowan School of Osteopathic Medicine, Stratford, NJ, USA
| | - Steven J Gray
- Department of Ophthalmology, UNC, Chapel Hill, NC, USA
| | | | - R Jude Samulski
- Department of Pharmacology and Gene Therapy Center, UNC, Chapel Hill, NC, USA
| | - Larissa T Bilaniuk
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Dah-Jyuu Wang
- Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | | | - Christopher G Janson
- Department of Neurology & Rehabilitation, University of Illinois at Chicago, Chicago, USA
| | - Paola Leone
- Department of Cell Biology, Cell & Gene Therapy Center, Rowan School of Osteopathic Medicine, Stratford, NJ, USA.
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Roscoe RB, Elliott C, Zarros A, Baillie GS. Non-genetic therapeutic approaches to Canavan disease. J Neurol Sci 2016; 366:116-124. [DOI: 10.1016/j.jns.2016.05.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Revised: 04/11/2016] [Accepted: 05/09/2016] [Indexed: 01/30/2023]
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Duncan ID, Radcliff AB. Inherited and acquired disorders of myelin: The underlying myelin pathology. Exp Neurol 2016; 283:452-75. [PMID: 27068622 PMCID: PMC5010953 DOI: 10.1016/j.expneurol.2016.04.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 04/01/2016] [Accepted: 04/04/2016] [Indexed: 01/26/2023]
Abstract
Remyelination is a major therapeutic goal in human myelin disorders, serving to restore function to demyelinated axons and providing neuroprotection. The target disorders that might be amenable to the promotion of this repair process are diverse and increasing in number. They range primarily from those of genetic, inflammatory to toxic origin. In order to apply remyelinating strategies to these disorders, it is essential to know whether the myelin damage results from a primary attack on myelin or the oligodendrocyte or both, and whether indeed these lead to myelin breakdown and demyelination. In some disorders, myelin sheath abnormalities are prominent but demyelination does not occur. This review explores the range of human and animal disorders where myelin pathology exists and focusses on defining the myelin changes in each and their cause, to help define whether they are targets for myelin repair therapy. We reviewed myelin disorders of the CNS in humans and animals. Myelin damage results from primary attack on the oligodendrocyte or myelin sheath. All major categories of disease can affect CNS myelin. Myelin vacuolation is common, yet does not always result in demyelination.
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Affiliation(s)
- Ian D Duncan
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, United States.
| | - Abigail B Radcliff
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI, United States
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Sarret C, Boespflug-Tanguy O, Rodriguez D. Atypical clinical and radiological course of a patient with Canavan disease. Metab Brain Dis 2016; 31:475-9. [PMID: 26586007 DOI: 10.1007/s11011-015-9767-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 11/13/2015] [Indexed: 11/26/2022]
Abstract
Canavan disease (CD) is a rare metabolic disorder caused by aspartoacylase (ASPA) deficiency. It leads to severe neurological degeneration with spongiform brain degeneration. Accumulation of N-acetylaspartate (NAA) in brain and urine is specific to the disease and guides diagnosis. Magnetic resonance imaging (MRI) usually shows diffuse white matter abnormalities with involvement of the basal ganglia. Mild forms of the disease with a more favorable clinical course and radiological involvement of the basal ganglia without white matter abnormalities have also been reported. Here we report an atypical case of a girl aged nine years with CD. The disease started at the classical age of five months. Classical elevation of NAA in brain and urine was present and genetic analysis identified mutations in the ASPA gene. However, clinical evolution was milder than typical CD, with partial motor impairment and relatively well-preserved cognitive skills. MRI was also atypical with low white matter involvement and unusual topography and evolution of abnormalities in the basal ganglia.
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Affiliation(s)
- Catherine Sarret
- Image-Guided Clinical Neuroscience and Connectomics (IGCNC), EA7282, University of Auvergne, Clermont-Ferrand University Hospital, 58 rue Montalembert, 63003, Clermont-Ferrand, cedex, France.
- Department of Pediatrics, Clermont-Ferrand University Hospital, Clermont-Ferrand, France.
| | - Odile Boespflug-Tanguy
- APHP, Department of Child Neurology and Metabolic Diseases, Leukodystrophies Reference Centre, Robert Debré Hospital, Paris, France
- Inserm U1141 Paris Diderot Sorbonne University - Paris Cité, DHU PROTECT, Robert Debré Hospital, Paris, France
| | - Diana Rodriguez
- Inserm U1141 Paris Diderot Sorbonne University - Paris Cité, DHU PROTECT, Robert Debré Hospital, Paris, France
- APHP, Department of Child Neurology, Armand Trousseau Hospital, Paris, France
- Sorbonne Universités, UPMC Univ Paris 06, Paris, France
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Wang Q, Zhao M, Parungao GG, Viola RE. Purification and characterization of aspartate N-acetyltransferase: A critical enzyme in brain metabolism. Protein Expr Purif 2016; 119:11-8. [DOI: 10.1016/j.pep.2015.11.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Revised: 11/02/2015] [Accepted: 11/03/2015] [Indexed: 10/22/2022]
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N-Acetylaspartate Synthase Deficiency Corrects the Myelin Phenotype in a Canavan Disease Mouse Model But Does Not Affect Survival Time. J Neurosci 2016; 35:14501-16. [PMID: 26511242 DOI: 10.1523/jneurosci.1056-15.2015] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Canavan disease (CD) is a severe, lethal leukodystrophy caused by deficiency in aspartoacylase (ASPA), which hydrolyzes N-acetylaspartate (NAA). In the brains of CD patients, NAA accumulates to high millimolar concentrations. The pathology of the disease is characterized by loss of oligodendrocytes and spongy myelin degeneration in the CNS. Whether accumulating NAA, absence of NAA-derived acetate, or absence of any unknown functions of the ASPA enzyme is responsible for the pathology of the disease is not fully understood. We generated ASPA-deficient (Aspa(nur7/nur7)) mice that are also deficient for NAA synthase Nat8L (Nat8L(-/-)/Aspa(nur7/nur7)). These mice have no detectable NAA. Nevertheless, they exhibited normal myelin content, myelin sphingolipid composition, and full reversal of spongy myelin and axonal degeneration. Surprisingly, although pathology was fully reversed, the survival time of the mice was not prolonged. In contrast, Aspa(nur7/nur7) mice with only one intact Nat8L allele accumulated less NAA, developed a less severe pathology, phenotypic improvements, and, importantly, an almost normal survival time. Therefore, inhibition of NAA synthase is a promising therapeutic option for CD. The reduced survival rate of Nat8L(-/-)/Aspa(nur7/nur7) mice, however, indicates that complete inhibition of NAA synthase may bear unforeseeable risks for the patient. Furthermore, we demonstrate that acetate derived from NAA is not essential for myelin lipid synthesis and that loss of NAA-derived acetate does not cause the myelin phenotype of Aspa(nur7/nur7) mice. Our data clearly support the hypothesis that NAA accumulation is the major factor in the development of CD.
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