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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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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: 9] [Impact Index Per Article: 4.5] [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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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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4
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mRNA Profiling for miR-124-mediated Repair in Spinal Cord Injury. Neuroscience 2020; 438:158-168. [DOI: 10.1016/j.neuroscience.2020.05.013] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2019] [Revised: 05/06/2020] [Accepted: 05/07/2020] [Indexed: 01/01/2023]
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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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Piguet F, Alves S, Cartier N. Clinical Gene Therapy for Neurodegenerative Diseases: Past, Present, and Future. Hum Gene Ther 2017; 28:988-1003. [DOI: 10.1089/hum.2017.160] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Affiliation(s)
- Françoise Piguet
- Translational Medicine and Neurogenetics Department, Institut de Genetique et de Biologie Moleculaire et Cellulaire, Strasbourg, France
- Inserm U596, Illkirch, France; CNRS, UMR7104, Illkirch, France
- Faculte des Sciences de la Vie, Universite de Strasbourg, Strasbourg, France
| | | | - Nathalie Cartier
- INSERM/CEA UMR1169, MIRCen Fontenay aux Roses, France
- Universite Paris-Sud, Orsay, France
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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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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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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: 27] [Impact Index Per Article: 3.4] [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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von Jonquieres G, Fröhlich D, Klugmann CB, Wen X, Harasta AE, Ramkumar R, Spencer ZHT, Housley GD, Klugmann M. Recombinant Human Myelin-Associated Glycoprotein Promoter Drives Selective AAV-Mediated Transgene Expression in Oligodendrocytes. Front Mol Neurosci 2016; 9:13. [PMID: 26941604 PMCID: PMC4763065 DOI: 10.3389/fnmol.2016.00013] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 02/05/2016] [Indexed: 11/13/2022] Open
Abstract
Leukodystrophies are hereditary central white matter disorders caused by oligodendrocyte dysfunction. Recent clinical trials for some of these devastating neurological conditions have employed an ex vivo gene therapy approach that showed improved endpoints because cross-correction of affected myelin-forming cells occurred following secretion of therapeutic proteins by transduced autologous grafts. However, direct gene transfer to oligodendrocytes is required for the majority of leukodystrophies with underlying mutations in genes encoding non-secreted oligodendroglial proteins. Recombinant adeno-associated viral (AAV) vectors are versatile tools for gene transfer to the central nervous system (CNS) and proof-of-concept studies in rodents have shown that the use of cellular promoters is sufficient to target AAV-mediated transgene expression to glia. The potential of this strategy has not been exploited. The major caveat of the AAV system is its limited packaging capacity of ~5 kb, providing the rationale for identifying small yet selective recombinant promoters. Here, we characterize the human myelin associated glycoprotein (MAG) promoter for reliable targeting of AAV-mediated transgene expression to oligodendrocytes in vivo. A homology screen revealed highly conserved genomic regions among mammalian species upstream of the transcription start site. Recombinant AAV expression cassettes carrying the cDNA encoding enhanced green fluorescent protein (GFP) driven by truncated versions of the recombinant MAG promoter (2.2, 1.5 and 0.3 kb in size) were packaged as cy5 vectors and delivered into the dorsal striatum of mice. At 3 weeks post-injection, oligodendrocytes, neurons and astrocytes expressing the reporter were quantified by immunohistochemical staining. Our results revealed that both 2.2 and 1.5 kb MAG promoters targeted more than 95% of transgene expression to oligodendrocytes. Even the short 0.3 kb fragment conveyed high oligodendroglial specific transgene expression (>90%) in vivo. Moreover, cy5-MAG2.2-GFP delivery to the neonate CNS resulted in selective GFP expression in oligodendrocytes for at least 8 months. Broadly, the characterization of the extremely short yet oligodendrocyte-specific human MAG promoter may facilitate modeling neurological diseases caused by oligodendrocyte pathology and has translational relevance for leukodystrophy gene therapy.
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Affiliation(s)
- Georg von Jonquieres
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Dominik Fröhlich
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Claudia B Klugmann
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Xin Wen
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Anne E Harasta
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Roshini Ramkumar
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Ziggy H T Spencer
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Gary D Housley
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
| | - Matthias Klugmann
- Translational Neuroscience Facility and Department of Physiology, School of Medical Sciences, UNSW Australia Sydney, NSW, Australia
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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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Septal Glucagon-Like Peptide 1 Receptor Expression Determines Suppression of Cocaine-Induced Behavior. Neuropsychopharmacology 2015; 40:1969-78. [PMID: 25669605 PMCID: PMC4839521 DOI: 10.1038/npp.2015.47] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 01/21/2015] [Accepted: 02/05/2015] [Indexed: 01/17/2023]
Abstract
Glucagon-like peptide 1 (GLP-1) and its receptor GLP-1R are a key component of the satiety signaling system, and long-acting GLP-1 analogs have been approved for the treatment of type-2 diabetes mellitus. Previous reports demonstrate that GLP-1 regulates glucose homeostasis alongside the rewarding effects of food. Both palatable food and illicit drugs activate brain reward circuitries, and pharmacological studies suggest that central nervous system GLP-1 signaling holds potential for the treatment of addiction. However, the role of endogenous GLP-1 in the attenuation of reward-oriented behavior, and the essential domains of the mesolimbic system mediating these beneficial effects, are largely unknown. We hypothesized that the central regions of highest Glp-1r gene activity are essential in mediating responses to drugs of abuse. Here, we show that Glp-1r-deficient (Glp-1r(-/-)) mice have greatly augmented cocaine-induced locomotor responses and enhanced conditional place preference compared with wild-type (Glp-1r(+/+)) controls. Employing mRNA in situ hybridization we located peak Glp-1r mRNA expression in GABAergic neurons of the dorsal lateral septum, an anatomical site with a crucial function in reward perception. Whole-cell patch-clamp recordings of dorsal lateral septum neurons revealed that genetic Glp-1r ablation leads to increased excitability of these cells. Viral vector-mediated Glp-1r gene delivery to the dorsal lateral septum of Glp-1r(-/-) animals reduced cocaine-induced locomotion and conditional place preference to wild-type levels. This site-specific genetic complementation did not affect the anxiogenic phenotype observed in Glp-1r(-/-) controls. These data reveal a novel role of GLP-1R in dorsal lateral septum function driving behavioral responses to cocaine.
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Abstract
The autosomal recessive Canavan disease (CD) is a neurological disorder that begins in infancy. CD is caused by mutations in the gene encoding the ASPA enzyme. It has been reported with high frequency in patients with Jewish ancestry, and with low frequency in non-Jewish patients. This review will shed light on some updates regarding CD prevalence and causative mutations across the Arab World. CD was reported in several Arab countries such as Saudi Arabia, Egypt, Jordan, Yemen, Kuwait, and Tunisia. The population with the highest risk is in Saudi Arabia due the prevalent consanguineous marriage culture. In several studies, four novel mutations were found among Arabian CD patients, including two missense mutations (p.C152R, p.C152W), a 3346bp deletion leading to the removal of exon 3 of the ASPA gene, and an insertion mutation (698insC). Other previously reported mutations, which led to damage in the ASPA enzyme activities found among CD Arab patients are c.530 T>C (p.I177T), c.79G>A (p.G27R), IVS4+1G>T, and a 92kb deletion, which is 7.16kb upstream from the ASPA start site. This review will help in developing customized molecular diagnostic approaches and promoting CD carrier screening in the Arab world in areas where consanguineous marriage is common particularly within Saudi Arabia.
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15
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Baymeeva NV, Miroshnichenko II. N-acetylaspartate is a biomarker of psychiatric and neurological disorders. Zh Nevrol Psikhiatr Im S S Korsakova 2015; 115:94-98. [DOI: 10.17116/jnevro20151158194-98] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Serikawa T, Mashimo T, Kuramoro T, Voigt B, Ohno Y, Sasa M. Advances on genetic rat models of epilepsy. Exp Anim 2014; 64:1-7. [PMID: 25312505 PMCID: PMC4329510 DOI: 10.1538/expanim.14-0066] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Considering the suitability of laboratory rats in epilepsy research, we and other groups
have been developing genetic models of epilepsy in this species. After epileptic rats or
seizure-susceptible rats were sporadically found in outbred stocks, the epileptic traits
were usually genetically-fixed by selective breeding. So far, the absence seizure models
GAERS and WAG/Rij, audiogenic seizure models GEPR-3 and GEPR-9, generalized tonic-clonic
seizure models IER, NER and WER, and Canavan-disease related epileptic models TRM and SER
have been established. Dissection of the genetic bases including causative genes in these
epileptic rat models would be a significant step toward understanding epileptogenesis.
N-ethyl-N-nitrosourea (ENU) mutagenesis provides a systematic approach which allowed us to
develop two novel epileptic rat models: heat-induced seizure susceptible (Hiss) rats with
an Scn1a missense mutation and autosomal dominant lateral temporal epilepsy (ADLTE) model
rats with an Lgi1 missense mutation. In addition, we have established episodic ataxia type
1 (EA1) model rats with a Kcna1 missense mutation derived from the ENU-induced rat mutant
stock, and identified a Cacna1a missense mutation in a N-Methyl-N-nitrosourea
(MNU)-induced mutant rat strain GRY, resulting in the discovery of episodic ataxia type 2
(EA2) model rats. Thus, epileptic rat models have been established on the two paths:
‘phenotype to gene’ and ‘gene to phenotype’. In the near future, development of novel
epileptic rat models will be extensively promoted by the use of sophisticated genome
editing technologies.
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Affiliation(s)
- Tadao Serikawa
- Graduate School of Medicine, Kyoto University, Sakyo-ku 606-8501; Laboratory of Pharmacology, Osaka University of Pharmaceutical Sciences, Takatsuki 569-1094, Japan
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Krauspe BM, Dreher W, Beyer C, Baumgartner W, Denecke B, Janssen K, Langhans CD, Clarner T, Kipp M. Short-term cuprizone feeding verifies N-acetylaspartate quantification as a marker of neurodegeneration. J Mol Neurosci 2014; 55:733-48. [PMID: 25189319 DOI: 10.1007/s12031-014-0412-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2014] [Accepted: 08/20/2014] [Indexed: 01/27/2023]
Abstract
Proton magnetic resonance spectroscopy (1H-MRS) is a quantitative MR imaging technique often used to complement conventional MR imaging with specific metabolic information. A key metabolite is the amino acid derivative N-Acetylaspartate (NAA) which is an accepted marker to measure the extent of neurodegeneration in multiple sclerosis (MS) patients. NAA is catabolized by the enzyme aspartoacylase (ASPA) which is predominantly expressed in oligodendrocytes. Since the formation of MS lesions is paralleled by oligodendrocyte loss, NAA might accumulate in the brain, and therefore, the extent of neurodegeneration might be underestimated. In the present study, we used the well-characterized cuprizone model. There, the loss of oligodendrocytes is paralleled by a reduction in ASPA expression and activity as demonstrated by genome-wide gene expression analysis and enzymatic activity assays. Notably, brain levels of NAA were not increased as determined by gas chromatography-mass spectrometry and 1H-MRS. These important findings underpin the reliability of NAA quantification as a valid marker for the paraclinical determination of the extent of neurodegeneration, even under conditions of oligodendrocyte loss in which impaired metabolization of NAA is expected. Future studies have to reveal whether other enzymes are able to metabolize NAA or whether an excess of NAA is cleared by other mechanisms rather than enzymatic metabolism.
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Affiliation(s)
- Barbara Maria Krauspe
- Institute of Neuroanatomy, Faculty of Medicine, RWTH Aachen University, Wendlingweg 2, 52074, Aachen, Germany
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18
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Hoshino H, Kubota M. Canavan disease: clinical features and recent advances in research. Pediatr Int 2014; 56:477-83. [PMID: 24977939 DOI: 10.1111/ped.12422] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2014] [Revised: 04/30/2014] [Accepted: 05/20/2014] [Indexed: 12/19/2022]
Abstract
Canavan disease (CD) is a genetic neurodegenerative leukodystrophy that results in the spongy degeneration of white matter in the brain. CD is characterized by mutations in the gene encoding aspartoacylase (ASPA), the substrate enzyme that hydrolyzes N-acetylaspartic acid (NAA) to acetate and aspartate. Elevated NAA and subsequent deficiency in acetate associated with this disease cause progressive neurological symptoms, such as macrocephaly, visuocognitive dysfunction, and psychomotor delay. The prevalence of CD is higher among Ashkenazi Jewish people, and several types of mutations have been reported in the gene coding ASPA. Highly elevated NAA is more specific to CD than other leukodystrophies, and an examination of urinary NAA concentration is useful for diagnosing CD. Many researchers are now examining the mechanisms responsible for white matter degeneration or dysmyelination in CD using mouse models, and several persuasive hypotheses have been suggested for the pathophysiology of CD. One is that NAA serves as a water pump; consequently, a disorder in NAA catabolism leads to astrocytic edema. Another hypothesis is that the hydrolyzation of NAA in oligodendrocytes is essential for myelin synthesis through the supply of acetate. Although there is currently no curative therapy for CD, dietary supplements are candidates that may retard the progression of the symptoms associated with CD. Furthermore, gene therapies using viral vectors have been investigated using rat models. These therapies have been found to be tolerable with no severe long-term adverse effects, reduce the elevated NAA in the brain, and may be applied to humans in the future.
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Affiliation(s)
- Hideki Hoshino
- Department of Pediatrics, University of Tokyo, Tokyo, Japan; Division of Neurology, National Center for Child Health and Development, Tokyo, Japan
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19
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20
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von Jonquieres G, Mersmann N, Klugmann CB, Harasta AE, Lutz B, Teahan O, Housley GD, Fröhlich D, Krämer-Albers EM, Klugmann M. Glial promoter selectivity following AAV-delivery to the immature brain. PLoS One 2013; 8:e65646. [PMID: 23799030 PMCID: PMC3683058 DOI: 10.1371/journal.pone.0065646] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Accepted: 04/11/2013] [Indexed: 11/18/2022] Open
Abstract
Recombinant adeno-associated virus (AAV) vectors are versatile tools for gene transfer to the central nervous system (CNS) and proof-of-concept studies in adult rodents have shown that the use of cell type-specific promoters is sufficient to target AAV-mediated transgene expression to glia. However, neurological disorders caused by glial pathology usually have an early onset. Therefore, modelling and treatment of these conditions require expanding the concept of targeted glial transgene expression by promoter selectivity for gene delivery to the immature CNS. Here, we have investigated the AAV-mediated green fluorescent protein (GFP) expression driven by the myelin basic protein (MBP) or glial fibrillary acidic protein (GFAP) promoters in the developing mouse brain. Generally, the extent of transgene expression after infusion at immature stages was widespread and higher than in adults. The GFAP promoter-driven GFP expression was found to be highly specific for astrocytes following vector infusion to the brain of neonates and adults. In contrast, the selectivity of the MBP promoter for oligodendrocytes was poor following neonatal AAV delivery, but excellent after vector injection at postnatal day 10. To extend these findings obtained in naïve mice to a disease model, we performed P10 infusions of AAV-MBP-GFP in aspartoacylase (ASPA)-deficient mouse mutants presenting with early onset oligodendrocyte pathology. Spread of GFP expression and selectivity for oligodendrocytes in ASPA-mutants was comparable with our observations in normal animals. Our data suggest that direct AAV infusion to the developing postnatal brain, utilising cellular promoters, results in targeted and long-term transgene expression in glia. This approach will be relevant for disease modelling and gene therapy for the treatment of glial pathology.
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Affiliation(s)
- Georg von Jonquieres
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, New South Wales, Sydney, Australia
| | - Nadine Mersmann
- Institute of Physiological Chemistry, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
| | - Claudia Bettina Klugmann
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, New South Wales, Sydney, Australia
| | - Anne Editha Harasta
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, New South Wales, Sydney, Australia
| | - Beat Lutz
- Institute of Physiological Chemistry, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
| | - Orla Teahan
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, New South Wales, Sydney, Australia
| | - Gary David Housley
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, New South Wales, Sydney, Australia
| | - Dominik Fröhlich
- Department of Molecular Cell Biology, University of Mainz, Mainz, Germany
| | | | - Matthias Klugmann
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales, New South Wales, Sydney, Australia
- Institute of Physiological Chemistry, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
- * E-mail:
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21
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Leone P, Shera D, McPhee SWJ, Francis JS, Kolodny EH, Bilaniuk LT, Wang DJ, Assadi M, Goldfarb O, Goldman HW, Freese A, Young D, During MJ, Samulski RJ, Janson CG. Long-term follow-up after gene therapy for canavan disease. Sci Transl Med 2013; 4:165ra163. [PMID: 23253610 DOI: 10.1126/scitranslmed.3003454] [Citation(s) in RCA: 186] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Canavan disease is a hereditary leukodystrophy caused by mutations in the aspartoacylase gene (ASPA), leading to loss of enzyme activity and increased concentrations of the substrate N-acetyl-aspartate (NAA) in the brain. Accumulation of NAA results in spongiform degeneration of white matter and severe impairment of psychomotor development. The goal of this prospective cohort study was to assess long-term safety and preliminary efficacy measures after gene therapy with an adeno-associated viral vector carrying the ASPA gene (AAV2-ASPA). Using noninvasive magnetic resonance imaging and standardized clinical rating scales, we observed Canavan disease in 28 patients, with a subset of 13 patients being treated with AAV2-ASPA. Each patient received 9 × 10(11) vector genomes via intraparenchymal delivery at six brain infusion sites. Safety data collected over a minimum 5-year follow-up period showed a lack of long-term adverse events related to the AAV2 vector. Posttreatment effects were analyzed using a generalized linear mixed model, which showed changes in predefined surrogate markers of disease progression and clinical assessment subscores. AAV2-ASPA gene therapy resulted in a decrease in elevated NAA in the brain and slowed progression of brain atrophy, with some improvement in seizure frequency and with stabilization of overall clinical status.
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Affiliation(s)
- Paola Leone
- Department of Cell Biology, Cell & Gene Therapy Center, University of Medicine & Dentistry of New Jersey, Stratford, NJ 08034, USA.
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22
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Klugmann M, Goepfrich A, Friemel CM, Schneider M. AAV-Mediated Overexpression of the CB1 Receptor in the mPFC of Adult Rats Alters Cognitive Flexibility, Social Behavior, and Emotional Reactivity. Front Behav Neurosci 2011; 5:37. [PMID: 21808613 PMCID: PMC3139222 DOI: 10.3389/fnbeh.2011.00037] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2011] [Accepted: 06/29/2011] [Indexed: 12/20/2022] Open
Abstract
The endocannabinoid (ECB) system is strongly involved in the regulation of cognitive processing and emotional behavior and evidence indicates that ECB signaling might affect these behavioral abilities by modulations of prefrontal cortical functions. The aim of the present study was to examine the role of the CB1 receptor in the medial prefrontal cortex (mPFC) on cognitive flexibility and emotional behavior. Therefore, the CB1 receptor was overexpressed by adeno-associated virus vector-mediated gene transfer specifically in the mPFC of adult Wistar rats. Animals were then tested in different anxiety-related paradigms for emotional reactivity [e.g., elevated plus maze (EPM), light/dark emergence test (EMT), social interaction] and the attentional set shift task (ASST) – an adaptation of the human Wisconsin card sorting test – for cognitive abilities and behavioral flexibility. A subtle increase in exploratory behavior was found in CB1 receptor overexpressing animals (CB1-R) compared to Empty vector injected controls (Empty) in the EMT and EPM, although general locomotor activity did not differ between the groups. During social interaction testing, social contact behavior toward the unknown conspecific was found to be decreased, whereas social withdrawal was increased in CB1-R animals and they showed an inadequate increase in exploratory behavior compared to control animals. In the ASST, impaired reversal learning abilities were detected in CB1-R animals compared to controls, indicating reduced behavioral flexibility. In conclusion, upregulation of the CB1 receptor specifically in the rat mPFC induces alterations in emotional reactivity, leads to inadequate social behavior, and impairs cognitive flexibility. These findings might be relevant for neuropsychiatric disorders, since higher cortical CB1 receptor expression levels as well as similar behavioral impairments as observed in the present study have been described in schizophrenic patients.
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Affiliation(s)
- Matthias Klugmann
- Translational Neuroscience Facility, Department of Physiology, School of Medical Sciences, University of New South Wales Sydney, NSW, Australia
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23
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Abstract
Abstract
Neuromodulation strategies have been proposed to treat a variety of neurological disorders, including medication-resistant epilepsy. Electrical stimulation of both central and peripheral nervous systems has emerged as a possible alternative for patients who are not deemed to be good candidates for resective procedures. In addition to well-established treatments such as vagus nerve stimulation, epilepsy centers around the world are investigating the safety and efficacy of neurostimulation at different brain targets, including the hippocampus, thalamus, and subthalamic nucleus. Also promising are the preliminary results of responsive neuromodulation studies, which involve the delivery of stimulation to the brain in response to detected epileptiform or preepileptiform activity. In addition to electrical stimulation, novel therapeutic methods that may open new horizons in the management of epilepsy include transcranial magnetic stimulation, focal drug delivery, cellular transplantation, and gene therapy. We review the current strategies and future applications of neuromodulation in epilepsy.
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Affiliation(s)
- Faisal A Al-Otaibi
- King Faisal Specialist Hospital & Research Centre, Neurosciences Department, Riyadh, Saudi Arabia
| | - Clement Hamani
- Division of Neurosurgery, Toronto Western Hospital, Toronto Western Research Institute, Ontario, Canada
| | - Andres M Lozano
- Division of Neurosurgery, Toronto Western Hospital, Toronto Western Research Institute, Ontario, Canada
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24
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Mersmann N, Tkachev D, Jelinek R, Röth PT, Möbius W, Ruhwedel T, Rühle S, Weber-Fahr W, Sartorius A, Klugmann M. Aspartoacylase-lacZ knockin mice: an engineered model of Canavan disease. PLoS One 2011; 6:e20336. [PMID: 21625469 PMCID: PMC3098885 DOI: 10.1371/journal.pone.0020336] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2011] [Accepted: 04/26/2011] [Indexed: 11/19/2022] Open
Abstract
Canavan Disease (CD) is a recessive leukodystrophy caused by loss of function mutations in the gene encoding aspartoacylase (ASPA), an oligodendrocyte-enriched enzyme that hydrolyses N-acetylaspartate (NAA) to acetate and aspartate. The neurological phenotypes of different rodent models of CD vary considerably. Here we report on a novel targeted aspa mouse mutant expressing the bacterial β-Galactosidase (lacZ) gene under the control of the aspa regulatory elements. X-Gal staining in known ASPA expression domains confirms the integrity of the modified locus in heterozygous aspa lacZ-knockin (aspalacZ/+) mice. In addition, abundant ASPA expression was detected in Schwann cells. Homozygous (aspalacZ/lacZ) mutants are ASPA-deficient, show CD-like histopathology and moderate neurological impairment with behavioural deficits that are more pronounced in aspalacZ/lacZ males than females. Non-invasive ultrahigh field proton magnetic resonance spectroscopy revealed increased levels of NAA, myo-inositol and taurine in the aspalacZ/lacZ brain. Spongy degeneration was prominent in hippocampus, thalamus, brain stem, and cerebellum, whereas white matter of optic nerve and corpus callosum was spared. Intracellular vacuolisation in astrocytes coincides with axonal swellings in cerebellum and brain stem of aspalacZ/lacZ mutants indicating that astroglia may act as an osmolyte buffer in the aspa-deficient CNS. In summary, the aspalacZ mouse is an accurate model of CD and an important tool to identify novel aspects of its complex pathology.
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Affiliation(s)
- Nadine Mersmann
- Institute of Physiological Chemistry, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
| | - Dmitri Tkachev
- Institute of Physiological Chemistry, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
| | - Ruth Jelinek
- Institute of Physiological Chemistry, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
| | - Philipp Thomas Röth
- Institute of Physiological Chemistry, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
| | - Wiebke Möbius
- Department of Neurogenetics, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
| | - Torben Ruhwedel
- Department of Neurogenetics, Max-Planck-Institute of Experimental Medicine, Göttingen, Germany
| | - Sabine Rühle
- Institute of Physiological Chemistry, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
| | - Wolfgang Weber-Fahr
- Neuroimaging Department, Central Institute of Mental Health, Mannheim, Mannheim, Germany
| | - Alexander Sartorius
- Neuroimaging Department, Central Institute of Mental Health, Mannheim, Mannheim, Germany
| | - Matthias Klugmann
- Institute of Physiological Chemistry, University Medical Centre of the Johannes Gutenberg University, Mainz, Germany
- Translational Neuroscience Facility, Department of Physiology, University of New South Wales, Sydney, New South Wales, Australia
- * E-mail:
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25
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CNS-targeted viral delivery of G-CSF in an animal model for ALS: improved efficacy and preservation of the neuromuscular unit. Mol Ther 2010; 19:284-92. [PMID: 21139572 DOI: 10.1038/mt.2010.271] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease characterized by progressive loss of motoneurons. We have recently uncovered a new neurotrophic growth factor, granulocyte-colony stimulating factor (G-CSF), which protects α-motoneurons, improves functional outcome, and increases life expectancy of SOD-1 (G93A) mice when delivered subcutaneously. However, chronic systemic delivery of G-CSF is complicated by elevation of neutrophilic granulocytes. Here, we used adeno-associated virus (AAV) to directly target and confine G-CSF expression to the spinal cord. Whereas intramuscular injection of AAV failed to transduce motoneurons retrogradely, and caused a high systemic load of G-CSF, intraspinal delivery led to a highly specific enrichment of G-CSF in the spinal cord with moderate peripheral effects. Intraspinal delivery improved motor functions, delayed disease progression, and increased survival by 10%, longer than after systemic delivery. Mechanistically, we could show that G-CSF in addition to rescuing motoneurons improved neuromuscular junction (NMJ) integrity and enhanced motor axon regeneration after nerve crush injury. Collectively, our results show that intraspinal delivery improves efficacy of G-CSF treatment in an ALS mouse model while minimizing the systemic load of G-CSF, suggesting a new therapeutic option for ALS treatment.
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26
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Pederzolli CD, Rosa AP, de Oliveira AS, Coelho JG, da Luz Becker D, Dalazen GR, Moraes TB, Dutra-Filho CS. Neuroprotective role of lipoic acid against acute toxicity of N-acetylaspartic acid. Mol Cell Biochem 2010; 344:231-9. [DOI: 10.1007/s11010-010-0547-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2010] [Accepted: 07/23/2010] [Indexed: 11/28/2022]
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27
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Boison D. Cell and gene therapies for refractory epilepsy. Curr Neuropharmacol 2010; 5:115-25. [PMID: 18615179 DOI: 10.2174/157015907780866938] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2006] [Revised: 03/07/2007] [Accepted: 03/08/2007] [Indexed: 12/20/2022] Open
Abstract
Despite recent advances in the development of antiepileptic drugs, refractory epilepsy remains a major clinical problem affecting up to 35% of patients with partial epilepsy. Currently, there are few therapies that affect the underlying disease process. Therefore, novel therapeutic concepts are urgently needed. The recent development of experimental cell and gene therapies may offer several advantages compared to conventional systemic pharmacotherapy: (i) Specificity to underlying pathogenetic mechanisms by rational design; (ii) specificity to epileptogenic networks by focal delivery; and (iii) avoidance of side effects. A number of naturally occurring brain substances, such as GABA, adenosine, and the neuropeptides galanin and neuropeptide Y, may function as endogenous anticonvulsants and, in addition, may interact with the process of epileptogenesis. Unfortunately, the systemic application of these compounds is compromised by limited bioavailability, poor penetration of the blood-brain barrier, or the widespread systemic distribution of their respective receptors. Therefore, in recent years a new field of cell and gene-based neuropharmacology has emerged, aimed at either delivering endogenous anticonvulsant compounds by focal intracerebral transplantation of bioengineered cells (ex vivo gene therapy), or by inducing epileptogenic brain areas to produce these compounds in situ (in vivo gene therapy). In this review, recent efforts to develop GABA-, adenosine-, galanin-, and neuropeptide Y- based cell and gene therapies are discussed. The neurochemical rationales for using these compounds are discussed, the advantages of focal applications are highlighted and preclinical cell transplantation and gene therapy studies are critically evaluated. Although many promising data have been generated recently, potential problems, such as long-term therapeutic efficacy, long-term safety, and efficacy in clinically relevant animal models, need to be addressed before clinical applications can be contemplated.
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Affiliation(s)
- Detlev Boison
- RS Dow Neurobiology Laboratories, Legacy Research, Portland, OR 97232, USA.
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28
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Knackstedt LA, Moussawi K, Lalumiere R, Schwendt M, Klugmann M, Kalivas PW. Extinction training after cocaine self-administration induces glutamatergic plasticity to inhibit cocaine seeking. J Neurosci 2010; 30:7984-92. [PMID: 20534846 PMCID: PMC2893028 DOI: 10.1523/jneurosci.1244-10.2010] [Citation(s) in RCA: 164] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 04/19/2010] [Accepted: 04/23/2010] [Indexed: 12/18/2022] Open
Abstract
Learning to inhibit drug seeking can be an important strategy for inhibiting relapse, and this can be modeled by extinguishing drug seeking in response to a drug-paired context. Rats were either extinguished or withdrawn without extinction training (abstinence) from cocaine self-administration, and measurements of postsynaptic density proteins in the core and shell subcompartments of the nucleus accumbens were compared with yoked-saline controls. Only extinguished rats had elevations of PSD-95, Homer1b/c, and Narp in the postsynaptic density of the core, whereas no proteins measured were altered in the postsynaptic density of the shell in either extinguished or abstinent rats. Using a biotinylation strategy, it was found that surface expression of mGluR5 was reduced only in the core of extinguished animals. Although both extinguished and abstinent animals showed a reduction in long-term potentiation elicited in the core by stimulating prefrontal cortex, blunted long-term depression was observed only in extinguished rats. These data indicate that the elevation in Homer1b/c in the core may have sequestered mGluR5 away from the membrane surface and that the loss of surface mGluR5 inhibits long-term depression. Accordingly, when Homer1c was overexpressed in the core of cocaine-naive rats with an adenoassociated virus, long-term depression was inhibited. This mechanism may contribute to the inhibition of cocaine seeking by extinction training because overexpression of Homer1c in the core also inhibited cue-induced reinstatement of cocaine seeking. These data identify a cellular mechanism that may contribute to extinction-induced inhibition of cocaine seeking.
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Affiliation(s)
- Lori A Knackstedt
- Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
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29
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Pederzolli CD, Mescka CP, Magnusson AS, Deckmann KB, de Souza Streck E, Sgaravatti AM, Sgarbi MB, Wyse ATS, Wannmacher CMD, Wajner M, Dutra-Filho CS. N-acetylaspartic acid impairs enzymatic antioxidant defenses and enhances hydrogen peroxide concentration in rat brain. Metab Brain Dis 2010; 25:251-9. [PMID: 20437087 DOI: 10.1007/s11011-010-9202-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/19/2009] [Accepted: 03/22/2010] [Indexed: 11/27/2022]
Abstract
N-Acetylaspartic acid accumulates in Canavan Disease, a severe inherited neurometabolic disease clinically characterized by severe mental retardation, hypotonia, macrocephaly and generalized tonic and clonic type seizures. Considering that the mechanisms of brain damage in this disease remain poorly understood, in the present study we investigated the in vitro and in vivo effects of N-acetylaspartic acid on the activities of catalase, superoxide dismutase and glutathione peroxidase, as well as on hydrogen peroxide concentration in cerebral cortex of 14-day-old rats. Catalase and glutathione peroxidase activities were significantly inhibited, while hydrogen peroxide concentration was significantly enhanced by N-acetylaspartic acid both in vitro and in vivo. In contrast, superoxide dismutase activity was not altered by N-acetylaspartic acid. Our results clearly show that N-acetylaspartic acid impairs the enzymatic antioxidant defenses in rat brain. This could be involved in the pathophysiological mechanisms responsible for the brain damage observed in patients affected by Canavan Disease.
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30
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Arun P, Madhavarao CN, Moffett JR, Hamilton K, Grunberg NE, Ariyannur PS, Gahl WA, Anikster Y, Mog S, Hallows WC, Denu JM, Namboodiri AMA. Metabolic acetate therapy improves phenotype in the tremor rat model of Canavan disease. J Inherit Metab Dis 2010; 33:195-210. [PMID: 20464498 PMCID: PMC2877317 DOI: 10.1007/s10545-010-9100-z] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2009] [Revised: 03/09/2010] [Accepted: 03/31/2010] [Indexed: 11/29/2022]
Abstract
Genetic mutations that severely diminish the activity of aspartoacylase (ASPA) result in the fatal brain dysmyelinating disorder, Canavan disease. There is no effective treatment. ASPA produces free acetate from the concentrated brain metabolite, N-acetylaspartate (NAA). Because acetyl coenzyme A is a key building block for lipid synthesis, we postulated that the inability to catabolize NAA leads to a brain acetate deficiency during a critical period of CNS development, impairing myelination and possibly other aspects of brain development. We tested the hypothesis that acetate supplementation during postnatal myelination would ameliorate the severe phenotype associated with ASPA deficiency using the tremor rat model of Canavan disease. Glyceryltriacetate (GTA) was administered orally to tremor rats starting 7 days after birth, and was continued in food and water after weaning. Motor function, myelin lipids, and brain vacuolation were analyzed in GTA-treated and untreated tremor rats. Significant improvements were observed in motor performance and myelin galactocerebroside content in tremor rats treated with GTA. Further, brain vacuolation was modestly reduced, and these reductions were positively correlated with improved motor performance. We also examined the expression of the acetyl coenzyme A synthesizing enzyme acetyl coenzyme A synthase 1 and found upregulation of expression in tremor rats, with a return to near normal expression levels in GTA-treated tremor rats. These results confirm the critical role played by NAA-derived acetate in brain myelination and development, and demonstrate the potential usefulness of acetate therapy for the treatment of Canavan disease.
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Affiliation(s)
- Peethambaran Arun
- Department of Anatomy, Physiology and Genetics, Neuroscience Program and Molecular and Cell Biology Program, Uniformed Services University of the Health Sciences, Building C, 4301 Jones Bridge Rd., Bethesda, MD 20814 USA
| | - Chikkathur N. Madhavarao
- Department of Anatomy, Physiology and Genetics, Neuroscience Program and Molecular and Cell Biology Program, Uniformed Services University of the Health Sciences, Building C, 4301 Jones Bridge Rd., Bethesda, MD 20814 USA
| | - John R. Moffett
- Department of Anatomy, Physiology and Genetics, Neuroscience Program and Molecular and Cell Biology Program, Uniformed Services University of the Health Sciences, Building C, 4301 Jones Bridge Rd., Bethesda, MD 20814 USA
| | - Kristen Hamilton
- Department of Medical and Clinical Psychology and Neuroscience Program, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Rd., Bethesda, MD 20814 USA
| | - Neil E. Grunberg
- Department of Medical and Clinical Psychology and Neuroscience Program, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Rd., Bethesda, MD 20814 USA
| | - Prasanth S. Ariyannur
- Department of Anatomy, Physiology and Genetics, Neuroscience Program and Molecular and Cell Biology Program, Uniformed Services University of the Health Sciences, Building C, 4301 Jones Bridge Rd., Bethesda, MD 20814 USA
| | - William A. Gahl
- National Human Genome Research Institute, NIH, Bethesda, MD 20892 USA
| | - Yair Anikster
- Metabolic Disease Unit, Sheba Medical Center, Tel Aviv, Israel
| | - Steven Mog
- Division of Comparative Pathology, Armed Forces Radiobiology Research Institute, Bethesda, MD 20889 USA
| | - William C. Hallows
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706 USA
| | - John M. Denu
- Department of Biomolecular Chemistry, School of Medicine and Public Health, University of Wisconsin, Madison, WI 53706 USA
| | - Aryan M. A. Namboodiri
- Department of Anatomy, Physiology and Genetics, Neuroscience Program and Molecular and Cell Biology Program, Uniformed Services University of the Health Sciences, Building C, 4301 Jones Bridge Rd., Bethesda, MD 20814 USA
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Lawlor PA, Bland RJ, Mouravlev A, Young D, During MJ. Efficient gene delivery and selective transduction of glial cells in the mammalian brain by AAV serotypes isolated from nonhuman primates. Mol Ther 2009; 17:1692-702. [PMID: 19638961 DOI: 10.1038/mt.2009.170] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Adeno-associated viral (AAV) vectors have become the primary delivery agent for somatic gene transfer into the central nervous system (CNS). To date, AAV-mediated gene delivery to the CNS is based on serotypes 1-9, with efficient gene transfer to neurons only-selective and widespread transduction of glial cells have not been observed. Recently, additional endogenous AAVs have been isolated from nonhuman primate tissues. In this study, transduction obtained with AAV serotypes bb2, cy5, rh20, rh39, and rh43 was compared to that obtained with AAV8, another nonhuman primate isolate previously shown to perform well in mammalian brain. Titer-matched vectors encoding the enhanced green fluorescent protein (EGFP) reporter, driven by the constitutive CAG promoter, were injected into the hippocampus, striatum, or substantia nigra (SN) of adult rats. More widespread neuronal transduction was observed following infusion of cy5, rh20, and rh39 than observed with AAV8. Of interest, preferential transduction of astrocytes was observed with rh43. To optimize glial transduction, vector stocks driven by cell-specific promoters were generated-widespread and targeted transduction of astrocytes and oligodendrocytes was observed using rh43 and AAV8, driven by the glial fibrillary acidic protein (GFAP) and myelin basic protein (MBP) promoters, expanding the utility of AAV for modeling and treating diseases involving glial cell pathology.
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Affiliation(s)
- Patricia A Lawlor
- Department of Molecular Medicine and Pathology, The University of Auckland, Auckland, New Zealand.
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Targeting Homer genes using adeno-associated viral vector: lessons learned from behavioural and neurochemical studies. Behav Pharmacol 2008; 19:485-500. [PMID: 18690104 DOI: 10.1097/fbp.0b013e32830c369f] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Over a decade of in-vitro data support a critical role for members of the Homer family of postsynaptic scaffolding proteins in regulating the functional architecture of glutamate synapses. Earlier studies of Homer knockout mice indicated a necessary role for Homer gene products in normal mesocorticolimbic glutamate transmission and behaviours associated therewith. The advent of adeno-associated viral vectors carrying cDNA for, or short hairpin RNA against, specific Homer isoforms enabled the site-directed targeting of Homers to neurons in the brain. This approach has allowed our groups to address developmental issues associated with conventional knockout mice, to confirm active roles for distinct Homer isoforms in regulating glutamate transmission in vivo, as well as in mediating a variety of behavioural processes. This review summarizes the existing data derived from our studies using adeno-associated viral vector-mediated neuronal targeting of Homer in rodents, implicating this family of proteins in drug and alcohol addiction, learning/memory and emotional processing.
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The ubiquitin-proteasome system in spongiform degenerative disorders. Biochim Biophys Acta Mol Basis Dis 2008; 1782:700-12. [PMID: 18790052 PMCID: PMC2612938 DOI: 10.1016/j.bbadis.2008.08.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Revised: 08/13/2008] [Accepted: 08/15/2008] [Indexed: 12/20/2022]
Abstract
Spongiform degeneration is characterized by vacuolation in nervous tissue accompanied by neuronal death and gliosis. Although spongiform degeneration is a hallmark of prion diseases, this pathology is also present in the brains of patients suffering from Alzheimer’s disease, diffuse Lewy body disease, human immunodeficiency virus (HIV) infection, and Canavan’s spongiform leukodystrophy. The shared outcome of spongiform degeneration in these diverse diseases suggests that common cellular mechanisms must underlie the processes of spongiform change and neurodegeneration in the central nervous system. Immunohistochemical analysis of brain tissues reveals increased ubiquitin immunoreactivity in and around areas of spongiform change, suggesting the involvement of ubiquitin–proteasome system dysfunction in the pathogenesis of spongiform neurodegeneration. The link between aberrant ubiquitination and spongiform neurodegeneration has been strengthened by the discovery that a null mutation in the E3 ubiquitin–protein ligase mahogunin ring finger-1 (Mgrn1) causes an autosomal recessively inherited form of spongiform neurodegeneration in animals. Recent studies have begun to suggest that abnormal ubiquitination may alter intracellular signaling and cell functions via proteasome-dependent and proteasome-independent mechanisms, leading to spongiform degeneration and neuronal cell death. Further elucidation of the pathogenic pathways involved in spongiform neurodegeneration should facilitate the development of novel rational therapies for treating prion diseases, HIV infection, and other spongiform degenerative disorders.
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Schneider M, Spanagel R, Zhang SJ, Bading H, Klugmann M. Adeno-associated virus (AAV)-mediated suppression of Ca2+/calmodulin kinase IV activity in the nucleus accumbens modulates emotional behaviour in mice. BMC Neurosci 2007; 8:105. [PMID: 18053176 PMCID: PMC2219998 DOI: 10.1186/1471-2202-8-105] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2007] [Accepted: 12/03/2007] [Indexed: 12/20/2022] Open
Abstract
Background Calcium/calmodulin-dependent protein kinase IV (CaMKIV) controls activity-dependent gene transcription by regulating the activity of the cyclic AMP response element binding protein (CREB). This signaling pathway is involved in gating emotional responses in the CNS but previous studies did not address the potential roles of CaMKIV in discrete brain regions. In the present study, we aimed at specifically dissecting the role of CaMKIV in the nucleus accumbens of adult mice. Results We used recombinant adeno-associated virus (rAAV)-mediated gene transfer of a dominant-negative CaMKIV variant (rAAV-dnCaMKIV) to inhibit endogenous CaMKIV in the nucleus accumbens. rAAV-dnCaMKIV treated animals were subjected to a battery of tests including, prepulse inhibition of the acoustic startle response, open field, social interaction and anxiety-related behaviour. We found that basal locomotor activity in the open field, and prepulse inhibition or startle performance were unaltered in mice infected with rAAV-dnCaMKIV in the nucleus accumbens. However, anxiogenic effects were revealed in social interaction testing and the light/dark emergence test. Conclusion Our findings suggest a modulatory role of CaMKIV in the nucleus accumbens in anxiety-like behaviour but not sensorimotor gating.
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Affiliation(s)
- Miriam Schneider
- Central Institute of Mental Health (ZI), Department of Psychopharmacology, J5, 68159 Mannheim, Germany.
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35
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Pederzolli CD, Mescka CP, Scapin F, Rockenbach FJ, Sgaravatti AM, Sgarbi MB, Wyse ATS, Wannmacher CMD, Wajner M, Dutra-Filho CS. N-acetylaspartic acid promotes oxidative stress in cerebral cortex of rats. Int J Dev Neurosci 2007; 25:317-24. [PMID: 17604935 DOI: 10.1016/j.ijdevneu.2007.04.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2007] [Revised: 04/23/2007] [Accepted: 04/25/2007] [Indexed: 11/18/2022] Open
Abstract
N-acetylaspartic acid accumulates in Canavan Disease, a severe leukodystrophy characterized by swelling and spongy degeneration of the white matter of the brain. This inherited metabolic disease, caused by deficiency of the enzyme aspartoacylase, is clinically characterized by severe mental retardation, hypotonia and macrocephaly, and also generalized tonic and clonic type seizures in about half of the patients. Considering that the mechanisms of brain damage in this disease remain not fully understood, in the present study we investigated whether oxidative stress is elicited by N-acetylaspartic acid. The in vitro effect of N-acetylaspartic acid (10-80 mM) was studied on oxidative stress parameters: total radical-trapping antioxidant potential (TRAP), total antioxidant reactivity (TAR), chemiluminescence, thiobarbituric acid-reactive substances (TBA-RS), reduced glutathione content, sufhydryl content and carbonyl content in the cerebral cortex of 14-day-old rats. The effect of the acute administration of N-acetylaspartic acid (0.1-0.6 mmol/g body weight) was studied on TRAP, TAR, carbonyl content, chemiluminescence and TBA-RS. TRAP, TAR, reduced glutathione content and sulfhydryl content were significantly reduced, while chemiluminescence, TBA-RS and carbonyl content were significantly enhanced by N-acetylaspartic acid in vitro. The enhancement in TBA-RS promoted by N-acetylaspartic acid was completely prevented by ascorbic acid plus Trolox, and partially prevented by glutathione and dithiothreitol. The acute administration of N-acetylaspartic acid also significantly reduced TRAP and TAR, and significantly enhanced carbonyl content, chemiluminescence and TBA-RS. Our results indicate that N-acetylaspartic acid promotes oxidative stress by stimulating lipid peroxidation, protein oxidation and by decreasing non-enzymatic antioxidant defenses in rat brain. This could be another pathophysiological mechanism involved in Canavan Disease.
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Affiliation(s)
- Carolina D Pederzolli
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 Anexo, CEP 90035-003, Porto Alegre, RS, Brazil
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Moffett JR, Ross B, Arun P, Madhavarao CN, Namboodiri AMA. N-Acetylaspartate in the CNS: from neurodiagnostics to neurobiology. Prog Neurobiol 2007; 81:89-131. [PMID: 17275978 PMCID: PMC1919520 DOI: 10.1016/j.pneurobio.2006.12.003] [Citation(s) in RCA: 991] [Impact Index Per Article: 58.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Revised: 12/07/2006] [Accepted: 12/11/2006] [Indexed: 01/02/2023]
Abstract
The brain is unique among organs in many respects, including its mechanisms of lipid synthesis and energy production. The nervous system-specific metabolite N-acetylaspartate (NAA), which is synthesized from aspartate and acetyl-coenzyme A in neurons, appears to be a key link in these distinct biochemical features of CNS metabolism. During early postnatal central nervous system (CNS) development, the expression of lipogenic enzymes in oligodendrocytes, including the NAA-degrading enzyme aspartoacylase (ASPA), is increased along with increased NAA production in neurons. NAA is transported from neurons to the cytoplasm of oligodendrocytes, where ASPA cleaves the acetate moiety for use in fatty acid and steroid synthesis. The fatty acids and steroids produced then go on to be used as building blocks for myelin lipid synthesis. Mutations in the gene for ASPA result in the fatal leukodystrophy Canavan disease, for which there is currently no effective treatment. Once postnatal myelination is completed, NAA may continue to be involved in myelin lipid turnover in adults, but it also appears to adopt other roles, including a bioenergetic role in neuronal mitochondria. NAA and ATP metabolism appear to be linked indirectly, whereby acetylation of aspartate may facilitate its removal from neuronal mitochondria, thus favoring conversion of glutamate to alpha ketoglutarate which can enter the tricarboxylic acid cycle for energy production. In its role as a mechanism for enhancing mitochondrial energy production from glutamate, NAA is in a key position to act as a magnetic resonance spectroscopy marker for neuronal health, viability and number. Evidence suggests that NAA is a direct precursor for the enzymatic synthesis of the neuron specific dipeptide N-acetylaspartylglutamate, the most concentrated neuropeptide in the human brain. Other proposed roles for NAA include neuronal osmoregulation and axon-glial signaling. We propose that NAA may also be involved in brain nitrogen balance. Further research will be required to more fully understand the biochemical functions served by NAA in CNS development and activity, and additional functions are likely to be discovered.
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Affiliation(s)
- John R Moffett
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Building C, 4301 Jones Bridge Rd., Bethesda, MD 20814, USA.
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Boughamoura L, Chaabane F, Tilouche S, Chabchoub I, Kabachi N, Tlili K, Yacoub M, Essoussi AS. [Canavan disease or N-acetyl aspartic aciduria: a case report]. Arch Pediatr 2007; 14:173-6. [PMID: 17196380 DOI: 10.1016/j.arcped.2006.10.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2006] [Accepted: 10/25/2006] [Indexed: 09/30/2022]
Abstract
Canavan disease or N-acetyl aspartic aciduria, is an autosomal recessive leukodystrophy characterized by spongy degeneration of brain. The disease is an inborn error of metabolism caused by aspartoacylase deficiency resulting from accumulation of N-acetyl aspartic acid in the brain. The authors report a case in a 10-month-old boy who presented with developmental delay and megalencephaly noticeable after 4 months of age. Magnetic resonance imaging of the brain showed diffuse white matter degeneration. The diagnosis of Canavan disease was confirmed by nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry.
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Affiliation(s)
- L Boughamoura
- Service de pédiatrie, CHU Farhat-Hached, avenue Ibn-El-Jazzar, 4000 Sousse, Tunisie.
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Namboodiri AMA, Peethambaran A, Mathew R, Sambhu PA, Hershfield J, Moffett JR, Madhavarao CN. Canavan disease and the role of N-acetylaspartate in myelin synthesis. Mol Cell Endocrinol 2006; 252:216-23. [PMID: 16647192 DOI: 10.1016/j.mce.2006.03.016] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Canavan disease (CD) is an autosomal-recessive neurodegenerative disorder caused by inactivation of the enzyme aspartoacylase (ASPA, EC 3.5.1.15) due to mutations. ASPA releases acetate by deacetylation of N-acetylaspartate (NAA), a highly abundant amino acid derivative in the central nervous system. CD results in spongiform degeneration of the brain and severe psychomotor retardation, and the affected children usually die by the age of 10. The pathogenesis of CD remains a matter of inquiry. Our hypothesis is that ASPA actively participates in myelin synthesis by providing NAA-derived acetate for acetyl CoA synthesis, which in turn is used for synthesis of the lipid portion of myelin. Consequently, CD results from defective myelin synthesis due to a deficiency in the supply of the NAA-derived acetate. The demonstration of the selective localization of ASPA in oligodendrocytes in the central nervous system (CNS) is consistent with the acetate deficiency hypothesis of CD. We have tested this hypothesis by determining acetate levels and studying myelin lipid synthesis in the ASPA gene knockout model of CD, and the results provided the first direct evidence in support of this hypothesis. Acetate supplementation therapy is proposed as a simple and inexpensive therapeutic approach to this fatal disease, and progress in our preclinical efforts toward this goal is presented.
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Passini MA, Dodge JC, Bu J, Yang W, Zhao Q, Sondhi D, Hackett NR, Kaminsky SM, Mao Q, Shihabuddin LS, Cheng SH, Sleat DE, Stewart GR, Davidson BL, Lobel P, Crystal RG. Intracranial delivery of CLN2 reduces brain pathology in a mouse model of classical late infantile neuronal ceroid lipofuscinosis. J Neurosci 2006; 26:1334-42. [PMID: 16452657 PMCID: PMC6675492 DOI: 10.1523/jneurosci.2676-05.2006] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Classical late infantile neuronal ceroid lipofuscinosis (cLINCL) is a lysosomal storage disorder caused by mutations in CLN2, which encodes lysosomal tripeptidyl peptidase I (TPP1). Lack of TPP1 results in accumulation of autofluorescent storage material and curvilinear bodies in cells throughout the CNS, leading to progressive neurodegeneration and death typically in childhood. In this study, we injected adeno-associated virus (AAV) vectors containing the human CLN2 cDNA into the brains of CLN2(-/-) mice to determine therapeutic efficacy. AAV2CUhCLN2 or AAV5CUhCLN2 were stereotaxically injected into the motor cortex, thalamus, and cerebellum of both hemispheres at 6 weeks of age, and mice were then killed at 13 weeks after injection. Mice treated with AAV2CUhCLN2 and AAV5CUhCLN2 contained TPP1 activity at each injection tract that was equivalent to 0.5- and 2-fold that of CLN2(+/+) control mice, respectively. Lysosome-associated membrane protein 1 immunostaining and confocal microscopy showed intracellular targeting of TPP1 to the lysosomal compartment. Compared with control animals, there was a marked reduction of autofluorescent storage in the AAV2CUhCLN2 and AAV5CUhCLN2 injected brain regions, as well as adjacent regions, including the striatum and hippocampus. Analysis by electron microscopy confirmed a significant decrease in pathological curvilinear bodies in cells. This study demonstrates that AAV-mediated TPP1 enzyme replacement corrects the hallmark cellular pathologies of cLINCL in the mouse model and raises the possibility of using AAV gene therapy to treat cLINCL patients.
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Affiliation(s)
- Marco A Passini
- Neuroscience, Genzyme Corporation, Framingham, Massachusetts 01701, USA.
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Warrington KH, Herzog RW. Treatment of human disease by adeno-associated viral gene transfer. Hum Genet 2006; 119:571-603. [PMID: 16612615 DOI: 10.1007/s00439-006-0165-6] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Accepted: 02/28/2006] [Indexed: 11/24/2022]
Abstract
During the past decade, in vivo administration of viral gene transfer vectors for treatment of numerous human diseases has been brought from bench to bedside in the form of clinical trials, mostly aimed at establishing the safety of the protocol. In preclinical studies in animal models of human disease, adeno-associated viral (AAV) vectors have emerged as a favored gene transfer system for this approach. These vectors are derived from a replication-deficient, non-pathogenic parvovirus with a single-stranded DNA genome. Efficient gene transfer to numerous target cells and tissues has been described. AAV is particularly efficient in transduction of non-dividing cells, and the vector genome persists predominantly in episomal forms. Substantial correction, and in some instances complete cure, of genetic disease has been obtained in animal models of hemophilia, lysosomal storage disorders, retinal diseases, disorders of the central nervous system, and other diseases. Therapeutic expression often lasted for months to years. Treatments of genetic disorders, cancer, and other acquired diseases are summarized in this review. Vector development, results in animals, early clinical experience, as well as potential hurdles and challenges are discussed.
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Affiliation(s)
- Kenneth H Warrington
- Cellular and Molecular Therapy, Department of Pediatrics, University of Florida, Gainesville, FL 32615-9586, USA
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Mandel RJ, Manfredsson FP, Foust KD, Rising A, Reimsnider S, Nash K, Burger C. Recombinant adeno-associated viral vectors as therapeutic agents to treat neurological disorders. Mol Ther 2006; 13:463-83. [PMID: 16412695 DOI: 10.1016/j.ymthe.2005.11.009] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2005] [Revised: 11/12/2005] [Accepted: 11/13/2005] [Indexed: 12/11/2022] Open
Abstract
Recombinant adeno-associated virus (rAAV) is derived from a small human parvovirus with an excellent safety profile. In addition, this viral vector efficiently transduces and supports long-term transgene expression in the nervous system. These properties make rAAV a reasonable candidate vector for treating neurological disorders. Indeed, rAAV is currently being used in five early stage clinical trials for various neurodegenerative disorders. Therefore, we will review the currently available preclinical data using rAAV in animal models of central nervous system (CNS) disorders. Moreover, potential caveats for rAAV-based gene therapy in the CNS are also presented.
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Affiliation(s)
- Ronald J Mandel
- Department of Neuroscience, and McKnight Brain Institute, University of Florida College of Medicine, Gainesville, FL 32610, USA.
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Abstract
Breakdown of oligodendrocyte-neuron interactions in white matter (WM), such as the loss of myelin, results in axonal dysfunction and hence a disruption of information processing between brain regions. The major feature of leukodystrophies is the lack of proper myelin formation during early development or the onset of myelin loss late in life. These early childhood WM diseases are described as hypomyelination or dysmyelination arising from a primary block in normal myelin synthesis because of a genetic mutation expressed in oligodendrocytes, or failure in myelination secondary to neuronal or astroglial dysfunctions (van der Knaap 2001 Dev. Med. Child Neurol. 43:705-712). Here, we describe the pathophysiological parameters of Canavan disease (CD), caused by genetic mutations of the aspartoacylase (ASPA) gene, a metabolic enzyme restricted in the central nervous system (CNS) to oligodendrocytes. CD presents pathophysiological dysfunctions similar to diseases caused by myelin gene mutations, such as Pelizaeus-Merzbacher disease (PMD) and several animal models, such as myelin deficient rat (md), jimpy (jp), shiverer (sh), and quaking (qk viable) mutant mice. These single gene mutations have pleiotropic effects, whereby the alteration of one myelin gene expression disrupts functional expression of other oligodendrocyte genes with an outcome of hypomyelination/dysmyelination. Among all of the known leukodystrophies, CD is the first disorder, which was approved and tested for the adeno-associated virus vector (AAV)-ASPA gene therapy (Leone et al. 2000 Ann. Neurol. 48:27-38; Janson et al. 2001 Trends Neurosci. 24:706-712) without much success following the first two attempts. ASPA gene delivery attempts in animal models have shown a lowering of N-acetyl L-aspartate and a change in motor functions, while sponginess of the WM, a characteristic of CD remained unchanged (Matalon et al. 2003 Mol. Ther. 7 (5, Part 1):580-587; McPhee et al. 2005 Brain Res. Mol. Brain Res. 135:112-121) even with better viral serotype and delivery of the gene during early phase of development (Klugmann et al. 2005 Mol. Ther. 11:745-753). While different approaches are being sought for the success of gene therapy, there are pivotal developmental questions to address regarding the specific regions of the CNS and cell lineages that become the target for the onset and progression of CD symptoms from early to late stages of development.
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Affiliation(s)
- Shalini Kumar
- Department of Neurobiology, Mental Retardation Research Center, Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, California 90095-7332, USA
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Mathew R, Arun P, Madhavarao CN, Moffett JR, Namboodiri MAA. Progress toward Acetate Supplementation Therapy for Canavan Disease: Glyceryl Triacetate Administration Increases Acetate, but NotN-Acetylaspartate, Levels in Brain. J Pharmacol Exp Ther 2005; 315:297-303. [PMID: 16002461 DOI: 10.1124/jpet.105.087536] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Canavan disease (CD) is a fatal genetic neurodegenerative disorder caused by mutations in the gene for aspartoacylase, an enzyme that hydrolyzes N-acetylaspartate (NAA) into L-aspartate and acetate. Because aspartoacylase is localized in oligodendrocytes, and NAA-derived acetate is incorporated into myelin lipids, we hypothesize that an acetate deficiency in oligodendrocytes is responsible for the pathology in CD, and we propose acetate supplementation as a possible therapy. In our preclinical efforts toward this goal, we studied the effectiveness of orally administered glyceryl triacetate (GTA) and calcium acetate for increasing acetate levels in the murine brain. The concentrations of brain acetate and NAA were determined simultaneously after intragastric administration of GTA. We found that the acetate levels in brain were increased in a dose- and time-dependent manner, with a 17-fold increase observed at 1 to 2 h in 20- to 21-day-old mice at a dose of 5.8 g/kg GTA. NAA levels in the brain were not significantly increased under these conditions. Studies using mice at varying stages of development showed that the dose of GTA required to maintain similarly elevated acetate levels in the brain increased with age. Also, GTA was significantly more effective as an acetate source than calcium acetate. Chronic administration of GTA up to 25 days of age did not result in any overt pathology in the mice. Based on these results and the current Food and Drug Administration-approved use of GTA as a food additive, we propose that it is a potential candidate for use in acetate supplementation therapy for CD.
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Affiliation(s)
- Raji Mathew
- Department of Anatomy, Physiology, and Genetics, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
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