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Chaudhary R, Rehman M, Agarwal V, Kumar A, Kaushik AS, Srivastava S, Srivastava S, Verma R, Rajinikanth PS, Mishra V. Terra incognita of glial cell dynamics in the etiology of leukodystrophies: Broadening disease and therapeutic perspectives. Life Sci 2024; 354:122953. [PMID: 39122110 DOI: 10.1016/j.lfs.2024.122953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 07/09/2024] [Accepted: 08/05/2024] [Indexed: 08/12/2024]
Abstract
Neuroglial cells, also known as glia, are primarily characterized as auxiliary cells within the central nervous system (CNS). The recent findings have shed light on their significance in numerous physiological processes and their involvement in various neurological disorders. Leukodystrophies encompass an array of rare and hereditary neurodegenerative conditions that were initially characterized by the deficiency, aberration, or degradation of myelin sheath within CNS. The primary cellular populations that experience significant alterations are astrocytes, oligodendrocytes and microglia. These glial cells are either structurally or metabolically impaired due to inherent cellular dysfunction. Alternatively, they may fall victim to the accumulation of harmful by-products resulting from metabolic disturbances. In either situation, the possible replacement of glial cells through the utilization of implanted tissue or stem cell-derived human neural or glial progenitor cells hold great promise as a therapeutic strategy for both the restoration of structural integrity through remyelination and the amelioration of metabolic deficiencies. Various emerging treatment strategies like stem cell therapy, ex-vivo gene therapy, infusion of adeno-associated virus vectors, emerging RNA-based therapies as well as long-term therapies have demonstrated success in pre-clinical studies and show promise for rapid clinical translation. Here, we addressed various leukodystrophies in a comprehensive and detailed manner as well as provide prospective therapeutic interventions that are being considered for clinical trials. Further, we aim to emphasize the crucial role of different glial cells in the pathogenesis of leukodystrophies. By doing so, we hope to advance our understanding of the disease, elucidate underlying mechanisms, and facilitate the development of potential treatment interventions.
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Affiliation(s)
- Rishabh Chaudhary
- Department of Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow 226025, U.P., India
| | - Mujeeba Rehman
- Department of Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow 226025, U.P., India
| | - Vipul Agarwal
- Department of Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow 226025, U.P., India
| | - Anand Kumar
- Department of Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow 226025, U.P., India
| | - Arjun Singh Kaushik
- Department of Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow 226025, U.P., India
| | - Siddhi Srivastava
- Department of Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow 226025, U.P., India
| | - Sukriti Srivastava
- Department of Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow 226025, U.P., India
| | - Rajkumar Verma
- University of Connecticut School of Medicine, 200 Academic Way, Farmington, CT 06032, USA
| | - P S Rajinikanth
- Department of Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow 226025, U.P., India
| | - Vikas Mishra
- Department of Pharmaceutical Sciences, Babasaheb Bhimrao Ambedkar University, Vidya Vihar, Raebareli Road, Lucknow 226025, U.P., India.
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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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Weiler M, Stieger KC, Shroff K, Klein JP, Wood WH, Zhang Y, Chandrasekaran P, Lehrmann E, Camandola S, Long JM, Mattson MP, Becker KG, Rapp PR. Transcriptional changes in the rat brain induced by repetitive transcranial magnetic stimulation. Front Hum Neurosci 2023; 17:1215291. [PMID: 38021223 PMCID: PMC10679736 DOI: 10.3389/fnhum.2023.1215291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 10/03/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction Transcranial Magnetic Stimulation (TMS) is a noninvasive technique that uses pulsed magnetic fields to affect the physiology of the brain and central nervous system. Repetitive TMS (rTMS) has been used to study and treat several neurological conditions, but its complex molecular basis is largely unexplored. Methods Utilizing three experimental rat models (in vitro, ex vivo, and in vivo) and employing genome-wide microarray analysis, our study reveals the extensive impact of rTMS treatment on gene expression patterns. Results These effects are observed across various stimulation protocols, in diverse tissues, and are influenced by time and age. Notably, rTMS-induced alterations in gene expression span a wide range of biological pathways, such as glutamatergic, GABAergic, and anti-inflammatory pathways, ion channels, myelination, mitochondrial energetics, multiple neuron-and synapse-specific genes. Discussion This comprehensive transcriptional analysis induced by rTMS stimulation serves as a foundational characterization for subsequent experimental investigations and the exploration of potential clinical applications.
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Affiliation(s)
- Marina Weiler
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Kevin C. Stieger
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Kavisha Shroff
- Laboratory of Genetics and Genomics, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Jessie P. Klein
- Laboratory of Genetics and Genomics, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - William H. Wood
- Laboratory of Genetics and Genomics, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Yongqing Zhang
- Laboratory of Genetics and Genomics, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Prabha Chandrasekaran
- Laboratory of Clinical Investigation, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Elin Lehrmann
- Laboratory of Genetics and Genomics, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Simonetta Camandola
- Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Jeffrey M. Long
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Mark P. Mattson
- Laboratory of Neurosciences, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Kevin G. Becker
- Laboratory of Genetics and Genomics, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
| | - Peter R. Rapp
- Laboratory of Behavioral Neuroscience, National Institute on Aging, National Institutes of Health, Baltimore, MD, United States
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Amorini AM, Lazzarino G, Di Pietro V, Signoretti S, Lazzarino G, Belli A, Tavazzi B. Severity of experimental traumatic brain injury modulates changes in concentrations of cerebral free amino acids. J Cell Mol Med 2016; 21:530-542. [PMID: 27696676 PMCID: PMC5323875 DOI: 10.1111/jcmm.12998] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Accepted: 08/26/2016] [Indexed: 12/29/2022] Open
Abstract
In this study, concentrations of free amino acids (FAA) and amino group containing compounds (AGCC) following graded diffuse traumatic brain injury (mild TBI, mTBI; severe TBI, sTBI) were evaluated. After 6, 12, 24, 48 and 120 hr aspartate (Asp), glutamate (Glu), asparagine (Asn), serine (Ser), glutamine (Gln), histidine (His), glycine (Gly), threonine (Thr), citrulline (Cit), arginine (Arg), alanine (Ala), taurine (Tau), γ‐aminobutyrate (GABA), tyrosine (Tyr), S‐adenosylhomocysteine (SAH), l‐cystathionine (l‐Cystat), valine (Val), methionine (Met), tryptophane (Trp), phenylalanine (Phe), isoleucine (Ile), leucine (Leu), ornithine (Orn), lysine (Lys), plus N‐acetylaspartate (NAA) were determined in whole brain extracts (n = 6 rats at each time for both TBI levels). Sham‐operated animals (n = 6) were used as controls. Results demonstrated that mTBI caused modest, transient changes in NAA, Asp, GABA, Gly, Arg. Following sTBI, animals showed profound, long‐lasting modifications of Glu, Gln, NAA, Asp, GABA, Ser, Gly, Ala, Arg, Citr, Tau, Met, SAH, l‐Cystat, Tyr and Phe. Increase in Glu and Gln, depletion of NAA and Asp increase, suggested a link between NAA hydrolysis and excitotoxicity after sTBI. Additionally, sTBI rats showed net imbalances of the Glu‐Gln/GABA cycle between neurons and astrocytes, and of the methyl‐cycle (demonstrated by decrease in Met, and increase in SAH and l‐Cystat), throughout the post‐injury period. Besides evidencing new potential targets for novel pharmacological treatments, these results suggest that the force acting on the brain tissue at the time of the impact is the main determinant of the reactions ignited and involving amino acid metabolism.
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Affiliation(s)
- Angela Maria Amorini
- Institute of Biochemistry and Clinical Biochemistry, Catholic University of Rome, Rome, Italy
| | - Giacomo Lazzarino
- Institute of Biochemistry and Clinical Biochemistry, Catholic University of Rome, Rome, Italy
| | - Valentina Di Pietro
- Neuroscience and Ophthalmology group, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Stefano Signoretti
- Division of Neurosurgery, Department of Neurosciences Head and Neck Surgery, S. Camillo Hospital, Rome, Italy
| | - Giuseppe Lazzarino
- Division of Medical Biochemistry, Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Antonio Belli
- Neuroscience and Ophthalmology group, School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.,National Institute for Health Research Surgical Reconstruction and Microbiology Research Centre, Queen Elizabeth Hospital, Birmingham, UK
| | - Barbara Tavazzi
- Institute of Biochemistry and Clinical Biochemistry, Catholic University of Rome, Rome, Italy
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Matalon R, Surendran S, McDonald JD, Okorodudu AO, Tyring SK, Michals-Matalon K, Harris P. Abnormal Expression of Genes Associated with Development and Inflammation in the Heart of Mouse Maternal Phenylketonuria Offspring. Int J Immunopathol Pharmacol 2016; 18:557-65. [PMID: 16164837 DOI: 10.1177/039463200501800316] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
This study descibes gene expression in the fetus hearts obtained from mouse model for Phenylketonuria. These hearts have cardiovascular disease (CVD). Therefore genes involved in CVD were examined. Several genes associated with heart development and inflammation were found to be altered. In order to investigate whether the abnormal gene expression alters transcription and translation, the levels of troponin mRNA and protein were determined. One step real time RT-PCR showed a reduction in cardiac troponin I, troponin T2 and ryanodine receptor 2. Determination of troponin I and T protein levels showed reduced levels of these proteins. Our results suggest that altered gene expression affects protein production. These changes are likely involved in the cardiovascular defects seen in the mouse.
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Affiliation(s)
- R Matalon
- Department of Pediatrics, The University of Texas Medical Branch (UTMB), Galveston, Texas 77555-0632, USA
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Francis JS, Strande L, Pu A, Leone P. Endogenous aspartoacylase expression is responsive to glutamatergic activity in vitro and in vivo. Glia 2011; 59:1435-46. [DOI: 10.1002/glia.21187] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2010] [Accepted: 04/20/2011] [Indexed: 11/10/2022]
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Genome-wide gene expression profiling and mutation analysis of Saudi patients with Canavan disease. Genet Med 2009; 10:675-84. [PMID: 18978679 DOI: 10.1097/gim.0b013e31818337a8] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Canavan disease, caused by a deficiency of aspartoacylase, is one of the most common cerebral degenerative diseases of infancy. The aims of this study were to identify the mutations associated with Canavan disease in Saudi Arabia and to identify differentially expressed genes likely to contribute to the development of this disease. METHODS Polymerase chain reaction, long polymerase chain reaction, multiplex ligation-dependent probe amplification, sequencing, array comparative genomic hybridization (aCGH), and global gene expression profiling were used to determine putative mutations and likely gene signatures in cultured fibroblasts of patients from Saudi Arabia. RESULTS One novel and one known large deletion and two previously known mutations (IVS4 + 1G>T and G27R) were identified. Compared with controls, 1440 genes were significantly modulated in Canavan patients (absolute fold change [FC] > or =4). Genome-wide gene expression profiling results indicated that some genes, involved in apoptosis, muscle contraction and development, mitochondrial oxidation, inflammation and glutamate, and aspartate metabolism, were significantly dysregulated. CONCLUSIONS Our findings indicate that the presence of muscle weakness and hypotonia in patients may be associated with the dysregulated gene activities of cell motility, muscle contraction and development, actin binding, and cytoskeletal-related activities. Overall, these observations are in accordance with previous studies performed in a knockout mouse model.
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Matalon R, Michals-Matalon K, Surendran S, Tyring SK. Canavan disease: studies on the knockout mouse. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2006; 576:77-93; discussion 361-3. [PMID: 16802706 DOI: 10.1007/0-387-30172-0_6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
Canavan disease (CD) is an autosomal recessive disorder, characterized by spongy degeneration of the brain. Patients with CD have aspartoacylase (ASPA) deficiency, which results accumulation of N-acetylaspartic acid (NAA) in the brain and elevated excretion of urinary NAA. Clinically, patients with CD have macrocephaly, mental retardation and hypotonia. A knockout mouse for CD which was engineered, also has ASPA deficiency and elevated NAA. Molecular studies of the mouse brain showed abnormal expression of multiple genes in addition to ASPA deficiency. Adenoassociated virus mediated gene transfer and stem cell therapy in the knockout mouse are the latest attempts to alter pathophysiology in the CD mouse.
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Affiliation(s)
- Reuben Matalon
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX 77555, USA.
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Surendran S, Matalon R, Tyring SK. Upregulation of aspartoacylase activity in the duodenum of obesity induced diabetes mouse: implications on diabetic neuropathy. Biochem Biophys Res Commun 2006; 345:973-5. [PMID: 16707098 DOI: 10.1016/j.bbrc.2006.04.179] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2006] [Accepted: 04/26/2006] [Indexed: 11/23/2022]
Abstract
Aspartoacylase (ASPA) hydrolyzes N-acetylaspartic acid (NAA) into aspartate and acetate. Normal hydrolysis of NAA is important to maintain healthy neurons. Since enteric neuropathy is one of the events seen in diabetes, whether ASPA activity is affected in diabetic condition is not known. In order to investigate the possibility, ASPA activity was examined in the duodenum and brain of obesity induced diabetes model mouse. Aspartoacylase activity was high in the diabetic mouse duodenum compared to control duodenum. The same result was also observed by immunostaining of the mouse duodenum. The activity of ASPA was found to be elevated in the brain of diabetic mouse compared to the control brain. These data suggest that normal hydrolysis of NAA is affected by ASPA activity seen in the type 2 diabetes model mouse and this change is likely to contribute to neuropathy seen in diabetes, if documented also in patients with type 2 diabetes.
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Affiliation(s)
- Sankar Surendran
- Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX, 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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Surendran S, Szucs S, Tyring SK, Matalon R. Aspartoacylase gene knockout in the mouse: impact on reproduction. Reprod Toxicol 2005; 20:281-3. [PMID: 15907664 DOI: 10.1016/j.reprotox.2005.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2004] [Revised: 12/31/2004] [Accepted: 02/04/2005] [Indexed: 10/25/2022]
Abstract
Canavan disease (CD) is an autosomal recessive disorder caused by aspartoacylase (ASPA) gene mutations resulting enzyme deficiency. The homozygous knockout mouse for CD showed symptoms similar observed in patients with CD. Canavan disease leads to early death. Therefore, a role of ASPA in reproduction was investigated using the mouse model for CD. Homozygous (KO/KO) pups, produced by mating female heterozygous (KO/+) mouse with KO/+ males had approximately 12% death incidence rates in the first 2 months of life. KO/KO mothers mated with KO/+ males showed fetal death. KO/KO mothers produced fewer offspring compared to KO/+ mothers. These data suggest that ASPA is necessary for normal reproduction and postnatal survival.
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Affiliation(s)
- Sankar Surendran
- Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX 77555, USA.
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Surendran S, Matalon D, Tyring SK, Rady PL, Velagaleti GV, Matalon R. Altered expression of myocilin in the brain of a mouse model for phenylketonuria (PKU). Neurosci Lett 2005; 382:323-6. [PMID: 15925112 DOI: 10.1016/j.neulet.2005.03.030] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2004] [Revised: 03/03/2005] [Accepted: 03/18/2005] [Indexed: 10/25/2022]
Abstract
Phenylketonuria (PKU) is an inborn error of amino acid metabolism. Phenylalanine hydroxylase (PAH) mutations resulting reduced enzyme levels lead to accumulation of phenylalanine (Phe) in brain, if Phe diet is not restricted. Patients with PKU show neurophysiological abnormalities including demyelination and cognitive defect. How PAH defect causes events seen in PKU is not obvious. Therefore, expression analysis was performed in the brain of a mouse model for PKU. Microarray expression profile of the brain showed lower expression of myocilin (Myoc) in the PKU mouse. Reduced expression of Myoc was further confirmed by one-step real-time RT-PCR. Western blotting analysis of the brain using equal quantities of protein showed a thin band in PKU compared to a prominent band in the wild type brain. In addition, expression of genes associated with transcription was found to be altered in the PKU mouse brain as observed by microarray analysis. These data suggest that PAH defect alters other genes expression likely to contribute neurophysiological abnormalities seen in the mouse, if documented also in patients with PKU.
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Affiliation(s)
- Sankar Surendran
- Department of Internal Medicine, The University of Texas Medical Branch, Galveston, TX 77555-0632, USA.
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Surendran S, Campbell GA, Tyring SK, Matalon R. Aspartoacylase gene knockout results in severe vacuolation in the white matter and gray matter of the spinal cord in the mouse. Neurobiol Dis 2005; 18:385-9. [PMID: 15686967 DOI: 10.1016/j.nbd.2004.10.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2004] [Revised: 09/24/2004] [Accepted: 10/21/2004] [Indexed: 11/26/2022] Open
Abstract
Canavan disease (CD) is a neurodegenerative disorder characterized by the spongy degeneration of the white matter of the brain. Aspartoacylase (ASPA) gene mutation resulting enzyme deficiency is the basic cause of CD. Whether the ASPA defect in CD affects the spinal cord has been investigated using the ASPA gene knockout mouse. Luxol fast blue-hematoxylin and eosin staining in the spinal cord of the knockout mouse showed vacuolation in both white matter and gray matter areas of cervical, thoracic, lumbar, and sacral segments of the spinal cord. However, more vacuoles were seen in the gray matter than the white matter of the spinal cord. ASPA activity in the cervical, thoracic, lumbar, and sacrococcygeal regions of the spinal cord was significantly lower in the knockout mouse compared to the wild type. The enzyme defect in the knockout mouse was also confirmed using the Western blot method. These observations suggest that the ASPA gene defect in the mouse leads to spinal cord pathology, and that these changes may be partly involved in the cause of the physiological/behavioral abnormalities seen in the knockout mouse, if documented also in patients with CD.
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Affiliation(s)
- Sankar Surendran
- Department of Pediatrics, The University of Texas Medical Branch, Childrens Hospital, 301 University Boulevard, Galveston, TX 77555-0359, USA.
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Surendran S, Shihabuddin LS, Clarke J, Taksir TV, Stewart GR, Parsons G, Yang W, Tyring SK, Michals-Matalon K, Matalon R. Mouse neural progenitor cells differentiate into oligodendrocytes in the brain of a knockout mouse model of Canavan disease. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 2004; 153:19-27. [PMID: 15464214 DOI: 10.1016/j.devbrainres.2004.07.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/07/2004] [Indexed: 12/14/2022]
Abstract
Canavan disease (CD) is an autosomal recessive disorder that leads to spongy degeneration in the white matter of the brain. Aspartoacylase (ASPA) synthesizing cells, oligodendrocytes, are lost in CD. Transplantation of neural progenitor cells (NPCs) offers an interesting therapeutic approach for treating neurodegenerative diseases by replacing the lost cells. Therefore, the NPCs transplantation to the brain of the CD mouse was studied. Injection of mouse NPCs to the striatum and cerebellum of juvenile CD mouse showed numerous BrdU positive cells at 1 month after injection. The same result was also observed in the adult CD mouse brain after 5 weeks of post-transplantation period. The implanted cells differentiated into oligodendrocytes and fibrous astrocytes, as observed using glial cell marker. This is the first report to describe the survival, distribution and differentiation of NPCs within the brain of CD mouse and a first step toward the potential clinical use of cell therapy to treat CD.
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Affiliation(s)
- Sankar Surendran
- Pediatrics Rm # 3.350, Department of Pediatrics, Childrens Hospital, The University of Texas Medical Branch, Galveston, TX 77555-0359, USA
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Surendran S, Ezell EL, Quast MJ, Wei J, Tyring SK, Michals-Matalon K, Matalon R. Aspartoacylase deficiency does not affect N-acetylaspartylglutamate level or glutamate carboxypeptidase II activity in the knockout mouse brain. Brain Res 2004; 1016:268-71. [PMID: 15246864 DOI: 10.1016/j.brainres.2004.05.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/10/2004] [Indexed: 10/26/2022]
Abstract
Aspartoacylase (ASPA)-deficient patients [Canavan disease (CD)] reportedly have increased urinary excretion of N-acetylaspartylglutamate (NAAG), a neuropeptide abundant in the brain. Whether elevated excretion of urinary NAAG is due to ASPA deficiency, resulting in an abnormal level of brain NAAG, is examined using ASPA-deficient mouse brain. The level of NAAG in the knockout mouse brain was similar to that in the wild type. The NAAG hydrolyzing enzyme, glutamate carboxypeptidase II (GCP II), activity was normal in the knockout mouse brain. These data suggest that ASPA deficiency does not affect the NAAG or GCP II level in the knockout mouse brain, if documented also in patients with CD.
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Affiliation(s)
- Sankar Surendran
- Department of Pediatrics, Childrens Hospital, The University of Texas Medical Branch, Rm# 3.350, Galveston, TX 77555-0359, USA
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Surendran S, Rady PL, Szucs S, Michals-Matalon K, Tyring SK, Matalon R. High level of orexin A observed in the phenylketonuria mouse brain is due to the abnormal expression of prepro-orexin. Biochem Biophys Res Commun 2004; 317:522-6. [PMID: 15063788 DOI: 10.1016/j.bbrc.2004.03.079] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2004] [Indexed: 11/22/2022]
Abstract
Orexins/hypocretins are recently discovered neuropeptides, synthesized mainly in the lateral hypothalamus of the brain. Orexins regulate various functions including sleep and apetite. We recently reported increased amount of orexin A in the phenylketonuria (PKU) mouse brain. Whether this is caused by overexpression of the precursor for orexins, prepro-orexin was studied in the PKU mouse brain. Microarray expression analysis revealed overexpression of orexin gene in the brain of PKU mouse. Quantitative real-time RT-PCR showed increased level of prepro-orexin mRNA in the PKU mouse brain. In addition, expression of genes associated with cell signal and growth regulation was also affected in the PKU mouse brain, as observed by microarray analysis. These data suggest that up-regulation of orexin mRNA expression is the possible factor for inducing high orexin A in the brain of PKU mouse. The metabolic environment in the brain of PKU mouse affects normal expression of other genes possibly to result in pathophysiology seen in the PKU mouse, if documented also in patients with PKU.
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Affiliation(s)
- Sankar Surendran
- Department of Pediatrics, University of Texas Medical Branch, Galveston, TX, USA
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17
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Surendran S, Ezell EL, Quast MJ, Wei J, Tyring SK, Michals-Matalon K, Matalon R. Mental retardation and hypotonia seen in the knock out mouse for Canavan disease is not due to succinate semialdehyde dehydrogenase deficiency. Neurosci Lett 2004; 358:29-32. [PMID: 15016427 DOI: 10.1016/j.neulet.2003.12.105] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2003] [Revised: 11/26/2003] [Accepted: 12/18/2003] [Indexed: 11/17/2022]
Abstract
Canavan disease (CD) is an autosomal recessive disorder caused by aspartoacylase deficiency leading to accumulation of N-acetylaspartic acid and spongy degeneration of the brain. The mouse model for CD showed low levels of glutamate and gamma-aminobutyric acid (GABA) in the brain. Whether the low levels of glutamate and GABA observed in the CD mouse brain lead to abnormal production of glutamate-GABA associated enzymes and resulting succinate production is not obvious. While glutamate dehydrogenase and alpha-ketoglutarate dehydrogenase complex activities are lower in the cerebellum and brain stem of the CD mouse, alanine aminotransferase and succinate semialdehyde dehydrogenase (SSADH) activities and succinate level are similar to the levels observed in the wild type. Deficiency of SSADH has been suggested to be associated with mental retardation and hypotonia, similar to the clinical features of CD. The normal SSADH activity in the CD mouse brain suggests that mental retardation and hypotonia seen in the CD mouse is not due to SSADH activity and if documented also in patients with CD.
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Affiliation(s)
- S Surendran
- Department of Pediatrics, Children's Hospital, The University of Texas Medical Branch, Galveston, TX 77555-0359, USA
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Surendran S, Michals-Matalon K, Quast MJ, Tyring SK, Wei J, Ezell EL, Matalon R. Canavan disease: a monogenic trait with complex genomic interaction. Mol Genet Metab 2003; 80:74-80. [PMID: 14567959 DOI: 10.1016/j.ymgme.2003.08.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Canavan disease (CD) is an inherited leukodystrophy, caused by aspartoacylase (ASPA) deficiency, and accumulation of N-acetylaspartic acid (NAA) in the brain. The gene for ASPA has been cloned and more than 40 mutations have been described, with two founder mutations among Ashkenazi Jewish patients. Screening of Ashkenazi Jews for these two common mutations revealed a high carrier frequency, approximately 1/40, so that programs for carrier testing are currently in practice. The enzyme deficiency in CD interferes with the normal hydrolysis of NAA, which results in disruption of myelin and spongy degeneration of the white matter of the brain. The clinical features of the disease are macrocephaly, head lag, progressive severe mental retardation, and hypotonia in early life, which later changes to spasticity. A knockout mouse for CD has been generated, and used to study the pathophysiological basis for CD. Findings from the knockout mouse indicate that this monogenic trait leads to a series of genomic interaction in the brain. Changes include low levels of glutamate and GABA. Microarray expression analysis showed low level of expression of GABA-A receptor (GABRA6) and glutamate transporter (EAAT4). The gene Spi2, a gene involved in apoptosis and cell death, showed high level of expression. Such complexity of gene interaction results in the phenotype, the proteome, with spongy degeneration of the brain and neurological impairment of the mouse, similar to the human counterpart. Aspartoacylase gene transfer trial in the mouse brain using adenoassociated virus (AAV) as a vector are encouraging showing improved myelination and decrease in spongy degeneration in the area of the injection and also beyond that site.
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Affiliation(s)
- Sankar Surendran
- Department of Pediatrics, Children's Hospital, The University of Texas Medical Branch, Galveston, TX 77555-0359, USA
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