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Xu F, Wu Y, Huang J, Zhou Y, Xu F, Duan J, Li H. Case report: A novel 5'-UTR-exon1-intron1 deletion in MLYCD in an IVF child with malonyl coenzyme A decarboxylase deficiency and literature review. Front Med (Lausanne) 2023; 10:1160879. [PMID: 37206471 PMCID: PMC10189016 DOI: 10.3389/fmed.2023.1160879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Accepted: 04/07/2023] [Indexed: 05/21/2023] Open
Abstract
The subject of the study is an 11-month old IVF baby girl with the typical clinical manifestation of malonyl coenzyme A decarboxylase deficiency, including developmental delay, limb weakness, cardiomyopathy, and excessive excretion of malonic acid and methylmalonic acid. Whole genome sequencing (WGS) revealed a novel heterozygous nonsense mutation (c.672delG, p.Trp224Ter) in the MLYCD gene of the proband and her father and a novel heterozygous deletion in 5'-UTR-exon1-intron1 of the MLYCD gene of the proband and her mother. The patient's cardiac function and limb weakness improved considerably after 3 months of a low-fat diet supplemented with L-carnitine. Furthermore, mapping of gene mutations and clinical manifestations was done by case collection.
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Affiliation(s)
- Fang Xu
- Cardiology Treatment Center, Jiangxi Provincial Children's Hospital, Nanchang, China
- JXHC Key Laboratory of Children's Cardiovascular Diseases, Jiangxi Provincial Children's Hospital, Nanchang, China
| | - Yangyang Wu
- Cardiology Treatment Center, Jiangxi Provincial Children's Hospital, Nanchang, China
- Pediatric Medical Department, Nanchang University, Nanchang, China
| | - Jiyi Huang
- JXHC Key Laboratory of Children's Cardiovascular Diseases, Jiangxi Provincial Children's Hospital, Nanchang, China
| | - Yunguo Zhou
- Cardiology Treatment Center, Jiangxi Provincial Children's Hospital, Nanchang, China
- JXHC Key Laboratory of Children's Cardiovascular Diseases, Jiangxi Provincial Children's Hospital, Nanchang, China
| | - Fei Xu
- Cardiology Treatment Center, Jiangxi Provincial Children's Hospital, Nanchang, China
- JXHC Key Laboratory of Children's Cardiovascular Diseases, Jiangxi Provincial Children's Hospital, Nanchang, China
| | - Junkai Duan
- Cardiology Treatment Center, Jiangxi Provincial Children's Hospital, Nanchang, China
- JXHC Key Laboratory of Children's Cardiovascular Diseases, Jiangxi Provincial Children's Hospital, Nanchang, China
- *Correspondence: Junkai Duan
| | - Hong Li
- JXHC Key Laboratory of Children's Cardiovascular Diseases, Jiangxi Provincial Children's Hospital, Nanchang, China
- Hong Li
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Zhao C, Peng H, Jiang N, Liu Y, Chen Y, Liu J, Guo Q, Wu Z, Wang L. A case of malonyl coenzyme A decarboxylase deficiency with novel mutations and literature review. Front Pediatr 2023; 11:1133134. [PMID: 37144154 PMCID: PMC10152364 DOI: 10.3389/fped.2023.1133134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 03/24/2023] [Indexed: 05/06/2023] Open
Abstract
Introduction Malonyl coenzyme A decarboxylase deficiency is caused by an abnormality in the MLYCD gene. The clinical manifestations of the disease involve multisystem and multiorgan. Methods We collected and analyzed a patient's clinical characteristics, genetic chain of evidence and RNA-seq. We use the search term "Malonyl-CoA Decarboxylase Deficiency" on Pubmed to collect cases reported. Results We report a 3-year-old girl who is presented with developmental retardation, myocardial damage and elevated C3DC. High-throughput sequencing identified heterozygous mutation (c.798G>A, p.Q266?) in the patient inherited from her father. The other heterozygous mutation (c.641+5G>C) was found in the patient inherited from her mother. RNA-seq showed that there were 254 differential genes in this child, among which 153 genes were up-regulated and 101 genes were down-regulated. Exon jumping events occurred in exons encoding PRMT2 on the positive chain of chromosome 21, which led to abnormal splicing of PRMT2. (P<0.05, FDR<0.05). The result of SNP showed that there were multiple mutation sites on chromosome 1, which may affect the downstream gene variation at the DNA level. The literature review identified 54 cases described since 1984. Discussion It is the first report about the locus, adding a new item to the MLYCD mutation library. Developmental retardation and cardiomyopathy are the most common clinical manifestations, with commonly elevated malonate and malonyl carnitine levels in children.
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Affiliation(s)
- Cong Zhao
- Department of Pediatrics, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Hua Peng
- Department of Pediatrics, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Nanchuan Jiang
- Department of Radiology,Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yalan Liu
- Department of Pediatrics, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yan Chen
- Department of Pediatrics, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jie Liu
- Department of Pediatrics, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Qing Guo
- Department of Pediatrics, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zubo Wu
- Department of Pediatrics, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lin Wang
- Department of Pediatrics, Wuhan Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Salomons GS, Jakobs C, Pope LL, Errami A, Potter M, Nowaczyk M, Olpin S, Manning N, Raiman JAJ, Slade T, Champion MP, Peck D, Gavrilov D, Hillman R, Hoganson GE, Donaldson K, Shield JPH, Ketteridge D, Wasserstein M, Gibson KM. Clinical, enzymatic and molecular characterization of nine new patients with malonyl-coenzyme A decarboxylase deficiency. J Inherit Metab Dis 2007; 30:23-8. [PMID: 17186413 DOI: 10.1007/s10545-006-0514-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/16/2006] [Revised: 12/01/2006] [Accepted: 12/04/2006] [Indexed: 10/23/2022]
Abstract
We report nine new patients with malonic aciduria associated with enzyme-confirmed malonyl-CoA decarboxylase (MCD) deficiency in eight. Clinical details were available on eight, and molecular genetic characterization was obtained for nine. As for 15 previously described patients, cardinal clinical manifestations included developmental delay and cardiomyopathy; metabolic perturbations (e.g. acidosis) and seizures, however, were infrequent or not observed in our patients. For all, detection of elevated malonic acid in urine (+/- increased C3DC acylcarnitine by analysis employing tandem mass spectrometry) led to pursuit of enzyme studies. MCD activities (nmol/h PER mg protein) revealed: control (n = 22), 16.2 +/- 1.8 (SEM; range 5.7-46.2); patients (n = 8, assayed in duplicate), 1.7 +/- 0.3 (10% of parallel control; range 0.6-2.8). Molecular characterization by DNA sequence analysis and multiplex ligation-dependent probe amplification revealed nine novel mutations (c.796C>T; p.Gln266X, c.481delC; p.Leu161CysfsX18, c.1367A>C; p.Tyr456Ser, c.1319G>T; p.Ser440Ile, c.1430C>T; p.Ser477Phe, c.899G>T; p.Gly300Val, c.799-1683_949-1293del3128, and two other large genomic deletions comprising exons 1 or the complete gene) and two known mutations in the MLYCD gene. Our findings increase the number of enzyme-confirmed MCD-deficient patients by >50%, and expand our understanding of the phenotypic and molecular heterogeneity of this rare disorder.
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Affiliation(s)
- G S Salomons
- Department of Clinical Chemistry, Metabolic Unit, VU University Medical Center, Amsterdam, The Netherlands
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4
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Wallace DM, Haramura M, Cheng JF, Arrhenius T, Nadzan AM. Novel trifluoroacetophenone derivatives as malonyl-CoA decarboxylase inhibitors. Bioorg Med Chem Lett 2007; 17:1127-30. [PMID: 17234415 DOI: 10.1016/j.bmcl.2006.09.023] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2006] [Revised: 09/07/2006] [Accepted: 09/08/2006] [Indexed: 10/23/2022]
Abstract
A series of trifluoroacetophenone derivatives were prepared and evaluated as malonyl-CoA decarboxylase (MCD) inhibitors. Some of the 'reverse amide' analogs were found to be potent inhibitors of MCD enzyme activity. The trifluoroacetyl group may interact with the MCD active site as the hydrate in a similar fashion to the hexafluoroisopropanol analogs reported previously. Adding electron-withdrawing groups to the phenyl ring stabilizes the hydrated species and enhances this interaction.
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Affiliation(s)
- David M Wallace
- Department of Chemistry, Chugai Pharma USA, LLC., 6275 Nancy Ridge Dr., San Diego, CA 92121, USA.
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5
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Cheng JF, Huang Y, Penuliar R, Nishimoto M, Liu L, Arrhenius T, Yang G, O'leary E, Barbosa M, Barr R, Dyck JRB, Lopaschuk GD, Nadzan AM. Discovery of potent and orally available malonyl-CoA decarboxylase inhibitors as cardioprotective agents. J Med Chem 2006; 49:4055-8. [PMID: 16821767 DOI: 10.1021/jm0605029] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Discovery of 5-(1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)-4,5-dihydroisoxazole-3-carboxamides as a new class of malonyl-coenzyme A decarboxylase (MCD) inhibitors is described. tert-Butyl 3-(5-(1,1,1,3,3,3-hexafluoro-2-hydroxypropan-2-yl)-4,5-dihydroisoxazole-3-carboxamido)butanoate (5, CBM-301940) exhibited excellent potency and in vivo PK/ADME properties. It is the most powerful stimulant of glucose oxidation reported to date in isolated working rat hearts. Compound 5 improved the cardiac efficiency and function in a rat heart global ischemia/reperfusion model, suggesting MCD inhibitors may be useful for the treatment of ischemic heart diseases.
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Affiliation(s)
- Jie-Fei Cheng
- Department of Chemistry, Chugai Pharma USA, LLC., 6275 Nancy Ridge Drive, San Diego, California 92121, USA.
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6
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Nam HW, Lee GY, Kim YS. Mass spectrometric identification of K210 essential for rat malonyl-CoA decarboxylase catalysis. J Proteome Res 2006; 5:1398-406. [PMID: 16739991 DOI: 10.1021/pr050487g] [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] [Indexed: 11/30/2022]
Abstract
Proteomic technology provides useful tools to detect protein modification sites in vivo and in vitro. In this work, we applied proteomics to identify an essential amino acid residue involved in Malonyl-CoA Decarboxylase (MCD) catalysis. A reaction with acetic anhydride and MCD, under mild conditions without acetyl CoA as a substrate, resulted in the acetylation of six lysyl residues, K210, K58, K167, K316, K388, and K444. When acetyl CoA was added to the reaction, K210 was protected from acetylation, indicating a potential role for this residue in catalysis. In addition, K210 was the only lysyl residue, out of six, that was not endogenously acetylated. Because K210, K308, and K388 are conserved across species, they were site-specifically mutated to methionine which is size-wise similar to lysine but not protonated. The K308M and K388M MCD mutants retained 60% of their enzyme activities, whereas the K210M mutant was completely inactive. These results strongly suggest that K210 is an essential residue in rat MCD catalysis and is a likely proton donor to the alpha carbon of malonyl-CoA. Therapeutic inhibition of MCD may be a viable approach to treating various clinical pathologies associated with defective fatty acid metabolism.
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Affiliation(s)
- Hyung Wook Nam
- Department of Biochemistry, College of Science, Protein Network Research Center, Yonsei University, Seoul, Korea 120-749
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Cheng JF, Mak CC, Huang Y, Penuliar R, Nishimoto M, Zhang L, Chen M, Wallace D, Arrhenius T, Chu D, Yang G, Barbosa M, Barr R, Dyck JRB, Lopaschuk GD, Nadzan AM. Heteroaryl substituted bis-trifluoromethyl carbinols as malonyl-CoA decarboxylase inhibitors. Bioorg Med Chem Lett 2006; 16:3484-8. [PMID: 16644218 DOI: 10.1016/j.bmcl.2006.03.100] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2006] [Accepted: 03/30/2006] [Indexed: 01/09/2023]
Abstract
A series of heteroaryl-substituted bis-trifluoromethyl carbinols were prepared and evaluated as malonyl-CoA decarboxylase (MCD) inhibitors. Some thiazole-based derivatives showed potent in vitro MCD inhibitory activities and significantly increased glucose oxidation rates in isolated working rat hearts.
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Affiliation(s)
- Jie-Fei Cheng
- Department of Chemistry and Discovery Biology, Chugai Pharma LLC., 6275 Nancy Ridge Dr., San Diego, CA 92121, USA.
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8
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Cheng JF, Chen M, Liu B, Hou Z, Arrhenius T, Nadzan AM. Design and synthesis of heterocyclic malonyl-CoA decarboxylase inhibitors. Bioorg Med Chem Lett 2006; 16:695-700. [PMID: 16257202 DOI: 10.1016/j.bmcl.2005.10.020] [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: 08/20/2005] [Revised: 10/06/2005] [Accepted: 10/07/2005] [Indexed: 10/25/2022]
Abstract
We have previously reported the discovery of small molecule inhibitors of malonyl-CoA decarboxylase (MCD) as novel metabolic modulators, which inhibited fatty acid oxidation and consequently increased the glucose oxidation rates in the isolated working rat hearts. MCD inhibitors were also shown to improve cardiac efficiency in rat and pig demand-induced ischemic models through the mechanism-based modulation of energy metabolism. Herein, we describe the design and synthesis of a series of novel heterocyclic MCD inhibitors with a preference for substituted imidazole and isoxazole.
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Affiliation(s)
- Jie-Fei Cheng
- Department of Chemistry, Chugai Pharma USA, LLC, 6275 Nancy Ridge Drive, San Diego, CA 92121, USA.
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Surendran S, Kondapaka SB. Altered expression of neuronal nitric oxide synthase in the duodenum longitudinal muscle-myenteric plexus of obesity induced diabetes mouse: implications on enteric neurodegeneration. Biochem Biophys Res Commun 2005; 338:919-22. [PMID: 16256069 DOI: 10.1016/j.bbrc.2005.10.039] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2005] [Accepted: 10/07/2005] [Indexed: 12/11/2022]
Abstract
Type 2 diabetes caused by obesity shows autonomic neuropathy. Molecular mechanism involved in enteric neurodegeneration is not clear. Neuronal nitric oxide synthase (nNOS) is one of the important agents involved in gastrointestinal function. Therefore, expression of nNOS in the duodenum LM-MP of type 2 diabetes model mouse was studied. Real time RT-PCR analysis showed reduction in nNOS expression in male diabetic LM-MP compared to male control. In contrast, female diabetic LM-MP had high level of nNOS mRNA compared to female control. Western blot determination of LM-MP showed reduction in nNOS protein in male diabetic LM-MP and high level of nNOS in female diabetic LM-MP compared to their respective controls. Expression of nNOS observed by Western blot was further confirmed by nNOS immunostaining of the mouse duodenum. TUNEL staining of mouse duodenum showed apoptosis in male diabetic enteric neurons. These studies suggest that nNOS expression in LM-MP varies with gender during early stage of type 2 diabetes. In addition, reduced expression of nNOS is likely to contribute to apoptosis seen in the enteric neurons of male type 2 diabetic mice.
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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, Tyring SK, Matalon R. Expression of calpastatin, minopontin, NIPSNAP1, rabaptin-5 and neuronatin in the phenylketonuria (PKU) mouse brain: Possible role on cognitive defect seen in PKU. Neurochem Int 2005; 46:595-9. [PMID: 15863237 DOI: 10.1016/j.neuint.2005.02.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2004] [Revised: 02/18/2005] [Accepted: 02/28/2005] [Indexed: 11/29/2022]
Abstract
Phenylketonuria (PKU) is an inborn error of amino acid metabolism. Phenylalanine hydroxylase (PAH) deficiency results in accumulation of phenylalanine (Phe) in the brain and leads to pathophysiological abnormalities including cognitive defect, if Phe diet is not restricted. Neuronatin and 4-nitrophenylphosphatase domain and non-neuronal SNAP25-like protein homolog 1 (NIPSNAP1) reportedly have role in memory. Therefore, gene expression was examined in the brain of mouse model for PKU. Microarray expression analysis revealed reduced expression of calpastatin, NIPSNAP 1, rabaptin-5 and minopontin genes and overexpression of neuronatin gene in the PKU mouse brain. Altered expression of these genes was further confirmed by one-step real time RT-PCR analysis. Western blot analysis of the mouse brain showed reduced levels of calpastatin and rabaptin-5 and higher amount of neuronatin in PKU compared to the wild type. These observations in the PKU mouse brain suggest that altered expression of these genes resulting in abnormal proteome. These changes in the PKU mouse brain are likely to contribute cognitive impairment seen in the PKU 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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Wightman PJ, Santer R, Ribes A, Dougherty F, McGill N, Thorburn DR, FitzPatrick DR. MLYCD mutation analysis: evidence for protein mistargeting as a cause of MLYCD deficiency. Hum Mutat 2003; 22:288-300. [PMID: 12955715 DOI: 10.1002/humu.10264] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Malonyl-CoA decarboxylase (MLYCD) deficiency is an autosomal recessive disorder characterized by malonic aciduria, developmental delay, seizure disorder, hypoglycemia, and cardiomyopathy. Genomic sequencing of MLYCD in nine unrelated patients identified 16 of 18 pathogenic alleles, which are documented in the newly created Human MLYCD Allelic Variant Database (http://mlycd.hgu.mrc.ac.uk/). Fibroblast cell lines were available from eight of these patients and two previously reported patients with homozygous MLYCD mutations. Western blot analysis using antisera raised to a C-terminal peptide detected a 66-kDa band that was absent in six patients and substantially reduced in three patients. One patient showed an increase in protein levels with a prominent smeary 68-l83-kDa band. Immunocytochemical analysis of MLYCD-expressing patient cell lines showed apparent intracellular mislocalization. An extreme N-terminal mutation c.8G>A (p.G3D) mislocalized to the plasma membrane, suggesting that a novel targeting signal may reside in a four-amino acid conserved N-terminal motif. A 25-base deletion between the putative mitochondrial and peroxisomal initiating codons (M1 and M40) and a point mutation ablating the second of these (c.119T>C, p.M40T) both showed punctate perinuclear staining. As none of the three mislocalizing mutations are predicted to alter the catalytic function of the peptide, it seems likely that correct subcellular localization of MLYCD is critical for it to function normally.
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Affiliation(s)
- P J Wightman
- Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh, UK
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Matalon R, Surendran S, Rady PL, Quast MJ, Campbell GA, Matalon KM, Tyring SK, Wei J, Peden CS, Ezell EL, Muzyczka N, Mandel RJ. Adeno-associated virus-mediated aspartoacylase gene transfer to the brain of knockout mouse for canavan disease. Mol Ther 2003; 7:580-7. [PMID: 12718900 DOI: 10.1016/s1525-0016(03)00066-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Canavan disease (CD) is an autosomal recessive leukodystrophy caused by deficiency of aspartoacylase (ASPA). Deficiency of ASPA leads to elevation of N-acetyl-L-aspartic acid (NAA) in the brain and urine. To explore the feasibility of gene transfer to replace ASPA in CD, we generated a knockout mouse and constructed an AAV vector that encodes human ASPA cDNA (hASPA) followed by green fluorescent protein (GFP) after an intraribosomal entry site. We injected CD mice with rAAV-hASPA-GFP in the striatum and thalamus or injected rAAV-GFP identically into control animals. Three to five months after the injection, we determined the presence of ASPA in the CD mouse brain by ASPA activity assay, GFP expression, and Western blot analysis. While rAAV-GFP-injected animals displayed undetectable levels of ASPA, all detection methods revealed significant ASPA levels in rAAV-hASPA-GFP-injected CD mice. We evaluated the functional effects of rAAV-hASPA-GFP-mediated ASPA expression by standard histological methods, magnetic resonance spectroscopy (MRS) for in vivo NAA levels, and magnetic resonance imaging of CD mice. rAAV-hASPA-injected animals displayed a remarkable lack of spongiform degeneration in the thalamus. However, pathology in sites unrelated to the injected areas showed no improvement in histopathology. The improvement in thalamic neuropathology was also detectable via in vivo MRI. MRS revealed that in vivo NAA levels were also reduced. These data indicate that rAAV-mediated ASPA delivery may be an interesting avenue for the treatment of CD.
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Affiliation(s)
- Reuben Matalon
- Department of Pediatrics, Galveston, Texas 77555-0359, USA.
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Santer R, Fingerhut R, Lässker U, Wightman PJ, Fitzpatrick DR, Olgemöller B, Roscher AA. Tandem mass spectrometric determination of malonylcarnitine: diagnosis and neonatal screening of malonyl-CoA decarboxylase deficiency. Clin Chem 2003; 49:660-2. [PMID: 12651823 DOI: 10.1373/49.4.660] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- René Santer
- Department of Pediatrics, University of Kiel, Germany.
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