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Abdulkadir Kocak, Muslum Yildiz
The disruption of aspartoacylase enzyme's catalytic activity causes fatal neurodegenerative Canavan disease. By molecular dynamics and docking methods, here we studied two deleterious mutations that have been identified in the Canavan patients' genotype E285A, F295S, and revealed the possible cause for the enzyme inhibition due to the drastic changes in active site dynamics, loss of interactions among Arg 71, Arg 168 and the substrate and pKa value of critical Glu178 residue. In addition to changes in the enzyme dynamics, free energy calculations show that the binding energy of substrate decreases dramatically up on mutations...
March 19, 2017: Journal of Molecular Graphics & Modelling
Eduard H Panosyan, Henry J Lin, Jan Koster, Joseph L Lasky
BACKGROUND: Amino acid (AA) pathways may contain druggable targets for glioblastoma (GBM). Literature reviews and GBM database ( ) analyses were carried out to screen for such targets among 95 AA related enzymes. METHODS: First, we identified the genes that were differentially expressed in GBMs (3 datasets) compared to non-GBM brain tissues (5 datasets), or were associated with survival differences. Further, protein expression for these enzymes was also analyzed in high grade gliomas (HGGs) (proteinatlas...
February 28, 2017: BMC Cancer
Dominic J Gessler, Danning Li, Hongxia Xu, Qin Su, Julio Sanmiguel, Serafettin Tuncer, Constance Moore, Jean King, Reuben Matalon, Guangping Gao
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...
February 9, 2017: JCI Insight
V K Kimiskidis, Vasileios Papaliagkas, S Papagiannopoulos, D Zafeiriou, D Kazis, E Tsatsali-Foroglou, Z Kouvatsou, V Kapina, D Koutsonikolas, G Anogianakis, T Geroukis, S Bostantjopoulou
Canavan's disease (CD) is a hereditary leukodystrophy caused by mutations in the aspartoacylase gene (ASPA), leading to spongiform degeneration of the white matter and severe impairment of psychomotor development. We present the cases of two non-Jewish sisters with CD that have a milder and protracted clinical course compared to typical CD. MRI imaging revealed bilateral high-signal-intensity areas in the thalami and the internal capsule and MR spectroscopy showed typical findings for CD (a marked increase in N-acetylaspartate (NAA) levels)...
April 2017: Metabolic Brain Disease
Marisa I Mendes, Desirée Ec Smith, Ana Pop, Pascal Lennertz, Matilde R Fernandez Ojeda, Warsha A Kanhai, Silvy Jm van Dooren, Yair Anikster, Ivo Barić, Caroline Boelen, Jaime Campistol, Lonneke de Boer, Ariana Kariminejad, Hulya Kayserili, Agathe Roubertie, Krijn T Verbruggen, Christine Vianey-Saban, Monique Williams, Gajja S Salomons
We describe 14 patients with 12 novel missense mutations in ASPA, the gene causing Canavan disease (CD). We developed a method to study the effect of these 12 variants on the function of aspartoacylase-the hydrolysis of N-acetyl-l-aspartic acid (NAA) to aspartate and acetate. The wild-type ASPA open reading frame (ORF) and the ORFs containing each of the variants were transfected into HEK293 cells. Enzyme activity was determined by incubating cell lysates with NAA and measuring the released aspartic acid by LC-MS/MS...
May 2017: Human Mutation
Jiho Sohn, Peter Bannerman, Fuzheng Guo, Travis Burns, Laird Miers, Christopher Croteau, Naveen K Singhal, Jennifer A McDonough, David Pleasure
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...
January 11, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Bharani Thangavelu, Vinay Mutthamsetty, Qinzhe Wang, Ronald E Viola
Canavan disease is a fatal neurological disorder caused by defects in the metabolism of N-acetyl-l-aspartate (NAA). Recent work has shown that the devastating symptoms of this disorder are correlated with the elevated levels of NAA observed in these patients, caused as a consequence of the inability of mutated forms of aspartoacylase to adequately catalyze its breakdown. The membrane-associated enzyme responsible for the synthesis of NAA, aspartate N-acetyltransferase (ANAT), has recently been purified and examined (Wang et al...
December 8, 2016: Bioorganic & Medicinal Chemistry
Jiho Sohn, Peter Bannerman, Fuzheng Guo, Travis Burns, Laird Miers, Christopher Croteau, Naveen K Singhal, Jennifer A McDonough, David Pleasure
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...
December 2, 2016: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Jeremy S Francis, Ireneusz Wojtas, Vladimir Markov, Steven J Gray, Thomas J McCown, R Jude Samulski, Larissa T Bilaniuk, Dah-Jyuu Wang, Darryl C De Vivo, Christopher G Janson, Paola Leone
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...
December 2016: Neurobiology of Disease
N K Singhal, H Huang, S Li, R Clements, J Gadd, A Daniels, E E Kooijman, P Bannerman, T Burns, F Guo, D Pleasure, E Freeman, L Shriver, J McDonough
The neuronal mitochondrial metabolite N-acetylaspartate (NAA) is decreased in the multiple sclerosis (MS) brain. NAA is synthesized in neurons by the enzyme N-acetyltransferase-8-like (NAT8L) and broken down in oligodendrocytes by aspartoacylase (ASPA) into acetate and aspartate. We have hypothesized that NAA links the metabolism of axons with oligodendrocytes to support myelination. To test this hypothesis, we performed lipidomic analyses using liquid chromatography-tandem mass spectrometry (LC-MS/MS) and high-performance thin-layer chromatography (HPTLC) to identify changes in myelin lipid composition in postmortem MS brains and in NAT8L knockout (NAT8L(-/-)) mice which do not synthesize NAA...
October 5, 2016: Experimental Brain Research. Experimentelle Hirnforschung. Expérimentation Cérébrale
Ana I Amaral, Mussie Ghezu Hadera, Mark Kotter, Ursula Sonnewald
Oligodendroglial cells are known to de-acetylate the N-acetylaspartate (NAA) synthesized and released by neurons and use it for lipid synthesis. However, the role of NAA regarding their intermediary metabolism remains poorly understood. Two hypotheses were proposed regarding the fate of aspartate after being released by de-acetylation: (1) aspartate is metabolized in the mitochondria of oligodendrocyte lineage cells; (2) aspartate is released to the medium. We report here that aspartoacylase mRNA expression increases when primary rat oligodendrocyte progenitor cells (OPCs) differentiate into mature cells in culture...
March 2017: Neurochemical Research
Ekaterina D Kots, Maria G Khrenova, Sofya V Lushchekina, Sergei D Varfolomeev, Bella L Grigorenko, Alexander V Nemukhin
The complete catalytic cycle of aspartoacylase (ASPA), a zinc-dependent enzyme responsible for cleavage of N-acetyl-l-aspartate, is characterized by the methods of molecular modeling. The reaction energy profile connecting the enzyme-substrate (ES) and the enzyme-product (EP) complexes is constructed by the quantum mechanics/molecular mechanics (QM/MM) method assisted by the molecular dynamics (MD) simulations with the QM/MM potentials. Starting from the crystal structure of ASPA complexed with the intermediate analogue, the minimum-energy geometry configurations and the corresponding transition states are located...
May 12, 2016: Journal of Physical Chemistry. B
A Prokesch, H J Pelzmann, A R Pessentheiner, K Huber, C T Madreiter-Sokolowski, A Drougard, M Schittmayer, D Kolb, C Magnes, G Trausinger, W F Graier, R Birner-Gruenberger, J A Pospisilik, J G Bogner-Strauss
Histone acetylation depends on the abundance of nucleo-cytoplasmic acetyl-CoA. Here, we present a novel route for cytoplasmic acetyl-CoA production in brown adipocytes. N-acetylaspartate (NAA) is a highly abundant brain metabolite catabolized by aspartoacylase yielding aspartate and acetate. The latter can be further used for acetyl-CoA production. Prior to this work, the presence of NAA has not been described in adipocytes. Here, we show that accumulation of NAA decreases the brown adipocyte phenotype. We increased intracellular NAA concentrations in brown adipocytes via media supplementation or knock-down of aspartoacylase and measured reduced lipolysis, thermogenic gene expression, and oxygen consumption...
April 5, 2016: Scientific Reports
Seemin Seher Ahmed, Stefan A Schattgen, Ashley E Frakes, Elif M Sikoglu, Qin Su, Jia Li, Thomas G Hampton, Andrew R Denninger, Daniel A Kirschner, Brian Kaspar, Reuben Matalon, Guangping Gao
Aspartoacylase (AspA) gene mutations cause the pediatric lethal neurodegenerative Canavan disease (CD). There is emerging promise of successful gene therapy for CD using recombinant adeno-associated viruses (rAAVs). Here, we report an intracerebroventricularly delivered AspA gene therapy regime using three serotypes of rAAVs at a 20-fold reduced dose than previously described in AspA(-/-) mice, a bona-fide mouse model of CD. Interestingly, central nervous system (CNS)-restricted therapy prolonged survival over systemic therapy in CD mice but failed to sustain motor functions seen in systemically treated mice...
June 2016: Molecular Therapy: the Journal of the American Society of Gene Therapy
Ai Nishitani, Miyuu Tanaka, Saki Shimizu, Naofumi Kunisawa, Mayuko Yokoe, Yusaku Yoshida, Toshiro Suzuki, Tetsushi Sakuma, Takashi Yamamoto, Mitsuru Kuwamura, Shigeo Takenaka, Yukihiro Ohno, Takashi Kuramoto
Essential tremor (ET) is a common movement disorder with a poorly understood etiology. The TRM/Kyo mutant rat, showing spontaneous tremor, is an animal model of ET. Recently, we demonstrated that tremors in these rats emerge when two mutant loci, a missense mutation in the hyperpolarization-activated cyclic nucleotide-gated potassium channel 1 (Hcn1) and the tremor (tm) deletion, are present simultaneously. However, we did not identify which gene within the tm deletion causes tremor expression in TRM/Kyo rats...
July 29, 2016: Experimental Animals
Vykuntaraju K Gowda, Maya D Bhat, Varun M Srinivasan, Chandrajit Prasad, Asha Benakappa, Mohammed Faruq
BACKGROUND: Canavan disease is an autosomal recessive disorder with spongy degeneration of white matter of the brain. It presents with developmental delay, visual problems and macrocephaly. PATIENT DESCRIPTION: We report a ten-month old boy with Canavan disease who presented with global developmental delay, seizures, abnormal eye movements and microcephaly. RESULTS: MRI brain revealed diffuse involvement of the supra tentorial white matter, globus pallidi, thalami, dentate nuclei and brainstem with sparing of the corpus callosum...
September 2016: Brain & Development
Navaneethakrishnan Krishnamoorthy, Hatem Zayed
Aspartoacylase (ASPA) is an abundant enzyme in the brain, which catalyzes the conversion of N-acetylaspartate into acetate and aspartate, deficiency in its activity leads to degeneration of the white matter of the brain and is a recognized cause of Canavan disease (CD), which affect children. Although genotype-phenotype correlation have been reported for Canavan disease patients, this relationships is still not straightforward. In this communication, we use molecular modeling to address the structural consequences resulting from the missense variant p...
June 2016: Metabolic Brain Disease
Jennifer Butenschön, Tina Zimmermann, Nikolai Schmarowski, Robert Nitsch, Barbara Fackelmeier, Kevin Friedemann, Konstantin Radyushkin, Jan Baumgart, Beat Lutz, Julia Leschik
BACKGROUND: Neural stem cells for the treatment of spinal cord injury (SCI) are of particular interest for future therapeutic use. However, until now, stem cell therapies are often limited due to the inhibitory environment following the injury. Therefore, in this study, we aimed at testing a combinatorial approach with BDNF (brain-derived neurotrophic factor) overexpressing early neural progenitors derived from mouse embryonic stem cells. BDNF is a neurotrophin, which both facilitates neural differentiation of stem cells and favors regeneration of damaged axons...
January 13, 2016: Stem Cell Research & Therapy
Mahmoudreza Ashrafi, Alireza Tavasoli, Pegah Katibeh, Omid Aryani, Mohammad Vafaee-Shahi
Objective Canavan disease (CD) is a type of vacuolating leukodystrophy with autosomal recessive inheritance. Aspartoacylase deficiency results in decrease of myelin biosynthesis, dysmyelination and brain edema. Although CD is a very common in Ashkenazi Jews patients, several cases have been reported from non-Jewish population. This report is based on a homozygous C.202G>A mutation in the ASPA gene identified from an Iranian patient. To our knowledge, this type of mutation has not been reported in non-Jewish population in the literature...
2015: Iranian Journal of Child Neurology
Catherine Sarret, Odile Boespflug-Tanguy, Diana Rodriguez
Canavan disease (CD) is a rare metabolic disorder caused by aspartoacylase (ASPA) deficiency. It leads to severe neurological degeneration with spongiform brain degeneration. Accumulation of N-acetylaspartate (NAA) in brain and urine is specific to the disease and guides diagnosis. Magnetic resonance imaging (MRI) usually shows diffuse white matter abnormalities with involvement of the basal ganglia. Mild forms of the disease with a more favorable clinical course and radiological involvement of the basal ganglia without white matter abnormalities have also been reported...
April 2016: Metabolic Brain Disease
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