The Experts below are selected from a list of 102 Experts worldwide ranked by ideXlab platform
James M. Wilson - One of the best experts on this subject based on the ideXlab platform.
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Efficient Mitochondrial Import of Newly Synthesized Ornithine Transcarbamylase (OTC) and Correction of Secondary Metabolic Alterations in spf^ash Mice following Gene Therapy of OTC Deficiency
Molecular Medicine, 1999Co-Authors: Klaus Peter Zimmer, Masataka Mori, Meike Bendiks, Eiki Kominami, Michael B. Robinson, James M. WilsonAbstract:Background The mouse strain sparse fur with abnormal skin and hair (spf^ash) is a model for the human ornithine transcarbamylase (OTC) deficiency, an X-linked inherited urea cycle disorder. The spf^ash mouse carries a single base-pair mutation in the OTC gene that leads to the production of OTC Enzyme at 10% of the normal level. Materials and Methods Recombinant adenoviruses carrying either mouse (Ad.mOTC) or human (Ad.hOTC) OTC cDNA were injected intravenously into the spf^ash mice. Expression of OTC Enzyme Precursor and its translocation to mitochondria in the vector-transduced hepatocytes were analyzed on an ultrastructural level. Liver OTC activity and mitochondrial OTC concentration were significantly increased (300% of normal) in mice treated with Ad.mOTC and were moderately increased in mice receiving Ad.hOTC (34% of normal). The concentration and subcellular location of OTC and associated Enzymes were studied by electron microscope immunolocalization and quantitative morphometry. Results Cytosolic OTC concentration remained unchanged in Ad.mOTC-injected mice but was significantly increased in mice receiving Ad.hOTC, suggesting a block of mitochondria translocation for the human OTC Precursor. Mitochondrial ATPase subunit c [ATPase(c)] was significantly reduced and mitochondrial carbamyΔphosphate synthetase I (CPSI) was significantly elevated in spf^ash mice relative to C3H. In Ad.mOTC-treated mice, the hepatic mitochondrial concentration of ATPase(c) was completely normalized and the CPSI concentration was partially corrected. Conclusions Taken together, we conclude that newly synthesized mouse OTC Enzyme was efficiently imported into mitochondria following vector-mediated gene delivery in spf^ash mice, correcting secondary metabolic alterations.
Meike Bendiks - One of the best experts on this subject based on the ideXlab platform.
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Efficient Mitochondrial Import of Newly Synthesized Ornithine Transcarbamylase (OTC) and Correction of Secondary Metabolic Alterations in spf^ash Mice following Gene Therapy of OTC Deficiency
Molecular Medicine, 1999Co-Authors: Klaus Peter Zimmer, Masataka Mori, Meike Bendiks, Eiki Kominami, Michael B. Robinson, James M. WilsonAbstract:Background The mouse strain sparse fur with abnormal skin and hair (spf^ash) is a model for the human ornithine transcarbamylase (OTC) deficiency, an X-linked inherited urea cycle disorder. The spf^ash mouse carries a single base-pair mutation in the OTC gene that leads to the production of OTC Enzyme at 10% of the normal level. Materials and Methods Recombinant adenoviruses carrying either mouse (Ad.mOTC) or human (Ad.hOTC) OTC cDNA were injected intravenously into the spf^ash mice. Expression of OTC Enzyme Precursor and its translocation to mitochondria in the vector-transduced hepatocytes were analyzed on an ultrastructural level. Liver OTC activity and mitochondrial OTC concentration were significantly increased (300% of normal) in mice treated with Ad.mOTC and were moderately increased in mice receiving Ad.hOTC (34% of normal). The concentration and subcellular location of OTC and associated Enzymes were studied by electron microscope immunolocalization and quantitative morphometry. Results Cytosolic OTC concentration remained unchanged in Ad.mOTC-injected mice but was significantly increased in mice receiving Ad.hOTC, suggesting a block of mitochondria translocation for the human OTC Precursor. Mitochondrial ATPase subunit c [ATPase(c)] was significantly reduced and mitochondrial carbamyΔphosphate synthetase I (CPSI) was significantly elevated in spf^ash mice relative to C3H. In Ad.mOTC-treated mice, the hepatic mitochondrial concentration of ATPase(c) was completely normalized and the CPSI concentration was partially corrected. Conclusions Taken together, we conclude that newly synthesized mouse OTC Enzyme was efficiently imported into mitochondria following vector-mediated gene delivery in spf^ash mice, correcting secondary metabolic alterations.
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Efficient Mitochondrial ImportofNewly Synthesized Ornithine Transcarbamylase (OTC) andCorrection ofSecondary Metabolic Alterations inSpfash Micefollowing Gene TherapyofOTC Deficiency
1999Co-Authors: Meike BendiksAbstract:Background: Themousestrain sparse furwithabnormalskinandhair(Spfash) isamodelforthehuman ornithine transcarbamylase (OTC)deficiency, an X-linked inherited ureacycle disorder. Thespfsh mouse carries asingle base-pair mutation intheOTCgenethat leads totheproduction ofOTCEnzymeat10%ofthe normal level. Materials andMethods:Recombinant adenovirusescarrying either mouse(Ad.mOTC) orhuman (Ad.hOTC) OTCcDNAwereinjected intravenously intotheSpfash mice.Expression ofOTC Enzyme Precursor anditstranslocation tomitochondria in thevector-transduced
Klaus Peter Zimmer - One of the best experts on this subject based on the ideXlab platform.
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Efficient Mitochondrial Import of Newly Synthesized Ornithine Transcarbamylase (OTC) and Correction of Secondary Metabolic Alterations in spf^ash Mice following Gene Therapy of OTC Deficiency
Molecular Medicine, 1999Co-Authors: Klaus Peter Zimmer, Masataka Mori, Meike Bendiks, Eiki Kominami, Michael B. Robinson, James M. WilsonAbstract:Background The mouse strain sparse fur with abnormal skin and hair (spf^ash) is a model for the human ornithine transcarbamylase (OTC) deficiency, an X-linked inherited urea cycle disorder. The spf^ash mouse carries a single base-pair mutation in the OTC gene that leads to the production of OTC Enzyme at 10% of the normal level. Materials and Methods Recombinant adenoviruses carrying either mouse (Ad.mOTC) or human (Ad.hOTC) OTC cDNA were injected intravenously into the spf^ash mice. Expression of OTC Enzyme Precursor and its translocation to mitochondria in the vector-transduced hepatocytes were analyzed on an ultrastructural level. Liver OTC activity and mitochondrial OTC concentration were significantly increased (300% of normal) in mice treated with Ad.mOTC and were moderately increased in mice receiving Ad.hOTC (34% of normal). The concentration and subcellular location of OTC and associated Enzymes were studied by electron microscope immunolocalization and quantitative morphometry. Results Cytosolic OTC concentration remained unchanged in Ad.mOTC-injected mice but was significantly increased in mice receiving Ad.hOTC, suggesting a block of mitochondria translocation for the human OTC Precursor. Mitochondrial ATPase subunit c [ATPase(c)] was significantly reduced and mitochondrial carbamyΔphosphate synthetase I (CPSI) was significantly elevated in spf^ash mice relative to C3H. In Ad.mOTC-treated mice, the hepatic mitochondrial concentration of ATPase(c) was completely normalized and the CPSI concentration was partially corrected. Conclusions Taken together, we conclude that newly synthesized mouse OTC Enzyme was efficiently imported into mitochondria following vector-mediated gene delivery in spf^ash mice, correcting secondary metabolic alterations.
Arnold J. J. Reuser - One of the best experts on this subject based on the ideXlab platform.
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structural modeling of mutant α glucosidases resulting in a processing transport defect in pompe disease
Journal of Human Genetics, 2009Co-Authors: Kanako Sugawara, Marian A. Kroos, Arnold J. J. Reuser, Seiji Saito, Masakazu Sekijima, Kazuki Ohno, Youichi Tajima, Hitoshi SakurabaAbstract:To elucidate the mechanism underlying transport and processing defects from the viewpoint of Enzyme folding, we constructed three-dimensional models of human acid alpha-glucosidase encompassing 27 relevant amino acid substitutions by means of homology modeling. Then, we determined in each separate case the number of affected atoms, the root-mean-square distance value and the solvent-accessible surface area value. The analysis revealed that the amino acid substitutions causing a processing or transport defect responsible for Pompe disease were widely spread over all of the five domains comprising the acid alpha-glucosidase. They were distributed from the core to the surface of the Enzyme molecule, and the predicted structural changes varied from large to very small. Among the structural changes, we paid particular attention to G377R and G483R. These two substitutions are predicted to cause electrostatic changes in neighboring small regions on the molecular surface. The quality control system of the endoplasmic reticulum apparently detects these very small structural changes and degrades the mutant Enzyme Precursor (G377R), but also the cellular sorting system might be misled by these minor changes whereby the Precursor is secreted instead of being transported to lysosomes (G483R).
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Structural modeling of mutant α-glucosidases resulting in a processing/transport defect in Pompe disease
Journal of Human Genetics, 2009Co-Authors: Kanako Sugawara, Marian A. Kroos, Arnold J. J. Reuser, Seiji Saito, Masakazu Sekijima, Kazuki Ohno, Youichi Tajima, Hitoshi SakurabaAbstract:To elucidate the mechanism underlying transport and processing defects from the viewpoint of Enzyme folding, we constructed three-dimensional models of human acid α-glucosidase encompassing 27 relevant amino acid substitutions by means of homology modeling. Then, we determined in each separate case the number of affected atoms, the root-mean-square distance value and the solvent-accessible surface area value. The analysis revealed that the amino acid substitutions causing a processing or transport defect responsible for Pompe disease were widely spread over all of the five domains comprising the acid α-glucosidase. They were distributed from the core to the surface of the Enzyme molecule, and the predicted structural changes varied from large to very small. Among the structural changes, we paid particular attention to G377R and G483R. These two substitutions are predicted to cause electrostatic changes in neighboring small regions on the molecular surface. The quality control system of the endoplasmic reticulum apparently detects these very small structural changes and degrades the mutant Enzyme Precursor (G377R), but also the cellular sorting system might be misled by these minor changes whereby the Precursor is secreted instead of being transported to lysosomes (G483R).
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Homozygous deletion of exon 18 leads to degradation of the lysosomal alpha-glucosidase Precursor and to the infantile form of glycogen storage disease type II.
Clinical genetics, 2008Co-Authors: Margreet G. E. M. Ausems, Marian A. Kroos, Magna Van Der Kraan, Jan A.m. Smeitink, Wim J. Kleijer, Hans Kristian Ploos Van Amstel, Arnold J. J. ReuserAbstract:We describe two unrelated Dutch patients with typical symptoms of infantile glycogen storage disease type II (GSD II) and virtual absence of acid alpha-glucosidase activity in leukocytes and cultured skin fibroblasts. The patients were identified as homozygotes for a deletion of exon 18 of the acid alpha-glucosidase gene (GAA). The in-frame deletion manifests at the protein level in a characteristic way: the Enzyme Precursor is smaller than normal and degraded in the endoplasmic reticulum or Golgi complex. These case present an evident example of a genotype-phenotype correlation in glycogen storage disease type II.
Masataka Mori - One of the best experts on this subject based on the ideXlab platform.
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Efficient Mitochondrial Import of Newly Synthesized Ornithine Transcarbamylase (OTC) and Correction of Secondary Metabolic Alterations in spf^ash Mice following Gene Therapy of OTC Deficiency
Molecular Medicine, 1999Co-Authors: Klaus Peter Zimmer, Masataka Mori, Meike Bendiks, Eiki Kominami, Michael B. Robinson, James M. WilsonAbstract:Background The mouse strain sparse fur with abnormal skin and hair (spf^ash) is a model for the human ornithine transcarbamylase (OTC) deficiency, an X-linked inherited urea cycle disorder. The spf^ash mouse carries a single base-pair mutation in the OTC gene that leads to the production of OTC Enzyme at 10% of the normal level. Materials and Methods Recombinant adenoviruses carrying either mouse (Ad.mOTC) or human (Ad.hOTC) OTC cDNA were injected intravenously into the spf^ash mice. Expression of OTC Enzyme Precursor and its translocation to mitochondria in the vector-transduced hepatocytes were analyzed on an ultrastructural level. Liver OTC activity and mitochondrial OTC concentration were significantly increased (300% of normal) in mice treated with Ad.mOTC and were moderately increased in mice receiving Ad.hOTC (34% of normal). The concentration and subcellular location of OTC and associated Enzymes were studied by electron microscope immunolocalization and quantitative morphometry. Results Cytosolic OTC concentration remained unchanged in Ad.mOTC-injected mice but was significantly increased in mice receiving Ad.hOTC, suggesting a block of mitochondria translocation for the human OTC Precursor. Mitochondrial ATPase subunit c [ATPase(c)] was significantly reduced and mitochondrial carbamyΔphosphate synthetase I (CPSI) was significantly elevated in spf^ash mice relative to C3H. In Ad.mOTC-treated mice, the hepatic mitochondrial concentration of ATPase(c) was completely normalized and the CPSI concentration was partially corrected. Conclusions Taken together, we conclude that newly synthesized mouse OTC Enzyme was efficiently imported into mitochondria following vector-mediated gene delivery in spf^ash mice, correcting secondary metabolic alterations.
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Molecular cloning and sequence analysis of the cDNA for human mitochondrial short-chain enoyl-CoA hydratase.
Enzyme & protein, 1993Co-Authors: Masaki Kanazawa, Masataka Mori, Akira Ohtake, Hiroki Abe, Shigenori Yamamoto, Yoshirtori Satoh, Masaki Takayanagi, Hiroo Niimi, Takashi HashimotoAbstract:Abstract Short chain enoyl-CoA hydratase (SCEH) catalyzes the second step of the mitochondrial fatty acid beta-oxidation spiral. We isolated cDNA clones for human SCEH to facilitate investigation of the Enzyme structure of the gene and to examine the genetic background of Reye's syndrome and sudden infant death. Oligo(dT)-primed and random primed human liver cDNA libraries in lambda gt11 were screened using the entire sequence of the rat SCEH cDNA as a probe. Three positive clones covered the full-length cDNA sequence with an open reading frame encoding a Precursor polypeptide of 290 amino acid residues, and deduced relative molecular mass (31,280) with a putative N-terminal presequence of 29 residues, a 5'-untranslated sequence of 21 bp and a 3'-untranslated sequence of 391 bp. Comparison with the rat SCEH cDNA showed that the deduced amino acid sequence of the human SCEH Precursor is 84% identical to that of the rat Enzyme Precursor. Northern blot analysis gave a single mRNA species of 1.6 kb in the human liver, fibroblast and muscle.