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Publications (47) View all
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Article: Defects of Vps15 in skeletal muscles lead to autophagic vacuolar myopathy and lysosomal disease.
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ABSTRACT: The complex of Vacuolar Protein Sorting 34 and 15 (Vps34 and Vps15) has Class III phosphatidylinositol 3-kinase activity and putative roles in nutrient sensing, mammalian Target Of Rapamycin (mTOR) activation by amino acids, cell growth, vesicular trafficking and autophagy. Contrary to expectations, here we show that Vps15-deficient mouse tissues are competent for LC3-positive autophagosome formation and maintain mTOR activation. However, an impaired lysosomal function in mutant cells is traced by accumulation of adaptor protein p62, LC3 and Lamp2 positive vesicles, which can be reverted to normal levels after ectopic overexpression of Vps15. Mice lacking Vps15 in skeletal muscles, develop a severe myopathy. Distinct from the autophagy deficient Atg7(-/-) mutants, pathognomonic morphological hallmarks of autophagic vacuolar myopathy (AVM) are observed in Vps15(-/-) mutants, including elevated creatine kinase plasma levels, accumulation of autophagosomes, glycogen and sarcolemmal features within the fibres. Importantly, Vps34/Vps15 overexpression in myoblasts of Danon AVM disease patients alleviates the glycogen accumulation. Thus, the activity of the Vps34/Vps15 complex is critical in disease conditions such as AVMs, and possibly a variety of other lysosomal storage diseases.EMBO Molecular Medicine 04/2013; · 10.33 Impact Factor -
Article: Neuronal ceroid lipofuscinoses.
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ABSTRACT: Neuronal ceroid lipofuscinoses (NCL) represent a group of autosomal recessive neurodegenerative disorders, presenting with myoclonic epilepsy, psychomotor delay, progressive loss of vision, and early death. Four main clinical forms have been delineated (infantile, late infantile, juvenile, and adult), but many other variants have also been described. At least 14 genetically distinct NCL, designated CLN1 to CLN14, are presently known.The identification of the deficient protein and/or the genetic defect is required for a specific diagnosis, which is necessary for a reliable genetic counseling in at-risk families.Handbook of Clinical Neurology 01/2013; 113:1701-6. -
Article: Characterization of seven novel mutations on the HEXB gene in French Sandhoff patients.
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ABSTRACT: Sandhoff disease (SD) is an autosomal recessive lysosomal storage disease caused by mutations in the HEXB gene encoding the beta subunit of hexosaminidases A and B, two enzymes involved in GM2 ganglioside degradation. Eleven French Sandhoff patients with infantile or juvenile forms of the disease were completely characterized using sequencing of the HEXB gene. A specific procedure was developed to facilitate the detection of the common 5'-end 16kb deletion which was frequent (36% of the alleles) in our study. Eleven other disease-causing mutations were found, among which four have previously been reported (c.850C>T, c.793T>G, c.115del and c.800_817del). Seven mutations were completely novel and were analyzed using molecular modelling. Two deletions (c.176del and c.1058_1060del), a duplication (c.1485_1487dup) and a nonsense mutation (c.552T>G) were predicted to strongly alter the enzyme spatial organization. The splice mutation c.558+5G>A affecting the intron 4 consensus splice site led to a skipping of exon 4 and to a truncated protein (p.191X). Two missense mutations were found among the patients studied. The c.448A>C mutation was probably a severe mutation as it was present in association with the known c.793T>G in an infantile form of Sandhoff disease and as it significantly modified the N-terminal domain structure of the protein. The c.171G>C mutation resulting in a p.W57C amino acid substitution in the N-terminal region is probably less drastic than the other abnormalities as it was present in a juvenile patient in association with the c.176del. Finally, this study reports a rapid detection of the Sandhoff disease-causing alleles facilitating genetic counselling and prenatal diagnosis in at-risk families.Gene 10/2012; · 2.34 Impact Factor -
Article: New insights into therapeutic options for Pompe disease.
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ABSTRACT: Different cellular steps of acid maltase synthesis and subsequent glycogen degradation, by Emmanuel Richard, Gaëlle Douillard-Guilloux, and Catherine Caillaud, pp. 979-986.International Union of Biochemistry and Molecular Biology Life 11/2011; 63(11):spcone. · 3.51 Impact Factor -
Article: New insights into therapeutic options for Pompe disease.
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ABSTRACT: Glycogen storage disease type II or Pompe disease (GSD II, MIM 232300) is a rare inherited metabolic myopathy caused by a deficiency of lysosomal acid α-glucosidase or acid maltase (GAA; EC 3.2.1.20), resulting in a massive lysosomal glycogen accumulation in cardiac and skeletal muscles. Affected individuals exhibit either severe hypotonia associated with hypertrophic cardiomyopathy (infantile forms) or progressive muscle weakness (late-onset forms). Even if enzyme replacement therapy has recently become a standard treatment, it suffers from several limitations. This review will present the main results of enzyme replacement therapy and the recent findings concerning alternative treatments for Pompe disease, such as gene therapy, enzyme enhancement therapy, and substrate reduction therapy.International Union of Biochemistry and Molecular Biology Life 11/2011; 63(11):979-86. · 3.51 Impact Factor
