Phosphatase-dead myotubularin ameliorates X-linked centronuclear myopathy phenotypes in mice
| Autor: | Gaëtan Chicanne, Bruno P. Klaholz, Belinda S. Cowling, Karim Hnia, Hélène Tronchère, Jocelyn Laporte, Arnaud Ferry, Dimitri L. Bertazzi, Bruno Rinaldi, Bernard Payrastre, Sylvie Friant, Leonela Amoasii |
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| Přispěvatelé: | IGBMC-Médecine translationnelle et neurogénétique, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), Génétique moléculaire, génomique, microbiologie (GMGM), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS), Institut des Maladies Métaboliques et Cardiovasculaires (I2MC), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National de la Santé et de la Recherche Médicale (INSERM), Centre de recherche en myologie, Université Pierre et Marie Curie - Paris 6 (UPMC)-Association française contre les myopathies (AFM-Téléthon)-Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS), IGBMC- Biologie structurale intégrative, CHU de Toulouse, Laboratoire d'Hématologie, CHU Toulouse [Toulouse], Laboratoire d'Hématologie [Purpan], Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-CHU Toulouse [Toulouse]-Hôpital Purpan [Toulouse], This work was supported by grants from INSERM, Collège de France (to JL and fellowship to BSC), CNRS ATIP-05-00932 and ATIP-Plus-08-3098 to SF), Université de Strasbourg, the Association Française contre les Myopathies (AFM grant to JL and fellowship to DLB), Fondation Recherche Médicale (FRM DEQ20071210538 to JL, INE20051105238 and FRM-Comité Alsace 2006CX67-1 to SF), Association pour la Recherche sur le Cancer (ARC JR/MLD/MDV-CR306/7901 to SF), Agence Nationale de la Recherche (ANR-07-BLAN-0065 to JL, BP, HT, GC, and SF), the E-rare program to JL, GC, BP, and HT, and a BDI-CNRS Région Alsace fellowship to LA., Université de Toulouse (UT)-Université de Toulouse (UT)-Institut National de la Santé et de la Recherche Médicale (INSERM), Service Hématologie - IUCT-Oncopole [CHU Toulouse], Pôle Biologie [CHU Toulouse], Centre Hospitalier Universitaire de Toulouse (CHU Toulouse)-Centre Hospitalier Universitaire de Toulouse (CHU Toulouse)-Pôle IUCT [CHU Toulouse], Centre Hospitalier Universitaire de Toulouse (CHU Toulouse), Simon, Marie Francoise |
| Jazyk: | angličtina |
| Rok vydání: | 2012 |
| Předmět: |
Male
Cancer Research Mouse Myotubularin Mutant Gene Expression Yeast and Fungal Models Vacuole MESH: Mice Knockout Desmin Mice 0302 clinical medicine Phosphatidylinositol Phosphates Molecular Cell Biology MESH: Animals Intermediate filament Genetics (clinical) Mice Knockout 0303 health sciences MESH: Muscle Skeletal MESH: Muscle Strength Animal Models Protein Tyrosine Phosphatases Non-Receptor MESH: Phosphatidylinositol Phosphates MESH: Saccharomyces cerevisiae 3. Good health Cell biology medicine.anatomical_structure Phenotype MESH: Desmin Biochemistry MESH: Phosphoric Monoester Hydrolases Membranes and Sorting Research Article Myopathies Structural Congenital MESH: Enzyme Activation MESH: Mutation MESH: Gene Expression lcsh:QH426-470 MESH: Myopathies Structural Congenital Phosphatase Saccharomyces cerevisiae Biology MESH: Phenotype MESH: Protein Tyrosine Phosphatases Non-Receptor 03 medical and health sciences Model Organisms medicine [SDV.BBM] Life Sciences [q-bio]/Biochemistry Molecular Biology Genetics Animals Humans [SDV.BBM]Life Sciences [q-bio]/Biochemistry Molecular Biology Muscle Strength Centronuclear myopathy Muscle Skeletal Molecular Biology MESH: Mice Ecology Evolution Behavior and Systematics 030304 developmental biology Congenital Hereditary Myopathies MESH: Humans Skeletal muscle Human Genetics X-Linked medicine.disease Phosphoric Monoester Hydrolases MESH: Male Enzyme Activation Disease Models Animal lcsh:Genetics Genetics of Disease Mutation MESH: Disease Models Animal 030217 neurology & neurosurgery |
| Zdroj: | PLoS Genetics PLoS Genetics, Public Library of Science, 2012, 8 (10), pp.e1002965. ⟨10.1371/journal.pgen.1002965⟩ PLoS Genetics, 2012, 8 (10), pp.e1002965. ⟨10.1371/journal.pgen.1002965⟩ PLoS Genetics, Vol 8, Iss 10, p e1002965 (2012) |
| ISSN: | 1553-7390 1553-7404 |
| DOI: | 10.1371/journal.pgen.1002965⟩ |
| Popis: | Myotubularin MTM1 is a phosphoinositide (PPIn) 3-phosphatase mutated in X-linked centronuclear myopathy (XLCNM; myotubular myopathy). We investigated the involvement of MTM1 enzymatic activity on XLCNM phenotypes. Exogenous expression of human MTM1 in yeast resulted in vacuolar enlargement, as a consequence of its phosphatase activity. Expression of mutants from patients with different clinical progression and determination of PtdIns3P and PtdIns5P cellular levels confirmed the link between vacuolar morphology and MTM1 phosphatase activity, and showed that some disease mutants retain phosphatase activity. Viral gene transfer of phosphatase-dead myotubularin mutants (MTM1C375S and MTM1S376N) significantly improved most histological signs of XLCNM displayed by a Mtm1-null mouse, at similar levels as wild-type MTM1. Moreover, the MTM1C375S mutant improved muscle performance and restored the localization of nuclei, triad alignment, and the desmin intermediate filament network, while it did not normalize PtdIns3P levels, supporting phosphatase-independent roles of MTM1 in maintaining normal muscle performance and organelle positioning in skeletal muscle. Among the different XLCNM signs investigated, we identified only triad shape and fiber size distribution as being partially dependent on MTM1 phosphatase activity. In conclusion, this work uncovers MTM1 roles in the structural organization of muscle fibers that are independent of its enzymatic activity. This underlines that removal of enzymes should be used with care to conclude on the physiological importance of their activity. Author Summary X-linked centronuclear myopathy is a muscle disorder characterized by neonatal hypotonia and abnormal organelle positioning in skeletal muscle. This myopathy is due to different mutations in the MTM1 gene encoding the phosphoinositide phosphatase myotubularin. Disease-causing mutations are found all along the protein sequence and not only in the phosphatase catalytic domain. We investigated the link between myotubularin phosphatase activity and disease phenotypes. We used brewer yeast as a simple cellular model to analyze the in vivo phosphatase activity of different disease mutants. Our results show that mutations responsible for severe forms of myopathy are either active or inactive phosphatases. To further question this finding, we used the mice myotubularin knock-out model that reproduces faithfully the histopathological findings from human patients. Expression of phosphatase-dead mutants improved most phenotypes of knock-out mice comparable to wild-type myotubularin. This shows that the maintenance of normal skeletal muscles is largely independent from myotubularin phosphatase activity, while defects in the activity may participate in the onset of the disease. Moreover, it could have important implications in the design of therapeutic approaches aimed at manipulating the phosphoinositide levels in the different diseases linked to myotubularin homologues. Finally, these data call for cautiousness when manipulating such enzymes to conclude on the physiological relevance of their activity. |
| Databáze: | OpenAIRE |
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