The reduced diameter of skeletal myofibres is a hallmark of several congenital myopathies,yet the underlying cellular and molecular mechanisms remain elusive.In this study,we investigate the role of HACD1/PTPLA,which ...The reduced diameter of skeletal myofibres is a hallmark of several congenital myopathies,yet the underlying cellular and molecular mechanisms remain elusive.In this study,we investigate the role of HACD1/PTPLA,which is involved in the elongation of the very long chain fatty acids,in muscle fibre formation.In humans and dogs,HACD1 deficiency leads to a congenital myopathy with fibre size disproportion associated with a generalized muscleweakness.Throughanalysis of HACD1-deficient Labradors,Hacd1-knockout mice,and Hacd1-deficient myoblasts,we provide evidence that HACD1 promotes myoblast fusion during muscle development and regeneration.We further demonstrate that in normal differentiating myoblasts,expression of the catalytically active HACD1 isoform,which is encoded by a muscle-enriched splice variant,yields decreased lysophosphatidylcholine content,a potent inhibitor of myoblast fusion,and increased concentrations of≥C18 and monounsaturated fatty acids of phospholipids.These lipid modifications correlate with a reduction in plasma membrane rigidity.In conclusion,we propose that fusion impairment constitutes a novel,non-exclusive pathological mechanism operating in congenital myopathies and reveal that HACD1 is a key regulator of a lipid-dependent muscle fibre growth mechanism.展开更多
基金This work was supported by the Agence Nationale de la Recherche(ANR-12-JSV1-0005)the Association Franc¸aise contre les Myopathies(14577,15882,and 16143)+4 种基金the CNM Project(www.labradorcnm.com)the Alliance program(22866ZM)the Myotubular Trust and Grants-in-Aid for Scientific Research(B)to A.K.from Japan Society for the Promotion of Science(23370057)J.B.was supported by the French Ministry of Research and Technologies and the Universite´Paris 6(Paris)V.G.,A.P.,and A.R.were supported by the ANR,N.B-G.and I.B.were supported by the AFM,and G.W.was supported by the BBSRC CASE and the Myotubular Trust.
文摘The reduced diameter of skeletal myofibres is a hallmark of several congenital myopathies,yet the underlying cellular and molecular mechanisms remain elusive.In this study,we investigate the role of HACD1/PTPLA,which is involved in the elongation of the very long chain fatty acids,in muscle fibre formation.In humans and dogs,HACD1 deficiency leads to a congenital myopathy with fibre size disproportion associated with a generalized muscleweakness.Throughanalysis of HACD1-deficient Labradors,Hacd1-knockout mice,and Hacd1-deficient myoblasts,we provide evidence that HACD1 promotes myoblast fusion during muscle development and regeneration.We further demonstrate that in normal differentiating myoblasts,expression of the catalytically active HACD1 isoform,which is encoded by a muscle-enriched splice variant,yields decreased lysophosphatidylcholine content,a potent inhibitor of myoblast fusion,and increased concentrations of≥C18 and monounsaturated fatty acids of phospholipids.These lipid modifications correlate with a reduction in plasma membrane rigidity.In conclusion,we propose that fusion impairment constitutes a novel,non-exclusive pathological mechanism operating in congenital myopathies and reveal that HACD1 is a key regulator of a lipid-dependent muscle fibre growth mechanism.
