title: DelK32-lamin A/C has abnormal location and induces incomplete tissue maturation and severe metabolic defects leading to premature death.
abstract: The LMNA gene encodes lamin A/C intermediate filaments that polymerize beneath the nuclear membrane, and are also found in the nucleoplasm in an uncharacterized assembly state. They are thought to have structural functions and regulatory roles in signaling pathways via interaction with transcription factors. Mutations in LMNA have been involved in numerous inherited human diseases, including severe congenital muscular dystrophy (L-CMD). We created the Lmna(ΔK32) knock-in mouse harboring a L-CMD mutation. Lmna(ΔK32/ΔK32) mice exhibited striated muscle maturation delay and metabolic defects, including reduced adipose tissue and hypoglycemia leading to premature death. The level of mutant proteins was markedly lower in Lmna(ΔK32/ΔK32), and while wild-type lamin A/C proteins were progressively relocated from nucleoplasmic foci to the nuclear rim during embryonic development, mutant proteins were maintained in nucleoplasmic foci. In the liver and during adipocyte differentiation, expression of ΔK32-lamin A/C altered sterol regulatory element binding protein 1 (SREBP-1) transcriptional activities. Taken together, our results suggest that lamin A/C relocation at the nuclear lamina seems important for tissue maturation potentially by releasing its inhibitory function on transcriptional factors, including but not restricted to SREBP-1. And importantly, L-CMD patients should be investigated for putative metabolic disorders.
authors.affiliation: Inserm, UMRS_974, Paris F-75013, France.
authors.forename: Anne T
authors.initials: AT
authors.lastname: Bertrand
authors.forename: Laure
authors.initials: L
authors.lastname: Renou
authors.forename: Aurélie
authors.initials: A
authors.lastname: Papadopoulos
authors.forename: Maud
authors.initials: M
authors.lastname: Beuvin
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Lacène
authors.forename: Catherine
authors.initials: C
authors.lastname: Massart
authors.forename: Chris
authors.initials: C
authors.lastname: Ottolenghi
authors.forename: Valérie
authors.initials: V
authors.lastname: Decostre
authors.forename: Sophia
authors.initials: S
authors.lastname: Maron
authors.forename: Saskia
authors.initials: S
authors.lastname: Schlossarek
authors.forename: Marie-Elodie
authors.initials: ME
authors.lastname: Cattin
authors.forename: Lucie
authors.initials: L
authors.lastname: Carrier
authors.forename: Marie
authors.initials: M
authors.lastname: Malissen
authors.forename: Takuro
authors.initials: T
authors.lastname: Arimura
authors.forename: Gisèle
authors.initials: G
authors.lastname: Bonne
mesh_terms: D017667:Adipocytes / Q000166:cytology; D050156:Adipogenesis; D000818:Animals; D000831:Animals, Newborn; D002467:Cell Nucleus / Q000378:metabolism*; D004622:Embryo, Mammalian; D055879:Gene Knock-In Techniques; D006130:Growth Disorders / Q000235:genetics / Q000378:metabolism; D006321:Heart / Q000254:growth & development; D034904:Lamin Type A / Q000235:genetics* / Q000378:metabolism*; D034921:Lamin Type B / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008659:Metabolic Diseases / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D061213:Mortality, Premature; D018482:Muscle, Skeletal / Q000033:anatomy & histology / Q000254:growth & development*; D050505:Mutant Proteins / Q000235:genetics / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000166:cytology; D034881:Nuclear Lamina / Q000378:metabolism*; D009929:Organ Size; D010641:Phenotype; D015398:Signal Transduction; D051780:Sterol Regulatory Element Binding Protein 1 / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D034904:Lamin Type A; D034921:Lamin Type B; D050505:Mutant Proteins; C497388:Srebf1 protein, mouse; D051780:Sterol Regulatory Element Binding Protein 1