FDX2 and ISCU Gene Variations Lead to Rhabdomyolysis With Distinct Severity and Iron Regulation

Autor: Sebastian Montealegre, Elise Lebigot, Hugo Debruge, Norma Romero, Bénédicte Héron, Pauline Gaignard, Antoine Legendre, Apolline Imbard, Stéphanie Gobin, Emmanuelle Lacène, Patrick Nusbaum, Arnaud Hubas, Isabelle Desguerre, Aude Servais, Pascal Laforêt, Peter van Endert, François Jérome Authier, Cyril Gitiaux, Pascale de Lonlay
Přispěvatelé: Institut Necker Enfants-Malades (INEM - UM 111 (UMR 8253 / U1151)), Institut National de la Santé et de la Recherche Médicale (INSERM)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), CHU Necker - Enfants Malades [AP-HP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP), Imagine - Institut des maladies génétiques (IHU) (Imagine - U1163), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Cité (UPCité), Hôpital Bicêtre, CHU Trousseau [APHP], Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Sorbonne Université (SU), Hôpital Cochin [AP-HP], Hôpital Raymond Poincaré [AP-HP], Handicap neuromusculaire : Physiopathologie, Biothérapie et Pharmacologies appliquées (END-ICAP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut National de la Santé et de la Recherche Médicale (INSERM), Hôpital Henri Mondor, Institut Mondor de Recherche Biomédicale (IMRB), Institut National de la Santé et de la Recherche Médicale (INSERM)-IFR10-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Association Française contre les Myopathies, AFM: AFM 2016-2018 19773, Agence Nationale de la Recherche, ANR: ANR-AAPG 2018 CE17 MetabInf, The Article Processing Charge was funded by the authors., HAL UVSQ, Équipe
Rok vydání: 2021
Předmět:
Zdroj: Neurology: Genetics
article-version (Version of Record) 3
Neurology Genetics
Neurology Genetics, American Academy of Neurology, 2022, 8 (1), ⟨10.1212/NXG.0000000000000648⟩
Neurology Genetics, 2022, 8 (1), ⟨10.1212/NXG.0000000000000648⟩
ISSN: 2376-7839
DOI: 10.1212/NXG.0000000000000648⟩
Popis: Background and ObjectivesTo determine common clinical and biological traits in 2 individuals with variants in ISCU and FDX2, displaying severe and recurrent rhabdomyolyses and lactic acidosis.MethodsWe performed a clinical characterization of 2 distinct individuals with biallelic ISCU or FDX2 variants from 2 separate families and a biological characterization with muscle and cells from those patients.ResultsThe individual with FDX2 variants was clinically more affected than the individual with ISCU variants. Affected FDX2 individual fibroblasts and myoblasts showed reduced oxygen consumption rates and mitochondrial complex I and PDHc activities, associated with high levels of blood FGF21. ISCU individual fibroblasts showed no oxidative phosphorylation deficiency and moderate increase of blood FGF21 levels relative to controls. The severity of the FDX2 individual was not due to dysfunctional autophagy. Iron was excessively accumulated in ISCU-deficient skeletal muscle, which was accompanied by a downregulation of IRP1 and mitoferrin2 genes and an upregulation of frataxin (FXN) gene expression. This excessive iron accumulation was absent from FDX2 affected muscle and could not be correlated with variable gene expression in muscle cells.DiscussionWe conclude that FDX2 and ISCU variants result in a similar muscle phenotype, that differ in severity and skeletal muscle iron accumulation. ISCU and FDX2 are not involved in mitochondrial iron influx contrary to frataxin.
Databáze: OpenAIRE
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