A disease-associated Aifm1 variant induces severe myopathy in knockin mice
MOLECULAR METABOLISM
Authors: Wischhof, Lena; Gioran, Anna; Sonntag-Bensch, Dagmar; Piazzesi, Antonia; Stork, Miriam; Nicotera, Pierluigi; Bano, Daniele
Abstract
Objective: Mutations in the AIFM1 gene have been identified in recessive X-linked mitochondrial diseases. Functional and molecular consequences of these pathogenic AIFM1 mutations have been poorly studied in vivo. Methods/results: Here we provide evidence that the disease-associated apoptosis-inducing factor (AIF) deletion arginine 201 (R200 in rodents) causes pathology in knockin mice. Within a few months, posttranslational loss of the mutant AIF protein induces severe myopathy associated with a lower number of cytochrome c oxidase-positive muscle fibers. At a later stage, Aifm1 (R200 del) knockin mice manifest peripheral neuropathy, but they do not show neurodegenerative processes in the cerebellum, as observed in age-matched hypomorphic Harlequin (Hq) mutant mice. Quantitative proteomic and biochemical data highlight signaling. Conclusion: Our findings indicate metabolic defects and distinct tissue-specific vulnerability due to a disease-causing AIFM1 mutation, with many pathological hallmarks that resemble those seen in patients. (C) 2018 The Authors. Published by Elsevier GmbH.
A slowly progressive mitochondrial encephalomyopathy widens the spectrum of AIFM1 disorders
NEUROLOGY
Authors: Ardissone, Anna; Piscosquito, Giuseppe; Legati, Andrea; Langella, Tiziana; Lamantea, Eleonora; Garavaglia, Barbara; Salsano, Ettore; Farina, Laura; Moroni, Isabella; Pareyson, Davide; Ghezzi, Daniele
Abstract
To date, 3 AIFM1 (apoptosis inducing factor mitochondrial 1, located on Xq26.1) mutations have been reported: 2 missense changes (c.923G>A/p.Gly308Glu; c.1478A>T/p.Glu493Val) and a 3-basepair deletion (c.601delAGA/p.Arg201del). Two mutations have been described in early-onset severe mitochondrial encephalomyopathy related to impaired oxidative phosphorylation.(1,2) A third mutation is associated with Cowchock syndrome, or Charcot-Marie-Tooth X4 (CMTX4), a slowly progressive disorder characterized by axonal neuropathy, hearing loss, and mental retardation.(3,4