Neumann, M.A.C.* ; Grossmann, D.* ; Schimpf-Linzenbold, S.* ; Dayan, D.* ; Stingl, K.* ; Ben-Menachem, R.* ; Pines, O.* ; Massart, F.* ; Delcambre, S.* ; Ghelfi, J.* ; Bohler, J.* ; Strom, T.M. ; Kessel, A.* ; Azem, A.* ; Schöls, L.* ; Grünewald, A.* ; Wissinger, B.* ; Krüger, R.*
Haploinsufficiency due to a novel ACO2 deletion causes mitochondrial dysfunction in fibroblasts from a patient with dominant optic nerve atrophy.
Sci. Rep. 10:16736 (2020)
ACO2 is a mitochondrial protein, which is critically involved in the function of the tricarboxylic acid cycle (TCA), the maintenance of iron homeostasis, oxidative stress defense and the integrity of mitochondrial DNA (mtDNA). Mutations in the ACO2 gene were identified in patients suffering from a broad range of symptoms, including optic nerve atrophy, cortical atrophy, cerebellar atrophy, hypotonia, seizures and intellectual disabilities. In the present study, we identified a heterozygous 51 bp deletion (c.1699_1749del51) in ACO2 in a family with autosomal dominant inherited isolated optic atrophy. A complementation assay using aco1-deficient yeast revealed a growth defect for the mutant ACO2 variant substantiating a pathogenic effect of the deletion. We used patient-derived fibroblasts to characterize cellular phenotypes and found a decrease of ACO2 protein levels, while ACO2 enzyme activity was not affected compared to two age- and gender-matched control lines. Several parameters of mitochondrial function, including mitochondrial morphology, mitochondrial membrane potential or mitochondrial superoxide production, were not changed under baseline conditions. However, basal respiration, maximal respiration, and spare respiratory capacity were reduced in mutant cells. Furthermore, we observed a reduction of mtDNA copy number and reduced mtDNA transcription levels in ACO2-mutant fibroblasts. Inducing oxidative stress led to an increased susceptibility for cell death in ACO2-mutant fibroblasts compared to controls. Our study reveals that a monoallelic mutation in ACO2 is sufficient to promote mitochondrial dysfunction and increased vulnerability to oxidative stress as main drivers of cell death related to optic nerve atrophy.
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Publikationstyp
Artikel: Journalartikel
Dokumenttyp
Wissenschaftlicher Artikel
Typ der Hochschulschrift
Herausgeber
Schlagwörter
Iron-sulfur Cluster; Metabolic-regulation; Oxidative Damage; Opa1 Isoforms; Dna Depletion; Aconitase; Protein; Neuropathy; Mutations; Alignment
Keywords plus
Sprache
englisch
Veröffentlichungsjahr
2020
Prepublished im Jahr
HGF-Berichtsjahr
2020
ISSN (print) / ISBN
2045-2322
e-ISSN
2045-2322
ISBN
Bandtitel
Konferenztitel
Konferzenzdatum
Konferenzort
Konferenzband
Quellenangaben
Band: 10,
Heft: 1,
Seiten: ,
Artikelnummer: 16736
Supplement: ,
Reihe
Verlag
Nature Publishing Group
Verlagsort
London
Tag d. mündl. Prüfung
0000-00-00
Betreuer
Gutachter
Prüfer
Topic
Hochschule
Hochschulort
Fakultät
Veröffentlichungsdatum
0000-00-00
Anmeldedatum
0000-00-00
Anmelder/Inhaber
weitere Inhaber
Anmeldeland
Priorität
Begutachtungsstatus
Peer reviewed
POF Topic(s)
30501 - Systemic Analysis of Genetic and Environmental Factors that Impact Health
Forschungsfeld(er)
Genetics and Epidemiology
PSP-Element(e)
G-500700-001
Förderungen
Israel Science Foundation
FNR within the ATTRACT program
German Research Council as part of a joint research project "TreatOPON"
Federal Ministry for Education and Research (BMBF)
European Union's (EU) Horizon2020 research and innovation program (WIDESPREAD; CENTRE-PD)
German Research Council
Fonds National de la Recherche de Luxembourg (FNR; NCER-PD)
Fonds National de la Recherche de Luxembourg (FNR; PEARL )
Copyright
Erfassungsdatum
2020-11-16