Browse by author
Lookup NU author(s): Syeda Ahmed, Charlotte Alston, Sila Hopton, Dr Langping He, Gavin Falkous, Dr Monika Olahova, Professor Bobby McFarlandORCiD, Emeritus Professor Doug Turnbull, Dr Mariana Rocha, Professor Robert Taylor
This work is licensed under a Creative Commons Attribution 4.0 International License (CC BY 4.0).
© 2017 The Author(s). Isolated Complex I (CI) deficiency is the most commonly observed mitochondrial respiratory chain biochemical defect, affecting the largest OXPHOS component. CI is genetically heterogeneous; pathogenic variants affect one of 38 nuclear-encoded subunits, 7 mitochondrial DNA (mtDNA)-encoded subunits or 14 known CI assembly factors. The laboratory diagnosis relies on the spectrophotometric assay of enzyme activity in mitochondrially-enriched tissue homogenates, requiring at least 50 mg skeletal muscle, as there is no reliable histochemical method for assessing CI activity directly in tissue cryosections. We have assessed a validated quadruple immunofluorescent OXPHOS (IHC) assay to detect CI deficiency in the diagnostic setting, using 10 μm transverse muscle sections from 25 patients with genetically-proven pathogenic CI variants. We observed loss of NDUFB8 immunoreactivity in all patients with mutations affecting nuclear-encoding structural subunits and assembly factors, whilst only 3 of the 10 patients with mutations affecting mtDNA-encoded structural subunits showed loss of NDUFB8, confirmed by BN-PAGE analysis of CI assembly and IHC using an alternative, commercially-available CI (NDUFS3) antibody. The IHC assay has clear diagnostic potential to identify patients with a CI defect of Mendelian origins, whilst highlighting the necessity of complete mitochondrial genome sequencing in the diagnostic work-up of patients with suspected mitochondrial disease.
Author(s): Ahmed ST, Alston CL, Hopton S, He L, Hargreaves IP, Falkous G, Olahova M, McFarland R, Turnbull DM, Rocha MC, Taylor RW
Publication type: Article
Publication status: Published
Journal: Scientific Reports
Year: 2017
Volume: 7
Issue: 1
Online publication date: 12/11/2017
Acceptance date: 12/10/2017
Date deposited: 12/12/2017
ISSN (electronic): 2045-2322
Publisher: Nature Publishing Group
URL: https://doi.org/10.1038/s41598-017-14623-2
DOI: 10.1038/s41598-017-14623-2
Altmetrics provided by Altmetric
