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OXPHOS bioenergetic compensation does not explain disease penetrance in Leber hereditary optic neuropathy
Lopez Sanchez, MIG and Van Bergen, NJ and Kearns, LS and Ziemann, M and Liang, H and Hewitt, AW and Mackey, DA and Trounce, IA, OXPHOS bioenergetic compensation does not explain disease penetrance in Leber hereditary optic neuropathy, Mitochondrion, 54 pp. 113-121. ISSN 1567-7249 (2020) [Refereed Article]
© 2020 Elsevier B.V. and Mitochondria Research Society.
Leber hereditary optic neuropathy (LHON) is one of the most common primary mitochondrial diseases. It is caused by point mutations in mitochondrial DNA (mtDNA) genes and in some cases, it can result in irreversible vision loss, primarily in young men. It is currently unknown why LHON mutations affect only some carriers and whether bioenergetic compensation enables unaffected carriers to overcome mitochondrial impairment and preserve cellular function. Here, we conducted bioenergetic metabolic assays and RNA sequencing to address this question using male-only, age-matched, m.11778G>A lymphoblasts and primary fibroblasts from both unaffected carriers and affected individuals.
Our work indicates that OXPHOS bioenergetic compensation in LHON peripheral cells does not explain disease phenotype. We show that complex I impairment is similar in cells from unaffected carrier and affected patients, despite a transcriptional downregulation of metabolic pathways including glycolysis in affected cells relative to carriers detected by RNA sequencing. Although we did not detect OXPHOS bioenergetic compensation in carrier cells under basal conditions, our results indicate that cells from affected patients suffer a growth impairment under metabolic challenge compared to carrier cells, which were unaffected by metabolic challenge. If recapitulated in retinal ganglion cells, decreased susceptibility to metabolic challenge in unaffected carriers may help preserve metabolic homeostasis in the face of the mitochondrial complex I bioenergetic defect.
|Item Type:||Refereed Article|
|Research Division:||Biomedical and Clinical Sciences|
|Research Group:||Ophthalmology and optometry|
|Objective Group:||Clinical health|
|Objective Field:||Clinical health not elsewhere classified|
|UTAS Author:||Hewitt, AW (Professor Alex Hewitt)|
|UTAS Author:||Mackey, DA (Professor David Mackey)|
|Web of Science® Times Cited:||5|
|Deposited By:||Menzies Institute for Medical Research|
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