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Intrinsic mitochondrial dysfunction in ATM-deficient lymphoblastoid cells


Ambrose, M and Goldstine, JV and Gatti, RA, Intrinsic mitochondrial dysfunction in ATM-deficient lymphoblastoid cells, Human Molecular Genetics, 16, (18) pp. 2154-64. ISSN 0964-6906 (2007) [Refereed Article]

Copyright Statement

Copyright 2007 The Author

DOI: doi:10.1093/hmg/ddm166


One of the characteristic features of cells from patients with ataxia telangiectasia (A-T) is that they are in a state of continuous oxidative stress and exhibit constitutive activation of pathways that normally respond to oxidative damage. In this report, we investigated whether the oxidative stress phenotype of A-T cells might be a reflection of an intrinsic mitochondrial dysfunction. Mitotracker Red staining showed that the structural organization of mitochondria in A-T cells was abnormal compared to wild-type. Moreover, A-T cells harbored a much larger population of mitochondria with decreased membrane potential (DeltaPsi) than control cells. In addition, the basal expression levels of several nuclear DNA-encoded oxidative damage responsive genes whose proteins are targeted to the mitochondria--polymerase gamma, mitochondrial topoisomerase I, peroxiredoxin 3 and manganese superoxide dismutase--are elevated in A-T cells. Consistent with these results, we found that overall mitochondrial respiratory activity was diminished in A-T compared to wild-type cells. Treating A-T cells with the antioxidant, alpha lipoic acid (ALA), restored mitochondrial respiration rates to levels approaching those of wild-type. When wild-type cells were transfected with ATM-targeted siRNA, we observed a small but significant reduction in the respiration rates of mitochondria. Moreover, mitochondria in A-T cells induced to stably express full-length ATM, exhibited respiration rates approaching those of wild-type cells. Taken together, our results provide evidence for an intrinsic mitochondrial dysfunction in A-T cells, and implicate a requirement for ATM in the regulation of mitochondrial function.

Item Details

Item Type:Refereed Article
Keywords:ATM, DNA repair, mitochondria
Research Division:Biological Sciences
Research Group:Genetics
Research Field:Anthropological genetics
Objective Division:Health
Objective Group:Clinical health
Objective Field:Clinical health not elsewhere classified
UTAS Author:Ambrose, M (Dr Mark Ambrose)
ID Code:87161
Year Published:2007
Web of Science® Times Cited:130
Deposited By:Medicine
Deposited On:2013-11-08
Last Modified:2014-07-21

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