Navegando por Palavras-chave "DNAmt"

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    Mitochondrial DNA damage associated with lipid peroxidation of the mitochondrial membrane induced by Fe2+-citrate
    (Academia Brasileira de Ciências, 2006-09-01) Almeida, Andréa M.; Bertoncini, Clelia Rejane Antonio [UNIFESP]; Borecký, Jiri; Souza-Pinto, Nadja C.; Vercesi, Aníbal E.; Universidade Estadual de Campinas (UNICAMP); Universidade Federal de São Paulo (UNIFESP); Universidade Federal de Viçosa Departamento de Biologia Vegetal; National Institute on Aging Laboratory of Molecular Gerontology
    Iron imbalance/accumulation has been implicated in oxidative injury associated with many degenerative diseases such as hereditary hemochromatosis, beta-thalassemia, and Friedreich's ataxia. Mitochondria are particularly sensitive to iron-induced oxidative stress - high loads of iron cause extensive lipid peroxidation and membrane permeabilization in isolated mitochondria. Here we detected and characterized mitochondrial DNA damage in isolated rat liver mitochondria exposed to a Fe2+-citrate complex, a small molecular weight complex. Intense DNA fragmentation was induced after the incubation of mitochondria with the iron complex. The detection of 3' phosphoglycolate ends at the mtDNA strand breaks by a 32P-postlabeling assay, suggested the involvement of hydroxyl radical in the DNA fragmentation induced by Fe2+-citrate. Increased levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine also suggested that Fe2+-citrate-induced oxidative stress causes mitochondrial DNA damage. In conclusion, our results show that iron-mediated lipid peroxidation was associated with intense mtDNA damage derived from the direct attack of reactive oxygen species.