Purchase this article with an account.
Adna Halilovic, Thore Schmedt, Ula Jurkunas; Oxidative DNA damage in Fuchs endothelial corneal dystrophy. Invest. Ophthalmol. Vis. Sci. 2014;55(13):997.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
The corneal endothelium is a highly metabolically active tissue and is known for its high abundance of mitochondria. Fuchs endothelial corneal dystrophy (FECD) is a progressive disease in which there is a loss of corneal endothelial cells leading to corneal edema and eventually corneal blindness. The goal of our study is to examine the effect of oxidative stress on DNA damage in FECD.
Long-amplicon quantitative PCR (LA-QPCR) was performed to asses DNA damage using small (250bp) and large (8.9kb) mtDNA primers. Normal immortalized human corneal endothelial (HCEnCi) and Fuchs (FECDi) cells were exposed to 25μM menadione (MN). DNA damage was quantified using a PicoGreen dsDNA quantitation assay. The PCR signal from a treated sample was compared to that from an untreated sample, which was expressed as lesion frequencies per 10kb DNA.
In this study, amplification of a small mitochondrial target is a relative measurement of mtDNA copy number changes. We found a 3.8-fold decrease in mtDNA copy number of a 250bp-fragment of mtDNA in FECDi compared to normal HCEnCi. A 5h exposure to 25uM MN resulted in 2.3-fold increase of mtDNA copy number in FECDi compared to normal HCECi cells. In addition, 25uM MN treatment increased lesion frequency from basal condition by 12-fold in FECDi cells compared to normal HCEnCi cells.
Our studies indicate that FECDi cells are preferentially damaged by MN treatment compared to normal HCEnCi cells. Decrease in small mtDNA fragment in FECD at basal state may signify a decrease in mitochondrial number and altered cellular dysfunction which may result in impaired energy metabolism yielding clinical manifestation of FECD. Hence, a decrease in amplified mtDNA target fragment resulted in an increase in DNA lesions in FECD as compared to normal endothelium suggesting a potential susceptibility of mtDNA damage in FECD pathogenesis.
This PDF is available to Subscribers Only