Coenzyme Q10 prevents human lens epithelial cells from light-induced apoptotic cell death by reducing oxidative stress and stabilizing BAX / Bcl-2 ratio.
BACKGROUND
Cataract is one of the most prevalent eye disease and a major cause for legal blindness in the world. Beside others, cumulative light-exposure and apoptotic cell death are significantly associated with cataract development. In contrast, supplementation with antioxidants has been suggested to prevent premature cataractogenesis. This study investigates possible protective effects of Coenzyme Q10 (CoQ10) regarding light-induced stress and apoptotic cell death in human lens epithelial cells (LEC).


METHODS
Human LEC were either pre-incubated with CoQ10 or not and then exposed to white light. After 10-40 min of irradiation viability, induction of intracellular reactive oxygen species (ROS), apoptosis and cell death was determined. Expression of apoptotic BAX and anti-apoptotic Bcl-2 protein and their mRNA were determined by RT-PCR and Western blot analysis.


RESULTS
Light exposure decreased LEC viability and Bcl-2 expression and increased intracellular ROS, apoptotic cell death, and BAX expression in a time-of-irradiation-dependent manner. Phototoxic cell death and apoptosis, as well as decrease of Bcl-2 and increase in BAX expression was significantly reduced, when cells were pre-incubated with CoQ10.


CONCLUSIONS
In this study, CoQ10 significantly reduced light-induced LEC-damage and attenuated phototoxic effects on BAX and Bcl-2 expression. Therefore, CoQ10 supplementation might also be useful in preventing LEC death and consecutive cataract formation in vivo.
Kernt
Marcus
M
Department of Ophthalmology, Ludwig Maximilian University, Munich, Germany. marcus.kernt@med.uni-muenchen.de <marcus.kernt@med.uni-muenchen.de>
Hirneiss
Christoph
C
Neubauer
Aljoscha S
AS
Ulbig
Michael W
MW
Kampik
Anselm
A
D017209:Apoptosis / Q000187:drug effects* / Q000528:radiation effects; D015153:Blotting, Western; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D045222:Electron Transport Chain Complex Proteins / Q000494:pharmacology; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D006801:Humans; D007908:Lens, Crystalline / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects*; D008027:Light; D008858:Microscopy, Phase-Contrast; D018384:Oxidative Stress / Q000187:drug effects* / Q000528:radiation effects; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000494:pharmacology; D014815:Vitamins / Q000494:pharmacology; D051028:bcl-2-Associated X Protein / Q000235:genetics / Q000378:metabolism*
C494826:BAX protein, human; D045222:Electron Transport Chain Complex Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D014815:Vitamins; D051028:bcl-2-Associated X Protein; D014451:Ubiquinone; C024989:coenzyme Q10