Abstract
Purpose: :
Purpose: Characterise the mechanism by which light as impinging on the retina in situ kills RGC-5 cells (cell line with certain ganglion cell properties) in vitro.
Methods: :
Methods: RGC-5 cell cultures in 96- or 12-well plates were exposed to white light (400-700nm, 1000 lux) or 5mM sodium azide. Their viability (MTT procedure) and production of reactive oxygen species (ROS) were analysed after 24-48 hours. Cultures were also processed for DNA breakdown (TUNEL method) and for certain antigens by immunocytochemistry and electrophoresis/western blotting after exposure to light for 48-96 hours.
Results: :
Results: Light and sodium azide caused a loss of cell viability and a stimulation of ROS and breakdown of DNA. The negative effect of light was attenuated by necrostatin-1 and not by the caspase inhibitor zVAD-fmk. In contrast, the influence of sodium azide was unaffected by necrostatin-1 but inhibited by zVAD-fmk. Moreover, light caused an activation of apoptosis inducing factor (AIF), c-Jun, JNK and HO-1 but did not affect alpha fodrin or caspase-3 content. Sodium azide, on the other hand activated of alpha fodrin, caused a stimulation of caspase-3 but did not influence basal expression of AIF, c-Jun, JNK or HO-1. Light, unlike sodium azide also caused p-c-Jun to be translocated from the nucleus to the cytoplasm.
Keywords: ganglion cells • mitochondria • cell survival