Abstract
Purpose :
To compare blue light injuries between cultured human retinal pigment epithelial cells and mouse cone photoreceptors.
Methods :
Retinal pigment epithelial (RPE) cells were cultured from a human ARPE-19 cell line, and cone photoreceptor cells were culture from a mouse 661W cell line. Cells were exposed to blue-light LED (50, 100, 250, 500, or 1000 lux) or none for 4 hours. Cell damage was assessed by various assays.
Results :
On trypan blue in situ staining of cultured cells after exposure to blue-light LED for 4 hours, trypan blue staining in the nucleus and morphological changes indicating damage were seen on ARPE-19 cells and 661W cells since 100 lux. On CellTiter-Blue cell viability assay, cell viabilities were reduced at a dose-dependent manner on both cells since 50 lux. On TUNEL staining of cultured cells exposed to blue-light LED for 4 hours, apoptosis were seen on both cells at 1000 lux. On annexin V-propidium iodide flow cytometry, apoptosis and necrosis showed a dose relationship on both cells. On MTT assay, proportions of functional cells were reduced at a dose-dependent manner on both cells since 50 lux. On rhodamine 123 efflux assay, mitochondrial transmembrane potentials were decreased on both cells since 50 lux. On H2DCF assay measuring free radicals of cultured cells, reactive oxygen species (ROS) were induced at a dose-dependent manner on both cells since 250 lux.
Conclusions :
Blue light damages retinal cells, including cultured human RPE cells and mouse cone photoreceptors at a dose-dependent manner through apoptosis and necrosis. The thresholds of injury between both cells were similar. Mitochondria and oxidative stress are involved. Our in vitro cell models are helpful in elucidating blue-light retinopathy.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.