[The role of light in the developement of RPE degeneration in AMD and potential cytoprotection of minocycline].

BACKGROUND

Light-induced oxidative stress is an suggested reason for retinal pigment epithelium (RPE) degeneration in age-related macular degeneration (AMD). This study investigates the influence of light on intracellular reactive oxygen species (ROS) and apoptosis in the human RPE and potential cytoprotective effects of the tetracycline antibiotic minocycline.

METHODS

Primary human RPE cells were either pre- or post-incubated with minocycline and then exposed to white light or oxidative stress (600 µM, H(2)O(2)). Then 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

Both light exposure and oxidative stress decreased RPE cell viability and Bcl-2 expression and increased intracellular ROS, apoptotic cell death, and BAX expression. Minocycline reduced these effects under certain conditions.

CONCLUSIONS

This study demonstrates that minocycline effectively protects human RPE cells against oxidative damage. However, in the light of minocycline's photosensitising properties its potential role in AMD treatment needs further evaluation.