Effect of photobiomodulation in suppression of oxidative stress on retinal pigment epithelium

Abstract Purpose: As the world undergoes aging, the number of age‐related diseases has increased. One of them is disease related to retinal pigment epithelium (RPE) degeneration, such as age‐related macular degeneration, causing vision loss without physical damage in the ocular system. It is the leading cause of blindness, with no cure. Although the exact pathogenesis is still unknown, the research shows that oxidative stress is one of the risk factors. Various molecules have been reported as anti‐oxidative materials; however, the disease has not yet been conquered. Here, we would like to introduce photobiomodulation (PBM). PBM is a non‐invasive treatment based on red and near‐infrared light and has been used to cure various diseases by regulating cellular functions. Methods: The BM‐ECM was prepared and the RPE cell line was cultured. The hypoxia condition was induced via cobalt chloride treatment. The barrier function was evaluated via ZO‐1, a marker of tight junction, expression, and Transepithelial Electrical Resistance (TEER) measurement. The clearance function was evaluated via MERTK expression and digestion of polystyrene beads. The visual function of RPE was examined via expression of RPE65, the enzyme for phototransduction. The oxidative stress was compared via ROS generation. Results: In this study, we confirm the antioxidant effect of PBM in retinal pigment epithelium via an RPE model with hypoxia. The function of RPE is protected by PBM against damage from hypoxia. Furthermore, we observed the protective mechanism of PBM by its suppression effect on reactive oxygen species generation. Conclusions: These results indicate that PBM shows great potential to cure RPE degeneration to help patients with blindness.