Improved effect of a mitochondria-targeted antioxidant on hydrogen peroxide-induced oxidative stress in human retinal pigment epithelium cells.

Background: Oxidative damage to retinal pigment epithelial (RPE) cells contributes to the development of age-related macular degeneration, which is among the leading causes of visual loss in elderly people. In the present study, we evaluated the protective role of triphenylphosphonium (TPP)-Niacin against hydrogen peroxide (H ₂ O ₂ )-induced oxidative stress in RPE cells.
Methods: The cellular viability, lactate dehydrogenase release, reactive oxygen species (ROS) generation, and mitochondrial function of retinal ARPE-19 cells were determined under treatment with H ₂ O ₂ or pre-treatment with TPP-Niacin. The expression level of mitochondrial related genes and some transcription factors were assessed using real-time polymerase chain reaction (RT-qPCR).
Results: TPP-Niacin significantly improved cell viability, reduced ROS generation, and increased the antioxidant enzymes in H ₂ O ₂ -treated ARPE-19 cells. Mitochondrial dysfunction from the H ₂ O ₂ -induced oxidative stress was also considerably diminished by TPP-Niacin treatment, along with reduction of the mitochondrial membrane potential (MMP) and upregulation of the mitochondrial-associated gene. In addition, TPP-Niacin markedly enhanced the expression of transcription factors (PGC-1α and NRF2) and antioxidant-associated genes (especially HO-1 and NQO-1).
Conclusion: We verified the protective effect of TPP-Niacin against H ₂ O ₂ -induced oxidative stress in RPE cells. TPP-Niacin is believed to protect against mitochondrial dysfunction by upregulating antioxidant-related genes, such as PGC-1α, NRF2, HO-1, and NQO-1, in RPE cells.