Abstract
Purpose:
Oxidative stress is one of the well-known pathogenesis of age-related macular degeneration (AMD). The contribution of pathological condition of retinal pigment epithelium (RPE) in AMD development and progression is also accepted. Thus, the trigger stimuli of oxidative stress in the RPE and the therapeutic approaches are the hot topics these days. On the other hand, the light exposure is one of the risks of AMD and lutein is an anti-oxidative nutrient supplement recognized for preventing AMD progression. In this study, we evaluate the influence of light exposure and protective effect of lutein in the RPE, using in vivo mouse model.
Methods:
Six-week-old BALB/c mice were exposed to light at 3000 lux for 3 hours, after 12 hours of dark-adaptation. Each animal was given an intraperitoneal injection of lutein (100mg/kg) or a vehicle 12 hours after the light exposure. Flat mount RPE samples were immunostained with anti ZO-1 antibody for evaluating tight junction. The ROS level was measured using DCFH-DA in the RPE-choroid complex sample.
Results:
Light exposure disrupted staining pattern of a tight junction marker, ZO-1, in the RPE, 12 hours after light exposure. This abnormal distribution of ZO-1 was still observed 48 hours after light exposure in the vehicle treated mice. However, in the mouse treated with lutein, the RPE change was already recovered 48 hours after light exposure. The ROS level that was increased in the RPE-choroid of the vehicle treated mice 24 hours after light exposure was suppressed in the RPE-choroid of the lutein treated mice at the same time point that is corresponded to the 12 hours after lutein administration.
Conclusions:
The Lutein had protective effect on the light-induced disruption of the tight junction in the RPE, reducing ROS in the RPE-choroid.
Keywords: 701 retinal pigment epithelium •
634 oxidation/oxidative or free radical damage •
412 age-related macular degeneration