βE2 activates Nrf2 pathway to resist light-induced retinal dysfunction in rats / 西安交通大学学报(医学版)

ABSTRACT

【Objective】 To investigate whether 17β-estradiol (βE2) can activate the NF-E2-related factor 2(Nrf2) pathway to resist the downregulation of retinal function induced by light damage. 【Methods】 Two weeks after female SD rats were castrated, they were divided into the following six groups control group (control), light-damage group (LD), saline group, saline light-damage group (saline-LD), βE2 group, and βE2 light-damage group (βE2-LD). Rats in the light-damage were exposed to 8000-lux fluorescence for 12 h after 18 h of dark adaptation. Then electroretinogram (ERG), immunofluorescence, Real-time PCR and immunohistochemical detection were performed after one day of dark recovery. 【Results】 The results of ERG showed that ERG was lower in LD group than in control group (P<0.05). After light damage, ROS was increased and the mRNA expressions of antioxidant genes, such as Sod1, Sod2, Cat, Glrx1, Glrx2, Txn1, and Txn2 were decreased (all P<0.05). After βE2 administration, compared with those in saline-LD, ROS level was decreased, the levels of Nrf2 protein and antioxidant genes were increased, and ERG was recovered to a certain extent in βE2-LD (P<0.05). 【Conclusion】 βE2 can restore the function of rat retina, and its mechanism might be related to the upregulation of Nrf2 and antioxidant genes.