Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, 980-8575, Japan; Department of Retinal Disease Control, Tohoku University Graduate School of Medicine, Sendai, 980-8575, Japan.
Department of Ophthalmology, Tohoku University Graduate School of Medicine, Sendai, 980-8575, Japan.
Exp Eye Res. 2024 Nov;248:110103. doi: 10.1016/j.exer.2024.110103. Epub 2024 Sep 18.
In this study, we aimed to investigate the effects of the deficient antioxidative gene, nuclear factor-erythroid 2-related factor 2 (Nrf2), on 17β-estradiol (E)-mediated oxidative stress response, with a specific focus on growth factor production and cell death in Müller cells and retinal tissue. Administration of hydrogen peroxide (HO) reduced the viability of Müller cells derived from Nrf2 wild-type (WT) and knockout (KO) mice. However, this effect was more significant in the KO cells than in the WT cells. Pretreatment with E inhibited HO-induced cell death in both Nrf2 WT and KO Müller cell genotypes. Small interfering RNA-mediated gene silencing of estrogen receptor 2 (Esr2) attenuated the cell survival-promoting activity of E in Nrf2 KO Müller cells, while other identified estrogen receptors, Esr1 or G protein-coupled estrogen receptor 1 (Gper1), had no effect. Western blotting revealed higher ESR2 expression levels in Nrf2 KO cells than in WT Müller cells. Conditioned media from E-and HO-treated Nrf2 WT or KO Müller cells enhanced the dissociated retinal cell viability compared with HO-treated cells. Both quantitative reverse-transcription polymerase chain reaction assay (qRT-PCR) and enzyme-linked immunosorbent assay exhibited a significant increase in fibroblast growth factor 2 (FGF2) expression levels in E-and HO-treated Nrf2 WT and KO Müller cells compared to those in E-treated cells. In vivo, administration of N-methyl-N-nitrosourea (MNU) reduced the thickness and cell density of the outer nuclear layer (ONL) in Nrf2 KO mice and enhanced the number of terminal deoxynucleotidyl transferase dUTP nick-end labeling-positive cells in the ONL. However, E administration attenuated these defects in MNU-treated mice. Concomitant administration of MNU and E enhanced FGF2 protein levels in retinal lysates of Nrf2 KO mice. In conclusion, E demonstrated a significant role in preventing oxidative stress-induced retinal cell death by stimulating FGF2 production in Müller cells, independent of the Nrf2 gene. Based on these findings, we anticipate that exogenous administration of estrogens or ESR2-selective agonists could aid in treating patients with oxidative stress-related retinal degenerative diseases such as age-related macular degeneration and retinitis pigmentosa.
在这项研究中，我们旨在探讨抗氧化基因核因子红细胞 2 相关因子 2（Nrf2）缺陷对 17β-雌二醇（E）介导的氧化应激反应的影响，特别是对 Müller 细胞和视网膜组织中生长因子产生和细胞死亡的影响。过氧化氢（HO）处理降低了来自 Nrf2 野生型（WT）和敲除（KO）小鼠的 Müller 细胞的活力。然而，这种作用在 KO 细胞中比在 WT 细胞中更为显著。E 的预处理抑制了两种 Nrf2 WT 和 KO Müller 细胞基因型中 HO 诱导的细胞死亡。雌激素受体 2（Esr2）的小干扰 RNA 介导的基因沉默减弱了 E 在 Nrf2 KO Müller 细胞中的促细胞存活活性，而其他鉴定的雌激素受体，Esr1 或 G 蛋白偶联雌激素受体 1（Gper1），则没有影响。Western blot 显示 Nrf2 KO 细胞中的 ESR2 表达水平高于 WT Müller 细胞。来自 E 和 HO 处理的 Nrf2 WT 或 KO Müller 细胞的条件培养基与 HO 处理的细胞相比，增强了分离的视网膜细胞的活力。定量逆转录聚合酶链反应（qRT-PCR）和酶联免疫吸附试验（ELISA）均显示，E 和 HO 处理的 Nrf2 WT 和 KO Müller 细胞中纤维母细胞生长因子 2（FGF2）的表达水平显著高于 E 处理的细胞。在体内，N-甲基-N-亚硝脲（MNU）的给药降低了 Nrf2 KO 小鼠的外核层（ONL）的厚度和细胞密度，并增强了 ONL 中末端脱氧核苷酸转移酶 dUTP 缺口末端标记阳性细胞的数量。然而，E 的给药减轻了 MNU 处理的小鼠的这些缺陷。MNU 和 E 的同时给药增强了 Nrf2 KO 小鼠视网膜裂解物中的 FGF2 蛋白水平。总之，E 通过刺激 Müller 细胞中 FGF2 的产生，在防止氧化应激诱导的视网膜细胞死亡方面发挥了重要作用，这与 Nrf2 基因无关。基于这些发现，我们预计外源性雌激素或 ESR2 选择性激动剂的给药可能有助于治疗与氧化应激相关的视网膜退行性疾病的患者，如年龄相关性黄斑变性和色素性视网膜炎。
