Eye Center, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, 430060, Hubei, China.
Eye Center, Renmin Hospital of Wuhan University, Wuhan University, Wuhan, 430060, Hubei, China; Urumqi City Ophthalmology and Otolaryngology Hospital, Urumqi, 830000, Xinjiang, China.
Exp Eye Res. 2019 Dec;189:107826. doi: 10.1016/j.exer.2019.107826. Epub 2019 Oct 2.
To investigate the potential protective effect of novel G protein coupled estrogen receptor (GPER1) against the neurotoxicity induced by NMDA in the mouse retina.
We induce retinal ganglion cells (RGCs) toxic injury through intravitreal injection of NMDA or acute ocular hypertension (AOH) induced by anterior chamber infusion with saline. Endogenous ligand 17-β-estradiol (E2), GPER1 agonist (G-1), and E2 with GPER1 antagonist (G-15) or classic estrogen receptor α and β (ERα and ERβ) antagonist tamoxifen (TAM) were subcutaneous administered before NMDA to identify the possible involved receptors. Immunofluorescence staining was performed to explore the survival of RGCs and Müller cell gliosis. TUNEL staining was used to evaluate the RGC apoptosis. The involved molecular pathway was detected via antibody array expression profiling.
Activation of estrogen receptor by E2 or G-1 could significantly rescue the RGCs injury in NMDA administration. The protective effect was carried exclusively by GPER1 activation. E2 application can still mimicked the protective function when estrogen receptor α and β (ERα and ERβ) blocked by tamoxifen (TAM), while the effects was blocked by GPER1 antagonist G-15. Moreover, the TUNEL positive RGCs and GFAP expression level were both attenuated in G-1 application and the effects could be reversed by G-15. In addition, application of the PI3K/Akt antagonist LY294002 counteracted the effect of G-1. And a number of apoptosis regulatory factors decreased dramatically in the G-1 group, including Bad, Caspase 3, Caspase 7, Smad2, P-53 and TAK1. Also, similar protective effect of G-1 was spotted in acute ocular hypertension (AOH) model.
Estrogen played a protective role via a novel estrogen receptor, GPER1, instead of classical receptors ERα or ERβ. Activation of GPER1 attenuated RGCs apoptosis and Müller cells gliosis, indicating GPER1 as a potential treatment target in RGCs degeneration diseases.
探讨新型 G 蛋白偶联雌激素受体（GPER1）对 NMDA 诱导的小鼠视网膜神经毒性的潜在保护作用。
通过玻璃体内注射 NMDA 或前房内注射盐水诱导急性眼内压升高（AOH），诱导视网膜神经节细胞（RGCs）毒性损伤。在 NMDA 给药前，通过皮下给予内源性配体 17-β-雌二醇（E2）、GPER1 激动剂（G-1）、E2 与 GPER1 拮抗剂（G-15）或经典雌激素受体α和β（ERα和 ERβ）拮抗剂他莫昔芬（TAM），以鉴定可能涉及的受体。免疫荧光染色用于探索 RGCs 存活和 Muller 细胞胶质增生。TUNEL 染色用于评估 RGC 细胞凋亡。通过抗体阵列表达谱检测涉及的分子途径。
E2 或 G-1 激活雌激素受体可显著挽救 NMDA 给药引起的 RGCs 损伤。这种保护作用仅由 GPER1 激活介导。当雌激素受体 α 和 β（ERα和 ERβ）被他莫昔芬（TAM）阻断时，E2 仍能模拟其保护作用，而 GPER1 拮抗剂 G-15 则阻断了这种作用。此外，G-1 应用可减弱 TUNEL 阳性 RGCs 和 GFAP 表达水平，而 G-15 可逆转该作用。此外，PI3K/Akt 拮抗剂 LY294002 可拮抗 G-1 的作用。在 G-1 组中，许多凋亡调节因子的表达水平显著降低，包括 Bad、Caspase 3、Caspase 7、Smad2、P-53 和 TAK1。同样，在急性眼内压升高（AOH）模型中也观察到 G-1 的类似保护作用。
雌激素通过一种新型雌激素受体 GPER1 发挥保护作用，而不是经典受体 ERα 或 ERβ。GPER1 的激活可减轻 RGCs 凋亡和 Muller 细胞胶质增生，表明 GPER1 可能成为 RGCs 退行性疾病的潜在治疗靶点。
