Tan Sih Min, Deliyanti Devy, Figgett William A, Talia Dean M, de Haan Judy B, Wilkinson-Berka Jennifer L
Oxidative Stress Laboratory, Diabetic Complications Division, Baker IDI Heart and Diabetes Institute, Melbourne, Victoria, Australia.
Department of Immunology and Pathology, Central Clinical School, Monash University, Melbourne, Victoria, Australia.
Exp Eye Res. 2015 Jul;136:1-8. doi: 10.1016/j.exer.2015.04.015. Epub 2015 Apr 24.
Oxidative stress is an important contributor to glial and vascular cell damage in ischemic retinopathies. We hypothesized that ebselen via its ability to reduce reactive oxygen species (ROS) and augment nuclear factor-like 2 (Nrf2) anti-oxidants would attenuate hypoxia-induced damage to macroglial Müller cells and also lessen retinal vasculopathy. Primary cultures of rat Müller cells were exposed to normoxia (21% O2), hypoxia (0.5% O2) and ebselen (2.5 μM) for up to 72 h. Oxygen-induced retinopathy (OIR) was induced in C57BL/6J mice while control mice were housed in room air. Mice received vehicle (saline, 5% dimethyl sulfoxide) or ebselen (10 mg/kg) each day between postnatal days 6-18. In cultured Müller cells, flow cytometry for dihydroethidium revealed that ebselen reduced the hypoxia-induced increase in ROS levels, whilst increasing the expression of Nrf2-regulated anti-oxidant genes, heme oxygenase 1, glutathione peroxidase-1, NAD(P)H dehydrogenase quinone oxidoreductase 1 and glutamate-cysteine ligase. Moreover, in Müller cells, ebselen reduced the hypoxia-induced increase in protein levels of pro-angiogenic and pro-inflammatory factors including vascular endothelial growth factor, interleukin-6, monocyte chemoattractant-protein 1 and intercellular adhesion molecule-1, and the mRNA levels of glial fibrillary acidic protein (GFAP), a marker of Müller cell injury. Ebselen improved OIR by attenuating capillary vaso-obliteration and neovascularization and a concomitant reduction in Müller cell gliosis and GFAP. We conclude that ebselen protects against hypoxia-induced injury of retinal Müller cells and the microvasculature, which is linked to its ability to reduce oxidative stress, vascular damaging factors and inflammation. Agents such as ebselen may be potential treatments for retinopathies that feature oxidative stress-mediated damage to glia and the microvasculature.
氧化应激是缺血性视网膜病变中神经胶质细胞和血管细胞损伤的重要因素。我们推测,依布硒啉通过其降低活性氧(ROS)和增强核因子样2(Nrf2)抗氧化剂的能力,将减轻缺氧诱导的大胶质Müller细胞损伤,并减轻视网膜血管病变。将大鼠Müller细胞原代培养物暴露于常氧(21% O₂)、缺氧(0.5% O₂)和依布硒啉(2.5 μM)中长达72小时。在C57BL/6J小鼠中诱导氧诱导性视网膜病变(OIR),而对照小鼠饲养在室内空气中。在出生后第6 - 18天期间,小鼠每天接受载体(生理盐水、5%二甲基亚砜)或依布硒啉(10 mg/kg)。在培养的Müller细胞中,二氢乙锭流式细胞术显示依布硒啉降低了缺氧诱导的ROS水平升高,同时增加了Nrf2调节的抗氧化基因、血红素加氧酶1(HO-1)、谷胱甘肽过氧化物酶-1(GPx-1)、NAD(P)H脱氢酶醌氧化还原酶1(NQO1)和谷氨酸-半胱氨酸连接酶(GCL)的表达。此外,在Müller细胞中,依布硒啉降低了缺氧诱导的促血管生成和促炎因子蛋白水平的升高,这些因子包括血管内皮生长因子(VEGF)、白细胞介素-6(IL-6)、单核细胞趋化蛋白-1(MCP-1)和细胞间黏附分子-1(ICAM-1),以及Müller细胞损伤标志物胶质纤维酸性蛋白(GFAP)的mRNA水平。依布硒啉通过减轻毛细血管闭塞和新生血管形成以及伴随的Müller细胞胶质增生和GFAP减少,改善了OIR。我们得出结论,依布硒啉可保护视网膜Müller细胞和微血管免受缺氧诱导的损伤,这与其降低氧化应激、血管损伤因子和炎症的能力有关。像依布硒啉这样的药物可能是治疗以氧化应激介导的神经胶质细胞和微血管损伤为特征的视网膜病变的潜在疗法。