Zhu Xue, Wang Ke, Zhang Kai, Zhou Fanfan, Zhu Ling
Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, Jiangsu Province, China.
Key Laboratory of Nuclear Medicine, Ministry of Health, Jiangsu Key Laboratory of Molecular Nuclear Medicine, Jiangsu Institute of Nuclear Medicine, Wuxi 214063, Jiangsu Province, China.
Exp Cell Res. 2016 Oct 15;348(1):87-94. doi: 10.1016/j.yexcr.2016.09.002. Epub 2016 Sep 8.
Delayed clearance of free form all-trans-retinal (atRAL) is estimated be the key cause of retinal pigment epithelium (RPE) cells injury during the pathogenesis of retinopathies such as age-related macular degeneration (AMD), however, the underlying molecular mechanisms are far from clear. In this study, we investigated the cytotoxicity effect and underlying molecular mechanism of atRAL on human retinal pigment epithelium ARPE-19 cells. The results indicated that atRAL could cause cell dysfunction by inducing oxidative and nitrosative stresses in ARPE-19 cells. The oxidative stress induced by atRAL was mediated through up-regulation of reactive oxygen species (ROS) generation, activating mitochondrial-dependent and MAPKs signaling pathways, and finally resulting in apoptosis of ARPE-19 cells. The NADPH oxidase inhibitor apocynin could partly attenuated ROS generation, indicating that NADPH oxidase activity was involved in atRAL-induced oxidative stress in ARPE-19 cells. The nitrosative stress induced by atRAL was mainly reflected in increasing nitric oxide (NO) production, enhancing iNOS, ICAM-1 and VCAM-1 expressions, and promoting monocyte adhesion. Furthermore, above effects could be dramatically blocked by using a nuclear factor kappa B (NF-κB) inhibitor SN50, indicated that atRAL-induced oxidative and nitrosative stresses were mediated by NF-κB. The results provide better understanding of atRAL-induced toxicity in human RPE cells.
游离形式的全反式视黄醛（atRAL）清除延迟被认为是年龄相关性黄斑变性（AMD）等视网膜病变发病过程中视网膜色素上皮（RPE）细胞损伤的关键原因，然而，其潜在的分子机制尚不清楚。在本研究中，我们研究了atRAL对人视网膜色素上皮ARPE-19细胞的细胞毒性作用及其潜在的分子机制。结果表明atRAL可通过诱导ARPE-19细胞的氧化应激和亚硝化应激导致细胞功能障碍。atRAL诱导的氧化应激是通过上调活性氧（ROS）生成、激活线粒体依赖性和丝裂原活化蛋白激酶（MAPKs）信号通路介导的，最终导致ARPE-19细胞凋亡。NADPH氧化酶抑制剂夹竹桃麻素可部分减弱ROS生成，表明NADPH氧化酶活性参与了atRAL诱导的ARPE-19细胞氧化应激。atRAL诱导的亚硝化应激主要表现为一氧化氮（NO）生成增加、诱导型一氧化氮合酶（iNOS）、细胞间黏附分子-1（ICAM-1）和血管细胞黏附分子-1（VCAM-1）表达增强以及促进单核细胞黏附。此外，使用核因子κB（NF-κB）抑制剂SN50可显著阻断上述效应，表明atRAL诱导的氧化应激和亚硝化应激是由NF-κB介导的。这些结果有助于更好地理解atRAL对人RPE细胞的毒性作用。
