Chen Lin, Wu Wayne, Dentchev Tzvete, Wong Robert, Dunaief Joshua L
F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA 19104, USA.
Exp Eye Res. 2004 Aug;79(2):287-93. doi: 10.1016/j.exer.2004.05.004.
Oxidative stress plays a role in human age-related macular degeneration and in the light damage model of retinal degeneration. Metallothionein (MT), an antioxidant, has been reported to protect retinal pigment epithelial cells against apoptosis and oxidative stress. The purpose of this study was to evaluate changes in MT expression level and retinal localization following light damage. To accomplish this, Balb/c mice were exposed to cool white fluorescent light (10,000 lx) for 7 hr. In three independent experiments, at several intervals after the light injury, retinal MTs were studied at the protein level by immunohistochemistry (IHC) and Western analysis, and at the mRNA level by quantitative PCR with isoform-specific primers. Western analysis and IHC indicated an increase in metallothionein protein following light damage. MT localized to the retinal pigment epithelium and several layers of neural retina. Quantitative PCR identified the expression of MT I-III isoforms, not the MT IV isoform in the mouse retina, and, following light damage, showed increased expression of retinal MT-I and MT-II mRNAs by 8- and 22-fold, respectively. Increased expression of the antioxidant MT in the light damaged mouse retina suggests that upregulation of MT is an important acute retinal response to photo-oxidative stress.
氧化应激在人类年龄相关性黄斑变性以及视网膜变性的光损伤模型中发挥作用。金属硫蛋白（MT）作为一种抗氧化剂，据报道可保护视网膜色素上皮细胞免受凋亡和氧化应激的影响。本研究的目的是评估光损伤后MT表达水平的变化以及在视网膜中的定位。为实现这一目的，将Balb/c小鼠暴露于冷白色荧光灯下（10,000勒克斯）7小时。在三个独立实验中，在光损伤后的几个时间间隔，通过免疫组织化学（IHC）和蛋白质印迹分析在蛋白质水平研究视网膜MT，通过使用亚型特异性引物的定量PCR在mRNA水平进行研究。蛋白质印迹分析和免疫组织化学表明光损伤后金属硫蛋白蛋白增加。MT定位于视网膜色素上皮和神经视网膜的几层。定量PCR鉴定了MT I-III亚型在小鼠视网膜中的表达，而非MT IV亚型，并且在光损伤后，视网膜MT-I和MT-II mRNA的表达分别增加了8倍和22倍。光损伤小鼠视网膜中抗氧化剂MT的表达增加表明MT的上调是视网膜对光氧化应激的重要急性反应。
