Ceruloplasmin/hephaestin knockout mice model morphologic and molecular features of AMD
Ceruloplasmin/hephaestin knockout mice model morphologic and molecular features of AMD
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DOI：
10.1167/iovs.07-1472
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发表时间：
2008-06-01
影响因子：
4.4
通讯作者：
Dunaief, Joshua L.
中科院分区：
文献类型：
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作者：
Hadziahmetovic, Majda;Dentchev, Tzvete;Dunaief, Joshua L.
目的。铁是人体新陈代谢中必不可少的元素，但也是氧化损伤的有力推动者，其水平会随着年龄的增长而增加。多项研究表明，铁蓄积可能是老年性黄斑变性(AMD)的一个因素。在先前的研究中，铁超载和AMD的特征都在铜蓝蛋白铁氧化酶(CP)及其同系物HEPH(双基因敲除，DKO)缺陷的小鼠中被发现。方法对DKO和对照组小鼠视网膜切片进行形态分析和Perls‘s染色组织化学铁检测。免疫荧光和免疫组织化学检测活化补体C3、转铁蛋白受体、L铁蛋白和巨噬细胞。用原子吸收分光光度法测组织铁含量。结果：DKO表现出高度可重复性的年龄依赖性铁超载，在6个月龄时停滞，随后的进行性视网膜变性持续至少12个月。该变性具有AMD的一些特征，包括RPE肥大和增生、光感受器变性、视网膜下新生血管、RPE脂褐素积聚、氧化应激和补体激活。结论DKO具有年龄依赖性的铁蓄积和视网膜变性，模拟了AMD的一些形态和分子特征。因此，这些小鼠是测试AMD治疗药物的一个很好的平台，如抗氧化剂、铁络合剂和抗血管生成药物。
PURPOSE. Iron is an essential element in human metabolism but also is a potent generator of oxidative damage with levels that increase with age. Several studies suggest that iron accumulation may be a factor in age-related macular degeneration (AMD). In prior studies, both iron overload and features of AMD were identified in mice deficient in the ferroxidase ceruloplasmin (Cp) and its homologue hephaestin (Heph) (double knockout, DKO). In this study, the location and timing of iron accumulation, the rate and reproducibility of retinal degeneration, and the roles of oxidative stress and complement activation were determined.METHODS. Morphologic analysis and histochemical iron detection by Perls' staining was performed on retina sections from DKO and control mice. Immunofluorescence and immunohistochemistry were performed with antibodies detecting activated complement factor C3, transferrin receptor, L-ferritin, and macrophages. Tissue iron levels were measured by atomic absorption spectrophotometry. Isoprostane F2 alpha-VI, a specific marker of oxidative stress, was quantified in the tissue by gas chromatography/mass spectrometry.RESULTS. DKOs exhibited highly reproducible age-dependent iron overload, which plateaued at 6 months of age, with subsequent progressive retinal degeneration continuing to at least 12 months. The degeneration shared some features of AMD, including RPE hypertrophy and hyperplasia, photoreceptor degeneration, subretinal neovascularization, RPE lipofuscin accumulation, oxidative stress, and complement activation.CONCLUSIONS. DKOs have age-dependent iron accumulation followed by retinal degeneration modeling some of the morphologic and molecular features of AMD. Therefore, these mice are a good platform on which to test therapeutic agents for AMD, such as antioxidants, iron chelators, and antiangiogenic agents.