Oczos Jadwiga, Sutter Iryna, Kloeckener-Gruissem Barbara, Berger Wolfgang, Riwanto Meliana, Rentsch Katharina, Hornemann Thorsten, von Eckardstein Arnold, Grimm Christian
Lab for Retinal Cell Biology, Department of Ophthalmology, University of Zurich, Zurich, Switzerland.
Zurich Center for Integrative Human Physiology (ZIHP), University of Zurich, Zurich, Switzerland Institute of Clinical Chemistry, University of Zurich, Zurich, Switzerland.
Invest Ophthalmol Vis Sci. 2014 Jul 15;55(8):4714-27. doi: 10.1167/iovs.14-14332.
Biochemical and genetic analyses established a contribution of lipid metabolism to AMD pathology. Paraoxonase 1 (PON1) is an antioxidative protein involved in high density lipoprotein (HDL) function and was found to be associated with AMD. Here, we used Pon1(-/-) mice to study the influence of PON1 on retinal physiology and to reveal the potential impact of PON1 on AMD etiology.
Laser capture microdissection served to isolate single retinal layers. Retinal function was assessed by ERG. Retinal and RPE morphology were monitored by fundus imaging, fluorescein angiography, light and transmission electron microscopy, and immunofluorescence microscopy. Levels of mRNA and composition of phospholipid species were determined by real-time PCR and LC-MS, respectively.
Adult (8 weeks old) Pon1(-/-) mice displayed normal retinal function and morphology, but their retinas contained reduced amounts of lysophosphatidylcholines (LPCs) compared to controls. Aged (12 months old) Pon1(-/-) animals did not show any morphologic or molecular signs of photoreceptor or RPE degeneration, or of accelerated aging. Photoreceptors of Pon1(-/-) and control mice were similarly susceptible to light damage.
Results indicated that PON1 is not essential for normal development, function, ageing, and the defense against light damage of the mouse retina. Reduced levels of LPCs in eyes of Pon1(-/-) mice may reflect a decreased activity of phospholipase A2 or altered antioxidative activity in aged eyes.
生化和遗传学分析证实脂质代谢与年龄相关性黄斑变性（AMD）病理有关。对氧磷酶1（PON1）是一种参与高密度脂蛋白（HDL）功能的抗氧化蛋白，且发现其与AMD相关。在此，我们使用PON1基因敲除（Pon1(-/-)）小鼠来研究PON1对视网膜生理的影响，并揭示PON1对AMD病因的潜在影响。
激光捕获显微切割用于分离单个视网膜层。通过视网膜电图（ERG）评估视网膜功能。通过眼底成像、荧光素血管造影、光学和透射电子显微镜以及免疫荧光显微镜监测视网膜和视网膜色素上皮（RPE）的形态。分别通过实时聚合酶链反应（PCR）和液相色谱 - 质谱联用（LC-MS）测定mRNA水平和磷脂种类组成。
成年（8周龄）Pon1(-/-)小鼠表现出正常的视网膜功能和形态，但其视网膜中溶血磷脂酰胆碱（LPCs）的含量低于对照组。老年（12月龄）Pon1(-/-)动物未显示出任何光感受器或RPE退化或加速衰老的形态学或分子学迹象。Pon1(-/-)小鼠和对照小鼠的光感受器对光损伤的敏感性相似。
结果表明，PON1对于小鼠视网膜的正常发育、功能、衰老以及抵御光损伤并非必不可少。Pon1(-/-)小鼠眼中LPCs水平降低可能反映了老年眼中磷脂酶A2活性降低或抗氧化活性改变。
