OXIDATION-INDUCED MEMBRANE DAMAGE IN CATARACTOGENESIS

白内障发生过程中氧化引起的膜损伤

• 批准号: 2158595
• 负责人: KAILASH C BHUYAN
• 金额: $ 26.7万
• 依托单位: COLUMBIA UNIV NEW YORK MORNINGSIDE
• 依托单位国家: 美国
• 财政年份: 1978
• 资助国家: 美国
• 起止时间: 1978-09-01 至 1996-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/2158595
• 关键词: aging; aminoacid analyzer; antioxidants; calcium transporting ATPase; cataract; disulfide bond; eye disorder chemotherapy; fluorimetry; free radical oxygen; gel electrophoresis; genetic strain; high performance liquid chromatography; human tissue; hydrogen peroxide; hydroxyl radical; ion transport; laboratory mouse; laboratory rabbit; lens proteins; lipid peroxides; membrane channels; membrane lipids; membrane permeability; membrane proteins; microspectrophotometry; oxidation; oxidative stress; pathogenic diet; phospholipids; polarography; radiotracer; sodium potassium exchanging ATPase; thin layer chromatography

Increase in cell membrane permeability to cations, is a common occurrence in cataracts, leading to intracellular ionic imbalance. Oxidation of protein occurs in human senile cataract, leading to crosslinking and the formation of high molecular weight crystallin aggregates. The peroxidation of membrane lipids may participate in both membrane permeability increases and protein oxidation. Lipids are more prone to oxidation than proteins, generating peroxide intermediates and free radicals that can initiate further oxidation of proteins. We hypothesize that oxygen-derived free radicals are the agents that trigger cataractogenesis by inducing peroxidation of membrane lipids, an early event in both membrane damage and protein oxidation. We will determine the sequence of appearance of relatively stable oxidants, hydrogen peroxide, lipid peroxide and the products of oxidation of cell membrane components in human donor normal lenses as a function of age, and in surgically extracted cataractous lenses by radioisotopic and enzyme-coupled spectrophotometric and spectrofluorometric techniques. Lipids and lipid peroxides will be identified by HPLC and their adducts by TLC. Adducts of lipid peroxidation products and proteins will be analysed by column chromatography and gel electrophoresis. Lipid repair mechanisms will be determined using radioactive probes. The formation of disulfide crosslinks in key plasma membrane proteins such as gap junction protein, MIP26 will be measured chromatographically and thiols spectrophotometrically. Na+, K+-activated and Ca2+-activated ATPases will be monitored biochemically for age-related loss in activity and oxidation. To test the hypothesis that oxidants will accelerate and antioxidants will retard the development of cataractous changes in the Emory mouse, a model of human senile cataract, we shall observe the effects of a low level of oxidative stress by feeding selenium in the diet, or an antioxidant, acetylsalicylate, in diet.

细胞膜对阳离子的渗透性增加是常见的发生 在白内障中，导致细胞内离子失衡。氧化 蛋白质发生在人类老年白内障中，导致交联，并 高分子量晶体聚集体的形成。 这 膜脂质的过氧化可能参与两种膜 渗透性增加和蛋白质氧化。 脂质更容易 氧化比蛋白质，产生过氧化物中间体和游离 可以引发蛋白质进一步氧化的自由基。 我们假设 氧气的自由基是触发的药物 白细胞生成通过诱导膜脂质的过氧化，早期 膜损伤和蛋白质氧化的事件。 我们将确定 相对稳定的氧化剂的外观顺序，氢 过氧化物，脂质过氧化物和细胞膜氧化产物 人类捐赠者正常镜片中的组成部分是年龄的函数，在 通过放射性病和 酶耦合分光光度计和光谱荧光测定法。 脂质和脂质过氧化物将通过HPLC及其加合物鉴定 由TLC。 脂质过氧化产物和蛋白质的加合物将是 通过柱色谱和凝胶电泳分析。 脂质修复 机制将使用放射性探针确定。 形成 关键质膜蛋白（例如间隙连接）中的二硫键交联 蛋白质，MIP26将通过色谱和硫醇测量 分光光度法。 Na+，K+激活和Ca2+活化的ATPase 将对生化监测，以了解活动与年龄相关的活动损失和 氧化。 测试氧化剂将加速和 抗氧化剂会阻碍白内障变化的发展 Emory Mouse是人类老年白内障模型，我们将观察到 低水平的氧化应激的影响通过进食硒 饮食中的饮食或抗氧化剂乙酰水杨酸酯。