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， 导致细胞内离子失衡。氧化 蛋白质发生在人类老年性白内障，导致交联和 形成高分子量晶状体蛋白聚集体。 的 膜脂过氧化作用可能参与了两种膜 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自由 自由基，可以引发蛋白质的进一步氧化。 我们假设 氧自由基是引发 通过诱导膜脂质过氧化而引起的白内障， 膜损伤和蛋白质氧化。 我们将确定 相对稳定的氧化剂，氢， 过氧化物、脂质过氧化物和细胞膜氧化产物 人类供体正常晶状体中的成分作为年龄的函数， 通过放射性同位素手术摘除白内障晶状体， 酶偶联分光光度法和荧光分光光度法。 将通过HPLC及其加合物鉴别脂质和脂质过氧化物 采用薄层色谱法 脂质过氧化产物和蛋白质的加合物将 通过柱层析和凝胶电泳分析。 脂质修复 将使用放射性探针确定机制。 的形成 关键质膜蛋白如间隙连接中的二硫键交联 蛋白质，MIP 26将通过色谱法测量，硫醇 从几何学上来说。 Na+、K+激活和Ca 2+激活ATP酶 将进行生化监测，以确定与年龄相关的活动损失， 氧化 为了验证氧化剂会加速 抗氧化剂将延缓白内障的发展， Emory小鼠作为人类老年性白内障的模型，我们将观察 低水平的氧化应激的影响，通过喂养硒在 饮食，或抗氧化剂，乙酰水杨酸，饮食。