CONTROL OF CELL DIVISION IN THE OCULAR LENS

长期的目标是了解晶状体上皮的变化。 伴随着白内障的形成和衰老。白内障手术是 60岁以上最常做的手术，以及 老年性白内障是世界上主要的致盲原因。 氧化侮辱可能会导致白内障。过氧化氢，一种 氧化剂存在于房水中，在水中升高 患有白内障的人类。近期目标是确定 H_2O_2诱导的形态和生化事件 幼年兔和老年兔、小鼠晶状体上皮细胞损伤及 在来自白内障患者和非白内障患者的人类细胞中。 将评估过氧化氢对这些细胞的长期影响，并 在活体和器官培养中的兔晶状体上。既不是类型 H_2O_2引起的损伤或H_2O_2对 晶状体上皮细胞或晶状体上皮细胞是已知的。这个项目 解决这些未知的问题。透射电子显微镜、扫描电子显微镜以及特定的探针 细胞骨架蛋白将被用来评估形态 细胞对亚致死剂量的过氧化氢的反应。 具体目的是：1)确定过氧化氢是否诱导单链 DNA断裂，如果断裂的数量与 过氧化氢对晶状体细胞有丝分裂的抑制作用； 确定细胞周期不同阶段的敏感性 H_2O_2损伤；3)确定H_2O_2损伤是否由 能量代谢。我们将确定过氧化氢对水平的影响 ATP、NAD、GSG、GSSG对甘油醛-3活性的影响 磷酸脱氢酶、己糖激酶和Na-K-ATPase对葡萄糖的影响 摄取和乳酸产生，以及在特定的水平上 糖酵解序列的中间体。磷酸盐的变化 活细胞中的代谢物和pH值将通过高密度的 分辨率核磁共振波谱；4)远期效应研究 青年和老年人前房内注射过氧化氢的研究 并测定损伤细胞的过氧化氢水平。 上皮细胞以及这是否会导致白内障的形成；5) 确定过氧化氢对大分子合成和IF的影响 H_2O_2诱导合成任何“新蛋白质” 对过氧化氢的抗性；6)比较晶状体细胞对过氧化氢的反应 和高压氧；以及7)调查年龄对 胰岛素受体和酪氨酸激酶活性，并确定是否 胰岛素或胰岛素样生长因子能刺激特定蛋白质的磷酸化。 成纤维细胞生长因子、胰岛素和胰岛素样生长因子的有丝分裂活性将在 培养细胞和在兔晶状体中进行器官培养。

The long objective is to understand changes in the lens epithelium which accompany cataract formation and aging. Cataract surgery is the most frequently performed operation for persons over 60, and senile cataract is the world's leading cause of blindness. Oxidative insult may cause cataracts. Hydrogen peroxide, an oxidant present in aqueous humor, is elevated in the aqueous of humans with cataracts. Immediate goals are to determine the morphological and biochemical events responsible for H2O2-induced injury in young and old rabbit and mouse lens epithelial cells and in human cells from cataractous and non-cataractous individuals. The long-term effect of H2O2 will be evaluated on these cells and on rabbit lenses in vivo and in organ culture. Neither the type of insult induced by H2O2 nor the long-term effects of H2O2 on lenses or on lens epithelial cells is known. This project addresses these unknowns. TEM, SEM as well as probes to specific cytoskeletal proteins will be used to evaluate the morphological response of cells to sublethal doses of H2O2. Specific aims are to: 1) determine if H2O2 induces single-strand DNA breaks and if the number of breaks correlates with the inhibition of mitosis noted in lens cells exposed to H2O2; 2) determine the susceptibility of various phases of the cell cycle to H2O2 insult; 3) determine if H2O2 damage is due to a defect in energy metabolism. We will ascertain the effect of H2O2 on levels of ATP, NAD, GSG, GSSG, on the activities of glyceraldehyde-3- phosphate dehydrogenase, hexokinase, and Na-K-ATPase, on glucose uptake and lactate production, and on the level of specific intermediates of the glycolytic sequence. Changes in phosphate metabolites and pH will be measured in living cells by high resolution NMR spectroscopy; 4) investigate the long-term effect of H2O2 injection into the anterior chamber of young and old rabbits, and determine the level of H2O2 that damages the epithelium and whether this leads to cataract formation; 5) determine the effect of H2O2 on macromolecular synthesis and if H2O2 induces the synthesis of any "new proteins" conferring resistance to H2O2; 6) compare the response of lens cells to H2O2 and hyper baric oxygen; and 7) investigate the effect of age on insulin receptors and tyrosine kinase activity, and determine if insulin or IGF stimulates the phosphorylation of specific proteins. The mitogenicity of FGF, insulin and IGF will be evaluated in cultured cells and in rabbit lenses in organ culture.