CONTROL OF CELL DIVISION IN THE OCULAR LENS

长期目标是了解透镜上皮细胞的变化 其伴随白内障形成和老化。 白内障手术是 60岁以上的人最常做的手术， 老年性白内障是世界上最主要的致盲性疾病。 氧化损伤可引起白内障。 过氧化氢 氧化剂存在于房水中，在眼房水中升高， 患有白内障的人 近期目标是确定 形态和生化事件负责H2 O2诱导 青年和老年兔和小鼠透镜上皮细胞损伤， 在白内障和非白内障个体的人类细胞中。 将评估H2 O2对这些细胞的长期影响， 在活体和器官培养中的作用。 也不是那种 H2 O2诱导的损伤，也不是H2 O2对 晶状体上或透镜上皮细胞上的细胞是已知的。 这个项目 解决这些未知数。 TEM、SEM以及针对特定 细胞骨架蛋白将被用来评估形态学 细胞对亚致死剂量H2 O2的反应。 具体目标是：1）确定H2 O2是否诱导单链 DNA断裂，如果断裂的数量与 在暴露于H2 O2的透镜细胞中观察到有丝分裂抑制; 2） 确定细胞周期各个阶段的易感性 H2 O2损伤; 3）确定H2 O2损伤是否是由于 能量代谢 我们将确定H2 O2对水平的影响 ATP、NAD、GSG、GSSG对甘油醛-3- 磷酸脱氢酶、己糖激酶和Na-K-ATP酶对葡萄糖 摄取和乳酸生产，并在特定的水平上 糖酵解序列的中间体。 磷酸盐变化 代谢物和pH值将在活细胞中通过高 分辨率NMR光谱; 4）研究长期效应 年轻人和老年人前房内注射H2 O2 兔，并确定H2 O2的水平，损害 上皮以及这是否导致白内障形成; 5） 确定H2 O2对大分子合成的影响， H2 O2诱导任何“新蛋白质”的合成， 抗H2 O2; 6）比较透镜细胞对H2 O2的响应 和高压氧;和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IGF刺激特定蛋白质的磷酸化。 FGF、胰岛素和IGF的促有丝分裂性将在 培养的细胞和器官培养中的兔晶状体。

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.