CALCIUM AND THE NORMAL LENS AND CATARACT

描述：白内障和后囊混浊(PCO)是主要的 耗尽了全世界的卫生预算，这是一个长期的 本项目的目标是制定预防这两种情况的策略 条件。众所周知，钙在皮质性白内障中起着关键作用， 此外，还牵涉到了钙蛋白酶的激活。最近，它已经做到了 研究表明，钙在正常人类晶状体中也有重要作用 内质网钙动员的细胞信号转导 商店，通过G蛋白偶联受体。这些受体的激动剂 包括三磷酸腺苷和乙酰胆碱，后者与白内障有关 队形。 具体目的是首先阐明激动剂诱导的部位。 在完整的人类晶状体中，细胞内储存的钙释放。 其次，对商店经营的钙进入途径进行本地化和研究 它们的激活和失活特性。第三，本土化 当钙的增加导致钙蛋白的激活和丢失 透明度，并测试钙蛋白酶拮抗剂。最终目标将是 开发和测试疏水性人工晶状体涂层以防止后发性白内障，基于 对thapsigargin等钙离子信号拮抗剂的认识 (Tg)。因为在晶状体上有相当大的种间差异 行为项目设计的一个重要方面是开发 技术，包括长期培养，只使用人类的镜头和 胶囊袋制剂。技术包括共聚焦荧光(Fluo-3) 细胞钙动力学与电生理和放射示踪剂的成像 方法对钙离子进入途径进行表征。钙蛋白酶的激活将 用荧光探头测量，晶状体混浊定位和 通过数字成像进行量化，并通过 免疫细胞化学和凝胶电泳法。钙蛋白酶拮抗剂将会是 测试以确定哪些镜头能最好地保持镜头透明度。这个 胶囊袋培养系统将是测试 眼内生长抑制(并因此抑制后囊混浊)特性 晶状体(IOL)涂有thapsigargin。~3H-Tg将用于 优化涂布工艺。甘油三酯包埋人工晶状体的消融能力 囊袋制剂中激动剂诱导的钙信号将作为 对涂层功效的准确评估。 因此，这项研究的目的不仅仅是阐明钙的作用 在正常的人类晶状体中，也是为了确定预防策略 皮质性白内障和后发性白内障都是基于这一知识。

DESCRIPTION: Cataract and posterior capsule opacification (PCO) are major drains on health budgets throughout the world and it is a long-term objective of this project to develop strategies to prevent both of these conditions. Calcium is known to play a critical role in cortical cataract, and activation of the protease calpain is implicated. More recently it has been revealed that calcium also has an important role in normal human lens cell signaling through calcium mobilization from endoplasmic reticulum stores, via G-protein coupled receptors. Agonists for these receptors include ATP and acetylcholine and the latter has been implicated in cataract formation. The specific aims are firstly to elucidate the sites of agonist-induced calcium release from intracellular stores in the intact human lens. Secondly to localize the store-operated calcium entry pathways and study their activation and inactivation characteristics. Thirdly to localize where a calcium increase leads to calpain activation and loss of transparency, and to test calpain antagonists. The final aim will be to develop and test hydrophobic intraocular lens coatings to prevent PCO, based on knowledge of calcium cell signaling antagonists such as thapsigargin (Tg). Since there are considerable interspecies differences in lens behaviour a significant aspect of project design has been the development of techniques, including long-term culture, employing only human lens and capsular bag preparations. Techniques include confocal fluorescent (Fluo-3) imaging for cell calcium dynamics and electrophysiological and radiotracer methods to characterize the calcium entry pathways. Calpain activation will be measured with a fluorescent probe, lens opacification localized and quantified by digital imaging, and proteolysis studied by immunocytochemistry and gel electrophoresis. Calpain antagonists will be tested to determine those which best preserve lens transparency. The capsular bag culture system will be invaluable for testing the growth-inhibiting (and hence PCO inhibiting) properties of intraocular lenses (IOLs) coated with thapsigargin. 3H-labeled Tg will be used to optimize the coating technology. The ability of Tg-coated IOLs to abolish agonist-induced calcium signaling in capsular bag preparations will serve as an accurate assessment of coating efficacy. This investigation aims therefore not only to elucidate the role of calcium in the normal human lens, but also to identify strategies for preventing both cortical cataract and PCO based on that knowledge.