MOLECULAR BIOLOGY OF DIABETIC CATARACT FORMATION

描述(摘自申请者的摘要)：糖尿病白内障是一种 严重且代价高昂的世界性健康问题。细胞内渗透应激 与糖尿病白内障的病因有关。定义的定义 导致并发症的基本分子和细胞过程的顺序 糖尿病白内障的发病机制尚未得到证实。有机物质的积累 渗透激素(山梨醇、肌醇、牛磺酸)通常保护晶状体免受 通过维持细胞内渗透平衡来实现渗透失衡。在 维持晶状体动态平衡的过程中，晶状体上皮层保存 通过利用几种渗透补偿机制本身，而 潜在的纤维细胞，可能是因为渗透调节能力减弱， 肿胀和水泡。为了获得一个真实的观点，以病理生理影响 渗透性应激对糖尿病白内障形成的影响--一种新的转基因动物模型 已被开发用于探索渗透性疾病的发病机制和治疗方法 白内障的发生。我们已经成功地引进了牛 钠/肌醇共转运蛋白基因(BSMIT)在几个小鼠系中的表达 结果表明，转基因在发育中的晶状体纤维中有功能表达。镜头 纤维肿胀和随之而来的白内障形成提供了生理性的 模拟人类糖尿病白内障进程的代用品。小心 对小鼠晶状体区域发育和早发性肿胀的仔细检查允许 对晶状体纤维没有能力的假设的验证 渗透调节。转基因的分子生物学和病理生理学 表现为糖尿病白内障的小鼠模型将通过关联 原位杂交和偶联反向杂交检测bSMIT基因的表达水平 转录/聚合酶链式反应与晶状体内含物 免费的肌醇。透镜的形态将跟随着光和电子 转基因和非转基因窝产仔的显微评价 六个月大的小鼠的胚胎晶状体通过晶状体向上生长。低 转基因小鼠，正常饲养不会形成晶状体混浊 和饮食，将使这样做与肌醇补充饮食。这个 糖尿病病理生理学中事件顺序的确定 白内障的形成将确定介入的部位，并允许 开发创新的药理药物以预防或阻止 糖尿病性白内障的进展。一种这样的干预是激活氯化物 通道，这促进了氯的排出和肌醇的外流。本研究 建议测试增强肌醇外流的潜在有用性 通过氯通道作为药物治疗的手段来缓解纤维内 渗透胁迫。

DESCRIPTION (Adapted from applicant's abstract): Diabetic cataract is a significant and costly worldwide health problem. Intracellular osmotic stress has been implicated in the etiology of diabetic cataract. The definition of the sequence of basic molecular and cellular processes leading to the complications of diabetic cataract have yet to be established. The accumulation of organic osmolytes (sorbitol, myo-inositol, taurine) normally protects the lens against osmotic imbalance by maintaining intracellular osmotic homoeostasis. In the course of maintaining lens homeostasis, the lens epithelial layer preserves itself by utilizing several osmotic compensatory mechanisms, whereas the subjacent fiber cells, likely because of a diminished capacity to osmoregulate, swell and bleb. To obtain a realistic view of the pathophysiological impact of osmotic stress on diabetic cataract formation, a novel transgenic animal model has been developed useful to exploring the pathogenesis and therapy of osmotic cataractogenesis. We have successfully introduced the bovine sodium/myo-inositol cotransporter gene (bSMIT) in several mouse lines and have shown the transgene is functionally expressed in developing lens fibers. Lens fiber swelling and consequent cataractous formation provide a physiological surrogate that simulates the progression of human diabetic cataract. Careful scrutiny of mouse lens regional development and early-onset swelling allows for verification of the hypothesis that the lens fibers are incapable of osmoregulation. The molecular biology and the pathophysiology of the transgenic mouse model exhibiting diabetic cataract will be linked by correlating the level of bSMIT gene expression via in situ hybridization and coupled reverse transcription/polymerase chain reaction with the intralenticular content of free myo-inositol. Lens morphology will be followed by light and electron microscopic evaluation of transgenic and nontransgenic littermates using embryonic lenses up through lenses from six month-old mice. Low transgene-expressing mice, which do not form lens opacities with normal rearing and diet, will be made to do so with a myo-inositol supplemented diet. The determination of the sequence of events in the pathophysiology of diabetic cataract formation will identify sites of intervention and allow for the development of innovative pharmacological agents to prevent or halt the progression of diabetic cataract. One such intervention is to activate chloride channels, which enhances both chloride exit and myo-inositol efflux. This study proposes to test the potential usefulness of enhancing myo-inositol efflux through chloride channels as a means for drug therapy to relieve intrafiber osmotic stress.