Electron Microscopic Studies of Crystalline Lenses

描述（由申请人提供）：我们研究项目的长期目标是阐明脊椎动物晶状体的正常形态，因为它与人类晶状体功能有关。这些信息可作为进一步研究晶状体年龄相关和/或病理变化如何表现为晶状体光学质量受损（聚焦清晰度下降和光散射增加）的基线，最终导致特定白内障的发展。在过去的三个资助期，我们已经表明，在缝合解剖学的基础上，有四种不同类型的透镜。缝合线复杂性的变化与透镜光学质量有关。此外，我们已经证明，由于一些眼部手术（玻璃体切除术）、全身性疾病（糖尿病）和慢性治疗介导的长期神经和行为可塑性，在发育过程中后路缝合线畸形（常染色体隐性视网膜色素变性[ARRP]）如何导致后囊膜下白内障（PSC）的形成。更重要的是，我们发现至少有一些psc可以通过透镜光学质量的显著恢复来预防或逆转。该基金未来五年的研究计划旨在扩展我们之前的研究并实现以下具体目标：1)在已建立的动物模型中表征白内障（psc通常在短期内形成[占所有患者的50%]）和核性硬化性白内障（占所有老年患者的50%）作为玻璃体切除术或小梁切除术并发症的结构/功能关系；2)首次描述了雏鸟（鸡）、非灵长类动物、哺乳动物（兔）、灵长类动物（猴和狒狒）和人类晶状体中晶状体缝合线与动态聚焦（调节和非调节）之间的关系；3)继续阐明MIP、MP19、Cx46和Cx50敲除小鼠发育和生长过程中主要纤维膜蛋白对晶状体功能的贡献。在这些研究中，我们将利用我们实验室开发的一种改进的sds -骨折标记制备方案，首次保证沿纤维长度（晶状体缝合线上和缝合线外）和整个纤维发育和生长过程中主要膜蛋白的免疫标记。所有动物研究的结果在推断到人类情况时都必须是合格的。然而，如果上述使用动物模型的研究中导致PSC、核硬化和先天性白内障形成的因素与存在于人类条件下的因素相似，那么我们在实验室中开发并常规应用的技术所提供的对晶状体结构和功能之间关系的更深入了解，应该会导致早期发现和改善人类白内障的临床管理，而不管其病因如何。

DESCRIPTION (provided by applicant): The long term objective of our research program is to elucidate the normal morphology in vertebrate lenses as it relates to human lens function. This information serves as the baseline for additional study of how age-related and/or pathological changes in lenses are manifested as compromised lens optical quality (decreased sharpness of focus and increased light scatter) leading ultimately to the development of specific cataracts. In the last three grant periods we have shown that on the basis of sutural anatomy, there are four different types of lenses. Variations in sutural complexity correlate with lens optical quality. Furthermore, we have shown how malformation of posterior sutures during development (autosomal recessive retinitis pigmentosa [ARRP]), as a consequence of some ocular surgery (vitrectomy), systemic disease (diabetes), and chronic treatment to mediate long-lasting neural and behavioral plasticity, all lead to posterior subcapsular cataract (PSC) formation. More importantly, we have found that at least some of these PSCs can be prevented or reversed with significant restoration of lens optical quality. The studies proposed in the next five years of this grant are designed to expand on our previous studies and accomplish the following specific aims: 1) to characterize the structure/function relationship of cataracts (PSCs typically formed in the short term [>50% of all patients) and nuclear sclerotic cataracts that arise in the long term (>50% of all older patients) as a complication of vitrectomy or trabeculectomy in an established animal model; 2) to characterize, for the first time, the relationship between lens sutures and dynamic focusing (accommodation and non-accommodation) in young vs. old avian (chicken), non-primate, mammalian (rabbit), primate (monkey and baboon)and human lenses; and 3) to continue to elucidate the contributions of the major fiber membrane proteins to lens function during development and growth in MIP, MP19, Cx46 and Cx50 knockout mice. In these studies we will utilize an improved preparative protocol for SDS-fracture labelling developed in our laboratory, that guarantees, for the first time, immunolabelling of the major membrane proteins along fiber length (on and off lens sutures) and throughout fiber development and growth. The results of all animal studies must be qualified when extrapolating to the human condition. However, if the factors that are responsible for PSC, nuclear sclerotic and congenital cataract formation in the above studies using animal models are similar to those that exist in the human condition, then a greater understanding of the relationship between lens structure and function afforded by techniques that we have developed and routinely apply in our laboratory, should lead to earlier detection and improved clinical management of cataracts in humans irrespective of their etiopathology.