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，因为它与人类透镜功能有关。该信息作为进一步研究的基线，研究晶状体中的年龄相关和/或病理变化如何表现为受损的透镜光学质量（焦点清晰度降低和光散射增加），最终导致特定白内障的发生。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，有四种不同类型的晶状体。缝线复杂性的变化与透镜光学质量相关。此外，我们已经证明了发育过程中的后缝畸形（常染色体隐性视网膜色素变性[ARRP]），作为某些眼科手术（玻璃体切除术）、全身性疾病（糖尿病）和慢性治疗的结果，以介导持久的神经和行为可塑性，所有这些都导致后囊下白内障（PSC）的形成。更重要的是，我们已经发现，这些PSC中的至少一些可以通过显著恢复透镜光学质量来预防或逆转。在未来五年内，这项赠款的研究旨在扩大我们以前的研究，并实现以下具体目标：1）表征白内障的结构/功能关系（PSC通常在短期内形成[> 50%的所有患者）和长期出现的核性巩膜白内障（> 50%的老年患者）作为玻璃体切除术或小梁切除术的并发症; 2）首次描述，透镜缝线与动态聚焦的关系（适应和非适应）幼龄与老龄禽类（鸡）、非灵长类、哺乳动物（兔）、灵长类（猴和狒狒）和人晶状体; 3）继续阐明MIP、MP 19、Cx46和Cx50敲除小鼠发育和生长期间主要纤维膜蛋白对透镜功能的贡献。在这些研究中，我们将利用我们实验室开发的SDS-断裂标记的改进制备方案，该方案首次保证了沿沿着纤维长度（在透镜缝线上和缝线下）以及整个纤维发育和生长过程中主要膜蛋白的免疫标记。当外推到人体状况时，所有动物研究的结果必须合格。然而，如果在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人类条件中存在的因素相似，那么通过我们在实验室中开发和常规应用的技术，应该导致人类白内障的早期检测和改善的临床管理，而不管其病因。

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.