ELECTRON MICROSCOPIC STUDIES OF THE CRYSTALLINE LENS

晶状体的电子显微镜研究

• 批准号: 6518371
• 负责人: Jer Kuszak
• 金额: $ 28.6万
• 依托单位: RUSH UNIVERSITY MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 1986
• 资助国家: 美国
• 起止时间: 1986-07-01 至 2003-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6518371
• 关键词: aging; animal tissue; cataract; confocal scanning microscopy; congenital eye disorder; crystallins; diabetes mellitus; drug adverse effect; freeze etching; gap junctions; genetically modified animals; hormone therapy; human tissue; immunoelectron microscopy; laboratory mouse; lens; light microscopy; macrophage inflammatory proteins; morphology; pathologic process; retinitis pigmentosa; scanning electron microscopy; steroid hormone; transmission electron microscopy

The long term objective of our research program has been, and continues to be, the elucidation of normal human lens morphology as it relates to lens function, and how age-related and/or pathological changes in the lens are manifested as compromised lens optics leading ultimately to specific cataracts. Our preliminary studies of posterior subcapsular cataracts (PSC) from experimental animal models for Retinitis Pigmentosa (RP) and for the effects of Hydroxymethlyglutaryl (HMG)-CoA reductase inhibitors on PSC formation, suggest that the PSC opacities of these lenses result from a progressive compromise in posterior sutural anatomy rather than from a proliferation of dysplastic 'Wedl' cell migrating to the posterior pole. In our previous studies we have developed, and successfully applied, correlative techniques that allow for the accurate quantification of progressive, negative changes in lens sutural anatomy, prior to and resulting in opacification. Thus, the studies proposed in the five years of this grant are designed to accomplish the following specific aims: First, to determine if a comparable, progressive, and quantifiable, negative relationship exists between lens structure (particularly sutural anatomy) and function (spherical aberration, i.e. focal length variability) before, during and after PSC formation, as a consequence of different etiologies including: 1) long term therapeutic treatment with HMG-CoA reductase inhibitors; 2) RP; 3) therapeutic treatment with steroids; 4) diabetes; and 5) AIDS. Second, to further elucidate the ultrastructure of primate lens cells (central, pre-germinative, germinative, and transitional zone epithelial cells, as well as elongating, mature and aged fibers) as a function of development, growth, age and pathology. As regards the first set of specific aims: The optical quality (focal length variability; i.e spherical aberration) of the experimental animal lenses will be assessed by analysis with a low power helium-neon laser scan unit of our own design with particular reference to lens sutures. The laser scanned lenses will then be precisely dissected by a method that we have developed permitting the retrieval of complete intact suture patterns at progressive depths from the anterior and posterior poles for structural analysis by scanning electron microscopy (SEM). In this manner, lens sutural anatomy as a function of development, growth, age and cataractogenesis can be accurately characterized. The in situ 3D sutural anatomy of all lenses dissected as above, will then be ascertained by 3D-CAD reconstructional analysis to determine if structural correlates found to adversely effect lens function by laser scan analysis, correspond to the PSC opacities. Comparable groups of experimental animal lenses will also be examined by biomicroscopic slit-lamp analysis to determine if compromised lens growth manifested as abnormal sutures, correlate with the production of zones of discontinuity that are not normally characteristic of these non primate lenses. These results will be compared to simulated slit-lamp images taken from the 3D-CAD reconstructions of laser scanned lenses and with slit-lamp images taken of human PSCs resulting from the above described etiologies. With a greater understanding of the inter-relationship between lens structure/function afforded by techniques that we have developed and applied in our laboratories, then the results of studies described in this proposal could lead to the earlier detection and improved clinical management of human PSCs as a consequence of different etiologies.

我们研究计划的长期目标一直是并将继续是阐明正常人类透镜形态与透镜功能的关系，以及透镜中年龄相关和/或病理变化如何表现为受损的透镜光学特性，最终导致特定的白内障。我们对色素性视网膜炎（RP）实验动物模型的后囊下白内障（PSC）以及羟甲基戊二酰（HMG）-CoA还原酶抑制剂对PSC形成的影响进行了初步研究，结果表明，这些晶状体的PSC混浊是由于后缝解剖结构的渐进性损害，而不是由于发育不良的“Wedl”细胞迁移到后极的增殖。在我们以前的研究中，我们已经开发并成功应用了相关技术，这些技术可以准确量化在混浊之前和导致混浊的透镜缝合解剖结构的进行性、负性变化。因此，在该补助金的五年内提出的研究旨在实现以下具体目标：首先，确定透镜结构之间是否存在可比较的、渐进的、可量化的负相关关系。（特别是缝合解剖）和功能在PSC形成之前、期间和之后，作为不同病因的结果，包括：1）用HMG-CoA还原酶抑制剂的长期治疗性治疗; 2）RP; 3）用类固醇的治疗性治疗; 4）糖尿病;和5）AIDS。第二，进一步阐明灵长类动物透镜细胞（中央、萌发前、萌发和移行区上皮细胞，以及伸长、成熟和老化纤维）的超微结构与发育、生长、年龄和病理的关系。关于第一组特定目标：将通过使用我们自己设计的低功率氦氖激光扫描装置（特别是透镜缝线）进行分析，评估实验动物晶状体的光学质量（焦距变化性;即球面像差）。然后通过我们开发的方法精确解剖激光扫描晶状体，该方法允许从前极和后极的渐进深度处取回完整的完整缝线图案，以通过扫描电子显微镜（SEM）进行结构分析。以这种方式，透镜缝合解剖学作为发育、生长、年龄和白内障发生的函数可以被准确地表征。然后通过3D-CAD重建分析确定如上解剖的所有晶状体的原位3D缝合解剖结构，以确定通过激光扫描分析发现的对透镜功能产生不利影响的结构相关性是否对应于PSC混浊。还将通过生物显微镜裂隙灯分析检查可比较的实验动物晶状体组，以确定表现为异常缝线的受损透镜生长是否与这些非灵长类动物晶状体通常不具有特征的不连续区的产生相关。将这些结果与从激光扫描晶状体的3D-CAD重建中拍摄的模拟裂隙灯图像以及从上述病因学产生的人PSC拍摄的裂隙灯图像进行比较。随着对我们在实验室开发和应用的技术所提供的透镜结构/功能之间的相互关系有了更深入的了解，本提案中描述的研究结果可能会导致早期检测和改善人类PSC的临床管理，这是不同病因的结果。