Molecular Mechanism of αAN101D-Transgene-Induced Age-Related Cataract

该提案的总体目标是确定老年性皮质性白内障的分子机制。 发展。白内障主要是晶状体结构蛋白(晶状体蛋白)的聚集和随后的 可由基因突变诱发的、因衰老而发生的沉淀病。在白内障期间 随着发展，聚集的和交联的晶体蛋白多聚体的尺寸变得如此之大，以至于它们 最后变得不溶于水，造成晶状体混浊。的几个翻译后修改(PTM) 已知晶状体蛋白可引起老年性白内障，而晶状体蛋白的脱酰胺化(最丰富的 在翻译后修饰中)被认为是导致白内障的主要因素。尽管有大量的 关于晶体蛋白脱酰胺化导致白内障发生的体外研究文献，尚不清楚 分子机制已经出现，可能牵涉到脱酰胺诱导的体外效应与In 活体发生了变化。因此，PI生成的独特的αA-N101D小鼠模型，其中天冬酰胺101是 去酰胺化为天冬氨酸，提供了一个直接将体外研究与体内变化联系起来的机会 表型和晶状体蛋白在皮质性白内障发生中的作用。该模型将提供信息 关于老年性白内障发生的分子机制。基于我们广泛的结果，我们有 假设αAN101D小鼠模型中的白内障是由晶状体蛋白属性改变引起的，细胞 αAN101D的缺陷和协同增加与膜的沉积，导致膜破裂和 离子失衡。我们计划通过以下三个问题的答案来检验上述假设 上述小鼠模型：(A)目的1：去胺化的αAN101D是否导致晶体蛋白的时间变化- 晶状体蛋白相互作用导致晶状体蛋白之间的聚集及其在体内的不溶解？(B) 目标2：在皮质期导致细胞缺陷的晶状体表型的时间顺序是什么？ 白内障的发展？(C)目标3：去胺化的αAN101D与 膜导致膜的解体和细胞内离子失衡？结果将是 对延缓老年性白内障的发生发展具有重要的治疗价值。

The proposal has the overall goal to determine the molecular mechanisms of an age-related cortical cataract development. Cataracts are principally a lens structural proteins' (crystallins) aggregation and subsequent precipitation disease that are inducible by genetic mutations, and occurs due to aging. During cataract development, the increased sizes of aggregated and cross-linked crystallin multimers become so large that they finally become water insoluble and cause lens opacity. Several post-translational modifications (PTMs) of crystallins are known to cause age-related cataracts, and the deamidation of crystallins (the most abundant among post-translational modifications) is considered as a major cataract-causative factor. In spite of voluminous literature on in vitro studies of effects of crystallins' deamidation leading to cataract-development, no clear molecular mechanism has emerged that could implicate the deamidation-induced link of the in vitro effects to in vivo changes. Therefore, the PI's-generated unique αA-N101D mouse model, where asparagine 101 is deamidated to aspartic acid, provides an opportunity to directly link the in vitro studies to in vivo changes in phenotypic and crystallins' properties to the cortical cataract development. The model would provide information about the molecular mechanism of age-related cataract development. Based on our extensive results, we have hypothesized that the cataract in αAN101D mouse model is caused by the altered crystallin properties, cellular defects and synergistically increased deposit of αAN101D with membrane, resulting in membrane disruption and ionic imbalance. We plan to test the above hypothesis by seeking answers the following three questions using the above mouse model: (A) Aim 1: Does deamidated αAN101D causes temporal alterations in crystallin- crystallin interactions leading to aggregation among crystallins and their insolubilization in vivo? (B) Aim 2: What are the temporal sequence of lens phenotypes that cause cellular defects during the cortical cataract development? (C) Aim 3: Does temporal increase in binding of deamidated αAN101D to membrane leads to membrane disorganization and intracellular ionic imbalance? The results will be of significant therapeutic value to delay the development and progression of age-related cataracts.