Berthoud Viviana M, Minogue Peter J, Yu Helena, Snabb Joseph I, Beyer Eric C
Department of Pediatrics, University of Chicago, Chicago, Illinois, United States.
Invest Ophthalmol Vis Sci. 2014 Aug 7;55(10):6639-48. doi: 10.1167/iovs.14-15012.
Although many connexin46 (Cx46) mutants have been linked to inherited human cataracts, there are no adequate animal models for their study. The current experiments were designed to characterize the consequences of expression of one such mutant, Cx46fs380, in the mouse lens.
Mice expressing Cx46fs380 were generated by a knockin strategy. Levels and distribution of specific proteins were analyzed by immunoblotting and immunofluorescence.
Dark-field microscopy revealed that lenses of young heterozygous and homozygous Cx46fs380 mice did not have opacities, but they developed anterior nuclear cataracts that became more severe with age. Immunofluorescence and immunoblotting showed that Cx46 was severely reduced in both heterozygous and homozygous Cx46fs380 lenses at 1 month of age, whereas immunoreactive connexin50 (Cx50) was moderately decreased. The reduction in Cx50 became more severe in older lenses. The solubilities of crystallins from young wild-type and fs380 mice were similar, but older fs380 lenses exhibited abnormalities of abundance, solubility, and modification of some crystallins.
Major decreases in connexin levels precede the development of cataracts. These mice represent a useful model for elucidation of the progression of lens abnormalities during cataractogenesis especially as caused by a mutant connexin.
尽管许多连接蛋白46（Cx46）突变体与人类遗传性白内障相关，但尚无合适的动物模型用于对其进行研究。当前实验旨在表征一种此类突变体Cx46fs380在小鼠晶状体中表达的后果。
通过敲入策略生成表达Cx46fs380的小鼠。通过免疫印迹和免疫荧光分析特定蛋白质的水平和分布。
暗视野显微镜检查显示，年轻的杂合子和纯合子Cx46fs380小鼠的晶状体没有混浊，但它们发展为前核性白内障，且随着年龄增长病情加重。免疫荧光和免疫印迹显示，1月龄时，杂合子和纯合子Cx46fs380晶状体中的Cx46均严重减少，而免疫反应性连接蛋白50（Cx50）中度降低。在较老的晶状体中，Cx50的减少更为严重。年轻野生型和fs380小鼠晶状体蛋白的溶解度相似，但较老的fs380晶状体表现出一些晶状体蛋白在丰度、溶解度和修饰方面的异常。
连接蛋白水平的大幅下降先于白内障的发展。这些小鼠是阐明白内障形成过程中晶状体异常进展的有用模型，尤其是由突变连接蛋白引起的异常进展。
