特殊表型先天性白内障小鼠晶状体中细胞缝隙连接蛋白的表达

目的观察γD-晶状体蛋白点突变导致的小鼠先天性白内障表型,检测该特殊表型先天性白内障小鼠晶状体中细胞缝隙连接蛋白（Cx）的表达。方法观察突变小鼠出生后不同时间晶状体的形态学变化;应用免疫荧光染色法分析晶状体内Cx46和Cx50的表达和分布。结果突变小鼠模型呈稳定一致的显性遗传,出生后7 d即表现为明显的核性白内障,出生后21 d纯合子小鼠晶状体混浊严重,后囊膜自然破裂;免疫荧光染色分析发现突变小鼠晶状体内Cx46和Cx50的表达均出现下降,越靠近晶状体中心部下降越明显。结论γD-晶状体蛋白点突变可导致晶状体后囊膜破裂这种特殊表型的先天性白内障,白内障的形成和后囊膜破裂的产生与晶状体内Cx46和Cx50的表达下降有关。

Expression of connexins in lens of congenital cataract mouse model with special phenotype

Background Congenital cataract remains a leading cause of children＇s blindness.However,the mechanism of lens opacity formation is still unknown so far.ObjectivePresent study was to investigate the phenotype of a congenital cataract mouse model induced by γD-crystallin point mutation,and investigate the expression of connexins in the lens of this mouse model with special phenotype.MethodsCongenital cataract C57BL/6J（B6） models were obtained by N-Ethyl-N-Nitrosourea（ENU） inducing the mutation of γD-crystallin V76D.The lenses with congenital cataract were collected from 7-day-old and 21-day-old wild-type,heterozygous and homozygous C57BL/6J（B6） mice respectively to observe the morphological changes with age.The expressions of connexin 46（Cx46）and connexin 50（Cx50） in lenses were analyzed using immunocytochemistry.ResultsThe congenital cataract of this stable genetic mouse model presented a dominant mutation pattern and characterized by obvious nuclear cataract at postnatal 7 days in both heterozygous and homozygous B6 mice.The homozygous lenses ruptured with severe cataract at postnatal 21 days.The data of immunocytochemistry showed the expressions of Cx46 and Cx50 in lenses with congenital cataract were decreased,especially in the center of the mutant lens.ConclusionThe point mutation of γD-crystallin cause special phenotype of congenital cataract with lens rupture.The formation of cataract and lens rupture are related to the low expression of connexins Cx46 and Cx50.