氯通道蛋白-3和水通道蛋白-1在大鼠半乳糖性白内障晶状体中表达水平的变化

目的研究大鼠半乳糖性白内障晶状体中氯离子通道蛋白-3（CLC-3）和水通道蛋白-1（AQP-1）表达水平的变化,探讨CLC-3和AQP-1与白内障发病的关系。方法健康清洁级Wistar大鼠88只随机分为空白对照组（8只）、生理盐水组（40只）和半乳糖性白内障模型组（Gal组）（40只）。生理盐水组和Gal组根据处理时间不同各亚分为5个亚组,每个亚组8只大鼠。Gal组单侧眼球后注射D-半乳糖生理盐水注射液,生理盐水组同期单侧眼球后注射等体积无菌生理盐水,每日裂隙灯下观察大鼠晶状体混浊的动态变化,并参照Kador等的分级标准分期记录。分别于第1次给药后第3、7、14、21、30天在全身麻醉下处死各组实验大鼠,摘出晶状体,应用实时荧光定量PCR法检测各组晶状体中CLC-3mRNA和AQP-1mRNA含量的变化。结果透明晶状体和半乳糖性白内障晶状体中均有CLC-3mRNA和AQP-1mRNA的表达;生理盐水组各时间点CLC-3mRNA和AQP-1mRNA的表达差异无统计学意义（P〉0.05）;Gal组于3、7、14d时CLC-3mRNA表达逐渐增高,均高于同期生理盐水组,到14d时约达正常水平的7倍,21d、30d时又有所下降,均低于同期生理盐水组（P〈0.01）;各时间点晶状体CLC-3mRNA含量两两比较,差异均有统计学意义（P〈0.01）;模型组于3d时AQP-1mRNA表达已下降,与同期生理盐水组比较差异有统计学意义（P〈0.05）,且随着白内障的进一步发展,AQP-1mRNA含量逐渐降低,均低于同期生理盐水组（P〈0.01）;各时间点晶状体AQP-1mRNA含量两两比较,差异均有统计学意义（P〈0.01）。结论晶状体中CLC-3和AQP-1表达的变化可能与白内障的发生发展有着密切的联系。

Expression of chloride channel protein-3 and aquaporin-1 in D-galactose cataractous rat lens

Background Cataract is the main cause for blindness and visual disability.So far,the mechanism of cataract is not yet clear.The disturbances of water and electrolyte in lens have been recognized as one of the causes of cataract.Objective Present study was to investigate the expression of chloride channel protein-3 （CLC-3） and aquaporin-1 （AQP-1） genes in lens with galactose-induced cataract and determine whether the expression of CLC-3 and AQP-1 genes was associated with the occurrence and progression of cataract.Methods Galactose was injected retrobulbarly in lateral eyes of 40 clean healthy Wistar rats.Normal saline solution was injected at the same way in other 40 matched rats,and 8 normal clean healthy Wistar rats were used as blank controls.The opacity of lens was examined under the slit lamp daily and graded on modified criteria of Kador.Lenses were collected in 3,7,14,21,30 days after injection.Expressions of CLC-3 mRNA and AQP-1 mRNA in lens during different cataract phases were detected by real-time influorescence quantitative PCR techniques.Results The amplified efficiency of target gene,or CLC-3 and AQP-1,was consistant with that of GAPDH.CLC-3 mRNA and AQP-1 mRNA were expressed in both lens of normal rats and cataractous rats.Expressions of CLC-3 mRNA and AQP-1 mRNA in lens of rats in blank control group were insignificantly changed upon the time after injection （P〉0.05）.The expression level of CLC-3 mRNA in lens was gradually increased at 3,7,14 days after injection of D-galactose and peaked in 14 days,showing significant differences in comparison with blank control group （all P〈0.01）.After that,CLC-3 mRNA level was less than that of blank normal group （P〈0.01）.Expression of AQP-1 mRNA in lens was decreased from 3 days through 30 days after injection of D-galactose with considerably differences in comparison with the blank control group.However,no evident change was found in the expression of AQP-1 mRNA in lens upon the time after injection of normal saline solution （F=0.317,P=0.900）.Conclusion There is an overexpression of CLC-3 mRNA in early stages of galactose-induced cataract and a downexpression of AQP-1 mRNA in the lens of cataractous rats,which may play an important role in the gataractgenesis.