Ca^2＋、Calpain-2和AQP1在糖尿病性白内障晶状体的变化及意义  

Change of Calcium, Calpain-2 and Aquaporin-1 in Lenses of Rat Diabetic Cataract

作　　者：张虹[1] 张新芳[1] 王芳[2] 陈芳[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院眼科,武汉430030 [2]华中科技大学同济医学院附属同济医院中西医结合研究所

出　　处：《实用医学进修杂志》2008年第4期205-212,共8页Journal of Practical Training of Medicine

摘　　要：目的：研究大鼠糖尿病性白内障（diabetic cataract，DC）晶状体中Ca^2＋含量及晶状体上皮细胞（lens epithelial cells，LECs）钙蛋白酶Ⅱ（m—calpain，calpain-2）、水通道蛋白-1（aquaporin-1，AQP1）表达水平的变化情况。方法：链脲佐菌素（streptozotocin，STZ）60mg／kg体重一次性注射大鼠尾静脉复制糖尿病模型，定期摘取各模型组及对照组大鼠的双侧眼球，后路取出一侧晶状体，用SpectrAA-40型原子吸收光谱仪测定Ca^2＋浓度；将另一侧眼球制成石蜡切片，应用免疫组织化学方法和计算机图像分析技术对LECs表达calpain-2、AQP1进行检测。结果：在晶状体浑浊之前，其Ca^2＋浓度和LECs胞浆calpain-2表达增加。随着糖尿病发展，晶状体Ca^2＋浓度逐渐增加，除DCⅡ期外，calpain-2表达亦逐渐增加。相反，在晶状体浑浊之前，LECs胞膜AQP1表达减少，且随着糖尿病发展逐渐减少。结论：糖尿病大鼠晶状体中Ca^2＋浓度增加、晶状体上皮细胞calpain-2的活性表达增加及AQP1的活性表达减少与DC的发生、发展关系密切。Objective： To investigate the change of total Ca2. level in lenses and the expression of calpain-2 and aquaporin-1 （ AQP1 ） in lens epithelial cells （LECs） of rat diabetic cataract（ DC）. Methods： An animal model of diabetes was prepared by intravenous injection of streptozotocin （ 60 mg/kg body weight） in 2-month-old Wistar rats. The eyeballs of both sides were extracted periodically from each experimental groups and control group. The lenses of one side were isolated and the concentration of Ca^2＋ was determined by a SpectrAA--40 atomic absorption spectrophotometer. The eyeballs of other side were made into paraffin sections. Immunohistochemical techniques and computer-imaging analysis were used to localize and semi-quantify the expression of calpain-2 and AQP1 in LECs. Results： The increased ion concentration of Ca^2＋ in lenses and the elevated level of calpain-2 in cytoplasm of LECs were observed before lens opacification began. The concentration of Ca^2＋ increased gradually with the diabetes development and the expression of calpain-2 did so except DC If. On the contrary, the expression of AQP1 on the cell membrane decreased significantly before the DC occurred and decreased gradually with the diabetes development. Conclusions： Increased ion concentration of Ca^2＋ in lens, elevated and activated expression of calpain-2 and decreased expression in LECs were closely correlated with DC formation and development.

关 键 词：CA^2+ 钙蛋白酶Ⅱ 水通道蛋白-1 糖尿病性白内障 晶状体上皮细胞 

分 类 号：R776.1[医药卫生—眼科] R285.5[医药卫生—临床医学]