葡萄糖调节蛋白在糖尿病性白内障发病机制中的作用

目的探讨葡萄糖调节蛋白（78 kd glucose-regu-lated protein,grp78）在糖尿病性白内障发病机制中的作用。方法32只Wistar大鼠随机分为4组：链脲佐菌素（strepto-zotocin，STZ）糖尿病大鼠1、2、3个月模型组及正常对照组，每组8只。对大鼠采用STZ60mg／kg的剂量一次性腹腔注射制备糖尿病模型。各时段分批处死大鼠，每只大鼠左眼采用免疫组织化学法．右眼用半定量RT-PCR的方法检测晶状体上皮细胞中grp78的表达情况。结果Grp78在正常大鼠晶状体上皮细胞中少量表达,免疫组化光密度值为28．66±5．90，RT-PCR检测光密度比值为0．889±0．006；糖尿病大鼠1、2、3个月组免疫组化光密度值分别为49．56±6．54、63．74±9．05、78．15±9．05，RT-PCR光密度比值分别为0．920±0．011、0．948±0．004、0．976±0．006。经统计学分析,糖尿病组大鼠晶状体上皮细胞中grp78的表达较正常组高（P〈0．01），并随着病程的延长而表达增加（P〈0．05）。结论葡萄糖调节蛋白参与了糖尿病性白内障的发生、发展。

A study of glucose-regulated protein in the pathogenesis of diabetic cataract

Objective To evaluate the role of glucose-regulated protein （grp78） in the pathogenesis of streptozotocin （STZ）-diabetic cataract. Methods Thirty-two Wistar rats were randomly divided into a normal control group （CON） and streptozotocin （STZ） cataract groups （diabetic 1-, 2- and 3-month groups）. Each group consisted of 8 rats. The diabetic cataract was induced by one-off intraperitoncal injection with STZ at a dose of 60 mg/kg. Lenses were examined once a week. The expression of grp78 in rat lens epithelial cells was detected by immunohistochemistry and semiquantitative RT-PCR methods at different points in time. Results The optical densities of grp78 expression of the four groups were 28.66±5.90, 49.56±6.54, 63.74±9.05 and 78.15±9.05; the A values of grp78 mRNA of the four groups were 0.889±0.006, 0.920±0.011, 0.948±0.004 and 0.976±0.006. Statistical analysis showed that the expression of grp78 was significantly different between normal and diabetic rat LECs, and was correlated with the development of cataract. Conclusion Grp78 may play an important role in the pathogenesis of diabetic cataract. The expression of grp78 in LECs increased as the disease course of diabetes was extended.