融合蛋白GST-hRI对糖尿病性白内障模型大鼠晶状体浑浊程度的改善作用研究

Improvement Effect of Fusion Protein GST-hRI on Lens Turbidness in Rats with Diabetic Cataract

目的:研究融合蛋白谷胱甘肽硫转移酶-人核糖核酸酶抑制因子(GST-hRI)对糖尿病性白内障模型大鼠晶状体浑浊程度的改善作用。方法:采用表达载体pGEX-6p-1-hri进行GST-hRI的融合表达,并进行纯化;另取大鼠一次性腹腔注射链脲佐菌素70mg·kg-1建立糖尿病性白内障模型,随机分为正常对照组、模型组(生理盐水)、白内停组(白内停8μg·d-1)、治疗组(GST-hRI100u·d-1),每组12只,双侧点眼给予相应药物,每天4次,连续6周,每周裂隙灯下观察大鼠晶状体浑浊程度,6周后处死大鼠,考察各组大鼠晶状体中超氧化物歧化酶(SOD)、谷胱甘肽(GSH)、谷胱甘肽过氧物酶(GSH-Px)及丙二醛(MDA)含量变化。结果:成功诱导表达并纯化GST-hRI,蛋白含量为0.413mg·mL-1,活性为9×103u·mL-1;与模型组和白内停组比较,治疗组大鼠晶状体浑浊程度显著减轻,其SOD、GSH、GSH-Px含量明显增加,MDA含量明显下降(P<0.05)。结论:融合蛋白GST-hRI具有明显的抗氧化作用,能够预防或延缓糖尿病性白内障晶状体浑浊。

OBJECTIVE：To observe the effect of fusion protein glutathione sulfurtransferase-human ribonuclease inhibitor（GST-hRI）on lens turbidness in rats with diabetic cataract . METHODS：The pGEX-6p-1-hri expressive plasmid was induced to express GST-hRI, and the expressed GST-hRI was purified. Rats were given intraperitoneal injection of streptozotocin 70 mg·kg-1 to establish diabetic cataract model. Except normal control group, model rats were randomly divided into model group （normal saline）, pirfenoxone group （pirfenoxone 8 μg·d-1） and treatment group （GST-hRI 100 u·d-1） with each group of 12 rats. Each group was given relevant drugs by eye-drop application 4 times a day for 6 weeks. The lens turbidness degree was inspected with the slit lamp once a week. The rats were sacrificed on the sixth week and their lens were removed to determine the levels of superoxidase dismutase （SOD）, glutathione （GSH）, glutathione peroxidase （GSH-Px） and malondialdehyde （MDA）. RESULTS：The expression of GST-hRI had been induced and purified successfully and the content of protein was 0.413 mg·mL-1 and activity was 9×103 u·mL-1. Compared with model group and pirfenoxone group, the degree of lens turbidness in treatment group was significantly relieved. The content of SOD, GSH and GSH-Px in treatment group increased and the content of MDA decreased significantly （P0.05）. CONCLUSION：The fusion protein GST-hRI has obvious antioxidant effect and has significant prevention and treatment effect on lens turbidness in rats with diabetic cataract.