三嵌段聚合物搭载藻蓝蛋白对人晶状体上皮细胞氧化损伤的保护作用

Protective Effect of Tri-Block Polymer Loaded with Phycocyanin on Oxidative Damage of Human Lens Epithelial Cells

【目的】观察三嵌段聚合物搭载藻蓝蛋白PPP-PC对2,2-偶氮(2-甲基丙基咪)二盐酸盐(AAPH)诱导的人晶状体上皮细胞氧化损伤后细胞形态及活力的影响,探索三嵌段聚合物搭载藻蓝蛋白对人晶状体上皮细胞氧化损伤的保护作用并初步探讨其机制。【方法】构建并纯化三嵌段聚合物搭载藻蓝蛋白,并建立AAPH诱导人晶状体上皮细胞氧化损伤模型;实验分为正常对照组、AAPH损伤组、PPP-PC+AAPH处理组,分别进行相应处理后,通过荧光倒置显微镜观察各组细胞形态及活力;应用Annexin V-FITC/PI双染法流式细胞仪检测各组细胞凋亡比例;蛋白免疫印迹法检测各组细胞Bax、Bcl-2和Caspase-3凋亡相关蛋白的表达水平。【结果】荧光显微镜下显示PPP-PC+AAPH处理组细胞形态与正常对照组细胞相似,细胞活力较AAPH损伤组有所提高;PPP-PC+AAPH处理组凋亡细胞比例为11.70%(10.63%,12.17%),比AAPH损伤组细胞凋亡比例32.35%(30.17%,33.42%)明显下降(P<0.05);与AAPH损伤组相比,PPP-PC+AAPH处理组Bcl-2表达增加而Bax表达减少,Caspase-3表达减少(P<0.05)。【结论】三嵌段聚合物搭载藻蓝蛋白对AAPH诱导的人晶状体上皮细胞氧化损伤具有保护作用,能抑制细胞凋亡,其机制可能是通过下调Bax/Bcl-2表达比例,抑制Caspase-3激活。

【Objective】To observe the effect of tri-block polymer loaded with phycocyanin(PPP-PC)on the mor?phology and viability of human lens epithelial cells(HLEC)after oxidative damage induced by 2,2′-azobis-2-methylpropanimidamide(AAPH),investigate PPP-PC′s role in this process and tentatively explore the potential mechanism.【Methods】We constructed and purified PPP-PC,and established AAPH induced oxidative damage model of HLEC.There were three groups divided:normal control group,AAPH damage group and PPP-PC+AAPH treatment group.The inverted fluorescence microscope was employed to examine the cell morphology and viability,flow cytometry after annexin V-FITC/PI double staining was used to detect cell apoptosis rates and western blotting was utilized to determine the expression levels of apoptosis related proteins such as Bax,Bcl-2 and Caspase-3.【Results】Fluorescence microscope showed that in PPP-PC+AAPH group,the cell morphology was similar to that in control group and the cell viability was higher than that in AAPH group.The percentage of apoptotic cells in PPP-PC+AAPH group was 11.70%(10.63%,12.17%),significantly lower than 32.35%(30.17%,33.42%)in AAPH group(P<0.05).Compared with those in AAPH group,Bcl-2 expression increased,but Bax and Caspase-3 expression decreased in PPP-PC+AAPH group(P<0.05).【Conclusions】PPP-PC can protect AAPH induced oxidative damage of HLEC and inhibit cell apoptosis,which may be achieved by down-regulating the Bax/Bcl-2 ratio and inhibiting the activation of Caspase-3.