VEGF、flk-1、bax、bcl-2在不同类型DR大鼠模型视网膜组织中表达变化的观察

Observation of the expression of VEGF,flk-1,bax and bcl-2 in the retina of different types of DR rat model

目的观察联合注药法建立的增殖型糖尿病性视网膜病变(proliferative diabetic retinopathy,PDR)大鼠模型视网膜组织中血管内皮生长因子(vascular endothelial growth factor,VEGF)、flk-1、bax、bcl-2的表达变化,确定联合注药法所造大鼠PDR模型的价值。方法 Sprague-Dawley大鼠分别采用链脲佐菌素(streptozotocin,STZ)腹腔注射(单纯注药组)和STZ腹腔注射联合VEGF玻璃体注射(联合注药组)制造糖尿病性视网膜病变(diabetic retinopathy,DR)模型,应用免疫组织化学法测定不同时间点各模型组视网膜组织中VEGF、flk-1、bax、bcl-2的表达,应用MIAS1998型图像分析系统测定VEGF、flk-1、bax、bcl-2在视网膜神经节细胞层和内网层的平均光密度值。结果单纯注药组、联合注药组VEGF、flk-1、bax、bcl-2在视网膜除视杆视锥层之外各层均有表达,前三者在节细胞层和神经纤维层表达最强;bcl-2视杆视锥层内节最强;VEGF表达次强为Müller细胞;bcl-2表达次强为节细胞层和神经纤维层。但所有指标联合注药组表达强度大于单纯注药组。bcl-2单纯注药组8周时间点比2周时间点在节细胞层和神经纤维层表达增强;单纯注药组8周时间点在内网层的表达最强。联合注药组2周时间点节细胞层和神经纤维层表达最强。结论联合注药法建立的DR大鼠模型较单纯注药组更能够代表人类PDR的病理改变,具有一定的科研价值。

Objective To observe the variation of vascular endothelial growth factor（ VEGF）,flk-1,bax,bcl-2 expression in PDR rat retina eatablished by symphysial injection and to definite its superiority. Methods Sprague-Dawley rats were made as diabetic retinopathy models by solitary injection with streptozotocin intraperitoneally or symphysial injection with streptozocin intraperitoneally and VEGF intravitreously respectively. Using factorial design empirical method,we observed the variation of VEGF,flk-1,bax,bcl-2 expression in retinas of diabetic rats established by different methods by immunohistochemistry and measured the average optical density value of VEGF,flk-1,bax,bcl-2 in retinal ganglion cell layer and inner plexiform layer by MIAS1998 type image analysis system. Results VEGF,flk-1,bax,bcl-2 were expressed in each layer of retina in both groups except the layer of rods and cones. The front three targets were expressed strongest in the ganglion and nerve fiber layer,while bcl-2 was expressed the strongest in inner segment of the rods and cones layer. The next strongest layer of VEGF expression was the Müller cells while the next strongest layer of bcl-2 expression was the ganglionand nerve fiber layer. All targets expression in symphysial injection groups were stronger than those in solitary injection groups. Bcl-2 expression in ganglion and nerve fiber layer at 8 weeks after VEGF injection was stronger than that at 2 weeks. The strongest bcl-2 expression was in inner plexiform layer at8 weeks in solitary injection groups,while in symphysial injection groups it was in ganglion and nerve fiber layer at 2 weeks after VEGF injection. Conclusion PDR rat model established by symphysial injection can represent the pathological changes of human PDR and has its scientific research worth.