摘要
目的观察糖尿病(diabetes mellitus,DM)大鼠视网膜中血管内皮生长因子(vascular endothelial growth factor,VEGF)和色素上皮源性因子(pigment epithelium-derived factor,PEDF)的表达及早期血-视网膜屏障的改变,探讨二者之间的关系。方法选取87只健康SD大鼠,应用链-脲佐菌素建立DM大鼠模型,随机分为正常对照组(N)、DM0.5个月组、DM1个月组、DM3个月组及DM5个月组。分别行RT-PCR及Western blot检测大鼠视网膜VEGF、PEDF的mENA及蛋白表达,应用伊文思蓝法及透射电镜法观察血-视网膜屏障损伤情况。结果正常大鼠视网膜有VEGF的mRNA及蛋白表达,DM0.5个月组表达开始增高,光密度值分别为0.5700±0.1580和0.5770±0.0279(均为P<0.05),随病程延长,表达量逐渐增高,至DM5个月组VEGF表达量约为正常对照组的2倍,分别为0.9560±0.0560和0.9790±0.0790(均为P<0.05)。PEDF mRNA表达于正常大鼠视网膜,DM1个月组表达开始减少,光密度值为0.3440±0.0437,与正常对照组比较差异有统计学意义(P<0.05),至DM5个月组视网膜表达量减少至0.2360±0.0455,约为正常对照组的1/2(P<0.05)。PEDF蛋白在各组大鼠视网膜的表达与其mRNA表达趋势一致。伊文思蓝法结果显示DM大鼠视网膜血管渗漏较正常大鼠增强,DM0.5个月组鼠即有增高,达(2.6310±0.2725)μL·g-1·h-1(P<0.05),随病程延长,渗漏逐渐增强,至DM5个月组,伊文思蓝渗漏量达(10.0260±1.1121)μL·g-1·h-1,约为正常对照组的6倍(P<0.05)。同时DM1个月时血-视网膜屏障超微结构发生改变,且呈逐渐加重趋势。结论早期DM大鼠血-视网膜屏障损伤,VEGF的正性表达增多与PEDF的负性表达减少可能对此病理改变起一定的促进作用。
Objtetive To investigate the expression of vascular endothelial growth factor（VEGF） and pigment epithelium-derived factor （PEDF） in retinas and ear- ly blood-retinal barrier injury of rats with diabetes, and discuss their relationship. Methods A total of 87 healthy adult SD rats were chosen, the diabetic models were established by streptozocin and randomly divided into normal control group, diabetes mellitus 0. 5 month group （DM 0. 5 month group ）, 1 month group （DM 1 month group） ,3 months group （DM 3 months group） and 5 months group （DM 5 months group）. The expression of VEGF and PEDF in retinas were detected by RT-PCR and Western blot. Evans blue method and transmission electron microscopy were used to observe the blood-retinal barrier injury. Results VEGF mRNA and protein were ex- pressed in retinas of normal rats, the expression began to increase in DM 0.5 month group,the OD value were 0. 570 0 ±0. 158 0 and 0. 577 0±0. 027 9（all P 〈0. 05）. With the disease duration prolonged, the expression was increased gradually, DM 5 months group were 0.956 0± 0.056 0 and 0.979 0 ±0.079 0 ,which were 2 times higher than that in normal control group （ all P 〈 0.05 ）. PEDF mRNA was expressed in normal control group, and began to decrease in DM 1 month group, the OD value was 0. 344 0±0. 043 7 ,compared with normal control group,there was statistical difference（P 〈 0.05 ）. With the course of diabetes, the expression was decreased gradually, in DM 5 months group the OD value only was 0. 235 0±0. 045 5, which was about one half of the normal con- trol group （P 〈 0.05 ）. PEDF protein had the same tendency with the expression of mR- NA. Evans blue method showed the vascular leakage in diabetic retinas was more severe than normal controls. From the early beginning of DM 0. 5 month group the leakage in- creased to （2.631 0±0.272 5） ）L·L^-1 g·L^-1 h-＇ （P 〈0.05）. The leakage in DM 5 monthsgroup was （ 10.026 0 ＋ 1. 112 1 ）L ·L^-1 ,which was 6 times higher than normal control animals（P 〈0.05 ）. The ultra- structural morphological changes of blood-retinal barrier were seen in DM 1 month group, and the impairment exacerbated with the progression of diabetes. Conclusion The early diabetic rats have blood-retinal barrier injury,and the increase of VEGF and reduction of PEDF may have promotive effect on this pathological change.
出处
《眼科新进展》
CAS
北大核心
2013年第1期29-32,共4页
Recent Advances in Ophthalmology
