摘要目的 探讨辛伐他汀对糖尿病视网膜病变(DR)大鼠外周血内皮祖细胞(EPCs)数量及视网膜病变的影响.方法 雄性成年Wistar大鼠80只,以随机数字表法分为正常对照组、模型对照组、安慰剂组、辛伐他汀组,每组各20只大鼠.采用腹腔注射链脲佐菌素(STZ)建立DR大鼠模型.正常对照组、模型对照组不给予任何干预；辛伐他汀组予辛伐他汀20 mg/kg灌胃,1次/d；安慰剂组给予等量蒸馏水灌胃,1次/d.分别于1、4及12周时取静脉血,采用流式细胞仪分别计数各组大鼠外周血EPCs数量的变化.于12周时处死大鼠,摘除眼球行苏木精-伊红(HE)染色,采用伊文思蓝(EB)定量检测血视网膜屏障的破坏程度,免疫组织化学法分析CD31在大鼠视网膜中的表达.实时定量逆转录聚合酶链反应检测内皮型一氧化氮合酶(eNOS)、诱导型一氧化氮合酶(iNOS)及血管生成素-1(Ang-1)在视网膜的表达.对比分析EPCs的数量改变与视网膜病理变化的相互关系.结果 与正常对照组大鼠相比,注射STZ后1、4、12周时安慰剂组大鼠外周血EPCs数均降低；注射STZ后1、4、12周时辛伐他汀组大鼠外周血EPCs数明显高于模型对照组和安慰剂组,差异均有统计学意义(t=4.967,5.648,6.688,6.042,7.392,7.454；P＜0.05)；模型对照组和安慰剂组大鼠外周血EPCs数相比,差异无统计学意义(t=0.525,-0.249,-0.619；P＞0.05)；正常对照组和辛伐他汀组大鼠外周血EPCs数相比,差异均有统计学意义(t=6.733,2.794,-5.535;P＜0.05).组织病理学检查显示,正常对照组大鼠视网膜各层结构清晰、排列整齐、形态正常；模型对照组和安慰剂组大鼠视网膜细胞排列紊乱,细胞核肿胀、体积增大,视网膜组织水肿；辛伐他汀组大鼠视网膜各层组织水肿减轻,细胞排列渐规则.模型对照组和辛伐他汀组大鼠视网膜平均EB渗漏量较正常对照组显著增加,辛伐他汀组较模型对照组明显减少,差异均有统计学意义(F=65.808,P＜0.05).正常对照组、模型对照组和安慰剂组中表达CD31的阳性细胞数显著低于辛伐他汀组,组间CD31阳性细胞数比较,差异有统计学意义(F=24.799,P＜0.05);eNOS在模型对照组表达较正常对照组明显减弱,辛伐他汀组表达强度较模型对照组增强(t=-2.750,2.230;P＜0.05)；iNOS和Ang-1在模型对照组表达较正常对照组明显增强,辛伐他汀组表达强度较模型对照组减弱,差异均有统计学意义(t=3.881,-1.144,4.244,-1.458;P＜0.05).安慰剂组视网膜EB渗漏量、eNOS、iNOS及Ang-1的相对表达量与模型对照组相比,差异均无统计学意义(t=0.480,-0.877,0.062,0.220;P＞0.05).结论 辛伐他汀可动员DR大鼠外周血EPCs,诱导视网膜内皮细胞迁徙分化,减缓DR进展.其可能机制为调节eNOS和iNOS等内皮形成相关因子.

abstractsObjective To observe the effects of simvastatin on endothelial progenitor cells (EPCs)from peripheral blood and retinopathy in rats with diabetic retinopathy (DR).Methods Eighty male Wistar rats were divided into normal control group (group A),DR model group (group B),DR with placebo group (group C),DR with simvastatin group (group D),with twenty rats in each group.The rats in group C and D received strcptozotocin (STZ) injection to induce diabetic retinopathy.The rats in the group A and B were not intervened.The rats were gavaged with 20 mg/kg simvastatin (group D) or same volume of distilled water (group C) once a day.Flow cytometry was used to identify and count the number of EPCs from peripheral blood at the 1st,4th and 12th week after injection.Evans blue perfusion was used to detect the blood-retinal barrier (BRB) permeability.Immunohistochemical staining was used to observe the expression of CD31 in the retina.Real-time reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the mRNA expression of eNOS,iNOS and Ang-1.The correlation between changes of EPCs and DR morphological changes was analyzed.Results At the 1st,4th and 12th week after injection,compared with the group A,the number of EPCs was decreased in group C; Compared with the group B and C,the number of EPCs was increased in group D (t=4.967,5.648,6.688,6.042,7.392,7.454 ; P＜0.05) ;there was no statistical difference of EPCs number between group B and C (t=0.525,-0.249,-0.619;P＞0.05),group A and D (t=6.733,2.794,-5.535; P＜0.05) respectively.The structure of retina was continuous and its capillary structure was normal in control group.The retinal layers were edema and the retina developed telangiectatic vessels and many ganglion cells developed vacuolar degeneration in group B and C.The layers tissue of retina was less edema and gradually arranged in group D.The BRB permeability was significantly increased in group B and D compared with group A. The BRB permeability was significantly decreased in group D compared with group B (F=65.808,P＜0.05).The CD31 expression in group D was obviously higher than that in group A,B and C (F=24.799,P＜0.05),The eNOS expression in group B was obviously lower than that in group A,while in group D was obviously higher than that in group B (t=-2.750,2.230; P＜0.05).The iNOS and Ang-1 expression in group B were obviously higher than those in group A,while in group D was obviously lower than that in group B (t =3.881,-1.144,4.244,-1.458; P＜0.05). There was no difference in BRB permeability,eNOS,iNOS and Ang-1expression between group B and C (t =0.480,- 0.877,0.062,0.220; P＞0.05).Conclusions Simvastatin could mobilize DR rats peripheral blood EPCs,induce migration and differentiation of retinal endothelial cell,slow down the DR progress by regulating the expression of endothelium factors such as eNOS and iNOS.