重组腺相关病毒介导的血管内皮生长因子反义核苷酸对糖尿病视网膜病变的影响

目的观察重组腺相关病毒（rAAV）介导的血管内皮生长因子（VEGF）反义核苷酸（rAAV-aVEGF165）对糖尿病大鼠视网膜VEGF表达的影响。方法 40只Sprague-Dawley大鼠用链尿佐菌素（STZ）腹腔注射诱导糖尿病大鼠模型。去除实验中途死亡和血糖恢复的大鼠，共计32只大鼠纳入研究，随机平均分为实验组和对照组,每组各16只。实验组和对照组大鼠玻璃体腔分别注射rAAV-aVEGF165（10¹⁰ pfu/ml）、磷酸盐缓冲液各10 μl，建模后1、5个月免疫组织化学及Western blot评价视网膜VEGF的表达，并对视网膜血管进行透射电子显微镜观察。结果 1个月时，实验组和对照组大鼠视网膜VEGF表达极低；5个月时，实验组大鼠视网膜VEGF表达较同期对照组降低，差异有统计学意义（t=23.87, P＜0.01）。透射电子显微镜观察显示，实验组视网膜未见明显异常改变，而对照组视网膜微血管腔明显狭窄，基底膜明显增厚，密度不均，并出现断裂，内皮细胞明显肿胀，突起增多，管腔明显狭窄，周细胞内细胞器结构模糊，细胞核固缩，呈凋亡状态，异染色质明显分布不均，浓集。结论 rAAV-aVEGF165能下调视网膜VEGF的表达，从而阻止糖尿病视网膜病变的发生、发展；rAAV是眼反义基因治疗的有效载体。 （中华眼底病杂志，2008，24：255-258）     

色素上皮衍生因子对糖尿病大鼠视网膜谷氨酸代谢的影响

目的 观察色素上皮衍生因子(PEDF)对糖尿病大鼠视网膜谷氨酸代谢的影响.方法 Sprague_Dawley大鼠78只,分为模型组、模型对照组、PEDF干预组(干预组)、干预对照组,实验结束时去除血糖恢复鼠和实验期间死亡鼠,每组以12只大鼠作为统计样本.模型组、干预组、干预对照组大鼠采用链脲佐菌素诱导糖尿病大鼠模型.模型组大鼠不作任何干预,模型对照组为相同月龄的正常大鼠.干预组大鼠左眼玻璃体腔注射0.1 μg/μl的PEDF 5.0μl,干预对照组大鼠左眼玻璃体腔注射相同容积的磷酸盐缓冲液.采用蛋白免疫印迹法(Western bolt)和实时荧光聚合酶链式反应(PCR)法检测视网膜L-谷氨酸-L-门冬氨酸转运体(GLAST)表达的变化,高压液相色谱法(HPLC)观察视网膜谷氨酸的含量变化.将体外培养的大鼠视网膜Müller细胞随机分为对照组、实验组、PEDF干预组(干预组)和干预对照组,荧光免疫法和实时荧光PCR法检测Müller细胞GLAST表达的改变,根据[3H]标记的D,L-谷氨酸摄入量判断Müller细胞的摄取功能.结果 实时荧光PCR法和Western bolt检测结果显示,相对于模型对照组大鼠,模型组大鼠视网膜GLAST表达降低(实时荧光PCR法:t=8.86,P＜0.01;Western blot:t=3.42,P＜0.05),视网膜谷氦酸含量升高(t=4.01,P＜0.05);干预组大鼠视网膜GLAST表达与干预对照组视网膜GLAST表达比较,干预组大鼠视网膜GLAST的表达升高(实时荧光PCR法:t=3.56,P＜0.05;Western blot:t=3.52,P＜O.05);视网膜谷氨酸含量下调(t=4.36,P＜0.05).实时荧光PCR法和荧光免疫法检测结果显示,高糖可以降低视网膜Müller细胞GLAST的表达(实时荧光PCR法:t=3.48,P＜O.05;荧光免疫法:t=4.72,P＜O.05);[3H]标记的D,L-谷氨酸摄人量结果显示,高糖可以下调视网膜Mü1ler细胞GIAST的功能(t=3.81,P＜0.05);经PEDF处理后,可以明显改善高糖状态下视网膜Müller细胞GLAST的表达(实时荧光PCR法:t=6.82,P＜O.01;荧光免疫法:t=3.72,P＜0.05)和对谷氨酸的摄取功能(t=4.14,P＜0.05).结论 PEDF可通过改善糖尿病大鼠视网膜Müller细胞中GLAST功能从而改善谷氨酸循环,抑制神经节细胞的死亡.

Abstract：

Objective To observe the effect of pigment epithelium-derived factor(PEDF)on glutamate metabolism in diabetic rat retina.Methods 78 Sprague-Dawley rats were randomly divided into the model group,model control group,PEDF intervention group and intervention control group.There were some dead and euglycemia rats at the end of experiment,so only 12 rats in each group were included in the statistical analysis.The diabetic retinopathy rat model of the model,PEDF intervention and intervention control group were induced with streptozotocin injection.The rats in the model group were not intervened.The monthly-age matched normal rats of model group were in the model control group.The left eyes of rats were received intravitreal injection with 5μl(0.1μg/μl)PEDF(PEDF intervention group)or 5μlphosphate buffer solution(intervention control group).The expressions of L-glutamate/L-aspartate transporter in retina were analyzed by western blot and real time RT-PCR techniques and glutamate content in retina was analyzed by high-pressure liquid chromatography(HPLC).Cultured rat Mailer cells were divided into the control,experimental,PEDF intervention and intervention control group,GLAST expressions were detected by fluorescence immunofluorescence and real-time RT-PCR techniques.The glutamate up-take activity of Müller cells was determined by intracellular[3H] labeled D,L-glutamate concentration with scintillation counting.Results Western blot and real-time RT-PCR showed that GLAST expression decreased(real-time RT-PCR:t=8.86,P＜0.01;Western blot:t=3.42,P＜0.05).glutamate content increased(t=4.01,P＜0.05)in model group compared with the model control group:GLAST expression increased(real-time RT-PCR:t=3.56,P＜0.05;Western blot:t=3.52,P＜0.05),glutamate content decreased(y=4.36,P＜0.05)in the PEDF intervention group compared with the intervention control group.Real-time RT-PCR and fluorescence immunofluorescenee showed that high glucose down-regulate GLAST expressions in Müller cells(real-time RT-PCR:t=3.48,P＜0.05;fluorescence immunofluoreseence:t=4.72,P＜0.05)and impair glutamate up-take activity of Müller cells(t=3.81,P＜0.05).Under high glucose conditions,PEDF up-regulated GLAST expression significantly(real-time RT-PCR:t=6.82,P＜0.01;fluorescence immunofluorescence:t=3.72,P＜0.05)and ameliorated the glutamate up-take activitv of Mailer cells(t=4.14,P＜0.05).Conclusions In diabetic rats,PEDF may improve the activitv of GLAST in Müller cells,thus ameliorate retinal glutamate metabolism and inhibit death of retinal ganglion cells.     

色素上皮衍生因子对糖尿病大鼠视网膜谷氨酸代谢的影响

Objective To observe the effect of pigment epithelium-derived factor(PEDF)on glutamate metabolism in diabetic rat retina.Methods 78 Sprague-Dawley rats were randomly divided into the model group,model control group,PEDF intervention group and intervention control group.There were some dead and euglycemia rats at the end of experiment,so only 12 rats in each group were included in the statistical analysis.The diabetic retinopathy rat model of the model,PEDF intervention and intervention control group were induced with streptozotocin injection.The rats in the model group were not intervened.The monthly-age matched normal rats of model group were in the model control group.The left eyes of rats were received intravitreal injection with 5μl(0.1μg/μl)PEDF(PEDF intervention group)or 5μlphosphate buffer solution(intervention control group).The expressions of L-glutamate/L-aspartate transporter in retina were analyzed by western blot and real time RT-PCR techniques and glutamate content in retina was analyzed by high-pressure liquid chromatography(HPLC).Cultured rat Mailer cells were divided into the control,experimental,PEDF intervention and intervention control group,GLAST expressions were detected by fluorescence immunofluorescence and real-time RT-PCR techniques.The glutamate up-take activity of Müller cells was determined by intracellular[3H] labeled D,L-glutamate concentration with scintillation counting.Results Western blot and real-time RT-PCR showed that GLAST expression decreased(real-time RT-PCR:t=8.86,P＜0.01;Western blot:t=3.42,P＜0.05).glutamate content increased(t=4.01,P＜0.05)in model group compared with the model control group:GLAST expression increased(real-time RT-PCR:t=3.56,P＜0.05;Western blot:t=3.52,P＜0.05),glutamate content decreased(y=4.36,P＜0.05)in the PEDF intervention group compared with the intervention control group.Real-time RT-PCR and fluorescence immunofluorescenee showed that high glucose down-regulate GLAST expressions in Müller cells(real-time RT-PCR:t=3.48,P＜0.05;fluorescence immunofluoreseence:t=4.72,P＜0.05)and impair glutamate up-take activity of Müller cells(t=3.81,P＜0.05).Under high glucose conditions,PEDF up-regulated GLAST expression significantly(real-time RT-PCR:t=6.82,P＜0.01;fluorescence immunofluorescence:t=3.72,P＜0.05)and ameliorated the glutamate up-take activitv of Mailer cells(t=4.14,P＜0.05).Conclusions In diabetic rats,PEDF may improve the activitv of GLAST in Müller cells,thus ameliorate retinal glutamate metabolism and inhibit death of retinal ganglion cells.     

色素上皮衍生因子对糖尿病大鼠视网膜谷氨酸代谢的影响

Objective To observe the effect of pigment epithelium-derived factor(PEDF)on glutamate metabolism in diabetic rat retina.Methods 78 Sprague-Dawley rats were randomly divided into the model group,model control group,PEDF intervention group and intervention control group.There were some dead and euglycemia rats at the end of experiment,so only 12 rats in each group were included in the statistical analysis.The diabetic retinopathy rat model of the model,PEDF intervention and intervention control group were induced with streptozotocin injection.The rats in the model group were not intervened.The monthly-age matched normal rats of model group were in the model control group.The left eyes of rats were received intravitreal injection with 5μl(0.1μg/μl)PEDF(PEDF intervention group)or 5μlphosphate buffer solution(intervention control group).The expressions of L-glutamate/L-aspartate transporter in retina were analyzed by western blot and real time RT-PCR techniques and glutamate content in retina was analyzed by high-pressure liquid chromatography(HPLC).Cultured rat Mailer cells were divided into the control,experimental,PEDF intervention and intervention control group,GLAST expressions were detected by fluorescence immunofluorescence and real-time RT-PCR techniques.The glutamate up-take activity of Müller cells was determined by intracellular[3H] labeled D,L-glutamate concentration with scintillation counting.Results Western blot and real-time RT-PCR showed that GLAST expression decreased(real-time RT-PCR:t=8.86,P＜0.01;Western blot:t=3.42,P＜0.05).glutamate content increased(t=4.01,P＜0.05)in model group compared with the model control group:GLAST expression increased(real-time RT-PCR:t=3.56,P＜0.05;Western blot:t=3.52,P＜0.05),glutamate content decreased(y=4.36,P＜0.05)in the PEDF intervention group compared with the intervention control group.Real-time RT-PCR and fluorescence immunofluorescenee showed that high glucose down-regulate GLAST expressions in Müller cells(real-time RT-PCR:t=3.48,P＜0.05;fluorescence immunofluoreseence:t=4.72,P＜0.05)and impair glutamate up-take activity of Müller cells(t=3.81,P＜0.05).Under high glucose conditions,PEDF up-regulated GLAST expression significantly(real-time RT-PCR:t=6.82,P＜0.01;fluorescence immunofluorescence:t=3.72,P＜0.05)and ameliorated the glutamate up-take activitv of Mailer cells(t=4.14,P＜0.05).Conclusions In diabetic rats,PEDF may improve the activitv of GLAST in Müller cells,thus ameliorate retinal glutamate metabolism and inhibit death of retinal ganglion cells.     

重组腺相关病毒载体介导的人色素上皮衍生因子对糖尿病大鼠血-视网膜屏障的影响

目的 以重组腺相关病毒(recombinant adeno-associated virus,rAAV)栽体介导的人色素上皮衍生因子(human pigment epithelium-derived factor,hPEDF)转染糖尿病大鼠视网膜,观察其对血-视网膜屏障的影响.方法 雄性Wistar大鼠75只应用链脲佐菌素诱导形成糖尿病模型后,随机分为1个月组、3个月组和6个月组,每组各25只.所有大鼠右眼玻璃体内注射rAAV2-cMV-hPEDF作为治疗组,左眼注射rAAV2-CMV-GFP做自身对照.正常大鼠20只右眼假注射,左眼不注射.应用Evans-Blue 测定血-视网膜屏障的渗漏变化,应用Western-blotting测定ICAM-1和Occludin蛋白的表达情况.结果 随着糖尿病病程进展,视网膜渗漏不断增强,视网膜中Evans-Blue含量不断增加,一直持续到6个月达到高峰.各治疗眼组与自身对照眼组相比视网膜渗漏减轻,其中1个月治疗眼组Evans-Blue含量(68.673±24.083)ng·mg-1低于自身对照眼组(93.850 4±24.969)ng·mg-1,二者比较,差异无统计学意义(P>0.05);3个月Evans-Blue含量(46.021±16.091)ng·mg-1及6个月(55.198±25.060)ng·mg-1治疗眼组均显著低于自身对照眼组Evans-Blue含量(102.528 4±39.421)ng·mg-1、(128.225±34.603)ng·mg-1(P<0.05).但各治疗眼组与正常眼注射组相比Evans-Blue含量仍显著增加(均为P<0.05).随糖尿病病程进展,视网膜中ICAM-1蛋白含量不断增加,Occludin蛋白含量不断降低.治疗眼组与自身对照眼组相比,ICAM-1蛋白含量均显著下降(均为P<0.01).3个月及6个月治疗眼组与自身对照眼组相比,Occludin蛋白含量均显著升高(均为P<0.01).糖尿病大鼠视网膜ICAM-1与Occludin蛋白表达呈显著负相关(r=-0.754,P<0.01).结论 rAAV2-CMV-hPEDF玻璃体内注射可增加糖尿病大鼠视网膜Occludin的表达,抑制ICAM-1表达,从而减轻糖尿病大鼠视网膜血管的渗漏.     

重组腺病毒载体介导色素上皮衍生因子基因抑制视网膜新生血管形成

目的 观察重组腺病毒载体介导色素上皮衍生因子（PEDF）基因对视网膜新生血管（RNV）发生的影响。方法 将20只鼠龄7 d 的Spraque-Dawley大鼠建立模型后随机分为2组，分别于出生后14 d 行玻璃体内注射空白腺病毒载体（AV-Blank组）及编码PEDF基因的重组腺病毒载体（AV-PEDF组），采用RNV内皮细胞计数、运用逆转录聚合酶链反应（RT-PCR）和免疫组织化学法检测玻璃体、视网膜中PEDF基因及其蛋白表达的变化。结果 注射药物后AV-PEDF组视网膜的新生血管数较AV-Blank组明显减少（t＝42.009，P＜0.001）；视网膜PEDF蛋白的表达较AV-Blank组明显增加（t=36.638，P＜0.001）；玻璃体组织中的PEDF mRNA表达量也较AV-Blank组明显增加（t=9.128，P＜0.001）。结论 重组腺病毒载体介导的PEDF基因可上调大鼠RNV眼玻璃体及视网膜组织中PEDF的表达；推测PEDF的表达可能与RNV的抑制与消退相关。     

糖尿病视网膜病变患者血清中血管内皮生长因子和色素上皮衍生因子水平的变化

糖尿病视网膜病变(DR)基本病理改变是血视网膜屏障破坏,新生血管形成.血管内皮生长因子(VEGF)是促进血管生成的重要因子之一,通过促进内皮细胞增生,改变细胞外基质及增加血管通透性促进血管新生.色素上皮衍生因子(PEDF)可以通过抑制炎症以及氧化应激反应,促进内皮细胞凋亡等抑制新生血管形成.为了解VEGF与PEDF水平在DR发生发展过程中的变化,我们对一组糖尿病患者和DR患者的血清VEGF与PEDF进行了测定,现将结果报道如下.     

增生型糖尿病视网膜病变玻璃体中血管内皮生长因子和色素上皮衍生因子水平

随着对糖尿病视网膜病变（DR）发病机制的深入研究，发现在DR的发生过程中各种促血管新生因子及抑制血管新生因子起了重要的作用，其中血管内皮生长因子（VEGF）和色素上皮衍生因子（PEDF）分别作为主要的促血管新生因子及抑制血管新生因子而成为研究的热点。我们对一组增生型糖尿病视网膜病变（PDR）患者玻璃体中VEGF、PEDF浓度进行了检测，现将结果报道如下。     

高度近视对糖尿病豚鼠视网膜血管内皮生长因子和色素上皮衍生因子表达的影响

背景 研究发现糖尿病合并高度近视患者较少发生糖尿病视网膜病变（DR）,高度近视对DR的发生和发展可能具有保护作用.DR的主要病理基础是新生血管的形成,而血管内皮生长因子（VEGF）和色素上皮衍生因子（PEDF）在DR的发生和发展过程中具有重要作用. 目的 观察高度近视合并糖尿病豚鼠视网膜中VEGF和PEDF表达的变化,探讨高度近视对DR的影响.方法 将出生3d的豚鼠48只采用随机数字表法随机分为正常对照组、高度近视组、糖尿病组和糖尿病合并高度近视组,每组12只.高度近视组豚鼠用半透明眼罩行右眼遮盖,构建高度近视动物模型;采用60 mg/kg的链脲佐菌素（STZ）腹腔内注射4次,每3天1次,制作糖尿病豚鼠模型;糖尿病合并高度近视组豚鼠采用半透明眼罩联合STZ制作糖尿病合并高度近视模型.造模成功后行常规苏木精-伊红染色观察视网膜结构,免疫组织化学染色检测视网膜中VEGF和PEDF的表达情况,应用Biosens数字成像分析系统分析阳性反应部位的平均吸光度（A）值. 结果 正常对照组、高度近视组、糖尿病组和糖尿病合并高度近视组的屈光度分别为（＋0.25±177;0.07）、（-7.50±177;0.04）、（＋0.25±177;0.03）和（-7.50±177;0.02）D;空腹血糖分别为（5.3±177;0.1）、（5.1±177;0.2）、（19.7±177;0.4）和（18.5±177;0.3）mmol/L.各组豚鼠均造模成功.与正常对照组相比,高度近视组视网膜组织变薄,神经节细胞数目减少;糖尿病组视网膜组织结构疏松、肿胀;糖尿病合并高度近视组视网膜组织变薄,结构肿胀.正常对照组、高度近视组、糖尿病组和糖尿病合并高度近视组VEGF阳性反应部位平均A值分别为128.61 ±177;5.57、118.24±177;2.59、155.60±177;9.70和135.15±177;5.22,各组间总体比较差异有统计学意义（F=17.365,P=0.032）,其中糖尿病合并高度近视组豚鼠视网膜中VEGF表达水平（A值）明显低于糖尿病组,差异有统计学意义（t=5.210,P＜0.05）;PEDF阳性反应部位平均A值分别为145.57±177;8.35、149.54±177;6.20、127.71 ±177;2.45和1 37.53±177;7.38,各组间总体比较差异有统计学意义（F=19.210,P=0.019）,其中糖尿病合并高度近视组豚鼠视网膜中PEDF水平明显高于糖尿病组,差异有统计学意义（t=4.521,P＜0.05）.结论 高度近视合并糖尿病的豚鼠视网膜中VEGF表达量下调,而PEDF表达上调,这可能是高度近视眼不易发生DR的主要机制.     

色素上皮衍生因子对糖尿病大鼠视网膜谷氨酰胺合成酶表达的影响

目的　观察色素上皮衍生因子（PEDF）对糖尿病大鼠视网膜Müller细胞谷氨酰胺合成酶（GS）表达的影响。方法　将Sprague-Dawley大鼠分为模型组、模型对照组、PEDF干预组（干预组）、干预对照组,每组均为8只大鼠。模型组、干预组、干预对照组大鼠链脲佐菌素诱导糖尿病大鼠模型。模型组大鼠不作任何干预,模型对照组为相同月龄的正常大鼠,干预组大鼠左眼玻璃体腔注射0.1 μg/μl的PEDF 10 μl,干预对照组大鼠左眼玻璃体腔注射相同容积的磷酸盐缓冲液。采用免疫组织化学法和实时荧光聚合酶链反应（PCR）法检测视网膜GS和白细胞介素-1β（IL-1β）的表达变化。将视网膜Müller细胞置于高糖环境下培养,实验干预组中加入100 ng/ml PEDF,空白对照组加入相同容积的培养液,24 h后通过蛋白质免疫印迹（Western blot）法和实时荧光PCR法检测PEDF对Müller细胞GS和IL-1β表达的改变。流式细胞仪锚定蛋白-异硫氰酸荧光素和碘化丙啶（Annexin V-FITC-PI）双染色法检测100ng/mlPEDF对高糖状态下Müller细胞凋亡的影响。结果　实时荧光PCR法从基因水平和免疫组织化学法从蛋白质水平检测均显示,相对于模型对照组大鼠,模型组大鼠视网膜GS表达降低,而IL-1β的表达升高,实时荧光PCR法：GS: t=4.23, P＜0.01;IL-1β: t=16.73,P＜0.01;免疫组织化学法：GS:t=5.13,P＜0.01;IL-1β: t=9.32, P＜0.01;干预组大鼠玻璃体腔注射PEDF 48 h后,IL-1β的表达下降,GS的表达升高,与干预对照组比较,实时荧光PCR法：GS: t=3.87,P＜0.01;IL-1β: t=3.61,P＜0.05;免疫组织化学法：GS:t=3.32, P＜0.05;IL-1β: t=2.63, P＜0.05。在高糖环境下,通过实时荧光PCR法和Western bot 法检测均显示PEDF可以下调IL-1β的表达,而上调GS的表达,与空白对照组比较,实时荧光PCR法：GS: t=2.89, P＜0.05;IL-1β: t=3.37, P＜0.05;Western blot：GS: t=2.66, P＜0.05;IL-1β: t=3.23, P＜0.05。流式细胞仪检测结果显示,PEDF可以抑制高糖环境下Müller细胞的凋亡,实验组凋亡率与空白对照组凋亡率比较,差异有统计学意义(t=3.21,P＜0.05)。结论　对于糖尿病大鼠,PEDF可能通过下调视网膜Müller细胞中IL-1β的表达来上调GS的表达,从而改善谷氨酸循环,抑制神经节细胞的死亡      

胰岛素对链脲佐菌素诱导的糖尿病大鼠视网膜血管内皮生长因子表达的影响

目的 观察胰岛素对链脲佐菌素（STZ）诱导的糖尿病大鼠视网膜血管内皮生长因子（VEGF）表达的影响。方法 60只雄性Sprague-Dawley(SD)大鼠随机分为柠檬酸钠缓冲液对照组(CIT-CON)和STZ诱导糖尿病组(STZ-DM)，每组各30只。16周时，在 CIT-CON组中随机抽取24只大鼠分为柠檬酸钠缓冲液对照组（A组）和柠檬酸钠缓冲液加胰岛素作用组（B组），每组各12只，剩余6只作为阴性对照。同时，在STZ-DM组中也随机抽取24只大鼠分为STZ诱导糖尿病组（C组）和STZ诱导糖尿病组加胰岛素作用组（D组），每组也为12只，同样剩余6只作为阴性对照。胰岛素作用组皮下注射4 IU胰岛素，24 h后处死各组大鼠，3只取眼球、4%多聚甲醛固定，供制备病理切片；9只取视网膜神经上皮层，保存于液氮中。实时聚合酶链反应（Rea l-time PCR）检测视网膜VEGF mRNA表达，免疫组织化学、蛋白免疫印迹（Western Blot）检测VEGF蛋白表达。结果 胰岛素作用于正常对照大鼠和STZ诱导的糖尿病大鼠后，正常大鼠VEGF mRNA 表达为7.71±0.25，蛋白表达为0.492 5±0.012 2，分别与胰岛素作用前比较，差异均有统计学意义（t=5.32，3.97；P<0.05）；STZ诱导的糖尿病大鼠VEGF mRNA表达为9.05±0.28，蛋白表达为0.515 2±0.010 9，分别与胰岛素作用前比较，差异均无统计学意义（t=0.34，0.36；P>0.05）。结论 胰岛素作用于STZ诱导的糖尿病大鼠不能显著上调视网膜VEGF mRNA 和蛋白水平。     

双靶点干预对糖尿病大鼠视网膜中血管内皮生长因子和结缔组织生长因子基因表达的影响

目的 观察糖尿病大鼠视网膜中以及双靶点干预后血管内皮生长因子（VEGF）和结缔组织生长因子（CTGF）mRNA表达变化。方法 Sprague-Dawley大鼠48只,随机分为正常对照组（CON1组）和糖尿病（DM）组。经鼠尾静脉注射链脲佐菌素制作糖尿病大鼠模型。建模后8、10、12周取大鼠视网膜标本行逆转录实时定量聚合酶链反应（RT-PCR）检测VEGF、CTGF mRNA表达变化。根据上述结果,选取相同条件的大鼠60只,随机选择50只大鼠依照上述方法建立糖尿病大鼠模型;10只大鼠为正常对照组（CON2组）。建模后第10周,将糖尿病大鼠随机分为双靶点干预组、ranibizumab单靶点干预组、CTGF小发夹RNA（shRNA)单靶点干预组、DM未干预组。干预1周后取各组大鼠视网膜标本,行实时定量RT-PCR检测VEGF、CTGF mRNA表达变化。结果 建模后第8周,DM组大鼠视网膜CTGF mRNA水平显著增高且一直持续到第12周,与CON1组比较,差异均有统计学意义（t=-2.49、-2.67、-2.42,P＜0.05）;第8周时DM组大鼠视网膜VEGF mRNA水平与CON1组比较,差异无统计学意义（t=-0.443,P=0.669）;第10周时显著上调且一直维持到第12周,与CON1组比较,差异有统计学意义（t=-2.35、-2.57,,P＜0.05）。 Ranibizumab单靶点干预组大鼠视网膜VEGF mRNA表达水平较DM未干预组显著降低,差异有统计学意义（t=-3.44,P＜0.05）,与CON2组比较,差异无统计学意义(t=-1.37,P＞0.05);CTGF mRNA表达显著高于DM未干预组,差异有统计学意义（t=2.48,P＜0.05）。CTGF shRNA单靶点干预组大鼠视网膜CTGF、VEGF mRNA表达均较DM未干预组显著降低,差异有统计学意义（t=0.23、-2.92,,P＜0.05）。双靶点干预组大鼠视网膜VEGF、CTGF mRNA表达均下调,与DM未干预组比较,差异均有统计学意义（t=-6.09、-5.11,,P＜0.001）;与CON2组比较,差异无统计学差异（t=-1.16、1.139,,P＞0.05）。结论 早期DM大鼠视网膜内VEGF、CTGF基因表达即升高,且CTGF升高较VEGF早。Ranibizumab结合CTGF shRNA双靶点干预能同时降低VEGF、CTGF基因在DM大鼠视网膜中的表达。     

糖尿病大鼠视网膜组织糖基转移酶表达改变的初步研究

目的 观察糖尿病大鼠视网膜组织糖基转移酶表达改变情况,为进一步研究糖基转移酶及其介导的酶促糖基化反应参与糖尿病性视网膜病变发病机制建立研究基础.方法 实验研究.STZ诱导建立糖尿病大鼠模型,应用RT-PCR法观察已明确基因序列的部分糖基转移酶在糖尿病大鼠视网膜组织的表达情况.提取视网膜组织蛋白,SDS-PAGE电泳,RCA-I凝集素染色以及大鼠眼球组织切片RCA-I凝集素染色,观察视网膜组织蛋白糖基化修饰变化情况.对实时荧光定量PCR及组织切片凝集素分析的相关结果采用独立样本t检验进行统计学分析.结果 实时PCR检测:6个受检糖基转移酶在糖尿病大鼠组及正常大鼠组相对基因表达量分别为:O-linked N-acetylglucosamine transferase(0.16.50±0.1160, 0.1160±0.0363);UDP-Gal:betaGlcNAc beta1,3-galactosyltransferase (0.0186±0.0122,0.0152±0.0047);alpha 1,4-galactosyltransferase(0.0040±0.0040,0.00.54±0.0022):mannoside acetylghcosaminyltransferase 1(0.0228±0.0166,0.0187±0.0050);UDP-glucose ceramide glucosyltransferase(0.0129±0.0096,0.0116±0.0040);UDP-Gal:betaGlcNAc beta 1,4-galactosyltransferase 1(0.0157±0.0010,0.0081±0.0016).糖尿病大鼠视网膜组织中β1,4半乳糖基转移酶-1(UDP-Gal:betaGlcNAc beta 1,4-galactosyltransferase 1,GalT-1)的表达上调(t=6.847,P=0.002);蛋白凝集素及组织凝集素染色分析发现:糖尿病大鼠视网膜组织中Galβ 1→4GlcNAc糖基化基团修饰表达上调.结论 糖尿病状态下,大鼠视网膜组织中β1,4半乳糖基转移酶-1的表达及其介导的酶促糖基化反应上调.初步的实验结果为进一步研究糖基转移酶及其介导的酶促糖基化反应参与糖尿病视网膜病变的发病机制建立了相关实验基础.     

胰岛素对链脲佐菌素诱导的糖尿病大鼠视网膜血管内皮生长因子表达的影响

Objective To investigate if insulin can affect the expression of vascular endothelial growth factor (VEGF) in the retina of streptozotocin-induced diabetic rats. Methods A total of 60 male Sprague-Dawley rats were randomly divided into sodium citrate buffer control group (CIT-CON, n= 30) and STZ-induced diabetic group (STZ-DM, n=30). At the 16th week, 24 rats from CIT-CON group at random were randomly divided to group A (sodium citrate buffer control group, n = 12) and group B (sodium citrate buffer plus insulin group, n= 12). The remaining 6 rats from as CIT-CON group served as negative control. At the same time, 24 rats from STZ-DM group at random were randomly divided to group C (STZ-induced diabetic group, n= 12) and group D (STZ-induced diabetic plus insulin group, n= 12). The remaining 6 rats from STZ-DM group also served as negative control. 4 IU of insulin was injected subcutaneously to rats of group B and D. Immunohistochemistry, Western blot and Real-time polymerase chain reaction (RT-PCR) were used to measure the expression level of VEGF protein and mRNA respectively. RESULTS Insulin significantly increased the VEGF mRNA (7.71 ± 0.25 vs 5.36 ±0. 37, t test P< 0. 05) and protein expression (0. 4925 ± 0. 0122 vs 0. 4272 ± 0. 0110, t test P< 0. 05) in the retina of CIT-CON rats.However, in retina of STZ-DM rats, insulin had no effect on VEGF mRNA (8. 92±0. 27 vs 9. 05±0. 28, t test, P>0. 05) and protein expression (0. 5152±0. 0109 vs 0. 5099±0. 0100, t test P>0.05). Conclusions Insulin had no effect on VEGF expression in the retina of STZ-DM rats.