Reduced retinal angiogenesis in MMP-2-deficient mice

PURPOSE: To study the putative role of endogenous matrix metalloproteinases (MMPs) in retinal neovascularization, an established mouse model was used to compare the retinal neovascularization observed in wild-type mice with that in mice without the MMP-2 or -9 genes. METHODS: C57Bl/6 (MMP-2(+/+) and -9(+/+)), MMP-2-deficient (MMP-2(-/-)), and MMP-9-deficient (MMP-9(-/-)) mice were used. After oxygen-induced retinopathy was induced in the mice, their eyes were rapidly removed and frozen in optimal cutting temperature embedding compound. Sections were histochemically stained with specific markers for vascular cells and angiogenesis-related factors. The area of new retinal vessels was measured using image-analysis software and compared between groups. RESULTS: Retinal neovascularization was not significantly different between wild-type and MMP-9(-/-) mice. The MMP-2(-/-) mice had significantly less extraretinal neovascularization than did wild-type mice. The mean number of extraretinal neovascular buds per cross section was significantly lower in MMP-2(-/-) mice than in wild-type mice (P < 0.05). The expression of other angiogenesis-related factors, vascular endothelial growth factor and pigment epithelium-derived factor, was not different between wild-type and MMP-2(-/-) mice. CONCLUSIONS: MMP-2 may be essential in the regulation of retinal neovascularization. Pharmacologic intervention using MMP inhibitors may be a future therapeutic approach for angiogenic retinal diseases.     

Role of cytochrome P450 2C epoxygenases in hypoxia-induced cell migration and angiogenesis in retinal endothelial cells

PURPOSE: Cytochrome P450 (CYP) epoxygenase-derived epoxyeicosatrienoic acids (EETs) elicit cell proliferation and promote angiogenesis. The aim of this study was to determine the expression of CYP epoxygenases in the bovine retina and the potential role of EETs in hypoxia-induced angiogenesis in bovine retinal endothelial cells. METHODS: Bovine retinal endothelial cells were cultured under normoxic (21% O(2)) or hypoxic (1% O(2)) conditions, and CYP2C expression was determined by Western blot analysis. The effect of hypoxia on EET levels was determined by LC-MS/MS. Cell migration (Transwell filter assays) and endothelial cell tube formation (on basement membrane matrix) were assessed in vitro in the absence and presence of pharmacologic inhibitors and CYP2C antisense oligonucleotides. RESULTS: Bovine retinal endothelial cells expressed CYP2C protein in culture and generated detectable levels of EETs under basal conditions. Hypoxia (6-48 hours) enhanced CYP2C protein expression (2-fold) and EET formation (1.5-fold). Moreover, endothelial cells preexposed to hypoxia demonstrated an increase in serum-induced cell migration that was sensitive to the CYP2C inhibitors sulfaphenazole and MS-PPOH and the EET antagonist 14,15-epoxyeicosa-5(Z)-enoic acid. Furthermore, preventing the hypoxia-induced expression of CYP2C (antisense oligonucleotides) suppressed hypoxia-induced cell migration. In an in vitro angiogenesis model, the preexposure of endothelial cells to hypoxia increased CYP2C expression and enhanced endothelial tube formation, which was blocked by the EET antagonist and by the CYP2C antisense oligonucleotides. CONCLUSIONS: Taken together, these data indicate that CYP2C-derived EETs are implicated in angiogenesis by retinal endothelial cells, especially under hypoxic conditions.     

Role of retinal detachment subretinal fluid on extracellular matrix metabolism

PURPOSE: To examine the in vitro effects of subretinal fluid (SRF) from patients with retinal detachment on extracellular matrix turnover. METHODS: Matrix metalloproteinase (MMP) activity was explored by radiolabeled substrate degradation and zymography. Human lung fibroblasts were used to analyze SRF effects on collagen synthesis and cell proliferation. Transforming growth factor-beta(2) (TGF-beta(2)) concentration was determined in SRF samples by a quantitative sandwich enzyme immunoassay. RESULTS: MMP-2 and MMP-9 gelatinolytic activity was observed in all SRF samples. Collagenase activity was not detected in SRF from patients with holes and recurrent retinal detachment. All SRF samples stimulated fibroblast proliferation and collagen synthesis but SRF samples from recurrent retinal detachment patients with previous retinal tears had the largest effect with the largest TGF-beta(2) concentration. CONCLUSIONS: The gelatinolytic activity found in all SRF samples might be associated with the retinal detachment process. Low collagenase activity with an increase in collagen synthesis could indicate a risk factor to the development of proliferative vitreoretinopathy.     

Roles of thrombospondin-1 and -2 in regulating corneal and iris angiogenesis

PURPOSE: Thrombospondin (TSP)-1 and -2 are important antiangiogenic factors thought to be involved in maintaining corneal avascularity (angiogenic privilege). This study was undertaken to investigate whether deficiencies of these factors altered developmental and inflammation-induced angiogenesis in the cornea and developmental angiogenesis of the iris of mice. METHODS: Expression of TSP-1 and -2 mRNA and protein was assayed in cornea and iris stroma by RT-PCR and Western blot. Corneas and irides of TSP-1(-/-), TSP-2(-/-), and TSP-1,2(-/-) mice aged 2, 3, and 6 months, and wild-type control mice, were analyzed for spontaneous angiogenesis biomicroscopically, histologically, and with CD31 immunohistochemistry. The mouse model of suture-induced, inflammatory corneal neovascularization was used to evaluate the lack of TSP-1,2 and both TSPs on induced-corneal angiogenesis. Seven days after intrastromal placement of three 11-0 sutures, vascularized areas were analyzed morphometrically on CD31-stained corneal flatmounts. RESULTS: Corneas and irises from normal mouse eyes constitutively expressed TSP-1 and -2 mRNAs and proteins. Corneas of TSP-1(-/-), -2(-/-), and -1,2(-/-) mice displayed no evidence of spontaneous developmental-postnatal angiogenesis, although irises of these mice contained significantly increased iris vessel density compared with wild-type animals (P < 0.01). One week after suturing, corneas of all TSP(-/-) mice had significantly greater corneal angiogenesis than those of control mice (P < 0.05). TSP-1(-/-) had a significantly greater effect on induced corneal neovascularization than did TSP-2(-/-), with the opposite being the case in developmental iris angiogenesis (P < 0.01). CONCLUSIONS: Corneal avascularity during development is redundantly regulated, shown by the fact that lack of the antiangiogenic factors TSP-1 and/or -2 resulted in no spontaneous corneal angiogenesis. By contrast, TSP-1, more than TSP-2, helps to suppress inflammation-induced corneal angiogenesis postnatally, implying that angiogenic privilege in the cornea is actively maintained.     

Hedgehog信号通路在视网膜细胞发育及病理性血管生成中的作用

视网膜细胞发育障碍和眼部血管的病理性生长可见于多种眼部疾病,严重影响患者视力.Hedgehog信号转导通路已被证实参与视网膜神经节细胞、无长突细胞、视锥细胞、视杆细胞、Müller胶质细胞、视网膜色素上皮(RPE)细胞等细胞生长发育的多个过程.近年来研究表明,Hedgehog信号通路可以调控视网膜细胞的分化和发育,并在眼部新生血管生成中起到关键性作用.本文从Hedgehog信号通路的组成、Hedgehog信号通路与视网膜细胞发育、视网膜再生、Hedgehog信号通路与眼部病理性血管生成4个方面就Hedgehog信号通路在视网膜细胞发育及病理性血管生成中的作用进行综述,以期为视网膜及眼部血管性疾病的治疗提供新的靶点.     

Role of extracellular signal-regulated kinase in glutamate-stimulated apoptosis of rat retinal ganglion cells

PURPOSE: To investigate the involvement of the extracellular signal-regulated kinase (ERK) signaling pathway after intravitrevous injection of glutamate in rat retina. METHODS: Three groups of five Sprague-Dawley rats each were studied. Group I was a normal control group, intravitreal saline injections. In Group II, one eye received an intravitreal glutamate injection (375 nmol, dissolved in saline) while the contralateral eye served as control. In Group III, intravitreal PD98059 (100 micro mol, an inhibitor of ERK) injections were administered 1 hr before glutamate injections. Seven days after injections, phosphorylated (activated) ERK in retina was localized by immunohistochemistry and fluorescent double labeling of retinal cryosections. Specific ERK blockade was documented to assess the functional significance of activated ERK. TUNEL staining was performed to assess apoptotic cell death. RESULTS: Expression of phosphorylated ERK in rat retina was observed in the inner nuclear layer, the outer nuclear layer, and the nerve fiber layer after 3 days intravitreous injection of glutamate, increasing significantly after 7 days. Double immunofluorescence labling demonstrated that the increased retinal immunostaining for phospho-ERK was predominantly localized to the retinal Müller cells after 7 days intravitreous injection of glutamate. Moreover, blocking activation of ERK significantly improved the number of TUNEL-positive cells in the eyes receiving intravitreal PD98059 injections compared with the eyes receiving glutamate injections. CONCLUSIONS: The ERK pathway is involved in signal transduction in the retina after excessive stimulation by glutamate, which may contribute to the antiapoptotic role in retinal ganglion cell death induced by glutamate.     

Inhibition of retinal angiogenesis by peptides derived from thrombospondin-1

PURPOSE: Thrombospondin (TSP)1 is a tumor suppressor with activity that is associated with its ability to inhibit neovascularization. Previous studies have mapped this antiangiogenic activity to the type 1 repeats and the amino-terminal portion of the molecule within the procollagen-like domain. The present study was performed to investigate the ability of TSP-1 and peptides derived from the type 1 repeats to inhibit retinal angiogenesis. METHODS: TSP-1 and peptides with tryptophan-rich, heparin-binding sequences and transforming growth factor (TGF)-beta1 activation sequences were evaluated in two models of retinal angiogenesis: a retinal explant assay and a rat model of retinopathy of prematurity (ROP). RESULTS: Platelet-derived TSP-1 inhibited angiogenesis in both experimental models. Peptides from the native TSP-1 sequence, which contained both the tryptophan-rich repeat and the TGF-beta1 activation sequence, were the most potent inhibitors of endothelial cell outgrowth in the retinal explant assay. In contrast, a peptide containing only the tryptophan-rich, heparin-binding sequence was most active in inhibiting neovascular disease in the rat ROP model. CONCLUSIONS: These results indicate that the type 1 repeats of TSP-1 contain two subdomains that may independently influence the process of neovascularization, and that peptides derived from these type 1 repeats may be promising pharmacologic agents for treatment of retinal angiogenesis.     

Quercetin inhibits choroidal and retinal angiogenesis in vitro

Background Quercetin is a natural substance found abundantly in grapes, red wine and other food products. In this study, we examined the effect of quercetin on choroidal and retinal angiogenesis in vitro using rhesus choroids-retina endothelial cell line (RF/6A). Methods RF/6A cells were cultured in Dulbecco’s Modified Eagle’s Medium (DMEM) containing 10% fetal bovine serum. Then cells were treated with different concentrations (from 0 to 100 μM) of quercetin. The cell proliferation was assessed using choromogenic methylthiazol tetrazolium bromide (MTT) dye after 24, 48 and 72 hours. Cell migration after 24-hour incubation with quercetin was investigated by wound assay. Following exposure to the various concentrations of quercetin for 24 hours, tube formation on matrigel by endothelial cells was also analyzed. Apoptosis was measured by flow cytometry using annexin V-FITC and propidium iodide staining. Results Quercetin inhibits endothelial cell proliferation in a dose-dependent fashion; 10.1%, 42.6% and 65.2% inhibition on treating with 10, 50 and 100 μM Quercetin respectively. The migration and tube formation of RA/6A cells were also significantly inhibited by quercetin in a dose-dependent manner. Flow cytometric analysis showed that the percentages of apoptotic cells were slightly increased only in 100 μM quercetin-treated cells. Conclusions Our results show that quercetin inhibits choroidal and retinal angiogenesis in vitro. Further studies are ongoing to evaluate this drug as a potential candidate for the treatment of choroidal or retinal neovascularization.     

COX-2 inhibition and retinal angiogenesis in a mouse model of retinopathy of prematurity

PURPOSE: The prostaglandin-cyclooxygenase (COX) pathway influences new blood vessel growth in a variety of tissues. This study was conducted to determine the cellular location of COX-2 in the retina and whether the inhibition of COX-2 would reduce retinal angiogenesis in a rodent model of retinopathy of prematurity (ROP). METHODS: ROP was induced in C57BL/6 mice by exposing 7-day-old mice to 75% oxygen (hyperoxia) for 5 days followed by 5 days in room air (relative hypoxia and retinal angiogenesis). Normal mice were those with a normally developing retinal vasculature exposed to room air from birth until postnatal day (P)17. The COX-2 inhibitor, rofecoxib (15 mg/kg body weight intraperitoneally) was administered to normal and ROP mice from P12 to P17. Immunohistochemistry for COX-2 was performed on retinas from all groups by the avidin-biotin method. Histologic methods were used to count blood vessel profiles (BVPs) in the inner retina (inner limiting membrane, ganglion cell layer, and inner plexiform layer) with a masked approach. RESULTS: Intense COX-2 immunolabeling was specifically localized to ganglion cells and blood vessels of all mice retinas. In ROP mice, COX-2 immunolabeling was detected on blood vessels extending into the vitreous cavity. Quantitation of BVPs in the inner retina revealed an increase in untreated ROP mice compared with untreated normal mice (P < 0.001). Rofecoxib decreased BVPs by approximately 45% in normal mice and 37% in ROP mice. CONCLUSIONS: COX-2 is localized to sites associated with retinal blood vessels. The finding that the selective COX-2 inhibitor, rofecoxib, attenuated the retinal angiogenesis that accompanies ROP, and normal retinal development indicates that COX-2 plays an important role in blood vessel formation in the retina.     

Role of the Norrie disease pseudoglioma gene in sprouting angiogenesis during development of the retinal vasculature

PURPOSE: To characterize developmental defects and the time course of Norrie disease in retinal and hyaloid vasculature during retinal development and to identify underlying molecular angiogenic pathways that may be affected in Norrie disease, exudative vitreoretinopathy, retinopathy of prematurity, and Coats' disease. METHODS: Norrie disease pseudoglioma homologue (Ndph)-knockout mice were studied during retinal development at early postnatal (p) stages (p5, p10, p15, and p21). Histologic techniques, quantitative RT-PCR, ELISA, and Western blot analyses provided molecular data, and scanning laser ophthalmoscopy (SLO) angiography and electroretinography (ERG) were used to obtain in vivo data. RESULTS: The data showed that regression of the hyaloid vasculature of Ndph-knockout mice occurred but was drastically delayed. The development of the superficial retinal vasculature was strongly delayed, whereas the deep retinal vasculature did not form because of the blockage of vessel outgrowth into the deep retinal layers. Subsequently, microaneurysm-like lesions formed. Several angiogenic factors were differentially transcribed during retinal development. Increased levels of hypoxia inducible factor-1alpha (HIF1alpha) and VEGFA, as well as a characteristic ERG pattern, confirmed hypoxic conditions in the inner retina of the Ndph-knockout mouse. CONCLUSIONS: These data provide evidence for a crucial role of Norrin in hyaloid vessel regression and in sprouting angiogenesis during retinal vascular development, especially in the development of the deep retinal capillary networks. They also suggest an early and a late phase of Norrie disease and may provide an explanation for similar phenotypic features of allelic retinal diseases in mice and patients as secondary consequences of pathologic hypoxia.     

内皮抑素基因转移抑制视网膜新生血管的实验研究

目的评价脂质体介导的内皮抑素(ES)基因转移抑制缺氧诱导的小鼠视网膜新生血管的效果。探讨基因转移抑制视网膜新生血管的可行性。方法制备阳离子脂质体及PCDNA3ES复合物。选1周龄C57Bl/6N小鼠置于氧浓度为(75±2)%的氧箱中5d。回到正常环境中诱导视网膜新生血管模型。在小鼠离开氧箱的当日,向ES注射组鼠玻璃体腔注射2μl脂质体PCDNA3ES复合物;载体对照组注射等量脂质体空白载体复合物;空白对照组小鼠注射等量PBS。采用ES抗体免疫组化方法检测ES蛋白在视网膜的表达;回到正常环境中后5d,采用荧光标记的右旋糖酐血管灌注下视网膜铺片方法观察视网膜新生血管的分布;组织学切片观察比较突破视网膜内界膜的血管内皮细胞数量;透射电镜观察ES转移对视网膜超微结构的影响。结果免疫组化检查发现ES注射组小鼠玻璃体腔注射ES后24h开始有ES表达,主要位于视网膜神经纤维层细胞中,维持至少2周仍见表达;视网膜铺片观察可见空白对照组在无灌注区边缘均可见新生血管芽及荧光渗漏。ES注射组见新生血管芽明显减少;组织学检查ES注射组较其他两组突破视网膜内界膜的细胞数量减少,差异有统计学意义;ES转移后电镜下视网膜各层超微结构未见明显改变。结论采用玻璃体腔注射方法行脂质体介导的内皮抑素基因转移可以一定程度抑制缺氧诱导的小鼠视网膜新生血管生长,对视网膜无明显的毒副作用。应进一步优化转移条件以提高治疗效果。     

血清脂质运载蛋白2在小鼠视网膜血管内皮细胞血管生成中的作用

目的：观察脂质运载蛋白2(lipocalin-2, LCN-2)对体外培养的小鼠视网膜内皮细胞(retinal vascular endothelial cells, RVECs)增殖、迁移和管腔形成的影响及其在视网膜新生血管中的作用。

方法：取生长状况良好的RVECs分为不同浓度组：分别以0、5、10μmol/L LCN-2作用细胞48h。采用EdU法检测细胞增殖,Transwell法检测细胞迁移,Matrigel法检测管腔形成。

结果：不同浓度LCN-2作用的细胞增殖率大于对照组,差异有统计学意义(P<0.05),不同浓度LCN-2组RVECs细胞迁移数目多于对照组,差异有统计学意义(P<0.05),不同浓度LCN-2组细胞管腔形成数明显多于对照组,差异有统计学意义(P<0.05),且细胞增殖、迁移和管腔形成均随着LCN-2浓度的升高而增加。

结论：LCN-2能够明显促进RVECs的血管生成过程,提示LCN-2是一种重要的促视网膜新生血管形成的因子。     

腺病毒介导的TSP-1f基因转移抑制视网膜新生血管的实验研究

目的 构建表达凝血酶敏感蛋白-1(thrombin sensitive protein-1,TSP-1)抗新生血管活性片段(TSP-1f)腺病毒载体,并观察其对氧诱导的小鼠视网膜新生血管形成的抑制作用.方法 应用RT-PCR 方法从正常人外周血单个核细胞扩增TSP-1f cDNA 序列;采用AdEasy 系统构建TSP-1f重组腺病毒ADV-TSP-1f.将鼠龄为7 d的40只C57BL/6J新生鼠置于体积分数75%的氧环境中连续生活5 d,然后回到正常环境中建立氧诱导的鼠血管增生性视网膜病变动物模型;每只鼠随机选取一眼为实验组,而对侧眼为对照组,在鼠生后12 d时实验组玻璃体腔注射ADV-TSP-1f,对照组注射ADV-LacZ.1周后麻醉处死小鼠,Western 印迹方法检测TSP-1f 在实验组视网膜中的表达;视网膜铺片ADP酶法观察视网膜血管变化,组织学切片观察比较突破视网膜内界膜的血管内皮细胞数量.结果 成功构建表达TSP-1f重组腺病毒载体并转染鼠视网膜,Western blotting检测到实验组视网膜目的基因表达.视网膜铺片实验组视网膜未见明显的无灌注区形成,新生血管几乎消失.组织切片实验组突破内界膜的内皮细胞核数目(10.18±1.74)明显减少,与对照组(48.89±2.98)相比差异有显著统计学意义(P＜0.01).结论 腺病毒介导的TSP-1f对氧诱导的鼠视网膜新生血管有显著的抑制作用,为视网膜新生血管性疾病的基因治疗奠定基础.     

Retinal vascular development and pathologic retinal angiogenesis are not impaired in matrix metalloproteinase-2 deficient mice

PURPOSE: Earlier studies have suggested a role for metalloproteinase-2 (MMP-2) in retinal angiogenesis. To investigate this further, we have studied retinal vascular development and pathologic ischemia-induced retinal angiogenesis in MMP-2-deficient and wild-type mice. METHODS: Vascular development of the retina was studied in retinal flatmounts, whereas pathologic retinal angiogenesis was analyzed in retinal flatmounts and on histologic sections using a model of ischemia-induced retinopathy. The time course of MMP-2 mRNA expression was determined by in situ hybridization and real-time polymerase chain reaction (PCR). RESULTS: Formation of the retinal vascular plexus was not significantly different in MMP-2-deficient mice as compared to wild-type mice. In ischemia-induced retinopathy, there was an increased formation of extraretinal neovascular tufts in the MMP-2-deficient mice (p < 0.05). MMP-2 mRNA expression did not correlate to either retinal vascular development or to ischemia-induced formation of extraretinal vascular tufts. CONCLUSIONS: The current data suggest that MMP-2 is not essential for either retinal vascular development or pathologic retinal neovascularization in the mouse.     

Inhibition of APE1/Ref-1 redox activity with APX3330 blocks retinal angiogenesis in vitro and in vivo

This study examines the role of APE1/Ref-1 in the retina and its potential as a therapeutic target for inhibiting retinal angiogenesis. APE1/Ref-1 expression was quantified by Western blot. The role of APE1/Ref-1 redox function in endothelial cell in vitro angiogenesis was examined by treating retinal vascular endothelial cells (RVECs) with APX3330, a small molecule inhibitor of APE1/Ref-1 redox activity. In vitro methods included a proliferation assay, a transwell migration assay, a Matrigel tube formation assay, and a Real-Time Cell Analysis (RTCA) using the xCELLigence System. In vivo functional studies of APE1/Ref-1 were carried out by treating very low density lipoprotein (VLDL) receptor knockout mice (Vldlr^−/−) with intravitreal injection of APX3330, and subsequent measurement of retinal angiomatous proliferation (RAP)-like neovascularization for one week. APE1/Ref-1 was highly expressed in the retina and in RVECs and pericytes in mice. APX3330 (1-10 μM) inhibited proliferation, migration and tube formation of RVECs in vitro in a dose-dependent manner. Vldlr^−/− RVECs were more sensitive to APX3330 than wild-type RVECs. In Vldlr^−/− mice, a single intravitreal injection of APX3330 at the onset of RAP-like neovascularization significantly reduced RAP-like neovascularization development. APE1/Ref-1 is expressed in retinal vascular cells. APX3330 inhibits RVEC angiogenesis in vitro and significantly reduces RAP-like neovascularization in Vldlr^−/− mice. These data support the conclusion that APE1/Ref-1 redox function is required for retinal angiogenesis. Thus, APE1/Ref-1 may have potential as a therapeutic target for treating neovascular age-related macular degeneration and other neovascular diseases.     

胰岛素样生长因子结合蛋白相关蛋白-1抑制视网膜血管新生的实验研究

背景寻求有效的血管内皮生长因子（VEGF）抑制剂是治疗和预防新生血管性眼病的关键。胰岛素样生长因子结合蛋白相关蛋白-1（IGFBP—rP1）是一种新发现的抑血管新生因子,推测其在眼内有抑制VEGF的作用。目的探讨IGFBP—rP1对VEGF体外诱导视网膜新生血管形成的抑制作用及其机制。方法使用含质量分数10％FBS的DMEM对猕猴视网膜／脉络膜血管内皮细胞株（RF／6A）进行扩增培养,利用免疫荧光细胞化学染色法观察RF／6A细胞表达IGFBP—rP1的情况。RF／6A细胞血清饥饿法培养24h后分为对照组、10mg／LVEGF组,50、100、200mg／LIGFBP—rP1＋10mg/L VEGF组进行干预,分别利用MTS比色法、Transwell实验和流式细胞术比较IGFBP—rP1（0、50、100、200mg／L）联合VEGF（10mg／L）作用后,RF／6A细胞在增生、移行和凋亡等生物学行为方面的变化。结果RF／6A细胞用不同质量浓度的IGFBP—rP1培养后细胞质呈FITC激发后的绿色荧光,细胞核呈PI激发后的红色荧光,而对照组细胞仅见细胞核的红色荧光。10mg／LVEGF组RF／6A细胞的A490值、移行细胞数与对照组相比明显增加,差异均有统计学意义（t=-15．191,P=0．000;t=-21．274,P=0．000）,细胞凋亡率明显下降,差异有统计学意义（t=10．228,P=0．000）。与10mg／LVEGF组相比,IGFBP—rP1（50、100、200mg／L）＋10mg／LVEGF组RF／6A细胞的A490值、移行细胞数明显下降（均P〈0．05）。50、100、200113geLIGFBP—rPl＋10mg／LVEGF组RF／6A细胞的细胞凋亡率分别提高了（1．26±0．04）％、（1．50±0．07）％和（1．93±0．27）％,各组的总体差异有统计学意义（F=274．273,P=0．000）。结论IGFBP—rP1作为一种内源性因子,通过促细胞凋亡机制抑制VEGF诱导的视网膜血管的生成。     

血管内皮生长因子受体KDR基因胞外段1-3区基因转染抑制氧诱导小鼠视网膜新生血管的研究

目的 评价脂质体介导的血管内皮生长因子受体KDR基因胞外段1-3区(KDRn3)基因转染抑制氧诱导的视网膜新生血管的效果.方法 选1周龄C57Bl/6N小鼠置于氧浓度为75%±2%的氧箱中5 d.回到正常环境中诱导视网膜新生血管模型.在小鼠离开氧箱的当日,向转染组小鼠玻璃体腔注射脂质体pEGFP-N1/KDRn3复合物1 μl;脂质体对照组注射等量脂质体;空白对照组小鼠注射等量PBS.回到正常环境中后5 d,采用视网膜铺片及视网膜冰冻切片在激光共聚焦显微镜下观察绿色荧光蛋白在视网膜的表达;采用荧光标记的右旋糖酐血管灌注下视网膜铺片方法观察视网膜新生血管的分布并测量无灌注区面积;组织学切片观察比较突破视网膜内界膜的血管内皮细胞数量.多组比较采用方差分析,有统计意义后进行两两比较的q检验.结果 转染组视网膜铺片见视网膜局部散在点状绿色荧光信号,空白对照组与脂质体对照组未见绿色荧光信号;视网膜冰冻切片见转染组视网膜神经节细胞层、内核层部分细胞胞质内见绿色荧光表达,空白对照组与脂质体对照组视网膜各层未见绿色荧光表达;视网膜铺片观察可见空白对照组与脂质体对照组在无灌注区边缘均可见新生血管芽及荧光渗漏,转染组见新生血管芽明显减少,生后第17天A、B、C 3组新生血管模型小鼠各组视网膜无灌注区面积分别为(1.33±0.49)、(2.75±0.70)、(2.12±0.35)mm2,组间比较差异有统计学意义(F=17.61,P＜0.01＝.正常对照组及A、B、C组视网膜表面突破内界膜的血管内皮细胞核计数分别为0.20±0.51、13.58±2.48、23.05±3.40及21.70±2.89,组间比较差异有统计学意义(F=1085.25,P＜0.05＝.结论 pEGFP-N1/KDRn3基因转染可不同程度抑制氧诱导C57,Bl/6J小鼠视网膜新生血管的生长.

Abstract：

Objective To evaluate the effect of liposome mediated plasmids KDRn3 injected into the vitreous to inhibit experimental retinal neovascularization. Methods One-week-old C57BL/6N mice were exposed to 75% ± 2% oxygen for 5 days, then returned to the room air to induce retinal neovascularization. Cationic liposome mediated KDRn3 comp-lex (1 μl) was injected into the vitreous in the treatment group. PBS 1 μl or liposome were injected in the control group. The pEGFP-N1/ KDRn3 expression was observed by using fluorescence microscope. Retinal neovascularization was evaluated by counting the number of vascular endothelial cell nuclei on the vitreal side of the inner limiting membrane of the retina and measuring the areas of non-perfusionsin in central retina. Results KDRn3 protein was expressed both in the ganglion layer and in the inner layer. Retinal wholemount preparation of retinal neovascular animal model showed that prominent neovascular tuft and fluorescein leakage and large areas of non-perfusionsin in central retina. Fewer neovascular tufts and fewer areas of non-perfusionsin could be seen after pEGFP-N1/KDRn3 injection. There were statistic differences between control group and pEGFP-N1/ KDRn3 injecting group with the number of vascular endothelial cell nuclei on the vitreal side of the inner limiting membrane of the retina(0. 20 ±0. 51, 13. 58 ±2. 48,23. 05 ±3. 40,21. 70 ± 2. 89;F = 1085. 25, P ＜ 0. 05 ) and the areas of non-perfusionsin in central retina [(1. 33 ± 0. 49 ) , ( 2. 75 ± 0. 70 ) , ( 2. 12 ± 0. 35) mm2; F = 17. 61 , P ＜ 0. 01] . Conclusion pEGFP-N1/KDRn3 gene transfer can inhibit retinal neovascularisation in C57Bl/6J mice of ischaemia-induced retinal neovascularisation on some extent.