色素上皮衍生因子对角膜碱烧伤后新生血管形成的抑制

背景：角膜新生血管导致角膜透明性降低,造成严重的视觉障碍。色素上皮衍生因子是一种内源性血管生成抑制剂,其对于角膜新生血管是否具有抑制作用尚不清楚。 目的：探索局部运用色素上皮衍生因子对大鼠角膜碱烧伤后角膜新生血管的抑制作用。 方法：将20只大鼠随机分为生理盐水组与色素上皮衍生因子组,每组10只。用NaOH溶液将大鼠右眼角膜烧伤诱导产生新生血管。碱烧伤后2组每日分别给予生理盐水和色素上皮衍生因子点眼,并采用裂隙灯显微镜观察和测量各组角膜新生血管生长情况。碱烧伤后12 d处死大鼠,将角膜组织固定切片,行苏木精-伊红染色观察,并进行免疫组织化学染色检测各组大鼠角膜血管内皮生长因子和CD31的表达。 结果与结论：大鼠角膜碱烧伤后3,7,12 d,色素上皮衍生因子组大鼠角膜新生血管面积均小于生理盐水组(P < 0.05)。角膜碱烧伤后12 d,苏木精-伊红染色显示生理盐水组大鼠角膜产生大量新生血管,角膜组织结构紊乱;色素上皮衍生因子组新生血管较少,角膜组织结构趋于整齐。角膜碱烧伤后12 d,免疫组织化学染色示生理盐水组大鼠角膜上皮和基质层可见血管内皮生长因子大量表达,角膜基质层可见血管内皮生长因子和CD31大量表达;色素上皮衍生因子组新生血管稀少,CD31表达较弱。证实局部应用色素上皮衍生因子可有效抑制大鼠角膜化学伤后的血管新生。     

兔角膜碱烧伤模型房水中肿瘤坏死因子α及血管内皮生长因子表达与姜黄素的抑制

背景：稳定的角膜新生血管动物模型是研究角膜新生血管调控机制,姜黄素对碱烧伤角膜新生血管具有抑制作用和保护作用。 目的：探讨姜黄素对碱烧伤角膜新生血管模型中肿瘤坏死因子α及血管内皮生长因子表达的影响,为防治角膜新生血管提供理论依据。 方法：纳入33只新西兰大耳白兔,随机取3只设为正常组,其余30只建立兔角膜碱烧伤诱发角膜新生血管模型,右眼设为对照组给予生理盐水,左眼设为干预组给予姜黄素,裂隙灯观察角膜新生血管生长及角膜混浊情况,酶联免疫吸附实验检测肿瘤坏死因子α和血管内皮生长因子在房水中的表达。 结果：正常组没有角膜新生血管生成。与对照组比较,干预组角膜新生血管受到抑制且角膜混浊较轻(P < 0.05)。房水肿瘤坏死因子α和血管内皮生长因子在3组中均有表达,对照组和干预组明显高于正常组,但干预组低于对照组(P < 0.05)。说明姜黄素可以有效降低角膜碱烧伤后房水肿瘤坏死因子α及血管内皮生长因子的表达进而抑制兔角膜碱烧伤后角膜新生血管的生长。     

不同浓度血管抑素抑制大鼠角膜血管的新生

背景：血管抑素在角膜中是否抑制组织中的新生血管生长尚不清楚。 目的：观察血管抑素溶液对大鼠角膜新生血管生长的作用。 方法：24只大鼠制备左眼碱烧伤角膜新生血管模型,随机抽签法分为4组,对照组给予生理盐水,25,50,75 mg/L AS组分别给与25,50,75 mg/L AS血管抑素溶液滴眼,4次/d至实验结束。 结果与结论：造模后第3天各组角膜均可见少量血管新生,但对照组角膜新生血管生长较其他3组明显。3~7 d,各组角膜新生血管生长速度加快,对照组角膜新生血管粗大。烧伤后14 d,对照组角膜新生血管仍然粗大未见明显消退,各浓度组较前消退明显。碱烧伤后不同时间点各浓度组角膜新生血管面积较对照组少(P < 0.05),75mg/L AS组碱烧伤14 d各时间新生血管面积较其他3组减少(P < 0.05)。Real-Time PCR结果显示：各浓度组间CD31 mRNA表达差异均有显著性意义(P < 0.01)。Western blot结果显示血管抑素作用大鼠后,各浓度组角膜组织的CD31表达均较对照组降低,且随着血管抑素溶液浓度的增加而减少。提示血管抑素能够阻止角膜新生血管的生长。     

重组IFN-α蛋白联合endostatin基因对碱烧伤诱导角膜新生血管的抑制作用

目的探讨重组IFN-α蛋白联合endostatin基因对碱烧伤诱导角膜新生血管的抑制作用。方法兔眼球结膜下注射包有绿色荧光蛋白表达载体的脂质体，3d后用激光共聚焦显微镜观察角膜绿色荧光蛋白表达。利用碱烧伤法制备兔眼角膜新生血管模型，球结膜下联合注射重组IFN-α蛋白及包有endostatin真核表达载体的脂质体，用裂隙灯显微镜观察对新生血管的抑制作用。结果实验组角膜有很强的绿色荧光，而在对照组则无荧光。联合应用重组IFN-α蛋白和endostatin基因治疗，第7、10、13天角膜新生血管长度、面积明显小于重组IFN-α蛋白和endostatin基因的单独治疗组（P〈0．05）。结论重组IFN-α蛋白联合endostatin基因可有效抑制碱烧伤诱导角膜新生血管的生长。     

Avastin对小鼠角膜新生血管形成和TGF-β1表达的影响

目的探讨Avastin对小鼠角膜新生血管形成和转化生长因子-β1(transforming growth factor-beta1,TGF-β1)表达的影响。方法制作小鼠角膜碱烧伤模型,随机分为碱烧伤组和Avastin治疗组,碱烧伤组连续两周内每日左氧氟沙星滴眼液滴眼3次,Avastin治疗组连续两周内应用25mg/ml Avastin结膜下隔日注射5μl+每日左氧氟沙星滴眼液滴眼3次,分别于碱烧伤后3d、7d和12d取材。体视显微镜观察角膜新生血管形成情况,应用HE染色法观察角膜组织的损伤情况,采用免疫组化法观察TGF-β1在碱烧伤后不同时间段角膜组织内的表达情况。结果在不同时间段,Avastin治疗组角膜新生血管的形成均少于碱烧伤组。在正常小鼠角膜组织内,TGF-β1表达于角膜上皮层和内皮层。在碱烧伤对照组角膜内,TGF-β1主要表达于角膜上皮细胞和角膜基质内入侵的炎性细胞,在碱烧伤后3d,TGF-β1的表达达到高峰(P0.05),在碱烧伤后12d,TGF-β1的表达恢复至正常水平。在Avastin治疗组角膜内,各时间段TGF-β1的表达均低于对照组。结论 Avastin能够抑制小鼠碱烧伤后角膜新生血管的形成,其机制可能与下调碱烧伤角膜组织TGF-β1的表达相关。     

壳聚糖/聚丙烯酸即型凝胶治疗兔眼干燥症角膜组织的病理学变化

背景：壳聚糖具有可再生、来源广、易降解及生物相容性好等特点,是一种潜在的制备即型凝胶的良好原料。 目的：观察壳聚糖/聚丙烯酸即型凝胶修复兔眼损伤角膜组织的效果。 方法：制作兔眼表干燥缺损症状模型,14 d后随机分组：实验组在兔眼表用壳聚糖/聚丙烯酸即型凝胶进行治疗,3次/d;对照组不用药。 结果与结论：经壳聚糖/聚丙烯酸即型凝胶治疗28 d后的兔角膜上皮超微结构趋于正常,上皮细胞排列完整紧密,上皮细胞剥脱所形成的缺损区已被新生上皮细胞覆盖,细胞排列较规则,水肿情况少见,上皮细胞微绒毛和微皱襞明显增多,即上皮干燥缺损病症得到修复。以上结果表明,壳聚糖/聚丙烯酸即型凝胶可修复眼表干燥缺损角膜上皮组织。     

羊膜接触镜输送人表皮干细胞重建兔角膜上皮

目的 利用眼表生物膜固定装置(BMFD)与羊膜(AM)制成接触镜,输送人表皮干细胞至角膜缘干细胞缺损(LSCD)的兔眼表,并评价其重建角膜上皮的效果.方法 制作去角膜上皮及角膜缘干细胞的雌性LSCD兔模型,分为3组:羊膜加人表皮干细胞移植组(n=20),将男性人表皮干细胞悬液注射到BMFD-AM接触镜(简称羊膜接触镜)与眼表之间;羊膜遮盖组(n=20),戴羊膜接触镜;对照组(n=20),单纯药物治疗.裂隙灯显微镜结合角膜荧光素钠染色观察并评价角膜修复情况.随访至角膜完全上皮化后,取角膜组织行病理学检查和免疫组织化学鉴定,PCR检测人Y-STR基因鉴定细胞来源.结果 羊膜加人表皮干细胞移植组角膜上皮修复快,平均(5.60±0.46)d达到完全上皮化,另外两组角膜上皮修复迟缓.羊膜遮盖组(9.25±0.51)d、对照组(12.45±0.65)d才完成角膜上皮化(P均<0.05).组织病理学示羊膜加人表皮干细胞移植组角膜上皮细胞形态接近正常,K3/K12(+)、Mucin 5AC(-)、K4(-).并可检测到人Y-STR基因.组织病理学示另外两组角膜上皮结膜化,K4(+)、Mucin 5AC(+)、K3/K12(-).结论 羊膜接触镜联合人表皮干细胞悬液注射能够重建LSCD兔角膜上皮.     

Avastin对小鼠角膜碱烧伤后新生淋巴管形成的影响

目的观察小鼠角膜碱烧伤后新生淋巴管形成情况,探讨Avastin对小鼠角膜碱烧伤后新生淋巴管形成的影响及其机制。方法制作小鼠角膜碱烧伤模型,随机分为治疗组和烧伤组,烧伤组连续两周内每日左氧氟沙星滴眼液滴眼3次,治疗组连续两周内应用25mg/ml Avastin结膜下隔日注射5μl+每日左氧氟沙星滴眼液滴眼3次,分别于碱烧伤后3d、5d、7d、12d和18d取材。采用免疫组化法,观察VEGF-C在碱烧伤后不同时间段角膜组织内的表达;应用淋巴管内皮透明质酸受体(LYVE-1)标记淋巴管内皮,观察小鼠角膜内新生淋巴管的形成情况。结果在正常小鼠角膜组织内,VEGF-C表达于角膜上皮层和内皮层。在烧伤组碱烧伤角膜内,VEGF-C主要表达于角膜上皮细胞和角膜基质内入侵的炎性细胞,于碱烧伤后3d,VEGF-C的表达达到高峰(0.05),碱烧伤后12d,VEGF-C的表达恢复至正常水平。在治疗组碱烧伤角膜内,VEGF-C的表达在碱烧伤后3d低于烧伤组。Avastin治疗组角膜内,碱烧伤后12d见LYVE-1阳性表达开放状态的新生淋巴管,淋巴管出现的时间较烧伤组明显延迟。结论 Avastin能减少小鼠碱烧伤后角膜新生淋巴管的形成,其机制可能与抑制角膜组织内淋巴管生成因子VEGF-C的表达相关。     

血管内皮生长因子D在小鼠碱烧伤后角膜的表达及其作用

目的观察血管内皮生长因子D(VEGF-D)在小鼠角膜碱烧伤后不同时间角膜组织内的表达,探讨VEGF-D在小鼠角膜碱烧伤后新生淋巴管形成过程中的作用。方法制作小鼠角膜碱烧伤模型,分别于碱烧伤后1d、3d、5d、7d、12d和18d取材。应用免疫组化SP法观察VEGF-D在正常角膜和碱烧伤后不同时间角膜内的表达,应用淋巴管内皮透明质酸受体1(LYVE-1)标记淋巴管,观察小鼠碱烧伤角膜内新生淋巴管的形成情况。结果碱烧伤后1d、3d、5d,角膜内VEGF-D表达水平明显高于正常角膜(P<0.01),于碱烧伤后3d,表达达到高峰。碱烧伤后7d,VEGF-D的表达下降至正常水平。在碱烧伤角膜内,可见阳性表达LYVE-1的新生淋巴管。结论 VEGF-D过表达可能参与小鼠角膜碱烧伤后新生淋巴管形成过程。     

血管抑素抑制兔眼表碱烧伤角膜缘移植术后的角膜血管新生

目的:检测眼表碱烧伤角膜缘移植术后血管抑素抑制角膜新生血管的作用。方法:16只新西兰大白兔双眼制作碱烧伤模型1d后,双眼行角膜缘移植术,术后左眼局部应用血管抑素治疗2周,右眼作对照;观测4周,根据新生血管侵入角膜缘内的范围、角膜混浊与水肿程度进行分级并作统计学处理;同时测量术后7、14、21及28d的眼压。结果:术后4周时,应用血管抑素的左眼的新生血管的评分为1.19±0.10,而对照组为1.63±0.72,统计学处理显示左眼的新生血管较右眼的明显减少(P<0.05),角膜混浊与水肿程度亦明显下降。各时间点各术眼的眼压均在正常范围,无统计学差异。结论:局部应用血管抑素能有效抑制眼表碱烧伤角膜缘移植术后的新生血管增生。     

Involvement of macrophage chemotactic protein-1 and interleukin-1beta during inflammatory but not basic fibroblast growth factor-dependent neovascularization in the mouse cornea

Corneal neovascularization develops in several pathologic conditions, but its underlying mechanisms remain elusive. We used a mouse inflammatory corneal model (corneas cauterized with silver nitrate) and assessed the role of monocyte/macrophage-attracting factors, macrophage chemotactic protein-1 (MCP-1), and a proinflammatory cytokine, IL-1beta, on macrophage recruitment and neovascularization. Both MCP-1, IL-1beta protein, and mRNA levels increased markedly 12 hours after the chemical cauterization. In situ hybridization showed that MCP-1 was located in corneal epithelial cells, and IL-1beta was located in corneal epithelial cells and infiltrating inflammatory cells. In addition, double staining of corneas with antibodies specific for monocytes/macrophages and IL-1beta revealed that IL-1beta was found in infiltrating monocytes/macrophages at Day 2 after cauterization. Both IL-1beta and MCP-1 induced neovascularization in a rat cornea model, and the cauterization-induced corneal neovascularization was partially inhibited by subconjunctival injection of anti-IL-1beta or anti-MCP-1. Coadministration of two antibodies inhibited corneal neovascularization slightly more than that by the administration of each. In contrast, administration of the anti-MCP-1 or anti-IL-1beta showed minimal inhibition of basic fibroblast growth factor-driven corneal neovascularization by mouse cornea assay. Cauterized corneas treated with anti-MCP-1 antibody had significantly fewer monocytes/macrophages than control. These results indicate the existence of distinct monocyte/macrophage-involved angiogenic pathways in mouse cornea, in which MCP-1 released from corneal epithelial cells attracts monocytes/macrophages into the cornea, where they release IL-1beta leading to inflammatory neovascularization. In addition, the IL-1beta and MCP-1 released from the corneal epithelial cells may directly induce corneal neovascularization.     

Expression of Smad7 in mouse eyes accelerates healing of corneal tissue after exposure to alkali

Damage to the cornea from chemical burns is a serious clinical problem that often leads to permanent visual impairment. Because transforming growth factor (TGF)-beta has been implicated in the response to corneal injury, we evaluated the effects of altered TGF-beta signaling in a corneal alkali burn model using mice treated topically with an adenovirus (Ad) expressing inhibitory Smad7 and mice with a targeted deletion of the TGF-beta/activin signaling mediator Smad3. Expression of exogenous Smad7 in burned corneal tissue resulted in reduced activation of Smad signaling and nuclear factor-kappaB signaling via RelA/p65. Resurfacing of the burned cornea by conjunctival epithelium and its differentiation to cornea-like epithelium were both accelerated in Smad7-Ad-treated corneas with suppressed stromal ulceration, opacification, and neovascularization 20 days after injury. Introduction of the Smad7 gene suppressed invasion of monocytes/macrophages and expression of monocyte/macrophage chemotactic protein-1, TGF-beta1, TGF-beta2, vascular endothelial growth factor, matrix metalloproteinase-9, and tissue inhibitors of metalloproteinase-2 and abolished the generation of myofibroblasts. Although acceleration of healing of the burned cornea was also observed in mice lacking Smad3, the effects on epithelial and stromal healing were less pronounced than those in corneas treated with Smad7. Together these data suggest that overexpression of Smad7 may have effects beyond those of simply blocking Smad3/TGF-beta signaling and may represent an effective new strategy for treatment of ocular burns.     

胶原润眼液能够加快眼角膜上皮损伤的修复*

背景：Ⅰ型胶原不仅是角膜的主要组成成分,还能对受伤角膜起到营养修复作用,具有很好的药物缓释功能。 目的：了解胶原润眼液对兔损伤角膜的修复作用,并评价其生物安全性。 方法：采用角膜环钻制备兔双眼角膜损伤模型,抗感染处理后,右眼滴胶原润眼液作为实验组,左眼滴生理盐水作为对照组,以结膜分泌物及水肿度、2%荧光素角膜染色评分、损伤愈合率等指标评价胶原润眼液对损伤角膜的修复作用。 结果与结论：对照组兔术后结膜分泌物增多,水肿严重;实验组动物术后结膜分泌物较少,无严重水肿和充血。实验组术后第11天,13天角膜损伤愈合率明显高于对照组(P < 0.05)。体外细胞毒性试验不大于2级反应,且无致敏和刺激反应,结果显示胶原润眼液无生物学危害,能够加快兔损伤角膜的愈合。 关键词：胶原润眼液;角膜;修复;安全性;组织工程 doi:10.3969/j.issn.1673-8225.2012.03.018      

The lectin KM+ induces corneal epithelial wound healing in rabbits

Neutrophil influx is essential for corneal regeneration ( Gan et al. 1999 ). KM+, a lectin from Artocarpus integrifolia , induces neutrophil migration ( Santos-de-Oliveira et al. 1994 ). This study aims at investigating a possible effect of KM+ on corneal regeneration in rabbits. A 6.0-mm diameter area of debridement was created on the cornea of both eyes by mechanical scraping. The experimental eyes received drops of KM+ (2.5 μg/ml) every 2 h. The control eyes received buffer. The epithelial wounded areas of the lectin-treated and untreated eyes were stained with fluorescein, photographed and measured. The animals were killed 12 h (group 1, n  = 5), 24 h (group 2, n  = 10) and 48 h (group 3, n  = 5) after the scraping. The corneas were analysed histologically (haematoxylin and eosin and immunostaining for proliferation cell nuclear antigen, p63, vascular endothelial growth factor, c-Met and laminin). No significant differences were found at the epithelial gap between treated and control eyes in the group 1. However, the number of neutrophils in the wounded area was significantly higher in treated eyes in this group. Three control and seven treated eyes were healed completely and only rare neutrophils persisted in the corneal stroma in group 2. No morphological distinction was observed between treated and control eyes in group 3. In treated corneas of group 2, there was an increase in immunostaining of factors involved in corneal healing compared to controls. Thus, topical application of KM+ may facilitate corneal epithelial wound healing in rabbits by means of a mechanism that involves increased influx of neutrophils into the wounded area induced by the lectin.     

Immunohistochemical expression of matrix metalloproteinases in the rabbit corneal epithelium upon UVA and UVB irradiation

Matrix metalloproteinases (MMPs) are proteolytic enzymes involved in tissue remodeling and wound healing. These enzymes degrade and also synthesize components of the extracellular matrix. Overexpression of MMPs results in excessive extracellular matrix degradation and tissue destruction. In the cornea, destructive processes may lead to scarring and loss of vision. In this study MMPs (types 1, 2, 7, 8, 9 and 14) were examined immunohistochemically in the normal rabbit corneal epithelium and in epithelium irradiated in vivo with similar doses of UVB or UVA radiation (UVB rays 312 nm, UVA rays 365 nm, daily dose 1.01 J/cm² for four days). Results show that MMPs studied revealed low expression in the normal corneal epithelium, whereas after repeated UVB irradiation the expression of MMPs was significantly increased in the corneal epithelium, in ascending order: MMP-2, MMP-9, MMP-1, and MMP-7 with MMP-8. In contrast, compared to normal corneas, repeated UVA radiation did not significantly change the expression of MMPs in the irradiated corneal epithelium. MMP-14 was expressed at very low levels in all studied corneas, whereas no significant changes were detected upon UV exposure. In conclusion, UV radiation of shorter wavelength (UVB) induced an increase in expression of all MMPs except MMP-14. It is suggested that overexpression of MMPs in the corneal epithelium contributes to the damaging effect of UVB radiation to the cornea.     

玻璃酸钠壳聚糖纳米粒对烧伤角膜新生血管生长的影响

BACKGROUND:Chitosan nanoparticles-encapsuled sodium hyaluronate is an effective drug for the burned cornea. OBJECTIVE:To verify the effect of sodium hyaluronate/chitosan nanoparticles on the neovascularization in burned cornea. METHODS:Thirty Sprague-Dawley rats were randomly divided into three groups, and the model of burned cornea caused by base was established in the rats of model and experimental groups, followed by respectively treated with 10 μL sodium hyaluronate/chitosan nanoparticle suspension and normal saline, once daily, for consecutive 4 weeks. Rats only given normal saline were used as controls. Four weeks later, the dynamic growth of newly formed blood vessels in the cornea was observed using silt lamp. The levels of tumor necrosis factor-α and interleukin-6 were detected by ELISA, histological changes of the cornea were observed by hematoxylin-eosin staining, and the mRNA expression levels of vascular endothelial growth factor and cyclooxygenase 2 were detected by real-time PCR. RESULTS AND CONCLUSION:Compared with the control group, the area of the newly formed blood vessel and the levels of tumor necrosis factor-α, vascular endothelial growth factor and cyclooxygenase 2 were significantly increased in the model group (P < 0.05, P < 0.01). In the experimental group, all above indicators were significantly lower than those in the model group (P < 0.05). There were a large number of inflammatory cells and neovascularization in the model group, but only few inflammatory cells in the experimental group. These results show that sodium hyaluronate/chitosan nanoparticles can inhibit the neovascularization in the burned cornea.     

以猪角膜脱细胞基质为载体培养人脐静脉内皮细胞构建实验性角膜后板层

 目的： 探讨以异种后弹力膜/基质为载体诱导人脐静脉内皮细胞向角膜内皮细胞分化的可行性及移植术后在活体的生理功能。方法：体外分离培养脐静脉内皮细胞作为诱导移植的种子细胞;取当地质检合格的猪眼球以直径6.2 mm、厚100 μm、冷冻脱水进行角膜深板层载体的制备;接种经CM-DiI荧光标记的第2~3代人脐静脉内皮细胞于载体的后弹力层面,体外培养7~10 d行细胞形态、密度、组织学和扫描电镜观察,待细胞与后弹力层面融合形成单层后,用于兔角膜移植。受眼：正常健康新西兰大白兔24只（24眼）,实验组（人脐静脉内皮细胞移植组）12眼,对照组（单纯猪角膜深板层移植组）12眼,全角膜范围去除术眼内皮细胞,实施移植手术。结果：人脐静脉内皮细胞在猪后弹力膜/基质载体上贴附生长,形成紧密连接的单层,形态近似六角形,呈铺路石状分布,具有正常兔角膜内皮细胞的超微结构。术后8周实验组角膜基本透明,周边角膜略有水肿。对照组单纯猪角膜深板层移植后,移植角膜明显水肿、混浊。结论：以异种角膜后弹力膜/基质为载体培养的人脐静脉内皮细胞,行异种异体移植后,能够在活体上成活,并能维持角膜透明,具有正常角膜内皮细胞的生物学功能。深板层角膜内皮移植术是体外培养血管内皮细胞移植的一种有效术式。