细胞因子在角膜新生血管和淋巴管生成中效应研究

正常角膜无血管组织,以维持角膜的透明性。角膜新生血管（CNV）形成是角膜化学损伤、角膜炎、角膜移植排斥反应等疾病导致的一个难治性眼表并发症。角膜新生淋巴管与新生血管平行生长,已证实新生淋巴管是角膜移植排斥反应的主要原因,眼表许多疾病的发生与角膜新生淋巴管的形成密切相关。细胞因子在角膜新生血管、新生淋巴管的形成中起重要作用,也成为治疗的主要靶点,现就目前发现的细胞因子在角膜新生血管、新生淋巴管发生以及治疗中的作用做如下综述。     

角膜新生淋巴管与血管内皮生长因子C

角膜新生淋巴管（CL）存在于血管化角膜上，常引起并加重角膜混浊和角膜移植排斥反应，是重要的致盲原因之一。血管内皮生长因子C（VEGF—C）是血管内皮生长因子（VEGF）家族成员之一，是VEGFR-2和VEGFR-3受体的配体。VEGF-C通过与VEGFR-3结合促进淋巴管增生，是一个特异性的淋巴管生长因子，在CL形成中起着重要的作用。就近年来CL研究进展及与VEGF—C的关系进行综述。     

角膜移植后角膜新生淋巴管与新生血管间的关联(英文)

目的:研究角膜移植后角膜新生淋巴管与新生血管间关联。方法:人角膜取自行二次角膜移植的19名患者。5核苷酸酶-碱性磷酸酶(5-nase-Alkaline phosphatase,5-NA-ALP)双重酶组织化学染色及淋巴内皮细胞受体(lymphatic vessel endothelial receptor,LYVE-1)、内皮细胞黏附因子-1(platelet endothelial cell adhesion modecule-1,PECAM-1)双重免疫组化法标记角膜中的新生血管和淋巴管,并进行淋巴管计数(lymphatic vessels counting,LVC)和血管计数(blood vessels counting,BVC),比较BVC与LVC之间的关联。结果:角膜中存在角膜新生血管12例(63%),存在角膜新生淋巴管5例(26%)。角膜新生淋巴管仅出现在血管化角膜中。角膜移植后BVC与LVC间呈显著性正相关(r=0.725;P<0.01)。结论:人角膜移植后角膜新生淋巴管与新生血管之间存在密切关联。     

球结膜下注射康柏西普对兔角膜新生血管和淋巴管的抑制作用

目的 观察康柏西普对兔碱烧伤诱导角膜新生血管(CNV)、新生淋巴管生成的作用。 方法 44只2～3 kg成年雄性新西兰大白兔按照随机数字表法分为康柏西普注射组9只、雷珠单抗注射组9只、生理盐水对照组9只、模型对照组9只和正常对照组8只。以左眼为实验眼,采用碱烧伤方法制作炎症性CNV动物模型,直径8 mm的滤纸片浸润1 mol/L NaOH,放至角膜中央烧灼30 s。造模后第1天,康柏西普注射组球结膜下注射康柏西普0.1 ml/1 mg,雷珠单抗注射组同法注射雷珠单抗0.1 ml/1 mg,生理盐水对照组同法注射0.1 ml质量分数0.9% NaCl溶液,模型对照组碱烧伤后不做任何处理,正常对照组不行碱烧伤和球结膜下注射药物处理。分别于造模后第4、7、14和21天计算CNV面积,每组耳缘静脉空气栓塞处死一定数量动物,抽取房水,检测血管内皮生长因子(VEGF);取角膜组织行苏木精－伊红染色,进行组织病理学检查;免疫组织化学检测淋巴管内皮透明质酸受体-1(LYVE-1)含量。 结果 造模后第4天,康柏西普注射组、雷珠单抗注射组、生理盐水对照组和模型对照组新生血管芽长入角膜边缘,角膜水肿减轻;第7天,康柏西普注射组、雷珠单抗注射组新生血管较生理盐水对照组、模型对照组稀疏。造模后第4天可见各造模组角膜上皮细胞增多,上皮层存在空泡,基质内大量炎性细胞,上皮层下可见小的血管腔。造模后第7天,新生血管浸润浅层基质,基质内有大量炎性细胞。造模后第14天,康柏西普注射组CNV面积为(15.20±9.16)mm ²,小于雷珠单抗注射组的(28.21±5.17)mm ²,差异有统计学意义( P<0.05);康柏西普注射组VEGF质量浓度为(7.75±6.56)pg/ml,低于雷珠单抗注射组的(16.98±2.17)pg/ml,差异有统计学意义( P<0.05)。正常对照组角膜组织无淋巴管生长,无LYVE-1阳性细胞。造模后第4天,康柏西普注射组、雷珠单抗注射组、生理盐水对照组和模型对照组角膜组织中出现新生淋巴管,与新生血管平行生长。造模后第7天,康柏西普注射组、雷珠单抗注射组角膜新生淋巴管计数分别为(4.33±0.58)个和(4.67±0.58)个,少于生理盐水对照组的(10.67±0.58)个和模型对照组的(12.33±0.58)个,差异均有统计学意义(均 P<0.05)。 结论 碱烧伤后早期球结膜下注射康柏西普能有效抑制CNV、新生淋巴管,其抑制作用可能与降低VEGF的质量浓度密切相关。     

角膜新生淋巴管的研究进展

近年来随着淋巴管内皮细胞特异性标记物VEGFR-3、LYVE-1、Podoplanin和Prox 1等的发现，对于角膜新生淋巴管的研究有了较大进展，成为近几年的研究热点。本文就角膜新生淋巴管是如何生成，其与新生血管之间的关系，新生淋巴管在角膜移植免疫排斥反应发生过程中的作用作一综述。     

角膜移植后患者角膜新生淋巴管与新生血管和炎症的关联

目的:研究角膜移植后角膜新生淋巴管与新生血管和炎症的关联。方法:人角膜取自行二次角膜移植的患者19例。淋巴内皮细胞受体(lymphatic vessel endothelial hyaluronan receptor,LYVE-1)和内皮细胞黏附因子-1(platelet endothelial celladhesion modecule-1,PECAM-1)双重免疫组化法标记角膜中的新生血管和淋巴管,进行淋巴管计数(lymphatic ves-sels counting,LVC)和血管计数(blood vessels counting,BVC),比较BVC、炎症指数(inflammation index,IF)、移植历史(transplantation history,TH)与LVC之间的关联。结果:角膜移植后BVC,IF与LVC间均呈显著性正相关,而TH与LVC间呈显著性负相关。角膜移植后新生淋巴管、血管、眼表炎症间大致成平行发展,新生淋巴管最先退化,其次是眼表炎症,新生血管最后消退。结论:人角膜移植后角膜新生淋巴管与新生血管、眼表炎症之间存在着极为密切的关联。     

角膜新生淋巴管的研究进展

角膜新生淋巴管多见于感染、炎症、外伤或角膜移植术后.临床上,如何有效的防治角膜移植术后排斥反应是角膜移植手术成功的关键.随着近年来角膜新生淋巴管内皮特异性标记物及重要淋巴管生长因子的相继发现,人们对角膜新生淋巴管的生成机制及与角膜移植排斥反应的关系有了深入的研究,此文就新生淋巴管的生成及其在角膜移植排斥中的作用作一综述.     

角膜新生淋巴管的研究进展

近年来随着淋巴管内皮细胞特异性标记物VEGFR-3、LYVE-1、Podoplanin和Prox 1等的发现,对于角膜新生淋巴管的研究有了较大进展,成为近几年的研究热点。本文就角膜新生淋巴管是如何生成,其与新生血管之间的关系,新生淋巴管在角膜移植免疫排斥反应发生过程中的作用作一综述。     

碱烧伤后角膜新生淋巴管的实验研究

目的动态检测大鼠角膜碱烧伤后的角膜新生淋巴管和血管的变化,并阐明二者之间的关联。方法制备大鼠角膜碱烧伤模型,于碱烧伤后1周、2周行角膜组织电镜检查,检测角膜新生淋巴管与新生血管。5’核苷酸酶-碱性磷酸酶(5’-nase-alkaline phos-phatase,5’-NA-ALP)双重酶组织化学染色及全角膜免疫荧光染色分别检测碱烧伤后6h、1d、3d、1周、2周、3周、4周、5周、6周、7周、8周的角膜新生淋巴管和新生血管的动态变化,并进行淋巴管计数(lymphatic vessels counting,LVC)和血管计数(blood vessels counting,BVC)比较。结果电镜观察结果:角膜碱烧伤后1周,角膜基质层出现新生血管,未见淋巴管;碱烧伤后2周,新生血管和新生淋巴管均出现。酶组织化学染色结果显示:碱烧伤后6h有新生血管,1周时角膜基质层存在新生淋巴管,2周时LVC和BVC均达到高峰,分别为(16.41±1.00)个和(50.40±1.56)个;以后逐渐下降,5周时LVC为(0.33±0.50)个,BVC为(12.52±2.51)个;8周时均为0。碱烧伤后,新生淋巴管和新生血管呈显著性正...     

血管抑素抑制大鼠角膜新生血管的研究

目的研究血管抑素（AS）对大鼠角膜碱烧伤后新生血管的抑制作用。方法120只Wistar大鼠制作碱烧伤角膜新生血管（CNV）模型,随机分为4组,分别为2.5μgAS组、5μgAS组、地塞米松组、生理盐水组,每组30只。分别给予2.5μg/0.1mLAS、5μg/0.1mLAS、0.1mg/0.1mL地塞米松、生理盐水各0.1mL,球结膜下注射,隔日1次,共4次。在大鼠角膜碱烧伤后不同时间裂隙灯下观察大鼠角膜混浊度,计算新生血管面积,分析角膜组织病理切片。结果2.5μgAS组、5μgAS组及地塞米松组在第7、10、14天较生理盐水组角膜混浊程度轻,差异均有统计学意义（P〈0.05）;2.5μgAS组、5μgAS组及地塞米松组在碱烧伤后第3天起各时间点新生血管面积小于生理盐水组,差异均有统计学意义（P〈0.05）。结论AS能有效抑制大鼠角膜碱烧伤后CNV的形成。     

Topical Ranibizumab inhibits inflammatory corneal hem‐ and lymphangiogenesis

Purpose: Ranibizumab (Lucentis^®) is a Fab‐Fragment of a recombinant, humanized, monoclonal VEGF (anti‐vascular endothelial growth factor) antibody. This study analyzed the ability of topical Ranibizumab to inhibit lymphangiogenesis in addition to hemangiogenesis after acute corneal inflammation in vivo. In addition, the effect of Ranibizumab on the proliferation of human lymphatic endothelial cells (LECs) and blood endothelial cells (BECs) in vitro was studied. Methods: The inhibitory effect of Ranibizumab on LECs and BECs was studied in vitro using a proliferation enzyme‐linked immunosorbent assay (ELISA) assay. To study the in vivo effects of Ranibizumab, the mouse model of suture induced inflammatory corneal neovascularization was used. Study mice received topical Ranibizumab as eye drops. After 1 week excised corneas were stained with LYVE‐1 and CD31. Hemangiogenesis and lymphangiogenesis were analyzed morphometrically by using a semiautomatic method based on the image analyzing program Cell^F. Results: An antiproliferative effect of Ranibizumab was seen in vitro on both human BECs and LECs with a significance of p < 0.0001 and p < 0.0004, respectively. In vivo experiments showed that topical application of Ranibizumab significantly inhibits both hemangiogenesis (p = 0.0026) and lymphangiogenesis (p = 0.0026) in the cornea. Conclusion: Ranibizumab is a potent inhibitor of inflammatory corneal hemangiogenesis and lymphangiogenesis in vivo with a direct inhibitory effect on both endothelial cell types in vitro. This study for the first time demonstrates an inhibitory effect of Ranibizumab on lymphatic vessels which could have a wider range of clinical applications.     

Improved semiautomatic method for morphometry of angiogenesis and lymphangiogenesis in corneal flatmounts

Purpose of the study was to describe a novel semiautomatic, quantitative image analysis method based on threshold analysis for morphometry of corneal (lymph)angiogenesis and to test its validity, reliability and objectivity. Murine corneas were vascularized by using a suture-induced neovascularization assay. For immunohistochemistry, flatmounts of the vascularized corneas were stained with LYVE-1 as a specific lymphatic vascular endothelial marker and with CD31 as panendothelial marker. Morphometry of corneal hem and lymphangiogenesis was performed semi-automatically on digital images using image analysis software. Data were analyzed by a paired t-test, intraclass-correlation and systemic difference analysis compared to a manual method. The semiautomatic method based on threshold analysis was more valid in measuring the area covered by blood or lymphatic vessels. Both methods had a good reproducibility with respect to both vessel types (blood vessels: manual: 0.969, semiautomatic: 0.982; lymphatic vessels: manual: 0.951, semiautomatic: 0.966), whereas the systemic difference was significant for both groups measuring lymphatic vessels (manual: p < 0.003; semiautomatic: p < 0.035) and for the manual method measuring blood vessels (manual: p < 0.0001; semiautomatic: p < 0.419). The new semiautomatic morphometry method based on threshold analysis provides higher accuracy, is more valid than and at least as reproducible and objective as the manual outlining method. Therefore the semiautomatic method can be used to detect even small effects on hem and lymphangiogenesis in murine corneal flatmounts with greater precision.     

Exacerbated corneal inflammation and neovascularization in the HO-2 null mice is ameliorated by biliverdin

Heme oxygenase (HO-1 and HO-2) represents an intrinsic cytoprotective and anti-inflammatory system based on its ability to modulate leukocyte migration and to inhibit expression of inflammatory cytokines and proteins. HO-2 deletion leads to unresolved corneal inflammation and chronic inflammatory complications including ulceration, perforation and neovascularization. We examined the consequences of HO-2 deletion on hemangiogenesis and lymphangiogenesis in the model of suture-induced inflammatory neovascularization. An 8.0 silk suture was placed at the corneal apex of wild type and HO-2 null mice. Neovascularization was assessed by vital microscopy and quantified by image analysis. Hemangiogenesis and lymphangiogenesis were determined by immunofluorescence staining using anti-CD31 and anti-LYVE-1 antibodies, respectively. Inflammation was quantified by histology and myeloperoxidase activity. The levels of HO-1 expression and inflammatory cytokines were determined by real time PCR and ELISA, respectively. Corneal sutures produced a consistent inflammatory response and a time-dependent neovascularization. The response in HO-2 null mice was associated with a greater increase compared to the wild type in the number of leukocytes (827,600+/-129,000 vs. 294,500+/-57,510; p<0.05), neovessels measured by vital microscopy (21.91+/-1.05 vs. 12.77+/-1.55mm; p<0.001) 4days after suture placement. Hemangiogenesis but not lymphangiogenesis was more pronounced in HO-2 null mice compared to wild type mice. Induction of HO-1 in sutured corneas was greatly attenuated in HO-2 null corneas and treatment with biliverdin diminished the exaggerated inflammatory and neovascular response in HO-2 null mice. The demonstration that the inflammatory responses, including expression of proinflammatory proteins, inflammatory cell influx and hemangiogenesis are exaggerated in HO-2 knockout mice strongly supports the notion that the HO system is critical for controlling the inflammatory and neovascular response in the cornea. Hence, pharmacological amplification of this system may constitute a novel therapeutic strategy for the treatment of corneal disorders associated with excessive inflammation and neovascularization.     

Age-related changes in murine limbal lymphatic vessels and corneal lymphangiogenesis

Important risk factors for graft rejection after corneal transplantation are pathologic corneal lymphangiogenesis and young recipient age. Purpose of this study was to investigate whether there are age-related differences in normal murine limbal and pathologic corneal lymphatic vessels, which could partly explain the unequal outcome of corneal transplantation in young versus old recipients. Furthermore, we investigated whether these observed differences correlate with changes in allograft survival in the murine model of corneal transplantation. Corneal whole mounts from untreated young (aged 6-8 weeks), untreated old (aged 9-15 months) and young and old mice after suture-induced, inflammatory corneal neovascularization were prepared and stained with LYVE-1 as a lymphendothelial marker. Angles of corneal parts with and without a main circumferential limbal lymphatic vessel were measured and then related to the total 360° of corneal circumference. Centrally directed vascular extensions from the main limbal lymphatic vessel (“sprouts”) of previously untreated old mice were counted. Concerning the outgrowth of pathologic lymphatic vessels after inflammatory corneal neovascularization, the area covered with pathologic lymphatic vessels was detected by an algorithm on digitized whole mounts using cell^F^® software. Low-risk allogeneic (C57Bl/6 to BALB/c) corneal transplantations were performed with one recipient group being young, the other group being old mice. In young, untreated mice, 70.5% of the total corneal circumference was covered by a main circumferential limbal lymphatic vessel versus 60.8% in old, untreated mice. Comparing the number of centripedal vascular extensions from the main limbal lymphatic vessel (“sprouts”), untreated old mice had significantly less extensions than young, untreated mice (p < 0.001). After an inflammatory stimulus, old mice had significantly less pathologic corneal lymphatic vessels than young mice (42% less, p < 0.001). Comparing the survival proportions after corneal transplantation, old recipient mice showed a significantly better graft survival 6 weeks after transplantation (65% versus 33%, p < 0.05). Thus, limbal lymphatic vascular sprouts and inflammation-induced pathologic corneal lymphangiogenesis decrease with age. The lower lymphangiogenic potency of older mice may explain the better outcome of corneal transplantations in old recipients, supporting the concept that lymphangiogenesis is an important risk-factor for corneal transplant rejection.     

A novel microscope system for time-lapse observation of corneal cells in a living mouse

A novel microscope system is presented for observation of corneal cells in a living mouse. It enables tracking of individual cells in all layers of the cornea at various times, thus allowing the generation of time-lapse recordings. The system consists of three major components: an upright fluorescence microscope for visualization of corneal cells, a mouse-holding unit for immobilization of the animal and the eye, and a set of gimbals which permit observation of a wide area of corneal surface without refocusing. The same cells could be observed at different limes with the help of fiducial marks in the cornea, allowing their changes in position to be determined under natural and experimental conditions. This technique should prove useful in investigation of the cell movement in normal and diseased corneas, including the study of wound healing after an injury or surgery.     

培养猫角膜内皮细胞的新方法——联合酶消化法

目的 寻找一种可以快速获得大量猫原代角膜内皮细胞的方法.方法 揭取猫角膜后弹力层,反复剪碎,用2 g·L-1复合胶原酶消化40 min,再用2.5 g·L-1胰蛋白酶-EDTA消化2 min,离心、细胞计数后以50×106 L-1的浓度接种.待细胞长满皿底后传代,接种浓度同原代培养.记录细胞的形态以及原代细胞的数目、原代细胞铺满皿底的时间、细胞传代时间和传代次数,并与组织块贴壁法和揭膜消化法相比较.结果 联合酶消化法获得的原代细胞可以形成典型的铺路石样结构,无基质细胞污染,每片角膜可以收获(100～200)×103个细胞,只需5 d就可以首次传代,传代后4 d即可达到80%融合,连续传代8次仍可以维持小多边形的形态.结论 胶原酶和胰蛋白酶联合消化法可以快速获得大量的猫角膜内皮细胞.     

A novel method for generating corneal haze in anterior stroma of the mouse eye with the excimer laser

Refractive surgery is a popular method used to reduce or eliminate dependence on glasses and contact lenses. Corneal haze is one of the common complications observed after photorefractive keratectmomy (PRK). The objective of this study was to develop an in vivo mouse model that consistently produces moderate to severe corneal haze in the anterior stroma of the mouse cornea after excimer laser treatment to study myofibroblast biology and corneal wound healing in a genetically defined model. Regular- or irregular-phototherapeutic keratectomy (PTK) was performed on black C57BL/6 mice with the Summit Apex excimer laser (Alcon, Ft. Worth, TX). Different numbers of laser pulses (45; ablation depth approximately 10 microm) were fired on the central cornea, after scraping the epithelium prior to excimer laser ablation. Irregularity was generated by positioning a fine mesh screen in the path of laser after firing 50% of the pulses. Eyes were collected 1, 2, 3 or 4 weeks after the procedure. Haze formation was gauged with slit lamp biomicroscopy. Immunocytochemistry was used to determine number of myofibroblasts in the mouse cornea using antibodies specific for the myofibroblast marker alpha-smooth muscle actin (SMA). The numbers of SMA-positive cells/400x microscopic were determined by counting within the stroma. Statistical analysis was performed using analysis of variance (AVOVA) with the Bonferonni-Dunn adjustment for repeated measures. Regular-PTK with epithelial scrape (group 3) and irregular-PTK with epithelial scrape (group 4) in the mouse eyes were performed to produce corneal haze. Eyes collected 4 weeks after regular- or irregular-PTK after epithelial scrape showed 22+/-6.6 (group 3) or 34+/-7.9 (group 4) SMA-positive cells in the anterior cornea. The difference in the SMA-positive cells detected among the groups was statistically significant (p<0.01). Less than 4 SMA-positive cells were detected in the tissue sections of the mouse eyes collected after 1, 2 or 3 weeks of regular (group 3) or irregular PTK (group 4) or controls (groups 1 and 2). The optimized PTK excimer laser conditions developed in this study produces haze selectively in anterior stroma of the mouse cornea immediately beneath the epithelial basement membrane. Irregular PTK performed after epithelial scrape by applying 45 laser pulses was found to be the most effective method to generate myofibroblasts. This PTK technique for inducing haze in mouse cornea in vivo provides a useful model for studying wound healing and myofibroblast biology in transgenic mice.     

脱细胞猪角膜基质体外支持角膜上皮和基质细胞的生长

目的:探讨脱细胞猪角膜基质体外能否支持兔角膜细胞的生长。方法:体外培养兔角膜上皮细胞和基质细胞,并接种到制备的脱细胞猪角膜基质上,倒置相差显微镜和组织学观察细胞生长情况。结果:上皮细胞能在脱细胞猪角膜基质上贴附生长,10d时可形成2~3层的复层结构。基质细胞在脱细胞猪角膜基质上贴附生长后可向材料深层迁徙。结论:制备的脱细胞猪角膜基质体外可支持兔角膜上皮细胞和基质细胞的生长。     

Circular polarization biomicroscopy: a method for determining human corneal stromal lamellar organization in vivo

The theory of polarization biomicroscopy is explored using Stokes vectors and Mueller matrices. It is established that circular polarization can be used to simultaneously detect birefringent elements at any orientation unlike orientation-sensitive techniques using linear polarized light alone. A method of biomicroscopy using circular polarized light is described and tested in a physical model. The method is then used to investigate the lamellar structure of human corneas in vivo in pairs of eyes of 38 subjects. An approximate confocal elliptic/hyperbolic distribution of stromal fibrils, presumed to be collagen, is clearly identified within central and intermediate areas of the cornea. All subjects tested demonstrate approximate mirror symmetry between pairs of eyes typically with a preferred orientation of central fibrils at approximately 15 degrees to the horizontal in a superotemporal-inferonasal direction.     

壳聚糖及其衍生物作为组织工程角膜支架的研究进展

利用组织工程技术构建组织工程角膜能够从根本上解决角膜移植供体不足和术后免疫排斥等问题.理想的支架材料是构建组织工程角膜的重要条件.壳聚糖及其衍生物具有良好的透明性、生物相容性、可降解性、力学性能和可塑性,在角膜组织工程中具有良好的应用前景.本文对壳聚糖及其衍生物在角膜组织工程中的研究现状进行了综述,讨论了目前存在的问题,为构建满足临床要求的组织工程角膜提供指导.