兔角膜移植后房水中血管内皮生长因子及肿瘤坏死因子α表达与 高压氧的影响

背景：血管内皮生长因子和肿瘤坏死因子α在角膜移植免疫反应中起重要作用,但二者与高压氧之间的关系尚不明确。 目的：探讨高压氧对角膜移植后房水中血管内皮生长因子及肿瘤坏死因子α表达的影响及其与角膜移植免疫反应的关系。 方法：分别以鸡、兔为供、受体建立异种异体穿透性角膜移植模型。将健康新西兰白兔16只随机分为2组,高压氧组从手术当日至术后第6天行高压氧治疗,对照组未行高压氧治疗。分别于角膜移植后第3,7,14,28天抽取房水,应用ELISA双抗体夹心法检测房水中肿瘤坏死因子α及血管内皮生长因子水平的变化。 结果与结论：正常兔眼房水中均可检测到少量的肿瘤坏死因子α和血管内皮生长因子。移植后早期两组房水中肿瘤坏死因子α和血管内皮生长因子水平即升高,与移植前比差异均有显著性意义(P < 0.05)。在移植后14 d左右急性排斥反应期,肿瘤坏死因子α和血管内皮生长因子达最高值。高压氧组中肿瘤坏死因子α和血管内皮生长因子的水平均明显低于对照组(P < 0.05)。结果表明高压氧可通过降低房水中肿瘤坏死因子α和血管内皮生长因子的含量,抑制角膜移植后的免疫反应。     

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。     

血管内皮生长因子C在小鼠碱烧伤角膜内的表达及意义

目的观察血管内皮生长因子C(VEGF-C)在小鼠角膜碱烧伤后不同时间段角膜组织内的表达情况,探讨VEGF-C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。采用免疫组化法(SP),观察VEGF-C在正常角膜和碱烧伤后不同时间段角膜组织内的表达情况。应用淋巴管内皮透明质酸受体(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。在碱烧伤角膜内,VEGF-C主要表达于角膜基质内入侵的炎性细胞和角膜上皮层细胞,并且表达增高,于碱烧伤后3d,VEGF-C的表达达到高峰(P<0.01)。碱烧伤后7d,VEGF-C的表达下降至正常水平,可见阳性表达LYVE-1的处于开放状态的新生淋巴管。结论VEGF-C可能参与小鼠角膜碱烧伤后角膜新生淋巴管形成过程。     

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。     

血管内皮生长因子与肿瘤坏死因子-α在佐剂关节炎大鼠滑膜中表达

目的:探讨血管内皮生长因子(VEGF)和肿瘤坏死因子-α(TNF-α)在佐剂关节炎(AA)大鼠滑膜组织中的表达及其与关节病理积分的关系。方法:建立AA大鼠模型,常规HE染色,计算关节病理积分,并用免疫组织化学染色检测VEGF和TNF-α蛋白表达。结果:AA组大鼠滑膜VEGF和TNF-α蛋白表达在3周、8周及20周时均明显高于健康对照组(均P<0.01),且二者均与关节病理积分呈显著正相关(均P<0.01),二者之间亦呈显著正相关(均P<0.01)。结论:VEGF和TNF-α在关节炎的形成及发展过程中起重要作用,二者互相作用并影响滑膜新生血管的形成。     

转化生长因子β1在兔房水中的浓度变化

背景：转化生长因子β1可参与角膜损伤后的修复。 目的：观察转化生长因子β1滴眼液滴眼后房水中的浓度变化规律。 方法：将新西兰大白兔随机分为5组,分别给予PBS和质量浓度为0.5,1.0,2.0,4.0 mg/L的转化生长因子β1滴眼液滴右眼。 结果与结论：通过裂隙灯观察兔角膜和结膜结构,各组兔眼均无结膜分泌物、球结膜充血、角膜水肿增厚、角膜后沉着物、前房炎性反应及晶状体混浊改变。ELISA检测结果显示,与PBS组比较,质量浓度2.0和4.0 mg/L转化生长因子β1滴眼液能有效提高兔眼房水中转化生长因子β1的质量浓度(P < 0.01),角膜穿透性良好,在房水中可以达到有效的治疗浓度。     

血管内皮生长因子及其受体家族在角膜组织及角膜病变中的作用和研究进展

BACKGROUND: Vascular endothelial growth factors are a family of multifunctional cytokines that can enhance vascular permeability, induce angiogenesis, promote endothelial cell growth and migration, and inhibit cell apoptosis. OBJECTIVE: To elaborate the latest progress in the role of vascular endothelial growth factor and its receptors in the corneal tissue. METHODS: A computer-based search of PubMed databases was performed for relevant articles published from 2005 to 2015. The key words were “vascular endothelial growth factor, cornea”. According to the inclusion and exclusion criteria, 43 articles were included in result analysis. RESULTS AND CONCLUSION: Vascular endothelial growth factor and its receptors are involved in the regulation of corneal neovascularization by causing Tip cell activation that affects the Notch signaling pathways. Corneal lymphatic regeneration mainly relies on macrophages to secrete vascular endothelial growth factor-C or vascular endothelial growth factor-D that further activate vascular endothelial growth factor receptor-3 in the lymphatic endothelial cells to cause cell proliferation and migration, and eventually lead to the formation of new lymphatic vessels. But herpes simplex keratitis HSK induces the corneal lymphatic regeneration by vascular endothelial growth factor-A/vascular endothelial growth factor receptor-2 pathway. Vascular endothelial growth factor family can significantly improve the damaged corneal nerve endings, epithelium and corneal sensitivity, has the function of nerve nutrition and promote restoration of the corneal epithelium.       

诺帝滴眼液抑制碱烧伤诱导大鼠角膜新生血管分子机制的初步研究

目的 初步探索0.1%诺帝滴眼液对角膜新生血管(corneal neovascularization,CRNV)抑制作用的分子机制.方法 建立大鼠碱烧伤角膜新生血管模型,分空白溶液组、0.1%诺帝滴眼液组、0.1%地塞米松滴眼液组.采用免疫组化及RT-PCR法检测VEGF、flk-1蛋白及mRNA表达.结果 治疗组及地塞米松组VEGF蛋白表达少于空白溶液组(P<0.05).7 d、14 d VEGF mRNA抑制率分别为:治疗组58.60%,74.60%;地塞米松组76.88%,80.95%.flk-1 mRNA抑制率:治疗组66.27%,69.63%;地塞米松组72.16%,74.81%.结论 0.1%诺帝滴眼液明显降低角膜VEGF和其受体flk-1 mRNA蛋白表达,通过下调VEGF受体量,间接减少VEGF受体后信号转导及效应蛋白合成,抑制了CRNV的发生.     

激素性股骨头坏死模型兔血管内皮细胞生长因子表达与普伐他汀的干预

背景：有研究表明他汀类药物可使体外培养的人脐静脉内皮细胞的血管内皮细胞生长因子呈高表达,血管内皮细胞生长因子可促进内皮细胞增殖,明显提高成骨细胞活性并加速骨形成。 目的：观察普伐他汀对激素性股骨头坏死兔模型血管内皮生长因子的蛋白表达的影响。 方法：将新西兰白兔随机分为对照组,模型组和普伐他汀组。模型组和普伐他汀组制备兔激素性股骨头缺血坏死模型。普伐他汀组建模成功后以普伐他汀(1.2 mg/kg)灌胃,1次/d,模型组和对照组以等体积的蒸馏水灌胃。于造模后8,12,16周截取各组股骨头行免疫组织化学检测血管内皮生长因子蛋白的表达情况。 结果与结论：对照组不同时间点股骨头血管内皮生长因子蛋白表达均为阳性。造模后8周,模型组血管内皮生长因子蛋白表达呈阴性表达,普伐他汀组呈弱阳性表达。造模后12周,模型组和普伐他汀组血管内皮生长因子蛋白表达呈阳性表达,16周呈弱阳性表达。结果证实,普伐他汀可有效促进早期激素性股骨头坏死兔模型坏死股骨头内源性血管内皮生长因子的蛋白表达。     

房水中转化生长因子水平与角膜内皮损伤及修复的关联分析

目的 探讨房水中转化生长因子水平与角膜内皮损伤及修复的关联.方法 研究选取本院就诊患者102例,检测患者房水中总TGF-β2和活化TGF-β2的水平,监测分析角膜内皮细胞密度水平、角膜内皮六角形细胞的比例水平以及中央角膜厚度.分析讨论房水中TGF-β2水平与角膜内皮损伤及修复的关联.使用SPSS软件处理数据.结果 对治疗前总TGF-β2水平与表征角膜内皮细胞损伤状态的四项指标水平进行相关分析结果提示,治疗前研究样本总TGF-β2水平与角膜内皮细胞密度之间的相关系数为-0.123、于角膜内皮六角细胞水平之间的相关系数为-0.198,另外治疗前总TGF-β2水平与中央角膜厚度水平之间的相关系数为0.254,且均P＜0.05;治疗前活化TGF-β2水平与表征角膜内皮细胞损伤状态的指标水平相关分析结果也提示了类似结果,除了活化TGF-β2水平与内皮细胞密度的r为-0.145,未见统计学意义之外,活化TGF-β2水平与其他指标的相关系数均有统计学意义.治疗后总TGF-β2水平以及活化TGF-β2水平与四项指标的相关系数也发现了类似规律,且均P＜0.05.结论 总TGF-β2水平以及活化TGF-β2水平增高与角膜内皮损伤有关,与内皮细胞密度、角膜内皮六角细胞比例下降,中央角膜厚度则会增加密切相关.     

Activin a in the regulation of corneal neovascularization and vascular endothelial growth factor expression

Activin A, a dimeric glycoprotein that belongs to the transforming growth factor-beta superfamily, governs cellular differentiation in a wide variety of models and has been implicated in the regulation of angiogenesis. We examined the role of activin A and its downstream signaling pathway in a murine model of inflammatory corneal neovascularization induced by mechanical injury (debridement), and in vitro in corneal epithelial cells. Activin A expression increased steadily from day 2 until day 8 after mechanical debridement in vivo, paralleling vascular endothelial growth factor (VEGF) expression. Administration of recombinant activin A in mice increased the area of neovascularization, VEGF expression, and the kinase activities of p38 and p42/44 MAPKs after mechanical debridement. Systemic inhibition of activin A in vivo with a neutralizing antibody reduced the area of neovascularization, VEGF expression, and p38 and p42/44 MAPK activity, whereas administration of an isotype-matched control antibody had no effect. In vitro treatment with activin A increased VEGF secretion, as well as p38 and p42/44 MAPK activity in corneal epithelial cells, whereas concurrent administration of specific inhibitors of p38 or p42/44 MAPK abolished the stimulatory effect of activin A on VEGF production. We conclude that activin A stimulates inflammatory corneal angiogenesis by increasing VEGF levels through a p38 and p42/44 MAPK-dependent mechanism.     

Nicotine potentiates vascular endothelial growth factor expression in balloon-injured rabbit aortas

Both nicotine and vascular endothelial growth factor (VEGF) have been proposed to play an important role in the development and progression of atherosclerosis. In vitro and ex vivo studies have demonstrated that nicotine significantly stimulates VEGF expression in several cell types. This study examined the effects and the mechanisms of nicotine on the expression of VEGF in a rabbit model of balloon-injured aortas. Forty-eight male New Zealand white rabbits were randomly divided into sham, control, nicotine, and nicotine plus hexamethonium (nicotine–hex) groups. Balloon catheter denuding injury iliac artery was performed in control, nicotine, and nicotine–hex animals fed with a high-cholesterol diet beginning 2 weeks before operation. Twenty-four hours after surgery, nicotine (0.05 μg/kg) or nicotine (0.05 μg/kg) and hexamethonium (6 mg/kg) was administered daily by intramuscular injection for 3 weeks in nicotine and nicotine–hex groups, respectively. Sham and control rabbits received an identical volume of phosphate-buffered saline injection, but without nicotine or hexamethonium. VEGF protein expression and intimal cell proliferation in balloon-injured aortas were determined by enzyme-link immunosorbent assay, immunohistochemistry, and Western blot analysis. Six rabbits died during the experiment. The remaining 42 rabbits were included in the study. VEGF protein expression in nicotine group was significantly higher than that in control group (P < 0.01). VEGF positive staining was seen in vascular endothelial cells, vascular smooth muscle cells, and infiltrative inflammatory cells. The number of the proliferative cells in intima was also significantly higher in nicotine group than in control group (P < 0.01). Hexamethonium, a nonselective antagonist of nicotinic acetylcholine receptors (nAChRs), significantly inhibited nicotine-induced VEGF protein expression (P < 0.01). The present study shows that intramuscular administration of nicotine markedly potentiates the expression of VEGF protein in balloon-injured rabbit aortas, which appears to be mediated through nAChRs.     

Nicotine potentiates vascular endothelial growth factor expression in balloon-injured rabbit aortas

Both nicotine and vascular endothelial growth factor (VEGF) have been proposed to play an important role in the development and progression of atherosclerosis. In vitro and ex vivo studies have demonstrated that nicotine significantly stimulates VEGF expression in several cell types. This study examined the effects and the mechanisms of nicotine on the expression of VEGF in a rabbit model of balloon-injured aortas. Forty-eight male New Zealand white rabbits were randomly divided into sham, control, nicotine, and nicotine plus hexamethonium (nicotine-hex) groups. Balloon catheter denuding injury iliac artery was performed in control, nicotine, and nicotine-hex animals fed with a high-cholesterol diet beginning 2 weeks before operation. Twenty-four hours after surgery, nicotine (0.05 microg/kg) or nicotine (0.05 microg/kg) and hexamethonium (6 mg/kg) was administered daily by intramuscular injection for 3 weeks in nicotine and nicotine-hex groups, respectively. Sham and control rabbits received an identical volume of phosphate-buffered saline injection, but without nicotine or hexamethonium. VEGF protein expression and intimal cell proliferation in balloon-injured aortas were determined by enzyme-link immunosorbent assay, immunohistochemistry, and Western blot analysis. Six rabbits died during the experiment. The remaining 42 rabbits were included in the study. VEGF protein expression in nicotine group was significantly higher than that in control group (P < 0.01). VEGF positive staining was seen in vascular endothelial cells, vascular smooth muscle cells, and infiltrative inflammatory cells. The number of the proliferative cells in intima was also significantly higher in nicotine group than in control group (P < 0.01). Hexamethonium, a nonselective antagonist of nicotinic acetylcholine receptors (nAChRs), significantly inhibited nicotine-induced VEGF protein expression (P < 0.01). The present study shows that intramuscular administration of nicotine markedly potentiates the expression of VEGF protein in balloon-injured rabbit aortas, which appears to be mediated through nAChRs.     

Inhibitory effect of suramin on receptor binding and cytotoxic activity of tumor necrosis factor alpha.

The effect of suramin on the binding of human Tumor Necrosis Factor alpha (huTNF alpha) to specific cell-surface receptors as well as on its cytotoxic activity in vitro was investigated. Suramin inhibited both activities in a dose-dependent manner. Experiments designed to discriminate if suramin exerted its inhibitory activity on the ligand or on the receptor showed that the ligand (huTNF alpha) was the most likely target for suramin in this system. These results may explain, in part, the immunosuppressive activities of suramin that have been observed in vivo and suggest that suramin could be useful in those disease states in which hyperproduction of huTNF alpha has been shown to play a pathogenic role.     

肿瘤坏死因子对体外培养的血管内皮细胞的作用

在体外研究了肿瘤坏死因子对人脐静脉血管内皮细胞的作用。在体外培养的ＨＶＥＣ中加入人重组的ＴＮＦａ，终浓度为４００Ｕ／ｍｌ，培养７２小时后取贴壁细胞及培养液进行研究。结果发现，与对照组相比，ＴＮＦ组细胞有如下变化：１、光镜观察可见ＮＴＦ组细胞明显拉长，电镜观察发现细胞表面微绒毛减少，胞质中次级溶酶体增多，线粒体肿胀，变性，髓样小体出现。２．ＴＮＦ对ＨＶＥＣ的增殖有抑制作用。３．细胞表面纤维连接蛋白的     

肿瘤坏死因子α和血管紧张素Ⅱ诱导血管内皮细胞组织因子基因表达及其机制的研究

目的:研究肿瘤坏死因子α(TNFα)、血管紧张素Ⅱ(AngⅡ)对内皮细胞组织因子(TF)表达的影响,并探讨TF基因5’上游序列在TNFα、AngⅡ诱导内皮细胞该基因转录中的调控作用。方法:应用细胞原位杂交技术检测TFmRNA水平。采用基因重组技术构建含有人TF基因不同上游序列荧光素酶报告基因质粒,经脂质体法转染内皮细胞,检测及分析报告基因活性。结果:TNFα和AngⅡ均可以诱导内皮细胞TFmRNA表达增强。在TF基因上游序列-244/+121bp存在时,TNFα、AngⅡ均可使转染内皮细胞荧光素酶表达量明显增加,而在-111/+121bp存在时TNFα、AngⅡ组与对照组荧光素酶表达量均无明显差异,而且较-244/+121bp存在时荧光素酶表达量明显降低。结论:TF基因上游-244/-112bp序列的存在对TNFα、AngⅡ诱导内皮细胞TF基因表达起重要的调节作用。