水通道蛋白1在大鼠角膜碱烧伤新生血管形成中的表达

目的检测大鼠角膜碱烧伤后新生血管形成过程中水通道蛋白1（AQP1）的表达变化，探讨其在角膜新生血管（CNV）形成中的作用。方法碱烧伤诱导CNV模型，将25只sD大鼠按处死的时间点不同分成5组，每组5只。每日裂隙灯下观察CNV的生长情况，并采用免疫组织化学法和RT-PCR法检测AQP1及VEGF在大鼠CNV形成中的表达。结果在正常大鼠角膜组织中，AQP1和VEGF不表达或弱表达。碱烧伤后1d，AQP1表达开始增强，第7天表达最强，14d下降，21d时仍有弱表达。RT—PCR检测显示碱烧伤后AQP1表达增强，在伤后第7天表达最明显，21d后呈弱表达（t1d=3．491，t4d=10．690，t7d=12．936，t14d=10．767，t21d=8．594，P〈0．05）。免疫组织化学检测结果表明，VEGF与AQP1的表达分布相似，强度较弱，统计学分析表明二者的表达水平呈正相关（r=0．834，P〈0．05）。结论AQP1在碱烧伤后角膜巾的表达水平与新生血管的形成明显相关。

Expression of AQP-1 in rat cornea neovascularization after alkali burn

Background Corneal alkali burn is a common cause of corneal neovascularization(CNV).Researches demonstrated that aquaporin 1(AQP1) plays key role in neovascularization of tumor tissue.So it is speculated that AQP1 participates in pathogenesis and development of CNV.ObjectivePresent study aims to investigate the expression of aquaporin 1(AQP1) in cornea after alkali burn and explore its role in corneal neovascularization.MethodsCornea neovascularization (CNV) models were established by putting a filter paper (the size of 3 mm in diameter immersed 1mol/L NaOH solution) on cornea for 20 seconds in the left eyes of 25 adult Sprague Dawley rats.The fellow eyes were treated using the filter paper with normal saline solution as normal control group.Corneal new blood vessel was evaluated under the slim lamp biomicroscopy once per day,and area of new vessel was calculated.The animals were sacrificed and corneal samples were obtained in day 1,4,7,14,21 after corneal alkali burn.The expression of AQP1 and VEGF in corneas were detected by immunochemistry,and the relative expression level of AQP1 mRNA in rat cornea was determined using RT-PCR.ResultsThe corneal neovascularization grew at the second day and reached the largest area at the fourteenth day after corneal alkali burn.The expression of VEGF protein (gray value) in corneal sample was significantly elevated from the first day through the fourteenth day after corneal alkali burn in comparison with control group(t_(1d)=12.410,t_(4d)=29.428,t_(7d)=16.030,t_(14d)=13.321,P＜0.05),and then the expression level declined till twenty-one day without obvious difference in comparison with control group(t_(21d)=1.587,P＞0.05).The expression of AQP1 protein showed the same tendency with that of VEGF protein(t_(1d)=7.623,t_(4d)=15.293,t_(7d)=18.291,t_(14d)=14.483,t_(21d)=6.381,P＜0.05).The dynamic change expressions of AQP1 and VEGF showed a significant positive correlation(r=0.834,P＜0.05).The expression of AQP1 mRNA (A value)was weaker in control group but considerably increased after alkali burn with the peak value in the seventh day,showing a significantly difference between day 1,4,7,14 and control group(t_(1d)=3.491,t_(4d)=10.690,t_(7d)=12.936,t_(14d)=10.767,t_(21d)=8.594,P＜0.05).ConclusionThe level of AQP1 expression is markedly related to inflammatory CNV in rat cornea after alkali burn.