暴露性干眼症大鼠模型角膜上皮细胞凋亡相关基因的表达

目的探讨暴露性干眼症大鼠模型角膜上皮细胞凋亡相关基因的表达与组织损伤的关系。方法25只健康成年Wistar大鼠随机分为4组实验组和1组正常组,每组5只。实验组通过睑缘缝线机械性阻止大鼠瞬目,充分暴露各组大鼠角膜0.5h、6h、24h及1周后,用角膜荧光素染色及SchirmerⅠ试验对实验组大鼠进行临床诊断;然后分别处死每组大鼠,取双眼角膜进行免疫组织化学染色,研究角膜组织中凋亡相关基因蛋白Bcl-2及Bax的表达。正常组大鼠不进行处理,处死后取双眼角膜标本按实验组同样步骤处理。结果不同实验组大鼠角膜上皮细胞Bax表达阳性细胞数与正常对照组相比增加,而Bcl-2表达阳性细胞数较对照组减少,且差异具有显著性(P<0.05);角膜上皮细胞Bax表达阳性细胞数与暴露时间呈正线性相关(r=0.76,P<0.05),而Bcl-2表达阳性细胞数与暴露时间呈负线性相关(r=-0.57,P<0.05)。结论暴露性干眼症角膜组织中上皮细胞凋亡可能是导致角膜上皮破坏进而功能丧失的原因之一,Bax增加及Bcl-2减少与角膜上皮细胞凋亡有关。

Expression of apoptosis-related genes in corneal epithelium of exposing dry eye rats

Objective To assess the relationships between the expression of the apoptosis-related genes and tissue injury in corneal epithelium in exposing dry eye rat models.Methods Twenty-five adult healthy Wistar rats were divided randomly into one normal control group and four experimental dry eye groups with 5 rats or 10 eyes in each group.For experimental dry eye rats,exposed their cornea for 0.5 hour,6 hours,24 hours and 1 week respectively by suturing their eyelids to the skin.The models were confirmed by Fluorescein staining and Schirmer I test and then the expression of Bcl-2 and Bax in corneal epithelium were detected by immunohistochemical staining.The control group rats were killed without any treatment and then controled like as experimental group.[WTF9]Results With the prolonged-time of exposing,the expression of Bax in corneal epithelium was increased(P<0.05)while Bcl-2 decreased(P<0.05).And there was significant positive correlation(r=0.76,P<0.05)between the Bax expression and the exposing time,while significant negative correlation(r=-0.57,P<0.05)between the Bcl-2 expression and the exposing time.Conclusion The apoptosis of the epithelial cells in the cornea may be one of the mechanisms leading to the corneal destruction found in experimental dry eye.Increased expression of Bax and decreased Bcl-2 expression may promote corneal epithelium apoptosis.