干眼小鼠模型的建立及眼表病理生理学改变

The physiology and pathology changes in eye functions by using dry eye mouse model

目的建立泪液分泌不足合并蒸发过强型干眼小鼠模型,对其病理生理学改变进行观察,分析该模型作为临床干眼研究动物模型的科学性及实用性。方法 6周龄C57BL/J雌性小鼠36只,据观察时间(1、5、12、20、35 d)随机分为6组,未干预的正常小鼠为对照。小鼠下肢皮下注射氢溴酸东莨菪碱配合风扇模拟干燥环境诱发小鼠干眼。使用酚红棉线实验检测泪液分泌量、裂隙灯下观察角膜荧光染色、PAS染色检测结膜杯状细胞数目,HE染色观察小鼠眼表组织病理学改变。Real-Time PCR检测小鼠结膜组织中TNF-α及IL-1β的表达。结果与对照组相比,各实验组小鼠的泪液分泌量均显著降低(P<0.001)、结膜杯状细胞数目明显减少(P<0.01),角膜荧光染色增加,同时眼表角结膜上皮表现出增生过度,细胞厚度增加,层次紊乱,基底细胞排列紊乱,表层细胞损伤脱落。与对照组相比,造模5、12、35 d时结膜组织中TNF-α表达明显上调(P<0.05)。而IL-1β表达在各实验组小鼠结膜组织中均显著上调(P<0.01)。结论皮下注射东莨菪碱配合风扇模拟干燥环境诱导的小鼠干眼模型能够引起与临床常见干眼患者眼表现的病理生理学相似的改变。诱发炎症反应是建立一种简单、快速且实用的干眼研究动物模型的方法,对干眼炎症及神经机能障碍发病机制方面的研究有一定价值。

Objective To establish a dry eye mouse model to study the physiology and pathology changes in eye functions and evaluate the scientific and practical value by using this model to investigate dry eye disease. Methods Thirty-six 6-week-old female C57 mice were divided randomly into the dry eye time point（1,5,12,20,35 d） groups and the normal control group. Dry eye mouse model was induced by subcutaneous injections of scopolamine hydrobromide and combined with a desiccated environment at different time point. The aqueous tear production was measured by using the phenolred impregnated cotton thread. Corneal fluorescein staining was examined under a slit lamp biomicroscope in cobalt blue light after fluorescein instillation. The eye sections were stained with periodic acid-Schiff （PAS） and hematoxylin-eosin （HE） to evaluate the physiology and pathology changes in conjunctival goblet cells. The expressions of TNF-α and IL-1β in conjunctiva were examined by Real-Time PCR. Results Compared with control group, the induced dry eye mouse model showed that aqueous tear production was significantly decreased （ P 〈 0. 001 ）, the number of goblet cell in conjunctiva was also significantly dropped（ P 〈 0.01 ）, and corneal fluorescein staining were markedly increased with time. The thickness and cell layers of corneal and conjunctival epithelium were increased with the appearance of cell damage in the surface layer and the disarrangement of cells in the basal layer. The expression of TNF-α mRNA was observably upregulated in the groups of 5,12 and 35 d when compared with control group（ P 〈 0.05 ）. More interestingly the levels of IL-1β mRNA expression were significantly upregulated in all treated groups （ P 〈 0.01 ） comparintg with control group. Conclusion The induced dry eye mouse model represents the similar symptom of dry eye disease in human. It is a simple, quick and feasible way to establish a mouse model to study the mechanism of inflammatoion and neurological function during the development of dry eye disease.