皮质类固醇激素性高眼压大鼠眼内水通道蛋白-1和水通道蛋白-4的表达

Expression of aquaporin-1 and aquaporin-4 in rats’ eyes with glucocorticoid induced intraocular hypertension

目的:探讨水通道蛋白-1(AQP-1)和AQP-4与皮质类固醇激素性高眼压(激素性高眼压)发病机制的关系。方法:健康Wistar大鼠30只随机分为A组(10只)、B组(20只),A组不做处理,B组右眼球结膜下隔日注射地塞米松磷酸钠制备大鼠激素性高眼压模型,左眼注射等量无菌生理盐水作为空白对照,用药4周后摘除眼球,分别采用免疫组化和RT-PCR检测2组大鼠房角组织AQP-1和AQP-4的表达情况。结果:小梁网、Schlemm管内皮细胞、细胞外基质、虹膜基质和睫状体无色素上皮细胞中有AQP-1蛋白的阳性表达,AQP-4阳性表达于虹膜基质和睫状体无色素上皮细胞,而房角组织中未见AQP-4的阳性表达;地塞米松作用4周后,虹膜基质和睫状体无色素上皮细胞中AQP-4蛋白的表达部位和表达量无明显变化,而AQP-1蛋白在房角组织中的表达明显减弱。A组AQP-1mRNA的相对表达量为1.195±0.159,与B组左眼(1.208±0.157)比较,差异无统计学意义(P>0.05);与B组右眼(0.745±0.114)比较,差异有统计学意义(t=5.592,P<0.05)。结论:一定浓度的地塞米松磷酸钠可使大鼠小梁网内皮细胞、Schlemm管内皮细胞及细胞外基质中AQP-1蛋白和mRNA的表达水平降低,其可能是诱发房水外流阻力增加、导致眼压升高的原因之一。

Aim：To discuss the relationship of AQP-I, AQP-4 and glucocorticoid induced intraoeular hypertension. Methods：30 healthy Wistar rats were divided randomly into two groups, Group A （10 rats ） -Control group, right eyes of Group B （20 rats） were treated with subconjunctival injections of dexamethasone sodium phosphate 0.05 mL every other day. Eye balls of Group A and B were removed at the 4th week after treatment. The expression of AQP-l and AQP-4 were measured with immunohistochemistry and RT-PCR. Results：The expression of AQP-1 in trabecular meshwork, endothelial ceils of Sehlemm tube and ECM decreased after injected subconjuncival with dexamethasone, while the expression of AQP- 4 was not changed; The expression of AQP-I and AQP-4 of Group B （left eyes） was the same as Group A and not changed. RT-PCR： the AQP-1 mRNA （gray scale ratio） of chamber angle of Group A was 1. 195 ± 0. 159, the AQP-1 mRNA of right eye （Group B） at 4 weeks after treatment was 0. 745 ± 0.114, decreased obviously （P 〈 0.05 ） , while that of left eye （ Group B） was 1. 208 ± 0. 157, no obvious change （P 〉 0.05 ）. Conclusion ： Certain density of dexamethasone can decrease the AQP-1 mRNA in trabecular meshwork, endothelial cells of Schlemm tube, and ECM, which may be one of the factors that lead to increase resistance to aqueous outflow and intraocular hypertension.