17-β雌二醇和他莫昔芬对小鼠慢性高眼压模型的作用研究

Effects of 17-beta estradiol and tamoxifen in chronic ocular hypertension mouse model

目的:探讨17-β雌二醇(17-β-estradiol,E2)和他莫昔芬(tamoxifen,TAM)在慢性高眼压小鼠模型中的调节作用。方法:通过前房注射磁珠堵塞房角构建小鼠慢性高眼压模型。将C57BL/6成年小鼠随机分为对照组、Beads组、E2组和E2+TAM组。采用眼压计监测各组眼内压(intraocular pressure,IOP)的变化;HE染色观察并测量中央视网膜厚度;Brn3a免疫组织化学染色观察并计数存活的视网膜神经节细胞(retinal ganglion cells,RGCs);Western blot法检测视网膜中胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)的表达。结果:造模后2wk内,Beads组小鼠平均眼压显著高于对照组,而E2组和E2+TAM组眼压均明显低于Beads组,差异均有统计学意义(P<0.05),且E2+TAM组小鼠平均眼压较E2组更低。造模2wk后,Beads组小鼠视网膜RGCs数量较对照组显著减少(P<0.05),而皮下注射E2+TAM可明显抑制该现象。造模2 wk后,各组小鼠中央视网膜厚度比较,差异无统计学意义(P>0.05)。Western blot结果显示,Beads组小鼠视网膜GFAP蛋白表达量升高,注射E2和E2+TAM后,GFAP蛋白表达量显著下降(P<0.05)。结论:皮下注射E2和E2+TAM均能降低慢性高眼压模型小鼠眼内压,增加RGCs存活数量,且降低视网膜GFAP蛋白表达量,表明E2和TAM在青光眼的发生发展过程中具有一定的保护作用。

AIM:To explore the modulation effects of 17-βestradiol(E2)and tamoxifen(TAM)in chronic intraocular hypertension mouse model.METHODS:We performed anterior chamber injection of magnetic beads to induced chronic ocular hypertension models.Adult C57BL/6 male mice were used in the experiments and randomly divided into four groups:control,Beads group,E2 group and E2+TAM group.The intraocular pressure(IOP)were measured by Tonolab tonometer.Central retinal thickness was evaluated by HE staining.Brn3a as a specific marker of retinal ganglion cells(RGCs),were stained and counted by immunohistochemistry(IHC)staining.Glial fibrillary acidic protein(GFAP)as a marker of proliferation of astrocytes,was quantified using western blotting.RESULTS:The IOP level was significantly elevated after anterior chamber injection of magnetic beads compared to control group(P<0.05),while in E2 and E2+TAM group,the IOP levels were reduced(P<0.05 vs Beads group),especially in E2+TAM group in 2wk.The RGCs happened to degenerated in Beads group after 2wk,while the effects were reversed by E2+TAM(P<0.05).The central retinal thickness showed no significant statistical difference among the four groups after 2wk(P>0.05).The expression level of GFAP increased caused via beads injection,however,decreased in E2 and E2+TAM group(P<0.05).CONCLUSION:E2 and E2+TAM could both effectively decrease the IOP level in chronic intraocular hypertension mouse model,increase the survival of RGCs from high intraocular pressure,suppress expression of GFAP,which indicated neuroprotective effects of E2 and TAM in glaucoma through an anti-inflammatory effects.