AQP4Gene Regulate The GFAP Expression Of Retinal Glial Cells In Chronic High Intraocular Pressure Mice

Background Retinal glial cells activate In the pathological process ofglaucoma,the expression of glial fibrillary acid protein(GFAP) increase and thischange is closely related to the changes of the retinal glial cells and the occurrenceand development of glaucoma. In the retina Aquaporin4mainly exist in glial cells.Objectives To investigate whether aquaporin4(AQP4) gene can regulate theexpression of GFAP of retinal glial cells, promote the activation of retinal glial cellsand lead to the injury of retina of glaucoma.Methods Selected male AQP4knockout mice(AQP-/-) and their wild-type(WT)male mice, The chronic high intraocular pressure models were established byburning the scleral venous of the lift eye, which as the experiment group, and theright eye without any treatment as the control group. Selected each of the successfulmodel of the two types of mice30.Start calculated the time of establishing the chronicocular hypertension model when the surgery ended. divided the two type of mice intofive groups after surgery according to the time of establishingmodels(24h,3d,1w,2w,4w after scleral venous burn),6mouse of each group.Theintraocular pressure (IOP) was measured by icare rebound tonometer. And thenRemoving the mouse retinal tissue，Western-blot was used to observe the expressionof the glial fibrillary acid protein(GFAP) in retina glial cells of AQP4knockout mice(AQP-/-) and their wild-type(WT) mice. Analyzed experimental data by t-test,ANOVA and SNK methods.Results After scleral venous burn (24h,3d,1w,2w,4w), AQP4knockout (AQP4-/-) mice experimental group IOP was11.4±1.45、11.35±1.40、10.75±1.35、10.95±1.50、10.25±1.39and the control group IOP was6.50±0.99、6.40±0.95、6.45±1.05、6.30±0.95、6.45±0.94. Wild-type(WT) mice experimental group IOP was11.35±1.05、11.35±1.33、10.85±0.95、10.35±1.33、10.50±1.25and the control groupIOP was6.45±1.10、6.60±1.13、6.50±1.15、6.20±1.05、6.60±1.16. there was asignificant difference(P<0.05) in the IOP of the two types of mice between theexperimental and control groups. Under normal circumstances, Western-blot wasused to observe that the retinal tissue of AQP4knockout mice(AQP-/-) and theirwild-type(WT) mice express glial fibrillary acid protein(GFAP).Since24hours afterthe scleral venous burn,the expression of GAFP of the two type mice began toincrease and reached to peak at1week after burning. Then the concentration ofGAFP began to decrease and reached to bottom at4weeks later, but still higher thancontrol groups. The expression of GAFP of WT mice was significantly higher thanthat of AQP4-/-mice (P <0.05), there is a statistically significant difference.Conclusion The chronic high intraocular pressure models can be establishedsuccessfully by burning the scleral venous. In chronic high intraocular pressure state,AQP4gene can regulate the expression of GFAP of retinal glial cells, promote theactivation of retinal glial cells and lead to the injury of retina of glaucoma, which maybe a new target to treatment of glaucoma.