| Objective: To investigate the effect of glucose transporter-1(GLUT1) inhibition on retinal glucose transport in diabetic mice.Methods: Thirty-six 8-week-old C57BL/6 mice were randomly divided into normal control, diabetic control, and GLUT1 si RNA treatment group. After establishing diabetic model by intraperitoneal injection with streptozotocin, 1 μL of si RNA mediated GLUT1 was intravitreally injected into the GLUT1 si RNA treatment group, whereas the other two groups received equal amount of non-specific si RNA. At 21 weeks after diabetic induction, expression of retinal GLUT1 were determined by immunoblotting and immunofluorescence.We also calculated and compared the glucose concentration.Results: We found that expression of GLUT1 in neural retinal in the GLUT1 si RNA treatment group decreased by about 77.00% compared with that in the normal control and only 8.07% of that in diabetic control(P < 0.01). Retinal glucose concentration of diabetic control and GLUT1 si RNA treatment group are both higher than normal control, but GLUT1 si RNA treatment group is only about 50.05% of diabetic control(P < 0.01).All differences were statistically significant.Conclusions:GLUT1 si RNA could effectively depress GLUT1 expression and restricts transport of glucose into retina, thereby decreasing the glucose content in retina.Objective: To investigate the effect of downregulation of glucose transport on retinal photoreceptors degeneration in diabetic mice.Methods: Three groups(normal control, diabetic control, and GLUT1 si RNA treatment group) received electroretinography(ERG) to determine the function of retinal rod photoreceptors and cone photoreceptors at 21 weeks after diabetic induction. We also utilized immunofluorescence colocalization to determine the density and morphology change of cone photoreceptors. Thicknesses of retinal outer nuclear layer(ONL)at 0.2mmã€04mmã€0.6mmã€0.8mmã€1.0mm ã€1.2mmã€1.4mmã€1.6mmã€1.8mmfrom optic nerve were recorded to compare the morphological changes of rod photoreceptors.Results: The amplitudes of a and b waves in scotopic ERG and photopic ERG in both diabetic control and GLUT1 si RNA treatment were lower than those of the normal control. By contrast, those in scotopic ERG in the GLUT1 si RNA treatment group were higher by 44.6% and 94.9% than those of the diabetic control group, whereas those in photopic ERG were higher by 47.59% and 42.61%. All the differences were statistically significant(P < 0.01). Upon inspection of morphology inspection, ONL thicknesses in the GLUT1 si RNA treatment and diabetic control groups were lower than those of the normal control group. However, ONL in the GLUT1 si RNA treatment were thicker than those of the diabetic control. The cone cells were more loosely arranged and shorter in morphology of outer segments in the diabetic control group than those of the GLUT1 si RNA treatment group.Conclusions:GLUT1 si RNA could effectively restricts transport of glucose into retina, which alleviates the functional and morphological degeneration of retinal photoreceptors, thereby creating protective effect on retinal photoreceptors degeneration in diabetic retinopathy.Objective: To investigate the effect of downregulation of glucose transport on retinal microvascular abnormalities in diabetic mice.Methods: Three groups(normal control, diabetic control, and GLUT1 si RNA treatment group) received immunoblotting to determine the expression ofinflammation markers ICAM-1 and TNF-α.Intracardiac injection of FITC-Con A is conducted to label adherent leukocytes and afterwards retina flat mount are utilized to process leukostasis assay.Femoral vein injection of FITC-BSA is conducted and afterwards retina flat mount are utilized to process vascular leakage assay.Results:The expression of ICAM-1 and TNF-α in retina of both diabetic control and GLUT1 si RNA treatment group was higher than that in the normal control group(P < 0.01). However, the expression of both inflammatory factors in the GLUT1 si RNA treatment group is only 66.14%(P < 0.05) and 54.76%(P < 0.01) of those in the diabetic control group. These differences were statistically significant. More WBCs were adhered to retinal vessels in the diabetic control group than those in of the GLUT1 si RNA treatment group. In stretched preparation of the retina, more fluorescence leakage regions with larger leakage area were presented in the diabetic control group than in the GLUT1 si RNA treatment group.Conclusions:GLUT1 si RNA could effectively restricts transport of glucose into retina, which alleviatesinflammatory reactions and breakdown of inner blood–retinal barrier in diabetic retina, thereby creating relieving effect on retinal microvascular abnormalities in diabetic retinopathy. |