Objective        To determine the effect of glucose transporter-1(GLUT1) suppression on cone photoreceptors in diabetic retinopathy in mice.       Methods        Twenty-seven 8-week-old C57BL/6 mice were divided into normal control

diabetic control and GLUT1 siRNA treatment group. Diabetic model was established by intraperitoneal inj

ection of streptozotocin. GLUT1 siRNA treatment group received intravitreal injection of siRNA-mediated GLUT1

and the other 2 groups received equal amount of non-specific siRNA. The intravitreal injection procedure was repeated every 2 weeks for 9 times in all. In 18 weeks after diabetic induction

photopic electroretinography (ERG) was performed to evaluate cone photoreceptors function

and immunofluorescence assay and Western blotting were carried out to examine the expression of GLUT1. The glucose concentration was determined in the retina. Immunofluorescence colocalization was employed to determine the density and morphological change of cone photoreceptors.       Results       The expression of GLUT1 was notably down-regulated in GLUT1 siRNA treatment group than diabetic control group

and was lower by 68.51% compared with normal control groups (

P

0.01). Retinal glucose concentration was obviously higher in the diabetic control and GLUT1 siRNA treatment group than the normal control

but GLUT1 siRNA treatment group was decreased by 42.67% compared with diabetic control（

P

0.01）. A-wave and b-wave amplitudes in photopic ERG were lower in diabetic control and GLUT1 siRNA treatment group than the normal control

but GLUT1 siRNA treatment group was increased by 47.59%（

P

0.01）and 42.61%（

P

0.01）compared with diabetic control

respectively. Morphology examination showed that density of cones were decreased significantly and had a shorten outer-segment appearance in diabetic control group.       Conclusion        GLUT1 siRNA controls the glucose transport into the retina by suppressing the expression of GLUT1

reduces the glucose concentration in retinal environment

and thus protects cone photoreceptors in diabetic retinopathy.