Expressions of SnoN protein and TGF-β in retinas of early diabetic rats and its significance

Objective To investigate the expression of SnoN and TGF-β in the retinas of diabetic rats,then study the role of the SnoN and TGF-β in diabetic retinopathy,and provide a new theoretical basis for studying DR pathogenesis. Methods Twenty male Wistar rats were randomly divided into normal control group and DM group,10 cases in each group. DM model was established by intraperitoneal injection of 50 mg·kg- 1STZ. At 8 weeks and 12 weeks,the rats were sacrificed and removed left eyeballs to make the eye cups. SnoN and TGF-β protein expression in the retina were detected by immunohistochemistry. Results At 8 weeks and 12 weeks,the blood glucose in DM group were( 22. 64 ± 3. 57) mmol·L- 1and( 24. 08 ± 1. 60) mmol·L- 1,respectively,which were higher than those in normal control group( 4. 64 ± 0. 91) mmol·L- 1and( 4.50 ± 0. 66) mmol·L- 1,there were significant differences( all P 0. 01). The TGF-β was ex-pressed weakly or was not expressed in rat retina of normal control group. At 8 weeks and 12 weeks,the value of average optical density of TGF-β were 0. 121 0 ± 0. 005 6 and 0. 155 0 ± 0. 007 0 in rat retina of DM group. Compared with normal control group( 0. 022 0 ± 0.007 9 and 0. 025 0 ± 0. 007 0),TGF-β of rat retina expression in DM group were elevated significantly( all P 0. 01). The SnoN protein was expressed highly in rat retina of normal control group. At 8 weeks and 12 weeks,the value of average optical density of SnoN were 0.412 0 ± 0. 011 3 and 0. 214 0 ± 0. 006 9 in rat retina of DM group. Compared with normal control group( 0. 945 0 ± 0. 007 0 and 0. 944 0± 0. 005 1),SnoN of rat retina expression in DM group were reduced significantly( all P 0. 01),and it was reduced furtherly with the extension of time. Conclusion The SnoN protein maybe reduce the intensity and duration of TGF-β signaling with the role of negative feedback inhibition,so has the great significance for the prevention and control of DR.