Effect Of Phase â…¡ Enzyme Inducer On The Expression Of Nuclear Factor Erythroid2-related Factor2and Heme Oxygenase-1in Retina Of Diabetic Rats

Objective: To establish a high fat and high sugar dietcombined with low dose of streptozotocin (STZ) injection to induce theformation of type2diabetic rat model to study the effect of phase Ⅱenzyme inducer5,6-dihydrocyclopenta-1,2-dithiole-3-thione (CPDT) onNrf2and HO-1in the retina of type2diabetic rats, to investigate themechanism of CPDT protecting the retina of diabetic rats. Methods:Thirty-five male Wistar rats were randomly divided into two group,normal group and model group. Model group in the model were randomlydivided into two group, diabetic group and CPDT intervention group. Thenormal group was eight rats and model group was twenty-seven rats.Diabetic group and CPDT intervention group were given high fat andhigh sugar diet for2months. After12hours of fasting, Type2diabetic ratmodel was induced by intraperitoneal injection of STZ (35mg/kg). As acontrol, Normal group fed basal diet for2months and injected the samedose of Citric acid-sodium citrate buffer. Normal group continued to usethe basal diet, DM Group continued to use the high fat and high sugarfeeding, after the modeling one week, CPDT intervention group addedCPDT in high fat and high sugar diets. After adding the intervention agent8weeks, detected the blood glucose, blood lipd, serum malondialdehyde in three groups of animals. The rat eyes, a portion for HE staining andimmunohistochemical staining, immunohistochemical detectedexpression of Nrf2and HO-1in each layer of the retina in3groups, theother part of the retina of Nrf2and HO-1mRNA expression level wereexamined by RT-PCR, the expression of Nrf2and HO-1protein wereexamined by Western blot. Results:①type2diabetic rat model wasestablished, the success rate was92.6%, DM group rats showedpolydipsia, polyphagia, polyuria, stooping and spirit flagging, fur dirty noluster and other symptoms. the CPDT intervention group, rats livingconditions improved in DM group.②In DM group, retinal photoreceptorcell layer and nerve fiber layer were arranged in disorder, each layer ofthe tissue were different degrees of cell edema phenomenon, inner andouter nuclear layer fusion. In CPDT intervention group, photoreceptorcell layer and retinal nerve fiber layer basic neatly arranged inside,individual ganglion cells appeared mild swelling.③The level of bloodlipid of DM group was higher than those of the Normal group(FTC=65.866, FTG=25.441, FLDL-C=38.889, P=0.000). There weresignificant differences in blood sugar and serum MDA levels in3groups（χ2血糖=25.812，P血糖=0.000；F血清MDA=59.545，P血清MDA=0.000）, bloodglucose of rats in the DM group was24.86±3.31mmol/L which washigher than those of the Normal group, blood glucose of rats in the CPDTgroup was11.51±2.45mmol/L which was lower than those of the DM group. Serum MDA in DM group was significantly higher than thenormal group (t=10.523，P=0.000) and CPDT group (t=7.766，P=0.000).④There was statistically significant difference between the groups ofretinal Nrf2mRNA and HO-1mRNA (FNrf2=19.503，PNrf2=0.000；FHO-1=9.737，PHO-1=0.001), compared with the diabetic group, expressionlevel of Nrf2mRNA and HO-1mRNA were significantly increased inCPDT intervention group (tNrf2=3.399， PNrf2=0.002； tHO-1=2.167，PHO-1=0.039); There was statistically significant difference between thegroups of retinal Nrf2and HO-1protein (FNrf2=112.823，FHO-1=119.361，P=0.000), compared with the diabetic group, expression level of Nrf2andHO-1protein were significantly increased in CPDT intervention group(tNrf2=6.203， tHO-1=6.388， P=0.000). Immunohistochemical detectionshowed, Nrf2and HO-1protein were expressed in retinal ganglion celllayer, inner plexiform layer and inner nuclear layer, There wasstatistically significant difference between the positive expression ofretinal Nrf2and HO-1protein (FNrf2=16.206，FHO-1=46.790，P=0.000),CPDT intervention group was higher than that in the diabetic group(tNrf2=3.172，PNrf2=0.003；tHO-1=6.321，PHO-1=0.000), diabetic group washigher than that in normal group (tNrf2=2.679，PNrf2=0.011；tHO-1=3.482，PHO-1=0.001). Conclusion:①After8weeks, a model of type2diabeticrat can produce apparent DR.②At8weeks, the function of antioxidantretinal tissue of diabetic rats are active.③CPDT can effectively induce the expression of Nrf2and HO-1, reduce oxidative stress in type2diabetes retinal and protect retinal in type2diabetic rats.④CPDT maybecome a retinal protective agent, may be useful in the prevention andtreatment of DR.