Objective　To observe the abnormal expression of  alpha;A-crystallin protein in neural retina in type 2 diabetic rats via proteomic technique.Methods　Twenty-eight male Sprague-Dawley (SD) rats were randomly divided into the normal control and the diabetic experimental groups with 14 rats in each group.A type 2 diabetes rat model (T2DM) was set up in the diabetic experimental group by feeding high fat diet combined with peritoneal injection of low dose streptozotocin (STZ);the successful diabetes model is with the randomlydetected blood glucose of ＞16.7 mmol/L.The rats in the control group underwent peritoneal injection of equivalent sodium citrate solution and were fed with normal diet.All of the animals were sacrificed by decapitation 56 days after the induction of diabetes.The eyes were enucleated and the neural retina layers were carefully peeled off and preserved.The total neural retinal proteins were extracted from the control and diabetic groups, respectively,and then subjected to two dimensional gel electrophoresis (2-DE).Some different proteins spots were identified by peptide mass fingerprinting (PMF) as well as by tandem mass spectrometric (MS/MS) measurements.Western blot and indirect immunofluorescence (IMF) were used to confirmed that  alpha;A-crystallin protein expression was upregulated in diabetic retina.Results　An average of （3122 plusmn;37） spots in normal retinas and（2702 plusmn;21）spots in diabetic group were found by 2-DE image analysis software; about 150 spots in 2-DE gel of diabetic retinae exhibited statistically significant variations (t＞2.77,P＜0.05).Compared with normal rats' retinae, diabetic ones presented 68 protein spots of up regulation expression and 82 of downregulation expression in 2DE gel.Furthermore,20 of the 150 protein spots were identified by mass spectrometry.The points of 2369 and 1048 in 2-DE gel, showing high expression in diabetic retinal tissues, were identified as  alpha;A-crystallin via PMF.Western blot validated that the expression level of  alpha;A-crystallin in diabetic neural retina was much higher than that in the control group. Significantly increased expression of  alpha;A-crystallin in nuclear retina in diabetic group was also observed by IMF. Fluorescence was mainly seen in the retinal nuclear layer; alpha;A-crystallin aggregation was detected in the perinuclear region of neurons.Conclusion　The expression of  alpha;A-crystallin　increases in neural retina of early T2DM rats.

Citation： 张民英,吴晓燕,王亚冬,刘庆淮. Abnormal expression of αA-crystallin in neural retina in type 2 diabetic rats. Chinese Journal of Ocular Fundus Diseases, 2010, 26(2): 160-164. doi: Copy