A Basic Proteome Map Of Normal Rat Retina And Comparison With The Proteome Of Early-staged Diabetic Rat Retina

The controlling of diabetes and its complications is an important issue for the public health and the development of all the countries around the world.About 20%to 24%of these complications affect eyes.Furthermore, the diabetic retinopathy(DR) is the major cause of blindness nowadays.A lot of papers has been reported which focused on the mechanism of vascular pathological changes of DR.However,the hotspot of the discussions and controversies have turned to the neuropathy happens in the early-staged diabetic retina.Diabetes is a multi-factored and a systemic disease concerning a mass of pathological courses such as the accumulation of the toxic products of metabolism disorder,ischemia, anoxia,oxidative stress responses,inflammatory and immune disorders. All of the courses above will finally cause neural apoptosis and the glial hyperplasia which character the retinal neuropathy.So here comes the question:which protein is the trigger of this pathological cascade? Is there any other protein makes a chain of the cascade? What' s the relation-ship among those factors?Recent technological advancements in proteomics allow us to study global patterns of protein content and activity and how these change during development or in response to disease,it has boosted our understanding of systems-level cellular behavior and mechanism of disease. In addition,proteomics benefits the identification of new drug targets and the development of new diagnostic markers in clinical research.The main outcome of this paper is the basic proteome map of normal rat retina and comparison with the proteome of early-staged(stage divided into lweek,2 weeks,4 weeks,6 weeks and 8 weeks after the onset of the diabetes) STZ-induced diabetic rat retina by using the SCX-RPLC-MSMS techniques.Our study provided the global information of proteomic alteration during the pathological course of the early-staged diabetes, the proteome map of normal rat retina as the baseline.These results uncover a lot of factors which are related to the retinal neuropathy and vascular changes,as well.Moreover,we could draw some curves of these alterations according to the progression of diabetes.The study provides us a new understanding of the pathogenesis of DR.This paper is composed with four parts.PartⅠis an overview of the papers of the pathogenesis of early-staged DR and the development of the proteomics techniques concerning two dimensional polyacrylamide gel electrophoresis(2D-PAGE),liquid chromatography(LC),mass spectrometry and microarray,etc.And then we introduce the applications of proteomics in the pathogenesis studies of DR,the purpose of our study following.PartⅡis the preparation work before the launch of the study.We gained 3mg of protein from the retinas of 6 normal SD rats.Protein were separated with 2-DE.The gels were stained by comassia brilliant blue and silver stain.The protein spots were clear.It is reported that proteomics is highly limited by the dose of protein and the purity of the sample. The result proved that the proteomics study of the rat retina is feasible although retinal is a kind of tiny and complicated tissue.We finally chose SCX-RPLC-MSMS as the major study method in order to improve the sensitivity and accuracy of the experiment.PartⅢis the establishment of the type I diabetic animal models. 43 SD rats were considered to be diabetic rats after the injection of STZ and took on the typical symptoms of type I DM.And the glucose dose of the placebo group was normal which was among 5.88±0.01mmol/L.The diabetic rats were losing weight along with their aging.The animal models were early-staged diabetic rats which were divided into 5 groups by the course of diabetes(1 week,2 weeks,4 weeks,6 weeks and 8 weeks).The last part work provides us a global proteome profile of normal rat retina containing 386 spots of protein and a differential expression profile of the early-staged diabetic rat retina.The differential expression profile contains 207 spots of protein,11 among which just exist in the normal rat retina.And 177 of them had some apparent changes of expression just after the onset of diabetes,early as 1 week to 2 weeks. We could draw curves of these changes according to time-point of the disease.Work has not been totally accomplished since the huge profile contains a mass of protein with different functions,such as house keeping, structure,cell signaling,metabolism,stress response,visual and neuronal functions.Hence,further study is needed.In this paper we mainly discussed some protein with close relations with the pathogenesis of early-staged DR,such as Hmgnl,Ywhag 14-3-3 protein,Pacsinl,and AQP4, etc.Furthermore,the global proteome profile of the normal rat retina will provide a reference to the future study of retinal diseases.