Objective To investigate the effect and mechanism of Ginkgo biloba extract EGb761 on protein expression in lightdamaged retinal pigment epithelial (RPE) cells. Methods The human RPE cells (ARPE19) were divided into normal control group, light damage group and EGb761 treatment group; the cells of latter 2 groups were exposed to the cold white light ［(2200 ± 300) lx］ to induce light damage responses. The lightdamaged RPE cells were treated with or without EGb761 (100 g/ml). The soluble protein of those cells were extracted and separated by twodimension electrophoresis and stained by silverstaining. Different proteins in the gel were analyzed by ImageMaster and identified by MALDITOFMS, and were further analyzed by mass spectrometry and bioinformatics.Results ImageMaster and MALDITOFMS identified 25, 33 and 11 different proteins between light damage group and EGb761 treatment group, between normal control and light damage group, between normal control and EGb761 treatment group of RPE cells respectively. Mass spectrometry and bioinformatics analysis successfully identified 16 proteins, including metabolic enzymes, cytoskeleton proteins, antioxidation protein and other types of proteins expressed differentially．Conclusion Protein expression profiles are different between normal control group, light damage group and Ginkgo biloba extract treatment group of RPE cells. The mechanism of protective effect of EGb761 may involve cathepsin B, heat shock protein, cytochrome C reductase, and other proteins.
Objective To observe the expression of proteins in light-injured retinal pigment epithelial (RPE) cells. Methods ARPE19 cells were exposed to the cool white light at the intensity of (2200plusmn;300) Lx for 6 hours to set up the light injured model. Cellular soluble proteins was extracted and analyzed by means of twodimensional electrophoresis to find out the changes of protein map of lightinjured RPE cells. Results Cellular soluble proteins had (390plusmn;10) spots on the map, in which 11 spots had obvious difference between the light injured group and the normal control group. In the lightinjured cells, the expressio of 8 proteins increased, 1 decreased, and 2 disappeared. Conclusion Twodimensional electrophoresis can find out the difference of expression of proteins in lightinjured and normal RPE cells.
Objective The article introduces the present status of the application of comparative proteomics in study of tumor marker. Methods This essay review the present status and advances of the application of comparative proteomics in study of tumor marker through refer considerable literatures about proteome, proteomics and tumor marker. Results Follow the study of human genome deepening; the paradox between the finiteness of genes’ number and stability of genes’ structure and the variety of the life phenomena is more conspicuous. Then, the study of proteomics was pushed to the advancing front of life science research. The application of comparative proteomics to tumor research becomes a hot spot nowadays. Conclusion Screening tumor marker via comparative proteomics is an extremely promising research.