The Role Of Retina Pigmented Epithelium In The Transmission Of Chromatic Light Signal

Object: To investigate the role of retina pigmented epithelium in the transmission of chromatic light signal,then try to discuss the pathogeny of myopia.Method: We isolated fetal and adult human RPE cells by enzyme digestion. To analyze the biologic propert of RPE cells, we calculatd the growth data,plotted growth curve and examine the ultrastructure by transmission electron microscopy. We irradiated the third generation RPE cells with red (772nm),yellow (590nm),blue(480nm),and plotted the growth curve, calculated the doubling time and the population doubling of every group respectively. We also examined the cell cycle of RPE cells that have been exposed to lights of different wave-lengthes for 24 hours by flow cytometry (FCM). We assayed the concentration of bFGF and TGF-β in the culture medium by enzyme-linked immunosorbent assay(ELISA). After extract the total RNA of RPE cells irradiated by chromatic lights for 24 hours,we detected the mRNA expression of TGF-βby RT-PCR. In addition, we used newborn guinea pigs in with red,yellow,blue light and measured the eye axis of every group respectively. We also detected the mRNA expression of bFGF and TGF-βin nerve retina and RPE by ISH. Results: Fetal RPE cells grow more actively than adult RPE cells,and the ultrastructure of RPE cells is normal in vitro. Lights of different wave-lengthes has different effects on the growth of RPE cells. After irradiated by chromatic lights of different wavelengths, RPE cells have different cell cycle and growth curves. The results of ELISA indicated that RPE cells can secrete bFGF and TGF-β. RPE cells secreted different amount of bFGF and TGF-β at different time after exposed to chromatic lights of different wave-lengthes. The mRNA expression map of TGF-β is different after the RPE cells irradiated by different chromatic lights for 24 hours. The eye axis of young guinea pigs reared in red light were - 2 -longer than that of control group, and the difference is significant by statistics. The results of ISH showed that every layer of retina expressed bFGF and TGF-β, and the amount of the mRNA expression of bFGF and TGF-β in red group Is more than other groups. Conclusion: From our various studies, we conformed the biologic properts of RPE cells and the role of RPE cells in the development of eyeballs. These results settled a background for the clarification of the pathogeny of myopia.