The Effect Of Different Wavelengh Lights On Cultured Human Retina Pigment Epithelium Cells In Vitro

Object:Retina can be damaged by exposed in strong light for a long time,especially the blue light.This photochemistry damage can implicate the photoreceptors and Retina Pigment Epithelium cells(RPE cells).The past study focused more on photoreceptors,while our study focused on RPE cells since they contribute greatly on maitaining the morphology and function of photoreceptors.Our study will start with it to investigate the impact of morphology and function on RPE cells,try to discuss the mechanism of lights damage on retina at cytobiology levels.Method:We isolated human RPE cells by enzyme digestion,analyzed the biologic characteristic of RPE cells by growth curve,morphology and immunology and transmission electron microscopy;The RPE cells were cultured under lights of different wavelengh,then investagated the effect of growth characteristic of RPE cells in vitro by MTT,transmission electron microscopy and etc.Results:The first part:1,Culture RPE cells and draw growth curve:Cultured human RPE cells in vitro began attached after seeding for 2 hours,spreaded after 3 days and cell confluence was observed on the 10th day.The confluence began on the 3rd day in passaged cells.The growth curve of RPE cells is simialr as "S".The number of RPE cells reduced slightly on the first day,then it rose up to logarithmic period after latent period for 2-3 days,it arrived at steady period after 7 days.2,Transmission electron microscopy:The ulturestructures of cultured human RPE cells in vitro are normal with oval nucleus,equal and dense chromatin,abundant organelles in cytoplasm including free ribosomes,mitochondria,Golgi Body,rough endoplasmic reticulum and few pigment.The microvillus on top of cell,infolding on base membrane and cell junction complex(tight conjuctions,desmosomes and etc.)can be observed on vertical section.3,RPE cells were identified with immunology:Cells were stained and identified with immunocytochemical anticytokeratin(AE1 /AE3)in the 3-5 subcultured human RPE cells.The second part:1,Effect of different wavelengh lights on subcultured human RPE cells: Proliferation of RPE cells can be slowed down by different wavelengh lights,the blue light do the most among them(P＜0.05),then the red and white light which have no significant statistics difference(P＜0.05).The proliferation is conspicuous in contrast group(P＜0.05)(F=12.579, P＜0.05).2,Transmission electron microscopy:The ultrastructure of subcultured RPE cells under red and white light group have no significant difference compare to contrast group.The number and structure of organelles in cytoplasm are normal with round nucleus and equal chromatin.But comparably different is revealed in blue light group:thin and swelling chromatin,reduced mitochondria,rough endoplasmic reticulum and ribosomes,blurry cell membrane and even disapeared in some cases.Conclusion:The morphology and function of human RPE cells cultured in vitro were affected by different wavelengh lights.The effect of blue light is stronger than red and white light.