| Objective:In this study,we will explore the effects of LED light on lens epithelial cells in vivo,including the damage effects of white LED on the morphology of the lens epithelial cells.We will also test the expression of Caspase-3 and P21waf1/cip1in these cells.This study will also explore the effects of different peak wavelengths of LED light on the activities of antioxidant enzymes（SOD、GSH-Px）in the lens and compare the contents of MDA in the lens after different wavelengths of LED.Finally,we will observe the treatment effect of lipoic acid on the imbalance of oxidation-antioxidant system in the lens induced by the LED light.Methods:In the first part,SD rats were irradiated with white LED light for 5 days,12hours a day.HE staining was used to observe the paraffin sections of rat lens epithelial cells.The levels of Caspase-3 and P21waf1/cip1mRNA in rat lens epithelial cells were detected by Real-time PCR.The expression of Caspase-3 and P21waf1/cip1protein in epithelial cells was detected by Western-blotting.The contents of SOD,GSH-Px and MDA in the lens were detected by automatic biochemical analyzer.The rat lens was irradiated with different peak wavelengths of LED light for 5 consecutive days,12 hours a day.In the third part,SD rats were irradiated with LED blue light at the same time and irradiation dose as the second part.The changes of MDA,SOD and GSH-Px were observed in the lens of SD rats in the administration group and the simple irradiation group.Results:1.HE staining showed that the lens epithelial cells of the control group were flat,monolayer and uniform.In the white LED irradiation group,the lens epithelial cells were disordered and swollen,and the lens epithelial cells were changed from single layer to double or even multi-layer.2.Lens epithelial cells in blue-light group were similar to those in white-light LED group in disorder and swelling.In green-light group,the lens epithelial cells were slightly swollen and some areas showed double-layer arrangement;in red-light group,the lens epithelial cells were enlarged.3.The expression levels of Caspase-3 and P21waf1/cip1in lens of rats irradiated by white LED were higher than those of control group.There was no statistical difference between the 500Lux group and the control group（P>0.05）,there was a signal difference between the other groups（P<0.05）.,and were positively correlated with the irradiation intensity.3.The content of MDA in rat lens from he control group,the red,green,blue group was about 0.0043 U/mgprot,0.0044 U/mgprot,0.0156 U/mgprot,0.0178 U/mgprot.There was no statistical difference between the red light group and the control group（P>0.05）,but there was a signal difference between the other groups（P<0.05）.The activity of SOD in the lens of the control group,the red,green,blue group were 1.30 U/mgprot,7.93 U/mgprot,3.07 U/mgprot,2.12 U/mgprot,respectively,and there were significant differences among the groups（P<0.05）;the activity of GSH-Px in the lens of the control group,the red,green,blue group were 1.41 U/mgprot、9.79 U/mgprot、2.69 U/mgprot、2.16 U/mgprot,there were significant differences among these groups（P<0.05）.After blue light irradiation,the content of MDA in the lens of rats in the non-administration group was 0.02210U/mgprot,which was significantly higher than that of rats fed with lipoic acid（0.01290 U/mgprot,P<0.05）.In addition,the SOD and GSH-Px activities in the lens of rats exposed to blue light alone were 2.1212 U/mgprot and 2.69 U/mgprot,respectively was significantly lower than SOD activity（2.9101 U/mgprot）and GSH-Px activity（4.70530 U/mgprot）in the lens of rats in the administration group（P<0.05）;SOD and GSH-Px activity in the lens of rats in the administration group were significantly lower than those in the blank control group（1.3035 U/mgprot）and GSH-Px activity（1.41340）.U/mgprot)also increased significantly compared with the difference（P<0.05）.Conclusion:1.White LED light cause abnormal morphological changes of lens epithelial cells in vivo.2.The shorter the spectral wavelength leaves the greater the risk of lens damage.The low color temperature LED light may be more harmful to the lens than the high color temperature LED light.3.Lipoic acid has certain therapeutic significance for the oxidative damage of the lens induced by LED light. |
