Effects of ultra-shortwave irradiation on the expression of the apoptosis-related genes Bcl-2 and Bax in the lens epithelial cells of the eye / 中华物理医学与康复杂志

ABSTRACT

Objective To observe the effects of low-dose ultra-shortwaves radiationon the expression of apoptosis-related genes Bcl-2 and Bax in lens epithelial cells(LECs) of rats.Methods Thirty-six Wistar rats were divided into a normal group(n=8 eyes),a control group(n=32 eyes) and an experiment group(n=32 eyes) randomly.Both eyes of each rat in the experiment group were exposed to a low-dose ultra-shortwave radiation for 7min,once a day until the end of experiment,while the control groups were not.Rats were executed after 1 w,3w,6w and 9w.Both eyes were resected,and lens were separated under a microscope and sectioned in paraffin.After Streptavidin-Biotin Complex (SABC) staining,Bcl-2 and Bax expression in the LECs were detected using an image analysis technique,and the data were analyzed using the software of SPSS 13.0.Results The average integral optical density (AIOD) of Bcl-2 expression in the experiment group was (0.391 ± 0.014) after 1 week,(0.4470.006) after2,(0.417 ±0.011) after3 and (0.275 ±0.007) after4 weeks.The corresponding AIODs for Bax expression were (0.180 ±0.015),(0.155 ± 0.007),(0.167 ± 0.003) and (0.251 ± 0.016) respectively.After l w of daily radiation,no significant difference was found in the expressions of Bcl-2 and Bax protein between the experimental and the other 2 groups(P ＞ 0.05).Three weeks after the radiation,however,the expression of Bcl-2 protein in the experimental group was significantly higher than the control groups(P＜0.001),with that of Bax being significantly lower(P＜0.001).However,the expressions of Bcl-2 protein was significantly down-regulated and the expression of Bax protein was significantly up-regulated 6w later compared with those after3 w of exposure in the experiment group(P＜0.001) After9w,in the experimental group,the expressions of Bcl-2 protein was obviously down-regulated and significantly lower than the control group.Moreover,the expression of Bax protein increased significantly compared to the control group (P＜0.01).And there was no significant difference between the control and normal group(P＞0.05) in the expression of Bcl-2 and Bax.Conclusions Low doses of ultra-shortwave radiation may protect LECs against apoptosis for a few days,but they may cause damage with repeated exposure.