实时定量PCR检测低剂量X射线对小鼠睾丸中CHOP和caspase-12 mRNA表达的影响

Effects of low dose X-rays on expressions of caspase-12 and CHOP mRNAin mouse testis cells by real time quantitative PCR

目的通过检测低剂量X射线照射后小鼠睾丸中CHOP和caspase-12 mRNA表达的变化,在mRNA水平探讨内质网通路参与凋亡调控的可能。方法健康雄性昆明小鼠经过低剂量(0、0.050、0.075、0.100和0.200 Gy)照射后12 h和0.075 Gy照射后不同时间(0、3、6、12和24 h),应用实时定量PCR(real time quantitative PCR)检测小鼠睾丸中C/EBP同源蛋白(C/EBP homologous protein,CHOP)和胱天蛋白酶-12(caspase-12)mRNA表达剂量与时程效应关系。结果 0-0.200 Gy X射线照射后12 h,小鼠睾丸中CHOP mRNA表达随剂量逐渐增高并一直维持较高水平,其中0.050和0.100 Gy组较0 Gy显著增高(P<0.05);caspase-12 mRNA表达随剂量逐渐增高,0.075和0.100 Gy组较0 Gy组显著增高(P<0.05,P<0.01)。0.075 Gy照射后0-24 h CHOP mRNA表达随时间延长逐渐增高,在24 h到达峰值,较0 h显著增高(P<0.05);caspase-12 mRNA表达在3和6 h稍有降低后,12 h到达峰值,较0 h显著增高(P<0.05),24 h时回降。结论低剂量X线照射诱导小鼠睾丸CHOP和caspase-12 mRNA表达具有剂量-时程-效应规律性,二者可能参与低剂量X线照射诱导小鼠睾丸生精细胞凋亡的调控。

Objective To detect the changes of CHOP and caspase-12 mRNA in mouse testis after low dose X rays and to investigate the possibility that endoplamic reticulum pathway regulate cell apoptosis at mRNA level.Methods Healthy male Kun Ming mouse testes 12 h after 0,0.050,0.075,0.100 and 0.200 Gy X rays irradiation and 0-24 h after 0.075 Gy X rays irradiation were got,the relationship of dose-and time-effect of CHOP and caspase-12 mRNA were detected with real time quantitative PCR.Results After 0-0.200 Gy X rays irradiation,CHOP mRNA expression in mouse testis increased with dose increasing and kept high level,it increased significantly after irradiaion with 0.050 and 0.100 Gy X rays（P0.05）;caspase-12 mRNA expression increased with dose increasing,it increased significantly after irradiaion with 0.075 and 0.100 Gy X rays（P 0.05,P0.01）.After 0.075 Gy X rays,CHOP mRNA expression increased with time prologation from 0 h to 24 h,and it reached the peak value at 24 h,it increased obviously compared with 0 h（P 0.05）;caspase-12 mRNA decreased at 3 and 6 h,but it increased at 12 h,and reached the peak value,it increased obviously compared with 0 h（P 0.05）,and it decreased again at 24 h.Conclusion Dose-and time-effect exist on the low-dose irradiation induced expressions of CHOP and caspase-12 mRNA in mouse testis,both may participate regulating spermatogenic cell apoptosis induced by low dose radiation.