抗辐射球菌pprI基因活体电转染救治小鼠γ射线损伤的实验研究

Research on pprI gene of deinococcus radiodurans transfered by electroporation in vivo for remedy of the γ-rays radiation injury with mice

为研究抗辐射球菌pprI基因活体电转染对哺乳动物急性放射损伤的影响,探讨一种新的救治放射损伤的转基因技术。将自行构建的pCMV-HA-pprI质粒注入接受γ射线照射的小鼠肌肉内,采用活体基因电转导技术将该基因导入细胞内,观察照后第1、7、14、28和35天小鼠死亡率、血细胞计数以及骨髓细胞、脾脏和胸腺淋巴细胞凋亡的变化。结果显示,6Gyγ射线可引起小鼠急性致死性放射损伤,转基因组小鼠死亡率(1/10)明显低于单纯照射组小鼠死亡率(4/10)。与单纯照射组和空载体转染组比较,pprI基因转染组小鼠外周血白细胞总数及红细胞总数于照后第7天显著增高(p<0.05);血小板数于第7、14天显著增高(p<0.05);血淋巴细胞百分率于照后35天恢复正常;pprI基因转染组脾细胞凋亡率于第7、14、28天显著降低(p<0.05);胸腺细胞凋亡率于第1、7、14、35天显著降低(p<0.05);骨髓细胞凋亡率于第1、7、14和28天显著降低(p<0.05),并且胸腺细胞和骨髓细胞凋亡率均于照后28天恢复正常。结果表明,抗辐射菌pprI基因活体电转染对动物急性致死性放射损伤具有明显的防治作用。

In this paper the effects of pprI gene from Deinococcus radiodurans transfered by electroporation in vivo on acute radiation injury of a mammalian had been investigated and clarified. After injecting the pCMV-HA plasmid into the muscle of mice exposed to γ-rays irradiation, pprI gene was transferred into the cell of mice with electroporation technology in vivo. The deaths of mice, blood cell count and the apoptotic rates of bone marrow cells, spleen cells and thymocyte cells on the 1st, 7th, 14th, 28th, and 35th day after irradiation were investigated. The re- sults show 6 Gy γ-rays can cause acute lethal radiation injury of mice and the death rate of transfer pCMV-HA-pprI group （1/10） is obvious lower than that of radiation group（4/10）. Compared with the radiation irradiated group and transfer pCMV-HA group, the leucocyte number and the erythrocyte number in peripheral blood of the mice trans- ferred with pCMV-HA-pprI group is significantly higher on the 7th day after irradiation （p〈0.05） meanwhile the platelet number is obvious higher on the 7th day and the 14th day （p〈0.05）. On the other hand, the lymphocyte ratio get right on the 35th day, the apoptotic rate of spleen cells is significantly lower on the 7th, 14th, and 28th day （p〈0.05）, the apoptotic rate of thymocytes is significantly lower on the 1st, 7th, 14th and 35th day （p 〈0.05）, the apoptotic rate of bone marrow cells is significantly lower on the 1st, 7th, 14th and 28th day （p〈0.05）, the apoptotic rates of thymocytes and bone marrow cells are return to normal level on the 28th day after irradiation had also been observed in the group transferred with pCMV-HA-pprI. The result indicates that the pprI gene of Deinococcus radi- odurans transfered by electroporation in vivo can prevent and cure the acute radiation injure for animals apparently.