摘要：
[目的]研究α2-巨球蛋白(α2M)对X线照射后人皮肤成纤维细胞(HSF)超氧阴离子(.O2-)含量、超氧化物歧化酶(SOD)活性和HSF细胞向肌成纤维细胞转化过程中的影响.[方法]分别使用0、5、10、15、20 Gy X线照射HSF细胞,在照射后第1天检测细胞培养基上清液中.O2-含量、SOD活性的变化,在照射后第5天采用Western blot检测α-平滑肌肌动蛋白(α-SMA)的蛋白表达变化,以选定合适的照射剂量.用以上合适剂量照射HSF细胞,分别于照射前1 h、照射后1 h实验组细胞培养基中加入终浓度为0.25 mg/mL,0.5 mg/mL的α2M,检测并比较不同实验组细胞培养基上清液中.O2-含量、SOD活性和α-SMA蛋白表达的变化情况.[结果]5~20 Gy X线照射HSF细胞后,.O2-含量逐渐增多,SOD活性逐渐降低,α-SMA蛋白表达量逐渐升高,差异具有统计学意义(P<0.05).10 Gy X线照射后1 h加入α2M,可明显减少照射后HSF细胞.O2-含量,提高SOD活性,下调放射后HSF细胞α-SMA的蛋白表达,差异具有统计学意义(P<0.05),照射前1 h给药则无明显变化.[结论]X线照射后的HSF细胞明显增加.O2-释放量,同时SOD活性降低,并有向肌成纤维细胞转化的趋势;而X线照射后加入α2M可明显减少受照射HSF细胞的.O2-释放量,提高其SOD活性,并抑制向肌成纤维细胞转化的趋势,说明α2M可通过抗氧化和抗纤维化起到放射保护作用.%[Objective]To explore the effect of alpha2-macroglobulin(α2M)on superoxide anion(.O2-)content, superoxide dismutase(SOD)activity and the process of cell-to-myofibroblast transformation in human skin fibroblasts (HSF)after X-ray irradiation.[Methods]HSF cells were irradiated with 0,5,10,15 and 20 Gy X-ray.The change of. O2- content and SOD activity in the supernatant of cell culture medium were measured on the first day after irradiation. The protein expression of alpha-smooth muscle actin(α-SMA)was detected by Western blot on the fifth day after irradia-tion.The most sensitive radiation dose is selected.HSF cells were irradiated with the above sensitive dose.Respectively, 1h before irradiation,1 h after irradiation,the experimental group cell culture medium was added to a final concentration of 0.25 mg/mL,0.5 mg/mL of α2M.The change of.O2-content,SOD activity and the protein expression of α-SMA were detected.[Results]HSF cells were irradiated with 5~20 Gy doses of X-ray..O2- content increased,SOD activity de-creased and α-SMA protein expression increased gradually(P<0.05).The addition of α2M at 1 h after 10Gy X-ray irradi-ation reduced the.O2- content,increased the SOD activity and downregulated the protein expression of α-SMA in HSF cells(P<0.05). There was no significant change in the administration at 1 h before irradiation.[Conclusion]HSF cells increased.O2-content significantly,while SOD activity decreased,and the tendency to transform myofibroblasts after X-ray irradiation.α2M can reduce the.O2-content,increase the SOD activity in HSF cells and inhibit the transformation of fibroblasts into myofibroblasts after irradiation.Indicating that α2M can play a role in radiation protection by anti-oxida-tion and anti-fibrosis.
