HO-1激动剂Copp对放射所致内皮细胞凋亡的抑制作用

Inhibition effect of Heme oxygenase-1 activator Copp on irradiation-induced endothelial cell apoptosis

目的探讨血红素加氧酶1(HO-1)在放射所致内皮细胞凋亡中的作用。方法预先通过HO-1激动剂Copp和(或)HO-1抑制剂Znpp分别处理人血管内皮细胞EA.hy926。然后,预处理后的部分细胞接受8 Gy的照射。分别通过Western blotting和流式细胞仪检测EA.hy926细胞HO-1蛋白、细胞色素C的表达以及EA.hy926细胞的凋亡率。结果PBS+R组EA.hy926细胞经8 Gy照射后低表达HO-1蛋白;而细胞先经Copp和(或)Znpp处理后,再行8 Gy照射,其HO-1蛋白的表达则显著增高(P<0.01)。与Znpp+R组相比,Copp+R组的增高较为明显(P<0.01);另外,Copp+R组HO-1蛋白的表达低于Copp+Znpp+R组(P<0.01)。进一步通过流式检测各组细胞凋亡的情况显示,与其他各组相比,Copp+R组细胞的凋亡率最低(P<0.01),这与相应各组细胞细胞色素C的表达水平结果一致。结论诱导并激活HO-1能够减少放射所致的内皮细胞凋亡。

Objective To explore protective effect of Heme oxygenase-1 （HO-1） on irradiation-induced endothelial cell apoptosis. Methods Human endothelial cell line EA. hy926 were administered with or without HO-1 activator Copp and/or HO-1 inhibitor Znpp, respectively. Then, cells were treated with or without 8 Gy radiation. The HO-1 protein expression of cells were assessed with Western blotting and apoptosis of cells treated with irradiation were evaluated with flow cytometry. Moreover, cytochrome C releasing into cytosol were also determined by Western blotting. Results In PBS ＋ R group, HO-1 protein expression of EA. hy926 was low posterior to irradiation. When cells were preconditioned with Copp and/or Znpp, then recieved with 8Gy irradiation, the HO-1 protein expression of EA. hy926 increased significantly in comparision with the PBS ＋ R group （ P 〈 0.01 ）. However, the HO-1 protein expression of cells in Copp ＋ R group was higher than that in Znpp ＋ R group （ P 〈 0.01 ） and was lower than that in Copp ＋ Znpp ＋ R group （ P 〈 0.01 ）. Flow cytometry assessment demonstrated that the apoptosis rate of the Copp ＋ R group was the lowest among the four groups （ P 〈0.01 ）. It was consistent with the results of cytochrome C examination. Conclusion Inducing and activating HO-1 prior to irradiation can reduce endothelial cell apoptosis.