IL-2对中子照射后肠上皮细胞生长和凋亡的影响及其机制

目的:观察中子照射对体外培养的IEC-6细胞生长的影响及IL-2对其损伤后增殖和恢复的作用,并进一步探讨IL-2调节受照射肠上皮细胞生长的相关机制。方法:单独用IL-2(1×105U/L)或同时施加JAK1激酶阻断剂(A77-1726)处理受4Gy中子照射的IEC-6细胞,并于照后10、15、30min和1、3、6、12、24、48及72h,用MTT比色法和流式细胞术检测受照射后IEC-6细胞的增殖活力和死亡方式的改变。以免疫细胞化学染色和Western blot检测IEC-6细胞上IL-2Rβ的表达和JAK1活化情况。结果:4Gy中子照射后24h,IEC-6细胞的增殖活力明显降低;而IL-2处理组该细胞的增殖活力有显著提高(P<0.05)。受中子照射的IEC-6细胞经IL-2作用24h,其凋亡率明显降低(P<0.05),而坏死率变化不明显。以IL-2刺激中子照射的IEC-6细胞后,于10及15min可见JAK1发生明显磷酸化活化,24h时IL-2Rβ的表达明显增多。同时应用A77-1726和IL-2处理受中子照射的IEC-6细胞后,其增殖活力明显低于单纯IL-2处理组。结论:IL-2可促进受中子照射的IEC-6细胞增殖,具有抗辐射作用。IL-2Rβ和JAK1活化参与了IL-2对中子损伤的IEC-6细胞生长的调控。

Effect of IL-2 on the growth and apoptosis of intestinal epithelial cells radiated by neutron and mechanisms of IL-2 on the injured IEC- 6

AIM: To observe the effect of neutron radiation on intestinal epithelial cells 6 (IEC-6), to study the effect of IL-2 on the proliferation and recovery of neutron-injured IEC-6, and to investigate the regulatory mechanisms of IL-2 on the injured IEC-6. METHODS: 4Gy-neutron-injured IEC-6 were treated by IL-2, with or without the blocking agent JAK(1) (A77-1726). The change of proliferative activity and death manner of the treated IEC-6 were detected by MTT colorimetry and flow cytometry at 10, 15, 30 minutes and 1, 3, 6, 12, 24, 48, 72 hours respectively. The expression of IL-2Rbeta and the activation of JAK(1) of neutron-injured IEC-6 treated by IL-2 were detected by immunocytochemical stainning and Western blot. RESULTS: After IEC-6 were radiated by 4 Gy neutron for 24 hours, the proliferative activity of IEC-6 decreased markedly but increased strikingly after IL-2 treatment (P<0.05). The apoptosis of IEC-6 in IL-2-treated group decreased (P<0.05), but there was no obvious difference in necrotic cell number. After neutron-injured IEC-6 were treated by IL-2, JAK(1) was activated at 10 and 15 minutes, and the expression of IL-2Rbeta increased apparently at 24 hours. When treated by JAK(1) and IL-2, the proliferative activity of neutron-injured IEC-6 was much lower than that in IL-2-treated group. CONCLUSION: IL-2 can accelerate the proliferation of neutron-radiated IEC-6 and protect them from neutron injury. IL-2Rbeta and JAK(1) participate in the regulation of neutron-injured IEC-6 by IL-2.