X射线及UVB对人表皮细胞细胞增殖及褪黑素受体表达的影响

Effects of X-ray and UVB for proliferation and the expression of melatonin receptor of human epidermal cells

目的:研究X射线和紫外线B(UVB)对表皮细胞增殖的影响,以及对褪黑素受体(MTNR)蛋白表达的影响,为生活在高海拔地区可能受到较高电离和非电离辐射的公众辐射效应及其防护提供指导。方法:经照射剂量为0 Gy(对照组)、0.5 Gy、2 Gy和5 Gy(照射组)X射线以及0 m J/cm2、20 m J/cm2、50 m J/cm2、100 m J/cm2和200 m J/cm2的UVB分别照射人表皮细胞Hacat和人黑色素瘤细胞A875,通过四甲基偶氮唑(MTT)和克隆形成率实验检测细胞增殖能力变化,采用蛋白质印迹法检测褪黑素受体MTNR-1B蛋白表达变化。结果:在照射剂量为0.5 Gy、2 Gy和5 Gy的X射线以及20 m J/cm2和50 m J/cm2UVB的照射下,可导致Hacat和A875细胞生长不同程度的降低。3种不同剂量X射线照射后Hacat细胞克隆形成率分别为对照组的71.2%、36.7%和16.3%,与对照组比较差异有统计学意义(F=249.96,P<0.05),A875细胞细胞克隆形成率分别为对照组的64.7%、49.5%和31.6%,与对照组比较差异有统计学意义(F=147.29,P<0.05);在照射剂量为20 m J/cm2和50 m J/cm2的UVB照射后Hacat细胞的克隆形成率分别为对照组的40.74%和12.96%,A875细胞的克隆形成率分别为对照组的16.33%和6.12%;50 m J/cm、100 m J/cm和200 m J/cm2的UVB照射后A875细胞中MTNR1B表达随着剂量的增大而显著增加,而3种不同剂量X射线对MTNR1B表达在不同剂量之间无显著影响。结论:X射线和UVB照射后均可引起细胞增殖和存活能力的降低,UVB照射后引起的细胞增殖抑制可能与褪黑素受体表达变化相关。

Objective： To explore the effects of X-rays and ultraviolet B （UVB） for the proliferation of human epidermal cells and the expression of melatonin receptor in human epidermal cells. This study can provide guidance about radiation effect and how to protect the public who may suffered higher ionization and non-ionizing radiation in high altitude region. Methods： Human epidermal cells （Hacat） and human melanoma cell lines A875 were irradiated with X-ray of different doses （0, 0.5, 2 and 5 Gy） and UVB of different doses （20, 50, 100 and 200 mJ/cm^2）, respectively. The change of cell proliferative capacity was detected by using methyl thiazolyl tetrazolium （MTT） and cloning efficiency experiment, and the change about expression of melatonin receptor （MTNR-1B） was detected by using western blot. Results： Cell proliferative capacity of Hacat and A875 were decreased in various degrees when they exposed in X-ray of different doses （0.5, 2 and 5 Gy） and ultraviolet B of different dose （20, 50 mJ/cm^2）. For Hacat cells, the cloning efficiencies of them in observation group after were irradiated by using X-ray of 3 kinds of doses were 71.2%, 36.7% and 16.3% of that in control group, and the differences between the two group were statistically significant （F=249.96, P〈0.05）, respectively. While for A875 cells, the cloning efficiencies of them in observation group were 64.7%, 49.5% and 31.6% of that in control group at the same 3 kinds of doses, and the differences between the two group also were statistically significant （F=147.29, P〈0.05）, respectively. On the other hand, after Hacat cells were radiated by using UVB of different doses （20 and 50 mJ/cm^2）, the cloning efficiencies of them in observation group were 40.74% and 12.96% of that in control group, respectively. And for A875 cell, they were 16.33% and 6.12% of that in control group at the same condition of dose, respectively. In addition, after Hacat cells were radiated by using UVB of 50 mJ/cm^2, 100 mJ/cm^2 and 200 mJ/cm^2, respectively, the results revealed that expression of MTNR1B was significantly increased with the enhancing of dose, while the X-ray of 3 kinds of doses were no significant effect for the expression of MTNR1B. Conclusion： Both of X-ray irradiation and UVB irradiation can cause the reductions of the capacities of proliferation and survival, and the inhibition of cell proliferation might be relative with the change of expression of melatonin receptor after UVB radiates cell.