窄谱中波紫外线对角质形成细胞角蛋白17表达的影响

【摘要】 目的 探讨窄谱中波紫外线（NB-UVB）对角质形成细胞角蛋白17（K17）表达的影响。 方法 不同剂量NB-UVB照射角质形成细胞后，培养6、12、24 h，分别用CCK8法检测细胞增殖情况，实时PCR、Western印迹检测K17 mRNA和蛋白表达以及Erk1/2、磷酸化Erk1/2的表达水平。 结果 低剂量（50、100 mJ/cm2）NB-UVB照射可刺激角质形成细胞增殖和K17表达，而较高剂量（200、400 mJ/cm2）NB-UVB照射则抑制细胞增殖和K17表达，其差异有统计学意义（P < 0.05或0.01）。通过对NB-UVB照射后相关信号通路进行筛查，发现100 mJ/cm2 NB-UVB照射可以上调角质形成细胞Erk1/2的磷酸化水平，而400 mJ/cm2 NB-UVB照射后Erk1/2的磷酸化水平明显下降，阻断这一信号通路可以抑制低剂量NB-UVB对K17的上调。 结论 NB-UVB对K17表达的影响受Erk1/2通路的调控。

Effects of narrow-band ultraviolet B on the expression of keratin 17 in keratinocytes

Han Changxu, Dang Erle, Jin Liang, Li Bing, Zhang Nan, Wang Gang. Department of Dermatology, Xijing Hospital, Fourth Military Medical University, Xi'an 710032, China Corresponding author: Wang Gang, Email: xjwgang@fmmu.edu.cn 【Abstract】 Objective To investigate the effects of narrow-band ultraviolet B （NB-UVB） on the expression of keratin 17 （K17） in the human keratinocyte cell line HaCaT. Methods Cultured HaCaT cells were irradiated with different doses （0, 50, 100, 200, 400 mJ/cm2） of NB-UVB followed by additional culture for 6, 12 and 24 hours respectively. To explore the mechanisms underlying the effects of NB-UVB on K17 expression, some HaCaT cells were pretreated with PD98059 （an inhibitor of mitogen-activated protein kinase kinase） followed by UVB radiation and additional culture as described above. Cell counting kit-8 （CCK 8） was used to evaluate the proliferation of, real time PCR to measure the mRNA expressions of K17 in, and Western blot to determine the protein expression of K17, Erk1/2 and phosphorylated Erk1/2 in, HaCaT cells. Results Both the proliferation of and K17 expression in HaCaT cells were promoted by NB-UVB radiation at low doses （50, 100 mJ/cm2）, but inhibited by NB-UVB radiation at high doses （200, 400 mJ/cm2）. Significant differences were observed for the proliferative activity between HaCaT cells irradiated with NB-UVB at 100 or 400 mJ/cm2 and unirradiated HaCaT cells at 12 and 24 hours （P < 0.01 or 0.05）. The phosphorylation of Erk1/2 was upregulated by NB-UVB radiation at 100 mJ/cm2, but downregulated by that at 400 mJ/cm2, and the upregulation induced by low dose NB-UVB could be suppressed by blocking the Erk 1/2 pathway. Conclusion The effects of NB-UVB radiation on K17 expression may be modulated by the Erk 1/2 pathway.