磷酸化MEK／ERK／核因子κB在寻常性银屑病皮损中高表达

High expression of phosphorylated MEK/ERK/NF-κB in lesions of psoriasis vulgaris

目的探讨MAPK信号转导通路中磷酸化MEK和ERK及核因子（NF）-κB在寻常性银屑病发病中的作用。方法采用免疫组化和Western印迹法检测30例寻常性银屑病皮损及15例正常人表皮中磷酸化MEK、ERK和NF—κB的表达，并利用计算机图像采集与分析系统对免疫组化结果进行平均吸光度（A值）测定，并对免疫印迹测定结果进行灰度扫描、统计学处理。结果免疫组化检测显示，寻常性银屑病皮损中磷酸化MEK、ERK和NF—κB的表达（A值分别为0．36±0．03、0．36±0．04和0．26±0．04）明显高于正常人皮肤（A值分别为0．22±0．02、0．18±0．03和0．16±0．03），两组比较，P值均〈0．01。Western印迹结果（两组比较，P值均〈0．01）与免疫组化检测一致。结论寻常性银屑病皮损中磷酸化MEK、ERK和NF-κB表达水平均增高，MAPK信号通路中上下游分子的异常激活可能参与了银屑病的发病。

Objective To investigate the role of phosphorylated extracellular signal-regulated kinase （p-ERK）, mitogen-activated protein kinase （MAPK）/ERK kinase （MEK）, and nuclear faetor-κB （NF-κB） in the pathogenesis of psoriasis vulgaris. Methods Immunohistochemistry and Western blot were used to detect the expression of p-MEK, p-ERK and p-NF-κB in tissue samples from 30 patients with psoriasis vulgaris and 15 normal human controls. The average optical density of immunostaining and relative grey scale of immuno- bloting were caleulated. Results Tile average optical density o（ immunostaining for p-MEK, p-ERK and p-NF-κB was 0.36 ± 0.03. 0.36 ± 0.04 and 0.26 ± 0.04, respectively in lesion samples of psoriasis, significantly higher than that in normal control tissue （0.22 ± 0.02, 0.18 ± 0.03 and 0. 16 ± 0.03, all P 〈 0.01 ）. A significant increase was also observed in the relative grey scale of p-MEK, p-ERK and p-NF-κB in psoriatic lesions compared with the nollnal controls （1.41 ± 0.14 vs 0.54 ± 0.10, 2.35 ± 0.34 vs 1.86 v 0.12, 1.07 ± 0.15 vs 0.87 ± 0.08, all P 〈 0.01 ）. Conclusions The expressions of p-MEK, p-ERK and p-NF-κB are enhanced in lesions of psoriasis vulgaris, and the abnormal activation of upstream and downstream molecules in the MAPK signaling pathways might be involved in the pathogenesis of psoriasis.