芳香烃受体在特应性皮炎患者外周血及皮损组织中的表达及意义

Expression and clinical significance of aryl hydrocarbon receptor in peripheral blood and skin lesions of patients with atopic dermatitis

目的检测特应性皮炎(AD)患者外周血单个核细胞(PBMC)及血清中芳香烃受体(AhR)及其下游分子的表达水平,并分析其表达与AD患者疾病严重程度与血清中细胞因子的相关性。方法采用实时PCR检测29例AD患者及17例健康对照PBMC中AhR、细胞色素P4501A(CYP1A1)、芳香烃受体抑制因子(AHRR)和芳香烃受体核转位蛋白(ARNT)mRNA表达水平,酶联免疫吸附试验(ELISA)检测AD患者血清中白细胞介素(IL)-1β、IL-6、肿瘤坏死因子(TNF)-α、IL-4、IL-22和AhR的表达水平,免疫组化检测AD患者皮损和色素痣患者(21例)的正常皮肤中AhR的表达水平。计量资料比较采用非配对Student′s t检验,计数资料采用χ^2检验比较,Pearson检验分析各指标间的相关性。结果AD组血清AhR水平(41.26±4.52)pmol/L高于健康对照组[(33.73±2.49)pmol/L,t=6.507,P<0.001]。AD患者PBMC中AhR mRNA(1.572±0.392比1.000±0.173,t=6.819,P=0.007)、AHRR mRNA(2.402±1.716比1.000±0.788,t=3.722,P=0.039)、CYP1A1 mRNA(2.258±1.598比1.000±0.796,t=3.400,P=0.002)和ARNT mRNA(1.383±0.842比1.000±0.586,t=1.653,P=0.105)相对表达量均显著高于健康对照组。AD组皮损组织中AhR的表达量高于正常皮肤对照组(0.191±0.041比0.087±0.017,t=10.036,P<0.001)。AD组PBMC中AhR mRNA表达与湿疹面积及严重程度指数呈正相关(r=0.448,P=0.019),与血清IL-6水平呈正相关(r=0.377,P=0.046),AHRR mRNA与血清IL-1β水平呈正相关(r=0.467,P=0.021)。结论AD患者AhR及其下游分子的表达高于健康对照组,且AhR表达与血清IL-6水平和严重程度呈正相关,推测AhR信号通路在AD发病机制中发挥一定作用,AhR可作为评价疾病严重程度的有效指标。

Objective To detect levels of aryl hydrocarbon receptor(AhR)and its downstream molecules in peripheral blood mononuclear cells(PBMCs)and sera from patients with atopic dermatitis(AD),and to analyze the correlation of their expression with serum cytokines and the severity of AD.Methods Real-time quantitative PCR(RT-PCR)was performed to analyze mRNA expression of AhR,cytochrome P4501A(CYP1A1),AhR repressor(AHRR),AhR nuclear translocator(ARNT)in PBMCs from 29 AD patients and 17 healthy controls,enzyme-linked immunosorbent assay(ELISA)to detect serum levels of interleukin(IL)-1β,IL-6,tumor necrosis factor(TNF)-α,IL-4,IL-22 and AhR in the AD patients,and immunohistochemical study to determine AhR expression in skin lesions of the AD patients and normal skin tissues of 21 patients with pigmented nevus.Measurement data were compared by using unpaired Student′s t test,enumeration data were compared by using chi-square test,and correlations between indices were analyzed by using Pearson correlation analysis.Results The serum level of AhR was significantly higher in the AD group(41.26±4.52 pmol/L)than in the healthy control group(33.73±2.49 pmol/L,t=6.507,P<0.001).Compared with the healthy control group,the AD group showed significantly increased mRNA expression of AhR(1.572±0.392 vs.1.000±0.173,t=6.819,P=0.007),AHRR(2.402±1.716 vs.1.000±0.788,t=3.722,P=0.039),CYP1A1(2.258±1.598 vs.1.000±0.796,t=3.400,P=0.002)and ARNT(1.383±0.842 vs.1.000±0.586,t=1.653,P=0.105)in PBMCs.The AhR expression in skin lesions in the AD group was significantly higher than that in normal skin tissues in the control group(0.191±0.041 vs.0.087±0.017,t=10.036,P<0.001).In the AD group,the mRNA expression of AhR in PBMCs was positively correlated with eczema area and severity index score(r=0.448,P=0.019)and the serum IL-6 level(r=0.377,P=0.046),and the AHRR mRNA expression was positively correlated with the serum IL-1βlevel(r=0.467,P=0.021).Conclusion AhR and its downstream molecules were highly expressed in the AD patients compared with healthy controls,and the AhR expression was positively correlated with the serum IL-6 level and AD severity in AD patients,suggesting that the AhR signaling pathway may play a certain role in pathogenesis of AD and AhR may serve as an efficient index for evaluating AD severity.