特应性皮炎患者外周血和皮损miR-155的表达及其与Th17细胞相关性研究

Expression of miR-155 in peripheral blood and skin lesions from as well as its relationship with Th17 cells in patients with atopic dermatitis

目的探讨特应性皮炎（AD）患者外周血与皮损组织中miR-155、Th17细胞、Th17细胞特异性转录因子RORγt及效应性细胞因子IL-17的表达及其相关性。方法用实时荧光定量RT—PCR检测37例AD患者外周血单-核细胞（PBMC）中miR-155、RORγt及IL-17的mRNA表达水平，流式细胞仪检测11117细胞比例，酶联免疫吸附试验（ELISA）检测血浆中IL-17的含量；并以33例性别、年龄匹配的健康儿童做对照。检测5例重度AD患者皮损与皮损周围组织中miR-155、RORγt及IL-17mRNA的表达水平，并以5例正常皮肤组织标本为对照。结果AD患者PBMC中miR-155、RORγt及IL-17的mRNA表达水平均明显高于健康对照（分别为5．78±1．78比1．82±0．46，6．08±1．04比1．64±0．52，7．09±1．75比1．71±0．46，均P〈0．01）；AD患者PBMC中Thl7细胞比例及IL-17血浆含量均明显高于健康对照，分别为（1．78±0．52）％比（0．47±0．15）％，（32．51±6．15）pg／ml比（11．80±2．24）pg／ml，均P〈0．01。AD患者皮损、皮损周围组织及正常皮肤组织中miR-155、RORγt及IL-17mRNA表达水平间比较，差异均具有统计学意义；皮损〉皮损周围组织〉正常皮肤组织，F值分别为41．803、17．040和37．064，均P〈0．01。AD患者PBMC中miR-155mRNA表达水平与疾病严重程度评分、Th17细胞比例、RORγtmRNA表达水平、IL-17mRNA表达水平及IL-17血浆含量呈正相关，r值分别为0．405、0．426、0．402、0．410、0．408，均P〈0．05；皮损及皮损周围组织中miR-155mRNA表达水平与RORγt、IL-17的mRNA表达水平呈正相关，r值分别为0．428和0．435，均P〈0．05。结论AD患者miR-155、Th17细胞及其效应性细胞因子高表达可能与AD发病有关。

Objective To detect the expressions of miR-155, T helper type 17 （Thl7） cells, and Th17 cell- specific transcription factor ROR＇yt and effector cytokine interleukin （IL）-17 in peripheral blood and skin lesions from, and to evaluate their relationship in, patients with atopic dermatitis （AD）. Methods Peripheral blood was obtained from 37 patients with AD and 33 age- and sex-matched healthy controls, and biopsy specimens from the lesional and perilesional skin of five patients with severe AD as well as from the normal skin of five healthy human controls. Real-time fluorescence-based reverse transcription （RT）-PCR was employed to measure the mRNA expression levels of miR-155, RORγt and IL-17 in peripheral blood mononuclear cells （PBMCs） and skin specimens, flow cytometry to detect the percentage of Thl7 cells in PBMCs, enzyme-linked immunosorbent assay （ELISA） to determine the plasma concentration of IL-17. Statistical analysis was done using independent sample＇s t test, one-way analysis of variance followed by the least significant difference test, and linear correlation analysis. Results Compared with the healthy controls, the patients with AD showed a significant increase in Th17 cell percentage （1.78% ± 0.52% vs. 0.47% ± 0.15%, P〈 0.01）, mRNA expression levels of miR-155 （5.78 ± 1.78 vs. 1.82 ± 0.46, P〈 0.01）, RORγt （6.08 ± 1.04 vs. 1.64 ± 0.52, P〈 0.01） and IL-17 （7.09 ± 1.75 vs. 1.71 ± 0.46, P〈 0.01）, as well as in the plasma concentration of IL-17 （（2.51 ± 6.15） pg/ml vs. （11.80 ± 2.24） pg/ml, P〈 0.01 ）. There was a sequential decrease in the expression levels of miR-155, RORγt and IL-17 mRNA from lesional skin, perilesional skin to normal skin （F = 41.803, 17.040 and 37.064 respectively, all P 〈 0.01 ）. The miR-155 mRNA expression level in PBMCs was positively correlated with the SCORing Atopic Dermatitis （SCORAD） index,Th17 cell percentage, RORγt and IL-17 mRNA expression levels as well as IL-17 plasma concentration （r = 0.405, 0.426, 0.402, 0.410 and 0.408 respectively, all P 〈 0.05）. Similarly, the miR-155 expression level was positively correlated with RORγt and IL-17 mRNA expression levels in lesional and paralesional specimens （r = 0.428 and 0.435 respectively, both P 〈 0.05）. Conehmion The up-regulated expression of miR-155, Thl7 cells and their effeetor cytokine IL-17 may be associated with the development of AD.