目的

探究盘状红斑狼疮（DLE）中上皮基底细胞液化变性的本质，并评估与DLE密切相关的Th1 型细胞因子白细胞介素2（IL-2）、干扰素γ（IFN-γ）、肿瘤坏死因子α（TNF-α）在DLE 上皮基底细胞发生液化变性过程中所发挥的作用。

方法

收集2023年5月至2024年10月就诊于空军军医大学口腔医院口腔黏膜病科的DLE患者组织标本10例，通过免疫组织化学方法检测E-cadherin、vimentin、CK19、β1 integrin和nestin在DLE上皮组织中的表达变化，与5例正常口腔黏膜组织比较分析。分别采用20 ng/mL IL-2、IFN-γ、TNF-α处理体外培养的人口腔黏膜上皮细胞，通过实时荧光定量反转录聚合酶链反应（RT-PCR）检测E-cadherin、vimentin mRNA的表达，采用细胞免疫荧光法检测经处理的上皮细胞中E-cadherin、vimentin 蛋白的表达。免疫组化分析使用Image J软件测量DLE组与正常对照组平均光密度（MOD）值，采用独立样本t检验比较两组的MOD值。其余重复测量资料采用单因素方差分析。

结果

DLE 上皮基底细胞vimentin 表达上升，E-cadherin 表达下降，呈现出与上皮-间质转化（EMT）相似的特征。同时，DLE上皮组织中干细胞标志物CK19、β1 integrin和nestin的表达增加。体外细胞实验结果表明，DLE相关的Th1型细胞因子IL-2、IFN-γ和TNF-α均能够诱导口腔黏膜上皮细胞发生EMT，与未处理组相比，处理组的vimentin 表达量均上升，而E-cadherin 表达均下降，其中IL-2诱导EMT的作用最强。

结论

DLE上皮基底细胞液化变性是一种EMT样现象，Th1型细胞因子IL-2、IFN-γ和TNF-α可能是触发这一现象的重要因素。

Objective

To explore the mechanism of liquefactive degeneration of basal epithelial cells in discoid lupus erythematosus（DLE）and to evaluate the impact of Th1-type cytokines interleukin-2（IL-2），interferon-γ（IFN-γ），tumor necrosis factor-α（TNF-α）closely related to DLE in the process of liquefactive degeneration.

Methods

Tissue specimens from 10 patients with DLE who visited the Department of Oral Mucosal Diseases，Stomatological Hospital of Air Force Medical University from May 2023 to October 2024 were collected. The expression changes of E-cadherin，vimentin，CK19，β1 integrin，and nestin in the DLE epithelium were detected by immunohistochemistry and compared with those in 5 normal oral mucosa tissues.Human oral mucosal epithelial cells were treated with 20 ng/mL IL-2，IFN-γ，and TNF-α in vitro. The expression of E-cadherin and vimentin mRNA was detected by realtime fluorescence quantitative polymerase chain reaction（RT-PCR），and the expression of E-cadherin and vimentin proteins in the treated epithelial cells was detected by cell immunofluorescence. The mean optical density（MOD）values of the DLE group and the normal control group were measured by Image J in immunohistochemical analysis. Independent sample t-test or Wilcoxon rank sum test was used to compare the MOD values between the two groups.One-Way ANOVA was used for repeated measurement data，and Tukey's method or Games-Howell method was used for pairwise comparisons within groups.

Results

Immunohistochemical staining showed that the MOD value of E-cadherin in the DLE group（0.156 ±0.006）was statistically lower than that in the normal control group（0.321±0.025；t=19.034，P=0.004）.The MOD value of vimentin in the DLE group was significantly higher than that in the normal control group（t=-49.875，P＜0.001）. The MOD value of nestin in the DLE group was higher than that in the normal control group（t=-17.79，P＜0.001）. The DLE group tended to express more CK19 and β1 integrin，but the difference was not statistically significant compared with the normal control group（P＞0.05）.RT-PCR results showed that the E-cadherin mRNA levels in the IL-2，IFN-γ，and TNF-α treatment groups were all decreased compared with the control group，and the differences in the IL-2 and TNF-α groups were statistically significant（q_IL-2group=12.350，P_IL-2group＜0.001；q_TNF-αgroup=6.416，P_TNF-αgroup=0.008）. Further pairwise comparisons revealed that the E-cadherin mRNA expression in the IL-2 group was lower than that in the IFN-γ and TNF-α groups，and the differences were statistically significant（qI_{L-2groupvs.IFN-γgroup}=9.576，P_{IL-2groupvs.IFN-γgroup}＜0.001；q_{IL-2groupvs.TNF-αgroup}=5.930，P_{IL-2groupvs.TNF-αgroup}=0.013）.The vimentin mRNA levels in each treatment group showed an upward trend，especially in the IL-2 group. Compared with the control group，the difference was statistically significant（q_IL-2group=115.6，P_IL-2group＜0.001），and the expression level of vimentin mRNA in the IL-2 group was higher than that in the IFN-γ and TNF-α groups，with statistically significant differences（q_{IL-2groupvs.IFN-γgroup}=115.6，P_{IL-2groupvs.IFN-γgroup}＜0.001；q_{IL-2groupvs.TNF-αgroup}=115.5，P_{IL-2groupvs.TNF-αgroup}＜0.001）. The results of cell immunofluorescence detection showed that the expression levels of E-cadherin protein in oral mucosal epithelial cells in the IL-2，IFN-γ，and TNF-α treatment groups decreased，and the differences compared with the control group were statistically significant（q_IL-2group=16.67，P_IL-2group＜0.001；q_IFN-γgroup=16.65，P_IFN-γgroup＜0.001；q_TNF-αgroup=16.63，P_TNF-αgroup＜0.001）. The expression levels of vimentin protein in oral mucosal epithelial cells in the three treatment groups increased，and the differences compared with the control group were statistically significant（q_IL-2group=28.06，P_IL-2group＜0.001；q_IFN-γgroup=21.24，P_IFN-γgroup＜0.001；q_TNF-αgroup=19.72，P_TNF-αgroup＜0.001），and the expression level of vimentin protein in the IL-2 group was higher than that in the IFN-γ and TNF-α groups，with statistically significant differences（q_IFN-γgroup=8.340，P_IFN-γgroup=0.002；q_TNF-αgroup=6.820，P_TNF-αgroup=0.006）.

Conclusions

The liquefaction degeneration of epidermal basal cells in DLE manifested features resembling the epithelial-mesenchymal transition（EMT）phenomenon，and Th1-type cytokines such as IL-2，IFN-γ and TNF-α may be significant factors that triggered this process.