目的：研究银屑病患者外周血单个核细胞（peripheral blood mononuclear cell,PBMC）内转录因子AP1家族中Fos家族中Fra2的表达情况,通过生物信息学分析银屑病中Fra2可能参与调节的下游基因,并通过双荧光素酶报告实验验证,初步探讨其在疾病中的发病机制。方法：采用实时定量PCR检测21例银屑病患者及30名健康者对照外周血中Fra2的表达水平;在基因转录调节数据库上预测Fra2的靶基因,并与GeneCards上银屑病相关基因交集分析,采用DAVID（The Database for Annotation, Visualization and Integrated Discovery）数据库查找靶基因本体功能分类和KEGG富集分析;用实时定量PCR验证Fra2可能参与调控的基因;R语言调用JASPAR 2018软件包预测Fra2结合位点;双荧光素酶报告实验验证Fra2对白细胞介素23受体（interleukin 23receptor, IL-23R）的调控关系。结果： 21例银屑病患者PBMC中Fra2的mRNA表达水平（0.711±0.072）显著低于健康人群（1.070±0.086）（P=0.004 2）;生物信息学分析显示,炎症反应和细胞因子-细胞因子受体互作是富集程度最为显著的条目（P=5.2×10-71;P=7.0×10-45）;实时定量PCR检测显示,IL-23R的mRNA表达水平显著高于健康人群（P=0.000 1）,且与Fra2表达水平呈显著负相关（r=-0.509 5,P=0.018 3）;用R语言调用JASPAR在启动子区域预测了Fra2的结合位点,双荧光素酶报告实验发现,Fra2调控了IL-23R的表达。结论：Fra2/AP1作为重要的转录因子,可能通过调节IL-23R的表达参与了银屑病的发生和发展。
Objective: To study the expression of Fra2, a member of Fos family of transcription factor AP1 family, in peripheral blood mononuclear cells (PBMC) of psoriatic patients, and to analyze the potential genes regulated by Fra2 via bioinformatics and confirmed by dual-luciferase reporter assay for investigating the role of Fra2 in the pathogenesis of psoriasis. Methods: The expression of Fra2 in 21 patients with psoriasis and 30 healthy controls were detected by quantitative real-time-PCR（qrt-RCR）. The target genes of Fra2 were predicted by gene transcription regulation Database (GTRD), and were intersected with psoriasis-related gene in GeneCards. The function classification of Gene Ontology (GO)and KEGG enrichment analysis were adopted by DAVID (The Database for Annotation, Visualization and Integrated Discovery); the potential genes regulated by Fra2 were verified by qrt -PCR; the binding sites of Fra2 were predicted by JASPAR package in R Programming Language;the relationship between Fra2 and IL23 receptor(IL23R) was verified by Dual-luciferase report assay. Results: The expression of Fra2 mRNA in PBMC of 21 patients with psoriasis (0.711±0.072) was significantly lower than that in healthy controls (1.070±0.086) (P=0.004 2). Bioinformatics analysis showed that inflammatory response and cytokine-cytokine receptor interaction was the most significant items(P=5.2×10-71; P=7.0×10-45). qrt-PCR found that the mRNA expression level of IL23R was significantly higher than healthy controls (P=0.000 1), and was correlated with Fra2 expression level(r=-0.509 5, P=0.018 3); the regulating effect of Fra2 on IL23R was verified by Dual-luciferase report assay. Conclusions: Fra2 is an important transcription factor involved in the development and progress of psoriasis by regulating the expression of IL23R.
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