HuR介导靶基因转录本3′末端非编码区多态性在鼻息肉发病中的调控作用及机理研究

Nasal polyps is reported to be final product of inammation response of the mucosa of the nose and paranasal sinuses. Lymphocytes, eosinophil and macrophages and associated cytokines participated in this inflammation. Recent studies have shown that tandem 3′UTRs produced by alternative polyadenylation (APA) play an important role in gene expression by impacting mRNA stability, translation, and translocation in immune cells , such as activated T lymphocytes, B lymphocytes and monocytes. The RNA-binding protein, HuR, binds to the AU-rich elements (AREs) of the 3′untranslated region (3′UTR) of certain mRNAs, resulting in an increased stability of these mRNAs with products that are involved in apoptosis and inflammation, mediates alternative polyadenylation events of target genes and regulates gene expression. Our preliminary data have demonstrated a widespread APA events and increased expression of HuR in patients with chronic rhinosinusitis with nasal polyps. We proposed that HuR might mediate the alternative 3’UTR pattern alteration of target genes and contribute to the pathogenesis of nasal polyp. This study, therefore, aim to explore the mechanism of 3’UTR pattern alteration associated with HuR using U937, THP-1 and BEAS-2B cell lines and molecular biological technology such as RNAi, PCR, RNA-Seq and RPA. This research will clarify the pathogenesis of nasal polyps from new visual and provide a novel therapy target.

鼻息肉是慢性炎性细胞介导的局部非特异性炎症反应终产物，淋巴细胞、巨噬细胞及粒细胞参与其中。近年发现基因可选择性多聚腺苷酸环化会导致mRNA的3′非编码区多态性，影响mRNA定位、代谢及翻译效率，在T、B细胞及单核巨噬细胞等免疫细胞中发挥调节作用。RNA结合蛋白HuR通过与3′末端元件结合，调节很多炎症及凋亡相关基因mRNA的稳定性，影响靶基因3′末端的可选择性多聚腺苷酸化，影响蛋白表达。我们前期实验发现鼻息肉组织广泛存在3′非编码区变化多态性调节及HuR蛋白高表达。我们假设HuR可能介导了基因3′末端可选择性多聚腺苷酸化并调控基因表达。我们采用RNAi、PCR、RPA、转录组测序等技术，利用单核细胞（U937）、巨噬细胞（THP-1）、气道上皮细胞（BEAS-2B）研究HuR介导靶基因3′非编码区变化在鼻息肉发生的影响及可能机制，为鼻息肉的有效治疗提供新理论和治疗新靶点。

项目背景：鼻息肉是慢性炎性细胞介导的局部非特异性炎症反应终产物，淋巴细胞、巨噬细胞及粒细胞参与其中。近年来研究多集中在鼻息肉发病中嗜酸性粒细胞的作用上面。il-4/il-13在嗜酸性鼻息肉组织中高表达。近年来发现基因可选择性多聚腺苷酸环化会导致mRNA的3′非编码区多态性，影响mRNA定位、代谢及翻译效率，在T、B细胞及单核巨噬细胞等免疫细胞中发挥调节作用。RNA结合蛋白HuR通过与3′末端元件结合，调节很多炎症及凋亡相关基因mRNA的稳定性，影响靶基因3′末端的可选择性多聚腺苷酸化，影响蛋白表达。研究内容：本研究分析了HuR介导的嗜酸性粒细胞趋化因子CCL26多态性及转录后调控在人鼻息肉来源上皮细胞中的作用。重要结果：研究发现HuR和CCL26在嗜酸性粒细胞中高表达；il-4可诱导HuR从核内向胞质穿梭并增加了CCL26转录本的稳定性；过表达及干扰HuR后CCL26表达发生改变；RNA免疫共沉淀及荧光素酶实验提示HuR与CCL26转录本3‘UTR发生作用。重要结论：HuR可通过与CCL26转录本mRNA3‘UTR发生相互作用而增加其稳定性，进而影响CCL26的表达。重要意义：’研究HuR介导靶基因3′非编码区变化在鼻息肉发生的影响及可能机制，为鼻息肉的有效治疗提供新理论和治疗新靶点。