ORAI1/CRACM1基因CDS区功能性SNP在慢性荨麻疹发病中的分子机制研究

Chronic urticaria is a common disease and mast cell is central to its pathogenesis. It has been reported that Ca2+ release-activated calcium (CRAC) channel plays an important role in mediating mast cell activation and its functional effect. We obtained the candidate single nucleotide polymorphism(SNP) by combing the public databases and bioinformatics methods. Using Sequenom MassARRAY system, our group discovered for the first time the significant association between a functional SNP which is located on the coding region of ORAI1/CRACM1 gene and chronic urticaria susceptibility. According to our preliminary functional studies, we proposed the hypothesis about molecular mechanisms that ORAI1/CRACM1 gene increases the susceptibility to chronic urticaria. In the current investigation, the applicant aims to validate this new correlation functionally. At the same time, we will focus on the CRAC channel activity and functional effects of mast cells. By using patch clamp, flow cytometry and molecular biological techniques such as Co-immunoprecipitation(Co-IP) and Electrophoretic Mobility Shift Assay (EMSA), together with transcription factor array and pathway array, we are expecting to elucidate the molecular pathogenesis of chronic urticaria deeply. Our research of this mechanism not only can open up a new entry point to the pathogenesis of chronic urticaria, but also provide a useful exploration of a new target to both chronic urticaria and other allergic disease at the molecular levels.

慢性荨麻疹是常见的过敏性疾病，肥大细胞是其发病的中心环节，而CRAC通道在介导肥大细胞活化和功能中起着至关重要的作用。本项目组在前期运用公共数据库和生物信息学方法获取的候选SNPs中，采用基于MassARRAY分子量阵列平台的基因分型和外显子测序技术，首次发现了CRAC通道核心分子Orai1编码基因CDS区的SNP与慢性自发性荨麻疹的易感性存在关联。经独立样本人群重复验证、并经初步的功能学研究，提出了ORAI1基因致慢性荨麻疹易感性增加的分子机制假说。本研究中，申请者欲从功能学层面深入阐述这一新的关联机制，以CRAC通道活性和肥大细胞功能效应为主线，以膜片钳、荧光光谱、免疫共沉淀等为主要手段，结合转录因子和信号通路芯片分析，以期最大限度地挖掘并阐述其分子机制。对该机制的研究，不仅可以为揭示慢性荨麻疹的发生机理开辟一个新的切入点，更为最终识别出有潜在临床应用价值的生物学靶标提供有益的前期探索

揭示了ORAI1基因多态性与慢性自发性荨麻疹的关系。发现ORAI1在慢性自发性荨麻疹患者显著增高，ORAI1能够作用肥大细胞脱颗影响疾病发生发展，同时发现其基因多态性位点能够影响ORAI1的表达。二代抗组胺药是皮肤科临床使用最常见的药物，其治疗疗效与不良反应千差万别，由于缺乏有效的评价方法，临床上无法进行精准施治。基因多态性是决定药物的有效性和安全性的关键因素，本项目通过病例（2000例慢性自发性荨麻疹患者）-对照研究，发现了ORAI1、FCER1A、C5AR1以及CRP等基因的多态性位点与二代抗组胺药治疗疗效密切相关；发现FCER1A、HRH1基因位点与药物不良反应密切相关，其中FCER1A基因位点多态性被英国《药物副作用年鉴》收录，用于指导临床用药。首次报道腺苷代谢与慢性荨麻疹密切相关，揭示腺苷能够作为慢性荨麻疹严重程度与治疗疗效评估的重要分子标志物。在该项目资助下共发表SCI收录的研究论文8篇，其中包括JACI（IF=14.11）、Allergy（IF=8.706）等顶级皮肤科期刊，获得国家发明专利1项，为慢性荨麻疹的精准治疗奠定了坚实的基础。