动态分析系统性红斑狼疮血清α2,6唾液酸化糖蛋白糖基化修饰及意义

Systemic lupus erythematosus (SLE), which pathogenesis is not yet entirely clear, is a common autoimmune disease that involves immune system disorders. Glycosylation is one of the most important and usual protein post-translational modifications and have great influence on both inate and acquired immunity, such as immune cells differentiation, development and immunoregulation. Glycan profiling of serum glycoprotein of SLE patients during various courses has not been reported yet. A hypothesis that there are specific glycan profiles changes according to the activity of SLE and might be correlated to pathogenesis and treatment of SLE was proposed on the basis of our previous research. In this subject, we prepare to build differential glycan profiles of various course of SLE by lectin microarray technology using serum samples, Then α2,6 sialylated glycoprotein was selected as a starting point based on our previous work, which will be screened and validated by iTRAQ. At last, glycosylation and carbohydrate chains of differentially expressed glycoproteins will be analysised using mass spectrometry techniques. Our research would contribute to the staging biomarker of SLE activity, and provide new theoretical basis and experimental foundation for pathogenesis and treatment research of SLE.

系统性红斑狼疮（SLE）是一种常见自身免疫病，发病机制涉及免疫功能紊乱，具体尚未明确。蛋白质糖基化修饰对机体天然和获得性免疫，包括免疫细胞分化、发育及免疫功能调节等均有重要影响。SLE病程中血清糖蛋白聚糖表达差异及其对功能影响目前尚未见报道。本项目在前期研究基础上提出“SLE在不同疾病活动期存在糖蛋白糖基化修饰特征性改变且可能与发病机制和治疗相关”假说，并拟以SLE不同活动期血清标本为研究对象，运用凝集素芯片技术构建SLE不同活动期特征性血清糖蛋白糖谱，并根据前期实验结果选择α2,6唾液酸化糖蛋白为切入点，运用iTRAQ质谱技术建立SLE不同阶段差异糖蛋白表达谱，筛选其中功能性差异蛋白进行糖基化位点研究及聚糖结构解析，分析其对免疫机制的影响。本项目首先探讨以特征性血清糖蛋白糖谱作为SLE疾病活动度分期生物学标志，其次对差异表达糖蛋白的糖基化修饰研究为SLE机制研究和靶向治疗策略提供新的思路。

系统性红斑狼疮（SLE）是一种常见自身免疫病，发病机制涉及免疫功能紊乱，具体尚未明确。每种自身免疫性疾病均表达独特的糖基化修饰谱。前期的研究结果提示：SLE病程中的血清低丰度蛋白糖基化表达谱的异常可能参与SLE疾病的进程。据此提出“SLE在不同疾病活动期存在糖蛋白糖基化修饰特征性改变且可能与发病机制和治疗相关”假说。本项目首先构建了高通量凝集素芯片检测体系，筛选了SLE血清低丰度蛋白糖基化表达谱，结果提示，SLE在不同的疾病进程具有特征性的糖基化表达谱。采用特异性凝集素印迹对凝集素芯片筛选的结果进行验证，发现LCA、PSA结合聚糖在初发SLE患者血清58kDa低丰度蛋白表达存在显著异常。进一步采用LC-MS/MS分析58kDa低丰度蛋白成分及对其糖链成分进行解析。同时，差异表达蛋白质生物信息学分析显示初发SLE患者与非初发SLE患者在蛋白分子组成、分子生物学功能、参与信号通路及蛋白互作关系上存在显著差异。结果提示，SLE患者血清58kDa低丰度蛋白在SLE疾病进程起到关键作用。本研究通过阐明SLE血清低丰度蛋白的糖基化表达谱及对差异表达糖蛋白生物信息学分析，探索以糖组学为发病机制及治疗潜在靶点的SLE诊疗新思路。