Abstract：
Idiopathic membranous nephropathy (IMN) is an antibody-mediated and kidney-specific autoimmune disease, with the antigen phospholipase A2 receptor 1 (PLA2R1) accounting for approximately 70% of IMN cases. Although a variety of new podocyte target antigens and their autoantibodies have been identified, they are still of limited diagnostic and therapeutic value due to lack of high specificity and sensitivity. N-glycans play vital roles in renal system and their pathobiological relevance has become increasingly recognized in many kidney diseases, but not fully explored in IMN. To find possible glyco-signatures for PLA2R1-related IMN diagnosis, we herein established a comprehensive workflow for total serum N-glycome analysis based on our recently developed mass spectrometry (MS)-based N-glycan purification method, named Ultrafast Glycoprotein Immobilization for Glycan extraction (UltraGIG). A total of 191 N-glycans were identified from IMN patients, representing the largest N-glycome dataset in IMN. Compared to healthy controls, up-regulation of sialylation and core-fucosylation as well as down-regulation of galactosylation were observed in PLA2R1-positive IMN patients, and up-regulation of hyper-galactosylation was specific for PLA2R1-negative IMN patients. A six-glycan marker panel consisting of H4N3S1, H4N3F1, H6N4S2, H6H5F1S2, H6N5 and H6N6F1S1, was proposed to aid in the accurate diagnosis of PLA2R1-related IMN, which provided new insights into IMN biomarker study. SIGNIFICANCE: PLA2R1-related IMN is a kidney-specific autoimmune disease with a high risk of developing end-stage renal disease (ESRD) and even kidney failure. Current biomarkers are still of limited diagnostic and therapeutic value due to lack of high specificity and sensitivity. An in-depth MS analysis of total serum N-glycome of PLA2R1-related IMN patients was conducted for the first time. We generated the largest dataset of serum N-glycome for IMN to date, and proposed a novel six-glycan marker panel that may help the accurate diagnosis of PLA2R1-related IMN.
摘要：
特发性膜性肾病（IMN）是一种抗体介导的肾脏特异性自身免疫性疾病，与抗原磷脂酶A2受体1（PLA2R1）约占IMN病例的70％。尽管已经鉴定出多种新的足细胞靶抗原及其自身抗体,由于缺乏高特异性和敏感性,它们的诊断和治疗价值仍然有限.N-聚糖在肾脏系统中起着至关重要的作用，其病理生物学相关性在许多肾脏疾病中得到了越来越多的认识。但在IMN中没有充分探索。为了找到PLA2R1相关IMN诊断的可能的糖特征，本文基于我们最近开发的基于质谱（MS）的N-聚糖纯化方法，建立了全面的血清N-聚糖分析工作流程，命名为超快糖蛋白固定化聚糖提取（UltraGIG）。从IMN患者中鉴定出总共191个N-聚糖，表示IMN中最大的N-glycome数据集。与健康对照相比，在PLA2R1阳性IMN患者中观察到唾液酸化和核心岩藻糖基化的上调以及半乳糖基化的下调，高半乳糖基化的上调对PLA2R1阴性IMN患者具有特异性。提出了由H4N3S1，H4N3F1，H6N4S2，H6H5F1S2，H6N5和H6N6F1S1组成的六聚糖标记物组，以帮助准确诊断PLA2R1相关的IMN，这为IMN生物标志物研究提供了新的见解。意义：PLA2R1相关的IMN是一种肾脏特异性自身免疫性疾病，具有发展为终末期肾病（ESRD）甚至肾衰竭的高风险。由于缺乏高特异性和敏感性,目前的生物标志物仍然具有有限的诊断和治疗价值。首次对PLA2R1相关IMN患者的总血清N糖进行了深入的MS分析。迄今为止，我们为IMN生成了最大的血清N-glycome数据集，并提出了一个新的六聚糖标记组，可能有助于PLA2R1相关IMN的准确诊断。
