DataSheet_1_Glycoproteoform Profiles of Individual Patients’ Plasma Alpha-1-Antichymotrypsin are Unique and Extensively Remodeled Following a Septic Episode.xlsx

Sepsis and septic shock remain the leading causes of death in intensive care units (ICUs), yet the pathogenesis originating from the inflammatory response during sepsis remains ambiguous. Acute-phase proteins are typically highly glycosylated, and the nature of the glycans have been linked to the incidence and severity of such inflammatory responses. To further build upon these findings we here monitored, the longitudinal changes in the plasma proteome and, in molecular detail, glycoproteoform profiles of alpha-1-antichymotrypsin (AACT) extracted from plasma of ten individual septic patients. For each patient we included four different time-points, including post-operative (before sepsis) and following discharge from the ICU. We isolated AACT from plasma depleted for albumin, IgG and serotransferrin and used high-resolution native mass spectrometry to qualitatively and quantitatively monitor the multifaceted glycan microheterogeneity of desialylated AACT, which allowed us to monitor how changes in the glycoproteoform profiles reflected the patient’s physiological state. Although we observed a general trend in the remodeling of the AACT glycoproteoform profiles, e.g. increased fucosylation and branching/LacNAc elongation, each patient exhibited unique features and responses, providing a resilient proof-of-concept for the importance of personalized longitudinal glycoproteoform profiling. Importantly, we observed that the AACT glycoproteoform changes induced by sepsis did not readily subside after discharge from ICU.

脓毒症（Sepsis）与脓毒性休克（septic shock）仍是重症监护病房（Intensive Care Unit, ICU）患者死亡的首要致死原因，然而脓毒症进程中由炎症反应介导的发病机制仍未明确。急性期蛋白（acute-phase proteins）通常具有高度糖基化修饰，其聚糖的结构特征与这类炎症反应的发生率及严重程度密切相关。为进一步拓展上述研究成果，本研究对10名脓毒症患者的血浆蛋白质组进行纵向监测，并从分子层面详细分析了从其血浆中提取的α1-抗糜蛋白酶（alpha-1-antichymotrypsin, AACT）的糖蛋白亚型谱。每名患者均采集4个不同时间点的样本，涵盖术后（脓毒症发作前）以及ICU出院后的时间点。本研究从去除了白蛋白、免疫球蛋白G（Immunoglobulin G, IgG）和血清转铁蛋白（serotransferrin）的血浆中分离得到AACT，并采用高分辨率非变性质谱（native mass spectrometry）技术，对去唾液酸化AACT的多维度聚糖微观异质性进行定性与定量分析，以此揭示糖蛋白亚型谱的变化如何反映患者的生理状态。尽管我们观察到AACT糖蛋白亚型谱存在整体重塑趋势，例如岩藻糖基化水平升高、分支结构/N-乙酰乳糖胺（LacNAc）延伸增加，但每名患者均表现出独特的特征与应答模式，这为个性化纵向糖蛋白亚型谱分析的重要性提供了稳健的概念验证。值得注意的是，本研究发现脓毒症诱导的AACT糖蛋白亚型谱变化在患者从ICU出院后并未迅速消退。