Glycocapture-Assisted Global Quantitative Proteomics (gagQP) Reveals Multiorgan Responses in Serum Toxicoproteome

Blood is an ideal window for viewing our health and disease status. Because blood circulates throughout the entire body and carries secreted, shed, and excreted signature proteins from every organ and tissue type, it is thus possible to use the blood proteome to achieve a comprehensive assessment of multiple-organ physiology and pathology. To date, the blood proteome has been frequently examined for diseases of individual organs; studies on compound insults impacting multiple organs are, however, elusive. We believe that a characterization of peripheral blood for organ-specific proteins affords a powerful strategy to allow early detection, staging, and monitoring of diseases and their treatments at a whole-body level. In this paper we test this hypothesis by examining a mouse model of acetaminophen (APAP)-induced hepatic and extra-hepatic toxicity. We used a glycocapture-assisted global quantitative proteomics (gagQP) approach to study serum proteins and validated our results using Western blot. We discovered in mouse sera both hepatic and extra-hepatic organ-specific proteins. From our validation, it was determined that selected organ-specific proteins had changed their blood concentration during the course of toxicity development and recovery. Interestingly, the peak responding time of proteins specific to different organs varied in a time-course study. The collected molecular information shed light on a complex, dynamic, yet interweaving, multiorgan-enrolled APAP toxicity. The developed technique as well as the identified protein markers is translational to human studies. We hope our work can broaden the utility of blood proteomics in diagnosis and research of the whole-body response to pathogenic cues.

血液是窥探人体健康与疾病状态的理想窗口。血液可在全身循环，携带来自各器官与组织的分泌、脱落及排泄特征蛋白，因此借助血液蛋白质组（blood proteome）能够实现多器官生理与病理状态的全面评估。迄今为止，血液蛋白质组常被应用于单个器官疾病的相关研究，但针对累及多器官的复合损伤的研究仍鲜有报道。我们认为，对外周血中的器官特异性蛋白进行表征，可为全身体系下的疾病早期检测、分期与疗效监测提供强有力的策略。本文以对乙酰氨基酚（acetaminophen, APAP）诱导的肝及肝外毒性小鼠模型为研究对象，验证这一假说。我们采用糖捕获辅助全局定量蛋白质组学（glycocapture-assisted global quantitative proteomics, gagQP）技术分析小鼠血清蛋白，并通过蛋白质免疫印迹（Western blot）对实验结果进行验证。我们在小鼠血清中同时检测到了肝源性及肝外器官特异性蛋白。经验证发现，部分筛选出的器官特异性蛋白在毒性发生发展与恢复过程中，其血液浓度发生了显著改变。有趣的是，在时间进程研究中，不同器官特异性蛋白的响应峰值出现时间存在差异。本研究获取的分子信息揭示了APAP毒性涉及多器官、复杂动态且相互交织的病理过程。本研究开发的技术与已鉴定的蛋白标志物均可向人体研究转化。我们期望本研究能够拓展血液蛋白质组学在全身应答致病因素的诊断与相关研究中的应用范畴。