Insoluble proteomics analysis of acute intracranial large vessel occlusive thrombus

Background: Acute large vessel occlusion (LVO) stroke is highly prevalent and severe. Despite thrombolytic therapy, many patients experience substantial complications. Understanding the origins, constituents, and pathologic processes involved in thrombus formation in acute intracranial large artery occlusion is crucial.

Objectives: To identify the characteristics of insoluble proteins from different sources of cerebral thrombus.

Methods: This study included 13 patients with cardiogenic embolic (CE) thrombus and 15 with large artery atherosclerotic (LAA) thrombus. High-performance liquid chromatography and liquid chromatography-tandem mass spectrometry were used to analyze insoluble proteins in thrombi. Bioinformatics analyses explored differential proteins and associated functional pathways. Least absolute shrinkage and selection operator and random forest identified biomarkers for diagnosing thrombus sources, validated by parallel reaction monitoring.

Results: We constructed an insoluble protein atlas of cerebral thrombi, identifying 6975 insoluble proteins, including 143 extracellular matrix (ECM)-related proteins. The enrichment pathways considerably varied between thrombi from different sources. Inflammation-related pathways, such as acute inflammatory response, along with ECM-related pathways such as laminin interactions, were notably upregulated in LAA compared with CE. Additionally, 2 biomarkers (IDH2 and HSPG2) exhibited strong diagnostic performance (area under the curve = 1) and robustness.

Conclusion: In the insoluble proteomics of thrombus, we highlighted the crucial roles of immune responses and ECM proteins in thrombus formation, providing new insights into its mechanisms and potential drug development. Additionally, we identified 2 biomarkers that offer new methods for determining thrombus sources in patients with LVO.