The time-dependent expression of FPR2 and ANXA1 in murine deep vein thrombosis model and its relation to thrombus age

Area of Science:

• Biomedical research
• Forensic pathology
• Molecular biology

Background:

• Thrombus age determination is crucial in forensic investigations of fatal venous thromboembolism.
• Accurate dating of deep vein thrombosis (DVT) aids in understanding disease progression and medico-legal contexts.

Purpose of the Study:

• To investigate the time-dependent expression patterns of formyl peptide receptor 2 (FPR2) and Annexin A1 (ANXA1) in a murine DVT model.
• To evaluate the potential of FPR2 and ANXA1 as biomarkers for estimating venous thrombus age.

Main Methods:

• Establishment of a stasis-induced DVT model in ICR mice by inferior vena cava (IVC) ligation.
• Analysis of FPR2 and ANXA1 expression using immunohistochemistry, double immunofluorescence staining, Western blotting, and quantitative real-time PCR at various time points post-ligation (1-21 days).

Main Results:

• FPR2 expression was primarily observed in intrathrombotic neutrophils and macrophages, with elevated levels in the early stages (1-7 days) post-ligation.
• ANXA1 expression was detected in neutrophils, neovascular endothelial cells, and fibroblastic cells, peaking at 10-14 days post-ligation for both mRNA and protein.
• Both FPR2 and ANXA1 demonstrated significant time-dependent up-regulation, with distinct expression profiles across different thrombus ages.

Conclusions:

• FPR2 and ANXA1 exhibit distinct and time-dependent expression patterns during DVT development in a murine model.
• These proteins are promising candidate biomarkers for forensic age estimation of venous thrombi.
• Further research can validate these findings for clinical and forensic applications in thrombus age determination.