Thromb Haemost
DOI: 10.1055/a-2569-6439
Stroke, Systemic or Venous Thromboembolism

Asn384Ser Mutation in Protein C is Associated with Multiple-Site Thrombosis in a Young Heterozygous Male

Authors

  • Junwei Yuan*

    1   Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
    2   College of Health Science and Technology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
  • Shijie Zhou*

    1   Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
  • Xi Wu*

    1   Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
  • Fang Li

    3   State Key Laboratory of Microbial Metabolism & Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
  • Zhe Lai

    1   Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
  • Qiulan Ding

    1   Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
  • Wenman Wu

    1   Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
  • Xuefeng Wang

    1   Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
  • Jing Dai

    1   Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
  • Xiaobo Hu

    4   Shanghai Center for Clinical Laboratory, Shanghai, China
  • Yeling Lu

    1   Department of Laboratory Medicine, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China

Funding This study was supported by Shanghai Natural Science Foundation Program (22ZR1439500), and the General Program of National Natural Science Foundation of China (81870107) to YL; Young Talent Support Program of College of Health Science and Technology, Shanghai Jiao Tong University School of Medicine (YX20230015) to XW; the General Program of National Natural Science Foundation of China (82070137) to XW; and the General Program of National Natural Science Foundation of China (81970127) to JD.


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Abstract

Background

Protein C (PC) is an important physiological anticoagulant factor in humans. Activated protein C (APC) is generated from the PC zymogen through proteolytic activation by thrombin. APC inhibits thrombin generation by inactivating activated factors V and VIII via limited proteolysis. In addition to its anticoagulant function, APC also exhibits potent cytoprotective and anti-inflammatory properties. We have identified a young male with multiple-site thrombosis, who carries a heterozygous mutation c.1151A > G,p.Asn384Ser(N384S) in PC. Although this mutation has been previously documented, limited functional research has been conducted to elucidate its pathogenesis.

Objective

To elucidate the functional alternations of the N384S mutant protein C and delineate the molecular mechanism underlying thrombosis in the patient carrying this mutation.

Methods

We expressed the recombinant PC-N384S in mammalian cells and characterized its properties in established coagulation and anti-inflammatory assay systems.

Results

The expression level of the PC-N384S was reduced to approximately 7% of that observed for PC-WT. The activation of PC-N384S by thrombin or thrombin–thrombomodulin (TM) complex was significantly impaired, although the addition of TM exhibited a slight enhancement in the activation process. In terms of cleaving a chromogenic substrate, the catalytic efficiency reduced to approximately 50% of that observed in the wild type. In addition, in comparison with APC-WT, APC-N384S demonstrated a pronounced decline in amidolytic activity following an extended incubation period at 37°C. APC-N384S exhibited slightly impaired anticoagulant activity in either FVa inhibition assay or plasma-based assay systems. Furthermore, anti-inflammatory activity of APC-N384S was dramatically impaired as determined by evaluating the barrier-protective effect.

Conclusion

The Asn384Ser mutation impairs both the anticoagulant and barrier-protective activities of protein C, thereby increasing the thrombosis risk in the heterozygous young male.

Authors' Contribution

J.Y. performed the research and wrote the manuscript; X.W. performed genetic analysis and coagulation assays of the subjects' plasma; F.L. performed structural analyses; S.Z. and Z.L. performed research; Q.D., W.W., and X.W. collected and provided clinical data; J.D. and X.H. supervised studies; and L.Y. designed experiments, analyzed data, supervised the project, and revised the manuscript. All authors approved the final version of this manuscript.


* These authors contributed equally to this work.




Publikationsverlauf

Eingereicht: 17. Dezember 2024

Angenommen: 30. März 2025

Artikel online veröffentlicht:
18. April 2025

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