Thromb Haemost 2025; 125(04): 317-336
DOI: 10.1055/a-2398-9532
Cellular Haemostasis and Platelets

Shear Stress Promotes Remodeling of Platelet Glycosylation via Upregulation of Platelet Glycosidase Activity: One More Thing

1   Department of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, Arizona, United States
2   Arizona Center for Accelerated Biomedical Innovation, Tucson, Arizona, United States
,
Sabrina Lewis
1   Department of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, Arizona, United States
,
Estevan Cleveland
1   Department of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, Arizona, United States
,
Joseph E. Italiano
3   Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, Boston, Massachusetts, United States
,
1   Department of Medicine and Biomedical Engineering, Sarver Heart Center, University of Arizona, Tucson, Arizona, United States
2   Arizona Center for Accelerated Biomedical Innovation, Tucson, Arizona, United States
› Institutsangaben

Funding This research is supported by grants from the American Heart Association (Career Development Award 935890 to Yana Roka-Moiia), the University of Arizona Sarver Heart Center (Jack and Mildred Michelson Cardiovascular Research Award and John H. Midkiff Cardiovascular Research Award to Yana Roka-Moiia), and the Arizona Center for Accelerated Biomedical Innovation (ACABI) of the University of Arizona (an unrestricted grant to Marvin J. Slepian).


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Abstract

Background

Mechanical circulatory support (MCS) is a mainstay of therapy for advanced and end-stage heart failure. Accompanied by systemic anticoagulation, contemporary MCS has become less thrombogenic, with bleeding complications emerging as a major cause of readmission and 1-year mortality. Shear-mediated platelet dysfunction and thrombocytopenia of undefined etiology are primary drivers of MCS-related bleeding. Recently, it has been demonstrated that deprivation of platelet surface glycosylation is associated with the decline of hemostatic function, microvesiculation, and premature apoptosis. We test the hypothesis that shear stress induces remodeling of platelet surface glycosylation via upregulation of glycosidase activity, thus facilitating platelet count decline and intense microvesiculation.

Methods

Human gel-filtered platelets were exposed to continuous shear stress in vitro. Platelets and platelet-derived microparticles (PDMPs) were quantified via flow cytometry using size standard fluorescent nanobeads. Platelet surface glycosylation and NEU1 expression were evaluated using lectin- or immune-staining and multicolor flow cytometry; lectin blotting was utilized to verify glycosylation of individual glycoproteins. Platelet neuraminidase, galactosidase, hexosaminidase, and mannosidase activities were quantified using 4-methylumbelliferone-based fluorogenic substrates.

Results

We demonstrate that shear stress promotes selective remodeling of platelet glycosylation via downregulation of 2,6-sialylation, terminal galactose, and mannose, while 2,3-sialylation remains largely unchanged. Shear-mediated deglycosylation is partially attenuated by neuraminidase inhibitors, strongly suggesting the involvement of platelet neuraminidase in observed phenomena. Shear stress increases platelet NEU1 surface expression and potentiates generation of numerous NEU1+ PDMPs. Platelets exhibit high basal hexosaminidase and mannosidase activities; basal activities of platelet neuraminidase and galactosidase are rather low and are significantly upregulated by shear stress. Shear stress of increased magnitude and duration promotes an incremental decline of platelet count and immense microvesiculation, both being further exacerbated by neuraminidase and partially attenuated by neuraminidase inhibition.

Conclusion

Our data indicate that shear stress accumulation, consistent with supraphysiologic conditions of device-supported circulation, promotes remodeling of platelet glycosylation via selective upregulation of platelet glycosidase activity. Shear-mediated platelet deglycosylation is associated with platelet count drop and increased microvesiculation, thus offering a direct link between deglycosylation and thrombocytopenia observed in device-supported patients. Based on our findings, we propose a panel of molecular markers to be used for reliable detection of shear-mediated platelet deglycosylation in MCS.

Authors' Contribution

Y. Roka-Moiia designed the study, performed experiments, analyzed and interpreted data, wrote and edited the article, and acquired funding; S. Lewis and E. Cleveland performed experiments; J. E. Italiano participated in discussions and edited the article; M. J. Slepian participated in discussions, edited the article, and acquired funding.


Supplementary Material



Publikationsverlauf

Eingereicht: 27. März 2024

Angenommen: 20. August 2024

Accepted Manuscript online:
21. August 2024

Artikel online veröffentlicht:
12. September 2024

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