Contractile forces in platelet aggregates under microfluidic shear gradients reflect platelet inhibition and bleeding risk

Lucas H Ting,Shirin Feghhi,Nikita Taparia,Annie O Smith,Esther Lim,Ari Karchin,Alex St John,Nathan J White,Tessa Rue,Xu Wang,Nathan J Sniadecki

doi:10.1038/s41467-019-09150-9

Lucas H Ting, Shirin Feghhi + Show 9 more

Open Access

https://doi.org/10.1038/s41467-019-09150-9

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Journal: Nature Communications	Publication Date: Mar 13, 2019
Citations: 72	License type: open-access

Affiliation: University of Washington, Seattle University

Abstract

Platelets contract forcefully after their activation, contributing to the strength and stability of platelet aggregates and fibrin clots during blood coagulation. Viscoelastic approaches can be used to assess platelet-induced clot strengthening, but they require thrombin and fibrin generation and are unable to measure platelet forces directly. Here, we report a rapid, microfluidic approach for measuring the contractile force of platelet aggregates for the detection of platelet dysfunction. We find that platelet forces are significantly reduced when blood samples are treated with inhibitors of myosin, GPIb-IX-V, integrin αIIbβ3, P2Y12, or thromboxane generation. Clinically, we find that platelet forces are measurably lower in cardiology patients taking aspirin. We also find that measuring platelet forces can identify Emergency Department trauma patients who subsequently require blood transfusions. Together, these findings indicate that microfluidic quantification of platelet forces may be a rapid and useful approach for monitoring both antiplatelet therapy and traumatic bleeding risk.

Highlights

Platelets contract forcefully after their activation, contributing to the strength and stability of platelet aggregates and fibrin clots during blood coagulation
We developed a microfluidic approach that uses a region of high shear as a mechanism to induce the formation of platelet aggregates to measure their contractile strength
We found that incubating with either AK2 to inhibit GPIb-IX-V or c7E3 to inhibit αIIbβ[3] led to a difference in platelet forces (one-way analysis of variance (ANOVA) F = 12.98, DF = 2, p = 0.001) (Fig. 3c) and aggregate size (Fig. 3c, d)

Summary

Introduction

Platelets contract forcefully after their activation, contributing to the strength and stability of platelet aggregates and fibrin clots during blood coagulation. We find that measuring platelet forces can identify Emergency Department trauma patients who subsequently require blood transfusions Together, these findings indicate that microfluidic quantification of platelet forces may be a rapid and useful approach for monitoring both antiplatelet therapy and traumatic bleeding risk. Platelet function is typically measured by measuring their adhesion or aggregation responses to agonists including thrombin, collagen, adenosine diphosphate (ADP), and arachidonic acid (AA)[6]. These approaches do not fully capture the complexity of platelets, which includes multiple activation pathways, intracellular signaling with calcium influx, exposure of surface integrins, and, cytoskeletal reorganization and contraction. Compaction of a plug by platelet forces reduces its porosity, thereby increasing the concentration and retention of agonists like ADP and TxA216–18

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