Morphometric and Nanomechanical Features of Platelets from Women with Early Pregnancy Loss Provide New Evidence of the Impact of Inherited Thrombophilia.

Tonya Andreeva,Ina Giosheva,Andrey Tchorbanov,Stefka G Taneva,Galya B Georgieva,Sashka Krumova,Nikolina Mihaylova,Georgi Golemanov,Svetla Todinova,Ariana Langari,Regina Komsa-Penkova

doi:10.3390/ijms22157778

Abstract

Pregnancy is associated with hypercoagulation states and increased thrombotic risk, especially in women with thrombophilia. We combine atomic force microscopy (AFM) and flow cytometry to examine the morphology and nanomechanics of platelets derived from women with early pregnancy loss (EPL) and control pregnant (CP) and non-pregnant (CNP) women. Both control groups exhibit similar morphometric parameters (height and surface roughness) and membrane stiffness of platelets. EPL patients’ platelets, on the other hand, are more activated than the control groups, with prominent cytoskeletal rearrangement. In particular, reduced membrane roughness (22.9 ± 6 nm vs. 39.1 ± 8 nm) (p < 0.05) and height (692 ± 128 nm vs. 1090 ± 131 nm) (p < 0.05), strong alteration in the membrane Young modulus, increased production of platelets’ microparticles, and higher expression of procoagulant surface markers, as well as increased occurrence of thrombophilia (FVL, FII20210A, PLA1/A2, MTHFR C677T or 4G/5G PAI-1) polymorphisms were found. We suggest that the carriage of thrombophilic mutations triggers structural and nanomechanical abnormalities in platelets, resulting in their increased activation. The activation state of platelets can be well characterized by AFM, and the morphometric and nanomechanical characteristics might serve as a new criterion for evaluation of the cause of miscarriage and offer the prospect of an innovative approach serving for diagnostic purposes.

Highlights

Platelets are small (1–2 μm in diameter) anucleate blood cells that have a discoid shape and smooth surface in a resting state
We compared the clinical and biophysical parameters of platelets isolated from volunteer women with early pregnancy loss (EPL), with those of age-matched healthy non-pregnant (CNP) and pregnant (CP) controls
The EPL group was further split into two subgroups depending on the pregnancy development: (1) EPL1 consisting of women in which the spontaneous abortion occurred between 6 and 9 gestational weeks (GW) and (2) EPL2 encompassing women in which this event took place between 10 and 12 GW

Summary

Introduction

Platelets are small (1–2 μm in diameter) anucleate blood cells that have a discoid shape and smooth surface in a resting state. The first event that takes place is related to a change in cells’ shape from discoid to spherical, followed by prominent cell–cell interactions and clustering through extending actin-rich philopodia; in the final phase, flattening and spreading of cells on the damaged surface is observed, which results in the sealing of the impaired vessels. Abnormalities in platelets size and shape, as well as in the activation process, are related to impaired haemostasis and to various pathologies and inherited platelet disorders [5,6]. The investigation of platelets’ activation is essential for understanding the regulation of blood coagulation in healthy and diseased individuals. This is important for pregnancy, which is defined as a hypercoagulable state

Methods

Results

Discussion

Conclusion