Microvesicles of women with gestational hypertension and preeclampsia affect human trophoblast fate and endothelial function

Antithrombotic treatment for pregnancy complications: which path for the journey to precision medicine?

Haemostatic and vascular biology mechanisms appear to play an important role in the pathogenesis of placenta-mediated pregnancy complications. Although low-dose aspirin (LDA) has a modest effect in preventing preeclampsia, antithrombotic interventions, LDA and low molecular weight heparin (LMWH) have not definitively proven their effectiveness in women with placenta-mediated pregnancy complications selected by previous pregnancy outcome alone. Given the heterogeneous aetiology of placenta-mediated pregnancy complications, it is critical to stratify patients according to maternal and fetal characteristics and disease mechanisms rather than simply by pregnancy outcome, such as miscarriage. Such stratification could identify those who could benefit from antithrombotic interventions in pregnancy. We lack data on genome-wide association studies, biomarkers and trials of interventions applied to specific homogeneous populations. Future studies should focus on elaborating different disease mechanisms and examining antithrombotic interventions in specific and more homogeneous groups, such as thrombophilic women with well-characterized placenta-mediated pregnancy complications, stratified by disease severity and pathological findings. Because of fetal safety concerns with new anticoagulants, the intervention should focus on heparins alone or in combination with LDA. Thus, placenta-mediated pregnancy complications deserve precision medicine, defining disease by mechanism rather than outcome with interventions focused on a more personalized approach.

Cryogenic transmission electron microscopy nanostructural study of shed microparticles

Microparticles (MPs) are sub-micron membrane vesicles (100–1000 nm) shed from normal and pathologic cells due to stimulation or apoptosis. MPs can be found in the peripheral blood circulation of healthy individuals, whereas elevated concentrations are found in pregnancy and in a variety of diseases. Also, MPs participate in physiological processes, e.g., coagulation, inflammation, and angiogenesis. Since their clinical properties are important, we have developed a new methodology based on nano-imaging that provides significant new data on MPs nanostructure, their composition and function. We are among the first to characterize by direct-imaging cryogenic transmitting electron microscopy (cryo-TEM) the near-to-native nanostructure of MP systems isolated from different cell types and stimulation procedures. We found that there are no major differences between the MP systems we have studied, as most particles were spherical, with diameters from 200 to 400 nm. However, each MP population is very heterogeneous, showing diverse morphologies. We investigated by cryo-TEM the effects of standard techniques used to isolate and store MPs, and found that either high-g centrifugation of MPs for isolation purposes, or slow freezing to –80°C for storage introduce morphological artifacts, which can influence MP nanostructure, and thus affect the efficiency of these particles as future diagnostic tools.