Background

Placenta-derived exosomes continuously increase in maternal circulation over the first trimester of pregnanc

Placental exosomes profile in maternal and fetal circulation in intrauterine growth restriction - Liquid biopsies to monitoring fetal growth

INTRODUCTION: Placenta-derived exosomes may represent an additional pathway by which the placenta communicates with the maternal system to induce maternal vascular adaptations to pregnancy and it may be affected during Fetal growth restriction (FGR). The objective of this study was to quantify the concentration of total and placenta-derived exosomes in maternal and fetal circulation in small fetuses classified as FGR or small for gestational age (SGA). METHODS: Prospective cohort study in singleton term gestations including 10 normally grown fetuses and 20 small fetuses, sub-classified into SGA and FGR accordingly to birth weight (BW) percentile and fetoplacental Doppler. Exosomes were isolated from maternal and fetal plasma and characterized by morphology, enrichment of exosomal proteins, and size distribution by electron microscopy, western blot, and nanoparticle tracking analysis, respectively. Total and specific placenta-derived exosomes were determined using quantum dots coupled with CD63+ve and placental-type alkaline phosphatase (PLAP)+ve antibodies, respectively. RESULTS: Maternal concentrations of CD63+ve and PLAP+ve exosomes were similar between the groups (all p > 0.05). However, there was a significant positive correlation between the ratio of placental-derived to total exosomes (PLAP+ve ratio) and BW percentile, [rho = 0.77 (95% CI: 0.57 to 0.89); p = 0.0001]. The contribution of placental exosomes to the total exosome concentration in maternal and fetal circulation showed a significant decrease among cases, with lower PLAP+ve ratios in FGR compared to controls and SGA cases. DISCUSSION: Quantification of placental exosomes in maternal plasma reflects fetal growth and it may be a useful indicator of placental function

Oxygen tension regulates the miRNA profile and bioactivity of exosomes released from extravillous trophoblast cells - liquid biopsies for monitoring complications of pregnancy

Our understanding of how cells communicate has undergone a paradigm shift since the recent recognition of the role of exosomes in intercellular signaling. In this study, we investigated whether oxygen tension alters the exosome release and miRNA profile from extravillous trophoblast (EVT) cells, modifying their bioactivity on endothelial cells (EC). Furthermore, we have established the exosomal miRNA profile at early gestation in women who develop pre-eclampsia (PE) and spontaneous preterm birth (SPTB). HTR-8/SVneo cells were used as an EVT model. The effect of oxygen tension (i.e. 8% and 1% oxygen) on exosome release was quantified using nanocrystals (Qdot®) coupled to CD63 by fluorescence NTA. A real-time, live-cell imaging system (Incucyte™) was used to establish the effect of exosomes on EC. Plasma samples were obtained at early gestation (<18 weeks) and classified according to pregnancy outcomes. An Illumina TrueSeq Small RNA kit was used to construct a small RNA library from exosomal RNA obtained from EVT and plasma samples. The number of exosomes was significantly higher in EVT cultured under 1% compared to 8% oxygen. In total, 741 miRNA were identified in exosomes from EVT. Bioinformatic analysis revealed that these miRNA were associated with cell migration and cytokine production. Interestingly, exosomes isolated from EVT cultured at 8% oxygen increased EC migration, whilst exosomes cultured at 1% oxygen decreased EC migration. These changes were inversely proportional to TNF-α released from EC. Finally, we have identified a set of unique miRNAs in exosomes from EVT cultured at 1% oxygen and exosomes isolated from the circulation of mothers at early gestation, who later developed PE and SPTB. We suggest that aberrant exosomal signalling by placental cells is a common aetiological factor in pregnancy complications characterised by incomplete SpA remodeling and is therefore a clinically relevant biomarker of pregnancy complications.Grace Truong, Dominic Guanzon, Vyjayanthi Kinhal, Omar Elfeky, Andrew Lai, Sherri Longo, Zarin Nuzhat, Carlos Palma, Katherin Scholz-Romero, Ramkumar Menon, Ben W. Mol, Gregory E. Rice, Carlos Salomo

Characterisation of the release of placenta-derived exosome in gestational diabetes mellitus

Objectives: We have established that the release of placenta-derived exosomes (PdE) increases gradually during gestation in healthy normal pregnancies. The release and composition of exosomes from placentae of pregnancies complicated by GDM, however, remain to be fully elucidated. The aim of this study was to establish the gestational-age profile of PdE in maternal plasma of GDM pregnancies. Methods: Plasma samples were obtained from normal (n=20 per group) and GDM (n=7 per group) pregnancies in the first (FT 11-14 weeks), second (ST 22-24 weeks) and third (TT 32-36 weeks) trimester pregnancy. All samples were collected from Davila Clinic (Santiago, Chile). Exosomes were isolated from plasma by differential and buoyant density centrifugation. The total number of exosomes and PdE were determined by quantifying immunoreactive exosomal CD63 and placenta-specific marker (PLAP) by ELISA and fluorescence nanoparticle tracking analysis (NTA, NanoSight NS500). The PLAP/CD63 ratio (i.e. immunoractive PLAP content per exosome) was used as a measure of the contribution of PdE to total exosomes in maternal blood. Results: Variation in the concentration of PdE in maternal plasma was assessed by ANOVA with the variance partitioned between gestational age and pregnancy status (i.e. normal or GDM). Both gestational age and pregnancy status were identified as significant factors (ANOVA,

Plasma from first trimester pre-symptomatic women who subsequently developed preeclampsia reduces extravillous trophoblast cells migration, a possible role of placental-derived particles

Objectives: The concentration of microparticles is increased in the circulation of women with pre-eclampsia (PE). Failed extravillous trophoblast invasion is associated with early onset of PE. The aim of this study was to quantify the number of particles in plasma from pre-symptomatic women who subsequently developed preeclampsia and establish their effect on EVT migration. Methods: Plasma samples were obtained from normal (NP, n=20) and PE (n=15) pregnancies in the first (11-14 weeks) trimester from Davila Clinic (Santiago, Chile). The number of total particles (TP) and particles with diameter ranging between 30-150 nm (P30-150) were determined using a nanoparticle tracking analysis (NTA, NanoSight NS500). HTR-8/SVneo (EVT) were used as target cells to establish the effect of plasma (10% plasma in RPMI media) from NP and PE pregnancies on migration using a real-time imaging system (Incucyte™). RPMI media was used as control. In addition, plasma was subjected to sonication before exposure to EVT. Results: TP and P30-150 were significantly higher (