Abstract:Introduction
We have previously shown that miRNAs produced from the Chromosome 19 MiRNA Cluster (C19MC), which are expressed almost exclusively in primate trophoblasts and are released into the maternal circulation, reduce viral replication in non-placental cells and can modulate migratory behavior of extravillous trophoblast. We sought to define the expression pattern of C19MC miRNA in early pregnancy and in response to viral infection in vitro and in vivo.
Methods
We prospectively followed women undergoing… Show more
“…Exposure of PPF or HUtMEC cells to PHT- or BeWo-derived sEVs led to a marked increase in intracellular miR-517a ( Figure 1d ). Importantly, exposure to PHT- or BeWo-derived sEVs attenuated the level of transduced vesicular stomatitis virus (VSV) in the recipient cells ( Figure 1e ), as we have previously shown [ 32 – 35 , 54 ], thus validating the functionality of the trophoblastic sEVs. Figure 1.…”
Pregnancy is a unique situation, in which placenta-derived small extracellular vesicles (sEVs) may communicate with maternal and foetal tissues. While relevant to homoeostatic and pathological functions, the mechanisms underlying sEV entry and cargo handling in target cells remain largely unknown. Using fluorescently or luminescently labelled sEVs, derived from primary human placental trophoblasts or from a placental cell line, we interrogated the endocytic pathways used by these sEVs to enter relevant target cells, including the neighbouring primary placental fibroblasts and human uterine microvascular endothelial cells. We found that trophoblastic sEVs can enter target cells, where they retain biological activity. Importantly, using a broad series of pharmacological inhibitors and siRNA-dependent silencing approaches, we showed that trophoblastic sEVs enter target cells using macropinocytosis and clathrin-mediated endocytosis pathways, but not caveolin-dependent endocytosis. Tracking their intracellular course, we localized the sEVs to early endosomes, late endosomes, and lysosomes. Finally, we used coimmunoprecipitation to demonstrate the association of the sEV microRNA (miRNA) with the P-body proteins AGO2 and GW182. Together, our data systematically detail endocytic pathways used by placental sEVs to enter relevant fibroblastic and endothelial target cells, and provide support for "endocytic escape" of sEV miRNA to P-bodies, a key site for cytoplasmic RNA regulation.
“…Exposure of PPF or HUtMEC cells to PHT- or BeWo-derived sEVs led to a marked increase in intracellular miR-517a ( Figure 1d ). Importantly, exposure to PHT- or BeWo-derived sEVs attenuated the level of transduced vesicular stomatitis virus (VSV) in the recipient cells ( Figure 1e ), as we have previously shown [ 32 – 35 , 54 ], thus validating the functionality of the trophoblastic sEVs. Figure 1.…”
Pregnancy is a unique situation, in which placenta-derived small extracellular vesicles (sEVs) may communicate with maternal and foetal tissues. While relevant to homoeostatic and pathological functions, the mechanisms underlying sEV entry and cargo handling in target cells remain largely unknown. Using fluorescently or luminescently labelled sEVs, derived from primary human placental trophoblasts or from a placental cell line, we interrogated the endocytic pathways used by these sEVs to enter relevant target cells, including the neighbouring primary placental fibroblasts and human uterine microvascular endothelial cells. We found that trophoblastic sEVs can enter target cells, where they retain biological activity. Importantly, using a broad series of pharmacological inhibitors and siRNA-dependent silencing approaches, we showed that trophoblastic sEVs enter target cells using macropinocytosis and clathrin-mediated endocytosis pathways, but not caveolin-dependent endocytosis. Tracking their intracellular course, we localized the sEVs to early endosomes, late endosomes, and lysosomes. Finally, we used coimmunoprecipitation to demonstrate the association of the sEV microRNA (miRNA) with the P-body proteins AGO2 and GW182. Together, our data systematically detail endocytic pathways used by placental sEVs to enter relevant fibroblastic and endothelial target cells, and provide support for "endocytic escape" of sEV miRNA to P-bodies, a key site for cytoplasmic RNA regulation.
“…Both clusters are imprinted, with C19MC miRNAs expressed solely from the paternal chromosome, and C14MC miRNA expressed solely from the maternal chromosome [7]. The C19MC miRNAs are expressed almost exclusively within trophoblasts, and are exported into the maternal circulation [8] where they can be detected as early as 2 weeks after implantation [9]. They are also detected in the maternal and newborn circulation after delivery [3].…”
Introduction:
The placenta produces microRNAs (miRNA) that may traffic to the maternal or fetal compartments and influence the physiology of pregnancy. The trafficking patterns of miRNA expressed from the large human chromosome 19 and chromosome 14 clusters (C19MC and C14MC), remains unclear. We interrogated the cross-sectional landscape of miRNA expression within the human placenta, fetal and maternal plasma to elucidate miRNA trafficking. We hypothesized that C19MC and C14MC miRNAs have similar expression patterns across the maternal-fetal compartments.
Methods:
Placental biopsies, maternal and fetal venous plasma were collected from 25 pregnancies, and RNA was quantified using next generation sequencing. We identified expression and correlations differences among the compartments, and uncovered distinct miRNA expression patterns using consensus clustering.
Results:
We found that the placenta exhibits the highest total abundance, average miRNA expression and lowest variance of both C19MC and C14MC miRNAs. The C19MC miRNAs had a comparable expression and variance in fetal and maternal plasma and higher expression in the placenta. In contrast, the C14MC miRNAs had comparable expression between the placenta and fetal plasma, which was higher than the maternal plasma. We also identified 5 distinct groups of trophoblastic miRNAs with different expression patterns in each compartment.
Discussion:
This is the first comprehensive analysis of C19MC and C14MC miRNA expression patterns in the human placental, maternal and fetal compartments. Our findings suggest that C14MC miRNAs are produced by both the fetus and placenta, but C19MC miRNAs are produced primarily in the placenta and are trafficked to the fetal and maternal compartments.
“…Additionally, one study showed that the expression of C19MC miRNAs in pNK cells were significantly upregulated in the third trimester compared with the first‐trimester, and the rapid clearance of C19MC miRNAs from the pNK cells occurred after delivery . This suggests that C19MC miRNA regulates migratory and invasive behaviors of extravillous trophoblasts and plays a role in the establishment of the maternal–fetal interface . In several studies, aberrant levels of pregnancy‐associated placental miRNAs on C19MC in maternal plasma were detected in complicated pregnancies (e.g.…”
Establishing the reference values for circulating pregnancy-associated placental microRNAs in maternal plasma could be useful for the evaluation of HDP.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
