Murine trophoblast-derived and pregnancy-associated exosome-enriched extracellular vesicle microRNAs: Implications for placenta driven effects on maternal physiology

Abstract

The role of extracellular vesicles (EVs), specifically exosomes, in intercellular communication likely plays a key role in placental orchestration of pregnancy and maternal immune sensing of the fetus. While murine models are powerful tools to study pregnancy and maternal-fetal immune interactions, in contrast to human placental exosomes, the content of murine placental and pregnancy exosomes remains largely understudied. Using a recently developed in vitro culture technique, murine trophoblast stem cells derived from B6 mice were differentiated into syncytial-like cells. EVs from the conditioned media, as well as from pregnant and non-pregnant sera, were enriched for exosomes. The RNA composition of these murine trophoblast-derived and pregnancy-associated exosome-enriched-EVs (ExoE-EVs) was determined using RNA-sequencing analysis and expression levels confirmed by qRT-PCR. Differentially abundant miRNAs were detected in syncytial differentiated ExoE-EVs, particularly from the X chromosome cluster (mmu-miR-322-3p, mmu-miR-322-5p, mmu-miR-503-5p, mmu-miR-542-3p, and mmu-miR-450a-5p). These were confirmed to be increased in pregnant mouse sera ExoE-EVs by qRT-PCR analysis. Interestingly, fifteen miRNAs were only present within the pregnancy-derived ExoE-EVs compared to non-pregnant controls. Mmu-miR-292-3p and mmu-miR-183-5p were noted to be some of the most abundant miRNAs in syncytial ExoE-EVs and were also present at higher levels in pregnant versus non-pregnant sera ExoE-EVs. The bioinformatics tool, MultiMir, was employed to query publicly available databases of predicted miRNA-target interactions. This analysis reveals that the X-chromosome miRNAs are predicted to target ubiquitin-mediated proteolysis and intracellular signaling pathways. Knowing the cargo of placental and pregnancy-specific ExoE-EVs as well as the predicted biological targets informs studies using murine models to examine not only maternal-fetal immune interactions but also the physiologic consequences of placental-maternal communication.

Exosomes as Messengers between Mother and Fetus in Pregnancy

“…The exosomal transfer of placenta-specific miR-571a-3p into NK cells repressed cGMP-dependent protein kinase 1, a key mediator of nitric oxide signaling [31]. In pregnant mice, 15 miRNAs specific for pregnant animals were identified in trophoblast-derived EVs [32].…”

“…The exosomal transfer of placenta-specific miR-571a-3p into NK cells repressed cGMP-dependent protein kinase 1, a key mediator of nitric oxide signaling [ 31 ]. In pregnant mice, 15 miRNAs specific for pregnant animals were identified in trophoblast-derived EVs [ 32 ]. Among the potential target pathways identified by bioinformatics analysis was the ubiquitin-mediated proteolysis, MAPK signaling and Focal Adhesion Pathways.…”

The Role of Extracellular Vesicles as Allies of HIV, HCV and SARS Viruses

“…EVs have been isolated from most cell types and biological fluids including blood, urine, saliva, breast milk, and cerebrospinal and synovial fluid [3][4][5][6][7]. In physiological conditions, they are involved in antigen presentation [8], neuronal communication and protection [9], blood coagulation [10], wound healing [11], sperm maturation [12] and regulation of the immune response against the fetus during pregnancy [13]. On the other hand, EVs play a key role also in pathogenic processes including cancer [14], autoimmune diseases [15], inflammation [16], as well as in viral infections [17].…”

Raman Spectroscopy characterization extracellular vesicles from bovine placenta and peripheral blood mononuclear cells

“…Placenta-derived exosomes have been found to suppress maternal Tcell signaling components possibly leading to immunomodulation and maternal immune tolerance to fetal antigens. [4,5] Reproductive efficiency of dairy cattle has reduced over the years. While the causes of this decrease are still unclear, it is known that embryonic loss is a major contributor.…”

“…Placenta-derived exosomes have been found to suppress maternal T-cell signaling components possibly leading to immunomodulation and maternal immune tolerance to fetal antigens. [ 4 , 5 ]…”