Quantifying murine placental extracellular vesicles across gestation and in preterm birth data with tidyNano: A computational framework for analyzing and visualizing nanoparticle data in R

Abstract

Extracellular vesicles (EVs) are increasingly recognized as important mediators of intercellular communication that carry protein, lipids, and nucleic acids via the circulation to target cells whereupon they mediate physiological changes. In pregnancy, EVs are released in high quantities from the placenta and have been postulated to target multiple cell types, including those of the vascular and immune systems. However, most studies of pregnancy-associated EVs have used clinical samples and in vitro models; to date, few studies have taken advantage of murine models in which pregnancy can be precisely timed and manipulated. In this study, we used a murine model to determine whether the quantity of EVs is altered during healthy pregnancy and during inflammation-associated preterm birth. To facilitate data analysis, we developed a novel software package, tidyNano, an R package that provides functions to import, clean, and quickly summarize raw data generated by the nanoparticle tracking device, NanoSight (Malvern Panalytical). We also developed shinySIGHT, a Shiny web application that allows for interactive exploration and visualization of EV data. In mice, EV concentration in blood increased linearly across pregnancy, with significant rises at GD14.5 and 17.5 relative to EV concentrations in nonpregnant females. Additionally, lipopolysaccharide treatment resulted in a significant reduction in circulating EV concentrations relative to vehicle-treated controls at GD16.5 within 4 hours. Use of tidyNano facilitated rapid analysis of EV data; importantly, this package provides a straightforward framework by which diverse types of large datasets can be simply and efficiently analyzed, is freely available under the MIT license, and is hosted on GitHub ( https://nguyens7.github.io/tidyNano/ ). Our data highlight the utility of the mouse as a model of EV biology in pregnancy, and suggest that placental dysfunction is associated with reduced circulating EVs.

Integrins Mediate Placental Extracellular Vesicle Trafficking to Lung and Liver in Vivo

“…Consistent with our prior results, 6 the concentration of EVs in the plasma of gestation day (GD)14.5 pregnant mice were ~2.4-fold higher than in nonpregnant females (P = 0.015) (Suppl. Fig.…”

“…The total quantity and concentration of EVs in maternal plasma rise across gestation, with the placenta contributing significantly to this increase. 5,6 While a number of effects of placental EVs have been suggested, few studies have attempted to quantify their biodistribution in vivo. In this study, we show that placental EVs traffic to the lung and the liver.…”

“…First, we used a quantity of EV that mimicked quantities found during pregnancy. 6 Second, we administered EVs into the tail vein, reasoning that this route most closely mimics hematogenous release of placental EV in situ , as both this and the uterine vein ultimately drain into the inferior vena cava. Thus, although we were surprised that our results did not show trafficking of placental EVs to the uterus, we believe that intravenous administration simulates the hematogenous route that EVs travel during pregnancy.…”

“…3,4 Because of this intimate association, placental EVs have the potential to communicate with virtually any tissue in the mother that they are able to access. As gestation advances, placental exosome concentration increases in maternal plasma; 5,6 additionally, their bioactivity may change in pathological conditions including preeclampsia and gestational diabetes. 7–9 These changes have spurred interest into possible roles of exosomes in regulating immune and cardiovascular responses to pregnancy and parturition.…”

Exosomes as Messengers between Mother and Fetus in Pregnancy

“…In pregnant mice, the concentration of exosomes was significantly lower in preterm birth induced by inflammation compared to animals with normal delivery [91]. Pathway analysis after determination of exosomal protein profiles at term and preterm birth pointed at changes in inflammatory and endocrine signaling, which might disrupt pregnancy maintenance [92].…”