Feto-Maternal Trafficking of Exosomes in Murine Pregnancy Models

Abstract

Timing and initiation of labor are well-orchestrated by signals communicated between the fetal and maternal compartments; however, how these signals are communicated is not completely understood. Fetal exosomes, intercellular signaling vesicles, may play a key role in the process. The objective of this study was to evaluate exosome trafficking in vivo from fetal to maternal compartments. Pregnant CD-1 mice were intra-amniotically injected on gestational day 16 and 17 with exosomes isolated from primary human amnion epithelial cells fluorescently labeled with the lipophilic dye 1,1-dioctadecyl-3,3,3,3-tetramethylindotricarbocyanine iodide (DiR). All our analyses were performed on samples collected on Day 18. After 24 h, mice were imaged using Bruker MS FX PRO In vivo Imager and tissues were collected. In vivo imaging of mouse showed fluorescence in the uterus, on the exosome-injected side whereas the uterine tissues from the uninjected side and saline and dye alone injected animals remained negative. Histological analysis of placenta showed exosome migration from the fetal to the maternal side of the placenta. Fluorescence released from exosomes was seen in maternal blood samples as well as in maternal uterus and kidneys. This study demonstrates that exosomal cargo can be carried through systemic route from the fetal to the maternal side of the uterine tissues during pregnancy, supporting the idea that fetal signals can be delivered via exosomes.

Damage-Associated molecular pattern markers HMGB1 and cell-Free fetal telomere fragments in oxidative-Stressed amnion epithelial cell-Derived exosomes

“…These exosomes can either diffuse through tissue layers or reach their destination via the systemic route. Animal model experiments have confirmed trafficking of fetal exosomes through both mechanisms in which intraamniotic injection of exosomes resulted in their localization in both maternal blood as well as uterine tissues (Sheller-Miller et al, 2016). Thus, senescent fetal cells can package inflammatory mediators inside exosomes and transport them to other uterine destinations.…”

“…Media were thawed at 4°C overnight prior to isolation. Exosomes were isolated as described (Sheller-Miller et al, 2016; Sheller et al, 2016) with the following modifications. After centrifugation at 2000 g, the supernatant was transferred to Amicon Ultra 15 centrifugation filters (Millipore, Billerica, MA) and centrifuged at 2000 g for 90 minutes.…”

“…The protocol for this experiment can be seen in our prior publications (Sheller-Miller et al, 2016; Sheller et al, 2016). Briefly, formvar/carbon-coated 300-mesh copper grids were treated with 10 seconds of hydrogen-oxygen plasma in a Gatan Solarus 950 plasma cleaning system (Gatan, Inc., Pleasanton, CA).…”

“…Western blot samples then were processed as described previously (Sheller-Miller et al, 2016; Sheller et al, 2016). The following anti-human antibodies were used for Western blot: exosome marker CD9 (Abcam, Cambridge, United Kingdom) diluted 1:400 and Alix (Santa Cruz Biotechnology, Dallas, TX) diluted 1:500.…”

Amnion epithelial cell–derived exosomes induce inflammatory changes in uterine cells

“…Importantly, animal model studies have shown that exosomes injected into the amniotic fluid cavity access the maternal tissues by local and systemic routes. 40 There are several studies which have reported exosome trafficking between tissues 41, 42 and that indicate exosomes are released from cells from both the apical and basolateral compartments. 43–47 Although these data support the core hypothesis that exosomes from the fetus access maternal tissues, the capacity for fetal exosomes in induce inflammatory changes in the maternal tissues remains unknown.…”