A method to isolate syncytiotrophoblast-derived medium-large extracellular vesicle small RNA from maternal plasma

• Published in: Placenta (Eastbourne)
• Main Authors: Cooke, William R., Zhang, Wei, Kandzija, Neva, Jones, Gabriel Davis, Redman, Christopher WG, Vatish, Manu
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 04-04-2024
• Subjects: Extracellular vesicles; Preeclampsia; Pregnancy; RNA; Syncytiotrophoblast; Pregnancy; Extracellular vesicles; Syncytiotrophoblast; RNA; Preeclampsia
• ISSN: 0143-4004; 1532-3102
• DOI: 10.1016/j.placenta.2024.03.010

Syncytiotrophoblast-derived extracellular vesicles (STB-EVs) have an important role in placental research: both as mediators of feto-maternal signalling and as liquid biopsies reflecting placental health. Recent evidence highlights the importance of STB-EV RNA. Isolation of STB-EV RNA from maternal blood is therefore an important challenge. We describe a novel technique where we first separate medium-large particles from plasma using centrifugation then use a highly specific bead-bound antibody to placental alkaline phosphatase to separate STB-EVs from other similar-sized particles. We demonstrate the yield and size profile of small RNA obtained from plasma STB-EVs. We present data confirming isolation of placenta-derived micro RNA from maternal plasma using this method. The technique has been successfully applied to validate novel RNA discoveries from placental perfusion models. We propose it could offer new insights through transcriptomic analyses, providing a syncytiotrophoblast-specific signal from maternal blood.
•Circulating syncytiotrophoblast extracellular vesicles represent placental biopsies.•Our method isolates syncytiotrophoblast extracellular vesicle RNA from maternal blood.•We demonstrate small RNA yield, size profile and isolation efficacy.•The method can validate findings from placental models and enable in-vivo discovery.