SnRNA Sequencing Defines Signaling by RBC-Derived Extracellular Vesicles in the Murine Heart

Extracellular vesicles (EVs) are thought to mediate intercellular signaling by transferring their cargo to recipient cells. Red blood cell (RBC)-derived EVs constitute a significant proportion of circulating EVs and have been implicated in regulating immune responses. Here, we describe the use of a transgenic mouse model for fluorescence-based mapping of RBC-EV recipient cells to assess the functional role of this intercellular signaling mechanism in the pathogenesis of ventricular remodeling after ischemic injury. In this model of ischemic heart failure, we detected an increase in RBC-EV-targeted cardiomyocytes in the heart by fluorescent-based mapping. Single cell nuclear RNA sequencing of the heart revealed a complex landscape of cardiac cells targeted by RBC-EVs, suggesting enriched expression of genes implicated in cell proliferation and metabolism pathways compared to non-targeted cells. Correspondingly, cardiomyocytes targeted by RBC-EVs are more likely to express cellular markers of DNA synthesis and proliferation, suggesting the functional significance of EV-mediated signaling. In conclusion, our mouse model for mapping of EV-recipient cells reveals a complex network of RBC-EV mediated intercellular communication in ischemic heart failure and suggests a functional role for this mode of intercellular signaling.