Paracrine effect of membrane vesicles released by mouse mesoangioblast stem cells

Introduction: Mouse mesoangioblasts are vessel-associated multipotent progenitor stem cells, which are able to differentiate into different mesodermal cell types. In our previous paper, we have demonstrated that mesoangioblasts are able to shed in the extracellular environment membrane vesicles (EVs), which contain both structural proteins and biological factors such as FGF2 and the two gelatinases MMP2/9. We investigated whether these EV interact in a paracrine way with other cell types different from mesoangioblasts, and eventually the effects of this interaction. Methods: Mesoangioblast EVs were collected from conditioned media by ultracentrifugation. Total mRNAs from mesoangioblasts and from two preparations of EVs were used to perform microarray. Different concentrations of mesoangioblast EV were used to evaluate in vitro migration modulation on human ECV304 cells by wound healing assay or study their influence on capillary-like structures formation. Murine RAW 264.7 macrophages were cultured with or without mesoangioblast-derived EVs to investigate their effect on cytokines secretion profile and RTK phosphorylation levels by array. Results: We observed that mesoangioblast EV contained a huge amount of mRNA; most of the transcripts are co-expressed in EV and cells, whereas 20 mRNA were accumulated within EV and absent in the cells. Gene ontology analysis showed that the common mRNA could be involved in cell survival and differentiation. We demonstrated that mesoangioblast EV interact with endothelial ECV304 cells by positively influencing their migration capability. Moreover, they induce in vitro the ECV304 differentiation versus capillary-like structures depending on their concentration. Mesoangioblast EVs are also able to interact with RAW 264.7 cells inducing dramatic changes in cytokines secretion and in RTK phosphorylation levels. Conclusions: We demonstrated that mesoangioblast EV interact with endothelial cells and macrophages and influence on their behaviour