Cardiac progenitor cell-derived extracellular vesicles promote angiogenesis through both associated- and co-isolated proteins
Marieke T. Roefs, Julia Bauzá‐Martinez, Simonides Immanuel van de Wakker, Jiabin Qin, Willem Theodoor Olijve, Robin Tuinte, Marjolein Rozeboom, C. Snijders Blok, Emma A. Mol, Wei Wu, Pieter Vader, Joost P. G. Sluijter
Abstract
Extracellular vesicles (EVs) are cell-derived lipid bilayer-enclosed particles that play a role in intercellular communication. Cardiac progenitor cell (CPC)-derived EVs have been shown to protect the myocardium against ischemia-reperfusion injury via pro-angiogenic effects. However, the mechanisms underlying CPC-EV-induced angiogenesis remain elusive. Here, we discovered that the ability of CPC-EVs to induce in vitro angiogenesis and to stimulate pro-survival pathways was lost upon EV donor cell exposure to calcium ionophore. Proteomic comparison of active and non-active EV preparations together with phosphoproteomic analysis of activated endothelial cells identified the contribution of candidate protein PAPP-A and the IGF-R signaling pathway in EV-mediated cell activation, which was further validated using in vitro angiogenesis assays. Upon further purification using iodixanol gradient ultracentrifugation, EVs partly lost their activity, suggesting a co-stimulatory role of co-isolated proteins in recipient cell activation. Our increased understanding of the mechanisms of CPC-EV-mediated cell activation will pave the way to more efficient EV-based therapeutics.