Mesenchymal Stem Cell-Derived Extracellular Vesicles as Mediators of Anti-Inflammatory Effects: Endorsement of Macrophage Polarization

作者：Claudia Lo Sicco, Daniele Reverberi, Carolina Balbi, Valentina Ulivi, Elisa Principi, Luisa Pascucci, Pamela Becherini, Maria Carla Bosco, Luigi Varesio, Chiara Franzin, Michela Pozzobon, Ranieri Cancedda, Roberta Tasso · 发表于：Stem Cells Translational Medicine · 年份：2017 · DOI：10.1002/sctm.16-0363 · 被引用次数：582 · 研究领域：Extracellular vesicles in disease、MicroRNA in disease regulation、Bone and Joint Diseases

Abstract Mesenchymal Stem Cells (MSCs) are effective therapeutic agents enhancing the repair of injured tissues mostly through their paracrine activity. Increasing evidences show that besides the secretion of soluble molecules, the release of extracellular vesicles (EVs) represents an alternative mechanism adopted by MSCs. Since macrophages are essential contributors toward the resolution of inflammation, which has emerged as a finely orchestrated process, the aim of the present study was to carry out a detailed characterization of EVs released by human adipose derived-MSCs to investigate their involvement as modulators of MSC anti-inflammatory effects inducing macrophage polarization. The EV-isolation method was based on repeated ultracentrifugations of the medium conditioned by MSC exposed to normoxic or hypoxic conditions (EVNormo and EVHypo). Both types of EVs were efficiently internalized by responding bone marrow-derived macrophages, eliciting their switch from a M1 to a M2 phenotype. In vivo, following cardiotoxin-induced skeletal muscle damage, EVNormo and EVHypo interacted with macrophages recruited during the initial inflammatory response. In injured and EV-treated muscles, a downregulation of IL6 and the early marker of innate and classical activation Nos2 were concurrent to a significant upregulation of Arg1 and Ym1, late markers of alternative activation, as well as an increased percentage of infiltrating CD206pos cells. These effects, accompanied by an accelerat...