Microvesicles from Mesenchymal Stem Cells Induce an Anti-Inflammatory Phenotype of Microglia Exposed to Human Abeta 1-42

Aim: Based on the evidence that microvesicles (MVs) shed from Bone -Marrow Mesenchymal Stem Cells (BMMSCs) can play an immunomodulatory role, protecting the injured tissue, we aimed at assessing the possible anti-inflammatory effects of BM-MSCs-deriving MVs in microglia cultures exposed to hAbeta 1-42. Methods: MV swere isolated by ultracentrifugation from mouse BM-MSCs and then characterized by FACS analysis. MVs were then incubated with primary microglia in the presence of human 1-42 Abeta peptide. The expression of different inflammatory or anti-inflammatory markerswas investigated by ELISA, FACS, RTPCR and immunocytochemistry. Results:Microglial cells assume an amoeboid phenotype, changing its morphology and releasing antiinflammatory cytokines, such as IL10, without significantly affecting the release of the pro-inflammatory cytokines TNFa and IL6. Also, MVs lead to the decrease in the expression ofmarkers like MHC II, which is associated with a pro-inflammatory phenotype. Conclusions: BM-MSCMVs down-regulate the inflammatory processes induced by exposureof microglia to h 1-42 Abeta peptide in vitro. The involved molecular mechanisms are under investigation.