Extracellular Vesicles Activate a CD36-Dependent Signaling Pathway to Inhibit Microvascular Endothelial Cell Migration and Tube Formation. Arterioscler Thromb Vasc Biol 2016 Mar;36(3):534-44
Date
01/30/2016Pubmed ID
26821945Pubmed Central ID
PMC4767682DOI
10.1161/ATVBAHA.115.307085Scopus ID
2-s2.0-84959464380 (requires institutional sign-in at Scopus site) 47 CitationsAbstract
OBJECTIVE: Literature on the effect of cell-derived extracellular vesicles (EV), ≤1 μm vesicles shed from various cell types during activation or apoptosis, on microvascular endothelial cell (MVEC) signaling is conflicting. Thrombospondin-1 and related proteins induce anti-angiogenic signals in MVEC via CD36. CD36 binds EV via phosphatidylserine exposed on their surface but the effects of this interaction on MVEC functions are not known. We hypothesized that EV would inhibit angiogenic MVEC functions via CD36.
APPROACH AND RESULTS: EV generated in vitro from various cell types or isolated from plasma inhibited MVEC tube formation in in vitro matrigel assays and endothelial cell migration in Boyden chamber assays. Exosomes derived from the same cells did not have inhibitory activity. Inhibition of migration required endothelial cell expression of CD36. In mouse in vivo matrigel plug assays, EV inhibited cell migration into matrigel plugs in wild type but not in cd36 null animals. Annexin V, an anionic phospholipid binding protein, when incubated with EV partially reversed inhibition of migration, suggesting a phosphatidylserine-dependent effect. EV exposure induced reactive oxygen species generation in MVEC in a NADPH oxidase and Src family kinase-dependent manner, and their inhibition by apocynin and PP2, respectively, partially reversed the EV-mediated inhibition of migration. Annexin V partially reversed EV-induced reactive oxygen species generation in murine CD36 cDNA-transfected HVUEC but not in CD36-negative human umbilical vein endothelial cell.
CONCLUSIONS: These studies establish a general inhibitory effect of EV on endothelial cell proangiogenic responses and identify a CD36-mediated mechanistic pathway through which EV inhibit MVEC migration and tube formation.
Author List
Ramakrishnan DP, Hajj-Ali RA, Chen Y, Silverstein RLAuthors
Yiliang Chen PhD Assistant Professor in the Medicine department at Medical College of WisconsinRoy L. Silverstein MD Professor in the Medicine department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AnimalsAnnexin A5
CD36 Antigens
Cell Line, Tumor
Cell Movement
Endothelial Cells
Enzyme Inhibitors
Extracellular Vesicles
Human Umbilical Vein Endothelial Cells
Humans
Male
Mice, Inbred C57BL
Mice, Knockout
Microvessels
NADPH Oxidases
Neovascularization, Physiologic
Phosphatidylserines
Reactive Oxygen Species
Signal Transduction
Transfection
src-Family Kinases
