title: TNF-α alters the release and transfer of microparticle-encapsulated miRNAs from endothelial cells.
abstract: MicroRNAs (miRNAs) encapsulated within microparticles (MPs) are likely to have a role in cell-to-cell signaling in a variety of diseases, including atherosclerosis. However, little is known about the mechanisms by which different cell types release and transfer miRNAs. Here, we examined TNF-α-induced release of MP-encapsulated miR-126, miR-21, and miR-155 from human aortic endothelial cells (ECs) and their transfer to recipient cells. ECs were treated with TNF-α (100 ng/ml) in the presence or absence of inhibitors that target different MP production pathways. MPs released in response to TNF-α were characterized by: 1) 70-80% decrease in miRNA/MP levels for miR-126 and -21 but a significant increase in pre-miR-155 and miR-155 (P < 0.05), 2) 50% reduction in uptake by recipient cells (P < 0.05), and 3) diminished ability to transfer miRNA to recipient cells. Cotreatment of donor ECs with TNF-α and caspase inhibitor (Q-VD-OPH, 10 μM) produced MPs that had: 1) 1.5- to 2-fold increase in miRNA/MP loading, 2) enhanced uptake by recipient cells (2-fold), and 3) increased ability to transfer miR-155. Cotreatment of ECs with TNF-α and Rho-associated kinase (ROCK) inhibitor (10 μM) produced MPs with features similar to those produced by TNF-α treatment alone. Our data indicate that TNF-α induced the production of distinct MP populations: ROCK-dependent, miRNA-rich MPs that effectively transferred their cargo and were antiapoptotic, and caspase-dependent, miRNA-poor MPs that were proapoptotic. These data provide insight into the relationship between MP production and extracellular release of miRNA, as well as the potential of encapsulated miRNA for cell-to-cell communication.
authors.affiliation: Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia; and.
authors.forename: Tamas
authors.initials: T
authors.lastname: Alexy
authors.affiliation: Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia; and.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Rooney
authors.affiliation: Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia; and.
authors.forename: Martina
authors.initials: M
authors.lastname: Weber
authors.affiliation: Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia; and.
authors.forename: Warren D
authors.initials: WD
authors.lastname: Gray
authors.affiliation: Division of Cardiology, Emory University School of Medicine, Atlanta, Georgia; and Section of Cardiology, Atlanta VA Medical Center, Decatur, Georgia csearle@emory.edu.
authors.forename: Charles D
authors.initials: CD
authors.lastname: Searles
mesh_terms: D001011:Aorta / Q000166:cytology; D061945:Caspase Inhibitors / Q000494:pharmacology; D020169:Caspases / Q000378:metabolism; D055252:Cell-Derived Microparticles / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D042783:Endothelial Cells / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism*; D006801:Humans; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism
chemical_list: D061945:Caspase Inhibitors; C527111:MIRN126 microRNA, human; C524942:MIRN155 microRNA, human; C524940:MIRN21 microRNA, human; D035683:MicroRNAs; D014409:Tumor Necrosis Factor-alpha; D054460:rho-Associated Kinases; D020169:Caspases
keywords: TNF-α; atherosclerosis; endothelial cells; extracellular RNA; miRNA release and transfer; microparticles