title: Lipid-based carriers of microRNAs and intercellular communication.
abstract: OBJECTIVE
  Extracellular microRNAs (miRNAs) are uniquely stable in plasma, and the levels of specific circulating miRNAs can differ with disease. Extracellular miRNAs are associated with lipid-based carriers and lipid-free proteins. miRNAs can be transferred from cell-to-cell by lipid-based carriers and affect gene expression. This review summarizes recent studies that demonstrate the transfer of miRNA between cells and their potential role in intercellular communication.
  
  
  RESULTS
  Microvesicles, exosomes, apoptotic bodies, lipoproteins, and large microparticles contain miRNAs. Recent studies have demonstrated that miRNAs are transferred between dendritic cells, hepatocellular carcinoma cells, and adipocytes in lipid-based carriers. miRNAs are also transferred from T cells to antigen-presenting cells, from stem cells to endothelial cells and fibroblasts, from macrophages to breast cancer cells, and from epithelial cells to hepatocytes in lipid-based carriers. The cellular export of miRNAs in lipid-based carriers is regulated by the ceramide pathway, and the delivery of lipid-associated miRNAs to recipient cells is achieved by various routes, including endocytotic uptake, membrane-fusion, and scavenger receptors.
  
  
  CONCLUSIONS
  Cellular miRNAs are exported in and to lipid-based carriers (vesicles and lipoprotein particles) and transferred to recipient cells with gene expression changes as intercellular communication.
authors.affiliation: National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA. vickerskc@nhlbi.nih.gov
authors.forename: Kasey C
authors.initials: KC
authors.lastname: Vickers
authors.forename: Alan T
authors.initials: AT
authors.lastname: Remaley
mesh_terms: D001692:Biological Transport; D002450:Cell Communication; D004705:Endocytosis; D055354:Exosomes / Q000737:chemistry / Q000378:metabolism*; D005786:Gene Expression Regulation; D006801:Humans; D008055:Lipids / Q000737:chemistry*; D035683:MicroRNAs / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011956:Receptors, Cell Surface / Q000378:metabolism
chemical_list: D008055:Lipids; D035683:MicroRNAs; D011956:Receptors, Cell Surface