15
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Exosomes derived from alcohol-treated hepatocytes horizontally transfer liver specific miRNA-122 and sensitize monocytes to LPS

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Hepatocyte damage and inflammation in monocytes/macrophages are central to the pathogenesis of alcoholic hepatitis (AH). MicroRNAs (miRNAs) regulate all of these processes. MiRNA-122 is abundantly expressed in hepatocytes while monocytes/macrophages have low levels. The role of exosomes in AH and possible cross talk between hepatocyte-derived exosomes and immune cells is not explored yet. Here, we show that the number of exosomes significantly increases in the sera of healthy individuals after alcohol binge drinking and in mice after binge or chronic alcohol consumption. Exosomes isolated from sera after alcohol consumption or from in vitro ethanol-treated hepatocytes contained miRNA-122. Exosomes derived from ethanol-treated Huh7.5 cells were taken up by the recipients THP1 monocytes and horizontally transferred a mature form of liver-specific miRNA-122. In vivo, liver mononuclear cells and Kupffer cells from alcohol-fed mice had increased miRNA-122 levels. In monocytes, miRNA-122 transferred via exosomes inhibited the HO-1 pathway and sensitized to LPS stimulation and increased levels of pro-inflammatory cytokines. Finally, inflammatory effects of exosomes from ethanol-treated hepatocytes were prevented by using RNA interference via exosome-mediated delivery of a miRNA-122 inhibitor. These results demonstrate that first, exosomes mediate communication between hepatocytes and monocytes/macrophages and second, hepatocyte-derived miRNA-122 can reprogram monocytes inducing sensitization to LPS.

          Related collections

          Most cited references26

          • Record: found
          • Abstract: found
          • Article: not found
          Is Open Access

          Decoding cell death signals in liver inflammation.

          Inflammation can be either beneficial or detrimental to the liver, depending on multiple factors. Mild (i.e., limited in intensity and destined to resolve) inflammatory responses have indeed been shown to exert consistent hepatoprotective effects, contributing to tissue repair and promoting the re-establishment of homeostasis. Conversely, excessive (i.e., disproportionate in intensity and permanent) inflammation may induce a massive loss of hepatocytes and hence exacerbate the severity of various hepatic conditions, including ischemia-reperfusion injury, systemic metabolic alterations (e.g., obesity, diabetes, non-alcoholic fatty liver disorders), alcoholic hepatitis, intoxication by xenobiotics and infection, de facto being associated with irreversible liver damage, fibrosis, and carcinogenesis. Both liver-resident cells (e.g., Kupffer cells, hepatic stellate cells, sinusoidal endothelial cells) and cells that are recruited in response to injury (e.g., monocytes, macrophages, dendritic cells, natural killer cells) emit pro-inflammatory signals including - but not limited to - cytokines, chemokines, lipid messengers, and reactive oxygen species that contribute to the apoptotic or necrotic demise of hepatocytes. In turn, dying hepatocytes release damage-associated molecular patterns that-upon binding to evolutionary conserved pattern recognition receptors-activate cells of the innate immune system to further stimulate inflammatory responses, hence establishing a highly hepatotoxic feedforward cycle of inflammation and cell death. In this review, we discuss the cellular and molecular mechanisms that account for the most deleterious effect of hepatic inflammation at the cellular level, that is, the initiation of a massive cell death response among hepatocytes. Copyright © 2013 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Codon-optimized Gaussia luciferase cDNA for mammalian gene expression in culture and in vivo.

            Photoproteins have played a major role in advancing our understanding of biological processes. A broader array of biocompatible, nontoxic, and novel reporters can serve to expand this potential. Here we describe the properties of a luciferase from the copepod marine organism Gaussia princeps. It is a monomeric protein composed of 185 aa (19.9 kDa) with a short coding sequence (555 bp) making it suitable for viral vectors. The humanized form of Gaussia luciferase (hGLuc) was efficiently expressed in mammalian cells following delivery by HSV-1 amplicon vectors. It was found to be nontoxic and naturally secreted, with flash bioluminescence characteristics similar to those of other coelenterazine luciferases. hGLuc generated over 1000-fold higher bioluminescent signal intensity from live cells together with their immediate environment and over 100-fold higher intensity from viable cells alone (not including secreted luciferase) or cell lysates, compared to humanized forms of firefly (hFLuc) and Renilla (hRLuc) luciferases expressed under similar conditions. Furthermore, hGLuc showed 200-fold higher signal intensity than hRLuc and intensity comparable to that of hFLuc in vivo under standard imaging conditions. Gaussia luciferase provides a sensitive means of imaging gene delivery and other events in living cells in culture and in vivo, with a unique combination of features including high signal intensity, secretion, and ATP independence, thus being able to report from the cells and their environment in real time.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              An exosome-based secretion pathway is responsible for protein export from Leishmania and communication with macrophages.

              Specialized secretion systems are used by numerous bacterial pathogens to export virulence factors into host target cells. Leishmania and other eukaryotic intracellular pathogens also deliver effector proteins into host cells; however, the mechanisms involved have remained elusive. In this report, we identify exosome-based secretion as a general mechanism for protein secretion by Leishmania, and show that exosomes are involved in the delivery of proteins into host target cells. Comparative quantitative proteomics unambiguously identified 329 proteins in Leishmania exosomes, accounting for >52% of global protein secretion from these organisms. Our findings demonstrate that infection-like stressors (37 degrees C +/- pH 5.5) upregulated exosome release more than twofold and also modified exosome protein composition. Leishmania exosomes and exosomal proteins were detected in the cytosolic compartment of infected macrophages and incubation of macrophages with exosomes selectively induced secretion of IL-8, but not TNF-alpha. We thus provide evidence for an apparently broad-based mechanism of protein export by Leishmania. Moreover, we describe a mechanism for the direct delivery of Leishmania molecules into macrophages. These findings suggest that, like mammalian exosomes, Leishmania exosomes function in long-range communication and immune modulation.
                Bookmark

                Author and article information

                Journal
                Sci Rep
                Sci Rep
                Scientific Reports
                Nature Publishing Group
                2045-2322
                14 May 2015
                2015
                : 5
                Affiliations
                [1 ]Department of Medicine, University of Massachusetts Medical School , Worcester, MA 01605, USA
                Author notes
                [*]

                These authors contributed equally to this work.

                Article
                srep09991
                10.1038/srep09991
                4650752
                25973575
                4f9bb612-abb9-4d7e-b1a5-22f5d3402726
                Copyright © 2015, Macmillan Publishers Limited

                This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/

                Categories
                Article

                Uncategorized
                Uncategorized

                Comments

                Comment on this article