664
views
0
recommends
+1 Recommend
0 collections
    10
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Targeting mitochondrial reactive oxygen species as novel therapy for inflammatory diseases and cancers

      review-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

          There are multiple sources of reactive oxygen species (ROS) in the cell. As a major site of ROS production, mitochondria have drawn considerable interest because it was recently discovered that mitochondrial ROS (mtROS) directly stimulate the production of proinflammatory cytokines and pathological conditions as diverse as malignancies, autoimmune diseases, and cardiovascular diseases all share common phenotype of increased mtROS production above basal levels. Several excellent reviews on this topic have been published, but ever-changing new discoveries mandated a more up-to-date and comprehensive review on this topic. Therefore, we update recent understanding of how mitochondria generate and regulate the production of mtROS and the function of mtROS both in physiological and pathological conditions. In addition, we describe newly developed methods to probe or scavenge mtROS and compare these methods in detail. Thorough understanding of this topic and the application of mtROS-targeting drugs in the research is significant towards development of better therapies to combat inflammatory diseases and inflammatory malignancies.

          Related collections

          Most cited references112

          • Record: found
          • Abstract: found
          • Article: not found

          TLR signaling augments macrophage bactericidal activity through mitochondrial ROS

          Reactive oxygen species (ROS) are essential components of the innate immune response against intracellular bacteria, and it is thought that professional phagocytes generate ROS primarily via the phagosomal NADPH oxidase (Phox) machinery 1 . However, recent studies have suggested that mitochondrial ROS (mROS) also contribute to macrophage bactericidal activity, although the mechanisms linking innate immune signaling to mitochondria for mROS generation remain unclear 2-4 . Here we demonstrate that engagement of a subset of Toll-like receptors (TLR1, TLR2 and TLR4) results in the recruitment of mitochondria to macrophage phagosomes and augments mROS production. This response involves translocation of the TLR signaling adapter tumor necrosis factor receptor-associated factor 6 (TRAF6) to mitochondria where it engages evolutionarily conserved signaling intermediate in Toll pathways (ECSIT), a protein implicated in mitochondrial respiratory chain assembly 5 . Interaction with TRAF6 leads to ECSIT ubiquitination and enrichment at the mitochondrial periphery, resulting in increased mitochondrial and cellular ROS generation. ECSIT and TRAF6 depleted macrophages exhibit decreased levels of TLR-induced ROS and are significantly impaired in their ability to kill intracellular bacteria. Additionally, reducing macrophage mROS by expressing catalase in mitochondria results in defective bacterial killing, confirming the role of mROS in bactericidal activity. These results therefore reveal a novel pathway linking innate immune signaling to mitochondria, implicate mROS as important components of antibacterial responses, and further establish mitochondria as hubs for innate immune signaling.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Reactive oxygen species promote TNFalpha-induced death and sustained JNK activation by inhibiting MAP kinase phosphatases.

            TNFalpha is a pleiotropic cytokine that induces either cell proliferation or cell death. Inhibition of NF-kappaB activation increases susceptibility to TNFalpha-induced death, concurrent with sustained JNK activation, an important contributor to the death response. Sustained JNK activation in NF-kappaB-deficient cells was suggested to depend on reactive oxygen species (ROS), but how ROS affect JNK activation was unclear. We now show that TNFalpha-induced ROS, whose accumulation is suppressed by mitochondrial superoxide dismutase, cause oxidation and inhibition of JNK-inactivating phosphatases by converting their catalytic cysteine to sulfenic acid. This results in sustained JNK activation, which is required for cytochrome c release and caspase 3 cleavage, as well as necrotic cell death. Treatment of cells or experimental animals with an antioxidant prevents H(2)O(2) accumulation, JNK phosphatase oxidation, sustained JNK activity, and both forms of cell death. Antioxidant treatment also prevents TNFalpha-mediated fulminant liver failure without affecting liver regeneration.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Mitochondrial complex III is required for hypoxia-induced ROS production and cellular oxygen sensing.

              Multicellular organisms initiate adaptive responses when oxygen (O(2)) availability decreases, but the underlying mechanism of O(2) sensing remains elusive. We find that functionality of complex III of the mitochondrial electron transport chain (ETC) is required for the hypoxic stabilization of HIF-1 alpha and HIF-2 alpha and that an increase in reactive oxygen species (ROS) links this complex to HIF-alpha stabilization. Using RNAi to suppress expression of the Rieske iron-sulfur protein of complex III, hypoxia-induced HIF-1 alpha stabilization is attenuated, and ROS production, measured using a novel ROS-sensitive FRET probe, is decreased. These results demonstrate that mitochondria function as O(2) sensors and signal hypoxic HIF-1 alpha and HIF-2 alpha stabilization by releasing ROS to the cytosol.
                Bookmark

                Author and article information

                Journal
                J Hematol Oncol
                J Hematol Oncol
                Journal of Hematology & Oncology
                BioMed Central
                1756-8722
                2013
                25 February 2013
                : 6
                : 19
                Affiliations
                [1 ]Cardiovascular Research Center, Department of Pharmacology and Thrombosis Research Center, Temple University School of Medicine, 3500 North Broad Street, Philadelphia, PA 19140, USA
                [2 ]Cardiovascular Research Center and Department of Surgery, Temple University School of Medicine, 3500 North Broad Street, Philadelphia, PA 19140, USA
                Article
                1756-8722-6-19
                10.1186/1756-8722-6-19
                3599349
                23442817
                27c98033-fb29-491c-9737-80ec4ef63c4e
                Copyright ©2013 Li et al; licensee BioMed Central Ltd.

                This is an Open Access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

                History
                : 16 January 2013
                : 20 February 2013
                Categories
                Review

                Oncology & Radiotherapy
                mitochondria,ros,inflammatory diseases
                Oncology & Radiotherapy
                mitochondria, ros, inflammatory diseases

                Comments

                Comment on this article