122
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Redox mechanisms in hepatic chronic wound healing and fibrogenesis

      review-article
      1 , 1 ,
      Fibrogenesis and Tissue Repair
      BioMed Central

      Read this article at

      ScienceOpenPublisherPMC
          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

          Reactive oxygen species (ROS) generated within cells or, more generally, in a tissue environment, may easily turn into a source of cell and tissue injury. Aerobic organisms have developed evolutionarily conserved mechanisms and strategies to carefully control the generation of ROS and other oxidative stress-related radical or non-radical reactive intermediates (that is, to maintain redox homeostasis), as well as to 'make use' of these molecules under physiological conditions as tools to modulate signal transduction, gene expression and cellular functional responses (that is, redox signalling). However, a derangement in redox homeostasis, resulting in sustained levels of oxidative stress and related mediators, can play a significant role in the pathogenesis of major human diseases characterized by chronic inflammation, chronic activation of wound healing and tissue fibrogenesis. This review has been designed to first offer a critical introduction to current knowledge in the field of redox research in order to introduce readers to the complexity of redox signalling and redox homeostasis. This will include ready-to-use key information and concepts on ROS, free radicals and oxidative stress-related reactive intermediates and reactions, sources of ROS in mammalian cells and tissues, antioxidant defences, redox sensors and, more generally, the major principles of redox signalling and redox-dependent transcriptional regulation of mammalian cells. This information will serve as a basis of knowledge to introduce the role of ROS and other oxidative stress-related intermediates in contributing to essential events, such as the induction of cell death, the perpetuation of chronic inflammatory responses, fibrogenesis and much more, with a major focus on hepatic chronic wound healing and liver fibrogenesis.

          Related collections

          Most cited references312

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

          ROS as signalling molecules: mechanisms that generate specificity in ROS homeostasis.

          Reactive oxygen species (ROS) have been shown to be toxic but also function as signalling molecules. This biological paradox underlies mechanisms that are important for the integrity and fitness of living organisms and their ageing. The pathways that regulate ROS homeostasis are crucial for mitigating the toxicity of ROS and provide strong evidence about specificity in ROS signalling. By taking advantage of the chemistry of ROS, highly specific mechanisms have evolved that form the basis of oxidant scavenging and ROS signalling systems.
            • Record: found
            • Abstract: found
            • Article: not found

            Induction of TNF receptor I-mediated apoptosis via two sequential signaling complexes.

            Apoptosis induced by TNF-receptor I (TNFR1) is thought to proceed via recruitment of the adaptor FADD and caspase-8 to the receptor complex. TNFR1 signaling is also known to activate the transcription factor NF-kappa B and promote survival. The mechanism by which this decision between cell death and survival is arbitrated is not clear. We report that TNFR1-induced apoptosis involves two sequential signaling complexes. The initial plasma membrane bound complex (complex I) consists of TNFR1, the adaptor TRADD, the kinase RIP1, and TRAF2 and rapidly signals activation of NF-kappa B. In a second step, TRADD and RIP1 associate with FADD and caspase-8, forming a cytoplasmic complex (complex II). When NF-kappa B is activated by complex I, complex II harbors the caspase-8 inhibitor FLIP(L) and the cell survives. Thus, TNFR1-mediated-signal transduction includes a checkpoint, resulting in cell death (via complex II) in instances where the initial signal (via complex I, NF-kappa B) fails to be activated.
              • 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.

                Author and article information

                Journal
                Fibrogenesis Tissue Repair
                Fibrogenesis and Tissue Repair
                BioMed Central
                1755-1536
                2008
                13 October 2008
                : 1
                : 5
                Affiliations
                [1 ]Dipartimento di Medicina e Oncologia Sperimentale and Centro Interuniversitario di Fisiopatologia Epatica, Università degli Studi di Torino, Corso Raffaello 30, 10125 Torino, Italy
                Article
                1755-1536-1-5
                10.1186/1755-1536-1-5
                2584013
                19014652
                463f62ef-12c2-4b31-ad38-7a18031e6b72
                Copyright © 2008 Novo 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
                : 21 May 2008
                : 13 October 2008
                Categories
                Review

                Molecular biology
                Molecular biology

                Comments

                Comment on this article

                Related Documents Log