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Mallat J. Exploring the Pathophysiological Mechanisms of Hyperlactatemia in Critically Ill Patients Following Cardiopulmonary Bypass. Crit Care Med 2024; 52:1315-1319. [PMID: 39007576 DOI: 10.1097/ccm.0000000000006319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Affiliation(s)
- Jihad Mallat
- Critical Care Institute, Cleveland Clinic Abu Dhabi, Al Maryah Island, Abu Dhabi, United Arab Emirates
- Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH
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2
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Reeder BJ, Svistunenko DA, Wilson MT. Hell's Gate Globin-I from Methylacidiphilum infernorum Displays a Unique Temperature-Independent pH Sensing Mechanism Utililized a Lipid-Induced Conformational Change. Int J Mol Sci 2024; 25:6794. [PMID: 38928500 PMCID: PMC11203436 DOI: 10.3390/ijms25126794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2024] [Revised: 06/05/2024] [Accepted: 06/14/2024] [Indexed: 06/28/2024] Open
Abstract
Hell's Gate globin-I (HGb-I) is a thermally stable globin from the aerobic methanotroph Methylacidiphilium infernorum. Here we report that HGb-I interacts with lipids stoichiometrically to induce structural changes in the heme pocket, changing the heme iron distal ligation coordination from hexacoordinate to pentacoordinate. Such changes in heme geometry have only been previously reported for cytochrome c and cytoglobin, linked to apoptosis regulation and enhanced lipid peroxidation activity, respectively. However, unlike cytoglobin and cytochrome c, the heme iron of HGb-I is altered by lipids in ferrous as well as ferric oxidation states. The apparent affinity for lipids in this thermally stable globin is highly pH-dependent but essentially temperature-independent within the range of 20-60 °C. We propose a mechanism to explain these observations, in which lipid binding and stability of the distal endogenous ligand are juxtaposed as a function of temperature. Additionally, we propose that these coupled equilibria may constitute a mechanism through which this acidophilic thermophile senses the pH of its environment.
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Affiliation(s)
- Brandon J. Reeder
- School of Biological Sciences, University of Essex, Wivenhoe Park Colchester, Essex CO4 3SQ, UK; (D.A.S.); (M.T.W.)
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3
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De Backer D, Deutschman CS, Hellman J, Myatra SN, Ostermann M, Prescott HC, Talmor D, Antonelli M, Pontes Azevedo LC, Bauer SR, Kissoon N, Loeches IM, Nunnally M, Tissieres P, Vieillard-Baron A, Coopersmith CM. Surviving Sepsis Campaign Research Priorities 2023. Crit Care Med 2024; 52:268-296. [PMID: 38240508 DOI: 10.1097/ccm.0000000000006135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
OBJECTIVES To identify research priorities in the management, epidemiology, outcome, and pathophysiology of sepsis and septic shock. DESIGN Shortly after publication of the most recent Surviving Sepsis Campaign Guidelines, the Surviving Sepsis Research Committee, a multiprofessional group of 16 international experts representing the European Society of Intensive Care Medicine and the Society of Critical Care Medicine, convened virtually and iteratively developed the article and recommendations, which represents an update from the 2018 Surviving Sepsis Campaign Research Priorities. METHODS Each task force member submitted five research questions on any sepsis-related subject. Committee members then independently ranked their top three priorities from the list generated. The highest rated clinical and basic science questions were developed into the current article. RESULTS A total of 81 questions were submitted. After merging similar questions, there were 34 clinical and ten basic science research questions submitted for voting. The five top clinical priorities were as follows: 1) what is the best strategy for screening and identification of patients with sepsis, and can predictive modeling assist in real-time recognition of sepsis? 2) what causes organ injury and dysfunction in sepsis, how should it be defined, and how can it be detected? 3) how should fluid resuscitation be individualized initially and beyond? 4) what is the best vasopressor approach for treating the different phases of septic shock? and 5) can a personalized/precision medicine approach identify optimal therapies to improve patient outcomes? The five top basic science priorities were as follows: 1) How can we improve animal models so that they more closely resemble sepsis in humans? 2) What outcome variables maximize correlations between human sepsis and animal models and are therefore most appropriate to use in both? 3) How does sepsis affect the brain, and how do sepsis-induced brain alterations contribute to organ dysfunction? How does sepsis affect interactions between neural, endocrine, and immune systems? 4) How does the microbiome affect sepsis pathobiology? 5) How do genetics and epigenetics influence the development of sepsis, the course of sepsis and the response to treatments for sepsis? CONCLUSIONS Knowledge advances in multiple clinical domains have been incorporated in progressive iterations of the Surviving Sepsis Campaign guidelines, allowing for evidence-based recommendations for short- and long-term management of sepsis. However, the strength of existing evidence is modest with significant knowledge gaps and mortality from sepsis remains high. The priorities identified represent a roadmap for research in sepsis and septic shock.
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Affiliation(s)
- Daniel De Backer
- Department of Intensive Care, CHIREC Hospitals, Université Libre de Bruxelles, Brussels, Belgium
| | - Clifford S Deutschman
- Department of Pediatrics, Cohen Children's Medical Center, Northwell Health, New Hyde Park, NY
- Sepsis Research Lab, the Feinstein Institutes for Medical Research, Manhasset, NY
| | - Judith Hellman
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA
| | - Sheila Nainan Myatra
- Department of Anaesthesiology, Critical Care and Pain, Tata Memorial Hospital, Homi Bhabha National Institute, Mumbai, India
| | - Marlies Ostermann
- Department of Critical Care, King's College London, Guy's & St Thomas' Hospital, London, United Kingdom
| | - Hallie C Prescott
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | - Daniel Talmor
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA
| | - Massimo Antonelli
- Department of Intensive Care, Emergency Medicine and Anesthesiology, Fondazione Policlinico Universitario A.Gemelli IRCCS, Rome, Italy
- Istituto di Anestesiologia e Rianimazione, Università Cattolica del Sacro Cuore, Rome, Italy
| | | | - Seth R Bauer
- Department of Pharmacy, Cleveland Clinic, Cleveland, OH
| | - Niranjan Kissoon
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Ignacio-Martin Loeches
- Department of Intensive Care Medicine, Multidisciplinary Intensive Care Research Organization (MICRO), St James's Hospital, Leinster, Dublin, Ireland
| | | | - Pierre Tissieres
- Pediatric Intensive Care, Neonatal Medicine and Pediatric Emergency, AP-HP Paris Saclay University, Bicêtre Hospital, Le Kremlin-Bicêtre, France
| | - Antoine Vieillard-Baron
- Service de Medecine Intensive Reanimation, Hopital Ambroise Pare, Universite Paris-Saclay, Le Kremlin-Bicêtre, France
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Lučić M, Wilson MT, Pullin J, Hough MA, Svistunenko DA, Worrall JAR. New insights into controlling radical migration pathways in heme enzymes gained from the study of a dye-decolorising peroxidase. Chem Sci 2023; 14:12518-12534. [PMID: 38020392 PMCID: PMC10646903 DOI: 10.1039/d3sc04453j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Accepted: 10/06/2023] [Indexed: 12/01/2023] Open
Abstract
In heme enzymes, such as members of the dye-decolorising peroxidase (DyP) family, the formation of the highly oxidising catalytic Fe(iv)-oxo intermediates following reaction with hydrogen peroxide can lead to free radical migration (hole hopping) from the heme to form cationic tyrosine and/or tryptophan radicals. These species are highly oxidising (∼1 V vs. NHE) and under certain circumstances can catalyse the oxidation of organic substrates. Factors that govern which specific tyrosine or tryptophan the free radical migrates to in heme enzymes are not well understood, although in the case of tyrosyl radical formation the nearby proximity of a proton acceptor is a recognised facilitating factor. By using an A-type member of the DyP family (DtpAa) as an exemplar, we combine protein engineering, X-ray crystallography, hole-hopping calculations, EPR spectroscopy and kinetic modelling to provide compelling new insights into the control of radical migration pathways following reaction of the heme with hydrogen peroxide. We demonstrate that the presence of a tryptophan/tyrosine dyad motif displaying a T-shaped orientation of aromatic rings on the proximal side of the heme dominates the radical migration landscape in wild-type DtpAa and continues to do so following the rational engineering into DtpAa of a previously identified radical migration pathway in an A-type homolog on the distal side of the heme. Only on disrupting the proximal dyad, through removal of an oxygen atom, does the radical migration pathway then switch to the engineered distal pathway to form the desired tyrosyl radical. Implications for protein design and biocatalysis are discussed.
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Affiliation(s)
- Marina Lučić
- School of Life Sciences, University of Essex Wivenhoe Park Colchester Essex CO4 3SQ UK
| | - Michael T Wilson
- School of Life Sciences, University of Essex Wivenhoe Park Colchester Essex CO4 3SQ UK
| | - Jacob Pullin
- School of Life Sciences, University of Essex Wivenhoe Park Colchester Essex CO4 3SQ UK
| | - Michael A Hough
- School of Life Sciences, University of Essex Wivenhoe Park Colchester Essex CO4 3SQ UK
- Diamond Light Source, Harwell Science and Innovation Campus Didcot Oxfordshire OX11 0DE UK
| | - Dimitri A Svistunenko
- School of Life Sciences, University of Essex Wivenhoe Park Colchester Essex CO4 3SQ UK
| | - Jonathan A R Worrall
- School of Life Sciences, University of Essex Wivenhoe Park Colchester Essex CO4 3SQ UK
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5
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Nedel W, Deutschendorf C, Portela LVC. Sepsis-induced mitochondrial dysfunction: A narrative review. World J Crit Care Med 2023; 12:139-152. [PMID: 37397587 PMCID: PMC10308342 DOI: 10.5492/wjccm.v12.i3.139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 03/08/2023] [Accepted: 04/14/2023] [Indexed: 06/08/2023] Open
Abstract
Sepsis represents a deranged and exaggerated systemic inflammatory response to infection and is associated with vascular and metabolic abnormalities that trigger systemic organic dysfunction. Mitochondrial function has been shown to be severely impaired during the early phase of critical illness, with a reduction in biogenesis, increased generation of reactive oxygen species and a decrease in adenosine triphosphate synthesis of up to 50%. Mitochondrial dysfunction can be assessed using mitochondrial DNA concentration and respirometry assays, particularly in peripheral mononuclear cells. Isolation of monocytes and lymphocytes seems to be the most promising strategy for measuring mitochondrial activity in clinical settings because of the ease of collection, sample processing, and clinical relevance of the association between metabolic alterations and deficient immune responses in mononuclear cells. Studies have reported alterations in these variables in patients with sepsis compared with healthy controls and non-septic patients. However, few studies have explored the association between mitochondrial dysfunction in immune mononuclear cells and unfavorable clinical outcomes. An improvement in mitochondrial parameters in sepsis could theoretically serve as a biomarker of clinical recovery and response to oxygen and vasopressor therapies as well as reveal unexplored pathophysiological mechanistic targets. These features highlight the need for further studies on mitochondrial metabolism in immune cells as a feasible tool to evaluate patients in intensive care settings. The evaluation of mitochondrial metabolism is a promising tool for the evaluation and management of critically ill patients, especially those with sepsis. In this article, we explore the pathophysiological aspects, main methods of measurement, and the main studies in this field.
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Affiliation(s)
- Wagner Nedel
- Intensive Care Unit, Grupo Hospitalar Conceição, Porto Alegre 91350200, Brazil
- Laboratory of Neurotrauma and Biomarkers, Departamento de Bioquímica, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre 90035-003, Brazil
- Brazilian Research in Intensive Care Network-BRICNet, São Paulo 04039-002, Brazil
| | - Caroline Deutschendorf
- Infection Control Committee, Hospital de Clínicas de Porto Alegre, Porto Alegre 90410-000, Brazil
| | - Luis Valmor Cruz Portela
- Laboratory of Neurotrauma and Biomarkers, Departamento de Bioquímica, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre 90035-003, Brazil
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Duan G, Huang P, Zheng C, Zheng J, Yu J, Zhang P, Wan M, Li F, Guo Q, Yin Y, Duan Y. Development and Recovery of Liver Injury in Piglets by Incremental Injection of LPS. Antioxidants (Basel) 2023; 12:1143. [PMID: 37371873 DOI: 10.3390/antiox12061143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 05/21/2023] [Accepted: 05/22/2023] [Indexed: 06/29/2023] Open
Abstract
This study aimed to explore the effects of the incremental injection of lipopolysaccharide (LPS) on liver histopathology, inflammation, oxidative status, and mitochondrial function in piglets. Forty healthy Duroc × Landrace × Yorkshire castrated boars (21 ± 2 days old, weight 6.84 ± 0.11 kg) were randomly assigned to five groups (n = 8) and then slaughtered on days 0 (group 0, without LPS injection), 1 (group 1), 5 (group 5), 9 (group 9), and 15 (group 15) of LPS injection, respectively. The results showed that, compared to the piglets without LPS injection, LPS injection caused liver injury in the early phase, as manifested by the increased activities of serum liver injury-related parameters (aspartate amino transferase, alanine aminotransferase, alkaline phosphatase, cholinesterase, and total bile acid) on day 1, and impaired liver morphology (disordered hepatic cell cord arrangement, dissolved and vacuolized hepatocytes, karyopycnosis, and inflammatory cell infiltration and congestion) on days 1 and 5. Meanwhile, LPS injection caused liver inflammation, oxidative stress, and mitochondrial dysfunction on days 1 and 5, as reflected by the upregulated mRNA expression of TNF-α, IL-6, IL-1β, TLR4, MyD88, and NF-κB; increased MPO and MDA content; and impaired mitochondrial morphology. However, these parameters were ameliorated in the later phase (days 9~15). Taken together, our data indicate that the incremental injection of the LPS-induced liver injury of piglets could be self-repaired.
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Affiliation(s)
- Geyan Duan
- CAS Key Laboratory of Agro-Ecological Processes in Subtropical Region, Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Pan Huang
- CAS Key Laboratory of Agro-Ecological Processes in Subtropical Region, Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China
| | - Changbing Zheng
- College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China
| | - Jie Zheng
- CAS Key Laboratory of Agro-Ecological Processes in Subtropical Region, Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Jiayi Yu
- CAS Key Laboratory of Agro-Ecological Processes in Subtropical Region, Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peiwen Zhang
- College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China
| | - Mengliao Wan
- College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China
| | - Fengna Li
- CAS Key Laboratory of Agro-Ecological Processes in Subtropical Region, Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Qiuping Guo
- CAS Key Laboratory of Agro-Ecological Processes in Subtropical Region, Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yulong Yin
- CAS Key Laboratory of Agro-Ecological Processes in Subtropical Region, Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- College of Animal Science and Technology, Hunan Agricultural University, Changsha 410128, China
| | - Yehui Duan
- CAS Key Laboratory of Agro-Ecological Processes in Subtropical Region, Hunan Provincial Key Laboratory of Animal Nutritional Physiology and Metabolic Process, National Engineering Laboratory for Pollution Control and Waste Utilization in Livestock and Poultry Production, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Scientific Observing and Experimental Station of Animal Nutrition and Feed Science in South-Central, Ministry of Agriculture, Changsha 410125, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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7
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Role of succinic acid in the regulation of sepsis. Int Immunopharmacol 2022; 110:109065. [PMID: 35853278 DOI: 10.1016/j.intimp.2022.109065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 07/13/2022] [Accepted: 07/13/2022] [Indexed: 11/23/2022]
Abstract
Sepsis is a life-threatening disease characterized by a defensive response to damage. The immune response in patients with sepsis is overenhanced in the early stages and suppressed in the later stages, leading to poor prognosis. Metabolic reprogramming and epigenetic changes play a role in sepsis. Metabolic intermediates such as elevated succinic acid levels are significantly altered in patients with sepsis. Succinic acid, a metabolic intermediate of the tricarboxylic acid cycle, participates in energy supply and plays a role in metabolic reprogramming. Simultaneously, as an epigenetic regulator, it participates in gene transcription, translation, and post-translational modifications. It also participates in the inflammatory response, hypoxia, and the production of reactive oxygen species via endocrine and paracrine pathways. In this review, we have discussed the effects of succinic acid on sepsis and its therapeutic potential.
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Preau S, Vodovar D, Jung B, Lancel S, Zafrani L, Flatres A, Oualha M, Voiriot G, Jouan Y, Joffre J, Huel F, De Prost N, Silva S, Azabou E, Radermacher P. Energetic dysfunction in sepsis: a narrative review. Ann Intensive Care 2021; 11:104. [PMID: 34216304 PMCID: PMC8254847 DOI: 10.1186/s13613-021-00893-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Accepted: 06/24/2021] [Indexed: 02/07/2023] Open
Abstract
Background Growing evidence associates organ dysfunction(s) with impaired metabolism in sepsis. Recent research has increased our understanding of the role of substrate utilization and mitochondrial dysfunction in the pathophysiology of sepsis-related organ dysfunction. The purpose of this review is to present this evidence as a coherent whole and to highlight future research directions. Main text Sepsis is characterized by systemic and organ-specific changes in metabolism. Alterations of oxygen consumption, increased levels of circulating substrates, impaired glucose and lipid oxidation, and mitochondrial dysfunction are all associated with organ dysfunction and poor outcomes in both animal models and patients. The pathophysiological relevance of bioenergetics and metabolism in the specific examples of sepsis-related immunodeficiency, cerebral dysfunction, cardiomyopathy, acute kidney injury and diaphragmatic failure is also described. Conclusions Recent understandings in substrate utilization and mitochondrial dysfunction may pave the way for new diagnostic and therapeutic approaches. These findings could help physicians to identify distinct subgroups of sepsis and to develop personalized treatment strategies. Implications for their use as bioenergetic targets to identify metabolism- and mitochondria-targeted treatments need to be evaluated in future studies. Supplementary Information The online version contains supplementary material available at 10.1186/s13613-021-00893-7.
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Affiliation(s)
- Sebastien Preau
- U1167 - RID-AGE - Facteurs de Risque et Déterminants Moléculaires des Maladies Liées au Vieillissement, University Lille, Inserm, CHU Lille, Institut Pasteur de Lille, F-59000, Lille, France.
| | - Dominique Vodovar
- Centre AntiPoison de Paris, Hôpital Fernand Widal, APHP, 75010, Paris, France.,Faculté de pharmacie, UMRS 1144, 75006, Paris, France.,Université de Paris, UFR de Médecine, 75010, Paris, France
| | - Boris Jung
- Medical Intensive Care Unit, Lapeyronie Teaching Hospital, Montpellier University Hospital and PhyMedExp, University of Montpellier, Montpellier, France
| | - Steve Lancel
- U1167 - RID-AGE - Facteurs de Risque et Déterminants Moléculaires des Maladies Liées au Vieillissement, University Lille, Inserm, CHU Lille, Institut Pasteur de Lille, F-59000, Lille, France
| | - Lara Zafrani
- Médecine Intensive Réanimation, Hôpital Saint-Louis, AP-HP, Université de Paris, Paris, France.,INSERM UMR 976, Hôpital Saint Louis, Université de Paris, Paris, France
| | | | - Mehdi Oualha
- Pediatric Intensive Care Unit, Necker Hospital, APHP, Centre - Paris University, Paris, France
| | - Guillaume Voiriot
- Service de Médecine Intensive Réanimation, Sorbonne Université, Assistance Publique - Hôpitaux de Paris, Hôpital Tenon, Paris, France
| | - Youenn Jouan
- Service de Médecine Intensive Réanimation, CHRU Tours, Tours, France.,Faculté de Médecine de Tours, INSERM U1100 Centre d'Etudes des Pathologies Respiratoires, Tours, France
| | - Jeremie Joffre
- Department of Anesthesia and Perioperative Care, University of California, San Francisco, CA, 94143, USA
| | - Fabrice Huel
- Réanimation médico-chirurgicale, Université de Paris, Assistance Publique - Hôpitaux de Paris, Hôpital Louis Mourier, Paris, France
| | - Nicolas De Prost
- Service de Réanimation Médicale, Hôpital Henri Mondor, Assistance Publique-Hôpitaux de Paris, Cedex 94010, Créteil, France
| | - Stein Silva
- Réanimation URM CHU Purpan, Cedex 31300, Toulouse, France.,Toulouse NeuroImaging Center INSERM1214, Cedex 31300, Toulouse, France
| | - Eric Azabou
- Clinical Neurophysiology and Neuromodulation Unit, Departments of Physiology and Critical Care Medicine, Raymond Poincaré Hospital, AP-HP, Inserm UMR 1173, Infection and Inflammation (2I), University of Versailles (UVSQ), Paris-Saclay University, Paris, France
| | - Peter Radermacher
- Institut für Anästhesiologische Pathophysiologie und Verfahrensentwicklung, Universitätsklinikum, Ulm, Germany
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Svistunenko DA. EPR spectroscopy of whole blood and blood components: can we diagnose abnormalities? J Biomed Res 2021; 35:294-300. [PMID: 34282059 PMCID: PMC8383175 DOI: 10.7555/jbr.35.20210011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
This mini-review gives a brief account of the emergence of the electron paramagnetic resonance (EPR) spectroscopy in the second half of the 20th century and reports the continuous wave EPR spectroscopy studies on human and animal blood. The question posed by this review is whether the EPR spectroscopy in the form it appeared 70 years ago is still able to provide useful information about different pathological conditions in humans, particularly in the area of diagnosis.
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10
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Hyatt HW, Powers SK. Mitochondrial Dysfunction Is a Common Denominator Linking Skeletal Muscle Wasting Due to Disease, Aging, and Prolonged Inactivity. Antioxidants (Basel) 2021; 10:antiox10040588. [PMID: 33920468 PMCID: PMC8070615 DOI: 10.3390/antiox10040588] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 04/02/2021] [Accepted: 04/07/2021] [Indexed: 12/29/2022] Open
Abstract
Skeletal muscle is the most abundant tissue in the body and is required for numerous vital functions, including breathing and locomotion. Notably, deterioration of skeletal muscle mass is also highly correlated to mortality in patients suffering from chronic diseases (e.g., cancer). Numerous conditions can promote skeletal muscle wasting, including several chronic diseases, cancer chemotherapy, aging, and prolonged inactivity. Although the mechanisms responsible for this loss of muscle mass is multifactorial, mitochondrial dysfunction is predicted to be a major contributor to muscle wasting in various conditions. This systematic review will highlight the biochemical pathways that have been shown to link mitochondrial dysfunction to skeletal muscle wasting. Importantly, we will discuss the experimental evidence that connects mitochondrial dysfunction to muscle wasting in specific diseases (i.e., cancer and sepsis), aging, cancer chemotherapy, and prolonged muscle inactivity (e.g., limb immobilization). Finally, in hopes of stimulating future research, we conclude with a discussion of important future directions for research in the field of muscle wasting.
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Alterations in Mitochondrial Function in Blood Cells Obtained From Patients With Sepsis Presenting to an Emergency Department. Shock 2020; 51:580-584. [PMID: 29905672 DOI: 10.1097/shk.0000000000001208] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
OBJECTIVE Mitochondrial dysfunction has been implicated as a key cellular event leading to organ dysfunction in sepsis. Our objective is to measure changes in mitochondrial bioenergetics in subjects with early presentation of sepsis to provide insight into the incompletely understood pathophysiology of the dysregulated host response in sepsis. DESIGN Prospective observational study. SETTING Single site tertiary academic emergency department. SUBJECTS We enrolled a total of 48 subjects in the study, 10 with sepsis or septic shock, 10 with infection without sepsis, 14 older and 14 younger healthy controls. INTERVENTIONS Peripheral blood mononuclear cells were measured with high-resolution respirometry (OROBOROS O2K). MEASUREMENTS AND MAIN RESULTS The median age in patients with sepsis, infection only, older control and younger controls were 63, 34, 61, and 29 years old, respectively. In the Sepsis group, the median 1st 24-h SOFA score was 8, and the initial median lactate was 4.2 mmol/dL, compared with 1.1 in the Infection Group. The 30-day mortality of the sepsis/septic shock group was 50%, with a median length of stay of 7-days. The Sepsis Group had significantly lower routine and Max respiration when compared with the other groups as well as uncoupled Complex I respiration. There was also a significant decrease in ATP-linked respiration along with the Spare Reserve Capacity in the Sepsis Group when compared with the other group. There were no age-related differences in respiration between the Older and Younger control group. CONCLUSIONS Bedside measurement of mitochondrial respiration can be minimally invasive and performed in a timely manner. Mitochondrial dysfunction, detected by decreased oxygen consumption utilized for energy production and depleted cellular bioenergetics reserve.
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12
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Wright JJ, Fedor JG, Hirst J, Roessler MM. Using a chimeric respiratory chain and EPR spectroscopy to determine the origin of semiquinone species previously assigned to mitochondrial complex I. BMC Biol 2020; 18:54. [PMID: 32429970 PMCID: PMC7238650 DOI: 10.1186/s12915-020-00768-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2019] [Accepted: 03/11/2020] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND For decades, semiquinone intermediates have been suggested to play an essential role in catalysis by one of the most enigmatic proton-pumping enzymes, respiratory complex I, and different mechanisms have been proposed on their basis. However, the difficulty in investigating complex I semiquinones, due to the many different enzymes embedded in the inner mitochondrial membrane, has resulted in an ambiguous picture and no consensus. RESULTS In this paper, we re-examine the highly debated origin of semiquinone species in mitochondrial membranes using a novel approach. Our combination of a semi-artificial chimeric respiratory chain with pulse EPR spectroscopy (HYSCORE) has enabled us to conclude, unambiguously and for the first time, that the majority of the semiquinones observed in mitochondrial membranes originate from complex III. We also identify a minor contribution from complex II. CONCLUSIONS We are unable to attribute any semiquinone signals unambiguously to complex I and, reconciling our observations with much of the previous literature, conclude that they are likely to have been misattributed to it. We note that, for this earlier work, the tools we have relied on here to deconvolute overlapping EPR signals were not available. Proposals for the mechanism of complex I based on the EPR signals of semiquinone species observed in mitochondrial membranes should thus be treated with caution until future work has succeeded in isolating any complex I semiquinone EPR spectroscopic signatures present.
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Affiliation(s)
- John J Wright
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Justin G Fedor
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Judy Hirst
- Medical Research Council Mitochondrial Biology Unit, University of Cambridge, Cambridge, CB2 0XY, UK
| | - Maxie M Roessler
- School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London, E1 4NS, UK.
- Department of Chemistry, Imperial College London, Molecular Sciences Research Hub, White City Campus, Wood Lane, London, W12 0BZ, UK.
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13
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Lučić M, Chaplin AK, Moreno-Chicano T, Dworkowski FSN, Wilson MT, Svistunenko DA, Hough MA, Worrall JAR. A subtle structural change in the distal haem pocket has a remarkable effect on tuning hydrogen peroxide reactivity in dye decolourising peroxidases fromStreptomyces lividans. Dalton Trans 2020; 49:1620-1636. [DOI: 10.1039/c9dt04583j] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A subtle positional shift of the distal haem pocket aspartate in two dye decolourising peroxidase homologs has a remarkable effect on their reactivity with H2O2.
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Affiliation(s)
- Marina Lučić
- School of Life Sciences
- University of Essex
- Colchester
- UK
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14
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Pellicer Martinez MT, Crack JC, Stewart MYY, Bradley JM, Svistunenko DA, Johnston AWB, Cheesman MR, Todd JD, Le Brun NE. Mechanisms of iron- and O 2-sensing by the [4Fe-4S] cluster of the global iron regulator RirA. eLife 2019; 8:e47804. [PMID: 31526471 PMCID: PMC6748827 DOI: 10.7554/elife.47804] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2019] [Accepted: 07/29/2019] [Indexed: 01/05/2023] Open
Abstract
RirA is a global regulator of iron homeostasis in Rhizobium and related α-proteobacteria. In its [4Fe-4S] cluster-bound form it represses iron uptake by binding to IRO Box sequences upstream of RirA-regulated genes. Under low iron and/or aerobic conditions, [4Fe-4S] RirA undergoes cluster conversion/degradation to apo-RirA, which can no longer bind IRO Box sequences. Here, we apply time-resolved mass spectrometry and electron paramagnetic resonance spectroscopy to determine how the RirA cluster senses iron and O2. The data indicate that the key iron-sensing step is the O2-independent, reversible dissociation of Fe2+ from [4Fe-4S]2+ to form [3Fe-4S]0. The dissociation constant for this process was determined as Kd = ~3 µM, which is consistent with the sensing of 'free' iron in the cytoplasm. O2-sensing occurs through enhanced cluster degradation under aerobic conditions, via O2-mediated oxidation of the [3Fe-4S]0 intermediate to form [3Fe-4S]1+. This work provides a detailed mechanistic/functional view of an iron-responsive regulator.
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Affiliation(s)
- Ma Teresa Pellicer Martinez
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | - Jason C Crack
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | - Melissa YY Stewart
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | - Justin M Bradley
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | | | - Andrew WB Johnston
- School of Biological SciencesUniversity of East AngliaNorwichUnited Kingdom
| | - Myles R Cheesman
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
| | - Jonathan D Todd
- School of Biological SciencesUniversity of East AngliaNorwichUnited Kingdom
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry, School of ChemistryUniversity of East AngliaNorwichUnited Kingdom
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15
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Mathematical modeling of septic shock: an innovative tool for assessing therapeutic hypotheses. SN APPLIED SCIENCES 2019. [DOI: 10.1007/s42452-019-0747-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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16
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Chaplin AK, Chicano TM, Hampshire BV, Wilson MT, Hough MA, Svistunenko DA, Worrall JAR. An Aromatic Dyad Motif in Dye Decolourising Peroxidases Has Implications for Free Radical Formation and Catalysis. Chemistry 2019; 25:6141-6153. [PMID: 30945782 DOI: 10.1002/chem.201806290] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Indexed: 01/27/2023]
Abstract
Dye decolouring peroxidases (DyPs) are the most recent class of heme peroxidase to be discovered. On reacting with H2 O2 , DyPs form a high-valent iron(IV)-oxo species and a porphyrin radical (Compound I) followed by stepwise oxidation of an organic substrate. In the absence of substrate, the ferryl species decays to form transient protein-bound radicals on redox active amino acids. Identification of radical sites in DyPs has implications for their oxidative mechanism with substrate. Using a DyP from Streptomyces lividans, referred to as DtpA, which displays low reactivity towards synthetic dyes, activation with H2 O2 was explored. A Compound I EPR spectrum was detected, which in the absence of substrate decays to a protein-bound radical EPR signal. Using a newly developed version of the Tyrosyl Radical Spectra Simulation Algorithm, the radical EPR signal was shown to arise from a pristine tyrosyl radical and not a mixed Trp/Tyr radical that has been widely reported in DyP members exhibiting high activity with synthetic dyes. The radical site was identified as Tyr374, with kinetic studies inferring that although Tyr374 is not on the electron-transfer pathway from the dye RB19, its replacement with a Phe does severely compromise activity with other organic substrates. These findings hint at the possibility that alternative electron-transfer pathways for substrate oxidation are operative within the DyP family. In this context, a role for a highly conserved aromatic dyad motif is discussed.
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Affiliation(s)
- Amanda K Chaplin
- Present address: Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK
| | - Tadeo Moreno Chicano
- Present address: Department of Molecular Mechanisms, Max Planck Institute for Medical Research, Jahnstraße 29, 69120, Heidelberg, Germany
| | - Bethany V Hampshire
- Present address: Department of Physics, University of Warwick, Coventry, CV4 7AL, UK
| | - Michael T Wilson
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
| | - Michael A Hough
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
| | - Dimitri A Svistunenko
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
| | - Jonathan A R Worrall
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK
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17
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Antholine WE, Vasquez-Vivar J, Quirk BJ, Whelan HT, Wu PK, Park JI, Myers CR. Treatment of Cells and Tissues with Chromate Maximizes Mitochondrial 2Fe2S EPR Signals. Int J Mol Sci 2019; 20:ijms20051143. [PMID: 30845710 PMCID: PMC6429069 DOI: 10.3390/ijms20051143] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Revised: 02/22/2019] [Accepted: 02/26/2019] [Indexed: 11/25/2022] Open
Abstract
In a previous study on chromate toxicity, an increase in the 2Fe2S electron paramagnetic resonance (EPR) signal from mitochondria was found upon addition of chromate to human bronchial epithelial cells and bovine airway tissue ex vivo. This study was undertaken to show that a chromate-induced increase in the 2Fe2S EPR signal is a general phenomenon that can be used as a low-temperature EPR method to determine the maximum concentration of 2Fe2S centers in mitochondria. First, the low-temperature EPR method to determine the concentration of 2Fe2S clusters in cells and tissues is fully developed for other cells and tissues. The EPR signal for the 2Fe2S clusters N1b in Complex I and/or S1 in Complex II and the 2Fe2S cluster in xanthine oxidoreductase in rat liver tissue do not change in intensity because these clusters are already reduced; however, the EPR signals for N2, the terminal cluster in Complex I, and N4, the cluster preceding the terminal cluster, decrease upon adding chromate. More surprising to us, the EPR signals for N3, the cluster preceding the 2Fe2S cluster in Complex I, also decrease upon adding chromate. Moreover, this method is used to obtain the concentration of the 2Fe2S clusters in white blood cells where the 2Fe2S signal is mostly oxidized before treatment with chromate and becomes reduced and EPR detectable after treatment with chromate. The increase of the g = 1.94 2Fe2S EPR signal upon the addition of chromate can thus be used to obtain the relative steady-state concentration of the 2Fe2S clusters and steady-state concentration of Complex I and/or Complex II in mitochondria.
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Affiliation(s)
- William E Antholine
- Department of Biophysics, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | | | - Brendan J Quirk
- Departments of Neurology and Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | - Harry T Whelan
- Departments of Neurology and Pediatrics, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | - Pui Kei Wu
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | - Jong-In Park
- Department of Biochemistry, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
| | - Charles R Myers
- Department of Pharmacology and Toxicology, Medical College Wisconsin, Wauwatosa, WI 53226, USA.
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18
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Increased Plasma Acetylcarnitine in Sepsis Is Associated With Multiple Organ Dysfunction and Mortality. Crit Care Med 2019; 47:210-218. [DOI: 10.1097/ccm.0000000000003517] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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19
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The role of mitochondria in sepsis-induced cardiomyopathy. Biochim Biophys Acta Mol Basis Dis 2018; 1865:759-773. [PMID: 30342158 DOI: 10.1016/j.bbadis.2018.10.011] [Citation(s) in RCA: 96] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2018] [Revised: 10/02/2018] [Accepted: 10/05/2018] [Indexed: 02/08/2023]
Abstract
Sepsis is defined as a life-threatening organ dysfunction caused by a dysregulated host response to infection. Myocardial dysfunction, often termed sepsis-induced cardiomyopathy, is a frequent complication and is associated with worse outcomes. Numerous mechanisms contribute to sepsis-induced cardiomyopathy and a growing body of evidence suggests that bioenergetic and metabolic derangements play a central role in its development; however, there are significant discrepancies in the literature, perhaps reflecting variability in the experimental models employed or in the host response to sepsis. The condition is characterised by lack of significant cell death, normal tissue oxygen levels and, in survivors, reversibility of organ dysfunction. The functional changes observed in cardiac tissue may represent an adaptive response to prolonged stress that limits cell death, improving the potential for recovery. In this review, we describe our current understanding of the pathophysiology underlying myocardial dysfunction in sepsis, with a focus on disrupted mitochondrial processes.
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20
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Sims CA, Guan Y, Mukherjee S, Singh K, Botolin P, Davila A, Baur JA. Nicotinamide mononucleotide preserves mitochondrial function and increases survival in hemorrhagic shock. JCI Insight 2018; 3:120182. [PMID: 30185676 DOI: 10.1172/jci.insight.120182] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 07/10/2018] [Indexed: 12/26/2022] Open
Abstract
Hemorrhagic shock depletes nicotinamide adenine dinucleotide (NAD) and causes metabolic derangements that, in severe cases, cannot be overcome, even after restoration of blood volume and pressure. However, current strategies to treat acute blood loss do not target cellular metabolism. We hypothesized that supplemental nicotinamide mononucleotide (NMN), the immediate biosynthetic precursor to NAD, would support cellular energetics and enhance physiologic resilience to hemorrhagic shock. In a rodent model of decompensated hemorrhagic shock, rats receiving NMN displayed significantly reduced lactic acidosis and serum IL-6 levels, two strong predictors of mortality in human patients. In both livers and kidneys, NMN increased NAD levels and prevented mitochondrial dysfunction. Moreover, NMN preserved mitochondrial function in isolated hepatocytes cocultured with proinflammatory cytokines, indicating a cell-autonomous protective effect that is independent from the reduction in circulating IL-6. In kidneys, but not in livers, NMN was sufficient to prevent ATP loss following shock and resuscitation. Overall, NMN increased the time animals could sustain severe shock before requiring resuscitation by nearly 25% and significantly improved survival after resuscitation (P = 0.018), whether NMN was given as a pretreatment or only as an adjunct during resuscitation. Thus, we demonstrate that NMN substantially mitigates inflammation, improves cellular metabolism, and promotes survival following hemorrhagic shock.
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Affiliation(s)
- Carrie A Sims
- Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,The Trauma Center at Penn, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Penn Acute Research Collaboration (PARC) and
| | - Yuxia Guan
- The Trauma Center at Penn, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sarmistha Mukherjee
- Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Khushboo Singh
- The Trauma Center at Penn, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Paul Botolin
- The Trauma Center at Penn, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | - Joseph A Baur
- Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Physiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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21
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Van Wyngene L, Vandewalle J, Libert C. Reprogramming of basic metabolic pathways in microbial sepsis: therapeutic targets at last? EMBO Mol Med 2018; 10:e8712. [PMID: 29976786 PMCID: PMC6079534 DOI: 10.15252/emmm.201708712] [Citation(s) in RCA: 150] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 04/27/2018] [Accepted: 05/25/2018] [Indexed: 12/15/2022] Open
Abstract
Sepsis is a highly lethal and urgent unmet medical need. It is the result of a complex interplay of several pathways, including inflammation, immune activation, hypoxia, and metabolic reprogramming. Specifically, the regulation and the impact of the latter have become better understood in which the highly catabolic status during sepsis and its similarity with starvation responses appear to be essential in the poor prognosis in sepsis. It seems logical that new interventions based on the recognition of new therapeutic targets in the key metabolic pathways should be developed and may have a good chance to penetrate to the bedside. In this review, we concentrate on the pathological changes in metabolism, observed during sepsis, and the presumed underlying mechanisms, with a focus on the level of the organism and the interplay between different organ systems.
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Affiliation(s)
- Lise Van Wyngene
- Center for Inflammation Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Jolien Vandewalle
- Center for Inflammation Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Claude Libert
- Center for Inflammation Research, VIB, Ghent, Belgium
- Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
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22
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Abstract
From the very first discovery of biological iron-sulfur clusters with EPR, the spectroscopy has been used to study not only purified proteins but also complex systems such as respiratory complexes, membrane particles and, later, whole cells. In recent times, the emphasis of iron-sulfur biochemistry has moved from characterization of individual proteins to the systems biology of iron-sulfur biosynthesis, regulation, degradation, and implications for human health. Although this move would suggest a blossoming of System-EPR as a specific, non-invasive monitor of Fe/S (dys)homeostasis in whole cells, a review of the literature reveals limited success possibly due to technical difficulties in adherence to EPR spectroscopic and biochemical standards. In an attempt to boost application of System-EPR the required boundary conditions and their practical applications are explicitly and comprehensively formulated.
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Affiliation(s)
- Wilfred R Hagen
- Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629HZ, Delft, The Netherlands.
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23
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Yamamoto K, Ikenaka Y, Ichise T, Bo T, Ishizuka M, Yasui H, Hiraoka W, Yamamori T, Inanami O. Evaluation of mitochondrial redox status and energy metabolism of X-irradiated HeLa cells by LC/UV, LC/MS/MS and ESR. Free Radic Res 2018; 52:648-660. [PMID: 29620489 DOI: 10.1080/10715762.2018.1460472] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
To evaluate the metabolic responses in tumour cells exposed to ionizing radiation, oxygen consumption rate (OCR), cellular lipid peroxidation, cellular energy status (intracellular nucleotide pool and ATP production), and mitochondrial reactive oxygen species (ROS), semiquinone (SQ), and iron-sulphur (Fe-S) cluster levels were evaluated in human cervical carcinoma HeLa cells at 12 and 24 h after X-irradiation. LC/MS/MS analysis showed that levels of 8-iso PGF2α and 5-iPF2α-VI, lipid peroxidation products of membrane arachidonic acids, were not altered significantly in X-irradiated cells, although mitochondrial ROS levels and OCR significantly increased in the cells at 24 h after irradiation. LC/UV analysis revealed that intracellular AMP, ADP, and ATP levels increased significantly after X-irradiation, but adenylate energy charge (adenylate energy charge (AEC) = [ATP + 0.5 × ADP]/[ATP + ADP + AMP]) remained unchanged after X-irradiation. In low-temperature electron spin resonance (ESR) spectra of HeLa cells, the presence of mitochondrial SQ at g = 2.004 and Fe-S cluster at g = 1.941 was observed and X-irradiation enhanced the signal intensity of SQ but not of the Fe-S cluster. Furthermore, this radiation-induced increase in SQ signal intensity disappeared on treatment with rotenone, which inhibits electron transfer from Fe-S cluster to SQ in complex I. From these results, it was suggested that an increase in OCR and imbalance in SQ and Fe-S cluster levels, which play a critical role in the mitochondrial electron transport chain (ETC), occur after X-irradiation, resulting in an increase in ATP production and ROS leakage from the activated mitochondrial ETC.
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Affiliation(s)
- Kumiko Yamamoto
- a Laboratory of Radiation Biology, Department of Applied Veterinary Sciences, Faculty of Veterinary Medicine , Hokkaido University , Sapporo , Japan
| | - Yoshinori Ikenaka
- b Laboratory of Toxicology, Department of Environmental Veterinary Science, Faculty of Veterinary Medicine , Hokkaido University , Sapporo , Japan
| | - Takahiro Ichise
- b Laboratory of Toxicology, Department of Environmental Veterinary Science, Faculty of Veterinary Medicine , Hokkaido University , Sapporo , Japan
| | - Tomoki Bo
- a Laboratory of Radiation Biology, Department of Applied Veterinary Sciences, Faculty of Veterinary Medicine , Hokkaido University , Sapporo , Japan
| | - Mayumi Ishizuka
- b Laboratory of Toxicology, Department of Environmental Veterinary Science, Faculty of Veterinary Medicine , Hokkaido University , Sapporo , Japan
| | - Hironobu Yasui
- c Central Institute of Isotope Science , Hokkaido University , Sapporo , Japan
| | - Wakako Hiraoka
- d Laboratory of Biophysics , School of Science and Technology, Meiji University , Kawasaki , Japan
| | - Tohru Yamamori
- a Laboratory of Radiation Biology, Department of Applied Veterinary Sciences, Faculty of Veterinary Medicine , Hokkaido University , Sapporo , Japan
| | - Osamu Inanami
- a Laboratory of Radiation Biology, Department of Applied Veterinary Sciences, Faculty of Veterinary Medicine , Hokkaido University , Sapporo , Japan
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24
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Pellicer Martinez MT, Martinez AB, Crack JC, Holmes JD, Svistunenko DA, Johnston AWB, Cheesman MR, Todd JD, Le Brun NE. Sensing iron availability via the fragile [4Fe-4S] cluster of the bacterial transcriptional repressor RirA. Chem Sci 2017; 8:8451-8463. [PMID: 29619193 PMCID: PMC5863699 DOI: 10.1039/c7sc02801f] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2017] [Accepted: 10/20/2017] [Indexed: 01/02/2023] Open
Abstract
The global iron regulator RirA controls transcription of iron metabolism genes via the binding of a fragile [4Fe–4S] cluster.
Rhizobial iron regulator A (RirA) is a global regulator of iron homeostasis in many nitrogen-fixing Rhizobia and related species of α-proteobacteria. It belongs to the widespread Rrf2 super-family of transcriptional regulators and features three conserved Cys residues that characterise the binding of an iron–sulfur cluster in other Rrf2 family regulators. Here we report biophysical studies demonstrating that RirA contains a [4Fe–4S] cluster, and that this form of the protein binds RirA-regulated DNA, consistent with its function as a repressor of expression of many genes involved in iron uptake. Under low iron conditions, [4Fe–4S] RirA undergoes a cluster conversion reaction resulting in a [2Fe–2S] form, which exhibits much lower affinity for DNA. Under prolonged low iron conditions, the [2Fe–2S] cluster degrades to apo-RirA, which does not bind DNA and can no longer function as a repressor of the cell's iron-uptake machinery. [4Fe–4S] RirA was also found to be sensitive to O2, suggesting that both iron and O2 are important signals for iron metabolism. Consistent with this, in vivo data showed that expression of RirA-regulated genes is also affected by O2. These data lead us to propose a novel regulatory model for iron homeostasis, in which RirA senses iron via the incorporation of a fragile iron–sulfur cluster that is sensitive to iron and O2 concentrations.
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Affiliation(s)
- Ma Teresa Pellicer Martinez
- Centre for Molecular and Structural Biochemistry , School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK . ; ; Tel: +44 1603 592699
| | - Ana Bermejo Martinez
- School of Biological Sciences , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK
| | - Jason C Crack
- Centre for Molecular and Structural Biochemistry , School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK . ; ; Tel: +44 1603 592699
| | - John D Holmes
- Centre for Molecular and Structural Biochemistry , School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK . ; ; Tel: +44 1603 592699
| | - Dimitri A Svistunenko
- School of Biological Sciences , University of Essex , Wivenhoe Park , Colchester CO4 3SQ , UK
| | - Andrew W B Johnston
- School of Biological Sciences , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK
| | - Myles R Cheesman
- Centre for Molecular and Structural Biochemistry , School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK . ; ; Tel: +44 1603 592699
| | - Jonathan D Todd
- School of Biological Sciences , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK
| | - Nick E Le Brun
- Centre for Molecular and Structural Biochemistry , School of Chemistry , University of East Anglia , Norwich Research Park , Norwich , NR4 7TJ , UK . ; ; Tel: +44 1603 592699
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25
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Bradley JM, Svistunenko DA, Moore GR, Le Brun NE. Tyr25, Tyr58 and Trp133 ofEscherichia colibacterioferritin transfer electrons between iron in the central cavity and the ferroxidase centre. Metallomics 2017; 9:1421-1428. [DOI: 10.1039/c7mt00187h] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Tyr58 and Trp133 play key roles in the formation and decay of the Tyr25 radical species ofE. coliBFR.
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Affiliation(s)
- Justin M. Bradley
- Centre for Molecular and Structural Biochemistry
- School of Chemistry
- University of East Anglia
- Norwich Research Park
- Norwich
| | | | - Geoffrey R. Moore
- Centre for Molecular and Structural Biochemistry
- School of Chemistry
- University of East Anglia
- Norwich Research Park
- Norwich
| | - Nick E. Le Brun
- Centre for Molecular and Structural Biochemistry
- School of Chemistry
- University of East Anglia
- Norwich Research Park
- Norwich
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26
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Oxidative stress in sepsis: Pathophysiological implications justifying antioxidant co-therapy. Burns 2016; 43:471-485. [PMID: 28034666 DOI: 10.1016/j.burns.2016.09.023] [Citation(s) in RCA: 149] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 08/10/2016] [Accepted: 09/19/2016] [Indexed: 01/20/2023]
Abstract
Sepsis is one of the main causes of death among critically ill patients. Sepsis pathogenesis includes infection by gram-negative and gram-positive bacteria, fungi, or both; exacerbated inflammatory response; hypotension, with potential to cause vasodilatory shock; and lesser delivery of oxygen to tissues due to impairment of oxygen utilization by cells. The participation of reactive species and/or free radicals such as nitric oxide (NO), peroxynitrite (ONOO-), superoxide (O2-), hydrogen peroxide (H2O2), and hydroxyl radical (OH) has been reported to underlie these effects. Mitochondrial dysfunction is related to loss of inner membrane potential and inhibition of the mitochondrial electron transfer chain and FoF1-adenosine triphosphate-synthase, resulting in cellular energetic failure. In addition, overproduction of NO due to inducible nitric oxide synthase (iNOS) activity has been associated with harmful effects such as general vasodilatation and hypo-responsiveness to therapeutic vasoconstrictor agents. Considering that iNOS expression is regulated by nuclear factor-κB, which may be activated by ROS, antioxidants could inhibit the overexpression of iNOS in sepsis. In line with this, several antioxidants such as vitamins C and E, polyphenols, melatonin, β-glucan, N-acetylcysteine, mitochondrion-targeted antioxidants (MitoQ, MitoE, and peptides associated with dimethyltyrosine), selenium salts, and organoselenium compounds were effective in ameliorating oxidative stress in animal models of sepsis and in a number of clinical trials with septic patients.
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Neri M, Riezzo I, Pomara C, Schiavone S, Turillazzi E. Oxidative-Nitrosative Stress and Myocardial Dysfunctions in Sepsis: Evidence from the Literature and Postmortem Observations. Mediators Inflamm 2016; 2016:3423450. [PMID: 27274621 PMCID: PMC4870364 DOI: 10.1155/2016/3423450] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Accepted: 04/11/2016] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Myocardial depression in sepsis is common, and it is associated with higher mortality. In recent years, the hypothesis that the myocardial dysfunction during sepsis could be mediated by ischemia related to decreased coronary blood flow waned and a complex mechanism was invoked to explain cardiac dysfunction in sepsis. Oxidative stress unbalance is thought to play a critical role in the pathogenesis of cardiac impairment in septic patients. AIM In this paper, we review the current literature regarding the pathophysiology of cardiac dysfunction in sepsis, focusing on the possible role of oxidative-nitrosative stress unbalance and mitochondria dysfunction. We discuss these mechanisms within the broad scenario of cardiac involvement in sepsis. CONCLUSIONS Findings from the current literature broaden our understanding of the role of oxidative and nitrosative stress unbalance in the pathophysiology of cardiac dysfunction in sepsis, thus contributing to the establishment of a relationship between these settings and the occurrence of oxidative stress. The complex pathogenesis of septic cardiac failure may explain why, despite the therapeutic strategies, sepsis remains a big clinical challenge for effectively managing the disease to minimize mortality, leading to consideration of the potential therapeutic effects of antioxidant agents.
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Affiliation(s)
- M. Neri
- Institute of Forensic Pathology, Department of Clinical and Experimental Medicine, University of Foggia, Ospedale Colonnello D'Avanzo, Viale degli Aviatori 1, 71100 Foggia, Italy
| | - I. Riezzo
- Institute of Forensic Pathology, Department of Clinical and Experimental Medicine, University of Foggia, Ospedale Colonnello D'Avanzo, Viale degli Aviatori 1, 71100 Foggia, Italy
| | - C. Pomara
- Institute of Forensic Pathology, Department of Clinical and Experimental Medicine, University of Foggia, Ospedale Colonnello D'Avanzo, Viale degli Aviatori 1, 71100 Foggia, Italy
| | - S. Schiavone
- Institute of Pharmacology, Department of Clinical and Experimental Medicine, University of Foggia, Via L. Pinto 1, 71100 Foggia, Italy
| | - E. Turillazzi
- Institute of Forensic Pathology, Department of Clinical and Experimental Medicine, University of Foggia, Ospedale Colonnello D'Avanzo, Viale degli Aviatori 1, 71100 Foggia, Italy
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Bennett B, Helbling D, Meng H, Jarzembowski J, Geurts AM, Friederich MW, Van Hove JLK, Lawlor MW, Dimmock DP. Potentially diagnostic electron paramagnetic resonance spectra elucidate the underlying mechanism of mitochondrial dysfunction in the deoxyguanosine kinase deficient rat model of a genetic mitochondrial DNA depletion syndrome. Free Radic Biol Med 2016; 92:141-151. [PMID: 26773591 PMCID: PMC5047058 DOI: 10.1016/j.freeradbiomed.2016.01.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Revised: 01/04/2016] [Accepted: 01/06/2016] [Indexed: 01/19/2023]
Abstract
A novel rat model for a well-characterized human mitochondrial disease, mitochondrial DNA depletion syndrome with associated deoxyguanosine kinase (DGUOK) deficiency, is described. The rat model recapitulates the pathologic and biochemical signatures of the human disease. The application of electron paramagnetic (spin) resonance (EPR) spectroscopy to the identification and characterization of respiratory chain abnormalities in the mitochondria from freshly frozen tissue of the mitochondrial disease model rat is introduced. EPR is shown to be a sensitive technique for detecting mitochondrial functional abnormalities in situ and, here, is particularly useful in characterizing the redox state changes and oxidative stress that can result from depressed expression and/or diminished specific activity of the distinct respiratory chain complexes. As EPR requires no sample preparation or non-physiological reagents, it provides information on the status of the mitochondrion as it was in the functioning state. On its own, this information is of use in identifying respiratory chain dysfunction; in conjunction with other techniques, the information from EPR shows how the respiratory chain is affected at the molecular level by the dysfunction. It is proposed that EPR has a role in mechanistic pathophysiological studies of mitochondrial disease and could be used to study the impact of new treatment modalities or as an additional diagnostic tool.
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Affiliation(s)
- Brian Bennett
- National Biomedical EPR Center, Department of Biophysics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
| | - Daniel Helbling
- Human Molecular Genetics Center and Division of Genetics, Department of Pediatrics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
| | - Hui Meng
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
| | - Jason Jarzembowski
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
| | - Aron M Geurts
- Department of Physiology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
| | - Marisa W Friederich
- Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Mailstop 8400, 13121 East 17th Avenue, Aurora, CO 80045, USA.
| | - Johan L K Van Hove
- Clinical Genetics and Metabolism, Department of Pediatrics, University of Colorado, Mailstop 8400, 13121 East 17th Avenue, Aurora, CO 80045, USA.
| | - Michael W Lawlor
- Division of Pediatric Pathology, Department of Pathology and Laboratory Medicine, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
| | - David P Dimmock
- Human Molecular Genetics Center and Division of Genetics, Department of Pediatrics, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
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Crack JC, Svistunenko DA, Munnoch J, Thomson AJ, Hutchings MI, Le Brun NE. Differentiated, Promoter-specific Response of [4Fe-4S] NsrR DNA Binding to Reaction with Nitric Oxide. J Biol Chem 2016; 291:8663-72. [PMID: 26887943 PMCID: PMC4861436 DOI: 10.1074/jbc.m115.693192] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2015] [Indexed: 12/19/2022] Open
Abstract
NsrR is an iron-sulfur cluster protein that regulates the nitric oxide (NO) stress response of many bacteria. NsrR from Streptomyces coelicolor regulates its own expression and that of only two other genes, hmpA1 and hmpA2, which encode HmpA enzymes predicted to detoxify NO. NsrR binds promoter DNA with high affinity only when coordinating a [4Fe-4S] cluster. Here we show that reaction of [4Fe-4S] NsrR with NO affects DNA binding differently depending on the gene promoter. Binding to the hmpA2 promoter was abolished at ∼2 NO per cluster, although for the hmpA1 and nsrR promoters, ∼4 and ∼8 NO molecules, respectively, were required to abolish DNA binding. Spectroscopic and kinetic studies of the NO reaction revealed a rapid, multi-phase, non-concerted process involving up to 8–10 NO molecules per cluster, leading to the formation of several iron-nitrosyl species. A distinct intermediate was observed at ∼2 NO per cluster, along with two further intermediates at ∼4 and ∼6 NO. The NsrR nitrosylation reaction was not significantly affected by DNA binding. These results show that NsrR regulates different promoters in response to different concentrations of NO. Spectroscopic evidence indicates that this is achieved by different NO-FeS complexes.
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Affiliation(s)
- Jason C Crack
- From the Centre for Molecular and Structural Biochemistry, School of Chemistry, and
| | - Dimitri A Svistunenko
- the School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester CO4 3SQ, United Kingdom
| | - John Munnoch
- the School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ and
| | - Andrew J Thomson
- From the Centre for Molecular and Structural Biochemistry, School of Chemistry, and
| | - Matthew I Hutchings
- the School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ and
| | - Nick E Le Brun
- From the Centre for Molecular and Structural Biochemistry, School of Chemistry, and
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Nakahira K, Choi AMK. Carbon monoxide in the treatment of sepsis. Am J Physiol Lung Cell Mol Physiol 2015; 309:L1387-93. [PMID: 26498251 DOI: 10.1152/ajplung.00311.2015] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Accepted: 10/21/2015] [Indexed: 12/31/2022] Open
Abstract
Carbon monoxide (CO), a low-molecular-weight gas, is endogenously produced in the body as a product of heme degradation catalyzed by heme oxygenase (HO) enzymes. As the beneficial roles of HO system have been elucidated in vitro and in vivo, CO itself has also been reported as a potent cytoprotective molecule. Whereas CO represents a toxic inhalation hazard at high concentration, low-dose exogenous CO treatment (~250-500 parts per million) demonstrates protective functions including but not limited to the anti-inflammatory and antiapoptotic effects in preclinical models of human diseases. Of note, CO exposure confers protection in animal models of sepsis by inhibiting inflammatory responses and also enhancing bacterial phagocytosis in leukocytes. These unique functions of CO including both dampening inflammation and promoting host defense mechanism are mediated by multiple pathways such as autophagy induction or biosynthesis of specialized proresolving lipid mediators. We suggest that CO gas may represent a novel therapy for patients with sepsis.
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Affiliation(s)
- Kiichi Nakahira
- Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College and New York-Presbyterian Hospital, New York, New York; and Division of Pulmonary and Crit Care Medicine, Weill Cornell Medical College, New York, New York
| | - Augustine M K Choi
- Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College and New York-Presbyterian Hospital, New York, New York; and Division of Pulmonary and Crit Care Medicine, Weill Cornell Medical College, New York, New York
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Srivastava A, McGinniss J, Wong Y, Shinn AS, Lam TT, Lee PJ, Mannam P. MKK3 deletion improves mitochondrial quality. Free Radic Biol Med 2015; 87:373-84. [PMID: 26119780 DOI: 10.1016/j.freeradbiomed.2015.06.024] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2015] [Revised: 05/18/2015] [Accepted: 06/14/2015] [Indexed: 11/23/2022]
Abstract
Sepsis, a severe response to infection, leads to excessive inflammation and is the major cause of mortality in intensive care units. Mitochondria have been shown to influence the outcome of septic injury. We have previously shown that MAP kinase kinase 3 (MKK3)(-/-) mice are resistant to septic injury and MKK3(-/-) macrophages have improved mitochondrial function. In this study we examined processes that lead to improved mitochondrial quality in MKK3(-/-) mouse embryonic fibroblasts (MEFs) and specifically the role of mitophagy in mitochondrial health. MKK3(-/-) MEFs had lower inflammatory cytokine release and oxidant production after lipopolysaccharide (LPS) stimulation, confirming our earlier observations. MKK3(-/-) MEFs had better mitochondrial function as measured by mitochondrial membrane potential (MMP) and ATP, even after LPS treatment. We observed higher mitophagy in MKK3(-/-) MEFs compared to wild type (WT). Transmission electron microscopy studies showed longer and larger mitochondria in MKK3(-/-) MEFs, indicative of healthier mitochondria. We performed a SILAC (stable isotope labeling by/with amino acids in cell culture) study to assess differences in mitochondrial proteome between WT and MKK3(-/-) MEFs and observed increased expression of tricarboxylic acid (TCA) cycle enzymes and respiratory complex subunits. Further, inhibition of mitophagy by Mdivi1 led to loss in MMP and increased cytokine secretion after LPS treatment in MKK3(-/-) MEFs. In conclusion, this study demonstrates that MKK3 influences mitochondrial quality by affecting the expression of mitochondrial proteins, including TCA cycle enzymes, and mitophagy, which consequently regulates the inflammatory response. Based on our results, MKK3 could be a potential therapeutic target for inflammatory diseases like sepsis.
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Affiliation(s)
- Anup Srivastava
- Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520-8057, USA
| | - John McGinniss
- Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520-8057, USA
| | - Yao Wong
- Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520-8057, USA
| | - Amanda S Shinn
- Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520-8057, USA
| | - TuKiet T Lam
- Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520-8057, USA; W.M. Keck Foundation Biotechnology Resource Laboratory, Yale University School of Medicine, New Haven, CT 06511, USA
| | - Patty J Lee
- Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520-8057, USA
| | - Praveen Mannam
- Pulmonary, Critical Care and Sleep Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520-8057, USA.
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The hydrogen-peroxide-induced radical behaviour in human cytochrome c-phospholipid complexes: implications for the enhanced pro-apoptotic activity of the G41S mutant. Biochem J 2015; 456:441-52. [PMID: 24099549 DOI: 10.1042/bj20130758] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have investigated whether the pro-apoptotic properties of the G41S mutant of human cytochrome c can be explained by a higher than wild-type peroxidase activity triggered by phospholipid binding. A key complex in mitochondrial apoptosis involves cytochrome c and the phospholipid cardiolipin. In this complex cytochrome c has its native axial Met(80) ligand dissociated from the haem-iron, considerably augmenting the peroxidase capability of the haem group upon H2O2 binding. By EPR spectroscopy we reveal that the magnitude of changes in the paramagnetic haem states, as well as the yield of protein-bound free radical, is dependent on the phospholipid used and is considerably greater in the G41S mutant. A high-resolution X-ray crystal structure of human cytochrome c was determined and, in combination with the radical EPR signal analysis, two tyrosine residues, Tyr(46) and Tyr(48), have been rationalized to be putative radical sites. Subsequent single and double tyrosine-to-phenylalanine mutations revealed that the EPR signal of the radical, found to be similar in all variants, including G41S and wild-type, originates not from a single tyrosine residue, but is instead a superimposition of multiple EPR signals from different radical sites. We propose a mechanism of multiple radical formations in the cytochrome c-phospholipid complexes under H2O2 treatment, consistent with the stabilization of the radical in the G41S mutant, which elicits a greater peroxidase activity from cytochrome c and thus has implications in mitochondrial apoptosis.
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E3 ligase subunit Fbxo15 and PINK1 kinase regulate cardiolipin synthase 1 stability and mitochondrial function in pneumonia. Cell Rep 2014; 7:476-487. [PMID: 24703837 PMCID: PMC4085683 DOI: 10.1016/j.celrep.2014.02.048] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Revised: 09/20/2013] [Accepted: 02/28/2014] [Indexed: 12/04/2022] Open
Abstract
Acute lung injury (ALI) is linked to mitochondrial injury, resulting in impaired cellular oxygen utilization; however, it is unknown how these events are linked on the molecular level. Cardiolipin, a mitochondrial-specific lipid, is generated by cardiolipin synthase (CLS1). Here, we show that S. aureus activates a ubiquitin E3 ligase component, Fbxo15, that is sufficient to mediate proteasomal degradation of CLS1 in epithelia, resulting in decreased cardiolipin availability and disrupted mitochondrial function. CLS1 is destabilized by the phosphatase and tensin homolog (PTEN)-induced putative kinase 1 (PINK1), which binds CLS1 to phosphorylate and regulates CLS1 disposal. Like Fbxo15, PINK1 interacts with and regulates levels of CLS1 through a mechanism dependent upon Thr219. S. aureus infection upregulates this Fbxo15-PINK1 pathway to impair mitochondrial integrity, and Pink1 knockout mice are less prone to S. aureus-induced ALI. Thus, ALI-associated disruption of cellular bioenergetics involves bioeffectors that utilize a phosphodegron to elicit ubiquitin-mediated disposal of a key mitochondrial enzyme.
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Abstract
The ideal set of variables for nutritional monitoring that may correlate with patient outcomes has not been identified. This is particularly difficult in the PICU patient because many of the standard modes of nutritional monitoring, although well described and available, are fraught with difficulties. Thus, repeated anthropometric and laboratory markers must be jointly analyzed but individually interpreted according to disease and metabolic changes, in order to modify and monitor the nutritional treatment. In addition, isotope techniques are neither clinically feasible nor compatible with the multiple measurements needed to follow progression. On the other hand, indirect alternatives exist but may have pitfalls, of which the clinician must be aware. Risks exist for both overfeeding and underfeeding of PICU patients so that an accurate monitoring of energy expenditure, using targeted indirect calorimetry, is necessary to avoid either extreme. This is very important, since the monitoring of the nutritional status of the critically ill child serves as a guide to early and effective nutritional intervention.
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Ceusters JD, Mouithys-Mickalad AA, Franck TJ, Derochette S, Vanderplasschen A, Deby-Dupont GP, Serteyn DA. Effect of myeloperoxidase and anoxia/reoxygenation on mitochondrial respiratory function of cultured primary equine skeletal myoblasts. Mitochondrion 2013; 13:410-6. [DOI: 10.1016/j.mito.2012.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2012] [Revised: 12/12/2012] [Accepted: 12/17/2012] [Indexed: 10/27/2022]
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Tumor necrosis factor-α levels early in severe acute pancreatitis: is there predictive value regarding severity and outcome? J Clin Gastroenterol 2013; 47:637-43. [PMID: 23470643 DOI: 10.1097/mcg.0b013e31828a6cfc] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
GOAL AND BACKGROUND One of the most important cytokines in pathogenesis of acute pancreatitis is tumor necrosis factor (TNF)-α. The aim of our study was to determine whether the plasma levels of TNF-α in patients with severe acute pancreatitis (SAP) on admission correlate with severity and outcome of SAP. STUDY Blood samples were obtained from 100 patients with SAP. Patients were divided into 2 groups according to severity: SAP group (n=69) and SAP-induced multiple organ dysfunction syndrome (MODS) group (n=31). Survivors were patients who were alive 90 days after taking the blood sample for cytokine measurement (53/100). Blood sample for cytokine measurement was drawn immediately after admission. TNF-α was measured by commercial ELISA test in plasma. RESULTS When comparing SAP group with SAP-induced MODS group, we found that mean values of TNF-α on admission were 191.5-fold lower in group with SAP-induced MODS (P<0.01). When comparing nonsurvivors with survivors, we found that mean values of TNF-α on admission were 63-fold higher in survivors (P<0.01). At cut-off level of 7.95 pg/mL sensitivity was 83.9% and specificity was 72.5%. Patients with TNF-α level lower than 7.95 pg/mL had 3.2-fold higher probability to develop SAP with MODS. At cut-off level of 10.5 pg/mL sensitivity was 83% and specificity was 77.4%. Patients with TNF-α level higher than 10.5 pg/mL had 4.8-fold higher probability to survive. CONCLUSIONS TNF-α is good predictor of severity and outcome. Low TNF-α concentration in patients with SAP predicts development of MODS and fatal outcome.
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Abstract
Cardiovascular dysfunction is common in severe sepsis or septic shock. Although functional alterations are often described, the elevated serum levels of cardiac proteins and autopsy findings of myocardial immune cell infiltration, edema, and damaged mitochondria suggest that structural changes to the heart during severe sepsis and septic shock may occur and may contribute to cardiac dysfunction. We explored the available literature on structural (versus functional) cardiac alterations during experimental and human endotoxemia and/or sepsis. Limited data suggest that the structural changes could be prevented, and myocardial function improved by (pre-)treatment with platelet-activating factor, cyclosporin A, glutamine, caffeine, simvastatin, or caspase inhibitors.
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Abstract
OBJECTIVES We hypothesized that resveratrol administration would reverse sepsis-dependent downregulation of peroxisome proliferator activated receptor-γ coactivator 1α, preserve mitochondrial integrity, and rescue animals from sepsis-induced myocardial failure. SETTING Teaching hospital research laboratory. INTERVENTIONS Cecal ligation and puncture in mice was performed to induce sepsis. Mice that underwent cecal ligation and puncture were randomly assigned to receive resveratrol (30 mg/kg or 60 mg/kg) or vehicle 1 mL sodium chloride 0.9% subcutaneously in the scruff of the neck directly after surgery and at 16, 24, and 40 hrs, respectively. MEASUREMENTS AND RESULTS Forty-eight hrs after cecal ligation and puncture, cardiac performance was established using echocardiography. Mitochondrial integrity was evaluated with electron microscopy, and changes in gene expression were evaluated with microarray analysis. Survival at 48 hrs was just under 50% and comparable between groups. Myocardial contractile function significantly improved after resveratrol treatment. Resveratrol-treated mice developed focal areas of edema, whereas vehicle-treated mice developed significant, diffuse myocardial edema. Electron microscopy revealed widespread swollen mitochondria with ruptured outer membranes, autophagosomes, and vacuolation of the internal compartment, which were significantly attenuated in resveratrol-treated animals. Resveratrol treatment significantly increased cardiac expression of peroxisome proliferator-activated receptor-γ coactivator 1a. Microarray analysis revealed that resveratrol treatment resulted in upregulation of the peroxisome proliferator-activated receptor-γ coactivator gene set containing genes known to be regulated by this transcriptional coactivator. Our data strongly suggest that administration of resveratrol modulates bioenergy metabolism, substrate utilization, oxidative stress, and detoxification pathways associated with both mitochondrial and cardiac pathological conditions, but does not alter mortality from sepsis. CONCLUSIONS The salutary effects of resveratrol on cecal ligation and puncture-induced myocardial dysfunction are associated with increased peroxisome proliferator-activated receptor-γ coactivator 1a abundance and function. Preservation of myocardial energy production capacity, prevention of secondary injury, mitigation of inflammation, and reversal of sepsis-induced myocardial remodeling are likely to underlie its beneficial effects. This however, does not result in improved survival.
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Reeder BJ, Svistunenko DA, Cooper CE, Wilson MT. Engineering Tyrosine-Based Electron Flow Pathways in Proteins: The Case of Aplysia Myoglobin. J Am Chem Soc 2012; 134:7741-9. [DOI: 10.1021/ja211745g] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Brandon J. Reeder
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ,
United Kingdom
| | - Dimitri A. Svistunenko
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ,
United Kingdom
| | - Chris E. Cooper
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ,
United Kingdom
| | - Michael T. Wilson
- School of Biological Sciences, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ,
United Kingdom
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Endotoxemia impairs heart mitochondrial function by decreasing electron transfer, ATP synthesis and ATP content without affecting membrane potential. J Bioenerg Biomembr 2012; 44:243-52. [PMID: 22426814 DOI: 10.1007/s10863-012-9426-3] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2012] [Accepted: 02/22/2012] [Indexed: 01/28/2023]
Abstract
Acute endotoxemia (LPS, 10 mg/kg ip, Sprague Dawley rats, 45 days old, 180 g) decreased the O₂ consumption of rat heart (1 mm³ tissue cubes) by 33% (from 4.69 to 3.11 μmol O₂/min. g tissue). Mitochondrial O₂ consumption and complex I activity were also decreased by 27% and 29%, respectively. Impaired respiration was associated to decreased ATP synthesis (from 417 to 168 nmol/min. mg protein) and ATP content (from 5.40 to 4.18 nmol ATP/mg protein), without affecting mitochondrial membrane potential. This scenario is accompanied by an increased production of O₂·⁻ and H₂O₂ due to complex I inhibition. The increased NO production, as shown by 38% increased mtNOS biochemical activity and 31% increased mtNOS functional activity, is expected to fuel an increased ONOO⁻ generation that is considered relevant in terms of the biochemical mechanism. Heart mitochondrial bioenergetic dysfunction with decreased O₂ uptake, ATP production and contents may indicate that preservation of mitochondrial function will prevent heart failure in endotoxemia.
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Svistunenko DA, Worrall JAR, Chugh SB, Haigh SC, Ghiladi RA, Nicholls P. Ferric haem forms of Mycobacterium tuberculosis catalase-peroxidase probed by EPR spectroscopy: Their stability and interplay with pH. Biochimie 2012; 94:1274-80. [PMID: 22381358 DOI: 10.1016/j.biochi.2012.02.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2011] [Accepted: 02/16/2012] [Indexed: 11/26/2022]
Abstract
Low temperature EPR spectroscopy was used to characterise Mycobacterium tuberculosis catalase-peroxidase in its resting ferric haem state. Several high spin ferric haem forms and no low spin forms were found in the enzyme samples frozen in methanol on dry ice. The EPR spectra depended not only on the pH but also on the buffer type. As a general trend, the higher the pH, the greater the 'rhombic' fraction of the high spin ferric haem that was observed. The rhombic form was characterised by well separated two lines in the g = 6 region whereas in the 'axial' form the two lines overlap. This pH dependence of the equilibrium of axial and rhombic ferric haem forms is also seen in rapidly freeze-quenched samples. Different high spin ferric haem forms were monitored during a 3 week storage of the enzyme at 4 °C. For some forms, extremal dependences, i.e. those progressing via maxima or minima over storage time, were found. This indicates that the mechanism of the time-dependent transition from one high spin ferric haem form to another must be more complex than a simple single site oxidation.
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Affiliation(s)
- Dimitri A Svistunenko
- School of Biological Science, University of Essex, Wivenhoe Park, Colchester, Essex CO4 3SQ, United Kingdom.
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MacGarvey NC, Suliman HB, Bartz RR, Fu P, Withers CM, Welty-Wolf KE, Piantadosi CA. Activation of mitochondrial biogenesis by heme oxygenase-1-mediated NF-E2-related factor-2 induction rescues mice from lethal Staphylococcus aureus sepsis. Am J Respir Crit Care Med 2012; 185:851-61. [PMID: 22312014 DOI: 10.1164/rccm.201106-1152oc] [Citation(s) in RCA: 140] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
RATIONALE Mitochondrial damage is an important component of multiple organ failure syndrome, a highly lethal complication of severe sepsis that lacks specific therapy. Mitochondrial quality control is regulated in part by the heme oxygenase-1 (HO-1; Hmox1) system through the redox-regulated NF-E2-related factor-2 (Nrf2) transcription factor, but its role in mitochondrial biogenesis in Staphylococcus aureus sepsis is unknown. OBJECTIVES To test the hypothesis that Nrf2-dependent up-regulation of the HO-1/carbon monoxide (CO) system would preserve mitochondrial biogenesis and rescue mice from lethal S. aureus sepsis. METHODS A controlled murine S. aureus peritonitis model with and without inhaled CO was examined for HO-1 and Nrf2 regulation of mitochondrial biogenesis and the resolution of hepatic mitochondrial damage. MEASUREMENTS AND MAIN RESULTS Sepsis survival was significantly enhanced using inhaled CO (250 ppm once-daily for 1 h), and linked mechanistically to Hmox1 induction and mitochondrial HO activity through Nrf2 transcriptional and Akt kinase activity. HO-1/CO stimulated Nrf2-dependent gene expression and nuclear accumulation of nuclear respiratory factor-1, -2α (Gabpa), and peroxisome proliferator-activated receptor gamma coactivator-1α; increased mitochondrial transcription factor-A and citrate synthase protein levels; and augmented mtDNA copy number. CO enhanced antiinflammatory IL-10 and reduced proinflammatory tumor necrosis factor-α production. By contrast, Nrf2(-/-) and Akt1(-/-) mice lacked CO induction of Hmox1 and mitochondrial biogenesis, and CO rescued neither strain from S. aureus sepsis. CONCLUSIONS We identify an inducible Nrf2/HO-1 regulatory cycle for mitochondrial biogenesis that is prosurvival and counter-inflammatory in sepsis, and describe targeted induction of mitochondrial biogenesis as a potential multiple organ failure therapy.
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Mayeux PR, MacMillan-Crow LA. Pharmacological targets in the renal peritubular microenvironment: implications for therapy for sepsis-induced acute kidney injury. Pharmacol Ther 2012; 134:139-55. [PMID: 22274552 DOI: 10.1016/j.pharmthera.2012.01.004] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 12/19/2011] [Indexed: 01/15/2023]
Abstract
One of the most frequent and serious complications to develop in septic patients is acute kidney injury (AKI), a disorder characterized by a rapid failure of the kidneys to adequately filter the blood, regulate ion and water balance, and generate urine. AKI greatly worsens the already poor prognosis of sepsis and increases cost of care. To date, therapies have been mostly supportive; consequently there has been little change in the mortality rates over the last decade. This is due, at least in part, to the delay in establishing clinical evidence of an infection and the associated presence of the systemic inflammatory response syndrome and thus, a delay in initiating therapy. A second reason is a lack of understanding regarding the mechanisms leading to renal injury, which has hindered the development of more targeted therapies. In this review, we summarize recent studies, which have examined the development of renal injury during sepsis and propose how changes in the peritubular capillary microenvironment lead to and then perpetuate microcirculatory failure and tubular epithelial cell injury. We also discuss a number of potential therapeutic targets in the renal peritubular microenvironment, which may prevent or lessen injury and/or promote recovery.
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Affiliation(s)
- Philip R Mayeux
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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Escames G, López LC, García JA, García-Corzo L, Ortiz F, Acuña-Castroviejo D. Mitochondrial DNA and inflammatory diseases. Hum Genet 2011; 131:161-73. [DOI: 10.1007/s00439-011-1057-y] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2011] [Accepted: 06/26/2011] [Indexed: 12/21/2022]
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Myers JM, Antholine WE, Myers CR. The intracellular redox stress caused by hexavalent chromium is selective for proteins that have key roles in cell survival and thiol redox control. Toxicology 2011; 281:37-47. [PMID: 21237240 DOI: 10.1016/j.tox.2011.01.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 12/22/2010] [Accepted: 01/04/2011] [Indexed: 01/14/2023]
Abstract
Hexavalent chromium [Cr(VI)] compounds (e.g. chromates) are strong oxidants that readily enter cells where they are reduced to reactive Cr intermediates that can directly oxidize some cell components and can promote the generation of reactive oxygen and nitrogen species. Inhalation is a major route of exposure which directly exposes the bronchial epithelium. Previous studies with non-cancerous human bronchial epithelial cells (BEAS-2B) demonstrated that Cr(VI) treatment results in the irreversible inhibition of thioredoxin reductase (TrxR) and the oxidation of thioredoxins (Trx) and peroxiredoxins (Prx). The mitochondrial Trx/Prx system is somewhat more sensitive to Cr(VI) than the cytosolic Trx/Prx system, and other redox-sensitive mitochondrial functions are subsequently affected including electron transport complexes I and II. Studies reported here show that Cr(VI) does not cause indiscriminant thiol oxidation, and that the Trx/Prx system is among the most sensitive of cellular protein thiols. Trx/Prx oxidation is not unique to BEAS-2B cells, as it was also observed in primary human bronchial epithelial cells. Increasing the intracellular levels of ascorbate, an endogenous Cr(VI) reductant, did not alter the effects on TrxR, Trx, or Prx. The peroxynitrite scavenger MnTBAP did not protect TrxR, Trx, Prx, or the electron transport chain from the effects of Cr(VI), implying that peroxynitrite is not required for these effects. Nitration of tyrosine residues of TrxR was not observed following Cr(VI) treatment, further ruling out peroxynitrite as a significant contributor to the irreversible inhibition of TrxR. Cr(VI) treatments that disrupt the TrxR/Trx/Prx system did not cause detectable mitochondrial DNA damage. Overall, the redox stress that results from Cr(VI) exposure shows selectivity for key proteins which are known to be important for redox signaling, antioxidant defense, and cell survival.
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Affiliation(s)
- Judith M Myers
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA
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Myers CR, Antholine WE, Myers JM. The pro-oxidant chromium(VI) inhibits mitochondrial complex I, complex II, and aconitase in the bronchial epithelium: EPR markers for Fe-S proteins. Free Radic Biol Med 2010; 49:1903-15. [PMID: 20883776 PMCID: PMC3005768 DOI: 10.1016/j.freeradbiomed.2010.09.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/30/2010] [Revised: 08/27/2010] [Accepted: 09/20/2010] [Indexed: 11/26/2022]
Abstract
Hexavalent chromium (Cr(VI)) compounds (e.g., chromates) are strong oxidants that readily enter cells, where they are reduced to reactive Cr species that also facilitate reactive oxygen species generation. Recent studies demonstrated inhibition and oxidation of the thioredoxin system, with greater effects on mitochondrial thioredoxin (Trx2). This implies that Cr(VI)-induced oxidant stress may be especially directed at the mitochondria. Examination of other redox-sensitive mitochondrial functions showed that Cr(VI) treatments that cause Trx2 oxidation in human bronchial epithelial cells also result in pronounced and irreversible inhibition of aconitase, a TCA cycle enzyme that has an iron-sulfur (Fe-S) center that is labile with respect to certain oxidants. The activities of electron transport complexes I and II were also inhibited, whereas complex III was not. Electron paramagnetic resonance (EPR) studies of samples at liquid helium temperature (10K) showed a strong signal at g=1.94 that is consistent with the inhibition of electron flow through complex I and/or II. A signal at g=2.02 was also observed, which is consistent with oxidation of the Fe-S center of aconitase. The g=1.94 signal was particularly intense and remained after extracellular Cr(VI) was removed, whereas the g=2.02 signal declined in intensity after Cr(VI) was removed. A similar inhibition of these activities and analogous EPR findings were noted in bovine airways treated ex vivo with Cr(VI). Overall, the data support the hypothesis that Cr(VI) exposure has deleterious effects on a number of redox-sensitive core mitochondrial proteins. The g=1.94 signal could prove to be an important biomarker for oxidative damage resulting from Cr(VI) exposure. The EPR spectra simultaneously showed signals for Cr(V) and Cr(III), which verify Cr(VI) exposure and its intracellular reductive activation.
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Affiliation(s)
- Charles R Myers
- Department of Pharmacology and Toxicology, Medical College of Wisconsin, Milwaukee, WI 53226, USA.
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Thompson MK, Franzen S, Ghiladi RA, Reeder BJ, Svistunenko DA. Compound ES of Dehaloperoxidase Decays via Two Alternative Pathways Depending on the Conformation of the Distal Histidine. J Am Chem Soc 2010; 132:17501-10. [DOI: 10.1021/ja106620q] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Matthew K. Thompson
- Department of Chemistry, North Carolina State University, Box 8204, Raleigh, North Carolina 27695-8204, United States, and Department of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Stefan Franzen
- Department of Chemistry, North Carolina State University, Box 8204, Raleigh, North Carolina 27695-8204, United States, and Department of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Reza A. Ghiladi
- Department of Chemistry, North Carolina State University, Box 8204, Raleigh, North Carolina 27695-8204, United States, and Department of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Brandon J. Reeder
- Department of Chemistry, North Carolina State University, Box 8204, Raleigh, North Carolina 27695-8204, United States, and Department of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
| | - Dimitri A. Svistunenko
- Department of Chemistry, North Carolina State University, Box 8204, Raleigh, North Carolina 27695-8204, United States, and Department of Biological Sciences, University of Essex, Colchester CO4 3SQ, United Kingdom
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Affiliation(s)
- M E Bernal
- Universidad de Monterrey, Escuela de Medicina, Monterrey, Nuevo León, MéxicoThe University of Texas Health Science Center of Houston, The University of Texas Medical Branch at Galveston, St. Luke's Episcopal Hospital/Texas Heart Institute, Houston, TX, USA The University of Texas Medical Branch, Galveston, TX, USAWorld Foundation for AIDS Research and Prevention, Paris, France
| | - J Varon
- Universidad de Monterrey, Escuela de Medicina, Monterrey, Nuevo León, MéxicoThe University of Texas Health Science Center of Houston, The University of Texas Medical Branch at Galveston, St. Luke's Episcopal Hospital/Texas Heart Institute, Houston, TX, USA The University of Texas Medical Branch, Galveston, TX, USAWorld Foundation for AIDS Research and Prevention, Paris, France
| | - P Acosta
- Universidad de Monterrey, Escuela de Medicina, Monterrey, Nuevo León, MéxicoThe University of Texas Health Science Center of Houston, The University of Texas Medical Branch at Galveston, St. Luke's Episcopal Hospital/Texas Heart Institute, Houston, TX, USA The University of Texas Medical Branch, Galveston, TX, USAWorld Foundation for AIDS Research and Prevention, Paris, France
| | - L Montagnier
- Universidad de Monterrey, Escuela de Medicina, Monterrey, Nuevo León, MéxicoThe University of Texas Health Science Center of Houston, The University of Texas Medical Branch at Galveston, St. Luke's Episcopal Hospital/Texas Heart Institute, Houston, TX, USA The University of Texas Medical Branch, Galveston, TX, USAWorld Foundation for AIDS Research and Prevention, Paris, France
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Wendel M, Heller AR. Mitochondrial function and dysfunction in sepsis. Wien Med Wochenschr 2010; 160:118-23. [PMID: 20364414 DOI: 10.1007/s10354-010-0766-5] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2010] [Accepted: 01/28/2010] [Indexed: 01/20/2023]
Abstract
Mitochondria are the key source of cellular ATP and their structure and function are markedly affected by pathophysiologic processes associated with the host's response to invading pathogens. In particular, the highly reactive compound peroxynitrite, generated by the reaction of nitric oxide and superoxide anions, inhibits mitochondrial enzymes and damages lipids, proteins, and nucleic acids. Enhanced oxidative stress induces DNA strand breaks that are repaired by activation of poly(ADP-ribose)polymerase (PARP). This process consumes large amounts of nicotinamide adenine dinucleotide (NAD(+)) leading to cellular NAD(+) depletion that impairs flux of reducing equivalents into the respiratory chain and also further promotes inflammation. In experimental studies, novel therapeutic strategies that aim to ameliorate the host's pathogen response or to modulate intracellular signaling events related to oxidative stress protected mitochondrial function and preserved cellular respiration ultimately leading to improved organ function.
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