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Bandyopadhyay S, Garland P, Gaastra B, Zolnourian A, Bulters D, Galea I. The Haptoglobin Response after Aneurysmal Subarachnoid Haemorrhage. Int J Mol Sci 2023; 24:16922. [PMID: 38069244 PMCID: PMC10707007 DOI: 10.3390/ijms242316922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 11/21/2023] [Accepted: 11/25/2023] [Indexed: 12/18/2023] Open
Abstract
Haptoglobin is the body's first line of defence against the toxicity of extracellular haemoglobin released following a subarachnoid haemorrhage (SAH). We investigated the haptoglobin response after SAH in cerebrospinal fluid (CSF) and serum. Paired CSF and serum samples from 19 controls and 92 SAH patients were assayed as follows: ultra-performance liquid chromatography for CSF haemoglobin and haptoglobin, immunoassay for serum haptoglobin and multiplexed CSF cytokines, and colorimetry for albumin. There was marked CSF haptoglobin deficiency: 99% of extracellular haemoglobin was unbound. The quotients for both CSF/serum albumin (qAlb) and haptoglobin (qHp) were used to compute the CSF haptoglobin index (qHp/qAlb). CSF from SAH patients had a significantly lower haptoglobin index compared to controls, especially in Haptoglobin-1 allele carriers. Serum haptoglobin levels increased after SAH and were correlated with CSF cytokine levels. Haptoglobin variables were not associated with long-term clinical outcomes post-SAH. We conclude that: (1) intrathecal haptoglobin consumption occurs after SAH, more so in haptoglobin-1 allele carriers; (2) serum haptoglobin is upregulated after SAH, in keeping with the liver acute phase response to central inflammation; (3) haptoglobin in the CSF is so low that any variation is too small for this to affect long-term outcomes, emphasising the potential for therapeutic haptoglobin supplementation.
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Affiliation(s)
- Soham Bandyopadhyay
- Clinical Neurosciences, Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK; (S.B.); (P.G.); (B.G.)
- Wessex Neurological Centre, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK;
| | - Patrick Garland
- Clinical Neurosciences, Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK; (S.B.); (P.G.); (B.G.)
| | - Ben Gaastra
- Clinical Neurosciences, Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK; (S.B.); (P.G.); (B.G.)
- Wessex Neurological Centre, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK;
| | - Ardalan Zolnourian
- Wessex Neurological Centre, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK;
| | - Diederik Bulters
- Clinical Neurosciences, Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK; (S.B.); (P.G.); (B.G.)
- Wessex Neurological Centre, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK;
| | - Ian Galea
- Clinical Neurosciences, Clinical & Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton SO16 6YD, UK; (S.B.); (P.G.); (B.G.)
- Wessex Neurological Centre, University Hospital Southampton NHS Foundation Trust, Southampton SO16 6YD, UK;
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di Masi A, De Simone G, Ciaccio C, D'Orso S, Coletta M, Ascenzi P. Haptoglobin: From hemoglobin scavenging to human health. Mol Aspects Med 2020; 73:100851. [PMID: 32660714 DOI: 10.1016/j.mam.2020.100851] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/23/2020] [Accepted: 03/25/2020] [Indexed: 02/07/2023]
Abstract
Haptoglobin (Hp) belongs to the family of acute-phase plasma proteins and represents the most important plasma detoxifier of hemoglobin (Hb). The basic Hp molecule is a tetrameric protein built by two α/β dimers. Each Hp α/β dimer is encoded by a single gene and is synthesized as a single polypeptide. Following post-translational protease-dependent cleavage of the Hp polypeptide, the α and β chains are linked by disulfide bridge(s) to generate the mature Hp protein. As human Hp gene is characterized by two common Hp1 and Hp2 alleles, three major genotypes can result (i.e., Hp1-1, Hp2-1, and Hp2-2). Hp regulates Hb clearance from circulation by the macrophage-specific receptor CD163, thus preventing Hb-mediated severe consequences for health. Indeed, the antioxidant and Hb binding properties of Hp as well as its ability to stimulate cells of the monocyte/macrophage lineage and to modulate the helper T-cell type 1 and type 2 balance significantly associate with a variety of pathogenic disorders (e.g., infectious diseases, diabetes, cardiovascular diseases, and cancer). Alternative functions of the variants Hp1 and Hp2 have been reported, particularly in the susceptibility and protection against infectious (e.g., pulmonary tuberculosis, HIV, and malaria) and non-infectious (e.g., diabetes, cardiovascular diseases and obesity) diseases. Both high and low levels of Hp are indicative of clinical conditions: Hp plasma levels increase during infections, inflammation, and various malignant diseases, and decrease during malnutrition, hemolysis, hepatic disease, allergic reactions, and seizure disorders. Of note, the Hp:Hb complexes display heme-based reactivity; in fact, they bind several ferrous and ferric ligands, including O2, CO, and NO, and display (pseudo-)enzymatic properties (e.g., NO and peroxynitrite detoxification). Here, genetic, biochemical, biomedical, and biotechnological aspects of Hp are reviewed.
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Affiliation(s)
- Alessandra di Masi
- Department of Sciences, Roma Tre University, Viale Guglielmo Marconi 446, I-00146 Roma, Italy
| | - Giovanna De Simone
- Department of Sciences, Roma Tre University, Viale Guglielmo Marconi 446, I-00146 Roma, Italy
| | - Chiara Ciaccio
- Department of Clinical Sciences and Translational Medicine, University of Roma "Tor Vergata", Via Montpellier 1, I-00133, Roma, Italy; Interuniversity Consortium for the Research on the Chemistry of Metals in Biological Systems, Via Celso Ulpiani 27, I-70126, Bari, Italy
| | - Silvia D'Orso
- Department of Sciences, Roma Tre University, Viale Guglielmo Marconi 446, I-00146 Roma, Italy
| | - Massimo Coletta
- Department of Clinical Sciences and Translational Medicine, University of Roma "Tor Vergata", Via Montpellier 1, I-00133, Roma, Italy; Interuniversity Consortium for the Research on the Chemistry of Metals in Biological Systems, Via Celso Ulpiani 27, I-70126, Bari, Italy
| | - Paolo Ascenzi
- Interdepartmental Laboratory for Electron Microscopy, Roma Tre University, Via della Vasca Navale 79, I-00146, Roma, Italy.
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Bozza MT, Jeney V. Pro-inflammatory Actions of Heme and Other Hemoglobin-Derived DAMPs. Front Immunol 2020; 11:1323. [PMID: 32695110 PMCID: PMC7339442 DOI: 10.3389/fimmu.2020.01323] [Citation(s) in RCA: 81] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/26/2020] [Indexed: 12/11/2022] Open
Abstract
Damage associated molecular patterns (DAMPs) are endogenous molecules originate from damaged cells and tissues with the ability to trigger and/or modify innate immune responses. Upon hemolysis hemoglobin (Hb) is released from red blood cells (RBCs) to the circulation and give a rise to the production of different Hb redox states and heme which can act as DAMPs. Heme is the best characterized Hb-derived DAMP that targets different immune and non-immune cells. Heme is a chemoattractant, activates the complement system, modulates host defense mechanisms through the activation of innate immune receptors and the heme oxygenase-1/ferritin system, and induces innate immune memory. The contribution of oxidized Hb forms is much less studied, but some evidence show that these species might play distinct roles in intravascular hemolysis-associated pathologies independently of heme release. This review aims to summarize our current knowledge about the formation and pro-inflammatory actions of heme and other Hb-derived DAMPs.
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Affiliation(s)
- Marcelo T Bozza
- Laboratório de Inflamação e Imunidade, Departamento de Imunologia, Universidade Federal Do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Viktória Jeney
- MTA-DE Lendület Vascular Pathophysiology Research Group, Research Centre for Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
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Formation and Detection of Highly Oxidized Hemoglobin Forms in Biological Fluids during Hemolytic Conditions. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:8929020. [PMID: 32377310 PMCID: PMC7196973 DOI: 10.1155/2020/8929020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/08/2020] [Accepted: 04/15/2020] [Indexed: 02/07/2023]
Abstract
Hemolytic diseases are characterized by an accelerated breakdown of red blood cells (RBCs) and the release of hemoglobin (Hb). Following, RBC lysis Hb oxidation occurs with the formation of different redox states of Hb (metHb and ferrylHb) and the release of heme. ferrylHb is unstable and decomposes to metHb with the concomitant formation of globin radicals and eventually covalently crosslinked Hb multimers. The goal of the present study was to determine the concentrations of the different redox states of Hb in biological samples during hemolytic conditions. We used plasma and urine samples of mice with intravascular hemolysis and human cerebrospinal fluid (CSF) samples following intraventricular hemorrhage. Because ferrylHb is highly unstable, we also addressed the fate of this species. metHb and free heme time-dependently accumulate in plasma and CSF samples following intravascular hemolysis and intraventricular hemorrhage, respectively. ferrylHb is hardly detectable in the biological samples during hemolytic conditions. Under in vitro conditions, ferrylHb decomposes quickly to metHb, which process is associated with the formation of covalently crosslinked Hb multimers. We detected these covalently crosslinked Hb multimers in plasma, urine, and CSF samples during hemolytic conditions. Because globin modification is specific for these Hb forms, we propose to call this heterogeneous form of Hb produced during ferrylHb decomposition as globin-modified oxidized Hb (gmoxHb). Understanding the formation and the contribution of gmoxHb species to the pathogenesis of hemolytic conditions could have therapeutic implications in the treatment of hemolytic diseases.
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Hostettler IC, Morton MJ, Ambler G, Kazmi N, Gaunt T, Wilson D, Shakeshaft C, Jäger HR, Cohen H, Yousry TA, Al-Shahi Salman R, Lip G, Brown MM, Muir K, Houlden H, Bulters DO, Galea I, Werring DJ. Haptoglobin genotype and outcome after spontaneous intracerebral haemorrhage. J Neurol Neurosurg Psychiatry 2020; 91:298-304. [PMID: 31924654 PMCID: PMC7612606 DOI: 10.1136/jnnp-2019-321774] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2019] [Revised: 10/05/2019] [Accepted: 10/28/2019] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Haptoglobin is a haemoglobin-scavenging protein that binds and neutralises free haemoglobin and modulates inflammation and endothelial progenitor cell function. A HP gene copy number variation (CNV) generates HP1 and HP2 alleles, while the single-nucleotide polymorphism rs2000999 influences their levels. The HP1 allele is hypothesised to improve outcome after spontaneous (non-traumatic) intracerebral haemorrhage (ICH). We investigated the associations of the HP CNV genotype and rs2000999 with haematoma volume, perihaematomal oedema (PHO) volume, functional outcome and mortality after ICH. METHODS We included patients with neuroimaging-proven ICH, available DNA and 6-month follow-up in an observational cohort study (CROMIS-2). We classified patients into three groups according to the HP CNV: 1-1, 2-1 or 2-2 and also dichotomised HP into HP1-containing genotypes (HP1-1 and HP2-1) and HP2-2 to evaluate the HP1 allele. We measured ICH and PHO volume on CT; PHO was measured by oedema extension distance. Functional outcome was assessed by modified Rankin score (unfavourable outcome defined as mRS 3-6). RESULTS We included 731 patients (mean age 73.4, 43.5% female). Distribution of HP CNV genotype was: HP1-1 n=132 (18.1%); HP2-1 n=342 (46.8%); and HP2-2 n=257 (35.2%). In the multivariable model mortality comparisons between HP groups, HP2-2 as reference, were as follows: OR HP1-1 0.73, 95% CI 0.34 to 1.56 (p value=0.41) and OR HP2-1 0.5, 95% CI 0.28 to 0.89 (p value=0.02) (overall p value=0.06). We found no evidence of association of HP CNV or rs200999 with functional outcome, ICH volume or PHO volume. CONCLUSION The HP2-1 genotype might be associated with lower 6-month mortality after ICH; this finding merits further study.
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Affiliation(s)
| | - Matthew J Morton
- Clinical Neurosciences, Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Gareth Ambler
- Department of Statistical Science, University College London, London, UK
| | - Nabila Kazmi
- MRC Integrative Epidemiology Unit (IEU), Faculty of Health Sciences, University of Bristol, Bristol, UK
| | - Tom Gaunt
- MRC Integrative Epidemiology Unit (IEU), Faculty of Health Sciences, University of Bristol, Bristol, UK
| | - Duncan Wilson
- Stroke Research Centre, University College London, Queen Square Institute of Neurology, London, UK
| | - Clare Shakeshaft
- Stroke Research Centre, University College London, Queen Square Institute of Neurology, London, UK
| | - H R Jäger
- Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, University College London, Queen Square Institute of Neurology, London, UK
| | - Hannah Cohen
- Department of Haematology, University College London, London, UK
| | - Tarek A Yousry
- Neuroradiological Academic Unit, Department of Brain Repair and Rehabilitation, University College London, Queen Square Institute of Neurology, London, UK
| | | | - Gregory Lip
- Liverpool Centre for Cardiovascular Science, University of Liverpool and Liverpool Heart and Chest Hospital, Liverepool, UK
| | - Martin M Brown
- Stroke Research Centre, University College London, Queen Square Institute of Neurology, London, UK
| | - Keith Muir
- Institute of Neuroscience and Psychology, Queen Elizabeth University Hospital, University of Glasgow, Glasgow, UK
| | - Henry Houlden
- MRC Centre for Neuromuscular Diseases, Department of Neuromuscular Diseases, UCL Queen Square Institute of Neurology and National Hospital for Neurology and Neurosurgery, London, UK
| | - Diederik O Bulters
- Department of Neurosurgery, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Ian Galea
- Faculty of Medicine, University of Southampton, Southampton, UK
| | - David J Werring
- Stroke Research Centre, University College London, Queen Square Institute of Neurology, London, UK
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Ligand-dependent inequivalence of the α and β subunits of ferric human hemoglobin bound to haptoglobin. J Inorg Biochem 2020; 202:110814. [DOI: 10.1016/j.jinorgbio.2019.110814] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Revised: 08/26/2019] [Accepted: 08/31/2019] [Indexed: 12/16/2022]
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Robicsek SA, Bhattacharya A, Rabai F, Shukla K, Doré S. Blood-Related Toxicity after Traumatic Brain Injury: Potential Targets for Neuroprotection. Mol Neurobiol 2019; 57:159-178. [PMID: 31617072 DOI: 10.1007/s12035-019-01766-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 08/29/2019] [Indexed: 02/07/2023]
Abstract
Emergency visits, hospitalizations, and deaths due to traumatic brain injury (TBI) have increased significantly over the past few decades. While the primary early brain trauma is highly deleterious to the brain, the secondary injury post-TBI is postulated to significantly impact mortality. The presence of blood, particularly hemoglobin, and its breakdown products and key binding proteins and receptors modulating their clearance may contribute significantly to toxicity. Heme, hemin, and iron, for example, cause membrane lipid peroxidation, generate reactive oxygen species, and sensitize cells to noxious stimuli resulting in edema, cell death, and increased morbidity and mortality. A wide range of other mechanisms such as the immune system play pivotal roles in mediating secondary injury. Effective scavenging of all of these pro-oxidant and pro-inflammatory metabolites as well as controlling maladaptive immune responses is essential for limiting toxicity and secondary injury. Hemoglobin metabolism is mediated by key molecules such as haptoglobin, heme oxygenase, hemopexin, and ferritin. Genetic variability and dysfunction affecting these pathways (e.g., haptoglobin and heme oxygenase expression) have been implicated in the difference in susceptibility of individual patients to toxicity and may be target pathways for potential therapeutic interventions in TBI. Ongoing collaborative efforts are required to decipher the complexities of blood-related toxicity in TBI with an overarching goal of providing effective treatment options to all patients with TBI.
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Affiliation(s)
- Steven A Robicsek
- Department of Anesthesiology, Center for Translational Research in Neurodegenerative Disease and McKnight Brain Institute, College of Medicine, University of Florida, 1275 Center Drive, Biomed Sci J493, Gainesville, FL, 32610, USA. .,Departments of Neurosurgery, Neuroscience, College of Medicine, University of Florida, Gainesville, FL, USA.
| | - Ayon Bhattacharya
- Department of Anesthesiology, Center for Translational Research in Neurodegenerative Disease and McKnight Brain Institute, College of Medicine, University of Florida, 1275 Center Drive, Biomed Sci J493, Gainesville, FL, 32610, USA.,Department of Pharmacology, KPC Medical College, West Bengal University of Health Sciences, Kolkata, West Bengal, India
| | - Ferenc Rabai
- Department of Anesthesiology, Center for Translational Research in Neurodegenerative Disease and McKnight Brain Institute, College of Medicine, University of Florida, 1275 Center Drive, Biomed Sci J493, Gainesville, FL, 32610, USA
| | - Krunal Shukla
- Department of Anesthesiology, Center for Translational Research in Neurodegenerative Disease and McKnight Brain Institute, College of Medicine, University of Florida, 1275 Center Drive, Biomed Sci J493, Gainesville, FL, 32610, USA
| | - Sylvain Doré
- Department of Anesthesiology, Center for Translational Research in Neurodegenerative Disease and McKnight Brain Institute, College of Medicine, University of Florida, 1275 Center Drive, Biomed Sci J493, Gainesville, FL, 32610, USA. .,Departments of Neurology, Psychiatry, Pharmaceutics and Neuroscience, College of Medicine, University of Florida, Gainesville, FL, USA.
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Griffiths S, Clark J, Adamides AA, Ziogas J. The role of haptoglobin and hemopexin in the prevention of delayed cerebral ischaemia after aneurysmal subarachnoid haemorrhage: a review of current literature. Neurosurg Rev 2019; 43:1273-1288. [PMID: 31493061 DOI: 10.1007/s10143-019-01169-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 07/23/2019] [Accepted: 08/26/2019] [Indexed: 01/01/2023]
Abstract
Delayed cerebral ischaemia (DCI) after aneurysmal subarachnoid haemorrhage (aSAH) is a major cause of mortality and morbidity. The pathophysiology of DCI after aSAH is thought to involve toxic mediators released from lysis of red blood cells within the subarachnoid space, including free haemoglobin and haem. Haptoglobin and hemopexin are endogenously produced acute phase proteins that are involved in the clearance of these toxic mediators. The aim of this review is to investigate the pathophysiological mechanisms involved in DCI and the role of both endogenous as well as exogenously administered haptoglobin and hemopexin in the prevention of DCI.
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Affiliation(s)
- Sean Griffiths
- Department of Neurosurgery, Royal Melbourne Hospital, 300 Grattan St, Parkville, 3050, Australia. .,Western Hospital, 160 Gordon St, Footscray, 3011, Australia.
| | - Jeremy Clark
- Department of Neurosurgery, Royal Melbourne Hospital, 300 Grattan St, Parkville, 3050, Australia
| | - Alexios A Adamides
- Department of Neurosurgery, Royal Melbourne Hospital, 300 Grattan St, Parkville, 3050, Australia
| | - James Ziogas
- Department of Pharmacology and Therapeutics, University of Melbourne, Parkville, 3010, Australia
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Abstract
Haemoglobin is released into the CNS during the breakdown of red blood cells after intracranial bleeding. Extracellular free haemoglobin is directly neurotoxic. Haemoglobin scavenging mechanisms clear haemoglobin and reduce toxicity; these mechanisms include erythrophagocytosis, haptoglobin binding of haemoglobin, haemopexin binding of haem and haem oxygenase breakdown of haem. However, the capacity of these mechanisms is limited in the CNS, and they easily become overwhelmed. Targeting of haemoglobin toxicity and scavenging is, therefore, a rational therapeutic strategy. In this Review, we summarize the neurotoxic mechanisms of extracellular haemoglobin and the peculiarities of haemoglobin scavenging pathways in the brain. Evidence for a role of haemoglobin toxicity in neurological disorders is discussed, with a focus on subarachnoid haemorrhage and intracerebral haemorrhage, and emerging treatment strategies based on the molecular pathways involved are considered. By focusing on a fundamental biological commonality between diverse neurological conditions, we aim to encourage the application of knowledge of haemoglobin toxicity and scavenging across various conditions. We also hope that the principles highlighted will stimulate research to explore the potential of the pathways discussed. Finally, we present a consensus opinion on the research priorities that will help to bring about clinical benefits.
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Maamoun H, Benameur T, Pintus G, Munusamy S, Agouni A. Crosstalk Between Oxidative Stress and Endoplasmic Reticulum (ER) Stress in Endothelial Dysfunction and Aberrant Angiogenesis Associated With Diabetes: A Focus on the Protective Roles of Heme Oxygenase (HO)-1. Front Physiol 2019; 10:70. [PMID: 30804804 PMCID: PMC6378556 DOI: 10.3389/fphys.2019.00070] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 01/21/2019] [Indexed: 12/17/2022] Open
Abstract
Type-2 diabetes prevalence is continuing to rise worldwide due to physical inactivity and obesity epidemic. Diabetes and fluctuations of blood sugar are related to multiple micro- and macrovascular complications, that are attributed to oxidative stress, endoplasmic reticulum (ER) activation and inflammatory processes, which lead to endothelial dysfunction characterized, among other features, by reduced availability of nitric oxide (NO) and aberrant angiogenic capacity. Several enzymatic anti-oxidant and anti-inflammatory agents have been found to play protective roles against oxidative stress and its downstream signaling pathways. Of particular interest, heme oxygenase (HO) isoforms, specifically HO-1, have attracted much attention as major cytoprotective players in conditions associated with inflammation and oxidative stress. HO operates as a key rate-limiting enzyme in the process of degradation of the iron-containing molecule, heme, yielding the following byproducts: carbon monoxide (CO), iron, and biliverdin. Because HO-1 induction was linked to pro-oxidant states, it has been regarded as a marker of oxidative stress; however, accumulating evidence has established multiple cytoprotective roles of the enzyme in metabolic and cardiovascular disorders. The cytoprotective effects of HO-1 depend on several cellular mechanisms including the generation of bilirubin, an anti-oxidant molecule, from the degradation of heme; the induction of ferritin, a strong chelator of free iron; and the release of CO, that displays multiple anti-inflammatory and anti-apoptotic actions. The current review article describes the major molecular mechanisms contributing to endothelial dysfunction and altered angiogenesis in diabetes with a special focus on the interplay between oxidative stress and ER stress response. The review summarizes the key cytoprotective roles of HO-1 against hyperglycemia-induced endothelial dysfunction and aberrant angiogenesis and discusses the major underlying cellular mechanisms associated with its protective effects.
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Affiliation(s)
- Hatem Maamoun
- Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Ain Shams University, Cairo, Egypt
| | - Tarek Benameur
- College of Medicine, King Faisal University, Al-Ahsa, Saudi Arabia
| | - Gianfranco Pintus
- Department of Biomedical Sciences, College of Health Sciences, Qatar University, Doha, Qatar
| | - Shankar Munusamy
- Department of Pharmaceutical and Administrative Sciences, College of Pharmacy and Health Sciences, Drake University, Des Moines, IA, United States
| | - Abdelali Agouni
- Department of Pharmaceutical Sciences, College of Pharmacy, Qatar University, Doha, Qatar
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Fluoride and azide binding to ferric human hemoglobin:haptoglobin complexes highlights the ligand-dependent inequivalence of the α and β hemoglobin chains. J Biol Inorg Chem 2019; 24:247-255. [DOI: 10.1007/s00775-019-01642-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Accepted: 12/31/2018] [Indexed: 01/21/2023]
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12
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Nyakundi BB, Tóth A, Balogh E, Nagy B, Erdei J, Ryffel B, Paragh G, Cordero MD, Jeney V. Oxidized hemoglobin forms contribute to NLRP3 inflammasome-driven IL-1β production upon intravascular hemolysis. Biochim Biophys Acta Mol Basis Dis 2018; 1865:464-475. [PMID: 30389578 DOI: 10.1016/j.bbadis.2018.10.030] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 10/16/2018] [Accepted: 10/26/2018] [Indexed: 12/17/2022]
Abstract
Damage associated molecular patterns (DAMPs) are released form red blood cells (RBCs) during intravascular hemolysis (IVH). Extracellular heme, with its pro-oxidant, pro-inflammatory and cytotoxic effects, is sensed by innate immune cells through pattern recognition receptors such as toll-like receptor 4 and nucleotide-binding domain and leucine rich repeat containing family, pyrin domain containing 3 (NLRP3), while free availability of heme is strictly controlled. Here we investigated the involvement of different hemoglobin (Hb) forms in hemolysis-associated inflammatory responses. We found that after IVH most of the extracellular heme molecules are localized in oxidized Hb forms. IVH was associated with caspase-1 activation and formation of mature IL-1β in plasma and in the liver of C57BL/6 mice. We showed that ferrylHb (FHb) induces active IL-1β production in LPS-primed macrophages in vitro and triggered intraperitoneal recruitment of neutrophils and monocytes, caspase-1 activation and active IL-1β formation in the liver of C57BL/6 mice. NLRP3 deficiency provided a survival advantage upon IVH, without influencing the extent of RBC lysis or the accumulation of oxidized Hb forms. However, both hemolysis-induced and FHb-induced pro-inflammatory responses were largely attenuated in Nlrp3-/- mice. Taken together, FHb is a potent trigger of NLRP3 activation and production of IL-1β in vitro and in vivo, suggesting that FHb may contribute to hemolysis-induced inflammation. Identification of RBC-derived DAMPs might allow us to develop new therapeutic approaches for hemolytic diseases.
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Affiliation(s)
- Benard Bogonko Nyakundi
- Research Centre for Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Andrea Tóth
- Research Centre for Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Enikő Balogh
- Research Centre for Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Béla Nagy
- Department of Laboratory Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Judit Erdei
- Research Centre for Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Bernhard Ryffel
- Experimental and Molecular Immunology and Neurogenetics, The National Center for Scientific Research, Orleans, France; Institute of Molecular Medicine, University of Cape Town, Cape Town, South Africa
| | - György Paragh
- Research Centre for Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Mario D Cordero
- Institute of Nutrition and Food Technology "José Mataix Verdú", Department of Physiology, Biomedical Research Center, University of Granada, Granada, Spain
| | - Viktória Jeney
- Research Centre for Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
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Zhang Z, Xiao Z, Deng B, Liu X, Liu W, Nie H, Li X, Chen Z, Yang D, Duan R. Therapeutic Efficacy of Methazolamide Against Intermittent Hypoxia-Induced Excessive Erythrocytosis in Rats. High Alt Med Biol 2018; 19:69-80. [DOI: 10.1089/ham.2017.0044] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Affiliation(s)
- Zhiqing Zhang
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China
| | - Zhonghai Xiao
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China
| | - Bingnan Deng
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China
| | - Xiaohua Liu
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China
| | - Wei Liu
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China
| | - Hongjing Nie
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China
| | - Xi Li
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China
| | - Zhaoli Chen
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China
| | - Danfeng Yang
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China
| | - Ruifeng Duan
- Tianjin Institute of Health and Environmental Medicine, Tianjin, China
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14
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Abstract
Damage-associated molecular patterns (DAMPs) or alarmins are endogenous danger signals that are derived from damaged cells and extracellular matrix degradation, capable of triggering innate immune response to promote tissue damage repair. Hemolytic or hemorrhagic episodes are often associated with inflammation, even when infectious agents are absent, suggesting that damaged red blood cells (RBCs) release DAMPs.Hemoglobin (Hb) composes 96% of the dry weight of RBCs; therefore upon hemolysis, tremendous amounts of Hb are released into the extracellular milieu. Hb oxidation occurs outside the protective environment of RBCs, leading to the formation of different Hb oxidation products and heme. Heme acts as a prototypic DAMP participating in toll-like receptor as well as intracellular nucleotide-binding oligomerization domain-like receptor signaling. Oxidized Hb forms also possess some inflammatory actions independently of their heme releasing capability. Non-Hb-derived DAMPs such as ATP, interleukin-33, heat shock protein 70, as well as RBC membrane-derived microparticles might also contribute to the innate immune response triggered by hemolysis/hemorrhage.In this chapter we will discuss the inflammatory properties of RBC-derived DAMPs with a particular focus on Hb derivatives, as well as therapeutic potential of the endogenous Hb and heme-binding proteins haptoglobin and hemopexin in the prevention of hemolysis/hemorrhage-associated inflammation.
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Affiliation(s)
- Viktória Jeney
- Faculty of Medicine, Department of Internal Medicine, University of Debrecen, Debrecen, Hungary.
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15
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Andersen CBF, Stødkilde K, Sæderup KL, Kuhlee A, Raunser S, Graversen JH, Moestrup SK. Haptoglobin. Antioxid Redox Signal 2017; 26:814-831. [PMID: 27650279 DOI: 10.1089/ars.2016.6793] [Citation(s) in RCA: 107] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Haptoglobin (Hp) is an abundant human plasma protein that tightly captures hemoglobin (Hb) during hemolysis. The Hb-Hp complex formation reduces the oxidative properties of heme/Hb and promotes recognition by the macrophage scavenger receptor CD163. This leads to Hb-Hp breakdown and heme catabolism by heme oxygenase and biliverdin reductase. Gene duplications of a part of or the entire Hp gene in the primate evolution have led to variant Hp gene products that collectively may be designated "the haptoglobins (Hps)" as they all bind Hb. These variant products include the human-specific multimeric Hp phenotypes in individuals, which are hetero- or homozygous for an Hp2 gene allele. The Hp-related protein (Hpr) is another Hp duplication product in humans and other primates. Alternative functions of the variant Hps are indicated by numerous reports on association between Hp phenotypes and disease as well as the elucidation of a specific role of Hpr in the innate immune defense. Recent Advances: Recent functional and structural information on Hp and receptor systems for Hb removal now provides insight on how Hp carries out essential functions such as the Hb detoxification/removal, and how Hpr, by acting as an Hp-lookalike, can sneak a lethal toxin into trypanosome parasites that cause mammalian sleeping sickness. Critical Issues and Future Directions: The new structural insight may facilitate ongoing attempts of developing Hp derivatives for prevention of Hb toxicity in hemolytic diseases such as sickle cell disease and other hemoglobinopathies. Furthermore, the new structural knowledge may help identifying yet unknown functions based on other disease-relevant biological interactions involving Hps. Antioxid. Redox Signal. 26, 814-831.
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Affiliation(s)
| | | | - Kirstine Lindhardt Sæderup
- 2 Cancer and Inflammation, Department of Molecular Medicine, University of Southern Denmark , Odense C, Denmark
| | - Anne Kuhlee
- 3 Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology , Dortmund, Germany
| | - Stefan Raunser
- 3 Department of Structural Biochemistry, Max-Planck Institute of Molecular Physiology , Dortmund, Germany
| | - Jonas H Graversen
- 2 Cancer and Inflammation, Department of Molecular Medicine, University of Southern Denmark , Odense C, Denmark
| | - Søren Kragh Moestrup
- 1 Department of Biomedicine, University of Aarhus , Aarhus C, Denmark .,2 Cancer and Inflammation, Department of Molecular Medicine, University of Southern Denmark , Odense C, Denmark .,4 Department of Clinical Biochemistry and Pharmacology, Odense University Hospital , Odense C, Denmark
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16
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Arachidonic acid causes hidden blood loss-like red blood cell damage through oxidative stress reactions. J Surg Res 2016; 211:14-20. [PMID: 28501110 DOI: 10.1016/j.jss.2016.11.060] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 10/12/2016] [Accepted: 11/30/2016] [Indexed: 01/31/2023]
Abstract
BACKGROUND Hidden blood loss (HBL) often occurs in the prosthetic replacement for joint, but the mechanism is still not clear. MATERIALS AND METHODS This study tried to establish an animal model of HBL by injecting arachidonic acid (AA) into the Sprague-Dawley rats. Different concentrations of AA were injected into the tail veins of the rats, and blood samples were collected before and after administration at 24, 48, and 72 h. A complete blood count was obtained by to find the hemoglobin (Hb) and red blood cell (RBC) count changes. The glutathione peroxidase (GSH-PX) and total superoxide dismutase (T-SOD) activities and hydrogen peroxide (H2O2) levels were detected. The morphological changes of erythrocyte were observed under a polarizing microscope. The absorbance values of the blood samples were tested to determine the presence of ferryl Hb. RESULTS HBL occurred in the experimental groups when the concentration of AA reached 10 mmol/L; Hb and RBC values decreased sharply at 24- and 48-h postinjection. This was followed by reduced activities of GSH-PX and T-SOD and decreased levels of H2O2. Moreover, the pathologic changes of red cell morphology mainly presented as pleomorphic RBC morphology, including cell rupture. The absorbance values of the blood samples were in accordance with ferryl Hb features. RBC and Hb values were relatively stable at 72 h. The GSH-PX and T-SOD activities and H2O2 levels gradually increased up to a balanced state. CONCLUSIONS The study concluded that high concentrations of AA can induce oxidative stress reactions in the body, causing acute injury of RBCs, which is closely related to HBL.
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17
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Welinder KG, Hansen R, Overgaard MT, Brohus M, Sønderkær M, von Bergen M, Rolle-Kampczyk U, Otto W, Lindahl TL, Arinell K, Evans AL, Swenson JE, Revsbech IG, Frøbert O. Biochemical Foundations of Health and Energy Conservation in Hibernating Free-ranging Subadult Brown Bear Ursus arctos. J Biol Chem 2016; 291:22509-22523. [PMID: 27609515 DOI: 10.1074/jbc.m116.742916] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 09/02/2016] [Indexed: 12/12/2022] Open
Abstract
Brown bears (Ursus arctos) hibernate for 5-7 months without eating, drinking, urinating, and defecating at a metabolic rate of only 25% of the summer activity rate. Nonetheless, they emerge healthy and alert in spring. We quantified the biochemical adaptations for hibernation by comparing the proteome, metabolome, and hematological features of blood from hibernating and active free-ranging subadult brown bears with a focus on conservation of health and energy. We found that total plasma protein concentration increased during hibernation, even though the concentrations of most individual plasma proteins decreased, as did the white blood cell types. Strikingly, antimicrobial defense proteins increased in concentration. Central functions in hibernation involving the coagulation response and protease inhibition, as well as lipid transport and metabolism, were upheld by increased levels of very few key or broad specificity proteins. The changes in coagulation factor levels matched the changes in activity measurements. A dramatic 45-fold increase in sex hormone-binding globulin levels during hibernation draws, for the first time, attention to its significant but unknown role in maintaining hibernation physiology. We propose that energy for the costly protein synthesis is reduced by three mechanisms as follows: (i) dehydration, which increases protein concentration without de novo synthesis; (ii) reduced protein degradation rates due to a 6 °C reduction in body temperature and decreased protease activity; and (iii) a marked redistribution of energy resources only increasing de novo synthesis of a few key proteins. The comprehensive global data identified novel biochemical strategies for bear adaptations to the extreme condition of hibernation and have implications for our understanding of physiology in general.
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Affiliation(s)
- Karen Gjesing Welinder
- From the Department of Chemistry and Bioscience, Section of Biotechnology, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg East, Denmark,
| | - Rasmus Hansen
- From the Department of Chemistry and Bioscience, Section of Biotechnology, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg East, Denmark
| | - Michael Toft Overgaard
- From the Department of Chemistry and Bioscience, Section of Biotechnology, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg East, Denmark
| | - Malene Brohus
- From the Department of Chemistry and Bioscience, Section of Biotechnology, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg East, Denmark
| | - Mads Sønderkær
- From the Department of Chemistry and Bioscience, Section of Biotechnology, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg East, Denmark
| | - Martin von Bergen
- From the Department of Chemistry and Bioscience, Section of Biotechnology, Aalborg University, Fredrik Bajers Vej 7H, 9220 Aalborg East, Denmark.,the Departments of Metabolomics and.,Proteomics, Helmholtz Centre for Environmental Research (UFZ), Permoserstrasse 15, 04318 Leipzig, Germany
| | | | - Wolfgang Otto
- Proteomics, Helmholtz Centre for Environmental Research (UFZ), Permoserstrasse 15, 04318 Leipzig, Germany
| | - Tomas L Lindahl
- the Department of Clinical and Experimental Medicine, Linköping University, 581 85 Linköping, Sweden
| | - Karin Arinell
- the Department of Cardiology, Faculty of Health, Örebro University, 701 85 Örebro, Sweden
| | - Alina L Evans
- the Department of Forestry and Wildlife Management, Hedmark University College, Campus Evenstrand, 2411 Elverum, Norway
| | - Jon E Swenson
- the Department for Ecology and Natural Resource Management, Norwegian University of Life Sciences, Postbox 5014, 1432 Ås, Norway.,the Norwegian Institute for Nature Research, Tungasletta 2, N-7485 Trondheim, Norway, and
| | - Inge G Revsbech
- the Department of Bioscience, Zoophysiology, Aarhus University, C.F. Møllers Allé 3, 8000 Aarhus C, Denmark
| | - Ole Frøbert
- the Department of Cardiology, Faculty of Health, Örebro University, 701 85 Örebro, Sweden
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18
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Vallelian F, Garcia-Rubio I, Puglia M, Kahraman A, Deuel JW, Engelsberger WR, Mason RP, Buehler PW, Schaer DJ. Spin trapping combined with quantitative mass spectrometry defines free radical redistribution within the oxidized hemoglobin:haptoglobin complex. Free Radic Biol Med 2015; 85:259-68. [PMID: 25933590 DOI: 10.1016/j.freeradbiomed.2015.04.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 03/31/2015] [Accepted: 04/20/2015] [Indexed: 11/24/2022]
Abstract
Extracellular or free hemoglobin (Hb) accumulates during hemolysis, tissue damage, and inflammation. Heme-triggered oxidative reactions can lead to diverse structural modifications of lipids and proteins, which contribute to the propagation of tissue damage. One important target of Hb׳s peroxidase reactivity is its own globin structure. Amino acid oxidation and crosslinking events destabilize the protein and ultimately cause accumulation of proinflammatory and cytotoxic Hb degradation products. The Hb scavenger haptoglobin (Hp) attenuates oxidation-induced Hb degradation. In this study we show that in the presence of hydrogen peroxide (H2O2), Hb and the Hb:Hp complex share comparable peroxidative reactivity and free radical generation. While oxidation of both free Hb and Hb:Hp complex generates a common tyrosine-based free radical, the spin-trapping reaction with 5,5-dimethyl-1-pyrroline N-oxide (DMPO) yields dissimilar paramagnetic products in Hb and Hb:Hp, suggesting that radicals are differently redistributed within the complex before reacting with the spin trap. With LC-MS(2) mass spectrometry we assigned multiple known and novel DMPO adduct sites. Quantification of these adducts suggested that the Hb:Hp complex formation causes extensive delocalization of accessible free radicals with drastic reduction of the major tryptophan and cysteine modifications in the β-globin chain of the Hb:Hp complex, including decreased βCys93 DMPO adduction. In contrast, the quantitative changes in DMPO adduct formation on Hb:Hp complex formation were less pronounced in the Hb α-globin chain. In contrast to earlier speculations, we found no evidence that free Hb radicals are delocalized to the Hp chain of the complex. The observation that Hb:Hp complex formation alters free radical distribution in Hb may help to better understand the structural basis for Hp as an antioxidant protein.
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Affiliation(s)
| | - Ines Garcia-Rubio
- Laboratory of Physical Chemistry, ETH Zürich, Switzerland; Centro Universitario de la Defensa, carretera de Huesca, Zaragoza, Spain
| | - Michele Puglia
- Division of Internal Medicine, University Hospital, Zurich, Switzerland; Functional Genomics Center, University of Zurich, Switzerland
| | - Abdullah Kahraman
- Institute of Molecular Life Sciences, University of Zurich, Switzerland
| | - Jeremy W Deuel
- Division of Internal Medicine, University Hospital, Zurich, Switzerland
| | | | - Ronald P Mason
- Laboratory of Toxicology & Pharmacology, NIEHS/NIH, Research Triangle Park, NC, USA
| | - Paul W Buehler
- Center of Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD, USA
| | - Dominik J Schaer
- Division of Internal Medicine, University Hospital, Zurich, Switzerland; Institute of Evolutionary Medicine, University of Zurich, Switzerland.
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19
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Leclerc JL, Blackburn S, Neal D, Mendez NV, Wharton JA, Waters MF, Doré S. Haptoglobin phenotype predicts the development of focal and global cerebral vasospasm and may influence outcomes after aneurysmal subarachnoid hemorrhage. Proc Natl Acad Sci U S A 2015; 112:1155-60. [PMID: 25583472 PMCID: PMC4313833 DOI: 10.1073/pnas.1412833112] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Cerebral vasospasm (CV) and the resulting delayed cerebral ischemia (DCI) significantly contribute to poor outcomes following aneurysmal subarachnoid hemorrhage (aSAH). Free hemoglobin (Hb) within the subarachnoid space has been implicated in the pathogenesis of CV. Haptoglobin (Hp) binds free pro-oxidant Hb, thereby modulating its harmful effects. Humans can be of three Hp phenotypes: Hp1-1, Hp2-1, or Hp2-2. In several disease states, the Hp2-2 protein has been associated with reduced ability to protect against toxic free Hb. We hypothesized that individuals with the Hp2-2 phenotype would have more CV, DCI, mortality, and worse functional outcomes after aSAH. In a sample of 74 aSAH patients, Hp2-2 phenotype was significantly associated with increased focal moderate (P = 0.014) and severe (P = 0.008) CV and more global CV (P = 0.014) after controlling for covariates. Strong trends toward increased mortality (P = 0.079) and worse functional outcomes were seen for the Hp2-2 patients with modified Rankin scale at 6 wk (P = 0.076) and at 1 y (P = 0.051) and with Glasgow Outcome Scale Extended at discharge (P = 0.091) and at 1 y (P = 0.055). In conclusion, Hp2-2 phenotype is an independent risk factor for the development of both focal and global CV and also predicts poor functional outcomes and mortality after aSAH. Hp phenotyping may serve as a clinically useful tool in the critical care management of aSAH patients by allowing for early prediction of those patients who require increased vigilance due to their inherent genetic risk for the development of CV and resulting DCI and poor outcomes.
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Affiliation(s)
| | | | | | | | | | | | - Sylvain Doré
- Departments of Anesthesiology, Neuroscience, Neurology, Psychiatry, and Pharmaceutics, University of Florida, Gainesville, FL 32610
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20
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Jeney V, Balla G, Balla J. Red blood cell, hemoglobin and heme in the progression of atherosclerosis. Front Physiol 2014; 5:379. [PMID: 25324785 PMCID: PMC4183119 DOI: 10.3389/fphys.2014.00379] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 09/13/2014] [Indexed: 01/02/2023] Open
Abstract
For decades plaque neovascularization was considered as an innocent feature of advanced atherosclerotic lesions, but nowadays growing evidence suggest that this process triggers plaque progression and vulnerability. Neovascularization is induced mostly by hypoxia, but the involvement of oxidative stress is also established. Because of inappropriate angiogenesis, neovessels are leaky and prone to rupture, leading to the extravasation of red blood cells (RBCs) within the plaque. RBCs, in the highly oxidative environment of the atherosclerotic lesions, tend to lyse quickly. Both RBC membrane and the released hemoglobin (Hb) possess atherogenic activities. Cholesterol content of RBC membrane contributes to lipid deposition and lipid core expansion upon intraplaque hemorrhage. Cell-free Hb is prone to oxidation, and the oxidation products possess pro-oxidant and pro-inflammatory activities. Defense and adaptation mechanisms evolved to cope with the deleterious effects of cell free Hb and heme. These rely on plasma proteins haptoglobin (Hp) and hemopexin (Hx) with the ability to scavenge and eliminate free Hb and heme form the circulation. The protective strategy is completed with the cellular heme oxygenase-1/ferritin system that becomes activated when Hp and Hx fail to control free Hb and heme-mediated stress. These protective molecules have pharmacological potential in diverse pathologies including atherosclerosis.
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Affiliation(s)
- Viktória Jeney
- Department of Medicine, University of Debrecen Debrecen, Hungary ; MTA-DE Vascular Biology, Thrombosis and Hemostasis Research Group, Hungarian Academy of Sciences Debrecen, Hungary
| | - György Balla
- MTA-DE Vascular Biology, Thrombosis and Hemostasis Research Group, Hungarian Academy of Sciences Debrecen, Hungary ; Department of Pediatrics, University of Debrecen Debrecen, Hungary
| | - József Balla
- Department of Medicine, University of Debrecen Debrecen, Hungary
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21
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Mollan TL, Jia Y, Banerjee S, Wu G, Kreulen RT, Tsai AL, Olson JS, Crumbliss AL, Alayash AI. Redox properties of human hemoglobin in complex with fractionated dimeric and polymeric human haptoglobin. Free Radic Biol Med 2014; 69:265-77. [PMID: 24486321 PMCID: PMC4104362 DOI: 10.1016/j.freeradbiomed.2014.01.030] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Revised: 01/22/2014] [Accepted: 01/23/2014] [Indexed: 12/30/2022]
Abstract
Haptoglobin (Hp) is an abundant and conserved plasma glycoprotein, which binds acellular adult hemoglobin (Hb) dimers with high affinity and facilitates their rapid clearance from circulation after hemolysis. Humans possess three main phenotypes of Hp, designated Hp 1-1, Hp 2-1, and Hp 2-2. These variants exhibit diverse structural configurations and have been reported to be functionally nonequivalent. We have investigated the functional and redox properties of Hb-Hp complexes prepared using commercially fractionated Hp and found that all forms exhibit similar behavior. The rate of Hb dimer binding to Hp occurs with bimolecular rate constants of ~0.9 μM(-1) s(-1), irrespective of the type of Hp assayed. Although Hp binding does accelerate the observed rate of HbO2 autoxidation by dissociating Hb tetramers into dimers, the rate observed for these bound dimers is three- to fourfold slower than that of Hb dimers free in solution. Co-incubation of ferric Hb with any form of Hp inhibits heme loss to below detectable levels. Intrinsic redox potentials (E1/2) of the ferric/ferrous pair of each Hb-Hp complex are similar, varying from +54 to +59 mV (vs NHE), and are essentially the same as reported by us previously for Hb-Hp complexes prepared from unfractionated Hp. All Hb-Hp complexes generate similar high amounts of ferryl Hb after exposure to hydrogen peroxide. Electron paramagnetic resonance data indicate that the yields of protein-based radicals during this process are approximately 4 to 5% and are unaffected by the variant of Hp assayed. These data indicate that the Hp fractions examined are equivalent to one another with respect to Hb binding and associated stability and redox properties and that this result should be taken into account in the design of phenotype-specific Hp therapeutics aimed at countering Hb-mediated vascular disease.
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Affiliation(s)
- Todd L Mollan
- Laboratory of Biochemistry and Vascular Biology, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20852, USA
| | - Yiping Jia
- Laboratory of Biochemistry and Vascular Biology, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20852, USA
| | | | - Gang Wu
- Hematology Division, Department of Internal Medicine, University of Texas-Houston Medical School, Houston, TX 77030, USA
| | | | - Ah-Lim Tsai
- Hematology Division, Department of Internal Medicine, University of Texas-Houston Medical School, Houston, TX 77030, USA
| | - John S Olson
- Biochemistry and Cell Biology Department, Rice University, Houston, TX 77251, USA
| | | | - Abdu I Alayash
- Laboratory of Biochemistry and Vascular Biology, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20852, USA.
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22
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Baek JH, Zhang X, Williams MC, Schaer DJ, Buehler PW, D'Agnillo F. Extracellular Hb enhances cardiac toxicity in endotoxemic guinea pigs: protective role of haptoglobin. Toxins (Basel) 2014; 6:1244-59. [PMID: 24691127 PMCID: PMC4014731 DOI: 10.3390/toxins6041244] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2014] [Revised: 03/18/2014] [Accepted: 03/21/2014] [Indexed: 12/13/2022] Open
Abstract
Endotoxemia plays a major causative role in the myocardial injury and dysfunction associated with sepsis. Extracellular hemoglobin (Hb) has been shown to enhance the pathophysiology of endotoxemia. In the present study, we examined the myocardial pathophysiology in guinea pigs infused with lipopolysaccharide (LPS), a Gram-negative bacterial endotoxin, and purified Hb. We also examined whether the administration of the Hb scavenger haptoglobin (Hp) could protect against the effects observed. Here, we show that Hb infusion following LPS administration, but not either insult alone, increased myocardial iron deposition, heme oxygenase-1 expression, phagocyte activation and infiltration, as well as oxidative DNA damage and apoptosis assessed by 8-hydroxy-2'-deoxyguanosine (8-OHdG) and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) immunostaining, respectively. Co-administration of Hp significantly attenuated the myocardial events induced by the combination of LPS and Hb. These findings may have relevant therapeutic implications for the management of sepsis during concomitant disease or clinical interventions associated with the increased co-exposures to LPS and Hb, such as trauma, surgery or massive blood transfusions.
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Affiliation(s)
- Jin Hyen Baek
- Laboratory of Biochemistry and Vascular Biology, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA.
| | - Xiaoyuan Zhang
- Laboratory of Biochemistry and Vascular Biology, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA.
| | - Matthew C Williams
- Laboratory of Biochemistry and Vascular Biology, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA.
| | - Dominik J Schaer
- Division of Internal Medicine, University Hospital, CH-8091 Zurich, Switzerland.
| | - Paul W Buehler
- Laboratory of Biochemistry and Vascular Biology, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA.
| | - Felice D'Agnillo
- Laboratory of Biochemistry and Vascular Biology, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, MD 20892, USA.
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23
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Lipiski M, Deuel JW, Baek JH, Engelsberger WR, Buehler PW, Schaer DJ. Human Hp1-1 and Hp2-2 phenotype-specific haptoglobin therapeutics are both effective in vitro and in guinea pigs to attenuate hemoglobin toxicity. Antioxid Redox Signal 2013; 19:1619-33. [PMID: 23418677 PMCID: PMC3809386 DOI: 10.1089/ars.2012.5089] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
AIMS Infusion of purified haptoglobin (Hp) functions as an effective hemoglobin (Hb) scavenging therapeutic in animal models of hemolysis to prevent cardiovascular and renal injury. Epidemiologic studies demonstrate the phenotype heterogeneity of human Hp proteins and suggest differing vascular protective potential imparted by the dimeric Hp1-1 and the polymeric Hp2-2. RESULTS In vitro experiments and in vivo studies in guinea pigs were performed to evaluate phenotype-specific differences in Hp therapeutics. We found no differences between the two phenotypes in Hb binding and intravascular compartmentalization of Hb in vivo. Both Hp1-1 and Hp2-2 attenuate Hb-induced blood pressure response and renal iron deposition. These findings were consistent with equal prevention of Hb endothelial translocation. The modulation of oxidative Hb reactions by the two Hp phenotypes was not found to be different. Both phenotypes stabilize the ferryl (Fe(4+)) Hb transition state, provide heme retention within the complex, and prevent Hb-driven low-density lipoprotein (LDL) peroxidation. Hb-mediated peroxidation of LDL resulted in endothelial toxicity, which was equally blocked by the addition of Hp1-1 and Hp2-2. INNOVATION AND CONCLUSION The present data do not provide support for the concept that phenotype-specific Hp therapeutics offer differential efficacy in mitigating acute Hb toxicity.
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Affiliation(s)
- Miriam Lipiski
- 1 Division of Internal Medicine, University of Zurich , Zurich, Switzerland
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24
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Schaer CA, Deuel JW, Bittermann AG, Rubio IG, Schoedon G, Spahn DR, Wepf RA, Vallelian F, Schaer DJ. Mechanisms of haptoglobin protection against hemoglobin peroxidation triggered endothelial damage. Cell Death Differ 2013; 20:1569-79. [PMID: 23995229 PMCID: PMC3792434 DOI: 10.1038/cdd.2013.113] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 06/20/2013] [Accepted: 07/15/2013] [Indexed: 01/30/2023] Open
Abstract
Extracellular hemoglobin (Hb) has been recognized as a disease trigger in hemolytic conditions such as sickle cell disease, malaria, and blood transfusion. In vivo, many of the adverse effects of free Hb can be attenuated by the Hb scavenger acute-phase protein haptoglobin (Hp). The primary physiologic disturbances that can be caused by free Hb are found within the cardiovascular system and Hb-triggered oxidative toxicity toward the endothelium has been promoted as a potential mechanism. The molecular mechanisms of this toxicity as well as of the protective activities of Hp are not yet clear. Within this study, we systematically investigated the structural, biochemical, and cell biologic nature of Hb toxicity in an endothelial cell system under peroxidative stress. We identified two principal mechanisms of oxidative Hb toxicity that are mediated by globin degradation products and by modified lipoprotein species, respectively. The two damage pathways trigger diverse and discriminative inflammatory and cytotoxic responses. Hp provides structural stabilization of Hb and shields Hb's oxidative reactions with lipoproteins, providing dramatic protection against both pathways of toxicity. By these mechanisms, Hp shifts Hb's destructive pseudo-peroxidative reaction to a potential anti-oxidative function during peroxidative stress.
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Affiliation(s)
- C A Schaer
- Institute of Anesthesiology, University Hospital, Zurich, Switzerland
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25
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Abstract
In the last several years, significant work has been done studying hemoglobin (Hb) oxidative reactions and clearance mechanisms using both in vitro and in vivo model systems. One active research area involves the study of molecular chaperones and other proteins that are thought to mitigate the toxicity of acellular Hb. For example, the plasma protein haptoglobin (Hp) and the pre-erythroid protein alpha-hemoglobin-stabilizing protein (AHSP) bind to acellular Hb and alpha-subunits of Hb, respectively, to reduce these adverse effects. Moreover, there has been significant work studying hemopexin and alpha-1 microglobulin, both of which are thought to be involved with hemin degradation. These studies have coincided with the timely publication of the first crystal structure of the Hb-Hp complex. In constructing this Forum, we have invited a number of researchers in the area of Hb and myoglobin (Mb) redox biochemistry, as well as those who have contributed fundamentally to our knowledge of Hp function. Our goal has been to update this critically important research area, because we believe that it will ultimately impact the practice of transfusion medicine in a number of important ways.
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Affiliation(s)
- Todd L. Mollan
- Laboratory of Biochemistry and Vascular Biology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland
| | - Abdu I. Alayash
- Laboratory of Biochemistry and Vascular Biology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland
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Bonaventura C, Henkens R, Alayash AI, Banerjee S, Crumbliss AL. Molecular controls of the oxygenation and redox reactions of hemoglobin. Antioxid Redox Signal 2013; 18:2298-313. [PMID: 23198874 PMCID: PMC4047995 DOI: 10.1089/ars.2012.4947] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2012] [Revised: 11/12/2012] [Accepted: 12/01/2012] [Indexed: 01/04/2023]
Abstract
SIGNIFICANCE The broad classes of O(2)-binding proteins known as hemoglobins (Hbs) carry out oxygenation and redox functions that allow organisms with significantly different physiological demands to exist in a wide range of environments. This is aided by allosteric controls that modulate the protein's redox reactions as well as its O(2)-binding functions. RECENT ADVANCES The controls of Hb's redox reactions can differ appreciably from the molecular controls for Hb oxygenation and come into play in elegant mechanisms for dealing with nitrosative stress, in the malarial resistance conferred by sickle cell Hb, and in the as-yet unsuccessful designs for safe and effective blood substitutes. CRITICAL ISSUES An important basic principle in consideration of Hb's redox reactions is the distinction between kinetic and thermodynamic reaction control. Clarification of these modes of control is critical to gaining an increased understanding of Hb-mediated oxidative processes and oxidative toxicity in vivo. FUTURE DIRECTIONS This review addresses emerging concepts and some unresolved questions regarding the interplay between the oxygenation and oxidation reactions of structurally diverse Hbs, both within red blood cells and under acellular conditions. Developing methods that control Hb-mediated oxidative toxicity will be critical to the future development of Hb-based blood substitutes.
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Affiliation(s)
- Celia Bonaventura
- Nicholas School of the Environment, Duke University Marine Laboratory, Beaufort, NC 28516, USA.
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The haptoglobin-CD163-heme oxygenase-1 pathway for hemoglobin scavenging. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2013; 2013:523652. [PMID: 23781295 PMCID: PMC3678498 DOI: 10.1155/2013/523652] [Citation(s) in RCA: 122] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2013] [Revised: 05/09/2013] [Accepted: 05/13/2013] [Indexed: 12/30/2022]
Abstract
The haptoglobin- (Hp-) CD163-heme oxygenase-1 (HO-1) pathway is an efficient captor-receptor-enzyme system to circumvent the hemoglobin (Hb)/heme-induced toxicity during physiological and pathological hemolyses. In this pathway, Hb tightly binds to Hp leading to CD163-mediated uptake of the complex in macrophages followed by lysosomal Hp-Hb breakdown and HO-1-catalyzed conversion of heme into the metabolites carbon monoxide (CO), biliverdin, and iron. The plasma concentration of Hp is a limiting factor as evident during accelerated hemolysis, where the Hp depletion may cause serious Hb-induced toxicity and put pressure on backup protecting systems such as the hemopexin-CD91-HO pathway. The Hp-CD163-HO-1 pathway proteins are regulated by the acute phase mediator interleukin-6 (IL-6), but other regulatory factors indicate that this upregulation is a counteracting anti-inflammatory response during inflammation. The heme metabolites including bilirubin converted from biliverdin have overall an anti-inflammatory effect and thus reinforce the anti-inflammatory efficacy of the Hp-CD163-HO-1 pathway. Future studies of animal models of inflammation should further define the importance of the pathway in the anti-inflammatory response.
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Natural history of the bruise: formation, elimination, and biological effects of oxidized hemoglobin. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2013; 2013:703571. [PMID: 23766858 PMCID: PMC3671564 DOI: 10.1155/2013/703571] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 04/12/2013] [Indexed: 02/02/2023]
Abstract
Numerous disease states are associated with hemolysis or hemorrhage. Because red cells in the extravascular space tend to lyse quickly, hemoglobin (Hb) is released and is prone to autoxidation producing MetHb. Inorganic and organic peroxides may convert Hb and MetHb to higher oxidation states such as ferrylHb. FerrylHb is not a single chemical entity but is a mixture of globin- and porphyrin-centered radicals and covalently cross-linked Hb multimers. Oxidized Hb species are potent prooxidants caused mainly by heme release from oxidized Hb. Moreover, ferrylHb is a strong proinflammatory agonist that targets vascular endothelial cells. This proinflammatory effect of ferrylHb requires actin polymerization, is characterized by the upregulation of proinflammatory adhesion molecules, and is independent of heme release. Deleterious effects of native Hb are controlled by haptoglobin (Hp) that binds cell-free Hb avidly and facilitates its removal from circulation through the CD163 macrophage scavenger receptor-mediated endocytosis. Under circumstances of Hb oxidation, Hp can prevent heme release from MetHb, but unfortunately the Hp-mediated removal of Hb is severely compromised when Hb is structurally altered such as in ferrylHb allowing deleterious downstream reactions to occur even in the presence of Hp.
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Jia Y, Wood F, Buehler PW, Alayash AI. Haptoglobin preferentially binds β but not α subunits cross-linked hemoglobin tetramers with minimal effects on ligand and redox reactions. PLoS One 2013; 8:e59841. [PMID: 23555800 PMCID: PMC3612097 DOI: 10.1371/journal.pone.0059841] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Accepted: 02/20/2013] [Indexed: 11/29/2022] Open
Abstract
Human hemoglobin (Hb) and haptoglobin (Hp) exhibit an extremely high affinity for each other, and the dissociation of Hb tetramers into dimers is generally believed to be a prerequisite for complex formation. We have investigated Hp interactions with native Hb, αα, and ββ cross-linked Hb (ααXLHb and ββXLHb, respectively), and rapid kinetics of Hb ligand binding as well as the redox reactivity in the presence of and absence of Hp. The quaternary conformation of ββ subunit cross-linking results in a higher binding affinity than that of αα subunit cross-linked Hb. However, ββ cross-linked Hb exhibits a four fold slower association rate constant than the reaction rate of unmodified Hb with Hp. The Hp contact regions in the Hb dimer interfaces appear to be more readily exposed in ββXLHb than ααXLHb. In addition, apart from the functional changes caused by chemical modifications, Hp binding does not induce appreciable effects on the ligand binding and redox reactions of ββXLHb. Our findings may therefore be relevant to the design of safer Hb-based oxygen therapeutics by utilizing this preferential binding of ββXLHb to Hp. This may ultimately provide a safe oxidative inactivation and clearance pathway for chemically modified Hbs in circulation.
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Affiliation(s)
- Yiping Jia
- Laboratory of Biochemistry and Vascular Biology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland, United States of America.
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30
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Mollan TL, Banerjee S, Wu G, Parker Siburt CJ, Tsai AL, Olson JS, Weiss MJ, Crumbliss AL, Alayash AI. α-Hemoglobin stabilizing protein (AHSP) markedly decreases the redox potential and reactivity of α-subunits of human HbA with hydrogen peroxide. J Biol Chem 2012; 288:4288-98. [PMID: 23264625 DOI: 10.1074/jbc.m112.412064] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
α-Hemoglobin stabilizing protein (AHSP) is a molecular chaperone that binds monomeric α-subunits of human hemoglobin A (HbA) and modulates heme iron oxidation and subunit folding states. Although AHSP·αHb complexes autoxidize more rapidly than HbA, the redox mechanisms appear to be similar. Both metHbA and isolated met-β-subunits undergo further oxidation in the presence of hydrogen peroxide (H(2)O(2)) to form ferryl heme species. Surprisingly, much lower levels of H(2)O(2)-induced ferryl heme are produced by free met-α-subunits as compared with met-β-subunits, and no ferryl heme is detected in H(2)O(2)-treated AHSP·met-α-complex at pH values from 5.0 to 9.0 at 23 °C. Ferryl heme species were similarly not detected in AHSP·met-α Pro-30 mutants known to exhibit different rates of autoxidation and hemin loss. EPR data suggest that protein-based radicals associated with the ferryl oxidation state exist within HbA α- and β-subunits. In contrast, treatment of free α-subunits with H(2)O(2) yields much smaller radical signals, and no radicals are detected when H(2)O(2) is added to AHSP·α-complexes. AHSP binding also dramatically reduces the redox potential of α-subunits, from +40 to -78 mV in 1 m glycine buffer, pH 6.0, at 8 °C, demonstrating independently that AHSP has a much higher affinity for Fe(III) versus Fe(II) α-subunits. Hexacoordination in the AHSP·met-α complex markedly decreases the rate of the initial H(2)O(2) reaction with iron and thus provides α-subunits protection against damaging oxidative reactions.
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Affiliation(s)
- Todd L Mollan
- Laboratory of Biochemistry and Vascular Biology, Division of Hematology, Center for Biologics Evaluation and Research, Food and Drug Administration, Bethesda, Maryland 20852, USA
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Hemolysis and free hemoglobin revisited: exploring hemoglobin and hemin scavengers as a novel class of therapeutic proteins. Blood 2012; 121:1276-84. [PMID: 23264591 DOI: 10.1182/blood-2012-11-451229] [Citation(s) in RCA: 576] [Impact Index Per Article: 48.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Hemolysis occurs in many hematologic and nonhematologic diseases. Extracellular hemoglobin (Hb) has been found to trigger specific pathophysiologies that are associated with adverse clinical outcomes in patients with hemolysis, such as acute and chronic vascular disease, inflammation, thrombosis, and renal impairment. Among the molecular characteristics of extracellular Hb, translocation of the molecule into the extravascular space, oxidative and nitric oxide reactions, hemin release, and molecular signaling effects of hemin appear to be the most critical. Limited clinical experience with a plasma-derived haptoglobin (Hp) product in Japan and more recent preclinical animal studies suggest that the natural Hb and the hemin-scavenger proteins Hp and hemopexin have a strong potential to neutralize the adverse physiologic effects of Hb and hemin. This includes conditions that are as diverse as RBC transfusion, sickle cell disease, sepsis, and extracorporeal circulation. This perspective reviews the principal mechanisms of Hb and hemin toxicity in different disease states, updates how the natural scavengers efficiently control these toxic moieties, and explores critical issues in the development of human plasma-derived Hp and hemopexin as therapeutics for patients with excessive intravascular hemolysis.
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Alayash AI, Andersen CBF, Moestrup SK, Bülow L. Haptoglobin: the hemoglobin detoxifier in plasma. Trends Biotechnol 2012; 31:2-3. [PMID: 23140673 DOI: 10.1016/j.tibtech.2012.10.003] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 10/11/2012] [Accepted: 10/11/2012] [Indexed: 11/30/2022]
Abstract
Hemoglobin (Hb) is one of the most studied proteins. However, oxidative toxicity associated with free Hb in circulation and its contribution to inflammation and complications of transfusion have only recently become active areas of research. New insights into the protective mechanisms of haptoglobin (Hp), a plasma protein, and a timely resolution of the crystal structure of the Hb-Hp complex made it possible to definitively link the functional and structural interplay between the two proteins. Here, we summarize current knowledge of the interactions between Hb and Hp under oxidative stress conditions, and how Hb's own damaging radicals are harnessed by complex formation. Potential therapeutic benefits of using Hp for inactivation and clearance of free Hb under a number of clinical settings are considered.
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