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Jacobson PK, Lind L, Persson HL. Applying the Rome Proposal on Exacerbations of Chronic Obstructive Pulmonary Disease: Does Comorbid Chronic Heart Failure Matter? Int J Chron Obstruct Pulmon Dis 2023; 18:2055-2064. [PMID: 37744733 PMCID: PMC10517701 DOI: 10.2147/copd.s425592] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 08/21/2023] [Indexed: 09/26/2023] Open
Abstract
Background Chronic heart failure (CHF) is a common comorbidity among patients with chronic obstructive pulmonary disease (COPD). Both exacerbations of COPD (ECOPDs) and exacerbations of CHF (ECHFs) display worsening of breathlessness at rest (BaR) and breathlessness at physical activity (BaPA). Comorbid CHF may have an impact on the vital signs assessed, when the Rome proposal (adopted by GOLD 2023) is applied on ECOPDs. Thus, the aim of the present study was to investigate the impact of comorbid CHF on ECOPDs severity, particularly focusing on the influence of comorbid CHF on BaR and BaPA. Methods We analysed data on COPD symptoms collected from the telehealth study The eHealth Diary. Patients with COPD (n = 43) and patients with CHF (n = 41) were asked to daily monitor BaR and BaPA, employing a digital pen and scales for BaR and BaPA (from 0 to 10). Twenty-eight patients of the COPD patients presented with comorbid CHF. Totally, 125 exacerbations were analysed. Results Exacerbations in the group with COPD patients and comorbid CHF were compared to the group with COPD patients without comorbid CHF and the group with CHF patients. Compared with GOLD 2022, the GOLD 2023 (the Rome proposal) significantly downgraded the ECOPD severity. Comorbid CHF did not interfere significantly on the observed difference. Comorbid CHF did not worsen BaR scores, assessed at inclusion and at the symptom peak of the exacerbations. Conclusion In the present study, we find no evidence that comorbid CHF would interfere significantly with the parameters included in the Rome proposal (GOLD 2023). We conclude that the Rome proposal can be safely applied even on COPD patients with very advanced comorbid CHF.
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Affiliation(s)
- Petra Kristina Jacobson
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
- Department of Respiratory Medicine in Linköping, Linköping University, Linköping, Sweden
| | - Leili Lind
- Department of Biomedical Engineering/Health Informatics, Linköping University, Linköping, Sweden
- Digital Systems Division, Unit Digital Health, RISE Research Institutes of Sweden, Linköping, Sweden
| | - Hans L Persson
- Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
- Department of Respiratory Medicine in Linköping, Linköping University, Linköping, Sweden
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2
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Emerging Roles of the Iron Chelators in Inflammation. Int J Mol Sci 2022; 23:ijms23147977. [PMID: 35887336 PMCID: PMC9318075 DOI: 10.3390/ijms23147977] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/13/2022] [Accepted: 07/14/2022] [Indexed: 02/06/2023] Open
Abstract
Iron is a crucial element for mammalian cells, considering its intervention in several physiologic processes. Its homeostasis is finely regulated, and its alteration could be responsible for the onset of several disorders. Iron is closely related to inflammation; indeed, during inflammation high levels of interleukin-6 cause an increased production of hepcidin which induces a degradation of ferroportin. Ferroportin degradation leads to decreased iron efflux that culminates in elevated intracellular iron concentration and consequently iron toxicity in cells and tissues. Therefore, iron chelation could be considered a novel and useful therapeutic strategy in order to counteract the inflammation in several autoimmune and inflammatory diseases. Several iron chelators are already known to have anti-inflammatory effects, among them deferiprone, deferoxamine, deferasirox, and Dp44mT are noteworthy. Recently, eltrombopag has been reported to have an important role in reducing inflammation, acting both directly by chelating iron, and indirectly by modulating iron efflux. This review offers an overview of the possible novel biological effects of the iron chelators in inflammation, suggesting them as novel anti-inflammatory molecules.
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3
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Persson HL, Sioutas A, Jacobson P, Vainikka LK. Human Lung Macrophages Challenged to Oxidants ex vivo: Lysosomal Membrane Sensitization is Associated with Inflammation and Chronic Airflow Limitation. J Inflamm Res 2020; 13:925-932. [PMID: 33235481 PMCID: PMC7678820 DOI: 10.2147/jir.s280419] [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] [Received: 09/04/2020] [Accepted: 10/20/2020] [Indexed: 12/14/2022] Open
Abstract
Background The lung macrophage (LM) is involved in most inflammatory processes of the human lung by clearance of dying cells and by wound repair. Upon cellular stress by oxidant challenge in vivo lysosomes may rupture in LMs and leakage of cellular content and cell debris may trigger airway inflammation and fibrosis, which may lead to chronic airflow limitation (CAL). Objective The aim of this study was to determine whether lysosomal membrane permeabilization (LMP) in LMs challenged to oxidants ex vivo is associated with airway inflammation and CAL, the latter assessed as the reduced forced expiratory volume in one second (FEV1) expressed as % of predicted. Materials and Methods Twenty-eight subjects were investigated; 13 lung-healthy subjects and 15 subjects with a variety of inflammatory disorders, demonstrating CAL on dynamic spirometry (defined as an FEV1/FVC ratio < 0.70). LMs were harvested by broncho-alveolar lavage (BAL) and challenged ex vivo by oxidants. LMP in oxidant-exposed LMs was assessed as the emitted acridine orange (AO) green fluorescence from oxidant-exposed LMs (using macrophage-like murine J774 cells as positive controls). Inflammatory cells in BAL were counted and lung volumes were recorded. Results Oxidant-induced LMP in LMs was significantly greater among subjects with CAL and particularly among those with ongoing inflammation. Previous tobacco history did not influence LMP. Among subjects with CAL, oxidant-induced LMP correlated negatively with FEV1% of predicted. Conclusion Lysosomes of LMs harvested from patients with CAL demonstrate an increased sensitivity to oxidants, which may trigger mechanisms behind CAL, eg, chronic airway inflammation and fibrotic re-modelling. The study suggests a mechanistic role for LMP in LMs on airway inflammation, suggesting an anti-inflammatory effect by drugs that prevent increased LMP.
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Affiliation(s)
- Hans Lennart Persson
- Department of Respiratory Medicine in Linköping, Linköping University, Linköping, Sweden.,Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Apostolos Sioutas
- Department of Respiratory Medicine in Linköping, Linköping University, Linköping, Sweden.,Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Petra Jacobson
- Department of Respiratory Medicine in Linköping, Linköping University, Linköping, Sweden.,Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Linda K Vainikka
- Department of Experimental Pathology, Linköping University, Linköping, Sweden.,Department of Biomedical and Clinical Sciences, Linköping University, Linköping, Sweden
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4
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Peng D, Chen CA, Ruhela D, Li Y, Regan RF. Deferoxamine deconditioning increases neuronal vulnerability to hemoglobin. Exp Cell Res 2020; 390:111926. [DOI: https:/doi.org/10.1016/j.yexcr.2020.111926] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/30/2023]
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5
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Peng D, Chen CA, Ruhela D, Li Y, Regan RF. Deferoxamine deconditioning increases neuronal vulnerability to hemoglobin. Exp Cell Res 2020; 390:111926. [PMID: 32112801 DOI: 10.1016/j.yexcr.2020.111926] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 02/12/2020] [Accepted: 02/25/2020] [Indexed: 01/23/2023]
Abstract
Concomitant treatment with deferoxamine (DFO) protects neural cells from iron and heme-mediated oxidative injury, but also disrupts cell responses to iron loading that may be protective. We hypothesized that DFO treatment and withdrawal would subsequently increase neuronal vulnerability to hemoglobin. Pretreatment with DFO followed by its washout increased neuronal loss after subsequent hemoglobin exposure by 3-4-fold compared with control vehicle-pretreated cultures. This was associated with reduced ferritin induction by hemoglobin; expression of heme oxygenase-1, which catalyzes iron release from heme, was not altered. Increased neuronal loss was prevented by exogenous apoferritin or by continuing DFO or antioxidants throughout the experimental course. Cell nonheme iron levels after hemoglobin treatment were similar in DFO-pretreated and control cultures. These results indicate that DFO deconditions neurons and subsequently increases their vulnerability to heme-mediated injury. Its net effect after CNS hemorrhage may be highly dependent on the timing and duration of its administration. Withdrawal of DFO while heme or iron levels remain elevated may be deleterious, and may negate any benefit of prior concomitant therapy.
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Affiliation(s)
- Denggao Peng
- Department of Emergency Medicine, University of Maryland, School of Medicine, USA
| | - Cindy Acon Chen
- Department of Emergency Medicine, University of Maryland, School of Medicine, USA
| | - Deepa Ruhela
- Department of Emergency Medicine, University of Maryland, School of Medicine, USA
| | - Yang Li
- Department of Emergency Medicine, University of Maryland, School of Medicine, USA
| | - Raymond F Regan
- Department of Emergency Medicine, University of Maryland, School of Medicine, USA.
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6
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Camiolo G, Tibullo D, Giallongo C, Romano A, Parrinello NL, Musumeci G, Di Rosa M, Vicario N, Brundo MV, Amenta F, Ferrante M, Copat C, Avola R, Li Volti G, Salvaggio A, Di Raimondo F, Palumbo GA. α-Lipoic Acid Reduces Iron-induced Toxicity and Oxidative Stress in a Model of Iron Overload. Int J Mol Sci 2019; 20:E609. [PMID: 30708965 PMCID: PMC6387298 DOI: 10.3390/ijms20030609] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 01/22/2019] [Accepted: 01/24/2019] [Indexed: 12/18/2022] Open
Abstract
Iron toxicity is associated with organ injury and has been reported in various clinical conditions, such as hemochromatosis, thalassemia major, and myelodysplastic syndromes. Therefore, iron chelation therapy represents a pivotal therapy for these patients during their lifetime. The aim of the present study was to assess the iron chelating properties of α-lipoic acid (ALA) and how such an effect impacts on iron overload mediated toxicity. Human mesenchymal stem cells (HS-5) and animals (zebrafish, n = 10 for each group) were treated for 24 h with ferric ammonium citrate (FAC, 120 µg/mL) in the presence or absence of ALA (20 µg/mL). Oxidative stress was evaluated by reduced glutathione content, reactive oxygen species formation, mitochondrial dysfunction, and gene expression of heme oxygenase-1b and mitochondrial superoxide dismutase; organ injury, iron accumulation, and autophagy were measured by microscopical, cytofluorimetric analyses, and inductively coupled plasma‒optical mission Spectrometer (ICP-OES). Our results showed that FAC results in a significant increase of tissue iron accumulation, oxidative stress, and autophagy and such detrimental effects were reversed by ALA treatment. In conclusion, ALA possesses excellent iron chelating properties that may be exploited in a clinical setting for organ preservation, as well as exhibiting a good safety profile and low cost for the national health system.
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Affiliation(s)
- Giuseppina Camiolo
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy.
| | - Daniele Tibullo
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy.
- EuroMediterranean Institute of Science and Technology, 90139 Palermo, Italy.
| | - Cesarina Giallongo
- Department of Medical and Surgical Specialties, Hematology Section, University of Catania, 95125 Catania, Italy.
| | - Alessandra Romano
- Department of Medical and Surgical Specialties, Hematology Section, University of Catania, 95125 Catania, Italy.
| | - Nunziatina L Parrinello
- Department of Medical and Surgical Specialties, Hematology Section, University of Catania, 95125 Catania, Italy.
| | - Giuseppe Musumeci
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy.
| | - Michelino Di Rosa
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy.
| | - Nunzio Vicario
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy.
| | - Maria V Brundo
- Department of Biological, Geological and Environmental Science, University of Catania, 95129 Catania, Italy.
| | - Francesco Amenta
- Section of Human Anatomy, School of Medicinal and Health Products Sciences, University of Camerino, Via Madonna delle Carceri 9, 62032 Camerino, Italy.
| | - Margherita Ferrante
- Department of Medical, Surgical Sciences and Advanced Technologies "GF Ingrassia", University of Catania, 95123 Catania, Italy.
| | - Chiara Copat
- Department of Medical, Surgical Sciences and Advanced Technologies "GF Ingrassia", University of Catania, 95123 Catania, Italy.
| | - Roberto Avola
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy.
| | - Giovanni Li Volti
- Department of Biomedical and Biotechnological Sciences, University of Catania, 95123 Catania, Italy.
- EuroMediterranean Institute of Science and Technology, 90139 Palermo, Italy.
| | - Antonio Salvaggio
- Experimental Zooprophylactic Institute of Sicily, 95125 Catania, Italy.
| | - Francesco Di Raimondo
- Department of Medical and Surgical Specialties, Hematology Section, University of Catania, 95125 Catania, Italy.
| | - Giuseppe A Palumbo
- Department of Medical, Surgical Sciences and Advanced Technologies "GF Ingrassia", University of Catania, 95123 Catania, Italy.
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Gutierrez E, Richardson DR, Jansson PJ. The anticancer agent di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT) overcomes prosurvival autophagy by two mechanisms: persistent induction of autophagosome synthesis and impairment of lysosomal integrity. J Biol Chem 2014; 289:33568-89. [PMID: 25301941 PMCID: PMC4246109 DOI: 10.1074/jbc.m114.599480] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2014] [Revised: 10/08/2014] [Indexed: 12/19/2022] Open
Abstract
Autophagy functions as a survival mechanism during cellular stress and contributes to resistance against anticancer agents. The selective antitumor and antimetastatic chelator di-2-pyridylketone 4,4-dimethyl-3-thiosemicarbazone (Dp44mT) causes lysosomal membrane permeabilization and cell death. Considering the integral role of lysosomes in autophagy and cell death, it was important to assess the effect of Dp44mT on autophagy to further understand its mechanism of action. Notably, Dp44mT affected autophagy by two mechanisms. First, concurrent with its antiproliferative activity, Dp44mT increased the expression of the classical autophagic marker LC3-II as a result of induced autophagosome synthesis. Second, this effect was supplemented by a reduction in autophagosome degradation as shown by the accumulation of the autophagic substrate and receptor p62. Conversely, the classical iron chelator desferrioxamine induced autophagosome accumulation only by inhibiting autophagosome degradation. The formation of redox-active iron or copper Dp44mT complexes was critical for its dual effect on autophagy. The cytoprotective antioxidant N-acetylcysteine inhibited Dp44mT-induced autophagosome synthesis and p62 accumulation. Importantly, Dp44mT inhibited autophagosome degradation via lysosomal disruption. This effect prevented the fusion of lysosomes with autophagosomes to form autolysosomes, which is crucial for the completion of the autophagic process. The antiproliferative activity of Dp44mT was suppressed by Beclin1 and ATG5 silencing, indicating the role of persistent autophagosome synthesis in Dp44mT-induced cell death. These studies demonstrate that Dp44mT can overcome the prosurvival activity of autophagy in cancer cells by utilizing this process to potentiate cell death.
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Affiliation(s)
- Elaine Gutierrez
- From the Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, Blackburn Building (D06), University of Sydney, Sydney, New South Wales 2006, Australia
| | - Des R Richardson
- From the Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, Blackburn Building (D06), University of Sydney, Sydney, New South Wales 2006, Australia
| | - Patric J Jansson
- From the Molecular Pharmacology and Pathology Program, Department of Pathology and Bosch Institute, Blackburn Building (D06), University of Sydney, Sydney, New South Wales 2006, Australia
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8
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Persson HL, Vainikka LK. Increased Lysosomal Membrane Permeabilization in Oxidant-exposed Macrophages of Human Fibrotic Lungs. J Cell Death 2013; 6:69-74. [PMID: 25278780 PMCID: PMC4147753 DOI: 10.4137/jcd.s13271] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 11/12/2013] [Accepted: 11/15/2013] [Indexed: 11/13/2022] Open
Abstract
A disrupted balance of reduced glutathione (GSH) and iron (Fe) and subsequent enhanced susceptibility of lysosomes of lung macrophages (LMs) to oxidants may play a role in lung fibrogenesis. We assessed cellular Fe/GSH, lysosomal membrane permeabilization (LMP), and cell death in cultures of oxidant exposed LMs. LMs from 7 lung fibrosis patients and healthy subjects were exposed to a physiologic concentration of H2O2 for 1 h. LMP was assessed with acridine orange green fluorescence, apoptosis/necrosis were estimated by apoptotic DNA and typical morphology, Fe was assessed with Prussian blue staining/atomic absorption spectrophotometry, and GSH was evaluated using a GSH assay kit. Oxidant-induced LMP and cell death were more pronounced in cultures of LMs from patients with lung fibrosis, and these cells contained less GSH and more cytochemically stained Fe. These observations indicate that LMP may be involved in fibrosis development, possibly through activation of the inflammasome complex. Further studies are warranted for a detailed understanding.
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Affiliation(s)
- Hans L Persson
- Division of Pulmonary Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, Department of Respiratory Medicine UHL, Centre for Surgery and Oncology, County Council of Östergötland, Linköping, Sweden
| | - Linda K Vainikka
- Division of Experimental Pathology, Department of Clinical and Experimental Medicine, Faculty of Health Sciences, Linköping University, Linköping, Sweden
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9
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Persson HL, Vainikka LK, Sege M, Wennerström U, Dam-Larsen S, Persson J. Leaky lysosomes in lung transplant macrophages: azithromycin prevents oxidative damage. Respir Res 2012; 13:83. [PMID: 23006592 PMCID: PMC3511206 DOI: 10.1186/1465-9921-13-83] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Accepted: 09/14/2012] [Indexed: 01/31/2023] Open
Abstract
Background Lung allografts contain large amounts of iron (Fe), which inside lung macrophages may promote oxidative lysosomal membrane permeabilization (LMP), cell death and inflammation. The macrolide antibiotic azithromycin (AZM) accumulates 1000-fold inside the acidic lysosomes and may interfere with the lysosomal pool of Fe. Objective Oxidative lysosomal leakage was assessed in lung macrophages from lung transplant recipients without or with AZM treatment and from healthy subjects. The efficiency of AZM to protect lysosomes and cells against oxidants was further assessed employing murine J774 macrophages. Methods Macrophages harvested from 8 transplant recipients (5 without and 3 with ongoing AZM treatment) and 7 healthy subjects, and J774 cells pre-treated with AZM, a high-molecular-weight derivative of the Fe chelator desferrioxamine or ammonium chloride were oxidatively stressed. LMP, cell death, Fe, reduced glutathione (GSH) and H-ferritin were assessed. Results Oxidant challenged macrophages from transplants recipients without AZM exhibited significantly more LMP and cell death than macrophages from healthy subjects. Those macrophages contained significantly more Fe, while GSH and H-ferritin did not differ significantly. Although macrophages from transplant recipients treated with AZM contained both significantly more Fe and less GSH, which would sensitize cells to oxidants, these macrophages resisted oxidant challenge well. The preventive effect of AZM on oxidative LMP and J774 cell death was 60 to 300 times greater than the other drugs tested. Conclusions AZM makes lung transplant macrophages and their lysososomes more resistant to oxidant challenge. Possibly, prevention of obliterative bronchiolitis in lung transplants by AZM is partly due to this action.
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Affiliation(s)
- H Lennart Persson
- Division of Pulmonary Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, Linköping, Sweden.
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10
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Chen-Roetling J, Liu W, Regan RF. Iron accumulation and neurotoxicity in cortical cultures treated with holotransferrin. Free Radic Biol Med 2011; 51:1966-74. [PMID: 21939754 PMCID: PMC3345563 DOI: 10.1016/j.freeradbiomed.2011.08.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Revised: 08/19/2011] [Accepted: 08/22/2011] [Indexed: 01/13/2023]
Abstract
Nonheme iron accumulates in CNS tissue after ischemic and hemorrhagic insults and may contribute to cell loss. The source of this iron has not been precisely defined. After blood-brain barrier disruption, CNS cells may be exposed to plasma concentrations of transferrin-bound iron (TBI), which exceed that in the CSF by over 50-fold. In this study, the hypothesis that these concentrations of TBI produce cell iron accumulation and neurotoxicity was tested in primary cortical cultures. Treatment with 0.5-3mg/ml holotransferrin for 24h resulted in the loss of 20-40% of neurons, associated with increases in malondialdehyde, ferritin, heme oxygenase-1, and iron; transferrin receptor-1 expression was reduced by about 50%. Deferoxamine, 2,2'-bipyridyl, Trolox, and ascorbate prevented all injury, but apotransferrin was ineffective. Cell TBI accumulation was significantly reduced by deferoxamine, 2,2'-bipyridyl, and apotransferrin, but not by ascorbate or Trolox. After treatment with (55)Fe-transferrin, approximately 40% of cell iron was exported within 16h. Net export was increased by deferoxamine and 2,2'-bipyridyl, but not by apotransferrin. These results suggest that downregulation of transferrin receptor-1 expression is insufficient to prevent iron-mediated death when neurons are exposed to plasma concentrations of TBI. Chelator therapy may be beneficial for acute CNS injuries associated with loss of blood-brain barrier integrity.
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Affiliation(s)
| | | | - Raymond F. Regan
- Corresponding Author: Department of Emergency Medicine, Thomas Jefferson University, 1025 Walnut Street, College Building Room 813, Philadelphia, PA 19107, Telephone: 215-955-2695; FAX: 215-923-6225
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Persson HL, Vainikka LK, Eriksson I, Wennerström U. TNF-α-stimulated macrophages protect A549 lung cells against iron and oxidation. ACTA ACUST UNITED AC 2011; 65:81-9. [PMID: 21741805 DOI: 10.1016/j.etp.2011.06.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2011] [Revised: 05/23/2011] [Accepted: 06/06/2011] [Indexed: 11/16/2022]
Abstract
Previously, we have shown that TNF-α protects iron-exposed J774 macrophages against iron-catalyzed oxidative lysosomal disruption and cell death by increasing reduced glutathione and H-ferritin in cells. Because J774 cells are able to harbor large amounts of iron, which is potentially harmful in a redox-active state, we hypothesized that TNF-α-stimulated J774 macrophages will prevent iron-driven oxidative killing of alveolar epithelial A549 cells in co-culture. In the present study, iron trichloride (which is endocytosed by cells as hydrated iron-phosphate complexes) was mainly deposited inside the lysosomes of J774 macrophages, while A549 cells, equally iron exposed, accumulated much less iron. When challenged by oxidants, however, reactive lysosomal iron in A549 cells promoted lysosomal disruption and cell death, particularly in the presence of TNF-α. This effect resulted from an elevation in ROS generation by TNF-α, while a compensatory upregulation of protective molecules (H-ferritin and/or reduced glutathione) by TNF-α was absent. A549 cell death was particularly pronounced when iron and TNF-α were present in the conditioned medium during oxidant challenge; thus, iron-driven oxidative reactions in the culture medium were a much greater hazard to A549 cells than those taking place inside their lysosomes. Consequently, the iron chelator, deferoxamine, efficiently prevented A549 cell death when added to the culture medium during an oxidant challenge. In co-cultures of TNF-α-stimulated lung cells, J774 macrophages sequestered iron inside their lysosomes and protected A549 cells from oxidative reactions and cell death. Thus, the collective effect of TNF-α on co-cultured lung cells was mainly cytoprotective.
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Affiliation(s)
- H Lennart Persson
- Division of Pulmonary Medicine, Department of Medical and Health Sciences, Faculty of Health Sciences, Linköping University, SE-581 85 Linköping, Sweden.
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13
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Persson HL, Vainikka LK. TNF-alpha preserves lysosomal stability in macrophages: a potential defense against oxidative lung injury. Toxicol Lett 2009; 192:261-7. [PMID: 19900513 DOI: 10.1016/j.toxlet.2009.10.031] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2009] [Revised: 10/23/2009] [Accepted: 10/30/2009] [Indexed: 12/18/2022]
Abstract
Iron-catalyzed oxidative damage on the respiratory epithelium is prevented by alveolar macrophages depositing iron inside their lysosomes. Bound in an un-reactive state to various metalloproteins, e.g. ferritin, most lysosomal iron is kept separated from reactive oxygen species (ROS) by intracellular anti-oxidative enzyme systems. Some ROS may, however, escape this protective shield of antioxidants, react with small amounts of free redox-active iron within lysosomes, thereby causing peroxidative damage on lysosomes and possibly also ensuing cell death. Since macrophages, containing large amounts of lysosomal iron, are very resistant to TNF-alpha, we hypothesized that this cell type has developed specific defense mechanisms against TNF-alpha-induced ROS generation. Murine macrophages were exposed (or not) to non-toxic concentrations of TNF-alpha and/or iron and were then challenged with H(2)O(2). Iron-exposed oxidatively stressed cells exhibited extensive lysosomal disruption resulting in pronounced cell death. In contrast, TNF-alpha stabilized lysosomes and protected cells, particularly those iron-exposed, by reducing cellular iron and increasing H-ferritin. Intracellular generation of H(2)O(2) under oxidative stress was kept unchanged by TNF-alpha and/or iron. However, TNF-alpha increased basal levels of glutathione by up-regulating the synthesis of gamma-glutamylcystein synthetase, thereby strengthening the anti-oxidative capacity. TNF-alpha inhibitors would block this novel anti-oxidative defense system, possibly explaining their adverse effects on the lung.
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Affiliation(s)
- H Lennart Persson
- Division of Pulmonary Medicine, Faculty of Health Sciences, University of Linköping, Linköping, Sweden.
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14
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Lu Z, Nie G, Li Y, Soe-Lin S, Tao Y, Cao Y, Zhang Z, Liu N, Ponka P, Zhao B. Overexpression of mitochondrial ferritin sensitizes cells to oxidative stress via an iron-mediated mechanism. Antioxid Redox Signal 2009; 11:1791-803. [PMID: 19271990 DOI: 10.1089/ars.2008.2306] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Mitochondrial ferritin (MtFt) is a newly identified H-ferritin-like protein expressed only in mitochondria. Previous studies have shown that its overexpression markedly affects intracellular iron homeostasis and rescues defects caused by frataxin deficiency. To assess how MtFt exerts its function under oxidative stress conditions, MtFt overexpressing cells were treated with tert-butyl-hydroperoxide (tBHP), and the effects of MtFt expression on cell survival and iron homeostasis were examined. We found that MtFt expression was associated with decreased mitochondrial metabolic activity and reduced glutathione levels as well as a concomitant increase in reactive oxygen species levels and apoptosis. Moreover, mechanistic studies demonstrated that tBHP treatment led to a prolonged decrease in cytosolic ferritins levels in MtFt-expressing cells, while ferritin levels recovered to basal levels in control counterparts. tBHP treatment also resulted in elevated transferrin receptors, followed by more iron acquisition in MtFt expressing cells. The high molecular weight desferrioxamine, targeting to lysosomes, as well as the hydrophobic iron chelator salicylaldehyde isonicotinoyl hydrazone significantly attenuated tBHP-induced cell damage. In conclusion, the current study indicates that both the newly acquired iron from the extracellular environment and internal iron redistribution from ferritin degradation may be responsible for the increased sensitivity to oxidative stress in MtFt-expressing cells.
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Affiliation(s)
- Zhongbing Lu
- State Key Laboratory of Brain and Recognition Laboratory, Institute of Biophysics, Beijing, China
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Galaris D, Pantopoulos K. Oxidative Stress and Iron Homeostasis: Mechanistic and Health Aspects. Crit Rev Clin Lab Sci 2008; 45:1-23. [DOI: 10.1080/10408360701713104] [Citation(s) in RCA: 206] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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Abstract
A novel mechanism of radiosensitization involves radiation-enhanced autophagy of damaged mitochondria and various metalloproteins, by which iron accumulates within lysosomes. Hydrogen peroxide, formed by the radiolytic cleavage of water, generates in the presence of lysosomal redox-active iron extremely reactive hydroxyl radicals by Fenton-type chemistry. Subsequent peroxidative damage of lysosomal membranes initiates release of harmful content from ruptured lysosomes that triggers a cascade of events eventuating in DNA damage and apoptotic or necrotic cell death. This article reviews the role of lysosomal destabilization in radiation-induced cell damage and death. The potential effects of iron chelation therapy targeted to the lysosomes for protection of normal tissues against unwanted effects by radiation is also discussed.
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Affiliation(s)
- H Lennart Persson
- Division of Pulmonary Medicine, Faculty of Health Sciences, University of Linköping, Linköping, Sweden.
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Basu-Modak S, Ali D, Gordon M, Polte T, Yiakouvaki A, Pourzand C, Rice-Evans C, Tyrrell RM. Suppression of UVA-mediated release of labile iron by epicatechin--a link to lysosomal protection. Free Radic Biol Med 2006; 41:1197-204. [PMID: 17015166 DOI: 10.1016/j.freeradbiomed.2006.06.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/07/2005] [Revised: 06/07/2006] [Accepted: 06/12/2006] [Indexed: 01/24/2023]
Abstract
UVA (320-380 nm) radiation generates an oxidative stress in cells and leads to an immediate release of potentially damaging labile iron pools in human skin cells. Treatment of cultured skin fibroblasts for several hours with physiologically relevant concentrations of either epicatechin (EC), a flavonoid plant constituent present in foods, or methylated epicatechin (3'-O-methyl epicatechin, MeOEC), its major human metabolite, prevents this iron release. The similarity of the effectiveness of EC and MeOEC argues against chelation as the mechanism of iron removal. Evidence based on measurements of lysosomal integrity strongly supports the hypothesis that the catechins protect against lysosomal destruction by UVA. Such damage would normally lead to protease release, which has been previously shown to cause ferritin degradation and release of labile iron.
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Affiliation(s)
- Sharmila Basu-Modak
- Department of Pharmacy and Pharmacology, University of Bath, Bath BA2 7AY, UK
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