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Zhao T, Guo X, Sun Y. Iron Accumulation and Lipid Peroxidation in the Aging Retina: Implication of Ferroptosis in Age-Related Macular Degeneration. Aging Dis 2021; 12:529-551. [PMID: 33815881 PMCID: PMC7990372 DOI: 10.14336/ad.2020.0912] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 09/12/2020] [Indexed: 01/19/2023] Open
Abstract
Iron is an essential component in many biological processes in the human body. It is critical for the visual phototransduction cascade in the retina. However, excess iron can be toxic. Iron accumulation and reduced efficiency of intracellular antioxidative defense systems predispose the aging retina to oxidative stress-induced cell death. Age-related macular degeneration (AMD) is characterized by retinal iron accumulation and lipid peroxidation. The mechanisms underlying AMD include oxidative stress-mediated death of retinal pigment epithelium (RPE) cells and subsequent death of retinal photoreceptors. Understanding the mechanism of the disruption of iron and redox homeostasis in the aging retina and AMD is crucial to decipher these mechanisms of cell death and AMD pathogenesis. The mechanisms of retinal cell death in AMD are an area of active investigation; previous studies have proposed several types of cell death as major mechanisms. Ferroptosis, a newly discovered programmed cell death pathway, has been associated with the pathogenesis of several neurodegenerative diseases. Ferroptosis is initiated by lipid peroxidation and is characterized by iron-dependent accumulation. In this review, we provide an overview of the mechanisms of iron accumulation and lipid peroxidation in the aging retina and AMD, with an emphasis on ferroptosis.
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Affiliation(s)
- Tantai Zhao
- 1Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,2Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan, China
| | - Xiaojian Guo
- 1Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,2Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan, China
| | - Yun Sun
- 1Department of Ophthalmology, the Second Xiangya Hospital, Central South University, Changsha, Hunan, China.,2Hunan Clinical Research Center of Ophthalmic Disease, Changsha, Hunan, China
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2
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Structure-activity relationships of novel salicylaldehyde isonicotinoyl hydrazone (SIH) analogs: iron chelation, anti-oxidant and cytotoxic properties. PLoS One 2014; 9:e112059. [PMID: 25393531 PMCID: PMC4231169 DOI: 10.1371/journal.pone.0112059] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2014] [Accepted: 10/11/2014] [Indexed: 01/08/2023] Open
Abstract
Salicylaldehyde isonicotinoyl hydrazone (SIH) is a lipophilic, tridentate iron chelator with marked anti-oxidant and modest cytotoxic activity against neoplastic cells. However, it has poor stability in an aqueous environment due to the rapid hydrolysis of its hydrazone bond. In this study, we synthesized a series of new SIH analogs (based on previously described aromatic ketones with improved hydrolytic stability). Their structure-activity relationships were assessed with respect to their stability in plasma, iron chelation efficacy, redox effects and cytotoxic activity against MCF-7 breast adenocarcinoma cells. Furthermore, studies assessed the cytotoxicity of these chelators and their ability to afford protection against hydrogen peroxide-induced oxidative injury in H9c2 cardiomyoblasts. The ligands with a reduced hydrazone bond, or the presence of bulky alkyl substituents near the hydrazone bond, showed severely limited biological activity. The introduction of a bromine substituent increased ligand-induced cytotoxicity to both cancer cells and H9c2 cardiomyoblasts. A similar effect was observed when the phenolic ring was exchanged with pyridine (i.e., changing the ligating site from O, N, O to N, N, O), which led to pro-oxidative effects. In contrast, compounds with long, flexible alkyl chains adjacent to the hydrazone bond exhibited specific cytotoxic effects against MCF-7 breast adenocarcinoma cells and low toxicity against H9c2 cardiomyoblasts. Hence, this study highlights important structure-activity relationships and provides insight into the further development of aroylhydrazone iron chelators with more potent and selective anti-neoplastic effects.
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Jansová H, Macháček M, Wang Q, Hašková P, Jirkovská A, Potůčková E, Kielar F, Franz KJ, Simůnek T. Comparison of various iron chelators and prochelators as protective agents against cardiomyocyte oxidative injury. Free Radic Biol Med 2014; 74:210-21. [PMID: 24992833 PMCID: PMC4243170 DOI: 10.1016/j.freeradbiomed.2014.06.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Revised: 06/17/2014] [Accepted: 06/24/2014] [Indexed: 01/28/2023]
Abstract
Oxidative stress is a common denominator of numerous cardiovascular disorders. Free cellular iron catalyzes the formation of highly toxic hydroxyl radicals, and iron chelation may thus be an effective therapeutic approach. However, using classical iron chelators in diseases without iron overload poses risks that necessitate more advanced approaches, such as prochelators that are activated to chelate iron only under disease-specific oxidative stress conditions. In this study, three cell-membrane-permeable iron chelators (clinically used deferasirox and experimental SIH and HAPI) and five boronate-masked prochelator analogs were evaluated for their ability to protect cardiac cells against oxidative injury induced by hydrogen peroxide. Whereas the deferasirox-derived agents TIP and TRA-IMM displayed negligible protection and even considerable toxicity, the aroylhydrazone prochelators BHAPI and BSIH-PD provided significant cytoprotection and displayed lower toxicity after prolonged cellular exposure compared to their parent chelators HAPI and SIH, respectively. Overall, the most favorable properties in terms of protective efficiency and low inherent cytotoxicity were observed with the aroylhydrazone prochelator BSIH. BSIH efficiently protected both H9c2 rat cardiomyoblast-derived cells and isolated primary rat cardiomyocytes against hydrogen peroxide-induced mitochondrial and lysosomal dysregulation and cell death. At the same time, BSIH was nontoxic at concentrations up to its solubility limit (600 μM) and in 72-h incubation. Hence, BSIH merits further investigation for prevention and/or treatment of cardiovascular disorders associated with a known (or presumed) component of oxidative stress.
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Affiliation(s)
- Hana Jansová
- Faculty of Pharmacy, Charles University in Prague, 500 05 Hradec Králové, Czech Republic
| | - Miloslav Macháček
- Faculty of Pharmacy, Charles University in Prague, 500 05 Hradec Králové, Czech Republic
| | - Qin Wang
- Department of Chemistry, Duke University, Durham, NC 22708, USA
| | - Pavlína Hašková
- Faculty of Pharmacy, Charles University in Prague, 500 05 Hradec Králové, Czech Republic
| | - Anna Jirkovská
- Faculty of Pharmacy, Charles University in Prague, 500 05 Hradec Králové, Czech Republic
| | - Eliška Potůčková
- Faculty of Pharmacy, Charles University in Prague, 500 05 Hradec Králové, Czech Republic
| | - Filip Kielar
- Department of Chemistry, Duke University, Durham, NC 22708, USA
| | | | - Tomáš Simůnek
- Faculty of Pharmacy, Charles University in Prague, 500 05 Hradec Králové, Czech Republic.
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4
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Macková E, Hrušková K, Bendová P, Vávrová A, Jansová H, Hašková P, Kovaříková P, Vávrová K, Šimůnek T. Methyl and ethyl ketone analogs of salicylaldehyde isonicotinoyl hydrazone: Novel iron chelators with selective antiproliferative action. Chem Biol Interact 2012; 197:69-79. [DOI: 10.1016/j.cbi.2012.03.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Revised: 03/13/2012] [Accepted: 03/30/2012] [Indexed: 01/06/2023]
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5
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Hašková P, Kovaříková P, Koubková L, Vávrová A, Macková E, Simůnek T. Iron chelation with salicylaldehyde isonicotinoyl hydrazone protects against catecholamine autoxidation and cardiotoxicity. Free Radic Biol Med 2011; 50:537-49. [PMID: 21147217 DOI: 10.1016/j.freeradbiomed.2010.12.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2010] [Revised: 11/17/2010] [Accepted: 12/03/2010] [Indexed: 12/20/2022]
Abstract
Elevated catecholamine levels are known to induce damage of the cardiac tissue. This catecholamine cardiotoxicity may stem from their ability to undergo oxidative conversion to aminochromes and concomitant production of reactive oxygen species (ROS), which damage cardiomyocytes via the iron-catalyzed Fenton-type reaction. This suggests the possibility of cardioprotection by iron chelation. Our in vitro experiments have demonstrated a spontaneous decrease in the concentration of the catecholamines epinephrine and isoprenaline during their 24-h preincubation in buffered solution as well as their gradual conversion to oxidation products. These changes were significantly augmented by addition of iron ions and reduced by the iron-chelating agent salicylaldehyde isonicotinoyl hydrazone (SIH). Oxidized catecholamines were shown to form complexes with iron that had significant redox activity, which could be suppressed by SIH. Experiments using the H9c2 cardiomyoblast cell line revealed higher cytotoxicity of oxidized catecholamines than of the parent compounds, apparently through the induction of caspase-independent cell death, whereas co-incubation of cells with SIH was able to significantly preserve cell viability. A significant increase in intracellular ROS formation was observed after the incubation of cells with catecholamine oxidation products; this could be significantly reduced by SIH. In contrast, parent catecholamines did not increase, but rather decreased, cellular ROS production. Hence, our results demonstrate an important role for redox-active iron in catecholamine autoxidation and subsequent toxicity. The iron chelator SIH has shown considerable potential to protect cardiac cells by both inhibition of deleterious catecholamine oxidation to reactive intermediates and prevention of ROS-mediated cardiotoxicity.
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Affiliation(s)
- Pavlína Hašková
- Faculty of Pharmacy, Charles University in Prague, 500 05 Hradec Králové, Czech Republic
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6
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Hruskova K, Kovarikova P, Bendova P, Haskova P, Mackova E, Stariat J, Vavrova A, Vavrova K, Simunek T. Synthesis and initial in vitro evaluations of novel antioxidant aroylhydrazone iron chelators with increased stability against plasma hydrolysis. Chem Res Toxicol 2011; 24:290-302. [PMID: 21214215 DOI: 10.1021/tx100359t] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Oxidative stress is known to contribute to a number of cardiovascular pathologies. Free intracellular iron ions participate in the Fenton reaction and therefore substantially contribute to the formation of highly toxic hydroxyl radicals and cellular injury. Earlier work on the intracellular iron chelator salicylaldehyde isonicotinoyl hydrazone (SIH) has demonstrated its considerable promise as an agent to protect the heart against oxidative injury both in vitro and in vivo. However, the major limitation of SIH is represented by its labile hydrazone bond that makes it prone to plasma hydrolysis. Hence, in order to improve the hydrazone bond stability, nine compounds were prepared by a substitution of salicylaldehyde by the respective methyl- and ethylketone with various electron donors or acceptors in the phenyl ring. All the synthesized aroylhydrazones displayed significant iron-chelating activities and eight chelators showed significantly higher stability in rabbit plasma than SIH. Furthermore, some of these chelators were observed to possess higher cytoprotective activities against oxidative injury and/or lower toxicity as compared to SIH. The results of the present study therefore indicate the possible applicability of several of these novel agents in the prevention and/or treatment of cardiovascular disorders with a known (or presumed) role of oxidative stress. In particular, the methylketone HAPI and nitro group-containing NHAPI merit further in vivo investigations.
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Affiliation(s)
- Katerina Hruskova
- Faculty of Pharmacy in Hradec Kralove, Charles University in Prague, Prague, Czech Republic
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7
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Bendova P, Mackova E, Haskova P, Vavrova A, Jirkovsky E, Sterba M, Popelova O, Kalinowski DS, Kovarikova P, Vavrova K, Richardson DR, Simunek T. Comparison of Clinically Used and Experimental Iron Chelators for Protection against Oxidative Stress-Induced Cellular Injury. Chem Res Toxicol 2010; 23:1105-14. [DOI: 10.1021/tx100125t] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Petra Bendova
- Faculty of Pharmacy in Hradec Kralove and Faculty of Medicine in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic, and Iron Metabolism and Chelation Program, Bosch Institute and Department of Pathology, University of Sydney, Sydney 2006, Australia
| | - Eliska Mackova
- Faculty of Pharmacy in Hradec Kralove and Faculty of Medicine in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic, and Iron Metabolism and Chelation Program, Bosch Institute and Department of Pathology, University of Sydney, Sydney 2006, Australia
| | - Pavlina Haskova
- Faculty of Pharmacy in Hradec Kralove and Faculty of Medicine in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic, and Iron Metabolism and Chelation Program, Bosch Institute and Department of Pathology, University of Sydney, Sydney 2006, Australia
| | - Anna Vavrova
- Faculty of Pharmacy in Hradec Kralove and Faculty of Medicine in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic, and Iron Metabolism and Chelation Program, Bosch Institute and Department of Pathology, University of Sydney, Sydney 2006, Australia
| | - Eduard Jirkovsky
- Faculty of Pharmacy in Hradec Kralove and Faculty of Medicine in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic, and Iron Metabolism and Chelation Program, Bosch Institute and Department of Pathology, University of Sydney, Sydney 2006, Australia
| | - Martin Sterba
- Faculty of Pharmacy in Hradec Kralove and Faculty of Medicine in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic, and Iron Metabolism and Chelation Program, Bosch Institute and Department of Pathology, University of Sydney, Sydney 2006, Australia
| | - Olga Popelova
- Faculty of Pharmacy in Hradec Kralove and Faculty of Medicine in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic, and Iron Metabolism and Chelation Program, Bosch Institute and Department of Pathology, University of Sydney, Sydney 2006, Australia
| | - Danuta S. Kalinowski
- Faculty of Pharmacy in Hradec Kralove and Faculty of Medicine in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic, and Iron Metabolism and Chelation Program, Bosch Institute and Department of Pathology, University of Sydney, Sydney 2006, Australia
| | - Petra Kovarikova
- Faculty of Pharmacy in Hradec Kralove and Faculty of Medicine in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic, and Iron Metabolism and Chelation Program, Bosch Institute and Department of Pathology, University of Sydney, Sydney 2006, Australia
| | - Katerina Vavrova
- Faculty of Pharmacy in Hradec Kralove and Faculty of Medicine in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic, and Iron Metabolism and Chelation Program, Bosch Institute and Department of Pathology, University of Sydney, Sydney 2006, Australia
| | - Des R. Richardson
- Faculty of Pharmacy in Hradec Kralove and Faculty of Medicine in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic, and Iron Metabolism and Chelation Program, Bosch Institute and Department of Pathology, University of Sydney, Sydney 2006, Australia
| | - Tomas Simunek
- Faculty of Pharmacy in Hradec Kralove and Faculty of Medicine in Hradec Kralove, Charles University in Prague, Heyrovskeho 1203, 500 05 Hradec Kralove, Czech Republic, and Iron Metabolism and Chelation Program, Bosch Institute and Department of Pathology, University of Sydney, Sydney 2006, Australia
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8
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Simunek T, Sterba M, Popelova O, Kaiserova H, Potacova A, Adamcova M, Mazurova Y, Ponka P, Gersl V. Pyridoxal Isonicotinoyl Hydrazone (PIH) and its Analogs as Protectants Against Anthracycline-Induced Cardiotoxicity. Hemoglobin 2009; 32:207-15. [DOI: 10.1080/03630260701680276] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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9
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Loh A, Hadziahmetovic M, Dunaief JL. Iron homeostasis and eye disease. Biochim Biophys Acta Gen Subj 2008; 1790:637-49. [PMID: 19059309 DOI: 10.1016/j.bbagen.2008.11.001] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2008] [Revised: 11/07/2008] [Accepted: 11/07/2008] [Indexed: 01/19/2023]
Abstract
BACKGROUND Iron is necessary for life, but excess iron can be toxic to tissues. Iron is thought to damage tissues primarily by generating oxygen free radicals through the Fenton reaction. METHODS We present an overview of the evidence supporting iron's potential contribution to a broad range of eye disease using an anatomical approach. RESULTS Iron can be visualized in the cornea as iron lines in the normal aging cornea as well as in diseases like keratoconus and pterygium. In the lens, we present the evidence for the role of oxidative damage in cataractogenesis. Also, we review the evidence that iron may play a role in the pathogenesis of the retinal disease age-related macular degeneration. Although currently there is no direct link between excess iron and development of optic neuropathies, ferrous iron's ability to form highly reactive oxygen species may play a role in optic nerve pathology. Lastly, we discuss recent advances in prevention and therapeutics for eye disease with antioxidants and iron chelators. GENERAL SIGNIFICANCE Iron homeostasis is important for ocular health.
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Affiliation(s)
- Allison Loh
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA 19104, USA
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10
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Simůnek T, Sterba M, Popelová O, Kaiserová H, Adamcová M, Hroch M, Hasková P, Ponka P, Gersl V. Anthracycline toxicity to cardiomyocytes or cancer cells is differently affected by iron chelation with salicylaldehyde isonicotinoyl hydrazone. Br J Pharmacol 2008; 155:138-48. [PMID: 18536744 PMCID: PMC2527851 DOI: 10.1038/bjp.2008.236] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Revised: 03/27/2008] [Accepted: 05/09/2008] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND AND PURPOSE The clinical utility of anthracycline antineoplastic drugs is limited by the risk of cardiotoxicity, which has been traditionally attributed to iron-mediated production of reactive oxygen species (ROS). EXPERIMENTAL APPROACH The aims of this study were to examine the strongly lipophilic iron chelator, salicylaldehyde isonicotinoyl hydrazone (SIH), for its ability to protect rat isolated cardiomyocytes against the toxicity of daunorubicin (DAU) and to investigate the effects of SIH on DAU-induced inhibition of proliferation in a leukaemic cell line. Cell toxicity was measured by release of lactate dehydrogenase and staining with Hoechst 33342 or propidium iodide and lipid peroxidation by malonaldehyde formation. KEY RESULTS SIH fully protected cardiomyocytes against model oxidative injury induced by hydrogen peroxide exposure. SIH also significantly but only partially and with no apparent dose-dependency, reduced DAU-induced cardiomyocyte death. However, the observed protection was not accompanied by decreased lipid peroxidation. In the HL-60 acute promyelocytic leukaemia cell line, SIH did not blunt the antiproliferative efficacy of DAU. Instead, at concentrations that reduced DAU toxicity to cardiomyocytes, SIH enhanced the tumoricidal action of DAU. CONCLUSIONS AND IMPLICATIONS This study demonstrates that iron is most likely involved in anthracycline cardiotoxicity and that iron chelation has protective potential, but apparently through mechanism(s) other than by inhibition of ROS-induced injury. In addition to cardioprotection, iron chelation may have considerable potential to improve the therapeutic action of anthracyclines by enhancing their anticancer efficiency and this potential warrants further investigation.
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MESH Headings
- Aldehydes/pharmacology
- Animals
- Animals, Newborn
- Antibiotics, Antineoplastic/toxicity
- Cell Proliferation/drug effects
- Cell Survival/drug effects
- Cytoprotection
- Daunorubicin/toxicity
- Dose-Response Relationship, Drug
- HL-60 Cells
- Humans
- Hydrazones/pharmacology
- Iron Chelating Agents/pharmacology
- Leukemia, Promyelocytic, Acute/metabolism
- Leukemia, Promyelocytic, Acute/pathology
- Lipid Peroxidation/drug effects
- Malondialdehyde/metabolism
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Oxidative Stress/drug effects
- Rats
- Rats, Wistar
- Time Factors
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Affiliation(s)
- T Simůnek
- Department of Biochemical Sciences, Faculty of Pharmacy, Charles University in Prague, Hradec Králové, Czech Republic.
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11
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He X, Hahn P, Iacovelli J, Wong R, King C, Bhisitkul R, Massaro-Giordano M, Dunaief JL. Iron homeostasis and toxicity in retinal degeneration. Prog Retin Eye Res 2007; 26:649-73. [PMID: 17921041 DOI: 10.1016/j.preteyeres.2007.07.004] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Iron is essential for many metabolic processes but can also cause damage. As a potent generator of hydroxyl radical, the most reactive of the free radicals, iron can cause considerable oxidative stress. Since iron is absorbed through diet but not excreted except through menstruation, total body iron levels buildup with age. Macular iron levels increase with age, in both men and women. This iron has the potential to contribute to retinal degeneration. Here we present an overview of the evidence suggesting that iron may contribute to retinal degenerations. Intraocular iron foreign bodies cause retinal degeneration. Retinal iron buildup resulting from hereditary iron homeostasis disorders aceruloplasminemia, Friedreich's ataxia, and panthothenate kinase-associated neurodegeneration cause retinal degeneration. Mice with targeted mutation of the iron exporter ceruloplasmin have age-dependent retinal iron overload and a resulting retinal degeneration with features of age-related macular degeneration (AMD). Post mortem retinas from patients with AMD have more iron and the iron carrier transferrin than age-matched controls. Over the past 10 years much has been learned about the intricate network of proteins involved in iron handling. Many of these, including transferrin, transferrin receptor, divalent metal transporter-1, ferritin, ferroportin, ceruloplasmin, hephaestin, iron-regulatory protein, and histocompatibility leukocyte antigen class I-like protein involved in iron homeostasis (HFE) have been found in the retina. Some of these proteins have been found in the cornea and lens as well. Levels of the iron carrier transferrin are high in the aqueous and vitreous humors. The functions of these proteins in other tissues, combined with studies on cultured ocular tissues, genetically engineered mice, and eye exams on patients with hereditary iron diseases provide clues regarding their ocular functions. Iron may play a role in a broad range of ocular diseases, including glaucoma, cataract, AMD, and conditions causing intraocular hemorrhage. While iron deficiency must be prevented, the therapeutic potential of limiting iron-induced ocular oxidative damage is high. Systemic, local, or topical iron chelation with an expanding repertoire of drugs has clinical potential.
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Affiliation(s)
- Xining He
- F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, 305 Stellar-Chance Labs, 422 Curie Boulevard, Philadelphia, PA 19104, USA
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12
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Sterba M, Popelová O, Simůnek T, Mazurová Y, Potácová A, Adamcová M, Guncová I, Kaiserová H, Palicka V, Ponka P, Gersl V. Iron chelation-afforded cardioprotection against chronic anthracycline cardiotoxicity: A study of salicylaldehyde isonicotinoyl hydrazone (SIH). Toxicology 2007; 235:150-66. [PMID: 17459556 DOI: 10.1016/j.tox.2007.03.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2007] [Revised: 03/12/2007] [Accepted: 03/13/2007] [Indexed: 01/09/2023]
Abstract
Pyridoxal-derived aroylhydrazone iron chelators have been previously shown as effective cardioprotectants against chronic anthracycline cardiotoxicity. In this study we focused on a novel salicylaldehyde analogue (salicylaldehyde isonicotinoyl hydrazone, SIH), which has been recently demonstrated to possess marked and dose-dependent protective effects against oxidative injury of cardiomyocytes. Therefore, in the present study the cardioprotective potential of SIH against daunorubicin (DAU) cardiotoxicity was assessed in vitro (isolated rat ventricular cardiomyocytes; DAU 10 microM, 48 h exposure) as well as in vivo (chronic DAU-induced cardiomyopathy in rabbits; DAU 3mg/kg, i.v. weekly, 10 weeks). In vitro, SIH (3-100 microM) was able to partially, but significantly decrease the LDH leakage from cardiomyocytes. In vivo, SIH co-administration was capable to reduce (SIH dose of 0.5mg/kg, i.v.) or even to completely prevent (1.0mg/kg, i.v.) the DAU-induced mortality. Moreover, the latter dose of the chelator significantly improved the left ventricular function (LV dP/dt(max)=1185+/-80 kPa/s versus 783+/-53 kPa/s in the DAU group; P<0.05) and decreased the severity of the myocardial morphological changes as well as the plasma levels of cardiac troponin T. Unfortunately, further escalation of the SIH dose (to 2.5mg/kg) resulted in a nearly complete reversal of the protective effects as judged by the overall mortality, functional, morphological as well as biochemical examinations. Hence, this study points out that aroylhydrazone iron chelators can induce a significant cardioprotection against anthracycline cardiotoxicity; however, they share the curious dose-response relationship which is unrelated to the chemical structure or the route of the administration of the chelator.
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Affiliation(s)
- Martin Sterba
- Department of Pharmacology, Faculty of Medicine in Hradec Králové, Charles University in Prague, Simkova 870, Hradec Králové 500 38, Czech Republic.
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13
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Kalinowski DS, Richardson DR. The Evolution of Iron Chelators for the Treatment of Iron Overload Disease and Cancer. Pharmacol Rev 2005; 57:547-83. [PMID: 16382108 DOI: 10.1124/pr.57.4.2] [Citation(s) in RCA: 554] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The evolution of iron chelators from a range of primordial siderophores and aromatic heterocyclic ligands has lead to the formation of a new generation of potent and efficient iron chelators. For example, various siderophore analogs and synthetic ligands, including ICL670A [4-[3,5-bis-(hydroxyphenyl)-1,2,4-triazol-1-yl]-benzoic acid], 4'-hydroxydesazadesferrithiocin, and Triapine, have been developed from predecessors and illustrate potent iron-mobilizing or antineoplastic activities. This review focuses on the evolution of iron chelators from initial lead compounds through to the development of novel chelating agents, many of which show great potential to be clinically applied in the treatment of iron overload disease and cancer.
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Affiliation(s)
- Danuta S Kalinowski
- The Iron Metabolism and Chelation Program, Children's Cancer Institute Australia for Medical Research, Sydney, New South Wales, Australia
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