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Denton WJ, Jordan CW, McGill WJ. Bilateral, geographic, peripapillary, chorioretinal atrophy in a patient with porphyria cutanea tarda and high iron stores. ACTA ACUST UNITED AC 2011; 82:632-41. [PMID: 21775216 DOI: 10.1016/j.optm.2011.02.017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2009] [Revised: 10/11/2010] [Accepted: 02/17/2011] [Indexed: 12/22/2022]
Abstract
PURPOSE Porphyria cutanea tarda (PCT) is a systemic disease caused by a deficiency of the enzyme uroporphyrinogen decarboxylase, which is the fifth enzyme in the heme biosynthetic pathway. This deficiency prevents porphyrin and its byproducts from producing heme. CASE REPORT This case report presents a patient with PCT that is further complicated by high iron stores, chronic hepatitis C virus (HCV), and a history of alcoholism. Bilateral, geographic, peripapillary chorioretinal atrophy is evident and shows progression over a significant period despite improving the PCT. CONCLUSION A bilateral and progressive appearance of a retinal pathology in a middle-age male patient, with no family ocular history, suggests systemic causation. One theory includes a back flow of porphyrin byproducts from PCT. This is exacerbated by a less-than-productive liver caused by high iron stores, chronic HCV, and a history of alcoholism, which prevents the normal filtering process to occur. We believe this is the first report of a case of presumed bilateral, geographic, peripapillary chorioretinal atrophy in a patient with PCT, complicated by high iron stores, HCV, and alcoholism.
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Affiliation(s)
- William J Denton
- Wm. Jennings Bryan Dorn Veterans Affairs Medical Center, Columbia, South Carolina, USA.
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Bacon BR, Adams PC, Kowdley KV, Powell LW, Tavill AS. Diagnosis and management of hemochromatosis: 2011 practice guideline by the American Association for the Study of Liver Diseases. Hepatology 2011; 54:328-43. [PMID: 21452290 PMCID: PMC3149125 DOI: 10.1002/hep.24330] [Citation(s) in RCA: 396] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Bruce R Bacon
- Division of Gastroenterology and Hepatology, Saint Louis University School of Medicine, Saint Louis, MO 63110-0250, USA.
| | - Paul C Adams
- Department of Medicine, University of Western Ontario, London Health Sciences CentreLondon, Ontario, Canada
| | - Kris V Kowdley
- Center for Liver Disease, Virginia Mason Medical CenterSeattle, WA
| | - Lawrie W Powell
- Royal Brisbane Hospital, University of Queensland Centre for Clinical ResearchBrisbane, Australia
| | - Anthony S Tavill
- Department of Gastroenterology, Case Western Reserve University, and Department of Gastroenterology and Hepatology, The Cleveland ClinicCleveland, OH
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Abstract
BACKGROUND Hereditary hemochromatosis (HH) is a common hereditary disorder that primarily afflicts patients of Northern European descent. A single mutation of the HFE gene results in unregulated dietary iron uptake with the potential to deleteriously affect multiple organ systems including the eye. If HH is suspected, a screening test measuring transferrin saturation is initially obtained. Confirmation of this disorder is accomplished with genetic testing and liver biopsy. Treatment should commence immediately and undergo venesection (phlebotomy) treatments 2 to 4 times a year for the remainder of the patient's life. CASE REPORT The following is a case of a 54-year-old male of Scottish-German descent who was evaluated for a subconjunctival hemorrhage (SCH). A review of the patient's record disclosed that he had 12 previous episodes of SCH over a 10-year period. He was undergoing a comprehensive evaluation for HH due to the recent diagnosis of this condition in his older brother. Hematologic analysis showed that our patient had a serum ferritin level 4 to 5 times higher than normal (1340 μg/L) and a homozygous recessive profile of the HFE gene. Once under maintenance venesection therapy, the frequency of the SCH diminished. CONCLUSIONS HH must be considered a differential diagnosis in cases of recurrent SCH. Coupled with the recognition of characteristic physical signs and symptoms of HH, hematologic analysis and genetic testing may further aid in diagnosis. With early detection and treatment, the optometrist can make a significant impact on the life expectancy of the patient.
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Graham RM, Chua ACG, Carter KW, Delima RD, Johnstone D, Herbison CE, Firth MJ, O'Leary R, Milward EA, Olynyk JK, Trinder D. Hepatic iron loading in mice increases cholesterol biosynthesis. Hepatology 2010; 52:462-71. [PMID: 20683946 DOI: 10.1002/hep.23712] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
UNLABELLED Iron and cholesterol are both essential metabolites in mammalian systems, and too much or too little of either can have serious clinical consequences. In addition, both have been associated with steatosis and its progression, contributing, inter alia, to an increase in hepatic oxidative stress. The interaction between iron and cholesterol is unclear, with no consistent evidence emerging with respect to changes in plasma cholesterol on the basis of iron status. We sought to clarify the role of iron in lipid metabolism by studying the effects of iron status on hepatic cholesterol synthesis in mice with differing iron status. Transcripts of seven enzymes in the cholesterol biosynthesis pathway were significantly up-regulated with increasing hepatic iron (R(2) between 0.602 and 0.164), including those of the rate-limiting enzyme, 3-hydroxy-3-methylglutarate-coenzyme A reductase (Hmgcr; R(2) = 0.362, P < 0.002). Hepatic cholesterol content correlated positively with hepatic iron (R(2) = 0.255, P < 0.007). There was no significant relationship between plasma cholesterol and either hepatic cholesterol or iron (R(2) = 0.101 and 0.014, respectively). Hepatic iron did not correlate with a number of known regulators of cholesterol synthesis, including sterol-regulatory element binding factor 2 (Srebf2; R(2) = 0.015), suggesting that the increases seen in the cholesterol biosynthesis pathway are independent of Srebf2. Transcripts of genes involved in bile acid synthesis, transport, or regulation did not increase with increasing hepatic iron. CONCLUSION This study suggests that hepatic iron loading increases liver cholesterol synthesis and provides a new and potentially important additional mechanism by which iron could contribute to the development of fatty liver disease or lipotoxicity.
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Affiliation(s)
- Ross M Graham
- School of Medicine and Pharmacology, University of Western Australia, Perth, WA, Australia.
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Chua ACG, Klopcic B, Lawrance IC, Olynyk JK, Trinder D. Iron: An emerging factor in colorectal carcinogenesis. World J Gastroenterol 2010; 16:663-72. [PMID: 20135713 PMCID: PMC2817053 DOI: 10.3748/wjg.v16.i6.663] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The carcinogenic potential of iron in colorectal cancer (CRC) is not fully understood. Iron is able to undergo reduction and oxidation, making it important in many physiological processes. This inherent redox property of iron, however, also renders it toxic when it is present in excess. Iron-mediated generation of reactive oxygen species via the Fenton reaction, if uncontrolled, may lead to cell damage as a result of lipid peroxidation and oxidative DNA and protein damage. This may promote carcinogenesis through increased genomic instability, chromosomal rearrangements as well as mutations of proto-oncogenes and tumour suppressor genes. Carcinogenesis is also affected by inflammation which is exacerbated by iron. Population studies indicate an association between high dietary iron intake and CRC risk. In this editorial, we examine the link between iron-induced oxidative stress and inflammation on the pathogenesis of CRC.
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Sartori M, Andorno S, Rossini A, Boldorini R, Bozzola C, Carmagnola S, Piano MD, Albano E. Phlebotomy improves histology in chronic hepatitis C males with mild iron overload. World J Gastroenterol 2010; 16:596-602. [PMID: 20128028 PMCID: PMC2816272 DOI: 10.3748/wjg.v16.i5.596] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the usefulness of mild iron depletion and the factors predictive for histological improvement following phlebotomy in Caucasians with chronic hepatitis C (CHC).
METHODS: We investigated 28 CHC Caucasians with persistently elevated serum aminotransferase levels and non responders to, or unsuitable for, antiviral therapy who underwent mild iron depletion (ferritin ≤ 70 ng/mL) by long-term phlebotomy. Histological improvement, as defined by at least one point reduction in the staging score or, in case of unchanged stage, as at least two points reduction in the grading score (Knodell), was evaluated in two subsequent liver biopsies (before and at the end of phlebotomy, 48 ± 16 mo apart).
RESULTS: Phlebotomy showed an excellent safety profile. Histological improvement occurred in 12/28 phlebotomized patients. Only males responded to phlebotomy. At univariate logistic analysis alcohol intake (P = 0.034), high histological grading (P = 0.01) and high hepatic iron concentration (HIC) (P = 0.04) before treatment were associated with histological improvement. Multivariate logistic analysis showed that in males high HIC was the only predictor of histological improvement following phlebotomy (OR = 1.41, 95% CI: 1.03-1.94, P = 0.031). Accordingly, 12 out of 17 (70%) patients with HIC ≥ 20 μmol/g showed histological improvements at the second biopsy.
CONCLUSION: Male CHC Caucasian non-responders to antiviral therapy with low-grade iron overload can benefit from mild iron depletion by long-term phlebotomy.
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Inoue M, Kurahashi N, Iwasaki M, Shimazu T, Tanaka Y, Mizokami M, Tsugane S. Effect of Coffee and Green Tea Consumption on the Risk of Liver Cancer: Cohort Analysis by Hepatitis Virus Infection Status. Cancer Epidemiol Biomarkers Prev 2009; 18:1746-53. [PMID: 19505908 DOI: 10.1158/1055-9965.epi-08-0923] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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Ruddell RG, Hoang-Le D, Barwood JM, Rutherford PS, Piva TJ, Watters DJ, Santambrogio P, Arosio P, Ramm GA. Ferritin functions as a proinflammatory cytokine via iron-independent protein kinase C zeta/nuclear factor kappaB-regulated signaling in rat hepatic stellate cells. Hepatology 2009; 49:887-900. [PMID: 19241483 PMCID: PMC2701483 DOI: 10.1002/hep.22716] [Citation(s) in RCA: 208] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
UNLABELLED Circulating ferritin levels reflect body iron stores and are elevated with inflammation in chronic liver injury. H-ferritin exhibits a number of extrahepatic immunomodulatory properties, although its role in hepatic inflammation and fibrogenesis is unknown. Hepatic stellate cells respond to liver injury through production of proinflammatory mediators that drive fibrogenesis. A specific receptor for ferritin has been demonstrated on activated hepatic stellate cells, although its identity and its role in stellate cell activation is unclear. We propose that ferritin acts as a cytokine regulating proinflammatory function via nuclear factor kappaB (NF-kappaB)-regulated signaling in hepatic stellate cell biology. Hepatic stellate cells were treated with tissue ferritin and iron-free apoferritin, recombinant H-ferritins and L-ferritins, to assess the role of ferritin versus ferritin-bound iron in the production of proinflammatory mediators of fibrogenesis, and to determine whether signaling pathways act via a proposed H-ferritin endocytosis receptor, T cell immunoglobulin-domain and mucin-domain 2 (Tim-2). This study demonstrated that ferritin activates an iron-independent signaling cascade, involving Tim-2 independent phosphoinositide 3 (PI3)-kinase phosphorylation, protein kinase C zeta (PKCzeta) and p44/p42-mitogen-activated protein kinase, resulting in p50/p65-NF-kappaB activation and markedly enhanced expression of hepatic proinflammatory mediators interleukin-1beta (IL-1beta), inducible nitric oxide synthase (iNOS), regulated on activation normal T cell expressed and secreted (RANTES), inhibitor of kappa Balpha (IkappaBalpha), and intercellular adhesion molecule 1 (ICAM1). CONCLUSIONS This study has defined the role of ferritin as a proinflammatory mediator of hepatic stellate cell biology acting through the NF-kappaB signaling pathway, and suggests a potential role in the inflammatory processes associated with hepatic fibrogenesis.
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Affiliation(s)
- Richard G Ruddell
- The Hepatic Fibrosis Group, Queensland Institute of Medical Research and The University of Queensland, PO Royal Brisbane and Women's Hospital, Brisbane, Australia
| | - Diem Hoang-Le
- The Hepatic Fibrosis Group, Queensland Institute of Medical Research and The University of Queensland, PO Royal Brisbane and Women's Hospital, Brisbane, Australia
| | - Joanne M Barwood
- The Hepatic Fibrosis Group, Queensland Institute of Medical Research and The University of Queensland, PO Royal Brisbane and Women's Hospital, Brisbane, Australia
| | - Paul S Rutherford
- The Hepatic Fibrosis Group, Queensland Institute of Medical Research and The University of Queensland, PO Royal Brisbane and Women's Hospital, Brisbane, Australia
| | - Terrance J Piva
- School of Medical Sciences, SET Portfolio, RMIT University, Melbourne, Australia
| | - Dianne J Watters
- Eskitis Institute for Cell and Molecular Therapies and School of Biomolecular and Physical Sciences, Griffith University, Nathan Campus, Brisbane, Australia
| | - Paolo Santambrogio
- Proteomics of Iron Metabolism Unit, Dibit, San Raffaele Scientific Institute, Milan, Italy
| | - Paolo Arosio
- Dipartimento Materno Infantile e Tecnologie Biomediche, University of Brescia, Brescia, Italy
| | - Grant A Ramm
- The Hepatic Fibrosis Group, Queensland Institute of Medical Research and The University of Queensland, PO Royal Brisbane and Women's Hospital, Brisbane, Australia
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Kell DB. Iron behaving badly: inappropriate iron chelation as a major contributor to the aetiology of vascular and other progressive inflammatory and degenerative diseases. BMC Med Genomics 2009; 2:2. [PMID: 19133145 PMCID: PMC2672098 DOI: 10.1186/1755-8794-2-2] [Citation(s) in RCA: 364] [Impact Index Per Article: 24.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2008] [Accepted: 01/08/2009] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular 'reactive oxygen species' (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. REVIEW We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation).The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible.This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, since in some circumstances (especially the presence of poorly liganded iron) molecules that are nominally antioxidants can actually act as pro-oxidants. The reduction of redox stress thus requires suitable levels of both antioxidants and effective iron chelators. Some polyphenolic antioxidants may serve both roles.Understanding the exact speciation and liganding of iron in all its states is thus crucial to separating its various pro- and anti-inflammatory activities. Redox stress, innate immunity and pro- (and some anti-)inflammatory cytokines are linked in particular via signalling pathways involving NF-kappaB and p38, with the oxidative roles of iron here seemingly involved upstream of the IkappaB kinase (IKK) reaction. In a number of cases it is possible to identify mechanisms by which ROSs and poorly liganded iron act synergistically and autocatalytically, leading to 'runaway' reactions that are hard to control unless one tackles multiple sites of action simultaneously. Some molecules such as statins and erythropoietin, not traditionally associated with anti-inflammatory activity, do indeed have 'pleiotropic' anti-inflammatory effects that may be of benefit here. CONCLUSION Overall we argue, by synthesising a widely dispersed literature, that the role of poorly liganded iron has been rather underappreciated in the past, and that in combination with peroxide and superoxide its activity underpins the behaviour of a great many physiological processes that degrade over time. Understanding these requires an integrative, systems-level approach that may lead to novel therapeutic targets.
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Affiliation(s)
- Douglas B Kell
- School of Chemistry and Manchester Interdisciplinary Biocentre, The University of Manchester, 131 Princess St, Manchester, M1 7DN, UK.
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Novo E, Parola M. Redox mechanisms in hepatic chronic wound healing and fibrogenesis. FIBROGENESIS & TISSUE REPAIR 2008; 1:5. [PMID: 19014652 PMCID: PMC2584013 DOI: 10.1186/1755-1536-1-5] [Citation(s) in RCA: 235] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 10/13/2008] [Indexed: 12/24/2022]
Abstract
Reactive oxygen species (ROS) generated within cells or, more generally, in a tissue environment, may easily turn into a source of cell and tissue injury. Aerobic organisms have developed evolutionarily conserved mechanisms and strategies to carefully control the generation of ROS and other oxidative stress-related radical or non-radical reactive intermediates (that is, to maintain redox homeostasis), as well as to 'make use' of these molecules under physiological conditions as tools to modulate signal transduction, gene expression and cellular functional responses (that is, redox signalling). However, a derangement in redox homeostasis, resulting in sustained levels of oxidative stress and related mediators, can play a significant role in the pathogenesis of major human diseases characterized by chronic inflammation, chronic activation of wound healing and tissue fibrogenesis. This review has been designed to first offer a critical introduction to current knowledge in the field of redox research in order to introduce readers to the complexity of redox signalling and redox homeostasis. This will include ready-to-use key information and concepts on ROS, free radicals and oxidative stress-related reactive intermediates and reactions, sources of ROS in mammalian cells and tissues, antioxidant defences, redox sensors and, more generally, the major principles of redox signalling and redox-dependent transcriptional regulation of mammalian cells. This information will serve as a basis of knowledge to introduce the role of ROS and other oxidative stress-related intermediates in contributing to essential events, such as the induction of cell death, the perpetuation of chronic inflammatory responses, fibrogenesis and much more, with a major focus on hepatic chronic wound healing and liver fibrogenesis.
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Affiliation(s)
- Erica Novo
- Dipartimento di Medicina e Oncologia Sperimentale and Centro Interuniversitario di Fisiopatologia Epatica, Università degli Studi di Torino, Corso Raffaello 30, 10125 Torino, Italy
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Abstract
Following the discovery of the HFE gene in 1996 and its linkage to the iron overload disorder hereditary hemochromatosis (HH) there have been profound developments in our understanding of the pathogenesis of the biochemical and clinical manifestations of a number of iron overload disorders. This article provides an update of recent developments and key issues relating to iron homeostasis and inherited disorders of iron overload, with emphasis on HFE-related HH, and is based on the content of the American Association for the Study of Liver Diseases Single-Topic Conference entitled "Hemochromatosis: What has Happened After HFE?" which was held at the Emory Convention Center in Atlanta, September 7-9, 2007.
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Affiliation(s)
- John K Olynyk
- School of Medicine and Pharmacology, University of Western Australia, Fremantle Hospital, Fremantle, Western Australia, Australia.
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Lagan AL, Melley DD, Evans TW, Quinlan GJ. Pathogenesis of the systemic inflammatory syndrome and acute lung injury: role of iron mobilization and decompartmentalization. Am J Physiol Lung Cell Mol Physiol 2008; 294:L161-74. [DOI: 10.1152/ajplung.00169.2007] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Changes in iron homeostatic responses routinely accompany infectious or proinflammatory insults. The systemic inflammatory response syndrome (SIRS) and the development of acute lung injury (ALI) feature pronounced systemic and lung-specific alterations in iron/heme mobilization and decompartmentalization; such responses may be of pathological significance for both the onset and progression of acute inflammation. The potential for excessive iron-catalyzed oxidative stress, altered proinflammatory redox signaling, and provision of iron as a microbial growth factor represent obvious adverse aspects of altered in vivo iron handling. The release of hemoglobin during hemolytic disease or surgical procedures such as those utilizing cardiopulmonary bypass procedures further impacts on iron mobilization, turnover, and storage with associated implications. Genetic predisposition may ultimately determine the extent to which SIRS and related syndromes develop in response to such changes. The design of specific therapeutic interventions based on endogenous stratagems to limit adverse aspects of altered iron handling may prove of therapeutic benefit for the treatment of SIRS and ALI.
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