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Huang C, Liang Y, Zeng X, Yang X, Xu D, Gou X, Sathiaseelan R, Senavirathna LK, Wang P, Liu L. Long Noncoding RNA FENDRR Exhibits Antifibrotic Activity in Pulmonary Fibrosis. Am J Respir Cell Mol Biol 2020; 62:440-453. [PMID: 31697569 PMCID: PMC7110975 DOI: 10.1165/rcmb.2018-0293oc] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 11/07/2019] [Indexed: 01/01/2023] Open
Abstract
Abnormal activation of lung fibroblasts contributes to the initiation and progression of idiopathic pulmonary fibrosis (IPF). The objective of the present study was to investigate the role of fetal-lethal noncoding developmental regulatory RNA (FENDRR) in the activation of lung fibroblasts. Dysregulated long noncoding RNAs in IPF lungs were identified by next-generation sequencing analysis from the two online datasets. FENDRR expression in lung tissues from patients with IPF and mice with bleomycin-induced pulmonary fibrosis was determined by quantitative real-time PCR. IRP1 (iron-responsive element-binding protein 1), a protein partner of FENDRR, was identified by RNA pulldown-coupled mass spectrometric analysis and confirmed by RNA immunoprecipitation. The interaction region between FENDRR and IRP1 was determined by cross-linking immunoprecipitation. The in vivo role of FENDRR in pulmonary fibrosis was studied using adenovirus-mediated gene transfer in mice. The expression of FENDRR was downregulated in fibrotic human and mouse lungs as well as in primary lung fibroblasts isolated from bleomycin-treated mice. TGF-β1 (transforming growth factor-β1)-SMAD3 signaling inhibited FENDRR expression in lung fibroblasts. FENDRR was preferentially localized in the cytoplasm of adult lung fibroblasts and bound IRP1, suggesting its role in iron metabolism. FENDRR reduced pulmonary fibrosis by inhibiting fibroblast activation by reducing iron concentration and acting as a competing endogenous RNA of the profibrotic microRNA-214. Adenovirus-mediated FENDRR gene transfer in the mouse lung attenuated bleomycin-induced lung fibrosis and improved lung function. Our data suggest that FENDRR is an antifibrotic long noncoding RNA and a potential therapeutic target for pulmonary fibrosis.
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Affiliation(s)
- Chaoqun Huang
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Yurong Liang
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Xiangming Zeng
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Xiaoyun Yang
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Dao Xu
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Xuxu Gou
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Roshini Sathiaseelan
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Lakmini Kumari Senavirathna
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
| | - Pengcheng Wang
- Department of Immunology and Microbiology, Medical School of Jinan University, Guangdong, China
| | - Lin Liu
- Oklahoma Center for Respiratory and Infectious Diseases, and
- Lundberg-Kienlen Lung Biology and Toxicology Laboratory, Department of Physiological Sciences, Oklahoma State University, Stillwater, Oklahoma; and
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Kopova I, Stráský J, Harcuba P, Landa M, Janeček M, Bačákova L. Newly developed Ti-Nb-Zr-Ta-Si-Fe biomedical beta titanium alloys with increased strength and enhanced biocompatibility. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2015; 60:230-238. [PMID: 26706526 DOI: 10.1016/j.msec.2015.11.043] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 08/16/2015] [Accepted: 11/16/2015] [Indexed: 01/30/2023]
Abstract
Beta titanium alloys are promising materials for load-bearing orthopaedic implants due to their excellent corrosion resistance and biocompatibility, low elastic modulus and moderate strength. Metastable beta-Ti alloys can be hardened via precipitation of the alpha phase; however, this has an adverse effect on the elastic modulus. Small amounts of Fe (0-2 wt.%) and Si (0-1 wt.%) were added to Ti-35Nb-7Zr-6Ta (TNZT) biocompatible alloy to increase its strength in beta solution treated condition. Fe and Si additions were shown to cause a significant increase in tensile strength and also in the elastic modulus (from 65 GPa to 85 GPa). However, the elastic modulus of TNZT alloy with Fe and Si additions is still much lower than that of widely used Ti-6Al-4V alloy (115 GPa), and thus closer to that of the bone (10-30 GPa). Si decreases the elongation to failure, whereas Fe increases the uniform elongation thanks to increased work hardening. Primary human osteoblasts cultivated for 21 days on TNZT with 0.5Si+2Fe (wt.%) reached a significantly higher cell population density and significantly higher collagen I production than cells cultured on the standard Ti-6Al-4V alloy. In conclusion, the Ti-35Nb-7Zr-6Ta-2Fe-0.5Si alloy proves to be the best combination of elastic modulus, strength and also biological properties, which makes it a viable candidate for use in load-bearing implants.
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Affiliation(s)
- Ivana Kopova
- Department of Biomaterials and Tissue Engineering, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, , Czech Republic.
| | - Josef Stráský
- Department of Physics of Materials, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Prague 2, Czech Republic
| | - Petr Harcuba
- Department of Physics of Materials, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Prague 2, Czech Republic
| | - Michal Landa
- Institute of Thermomechanics, Academy of Sciences of the Czech Republic, Dolejskova 5, 182 00 Prague 8, Czech Republic
| | - Miloš Janeček
- Department of Physics of Materials, Faculty of Mathematics and Physics, Charles University in Prague, Ke Karlovu 5, 121 16 Prague 2, Czech Republic
| | - Lucie Bačákova
- Department of Biomaterials and Tissue Engineering, Institute of Physiology of the Czech Academy of Sciences, Videnska 1083, 14220 Prague 4, , Czech Republic
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3
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Madl AK, Pinkerton KE. Health effects of inhaled engineered and incidental nanoparticles. Crit Rev Toxicol 2010; 39:629-58. [PMID: 19743943 DOI: 10.1080/10408440903133788] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Engineered nanoscale materials provide tremendous promise for technological advancements; however, concerns have been raised about whether research of the possible health risks of these nanomaterials is keeping pace with products going to market. Research on nanomaterials, including carbon nanotubes, semiconductor crystals, and other ultrafine particles (i.e., titanium dioxide, quantum dots, iridium) will be examined to illustrate what is currently known or unknown about how particle characteristics (e.g., size, agglomeration, morphology, solubility, surface chemistry) and exposure/dose metrics (e.g., mass, size, surface area) influence the biological fate and toxicity of inhaled nanosized particles. The fact that nanosized particles (1) have a potentially high efficiency for deposition; (2) target both the upper and lower regions of the respiratory tract; (3) are retained in the lungs for a long period of time, and (4) induce more oxidative stress and cause greater inflammatory effects than their fine-sized equivalents suggest a need to study the impact of these particles on the body. Achieving a better understanding of the dynamics at play between particle physicochemistry, transport patterns, and cellular responses in the lungs and other organs will provide a future basis for establishing predictive measures of toxicity or biocompatibility and a framework for assessing potential human health risks.
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Affiliation(s)
- Amy K Madl
- Center for Health and the Environment, University of California, Davis, Davis, California 95616, USA.
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Collard KJ. Is there a causal relationship between the receipt of blood transfusions and the development of chronic lung disease of prematurity? Med Hypotheses 2005; 66:355-64. [PMID: 16236459 DOI: 10.1016/j.mehy.2005.04.046] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2005] [Accepted: 04/26/2005] [Indexed: 12/16/2022]
Abstract
The number and total volume of blood transfusions received by premature babies is, after gestational age and birth weight a good predictor of the likelihood of developing chronic lung disease of prematurity (CLD) and retinopathy of prematurity (ROP). Oxidative damage, inflammation and pulmonary infections are also strongly associated with the development of CLD. It is currently not clear whether there is a causal relationship between the receipt of blood transfusions and oxidative damage, infection, inflammation and CLD in these babies. Strong arguments may be made both for and against a causal relationship. The babies who receive blood transfusions are usually smaller than those who do not, and are ventilated, often with high oxygen levels, for a longer period of time. The longer the baby is on a ventilator the more likely it is to develop pulmonary infection and inflammation. All these factors will promote free radical production and oxidative damage irrespective of the receipt of blood transfusion. This would argue against a causal relationship. On the other hand, an argument may be presented which is based on iron promoted free radical generation, infection and fibrosis consequent to the breakdown of haeme released from transfused erythrocytes. Haeme is broken down by haeme oxygenase (HO) to iron, CO and bilirubin. Under normal circumstances the products of HO activity are beneficial to the organism, but when HO activity is excessive, the products are potentially damaging. Free iron, (in the Fe2+ form) if not sequestered with protein or urate, will generate highly toxic free radicals via the Fenton and Heber-Wiess reactions, predispose the tissue to infection and promote fibrosis. The iron chelating ability of the premature baby appears to be limited so that it would be difficult to deal with any increase in free iron production. Free iron will in turn induce HO activity leading to a potentially serious positive feedback process. The lung is particularly sensitive to iron induced HO activity. In addition, HO activity may be enhanced by other events occurring in the premature lung such as the production of proinflammatory cytokines and the reduced level of glutathione. Thus, the possibility of a causal relationship clearly exists and needs to be examined. This can be attempted by measuring the products of HO activity in relation to the receipt of blood transfusions.
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Affiliation(s)
- Keith J Collard
- University of Plymouth, School of Health Professions, Millbrook House Site, Millbrook Lane, Topsham Road, Exeter, Devon EX2 6ES, UK.
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Monetti C, Bernardini G, Vigetti D, Prati M, Fortaner S, Sabbioni E, Gornati R. Platinum toxicity and gene expression in Xenopus embryos: analysis by FETAX and differential display. Altern Lab Anim 2005; 31:401-8. [PMID: 15601245 DOI: 10.1177/026119290303100406] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Since the level of platinum in the environment is destined to increase, because of its use in vehicle catalytic converters, the toxicity of platinum needs further investigation. In this study, the frog embryo teratogenesis assay-Xenopus (FETAX) was used to compare the embryotoxicity and teratogenicity of two common platinum species, (NH4)2PtCl4 and (NH4)2PtCl6. The uptake rates of the two platinum species were studied, and also their effects on the expression of genes encoding metallothionein and heat-shock protein 70, which are known to be induced by several stress factors. In addition, the differential display technique was used to search for genes that were specifically induced by platinum. A gene for the type I collagen alpha-chain and a novel gene were identified.
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Affiliation(s)
- Claudio Monetti
- Department of Structural and Functional Biology, Università dell'Insubria, 3 Via Dunant, 21100 Varese, Italy
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6
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Gardi C, Arezzini B, Fortino V, Comporti M. Effect of free iron on collagen synthesis, cell proliferation and MMP-2 expression in rat hepatic stellate cells. Biochem Pharmacol 2002; 64:1139-45. [PMID: 12234617 DOI: 10.1016/s0006-2952(02)01257-1] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Various studies on hepatic fibrosis occurring in iron overload suggest that excess of tissue iron may be involved in the stimulation of collagen synthesis. Anyway, up to date, direct evidence on the role of iron in hepatic fibrosis is lacking. Moreover, it is not clear whether iron acts as direct initiator of fibrogenesis or as mediator of hepatocellular necrosis. In the present study, we investigated the effect of nontoxic doses of iron on collagen metabolism and proliferation, key features of liver fibrosis, by means of cultures of hepatic stellate cells, the liver cells responsible for collagen production. Iron treatment increased collagen synthesis without affecting noncollagen proteins. The maximum effect was observed at 5 microM iron (+132%). At this dose, no cell damage or proliferation was detected. Conversely, higher doses of iron (10 and 25 microM) induced cell proliferation and a lower increase in collagen synthesis, suggesting the prevalence of proliferative effect on the synthetic one. These effects occurred without the intervention of serum factors and were not mediated by lipid peroxidation. Our results strongly support the hypothesis that iron "per sé" may act as a profibrogenic agent. Finally, we provide evidence that iron plays a role also in matrix degradation, by stimulating some metalloprotease activities. Iron treatment increased metalloprotease-2 activity in hepatic stellate cells, while no changes were observed for interstitial collagenase activity suggesting that, in these conditions, a pathological accumulation of hepatic extracellular matrix may occur.
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Affiliation(s)
- Concetta Gardi
- Department of Pathophysiology and Experimental Medicine, University of Siena, via Aldo Moro, I-53100 Siena, Italy.
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7
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Flaherty DM, Monick MM, Carter AB, Peterson MW, Hunninghake GW. Oxidant-mediated increases in redox factor-1 nuclear protein and activator protein-1 DNA binding in asbestos-treated macrophages. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 168:5675-81. [PMID: 12023366 DOI: 10.4049/jimmunol.168.11.5675] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Alveolar macrophages have been implicated in the pathogenesis of a number of acute and chronic lung disorders. We have previously shown that normal human alveolar macrophages exhibit decreased DNA binding activity of the transcription factor, AP-1, compared with monocytes. Furthermore, this decrease in AP-1 DNA binding appears to be due to a decrease in the redox active protein, redox factor (Ref)-1. Ref-1 is an important redox regulator of a number of transcription factors, including NF-kappaB and AP-1. In this study we evaluated the role of asbestos, a prototypic model of chronic fibrotic lung disease, in Ref-1 expression and activity. We found that incubation with low concentrations of crocidolite asbestos (0.5-1.25 microg/cm(2)) resulted in an increase in nuclear Ref-1 protein after 5 min, with a persistent elevation in protein up to 24 h. Additionally, an increase in nuclear Ref-1 could be induced by treating the cells with an oxidant-generating stimulus (iron loading plus PMA) and inhibited by diphenyleneiodonium chloride, an inhibitor of NADPH oxidase. The asbestos-induced accumulation of nuclear Ref-1 was associated with an increase in AP-1 DNA binding activity. These findings suggest that an exposure associated with fibrotic lung disease, i.e., asbestos, modulates accumulation of nuclear Ref-1 in macrophages, and that this effect is mediated by an oxidant stimulus.
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Affiliation(s)
- Dawn M Flaherty
- Department of Internal Medicine, University of Iowa College of Medicine and Veterans Affairs Medical Center, Iowa City, IA 52243, USA.
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Dai J, Xie C, Churg A. Iron loading makes a nonfibrogenic model air pollutant particle fibrogenic in rat tracheal explants. Am J Respir Cell Mol Biol 2002; 26:685-93. [PMID: 12034567 DOI: 10.1165/ajrcmb.26.6.4651] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
To examine the potential role of particle iron in fibrogenicity, we loaded nonfibrogenic fine (0.12micro) TiO(2) with increasing amounts of Fe(II)-Fe(III) chloride. Dusts were applied to rat tracheal explants, which were maintained in air organ culture for 1 wk. Iron-loaded dust increased procollagen gene expression and tissue hydroxyproline. The active oxygen species (AOS) scavenger tetramethylthiourea prevented these effects. Iron loading caused nuclear factor (NF)-kappaB activation, decreased levels of total IkappaBalpha, but relatively increased levels of both IkappaBalpha-phosphoserine 32/36 and IkappaBalpha-phosphotyrosine. A citrate extract of iron-loaded dust increased procollagen expression. Gel shift using a probe consisting of the NF-kappaB consensus sequence from the prolyl-4-hydroxylase promoter and adjacent bases showed increased nuclear binding, and RT-PCR examination showed increased prolyl-hydroxylase alpha-chain gene expression after iron loading. We conclude that addition of surface iron can convert a nonreactive model air pollutant particle into a fibrogenic particle via AOS- and NF-kappaB-dependent pathways, probably through two different NF-kappaB activation pathways in two different anatomic compartments. This process may proceed in vivo through iron extracted from the dust into the cytoplasm. NF-kappaB activation may directly increase expression of prolyl hydroxylase, an enzyme involved in collagen synthesis. These findings suggest that air pollutant particles containing significant quantities of transition metals may produce airway wall fibrosis and lead to chronic obstructive pulmonary disease.
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Affiliation(s)
- Jin Dai
- Department of Pathology, University of British Columbia, Vancouver, Canada
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9
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Abstract
Iron, to be redox cycling active, has to be released from its macromolecular complexes (ferritin, transferrin, hemoproteins, etc.). Iron is released from hemoglobin or its derivatives in a nonprotein-bound, desferrioxamine-chelatable form (DCI) in a number of conditions in which the erythrocytes are subjected to oxidative stress. Such conditions can be related to toxicological events (haemolytic drugs) or to physiological situations (erythrocyte ageing, reproduced in a model of prolonged aerobic incubation), but can also result from more subtle circumstances in which a state of ischemia-reperfusion is imposed on erythrocytes (e.g., childbirth). The released iron could play a central role in oxidation of membrane proteins and senescent cell antigen (SCA) formation, one of the major pathways for erythrocyte removal. Iron chelators able to enter cells (such as ferrozine, quercetin, and fluor-benzoil-pyridoxal hydrazone) prevent both membrane protein oxidation and SCA formation. The increased release of iron observed in beta-thalassemia patients and newborns (particularly premature babies) suggests that fetal hemoglobin is more prone to release iron than adult hemoglobin. In newborns the release of iron in erythrocytes is correlated with plasma nonprotein-bound iron and may contribute to its appearance.
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Affiliation(s)
- Mario Comporti
- Department of Pathophysiology and Experimental Medicine, University of Siena, Siena, Italy.
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Dai J, Churg A. Relationship of fiber surface iron and active oxygen species to expression of procollagen, PDGF-A, and TGF-beta(1) in tracheal explants exposed to amosite asbestos. Am J Respir Cell Mol Biol 2001; 24:427-35. [PMID: 11306436 DOI: 10.1165/ajrcmb.24.4.4225] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
To investigate the role of iron and active oxygen species (AOS) in asbestos-induced fibrosis, we loaded increasing amounts of Fe(II)/Fe(III) onto the surface of amosite asbestos fibers and then applied the fibers to rat tracheal explants. Explants were harvested after 7 d in air organ culture. Asbestos by itself doubled procollagen gene expression, and a further increase was seen with increasing iron loading; actual collagen content measured as hydroxyproline was increased in a similar pattern. Iron loading also increased gene expression of platelet-derived growth factor (PDGF)-A and transforming growth factor (TGF)-beta(1). Neither asbestos alone nor iron-loaded asbestos affected gene expression of PDGF-B, tumor necrosis factor-alpha, or TGF-alpha. The AOS scavenger tetramethylthiourea or treatment of fibers with the iron chelator deferoxamine prevented asbestos-induced increases in procollagen, PDGF-A, and TGF-beta gene expression, whereas glutathione had no effect. The proteasome inhibitor MG-132 abolished asbestos-induced increases in procollagen gene expression but did not affect increases in PDGF-A or TGF-beta(1) expression, whereas the extracellular signal-regulated protein kinase (ERK) inhibitor PD98059 had exactly the opposite effect. We conclude that surface iron as well as the iron-catalyzed generation of AOS play a role in asbestos-induced matrix (procollagen) production and that this process is driven in part through oxidant-induced nuclear factor kappa B activation. Surface iron and AOS also play a role in PDGF-A and TGF-beta gene expression, but through an ERK-dependent mechanism.
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Affiliation(s)
- J Dai
- Department of Pathology, University of British Columbia, Vancouver, British Columbia, Canada
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Ciccoli L, Ferrali M, Rossi V, Signorini C, Alessandrini C, Comporti M. Hemolytic drugs aniline and dapsone induce iron release in erythrocytes and increase the free iron pool in spleen and liver. Toxicol Lett 1999; 110:57-66. [PMID: 10593595 DOI: 10.1016/s0378-4274(99)00138-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Incubation of rat erythrocytes with the hydroxylated metabolites of aniline and dapsone (4-4'-diaminodiphenylsulfone), phenylhydroxylamine and dapsone hydroxylamine, respectively, induced marked release of iron and methemoglobin formation. On the contrary, no release of iron nor methemoglobin formation was seen when the erythrocytes were incubated with the parent compounds (aniline and dapsone). The acute intoxication of rats with aniline or dapsone induced a marked increase in the erythrocyte content of free iron and methemoglobin, indicating that the xenobiotics are effective only after biotransformation to toxic metabolites in vivo. Prolonged administration of aniline or dapsone to rats produced continuous release of iron from erythrocytes. Marked iron overload was seen in the spleen and in the liver Kupffer cells, as detected histochemically. The spleen weight in these subchronically treated animals was significantly increased. The free iron pool was markedly increased in the spleen and to a lower extent in the liver. The possible relationships between iron release in erythrocytes, oxidative damage seen in senescent cells, hemolysis, overwhelmed capacity of spleen and liver to keep iron in storage forms and subsequent increase in low molecular weight, catalitically active iron is discussed.
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Affiliation(s)
- L Ciccoli
- Istituto di Patologia Generale, Università di Siena, Italy
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12
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Affiliation(s)
- D W Kamp
- Department of Medicine, Pulmonary & Critical Care Medicine, Veterans Affairs Chicago Health Care System (Lakeside Division) and Northwestern University Medical School, Chicago, Illinois 60611, USA
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