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Li S, Zhang H, Chang J, Li D, Cao P. Iron overload and mitochondrial dysfunction orchestrate pulmonary fibrosis. Eur J Pharmacol 2021; 912:174613. [PMID: 34740581 DOI: 10.1016/j.ejphar.2021.174613] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 09/06/2021] [Accepted: 09/11/2021] [Indexed: 12/26/2022]
Abstract
Pulmonary fibrosis (PF) is a chronic, progressive heterogeneous disease of lung tissues with poor lung function caused by scar tissue. Due to our limited understanding of its mechanism, there is currently no treatment strategy that can prevent the development of PF. In recent years, iron accumulation and mitochondrial damage have been reported to participate in PF, and drugs that reduce iron content and improve mitochondrial function have shown significant efficacy in animal experimental models. Excessive iron leads to mitochondrial impairment, which may be the key cause that results in the dysfunction of various kinds of pulmonary cells and further promotes PF. As an emerging research hotspot, there are few targeted effective therapeutic strategies at present due to limited mechanistic understanding. In this review, the roles of iron homeostasis imbalance and mitochondrial damage in PF are summarized and discussed, highlighting a promising direction for finding truly effective therapeutics for PF.
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Affiliation(s)
- Shuxin Li
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, 050024, People's Republic of China
| | - Hongmin Zhang
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, 050024, People's Republic of China
| | - Jing Chang
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, 050024, People's Republic of China
| | - Dongming Li
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, 050024, People's Republic of China.
| | - Pengxiu Cao
- Ministry of Education Key Laboratory of Molecular and Cellular Biology, Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, 050024, People's Republic of China.
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2
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Guo H, Nomoto T, Muttaqien SE, Sun X, Komoto K, Matsui M, Miura Y, Nishiyama N. Polymeric Iron Chelators Enhancing Pro-Oxidant Antitumor Efficacy of Vitamin C by Inhibiting the Extracellular Fenton Reaction. Mol Pharm 2021; 18:4475-4485. [PMID: 34726400 DOI: 10.1021/acs.molpharmaceut.1c00673] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Intravenously injected high-dose vitamin C (VC) induces extracellular H2O2, which can penetrate into the tumor cells and suppress tumor growth. However, extracellular labile iron ions in the tumor decompose H2O2 via the Fenton reaction, limiting the therapeutic effect. In this regard, we recently developed a polymeric iron chelator that can inactivate the intratumoral labile iron ions. Here, we examined the effect of our polymeric iron chelator on the high-dose VC therapy in in vitro and in vivo. In the in vitro study, the polymeric iron chelator could inactivate the extracellular labile iron ions and prevent the unfavorable decomposition of VC-induced H2O2, augmenting pro-oxidative damage to DNA and inducing apoptosis in cultured cancer cells. Even in the in vivo study, the polymeric iron chelator significantly improved the antitumor effect of VC in subcutaneous DLD-1 and CT26 tumors in mice, while conventional iron chelators could not. This work indicates the importance of modulating tumor-associated iron ions in the high-dose VC therapy and should contribute to a better understanding of its mechanism.
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Affiliation(s)
- Haochen Guo
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.,Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - Takahiro Nomoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.,Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - Sjaikhurrizal El Muttaqien
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.,Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.,Center for Pharmaceutical and Medical Technology, Agency for the Assessment and Application of Technology (BPPT), LAPTIAB I, PUSPITEK, Serpong, Banten 15314, Indonesia
| | - Xiaohang Sun
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.,Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - Kana Komoto
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.,Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - Makoto Matsui
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - Yutaka Miura
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.,Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan
| | - Nobuhiro Nishiyama
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.,Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa 226-8503, Japan.,Innovation Center of Nanomedicine (iCONM), Kawasaki Institute of Industrial Promotion, 3-25-14 Tonomachi, Kawasaki-ku, Kawasaki, Kanagawa 210-0821, Japan
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3
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Zhang WZ, Butler JJ, Cloonan SM. Smoking-induced iron dysregulation in the lung. Free Radic Biol Med 2019; 133:238-247. [PMID: 30075191 PMCID: PMC6355389 DOI: 10.1016/j.freeradbiomed.2018.07.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 07/26/2018] [Accepted: 07/30/2018] [Indexed: 12/12/2022]
Abstract
Iron is one of the most abundant transition elements and is indispensable for almost all organisms. While the ability of iron to participate in redox chemistry is an essential requirement for participation in a range of vital enzymatic reactions, this same feature of iron also makes it dangerous in the generation of hydroxyl radicals and superoxide anions. Given the high local oxygen tensions in the lung, the regulation of iron acquisition, utilization, and storage therefore becomes vitally important, perhaps more so than in any other biological system. Iron plays a critical role in the biology of essentially every cell type in the lung, and in particular, changes in iron levels have important ramifications on immune function and the local lung microenvironment. There is substantial evidence that cigarette smoke causes iron dysregulation, with the implication that iron may be the link between smoking and smoking-related lung diseases. A better understanding of the connection between cigarette smoke, iron, and respiratory diseases will help to elucidate pathogenic mechanisms and aid in the identification of novel therapeutic targets.
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Affiliation(s)
- William Z Zhang
- Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021, USA; Department of Medicine, New York Presbyterian Hospital-Weill Cornell Medical Center, New York, NY 10021, USA
| | - James J Butler
- Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021, USA
| | - Suzanne M Cloonan
- Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, NY 10021, USA.
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4
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Cloonan SM, Mumby S, Adcock IM, Choi AMK, Chung KF, Quinlan GJ. The "Iron"-y of Iron Overload and Iron Deficiency in Chronic Obstructive Pulmonary Disease. Am J Respir Crit Care Med 2017; 196:1103-1112. [PMID: 28410559 DOI: 10.1164/rccm.201702-0311pp] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Affiliation(s)
- Suzanne M Cloonan
- 1 Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, New York
| | | | | | - Augustine M K Choi
- 1 Division of Pulmonary and Critical Care Medicine, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College, New York, New York.,3 New York-Presbyterian Hospital, New York, New York
| | | | - Gregory J Quinlan
- 4 Vascular Biology, National Heart and Lung Institute, Imperial College London, London, United Kingdom; and
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5
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Non-linear actions of physiological agents: Finite disarrangements elicit fitness benefits. Redox Biol 2017; 13:235-243. [PMID: 28595161 PMCID: PMC5460745 DOI: 10.1016/j.redox.2017.05.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2017] [Accepted: 05/11/2017] [Indexed: 12/16/2022] Open
Abstract
Finite disarrangements of important (vital) physiological agents and nutrients can induce plethora of beneficial effects, exceeding mere attenuation of the specific stress. Such response to disrupted homeostasis appears to be universally conserved among species. The underlying mechanism of improved fitness and longevity, when physiological agents act outside their normal range is similar to hormesis, a phenomenon whereby toxins elicit beneficial effects at low doses. Due to similarity with such non-linear response to toxins described with J-shaped curve, we have coined a new term “mirror J-shaped curves” for non-linear response to finite disarrangement of physiological agents. Examples from the clinical trials and basic research are provided, along with the unifying mechanisms that tie classical non-linear response to toxins with the non-linear response to physiological agents (glucose, oxygen, osmolarity, thermal energy, calcium, body mass, calorie intake and exercise). Reactive oxygen species and cytosolic calcium seem to be common triggers of signaling pathways that result in these beneficial effects. Awareness of such phenomena and exploring underlying mechanisms can help physicians in their everyday practice. It can also benefit researchers when designing studies and interpreting growing number of scientific data showing non-linear responses to physiological agents.
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6
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Abstract
Here, I address the topic of suitability for redox research of common settings in cell cultures. This is done through the prism of in vitro anticancer effects of vitamin C. Cell culture media show lower concentrations of iron and a higher level of oxygen compared to interstitial fluid. Such a setup promotes ascorbate-mediated production and accumulation of hydrogen peroxide, which efficiently kills a variety of cancer cell lines. However, the anticancer effects are annihilated if the iron level is corrected to mimic in vivo concentrations. It appears that the potential benefits of application of vitamin C in cancer treatment have been significantly overestimated. This might be true for other pro-oxidative agents as well, such as some (poly)phenols. We urgently need to establish medium formula and culture maintenance settings that are optimal for redox research.
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Affiliation(s)
- Ivan Spasojević
- a Department of Life Sciences, Institute for Multidisciplinary Research , University of Belgrade , Belgrade, Kneza Višeslava 1, Serbia
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7
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Extracellular iron diminishes anticancer effects of vitamin C: an in vitro study. Sci Rep 2014; 4:5955. [PMID: 25092529 PMCID: PMC4121606 DOI: 10.1038/srep05955] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Accepted: 07/16/2014] [Indexed: 12/18/2022] Open
Abstract
In vitro studies have shown that hydrogen peroxide (H2O2) produced by high-concentration ascorbate and cell culture medium iron efficiently kills cancer cells. This provided the rationale for clinical trials of high-dose intravenous ascorbate-based treatment for cancer. A drawback in all the in vitro studies was their failure to take into account the in vivo concentration of iron to supplement cell culture media which are characterized by low iron content. Here we showed, using two prostate cancer cell lines (LNCaP and PC-3) and primary astrocytes, that the anticancer/cytotoxic effects of ascorbate are completely abolished by iron at physiological concentrations in cell culture medium and human plasma. A detailed examination of mechanisms showed that iron at physiological concentrations promotes both production and decomposition of H2O2. The latter is mediated by Fenton reaction and prevents H2O2 accumulation. The hydroxyl radical, which is produced in the Fenton reaction, is buffered by extracellular proteins, and could not affect intracellular targets like H2O2. These findings show that anticancer effects of ascorbate have been significantly overestimated in previous in vitro studies, and that common cell culture media might be unsuitable for redox research.
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Ortíz-Estrada G, Luna-Castro S, Piña-Vázquez C, Samaniego-Barrón L, León-Sicairos N, Serrano-Luna J, de la Garza M. Iron-saturated lactoferrin and pathogenic protozoa: could this protein be an iron source for their parasitic style of life? Future Microbiol 2012; 7:149-64. [PMID: 22191452 DOI: 10.2217/fmb.11.140] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Iron is an essential nutrient for the survival of pathogens inside a host. As a general strategy against microbes, mammals have evolved complex iron-withholding systems for efficiently decreasing the iron accessible to invaders. Pathogens that inhabit the respiratory, intestinal and genitourinary tracts encounter an iron-deficient environment on the mucosal surface, where ferric iron is chelated by lactoferrin, an extracellular glycoprotein of the innate immune system. However, parasitic protozoa have developed several mechanisms to obtain iron from host holo-lactoferrin. Tritrichomonas fetus, Trichomonas vaginalis, Toxoplasma gondii and Entamoeba histolytica express lactoferrin-binding proteins and use holo-lactoferrin as an iron source for growth in vitro; in some species, these binding proteins are immunogenic and, therefore, may serve as potential vaccine targets. Another mechanism to acquire lactoferrin iron has been reported in Leishmania spp. promastigotes, which use a surface reductase to recognize and reduce ferric iron to the accessible ferrous form. Cysteine proteases that cleave lactoferrin have been reported in E. histolytica. This review summarizes the available information on how parasites uptake and use the iron from lactoferrin to survive in hostile host environments.
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Affiliation(s)
- Guillermo Ortíz-Estrada
- Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Apdo. 14-740, México DF 07000, México
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9
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Epp TS, McDonough P, Myers DE, Carlin DJ, Behnke BJ, Kindig CA, Poole DC, Erickson HH. The Effectiveness of Immunotherapy in Treating Exercise-Induced Pulmonary Hemorrhage. J Equine Vet Sci 2009. [DOI: 10.1016/j.jevs.2009.04.192] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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10
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Basaraba RJ, Bielefeldt-Ohmann H, Eschelbach EK, Reisenhauer C, Tolnay AE, Taraba LC, Shanley CA, Smith EA, Bedwell CL, Chlipala EA, Orme IM. Increased expression of host iron-binding proteins precedes iron accumulation and calcification of primary lung lesions in experimental tuberculosis in the guinea pig. Tuberculosis (Edinb) 2007; 88:69-79. [PMID: 17942369 DOI: 10.1016/j.tube.2007.09.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2007] [Revised: 08/26/2007] [Accepted: 09/09/2007] [Indexed: 11/25/2022]
Abstract
The growth and virulence of Mycobacterium tuberculosis depends on its ability to scavenge host iron, an essential and limited micronutrient in vivo. In this study, we show that ferric iron accumulates both intra- and extra-cellularly in the primary lung lesions of guinea pigs aerosol-infected with the H37Rv strain of M. tuberculosis. Iron accumulated within macrophages at the periphery of the primary granulomatous lesions while extra-cellular ferric iron was concentrated in areas of lesion necrosis. Accumulation of iron within primary lesions was preceded by an increase in expression of heavy chain (H) ferritin, lactoferrin and receptors for transferrin, primarily by macrophages and granulocytes. The increased expression of intra-cellular H ferritin and extra-cellular lactoferrin, more so than transferrin receptor, paralleled the development of necrosis within primary lesions. The deposition of extra-cellular ferric iron within necrotic foci coincided with the accumulation of calcium and phosphorus and other cations in the form of dystrophic calcification. Primary lung lesions from guinea pigs vaccinated with Mycobactrium bovis BCG prior to experimental infection, had reduced iron accumulation as well as H ferritin, lactoferrin and transferrin receptor expression. The amelioration of primary lesion necrosis and dystrophic calcification by BCG vaccination was coincident with the lack of extra-cellular ferric iron and lactoferrin accumulation. These data demonstrate that BCG vaccination ameliorates primary lesion necrosis, dystrophic mineralization and iron accumulation, in part by down-regulating the expression of macrophage H ferritin, lactoferrin and transferrin receptors, in vivo.
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Affiliation(s)
- Randall J Basaraba
- Department of Microbiology, Immunology and Pathology, 1619 Campus Delivery, Colorado State University, Fort Collins, CO 80523-1619, USA.
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11
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Ray JCJ, Kirschner DE. Requirement for multiple activation signals by anti-inflammatory feedback in macrophages. J Theor Biol 2006; 241:276-94. [PMID: 16460764 DOI: 10.1016/j.jtbi.2005.11.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2005] [Revised: 10/25/2005] [Accepted: 11/26/2005] [Indexed: 12/19/2022]
Abstract
Pathogen killing is one of the primary roles of macrophages, utilizing potent effectors such as nitric oxide (NO) and involving other cellular machinery including iron regulatory apparatus. Macrophages become strongly activated upon receipt of appropriate signaling with cytokines and pathogen-derived endotoxins. However, they must resist activation in the absence of decisive signaling due to the energetic demands of activation coupled with the toxic nature of effector molecules to surrounding tissues. We have developed a mathematical model of the modular biochemical network of macrophages involved with activation, pathogen killing and iron regulation. This model requires synergistic interaction of multiple activation signals to overcome the quiescent state. To achieve a trade-off between macrophage quiescence and activation, strong activation signals are modulated via negative regulation by NO. In this way a single activation signal is insufficient for complete activation. In addition, our results suggest that iron regulation is usually controlled by activation signals. However, under conditions of partial macrophage activation, exogenous iron levels play a key role in regulating NO production. This model will be useful for evaluating macrophage control of intracellular pathogens in addition to the biochemical mechanisms examined here.
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Affiliation(s)
- J Christian J Ray
- Department of Microbiology and Immunology, The University of Michigan Medical School, Ann Arbor, MI 48109-0620, USA
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12
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Beck JM, Preston AM, Wilcoxen SE, Morris SB, White ES, Paine R. Pneumocystis pneumonia increases the susceptibility of mice to sublethal hyperoxia. Infect Immun 2003; 71:5970-8. [PMID: 14500517 PMCID: PMC201097 DOI: 10.1128/iai.71.10.5970-5978.2003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Patients with Pneumocystis pneumonia often develop respiratory failure after entry into medical care, and one mechanism for this deterioration may be increased alveolar epithelial cell injury. In vitro, we previously demonstrated that Pneumocystis is not cytotoxic for alveolar epithelial cells. In vivo, however, infection with Pneumocystis could increase susceptibility to injury by stressors that, alone, would be sublethal. We examined transient exposure to hyperoxia as a prototypical stress that does cause mortality in normal mice. Mice were depleted of CD4+ T cells and inoculated intratracheally with Pneumocystis. Control mice were depleted of CD4+ T cells but did not receive Pneumocystis. After 4 weeks, mice were maintained in normoxia, were exposed to hyperoxia for 4 days, or were exposed to hyperoxia for 4 days followed by return to normoxia. CD4-depleted mice with Pneumocystis pneumonia demonstrated significant mortality after transient exposure to hyperoxia, while all uninfected control mice survived this stress. We determined that organism burdens were not different. However, infected mice exposed to hyperoxia and then returned to normoxia demonstrated significant increases in inflammatory cell accumulation and lung cell apoptosis. We conclude that Pneumocystis pneumonia leads to increased mortality following a normally sublethal hyperoxic insult, accompanied by alveolar epithelial cell injury and increased pulmonary inflammation.
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Affiliation(s)
- James M Beck
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School Medical Service, Department of Veterans Affairs Medical Center, 2215 Fuller Road, Ann Arbor, MI 48105, USA.
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Abstract
Iron is an element essential for the survival of most aerobic organisms. However, when its availability is not adequately controlled, iron, can catalyze the formation of a range of aggressive and damaging reactive oxygen species, and act as a microbial growth promoter. Depending on the concentrations formed such species can cause molecular damage or influence redox signaling mechanisms. This review describes recent knowledge concerning iron metabolism in the lung, during both health and disease. In the lower part of the lung a small redox active pool of iron is required for reasons that are at present unclear, but may be related to antimicrobial functions. When the concentration of iron is increased in the lung (usually because of environmental exposure), iron is deleterious and contributes to a range of chronic and acute respiratory diseases. Moreover, aberrant regulation of iron metabolism, and/or deficient antioxidant protection, is also associated with acute lung diseases, such as the acute respiratory distress syndrome (ARDS). Iron, with the consequent production of reactive oxygen species (ROS), microbial growth promotion, and adverse signaling is strongly implicated as a major contributor to the pathogenesis of numerous disease processes involving the lung. Heme oxgenase, an enzyme that produces reactive iron from heme catabolism, is also briefly discussed in relation to lung disease.
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Affiliation(s)
- G J Quinlan
- Unit of Critical Care, Royal Brompton Hospital, Imperial College Faculty of Medicine, London, UK
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14
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Yang F, Wang X, Haile DJ, Piantadosi CA, Ghio AJ. Iron increases expression of iron-export protein MTP1 in lung cells. Am J Physiol Lung Cell Mol Physiol 2002; 283:L932-9. [PMID: 12376346 DOI: 10.1152/ajplung.00114.2002] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Accumulation of reactive iron in acute and chronic lung disease suggests that iron-driven free radical formation could contribute to tissue injury. Safe transport and sequestration of this metal is likely to be of importance in lung defense. We provide evidence for the expression and iron-induced upregulation of the metal transporter protein-1 (MTP1) genes in human and rodent lung cells at both the protein and mRNA levels. In human bronchial epithelial cells, a 3.8-fold increase in mRNA level and a 2.4-fold increase in protein level of MTP1 were observed after iron exposure. In freshly isolated human macrophages, as much as an 18-fold increase in the MTP1 protein level was detected after incubation with an iron compound. The elevation in expression of MTP1 gene was also demonstrated in iron-instilled rat lungs and in hypotransferrinemic mouse lungs. This is similar to our previous findings with divalent metal transporter-1 (DMT1), an iron transporter that is required for iron uptake and intracellular iron trafficking. These studies suggest the presence of iron mobilization and/or detoxification pathways in the lung that are crucial for iron homeostasis and lung defense.
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Affiliation(s)
- Funmei Yang
- Department of Cellular and Structural Biology, University of Texas Health Science Center, San Antonio, Texas 78284, USA
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15
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Reid D, Snell G, Ward C, Krishnaswamy R, Ward R, Zheng L, Williams T, Walters H. Iron overload and nitric oxide-derived oxidative stress following lung transplantation. J Heart Lung Transplant 2001; 20:840-9. [PMID: 11502406 DOI: 10.1016/s1053-2498(01)00282-0] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Reactive oxygen species (ROS) may contribute to airway injury and the development of the bronchiolitis obliterans syndrome (BOS) following lung transplantation (LT). Chemically active iron released from ferritin stores and nitric oxide (NO)-derived radicals may add to the oxidative burden. METHODS We determined the concentrations of ferritin and the aqueous NO derivative nitrite (NO2(-)) within bronchoalveolar lavage fluid (BALF) of 14 stable LT recipients (ST) and 7 subjects with BOS and 21 normal controls. We also assessed the relationship between BALF ferritin and hemosiderin-laden macrophages (HLMs) using a hemosiderin score (HS) and determined BALF albumin concentration as a marker of microvascular leakage. RESULTS BALF ferritin concentrations and HSs were significantly elevated in LT recipients overall compared with normal controls (p < 0.05). BALF NO2(-) levels were elevated in BOS subjects and STs compared with normal controls (p = 0.002 and p = 0.09, respectively), but there was no difference between transplant groups. BALF albumin concentrations were elevated in BOS patients compared with normal controls (p = 0.02) and ST (p = 0.05), but there was no difference between STs and controls. There was a significant relationship between BALF ferritin concentration and HS in LT recipients overall (r(s) = 0.7, p < 0.001). In BOS subjects, but not ST, BALF ferritin was significantly related to BALF albumin (r(s) = 0.8, p = 0.05) and there was a weak relationship with NO2(-) concentration (r(s) = 0.6, p = 0.1). BALF NO2(-) was strongly related to BALF % neutrophils in BOS subjects (r(s) = 0.9, p < 0.01), but there was no such relationship in STs. CONCLUSIONS Our findings suggest that the allograft could be subject to significant iron-generated oxidative stress, which may be exacerbated by NO and neutrophil-derived ROS, particularly in BOS. Microvascular leakage may be a feature of established chronic rejection, which potentiates the iron overload and contributes to further airway damage and remodeling.
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Affiliation(s)
- D Reid
- Department of Respiratory Medicine, Alfred Hospital, Melbourne, Victoria, Australia
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16
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Kuriyama-Matsumura K, Sato H, Suzuki M, Bannai S. Effects of hyperoxia and iron on iron regulatory protein-1 activity and the ferritin synthesis in mouse peritoneal macrophages. BIOCHIMICA ET BIOPHYSICA ACTA 2001; 1544:370-7. [PMID: 11341946 DOI: 10.1016/s0167-4838(00)00251-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Ferritin is an intracellular iron storage protein and its translation is inhibited by binding of iron regulatory proteins (IRPs) to the iron-responsive element (IRE) located in the 5' untranslated region of its mRNA. In this paper, we have investigated the effect of hyperoxia and iron on the binding activity of IRP-1 and the ferritin synthesis in mouse peritoneal macrophages. The binding activity of IRP-1 was increased and the ferritin synthesis was suppressed when the macrophages were cultured under hyperoxia, and the reverse occurred under hypoxia. Iron diminished the IRP-1-binding activity and the enhanced synthesis of ferritin. However, this effect was arrested under hyperoxia. Consistently, hypoxia-induced loss of binding activity of IRP-1 and the enhanced synthesis of ferritin were blocked in the presence of an iron chelator deferoxamine. These alterations of the binding activity of IRP-1 in response to oxygen and iron were not reproduced in the cell-free extract. The data suggest that in the macrophages oxygen and iron inversely act on the binding activity of IRP-1 and the ferritin synthesis, and that intracellular mechanism(s) to sense iron and/or oxygen is required for these actions.
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Affiliation(s)
- K Kuriyama-Matsumura
- Department of Biochemistry, Institute of Basic Medical Sciences, University of Tsukuba, Ibaraki 305-8575, Tsukuba, Japan
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Abstract
Articular cartilage is a physiologically hypoxic tissue with a proposed gradient of oxygen tension ranging from about 10% oxygen at the cartilage surface to less than 1% in the deepest layers. The position of the chondrocyte within this gradient may modulate the cell's behavior and phenotype. Moreover, the oxygen gradient is likely to be disturbed during joint diseases in which the pO(2)of the synovial fluid declines which may cause changes in chondrocyte behavior and gene expression. Thus, there is a need to understand the chondrocyte's response to different oxygen tensions. We compared the behavior of bovine articular chondrocytes cultured in alginate beads for 7 days in medium maintained at <0.1, 5, 10 or 20% oxygen. The chondrocytes' survival, differentiation, cell division, viability and matrix production were assessed at each oxygen tension and rRNA and mRNA abundance was measured. Chondrocytes were able to survive under all oxygen tensions for at least 7 days but cells cultured under anoxic conditions were metabolically less active than cells maintained in higher oxygen tensions; this was associated with a decrease in matrix production. In <0.1% oxygen there was a marked decrease in rRNA and mRNA abundance in the cells. There were no differences in cell division or differentiation between any oxygen tensions. These findings indicate that articular chondrocytes can be cultured successfully in the pO(2)range in which they are thought to exist in vivo (5-10% pO(2)) and are fully active under these conditions. Under anoxic conditions (<0.1% pO(2)) function is severely compromised.
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Affiliation(s)
- M J Grimshaw
- Molecular Pathology Section, Division of Biomedical Sciences, Imperial College School of Medicine, Sir Alexander Fleming Building, South Kensington, London SW7 2AZ, UK
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