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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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Iron deposition-induced ferroptosis in alveolar type II cells promotes the development of pulmonary fibrosis. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166204. [PMID: 34175430 DOI: 10.1016/j.bbadis.2021.166204] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Revised: 05/29/2021] [Accepted: 06/17/2021] [Indexed: 02/06/2023]
Abstract
Ferroptosis is a newly discovered type of regulated cell death, characterized by the iron-dependent accumulation of lipid reactive oxygen species, which has been implicated in numerous human diseases. However, its role in pulmonary fibrosis, a fatal lung disease with unknown etiology, is largely unknown. Here, we investigated the role of ferroptosis in pulmonary fibrosis. We found a large amount of iron deposition in the lung tissue of patients with pulmonary fibrosis. We observed ferroptosis in alveolar type II (ATII) cells, fibrotic lung tissues of BLM-induced pulmonary fibrosis mice. BLM-induced increase in iron level was accompanied by pathological changes, collagen deposition, and ferroptosis in ATII cells, indicating iron deposition-induced ferroptosis, which promoted the development of pulmonary fibrosis. Moreover, deferoxamine (DFO) completely prevented the pro-fibrosis effects of BLM by reducing iron deposition and ferroptosis in ATII cells. Genes associated with intracellular iron metabolism and homeostasis, such as transferrin receptor 1, divalent metal transporter 1, and ferroportin-1, and showed abnormal expression levels in animal tissues and lung epithelial MLE-12 cells, which responded to BLM stimulation. Overall, we demonstrated that BLM-induced iron deposition in MLE-12 cells is prone to both mitochondrial dysfunction and ferroptosis and that DFO reverses this phenotype. In the future, understanding the role of ferroptosis may shed new light on the etiology of pulmonary fibrosis. Ferroptosis inhibitors or genetic engineering of ferroptosis-related genes might offer potential targets to treat pulmonary fibrosis.
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Zhu Y, Chang J, Tan K, Huang SK, Liu X, Wang X, Cao M, Zhang H, Li S, Duan X, Chang Y, Fan Y, Cao P. Clioquinol Attenuates Pulmonary Fibrosis through Inactivation of Fibroblasts via Iron Chelation. Am J Respir Cell Mol Biol 2021; 65:189-200. [PMID: 33861690 DOI: 10.1165/rcmb.2020-0279oc] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Strict control of iron homeostasis is critical for the maintenance of normal lung function. Iron accumulates in the lungs of patients with idiopathic pulmonary fibrosis (PF), but the characteristics of iron metabolism in the pathogenesis of PF and related targeting therapeutics are not well studied. In this study, we investigated the cellular and molecular characteristics of iron metabolism in fibrotic lungs and further explored the efficacy of clioquinol (CQ) for the treatment of PF as well as its functional mechanism. Iron aggregates accumulated in the lungs of patients with idiopathic PF, and FTL (ferritin light chain) transcripts were increased in their pulmonary fibroblasts. In the bleomycin (BLM)-induced PF (BLM-PF) mouse model, pulmonary iron accumulation is a very early and concomitant event of PF. Labile iron pool levels in both fibroblasts and macrophages from the BLM-PF model were elevated, and iron metabolism was dysregulated. CQ attenuated PF induced by BLM and FITC, and iron-saturated CQ did not alleviate BLM-PF. Furthermore, CQ inhibited the activation of fibroblasts, including proliferation, fibrotic differentiation, proinflammatory cytokine secretion, and migration. In conclusion, our study demonstrated that CQ, acting as an iron chelator, attenuates experimental PF through inactivation of fibroblasts, providing support for targeting iron metabolism as a basis for PF treatment.
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Affiliation(s)
- Yumeng Zhu
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Jing Chang
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Ke Tan
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Steven K Huang
- Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, University of Michigan Medical School, University of Michigan, Ann Arbor, Michigan; and
| | - Xin Liu
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Xiaofan Wang
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Mengshu Cao
- Department of Respiratory and Critical Care Medicine, Nanjing University Medical School Affiliated Nanjing Drum Tower Hospital, Nanjing, Jiangsu, China
| | - Hongmin Zhang
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Shuxin Li
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Xianglin Duan
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Yanzhong Chang
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Yumei Fan
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
| | - Pengxiu Cao
- Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, Shijiazhuang, Hebei, China
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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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Iron in Lung Pathology. Pharmaceuticals (Basel) 2019; 12:ph12010030. [PMID: 30781366 PMCID: PMC6469192 DOI: 10.3390/ph12010030] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 01/30/2019] [Accepted: 02/10/2019] [Indexed: 12/21/2022] Open
Abstract
The lung presents a unique challenge for iron homeostasis. The entire airway is in direct contact with the environment and its iron particulate matter and iron-utilizing microbes. However, the homeostatic and adaptive mechanisms of pulmonary iron regulation are poorly understood. This review provides an overview of systemic and local lung iron regulation, as well as the roles of iron in the development of lung infections, airway disease, and lung injury. These mechanisms provide an important foundation for the ongoing development of therapeutic applications.
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Kell DB. Towards a unifying, systems biology understanding of large-scale cellular death and destruction caused by poorly liganded iron: Parkinson's, Huntington's, Alzheimer's, prions, bactericides, chemical toxicology and others as examples. Arch Toxicol 2010; 84:825-89. [PMID: 20967426 PMCID: PMC2988997 DOI: 10.1007/s00204-010-0577-x] [Citation(s) in RCA: 286] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Accepted: 07/14/2010] [Indexed: 12/11/2022]
Abstract
Exposure to a variety of toxins and/or infectious agents leads to disease, degeneration and death, often characterised by circumstances in which cells or tissues do not merely die and cease to function but may be more or less entirely obliterated. It is then legitimate to ask the question as to whether, despite the many kinds of agent involved, there may be at least some unifying mechanisms of such cell death and destruction. I summarise the evidence that in a great many cases, one underlying mechanism, providing major stresses of this type, entails continuing and autocatalytic production (based on positive feedback mechanisms) of hydroxyl radicals via Fenton chemistry involving poorly liganded iron, leading to cell death via apoptosis (probably including via pathways induced by changes in the NF-κB system). While every pathway is in some sense connected to every other one, I highlight the literature evidence suggesting that the degenerative effects of many diseases and toxicological insults converge on iron dysregulation. This highlights specifically the role of iron metabolism, and the detailed speciation of iron, in chemical and other toxicology, and has significant implications for the use of iron chelating substances (probably in partnership with appropriate anti-oxidants) as nutritional or therapeutic agents in inhibiting both the progression of these mainly degenerative diseases and the sequelae of both chronic and acute toxin exposure. The complexity of biochemical networks, especially those involving autocatalytic behaviour and positive feedbacks, means that multiple interventions (e.g. of iron chelators plus antioxidants) are likely to prove most effective. A variety of systems biology approaches, that I summarise, can predict both the mechanisms involved in these cell death pathways and the optimal sites of action for nutritional or pharmacological interventions.
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Affiliation(s)
- Douglas B Kell
- School of Chemistry and the Manchester Interdisciplinary Biocentre, The University of Manchester, Manchester M1 7DN, UK.
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