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Qian ZM, Li W, Guo Q. Lactoferrin/lactoferrin receptor: Neurodegenerative or neuroprotective in Parkinson's disease? Ageing Res Rev 2024:102474. [PMID: 39197711 DOI: 10.1016/j.arr.2024.102474] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2024] [Revised: 08/04/2024] [Accepted: 08/25/2024] [Indexed: 09/01/2024]
Abstract
Lactoferrin (Lf) is a multifunctional protein in the transferrin family. It is involved in many physiological functions, including the regulation of iron absorption and immune response. It also has antibacterial, antiviral, anti-inflammatory, anticancer and antioxidant capabilities under pathophysiological conditions. The mammalian lactoferrin receptor (LfR) plays a key role in mediating multiple functions of Lf. Studies have shown that Lf/LfR is abnormally expressed in the brain of Parkinson's disease, and the excessive accumulation of iron in the brain caused by the overexpression of Lf and LfR is considered to be one of the initial causes of the degeneration of dopaminergic neurons in Parkinson's disease. On the other hand, a number of recent studies have reported that Lf/LfR has a significant neuroprotective effect on Parkinson's disease. In other words, it seems paradoxical that Lf/LfR has both neurodegenerative and neuroprotective effects in Parkinson's disease. This article focuses on recent advances in the possible mechanisms of the neurodegenerative and neuroprotective effects of Lf/LfR in Parkinson's disease and discusses why Lf/LfR has a seemingly contradictory role in the development of Parkinson's disease. Based on the evidence obtained so far, we believed that Lf/LfR has a neuroprotective effect on Parkinson's disease, while as to whether the overexpressed Lf/LfR is the cause of the development of Parkinson's disease, the current evidence is insufficient and further investigation needed.
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Affiliation(s)
- Zhong-Ming Qian
- Institute of Translational and Precision Medicine, Nantong University, 19 Qi Xiu Road, Nantong, China 226001 and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai China 200040,.
| | - Wei Li
- Institute of Translational and Precision Medicine, Nantong University, 19 Qi Xiu Road, Nantong, China 226001 and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai China 200040
| | - Qian Guo
- Laboratory of Drug Delivery, School of Medicine, Shanghai University, 99 Shangda Road, Shanghai, China 200444.
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Zheng J, Qian ZM, Sun YX, Bao YX. Downregulation of hepcidin by norcantharidin in macrophage. Nat Prod Res 2024; 38:673-678. [PMID: 36855296 DOI: 10.1080/14786419.2023.2185236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 02/23/2023] [Indexed: 03/02/2023]
Abstract
Norcantharidin (NCTD) is a demethylated analogue of cantharidin. It was recently demonstrated that NCTD reduces iron contents in the liver and spleen of mice in vivo, indicating that NCTD can affect iron metabolism via hepcidin. Here, we investigated the effects of NCTD on expression of iron storage protein ferritin-light chain (Ft-L), transferrin receptor 1 (TfR1), divalent metal transporter 1 (DMT1), ferroportin 1 (Fpn1), hepcidin, iron regulatory protein 1 (IRP1), IL-6, p-JAK2 and p-STAT3 in lipopolysaccharides (LPS)-treated RAW264.7 cells in vitro via Real-time PCR and Western blotting analysis. We demonstrate that NCTD down-regulates Ft-L, hepcidin, IL-6, pJAK2, pSTAT3 and up-regulates TfR1, DMT1, Fpn1 and IRP1 expression in LPS treated cells, showing that NCTD can inhibit hepcidin via the IL-6/JAK2/STAT3 signalling pathway and also increase TfR1, DMT1 and Fpn1 expression via down-regulating hepcidin and up-regulating IRP1. Our findings provide further evidence in vitro for the role of NCTD in iron metabolism.
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Affiliation(s)
- Jie Zheng
- Research Center for Medicine and Biology, Zunyi Medical University, Zunyi, Guizhou, China
| | - Zhong-Ming Qian
- Institute of Translational and Precision Medicine, Nantong University, Nantong, Jiangsu, China
| | - Yu-Xin Sun
- School of Physics and Technology, Nanjing Normal University, Nanjing, Jiangsu, China
| | - Yu-Xin Bao
- Research Center for Medicine and Biology, Zunyi Medical University, Zunyi, Guizhou, China
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3
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Huang J, Chen L, Yao ZM, Sun XR, Tong XH, Dong SY. The role of mitochondrial dynamics in cerebral ischemia-reperfusion injury. Biomed Pharmacother 2023; 162:114671. [PMID: 37037094 DOI: 10.1016/j.biopha.2023.114671] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 04/04/2023] [Accepted: 04/06/2023] [Indexed: 04/12/2023] Open
Abstract
Stroke is one of the leading causes of death and long-term disability worldwide. More than 80 % of strokes are ischemic, caused by an occlusion of cerebral arteries. Without question, restoration of blood supply as soon as possible is the first therapeutic strategy. Nonetheless paradoxically, reperfusion can further aggravate the injury through a series of reactions known as cerebral ischemia-reperfusion injury (CIRI). Mitochondria play a vital role in promoting nerve survival and neurological function recovery and mitochondrial dysfunction is considered one of the characteristics of CIRI. Neurons often die due to oxidative stress and an imbalance in energy metabolism following CIRI, and there is a strong association with mitochondrial dysfunction. Altered mitochondrial dynamics is the first reaction of mitochondrial stress. Mitochondrial dynamics refers to the maintenance of the integrity, distribution, and size of mitochondria as well as their ability to resist external stimuli through a continuous cycle of mitochondrial fission and fusion. Therefore, improving mitochondrial dynamics is a vital means of treating CIRI. This review discusses the relationship between mitochondria and CIRI and emphasizes improving mitochondrial dynamics as a potential therapeutic approach to improve the prognosis of CIRI.
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Affiliation(s)
- Jie Huang
- Department of Pharmacology, School of Pharmacy, Bengbu Medical College, Bengbu, China; Anhui Engineering Technology Research Center of Biochemical Pharmaceutical, Bengbu, China
| | - Lei Chen
- Department of Pharmacology, School of Pharmacy, Bengbu Medical College, Bengbu, China; Anhui Engineering Technology Research Center of Biochemical Pharmaceutical, Bengbu, China
| | - Zi-Meng Yao
- Department of Pharmacology, School of Pharmacy, Bengbu Medical College, Bengbu, China; Anhui Engineering Technology Research Center of Biochemical Pharmaceutical, Bengbu, China
| | - Xiao-Rong Sun
- Department of Pharmacology, School of Pharmacy, Bengbu Medical College, Bengbu, China; Anhui Engineering Technology Research Center of Biochemical Pharmaceutical, Bengbu, China
| | - Xu-Hui Tong
- Department of Pharmacology, School of Pharmacy, Bengbu Medical College, Bengbu, China; Anhui Engineering Technology Research Center of Biochemical Pharmaceutical, Bengbu, China
| | - Shu-Ying Dong
- Department of Pharmacology, School of Pharmacy, Bengbu Medical College, Bengbu, China; Anhui Engineering Technology Research Center of Biochemical Pharmaceutical, Bengbu, China; Bengbu Medical College Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Bengbu, China.
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Ma J, Ma HM, Shen MQ, Wang YY, Bao YX, Liu Y, Ke Y, Qian ZM. The Role of Iron in Atherosclerosis in Apolipoprotein E Deficient Mice. Front Cardiovasc Med 2022; 9:857933. [PMID: 35669479 PMCID: PMC9163807 DOI: 10.3389/fcvm.2022.857933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 04/21/2022] [Indexed: 11/13/2022] Open
Abstract
The role of iron in atherosclerosis is still a controversial and unsolved issue. Here, we investigated serum iron, expression of iron regulatory, transport and storage proteins, pro-inflammatory chemokines and cytokines in ApoE–/– mice. We demonstrated that ApoE–/– induced atherosclerosis and an increase in iron contents, expression of transferrin receptor 1 (TfR1), iron regulatory proteins (IRPs), heme oxygenase 1 (HO1), cellular adhesion molecules and pro-inflammatory cytokines, production of reactive oxygen species (ROS), and a reduction in expression of superoxide dismutase and glutathione peroxidase enzyme in aortic tissues. All of these changes induced by ApoE deficiency could be significantly abolished by deferoxamine. The data showed that the increased iron in aortic tissues was mainly due to the increased iron uptake via IRP/TfR1 upregulation. These findings plus a brief analysis of the controversial results reported previously showed that ApoE deficiency-induced atherosclerosis is partly mediated by the increased iron in aortic tissues.
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Affiliation(s)
- Juan Ma
- Institute of Translational and Precision Medicine, Nantong University, Nantong, China
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Hui-Min Ma
- Institute of Translational and Precision Medicine, Nantong University, Nantong, China
| | - Meng-Qi Shen
- Institute of Translational and Precision Medicine, Nantong University, Nantong, China
| | - Yuan Yuan Wang
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy, Shanghai, China
- National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Yu-Xin Bao
- Research Center for Medicine and Biology, Zunyi Medical University, Zunyi, China
| | - Yong Liu
- Department of Pain and Rehabilitation, The Second Affiliated Hospital, The Army Medical University, Chongqing, China
| | - Ya Ke
- School of Biomedical Sciences and Gerald Choa Neuroscience Center, Faculty of Medicine, The Chinese University of Hong Kong, Sha Tin, Hong Kong SAR, China
- *Correspondence: Ya Ke,
| | - Zhong-Ming Qian
- Institute of Translational and Precision Medicine, Nantong University, Nantong, China
- Zhong-Ming Qian,
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Arif HM, Qian Z, Wang R. Signaling Integration of Hydrogen Sulfide and Iron on Cellular Functions. Antioxid Redox Signal 2022; 36:275-293. [PMID: 34498949 DOI: 10.1089/ars.2021.0203] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Significance: Hydrogen sulfide (H2S) is an endogenous signaling molecule, regulating numerous physiological functions from vasorelaxation to neuromodulation. Iron is a well-known bioactive metal ion, being the central component of hemoglobin for oxygen transportation and participating in biomolecule degradation, redox balance, and enzymatic actions. The interplay between H2S and iron metabolisms and functions impacts significantly on the fate and wellness of different types of cells. Recent Advances: Iron level in vivo affects the production of H2S via nonenzymatic reactions. On the contrary, H2S quenches excessive iron inside the cells and regulates the redox status of iron. Critical Issues: Abnormal metabolisms of both iron and H2S are associated with various conditions and diseases such as iron overload, anemia, oxidative stress, and cardiovascular and neurodegenerative diseases. The molecular mechanisms for the interactions between H2S and iron are unsettled yet. Here we review signaling links of the production, metabolism, and their respective and integrative functions of H2S and iron in normalcy and diseases. Future Directions: Physiological and pathophysiological importance of H2S and iron as well as their therapeutic applications should be evaluated jointly, not separately. Future investigation should expand from iron-rich cells and tissues to the others, in which H2S and iron interaction has not received due attention. Antioxid. Redox Signal. 36, 275-293.
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Affiliation(s)
| | - Zhongming Qian
- Institute of Translational & Precision Medicine, Nantong University, Nantong, China
| | - Rui Wang
- Department of Biology, York University, Toronto, Canada
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Shui S, Zhao Z, Wang H, Conrad M, Liu G. Non-enzymatic lipid peroxidation initiated by photodynamic therapy drives a distinct ferroptosis-like cell death pathway. Redox Biol 2021; 45:102056. [PMID: 34229160 PMCID: PMC8264218 DOI: 10.1016/j.redox.2021.102056] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 06/21/2021] [Indexed: 01/18/2023] Open
Abstract
Ferroptosis is primarily triggered by a failure of the glutathione (GSH)-glutathione peroxidase 4 (GPX4) reductive system and associated overwhelming lipid peroxidation, in which enzymes regulating polyunsaturated fatty acid (PUFA) metabolism, and in particular acyl-CoA synthetase long chain family member 4 (ACSL4), are central. Here, we found that exogenous oxygen radicals generated by photodynamic therapy (PDT) can directly peroxidize PUFAs and initiate lipid autoxidation, coinciding with cellular GSH depletion. Different from canonical ferroptosis induced by RSL3 or erastin, PDT-initiated lipid peroxidation and ferroptotis-like cell death is independent of lipoxygenase (ALOXs) and ACSL4. Especially, this form of cell death modality can be triggered in malignant cells insensitive to or acquired resistance to canonical ferroptosis inducers. We also observed a distinct iron metabolism pathway in this PDT-triggered cell death modality, in which cytosolic labile iron is decreased probably due to its relocation to mitochondria. Inhibition of the mitochondrial Ca2+ and Fe2+ uniporter (MCU) effectively prevented PDT-triggered lipid peroxidation and subsequent cell death. Therefore, we tentatively term this distinct ferroptosis-like cell death as liperoptosis. Moreover, using the clinically approved photosensitizer Verteporfin, PDT inhibited tumor growth through inducing prevailing ferroptosis-like cell death in a mouse xenograft model. With its site-specific advantages, these findings highlight the value of using PDT to trigger lipid peroxidation and ferroptosis-like cell death in vivo, and will benefit exploring the exact molecular mechanism of immunological effects of PDT in cancer treatment.
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Affiliation(s)
- Sufang Shui
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China; Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Zenglu Zhao
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China; Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Hao Wang
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China; Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, China
| | - Marcus Conrad
- Institute of Metabolism and Cell Death, Helmholtz Zentrum München, Neuherberg, Germany; Pirogov Russian National Research Medical University, Moscow, Russia
| | - Guoquan Liu
- State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing, China; Department of Chemical Biology, School of Pharmaceutical Sciences, Peking University, Beijing, China.
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Hepatocyte growth factor protects PC12 cells against OGD/R-induced injury by reducing iron. Biosci Rep 2021; 40:222408. [PMID: 32186328 PMCID: PMC7109004 DOI: 10.1042/bsr20200287] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 03/11/2020] [Accepted: 03/16/2020] [Indexed: 01/20/2023] Open
Abstract
In the light of hepatocyte growth factor (HGF) the inhibiting role on the expression of hepcidin, we hypothesized that HGF might be able to reduce cell and tissue iron by increasing ferroportin 1 (Fpn1) content and Fpn1-mediated iron release from cells and tissues. The hypothesized ability of HGF to reduce iron might be one of the mechanisms associated with its neuroprotective action under the conditions of ischemia/reperfusion (I/R). Here, we investigated the effects of HGF on the expression of hepcidin as well as transferrin receptor 1 (TfR1), divalent metal transporter 1 (DMT1), Fpn1, ferritin and iron regulatory proteins (IRPs) in oxygen-glucose deprivation and reoxygenation (OGD/R)-treated PC12 cells by real-time PCR and Western blot analysis. We demonstrated that HGF could completely reverse the OGD/R-induced reduction in Fpn1 and IRP1 expression and increase in ferritin light chain protein and hepcidin mRNA levels in PC12 cells. It was concluded that HGF protects PC12 cells against OGD/R-induced injury mainly by reducing cell iron contents via the up-regulation of Fpn1 and increased Fpn1-mediated iron export from cells. Our findings suggested that HGF may also be able to ameliorate OGD/R or I/R-induced overloading of brain iron by promoting Fpn1 expression.
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Chen YJ, Qian ZM, Sheng Y, Zheng J, Liu Y. Angiotensin II down-regulates transferrin receptor 1 and ferroportin 1 expression in Neuro-2a cells via activation of type-1 receptor. Neurosci Lett 2019; 716:134684. [PMID: 31830506 DOI: 10.1016/j.neulet.2019.134684] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 11/30/2019] [Accepted: 12/09/2019] [Indexed: 12/14/2022]
Abstract
Angiotensin II (ANGII) modulates expression of iron intake and export proteins in cultured neurons. However, the relevant mechanisms have not been fully elucidated. Here, we investigated the effects of ANGII and/or candesartan, a ANGII-Type-1 Receptor (AT1R) antagonist, and PD123319, a ANGII-Type-2 Receptor (AT2R) antagonist on expression of transferrin receptor 1 (TfR1), ferroportin 1 (Fpn1)and ferritin as well as iron regulatory proteins (IRPs), hepcidin and nuclear factor E2-related factor 2 (Nrf2) in Neuro-2a cells. We demonstrated that ANGII induces a significant reduction in expression of TfR1, Fpn1, IRP2 proteins and Nrf2 mRNA and an increase in ferritin protein and hepcidin mRNA, while candesartan, but not PD123319, significantly attenuated or reversed all these ANGII-induced changes in Neuro-2a cells. These findings imply that ANGII down-regulates TfR1 expression likely via the AT1R/IRP2 pathway, and Fpn1 expression via ATR1/hepcidin and AT1R/ Nrf2 pathways.
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Affiliation(s)
- Yun-Jin Chen
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy, Shanghai, 201203, China; National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Zhong-Ming Qian
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy, Shanghai, 201203, China; National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, 200040, China; Institute of Translational & Precision Medicine, Nantong University, Nantong, JS, 226019, China.
| | - Yuan Sheng
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy, Shanghai, 201203, China; National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Jie Zheng
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy, Shanghai, 201203, China; National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Yong Liu
- Department of Neurology, The Second Affiliated (Xinqiao) Hospital, The Army (Third Military) Medical University, Chongqing, China.
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Qian ZM, Ke Y. Brain iron transport. Biol Rev Camb Philos Soc 2019; 94:1672-1684. [PMID: 31190441 DOI: 10.1111/brv.12521] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 04/22/2019] [Accepted: 04/24/2019] [Indexed: 12/19/2022]
Abstract
Brain iron is a crucial participant and regulator of normal physiological activity. However, excess iron is involved in the formation of free radicals, and has been associated with oxidative damage to neuronal and other brain cells. Abnormally high brain iron levels have been observed in various neurodegenerative diseases, including neurodegeneration with brain iron accumulation, Alzheimer's disease, Parkinson's disease and Huntington's disease. However, the key question of why iron levels increase in the relevant regions of the brain remains to be answered. A full understanding of the homeostatic mechanisms involved in brain iron transport and metabolism is therefore critical not only for elucidating the pathophysiological mechanisms responsible for excess iron accumulation in the brain but also for developing pharmacological interventions to disrupt the chain of pathological events occurring in these neurodegenerative diseases. Numerous studies have been conducted, but to date no effort to synthesize these studies and ideas into a systematic and coherent summary has been made, especially concerning iron transport across the luminal (apical) membrane of the capillary endothelium and the membranes of different brain cell types. Herein, we review key findings on brain iron transport, highlighting the mechanisms involved in iron transport across the luminal (apical) as well as the abluminal (basal) membrane of the blood-brain barrier, the blood-cerebrospinal fluid barrier, and iron uptake and release in neurons, oligodendrocytes, astrocytes and microglia within the brain. We offer suggestions for addressing the many important gaps in our understanding of this important topic, and provide new insights into the potential causes of abnormally increased iron levels in regions of the brain in neurodegenerative disorders.
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Affiliation(s)
- Zhong-Ming Qian
- Institute of Translational & Precision Medicine, Nantong University, Nantong, 226019, China.,Laboratory of Neuropharmacology, School of Pharmacy, & National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, 201203, China
| | - Ya Ke
- School of Biomedical Sciences and Gerald Choa Neuroscience Centre, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong
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Abstract
With the development of research, more and more evidences suggested that mutations in the genes associated with brain iron metabolism induced diseases in the brain. Brain iron metabolism disorders might be one cause of neurodegenerative diseases. This review mainly summarizes the normal process of iron entry into the brain across the blood-brain barrier, and the distribution and transportation of iron among neurons and glial cells, as well as the underlying regulation mechanisms. To understand the mechanisms of iron metabolism in the brain will provide theoretical basis to prevent and cure brain diseases related to iron metabolism disorders.
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Affiliation(s)
- Peng Yu
- Laboratory of Molecular Iron Metabolism, Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, 20, Nanerhuan Eastern Road, Shijiazhuang, Hebei Province, 050024, China.
| | - Yan-Zhong Chang
- Laboratory of Molecular Iron Metabolism, Key Laboratory of Animal Physiology, Biochemistry and Molecular Biology of Hebei Province, College of Life Sciences, Hebei Normal University, 20, Nanerhuan Eastern Road, Shijiazhuang, Hebei Province, 050024, China.
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Zhang FL, Hou HM, Yin ZN, Chang L, Li FM, Chen YJ, Ke Y, Qian ZM. Impairment of Hepcidin Upregulation by Lipopolysaccharide in the Interleukin-6 Knockout Mouse Brain. Front Mol Neurosci 2017; 10:367. [PMID: 29163042 PMCID: PMC5681933 DOI: 10.3389/fnmol.2017.00367] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 10/24/2017] [Indexed: 01/18/2023] Open
Abstract
To find out whether the Interleukin-6 (IL-6)/signal transducer and activator of transcription 3 (STAT3) signaling pathway is involved in the expression of hepcidin in the mouse brain in vivo, we investigated the phosphorylation of STAT3, as well as the expression of hepcidin mRNA, ferroportin 1 (Fpn1) and ferritin light chain (Ft-L) proteins in the cortex and hippocampus of LPS-treated wild type (IL-6+/+) and IL-6 knockout (IL-6-/-) mice. We demonstrated that IL-6 knockout could significantly reduce the response of hepcidin mRNA, phospho-STAT3, Fpn1 and Ft-L protein expression to LPS treatment, in both the cortex and hippocampus of mice. Also, Stattic, an inhibitor of STAT3, significantly reduced the expression of phospho-STAT3 and hepcidin mRNA in the cortex and hippocampus of the LPS-treated wild type mice. These findings provide in vivo evidence for the involvement of the IL-6/STAT3 signaling pathway in the expression of hepcidin.
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Affiliation(s)
- Fa-Li Zhang
- Laboratory of Neuropharmacology, School of Pharmacy, Fudan University, Shanghai, China.,National Pharmaceutical Engineering Research Center, Shanghai Institute of Pharmaceutical Industry, Shanghai, China
| | - Hui-Min Hou
- National Pharmaceutical Engineering Research Center, Shanghai Institute of Pharmaceutical Industry, Shanghai, China
| | - Zhi-Nan Yin
- The First Affiliate Hospital, Biomedical Translational Research Institute, Guangdong Province Key Laboratory of Molecular Immunology and Antibody Engineering, Jinan University, Guangzhou, China
| | - Lan Chang
- Laboratory of Neuropharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Fe-Mi Li
- Laboratory of Neuropharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Y-J Chen
- Laboratory of Neuropharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Ya Ke
- School of Biomedical Sciences and Gerald Choa Neuroscience Centre, Faculty of Medicine, The Chinese University of Hong Kong, Sha Tin, Hong Kong
| | - Zhong-Ming Qian
- Laboratory of Neuropharmacology, School of Pharmacy, Fudan University, Shanghai, China
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12
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Garton T, Keep RF, Hua Y, Xi G. Brain iron overload following intracranial haemorrhage. Stroke Vasc Neurol 2016; 1:172-184. [PMID: 28959481 PMCID: PMC5435218 DOI: 10.1136/svn-2016-000042] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 11/01/2016] [Accepted: 11/02/2016] [Indexed: 12/15/2022] Open
Abstract
Intracranial haemorrhages, including intracerebral haemorrhage (ICH), intraventricular haemorrhage (IVH) and subarachnoid haemorrhage (SAH), are leading causes of morbidity and mortality worldwide. In addition, haemorrhage contributes to tissue damage in traumatic brain injury (TBI). To date, efforts to treat the long-term consequences of cerebral haemorrhage have been unsatisfactory. Incident rates and mortality have not showed significant improvement in recent years. In terms of secondary damage following haemorrhage, it is becoming increasingly apparent that blood components are of integral importance, with haemoglobin-derived iron playing a major role. However, the damage caused by iron is complex and varied, and therefore, increased investigation into the mechanisms by which iron causes brain injury is required. As ICH, IVH, SAH and TBI are related, this review will discuss the role of iron in each, so that similarities in injury pathologies can be more easily identified. It summarises important components of normal brain iron homeostasis and analyses the existing evidence on iron-related brain injury mechanisms. It further discusses treatment options of particular promise.
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Affiliation(s)
- Thomas Garton
- Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA
| | - Richard F Keep
- Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA
| | - Ya Hua
- Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA
| | - Guohua Xi
- Department of Neurosurgery, University of Michigan, Ann Arbor, Michigan, USA
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Chen P, Li FM, Zhou YF, Qian C, Li J, Jiang LR, Qian ZM. Effects of alpha-lipoic acid on expression of iron transport and storage proteins in BV-2 microglia cells. Pharmacol Rep 2016; 69:1-5. [PMID: 27755990 DOI: 10.1016/j.pharep.2016.09.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Revised: 08/29/2016] [Accepted: 09/09/2016] [Indexed: 01/19/2023]
Abstract
BACKGROUND The antioxidant properties of alpha-lipoic acid (ALA) are associated with its ability to reduce iron in cells and tissues, which is partly due to its inhibiting effect on iron uptake from transferrin and its promoting effect on iron deposition into ferritin. However, the relevant mechanisms are unknown. METHODS We therefore investigated the effects of ALA on the expression of transferrin receptor 1 (TfR1), divalent metal transporter 1 (DMT1), ferroportin 1 (Fpn1) and ferritin in BV-2 microglia cells. RESULTS We demonstrated that ALA significantly inhibited DMT1 expression, lowered ferritin-light-chain (Ft-L) and ferritin-heavy-chain (Ft-H) content, and had no effect on TfR1 and Fpn1 in BV-2 microglia cells. This indicated that the inhibiting effect of ALA on DMT1 might be one of the causes of the ALA-induced reduction in cellular transferrin-bound-iron uptake. We also demonstrated that ALA enhanced DMT1 and TfR1 expression in ferric ammonium citrate (FAC)-treated cells. FAC treatment led to a significant increase in Ft-L, Ft-H and Fpn1, and pre-treatment with ALA resulted in a further increase in the contents of Ft-L and Ft-H but not Fpn1 in cells. CONCLUSIONS ALA could up-regulate TfR1, DMT1 and ferritin expression when iron is increased outside of the cell, promoting iron deposition into ferritin by increasing cell iron uptake, and then reducing free iron both inside and outside of the cell.
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Affiliation(s)
- Ping Chen
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy, 826 Zhang Heng Road, Pu Dong, Shanghai 201203, China
| | - Fei-Mi Li
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy, 826 Zhang Heng Road, Pu Dong, Shanghai 201203, China
| | - Yu-Fu Zhou
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy, 826 Zhang Heng Road, Pu Dong, Shanghai 201203, China
| | - Christopher Qian
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy, 826 Zhang Heng Road, Pu Dong, Shanghai 201203, China
| | - Juan Li
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy, 826 Zhang Heng Road, Pu Dong, Shanghai 201203, China
| | - Li-Rong Jiang
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy, 826 Zhang Heng Road, Pu Dong, Shanghai 201203, China
| | - Zhong-Ming Qian
- Laboratory of Neuropharmacology, Fudan University School of Pharmacy, 826 Zhang Heng Road, Pu Dong, Shanghai 201203, China.
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14
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Almutairi MMA, Gong C, Xu YG, Chang Y, Shi H. Factors controlling permeability of the blood-brain barrier. Cell Mol Life Sci 2016; 73:57-77. [PMID: 26403789 PMCID: PMC11108286 DOI: 10.1007/s00018-015-2050-8] [Citation(s) in RCA: 180] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 09/15/2015] [Accepted: 09/17/2015] [Indexed: 12/27/2022]
Abstract
As the primary protective barrier for neurons in the brain, the blood-brain barrier (BBB) exists between the blood microcirculation system and the brain parenchyma. The normal BBB integrity is essential in protecting the brain from systemic toxins and maintaining the necessary level of nutrients and ions for neuronal function. This integrity is mediated by structural BBB components, such as tight junction proteins, integrins, annexins, and agrin, of a multicellular system including endothelial cells, astrocytes, pericytes, etc. BBB dysfunction is a significant contributor to the pathogeneses of a variety of brain disorders. Many signaling factors have been identified to be able to control BBB permeability through regulating the structural components. Among those signaling factors are inflammatory mediators, free radicals, vascular endothelial growth factor, matrix metalloproteinases, microRNAs, etc. In this review, we provide a summary of recent progress regarding these structural components and signaling factors, relating to their roles in various brain disorders. Attention is also devoted to recent research regarding impact of pharmacological agents such as isoflurane on BBB permeability and how iron ion passes across BBB. Hopefully, a better understanding of the factors controlling BBB permeability helps develop novel pharmacological interventions of BBB hyperpermeability under pathological conditions.
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Affiliation(s)
- Mohammed M A Almutairi
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, 1251 Wescoe Hall Drive, Malott Hall 5044, Lawrence, KS, 66045, USA
| | - Chen Gong
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, 1251 Wescoe Hall Drive, Malott Hall 5044, Lawrence, KS, 66045, USA
| | - Yuexian G Xu
- Department of Anesthesiology, School of Medicine, University of Kansas, Kansas City, KS, 66160, USA
| | - Yanzhong Chang
- Laboratory of Molecular Iron Metabolism, College of Life Science, Hebei Normal University, Shijiazhuang, 050016, China
| | - Honglian Shi
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, 1251 Wescoe Hall Drive, Malott Hall 5044, Lawrence, KS, 66045, USA.
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15
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Huang XT, Qian ZM, He X, Gong Q, Wu KC, Jiang LR, Lu LN, Zhu ZJ, Zhang HY, Yung WH, Ke Y. Reducing iron in the brain: a novel pharmacologic mechanism of huperzine A in the treatment of Alzheimer's disease. Neurobiol Aging 2013; 35:1045-54. [PMID: 24332448 DOI: 10.1016/j.neurobiolaging.2013.11.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 10/14/2013] [Accepted: 11/05/2013] [Indexed: 02/02/2023]
Abstract
Huperzine A (HupA), a natural inhibitor of acetylcholinesterase derived from a plant, is a licensed anti-Alzheimer's disease (AD) drug in China and a nutraceutical in the United States. In addition to acting as an acetylcholinesterase inhibitor, HupA possesses neuroprotective properties. However, the relevant mechanism is unknown. Here, we showed that the neuroprotective effect of HupA was derived from a novel action on brain iron regulation. HupA treatment reduced insoluble and soluble beta amyloid levels, ameliorated amyloid plaques formation, and hyperphosphorylated tau in the cortex and hippocampus of APPswe/PS1dE9 transgenic AD mice. Also, HupA decreased beta amyloid oligomers and amyloid precursor protein levels, and increased A Disintegrin And Metalloprotease Domain 10 (ADAM10) expression in these treated AD mice. However, these beneficial effects of HupA were largely abolished by feeding the animals with a high iron diet. In parallel, we found that HupA decreased iron content in the brain and demonstrated that HupA also has a role to reduce the expression of transferrin-receptor 1 as well as the transferrin-bound iron uptake in cultured neurons. The findings implied that reducing iron in the brain is a novel mechanism of HupA in the treatment of Alzheimer's disease.
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Affiliation(s)
- Xiao-Tian Huang
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China; State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Zhong-Ming Qian
- Laboratory of Neuropharmacology, School of Pharmacy, Fudan University, Shanghai, China.
| | - Xuan He
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Qi Gong
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Ka-Chun Wu
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Li-Rong Jiang
- Laboratory of Neuropharmacology, School of Pharmacy, Fudan University, Shanghai, China
| | - Li-Na Lu
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Zhou-Jing Zhu
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Hai-Yan Zhang
- State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, Shanghai, China
| | - Wing-Ho Yung
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
| | - Ya Ke
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China.
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16
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Study of the transcytosis of an anti-transferrin receptor antibody with a Fab′ cargo across the blood–brain barrier in mice. Eur J Pharm Sci 2013; 49:556-64. [DOI: 10.1016/j.ejps.2013.05.027] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 05/28/2013] [Accepted: 05/28/2013] [Indexed: 11/23/2022]
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17
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Du F, Fan M, Gong Q, Zhu LL, Zhu ZJ, Lu L, Ke Y. Effects of hypoxic preconditioning on the expression of iron influx and efflux proteins in primary neuron culture. Neurochem Int 2012; 60:335-43. [DOI: 10.1016/j.neuint.2012.01.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 01/05/2012] [Accepted: 01/10/2012] [Indexed: 12/01/2022]
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18
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Indira Chandran V, Matesic L, Locke JM, Skropeta D, Ranson M, Vine KL. Anti-cancer activity of an acid-labile N-alkylisatin conjugate targeting the transferrin receptor. Cancer Lett 2012; 316:151-6. [DOI: 10.1016/j.canlet.2011.10.021] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Revised: 09/21/2011] [Accepted: 10/16/2011] [Indexed: 12/18/2022]
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19
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Nakamura Y, Nakamichi N, Takarada T, Ogita K, Yoneda Y. Transferrin receptor-1 suppresses neurite outgrowth in neuroblastoma Neuro2A cells. Neurochem Int 2011; 60:448-57. [PMID: 22019713 DOI: 10.1016/j.neuint.2011.08.018] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2011] [Revised: 08/24/2011] [Accepted: 08/25/2011] [Indexed: 10/16/2022]
Abstract
Transferrin receptor-1 (TfR1) is a cell membrane-associated glycoprotein responsible for incorporation of the iron bound to transferrin through an endocytotic process from the circulating blood. Iron is believed to play a dual role as an active center of the electron transfer system in mitochondria and as an endogenous cytotoxin through promoted generation of reactive oxygen species in different eukaryotic cells. In this study, we evaluated expression profiles of different genes related to iron mobilization across plasma membranes in neuronal cells. Marked mRNA expression was seen for various iron-related genes such as TfR1 in cultured mouse neocortical neurons, while TfR1 mRNA levels were more than doubled during culture from 3 to 6days. In mouse embryonal carcinoma P19 cells endowed to differentiate into neuronal and astroglial lineages, a transient increase was seen in both mRNA and corresponding protein for TfR1 in association with neuronal marker expression during culture with all-trans retinoic acid (ATRA). In neuronal Neuro2A cells cultured with ATRA, moreover, neurite was elongated together with increased expression of both mRNA and protein for TfR1. Overexpression of TfR1 significantly decreased the length of neurite elongated, however, while significant promotion was invariably seen in the neurite elongation in Neuro2A cells transfected with TfR1 siRNA as well as in Neuro2A cells cultured with an iron chelator. These results suggest that TfR1 would be highly expressed by neurons rather than astroglia to play a negative role in the neurite outgrowth after the incorporation of circulating transferrin in the brain.
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Affiliation(s)
- Yukary Nakamura
- Laboratory of Molecular Pharmacology, Division of Pharmaceutical Sciences, Kanazawa University Graduate School of Natural Science and Technology, Kakuma-machi, Kanazawa, Ishikawa 920-1192, Japan
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20
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Qian ZM, Mei Wu X, Fan M, Yang L, Du F, Yung WH, Ke Y. Divalent metal transporter 1 is a hypoxia-inducible gene. J Cell Physiol 2011; 226:1596-603. [DOI: 10.1002/jcp.22485] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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21
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Structure and metal ion binding of the first transmembrane domain of DMT1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2010; 1808:1639-44. [PMID: 21074515 DOI: 10.1016/j.bbamem.2010.11.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2010] [Revised: 11/03/2010] [Accepted: 11/04/2010] [Indexed: 11/21/2022]
Abstract
DMT1 is an integral membrane protein with 12 putative transmembrane domains. As a divalent metal ion transporter, it plays an important role in metal ion homeostasis from bacteria to human. Loss-function mutations at the conserved motif DPGN located within the first transmembrane domain (TMD1) of DMT1 indicate the significance of TMD1 in the biological function of the protein. In the present work, we study the structure, topology and metal ion binding of DMT1-TMD1 peptide by nuclear magnetic resonance using sodium dodecyl sulfate and dodecylphosphocholine micelles as membrane mimics. We find that the peptide forms an α-helix-extended segment-α-helix configuration in which the motif DPGN locates at the central flexible region. The N-terminal part of the peptide is deeply embedded in micelles, while the motif section and the C-terminal part are close to the surface of micelles. The peptide can bind to Mn2+ and Co2+ ions by the side chains of the negatively charged residues in the motif section and the C-terminal part of TMD1. The crucial role of the central flexible region and the C-terminal part of TMD1 in metal ion capture is confirmed by the binding of the N-terminal part truncated TMD1 to metal ions.
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22
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Li Z, Lai Z, Ya K, Fang D, Ho YW, Lei Y, Ming QZ. Correlation between the expression of divalent metal transporter 1 and the content of hypoxia-inducible factor-1 in hypoxic HepG2 cells. J Cell Mol Med 2008; 12:569-79. [PMID: 18419598 PMCID: PMC3822544 DOI: 10.1111/j.1582-4934.2007.00145.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Transferrin and transferrin receptor are two key proteins of iron metabolism that have been identified to be hypoxia-inducible genes. Divalent metal transporter 1 (DMT1) is also a key transporter of iron under physiological conditions. In addition, in the 5' regulatory region of human DMT1 (between -412 and -570), there are two motifs (CCAAAGTGCTGGG) that are similar to hypoxia-inducible factor-1 (HIF-1) binding sites. It was therefore speculated that DMT1 might also be a hypoxia-inducible gene. We investigated the effects of hypoxia and hypoxia/re-oxygenation on the expression of DMT1 and the content of HIF-1alpha in HepG2 cells. As we expected, a very similar tendency in the responses of the expression of HIF-1alpha, DMT1+IRE (iron response element) and DMT1-IRE proteins to chemical (CoCl(2)) or physical hypoxia was observed. A highly significant correlation was found between the expression of DMT1 proteins and the contents of HIF-1 in hypoxic cells. After the cells were exposed to hypoxia and subsequent normoxia, no HIF-1alpha could be detected and a significant decrease in DMT1+IRE expression (P<0.05), but not in DMT1-IRE protein (versus the hypoxia group), was observed. The findings implied that the HIF-1 pathway might have a role in the regulation of DMT1+IRE expression during hypoxia.
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Affiliation(s)
- Zhu Li
- Institute for Nautical Medicine and Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong, PR China
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23
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Ke Y, Qian ZM. Brain iron metabolism: neurobiology and neurochemistry. Prog Neurobiol 2007; 83:149-73. [PMID: 17870230 DOI: 10.1016/j.pneurobio.2007.07.009] [Citation(s) in RCA: 188] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2007] [Revised: 04/10/2007] [Accepted: 07/26/2007] [Indexed: 01/09/2023]
Abstract
New findings obtained during the past years, especially the discovery of mutations in the genes associated with brain iron metabolism, have provided key insights into the homeostatic mechanisms of brain iron metabolism and the pathological mechanisms responsible for neurodegenerative diseases. The accumulated evidence demonstrates that misregulation in brain iron metabolism is one of the initial causes for neuronal death in some neurodegenerative disorders. The errors in brain iron metabolism found in these disorders have a multifactorial pathogenesis, including genetic and nongenetic factors. The disturbances of iron metabolism might occur at multiple levels, including iron uptake and release, storage, intracellular metabolism and regulation. It is the increased brain iron that triggers a cascade of deleterious events, leading to neuronal death in these diseases. In the article, the recent advances in studies on neurochemistry and neuropathophysiology of brain iron metabolism were reviewed.
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Affiliation(s)
- Ya Ke
- Department of Physiology, Faculty of Medicine, The Chinese University of Hong Kong, NT, Hong Kong
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24
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Qian ZM, Chang YZ, Leung G, Du JR, Zhu L, Wang Q, Niu L, Xu YJ, Yang L, Ho KP, Ke Y. Expression of ferroportin1, hephaestin and ceruloplasmin in rat heart. Biochim Biophys Acta Mol Basis Dis 2007; 1772:527-32. [PMID: 17383861 DOI: 10.1016/j.bbadis.2007.02.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2006] [Revised: 02/12/2007] [Accepted: 02/15/2007] [Indexed: 01/28/2023]
Abstract
Iron-mediated injury plays an important role in a number of heart disorders. Studies on heart iron are therefore crucial for understanding the causes of excessive heart iron. Heart cells have the ability to accumulate transferrin-bound-iron via the transferrin receptor and non-transferrin-bound-iron probably via the L-type Ca2+ channel and the divalent metal transporter1. However, little is known about the mechanisms of iron export in the heart cells. Here, we investigated expression of iron exporters including ferroportin 1 (Fpn1), ceruloplasmin (CP) and hephaestin (Heph) and provided evidence for their existence in the heart. We demonstrated that iron has a significant effect on expression of Fpn1 and CP, but not Heph. Treatment of a high-iron diet induced a significant increase in Fpn1, a decrease in CP but no change in Heph mRNA and protein. The control of Fpn1 and CP protein expression by iron was parallel to that of their mRNA expression, suggesting a transcriptional regulation of Fpn1 and CP by iron. The existence of these proteins in the heart implies that they might have a role in heart iron homeostasis.
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Affiliation(s)
- Zhong Ming Qian
- Laboratory of Iron Metabolism, Department of Applied Biology and Chemical Technology and National Key Laboratory of Chinese Medicine and Molecular Pharmacology (Shenzhen), Hong Kong, PR China.
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25
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Probing molecular interaction between transferrin and anti-transferrin by atomic force microscope. ACTA ACUST UNITED AC 2006. [DOI: 10.1007/s11434-006-0405-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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26
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Chang YZ, Ke Y, Du JR, Halpern GM, Ho KP, Zhu L, Gu XS, Xu YJ, Wang Q, Li LZ, Wang CY, Qian ZM. Increased divalent metal transporter 1 expression might be associated with the neurotoxicity of L-DOPA. Mol Pharmacol 2005; 69:968-74. [PMID: 16317110 DOI: 10.1124/mol.105.017756] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Based on the available data, we speculated that changes in brain iron metabolism induced by L-DOPA might be associated with the neurotoxicity of L-DOPA. To investigate this possibility, the effects of L-DOPA on the expression of iron influx proteins [transferrin receptor (TfR) and divalent metal transporter 1 (DMT1)], iron efflux protein (ferroportin 1), and iron uptake in C6 glioma cells were determined in this study using Northern blot and Western blot analysis and the calcein method. The findings showed that treatment of C6 cells with different concentrations of L-DOPA (0-100 microM) did not affect the expression of mRNA and protein of TfR and DMT1 with iron-responsive element (+IRE) and protein of ferroportin 1. However, a significant increase in the expression of DMT1(-IRE) mRNA and protein was found in cells treated, respectively, with 10 and 30 microM L-DOPA (mRNA) and 1, 5, 10 and 30 microM L-DOPA (protein). The increase in DMT(-IRE) protein induced by L-DOPA treatment was in parallel with the increase in DMT(-IRE) mRNA. The levels of DMT1(-IRE) mRNA and protein peaked in the cells treated with 10 microM L-DOPA and then decreased progressively with increasing concentrations of L-DOPA. Further study demonstrated that treatment of the cells with 10 microM L-DOPA induced a significant increase in ferrous uptake by C6 glioma cells. The findings suggested that the increased DMT1(-IRE) expression might be partly associated with the neurotoxicity of L-DOPA. Clinical relevance of the findings needs to be investigated further.
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Affiliation(s)
- Yan-Zhong Chang
- Department of Applied Biology and Chemistry Technology, The Hong Kong Polytechnic University, Kowloon, Hong Kong
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27
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Wang J, Qian ZM, Jiang H, Xie J, Ke Y. Treatment with nerve growth factor decreases expression of divalent metal transporter 1 and transferrin receptor in PC12 cells. Neurochem Int 2005; 47:514-7. [PMID: 16137791 DOI: 10.1016/j.neuint.2005.02.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2004] [Revised: 02/24/2005] [Accepted: 02/28/2005] [Indexed: 11/22/2022]
Abstract
Divalent metal transporter 1 (DMT1) and transferrin receptor (TfR) might play a key role in non-transferrin-bound iron (NTBI) and transferrin-bound iron (Tf-Fe) uptake by neuronal cells. Recent studies demonstrated that nerve growth factor (NGF)-treated PC12 cells (the neuronal phenotype) have higher NTBI as well as Tf-Fe uptake compared with untreated cells (the undifferentiated cells). We speculated the increased NTBI and Tf-Fe uptake induced by NGF treatment might be associated with the increased expression of DMT1 and TfR. In this study, we investigated the effect of NGF treatment on DMT1 and TfR expression in PC12 cells. Contrary to our expectation, treatment with NGF induced a significant decrease rather than increase in DMT1+IRE, DMT1-IRE and TfR expression in the cells. The data demonstrate that the increase in iron uptake is not associated with the DMT1 and TfR in NGF-treated PC12 cells. The RT-PCR findings of no change in DMT1 mRNA plus our data suggest that regulation of DMT1 expression by NGF might be at the post-transcriptional level.
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Affiliation(s)
- Jun Wang
- Laboratory of Iron Metabolism, Department of Applied Biology and Chemical Technology, Hong Kong Polytechnic University, Kowloon, Hong Kong, PR China
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28
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Xiu-Lian D, Kui W, Ya K, Lan Y, Rong-Chang L, Yan Zhong C, Kwok Ping H, Zhong Ming Q. Apotransferrin is internalized and distributed in the same way as holotransferrin in K562 cells. J Cell Physiol 2004; 201:45-54. [PMID: 15281088 DOI: 10.1002/jcp.20051] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Transferrin (Tf), a naturally existing protein, has received considerable attention in the area of drug targeting since it is biodegradable, non-toxic, and non-immunogenic. The efficient cellular uptake of Tf shows it has potential in the delivery of anti-cancer drugs, proteins, and therapeutic genes into proliferating malignant cells that overexpress transferrin receptor (TfR). In human serum, about 30% of Tf exists in the iron-saturated form (Fe(2)-Tf) and the remainder exists as apotransferrin (apo-Tf). Understanding the uptake of apo-Tf by cells will provide key insights into studies on Tf-mediated drug delivery. In the present study, we investigated visually the transport of apo-Tf into K562 cells and its intracellular localization by laser-scanning confocal microscopy (LSCM) and flow cytometry analysis (FCA). It was found that, like Fe(2)-Tf, apo-Tf can be taken up into the cells. The process is time- and temperature-dependent, competitively inhibited by Fe(2)-Tf, and significantly abolished by pronase pretreatment. Visual evidence showed that the transport of apo-Tf into K562 cells is a TfR-mediated process. Furthermore, the investigations using optical-slicing technique demonstrated that the distribution of apo-Tf is similar to that of Fe(2)-Tf, both appearing in the perinuclear region in ball-in-bowl shape.
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Affiliation(s)
- Du Xiu-Lian
- School of Pharmaceutical Science and Joint Laboratory of Perking University & The Hong Kong Polytechnic University, Perking University, Beijing, People's Republic of China
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29
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Li H, Li F, Sun H, Qian ZM. Membrane-inserted conformation of transmembrane domain 4 of divalent-metal transporter. Biochem J 2003; 372:757-66. [PMID: 12646040 PMCID: PMC1223444 DOI: 10.1042/bj20030075] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2003] [Revised: 02/18/2003] [Accepted: 03/19/2003] [Indexed: 11/17/2022]
Abstract
Divalent-metal transporter 1 (DMT1) is involved in the intestinal iron absorption and in iron transport in the transferrin cycle. It transports metal ions at low pH ( approximately 5.5), but not at high pH (7.4), and the transport is a proton-coupled process. Previously it has been shown that transmembrane domain 4 (TM4) is crucial for the function of this protein. Here we provide the first direct experimental evidence for secondary-structural features and membrane insertions of a 24-residue peptide, corresponding to TM4 of DMT1 (DMTI-TM4), in various membrane-mimicking environments by the combined use of CD and NMR spectroscopies. The peptide mainly adopts an alpha-helical structure in trifluoroethanol, SDS and dodecylphosphocholine micelles, and dimyristoyl phosphatidylcholine and dimyristoyl phosphatidylglycerol small unilamellar vesicles. It has been demonstrated from both Halpha secondary shifts and nuclear-Overhauser-enhancement (NOE) connectivities that the peptide is well folded into an alpha-helix from Val(8) to Lys(23) in SDS micelles at pH 4.0, whereas the N-terminus is highly flexible. The alpha-helical content estimated from NMR data is in agreement with that extracted from CD simulations. The highest helicity was observed in the anionic phospholipids [1,2-dimyristoyl- sn -glycero-3-[phospho-rac -(1-glycerol)]], indicating that electrostatic attraction is important for peptide binding and insertion into the membranes. The secondary-structural transition of the peptide occurred at pH 4.3 in the 2,2,2-trifluoroethanol (TFE) water mixed solvent, whereas at a higher pH value (5.6) in SDS micelles, DMT1-TM4 exhibited a more stable structure in SDS micelles than that in TFE in terms of changing the pH and temperature. PAGE did not show high-molecular-mass aggregates in SDS micelles. The position of the peptide relative to SDS micelles was probed by the effects of 5- and 16-doxylstearic acids on the intensities of the peptide proton resonances. The results showed that the majority of the peptide is inserted into the hydrophobic interior of SDS micelles, whereas the C-terminal residues are surface-exposed. The ability of DMT1-TM4 to assume transmembrane features may be crucial for its biological function in vivo.
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Affiliation(s)
- Hongyan Li
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon, Hung Hom, Peoples' Republic of China
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30
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Ming Qian Z, Sheng Xiao D, Kui Liao Q, Ping Ho K. Effect of different durations of exercise on transferrin-bound iron uptake by rat erythroblast. J Nutr Biochem 2002; 13:47-54. [PMID: 11834219 DOI: 10.1016/s0955-2863(01)00194-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
This study evaluated effects of different durations of exercise on transferrin receptor (TfR) expression on the membrane of rat erythroblasts. Female rats were assigned to six groups: 3, 6 and 12 months of strenuous exercise (swimming 2 h/day, 5 days/wk) groups and their corresponding controls. At the end of experiments, the erythroblasts were isolated for Tf binding assay and transferrin-bound iron (Tf-Fe) uptake. Tissue non-heme iron and hematological iron indices were also measured. The TfR number on the cells was about 603,189 plus minus 107,562, 890,150 plus minus 164,849 and 384,695 plus minus 46,295 molecules/cell in three control groups (3, 6, 12 months) respectively. Exercise groups had significantly higher levels of TfR than those of the control groups, being 1,374,137 plus minus 243,677, 2,175,360 plus minus 462,737 and 1,012,759 plus minus 249,423 molecules/cell in 3, 6 and 12 months of exercise groups respectively (p < 0.05). After 30 min of incubation, cellular Tf approached to levels of 8.28 plus minus 1.94, 10.73 plus minus 3.30 and 6.60 plus minus 0.93 fmole/10(6) cells in 3, 6 and 12 months of exercise groups, while the corresponding control values were 3.09 plus minus 0.36, 5.03 plus minus 1.01 and 2.51 plus minus 0.88 fmole/10(6) cells respectively (all P < 0.05). The rates of cellular iron accumulation were 7.07 (3), 8.79 (6) and 5.96 (12 month) fmole/10(6) cells/min in the exercised rats and 2.91, 3.85, and 2.03 fmole/10(6) cells/min in their corresponding controls (all p < 0.05). However, no significant difference was observed in the ratios (Exercise/Corresponding control) of the increased TfR expression, Tf-Fe uptake and Tf endocytosis as well as of the decreased plasma iron and tissue non-heme iron levels induced by different periods of exercise. Furthermore, the increase in the length of exercise (6 or 12 month) did not induce a remarkable decrease in plasma hemoglobin and hematocrit. These results indicate that a true iron deficiency or 'sport anemia' can not develop even if under longer periods (6 or 12 month) of strenuous exercise.
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Affiliation(s)
- Zhong Ming Qian
- Department of Applied Biology & Chemical Technology, The Hong Kong Polytechnic University, Kowloon, Hong Kong
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31
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Liao QK, Kong PA, Gao J, Li FY, Qian ZM. Expression of ferritin receptor in placental microvilli membrane in pregnant women with different iron status at mid-term gestation. Eur J Clin Nutr 2001; 55:651-6. [PMID: 11477463 DOI: 10.1038/sj.ejcn.1601195] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2000] [Revised: 01/05/2001] [Accepted: 01/17/2001] [Indexed: 11/09/2022]
Abstract
OBJECTIVE The effect of iron status in pregnant women on expression of ferritin receptor in placental microvilli membrane at mid-term gestation was investigated. DESIGN Ferritin receptor binding sites and dissociation constants (K(d)) were determined in specimens of placental microvilli from 30 pregnant women at mid-term gestation and six women at term-delivery. RESULTS The ferritin receptor binding sites in the placental microvilli membrane in pregnant women with mild iron deficiency and moderate iron deficiency anemia were significantly higher then those in pregnant women with normal iron status. However, no significant difference was found between pregnant women with severe iron deficiency anemia and with normal measurements. No significant differences of K(d) values were detected between pregnant women with normal iron status and those with iron-deficiency. Data also revealed that the ferritin receptor binding sites in placental microvilli membrane and K(d) values at mid-term gestation did not differ significantly from those at term gestation. CONCLUSION Lower iron status in pregnant women could lead to an increase in expression of ferritin receptor in placental microvilli membrane at mid-term gestation while the dissociation constant of ferritin receptor remains unchanged. This implies that the regulation of maternal-fetal iron homeostasis via the ferritin receptor-mediated pathway is achieved by changes in the numbers of ferritin receptors rather then binding properties.
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Affiliation(s)
- Q K Liao
- Department of Pediatrics, The Second University Hospital, The West China University of Medical Sciences, Chengdu, People's Republic of China
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32
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Abstract
Despite years of investigation, it is still not known why iron levels are abnormally high in some regions of the brain in neurodegenerative disorders. Also, it is not clear whether iron accumulation in the brain is an initial event that causes neuronal death or is a consequence of the disease process. Here, we propose that iron and iron-induced oxidative stress constitute a common mechanism that is involved in the development of neurodegeneration. Also, we suggest that, at least in some neurodegenerative disorders, brain iron misregulation is an initial cause of neuronal death and that this misregulation might be the result of either genetic or non-genetic factors.
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Affiliation(s)
- Z M Qian
- Laboratory of Brain Iron Metabolism, Dept of Applied Biology & Chemical Technology, The Hong Kong Polytechnic University, Hong Kong, Kowloon, People's Republic of China.
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33
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Knöpfel M, Schulthess G, Funk F, Hauser H. Characterization of an integral protein of the brush border membrane mediating the transport of divalent metal ions. Biophys J 2000; 79:874-84. [PMID: 10920019 PMCID: PMC1300985 DOI: 10.1016/s0006-3495(00)76343-0] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The transport of Fe(2+) and other divalent transition metal ions across the intestinal brush border membrane (BBM) was investigated using brush border membrane vesicles (BBMVs) as a model. This transport is an energy-independent, protein-mediated process. The divalent metal ion transporter of the BBM is a spanning protein, very likely a protein channel, that senses the phase transition of the BBM, as indicated by a break in the Arrhenius plot. The transporter has a broad substrate range that includes Mn(2+), Fe(2+), Co(2+), Ni(2+), Cu(2+), and Zn(2+). Under physiological conditions the transport of divalent metal ions is proton-coupled, leading to the acidification of the internal cavity of BBMVs. The divalent metal ion transporter can be solubilized in excess detergent (30 mM diheptanoylphosphatidylcholine or 1% Triton X-100) and reconstituted into an artificial membrane system by detergent removal. The reconstituted membrane system showed metal ion transport characteristics similar to those of the original BBMVs. The properties of the protein described here closely resemble those of the proton-coupled divalent cation transporter (DCT1, Nramp2) described by, Nature. 388:482-488). We may conclude that a protein of the Nramp family is present in the BBM, facilitating the transport of Fe(2+) and other divalent transition metal ions.
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Affiliation(s)
- M Knöpfel
- Institute of Biochemistry, Swiss Federal Institute of Technology, ETH Centre, CH-8092 Zurich, Switzerland
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Ming QZ, De Sheng X, Lai TP. Changes of transferrin-free iron uptake by bone marrow erythroblasts in strenuously exercised rats. J Nutr Biochem 2000; 11:367-73. [PMID: 11044631 DOI: 10.1016/s0955-2863(00)00092-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The effects of strenuous exercise on transferrin-free iron (Fe II) uptake by bone marrow erythroblasts in rats were investigated. Female Sprague-Dawley rats were randomly assigned to one of six groups, three of which underwent 3, 6, or 12 months of strenuous exercise (swimming 2 hr/day, 5 days/week) or their corresponding three control groups. At the end of experiments, bone marrow erythroblasts were isolated for Fe II uptake assay in vitro. It was found that the amounts of iron uptake into cytosole and stroma of the cells of rats in the groups undergoing 3 and 12 months of exercise did not differ from those in their corresponding sedentary groups. In addition, analysis of nonspecific and specific Fe II uptake by cytosole and stroma did not display any significant difference between the exercise and corresponding sedentary groups. However, the amount of Fe II uptake into cytosole and stroma was significantly increased in rats that exercised for 6 months compared with the corresponding controls. Nonspecific iron uptake into stroma was significantly higher in the exercise group than in the sedentary group (0.120 +/- 0.018 vs. 0.049 +/- 0.006 pM/10(6) cells, P < 0.01). The V(max) of the specific iron uptake into stroma was significantly higher (0.326 +/- 0.024 vs. 0.238 +/- 0.037 pM/10(6) cells, P < 0.05) and the K(m) of iron uptake into cytosol lower (0.08 +/- 0.01 vs. 0.21 +/- 0.03 microM, P < 0.001) in the exercise groups than in the control groups. These results indicate that 6 months of strenuous exercise could significantly increase Fe II uptake by the cells, probably by affecting the number and/or affinity of the putative iron carrier and the permeability to iron of cell membrane. The increased ability of cell-free iron accumulation in exercise might be a self-protective mechanism for body cells from the free iron-induced free radical reaction in addition to providing more iron for cell heme synthesis.
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Affiliation(s)
- Q Z Ming
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon, Hong Kong
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35
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Affiliation(s)
- H Sun
- Department of Chemistry, University of Edinburgh, King's Buildings, West Mains Road, Edinburgh EH9 3JJ, U.K., and Department of Chemistry, the University of Hong Kong, Pokfulam Road, Hong Kong SAR, China
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Smythies J. The neurotoxicity of glutamate, dopamine, iron and reactive oxygen species: functional interrelationships in health and disease: a review-discussion. Neurotox Res 1999; 1:27-39. [PMID: 12835112 DOI: 10.1007/bf03033337] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The fact that glutamate, dopamine, iron and reactive oxygen species are potentially individually highly neurotoxic molecules is well known. The purpose of this review is to examine the less well known complex ways in which their normal biological, as well as their neurotoxic activity, are interconnected in relation to fundamental neuronal functions. These functions include synaptic plasticity (formation and removal of synapses), endocytosis-based recycling of receptors for neurotransmitters and neuromodulators, the role of the redox balance between reactive oxygen species and antioxidants in synaptic function, and the possible role of iron-catecholamine complexes in antioxidant protection and intraneuronal iron transport. These systems are closely involved in several diseases of the nervous system including Parkinson's disease, schizophrenia and Alzheimer's disease. In all these oxidative stress and a failure of antioxidant defenses are involved. In the former two the neurotoxicity of catecholaminergic o-quinones is important. In the later excessive oxidation of neuronal membranes and excessive endocytosis and receptor recycling may be an important factor.
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Affiliation(s)
- J Smythies
- Center for Brain and Cognition, Department of Psychology, UCSD, La Jolla, CA 92093-0109, USA.
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Qian ZM, Xiao DS, Tang PL, Yao FY, Liao QK. Increased expression of transferrin receptor on membrane of erythroblasts in strenuously exercised rats. J Appl Physiol (1985) 1999; 87:523-9. [PMID: 10444608 DOI: 10.1152/jappl.1999.87.2.523] [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: 11/22/2022] Open
Abstract
This study investigated the effects of strenuous exercise on transferrin (Tf)-receptor (TfR) expression and Tf-bound iron (Tf-Fe) uptake in erythroblasts of rat bone marrow. Female Sprague-Dawley rats were randomly assigned to either an exercise or sedentary group. Animals in the exercise group swam 2 h/day for 3 mo in a glass swimming basin. Both groups received the same amount of handling. At the end of 3 mo, the bone marrow erythroblasts were freshly isolated for Tf-binding assay and determination of Tf-Fe uptake in vitro. Tissue nonheme iron and hematological iron indexes were measured. The number of Tf-binding sites found in erythroblasts was approximately 674,500 +/- 132,766 and 1,270,011 +/- 235,321 molecules/cell in control and exercised rats, respectively (P < 0. 05). Total Fe and Tf uptake by the cells was also significantly increased in the exercised rats after 30 min of incubation. Rates of cellular Fe accumulation were 5.68 and 2.58 fmol. 10(6) cells(-1). min(-1) in the exercised and control rats, respectively (P < 0.05). Tf recycling time and TfR affinity were not different in exercised and control rats. Increased cellular Fe was mainly located in the stromal fraction, suggesting that most of accumulated Fe was transported to the mitochondria for heme synthesis. The findings demonstrated that the increased cellular Fe uptake in exercised rats was a consequence of the increased TfR expression rather than the changes in TfR affinity and Tf recycling time. The increase in TfR expression and cellular Fe accumulation, as well as the decreased serum Fe concentration and nonheme Fe in the liver and the spleen induced by exercise, probably represented the early signs of Fe deficiency.
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Affiliation(s)
- Z M Qian
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon, Hong Kong.
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Qian ZM, Pu YM, Wang Q, Ke Y, Yao YD, Chen WF, Shen X, Feng YM, Tang PL. Cerebellar granule cells acquire transferrin-free iron by a carrier-mediated process. Neuroscience 1999; 92:577-82. [PMID: 10408606 DOI: 10.1016/s0306-4522(99)00008-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
In this study, the mechanism of transferrin-free iron uptake by brain neuronal cells was investigated using the cultured cerebellar granule cells. Effects of incubation time, iron concentration, temperature and other divalent metals on the cellular uptake were determined. After five days of plating, the cells were incubated with different concentrations of transferrin-free iron in isotonic sucrose solution at different temperatures for a certain time. The cellular transferrin-free iron uptake was analysed by measuring the cellular radioactivity with a gamma-counter. The result showed that the cultured cerebellar granule cells had the capacity to acquire transferrin-free iron at pH 6.5, at which it was demonstrated that transferrin binds iron very poorly and only very little transferrin can be internalized by reticulocytes and HeLa cells. The iron uptake by cells increased with incubation time in a linear manner at a rate of 0.1076 pmol/microg protein/min within the first 10 min. The uptake was time- and temperature-dependent, iron concentration saturable, and inhibited by several divalent metal ions, such as Co2+, Zn2+, Mn2+ and Ni2+. These characteristics of transferrin-free iron uptake by the cultured cerebellar granule cells observed in this study, similar to those obtained from cells outside of the brain, implied that a carrier-mediated iron transport system might be present on the membrane of this type of brain neuronal cells. In addition, no significant difference in malondialdehyde measurement was found when the cells were incubated without or with the lower concentrations of iron (< 4 microM) for 20 min at 37 degrees C, demonstrating that this system was valid for studying membrane iron transport in this type of brain neuronal cell.
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Affiliation(s)
- Z M Qian
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon
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39
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Qian ZM, Wang Q. Expression of iron transport proteins and excessive iron accumulation in the brain in neurodegenerative disorders. BRAIN RESEARCH. BRAIN RESEARCH REVIEWS 1998; 27:257-67. [PMID: 9729418 DOI: 10.1016/s0165-0173(98)00012-5] [Citation(s) in RCA: 176] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
New findings on the role of LfR (lactotransferrin receptor), MTf (melanotransferrin), CP (ceruloplasmin) and DCT1 (Divalent Cation Transporter) in brain iron transport, obtained during the past 3 years, are important advances in the fields of physiology and pathophysiology of brain iron metabolism. According to these findings, disruption in the expression of these proteins in the brain is probably one of the important causes of the altered brain iron metabolism in age-related neurodegenerative diseases, including Parkinson's Disease, Alzheimer's disease, Huntington's disease and amyotrophic lateral sclerosis. Further studies on the involvement of LfR, MTf and DCT1 in iron uptake by and CP in iron egress from different types of brain cells as well as control mechanisms of expression of these proteins in the brain are critical for elucidating the causes of excessive accumulation of iron in the brain and neuronal death in neurodegenerative diseases.
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Affiliation(s)
- Z M Qian
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong, China.
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40
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Qian ZM, Pu YM, Tang PL, Wang Q. Transferrin-bound iron uptake by the cultured cerebellar granule cells. Neurosci Lett 1998; 251:9-12. [PMID: 9714452 DOI: 10.1016/s0304-3940(98)00486-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Excessive brain iron has been found in several neurodegenerative diseases. However, little information is available about mechanism of iron uptake by different types of brain cells including neurons. In this study, transferrin-bound iron (Tf-Fe) accumulation in the cultured cerebellar granule cell was investigated in vitro. After 5 days of culture, the cells were incubated with 1 microM of double-labelled transferrin (1251-Tf-59Fe) at 37 degrees C for 60 min. The cellular Tf-Fe and transferrin (Tf) uptake was analysed. The result showed (1) Tf uptake by the cells increased rapidly at the first 5 min, reaching its maximum after about 20 min of incubation; (2) Tf-Fe uptake kept increasing in a linear manner during the whole period of incubation; (3) the addition of either NH4Cl or CH3NH2, the blockers of Tf-Fe uptake via inhibiting iron release from Tf within endosomes, decreased the cellular Tf-Fe uptake but had no significant effect on Tf uptake; (4) trypsin and unlabelled Tf-Fe inhibited the uptake rate of Tf-Fe as well as Tf. The results suggested that Tf-Fe transport across the membrane of this type of neuron, much like other mammalian cells, was mediated by Tf-TfR endocytosis. Dysfunction of Tf or TfR would possibly lead to iron irregulation in the brain and consequently cause damage to neuronal functions.
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Affiliation(s)
- Z M Qian
- Department of Applied Biology and Chemical Technology, The Hong Kong Polytechnic University, Kowloon.
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