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Zhang DL, Ollivierre H, Rouault TA. Using Biotinylated Iron-Responsive Element to Analyze the Activity of Iron Regulatory Proteins. Int J Mol Sci 2024; 25:4852. [PMID: 38732071 PMCID: PMC11084215 DOI: 10.3390/ijms25094852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2024] [Revised: 04/26/2024] [Accepted: 04/27/2024] [Indexed: 05/13/2024] Open
Abstract
Iron regulatory proteins (IRP1 and IRP2) are the master regulators of mammalian iron homeostasis. They bind to the iron-responsive elements (IREs) of the transcripts of iron-related genes to regulate their expression, thereby maintaining cellular iron availability. The primary method to measure the IRE-binding activity of IRPs is the electrophoresis mobility shift assay (EMSA). This method is particularly useful for evaluating IRP1 activity, since IRP1 is a bifunctional enzyme and its protein levels remain similar during conversion between the IRE-binding protein and cytosolic aconitase forms. Here, we exploited a method of using a biotinylated-IRE probe to separate IRE-binding IRPs followed by immunoblotting to analyze the IRE-binding activity. This method allows for the successful measurement of IRP activity in cultured cells and mouse tissues under various iron conditions. By separating IRE-binding IRPs from the rest of the lysates, this method increases the specificity of IRP antibodies and verifies whether a band represents an IRP, thereby revealing some previously unrecognized information about IRPs. With this method, we showed that the S711-phosphorylated IRP1 was found only in the IRE-binding form in PMA-treated Hep3B cells. Second, we found a truncated IRE-binding IRP2 isoform that is generated by proteolytic cleavage on sites in the 73aa insert region of the IRP2 protein. Third, we found that higher levels of SDS, compared to 1-2% SDS in regular loading buffer, could dramatically increase the band intensity of IRPs in immunoblots, especially in HL-60 cells. Fourth, we found that the addition of SDS or LDS to cell lysates activated protein degradation at 37 °C or room temperature, especially in HL-60 cell lysates. As this method is more practical, sensitive, and cost-effective, we believe that its application will enhance future research on iron regulation and metabolism.
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Affiliation(s)
| | | | - Tracey A. Rouault
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA; (D.-L.Z.); (H.O.)
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2
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Niu L, Zhou Y, Wang J, Zeng W. Nuclear translocation of STAT5 initiates iron overload in huntington's disease by up-regulating IRP1 expression. Metab Brain Dis 2024; 39:559-567. [PMID: 38261161 DOI: 10.1007/s11011-024-01340-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 12/30/2023] [Indexed: 01/24/2024]
Abstract
Mutant huntingtin (mHtt) proteins interact to form aggregates, disrupting cellular functions including transcriptional dysregulation and iron imbalance in patients with Huntington's disease (HD) and mouse disease models. Previous studies have indicated that mHtt may lead to abnormal iron homeostasis by upregulating the expression of iron response protein 1 (IRP1) in the striatum and cortex of N171-82Q HD transgenic mice, as well as in HEK293 cells expressing the N-terminal fragment of mHtt containing 160 CAG repeats. However, the mechanism underlying the upregulation of IRP1 remains unclear. We investigated the levels and phosphorylation status of signal transducer and activator of transcription 5 (STAT5) in the brains of N171-82Q HD transgenic mice using immunohistochemistry staining. We also assessed the nuclear localization of STAT5 protein through western blot and immunofluorescence, and measured the relative RNA expression levels of STAT5 and IRP1 using RT-PCR in both N171-82Q HD transgenic mice and HEK293 cells expressing the N-terminal fragment of huntingtin. Our findings demonstrate that the transcription factor STAT5 regulates the transcription of the IPR1 gene in HEK293 cells. Notably, both the brains of N171-82Q mice and 160Q HEK293 cells exhibited increased nuclear content of STAT5, despite unchanged total STAT5 expression. These results suggest that mHtt promotes the nuclear translocation of STAT5, leading to enhanced expression of IRP1. The nuclear translocation of STAT5 initiates abnormal iron homeostatic pathways, characterized by elevated IRP1 expression, increased levels of transferrin and transferrin receptor, and iron accumulation in the brains of HD mice. These findings provide valuable insights into potential therapeutic strategies targeting iron homeostasis in HD.
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Affiliation(s)
- Li Niu
- Department of Pathology, Zhongnan Hospital of Wuhan University, 430071, Wuhan, China
| | - Yongze Zhou
- Department of Pathology, Zhongnan Hospital of Wuhan University, 430071, Wuhan, China
| | - Jie Wang
- Department of Pathology, Zhongnan Hospital of Wuhan University, 430071, Wuhan, China
| | - Wei Zeng
- Department of Radiation and Medical Oncology, Zhongnan Hospital of Wuhan University, 169 Donghu Road, Wuchang District, 430071, Wuhan, China.
- Hubei Cancer Clinical Study Centre & Hubei Key Laboratory of Tumor Biological Behaviors, Zhongnan Hospital of Wuhan University, 430071, Wuhan, China.
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3
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Yang J, Du C, Li Y, Liu R, Jing C, Xie J, Wang J. Contrasting Iron Metabolism in Undifferentiated Versus Differentiated MO3.13 Oligodendrocytes via IL-1β-Induced Iron Regulatory Protein 1. Neurochem Res 2024; 49:466-476. [PMID: 37917337 DOI: 10.1007/s11064-023-04047-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Revised: 09/28/2023] [Accepted: 10/14/2023] [Indexed: 11/04/2023]
Abstract
Parkinson's disease (PD) is a prevalent neurodegenerative disorder characterized by the loss of dopaminergic neurons and the accumulation of iron in the substantia nigra. While iron accumulation and inflammation are implicated in PD pathogenesis, their impact on oligodendrocytes, the brain's myelin-forming cells, remains elusive. This study investigated the influence of interleukin-1β (IL-1β), an elevated proinflammatory cytokine in PD, on iron-related proteins in MO3.13 oligodendrocytes. We found that IL-1β treatment in undifferentiated MO3.13 oligodendrocytes increased iron regulatory protein 1 and transferrin receptor 1 (TfR1) expression while decreasing ferroportin 1 (FPN1) expression. Consequently, iron uptake was enhanced, and iron release was reduced, leading to intracellular iron accumulation. Conversely, IL-1β treatment in differentiated MO3.13 oligodendrocytes exhibited the opposite effect, with decreased TfR1 expression, increased FPN1 expression, and reduced iron uptake. These findings suggest that IL-1β-induced dysregulation of iron metabolism in oligodendrocytes may contribute to the pathological processes observed in PD. IL-1β can increase the iron content in undifferentiated oligodendrocytes, thus facilitating the differentiation of undifferentiated MO3.13 oligodendrocytes. In differentiated oligodendrocytes, IL-1β may facilitate iron release, providing a potential source of iron for neighboring dopaminergic neurons, thereby initiating a cascade of deleterious events. This study provides valuable insights into the intricate interplay between inflammation, abnormal iron accumulation, and oligodendrocyte dysfunction in PD. Targeting the IL-1β-mediated alterations in iron metabolism may hold therapeutic potential for mitigating neurodegeneration and preserving dopaminergic function in PD.
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Affiliation(s)
- Jiahua Yang
- School of Basic Medicine, Qingdao University, Qingdao, 266071, China
| | - Chenchen Du
- School of Basic Medicine, Qingdao University, Qingdao, 266071, China
- Institute of Senior Care and Art, Guangdong Vocational College of Hotel Management, Dongguan, China
| | - Yinghui Li
- School of Basic Medicine, Qingdao University, Qingdao, 266071, China
| | - Rong Liu
- School of Basic Medicine, Qingdao University, Qingdao, 266071, China
| | - Cuiting Jing
- School of Basic Medicine, Qingdao University, Qingdao, 266071, China
| | - Junxia Xie
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, 266071, China
| | - Jun Wang
- School of Basic Medicine, Qingdao University, Qingdao, 266071, China.
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao, 266071, China.
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4
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Ghatpande N, Harrer A, Azoulay-Botzer B, Guttmann-Raviv N, Bhushan S, Meinhardt A, Meyron-Holtz EG. Iron regulatory proteins 1 and 2 have opposing roles in regulating inflammation in bacterial orchitis. JCI Insight 2024; 9:e175845. [PMID: 38301068 DOI: 10.1172/jci.insight.175845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 01/30/2024] [Indexed: 02/03/2024] Open
Abstract
Acute bacterial orchitis (AO) is a prevalent cause of intrascrotal inflammation, often resulting in sub- or infertility. A frequent cause eliciting AO is uropathogenic Escherichia coli (UPEC), a gram negative pathovar, characterized by the expression of various iron acquisition systems to survive in a low-iron environment. On the host side, iron is tightly regulated by iron regulatory proteins 1 and 2 (IRP1 and -2) and these factors are reported to play a role in testicular and immune cell function; however, their precise role remains unclear. Here, we showed in a mouse model of UPEC-induced orchitis that the absence of IRP1 results in less testicular damage and a reduced immune response. Compared with infected wild-type (WT) mice, testes of UPEC-infected Irp1-/- mice showed impaired ERK signaling. Conversely, IRP2 deletion led to a stronger inflammatory response. Notably, differences in immune cell infiltrations were observed among the different genotypes. In contrast with WT and Irp2-/- mice, no increase in monocytes and neutrophils was detected in testes of Irp1-/- mice upon UPEC infection. Interestingly, in Irp1-/- UPEC-infected testes, we observed an increase in a subpopulation of macrophages (F4/80+CD206+) associated with antiinflammatory and wound-healing activities compared with WT. These findings suggest that IRP1 deletion may protect against UPEC-induced inflammation by modulating ERK signaling and dampening the immune response.
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Affiliation(s)
- Niraj Ghatpande
- Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Technion City, Haifa, Israel
| | - Aileen Harrer
- Institute of Anatomy and Cell Biology, Unit of Reproductive Biology, Justus-Liebig-University of Giessen, Giessen, Germany
| | - Bar Azoulay-Botzer
- Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Technion City, Haifa, Israel
| | - Noga Guttmann-Raviv
- Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Technion City, Haifa, Israel
| | - Sudhanshu Bhushan
- Institute of Anatomy and Cell Biology, Unit of Reproductive Biology, Justus-Liebig-University of Giessen, Giessen, Germany
| | - Andreas Meinhardt
- Institute of Anatomy and Cell Biology, Unit of Reproductive Biology, Justus-Liebig-University of Giessen, Giessen, Germany
| | - Esther G Meyron-Holtz
- Faculty of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Technion City, Haifa, Israel
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Zhu J, Wang Y, Rivett A, Yang G. H 2S regulation of iron homeostasis by IRP1 improves vascular smooth muscle cell functions. Cell Signal 2023; 110:110826. [PMID: 37487913 DOI: 10.1016/j.cellsig.2023.110826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2023] [Revised: 07/17/2023] [Accepted: 07/21/2023] [Indexed: 07/26/2023]
Abstract
Either H2S or iron is essential for cellular processes. Abnormal metabolism of H2S and iron has increased risk for cardiovascular diseases. The aim of the present study is to examine the mutual interplay of iron and H2S signals in regulation of vascular smooth muscle cell (SMC) functions. Here we found that deficiency of cystathionine gamma-lyase (CSE, a major H2S-producing enzyme in vascular system) induced but NaHS (a H2S donor) administration attenuated iron accumulation in aortic tissues from angiotensin II-infused mice. In vitro, iron overload induced labile iron levels, promoted cell proliferation, disrupted F-actin filaments, and inhibited protein expressions of SMC-specific markers (αSMA and calponin) more significantly in SMCs from CSE knockout mice (KO-SMCs) than the cells from wild-type mice (WT-SMCs), which could be reversed by exogenously applied NaHS. In contrast, KO-SMCs were more vulnerable to iron starvation-induced cell death. Either iron overload or NaHS did not affect elastin level and gelatinolytic activity. We further found that H2S induced more aconitase activity of iron regulatory protein 1 (IRP1) but inhibited its RNA binding activity accompanied with increased protein levels of ferritin and ferriportin, which would contribute to the lower level of labile iron level inside the cells. In addition, iron was able to suppress CSE-derived H2S generation, while iron also non-enzymatically induced H2S release from cysteine. This study reveals the mutual interaction between iron and H2S signals in regulating SMC phenotypes and functions; CSE/H2S system would be a target for preventing iron metabolic disorder-related vascular diseases.
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Affiliation(s)
- Jiechun Zhu
- School of Natural Sciences, Laurentian University, Sudbury, Canada; Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, Canada
| | - Yuehong Wang
- School of Natural Sciences, Laurentian University, Sudbury, Canada; Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, Canada
| | - Alexis Rivett
- School of Natural Sciences, Laurentian University, Sudbury, Canada; Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, Canada
| | - Guangdong Yang
- School of Natural Sciences, Laurentian University, Sudbury, Canada; Cardiovascular and Metabolic Research Unit, Laurentian University, Sudbury, Canada.
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Chang S, Wang P, Han Y, Ma Q, Liu Z, Zhong S, Lu Y, Chen R, Sun L, Wu Q, Gao G, Wang X, Chang YZ. Ferrodifferentiation regulates neurodevelopment via ROS generation. Sci China Life Sci 2023; 66:1841-1857. [PMID: 36929272 DOI: 10.1007/s11427-022-2297-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 02/16/2023] [Indexed: 03/18/2023]
Abstract
Iron is important for life, and iron deficiency impairs development, but whether the iron level regulates neural differentiation remains elusive. In this study, with iron-regulatory proteins (IRPs) knockout embryonic stem cells (ESCs) that showed severe iron deficiency, we found that the Pax6- and Sox2-positive neuronal precursor cells and Tuj1 fibers in IRP1-/-IRP2-/- ESCs were significantly decreased after inducing neural differentiation. Consistently, in vivo study showed that the knockdown of IRP1 in IRP2-/- fetal mice remarkably affected the differentiation of neuronal precursors and the migration of neurons. These findings suggest that low intracellular iron status significantly inhibits neurodifferentiation. When supplementing IRP1-/-IRP2-/- ESCs with iron, these ESCs could differentiate normally. Further investigations revealed that the underlying mechanism was associated with an increase in reactive oxygen species (ROS) production caused by the substantially low level of iron and the down-regulation of iron-sulfur cluster protein ISCU, which, in turn, affected the proliferation and differentiation of stem cells. Thus, the appropriate amount of iron is crucial for maintaining normal neural differentiation that is termed ferrodifferentiation.
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Affiliation(s)
- Shiyang Chang
- Laboratory of Molecular Iron Metabolism, Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Animal Physiology, Biochemistry, and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China
- College of Basic Medicine, Hebei Medical University, Shijiazhuang, 050017, China
- State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology (Shanghai), Institute of Biophysics, Chinese Academy of Sciences (CAS), BNU IDG/McGovern Institute for Brain Research, Beijing, 100101, China
| | - Peina Wang
- Laboratory of Molecular Iron Metabolism, Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Animal Physiology, Biochemistry, and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China
- College of Basic Medicine, Hebei Medical University, Shijiazhuang, 050017, China
| | - Yingying Han
- Laboratory of Molecular Iron Metabolism, Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Animal Physiology, Biochemistry, and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China
| | - Qiang Ma
- State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology (Shanghai), Institute of Biophysics, Chinese Academy of Sciences (CAS), BNU IDG/McGovern Institute for Brain Research, Beijing, 100101, China
| | - Zeyuan Liu
- State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology (Shanghai), Institute of Biophysics, Chinese Academy of Sciences (CAS), BNU IDG/McGovern Institute for Brain Research, Beijing, 100101, China
| | - Suijuan Zhong
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, 100875, China
| | - Yufeng Lu
- State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology (Shanghai), Institute of Biophysics, Chinese Academy of Sciences (CAS), BNU IDG/McGovern Institute for Brain Research, Beijing, 100101, China
| | - Ruiguo Chen
- State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology (Shanghai), Institute of Biophysics, Chinese Academy of Sciences (CAS), BNU IDG/McGovern Institute for Brain Research, Beijing, 100101, China
| | - Le Sun
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain Disorders, Capital Medical University, Beijing, 100069, China
| | - Qian Wu
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, 100875, China
| | - Guofen Gao
- Laboratory of Molecular Iron Metabolism, Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Animal Physiology, Biochemistry, and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China.
| | - Xiaoqun Wang
- State Key Laboratory of Brain and Cognitive Science, CAS Center for Excellence in Brain Science and Intelligence Technology (Shanghai), Institute of Biophysics, Chinese Academy of Sciences (CAS), BNU IDG/McGovern Institute for Brain Research, Beijing, 100101, China.
| | - Yan-Zhong Chang
- Laboratory of Molecular Iron Metabolism, Ministry of Education Key Laboratory of Molecular and Cellular Biology, Hebei Key Laboratory of Animal Physiology, Biochemistry, and Molecular Biology, College of Life Sciences, Hebei Normal University, Shijiazhuang, 050024, China.
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7
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Bonadonna M, Altamura S, Tybl E, Palais G, Qatato M, Polycarpou-Schwarz M, Schneider M, Kalk C, Rüdiger W, Ertl A, Anstee N, Bogeska R, Helm D, Milsom MD, Galy B. Iron regulatory protein (IRP)-mediated iron homeostasis is critical for neutrophil development and differentiation in the bone marrow. Sci Adv 2022; 8:eabq4469. [PMID: 36197975 PMCID: PMC9534496 DOI: 10.1126/sciadv.abq4469] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 08/18/2022] [Indexed: 06/01/2023]
Abstract
Iron is mostly devoted to the hemoglobinization of erythrocytes for oxygen transport. However, emerging evidence points to a broader role for the metal in hematopoiesis, including the formation of the immune system. Iron availability in mammalian cells is controlled by iron-regulatory protein 1 (IRP1) and IRP2. We report that global disruption of both IRP1 and IRP2 in adult mice impairs neutrophil development and differentiation in the bone marrow, yielding immature neutrophils with abnormally high glycolytic and autophagic activity, resulting in neutropenia. IRPs promote neutrophil differentiation in a cell intrinsic manner by securing cellular iron supply together with transcriptional control of neutropoiesis to facilitate differentiation to fully mature neutrophils. Unlike neutrophils, monocyte count was not affected by IRP and iron deficiency, suggesting a lineage-specific effect of iron on myeloid output. This study unveils the previously unrecognized importance of IRPs and iron metabolism in the formation of a major branch of the innate immune system.
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Affiliation(s)
- Michael Bonadonna
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- Biosciences Faculty, University of Heidelberg, 69120 Heidelberg, Germany
| | - Sandro Altamura
- University of Heidelberg, Department of Pediatric Hematology, Oncology and Immunology, Im Neuenheimer Feld 350, 69120 Heidelberg, Germany
| | - Elisabeth Tybl
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- IB-Cancer Research Foundation, Science Park 2, 66123 Saarbrücken, Germany
| | - Gael Palais
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Maria Qatato
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Maria Polycarpou-Schwarz
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Martin Schneider
- German Cancer Research Center, Mass Spectrometry based Protein Analysis Unit, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Christina Kalk
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Wibke Rüdiger
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Alina Ertl
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Natasha Anstee
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- German Cancer Research Center, “Division of Experimental Hematology”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Ruzhica Bogeska
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- German Cancer Research Center, “Division of Experimental Hematology”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Dominic Helm
- German Cancer Research Center, Mass Spectrometry based Protein Analysis Unit, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Michael D. Milsom
- Heidelberg Institute for Stem Cell Technology and Experimental Medicine, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
- German Cancer Research Center, “Division of Experimental Hematology”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
| | - Bruno Galy
- German Cancer Research Center, “Division of Virus-Associated Carcinogenesis”, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany
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Wang J, Jiang M, Yue G, Zhu L, Wang X, Liang M, Wu X, Li B, Pang Y, Tan G, Li J. ISCA2 deficiency leads to heme synthesis defects and impaired erythroid differentiation in K562 cells by indirect ROS-mediated IRP1 activation. Biochim Biophys Acta Mol Cell Res 2022; 1869:119307. [PMID: 35714932 DOI: 10.1016/j.bbamcr.2022.119307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Revised: 05/30/2022] [Accepted: 06/08/2022] [Indexed: 06/15/2023]
Abstract
Iron‑sulfur (Fe-S) clusters have been shown to play important roles in various cellular physiological process. Iron‑sulfur cluster assembly 2 (ISCA2) is a vital component of the [4Fe-4S] cluster assembly machine. Several studies have shown that ISCA2 is highly expressed during erythroid differentiation. However, the role and specific regulatory mechanisms of ISCA2 in erythroid differentiation and erythroid cell growth remain unclear. RNA interference was used to deplete ISCA2 expression in human erythroid leukemia K562 cells. The proliferation, apoptosis, and erythroid differentiation ability of the cells were assessed. We show that knockdown of ISCA2 has profound effects on [4Fe-4S] cluster formation, diminishing mitochondrial respiratory chain complexes, leading to reactive oxygen species (ROS) accumulation and mitochondrial damage, inhibiting cell proliferation. Excessive ROS can inhibit the activity of cytoplasmic aconitase (ACO1) and promote ACO1, a bifunctional protein, to perform its iron-regulating protein 1(IRP1) function, thus inhibiting the expression of 5'-aminolevulinate synthase 2 (ALAS2), which is a key enzyme in heme synthesis. Deficiency of ISCA2 results in the accumulation of iron divalent. In addition, the combination of excessive ferrous iron and ROS may lead to damage of the ACO1 cluster and higher IRP1 function. In brief, ISCA2 deficiency inhibits heme synthesis and erythroid differentiation by double indirect downregulation of ALAS2 expression. We conclude that ISCA2 is essential for normal functioning of mitochondria, and is necessary for erythroid differentiation and cell proliferation.
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Affiliation(s)
- Jing Wang
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Mengyao Jiang
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Guanru Yue
- School of Basic Medical Sciences, Nanchang University, Nanchang, China
| | - Lifei Zhu
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Xueqing Wang
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Mengxiang Liang
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Xiaolin Wu
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Beibei Li
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Yilin Pang
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China
| | - Guoqiang Tan
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.
| | - Jianghui Li
- Key Laboratory of Laboratory Medicine, Ministry of Education, Zhejiang Provincial Key Laboratory of Medical Genetics, College of Laboratory Medicine and Life Sciences, Wenzhou Medical University, Wenzhou, China.
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9
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Gu W, Fillebeen C, Pantopoulos K. Human IRP1 Translocates to the Nucleus in a Cell-Specific and Iron-Dependent Manner. Int J Mol Sci 2022; 23:ijms231810740. [PMID: 36142654 PMCID: PMC9502121 DOI: 10.3390/ijms231810740] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/08/2022] [Accepted: 09/11/2022] [Indexed: 11/16/2022] Open
Abstract
Iron regulatory protein 1 (IRP1) is a bifunctional protein with mutually exclusive RNA-binding or enzymatic activities that depend on the presence of a 4Fe-4S cluster. While IRP1 is a well-established cytosolic protein, work in a Drosophila model suggested that it may also exhibit nuclear localization. Herein, we addressed whether mammalian IRP1 can likewise translocate to the nucleus. We utilized primary cells and tissues from wild type and Irp1−/− mice, as well as human cell lines and tissue biopsy sections. IRP1 subcellular localization was analyzed by Western blotting, immunofluorescence and immunohistochemistry. We did not detect presence of nuclear IRP1 in wild type mouse embryonic fibroblasts (MEFs), primary hepatocytes or whole mouse liver. However, we observed IRP1-positive nuclei in human liver but not ovary sections. Biochemical fractionation studies revealed presence of IRP1 in the nucleus of human Huh7 and HepG2 hepatoma cells, but not HeLa cervical cancer cells. Importantly, nuclear IRP1 was only evident in iron-replete cells and disappeared following pharmacological iron chelation. These data provide the first experimental evidence for nuclear IRP1 expression in mammals, which appears to be species- and cell-specific. Furthermore, they suggest that the nuclear translocation of IRP1 is mediated by an iron-dependent mechanism.
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Affiliation(s)
- Wen Gu
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC H3T 1E2, Canada
| | - Carine Fillebeen
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC H3T 1E2, Canada
| | - Kostas Pantopoulos
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC H3T 1E2, Canada
- Department of Medicine, McGill University, Montreal, QC H4A 3J1, Canada
- Correspondence: ; Tel.: +1-514-340-8260 (ext. 25293)
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10
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Xu M, Li Y, Meng D, Zhang D, Wang B, Xie J, Wang J. 6-Hydroxydopamine Induces Abnormal Iron Sequestration in BV2 Microglia by Activating Iron Regulatory Protein 1 and Inhibiting Hepcidin Release. Biomolecules 2022; 12:biom12020266. [PMID: 35204767 PMCID: PMC8961664 DOI: 10.3390/biom12020266] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/22/2021] [Accepted: 01/11/2022] [Indexed: 02/04/2023] Open
Abstract
Disrupted iron homeostasis in the substantia nigra pars compacta (SNpc) is an important pathological mechanism in Parkinson’s disease (PD). It is unclear what role microglia play in iron metabolism and selective iron deposition in the SNpc of PD brain. In this study, we observed that 6-hydroxydopamine (6-OHDA) induced the expression of divalent metal transporter-1 (DMT1) and iron influx in BV2 microglia cells, which might be associated with the upregulation of iron regulatory protein 1 (IRP1) expression. Moreover, we found that 6-OHDA had no significant effect on the expression of ferroportin 1 (FPN1) and iron efflux in BV2 microglial cells, which might be the combined action of IRP1 upregulation and reduced hepcidin levels. Furthermore, 6-OHDA treatment activated BV2 microglia and enhanced the release of pro-inflammatory cytokines. Interestingly, iron overloading suppressed IRP1 expression, thus downregulating DMT1 and upregulating FPN1 levels in these microglial cells. On the contrary, iron deficiency activated IRP1, leading to increased expression of DMT1 and decreased expression of FPN1—which indicates that activated IRP1 induces iron overloading in 6-OHDA-treated microglia, but not iron overloading modulates the expression of IRP1. Taken together, our data suggest that 6-OHDA can regulate the expression of DMT1 and FPN1 by activating IRP1 and inhibiting hepcidin release, thus leading to abnormal iron sequestration in microglia. In addition, 6-OHDA can activate microglia, which leads to increased release of pro-inflammatory factors that can further induce genome damage in dopaminergic neurons.
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Affiliation(s)
- Manman Xu
- School of Basic Medicine, Qingdao University, Qingdao 266071, China; (M.X.); (Y.L.); (D.M.); (D.Z.); (B.W.)
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao 266071, China
- Medical Service Section, The Affiliated Hospital of Qingdao University, Qingdao 266071, China
| | - Yinghui Li
- School of Basic Medicine, Qingdao University, Qingdao 266071, China; (M.X.); (Y.L.); (D.M.); (D.Z.); (B.W.)
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao 266071, China
| | - Dapeng Meng
- School of Basic Medicine, Qingdao University, Qingdao 266071, China; (M.X.); (Y.L.); (D.M.); (D.Z.); (B.W.)
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao 266071, China
| | - Danyang Zhang
- School of Basic Medicine, Qingdao University, Qingdao 266071, China; (M.X.); (Y.L.); (D.M.); (D.Z.); (B.W.)
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao 266071, China
| | - Bingjing Wang
- School of Basic Medicine, Qingdao University, Qingdao 266071, China; (M.X.); (Y.L.); (D.M.); (D.Z.); (B.W.)
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao 266071, China
| | - Junxia Xie
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao 266071, China
- Correspondence: author: (J.X.); (J.W.)
| | - Jun Wang
- School of Basic Medicine, Qingdao University, Qingdao 266071, China; (M.X.); (Y.L.); (D.M.); (D.Z.); (B.W.)
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Qingdao University, Qingdao 266071, China
- Correspondence: author: (J.X.); (J.W.)
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11
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Votava JA, Reese SR, Deck KM, Nizzi CP, Anderson SA, Djamali A, Eisenstein RS. Dysregulation of the sensory and regulatory pathways controlling cellular iron metabolism in unilateral obstructive nephropathy. Am J Physiol Renal Physiol 2022; 322:F89-F103. [PMID: 34843656 PMCID: PMC8742730 DOI: 10.1152/ajprenal.00537.2020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 11/16/2021] [Accepted: 11/23/2021] [Indexed: 01/03/2023] Open
Abstract
Chronic kidney disease involves disturbances in iron metabolism including anemia caused by insufficient erythropoietin (EPO) production. However, underlying mechanisms responsible for the dysregulation of cellular iron metabolism are incompletely defined. Using the unilateral ureteral obstruction (UUO) model in Irp1+/+ and Irp1-/- mice, we asked if iron regulatory proteins (IRPs), the central regulators of cellular iron metabolism and suppressors of EPO production, contribute to the etiology of anemia in kidney failure. We identified a significant reduction in IRP protein level and RNA binding activity that associates with a loss of the iron uptake protein transferrin receptor 1 (TfR1), increased expression of the iron storage protein subunits H- and L-ferritin, and a low but overall variable level of stainable iron in the obstructed kidney. This reduction in IRP RNA binding activity and ferritin RNA levels suggests the concomitant rise in ferritin expression and iron content in kidney failure is IRP dependent. In contrast, the reduction in the Epo mRNA level in the obstructed kidney was not rescued by genetic ablation of IRP1, suggesting disruption of normal hypoxia-inducible factor (HIF)-2α regulation. Furthermore, reduced expression of some HIF-α target genes in UUO occurred in the face of increased expression of HIF-α proteins and prolyl hydroxylases 2 and 1, the latter of which is not known to be HIF-α mediated. Our results suggest that the IRP system drives changes in cellular iron metabolism that are associated with kidney failure in UUO but that the impact of IRPs on EPO production is overridden by disrupted hypoxia signaling.NEW & NOTEWORTHY This study demonstrates that iron metabolism and hypoxia signaling are dysregulated in unilateral obstructive nephropathy. Expression of iron regulatory proteins (IRPs), central regulators of cellular iron metabolism, and the iron uptake (transferrin receptor 1) and storage (ferritins) proteins they target is strongly altered. This suggests a role of IRPs in previously observed changes in iron metabolism in progressive renal disease. Hypoxia signaling is disrupted and appeared to dominate the action of IRP1 in controlling erythropoietin expression.
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Affiliation(s)
- James A Votava
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - Shannon R Reese
- Division of Nephrology, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin
| | - Kathryn M Deck
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - Christopher P Nizzi
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - Sheila A Anderson
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
| | - Arjang Djamali
- Division of Nephrology, Department of Medicine, University of Wisconsin-Madison, Madison, Wisconsin
- Division of Transplant, Department of Surgery, University of Wisconsin-Madison, Madison, Wisconsin
| | - Richard S Eisenstein
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, Wisconsin
- Morgridge Institute for Research, University of Wisconsin-Madison, Madison, Wisconsin
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12
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Hider R, Aviles MV, Chen YL, Latunde-Dada GO. The Role of GSH in Intracellular Iron Trafficking. Int J Mol Sci 2021; 22:ijms22031278. [PMID: 33525417 PMCID: PMC7865746 DOI: 10.3390/ijms22031278] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/14/2021] [Accepted: 01/18/2021] [Indexed: 12/15/2022] Open
Abstract
Evidence is reviewed for the role of glutathione in providing a ligand for the cytosolic iron pool. The possibility of histidine and carnosine forming ternary complexes with iron(II)glutathione is discussed and the physiological significance of these interactions considered. The role of carnosine in muscle, brain, and kidney physiology is far from established and evidence is presented that the iron(II)-binding capability of carnosine relates to this role.
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13
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Yook JS, You M, Kim Y, Zhou M, Liu Z, Kim YC, Lee J, Chung S. The thermogenic characteristics of adipocytes are dependent on the regulation of iron homeostasis. J Biol Chem 2021; 296:100452. [PMID: 33631196 PMCID: PMC8010711 DOI: 10.1016/j.jbc.2021.100452] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/09/2021] [Accepted: 02/18/2021] [Indexed: 12/15/2022] Open
Abstract
The development of thermogenic adipocytes concurs with mitochondrial biogenesis, an iron-dependent pathway. Iron regulatory proteins (IRP) 1 and 2 are RNA-binding proteins that regulate intracellular iron homeostasis. IRPs bind to the iron-response element (IRE) of their target mRNAs, balancing iron uptake and deposition at the posttranscriptional levels. However, IRP/IRE-dependent iron regulation in adipocytes is largely unknown. We hypothesized that iron demands are higher in brown/beige adipocytes than white adipocytes to maintain the thermogenic mitochondrial capacity. To test this hypothesis, we investigated the IRP/IRE regulatory system in different depots of adipose tissue. Our results revealed that 1) IRP/IRE interaction was increased in proportional to the thermogenic function of the adipose depot, 2) adipose iron content was increased in adipose tissue browning upon β3-adrenoceptor stimulation, while decreased in thermoneutral conditions, and 3) modulation of iron content was linked with mitochondrial biogenesis. Moreover, the iron requirement was higher in HIB1B brown adipocytes than 3T3-L1 white adipocytes during differentiation. The reduction of the labile iron pool (LIP) suppressed the differentiation of brown/beige adipocytes and mitochondrial biogenesis. Using the 59Fe-Tf, we also demonstrated that thermogenic stimuli triggered cell-autonomous iron uptake and mitochondrial compartmentalization as well as enhanced mitochondrial respiration. Collectively, our work demonstrated that IRP/IRE signaling and subsequent adaptation in iron metabolism are a critical determinant for the thermogenic function of adipocytes.
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Affiliation(s)
- Jin-Seon Yook
- Department of Nutrition and Health Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Mikyoung You
- Department of Nutrition and Health Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Yongeun Kim
- Department of Nutrition and Health Sciences, University of Nebraska, Lincoln, Nebraska, USA
| | - Mi Zhou
- Department of Nutrition and Health Sciences, University of Nebraska, Lincoln, Nebraska, USA
| | - Zhenhua Liu
- Department of Nutrition and Health Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Young-Cheul Kim
- Department of Nutrition and Health Sciences, University of Massachusetts, Amherst, Massachusetts, USA
| | - Jaekwon Lee
- Department of Biochemistry, University of Nebraska, Lincoln, Nebraska, USA
| | - Soonkyu Chung
- Department of Nutrition and Health Sciences, University of Massachusetts, Amherst, Massachusetts, USA; Department of Nutrition and Health Sciences, University of Nebraska, Lincoln, Nebraska, USA.
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14
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Fillebeen C, Lam NH, Chow S, Botta A, Sweeney G, Pantopoulos K. Regulatory Connections between Iron and Glucose Metabolism. Int J Mol Sci 2020; 21:ijms21207773. [PMID: 33096618 PMCID: PMC7589414 DOI: 10.3390/ijms21207773] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/07/2020] [Accepted: 10/16/2020] [Indexed: 02/06/2023] Open
Abstract
Iron is essential for energy metabolism, and states of iron deficiency or excess are detrimental for organisms and cells. Therefore, iron and carbohydrate metabolism are tightly regulated. Serum iron and glucose levels are subjected to hormonal regulation by hepcidin and insulin, respectively. Hepcidin is a liver-derived peptide hormone that inactivates the iron exporter ferroportin in target cells, thereby limiting iron efflux to the bloodstream. Insulin is a protein hormone secreted from pancreatic β-cells that stimulates glucose uptake and metabolism via insulin receptor signaling. There is increasing evidence that systemic, but also cellular iron and glucose metabolic pathways are interconnected. This review article presents relevant data derived primarily from mouse models and biochemical studies. In addition, it discusses iron and glucose metabolism in the context of human disease.
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Affiliation(s)
- Carine Fillebeen
- Lady Davis Institute for Medical Research, Jewish General Hospital and Department of Medicine, McGill University, Montreal, QC H3Y 1P3, Canada;
| | - Nhat Hung Lam
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada; (N.H.L.); (S.C.); (A.B.); (G.S.)
| | - Samantha Chow
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada; (N.H.L.); (S.C.); (A.B.); (G.S.)
| | - Amy Botta
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada; (N.H.L.); (S.C.); (A.B.); (G.S.)
| | - Gary Sweeney
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada; (N.H.L.); (S.C.); (A.B.); (G.S.)
| | - Kostas Pantopoulos
- Lady Davis Institute for Medical Research, Jewish General Hospital and Department of Medicine, McGill University, Montreal, QC H3Y 1P3, Canada;
- Correspondence: ; Tel.: +1-514-340-8260 (ext. 25293)
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15
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Oskarsson GR, Oddsson A, Magnusson MK, Kristjansson RP, Halldorsson GH, Ferkingstad E, Zink F, Helgadottir A, Ivarsdottir EV, Arnadottir GA, Jensson BO, Katrinardottir H, Sveinbjornsson G, Kristinsdottir AM, Lee AL, Saemundsdottir J, Stefansdottir L, Sigurdsson JK, Davidsson OB, Benonisdottir S, Jonasdottir A, Jonasdottir A, Jonsson S, Gudmundsson RL, Asselbergs FW, Tragante V, Gunnarsson B, Masson G, Thorleifsson G, Rafnar T, Holm H, Olafsson I, Onundarson PT, Gudbjartsson DF, Norddahl GL, Thorsteinsdottir U, Sulem P, Stefansson K. Predicted loss and gain of function mutations in ACO1 are associated with erythropoiesis. Commun Biol 2020; 3:189. [PMID: 32327693 PMCID: PMC7181819 DOI: 10.1038/s42003-020-0921-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 03/24/2020] [Indexed: 12/28/2022] Open
Abstract
Hemoglobin is the essential oxygen-carrying molecule in humans and is regulated by cellular iron and oxygen sensing mechanisms. To search for novel variants associated with hemoglobin concentration, we performed genome-wide association studies of hemoglobin concentration using a combined set of 684,122 individuals from Iceland and the UK. Notably, we found seven novel variants, six rare coding and one common, at the ACO1 locus associating with either decreased or increased hemoglobin concentration. Of these variants, the missense Cys506Ser and the stop-gained Lys334Ter mutations are specific to eight and ten generation pedigrees, respectively, and have the two largest effects in the study (EffectCys506Ser = -1.61 SD, CI95 = [-1.98, -1.35]; EffectLys334Ter = 0.63 SD, CI95 = [0.36, 0.91]). We also find Cys506Ser to associate with increased risk of persistent anemia (OR = 17.1, P = 2 × 10-14). The strong bidirectional effects seen in this study implicate ACO1, a known iron sensing molecule, as a major homeostatic regulator of hemoglobin concentration.
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Affiliation(s)
- Gudjon R Oskarsson
- deCODE genetics/Amgen Inc., Reykjavik, Iceland
- Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland
| | | | - Magnus K Magnusson
- deCODE genetics/Amgen Inc., Reykjavik, Iceland
- Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland
| | | | | | | | | | | | | | | | | | | | | | | | - Amy L Lee
- deCODE genetics/Amgen Inc., Reykjavik, Iceland
| | | | | | | | | | | | | | | | | | | | - Folkert W Asselbergs
- Department of Cardiology, Division Heart & Lungs, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
- Institute of Cardiovascular Science, Faculty of Population Health Sciences, University College London, London, UK
- Health Data Research UK and Institute of Health Informatics, University College London, London, UK
| | - Vinicius Tragante
- deCODE genetics/Amgen Inc., Reykjavik, Iceland
- Department of Cardiology, Division Heart & Lungs, University Medical Center Utrecht, Utrecht University, Utrecht, The Netherlands
| | | | | | | | | | - Hilma Holm
- deCODE genetics/Amgen Inc., Reykjavik, Iceland
| | - Isleifur Olafsson
- Department of Clinical Biochemistry, Landspitali, the National University Hospital of Iceland, Reykjavik, Iceland
| | - Pall T Onundarson
- Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland
- Department of Laboratory Hematology, Landspitali, the National University Hospital of Iceland, Reykjavik, Iceland
| | - Daniel F Gudbjartsson
- deCODE genetics/Amgen Inc., Reykjavik, Iceland
- School of Engineering and Natural Sciences, University of Iceland, Reykjavik, Iceland
| | | | - Unnur Thorsteinsdottir
- deCODE genetics/Amgen Inc., Reykjavik, Iceland
- Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland
| | | | - Kari Stefansson
- deCODE genetics/Amgen Inc., Reykjavik, Iceland.
- Faculty of Medicine, School of Health Sciences, University of Iceland, Reykjavik, Iceland.
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16
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Zhao H, Lewellen BM, Wilson RJ, Cui D, Drake JC, Zhang M, Yan Z. Long-term voluntary running prevents the onset of symptomatic Friedreich's ataxia in mice. Sci Rep 2020; 10:6095. [PMID: 32269244 PMCID: PMC7142077 DOI: 10.1038/s41598-020-62952-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 03/09/2020] [Indexed: 12/29/2022] Open
Abstract
The common clinical symptoms of Friedreich's ataxia (FRDA) include ataxia, muscle weakness, type 2 diabetes and heart failure, which are caused by impaired mitochondrial function due to the loss of frataxin (FXN) expression. Endurance exercise is the most powerful intervention for promoting mitochondrial function; however, its impact on FRDA has not been studied. Here we found that mice with genetic knockout and knock-in of the Fxn gene (KIKO mice) developed exercise intolerance, glucose intolerance and moderate cardiac dysfunction at 6 months of age. These abnormalities were associated with impaired mitochondrial respiratory function concurrent with reduced iron regulatory protein 1 (Irp1) expression as well as increased oxidative stress, which were not due to loss of mitochondrial content and antioxidant enzyme expression. Importantly, long-term (4 months) voluntary running in KIKO mice starting at a young age (2 months) completely prevented the functional abnormalities along with restored Irp1 expression, improved mitochondrial function and reduced oxidative stress in skeletal muscle without restoring Fxn expression. We conclude that endurance exercise training prevents symptomatic onset of FRDA in mice associated with improved mitochondrial function and reduced oxidative stress. These preclinical findings may pave the way for clinical studies of the impact of endurance exercise in FRDA patients.
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Affiliation(s)
- Henan Zhao
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, 22908, USA
- Dalian Medical University, Dalian, Liaoning, 116044, China
| | - Bevan M Lewellen
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, 22908, USA
| | - Rebecca J Wilson
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, 22908, USA
| | - Di Cui
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, 22908, USA
| | - Joshua C Drake
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, 22908, USA
| | - Mei Zhang
- Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia, 22908, USA
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, 22908, USA
| | - Zhen Yan
- Department of Medicine, University of Virginia School of Medicine, Charlottesville, Virginia, 22908, USA.
- Department of Pharmacology, University of Virginia School of Medicine, Charlottesville, Virginia, 22908, USA.
- Department of Molecular Physiology and Biological Physics, University of Virginia School of Medicine, Charlottesville, Virginia, 22908, USA.
- Center for Skeletal Muscle Research at Robert M. Berne Cardiovascular Research Center, University of Virginia School of Medicine, Charlottesville, Virginia, 22908, USA.
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17
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Jung SJ, Choi Y, Lee D, Roe JH. Nuclear aconitase antagonizes heterochromatic silencing by interfering with Chp1 binding to DNA. Biochem Biophys Res Commun 2019; 516:806-811. [PMID: 31255284 DOI: 10.1016/j.bbrc.2019.06.090] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 06/15/2019] [Indexed: 11/17/2022]
Abstract
In Schizosaccharomyces pombe, there are two aconitases, Aco1 and Aco2, involved in the Krebs cycle in mitochondria. Interestingly, Aco2 is localized to nucleus as well. Here, we investigated the nuclear role of Aco2 by deleting its nuclear localization signal. The aco2ΔNLS mutation suppressed the gene-silencing defects of RNAi mutants at the centromere, where heterochromatin formation depends on RNAi pathway. In Δago1, the aco2ΔNLS mutation restored heterochromatin through elevating Chp1 binding. Aco2 physically interacted with Chp1 via the N-terminal chromodomain that binds to methylated histone H3K9. In the sub-telomeric region, where heterochromatin forms independent of RNAi pathway, the single aco2ΔNLS mutation caused extra gene silencing via elevating Chp1 binding, without increasing histone methylation. The anti-silencing effect did not require the catalytic function of aconitase. Taken together, Aco2 functions as an epigenetic regulator of gene expression, through associating with chromodomain of Chp1 to maintain heterochromatin.
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Affiliation(s)
- Soo-Jin Jung
- School of Biological Sciences, Institute of Microbiology, Seoul National University, Seoul, 151-742, South Korea
| | - Yoonjung Choi
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea
| | - Daeyoup Lee
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, 34141, Republic of Korea.
| | - Jung-Hye Roe
- School of Biological Sciences, Institute of Microbiology, Seoul National University, Seoul, 151-742, South Korea.
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18
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Abstract
Heart disease is a common manifestation in conditions of iron imbalance. Normal heart function requires coupling of iron supply for oxidative phosphorylation and redox signalling with tight control of intracellular iron to below levels at which excessive ROS are generated. Iron supply to the heart is dependent on systemic iron availability which is controlled by the systemic hepcidin/ferroportin axis. Intracellular iron in cardiomyocytes is controlled in part by the iron regulatory proteins IRP1/2. This mini-review summarises current understanding of how cardiac cells regulate intracellular iron levels, and of the mechanisms linking cardiac dysfunction with iron imbalance. It also highlights a newly-recognised mechanism of intracellular iron homeostasis in cardiomyocytes, based on a cell-autonomous cardiac hepcidin/ferroportin axis. This new understanding raises pertinent questions on the interplay between systemic and local iron control in the context of heart disease, and the effects on heart function of therapies targeting the systemic hepcidin/ferroportin axis.
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Affiliation(s)
- Samira Lakhal-Littleton
- Department of Physiology, Anatomy and Genetics, University of Oxford, Parks Road, Oxford OX1 3PT, United Kingdom.
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19
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Iwai K. Regulation of cellular iron metabolism: Iron-dependent degradation of IRP by SCF FBXL5 ubiquitin ligase. Free Radic Biol Med 2019; 133:64-68. [PMID: 30218771 DOI: 10.1016/j.freeradbiomed.2018.09.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 09/10/2018] [Accepted: 09/12/2018] [Indexed: 12/30/2022]
Abstract
Because of essentiality and toxicity of iron in our body, iron metabolism is tightly regulated in cells. In mammalian cells, iron regulatory protein 1 and 2 (IRP1 and IRP2) are the central regulators of cellular iron metabolism. IRPs regulate iron metabolism by interacting with the RNA stem-loop structures, iron-responsive elements (IREs), found on the transcripts encoding proteins involved in iron metabolism only in iron depleted condition. It is also well-known that the ubiquitin system plays central roles in cellular iron regulation because both IRPs having the IRE binding activity are recognized and ubiquitinated by the SCFFBXL5 ubiquitin ligase in condition of iron-replete. FBXL5, which is a substrate recognition subunit of SCFFBXL5, senses iron availability via its hemerythrin-like domain. In this small article, current understanding of the roles of SCFFBXL5-mediated degradation of IRPs played in cellular iron metabolism is discussed.
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Affiliation(s)
- Kazuhiro Iwai
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, Kyoto University, Yoshida-konoe-cho, Sakyo-ku, Kyoto 606-8501, Japan.
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20
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Li Q, Ding Y, Krafft P, Wan W, Yan F, Wu G, Zhang Y, Zhan Q, Zhang JH. Targeting Germinal Matrix Hemorrhage-Induced Overexpression of Sodium-Coupled Bicarbonate Exchanger Reduces Posthemorrhagic Hydrocephalus Formation in Neonatal Rats. J Am Heart Assoc 2018; 7:e007192. [PMID: 29386206 PMCID: PMC5850237 DOI: 10.1161/jaha.117.007192] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 11/21/2017] [Indexed: 02/01/2023]
Abstract
BACKGROUND Germinal matrix hemorrhage (GMH) is a leading cause of mortality and lifelong morbidity in preterm infants. Posthemorrhagic hydrocephalus (PHH) is a common complication of GMH. A sodium-coupled bicarbonate exchanger (NCBE) encoded by solute carrier family 4 member 10 gene is expressed on the choroid plexus basolateral membrane and may play a role in cerebrospinal fluid production and the development of PHH. Following GMH, iron degraded from hemoglobin has been linked to PHH. Choroid plexus epithelial cells also contain iron-responsive element-binding proteins (IRPs), IRP1, and IRP2 that bind to mRNA iron-responsive elements. The present study aims to resolve the following issues: (1) whether the expression of NCBE is regulated by IRPs; (2) whether NCBE regulates the formation of GMH-induced hydrocephalus; and (3) whether inhibition of NCBE reduces PHH development. METHODS AND RESULTS GMH model was established in P7 rat pups by injecting bacterial collagenase into the right ganglionic eminence. Another group received iron trichloride injections instead of collagenase. Deferoxamine was administered intraperitoneally for 3 consecutive days after GMH/iron trichloride. Solute carrier family 4 member 10 small interfering RNA or scrambled small interfering RNA was administered by intracerebroventricular injection 24 hours before GMH and followed with an injection every 7 days over 21 days. NCBE expression increased while IRP2 expression decreased after GMH/iron trichloride. Deferoxamine ameliorated both the GMH-induced and iron trichloride-induced decrease of IRP2 and decreased NCBE expressions. Deferoxamine and solute carrier family 4 member 10 small interfering RNA improved cognitive and motor functions at 21 to 28 days post GMH and reduced cerebrospinal fluid production as well as the degree of hydrocephalus at 28 days after GMH. CONCLUSIONS Targeting iron-induced overexpression of NCBE may be a translatable therapeutic strategy for the treatment of PHH following GMH.
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Affiliation(s)
- Qian Li
- Department of Neurology, The Fifth People's Hospital of Chongqing, Chongqing, China
| | - Yan Ding
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA
| | - Paul Krafft
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA
| | - Weifeng Wan
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA
| | - Feng Yan
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA
| | - Guangyong Wu
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA
| | - Yixin Zhang
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA
| | - Qunling Zhan
- Department of Neurology, The Fifth People's Hospital of Chongqing, Chongqing, China
| | - John H Zhang
- Department of Physiology and Pharmacology, Loma Linda University School of Medicine, Loma Linda, CA
- Department of Anesthesiology, Loma Linda University School of Medicine, Loma Linda, CA
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21
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Abstract
Iron regulatory proteins 1 and 2 (IRP1 and IRP2) are two cytosolic proteins that maintain cellular iron homeostasis by regulating the expression of genes involved in iron metabolism. IRPs respond to cellular iron deficiency by binding to iron-responsive elements (IREs) found in the mRNAs of iron metabolism transcripts, enhancing iron import, and reducing iron storage, utilization, and export. IRP1, a bifunctional protein, exists in equilibrium between a [Fe4S4] cluster containing cytosolic aconitase, and an apoprotein that binds to IREs. At high cellular iron levels, this equilibrium is shifted more toward iron-sulfur cluster containing aconitase, whereas IRP2 undergoes proteasomal degradation by an E3 ubiquitin ligase complex that contains an F-box protein, FBXL5. Irp1-/- mice develop polycythemia and pulmonary hypertension, whereas Irp2-/- mice develop microcytic anemia and progressive neurodegeneration, indicating that Irp1 has important functions in the erythropoietic and pulmonary systems, and Irp2 has essential roles in supporting erythropoiesis and nervous system functions. Mice lacking both Irp1 and Irp2 die during embryogenesis, suggesting that functions of Irp1 and Irp2 are redundant. In this review, we will focus on the methods for studying IRP1 activities and function in cells and animals.
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Affiliation(s)
- Gregory P Holmes-Hampton
- Molecular Medicine Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, United States
| | - Manik C Ghosh
- Molecular Medicine Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, United States
| | - Tracey A Rouault
- Molecular Medicine Branch, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, MD, United States.
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22
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Abstract
Iron is an essential trace element, but it is also toxic in excess, and thus mammals have developed elegant mechanisms for keeping both cellular and whole-body iron concentrations within the optimal physiologic range. In the diet, iron is either sequestered within heme or in various nonheme forms. Although the absorption of heme iron is poorly understood, nonheme iron is transported across the apical membrane of the intestinal enterocyte by divalent metal-ion transporter 1 (DMT1) and is exported into the circulation via ferroportin 1 (FPN1). Newly absorbed iron binds to plasma transferrin and is distributed around the body to sites of utilization with the erythroid marrow having particularly high iron requirements. Iron-loaded transferrin binds to transferrin receptor 1 on the surface of most body cells, and after endocytosis of the complex, iron enters the cytoplasm via DMT1 in the endosomal membrane. This iron can be used for metabolic functions, stored within cytosolic ferritin, or exported from the cell via FPN1. Cellular iron concentrations are modulated by the iron regulatory proteins (IRPs) IRP1 and IRP2. At the whole-body level, dietary iron absorption and iron export from the tissues into the plasma are regulated by the liver-derived peptide hepcidin. When tissue iron demands are high, hepcidin concentrations are low and vice versa. Too little or too much iron can have important clinical consequences. Most iron deficiency reflects an inadequate supply of iron in the diet, whereas iron excess is usually associated with hereditary disorders. These disorders include various forms of hemochromatosis, which are characterized by inadequate hepcidin production and, thus, increased dietary iron intake, and iron-loading anemias whereby both increased iron absorption and transfusion therapy contribute to the iron overload. Despite major recent advances, much remains to be learned about iron physiology and pathophysiology.
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Affiliation(s)
- Gregory J Anderson
- Iron Metabolism Laboratory, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia; and Schools of
- Chemistry and Molecular Bioscience and
- Medicine, University of Queensland, St. Lucia, Queensland, Australia
| | - David M Frazer
- Iron Metabolism Laboratory, QIMR Berghofer Medical Research Institute, Herston, Queensland, Australia; and Schools of
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23
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Aron AT, Heffern MC, Lonergan ZR, Vander Wal MN, Blank BR, Spangler B, Zhang Y, Park HM, Stahl A, Renslo AR, Skaar EP, Chang CJ. In vivo bioluminescence imaging of labile iron accumulation in a murine model of Acinetobacter baumannii infection. Proc Natl Acad Sci U S A 2017; 114:12669-12674. [PMID: 29138321 PMCID: PMC5715752 DOI: 10.1073/pnas.1708747114] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Iron is an essential metal for all organisms, yet disruption of its homeostasis, particularly in labile forms that can contribute to oxidative stress, is connected to diseases ranging from infection to cancer to neurodegeneration. Iron deficiency is also among the most common nutritional deficiencies worldwide. To advance studies of iron in healthy and disease states, we now report the synthesis and characterization of iron-caged luciferin-1 (ICL-1), a bioluminescent probe that enables longitudinal monitoring of labile iron pools (LIPs) in living animals. ICL-1 utilizes a bioinspired endoperoxide trigger to release d-aminoluciferin for selective reactivity-based detection of Fe2+ with metal and oxidation state specificity. The probe can detect physiological changes in labile Fe2+ levels in live cells and mice experiencing iron deficiency or overload. Application of ICL-1 in a model of systemic bacterial infection reveals increased iron accumulation in infected tissues that accompany transcriptional changes consistent with elevations in both iron acquisition and retention. The ability to assess iron status in living animals provides a powerful technology for studying the contributions of iron metabolism to physiology and pathology.
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Affiliation(s)
- Allegra T Aron
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Marie C Heffern
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Zachery R Lonergan
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Mark N Vander Wal
- Department of Chemistry, University of California, Berkeley, CA 94720
| | - Brian R Blank
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158
| | - Benjamin Spangler
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158
| | - Yaofang Zhang
- Mass Spectrometry Research Center, Vanderbilt University, Nashville, TN 37232
- Department of Biochemistry, Vanderbilt University, Nashville, TN 37232
| | - Hyo Min Park
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720
| | - Andreas Stahl
- Department of Nutritional Sciences and Toxicology, University of California, Berkeley, CA 94720
| | - Adam R Renslo
- Department of Pharmaceutical Chemistry, University of California, San Francisco, CA 94158
| | - Eric P Skaar
- Department of Pathology, Microbiology, and Immunology, Vanderbilt University Medical Center, Nashville, TN 37232;
| | - Christopher J Chang
- Department of Chemistry, University of California, Berkeley, CA 94720;
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- Howard Hughes Medical Institute, University of California, Berkeley, CA 94720
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Zhou S, Du X, Xie J, Wang J. Interleukin-6 regulates iron-related proteins through c-Jun N-terminal kinase activation in BV2 microglial cell lines. PLoS One 2017; 12:e0180464. [PMID: 28672025 PMCID: PMC5495437 DOI: 10.1371/journal.pone.0180464] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 06/15/2017] [Indexed: 01/01/2023] Open
Abstract
Parkinson's disease (PD) is a common neurodegenerative disorder characterized by the loss of dopaminergic (DA) neurons in the substantia nigra (SN) and subsequent DA depletion in the striatum. Microglia activation and nigral iron accumulation play important roles in the pathogenesis of PD. Activated microglia show increased iron deposits. However, the relationship between microglia activation and iron accumulation remains unclear. In the present study, we aimed to determine how iron levels affect interleukin-6 (IL-6) synthesis, and the effect of IL-6 on cellular iron metabolism in BV2 microglial cells.IL-6 mRNA was up-regulated after FAC treatment for 12 h in BV2 cells. Iron regulatory protein 1 (IRP1) and divalent metal transporter 1 (DMT1) were up-regulated and iron exporter ferroportin 1 (FPN1) was down-regulated in BV2 cells after 24 h of IL-6 treatment. Phosphorylated JNK increased significantly compared to the control after BV2 cells were treated with IL-6 for 1 h. Pretreatment with SP600125 attenuated the up-regulation of IRP1 and DMT1 and down-regulation of FPN1 (compared to IL-6-treated group). These results suggest that iron load could increase IL-6 mRNA expression in BV2 cells. Further, IL-6 likely up-regulates IRP1 and DMT1 expression and down-regulates FPN1 expression in BV2 microglial cells through JNK signaling pathways.
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Affiliation(s)
- Shida Zhou
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, Medical College of Qingdao University, Qingdao, China
| | - Xinxing Du
- Class 7, Grade 2014, Medical College of Qingdao University, Qingdao, China
| | - Junxia Xie
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, Medical College of Qingdao University, Qingdao, China
| | - Jun Wang
- Department of Physiology, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders and State Key Disciplines: Physiology, Medical College of Qingdao University, Qingdao, China
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Milczarek A, Starzyński RR, Styś A, Jończy A, Staroń R, Grzelak A, Lipiński P. A drastic superoxide-dependent oxidative stress is prerequisite for the down-regulation of IRP1: Insights from studies on SOD1-deficient mice and macrophages treated with paraquat. PLoS One 2017; 12:e0176800. [PMID: 28542246 PMCID: PMC5438123 DOI: 10.1371/journal.pone.0176800] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 04/17/2017] [Indexed: 12/21/2022] Open
Abstract
Iron regulatory protein 1 (IRP1) is a cytosolic bifunctional [4Fe-4S] protein which exhibits aconitase activity or binds iron responsive elements (IREs) in untranslated regions of specific mRNA encoding proteins involved in cellular iron metabolism. Superoxide radical (O2.-) converts IRP1 from a [4Fe-4S] aconitase to a [3Fe-4S] „null” form possessing neither aconitase nor trans-regulatory activity. Genetic ablation of superoxide dismutase 1 (SOD1), an antioxidant enzyme that acts to reduce O2.- concentration, revealed a new O2.--dependent regulation of IRP1 leading to the reduction of IRP1 protein level and in consequence to the diminution of IRP1 enzymatic and IRE-binding activities. Here, we attempted to establish whether developmental changes in SOD1 activity occurring in the mouse liver, impact IRP1 expression. We show no correlation between hepatic SOD1 activity and IRP1 protein level neither in pre- nor postnatal period probably because the magnitude of developmental fluctuations in SOD1 activity is relatively small. The comparison of SOD1 activity in regards to IRP1 protein level in the liver of threeSOD1 genotypes (Sod1+/+, Sod1+/- and Sod1-/-) demonstrates that only drastic SOD1 deficiency leads to the reduction of IRP1 protein level. Importantly, we found that in the liver of fetuses lacking SOD1, IRP1 is not down-regulated. To investigate O2.--dependent regulation of IRP1 in a cellular model, we exposed murine RAW 264.7 and bone marrow-derived macrophages to paraquat, widely used as a redox cycler to stimulate O2.-production in cells. We showed that IRP1 protein level as well as aconitase and IRE-binding activities are strongly reduced in macrophages treated with paraquat. The analysis of the expression of IRP1-target genes revealed the increase in L-ferritin protein level resulting from the enhanced transcriptional regulation of the LFt gene and diminished translational repression of L-ferritin mRNA by IRP1. We propose that O2.--dependent up-regulation of this cellular protectant in paraquat-treated macrophages may counterbalance iron-related toxic effects of O2.-.
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Affiliation(s)
- Anna Milczarek
- Department of Molecular Biology, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Jastrzębiec, Poland
| | - Rafał R. Starzyński
- Department of Molecular Biology, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Jastrzębiec, Poland
| | - Agnieszka Styś
- Department of Molecular Biology, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Jastrzębiec, Poland
| | - Aneta Jończy
- Department of Molecular Biology, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Jastrzębiec, Poland
| | - Robert Staroń
- Department of Molecular Biology, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Jastrzębiec, Poland
| | - Agnieszka Grzelak
- Department of Molecular Biophysics, University of Łódź, Łódź, Poland
| | - Paweł Lipiński
- Department of Molecular Biology, Institute of Genetics and Animal Breeding, Polish Academy of Sciences, Jastrzębiec, Poland
- * E-mail:
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26
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Villafuerte BC, Barati MT, Rane MJ, Isaacs S, Li M, Wilkey DW, Merchant ML. Over-expression of insulin-response element binding protein-1 (IRE-BP1) in mouse pancreatic islets increases expression of RACK1 and TCTP: Beta cell markers of high glucose sensitivity. Biochim Biophys Acta Proteins Proteom 2016; 1865:186-194. [PMID: 27816562 DOI: 10.1016/j.bbapap.2016.10.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 10/16/2016] [Accepted: 10/31/2016] [Indexed: 12/29/2022]
Abstract
BACKGROUND A targeted analysis of the 50kDa C-terminal fragment of insulin-response element binding protein-1 (IRE-BP1) activation of target genes through the insulin receptor substrate receptor/PI-3 kinase/Akt pathway has been demonstrated for the insulin growth factor-1 receptor. The broader effects of 50kDa C-terminal IRE-BP1 fragment over-expression on protein abundance in pancreatic islet beta cells have not been determined. RESULTS Liquid-chromatography coupled to tandem mass spectrometry (LC-MS/MS) analyses of replicate lysates of pancreatic islets isolated from background strain animals and transgenic animals, overexpressing IRE-BP1 in pancreatic islet beta cells, demonstrated statistically significant increases in the expression of proteins involved in protein synthesis, endoplasmic reticulum (ER) stress and scaffolding proteins important for protein kinase C signaling; some of which were confirmed by immunoblot analyses. Bioinformatic analysis of protein expression network patterns suggested IRE-BP1 over-expression leads to protein expression patterns indicative of activation of functional protein networks utilized for protein post-translational modification, protein folding, and protein synthesis. Co-immunoprecipitation experiments demonstrate a novel interaction between two differentially regulated proteins receptor for activated protein kinase C (RACK1) and translationally controlled tumor protein (TCTP). CONCLUSIONS Proteomic analysis of IRE-BP1 over-expression in pancreatic islet beta cells suggest IRE-BP1 (a) directly or indirectly through establishing hyperglycemia results in increased expression of ribosomal proteins and markers of ER stress and (b) leads to the enhanced and previously un-described interaction of RACK1 and TCTP. SIGNIFICANCE This study identified C-terminal 50kDa domain of IRE-BP1 over-expression results in increased markers of ER-stress and a novel interaction between the scaffolding proteins RACK1 and TCTP.
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Affiliation(s)
- Betty C Villafuerte
- Department of Medicine, University of Louisville, Louisville, KY, United States
| | - Michelle T Barati
- Department of Medicine, University of Louisville, Louisville, KY, United States
| | - Madhavi J Rane
- Department of Medicine, University of Louisville, Louisville, KY, United States
| | - Susan Isaacs
- Department of Medicine, University of Louisville, Louisville, KY, United States; Core Proteomics Laboratory, University of Louisville, Louisville, KY, United States
| | - Ming Li
- Department of Medicine, University of Louisville, Louisville, KY, United States; Core Proteomics Laboratory, University of Louisville, Louisville, KY, United States
| | - Daniel W Wilkey
- Department of Medicine, University of Louisville, Louisville, KY, United States; Core Proteomics Laboratory, University of Louisville, Louisville, KY, United States
| | - Michael L Merchant
- Department of Medicine, University of Louisville, Louisville, KY, United States; Core Proteomics Laboratory, University of Louisville, Louisville, KY, United States.
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Okazaki F, Matsunaga N, Okazaki H, Azuma H, Hamamura K, Tsuruta A, Tsurudome Y, Ogino T, Hara Y, Suzuki T, Hyodo K, Ishihara H, Kikuchi H, To H, Aramaki H, Koyanagi S, Ohdo S. Circadian Clock in a Mouse Colon Tumor Regulates Intracellular Iron Levels to Promote Tumor Progression. J Biol Chem 2016; 291:7017-28. [PMID: 26797126 PMCID: PMC4807285 DOI: 10.1074/jbc.m115.713412] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2015] [Revised: 01/21/2016] [Indexed: 11/06/2022] Open
Abstract
Iron is an important biological catalyst and is critical for DNA synthesis during cell proliferation. Cellular iron uptake is enhanced in tumor cells to support increased DNA synthesis. Circadian variations in DNA synthesis and proliferation have been identified in tumor cells, but their relationship with intracellular iron levels is unclear. In this study, we identified a 24-h rhythm in iron regulatory protein 2 (IRP2) levels in colon-26 tumors implanted in mice. Our findings suggest that IRP2 regulates the 24-h rhythm of transferrin receptor 1 (Tfr1) mRNA expression post-transcriptionally, by binding to RNA stem-loop structures known as iron-response elements. We also found thatIrp2mRNA transcription is promoted by circadian clock genes, including brain and muscle Arnt-like 1 (BMAL1) and the circadian locomotor output cycles kaput (CLOCK) heterodimer. Moreover, growth in colon-26(Δ19) tumors expressing the clock-mutant protein (CLOCK(Δ19)) was low compared with that in wild-type colon-26 tumor. The time-dependent variation of cellular iron levels, and the proliferation rate in wild-type colon-26 tumor was decreased by CLOCK(Δ19)expression. Our findings suggest that circadian organization contributes to tumor cell proliferation by regulating iron metabolism in the tumor.
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Affiliation(s)
- Fumiyasu Okazaki
- From the Department of Medical Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, Toyama 930-0194, the Department of Pharmaceutics and
| | | | | | | | | | | | | | | | | | - Takuya Suzuki
- the Formulation Research, Pharmaceutical Science & Technology Core Function Unit and
| | - Kenji Hyodo
- the Formulation Research, Pharmaceutical Science & Technology Core Function Unit and
| | - Hiroshi Ishihara
- the Formulation Research, Pharmaceutical Science & Technology Core Function Unit and
| | - Hiroshi Kikuchi
- Chief Innovation Officer Group, Eisai Product Creation Systems, Eisai Co., Ltd., Ibaraki 300-2635, Japan
| | - Hideto To
- From the Department of Medical Pharmaceutics, Graduate School of Medicine and Pharmaceutical Sciences for Research, University of Toyama, Toyama 930-0194
| | - Hironori Aramaki
- the Department of Molecular Biology and Drug Innovation Research Center, Daiichi University of Pharmacy, Fukuoka 815-8511, and
| | - Satoru Koyanagi
- the Department of Global Healthcare Science, Faculty of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582
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28
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Abstract
Iron is required for the survival of most organisms, including bacteria, plants, and humans. Its homeostasis in mammals must be fine-tuned to avoid iron deficiency with a reduced oxygen transport and diminished activity of Fe-dependent enzymes, and also iron excess that may catalyze the formation of highly reactive hydroxyl radicals, oxidative stress, and programmed cell death. The advance in understanding the main players and mechanisms involved in iron regulation significantly improved since the discovery of genes responsible for hemochromatosis, the IRE/IRPs machinery, and the hepcidin-ferroportin axis. This review provides an update on the molecular mechanisms regulating cellular and systemic Fe homeostasis and their roles in pathophysiologic conditions that involve alterations of iron metabolism, and provides novel therapeutic strategies to prevent the deleterious effect of its deficiency/overload.
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Affiliation(s)
- Raffaella Gozzelino
- Inflammation and Neurodegeneration Laboratory, Chronic Diseases Research Center (CEDOC), Nova Medical School (NMS)/Faculdade de Ciências Médicas, University of Lisbon, Lisbon 1150-082, Portugal.
| | - Paolo Arosio
- Department of Molecular and Translational Medicine (DMMT), University of Brescia, Brescia 25123, Italy.
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29
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Megías Z, Martínez C, Manzano S, García A, Rebolloso-Fuentes MDM, Garrido D, Valenzuela JL, Jamilena M. Individual Shrink Wrapping of Zucchini Fruit Improves Postharvest Chilling Tolerance Associated with a Reduction in Ethylene Production and Oxidative Stress Metabolites. PLoS One 2015; 10:e0133058. [PMID: 26177024 PMCID: PMC4503597 DOI: 10.1371/journal.pone.0133058] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 06/23/2015] [Indexed: 11/18/2022] Open
Abstract
We have studied the effect of individual shrink wrapping (ISW) on the postharvest performance of refrigerated fruit from two zucchini cultivars that differ in their sensitivity to cold storage: Sinatra (more sensitive) and Natura (more tolerant). The fruit was individually shrink wrapped before storing at 4°C for 0, 7 and 14 days. Quality parameters, ethylene and CO2 productions, ethylene gene expression, and oxidative stress metabolites were assessed in shrink wrapped and non-wrapped fruit after conditioning the fruit for 6 hours at 20°C. ISW decreased significantly the postharvest deterioration of chilled zucchini in both cultivars. Weight loss was reduced to less than 1%, pitting symptoms were completely absent in ISW fruit at 7 days, and were less than 25% those of control fruits at 14 days of cold storage, and firmness loss was significantly reduced in the cultivar Sinatra. These enhancements in quality of ISW fruit were associated with a significant reduction in cold-induced ethylene production, in the respiration rate, and in the level of oxidative stress metabolites such as hydrogen peroxide and malonyldialdehyde (MDA). A detailed expression analysis of ethylene biosynthesis, perception and signaling genes demonstrated a downregulation of CpACS1 and CpACO1 genes in response to ISW, two genes that are upregulated by cold storage. However, the expression patterns of six other ethylene biosynthesis genes (CpACS2 to CpACS7) and five ethylene signal transduction pathway genes (CpCTR1, CpETR1, CpERS1, CpEIN3.1 and CpEN3.2), suggest that they do not play a major role in response to cold storage and ISW packaging. In conclusion, ISW zucchini packaging resulted in improved tolerance to chilling concomitantly with a reduction in oxidative stress, respiration rate and ethylene production, as well as in the expression of ethylene biosynthesis genes, but not of those involved in ethylene perception and sensitivity.
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Affiliation(s)
- Zoraida Megías
- Departamento de Biología y Geología, Agrifood, Campus of International Excellence (ceiA3), Universidad de Almería, La Cañada de San Urbano s/n, 04120 Almería, Spain
| | - Cecilia Martínez
- Departamento de Biología y Geología, Agrifood, Campus of International Excellence (ceiA3), Universidad de Almería, La Cañada de San Urbano s/n, 04120 Almería, Spain
| | - Susana Manzano
- Departamento de Biología y Geología, Agrifood, Campus of International Excellence (ceiA3), Universidad de Almería, La Cañada de San Urbano s/n, 04120 Almería, Spain
| | - Alicia García
- Departamento de Biología y Geología, Agrifood, Campus of International Excellence (ceiA3), Universidad de Almería, La Cañada de San Urbano s/n, 04120 Almería, Spain
| | - María del Mar Rebolloso-Fuentes
- Departamento de Agronomía, Agrifood, Campus of International Excellence (ceiA3), Universidad de Almería, La Cañada de San Urbano s/n, 04120 Almería, Spain
| | - Dolores Garrido
- Departamento de Fisiología Vegetal, Facultad de Ciencias, Universidad de Granada, Fuentenueva s/n, 18071 Granada, Spain
| | - Juan Luis Valenzuela
- Departamento de Biología y Geología, Agrifood, Campus of International Excellence (ceiA3), Universidad de Almería, La Cañada de San Urbano s/n, 04120 Almería, Spain
| | - Manuel Jamilena
- Departamento de Biología y Geología, Agrifood, Campus of International Excellence (ceiA3), Universidad de Almería, La Cañada de San Urbano s/n, 04120 Almería, Spain
- * E-mail:
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Martelli A, Schmucker S, Reutenauer L, Mathieu JRR, Peyssonnaux C, Karim Z, Puy H, Galy B, Hentze MW, Puccio H. Iron regulatory protein 1 sustains mitochondrial iron loading and function in frataxin deficiency. Cell Metab 2015; 21:311-323. [PMID: 25651183 DOI: 10.1016/j.cmet.2015.01.010] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Revised: 12/22/2014] [Accepted: 01/16/2015] [Indexed: 12/22/2022]
Abstract
Mitochondrial iron accumulation is a hallmark of diseases associated with impaired iron-sulfur cluster (Fe-S) biogenesis, such as Friedreich ataxia linked to frataxin (FXN) deficiency. The pathophysiological relevance of the mitochondrial iron loading and the underlying mechanisms are unknown. Using a mouse model of hepatic FXN deficiency in combination with mice deficient for iron regulatory protein 1 (IRP1), a key regulator of cellular iron metabolism, we show that IRP1 activation in conditions of Fe-S deficiency increases the available cytosolic labile iron pool. Surprisingly, our data indicate that IRP1 activation sustains mitochondrial iron supply and function rather than driving detrimental iron overload. Mitochondrial iron accumulation is shown to depend on mitochondrial dysfunction and heme-dependent upregulation of the mitochondrial iron importer mitoferrin-2. Our results uncover an unexpected protective role of IRP1 in pathological conditions associated with altered Fe-S metabolism.
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Affiliation(s)
- Alain Martelli
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France; INSERM, U596, 67400 Illkirch, France; CNRS, UMR7104, 67400 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France; Collège de France, Chaire de génétique humaine, 67400 Illkirch, France.
| | - Stéphane Schmucker
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France; INSERM, U596, 67400 Illkirch, France; CNRS, UMR7104, 67400 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France; Collège de France, Chaire de génétique humaine, 67400 Illkirch, France
| | - Laurence Reutenauer
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France; INSERM, U596, 67400 Illkirch, France; CNRS, UMR7104, 67400 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France; Collège de France, Chaire de génétique humaine, 67400 Illkirch, France
| | - Jacques R R Mathieu
- Institut Cochin, INSERM, U1016, CNRS, UMR8104, Université Paris Descartes, 75014 Paris, France
| | - Carole Peyssonnaux
- Institut Cochin, INSERM, U1016, CNRS, UMR8104, Université Paris Descartes, 75014 Paris, France
| | - Zoubida Karim
- Inserm Unité 1149, Center for Research on Inflammation (CRI), Université Paris Diderot, Sorbonne Paris Cité, site Bichat, 75018 Paris, France
| | - Hervé Puy
- Inserm Unité 1149, Center for Research on Inflammation (CRI), Université Paris Diderot, Sorbonne Paris Cité, site Bichat, 75018 Paris, France; AP-HP, Centre Français des Porphyries, Hôpital Louis Mourier, 92701 Colombes, France
| | - Bruno Galy
- European Molecular Biology Laboratory, 69117 Heidelberg, Germany
| | | | - Hélène Puccio
- Translational Medecine and Neurogenetics, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), 67400 Illkirch, France; INSERM, U596, 67400 Illkirch, France; CNRS, UMR7104, 67400 Illkirch, France; Université de Strasbourg, 67000 Strasbourg, France; Collège de France, Chaire de génétique humaine, 67400 Illkirch, France.
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31
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Abstract
The survival and growth of tumor cells within the microenvironment of a solid tumor necessitates the adaptation of these cells to ER stress. Hypoxia, in the context of the tumor microenvironment, is a critical ER stress that activates the unfolded protein response (UPR). This review focuses on the role of the IRE1-XBP1 branch of the UPR and its role in mediating cell survival and tumor growth. Inhibition of this pathway will be discussed as a therapeutic strategy.
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Affiliation(s)
- Albert C Koong
- Stanford University, Department of Radiation Oncology, CA 94305-5152, USA.
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Shpyleva S, Pogribna M, Cozart C, Bryant MS, Muskhelishvili L, Tryndyak VP, Ross SA, Beland FA, Pogribny IP. Interstrain differences in the progression of nonalcoholic steatohepatitis to fibrosis in mice are associated with altered hepatic iron metabolism. J Nutr Biochem 2014; 25:1235-42. [PMID: 25256357 DOI: 10.1016/j.jnutbio.2014.06.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/02/2014] [Accepted: 06/13/2014] [Indexed: 12/13/2022]
Abstract
Nonalcoholic fatty liver disease (NAFLD) is a major health problem worldwide. Currently, there is a lack of conclusive information to clarify the molecular events and mechanisms responsible for the progression of NAFLD to fibrosis and cirrhosis and, more importantly, for differences in interindividual disease severity. The aim of this study was to investigate a role of interindividual differences in iron metabolism among inbred mouse strains in the pathogenesis and severity of fibrosis in a model of NAFLD. Feeding male A/J, 129S1/SvImJ and WSB/EiJ mice a choline- and folate-deficient diet caused NAFLD-associated liver injury and iron metabolism abnormalities, especially in WSB/EiJ mice. NAFLD-associated fibrogenesis was correlated with a marked strain- and injury-dependent increase in the expression of iron metabolism genes, especially transferrin receptor (Tfrc), ferritin heavy chain (Fth1), and solute carrier family 40 (iron-regulated transporter), member 1 (Slc40a1, Fpn1) and their related proteins, and pronounced down-regulation of the iron regulatory protein 1 (IRP1), with the magnitude being A/J<129S1/SvImJ<WSB/EiJ. Mechanistically, down-regulation of IRP1 was linked to an increased expression of microRNAs miR-200a and miR-223, which was negatively correlated with IRP1. The results of this study demonstrate that the interstrain variability in the extent of fibrogenesis was associated with a strain-dependent deregulation of hepatic iron homeostasis.
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Affiliation(s)
- Svitlana Shpyleva
- Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, AR 72079
| | - Marta Pogribna
- Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, AR 72079
| | - Christy Cozart
- Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, AR 72079
| | - Matthew S Bryant
- Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, AR 72079
| | - Levan Muskhelishvili
- Toxicologic Pathology Associates, National Center for Toxicological Research, FDA, Jefferson, AR 72079
| | - Volodymyr P Tryndyak
- Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, AR 72079
| | - Sharon A Ross
- Division of Cancer Prevention, National Cancer Institute, Bethesda, MD 20892
| | - Frederick A Beland
- Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, AR 72079
| | - Igor P Pogribny
- Division of Biochemical Toxicology, National Center for Toxicological Research, FDA, Jefferson, AR 72079.
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Khan MA, Ma J, Walden WE, Merrick WC, Theil EC, Goss DJ. Rapid kinetics of iron responsive element (IRE) RNA/iron regulatory protein 1 and IRE-RNA/eIF4F complexes respond differently to metal ions. Nucleic Acids Res 2014; 42:6567-77. [PMID: 24728987 PMCID: PMC4041422 DOI: 10.1093/nar/gku248] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Metal ion binding was previously shown to destabilize IRE-RNA/IRP1 equilibria and enhanced IRE-RNA/eIF4F equilibria. In order to understand the relative importance of kinetics and stability, we now report rapid rates of protein/RNA complex assembly and dissociation for two IRE-RNAs with IRP1, and quantitatively different metal ion response kinetics that coincide with the different iron responses in vivo. kon, for FRT IRE-RNA binding to IRP1 was eight times faster than ACO2 IRE-RNA. Mn2+ decreased kon and increased koff for IRP1 binding to both FRT and ACO2 IRE-RNA, with a larger effect for FRT IRE-RNA. In order to further understand IRE-mRNA regulation in terms of kinetics and stability, eIF4F kinetics with FRT IRE-RNA were determined. kon for eIF4F binding to FRT IRE-RNA in the absence of metal ions was 5-times slower than the IRP1 binding to FRT IRE-RNA. Mn2+ increased the association rate for eIF4F binding to FRT IRE-RNA, so that at 50 µM Mn2+ eIF4F bound more than 3-times faster than IRP1. IRP1/IRE-RNA complex has a much shorter life-time than the eIF4F/IRE-RNA complex, which suggests that both rate of assembly and stability of the complexes are important, and that allows this regulatory system to respond rapidly to change in cellular iron.
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Affiliation(s)
- Mateen A Khan
- Department of Chemistry and Biochemistry, Hunter College, City University of New York, New York, NY 10065, USA
| | - Jia Ma
- Department of Chemistry and Biochemistry, Hunter College, City University of New York, New York, NY 10065, USA
| | - William E Walden
- Department of Microbiology and Immunology, University of Illinois at Chicago, Chicago, IL 60612-7334, USA
| | - William C Merrick
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Elizabeth C Theil
- Childeren's Hospital Oakland Research Institute, Oakland, CA 94609, USA
| | - Dixie J Goss
- Department of Chemistry and Biochemistry, Hunter College, City University of New York, New York, NY 10065, USA
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Abstract
Several dietary factors and their genetic modifiers play a role in neurological disease and affect the human brain. The structural and functional integrity of the living brain can be assessed using neuroimaging, enabling large-scale epidemiological studies to identify factors that help or harm the brain. Iron is one nutritional factor that comes entirely from our diet, and its storage and transport in the body are under strong genetic control. In this review, we discuss how neuroimaging can help to identify associations between brain integrity, genetic variations, and dietary factors such as iron. We also review iron's essential role in cognition, and we note some challenges and confounds involved in interpreting links between diet and brain health. Finally, we outline some recent discoveries regarding the genetics of iron and its effects on the brain, suggesting the promise of neuroimaging in revealing how dietary factors affect the brain.
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Affiliation(s)
- Neda Jahanshad
- Imaging Genetics Center, Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Neuroscience Research Building 225E, 635 Charles Young Drive, Los Angeles, CA 90095-1769 USA
| | - Priya Rajagopalan
- Imaging Genetics Center, Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Neuroscience Research Building 225E, 635 Charles Young Drive, Los Angeles, CA 90095-1769 USA
| | - Paul M. Thompson
- Imaging Genetics Center, Laboratory of Neuro Imaging, Department of Neurology, UCLA School of Medicine, Neuroscience Research Building 225E, 635 Charles Young Drive, Los Angeles, CA 90095-1769 USA
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Chen J, Marks E, Lai B, Zhang Z, Duce JA, Lam LQ, Volitakis I, Bush AI, Hersch S, Fox JH. Iron accumulates in Huntington's disease neurons: protection by deferoxamine. PLoS One 2013; 8:e77023. [PMID: 24146952 PMCID: PMC3795666 DOI: 10.1371/journal.pone.0077023] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2013] [Accepted: 08/26/2013] [Indexed: 01/13/2023] Open
Abstract
Huntington’s disease (HD) is a progressive neurodegenerative disorder caused by a polyglutamine-encoding CAG expansion in the huntingtin gene. Iron accumulates in the brains of HD patients and mouse disease models. However, the cellular and subcellular sites of iron accumulation, as well as significance to disease progression are not well understood. We used independent approaches to investigate the location of brain iron accumulation. In R6/2 HD mouse brain, synchotron x-ray fluorescence analysis revealed iron accumulation as discrete puncta in the perinuclear cytoplasm of striatal neurons. Further, perfusion Turnbull’s staining for ferrous iron (II) combined with transmission electron microscope ultra-structural analysis revealed increased staining in membrane bound peri-nuclear vesicles in R6/2 HD striatal neurons. Analysis of iron homeostatic proteins in R6/2 HD mice revealed decreased levels of the iron response proteins (IRPs 1 and 2) and accordingly decreased expression of iron uptake transferrin receptor (TfR) and increased levels of neuronal iron export protein ferroportin (FPN). Finally, we show that intra-ventricular delivery of the iron chelator deferoxamine results in an improvement of the motor phenotype in R6/2 HD mice. Our data supports accumulation of redox-active ferrous iron in the endocytic / lysosomal compartment in mouse HD neurons. Expression changes of IRPs, TfR and FPN are consistent with a compensatory response to an increased intra-neuronal labile iron pool leading to increased susceptibility to iron-associated oxidative stress. These findings, together with protection by deferoxamine, support a potentiating role of neuronal iron accumulation in HD.
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Affiliation(s)
- Jianfang Chen
- Department of Veterinary Sciences and Neuroscience Graduate Program, University of Wyoming, Laramie, Wyoming, United States of America
| | - Eileen Marks
- Department of Veterinary Sciences and Neuroscience Graduate Program, University of Wyoming, Laramie, Wyoming, United States of America
| | - Barry Lai
- Argonne National Laboratory, Lemont, Illinois, United States of America
| | - Zhaojie Zhang
- Department of Zoology and Physiology, University of Wyoming, Laramie, Wyoming, United States of America
| | - James A. Duce
- Mental Health Research Institute, Parkville, Melbourne, Victoria, Australia
- School of Molecular and Cellular Biology, the Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Linh Q. Lam
- Mental Health Research Institute, Parkville, Melbourne, Victoria, Australia
| | - Irene Volitakis
- Mental Health Research Institute, Parkville, Melbourne, Victoria, Australia
| | - Ashley I. Bush
- Mental Health Research Institute, Parkville, Melbourne, Victoria, Australia
| | - Steven Hersch
- MassGeneral Institute for Neurodegenerative Disease, Charlestown, Massachusetts, United States of America
| | - Jonathan H. Fox
- Department of Veterinary Sciences and Neuroscience Graduate Program, University of Wyoming, Laramie, Wyoming, United States of America
- * E-mail:
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Bandyopadhyay S, Cahill C, Balleidier A, Huang C, Lahiri DK, Huang X, Rogers JT. Novel 5' untranslated region directed blockers of iron-regulatory protein-1 dependent amyloid precursor protein translation: implications for down syndrome and Alzheimer's disease. PLoS One 2013; 8:e65978. [PMID: 23935819 PMCID: PMC3729844 DOI: 10.1371/journal.pone.0065978] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2013] [Accepted: 04/30/2013] [Indexed: 11/19/2022] Open
Abstract
We reported that iron influx drives the translational expression of the neuronal amyloid precursor protein (APP), which has a role in iron efflux. This is via a classic release of repressor interaction of APP mRNA with iron-regulatory protein-1 (IRP1) whereas IRP2 controls the mRNAs encoding the L- and H-subunits of the iron storage protein, ferritin. Here, we identified thirteen potent APP translation blockers that acted selectively towards the uniquely configured iron-responsive element (IRE) RNA stem loop in the 5' untranslated region (UTR) of APP mRNA. These agents were 10-fold less inhibitory of 5'UTR sequences of the related prion protein (PrP) mRNA. Western blotting confirmed that the 'ninth' small molecule in the series selectively reduced neural APP production in SH-SY5Y cells at picomolar concentrations without affecting viability or the expression of α-synuclein and ferritin. APP blocker-9 (JTR-009), a benzimidazole, reduced the production of toxic Aβ in SH-SY5Y neuronal cells to a greater extent than other well tolerated APP 5'UTR-directed translation blockers, including posiphen, that were shown to limit amyloid burden in mouse models of Alzheimer's disease (AD). RNA binding assays demonstrated that JTR-009 operated by preventing IRP1 from binding to the IRE in APP mRNA, while maintaining IRP1 interaction with the H-ferritin IRE RNA stem loop. Thus, JTR-009 constitutively repressed translation driven by APP 5'UTR sequences. Calcein staining showed that JTR-009 did not indirectly change iron uptake in neuronal cells suggesting a direct interaction with the APP 5'UTR. These studies provide key data to develop small molecules that selectively reduce neural APP and Aβ production at 10-fold lower concentrations than related previously characterized translation blockers. Our data evidenced a novel therapeutic strategy of potential impact for people with trisomy of the APP gene on chromosome 21, which is a phenotype long associated with Down syndrome (DS) that can also cause familial Alzheimer's disease.
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Affiliation(s)
- Sanghamitra Bandyopadhyay
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Catherine Cahill
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
- Department of Pediatrics, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Amelie Balleidier
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Conan Huang
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Debomoy K. Lahiri
- Laboratory of Molecular Neurogenetics, Department of Psychiatry, Institute of Psychiatric Research, Indiana University School of Medicine, Indianapolis, Indiana, United States of America
| | - Xudong Huang
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
| | - Jack T. Rogers
- Neurochemistry Laboratory, Department of Psychiatry, Massachusetts General Hospital and Harvard Medical School, Charlestown, Massachusetts, United States of America
- * E-mail:
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Meli R, Mattace Raso G, Irace C, Simeoli R, Di Pascale A, Paciello O, Pagano TB, Calignano A, Colonna A, Santamaria R. High Fat Diet Induces Liver Steatosis and Early Dysregulation of Iron Metabolism in Rats. PLoS One 2013; 8:e66570. [PMID: 23805238 PMCID: PMC3689747 DOI: 10.1371/journal.pone.0066570] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2013] [Accepted: 05/09/2013] [Indexed: 02/06/2023] Open
Abstract
This paper is dedicated to the memory of our wonderful colleague Professor Alfredo Colonna, who passed away the same day of its acceptance. Fatty liver accumulation, inflammatory process and insulin resistance appear to be crucial in non-alcoholic fatty liver disease (NAFLD), nevertheless emerging findings pointed an important role also for iron overload. Here, we investigate the molecular mechanisms of hepatic iron metabolism in the onset of steatosis to understand whether its impairment could be an early event of liver inflammatory injury. Rats were fed with control diet or high fat diet (HFD) for 5 or 8 weeks, after which liver morphology, serum lipid profile, transaminases levels and hepatic iron content (HIC), were evaluated. In liver of HFD fed animals an increased time-dependent activity of iron regulatory protein 1 (IRP1) was evidenced, associated with the increase in transferrin receptor-1 (TfR1) expression and ferritin down-regulation. Moreover, ferroportin (FPN-1), the main protein involved in iron export, was down-regulated accordingly with hepcidin increase. These findings were indicative of an increased iron content into hepatocytes, which leads to an increase of harmful free-iron also related to the reduction of hepatic ferritin content. The progressive inflammatory damage was evidenced by the increase of hepatic TNF-α, IL-6 and leptin, in parallel to increased iron content and oxidative stress. The major finding that emerged of this study is the impairment of iron homeostasis in the ongoing and sustaining of liver steatosis, suggesting a strong link between iron metabolism unbalance, inflammatory damage and progression of disease.
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Affiliation(s)
- Rosaria Meli
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
- * E-mail: (RM); (AC)
| | | | - Carlo Irace
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Raffaele Simeoli
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | | | - Orlando Paciello
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Naples, Italy
| | - Teresa Bruna Pagano
- Department of Veterinary Medicine and Animal Productions, University of Naples Federico II, Naples, Italy
| | - Antonio Calignano
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
| | - Alfredo Colonna
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
- * E-mail: (RM); (AC)
| | - Rita Santamaria
- Department of Pharmacy, University of Naples Federico II, Naples, Italy
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Fiorito F, Irace C, Di Pascale A, Colonna A, Iovane G, Pagnini U, Santamaria R, De Martino L. 2,3,7,8-Tetrachlorodibenzo-p-dioxin promotes BHV-1 infection in mammalian cells by interfering with iron homeostasis regulation. PLoS One 2013; 8:e58845. [PMID: 23520538 PMCID: PMC3592816 DOI: 10.1371/journal.pone.0058845] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2012] [Accepted: 02/07/2013] [Indexed: 12/12/2022] Open
Abstract
Mammalian cells require iron to satisfy metabolic needs or to accomplish specialized functions, and DNA viruses, like bovine herpesvirus 1 (BHV-1), require an iron-replete host to efficiently replicate, so that iron bioavailability is an important component of viral virulence. Cellular iron metabolism is coordinately controlled by the Iron Regulatory Proteins (IRP1 and IRP2), whose activity is affected by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a current and persistent environmental contaminant. Considering that TCDD enhances BHV-1 replication, herein we analyzed the effects of TCDD on iron metabolism during BHV-1 infection in MDBK cells, and presented evidences of a divergent modulation of IRP1 and IRP2 RNA-binding capacity. Moreover, an up-regulation of transferrin receptor 1 (TfR1) and a concomitant down-regulation of ferritin were observed. This scenario led to an expansion of the labile iron pool (LIP) and induces a significant enhance of viral titer, as confirmed by increased levels of BHV-1 infected cell protein 0 (bICP0), the major transcriptional regulatory protein of BHV-1. Taken together, our data suggest that TCDD increases the free intracellular iron availability thereby promoting the onset of BHV-1 infection and rendering bovine cells more vulnerable to the virus.
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Affiliation(s)
- Filomena Fiorito
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli “Federico II”, Naples, Italy
| | - Carlo Irace
- Dipartimento di Farmacia, Università degli Studi di Napoli “Federico II”, Naples, Italy
| | - Antonio Di Pascale
- Dipartimento di Farmacia, Università degli Studi di Napoli “Federico II”, Naples, Italy
| | - Alfredo Colonna
- Dipartimento di Farmacia, Università degli Studi di Napoli “Federico II”, Naples, Italy
| | - Giuseppe Iovane
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli “Federico II”, Naples, Italy
| | - Ugo Pagnini
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli “Federico II”, Naples, Italy
- * E-mail: (UP); (RS)
| | - Rita Santamaria
- Dipartimento di Farmacia, Università degli Studi di Napoli “Federico II”, Naples, Italy
- * E-mail: (UP); (RS)
| | - Luisa De Martino
- Dipartimento di Medicina Veterinaria e Produzioni Animali, Università degli Studi di Napoli “Federico II”, Naples, Italy
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Wang J, Song N, Jiang H, Wang J, Xie J. Pro-inflammatory cytokines modulate iron regulatory protein 1 expression and iron transportation through reactive oxygen/nitrogen species production in ventral mesencephalic neurons. Biochim Biophys Acta Mol Basis Dis 2013; 1832:618-25. [PMID: 23376588 DOI: 10.1016/j.bbadis.2013.01.021] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 12/11/2012] [Accepted: 01/24/2013] [Indexed: 12/24/2022]
Abstract
Both inflammatory processes associated with microglia activation and abnormal iron deposit in dopaminergic neurons are involved in the pathogenesis of Parkinson's disease (PD). However, the relationship between neuroinflammation and iron accumulation was not fully elucidated. In the present study, we aimed to investigate whether the pro-inflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) released by microglia, could affect cellular iron transportation in primary cultured ventral mesencephalic (VM) neurons. The results showed that IL-1β or TNF-α treatment led to increased ferrous iron influx and decreased iron efflux in these cells, due to the upregulation of divalent metal transporter 1 with the iron response element (DMT1+IRE) and downregulation of ferroportin1 (FPN1). Increased levels of iron regulatory protein 1 (IRP1), transferrin receptor 1 (TfR1) and hepcidin were also observed in IL-1β or TNF-α treated VM neurons. IRP1 upregulation could be fully abolished by co-administration of radical scavenger N-acetyl-l-cysteine and inducible NO synthetase inhibitor Nω-nitro-l-arginine methyl ester hydrochloride. Further experiments demonstrated that IL-1β and TNF-α release was remarkably enhanced by iron load in activated microglia triggered by lipopolysaccharide or 1-methyl-4-phenylpyridinium (MPP(+)). In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-intoxicated mice, salicylate application could not block DMT1+IRE upregulation in dopaminergic neurons of substantia nigra. These results suggested that IL-1β and TNF-α released by microglia, especially under the condition of iron load, might contribute to iron accumulation in VM neurons by upregulating IRP1 and hepcidin levels through reactive oxygen/nitrogen species production. This might provide a new insight into unraveling that microglia might aggravate this iron mediated neuropathologies in PD.
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Affiliation(s)
- Jia Wang
- Department of Physiology, Medical College of Qingdao University, Qingdao, China
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40
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Li Y, He Y, Guan Q, Liu W, Han H, Nie Z. Disrupted iron metabolism and ensuing oxidative stress may mediate cognitive dysfunction induced by chronic cerebral hypoperfusion. Biol Trace Elem Res 2012; 150:242-8. [PMID: 22639386 DOI: 10.1007/s12011-012-9455-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 05/14/2012] [Indexed: 01/17/2023]
Abstract
Iron is a highly reactive free radical catalyst that has been shown to exacerbate oxidative stress and cell death in many neurodegenerative diseases. In this study, we produced a rat model of chronic cerebral hypoperfusion (CCH) by permanent bilateral carotid artery occlusion to investigate markers of iron and oxidative stress associated with it. We found CCH led to significant spatial memory impairment in the Morris water maze at 4 months after bilateral ligation. Iron deposition was observed in both the hippocampal CA1 area and cerebral cortex, and was correlated with localized neuronal death and increased lipid peroxidation. Western blotting revealed that the expression levels of ferritin heavy chain and the transferrin receptor were significantly elevated in hippocampus and cortex after CCH, whereas expression of iron regulatory protein 1 was significantly lower than in sham-treated rats. We conclude that localized neurodegeneration and concomitant cognitive impairments following CCH may result, at least in part, from local disruption of neuronal iron metabolism.
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Affiliation(s)
- Yunxia Li
- Department of Neurology, Tongji Hospital, Tongji University, 389 Xincun Road, Shanghai, China
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41
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Li C, Lönn ME, Xu X, Maghzal GJ, Frazer DM, Thomas SR, Halliwell B, Richardson DR, Anderson GJ, Stocker R. Sustained expression of heme oxygenase-1 alters iron homeostasis in nonerythroid cells. Free Radic Biol Med 2012; 53:366-74. [PMID: 22579918 DOI: 10.1016/j.freeradbiomed.2012.03.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2010] [Revised: 02/08/2012] [Accepted: 03/07/2012] [Indexed: 10/28/2022]
Abstract
Heme oxygenases initiate the catabolism of heme, releasing carbon monoxide, iron, and biliverdin. Sustained induction of heme oxygenase-1 (HO-1) in nonerythroid cells plays a key role in many pathological processes, yet the effect of long-term HO-1 expression on cellular iron metabolism in the absence of exogenous heme is poorly understood. Here we report that in a model nonerythroid cell, both transient and stable HO-1 expression increased heme oxygenase activity, but total cellular heme content was decreased only with transient enzyme expression. Sustained HO-1 activity increased the expression of both the mitochondrial iron importer mitoferrin-2 and the rate-limiting enzyme in heme synthesis, aminolevulinate synthase-1, and it augmented the mitochondrial content of heme. Also, the expression of transferrin receptor-1 and the activities of iron-regulatory proteins 1 and 2 decreased, whereas total labile iron and the regulatory activity of the heme-binding transcription factor Bach1 were unaltered. In addition, stable, but not transient, HO-1 expression decreased the activities of aconitase, as well as increasing proteasomal degradation of ferritin. Together, our results reveal a novel and coordinated adaptive response of nonerythroid cells to sustained HO-1 induction that has an impact on cellular iron homeostasis.
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Affiliation(s)
- Cheng Li
- Centre for Vascular Research, School of Medical Sciences (Pathology) and Bosch Institute, University of Sydney, Sydney, NSW 2006, Australia
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42
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Thulluri S, Wu M, Blough ER, Manne NDPK, Litchfield AB, Wang B. Regulation of iron-related molecules in the rat hippocampus: sex- and age-associated differences. Ann Clin Lab Sci 2012; 42:145-151. [PMID: 22585610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Iron accumulation, especially that of free oxidized ferrous iron, has been shown to induce tissue oxidative damage and contribute to brain aging and the development of neurodegenerative disease. Here we examine whether sex and advanced age affect the expression of iron-related molecules that participate in regulating free iron levels (heme oxygenase 1 (HO1), iron-regulatory protein 1 (IRP1), and ferritin heavy chain (FTH)) and whether changes in the expression of these molecules are associated with differences in the expression of alpha-synuclein (ASN) which is thought to be a critical regulator in the pathogenesis of neurodegeneration. Using a well-established aging animal model, we demonstrate that the expression of HO1, FTH, and IRP1 mRNAs is higher in the female hippocampus than that observed in male Fischer 344/NNiaHSD x Brown Norway/BiNia (F344BN) rats, regardless of age group. Consistent with these sex-associated alterations in iron-related regulators, the expression of ASN mRNA and protein in the female hippocampus was lower than that found in male rats. These results suggest a sex-dependent difference in regulating the expression of molecules involved in iron metabolism and neurodegeneration. A similar finding in humans, if present, may help to shed light on why sex may affect the incidence of neurodegenerative disorders.
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43
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Jeong SY, Crooks DR, Wilson-Ollivierre H, Ghosh MC, Sougrat R, Lee J, Cooperman S, Mitchell JB, Beaumont C, Rouault TA. Iron insufficiency compromises motor neurons and their mitochondrial function in Irp2-null mice. PLoS One 2011; 6:e25404. [PMID: 22003390 PMCID: PMC3189198 DOI: 10.1371/journal.pone.0025404] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2011] [Accepted: 09/02/2011] [Indexed: 12/12/2022] Open
Abstract
Genetic ablation of Iron Regulatory Protein 2 (Irp2, Ireb2), which post-transcriptionally regulates iron metabolism genes, causes a gait disorder in mice that progresses to hind-limb paralysis. Here we have demonstrated that misregulation of iron metabolism from loss of Irp2 causes lower motor neuronal degeneration with significant spinal cord axonopathy. Mitochondria in the lumbar spinal cord showed significantly decreased Complex I and II activities, and abnormal morphology. Lower motor neurons appeared to be the most adversely affected neurons, and we show that functional iron starvation due to misregulation of iron import and storage proteins, including transferrin receptor 1 and ferritin, may have a causal role in disease. We demonstrated that two therapeutic approaches were beneficial for motor neuron survival. First, we activated a homologous protein, IRP1, by oral Tempol treatment and found that axons were partially spared from degeneration. Secondly, we genetically decreased expression of the iron storage protein, ferritin, to diminish functional iron starvation. These data suggest that functional iron deficiency may constitute a previously unrecognized molecular basis for degeneration of motor neurons in mice.
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Affiliation(s)
- Suh Young Jeong
- Eunice Kennedy Shriver National Institute of Child Health and Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Daniel R. Crooks
- Eunice Kennedy Shriver National Institute of Child Health and Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Hayden Wilson-Ollivierre
- Eunice Kennedy Shriver National Institute of Child Health and Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Manik C. Ghosh
- Eunice Kennedy Shriver National Institute of Child Health and Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Rachid Sougrat
- Nanobiology Lab, King Abdullah University of Science and Technology (KAUST), Thuwal, Saudi Arabia
| | - Jaekwon Lee
- Department of Biochemistry, University of Nebraska, Lincoln, Nebraska, United States of America
| | - Sharon Cooperman
- Eunice Kennedy Shriver National Institute of Child Health and Development, National Institutes of Health, Bethesda, Maryland, United States of America
| | - James B. Mitchell
- National Cancer Institute, National Institutes of Health, Bethesda, Maryland, United States of America
| | - Carole Beaumont
- INSERM U773, Centre de Recherche Biomédicale Bichat-Beaujon, Université Paris Diderot, Paris, France
| | - Tracey A. Rouault
- Eunice Kennedy Shriver National Institute of Child Health and Development, National Institutes of Health, Bethesda, Maryland, United States of America
- * E-mail:
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44
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Tong WH, Sourbier C, Kovtunovych G, Jeong SY, Vira M, Ghosh M, Romero VV, Sougrat R, Vaulont S, Viollet B, Kim YS, Lee S, Trepel J, Srinivasan R, Bratslavsky G, Yang Y, Linehan WM, Rouault TA. The glycolytic shift in fumarate-hydratase-deficient kidney cancer lowers AMPK levels, increases anabolic propensities and lowers cellular iron levels. Cancer Cell 2011; 20:315-27. [PMID: 21907923 PMCID: PMC3174047 DOI: 10.1016/j.ccr.2011.07.018] [Citation(s) in RCA: 167] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 01/06/2011] [Accepted: 07/28/2011] [Indexed: 11/15/2022]
Abstract
Inactivation of the TCA cycle enzyme, fumarate hydratase (FH), drives a metabolic shift to aerobic glycolysis in FH-deficient kidney tumors and cell lines from patients with hereditary leiomyomatosis renal cell cancer (HLRCC), resulting in decreased levels of AMP-activated kinase (AMPK) and p53 tumor suppressor, and activation of the anabolic factors, acetyl-CoA carboxylase and ribosomal protein S6. Reduced AMPK levels lead to diminished expression of the DMT1 iron transporter, and the resulting cytosolic iron deficiency activates the iron regulatory proteins, IRP1 and IRP2, and increases expression of the hypoxia inducible factor HIF-1α, but not HIF-2α. Silencing of HIF-1α or activation of AMPK diminishes invasive activities, indicating that alterations of HIF-1α and AMPK contribute to the oncogenic growth of FH-deficient cells.
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Affiliation(s)
- Wing-Hang Tong
- Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Development, Bethesda, Maryland, USA
| | - Carole Sourbier
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Gennady Kovtunovych
- Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Development, Bethesda, Maryland, USA
| | - Suh Young Jeong
- Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Development, Bethesda, Maryland, USA
| | - Manish Vira
- Albert Einstein College of Medicine, New York, USA
| | - Manik Ghosh
- Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Development, Bethesda, Maryland, USA
| | - Vladimir Valera Romero
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Rachid Sougrat
- King Abdullah University of Science and Technology, Saudi Arabia
| | - Sophie Vaulont
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), Paris, France
- Inserm U 1016, Paris, France
| | - Benoit Viollet
- Institut Cochin, Université Paris Descartes, CNRS (UMR8104), Paris, France
- Inserm U 1016, Paris, France
| | - Yeong-Sang Kim
- Medical Oncology Branch, National Cancer Institute, Bethesda, Maryland, USA
| | - Sunmin Lee
- Medical Oncology Branch, National Cancer Institute, Bethesda, Maryland, USA
| | - Jane Trepel
- Medical Oncology Branch, National Cancer Institute, Bethesda, Maryland, USA
| | - Ramaprasad Srinivasan
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Gennady Bratslavsky
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Youfeng Yang
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - W. Marston Linehan
- Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland, USA
| | - Tracey A. Rouault
- Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Development, Bethesda, Maryland, USA
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45
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Wang L, Wang H, Li L, Li W, Dong X, Li M, Lv L. Corticosterone induces dysregulation of iron metabolism in hippocampal neurons in vitro. Biol Trace Elem Res 2010; 137:88-95. [PMID: 19957051 DOI: 10.1007/s12011-009-8565-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2009] [Accepted: 10/29/2009] [Indexed: 12/27/2022]
Abstract
Iron is required for neuronal function but in excess generates neurodegeneration. Although the iron homeostasis machinery in neurons has been described extensively, little is known about the influence of corticosterone on the iron homeostasis in neurons. In this study, we characterized the response of hippocampal neurons to a model of progressive corticosterone condition. We found that increasing extracellular corticosterone-induced iron accumulation killed a large proportion of neurons. Iron concentrations were significantly increased in the corticosterone-treated cells. In the hippocampal neurons, corticosterone decreased expression of ferritin and increased expression of transferrin receptor1 (TfR1), iron regulatory protein1 (IRP1), and divalent metal transporter 1. Corticosterone-induced elevation of IRP1 expression can cause increase of TfR1 and decrease of ferritin expression, which further leads to iron accumulation in hippocampal neurons and subsequently increases the oxidative damage of the neurons; it is indicated that corticosterone might be an important reason for iron deposition-caused neurodegenerative diseases.
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Affiliation(s)
- Lei Wang
- Department of Clinical Nutrition, General Hospital of Armed Police Forces, 69 Yongding Road, Beijing, 100039, People's Republic of China
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46
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Simonis G, Mueller K, Schwarz P, Wiedemann S, Adler G, Strasser RH, Kulaksiz H. The iron-regulatory peptide hepcidin is upregulated in the ischemic and in the remote myocardium after myocardial infarction. Peptides 2010; 31:1786-90. [PMID: 20553779 DOI: 10.1016/j.peptides.2010.05.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2010] [Revised: 05/19/2010] [Accepted: 05/19/2010] [Indexed: 12/23/2022]
Abstract
Recent evidence suggests that iron metabolism contributes to the ischemic damage after myocardial infarction. Hepcidin, a recently discovered peptide hormone, regulates iron uptake and metabolism, protecting the body from iron overload. In this study we analyzed the regulation of hepcidin in the heart and blood of rats after myocardial infarction. To induce a myocardial infarction in the rats, left anterior descending coronary artery ligation was performed. After 1-24h, biopsies from the ischemic and the non-ischemic myocardium were taken. In these biopsies, the mRNA levels and the protein expression of hepcidin were analyzed by quantitative RT-PCR and immunoblot analysis, respectively. In parallel, the serum levels of prohepcidin were measured by ELISA. Six hours after myocardial infarction, the hepcidin mRNA expression was temporally upregulated in the ischemic and in the non-ischemic myocardium. The upregulation was specific for hepcidin, since other iron-related genes (hemojuvelin, IREG-1) remained unchanged. Furthermore, the alteration of the hepcidin protein expression in the ischemic area was connected to the level of hepcidin in the serum of the infarcted rats, where hepcidin also raised up. Angiotensin receptor blockade with candesartan did not influence the mRNA regulation of hepcidin. Together, these data show a particular upregulation of the iron-regulatory peptide hepcidin in the ischemic and the non-ischemic myocardium after myocardial infarction. It is speculated that upregulation of hepcidin may reduce iron toxicity and thus infarct size expansion in an infarcted heart.
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Affiliation(s)
- Gregor Simonis
- Department of Medicine and Cardiology, Dresden University of Technology, Heart Center, D-01307 Dresden, Germany
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47
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Condò I, Malisan F, Guccini I, Serio D, Rufini A, Testi R. Molecular control of the cytosolic aconitase/IRP1 switch by extramitochondrial frataxin. Hum Mol Genet 2010; 19:1221-9. [PMID: 20053667 DOI: 10.1093/hmg/ddp592] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
The inability to produce normal levels of the mitochondrial protein frataxin causes the hereditary degenerative disorder Friedreich's Ataxia (FRDA), a syndrome characterized by progressive gait instability, cardiomyopathy and high incidence of diabetes. Frataxin is an iron-binding protein involved in the biogenesis of iron-sulfur clusters (ISC), prosthetic groups allowing essential cellular functions such as oxidative phosphorylation, enzyme catalysis and gene regulation. Although several evidence suggest that frataxin acts as an iron-chaperone within the mitochondrial compartment, we have recently demonstrated the existence of a functional extramitochondrial pool of mature frataxin in various human cell types. Here, we show that a similar proteolytic process generates both mature mitochondrial and extramitochondrial frataxin. To address the physiological function of human extramitochondrial frataxin, we searched for ISC-dependent interaction partners. We demonstrate that the extramitochondrial form of frataxin directly interacts with cytosolic aconitase/iron regulatory protein-1 (IRP1), a bifunctional protein alternating between an enzymatic and a RNA-binding function through the 'iron-sulfur switch' mechanism. Importantly, we found that the cytosolic aconitase defect and consequent IRP1 activation occurring in FRDA cells are reversed by the action of extramitochondrial frataxin. These results provide new insight into the control of cytosolic aconitase/IRP1 switch and expand current knowledge about the molecular pathogenesis of FRDA.
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Affiliation(s)
- Ivano Condò
- Department of Experimental Medicine and Biochemical Sciences, University of Rome Tor Vergata, Rome, Italy
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48
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Song N, Wang J, Jiang H, Xie J. Ferroportin 1 but not hephaestin contributes to iron accumulation in a cell model of Parkinson's disease. Free Radic Biol Med 2010; 48:332-41. [PMID: 19913091 DOI: 10.1016/j.freeradbiomed.2009.11.004] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/06/2009] [Revised: 10/22/2009] [Accepted: 11/06/2009] [Indexed: 12/01/2022]
Abstract
Iron-induced oxidative stress is thought to play a crucial role in the pathogenesis of Parkinson's disease (PD). Based on our previous in vivo experiments showing that down-regulation of the iron transporters ferroportin 1 (FP1) and hephaestin (HP) might account for the nigral iron accumulation in 6-hydroxydopamine (6-OHDA)-lesioned animal models, in this study we investigated whether FP1 and HP were involved in cellular iron accumulation and the underlying mechanisms in a cell model of PD. The findings showed that 6-OHDA induced FP1 and HP down-regulation, followed by decreased iron efflux and iron accumulation in primary ventral mesencephalic neurons and MES23.5 dopaminergic cells. Silencing of FP1 but not HP led to increased iron levels and aggravated reactive oxygen species generation in MES23.5 cells. Under iron-overloaded conditions, FP1 showed dose-dependent up-regulation, whereas HP showed no response, indicating their down-regulation was not due to the increased intracellular iron content. In 6-OHDA-treated cells, both iron-regulatory protein (IRP) 1 and IRP2 were up-regulated, and silencing of IRPs in MES23.5 cells dramatically blocked 6-OHDA-induced FP1 down-regulation and reversed HP down-regulation. These results suggest that FP1 but not HP contributes to 6-OHDA-induced intracellular iron accumulation, and down-regulation of FP1 and HP by 6-OHDA is IRPs-dependent.
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Affiliation(s)
- Ning Song
- State Key Disciplines: Physiology (in Incubation), Department of Physiology, Medical College of Qingdao University, Qingdao 266071, China
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49
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Goforth JB, Anderson SA, Nizzi CP, Eisenstein RS. Multiple determinants within iron-responsive elements dictate iron regulatory protein binding and regulatory hierarchy. RNA 2010; 16:154-69. [PMID: 19939970 PMCID: PMC2802025 DOI: 10.1261/rna.1857210] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Iron regulatory proteins (IRPs) are iron-regulated RNA binding proteins that, along with iron-responsive elements (IREs), control the translation of a diverse set of mRNA with 5' IRE. Dysregulation of IRP action causes disease with etiology that may reflect differential control of IRE-containing mRNA. IREs are defined by a conserved stem-loop structure including a midstem bulge at C8 and a terminal CAGUGH sequence that forms an AGU pseudo-triloop and N19 bulge. C8 and the pseudo-triloop nucleotides make the majority of the 22 identified bonds with IRP1. We show that IRP1 binds 5' IREs in a hierarchy extending over a ninefold range of affinities that encompasses changes in IRE binding affinity observed with human L-ferritin IRE mutants. The limits of this IRE binding hierarchy are predicted to arise due to small differences in binding energy (e.g., equivalent to one H-bond). We demonstrate that multiple regions of the IRE stem not predicted to contact IRP1 help establish the binding hierarchy with the sequence and structure of the C8 region displaying a major role. In contrast, base-pairing and stacking in the upper stem region proximal to the terminal loop had a minor role. Unexpectedly, an N20 bulge compensated for the lack of an N19 bulge, suggesting the existence of novel IREs. Taken together, we suggest that a regulatory binding hierarchy is established through the impact of the IRE stem on the strength, not the number, of bonds between C8 or pseudo-triloop nucleotides and IRP1 or through their impact on an induced fit mechanism of binding.
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Affiliation(s)
- Jeremy B Goforth
- Department of Nutritional Sciences, University of Wisconsin, Madison, Wisconsin 53706, USA
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50
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Abstract
A protein with a domain that binds to oxygen and iron acts as a sensor to control iron metabolism in human cells.
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Affiliation(s)
- Tracey A Rouault
- Molecular Medicine Program, National Institute of Child Health and Human Development, Bethesda, MD 20892, USA.
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