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Yiwen W, Xiaohan T, Chunfeng Z, Xiaoyu Y, Yaodong M, Huanhuan Q. Genetics of metallothioneins in Drosophilamelanogaster. CHEMOSPHERE 2022; 288:132562. [PMID: 34653491 DOI: 10.1016/j.chemosphere.2021.132562] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 10/08/2021] [Accepted: 10/11/2021] [Indexed: 06/13/2023]
Abstract
Metallothioneins (MTs) are ubiquitous metal-chelating proteins involved in cellular metal homeostasis. MTs were found to be related with almost all the biological processes and their malfunctioning is responsible for a lot of important human diseases. Invertebrate MTs were also used broadly as biomarkers of metal contamination due to their inducible expression by metal exposure. MT system plays a significant role in maintaining human health and ecological stability. Drosophila melanogaster, the vinegar fly, is a perfect model for studying insect MT systems. Six MTs were identified in D. melanogaster, and were designated MtnA to F. All the MTs are considered as Cu-thioneins except for MtnF, which is putatively a Zn-thionein. Expression of all the MTs are regulated by MTF-1/MRE system, thus being able to be induced by heavy metal exposure. The expression pattern and function of separated MTs are partially overlapped and partially distinct. In this work, we made a summary of all the studies on D. melanogaster MTs. From this review, we noted that, compared with studies on mammalian MTs, the understanding of the MT system of D. melanogaster and other invertebrates, especially the regulation mechanism for MT expression and protein-protein interaction with them, is still in a low level.
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Affiliation(s)
- Wang Yiwen
- School of Pharmaceutical Science and Technology, Tianjin University, 300072, Tianjin, China
| | - Tian Xiaohan
- School of Pharmaceutical Science and Technology, Tianjin University, 300072, Tianjin, China
| | - Zhu Chunfeng
- School of Life Sciences, Tianjin University, 300072, Tianjin, China
| | - Yu Xiaoyu
- School of Pharmaceutical Science and Technology, Tianjin University, 300072, Tianjin, China
| | - Miao Yaodong
- Second Affiliated Hospital of Tianjin University of Traditional Chinese Medicine, 300250, Tianjin, China
| | - Qiao Huanhuan
- Academy of Medical Engineering and Translational Medicine, Tianjin University, 300072, Tianjin, China.
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Álvarez-Barrios A, Álvarez L, García M, Artime E, Pereiro R, González-Iglesias H. Antioxidant Defenses in the Human Eye: A Focus on Metallothioneins. Antioxidants (Basel) 2021; 10:89. [PMID: 33440661 PMCID: PMC7826537 DOI: 10.3390/antiox10010089] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/03/2021] [Accepted: 01/04/2021] [Indexed: 12/12/2022] Open
Abstract
The human eye, the highly specialized organ of vision, is greatly influenced by oxidants of endogenous and exogenous origin. Oxidative stress affects all structures of the human eye with special emphasis on the ocular surface, the lens, the retina and its retinal pigment epithelium, which are considered natural barriers of antioxidant protection, contributing to the onset and/or progression of eye diseases. These ocular structures contain a complex antioxidant defense system slightly different along the eye depending on cell tissue. In addition to widely studied enzymatic antioxidants, including superoxide dismutase, glutathione peroxidase, catalase, peroxiredoxins and selenoproteins, inter alia, metallothioneins (MTs) are considered antioxidant proteins of growing interest with further cell-mediated functions. This family of cysteine rich and low molecular mass proteins captures and neutralizes free radicals in a redox-dependent mechanism involving zinc binding and release. The state of the art of MTs, including the isoforms classification, the main functions described to date, the Zn-MT redox cycle as antioxidant defense system, and the antioxidant activity of Zn-MTs in the ocular surface, lens, retina and its retinal pigment epithelium, dependent on the number of occupied zinc-binding sites, will be comprehensively reviewed.
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Affiliation(s)
- Ana Álvarez-Barrios
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería, 8, 33006 Oviedo, Spain
| | - Lydia Álvarez
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
| | - Montserrat García
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega, 34, 33012 Oviedo, Spain
| | - Enol Artime
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
| | - Rosario Pereiro
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Department of Physical and Analytical Chemistry, Faculty of Chemistry, University of Oviedo, Julián Clavería, 8, 33006 Oviedo, Spain
| | - Héctor González-Iglesias
- Instituto Universitario Fernández-Vega (Fundación de Investigación Oftalmológica, Universidad de Oviedo), 33012 Oviedo, Spain; (A.Á.-B.); (L.Á.); (M.G.); (E.A.); (R.P.)
- Instituto Oftalmológico Fernández-Vega, Avda. Dres. Fernández-Vega, 34, 33012 Oviedo, Spain
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Chen GH, Lv W, Xu YH, Wei XL, Xu YC, Luo Z. Functional analysis of MTF-1 and MT promoters and their transcriptional response to zinc (Zn) and copper (Cu) in yellow catfish Pelteobagrus fulvidraco. CHEMOSPHERE 2020; 246:125792. [PMID: 31918101 DOI: 10.1016/j.chemosphere.2019.125792] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Revised: 12/27/2019] [Accepted: 12/29/2019] [Indexed: 06/10/2023]
Abstract
Metal-responsive transcription factor-1 (MTF-1) and metallothionein (MT) expression are involved in metal homeostasis and detoxification. Here, we characterized the structure and functions of mtf-1 and mt promoters in yellow catfish Pelteobagrus fulvidraco. Many important binding sites of transcriptional factors, such as heat shock promoter element (HSE) and metal responsive element (MRE), were predicted on their promoter regions. Cu did not significantly influence the activity of mtf-1 promoter, but Zn increased its promoter activity. Cu and Zn induced the increase of mt promoter activity. HSE site of mtf-1 promoter was the functional binding locus responsible for Zn-induced mtf-1 transcriptional activation. Zn and Cu induced transcriptional activation of mt gene through the MTF-1- and MRE-dependent pathway. Using primary hepatocytes of yellow catfish, we found that Cu and Zn induced the mt expression; Cu did not significantly influence the mRNA and total protein levels of MTF-1, but Zn up-regulated its mRNA and total protein expression. Both Zn and Cu treatment also up-regulated MTF-1 nuclear protein expression, which in turn increased the mt expression. Taken together, these findings delineated the transcriptional regulation of MT and MTF-1 under Zn or Cu treatments, and provided some mechanisms for the regulation of Cu and Zn homeostasis in vertebrates.
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Affiliation(s)
- Guang-Hui Chen
- Laboratory of Molecular Nutrition for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wuhong Lv
- Laboratory of Molecular Nutrition for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yi-Huan Xu
- Laboratory of Molecular Nutrition for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan, 430070, China
| | - Xiao-Lei Wei
- Laboratory of Molecular Nutrition for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan, 430070, China
| | - Yi-Chuang Xu
- Laboratory of Molecular Nutrition for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan, 430070, China
| | - Zhi Luo
- Laboratory of Molecular Nutrition for Aquatic Economic Animals, Fishery College, Huazhong Agricultural University, Wuhan, 430070, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266237, China.
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Krizkova S, Kepinska M, Emri G, Eckschlager T, Stiborova M, Pokorna P, Heger Z, Adam V. An insight into the complex roles of metallothioneins in malignant diseases with emphasis on (sub)isoforms/isoforms and epigenetics phenomena. Pharmacol Ther 2017; 183:90-117. [PMID: 28987322 DOI: 10.1016/j.pharmthera.2017.10.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Metallothioneins (MTs) belong to a group of small cysteine-rich proteins that are ubiquitous throughout all kingdoms. The main function of MTs is scavenging of free radicals and detoxification and homeostating of heavy metals. In humans, 16 genes localized on chromosome 16 have been identified to encode four MT isoforms labelled by numbers (MT-1-MT-4). MT-2, MT-3 and MT-4 proteins are encoded by a single gene. MT-1 comprises many (sub)isoforms. The known active MT-1 genes are MT-1A, -1B, -1E, -1F, -1G, -1H, -1M and -1X. The rest of the MT-1 genes (MT-1C, -1D, -1I, -1J and -1L) are pseudogenes. The expression and localization of individual MT (sub)isoforms and pseudogenes vary at intra-cellular level and in individual tissues. Changes in MT expression are associated with the process of carcinogenesis of various types of human malignancies, or with a more aggressive phenotype and therapeutic resistance. Hence, MT (sub)isoform profiling status could be utilized for diagnostics and therapy of tumour diseases. This review aims on a comprehensive summary of methods for analysis of MTs at (sub)isoforms levels, their expression in single tumour diseases and strategies how this knowledge can be utilized in anticancer therapy.
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Affiliation(s)
- Sona Krizkova
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic; Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic
| | - Marta Kepinska
- Department of Biomedical and Environmental Analysis, Faculty of Pharmacy, Wroclaw Medical University, Borowska 211, 50-556 Wroclaw, Poland
| | - Gabriella Emri
- Department of Dermatology, Faculty of Medicine, University of Debrecen, Nagyerdei krt 98, H-4032 Debrecen, Hungary
| | - Tomas Eckschlager
- Department of Paediatric Haematology and Oncology, 2nd Faculty of Medicine, Charles University, and University Hospital Motol, V Uvalu 84, CZ-150 06 Prague 5, Czech Republic
| | - Marie Stiborova
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, CZ-128 40 Prague 2, Czech Republic
| | - Petra Pokorna
- Department of Biochemistry, Faculty of Science, Charles University, Albertov 2030, CZ-128 40 Prague 2, Czech Republic; Department of Oncology, 2nd Faculty of Medicine, Charles University, and University Hospital Motol, V Uvalu 84, CZ-150 06 Prague 5, Czech Republic
| | - Zbynek Heger
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic; Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic
| | - Vojtech Adam
- Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic; Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic.
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Drechsel V, Schauer K, Šrut M, Höckner M. Regulatory Plasticity of Earthworm wMT-2 Gene Expression. Int J Mol Sci 2017; 18:ijms18061113. [PMID: 28538660 PMCID: PMC5485937 DOI: 10.3390/ijms18061113] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2017] [Revised: 05/16/2017] [Accepted: 05/21/2017] [Indexed: 12/11/2022] Open
Abstract
Metallothioneins (MTs) are multifunctional proteins occurring throughout the animal kingdom. While the expression and transcriptional regulation of MTs is well-studied in vertebrates, the mechanism of MT activation is still unknown for most invertebrates. Therefore, we examined wMT-2 gene regulation and expression patterns in Lumbricus rubellus and L. terrestris. Transcription levels, the occupation of DNA binding sites, the expression of putative transcriptional regulators, and promotor DNA methylation were determined. We found that wMT-2 expression does not follow a circadian pattern. However, Cd-induced wMT-2 induction was observed, and was, interestingly, suppressed by physical injury. Moreover, the promotor region that is responsible for the wMT-2 gene regulation was elucidated. ATF, a putative transcriptional regulator, showed increased phosphorylation upon Cd exposure, suggesting that it plays a major role in wMT-2 gene activation. The promotor methylation of wMT-2, on the other hand, is probably not involved in transcriptional regulation. Elucidating the regulatory mechanism of the earthworm MT gene activation might provide insights into the molecular coordination of the environmental stress response in invertebrates, and might also reveal a link to wound repair and, in a broader sense, to immunity.
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Affiliation(s)
- Victoria Drechsel
- Institute of Zoology, Center for Molecular Biosciences, University of Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria.
| | - Karl Schauer
- Institute of Zoology, Center for Molecular Biosciences, University of Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria.
| | - Maja Šrut
- Division of Zoology, Faculty of Science, University of Zagreb, Rooseveltov trg 6, 10000 Zagreb, Croatia.
| | - Martina Höckner
- Institute of Zoology, Center for Molecular Biosciences, University of Innsbruck, Technikerstr. 25, 6020 Innsbruck, Austria.
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A tumor suppressor role for C/EBPα in solid tumors: more than fat and blood. Oncogene 2017; 36:5221-5230. [PMID: 28504718 DOI: 10.1038/onc.2017.151] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 03/29/2017] [Accepted: 04/10/2017] [Indexed: 12/12/2022]
Abstract
The transcription factor CCAAT/enhancer-binding protein alpha (C/EBPα) plays a critical role during embryogenesis and is thereafter required for homeostatic glucose metabolism, adipogenesis and myeloid development. Its ability to regulate the expression of lineage-specific genes and induce growth arrest contributes to the terminal differentiation of several cell types, including hepatocytes, adipocytes and granulocytes. CEBPA loss of-function mutations contribute to the development of ~10% of acute myeloid leukemia (AML), stablishing a tumor suppressor role for C/EBPα. Deregulation of C/EBPα expression has also been reported in a variety of additional human neoplasias, including liver, breast and lung cancer. However, functional CEBPA mutations have not been found in solid tumors, suggesting that abrogation of C/EBPα function in non-hematopoietic tissues is regulated by alternative mechanisms. Here we review the function of C/EBPα in solid tumors and focus on the molecular mechanisms underlying its tumor suppressive role.
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Takahashi S. Positive and negative regulators of the metallothionein gene (review). Mol Med Rep 2015; 12:795-9. [PMID: 25760317 DOI: 10.3892/mmr.2015.3459] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2014] [Accepted: 02/26/2015] [Indexed: 11/05/2022] Open
Abstract
Metallothioneins (MTs) are metal-binding proteins involved in diverse processes, including metal homeostasis and detoxification, the oxidative stress response and cell proliferation. Aberrant expression and silencing of these genes are important in a number of diseases. Several positive regulators of MT genes, including metal-responsive element-binding transcription factor (MTF)-1 and upstream stimulatory factor (USF)-1, have been identified and mechanisms of induction have been well described. However, the negative regulators of MT genes remain to be elucidated. Previous studies from the group of the present review have revealed that the hematopoietic master transcription factor, PU.1, directly represses the expression levels of MT genes through its epigenetic activities, and upregulation of MT results in the potent inhibition of myeloid differentiation. The present review focuses on PU.1 and several other negative regulators of this gene, including PZ120, DNA methyltransferase 3a with Mbd3 and Brg1 complex, CCAAT enhancer binding protein α and Ku protein, and describes the suppression of the MT genes through these transcription factors.
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Affiliation(s)
- Shinichiro Takahashi
- Division of Molecular Hematology, Kitasato University Graduate School of Medical Sciences and Division of Hematology, Kitasato University School of Allied Health Sciences, Sagamihara, Kanagawa 252‑0373, Japan
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Höckner M, Dallinger R, Stürzenbaum SR. Metallothionein gene activation in the earthworm (Lumbricus rubellus). Biochem Biophys Res Commun 2015; 460:537-42. [PMID: 25797623 PMCID: PMC4427108 DOI: 10.1016/j.bbrc.2015.03.065] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Accepted: 03/11/2015] [Indexed: 01/09/2023]
Abstract
In order to cope with changing environmental conditions, organisms require highly responsive stress mechanisms. Heavy metal stress is handled by metallothioneins (MTs), the regulation of which is evolutionary conserved in insects and vertebrates and involves the binding of metal transcription factor 1 (MTF-1) to metal responsive elements (MREs) positioned in the promoter of MT genes. However, in most invertebrate phyla, the transcriptional activation of MTs is different and the exact mechanism is still unknown. Interestingly, although MREs are typically present also in invertebrate MT gene promoters, MTF-1 is notably absent. Here we use Lumbricus rubellus, the red earthworm, to study the elusive mechanism of wMT-2 activation in control and Cd-exposed conditions. EMSA and DNase I footprinting approaches were used to pinpoint functional binding sites within the wMT-2 promoter region, which revealed that the cAMP responsive element (CRE) is a promising candidate which may act as a transcriptional activator of invertebrate MTs. The wMT-2 promoter region of Lumbricus rubellus was analyzed and revealed a CRE binding site acting as putative transcriptional activator. MREs from the wMT-2 promoter region were shown to be functional protein binding sites. The wMT-2 transcription revealed an induction at the mRNA and protein level upon Cd exposure.
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Affiliation(s)
- M Höckner
- University of Innsbruck, Institute of Zoology, Innsbruck, Austria; King's College London, Faculty of Life Sciences & Medicine, London, United Kingdom.
| | - R Dallinger
- University of Innsbruck, Institute of Zoology, Innsbruck, Austria.
| | - S R Stürzenbaum
- King's College London, Faculty of Life Sciences & Medicine, London, United Kingdom.
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Erickson DR, Schwarze SR, Dixon JK, Clark CJ, Hersh MA. Differentiation associated changes in gene expression profiles of interstitial cystitis and control urothelial cells. J Urol 2008; 180:2681-7. [PMID: 18951569 DOI: 10.1016/j.juro.2008.08.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2008] [Indexed: 12/14/2022]
Abstract
PURPOSE We evaluated gene expression profiles after inducing differentiation in cultured interstitial cystitis and control urothelial cells. MATERIALS AND METHODS Bladder biopsies were taken from patients with interstitial cystitis and controls, that is women undergoing surgery for stress incontinence. Primary cultures were grown in keratinocyte growth medium with supplements. To induce differentiation in some plates the medium was changed to Dulbecco's modified Eagle's minimal essential medium-F12 (Media Tech, Herndon, Virginia) with supplements. RNA was analyzed with Affymetrix(R) chips. Three patients with nonulcerative interstitial cystitis were compared with 3 controls. RESULTS After inducing differentiation 302 genes with a described function were altered at least 3-fold in interstitial cystitis and control cells (p <0.01). Functions of the 162 up-regulated genes included cell adhesion (eg claudins, occludin and cingulin), urothelial differentiation, the retinoic acid pathway and keratinocyte differentiation (eg skin cornified envelope components). The 140 down-regulated transcripts included genes associated with basal urothelium (eg p63, integrins beta4, alpha5 and alpha6, basonuclin 1 and extracellular matrix components), vimentin, metallothioneins, and members of the Wnt and Notch pathways. When comparing interstitial cystitis control cells after differentiation, only 7 genes with a described function were altered at least 3-fold (p <0.01). PI3, SERPINB4, CYP2C8, EFEMP2 and SEPP1 were decreased, and AKR1C2 and MKNK1 were increased in interstitial cystitis cases. CONCLUSIONS Differentiation associated changes occurred in interstitial cystitis and control cells. Comparing interstitial cystitis vs control cases revealed few differences. This study may have included patients with interstitial cystitis and minimal urothelial deficiency, and/or we may have selected cells that were most robust in culture. Also, the abnormal urothelium in interstitial cystitis cases may be due to post-translational changes and/or to the bladder environment.
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Affiliation(s)
- Deborah R Erickson
- Department of Surgery, Division of Urology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536-0298, USA.
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LaRochelle O, Labbé S, Harrisson JF, Simard C, Tremblay V, St-Gelais G, Govindan MV, Séguin C. Nuclear factor-1 and metal transcription factor-1 synergistically activate the mouse metallothionein-1 gene in response to metal ions. J Biol Chem 2008; 283:8190-201. [PMID: 18230604 DOI: 10.1074/jbc.m800640200] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Metal activation of metallothionein (MT) gene transcription is dependent on the presence of metal regulatory elements (MREs), which are present in five non-identical copies (MREa through MREe) in the promoter of the mouse MT-1 gene and on the capacity of metal transcription factor-1 (MTF-1) to bind to the MREs in the presence of zinc. We detected a protein, distinct from MTF-1, specifically binding to the MREc region. DNA binding competition experiments using synthetic oligonucleotides and specific anti-NF1 antibodies showed that this protein binds to an NF1 site overlapping the MREc element as well as to a second site upstream of the Sp1a site and corresponds to NF1 or a related protein. Transfection experiments showed that loss of the two NF1 sites decreased metal-induced MT promoter activity by 55-70% in transiently transfected cells and almost completely abrogated metal and tert-butylhydroquinone (tBHQ) induction in stably transfected cells. Similarly, expression of an inactive NF1 protein strongly inhibited MT-1 promoter activity. Using synthetic promoters containing NF1 and MRE sites fused to a minimal MT promoter, we showed that these NF1 sites did not confer metal induction but enhanced metal-induced promoter activity. Chromatin immunoprecipitation assays confirmed that NF1 binds to the mouse MT-1 promoter in vivo and showed that NF1 binding is zinc-inducible. In addition, zinc-induced NF1 DNA binding was MTF-1-dependent. Taken together, these studies show that NF1 acts synergistically with MTF-1 to activate the mouse MT-1 promoter in response to metal ions and tert-butylhydroquinone and contributes to maximal activation of the gene.
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Affiliation(s)
- Olivier LaRochelle
- Centre de Recherche en Cancérologie de l'Université Laval, CHUQ, Hôtel-Dieu de Québec, Québec, Canada
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Wei H, Desouki MM, Lin S, Xiao D, Franklin RB, Feng P. Differential expression of metallothioneins (MTs) 1, 2, and 3 in response to zinc treatment in human prostate normal and malignant cells and tissues. Mol Cancer 2008; 7:7. [PMID: 18208603 PMCID: PMC2265743 DOI: 10.1186/1476-4598-7-7] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Accepted: 01/21/2008] [Indexed: 11/10/2022] Open
Abstract
Background The disturbance of zinc homeostasis featured with a significant decrease of cellular zinc level was well documented to associate with the development and progression of human prostate malignancy. We have previously reported that zinc treatment induces prostate malignant cell apoptosis through mitochondrial pathway. Metallothionein (MT) is a major receptor/donor of zinc in the cells. However, the studies on the expression of MT in association with the prostate pathological and malignant status are very limited, and the zinc regulation of MT isoform expression in prostate cells remains elusive. The goals of this study were to define the expression of endogenous MTs, the isoforms of MT 1, 2, 3 at both messenger ribonucleic acid (mRNA) and protein levels; and to investigate the zinc effect on MT expression in normal prostate, benign prostatic hyperplasia (BPH) and malignant PC-3 cells, and in relevant human tissues. Cellular MT proteins were detected by immunohistochemistry, fluorescence staining and Western blot analysis; reverse transcription polymerase chain reaction (RT-PCR) was used to determine the MT isoform-specific mRNAs. Results Our results demonstrated a significant suppression of endogenous levels of MT1/2 in malignant PC-3 cells (95% reduction compared to the normal prostate cells) and in human adenocarcinoma tissues (73% MT1/2 negative). A moderate reduction of MT1/2 expression was observed in BPH. Zinc treatment remarkably induced MT1/2 expression in PC-3 and BPH cells, which was accordant with the restored cellular zinc level. MT 3, as a growth inhibitory factor, was detected and up-regulated by zinc mainly in BPH cells. Conclusion This study provided evidence of the association of attenuated MT1/2 with prostate tumor progression, and the zinc induction of MT1/2 expression resulting in cellular zinc restoration. The results suggest the potential of MT1/2 as a candidate biomarker for prostate cancer and the utilization of zinc in prostate cancer prevention and treatment.
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Affiliation(s)
- Hua Wei
- Department of Biomedical Sciences, Dental School, University of Maryland at Baltimore, Maryland, USA.
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Janssens TKS, Mariën J, Cenijn P, Legler J, van Straalen NM, Roelofs D. Recombinational micro-evolution of functionally different metallothionein promoter alleles from Orchesella cincta. BMC Evol Biol 2007; 7:88. [PMID: 17562010 PMCID: PMC1913499 DOI: 10.1186/1471-2148-7-88] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2007] [Accepted: 06/11/2007] [Indexed: 11/16/2022] Open
Abstract
Background Metallothionein (mt) transcription is elevated in heavy metal tolerant field populations of Orchesella cincta (Collembola). This suggests that natural selection acts on transcriptional regulation of mt in springtails at sites where cadmium (Cd) levels in soil reach toxic values This study investigates the nature and the evolutionary origin of polymorphisms in the metallothionein promoter (pmt) and their functional significance for mt expression. Results We sequenced approximately 1600 bp upstream the mt coding region by genome walking. Nine pmt alleles were discovered in NW-European populations. They differ in the number of some indels, consensus transcription factor binding sites and core promoter elements. Extensive recombination events between some of the alleles can be inferred from the alignment. A deviation from neutral expectations was detected in a cadmium tolerant population, pointing towards balancing selection on some promoter stretches. Luciferase constructs were made from the most abundant alleles, and responses to Cd, paraquat (oxidative stress inducer) and moulting hormone were studied in cell lines. By using paraquat we were able to dissect the effect of oxidative stress from the Cd specific effect, and extensive differences in mt induction levels between these two stressors were observed. Conclusion The pmt alleles evolved by a number of recombination events, and exhibited differential inducibilities by Cd, paraquat and molting hormone. In a tolerant population from a metal contaminated site, promoter allele frequencies differed significantly from a reference site and nucleotide polymorphisms in some promoter stretches deviated from neutral expectations, revealing a signature of balancing selection. Our results suggest that the structural differences in the Orchesella cincta metallothionein promoter alleles contribute to the metallothionein -over-expresser phenotype in cadmium tolerant populations.
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Affiliation(s)
- Thierry KS Janssens
- Vrije Universiteit, Institute of Ecological Sciences, Department of Animal Ecology, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands
| | - Janine Mariën
- Vrije Universiteit, Institute of Ecological Sciences, Department of Animal Ecology, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands
| | - Peter Cenijn
- Vrije Universiteit Amsterdam, Institute for Environmental Studies (IVM), de Boelelaan 1085, 1081 HV Amsterdam, the Netherlands
| | - J Legler
- Vrije Universiteit Amsterdam, Institute for Environmental Studies (IVM), de Boelelaan 1085, 1081 HV Amsterdam, the Netherlands
| | - Nico M van Straalen
- Vrije Universiteit, Institute of Ecological Sciences, Department of Animal Ecology, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands
| | - Dick Roelofs
- Vrije Universiteit, Institute of Ecological Sciences, Department of Animal Ecology, De Boelelaan 1085, 1081 HV Amsterdam, the Netherlands
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Gery S, Gombart AF, Yi WS, Koeffler C, Hofmann WK, Koeffler HP. Transcription profiling of C/EBP targets identifies Per2 as a gene implicated in myeloid leukemia. Blood 2005; 106:2827-36. [PMID: 15985538 PMCID: PMC1895299 DOI: 10.1182/blood-2005-01-0358] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2005] [Accepted: 06/06/2005] [Indexed: 12/16/2022] Open
Abstract
CCAAT/enhancer-binding proteins (C/EBPs) are a family of transcription factors that regulate cell growth and differentiation in numerous cell types. To identify novel C/EBP-target genes, we performed transcriptional profiling using inducible NIH 3T3 cell lines expressing 1 of 4 members of the C/EBP family. Functional analysis revealed a previously unknown link between C/EBP proteins and circadian clock genes. Our microarray data showed that the expression levels of 2 core components of the circadian network, Per2 and Rev-Erbalpha, were significantly altered by C/EBPs. Recent studies suggested that Per2 behaves as a tumor suppressor gene in mice. Therefore, we focused our additional studies on Per2. We showed that Per2 expression is up-regulated by C/EBPalpha and C/EBPepsilon. Per2 levels were reduced in lymphoma cell lines and in acute myeloid leukemia (AML) patient samples. In addition, we generated stable K562 cells that expressed an inducible Per2 gene. Induction of Per2 expression resulted in growth inhibition, cell cycle arrest, apoptosis, and loss of clonogenic ability. These results suggest that Per2 is a downstream C/EBPalpha-target gene involved in AML, and its disruption might be involved in initiation and/or progression of AML.
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Affiliation(s)
- Sigal Gery
- Cedars-Sinai Medical Center, Davis Bldg 5066, 8700 Beverly Blvd, Los Angeles, CA 90048, USA.
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Magda D, Lecane P, Miller RA, Lepp C, Miles D, Mesfin M, Biaglow JE, Ho VV, Chawannakul D, Nagpal S, Karaman MW, Hacia JG. Motexafin Gadolinium Disrupts Zinc Metabolism in Human Cancer Cell Lines. Cancer Res 2005; 65:3837-45. [PMID: 15867382 DOI: 10.1158/0008-5472.can-04-4099] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To gain a better understanding of the mechanism of action of the metal cation-containing chemotherapeutic drug motexafin gadolinium (MGd), gene expression profiling analyses were conducted on plateau phase human lung cancer (A549) cell cultures treated with MGd. Drug treatment elicited a highly specific response that manifested in elevated levels of metallothionein isoform and zinc transporter 1 (ZnT1) transcripts. A549 cultures incubated with MGd in the presence of exogenous zinc acetate displayed synergistic increases in the levels of intracellular free zinc, metallothionein transcripts, inhibition of thioredoxin reductase activity, and cell death. Similar effects were observed in PC3 prostate cancer and Ramos B-cell lymphoma cell lines. Intracellular free zinc levels increased in response to treatment with MGd in the absence of exogenous zinc, indicating that MGd can mobilize bound intracellular zinc. These findings lead us to suggest that an important component of the anticancer activity of MGd is related to its ability to disrupt zinc metabolism and alter cellular availability of zinc. This class of compounds may provide insight into the development of novel cancer drugs targeting control of intracellular free zinc and the roles that zinc and other metal cations play in biochemical pathways relevant to cancer.
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