1
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Ballestín R, Torres J, Ponsoda X. TSQ Incubation Enhances Autometallographic Zinc Detection in Cultured Astrocytes. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2024; 30:759-770. [PMID: 39027929 DOI: 10.1093/mam/ozae060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Revised: 04/01/2024] [Accepted: 06/18/2024] [Indexed: 07/20/2024]
Abstract
Zinc is a critical ion for a large number of cellular functions. In the central nervous system, zinc ions are involved in synaptic transmission. Therefore, zinc homeostasis is essential, and cells have developed a variety of mechanisms to control cellular zinc concentration, including the zincosome formation. Alterations of free zinc levels have been associated with brain dysfunction and are present in many illnesses and syndromes. Astrocytes are implicated in the maintenance of the neuronal milleu and brain homeostasis. In this work, we have analyzed the combination of direct (TSQ) and indirect (autometallography) zinc detection methods to increase sensitivity for studying zinc uptake by rat astrocytes in vitro. Zincosome formation was visualized with the zinc fluorochrome TSQ by light microscopy. Additionally, we improved both zinc precipitation and cellular fixation methods to preserve zinc ions and make them suitable for autometallography development. Our tests pinpointed paraformaldehyde and sodium sulfide as the more adequate methods for cellular fixation and zinc precipitation, respectively. TSQ incubation and pH of the fixative were shown to be crucial for autometallography. Using this improved method, we visualized the zinc content of zincosomes at the ultrastructural level both as silver autometallographic precipitates and as electrodense sulfide-osmium zinc precipitates.
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Affiliation(s)
- Raúl Ballestín
- Departamento Biología Celular, Biología Funcional y Antropología Física, Universitat de València, 46100 Burjassot, Valencia, Spain
| | - Josema Torres
- Departamento Biología Celular, Biología Funcional y Antropología Física, Universitat de València, 46100 Burjassot, Valencia, Spain
| | - Xavier Ponsoda
- Departamento Biología Celular, Biología Funcional y Antropología Física, Universitat de València, 46100 Burjassot, Valencia, Spain
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2
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Fang L, Watkinson M. Subcellular localised small molecule fluorescent probes to image mobile Zn 2. Chem Sci 2020; 11:11366-11379. [PMID: 34094379 PMCID: PMC8162803 DOI: 10.1039/d0sc04568c] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 10/07/2020] [Indexed: 12/26/2022] Open
Abstract
Zn2+, as the second most abundant d-block metal in the human body, plays an important role in a wide range of biological processes, and the dysfunction of its homeostasis is related to many diseases, including Type 2 diabetes, Alzheimer's disease and prostate and breast cancers. Small molecule fluorescent probes, as effective tools for real-time imaging, have been widely used to study Zn2+ related processes. However, the failure to control their localisation in cells has limited their utility somewhat, as they are generally incapable of studying individual processes in a specific cellular location. This perspective presents an overview of the recent developments in specific organelle localised small molecule fluorescent Zn2+ probes and their application in biological milieu, which could help to extend our understanding of the mechanisms that cells use to respond to dysfunction of zinc homeostasis and its roles in disease initiation and development.
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Affiliation(s)
- Le Fang
- The Joseph Priestley Building, School of Biological and Chemical Science, Queen Mary University of London Mile End Road London E1 4NS UK
| | - Michael Watkinson
- The Lennard-Jones Laboratories, School of Chemical and Physical Science, Keele University ST5 5BG UK
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3
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Zhu H, Tamura T, Hamachi I. Chemical proteomics for subcellular proteome analysis. Curr Opin Chem Biol 2019; 48:1-7. [DOI: 10.1016/j.cbpa.2018.08.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Revised: 08/02/2018] [Accepted: 08/03/2018] [Indexed: 11/17/2022]
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4
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Ariani A, Barozzi F, Sebastiani L, di Toppi LS, di Sansebastiano GP, Andreucci A. AQUA1 is a mercury sensitive poplar aquaporin regulated at transcriptional and post-translational levels by Zn stress. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2019; 135:588-600. [PMID: 30424909 DOI: 10.1016/j.plaphy.2018.10.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 10/30/2018] [Accepted: 10/30/2018] [Indexed: 05/19/2023]
Abstract
Aquaporins are water channel proteins that regulate plant development, growth, and response to environmental stresses. Populus trichocarpa is one of the plants with the highest number of aquaporins in its genome, but only few of them have been characterized at the whole plant functional level. Here we analyzed a putative aquaporin gene, aqua1, a gene that encodes for a protein of 257 amino acid with the typical NPA (Asp-Pro-Ala) signature motif of the aquaporin gene family. aqua1 was down-regulated of ∼10 fold under excess Zn in both leaves and roots, and conferred Zn tolerance when expressed in yeast Zn hypersensitive strain. In vivo localization of AQUA1-GFP in Arabidopsis protoplast showed a heterogeneous distribution of this protein on different membranes destined to form aggregates related to autophagic multivesicular bodies. Zn-dependent AQUA1-GFP re-localization was perturbed by phosphatases' and kinases' inhibitors that could affect both intracellular trafficking and aquaporins' activity. Exposed to high concentration of Zn, AQUA1 also co-localized with AtTIP1;1, a well-known Arabidopsis vacuolar marker, probably in pro-vacuolar multivesicular bodies. These findings suggest that high concentration of Zn down-regulates aqua1 and causes its re-localization in new forming pro-vacuoles. This Zn-dependent re-localization appears to be mediated by mechanisms regulating intracellular trafficking and aquaporins' post-translational modifications. This functional characterization of a poplar aquaporin in response to excess Zn will be a useful reference for understanding aquaporins' roles and regulation in response to high concentration of Zn in poplar.
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Affiliation(s)
- Andrea Ariani
- BioLabs, Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy
| | - Fabrizio Barozzi
- DISTEBA, Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Prov. le Lecce - Monteroni, 73100, Lecce, Italy
| | - Luca Sebastiani
- BioLabs, Institute of Life Sciences, Scuola Superiore Sant'Anna, Pisa, Italy
| | | | - Gian Pietro di Sansebastiano
- DISTEBA, Department of Biological and Environmental Sciences and Technologies, University of Salento, Via Prov. le Lecce - Monteroni, 73100, Lecce, Italy
| | - Andrea Andreucci
- Department of Biology, Università degli Studi di Pisa, I-56126, Pisa, Italy.
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5
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Essential Role of Zinc and Zinc Transporters in Myeloid Cell Function and Host Defense against Infection. J Immunol Res 2018; 2018:4315140. [PMID: 30417019 PMCID: PMC6207864 DOI: 10.1155/2018/4315140] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/27/2018] [Indexed: 12/19/2022] Open
Abstract
Zinc is an essential micronutrient known to play a vital role in host defense against pathogens. Diets that are deficient in zinc lead to impaired immunity and delayed recovery from and worse outcomes following infection. Sustained insufficient zinc intake leads to dysregulation of the innate immune response and increases susceptibility to infection whereas zinc supplementation in at-risk populations has been shown to restore host defense and reduce pathogen-related morbidity and mortality. Upon infection, zinc deficiency leads to increased pathology due to imbalance in key signaling networks that result in excessive inflammation and collateral tissue damage. In particular, zinc impacts macrophage function, a critical front-line cell in host defense, in addition to other immune cells. Deficits in zinc adversely impact macrophage function resulting in dysregulation of phagocytosis, intracellular killing, and cytokine production. An additional work in this field has revealed a vital role for several zinc transporter proteins that are required for proper bioredistribution of zinc within mononuclear cells to achieve an optimal immune response against invading microorganisms. In this review, we will discuss the most recent developments regarding zinc's role in innate immunity and protection against pathogen invasion.
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6
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Sturikova H, Krystofova O, Huska D, Adam V. Zinc, zinc nanoparticles and plants. JOURNAL OF HAZARDOUS MATERIALS 2018; 349:101-110. [PMID: 29414741 DOI: 10.1016/j.jhazmat.2018.01.040] [Citation(s) in RCA: 114] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 01/18/2018] [Accepted: 01/21/2018] [Indexed: 05/20/2023]
Abstract
Zinc belongs to the mineral elements, the so-called micronutrients, which are essential for all types of plants. Embedding itself into the enzymes associated with proteosynthesis and energy processes, zinc is necessary for maintaining the integrity of biomembranes and also plays an important role in the development of seeds and generative organs. This review focuses on summarising the findings on the interaction of zinc and plants and translates into the knowledge of the effect of zinc nanoparticles on plants. The findings include an overview of both positive and negative effects on plants. In conclusion there is a great interest in nano-zinc as improving the knowledge about individual forms of zinc and their uptake and assimilation within higher plants may be the first step towards a wider involvement of zinc nanoparticles into agriculture.
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Affiliation(s)
- Helena Sturikova
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Purkyňova 656/123, 612 00 BRNO, Czech Republic
| | - Olga Krystofova
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Purkyňova 656/123, 612 00 BRNO, Czech Republic
| | - Dalibor Huska
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Purkyňova 656/123, 612 00 BRNO, Czech Republic
| | - Vojtech Adam
- Department of Chemistry and Biochemistry, Mendel University in Brno, Zemedelska 1, 613 00 Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Purkyňova 656/123, 612 00 BRNO, Czech Republic.
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7
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Rudolf E. Depletion of ATP and Oxidative Stress Underlie Zinc-Induced Cell Injury. ACTA MEDICA (HRADEC KRÁLOVÉ) 2018. [DOI: 10.14712/18059694.2017.58] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The mechanisms of cell injury resulting in a special type of cell death combining the features of apoptosis and necrosis were examined in Hep-2 cells exposed to 300 μM zinc sulfate during 24h. Acute exposure to zinc induced a rapid rise in metallothionein levels and increased oxidative stress occurring in the absence of a significant early ATP depletion. Accentuated ATP loss and elevated levels of superoxide at later treatment intervals (12h and longer) were present along with increased DNA damage. Manipulation with ATP production and inhibition of NADPH oxidase had a positive effect on zinc-related increase in oxidative stress and influenced the observed type of cell death. These results suggest that Hep-2 cells acutely exposed to zinc increase intracellular labile zinc stores and over express metalothioneins. Elevated production of peroxides in zinc-treated cells is at later treatment intervals accompanied by an increase in superoxide levels, possibly by activation of NADPH oxidase, DNA damage and severe ATP loss. Prevention of critical ATP depletion and, in particular, inhibition of oxidative stress attenuates zinc-mediated cell injury and stimulates apoptosis-like phenotype in exposed cells.
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8
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Bafaro E, Liu Y, Xu Y, Dempski RE. The emerging role of zinc transporters in cellular homeostasis and cancer. Signal Transduct Target Ther 2017; 2:17029. [PMID: 29218234 PMCID: PMC5661630 DOI: 10.1038/sigtrans.2017.29] [Citation(s) in RCA: 157] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 04/21/2017] [Accepted: 04/25/2017] [Indexed: 12/21/2022] Open
Abstract
Zinc is an essential micronutrient that plays a role in the structural or enzymatic functions of many cellular proteins. Cellular zinc homeostasis involves the opposing action of two families of metal transporters: the ZnT (SLC30) family that functions to reduce cytoplasmic zinc concentrations and the ZIP (SLC39) family that functions to increase cytoplasmic zinc concentrations. Fluctuations in intracellular zinc levels mediated by these transporter families affect signaling pathways involved in normal cell development, growth, differentiation and death. Consequently, changes in zinc transporter localization and function resulting in zinc dyshomeostasis have pathophysiological effects. Zinc dyshomeostasis has been implicated in the progression of cancer. Here we review recent progress toward understanding the structural basis for zinc transport by ZnT and ZIP family proteins, as well as highlight the roles of zinc as a signaling molecule in physiological conditions and in various cancers. As zinc is emerging as an important signaling molecule in the development and progression of cancer, the ZnT and ZIP transporters that regulate cellular zinc homeostasis are promising candidates for targeted cancer therapy.
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Affiliation(s)
- Elizabeth Bafaro
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Yuting Liu
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
| | - Yan Xu
- Department of Obstetrics and Gynecology, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | - Robert E Dempski
- Department of Chemistry and Biochemistry, Worcester Polytechnic Institute, Worcester, Massachusetts, USA
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9
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Rudolf E. Increased Uptake of Zinc in Malignant Cells is Associated with Enhanced Activation of MAPK Signalling and P53-Dependent Cell Injury. ACTA MEDICA (HRADEC KRÁLOVÉ) 2017; 51:43-9. [DOI: 10.14712/18059694.2017.7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Excess intracellular zinc has been demonstrated to be responsible for cell injury and cell death in various experimental as well as clinical models. While the cells possess a system of mechanisms regulating intracellular zinc homeostasis, their saturation by acutely increased zinc levels or by a sustained exposure to elevated zinc levels results in liberation of free zinc stores within the cells and ultimate cell damage and cell death. Here we report that in Hep-2 malignant cells enhanced uptake of zinc causes activation of mitogen-activated protein kinase (MAPK) signaling with resulting p53-dependent cell injury which can be significantly prevented by specific p53 inhibition and by prevention of oxidative stress. Our observations are consistent with the view that subacutely increased intracellular free zinc levels stimulate via oxidative stress p53-dependent pathways which are responsible for the final cell damage in tumor cells.
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10
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A conditional proteomics approach to identify proteins involved in zinc homeostasis. Nat Methods 2016; 13:931-937. [PMID: 27617391 DOI: 10.1038/nmeth.3998] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Accepted: 07/21/2016] [Indexed: 12/19/2022]
Abstract
Zinc signaling and dynamics play significant roles in many physiological responses and diseases. To understand the physiological roles of zinc in detail, comprehensive identification of proteins under high concentration of mobile zinc ion is crucial. We developed a 'conditional proteomics' approach to identify proteins involved in zinc homeostasis based on a chemical proteomic strategy that utilizes designer zinc-responsive labeling reagents to tag such proteins and quantitative mass spectrometry for their identification. We used this method to elucidate zinc dyshomeostasis induced by nitric-oxide-triggered oxidative stress in glioma cells, and we unveiled dynamic changes of the zinc-related proteomes. Moreover, we characterized unknown zinc-rich vesicles generated by oxidative stress as endoplasmic-reticulum- and Golgi-related vesicles.
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11
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Sharma SS, Dietz KJ, Mimura T. Vacuolar compartmentalization as indispensable component of heavy metal detoxification in plants. PLANT, CELL & ENVIRONMENT 2016; 39:1112-26. [PMID: 26729300 DOI: 10.1111/pce.12706] [Citation(s) in RCA: 259] [Impact Index Per Article: 32.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 12/15/2015] [Accepted: 12/22/2015] [Indexed: 05/02/2023]
Abstract
Plant cells orchestrate an array of molecular mechanisms for maintaining plasmatic concentrations of essential heavy metal (HM) ions, for example, iron, zinc and copper, within the optimal functional range. In parallel, concentrations of non-essential HMs and metalloids, for example, cadmium, mercury and arsenic, should be kept below their toxicity threshold levels. Vacuolar compartmentalization is central to HM homeostasis. It depends on two vacuolar pumps (V-ATPase and V-PPase) and a set of tonoplast transporters, which are directly driven by proton motive force, and primary ATP-dependent pumps. While HM non-hyperaccumulator plants largely sequester toxic HMs in root vacuoles, HM hyperaccumulators usually sequester them in leaf cell vacuoles following efficient long-distance translocation. The distinct strategies evolved as a consequence of organ-specific differences particularly in vacuolar transporters and in addition to distinct features in long-distance transport. Recent molecular and functional characterization of tonoplast HM transporters has advanced our understanding of their contribution to HM homeostasis, tolerance and hyperaccumulation. Another important part of the dynamic vacuolar sequestration syndrome involves enhanced vacuolation. It involves vesicular trafficking in HM detoxification. The present review provides an updated account of molecular aspects that contribute to the vacuolar compartmentalization of HMs.
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Affiliation(s)
- Shanti S Sharma
- Department of Biosciences, Himachal Pradesh University, Shimla, 171005, India
| | - Karl-Josef Dietz
- Department of Biochemistry and Physiology of Plants, Faculty of Biology, University of Bielefeld, D-33501, Bielefeld, Germany
| | - Tetsuro Mimura
- Department of Biology, Graduate School of Science, Kobe University, Nada-ku, Kobe, 657-8501, Japan
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12
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Nowakowski AB, Meeusen JW, Menden H, Tomasiewicz H, Petering DH. Chemical–Biological Properties of Zinc Sensors TSQ and Zinquin: Formation of Sensor-Zn-Protein Adducts versus Zn(Sensor)2 Complexes. Inorg Chem 2015; 54:11637-47. [DOI: 10.1021/acs.inorgchem.5b01535] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Andrew B. Nowakowski
- Department of Chemistry
and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Jeffrey W. Meeusen
- Department of Chemistry
and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | - Heather Menden
- Department of Chemistry
and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
| | | | - David H. Petering
- Department of Chemistry
and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, United States
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13
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Kiedrowski L. Neuronal acid-induced [Zn²⁺]i elevations calibrated using the low-affinity ratiometric probe FuraZin-1. J Neurochem 2015; 135:777-86. [PMID: 26263185 DOI: 10.1111/jnc.13282] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 08/03/2015] [Accepted: 08/07/2015] [Indexed: 11/30/2022]
Abstract
The experiments were carried out on primary cultures of murine cortical neurons from cryopreserved preparations obtained from embryonic-day-16 fetuses. To calibrate acid-induced intracelluar [Zn(2+) ] ([Zn(2+) ]i ) elevations, a low affinity (Kd = 39 μM at pH 6.1) ratiometric Zn(2+) probe, FuraZin-1, was used. A pHi drop from 7.2 to 6.1 caused [Zn(2+) ]i elevations reaching 2 μM; when the thiol-reactive agent N-ethylmaleimide (NEM) was subsequently applied, [Zn(2+) ]i increased further to 5.6 μM; analogous acid- and NEM-induced [Zn(2+) ]i elevations could also be detected but not calibrated, using the high affinity Zn(2+) probe FluoZin-3. The data indicate that NEM causes Zn(2+) release from ligands that chelate Zn(2+) at pH 6.1. ATP could also chelate Zn(2+) at pH 6.1 because its pKa is about 6.8. Therefore, it was tested whether an ATP depletion affects the acid-induced [Zn(2+) ]i elevations. The ATP depletion was induced by inhibiting mitochondrial and glycolytic ATP production. Interestingly, an almost complete ATP depletion (confirmed using a luciferin/luciferase assay) failed to affect the acid-induced [Zn(2+) ]i increases. These data suggest that the total amount of Zn(2+) accumulated in intracellular ATP-dependent stores (Zn(2+) -ATP complexes and organelles that accumulate Zn(2+) in an ATP-dependent manner) is negligible compared to the amount of Zn(2+) accumulated in the acid-sensitive intracellular ligands. In vitro, upon acidification, Zn(2+) -cysteine complexes release Zn(2+) and ATP chelates the released Zn(2+) . However, in vivo (cultured neurons), an ATP depletion failed to enhance acid-induced [Zn(2+) ]i elevations. These [Zn(2+) ]i elevations were calibrated using a low affinity ratiometric probe FuraZin-1; they reached 2 µM levels and increased to 5 µM when a thiol-reactive agent, N-ethylmaleimide, compromised Zn(2+) binding by cysteines.
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Affiliation(s)
- Lech Kiedrowski
- The Psychiatric Institute, Departments of Psychiatry and Pharmacology, The University of Illinois at Chicago, Chicago, Illinois, USA
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14
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Lee SR, Noh SJ, Pronto JR, Jeong YJ, Kim HK, Song IS, Xu Z, Kwon HY, Kang SC, Sohn EH, Ko KS, Rhee BD, Kim N, Han J. The Critical Roles of Zinc: Beyond Impact on Myocardial Signaling. THE KOREAN JOURNAL OF PHYSIOLOGY & PHARMACOLOGY : OFFICIAL JOURNAL OF THE KOREAN PHYSIOLOGICAL SOCIETY AND THE KOREAN SOCIETY OF PHARMACOLOGY 2015; 19:389-99. [PMID: 26330751 PMCID: PMC4553398 DOI: 10.4196/kjpp.2015.19.5.389] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Revised: 06/04/2015] [Accepted: 06/08/2015] [Indexed: 12/15/2022]
Abstract
Zinc has been considered as a vital constituent of proteins, including enzymes. Mobile reactive zinc (Zn(2+)) is the key form of zinc involved in signal transductions, which are mainly driven by its binding to proteins or the release of zinc from proteins, possibly via a redox switch. There has been growing evidence of zinc's critical role in cell signaling, due to its flexible coordination geometry and rapid shifts in protein conformation to perform biological reactions. The importance and complexity of Zn(2+) activity has been presumed to parallel the degree of calcium's participation in cellular processes. Whole body and cellular Zn(2+) levels are largely regulated by metallothioneins (MTs), Zn(2+) importers (ZIPs), and Zn(2+) transporters (ZnTs). Numerous proteins involved in signaling pathways, mitochondrial metabolism, and ion channels that play a pivotal role in controlling cardiac contractility are common targets of Zn(2+). However, these regulatory actions of Zn(2+) are not limited to the function of the heart, but also extend to numerous other organ systems, such as the central nervous system, immune system, cardiovascular tissue, and secretory glands, such as the pancreas, prostate, and mammary glands. In this review, the regulation of cellular Zn(2+) levels, Zn(2+)-mediated signal transduction, impacts of Zn(2+) on ion channels and mitochondrial metabolism, and finally, the implications of Zn(2+) in health and disease development were outlined to help widen the current understanding of the versatile and complex roles of Zn(2+).
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Affiliation(s)
- Sung Ryul Lee
- Department of Integrated Biomedical Science, Cardiovascular and Metabolic disease Center, College of Medicine, Inje University, Busan 614-735, Korea
| | - Su Jin Noh
- Department of Physiology, Graduate School of Inje University, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | - Julius Ryan Pronto
- Department of Physiology, Graduate School of Inje University, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | - Yu Jeong Jeong
- Department of Physiology, Graduate School of Inje University, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | - Hyoung Kyu Kim
- Department of Integrated Biomedical Science, Cardiovascular and Metabolic disease Center, College of Medicine, Inje University, Busan 614-735, Korea
| | - In Sung Song
- College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | - Zhelong Xu
- Department of Physiology and Pathophysiology, Tianjin Medical University, Tainjin 300070, P.R. China
| | - Hyog Young Kwon
- Soonchunhyang Institute of Medio-bio Science (SIMS), Soonchunhyang University, Cheonan 336-745, Korea
| | - Se Chan Kang
- Department of Life Science, Gachon University, Seongnam 461-701, Korea
| | - Eun-Hwa Sohn
- Department of Herbal Medicine Resource, Kangwon National University, Samcheok 245-711, Korea
| | - Kyung Soo Ko
- College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | - Byoung Doo Rhee
- College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | - Nari Kim
- College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
| | - Jin Han
- College of Medicine, Cardiovascular and Metabolic Disease Center, Inje University, Busan 614-735, Korea
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15
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Prakash A, Bharti K, Majeed ABA. Zinc: indications in brain disorders. Fundam Clin Pharmacol 2015; 29:131-49. [PMID: 25659970 DOI: 10.1111/fcp.12110] [Citation(s) in RCA: 73] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2014] [Revised: 07/08/2014] [Accepted: 12/24/2014] [Indexed: 12/14/2022]
Abstract
Zinc is the authoritative metal which is present in our body, and reactive zinc metal is crucial for neuronal signaling and is largely distributed within presynaptic vesicles. Zinc also plays an important role in synaptic function. At cellular level, zinc is a modulator of synaptic activity and neuronal plasticity in both development and adulthood. Different importers and transporters are involved in zinc homeostasis. ZnT-3 is a main transporter involved in zinc homeostasis in the brain. It has been found that alterations in brain zinc status have been implicated in a wide range of neurological disorders including impaired brain development and many neurodegenerative disorders such as Alzheimer's disease, and mood disorders including depression, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, and prion disease. Furthermore, zinc has also been implicated in neuronal damage associated with traumatic brain injury, stroke, and seizure. Understanding the mechanisms that control brain zinc homeostasis is thus critical to the development of preventive and treatment strategies for these and other neurological disorders.
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Affiliation(s)
- Atish Prakash
- Brain Degeneration and Therapeutics Group, Brain and Neuroscience Communities of Research, Universiti Teknologi MARA (UiTM), Shah Alam, 40450, Malaysia; Department of Pharmacology, ISF college of Pharmacy, Ghal kalan, Moga, 142-001, India; Brain Research Laboratory, Faculty of Pharmacy, Campus Puncak Alam, Universiti Teknologi MARA (UiTM), Bandar Puncak Alam, 42300, Malaysia
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16
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Chen Y, Bai Y, Han Z, He W, Guo Z. Photoluminescence imaging of Zn2+in living systems. Chem Soc Rev 2015; 44:4517-46. [DOI: 10.1039/c5cs00005j] [Citation(s) in RCA: 195] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Advances in PL imaging techniques, such as confocal microscopy, two photon microscopy, lifetime and optical imaging techniques, have made remarkable contributions in Zn2+tracking.
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Affiliation(s)
- Yuncong Chen
- State Key Laboratory of Coordination Chemistry
- Coordination Chemistry Institute
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Yang Bai
- State Key Laboratory of Coordination Chemistry
- Coordination Chemistry Institute
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Zhong Han
- State Key Laboratory of Coordination Chemistry
- Coordination Chemistry Institute
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Weijiang He
- State Key Laboratory of Coordination Chemistry
- Coordination Chemistry Institute
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
| | - Zijian Guo
- State Key Laboratory of Coordination Chemistry
- Coordination Chemistry Institute
- School of Chemistry and Chemical Engineering
- Nanjing University
- Nanjing 210093
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17
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Abstract
Metal ion assimilation is essential for all forms of life. However, organisms must properly control the availability of these nutrients within the cell to avoid inactivating proteins by mismetallation. To safeguard against an imbalance between supply and demand in eukaryotes, intracellular compartments contain metal transporters that load and unload metals. Although the vacuoles of Saccharomyces cerevisiae and Arabidopsis thaliana are well established locales for the storage of copper, zinc, iron, and manganese, related compartments are emerging as important mediators of metal homeostasis. Here we describe these compartments and review their metal transporter complement.
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Affiliation(s)
| | - Sabeeha S Merchant
- From the Department of Chemistry and Biochemistry and the Institute for Genomics and Proteomics, UCLA, Los Angeles, California 90095
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18
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Kiedrowski L. Proton-dependent zinc release from intracellular ligands. J Neurochem 2014; 130:87-96. [PMID: 24606401 DOI: 10.1111/jnc.12712] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 03/01/2014] [Accepted: 03/06/2014] [Indexed: 11/30/2022]
Abstract
In cultured cortical and hippocampal neurons when intracellular pH drops from 6.6 to 6.1, yet unclear intracellular stores release micromolar amounts of Zn(2+) into the cytosol. Mitochondria, acidic organelles, and/or intracellular ligands could release this Zn(2+) . Although exposure to the protonophore FCCP precludes reloading of the mitochondria and acidic organelles with Zn(2+) , FCCP failed to compromise the ability of the intracellular stores to repeatedly release Zn(2+) . Therefore, Zn(2+) -releasing stores were not mitochondria or acidic organelles but rather intracellular Zn(2+) ligands. To test which ligands might be involved, the rate of acid-induced Zn(2+) release from complexes with cysteine, glutathione, histidine, aspartate, glutamate, glycine, and carnosine was investigated; [Zn(2+) ] was monitored in vitro using the ratiometric Zn(2+) -sensitive fluorescent probe FuraZin-1. Carnosine failed to chelate Zn(2+) but did chelate Cu(2+) ; the remaining ligands chelated Zn(2+) and upon acidification were releasing it into the medium. However, when pH was decreasing from 6.6 to 6.1, only zinc-cysteine complexes rapidly accelerated the rate of Zn(2+) release. The zinc-cysteine complexes also released Zn(2+) when a histidine-modifying agent, diethylpyrocarbonate, was applied at pH 7.2. Since the cytosolic zinc-cysteine complexes can contain micromolar amounts of Zn(2+) , these complexes may represent the stores responsible for an acid-induced intracellular Zn(2+) release. This study aimed at identifying intracellular stores which release Zn(2+) when pHi drops from 6.6 to 6.1. It was found that these stores are not mitochondria or acidic organelles, but rather intracellular Zn(2+) ligands. When the pH was decreasing from 6.6 to 6.1, only zinc-cysteine complexes showed a rapid acceleration in the rate of Zn(2+) release. Therefore, the stores responsible for an acid-induced intracellular Zn(2+) release in neurons may be the cytosolic zinc-cysteine complexes.
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Affiliation(s)
- Lech Kiedrowski
- Departments of Psychiatry and Pharmacology, The Psychiatric Institute, The University of Illinois at Chicago, Chicago, Illinois, USA
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19
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Schweigel-Röntgen M. The families of zinc (SLC30 and SLC39) and copper (SLC31) transporters. CURRENT TOPICS IN MEMBRANES 2014; 73:321-55. [PMID: 24745988 DOI: 10.1016/b978-0-12-800223-0.00009-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The solute carriers families 30 (SLC30; ZnT), 39 (SLC39; ZIP), and 31 (SLC31; CTR) are involved in the essential maintenance of cellular zinc (Zn²⁺) and copper (Cu²⁺) homeostasis, respectively. ZnTs mediate Zn²⁺ extrusion from cells (SLC30A1) or transport Zn²⁺ into organelles and secretory vesicles/granules (SLC30A2-SLC30A8). SLC39 family members are predominantly localized to the cell membrane where they perform Zn²⁺ uptake and increase the availability of cytosolic Zn²⁺. SLC39A1 is ubiquitously expressed, whereas other ZIP transporters (e.g., SLC39A2 and SLC39A3) show a more tissue-restricted expression consistent with organ-specific functions of these proteins. The members A1 (CTR1) and A2 (CTR2) of the SLC31 family of solute carriers belong to a network of proteins that acts to regulate the intracellular Cu²⁺ concentration within a certain range. SLC31A1 is predominantly localized to the plasma membrane, whereas SLC31A2 is mainly found in intracellular membranes of the late endosome and lysosome. The specific function of SLC31A2 is not known. SLC31A1 is ubiquitously expressed and has been characterized as a high-affinity importer of reduced copper (Cu⁺). Cu²⁺ transport function of CTR proteins is associated with oligomerization; SLC31A1 trimerizes and thereby forms a channel-like structure enabling Cu²⁺ translocation across the cell membrane. The molecular characteristics and structural details (e.g., membrane topology, conserved Zn²⁺, and Cu²⁺ binding sites) and mechanisms of translational and posttranslational regulation of expression and/or activity have been described for SLC30 and SLC39 family members, and for SLC31A1. For SLC31A1, data on tissue-specific functions (e.g., in the intestine, heart, and liver) are also available. A link between SLC31A1, immune function, and disorders such as Alzheimer's disease or cancer makes the protein a candidate therapeutic target. In secretory tissues (e.g., the mammary gland and pancreas), Zn²⁺ transporters of SLC families 30 and 39 are involved in specific functions such as insulin synthesis and secretion, metallation of digestive proenzymes, and transfer of nutrients into milk. Defective or dysregulated Zn²⁺ metabolism in these organs is associated with disorders such as diabetes and cancer, and impaired Zn²⁺ secretion into milk.
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Affiliation(s)
- Monika Schweigel-Röntgen
- Institute for Muscle Biology & Growth, Leibniz Institute for Farm Animal Biology, Dummerstorf, Germany.
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20
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Zhang ZY, Xu YD, Ma YY, Qiu LL, Wang Y, Kong JL, Xiong HM. Biodegradable ZnO@polymer Core-Shell Nanocarriers: pH-Triggered Release of Doxorubicin In Vitro. Angew Chem Int Ed Engl 2013. [DOI: 10.1002/ange.201300431] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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21
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Zhang ZY, Xu YD, Ma YY, Qiu LL, Wang Y, Kong JL, Xiong HM. Biodegradable ZnO@polymer Core-Shell Nanocarriers: pH-Triggered Release of Doxorubicin In Vitro. Angew Chem Int Ed Engl 2013; 52:4127-31. [DOI: 10.1002/anie.201300431] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Indexed: 12/17/2022]
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22
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Zhang C, Liu Z, Li Y, He W, Gao X, Guo Z. In vitro and in vivo imaging application of a 1,8-naphthalimide-derived Zn2+ fluorescent sensor with nuclear envelope penetrability. Chem Commun (Camb) 2013; 49:11430-2. [DOI: 10.1039/c3cc46862c] [Citation(s) in RCA: 62] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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23
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Jeong J, Walker JM, Wang F, Park JG, Palmer AE, Giunta C, Rohrbach M, Steinmann B, Eide DJ. Promotion of vesicular zinc efflux by ZIP13 and its implications for spondylocheiro dysplastic Ehlers-Danlos syndrome. Proc Natl Acad Sci U S A 2012; 109:E3530-8. [PMID: 23213233 PMCID: PMC3529093 DOI: 10.1073/pnas.1211775110] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Zinc is essential but potentially toxic, so intracellular zinc levels are tightly controlled. A key strategy used by many organisms to buffer cytosolic zinc is to store it within vesicles and organelles.It is yet unknown whether vesicular or organellar sites perform this function in mammals. Human ZIP13, a member of the Zrt/Irt-like protein (ZIP) metal transporter family, might provide an answer to this question. Mutations in the ZIP13 gene, SLC39A13, previously were found to cause the spondylocheiro dysplastic form of Ehlers–Danlos syndrome (SCD-EDS), a heritable connective tissue disorder.Those previous studies suggested that ZIP13 transports excess zinc out of the early secretory pathway and that zinc overload in the endoplasmic reticulum (ER) occurs in SCD-EDS patients. In contrast,this study indicates that ZIP13’s role is to release labile zinc from vesicular stores for use in the ER and other compartments. We propose that SCD-EDS is the result of vesicular zinc trapping and ER zinc deficiency rather than overload.
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Affiliation(s)
- Jeeyon Jeong
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI 53706, USA.
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24
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Abstract
Bioavailable levels of trace metals, such as iron and zinc, for bacterial growth in nature are sufficiently low that most microbes have evolved high-affinity binding and transport systems. The microbe Campylobacter jejuni lives in the gastrointestinal tract of chickens, the principal source of human infection. A high-affinity ABC transporter for zinc uptake is required for Campylobacter survival in chicken intestines in the presence of a normal microbiota but not when chickens are raised with a limited microbiota. Mass spectrometric analysis of cecal contents revealed the presence of numerous zinc-binding proteins in conventional chicks compared to the number in limited-microbiota chicks. The presence of a microbiota results in the production of host zinc-binding enzymes, causing a growth restriction for bacteria that lack the high-affinity zinc transporter. Such transporters in a wide range of pathogenic bacteria make them good targets for the development of broad-spectrum antimicrobials. Importance Zinc is an essential trace element for the growth of most organisms. Quantities of zinc inside cells are highly regulated, as too little zinc does not support growth, while too much zinc is toxic. Numerous bacterial cells require zinc uptake systems for growth and virulence. The work presented here demonstrates that the microbiota in the gastrointestinal tract reduces the quantity of zinc. Without a high-affinity zinc transporter, Campylobacter jejuni, a commensal organism of chickens, is unable to replicate or colonize the gastrointestinal tract. This is the first demonstration of zinc competition between microbiota in the gastrointestinal tract of a host. These results could have profound implications in the field of microbial pathogenesis and in our understanding of host metabolism and the microbiota. Zinc is an essential trace element for the growth of most organisms. Quantities of zinc inside cells are highly regulated, as too little zinc does not support growth, while too much zinc is toxic. Numerous bacterial cells require zinc uptake systems for growth and virulence. The work presented here demonstrates that the microbiota in the gastrointestinal tract reduces the quantity of zinc. Without a high-affinity zinc transporter, Campylobacter jejuni, a commensal organism of chickens, is unable to replicate or colonize the gastrointestinal tract. This is the first demonstration of zinc competition between microbiota in the gastrointestinal tract of a host. These results could have profound implications in the field of microbial pathogenesis and in our understanding of host metabolism and the microbiota.
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25
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Alam S, Kelleher SL. Cellular mechanisms of zinc dysregulation: a perspective on zinc homeostasis as an etiological factor in the development and progression of breast cancer. Nutrients 2012; 4:875-903. [PMID: 23016122 PMCID: PMC3448077 DOI: 10.3390/nu4080875] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2012] [Revised: 07/11/2012] [Accepted: 07/17/2012] [Indexed: 12/29/2022] Open
Abstract
Worldwide, breast cancer is the most commonly diagnosed cancer among women and is the leading cause of female cancer deaths. Zinc (Zn) functions as an antioxidant and plays a role in maintaining genomic stability. Zn deficiency results in oxidative DNA damage and increased cancer risk. Studies suggest an inverse association between dietary and plasma Zn levels and the risk for developing breast cancer. In contrast, breast tumor biopsies display significantly higher Zn levels compared with normal tissue. Zn accumulation in tumor tissue also correlates with increased levels of Zn importing proteins. Further, aberrant expression of Zn transporters in tumors correlates with malignancy, suggesting that altered metal homeostasis in the breast could contribute to malignant transformation and the severity of cancer. However, studies have yet to link dysregulated Zn transport and abnormal Zn-dependent functions in breast cancer development. Herein, we summarize studies that address the multi-modal role of Zn dyshomeostasis in breast cancer with respect to the role of Zn in modulating oxidative stress, DNA damage response/repair pathways and cell proliferation/apoptosis, and the relationship to aberrant regulation of Zn transporters. We also compare Zn dysregulation in breast tissue to that of prostate, pancreatic and ovarian cancer where possible.
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Affiliation(s)
- Samina Alam
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA 16802, USA;
| | - Shannon L. Kelleher
- Department of Nutritional Sciences, The Pennsylvania State University, University Park, PA 16802, USA;
- Department of Surgery, the Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
- Cell and Molecular Physiology, the Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
- Author to whom correspondence should be addressed; ; Tel.: +1-814-863-9680; Fax: +1-814-863-6103
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26
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Affiliation(s)
- Kasper P Kepp
- DTU Chemistry, Technical University of Denmark, DK 2800 Kongens Lyngby, Denmark.
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27
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Nowakowski A, Petering D. Sensor specific imaging of proteomic Zn2+ with zinquin and TSQ after cellular exposure to N-ethylmaleimide. Metallomics 2012; 4:448-56. [PMID: 22498931 DOI: 10.1039/c2mt00189f] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The impact of the thiol binding reagent N-ethylmaleimide (NEM) on proteomic Zn(2+) availability was investigated in rat glioma cells. Zinquin (ZQ) or TSQ, two related fluorescent sensors, were used to observe reactive Zn(2+). Control cells contained proteomic Zn(2+) but no detectable low molecular weight (LMW) Zn(2+). With either sensor, basal cellular fluorescence emission centered near 470 nm, indicative of sensor-Zn-proteins. ZQ sequestered 13% of proteomic Zn(2+) as Zn(ZQ)(2); TSQ reacted only with the Zn-proteome. NEM (100 μM) abolished LMW thiols, including glutathione (GSH) and lowered proteomic sulfhydryl content about 30%. In ZQ-treated cells, NEM exposure enhanced fluorescent intensity and the formation of Zn(ZQ)(2) (λ(MAX), 492 nm). Cells incubated with TSQ and NEM also displayed increased fluorescence without a spectral shift in wavelength maximum, consistent with increased formation of TSQ-Zn-protein adducts but not Zn(TSQ)(2). In neither experiment was Zn(2+) lost from cells. NEM altered Zn(2+) accessibility to sensors in membrane-nuclear and cytosolic fractions, but Zn(ZQ)(2) was only generated in the cytosol. Similar results were obtained when cell supernatant replaced cells. In contrast, when isolated proteome was reacted with ZQ and 100 μM NEM in the absence of GSH, 70% of the proteomic thiols underwent reaction. As a consequence, most of the ZQ-Zn-protein adducts were converted to Zn(ZQ)(2). Substituting TSQ for ZQ, only increased TSQ-Zn-proteins were observed. Evidently, the results of imaging cells with Zn(2+) sensors are dependent upon the specific chemical properties of the sensors and can only be understood after detailed chemical analysis.
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Affiliation(s)
- Andrew Nowakowski
- Department of Chemistry and Biochemistry, University of Wisconsin, Milwaukee 53201, USA.
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28
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Yuan DS. Dithizone staining of intracellular zinc: an unexpected and versatile counterscreen for auxotrophic marker genes in Saccharomyces cerevisiae. PLoS One 2011; 6:e25830. [PMID: 21998704 PMCID: PMC3187812 DOI: 10.1371/journal.pone.0025830] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2011] [Accepted: 09/12/2011] [Indexed: 12/26/2022] Open
Abstract
Auxotrophic marker genes such as URA3, LEU2, and HIS3 in Saccharomyces cerevisiae have long been used to select cells that have been successfully transformed with recombinant DNA. A longstanding challenge in working with these genes is that counterselection procedures are often lacking. This paper describes the unexpected discovery of a simple plate assay that imparts a bright red stain to cells experiencing nutritional stress from the lack of a marker gene. The procedure specifically stains a zinc-rich vesicular compartment analogous to the zinc-rich secretory vesicles found in insulin-secreting pancreatic islet cells and glutamate-secreting neurons. Staining was greatly diminished in zap1 mutants, which lack a homeostatic activator of zinc uptake, and in cot1 zrc1 double mutants, which lack the two yeast homologs of mammalian vesicle-specific zinc export proteins. Only one of 93 strains with temperature-sensitive alleles of essential genes exhibited an increase in dithizone staining at its non-permissive temperature, indicating that staining is not simply a sign of growth-arrested or dying cells. Remarkably, the procedure works with most commonly used marker genes, highlights subtle defects, uses no reporter constructs or expensive reagents, requires only a few hours of incubation, yields visually striking results without any instrumentation, and is not toxic to the cells. Many potential applications exist for dithizone staining, both as a versatile counterscreen for auxotrophic marker genes and as a powerful new tool for the genetic analysis of a biomedically important vesicular organelle.
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Affiliation(s)
- Daniel S Yuan
- Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America.
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29
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Nowakowski AB, Petering DH. Reactions of the fluorescent sensor, Zinquin, with the zinc-proteome: adduct formation and ligand substitution. Inorg Chem 2011; 50:10124-33. [PMID: 21905645 DOI: 10.1021/ic201076w] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Zinquin (ZQ) is a commonly used sensor for cellular Zn(2+) status. It has been assumed that it measures accessible Zn(2+) concentrations in the nanomolar range. Instead, this report shows a consistent pattern across seven mammalian cell and tissue types that ZQ reacts with micromolar concentrations of Zn(2+) bound as Zn-proteins. The predominant class of products were ZQ-Zn-protein adducts that were characterized in vivo and in vitro by a fluorescence emission spectrum centered at about 470 nm, by their migration over Sephadex G-75 as protein not low molecular weight species, by the exclusion of reaction with lipid vesicles, and by their large aggregate concentration. In addition, variable, minor formation of Zn(ZQ)(2) with a fluorescence band at about 490 nm was observed in vivo in each case. Because incubation of isolated Zn-proteome with ZQ also generated similar amounts of Zn(ZQ)(2), it was concluded that this species had formed through direct ligand substitution in which ZQ had successfully competed for protein-bound Zn(2+). Parallel studies with the model Zn-proteins, alcohol dehydrogenase (ADH), and alkaline phosphatase (AP) revealed a similar picture of reactivity: ZQ(ACID) (Zinquin acid, (2-methyl-8-p-toluenesulfonamido-6-quinolyloxy)acetate)) able to bind to one Zn(2+) and extract the other in Zn(2)-ADH, whereas it removed one Zn(2+) from Zn(2)-AP and did not bind to the other. Zinquin ethyl ester (ethyl(2-methyl-8-p-toluenesulfonamido-6-quinolyloxy)acetate); ZQ(EE)) bound to both proteins without sequestering Zn(2+) from either one. In contrast to a closely related sensor, 6-methoxy-8-p-toluenesulfonamido-quinoline (TSQ), neither ZQ(ACID) nor ZQ(EE) associated with Zn-carbonic anhydrase. A survey of reactivity of these sensors with partially fractionated Zn-proteome confirmed that ZQ and TSQ bind to distinct, overlapping subsets of the Zn-proteome.
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Affiliation(s)
- Andrew B Nowakowski
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201, USA
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30
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Wang D, Hurst TK, Thompson RB, Fierke CA. Genetically encoded ratiometric biosensors to measure intracellular exchangeable zinc in Escherichia coli. JOURNAL OF BIOMEDICAL OPTICS 2011; 16:087011. [PMID: 21895338 PMCID: PMC3166341 DOI: 10.1117/1.3613926] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2011] [Revised: 06/07/2011] [Accepted: 06/27/2011] [Indexed: 05/31/2023]
Abstract
Zinc is an essential element for numerous cellular processes, therefore zinc homeostasis is regulated in living organisms. Fluorescent sensors have been developed as important tools to monitor the concentrations of readily exchangeable zinc in live cells. One type of biosensor uses carbonic anhydrase (CA) as the recognition element based on its tunable affinity, superior metal selectivity, and fluorescence signal from aryl sulfonamide ligands coupled to zinc binding. Here, we fuse carbonic anhydrase with a red fluorescent protein to create a series of genetically-encoded Förster resonance energy transfer-based excitation ratiometric zinc sensors that exhibit large signal increases in response to alterations in physiological-free zinc concentrations. These sensors were applied to the prokaryotic model organism Escherichia coli to quantify the readily exchangeable zinc concentration. In minimal media, E. coli BL21(DE3) cells expressing the CA sensor, exhibit a median intracellular readily exchangeable zinc concentration of 20 pM, much less than the total cellular zinc concentration of ∼0.2 mM. Furthermore, the intracellular readily exchangeable zinc concentration varies with the concentration of environmental zinc.
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Affiliation(s)
- Da Wang
- University of Michigan, Department of Chemistry, Ann Arbor, Michigan 48109, USA.
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31
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Abstract
Overactivation of certain K(+) channels can mediate excessive K(+) efflux and intracellular K(+) depletion, which are early ionic events in apoptotic cascade. The present investigation examined a possible role of the KCNQ2/3 channel or M-channel (also named Kv7.2/7.3 channels) in the pro-apoptotic process. Whole-cell recordings detected much larger M-currents (212 ± 31 pA or 10.5 ± 1.5 pA/pF) in cultured hippocampal neurons than that in cultured cortical neurons (47 ± 21 pA or 2.4 ± 0.8 pA/pF). KCNQ2/3 channel openers N-ethylmaleimide (NEM) and flupirtine caused dose-dependent K(+) efflux, intracellular K(+) depletion, and cell death in hippocampal cultures, whereas little cell death was induced by NEM in cortical cultures. The NEM-induced cell death was antagonized by co-applied KCNQ channel inhibitor XE991 (10 μM), or by elevated extracellular K(+) concentration. Supporting a mediating role of KCNQ2/3 channels in apoptosis, expression of KCNQ2 or KCNQ2/3 channels in Chinese hamster ovary (CHO) cells initiated caspase-3 activation. Consistently, application of NEM (20 μM, 8 h) in hippocampal cultures similarly caused caspase-3 activation assessed by immunocytochemical staining and western blotting. NEM increased the expression of extracellular signal-regulated protein kinases 1 and 2 (ERK1/2), induced mitochondria membrane depolarization, cytochrome c release, formation of apoptosome complex, and apoptosis-inducing factor (AIF) translocation into nuclear. All these events were attenuated by blocking KCNQ2/3 channels. These findings provide novel evidence that KCNQ2/3 channels could be an important regulator in neuronal apoptosis.
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32
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Gibon J, Tu P, Frazzini V, Sensi SL, Bouron A. The thiol-modifying agent N-ethylmaleimide elevates the cytosolic concentration of free Zn(2+) but not of Ca(2+) in murine cortical neurons. Cell Calcium 2010; 48:37-43. [PMID: 20667413 DOI: 10.1016/j.ceca.2010.06.004] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2010] [Revised: 06/22/2010] [Accepted: 06/22/2010] [Indexed: 10/19/2022]
Abstract
The membrane permeant alkylating agent N-ethylmaleimide (NEM) regulates numerous biological processes by reacting with thiol groups. Among other actions, NEM influences the cytosolic concentration of free Ca(2+) ([Ca(2+)]i). Depending on the cell type and the concentration used, NEM can promote the release of Ca(2+), affect its extrusion, stimulate or block its entry. However, most of these findings were obtained in experiments that employed fluorescent Ca(2+) probes and one major disadvantage of such experimental setting derives from the lack of specificity of the probes as all the so-called "Ca(2+)-sensitive" indicators also bind metals like Zn(2+) or Mn(2+) with higher affinities than Ca(2+). In this study, we examined the effects of NEM on the [Ca(2+)]i homeostasis of murine cortical neurons. We performed live-cell Ca(2+) and Zn(2+) imaging experiments using the fluorescent probes Fluo-4, FluoZin-3 and RhodZin-3 and found that NEM does not affect the neuronal [Ca(2+)]i homeostasis but specifically increases the cytosolic and mitochondrial concentration of free Zn(2+)([Zn(2+)]i). In addition, NEM triggers some neuronal loss that is prevented by anti-oxidants such as N-acetylcysteine or glutathione. NEM-induced toxicity is dependent on changes in [Zn(2+)]i levels as chelation of the cation with the cell-permeable heavy metal chelator, N,N,N'N'-tetrakis(-)[2-pyridylmethyl]-ethylenediamine (TPEN), promotes neuroprotection of cortical neurons exposed to NEM. Our data indicate that NEM affects [Zn(2+)]i but not [Ca(2+)]i homeostasis and shed new light on the physiological actions of this alkylating agent on central nervous system neurons.
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33
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Kaltenberg J, Plum LM, Ober-Blöbaum JL, Hönscheid A, Rink L, Haase H. Zinc signals promote IL-2-dependent proliferation of T cells. Eur J Immunol 2010; 40:1496-503. [PMID: 20201035 DOI: 10.1002/eji.200939574] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Zinc signals, i.e. a change of the intracellular concentration of free zinc ions in response to receptor stimulation, are involved in signal transduction in several immune cells. Here, the role of zinc signals in T-cell activation by IL-2 was investigated in the murine cytotoxic T-cell line CTLL-2 and in primary human T cells. Measurements with the fluorescent dyes FluoZin-3 and Zinquin showed that zinc is released from lysosomes into the cytosol in response to stimulation of the IL-2-receptor. Activation of the ERK-pathway was blocked by chelation of free zinc with N,N,N',N'-tetrakis-2(pyridyl-methyl)ethylenediamine, whereas zinc was not required for STAT5 phosphorylation. In addition, the key signaling molecules MEK and ERK were activated in response to elevated free intracellular zinc, induced by incubation with zinc and the ionophore pyrithione. Downstream of ERK activation, ERK-specific gene expression of c-fos and IL-2-induced proliferation was found to depend on zinc. Further experiments indicated that inhibition of MEK and ERK-dephosphorylating protein phosphatases is the molecular mechanism for the influence of zinc on this pathway. In conclusion, an increase of cytoplasmic free zinc is required for IL-2-induced ERK signaling and proliferation of T cells.
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Affiliation(s)
- Jennifer Kaltenberg
- Institute of Immunology, Medical Faculty, RWTH Aachen University, Aachen, Germany
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34
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Moulis JM. Cellular mechanisms of cadmium toxicity related to the homeostasis of essential metals. Biometals 2010; 23:877-96. [DOI: 10.1007/s10534-010-9336-y] [Citation(s) in RCA: 177] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2009] [Accepted: 04/01/2010] [Indexed: 01/12/2023]
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35
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Atkinson A, Khalimonchuk O, Smith P, Sabic H, Eide D, Winge DR. Mzm1 influences a labile pool of mitochondrial zinc important for respiratory function. J Biol Chem 2010; 285:19450-9. [PMID: 20404342 DOI: 10.1074/jbc.m110.109793] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Zinc is essential for function of mitochondria as a cofactor for several matrix zinc metalloproteins. We demonstrate that a labile cationic zinc component of low molecular mass exists in the yeast mitochondrial matrix. This zinc pool is homeostatically regulated in response to the cellular zinc status. This pool of zinc is functionally important because matrix targeting of a cytosolic zinc-binding protein reduces the level of labile zinc and interferes with mitochondrial respiratory function. We identified a series of proteins that modulate the matrix zinc pool, one of which is a novel conserved mitochondrial protein designated Mzm1. Mutant mzm1Delta cells have reduced total and labile mitochondrial zinc, and these cells are hypersensitive to perturbations of the labile pool. In addition, mzm1Delta cells have a destabilized cytochrome c reductase (Complex III) without any effects on Complexes IV or V. Thus, we have established that a link exists between Complex III integrity and the labile mitochondrial zinc pool.
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Affiliation(s)
- Aaron Atkinson
- Department of Medicine and Biochemistry, University of Utah Health Sciences Center, Salt Lake City, Utah 84132, USA
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36
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Zhang N, Chen Y, Yu M, Liu Y. Benzenesulfonamidoquinolino-β-cyclodextrin as a Cell-Impermeable Fluorescent Sensor for Zn2+. Chem Asian J 2009; 4:1697-702. [DOI: 10.1002/asia.200900233] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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37
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Peterson QP, Hsu DC, Goode DR, Novotny CJ, Totten RK, Hergenrother PJ. Procaspase-3 activation as an anti-cancer strategy: structure-activity relationship of procaspase-activating compound 1 (PAC-1) and its cellular co-localization with caspase-3. J Med Chem 2009; 52:5721-31. [PMID: 19708658 DOI: 10.1021/jm900722z] [Citation(s) in RCA: 125] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
A goal of personalized medicine as applied to oncology is to identify compounds that exploit a defined molecular defect in a cancerous cell. A compound called procaspase-activating compound 1 (PAC-1) was reported that enhances the activity of procaspase-3 in vitro and induces apoptotic death in cancer cells in culture and in mouse xenograft models. Experimental evidence indicates that PAC-1 activates procaspase-3 in vitro through chelation of inhibitory zinc ions. Described herein is the synthesis and biological activity of a family of PAC-1 derivatives where key functional groups have been systematically altered. Analysis of these compounds reveals a strong correlation between the in vitro procaspase-3 activating effect and their ability to induce death in cancer cells in culture. Importantly, we also show that a fluorescently labeled version of PAC-1 co-localizes with sites of caspase-3 activity in cancer cells. The data presented herein further bolster the hypothesis that PAC-1 induces apoptosis in cancer cells through the direct activation of procaspase-3, has implications for the design and discovery of next-generation procaspase-3 activating compounds, and sheds light on the anti-apoptotic role of cellular zinc.
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Affiliation(s)
- Quinn P Peterson
- Department of Biochemistry, Roger Adams Laboratory, University of Illinois, Urbana, Illinois 61801, USA
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38
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Affiliation(s)
- Aaron Atkinson
- Departments of Medicine and Biochemistry, University of Utah Health Sciences Center, Salt Lake City, Utah 84132
| | - Dennis R. Winge
- Departments of Medicine and Biochemistry, University of Utah Health Sciences Center, Salt Lake City, Utah 84132
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39
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Kawachi M, Kobae Y, Mori H, Tomioka R, Lee Y, Maeshima M. A mutant strain Arabidopsis thaliana that lacks vacuolar membrane zinc transporter MTP1 revealed the latent tolerance to excessive zinc. PLANT & CELL PHYSIOLOGY 2009; 50:1156-70. [PMID: 19433490 DOI: 10.1093/pcp/pcp067] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
A mutant line of Arabidopsis thaliana that lacks a vacuolar membrane Zn(2+)/H(+) antiporter MTP1 is sensitive to zinc. We examined the physiological changes in this loss-of-function mutant under high-Zn conditions to gain an understanding of the mechanism of adaptation to Zn stress. When grown in excessive Zn and observed using energy-dispersive X-ray analysis, wild-type roots were found to accumulate Zn in vacuolar-like organelles but mutant roots did not. The Zn content of mutant roots, determined by chemical analysis, was one-third that of wild-type roots grown in high-Zn medium. Severe inhibition of root growth was observed in mtp1-1 seedlings in 500 muM ZnSO(4). Suppression of cell division and elongation by excessive Zn was reversible and the cells resumed growth in normal medium. In mutant roots, a marked formation of reactive oxygen species (ROS) appeared in the meristematic zone, where the MTP1 gene was highly expressed. Zn treatment enhanced the expression of several genes involved in Zn tolerance: namely, the plasma membrane Zn(2+)-export ATPase, HMA4, and plasma and vacuolar membrane proton pumps. CuZn-superoxide dismutases, involved in the detoxification of ROS, were also induced. The expression of plasma membrane Zn-uptake transporter, ZIP1, was suppressed. The up- or down-regulation of these genes might confer the resistance to Zn toxicity. These results indicate an essential role of MTP1 in detoxification of excessive Zn and provide novel information on the latent adaptation mechanism to Zn stress, which is hidden by MTP1.
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Affiliation(s)
- Miki Kawachi
- Laboratory of Cell Dynamics, Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
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40
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Wellenreuther G, Cianci M, Tucoulou R, Meyer-Klaucke W, Haase H. The ligand environment of zinc stored in vesicles. Biochem Biophys Res Commun 2009; 380:198-203. [PMID: 19171119 DOI: 10.1016/j.bbrc.2009.01.074] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2009] [Accepted: 01/14/2009] [Indexed: 11/28/2022]
Abstract
Zinc serves regulatory functions in cells and thus, several mechanisms exist for tight control of its homeostasis. One mechanism is storage in and retrieval from vesicles, so-called zincosomes, but the chemical speciation of zincosomal zinc has remained enigmatic. Here, we determine the intravesicular zinc-coordination in isolated zincosomes in comparison to intact RAW264.7 murine macrophage cells. In elemental maps of a cell monolayer, generated by microbeam X-ray fluorescence, zincosomes were identified as spots of high zinc accumulation. A fingerprint for the binding motif obtained by muXANES (X-ray absorption near edge structure) matches the XANES from isolated vesicles; zinc is not free, but present as a complexed form (average coordination; 1.0 sulfur, 2,5 histidines 30 and 1.0 oxygen), resembling regulatory or catalytic zinc sites in proteins. Such coordination enables reversible binding, acting as a 'zinc sink', facilitating the accumulation of high amounts of zinc against a concentration gradient.
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Affiliation(s)
- Gerd Wellenreuther
- European Molecular Biology Laboratory, Hamburg Outstation, c/o DESY, Notkestrasse 85, D-22603 Hamburg, Germany
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41
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Lovell MA. A potential role for alterations of zinc and zinc transport proteins in the progression of Alzheimer's disease. J Alzheimers Dis 2009; 16:471-83. [PMID: 19276540 PMCID: PMC2881701 DOI: 10.3233/jad-2009-0992] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Although multiple studies have suggested a role for alterations of zinc (Zn) and zinc transport (ZnT) proteins in the pathogenesis of Alzheimer's disease, the exact role of this essential trace element in the progression of the disease remains unclear. The following review discusses the normal role of Zn and ZnT proteins in brain and the potential effects of their alteration in the pathogenesis of Alzheimer's disease, particularly in the processing of the amyloid-beta protein precursor and amyloid-beta peptide generation and aggregation.
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Affiliation(s)
- Mark A Lovell
- Department of Chemistry and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, USA.
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42
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Antiviral activity of the zinc ionophores pyrithione and hinokitiol against picornavirus infections. J Virol 2008; 83:58-64. [PMID: 18922875 DOI: 10.1128/jvi.01543-08] [Citation(s) in RCA: 105] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
We have discovered two metal ion binding compounds, pyrithione (PT) and hinokitiol (HK), that efficiently inhibit human rhinovirus, coxsackievirus, and mengovirus multiplication. Early stages of virus infection are unaffected by these compounds. However, the cleavage of the cellular eukaryotic translation initiation factor eIF4GI by the rhinoviral 2A protease was abolished in the presence of PT and HK. We further show that these compounds inhibit picornavirus replication by interfering with proper processing of the viral polyprotein. In addition, we provide evidence that these structurally unrelated compounds lead to a rapid import of extracellular zinc ions into cells. Imported Zn(2+) was found to be localized in punctate structures, as well as in mitochondria. The observed elevated level of zinc ions was reversible when the compounds were removed. As the antiviral activity of these compounds requires the continuous presence of the zinc ionophore PT, HK, or pyrrolidine-dithiocarbamate, the requirement for zinc ions for the antiviral activity is further substantiated. Therefore, an increase in intracellular zinc levels provides the basis for a new antipicornavirus mechanism.
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43
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Donadelli M, Dalla Pozza E, Scupoli MT, Costanzo C, Scarpa A, Palmieri M. Intracellular zinc increase inhibits p53(-/-) pancreatic adenocarcinoma cell growth by ROS/AIF-mediated apoptosis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1793:273-80. [PMID: 18951928 DOI: 10.1016/j.bbamcr.2008.09.010] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2008] [Revised: 09/15/2008] [Accepted: 09/15/2008] [Indexed: 10/21/2022]
Abstract
We show that treatment with non-toxic doses of zinc in association to the ionophore compound pyrrolidine dithiocarbamate (PDTC) inhibits p53(-/-) pancreatic cancer cell growth much more efficiently than gemcitabine, the gold standard chemotherapeutic agent for pancreatic cancer. Both the metal chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine and the radical scavenger N-acetyl-l-cysteine are able to recover cell growth inhibition by Zn/PDTC, demonstrating that this effect depends on the increased levels of intracellular zinc and of reactive oxygen species (ROS). Zn/PDTC treatment induces a strong apoptotic cell death that is associated to ROS-dependent nuclear translocation of the mitochondrial factor AIF, but not to the regulation of apoptotic genes and caspase activation. Primary fibroblasts are more resistant than pancreatic cancer cells to Zn/PDTC treatment and exhibit a lower basal and Zn/PDTC-induced enhancement of intracellular zinc. We show that Zn/PDTC induces p53 proteasomal degradation and that the proteasome inhibitor MG132 further increases fibroblast growth inhibition by Zn/PDTC, suggesting that p53 degradation plays an important role in fibroblast resistance to Zn/PDTC.
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Affiliation(s)
- M Donadelli
- Department of Morphological and Biomedical Sciences, Section of Biochemistry, University of Verona, Strada Le Grazie, 8, 37134 Verona, Italy
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44
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Besecker B, Bao S, Bohacova B, Papp A, Sadee W, Knoell DL. The human zinc transporter SLC39A8 (Zip8) is critical in zinc-mediated cytoprotection in lung epithelia. Am J Physiol Lung Cell Mol Physiol 2008; 294:L1127-36. [PMID: 18390834 DOI: 10.1152/ajplung.00057.2008] [Citation(s) in RCA: 120] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Zinc is an essential micronutrient and cytoprotectant involved in the host response to inflammatory stress. We tested whether zinc transporters, the critical regulators that maintain intracellular zinc concentrations, play a role in cell survival, particularly in lung epithelia, during inflammation. Initially, mRNA transcripts were quantitatively measured by RT-PCR for all known human zinc transporters, including 14 importers (SLC39A(1-14)) and 10 exporters (SLC30A(1-10)), in primary human lung epithelia obtained from multiple human donors and BEAS-2B cell cultures under baseline and TNF-alpha-stimulated conditions. While many zinc transporters were constitutively expressed, only SLC39A8 (Zip8) mRNA was strongly induced by TNF-alpha. Endogenous Zip8 protein was not routinely detected under baseline conditions. In sharp contrast, TNF-alpha induced the expression of a glycosylated protein that translocated to the plasma membrane and mitochondria. Increased Zip8 expression resulted in an increase in intracellular zinc content and coincided with cell survival in the presence of TNF-alpha. Inhibition of Zip8 expression using a short interfering RNA probe reduced cellular zinc content and impaired mitochondrial function in response to TNF-alpha, resulting in loss of cell viability. These data are the first to characterize human Zip8 and remarkably demonstrate that upregulation of Zip8 is sufficient to protect lung epithelia against TNF-alpha-induced cytotoxicity. We conclude that Zip8 is unique, relative to other Zip proteins, by functioning as an essential zinc importer at the onset of inflammation, thereby facilitating cytoprotection within the lung.
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Affiliation(s)
- Beth Besecker
- Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, 473 W. 12th Ave., Rm. 405A, Columbus, OH 43210, USA
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45
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Dehnhardt M, Zoriy MV, Khan Z, Reifenberger G, Ekström TJ, Sabine Becker J, Zilles K, Bauer A. Element distribution is altered in a zone surrounding human glioblastoma multiforme. J Trace Elem Med Biol 2008; 22:17-23. [PMID: 18319136 DOI: 10.1016/j.jtemb.2007.08.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2006] [Revised: 05/03/2007] [Accepted: 08/28/2007] [Indexed: 11/23/2022]
Abstract
Recent data indicate that A(1) adenosine receptor (A(1)AR) density is increased in a zone surrounding human and experimental gliomas. On the contrary, tumor tissue and adjacent brain tissue show low to intermediate A(1)AR densities. In order to assess whether changes in A(1)AR expression are indicating further processes of a chemical reorganization of the peritumoral zone, we investigated element concentrations and distribution patterns of copper and zinc in six human glioblastoma multiforme (GBM) specimens by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). Uranium and lead were used as external standards. Copper and zinc levels were increased in a peritumoral zone corresponding to the region of elevated A(1)AR density. They showed a lower density in the solid tumor in comparison to surrounding brain tissue, although the cellular density was higher within GBM. Our findings suggest that the immediate vicinity of GBM is characterized by increased levels of copper and zinc supporting the view that higher A(1)AR density surrounding GBM is not an isolated alteration of peritumoral tissue but an indicator of complex changes in the vicinity of infiltrative tumors. Further research is needed to explore the pathophysiological consequences of altered peritumoral element distribution.
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Affiliation(s)
- Markus Dehnhardt
- Institut für Medizin, Forschungszentrum Jülich, 52425 Jülich, Germany; Brain Imaging Center West, Forschungszentrum Jülich, 52425 Jülich, Germany
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46
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Lazarczyk M, Pons C, Mendoza JA, Cassonnet P, Jacob Y, Favre M. Regulation of cellular zinc balance as a potential mechanism of EVER-mediated protection against pathogenesis by cutaneous oncogenic human papillomaviruses. ACTA ACUST UNITED AC 2007; 205:35-42. [PMID: 18158319 PMCID: PMC2234378 DOI: 10.1084/jem.20071311] [Citation(s) in RCA: 138] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Epidermodysplasia verruciformis (EV) is a genodermatosis associated with skin cancers that results from a selective susceptibility to related human papillomaviruses (EV HPV). Invalidating mutations in either of two genes (EVER1 and EVER2) with unknown functions cause most EV cases. We report that EVER1 and EVER2 proteins form a complex and interact with the zinc transporter 1 (ZnT-1), as shown by yeast two-hybrid screening, GST pull-down, and immunoprecipitation experiments. In keratinocytes, EVER and ZnT-1 proteins do not influence intracellular zinc concentration, but do affect intracellular zinc distribution. EVER2 was found to inhibit free zinc influx to nucleoli. Keratinocytes with a mutated EVER2 grew faster than wild-type keratinocytes. In transiently and stably transfected HaCaT cells, EVER and ZnT-1 down-regulated transcription factors stimulated by zinc (MTF-1) or cytokines (c-Jun and Elk), as detected with luciferase assays. To get some insight into the control of EV HPV infection, we searched for interaction between EVER and ZnT-1 and oncoproteins of cutaneous (HPV5) and genital (HPV16) genotypes. HPV16 E5 protein binds to EVER and ZnT-1 and blocks their negative regulation. The lack of a functional E5 protein encoded by EV HPV genome may account for host restriction of these viruses.
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Affiliation(s)
- Maciej Lazarczyk
- Unité de Génétique, Papillomavirus et Cancer Humain, Institut Pasteur, 75015 Paris, France
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47
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Kröncke KD. Cellular stress and intracellular zinc dyshomeostasis. Arch Biochem Biophys 2007; 463:183-7. [PMID: 17442256 DOI: 10.1016/j.abb.2007.03.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2007] [Revised: 03/09/2007] [Accepted: 03/12/2007] [Indexed: 11/20/2022]
Abstract
Various stressful conditions like oxidative or nitrosative stress, heavy metal load or thiol-modifying compounds have been shown to disturb the intracellular zinc homeostasis leading to increasing concentrations of free zinc within the cytoplasm or nuclei of cells. However, much less is known about the consequences of a disturbed intracellular Zn2+ homeostasis under these conditions. Current knowledge is reviewed here.
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Affiliation(s)
- Klaus-D Kröncke
- Institute of Biochemistry and Molecular Biology I, Heinrich-Heine-University of Düsseldorf, Universitätsstr.1, D-40225, Düsseldorf, Germany.
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48
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Abstract
The development of atherosclerosis is influenced by genetic, lifestyle and nutritional risk factors. Zn and metallothionein deficiency can enhance oxidative-stress-related signalling processes in endothelial cells, and since changes in available plasma Zn may affect the Zn status of the endothelium, Zn deficiency could be a risk factor for IHD. Although the association of Zn with many proteins is essential for their function, three key signalling processes are highlighted as being principal targets for the effect of Zn deficiency: the activation of NF-κB, the activation of caspase enzymes and the signalling of NO. The need to develop a reliable indicator of Zn status is critical to any epidemiological approach for studying the relationship between Zn status and disease incidence. Studies using appropriate animal models and investigating how the plasma Zn pool influences endothelial intracellular labile Zn would be helpful in appreciating the importance of Zn deficiency in atherogenesis.
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Affiliation(s)
- John H Beattie
- Division of Cellular Integrity, Rowett Research Institute, Greenburn Road, Bucksburn, Aberdeen AB21 9SB, Scotland, UK.
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49
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Karagulova G, Yue Y, Moreyra A, Boutjdir M, Korichneva I. Protective Role of Intracellular Zinc in Myocardial Ischemia/Reperfusion Is Associated with Preservation of Protein Kinase C Isoforms. J Pharmacol Exp Ther 2007; 321:517-25. [PMID: 17322024 DOI: 10.1124/jpet.107.119644] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The recent discovery of zinc signals and their essential role in the redox signaling network implies that zinc homeostasis and the function of zinc-containing proteins are probably altered as a result of oxidative stress, suggesting new targets for pharmacological intervention. We hypothesized that the level of intracellular labile zinc is changed in hearts subjected to ischemia/reperfusion (I/R) and investigated whether the maintenance of myocardial zinc status protected heart functions. Using fluorescent imaging, we demonstrated decreased levels of labile zinc in the I/R hearts. Phorbol 12-myristate 13-acetate, a known trigger of zinc release, liberated zinc ions in control hearts but failed to produce any increase in zinc levels in the I/R rat hearts. Adding the zinc ionophore pyrithione at reperfusion improved myocardial recovery up to 100% and reduced the incidence of arrhythmias more than 2-fold. This effect was dose-dependent, and high concentrations of zinc were toxic. Adding membrane-impermeable zinc chloride was ineffective. Hearts from rats receiving zinc pyrithione supplements in their diet fully recovered from I/R. The recovery was associated with the prevention of degradation of the two protein kinase C isoforms, delta and epsilon, during I/R. In conclusion, our results suggest a protective role of intracellular zinc in myocardial recovery from oxidative stress imposed by I/R. The data support the potential clinical use of zinc ionophores in the settings of acute redox stress in the heart.
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Affiliation(s)
- Gulnura Karagulova
- Department of Medicine, University of Medicine and Dentistry of New Jersey-Robert Wood Johnson Medical School, New Brunswick 08903, and Molecular and Cellular Cardiology Program, Veterans Administration New York Harbor Healthcare System, New York, NY, USA
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50
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Falcón-Pérez JM, Dell'Angelica EC. Zinc transporter 2 (SLC30A2) can suppress the vesicular zinc defect of adaptor protein 3-depleted fibroblasts by promoting zinc accumulation in lysosomes. Exp Cell Res 2007; 313:1473-83. [PMID: 17349999 PMCID: PMC1885236 DOI: 10.1016/j.yexcr.2007.02.006] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2006] [Revised: 01/26/2007] [Accepted: 02/01/2007] [Indexed: 10/23/2022]
Abstract
Zinc accumulation in the lumen of cytoplasmic vesicles is one of the mechanisms by which cells can store significant amounts of this essential but potentially toxic biometal. Previous studies had demonstrated reduced vesicular zinc levels in fibroblasts from mutant mice deficient in adaptor protein 3 (AP-3), a complex involved in protein trafficking to late endosomes and lysosomes. We have observed a similar phenotype in the human fibroblastoid cell line, M1, upon small interference RNA-mediated AP-3 knockdown. A survey of the expression and localization of zinc transporter (ZnT) family members identified ZnT2, ZnT3, and ZnT4 as likely mediators of vesicular zinc accumulation in M1 cells. Expression of green fluorescence protein (GFP)-tagged ZnT2 and ZnT3 promoted accumulation of vesicular zinc as visualized using the indicator zinquin. Moreover, GFP-ZnT2 overexpression elicited a significant accumulation of zinc within mature lysosomes, which in untransfected M1 cells contained little or no chelatable zinc, and restored the zinc storage capability of AP-3-deficient cells. These results suggest that ZnT2 can facilitate vesicular zinc accumulation independently of AP-3 function, and validate the M1 fibroblastoid line as a human cell culture system amenable to the study of vesicular zinc regulation using techniques compatible with functional genomic approaches.
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Affiliation(s)
- Juan M Falcón-Pérez
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA.
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