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Song CC, Chen GH, Zhong CC, Chen F, Chen SW, Luo Z. Transcriptional responses of four slc30a/znt family members and their roles in Zn homeostatic modulation in yellow catfish Pelteobagrus fulvidraco. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2021; 1864:194723. [PMID: 34116248 DOI: 10.1016/j.bbagrm.2021.194723] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 05/09/2021] [Accepted: 05/29/2021] [Indexed: 12/12/2022]
Abstract
The study characterized their regulatory functions of four znt members (znt1, znt2, znt6 and znt8) in Zn homeostasis in vertebrates. We found that the -1281/-1296 bp locus on the znt1 promoter, the -1/-16 bp locus on the znt2 promoter, the -825/-839 bp locus on the znt6 promoter, the -165/-180 bp locus and the -274/-292 bp STAT3 locus on the znt8 promoter were functional MTF-1 binding sites and had metal responsive element (MRE). Zn incubation increased activities of four znt promoters, which was mediated by MRE sites on znt1, znt2, znt6 and znt8 promoters and by STAT3 binding site on znt8 promoter. Moreover, Zn activated the transcription of these znts genes through MTF-1-MRE-dependent pathway. Zn incubation up-regulated the mRNA and total protein expression of ZnT1, ZnT2 and ZnT8 at both 24 h and 48 h. Overall, for the first time, this study offered novel insights for regulatory mechanism of Zn homeostasis in vertebrates.
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Affiliation(s)
- Chang-Chun Song
- Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Fishery College, Huazhong Agricultural University, Wuhan 430070, China
| | - Guang-Hui Chen
- Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Fishery College, Huazhong Agricultural University, Wuhan 430070, China
| | - Chong-Chao Zhong
- Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Fishery College, Huazhong Agricultural University, Wuhan 430070, China
| | - Fang Chen
- Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Fishery College, Huazhong Agricultural University, Wuhan 430070, China
| | - Shu-Wei Chen
- Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Fishery College, Huazhong Agricultural University, Wuhan 430070, China
| | - Zhi Luo
- Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Fishery College, Huazhong Agricultural University, Wuhan 430070, China; Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266237, China.
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Tibbett M, Green I, Rate A, De Oliveira VH, Whitaker J. The transfer of trace metals in the soil-plant-arthropod system. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 779:146260. [PMID: 33744587 DOI: 10.1016/j.scitotenv.2021.146260] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Revised: 02/26/2021] [Accepted: 02/28/2021] [Indexed: 06/12/2023]
Abstract
Essential and non-essential trace metals are capable of causing toxicity to organisms above a threshold concentration. Extensive research has assessed the behaviour of trace metals in biological and ecological systems, but has typically focused on single organisms within a trophic level and not on multi-trophic transfer through terrestrial food chains. This reinforces the notion of metal toxicity as a closed system, failing to consider one trophic level as a pollution source to another; therefore, obscuring the full extent of ecosystem effects. Given the relatively few studies on trophic transfer of metals, this review has taken a compartment-based approach, where transfer of metals through trophic pathways is considered as a series of linked compartments (soil-plant-arthropod herbivore-arthropod predator). In particular, we consider the mechanisms by which trace metals are taken up by organisms, the forms and transformations that can occur within the organism and the consequences for trace metal availability to the next trophic level. The review focuses on four of the most prevalent metal cations in soil which are labile in terrestrial food chains: Cd, Cu, Zn and Ni. Current knowledge of the processes and mechanisms by which these metals are transformed and moved within and between trophic levels in the soil-plant-arthropod system are evaluated. We demonstrate that the key factors controlling the transfer of trace metals through the soil-plant-arthropod system are the form and location in which the metal occurs in the lower trophic level and the physiological mechanisms of each organism in regulating uptake, transformation, detoxification and transfer. The magnitude of transfer varies considerably depending on the trace metal concerned, as does its toxicity, and we conclude that biomagnification is not a general property of plant-arthropod and arthropod-arthropod systems. To deliver a more holistic assessment of ecosystem toxicity, integrated studies across ecosystem compartments are needed to identify critical pathways that can result in secondary toxicity across terrestrial food-chains.
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Affiliation(s)
- Mark Tibbett
- Department of Sustainable Land Management & Soil Research Centre, School of Agriculture Policy and Development, University of Reading, Whiteknights, RG6 6AR, UK.
| | - Iain Green
- Department of Life and Environmental Sciences, Faculty of Science and Technology, Bournemouth University, Poole, Dorset BH12 5BB, UK
| | - Andrew Rate
- School of Agriculture and Environment, The University of Western Australia, Perth, WA 6009, Australia
| | - Vinícius H De Oliveira
- Department of Plant Biology, Institute of Biology, University of Campinas, Campinas, Sao Paulo 13083-970, Brazil
| | - Jeanette Whitaker
- UK Centre for Ecology & Hydrology, Lancaster Environment Centre, Library Avenue, Lancaster LA1 4AP, UK
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Xue J, Xie L, Liu B, Zhou L, Hu Y, Ajuwon KM, Fang R. Dietary Supplementation of EGF Ameliorates the Negatively Effects of LPS on Early-Weaning Piglets: From Views of Growth Performance, Nutrient Digestibility, Microelement Absorption and Possible Mechanisms. Animals (Basel) 2021; 11:ani11061598. [PMID: 34071588 PMCID: PMC8227379 DOI: 10.3390/ani11061598] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2021] [Revised: 05/22/2021] [Accepted: 05/26/2021] [Indexed: 12/13/2022] Open
Abstract
Simple Summary This study aims to investigate how epidermal growth factor (EGF) attenuates the effect of lipopolysaccharide (LPS) on the growth performance, nutrient digestibility, microelement absorption of early-weaned pigs. A total of 48 early weaned piglets were randomly distributed to four groups consisting of a 2 × 2 factorial design. The main factors were the level of LPS (HLPS = high LPS: 100 μg/kg body weight; ZLPS = low LPS: 0 μg/kg body weight) and EGF (HEGF = high EGF: 2 mg/kg diet; ZEGF = low EGF: 0 mg/kg diet). Each group had four replicates and each replicate consisted of three piglets. The results showed that HLPS level decreased the growth performance and the apparent digestibility of crude fat, while HEGF level increased the average daily feed intake. The concentration of most microelements in the gastrointestinal tract chyme and feces were increased by HLPS level and decreased by HEGF level. The expression levels of most microelement transport-relative genes in the mucosa of gastrointestinal tissues were decreased by HLPS level and increased by HEGF level. In conclusion, dietary EGF could attenuate the negative effect of LPS exposure on the apparent digestibility of crude fat and microelement absorption through changing the expression levels of microelement transport-relative genes. EGF can be used as an additive to increase the essential trace elements absorption in the early weaning piglets. Abstract Epidermal growth factor (EGF) plays an important role in nutrients absorption. However, whether it can be an effective additive to improve the growth performance and nutrients absorption in lipopolysaccharide (LPS) challenged early weaning piglets is still unknown. A 14-days trial was conducted to investigate how EGF attenuates the effect of LPS on the growth performance, nutrient digestibility, microelement absorption of early-weaned pigs, and study the underlying mechanism. A total of 48 early weaned piglets, aged 25 days, were randomly distributed to four groups (control, EGF, LPS and EGF + LPS groups) consisting of a 2 × 2 factorial design. The main factors were the level of LPS (HLPS = high LPS: 100 μg/kg body weight; ZLPS = low LPS: 0 μg/kg body weight) and EGF (HEGF = high EGF: 2 mg/kg diet; ZEGF = low EGF: 0 mg/kg diet). Each group had four replicates and each replicate consisted of three piglets. The results showed that piglets injected with HLPS level significantly decreased the average daily gain (ADG), and significantly increased the feed conversion ratio (FCR) compared with the piglets injected with ZLPS level, while piglets fed HEGF level significantly increased the average daily feed intake (ADFI) compared with the piglets fed ZEGF level (p < 0.05). Piglets injected with HLPS level significantly decreased the apparent digestibility of crude fat compared with the piglets injected with ZLPS level (p < 0.05). Piglets injected with HLPS level significantly increased the concentration of most microelements in the gastrointestinal tract chyme and feces, and significantly decreased the expression levels of most microelement transport-relative genes in the mucosa of gastrointestinal tissues compared with the piglets injected with ZLPS level (p < 0.05). Piglets fed HEGF level significantly decreased the concentration of microelement in the gastrointestinal tract chyme and feces, and significantly increased the expression levels of the microelement transport-relative genes in the mucosa of gastrointestinal tissues compared with the piglets fed ZEGF level (p < 0.05). In conclusion, dietary EGF could attenuate the negative effect of LPS exposure on the apparent digestibility of crude fat and microelement absorption of early-weaning piglets. EGF and LPS influenced the absorption of essential trace element through changing the expression levels of microelement transport-relative genes in the mucosa of gastrointestinal tissues. In the early weaning piglets, EGF can be used as an additive to increase the essential trace elements absorption.
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Affiliation(s)
- Junjing Xue
- College of Animal Science and Technology, Hunan Agricultural University, No. 1 Nongda Road, Furong District, Changsha 410128, China; (J.X.); (L.X.); (B.L.); (L.Z.); (Y.H.)
- Hunan Co-Innovation Center of Animal Production Safety, Changsha 410128, China
| | - Liang Xie
- College of Animal Science and Technology, Hunan Agricultural University, No. 1 Nongda Road, Furong District, Changsha 410128, China; (J.X.); (L.X.); (B.L.); (L.Z.); (Y.H.)
- Hunan Co-Innovation Center of Animal Production Safety, Changsha 410128, China
| | - Bo Liu
- College of Animal Science and Technology, Hunan Agricultural University, No. 1 Nongda Road, Furong District, Changsha 410128, China; (J.X.); (L.X.); (B.L.); (L.Z.); (Y.H.)
- Hunan Co-Innovation Center of Animal Production Safety, Changsha 410128, China
| | - Liyuan Zhou
- College of Animal Science and Technology, Hunan Agricultural University, No. 1 Nongda Road, Furong District, Changsha 410128, China; (J.X.); (L.X.); (B.L.); (L.Z.); (Y.H.)
- Hunan Co-Innovation Center of Animal Production Safety, Changsha 410128, China
| | - Yajun Hu
- College of Animal Science and Technology, Hunan Agricultural University, No. 1 Nongda Road, Furong District, Changsha 410128, China; (J.X.); (L.X.); (B.L.); (L.Z.); (Y.H.)
- Hunan Co-Innovation Center of Animal Production Safety, Changsha 410128, China
| | - Kolapo Matthew Ajuwon
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47907-2054, USA;
| | - Rejun Fang
- College of Animal Science and Technology, Hunan Agricultural University, No. 1 Nongda Road, Furong District, Changsha 410128, China; (J.X.); (L.X.); (B.L.); (L.Z.); (Y.H.)
- Hunan Co-Innovation Center of Animal Production Safety, Changsha 410128, China
- Correspondence: ; Tel.: +86-(0)731-8618177
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Abstract
Cadmium (Cd) is an environmental toxicant with serious public health consequences due to its persistence within arable soils, and the ease with which it enters food chains and then, accumulates in human tissues to induce a broad range of adverse health effects. The present review focuses on the role of zinc (Zn), a nutritionally essential metal, to protect against the cytotoxicity and carcinogenicity of Cd in urinary bladder epithelial cells. The stress responses and defense mechanisms involving the low-molecular-weight metal binding protein, metallothionein (MT), are highlighted. The efflux and influx transporters of the ZnT and Zrt-/Irt-like protein (ZIP) gene families are discussed with respect to their putative role in retaining cellular Zn homeostasis. Among fourteen ZIP family members, ZIP8 and ZIP14 mediate Cd uptake by cells, while ZnT1 is among ten ZnT family members solely responsible for efflux of Zn (Cd), representing cellular defense against toxicity from excessively high Zn (Cd) intake. In theory, upregulation of the efflux transporter ZnT1 concomitant with the downregulation of influx transporters such as ZIP8 and ZIP14 can prevent Cd accumulation by cells, thereby increasing tolerance to Cd toxicity. To link the perturbation of Zn homeostasis, reflected by the aberrant expression of ZnT1, ZIP1, ZIP6, and ZIP10, with malignancy, tolerance to Cd toxicity acquired during Cd-induced transformation of a cell model of human urothelium, UROtsa, is discussed as a particular example.
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Pizzagalli MD, Bensimon A, Superti‐Furga G. A guide to plasma membrane solute carrier proteins. FEBS J 2021; 288:2784-2835. [PMID: 32810346 PMCID: PMC8246967 DOI: 10.1111/febs.15531] [Citation(s) in RCA: 178] [Impact Index Per Article: 59.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/07/2020] [Accepted: 08/17/2020] [Indexed: 12/13/2022]
Abstract
This review aims to serve as an introduction to the solute carrier proteins (SLC) superfamily of transporter proteins and their roles in human cells. The SLC superfamily currently includes 458 transport proteins in 65 families that carry a wide variety of substances across cellular membranes. While members of this superfamily are found throughout cellular organelles, this review focuses on transporters expressed at the plasma membrane. At the cell surface, SLC proteins may be viewed as gatekeepers of the cellular milieu, dynamically responding to different metabolic states. With altered metabolism being one of the hallmarks of cancer, we also briefly review the roles that surface SLC proteins play in the development and progression of cancer through their influence on regulating metabolism and environmental conditions.
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Affiliation(s)
- Mattia D. Pizzagalli
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Ariel Bensimon
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
| | - Giulio Superti‐Furga
- CeMM, Research Center for Molecular Medicine of the Austrian Academy of SciencesViennaAustria
- Center for Physiology and PharmacologyMedical University of ViennaAustria
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Satarug S, Garrett SH, Somji S, Sens MA, Sens DA. Zinc, Zinc Transporters, and Cadmium Cytotoxicity in a Cell Culture Model of Human Urothelium. TOXICS 2021; 9:toxics9050094. [PMID: 33923173 PMCID: PMC8145463 DOI: 10.3390/toxics9050094] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 04/18/2021] [Accepted: 04/23/2021] [Indexed: 01/27/2023]
Abstract
We explored the potential role of zinc (Zn) and zinc transporters in protection against cytotoxicity of cadmium (Cd) in a cell culture model of human urothelium, named UROtsa. We used real-time qRT-PCR to quantify transcript levels of 19 Zn transporters of the Zrt-/Irt-like protein (ZIP) and ZnT gene families that were expressed in UROtsa cells and were altered by Cd exposure. Cd as low as 0.1 µM induced expression of ZnT1, known to mediate efflux of Zn and Cd. Loss of cell viability by 57% was seen 24 h after exposure to 2.5 µM Cd. Exposure to 2.5 µM Cd together with 10–50 µM Zn prevented loss of cell viability by 66%. Pretreatment of the UROtsa cells with an inhibitor of glutathione biosynthesis (buthionine sulfoximine) diminished ZnT1 induction by Cd with a resultant increase in sensitivity to Cd cytotoxicity. Conversely, pretreatment of UROtsa cells with an inhibitor of DNA methylation, 5-aza-2’-deoxycytidine (aza-dC) did not change the extent of ZnT1 induction by Cd. The induced expression of ZnT1 that remained impervious in cells treated with aza-dC coincided with resistance to Cd cytotoxicity. Therefore, expression of ZnT1 efflux transporter and Cd toxicity in UROtsa cells could be modulated, in part, by DNA methylation and glutathione biosynthesis. Induced expression of ZnT1 may be a viable mechanistic approach to mitigating cytotoxicity of Cd.
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Affiliation(s)
- Soisungwan Satarug
- Kidney Disease Research Collaborative, Centre for Health Service Research, University of Queensland Translational Research Institute, Woolloongabba, Brisbane 4102, Australia
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202, USA; (S.H.G.); (S.S.); (M.A.S.); (D.A.S.)
- Correspondence:
| | - Scott H. Garrett
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202, USA; (S.H.G.); (S.S.); (M.A.S.); (D.A.S.)
| | - Seema Somji
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202, USA; (S.H.G.); (S.S.); (M.A.S.); (D.A.S.)
| | - Mary Ann Sens
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202, USA; (S.H.G.); (S.S.); (M.A.S.); (D.A.S.)
| | - Donald A. Sens
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202, USA; (S.H.G.); (S.S.); (M.A.S.); (D.A.S.)
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Aberrant Expression of ZIP and ZnT Zinc Transporters in UROtsa Cells Transformed to Malignant Cells by Cadmium. STRESSES 2021. [DOI: 10.3390/stresses1020007] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Maintenance of zinc homeostasis is pivotal to the regulation of cell growth, differentiation, apoptosis, and defense mechanisms. In mammalian cells, control of cellular zinc homeostasis is through zinc uptake, zinc secretion, and zinc compartmentalization, mediated by metal transporters of the Zrt-/Irt-like protein (ZIP) family and the Cation Diffusion Facilitators (CDF) or ZnT family. We quantified transcript levels of ZIP and ZnT zinc transporters expressed by non-tumorigenic UROtsa cells and compared with those expressed by UROtsa clones that were experimentally transformed to cancer cells by prolonged exposure to cadmium (Cd). Although expression of the ZIP8 gene in parent UROtsa cells was lower than ZIP14 (0.1 vs. 83 transcripts per 1000 β-actin transcripts), an increased expression of ZIP8 concurrent with a reduction in expression of one or two zinc influx transporters, namely ZIP1, ZIP2, and ZIP3, were seen in six out of seven transformed UROtsa clones. Aberrant expression of the Golgi zinc transporters ZIP7, ZnT5, ZnT6, and ZnT7 were also observed. One transformed clone showed distinctively increased expression of ZIP6, ZIP10, ZIP14, and ZnT1, with a diminished ZIP8 expression. These data suggest intracellular zinc dysregulation and aberrant zinc homeostasis both in the cytosol and in the Golgi in the transformed UROtsa clones. These results provide evidence for zinc dysregulation in transformed UROtsa cells that may contribute in part to their malignancy and/or muscle invasiveness.
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Kambe T, Taylor KM, Fu D. Zinc transporters and their functional integration in mammalian cells. J Biol Chem 2021; 296:100320. [PMID: 33485965 PMCID: PMC7949119 DOI: 10.1016/j.jbc.2021.100320] [Citation(s) in RCA: 112] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/15/2021] [Accepted: 01/20/2021] [Indexed: 12/14/2022] Open
Abstract
Zinc is a ubiquitous biological metal in all living organisms. The spatiotemporal zinc dynamics in cells provide crucial cellular signaling opportunities, but also challenges for intracellular zinc homeostasis with broad disease implications. Zinc transporters play a central role in regulating cellular zinc balance and subcellular zinc distributions. The discoveries of two complementary families of mammalian zinc transporters (ZnTs and ZIPs) in the mid-1990s spurred much speculation on their metal selectivity and cellular functions. After two decades of research, we have arrived at a biochemical description of zinc transport. However, in vitro functions are fundamentally different from those in living cells, where mammalian zinc transporters are directed to specific subcellular locations, engaged in dedicated macromolecular machineries, and connected with diverse cellular processes. Hence, the molecular functions of individual zinc transporters are reshaped and deeply integrated in cells to promote the utilization of zinc chemistry to perform enzymatic reactions, tune cellular responsiveness to pathophysiologic signals, and safeguard cellular homeostasis. At present, the underlying mechanisms driving the functional integration of mammalian zinc transporters are largely unknown. This knowledge gap has motivated a shift of the research focus from in vitro studies of purified zinc transporters to in cell studies of mammalian zinc transporters in the context of their subcellular locations and protein interactions. In this review, we will outline how knowledge of zinc transporters has been accumulated from in-test-tube to in-cell studies, highlighting new insights and paradigm shifts in our understanding of the molecular and cellular basis of mammalian zinc transporter functions.
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Affiliation(s)
- Taiho Kambe
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Kathryn M Taylor
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, United Kingdom
| | - Dax Fu
- Department of Physiology, Johns Hopkins School of Medicine, Johns Hopkins University, Baltimore, Maryland, USA.
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Krall RF, Tzounopoulos T, Aizenman E. The Function and Regulation of Zinc in the Brain. Neuroscience 2021; 457:235-258. [PMID: 33460731 DOI: 10.1016/j.neuroscience.2021.01.010] [Citation(s) in RCA: 61] [Impact Index Per Article: 20.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 01/05/2021] [Accepted: 01/08/2021] [Indexed: 12/31/2022]
Abstract
Nearly sixty years ago Fredrich Timm developed a histochemical technique that revealed a rich reserve of free zinc in distinct regions of the brain. Subsequent electron microscopy studies in Timm- stained brain tissue found that this "labile" pool of cellular zinc was highly concentrated at synaptic boutons, hinting a possible role for the metal in synaptic transmission. Although evidence for activity-dependent synaptic release of zinc would not be reported for another twenty years, these initial findings spurred decades of research into zinc's role in neuronal function and revealed a diverse array of signaling cascades triggered or regulated by the metal. Here, we delve into our current understanding of the many roles zinc plays in the brain, from influencing neurotransmission and sensory processing, to activating both pro-survival and pro-death neuronal signaling pathways. Moreover, we detail the many mechanisms that tightly regulate cellular zinc levels, including metal binding proteins and a large array of zinc transporters.
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Affiliation(s)
- Rebecca F Krall
- Department of Neurobiology, University of Pittsburgh School of Medicine, USA; Department of Otolaryngology, University of Pittsburgh School of Medicine, USA; Pittsburgh Hearing Research Center, University of Pittsburgh School of Medicine, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, USA
| | - Thanos Tzounopoulos
- Department of Otolaryngology, University of Pittsburgh School of Medicine, USA; Pittsburgh Hearing Research Center, University of Pittsburgh School of Medicine, USA.
| | - Elias Aizenman
- Department of Neurobiology, University of Pittsburgh School of Medicine, USA; Pittsburgh Hearing Research Center, University of Pittsburgh School of Medicine, USA; Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, USA.
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Wang Z, Li X, Zhou B. Drosophila ZnT1 is essential in the intestine for dietary zinc absorption. Biochem Biophys Res Commun 2020; 533:1004-1011. [PMID: 33012507 DOI: 10.1016/j.bbrc.2020.09.077] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 09/20/2020] [Indexed: 12/12/2022]
Abstract
Zinc is an essential trace element and participates in a variety of biological processes. ZnT (SLC30) family members are generally responsible for zinc efflux across the membrane regulating zinc homeostasis. In mammals, the only predominantly plasma membrane resident ZnT has been reported to be ZnT1, and ZnT1-/ZnT1- mice die at the embryonic stage. In Drosophila, knock down of ZnT1 homologue (dZnT1//ZnT63C/CG17723) results in growth arrest under zinc-limiting conditions. To investigate the essentiality of dZnT1 for zinc homeostasis, as well as its role in dietary zinc uptake especially under normal physiological conditions, we generated dZnT1 mutants by the CRISPER/Cas9 method. Homozygous mutant dZnT1 is lethal, with substantial zinc accumulation in the iron cell region, posterior midgut as well as gastric caeca. Expression of human ZnT1 (hZnT1), in the whole body or in the entire midgut, fully rescued the dZnT1 mutant lethality, whereas tissue-specific expression of hZnT1 in the iron cell region and posterior midgut partially rescued the developmental defect of the dZnT1 mutant. Supplementation of zinc together with clioquinol or hinokitiol conferred a limited but observable rescue upon dZnT1 loss. Our work demonstrated the absolute requirement of dZnT1 in Drosophila survival and indicated that the most essential role of dZnT1 is in the gut.
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Affiliation(s)
- Zhiqing Wang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Xinxin Li
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Bing Zhou
- State Key Laboratory of Membrane Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, China.
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Zinc Deficiency Disturbs Mucin Expression, O-Glycosylation and Secretion by Intestinal Goblet Cells. Int J Mol Sci 2020; 21:ijms21176149. [PMID: 32858966 PMCID: PMC7504335 DOI: 10.3390/ijms21176149] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 08/22/2020] [Accepted: 08/24/2020] [Indexed: 12/14/2022] Open
Abstract
Approximately 1 billion people worldwide suffer from zinc deficiency, with severe consequences for their well-being, such as critically impaired intestinal health. In addition to an extreme degeneration of the intestinal epithelium, the intestinal mucus is seriously disturbed in zinc-deficient (ZD) animals. The underlying cellular processes as well as the relevance of zinc for the mucin-producing goblet cells, however, remain unknown. To this end, this study examines the impact of zinc deficiency on the synthesis, production, and secretion of intestinal mucins as well as on the zinc homeostasis of goblet cells using the in vitro goblet cell model HT-29-MTX. Zinc deprivation reduced their cellular zinc content, changed expression of the intestinal zinc transporters ZIP-4, ZIP-5, and ZnT1 and increased their zinc absorption ability, outlining the regulatory mechanisms of zinc homeostasis in goblet cells. Synthesis and secretion of mucins were severely disturbed during zinc deficiency, affecting both MUC2 and MUC5AC mRNA expression with ongoing cell differentiation. A lack of zinc perturbed mucin synthesis predominantly on the post-translational level, as ZD cells produced shorter O-glycans and the main O-glycan pattern was shifted in favor of core-3-based mucins. The expression of glycosyltransferases that determine the formation of core 1-4 O-glycans was altered in zinc deficiency. In particular, B3GNT6 mRNA catalyzing core 3 formation was elevated and C2GNT1 and C2GNT3 elongating core 1 were downregulated in ZD cells. These novel insights into the molecular mechanisms impairing intestinal mucus stability during zinc deficiency demonstrate the essentiality of zinc for the formation and maintenance of this physical barrier.
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62
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Krall RF, Moutal A, Phillips MB, Asraf H, Johnson JW, Khanna R, Hershfinkel M, Aizenman E, Tzounopoulos T. Synaptic zinc inhibition of NMDA receptors depends on the association of GluN2A with the zinc transporter ZnT1. SCIENCE ADVANCES 2020; 6:eabb1515. [PMID: 32937457 PMCID: PMC7458442 DOI: 10.1126/sciadv.abb1515] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 05/20/2020] [Indexed: 05/08/2023]
Abstract
The NMDA receptor (NMDAR) is inhibited by synaptically released zinc. This inhibition is thought to be the result of zinc diffusion across the synaptic cleft and subsequent binding to the extracellular domain of the NMDAR. However, this model fails to incorporate the observed association of the highly zinc-sensitive NMDAR subunit GluN2A with the postsynaptic zinc transporter ZnT1, which moves intracellular zinc to the extracellular space. Here, we report that disruption of ZnT1-GluN2A association by a cell-permeant peptide strongly reduced NMDAR inhibition by synaptic zinc in mouse dorsal cochlear nucleus synapses. Moreover, synaptic zinc inhibition of NMDARs required postsynaptic intracellular zinc, suggesting that cytoplasmic zinc is transported by ZnT1 to the extracellular space in close proximity to the NMDAR. These results challenge a decades-old dogma on how zinc inhibits synaptic NMDARs and demonstrate that presynaptic release and a postsynaptic transporter organize zinc into distinct microdomains to modulate NMDAR neurotransmission.
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Affiliation(s)
- Rebecca F Krall
- Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
- Pittsburgh Hearing Research Center, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
| | - Aubin Moutal
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ 85724, USA
| | - Matthew B Phillips
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Hila Asraf
- Department of Physiology and Cell Biology, Ben-Gurion University of the Negev, Faculty of Health Sciences, Beer-Sheva, Israel
| | - Jon W Johnson
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Rajesh Khanna
- Department of Pharmacology, College of Medicine, University of Arizona, Tucson, AZ 85724, USA
| | - Michal Hershfinkel
- Department of Physiology and Cell Biology, Ben-Gurion University of the Negev, Faculty of Health Sciences, Beer-Sheva, Israel
| | - Elias Aizenman
- Pittsburgh Hearing Research Center, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
- Pittsburgh Institute for Neurodegenerative Diseases, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
- Department of Physiology and Cell Biology, Ben-Gurion University of the Negev, Faculty of Health Sciences, Beer-Sheva, Israel
| | - Thanos Tzounopoulos
- Department of Otolaryngology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA.
- Pittsburgh Hearing Research Center, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
- Department of Neurobiology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261, USA
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63
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Stocks CJ, von Pein JB, Curson JEB, Rae J, Phan MD, Foo D, Bokil NJ, Kambe T, Peters KM, Parton RG, Schembri MA, Kapetanovic R, Sweet MJ. Frontline Science: LPS-inducible SLC30A1 drives human macrophage-mediated zinc toxicity against intracellular Escherichia coli. J Leukoc Biol 2020; 109:287-297. [PMID: 32441444 PMCID: PMC7891337 DOI: 10.1002/jlb.2hi0420-160r] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 04/22/2020] [Accepted: 04/28/2020] [Indexed: 12/12/2022] Open
Abstract
TLR-inducible zinc toxicity is an antimicrobial mechanism utilized by macrophages, however knowledge of molecular mechanisms mediating this response is limited. Here, we show that E. coli exposed to zinc stress within primary human macrophages reside in membrane-bound vesicular compartments. Since SLC30A zinc exporters can deliver zinc into the lumen of vesicles, we examined LPS-regulated mRNA expression of Slc30a/SLC30A family members in primary mouse and human macrophages. A number of these transporters were dynamically regulated in both cell populations. In human monocyte-derived macrophages, LPS strongly up-regulated SLC30A1 mRNA and protein expression. In contrast, SLC30A1 was not LPS-inducible in macrophage-like PMA-differentiated THP-1 cells. We therefore ectopically expressed SLC30A1 in these cells, finding that this was sufficient to promote zinc-containing vesicle formation. The response was similar to that observed following LPS stimulation. Ectopically expressed SLC30A1 localized to both the plasma membrane and intracellular zinc-containing vesicles within LPS-stimulated THP-1 cells. Inducible overexpression of SLC30A1 in THP-1 cells infected with the Escherichia coli K-12 strain MG1655 augmented the zinc stress response of intracellular bacteria and promoted clearance. Furthermore, in THP-1 cells infected with an MG1655 zinc stress reporter strain, all bacteria contained within SLC30A1-positive compartments were subjected to zinc stress. Thus, SLC30A1 marks zinc-containing compartments associated with TLR-inducible zinc toxicity in human macrophages, and its ectopic over-expression is sufficient to initiate this antimicrobial pathway in these cells. Finally, SLC30A1 silencing did not compromise E. coli clearance by primary human macrophages, suggesting that other zinc exporters may also contribute to the zinc toxicity response.
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Affiliation(s)
- Claudia J Stocks
- Institute for Molecular Bioscience (IMB), The University of Queensland, St. Lucia, Queensland, Australia.,IMB Centre for Inflammation and Disease Research, The University of Queensland, St. Lucia, Queensland, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Queensland, Australia
| | - Jessica B von Pein
- Institute for Molecular Bioscience (IMB), The University of Queensland, St. Lucia, Queensland, Australia.,IMB Centre for Inflammation and Disease Research, The University of Queensland, St. Lucia, Queensland, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Queensland, Australia
| | - James E B Curson
- Institute for Molecular Bioscience (IMB), The University of Queensland, St. Lucia, Queensland, Australia.,IMB Centre for Inflammation and Disease Research, The University of Queensland, St. Lucia, Queensland, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Queensland, Australia
| | - James Rae
- Institute for Molecular Bioscience (IMB), The University of Queensland, St. Lucia, Queensland, Australia
| | - Minh-Duy Phan
- Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Queensland, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Darren Foo
- Institute for Molecular Bioscience (IMB), The University of Queensland, St. Lucia, Queensland, Australia.,IMB Centre for Inflammation and Disease Research, The University of Queensland, St. Lucia, Queensland, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Queensland, Australia
| | - Nilesh J Bokil
- Institute for Molecular Bioscience (IMB), The University of Queensland, St. Lucia, Queensland, Australia.,IMB Centre for Inflammation and Disease Research, The University of Queensland, St. Lucia, Queensland, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Queensland, Australia
| | - Taiho Kambe
- Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Kate M Peters
- Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Queensland, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Robert G Parton
- Institute for Molecular Bioscience (IMB), The University of Queensland, St. Lucia, Queensland, Australia.,Centre for Microscopy and Microanalysis, The University of Queensland, St. Lucia, Queensland, Australia
| | - Mark A Schembri
- Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Queensland, Australia.,School of Chemistry and Molecular Biosciences, The University of Queensland, St. Lucia, Queensland, Australia
| | - Ronan Kapetanovic
- Institute for Molecular Bioscience (IMB), The University of Queensland, St. Lucia, Queensland, Australia.,IMB Centre for Inflammation and Disease Research, The University of Queensland, St. Lucia, Queensland, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Queensland, Australia
| | - Matthew J Sweet
- Institute for Molecular Bioscience (IMB), The University of Queensland, St. Lucia, Queensland, Australia.,IMB Centre for Inflammation and Disease Research, The University of Queensland, St. Lucia, Queensland, Australia.,Australian Infectious Diseases Research Centre, The University of Queensland, St. Lucia, Queensland, Australia
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64
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Suzuki E, Ogawa N, Takeda TA, Nishito Y, Tanaka YK, Fujiwara T, Matsunaga M, Ueda S, Kubo N, Tsuji T, Fukunaka A, Yamazaki T, Taylor KM, Ogra Y, Kambe T. Detailed analyses of the crucial functions of Zn transporter proteins in alkaline phosphatase activation. J Biol Chem 2020; 295:5669-5684. [PMID: 32179649 PMCID: PMC7186172 DOI: 10.1074/jbc.ra120.012610] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Revised: 03/04/2020] [Indexed: 11/06/2022] Open
Abstract
Numerous zinc ectoenzymes are metalated by zinc and activated in the compartments of the early secretory pathway before reaching their destination. Zn transporter (ZNT) proteins located in these compartments are essential for ectoenzyme activation. We have previously reported that ZNT proteins, specifically ZNT5-ZNT6 heterodimers and ZNT7 homodimers, play critical roles in the activation of zinc ectoenzymes, such as alkaline phosphatases (ALPs), by mobilizing cytosolic zinc into these compartments. However, this process remains incompletely understood. Here, using genetically-engineered chicken DT40 cells, we first determined that Zrt/Irt-like protein (ZIP) transporters that are localized to the compartments of the early secretory pathway play only a minor role in the ALP activation process. These transporters included ZIP7, ZIP9, and ZIP13, performing pivotal functions in maintaining cellular homeostasis by effluxing zinc out of the compartments. Next, using purified ALP proteins, we showed that zinc metalation on ALP produced in DT40 cells lacking ZNT5-ZNT6 heterodimers and ZNT7 homodimers is impaired. Finally, by genetically disrupting both ZNT5 and ZNT7 in human HAP1 cells, we directly demonstrated that the tissue-nonspecific ALP-activating functions of both ZNT complexes are conserved in human cells. Furthermore, using mutant HAP1 cells, we uncovered a previously-unrecognized and unique spatial regulation of ZNT5-ZNT6 heterodimer formation, wherein ZNT5 recruits ZNT6 to the Golgi apparatus to form the heterodimeric complex. These findings fill in major gaps in our understanding of the molecular mechanisms underlying zinc ectoenzyme activation in the compartments of the early secretory pathway.
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Affiliation(s)
- Eisuke Suzuki
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Namino Ogawa
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Taka-Aki Takeda
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Yukina Nishito
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Yu-Ki Tanaka
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Takashi Fujiwara
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya 464-8601, Japan
| | - Mayu Matsunaga
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Sachiko Ueda
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Naoya Kubo
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Tokuji Tsuji
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan
| | - Ayako Fukunaka
- Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-machi, Maebashi, Gunma 371-8512, Japan
| | - Tomohiro Yamazaki
- Institute for Genetic Medicine, Hokkaido University, Sapporo 060-0815, Japan
| | - Kathryn M Taylor
- School of Pharmacy and Pharmaceutical Sciences, Redwood Building, Cardiff University, King Edward VIIth Avenue, Cardiff CF10 3NB, United Kingdom
| | - Yasumitsu Ogra
- Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan
| | - Taiho Kambe
- Graduate School of Biostudies, Kyoto University, Kyoto 606-8502, Japan.
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65
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Reis BZ, Vieira DADS, Maynard DDC, Silva DGD, Mendes-Netto RS, Cozzolino SMF. Zinc nutritional status influences ZnT1 and ZIP4 gene expression in children with a high risk of zinc deficiency. J Trace Elem Med Biol 2020; 61:126537. [PMID: 32388102 DOI: 10.1016/j.jtemb.2020.126537] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 03/10/2020] [Accepted: 04/17/2020] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Subclinical deficiency of zinc is associated with impairment of immune system function, growth, and cognitive development in children. Although plasma zinc is the best available biomarker of the risk of zinc deficiency in populations, its sensitivity for early detection of deficiency is limited. Therefore, we aimed to investigate zinc deficiency among preschool children and its relationship with whole blood gene expression of zinc transporters ZIP4 and ZnT1. MATERIAL AND METHODS This cross-sectional study included 139 children aged 32-76 months enrolled in philanthropic day-care centers. We performed an anthropometric evaluation, weighed food record and dietary record for dietary assessment, blood sample collection for zinc, and whole blood gene expression analyses of ZnT1 (SLC30A1) and ZIP4 (SLC39A4). RESULTS Zinc deficiency was observed in 26.6 % of the children despite adequate zinc intake and a phytate:zinc molar ratio < 18. Usual zinc intake did not affect whole blood gene expression of zinc transporters, but zinc status influenced ZnT1 and ZIP4 whole blood mRNA. Children with zinc deficiency exhibited 37.1 % higher ZnT1 expression and 45.3 % lower ZIP4 expression than children with adequate zinc (p < 0.05). CONCLUSION Children with plasma zinc deficiency exhibited higher expression of ZnT1 and lower expression of ZIP4 in whole blood mRNA, reinforcing the existence of strong regulation of mineral homeostasis according to the nutritional status, indicating that this analysis may be useful in the evaluation of dietary interventions.
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Affiliation(s)
- Bruna Zavarize Reis
- Postgraduate Program in Applied Human Nutrition (PRONUT), Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Science, University of São Paulo, Av. Prof. Lineu Prestes 580, Bloco 14, Butantã, 05508-000, São Paulo, SP, Brazil.
| | - Diva Aliete Dos Santos Vieira
- Department of Nutrition, Federal University of Sergipe, Av. Universitária Marcelo Deda Chagas, 13. Jardim Campo Novo, 49400-000. Lagarto, SE, Brazil.
| | - Dayanne da Costa Maynard
- Department of Nutrition, Federal University of Sergipe, Av. Marechal Rondon s/n. Jardim Rosa Elze, 49100-000, São Cristóvão, SE, Brazil.
| | - Danielle Góes da Silva
- Department of Nutrition, Federal University of Sergipe, Av. Marechal Rondon s/n. Jardim Rosa Elze, 49100-000, São Cristóvão, SE, Brazil.
| | - Raquel Simões Mendes-Netto
- Department of Nutrition, Federal University of Sergipe, Av. Marechal Rondon s/n. Jardim Rosa Elze, 49100-000, São Cristóvão, SE, Brazil.
| | - Silvia Maria Franciscato Cozzolino
- Postgraduate Program in Applied Human Nutrition (PRONUT), Department of Food and Experimental Nutrition, Faculty of Pharmaceutical Science, University of São Paulo, Av. Prof. Lineu Prestes 580, Bloco 14, Butantã, 05508-000, São Paulo, SP, Brazil.
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66
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Eide DJ. Transcription factors and transporters in zinc homeostasis: lessons learned from fungi. Crit Rev Biochem Mol Biol 2020; 55:88-110. [PMID: 32192376 DOI: 10.1080/10409238.2020.1742092] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Zinc is an essential nutrient for all organisms because this metal serves as a critical structural or catalytic cofactor for many proteins. These zinc-dependent proteins are abundant in the cytosol as well as within organelles of eukaryotic cells such as the nucleus, mitochondria, endoplasmic reticulum, Golgi, and storage compartments such as the fungal vacuole. Therefore, cells need zinc transporters so that they can efficiently take up the metal and move it around within cells. In addition, because zinc levels in the environment can vary drastically, the activity of many of these transporters and other components of zinc homeostasis is regulated at the level of transcription by zinc-responsive transcription factors. Mechanisms of post-transcriptional control are also important for zinc homeostasis. In this review, the focus will be on our current knowledge of zinc transporters and their regulation by zinc-responsive transcription factors and other mechanisms in fungi because these organisms have served as useful paradigms of zinc homeostasis in all organisms. With this foundation, extension to other organisms will be made where warranted.
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Affiliation(s)
- David J Eide
- Department of Nutritional Sciences, University of Wisconsin-Madison, Madison, WI, USA
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67
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Maares M, Haase H. A Guide to Human Zinc Absorption: General Overview and Recent Advances of In Vitro Intestinal Models. Nutrients 2020; 12:E762. [PMID: 32183116 PMCID: PMC7146416 DOI: 10.3390/nu12030762] [Citation(s) in RCA: 146] [Impact Index Per Article: 36.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Revised: 02/23/2020] [Accepted: 03/09/2020] [Indexed: 12/17/2022] Open
Abstract
Zinc absorption in the small intestine is one of the main mechanisms regulating the systemic homeostasis of this essential trace element. This review summarizes the key aspects of human zinc homeostasis and distribution. In particular, current knowledge on human intestinal zinc absorption and the influence of diet-derived factors on bioaccessibility and bioavailability as well as intrinsic luminal and basolateral factors with an impact on zinc uptake are discussed. Their investigation is increasingly performed using in vitro cellular intestinal models, which are continually being refined and keep gaining importance for studying zinc uptake and transport via the human intestinal epithelium. The vast majority of these models is based on the human intestinal cell line Caco-2 in combination with other relevant components of the intestinal epithelium, such as mucin-secreting goblet cells and in vitro digestion models, and applying improved compositions of apical and basolateral media to mimic the in vivo situation as closely as possible. Particular emphasis is placed on summarizing previous applications as well as key results of these models, comparing their results to data obtained in humans, and discussing their advantages and limitations.
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Affiliation(s)
- Maria Maares
- Technische Universität Berlin, Chair of Food Chemistry and Toxicology, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - Hajo Haase
- Technische Universität Berlin, Chair of Food Chemistry and Toxicology, Straße des 17. Juni 135, 10623 Berlin, Germany
- TraceAge-DFG Research Unit on Interactions of Essential Trace Elements in Healthy and Diseased Elderly, D-13353 Potsdam-Berlin-Jena, Germany
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