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Vahidi Ferdowsi P, Ng R, Adulcikas J, Sohal SS, Myers S. Zinc Modulates Several Transcription-Factor Regulated Pathways in Mouse Skeletal Muscle Cells. Molecules 2020; 25:molecules25215098. [PMID: 33153045 PMCID: PMC7663025 DOI: 10.3390/molecules25215098] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2020] [Accepted: 10/28/2020] [Indexed: 02/07/2023] Open
Abstract
Zinc is an essential metal ion involved in many biological processes. Studies have shown that zinc can activate several molecules in the insulin signalling pathway and the concomitant uptake of glucose in skeletal muscle cells. However, there is limited information on other potential pathways that zinc can activate in skeletal muscle. Accordingly, this study aimed to identify other zinc-activating pathways in skeletal muscle cells to further delineate the role of this metal ion in cellular processes. Mouse C2C12 skeletal muscle cells were treated with insulin (10 nM), zinc (20 µM), and the zinc chelator TPEN (various concentrations) over 60 min. Western blots were performed for the zinc-activation of pAkt, pErk, and pCreb. A Cignal 45-Reporter Array that targets 45 signalling pathways was utilised to test the ability of zinc to activate pathways that have not yet been described. Zinc and insulin activated pAkt over 60 min as expected. Moreover, the treatment of C2C12 skeletal muscle cells with TPEN reduced the ability of zinc to activate pAkt and pErk. Zinc also activated several associated novel transcription factor pathways including Nrf1/Nrf2, ATF6, CREB, EGR1, STAT1, AP-1, PPAR, and TCF/LEF, and pCREB protein over 120 min of zinc treatment. These studies have shown that zinc’s activity extends beyond that of insulin signalling and plays a role in modulating novel transcription factor activated pathways. Further studies to determine the exact role of zinc in the activation of transcription factor pathways will provide novel insights into this metal ion actions.
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Abstract
The liver is an essential organ for nutrient and drug metabolism - possessing the remarkable ability to sense environmental and metabolic stimuli and provide an optimally adaptive response. Early growth response 1 (Egr1), an immediate early transcriptional factor which acts as a coordinator of the complex response to stress, is induced during liver injury and controls the expression of a wide range of genes involved in metabolism, cell proliferation, and role of Egr1 in liver injury and repair, deficiency of Egr1 delays liver regeneration process. The known upstream regulators of Egr1 include, but are not limited to, growth factors (e.g. transforming growth factor β1, platelet-derived growth factor, epidermal growth factor, hepatocyte growth factor), nuclear receptors (e.g. hepatocyte nuclear factor 4α, small heterodimer partner, peroxisome proliferator-activated receptor-γ), and other transcription factors (e.g. Sp1, E2F transcription factor 1). Research efforts using various animal models such as fatty liver, liver injury, and liver fibrosis contribute greatly to the elucidation of Egr1 function in the liver. Hepatocellular carcinoma (HCC) represents the second leading cause of cancer mortality worldwide due to the heterogeneity and the late stage at which cancer is generally diagnosed. Recent studies highlight the involvement of Egr1 in HCC development. The purpose of this review is to summarize current studies pertaining to the role of Egr1 in liver metabolism and liver diseases including liver cancer.
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Affiliation(s)
- Nancy Magee
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA
| | - Yuxia Zhang
- Department of Pharmacology, Toxicology & Therapeutics, University of Kansas Medical Center, Kansas City, KS 66160, USA
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Speake PF, Zipitis CS, Houston A, D'Souza S. Taurine Transport Into Fetal Cord Blood Cells: Inhibition by Cyclosporine A. ACTA ACUST UNITED AC 2016; 11:472-7. [PMID: 15458744 DOI: 10.1016/j.jsgi.2004.05.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
OBJECTIVES Pregnant women undergoing long-term organ transplant treatment have an increased incidence of delivering infants with intrauterine growth restriction (IUGR). Cyclosporine A is used as an immunosuppressant in such women and indirect evidence suggests that IUGR might result from an effect of cyclosporine A on amino acid transport by the placenta. In this study we tested the hypothesis that the transport of an essential amino acid, taurine, by fetal tissue other than the placenta is modulated by cyclosporine A. METHODS Cord blood cells (CBCs) were used to test this hypothesis as an easily obtainable fetal tissue. Transport of taurine into CBCs was measured using standard tracer flux assays. RESULTS Uptake of [(3)H] taurine by CBCs was linear over 15 minutes (76.2 +/- 16.6 fmol/10(6) cells/min, mean +/- SEM, n = 6) and inhibitable by 10 mM beta-alanine, a substrate of the system-beta taurine transport protein (6.7 +/- 1.0 fmol/10(6) cells/min, n = 6, P <.05, paired Student t test). Pre-incubation with cyclosporine A (5 microM) inhibited [(3)H] taurine uptake by 29.3%-5.3% (n = 8, P <.05, paired Student t test). CONCLUSIONS These data show that amino acid transport via system-beta can be measured in CBCs and may be a useful model for amino acid transport studies in fetal cells. We also show that system-beta was inhibited by the immunosuppressant, cyclosporine A. This suggests that the increased incidence of IUGR reported in mothers treated with cyclosporine A may be due partially to effects on taurine uptake into fetal cells outside the placenta.
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Affiliation(s)
- Paul F Speake
- Human Development and Reproductive Health Academic Group, Academic Unit of Child Health, University of Manchester, St Mary's Hospital, Manchester, United Kingdom.
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Li G, Da M, Zhang W, Wu H, Ye J, Chen J, Ma L, Gu N, Wu Y, Song X. Alteration of serum lipid profile and its prognostic value in head and neck squamous cell carcinoma. J Oral Pathol Med 2015; 45:167-72. [PMID: 26189546 DOI: 10.1111/jop.12344] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2015] [Indexed: 01/04/2023]
Abstract
BACKGROUND Several serum lipid components have been implicated in the development of cancer. However, the prognostic significance of serum lipid components in head and neck squamous cell carcinoma is unknown. Here, we investigated the predictive value of serum lipid profile at diagnosis and in the overall survival of the patients. METHODS The study population consists of 136 pathologically confirmed head and neck squamous cell carcinoma cases diagnosed between years 2009 and 2014 at a tertiary medical center. Levels of preoperative serum lipid component's total cholesterol, triglycerides, high-density lipoprotein, low-density lipoprotein, apolipoprotein A, apolipoprotein B, and lipoprotein (a) were compared between patients and normal controls matched for age and gender. Serum lipid profiles and their association with clinical parameters were analyzed. The effects of the serum lipid components on survival were examined using the proportional hazards regression model to estimate hazard ratio. RESULTS Significant lower levels of cholesterol, low-density lipoprotein, apolipoprotein A, and apolipoprotein B were found in patients with oral cancer (P < 0.0001). However, a significantly higher level of lipoprotein (a) was found in the cancer group (P < 0.0001). Patients with higher lipoprotein (a) had significantly shorter overall survival than those with lower lipoprotein (a) (P = 0.0042). Multivariate analysis showed that both higher lipoprotein (a) and lymph node metastasis are independent prognostic factors in the patient population (P < 0.01). CONCLUSION A higher lipoprotein (a) was associated with poorer prognosis and might be a novel marker in patients with head and neck squamous cell carcinoma.
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Affiliation(s)
- Gang Li
- Department of Stomatology, Affiliated Hospital of Xuzhou Medical College, Xuzhou, China
| | - Mingjie Da
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China.,Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Wei Zhang
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China.,Department of Oral Special Consultation, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Heming Wu
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China.,Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Jinhai Ye
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China.,Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Jie Chen
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China.,Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Lu Ma
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China.,Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Ning Gu
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China.,Department of Laboratory Medicine, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Yunong Wu
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China.,Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
| | - Xiaomeng Song
- Jiangsu Key Laboratory of Oral Diseases, Nanjing Medical University, Nanjing, China.,Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Stomatology, Nanjing Medical University, Nanjing, China
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Kardassis D, Gafencu A, Zannis VI, Davalos A. Regulation of HDL genes: transcriptional, posttranscriptional, and posttranslational. Handb Exp Pharmacol 2015; 224:113-179. [PMID: 25522987 DOI: 10.1007/978-3-319-09665-0_3] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
HDL regulation is exerted at multiple levels including regulation at the level of transcription initiation by transcription factors and signal transduction cascades; regulation at the posttranscriptional level by microRNAs and other noncoding RNAs which bind to the coding or noncoding regions of HDL genes regulating mRNA stability and translation; as well as regulation at the posttranslational level by protein modifications, intracellular trafficking, and degradation. The above mechanisms have drastic effects on several HDL-mediated processes including HDL biogenesis, remodeling, cholesterol efflux and uptake, as well as atheroprotective functions on the cells of the arterial wall. The emphasis is on mechanisms that operate in physiologically relevant tissues such as the liver (which accounts for 80% of the total HDL-C levels in the plasma), the macrophages, the adrenals, and the endothelium. Transcription factors that have a significant impact on HDL regulation such as hormone nuclear receptors and hepatocyte nuclear factors are extensively discussed both in terms of gene promoter recognition and regulation but also in terms of their impact on plasma HDL levels as was revealed by knockout studies. Understanding the different modes of regulation of this complex lipoprotein may provide useful insights for the development of novel HDL-raising therapies that could be used to fight against atherosclerosis which is the underlying cause of coronary heart disease.
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Affiliation(s)
- Dimitris Kardassis
- Department of Biochemistry, University of Crete Medical School and Institute of Molecular Biology and Biotechnology, Foundation of Research and Technology of Hellas, Heraklion, Crete, 71110, Greece,
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Xu H, Finkelstein DI, Adlard PA. Interactions of metals and Apolipoprotein E in Alzheimer's disease. Front Aging Neurosci 2014; 6:121. [PMID: 24971061 PMCID: PMC4054654 DOI: 10.3389/fnagi.2014.00121] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 05/27/2014] [Indexed: 12/14/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common form of dementia, which is characterized by the neuropathological accumulation of extracellular amyloid plaques and intracellular neurofibrillary tangles (NFTs). Clinically, patients will endure a gradual erosion of memory and other higher order cognitive functions. Whilst the underlying etiology of the disease remains to be definitively identified, a body of work has developed over the last two decades demonstrating that AD plasma/serum and brain are characterized by a dyshomeostasis in a number of metal ions. Furthermore, these metals (such as zinc, copper and iron) play roles in the regulation of the levels of AD-related proteins, including the amyloid precursor protein (APP) and tau. It is becoming apparent that metals also interact with other proteins, including apolipoprotein E (ApoE). The Apolipoprotein E gene (APOE) is critically associated with AD, with APOE4 representing the strongest genetic risk factor for the development of late-onset AD. In this review we will summarize the evidence supporting a role for metals in the function of ApoE and its consequent role in the pathogenesis of AD.
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Affiliation(s)
- He Xu
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne Melbourne, VIC, Australia
| | - David I Finkelstein
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne Melbourne, VIC, Australia
| | - Paul A Adlard
- The Florey Institute of Neuroscience and Mental Health, The University of Melbourne Melbourne, VIC, Australia
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Bondzio A, Pieper R, Gabler C, Weise C, Schulze P, Zentek J, Einspanier R. Feeding low or pharmacological concentrations of zinc oxide changes the hepatic proteome profiles in weaned piglets. PLoS One 2013; 8:e81202. [PMID: 24282572 PMCID: PMC3839893 DOI: 10.1371/journal.pone.0081202] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Accepted: 10/15/2013] [Indexed: 12/15/2022] Open
Abstract
Pharmacological levels of zinc oxide can promote growth and health of weaning piglets, but the underlying molecular mechanisms are yet not fully understood. The aim of this study was to determine changes in the global hepatic protein expression in response to dietary zinc oxide in weaned piglets. Nine half-sib piglets were allocated to three dietary zinc treatment groups (50, 150, 2500 mg/kg dry matter). After 14 d, pigs were euthanized and liver samples taken. The increase in hepatic zinc concentration following dietary supplementation of zinc was accompanied by up-regulation of metallothionein mRNA and protein expression. Global hepatic protein profiles were obtained by two-dimensional difference gel electrophoresis following matrix-assisted laser desorption ionization/time-of-flight mass spectrometry. A total of 15 proteins were differentially (P<0.05) expressed between groups receiving control (150 mg/kg) or pharmacological levels of zinc (2500 mg/kg) with 7 down- (e.g. arginase1, thiosulfate sulfurtransferase, HSP70) and 8 up-regulated (e.g. apolipoprotein AI, transferrin, C1-tetrahydrofolate synthase) proteins. Additionally, three proteins were differentially expressed with low zinc supply (50 mg/kg Zn) in comparison to the control diet. The identified proteins were mainly associated with functions related to cellular stress, transport, metabolism, and signal transduction. The differential regulation was evaluated at the mRNA level and a subset of three proteins of different functional groups was selected for confirmation by western blotting. The results of this proteomic study suggest that zinc affects important liver functions such as blood protein secretion, protein metabolism, detoxification and redox homeostasis, thus supporting the hypothesis of intermediary effects of pharmacological levels of zinc oxide fed to pigs.
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Affiliation(s)
- Angelika Bondzio
- Institute of Veterinary Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Robert Pieper
- Institute of Animal Nutrition, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Christoph Gabler
- Institute of Veterinary Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Christoph Weise
- Institute of Chemistry and Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Petra Schulze
- Institute of Veterinary Biochemistry, Freie Universität Berlin, Berlin, Germany
| | - Juergen Zentek
- Institute of Animal Nutrition, Department of Veterinary Medicine, Freie Universität Berlin, Berlin, Germany
| | - Ralf Einspanier
- Institute of Veterinary Biochemistry, Freie Universität Berlin, Berlin, Germany
- * E-mail:
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Fernández-Millán E, Gangnerau MN, De Miguel-Santos L, Calderari S, Serradas P, Escrivá F, Portha B, Alvarez C. Undernutrition of the GK rat during gestation improves pancreatic IGF-2 and beta-cell mass in the fetuses. Growth Factors 2009; 27:409-18. [PMID: 19919529 DOI: 10.3109/08977190903199074] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The Goto-Kakizaki (GK) rat is a type 2 diabetes model with a defective beta-cell mass detectable in late fetal development. Diminished IGF-2 production seems to be involved in this effect. Herein, we analyzed the effect of maternal food-restriction on the beta-cell mass of GK fetuses and the involvement of the IGF system, highly responsive to nutritional status in this process. To this end, in undernourished GK fetuses (U-GK), we measured serum GH/IGF levels, beta-cell mass, replication and differentiation, and IGF-1/-2 protein content in liver and pancreas tissue. Pregnant GK females were food restricted (65% restriction) during the last week of gestation. Our results show that maternal malnutrition ameliorates beta-cell mass in U-GK fetuses and a specific pancreatic IGF-2 increase may be instrumental in this effect. Further studies are needed to determine whether maternal undernutrition is sufficient to delay or decrease the risk of the GK rat for developing diabetes.
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Kang X, Song Z, McClain CJ, Kang YJ, Zhou Z. Zinc supplementation enhances hepatic regeneration by preserving hepatocyte nuclear factor-4alpha in mice subjected to long-term ethanol administration. THE AMERICAN JOURNAL OF PATHOLOGY 2008; 172:916-25. [PMID: 18349129 DOI: 10.2353/ajpath.2008.070631] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Alcoholic liver disease is associated with sustained liver damage and impaired regeneration, as well as significant zinc deficiency. This study was undertaken to examine whether dietary zinc supplementation could improve liver regeneration by increasing the expression of genes involved in hepatic cellular proliferation in a mouse model of alcoholic liver disease. Adult 129S6 mice fed an ethanol-containing liquid diet for 6 months developed alcoholic liver disease as measured by serum alanine transferase activity and histopathological changes. Zinc supplementation to ethanol-exposed mice enhanced liver regeneration as indicated by increased numbers of proliferation cell nuclear antigen (PCNA)-positive and bromodeoxyuridine (BrdU)-labeled hepatocytes. Zinc-enhanced liver regeneration was associated with an increase in hepatocyte nuclear factor-4alpha (HNF-4alpha), a liver-enriched, zinc-finger transcription factor. Studies using cultured HepG2 cells showed that zinc deficiency suppressed cell proliferation and cell proliferation-related proteins, including hepatocyte growth factor (HGF), insulin-like growth factor I (IGF-I), insulin-like growth factor binding protein 1 (IGFBP1), metallothionein (MT), and cyclin D1, as well as HNF-4alpha. HNF-4alpha gene silencing inhibited cell proliferation in association with decreased protein levels of IGF-I, IGFBP1, MT, and cyclin D1. The present study provides evidence that zinc supplementation enhances liver regeneration at least in part by HNF-4alpha through the up-regulation of cell proliferation-related proteins, suggesting that dietary zinc supplementation may have beneficial effects in alcoholic liver disease.
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Affiliation(s)
- Xinqin Kang
- Department of Medicine, University of Louisville School of Medicine, 511 South Floyd Street, Louisville, KY 40292, USA
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Wong SHK, Zhao Y, Schoene NW, Han CT, Shih RSM, Lei KY. Zinc deficiency depresses p21 gene expression: inhibition of cell cycle progression is independent of the decrease in p21 protein level in HepG2 cells. Am J Physiol Cell Physiol 2007; 292:C2175-84. [PMID: 17303651 DOI: 10.1152/ajpcell.00256.2006] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The influence of zinc status on p21 gene expression was examined in human hepatoblastoma (HepG2) cells. Cells were cultured for one passage in a basal medium depleted of zinc to induce severely zinc-deficient (ZD) cells or in basal medium supplemented with 0.4, 4.0, 16, or 32 μM zinc to represent mild zinc deficiency (ZD0.4), the amount of zinc in most normal media (ZN), the normal human plasma zinc level (zinc-adequate; ZA), or the high end of plasma zinc attainable by oral supplementation (ZS), respectively. In ZD and ZD0.4 cells, the nuclear p21 protein level, mRNA abundance, and promoter activity were reduced to 40, 70, and 65%, respectively, of ZN cells. However, p21 protein and mRNA levels, as well as p21 promoter activity, were not altered in ZA and ZS cells compared with ZN cells. Moreover, the amounts of acetylated histone-4 associated with the proximal and distal p21 promoter regions, as a measure of p21 promoter accessibility, were decreased in ZD (73 and 64%, respectively) and ZD0.4 (82 and 77%, respectively) cells compared with ZN cells (100 and 100%, respectively). Thus multiple lines of evidence indicate that the transcriptional process of p21 is downregulated by depressed zinc status in HepG2 cells. Furthermore, the transfection of 5 μg of plasmid cytomegalovirus-p21 plasmid, which constitutively expressed p21, was able to normalize the reduction in p21 protein level and cyclin D1-cdk4 complex activity but not the inhibition of cell growth and G1/S cell cycle progression in ZD cells.
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Affiliation(s)
- Stephen H K Wong
- Dept. of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA
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Cho YE, Lomeda RAR, Ryu SH, Lee JH, Beattie JH, Kwun IS. Cellular Zn depletion by metal ion chelators (TPEN, DTPA and chelex resin) and its application to osteoblastic MC3T3-E1 cells. Nutr Res Pract 2007; 1:29-35. [PMID: 20535382 PMCID: PMC2882573 DOI: 10.4162/nrp.2007.1.1.29] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2007] [Revised: 03/03/2007] [Accepted: 03/14/2007] [Indexed: 11/04/2022] Open
Abstract
Trace mineral studies involving metal ion chelators have been conducted in investigating the response of gene and protein expressions of certain cell lines but a few had really focused on how these metal ion chelators could affect the availability of important trace minerals such as Zn, Mn, Fe and Cu. The aim of the present study was to investigate the availability of Zn for the treatment of MC3T3-E1 osteoblast-like cells and the availability of some trace minerals in the cell culture media components after using chelexing resin in the FBS and the addition of N,N,N',N'-tetrakis-(2-pyridylmethyl)ethylenediamine (TPEN, membrane-permeable chelator) and diethylenetriaminepentaacetic acid (DTPA, membrane-impermeable chelator) in the treatment medium. Components for the preparation of cell culture medium and Zn-treated medium have been tested for Zn, Mn, Fe and Cu contents by atomic absorption spectrophotometer or inductively coupled plasma spectrophotometer. Also, the expression of bone-related genes (ALP, Runx2, PTH-R, ProCOL I, OPN and OC) was measured on the cellular Zn depletion such as chelexing or TPEN treatment. Results have shown that using the chelexing resin in FBS would significantly decrease the available Zn (p<0.05) (39.4 +/- 1.5 microM vs 0.61 +/- 10.15 microM) and Mn (p<0.05) (0.74 +/- 0.01 microM vs 0.12 +/- 0.04 microM). However, levels of Fe and Cu in FBS were not changed by chelexing FBS. The use of TPEN and DTPA as Zn-chelators did not show significant difference on the final concentration of Zn in the treatment medium (0, 3, 6, 9, 12 microM) except for in the addition of higher 15 microM ZnCl(2) which showed a significant increase of Zn level in DTPA-chelated treatment medium. Results have shown that both chelators gave the same pattern for the expression of the five bone-related genes between Zn- and Zn+, and TPEN-treated experiments, compared to chelex-treated experiment, showed lower bone-related gene expression, which may imply that TPEN would be a stronger chelator than chelex resin. This study showed that TPEN would be a stronger chelator compared to DTPA or chelex resin and TPEN and chelex resin exerted cellular zinc depletion to be enough for cell study for Zn depletion.
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Affiliation(s)
- Young-Eun Cho
- Department of Food and Nutrition, Andong National University, Gyeongbuk 760-749, Korea
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Alshatwi AA, Han CT, Schoene NW, Lei KY. Nuclear accumulations of p53 and Mdm2 are accompanied by reductions in c-Abl and p300 in zinc-depleted human hepatoblastoma cells. Exp Biol Med (Maywood) 2006; 231:611-8. [PMID: 16636310 DOI: 10.1177/153537020623100516] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The influence of zinc status on the expression of proteins known to be involved in the stability of p53, the human tumor suppressor gene product, was examined in hepatoblastoma (HepG2) cells. Cells were cultured in zinc-deficient (ZD0.2, ZD0.4), zinc normal (ZN), zinc adequate (ZA), or zinc-supplemented (ZS) medium, which contained 0.2, 0.4, 4, 16, or 32 microM zinc, respectively. Nuclear p53 levels were almost 100% and 40% higher in ZD0.2 and ZD0.4 cells, respectively, than in ZN cells. Mdm2 protein, which mediates p53 degradation, was 174% and 148% higher in the nucleus of ZD0.2 and ZD0.4 cells, respectively, than in ZN cells. In addition, the observed reductions of nuclear c-Abl in ZD0.2 and ZD0.4 cells to 50% and 60% of ZN cells, respectively, may be a cellular response attempting to normalize nuclear p53 accumulation because nuclear c-Abl is known to down-regulate ubiquitination and nuclear export of p53. Moreover, no changes in total cellular p53, Mdm2, and c-Abl or nuclear Mdmx were observed among the treatment groups. Furthermore, in ZD0.2 and ZD0.4 cells, the reduction in total and nuclear p300, which is known to complex with CREB-binding protein and Mdm2 in the nucleus for the generation of degradable polyubiquitinated form of p53, may have depressed the degradation pathway for p53 and Mdm2, and contributed to the nuclear accumulation of these proteins in ZD cells.
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Affiliation(s)
- Ali A Alshatwi
- Department of Nutrition and Food Science, University of Maryland, College Park, MD 20742, USA
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Abstract
Zinc deficiency is characterized by an attenuation of growth factor signaling pathways and an amplification of p53 pathways. This outcome is facilitated by hypo-phosphorylation of AKT and ERK secondary to zinc deficiency, which are permissive events to the activation of the intrinsic cell death pathway. Low zinc concentrations provide an environment that is also conducive to the production of reactive oxygen/reactive nitrogen species (ROS/RNS) and caspase activation. Additionally, during zinc deficiency endogenous survival pathways such as NF-kappaB are inhibited in their transactivation potential. The above factors contribute to the irreversible commitment of the zinc deficient cell to death.
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Affiliation(s)
- Michael S Clegg
- Department of Nutrition, University of California at Davis, Davis, CA 95616, USA.
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Portha B. Programmed disorders of beta-cell development and function as one cause for type 2 diabetes? The GK rat paradigm. Diabetes Metab Res Rev 2005; 21:495-504. [PMID: 15926190 DOI: 10.1002/dmrr.566] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Now that the reduction in beta-mass has been clearly established in humans with type 2 diabetes mellitus (T2DM) 1-4, the debate focuses on the possible mechanisms responsible for decreased beta-cell number and impaired beta-cell function and their multifactorial etiology. Appropriate inbred rodent models are essential tools for identification of genes and environmental factors that increase the risk of abnormal beta-cell function and of T2DM. The information available in the Goto-Kakizaki (GK) rat, one of the best characterized animal models of spontaneous T2DM, are reviewed in such a perspective. We propose that the defective beta-cell mass and function in the GK model reflect the complex interactions of three pathogenic players: (1) several independent loci containing genes causing impaired insulin secretion; (2) gestational metabolic impairment inducing a programming of endocrine pancreas (decreased beta-cell neogenesis) which is transmitted to the next generation; and (3) secondary (acquired) loss of beta-cell differentiation due to chronic exposure to hyperglycemia (glucotoxicity). An important message is that the 'heritable' determinants of T2DM are not simply dependant on genetic factors, but probably involve transgenerational epigenetic responses.
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Affiliation(s)
- Bernard Portha
- Lab. Physiopathologie de la Nutrition, Université Paris 7/D. Diderot, Paris Cedex, France.
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Morello F, de Bruin TWA, Rotter JI, Pratt RE, van der Kallen CJH, Hladik GA, Dzau VJ, Liew CC, Chen YDI. Differential Gene Expression of Blood-Derived Cell Lines in Familial Combined Hyperlipidemia. Arterioscler Thromb Vasc Biol 2004; 24:2149-54. [PMID: 15388524 DOI: 10.1161/01.atv.0000145978.70872.63] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVES The genetic background of familial combined hyperlipidemia (FCHL) is currently unclear. We propose transcriptional profiling as a complementary tool for its understanding. Two hypotheses were tested: the existence of a disease-specific modification of gene expression in FCHL and the detectability of such a transcriptional profile in blood derived cell lines. METHODS AND RESULTS We established lymphoblastic cell lines from FCHL patients and controls. The cells were cultured in fixed conditions and their basal expression profile was compared using microarrays; 166 genes were differentially expressed in FCHL-derived cell lines compared with controls, with enrichment in metabolism-related genes. Of note was the upregulation of EGR-1, previously found to be upregulated in the adipose tissue of FCHL patients, the upregulation of DCHR-7, the downregulation of LYPLA2, and the differential expression of several genes previously unrelated to FCHL. A cluster of potential EGR-1-regulated transcripts was also differentially expressed in FCHL cells. CONCLUSIONS Our data indicate that in FCHL, a disease-specific transcription profile is detectable in immortalized cell lines easily obtained from peripheral blood and provide complementary information to classical genetic approaches to FCHL and/or the metabolic syndrome.
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Affiliation(s)
- Fulvio Morello
- Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Mass, USA
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Lamon-Fava S, Micherone D. Regulation of apoA-I gene expression: mechanism of action of estrogen and genistein. J Lipid Res 2003; 45:106-12. [PMID: 14563824 DOI: 10.1194/jlr.m300179-jlr200] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
We have previously shown that 17-beta-estradiol (E2) and genistein increase the expression of apolipoprotein A-I (apoA-I), the major protein component of HDL, in Hep G2 cells. To elucidate the mechanism mediating the increase in apoA-I gene expression by these compounds, plasmid constructs containing serial deletions of the apoA-I promoter region were generated. The smallest region maintaining response to E2 and genistein spanned the -220 to -148 sequence, and the estrogen antagonist ICI182,780 completely inhibited the E2 and genistein effect. Nuclear extracts from cells treated with E2 and genistein showed increased binding to site B oligonucleotide (-169 to -146), and nuclear extracts from genistein-treated cells showed increased binding to an early growth response factor 1 (Egr-1) oligonucleotide compared to control cells. An increase in the concentrations of Egr-1 and hepatocyte nuclear factor-3beta was observed in nuclear extracts of cells treated with both compounds compared to control cells. Treatment with a specific inhibitor of mitogen-activated protein (MAP) kinase, but not with other inhibitors, abolished the stimulation of apoA-I gene expression by E2 and genistein. These results indicate that the MAP kinase pathway is involved in the regulation of apoA-I gene expression by genistein and E2, possibly through downstream regulation of transcription factors binding to the promoter region.
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Affiliation(s)
- Stefania Lamon-Fava
- Lipid Metabolism Laboratory, Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston, MA 02111, USA.
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Current awareness in NMR in biomedicine. NMR IN BIOMEDICINE 2003; 16:56-65. [PMID: 12619641 DOI: 10.1002/nbm.799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
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Fanzo JC, Reaves SK, Cui L, Zhu L, Lei KY. p53 protein and p21 mRNA levels and caspase-3 activity are altered by zinc status in aortic endothelial cells. Am J Physiol Cell Physiol 2002; 283:C631-8. [PMID: 12107073 DOI: 10.1152/ajpcell.00248.2001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The influence of zinc status on the levels of p53, as well as downstream targets of p53 in cell repair and survival, was examined in human aortic endothelial cells (HAECs). A serum-reduced low-zinc medium (ZD) was used to deplete zinc over one passage. Other treatments included zinc-normal control (ZN), zinc-adequate (ZA), and zinc-supplemented (ZS) treatment with 3.0, 16.0, and 32.0 microM zinc, respectively. Cellular zinc levels in the ZD cells were 64% of ZN controls; levels in the ZA cells were not different, but levels in ZS cells were significantly higher (40%) than in ZN cells. No difference in p53 mRNA abundance was detected among all treatments; however, p53 nuclear protein levels were >100% higher in the ZD and ZS cells and almost 200% higher in the ZA cells than in ZN controls. In addition, p21 mRNA abundance, a downstream target of p53 protein, was increased in the ZS cells compared with both the ZN control and ZD cells. In the ZS cells, bax and mcl-1 were also approximately 50% higher compared with ZN controls, whereas bcl-2 mRNA was increased compared with ZA cells. Moreover, caspase-3 activity of ZD cells was not different from that of ZN controls but was reduced to 83 and 69% of ZN controls in ZA and ZS cells, respectively. Thus p53 protein and p53 downstream target genes appeared to be modulated by intracellular zinc status in HAECs.
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Affiliation(s)
- Jessica C Fanzo
- Department of Nutritional Sciences, University of Arizona, Tucson, Arizona 85721, USA
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