Rechargeable zinc cell with alkaline electrolyte which inhibits shape change in zinc electrode

DOEpatents

Adler, Thomas C.; McLarnon, Frank R.; Cairns, Elton J.

1995-01-01

An improved rechargeable zinc cell is described comprising a zinc electrode and another electrode such as, for example, a nickel-containing electrode, and having an electrolyte containing one or more hydroxides having the formula M(OH), one or more fluorides having the formula MF, and one or more carbonates having the formula M.sub.2 CO.sub.3, where M is a metal selected from the group consisting of alkali metals. The electrolyte inhibits shape change in the zinc electrode, i.e., the zinc electrode exhibits low shape change, resulting in an improved capacity retention of the cell over an number of charge-discharge cycles, while still maintaining high discharge rate characteristics.

Effect of resveratrol and zinc on intracellular zinc status in normal human prostate epithelial cells

USDA-ARS?s Scientific Manuscript database

To evaluate the influence of resveratrol on cellular zinc status, normal human prostate epithelial (NHPrE) cells were treated with 6 levels of resveratrol (0, 0.5, 1, 2.5, 5 and 10 microM) and 4 levels of zinc [0, 4, 16, and 32 microM for zinc-deficient (ZD), zinc-normal (ZN), zinc-adequate (ZA), an...

Effects of cadmium and zinc on solar-simulated light-irradiated cells: potential role of zinc-metallothionein in zinc-induced genoprotection.

PubMed

Jourdan, Eric; Emonet-Piccardi, Nathalie; Didier, Christine; Beani, Jean-Claude; Favier, Alain; Richard, Marie-Jeanne

2002-09-15

Zinc is an essential oligoelement for cell growth and cell survival and has been demonstrated to protect cells from oxidative stress induced by UVA or from genotoxic stress due to UVB. In a recent work we demonstrated that the antioxidant role of zinc could be related to its ability to induce metallothioneins (MTs). In this study we identified the mechanism of zinc protection against solar-simulated light (SSL) injury. Cultured human keratinocytes (HaCaT) were used to examine MTs expression and localization in response to solar-simulated radiation. We found translocation to the nucleus, with overexpression of MTs in irradiated cells, a novel observation. The genoprotective effect of zinc was dependent on time and protein synthesis. DNA damage was significantly decreased after 48 h of ZnCl(2) (100 microM) treatment and is inhibited by actinomycin D. ZnCl(2) treatment (100 microM) led to an intense induction, redistribution, and accumulation of MT in the nucleus of irradiated cells. MT expression correlated with the time period of ZnCl(2) treatment. CdCl(2), a potent MT inducer, did not show any genoprotection, although the MTs were expressed in the nucleus. Overall our findings demonstrate that MTs could be a good candidate for explaining the genoprotection mediated by zinc on irradiated cells.

Zinc supplements for treating thalassaemia and sickle cell disease.

PubMed

Swe, Kye Mon Min; Abas, Adinegara B L; Bhardwaj, Amit; Barua, Ankur; Nair, N S

2013-06-28

Haemoglobinopathies, inherited disorders of haemoglobin synthesis (thalassaemia) or structure (sickle cell disease), are responsible for significant morbidity and mortality throughout the world. The WHO estimates that, globally, 5% of adults are carriers of a haemoglobin condition, 2.9% are carriers of thalassaemia and 2.3% are carriers of sickle cell disease. Carriers are found worldwide as a result of migration of various ethnic groups to different regions of the world. Zinc is an easily available supplement and intervention programs have been carried out to prevent deficiency in people with thalassaemia or sickle cell anaemia. It is important to evaluate the role of zinc supplementation in the treatment of thalassaemia and sickle cell anaemia to reduce deaths due to complications. To assess the effect of zinc supplementation in the treatment of thalassaemia and sickle cell disease. We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group's Haemoglobinopathies Trials Register comprising references identified from comprehensive electronic database searches and handsearches of relevant journals and abstract books of conference proceedings.Date of most recent search: 01 February 2013. Randomised, placebo-controlled trials of zinc supplements for treating thalassaemia or sickle cell disease administered at least once a week for at least a month. Two review authors assessed the eligibility and risk of bias of the included trials, extracted and analysed data and wrote the review. We summarised results using risk ratios or rate ratios for dichotomous data and mean differences for continuous data. We combined trial results where appropriate. We identified nine trials for inclusion with all nine contributing outcome data. Two trials reported on people with thalassaemia (n = 152) and seven on sickle cell anaemia (n = 307).In people with thalassaemia, in one trial, the serum zinc level value showed no difference between the zinc supplemented group and the

Heat Shock Proteins In The Retina: Focus On Hsp70 and Alpha Crystallins In Ganglion Cell Survival

PubMed Central

Piri, Natik; Kwong, Jacky MK; Gu, Lei; Caprioli, Joseph

2016-01-01

Heat shock proteins (HSPs) belong to a superfamily of stress proteins that are critical constituents of a complex defense mechanism that enhances cell survival under adverse environmental conditions. Cell protective roles of HSPs are related to their chaperone functions, antiapoptotic and antinecrotic effects. HSPs' antiapoptotic and cytoprotective characteristics, their ability to protect cells from a variety of stressful stimuli, and the possibility of their pharmacological induction in cells under pathological stress make these proteins an attractive therapeutic target for various neurodegenerative diseases; these include Alzheimer's, Parkinson's, Huntington's, prion disease, and others. This review discusses the possible roles of HSPs, particularly HSP70 and small HSPs (alpha A and alpha B crystallins) in enhancing the survival of retinal ganglion cells (RGCs) in optic neuropathies such as glaucoma, which is characterized by progressive loss of vision caused by degeneration of RGCs and their axons in the optic nerve. Studies in animal models of RGC degeneration induced by ocular hypertension, optic nerve crush and axotomy show that upregulation of HSP70 expression by hyperthermia, zinc, geranyl-geranyl acetone, 17-AAG (a HSP90 inhibitor), or through transfection of retinal cells with AAV2-HSP70 effectively supports the survival of injured RGCs. RGCs survival was also stimulated by overexpression of alpha A and alpha B crystallins. These findings provide support for translating the HSP70- and alpha crystallin-based cell survival strategy into therapy to protect and rescue injured RGCs from degeneration associated with glaucomatous and other optic neuropathies. PMID:27017896

Zinc enhances the number of regulatory T cells in allergen-stimulated cells from atopic subjects.

PubMed

Rosenkranz, Eva; Hilgers, Ralf-Dieter; Uciechowski, Peter; Petersen, Arnd; Plümäkers, Birgit; Rink, Lothar

2017-03-01

The trace element zinc is essential for immune function and its regulation. Since zinc deficiency and allergic hyperresponsive reactions are often accompanied, the influence of zinc on allergen-induced cell growth, CD4+ regulatory T (Treg) cell numbers and cytokine expression during allergic immune reactions was investigated. Peripheral blood mononuclear cells (PBMCs) from non-atopic and atopic subjects were treated with timothy grass allergen pre-incubated with or without zinc. Proliferation was determined by analyzing the incorporation of 3 H-thymidine. Intracellular zinc and Foxp3 levels and cell surface antigens were measured by FACS, cytokine expression by ELISA and real-time PCR. Incubation with 50 μM zinc sulfate (Zn50) enhances cytosolic zinc concentrations in CD3+ T cells. The data also reveal that the combination of Zn50 plus allergen significantly reduces PBMC proliferation of atopic subjects. Additionally, Zn50 plus allergen enhances Th1 cytokine responses shown by increased interferon (IFN)-γ/interleukin (IL)-10 ratios as well as enhanced tumor necrosis factor-α release. In response to allergen, zinc increases Treg cells and upregulates the mRNA expression of cytotoxic T-lymphocyte antigen-4 in atopic subjects. Interestingly, Zn50 alone leads to an increase of CD4+CD25high(hi)+ cells in atopic and non-atopic subjects. Zinc may regulate unwanted hyperresponsive immune reactions by suppressing proliferation through a significant shift from IL-10 to the Th1 cytokine IFN-γ, and enhanced regulatory T cell numbers. Therefore, zinc supplementation may be a promising tool for the therapy of allergies, without negatively affecting the immune system.

Development and fabrication of large vented nickel-zinc cells

NASA Technical Reports Server (NTRS)

Donnel, C. P., III

1975-01-01

A preliminary cell design for a 300AH vented nickel-zinc cell was established based on volume requirements and cell component materials selected by NASA Lewis Research Center. A 100AH cell configuration was derived from the 300AH cell design utilizing the same size electrodes, separators, and cell terminal hardware. The first cells fabricated were four groups of three cells each in the 100AH size. These 100AH experimental nickel-zinc cells had as common components the nickel positive electrodes (GFM), flexible inorganic separator (GFM) bags on the negative electrodes, pressed powder zinc oxide electrodes, and cell containers with hardware. The variations introduced were four differing electrolyte absorber (interseparator) systems used to encase the nickel positive electrodes of each cell group. The four groups of 100AH experimental vented nickel-zinc cells were tested to determine, based on cell performance, the best two interseparator systems. Using the two interseparator systems, two groups of experimental 300AH cells were fabricated. Each group of three cells differed only in the interseparator material used. The six cells were filled, formed and tested to evaluate the interseparator materials and investigate the performance characteristics of the 300AH cell configuration and its components.

Colchicine induced intraneuronal free zinc accumulation and dentate granule cell degeneration.

PubMed

Choi, Bo Young; Lee, Bo Eun; Kim, Jin Hee; Kim, Hyun Jung; Sohn, Min; Song, Hong Ki; Chung, Tae Nyoung; Suh, Sang Won

2014-08-01

Colchicine has been discovered to inhibit many inflammatory processes such as gout, familial Mediterranean fever, pericarditis and Behcet disease. Other than these beneficial anti-inflammatory effects, colchicine blocks microtubule-assisted axonal transport, which results in the selective loss of dentate granule cells of the hippocampus. The mechanism of the colchicine-induced dentate granule cell death and depletion of mossy fiber terminals still remains unclear. In the present study, we hypothesized that colchicine-induced dentate granule cell death may be caused by accumulation of labile intracellular zinc. 10 μg kg(-1) of colchicine was injected into the adult rat hippocampus and then brain sections were evaluated at 1 day or 1 week later. Neuronal cell death was evaluated by H&E staining or Fluoro-Jade B. Zinc accumulation and vesicular zinc were detected by N-(6-methoxy-8-quinolyl)-para-toluene sulfonamide (TSQ) staining. To test whether an extracellular zinc chelator can prevent this process, CaEDTA was injected into the hippocampus over a 5 min period with colchicine. To test whether other microtubule toxins also produce similar effects as colchicine, vincristine was injected into the hippocampus. The present study found that colchicine injection induced intracellular zinc accumulation in the dentate granule cells and depleted vesicular zinc from mossy fiber terminals. Injection of a zinc chelator, CaEDTA, did not block the zinc accumulation and neuronal death. Vincristine also produced intracellular zinc accumulation and neuronal death. These results suggest that colchicine-induced dentate granule cell death is caused by blocking axonal zinc flow and accumulation of intracellular labile zinc.

The alpha subunit of Go interacts with promyelocytic leukemia zinc finger protein and modulates its functions.

PubMed

Won, Jung Hee; Park, Jung Sik; Ju, Hyun Hee; Kim, Soyeon; Suh-Kim, Haeyoung; Ghil, Sung Ho

2008-05-01

Heterotrimeric GTP-binding proteins (G proteins) mediate signal transduction generated by neurotransmitters and hormones. Go, a member of the Go/Gi family, is the most abundant heterotrimeric G protein in the brain. Most mechanistic analyses on Go activation demonstrate that its action is mediated by the Gbetagamma dimer; downstream effectors for its alpha subunit (Goalpha) have not been clearly defined. Here, we employ the yeast two-hybrid system to screen for Goalpha-interacting partners in a cDNA library from human fetal brain. The transcription factor promyelocytic leukemia zinc finger protein (PLZF) specifically bound to Goalpha. Interactions between PLZF and Goalpha were confirmed using in vitro and in vivo affinity binding assays. Activated Goalpha interacted directly with PLZF, and enhanced its function as a transcriptional and cell growth suppressor. Notably, PLZF activity was additionally promoted by the Go/ialpha-coupled cannabinoid receptor (CB) in HL60 cells endogenously expressing CB and PLZF. These results collectively suggest that Goalpha modulates the function of PLZF via direct interactions. Our novel findings provide insights into the diverse cellular roles of Goalpha and its coupled receptor.

Zinc oxide nanoparticles as selective killers of proliferating cells.

PubMed

Taccola, Liuba; Raffa, Vittoria; Riggio, Cristina; Vittorio, Orazio; Iorio, Maria Carla; Vanacore, Renato; Pietrabissa, Andrea; Cuschieri, Alfred

2011-01-01

It has recently been demonstrated that zinc oxide nanoparticles (ZnO NPs) induce death of cancerous cells whilst having no cytotoxic effect on normal cells. However, there are several issues which need to be resolved before translation of zinc oxide nanoparticles into medical use, including lack of suitable biocompatible dispersion protocols and a better understanding being needed of the mechanism of their selective cytotoxic action. Nanoparticle dose affecting cell viability was evaluated in a model of proliferating cells both experimentally and mathematically. The key issue of selective toxicity of ZnO NPs toward proliferating cells was addressed by experiments using a biological model of noncancerous cells, ie, mesenchymal stem cells before and after cell differentiation to the osteogenic lineage. In this paper, we report a biocompatible protocol for preparation of stable aqueous solutions of monodispersed zinc oxide nanoparticles. We found that the threshold of intracellular ZnO NP concentration required to induce cell death in proliferating cells is 0.4 ± 0.02 mM. Finally, flow cytometry analysis revealed that the threshold dose of zinc oxide nanoparticles was lethal to proliferating pluripotent mesenchymal stem cells but exhibited negligible cytotoxic effects to osteogenically differentiated mesenchymal stem cells. Results confirm the ZnO NP selective cytotoxic action on rapidly proliferating cells, whether benign or malignant.

Zinc Up-Regulates Insulin Secretion from β Cell-Like Cells Derived from Stem Cells from Human Exfoliated Deciduous Tooth (SHED).

PubMed

Kim, Gyuyoup; Shin, Ki-Hyuk; Pae, Eung-Kwon

2016-12-13

Stem cells from human exfoliated deciduous tooth (SHED) offer several advantages over other stem cell sources. Using SHED, we examined the roles of zinc and the zinc uptake transporter ZIP8 (Zrt- and irt-like protein 8) while inducing SHED into insulin secreting β cell-like stem cells (i.e., SHED-β cells). We observed that ZIP8 expression increased as SHED differentiated into SHED-β cells, and that zinc supplementation at day 10 increased the levels of most pancreatic β cell markers-particularly Insulin and glucose transporter 2 (GLUT2). We confirmed that SHED-β cells produce insulin successfully. In addition, we note that zinc supplementation significantly increases insulin secretion with a significant elevation of ZIP8 transporters in SHED-β cells. We conclude that SHED can be converted into insulin-secreting β cell-like cells as zinc concentration in the cytosol is elevated. Insulin production by SHED-β cells can be regulated via modulation of zinc concentration in the media as ZIP8 expression in the SHED-β cells increases.

Suppressive effect of zinc ion on iNOS expression induced by interferon-gamma or tumor necrosis factor-alpha in murine keratinocytes.

PubMed

Yamaoka, J; Kume, T; Akaike, A; Miyachi, Y

2000-05-01

Zinc, an essential metal, is a critical component of zinc binding proteins such as zinc fingers, zinc enzymes and metallothioneins. Recently, evidence for its anti-inflammatory property in skin has been accumulating, as shown in the treatment of acne, alopecia and zinc deficiency. In cutaneous inflammations, a large amount of nitric oxide (NO) is produced through induction of inducible nitric oxide synthase (iNOS) under the influence of proinflammatory cytokines, resulting in tissue damages in skin, as clarified in other organs. Therefore, we asked if the effect of zinc on NO production and/or on iNOS expression in keratinocytes may explain the anti-inflammatory property of zinc in skin. Accordingly, we sought to determine in this study whether zinc ion may have effect on IFN-gamma or TNF-alpha induced NO production and iNOS expression in cultured murine keratinocytes. Ten microM of zinc ion remarkably suppressed cytokine-induced NO production in keratinocytes. Furthermore, zinc ion also suppressed cytokine-induced iNOS expression in the protein level as well as in the messenger RNA level. These results suggest the possibility that the suppressive effect of zinc ion on cytokine-induced NO production in keratinocytes may be in part implicated in the anti-inflammatory property of zinc in some of skin disorders.

Moderate zinc deficiency increases cell death after brain injury in the rat.

PubMed

Yeiser, E Carden; Vanlandingham, Jacob W; Levenson, Cathy W

2002-10-01

Zinc supplementation has been used clinically to reduce Zn losses and protein turnover in patients suffering from traumatic brain injury. Despite the known role of zinc in cell survival and integrity, the influence of zinc status on central nervous system wound healing in the weeks and months after brain injury has not been addressed. In this investigation, we examined cell death after unilateral cortical stab wounds in adult rats (n = 5 per group) that were provided diets containing adequate zinc (30 mg Zn/kg diet), supplemental zinc (180 mg/kg), or moderately deficient zinc (5 mg/kg). Four weeks following the brain injury there was a 1.82-2.65-fold increase in terminal deoxynucleotidyl transferase-mediated biotinylated dUTP nick-end labeling (TUNEL)-positive cells with DNA fragmentation at the site of injury in animals receiving a moderately zinc deficient diet compared to animals receiving a zinc-adequate or supplemented diet (p0.05). Examination of the nuclear morphology of these cells suggested the presence of both apoptosis and necrosis. Immunohistochemistry showed that the TUNEL-positive cells expressed both ED-1 and OX-42, identifying them as microglia/macrophages. Thus it appears that adequate zinc status may be necessary to minimize the amount of neuroimmune cell death after brain injury.

Zinc oxide nanoparticles as selective killers of proliferating cells

PubMed Central

Taccola, Liuba; Raffa, Vittoria; Riggio, Cristina; Vittorio, Orazio; Iorio, Maria Carla; Vanacore, Renato; Pietrabissa, Andrea; Cuschieri, Alfred

2011-01-01

Background: It has recently been demonstrated that zinc oxide nanoparticles (ZnO NPs) induce death of cancerous cells whilst having no cytotoxic effect on normal cells. However, there are several issues which need to be resolved before translation of zinc oxide nanoparticles into medical use, including lack of suitable biocompatible dispersion protocols and a better understanding being needed of the mechanism of their selective cytotoxic action. Methods: Nanoparticle dose affecting cell viability was evaluated in a model of proliferating cells both experimentally and mathematically. The key issue of selective toxicity of ZnO NPs toward proliferating cells was addressed by experiments using a biological model of noncancerous cells, ie, mesenchymal stem cells before and after cell differentiation to the osteogenic lineage. Results: In this paper, we report a biocompatible protocol for preparation of stable aqueous solutions of monodispersed zinc oxide nanoparticles. We found that the threshold of intracellular ZnO NP concentration required to induce cell death in proliferating cells is 0.4 ± 0.02 mM. Finally, flow cytometry analysis revealed that the threshold dose of zinc oxide nanoparticles was lethal to proliferating pluripotent mesenchymal stem cells but exhibited negligible cytotoxic effects to osteogenically differentiated mesenchymal stem cells. Conclusion: Results confirm the ZnO NP selective cytotoxic action on rapidly proliferating cells, whether benign or malignant. PMID:21698081

Zinc supplementation augments TGF-β1-dependent regulatory T cell induction.

PubMed

Maywald, Martina; Meurer, Steffen K; Weiskirchen, Ralf; Rink, Lothar

2017-03-01

Regulatory T cells (Treg) play a pivotal role in immune regulation. For proper immune function, also trace elements such as zinc, and anti-inflammatory cytokines, including transforming growth factor beta 1 (TGF-β1) and interleukin (IL)-10 are indispensable. Hence, in this study the influence of TGF-β1, IL-10, and zinc supplementation on Treg cells differentiation was investigated. A synergistic effect of a combined zinc and TGF-β1 treatment on Foxp3 expression in peripheral blood mononuclear cells and mixed lymphocyte cultures (MLC) was found by performing Western blot analysis. Additionally, combined treatment causes elevated Smad 2/3 phosphorylation, which plays an important role in Foxp3 expression. This is due to a TGF-β1-mediated increase of intracellular-free zinc measured by zinc probes Fluozin3-AM and ZinPyr-1. Moreover, zinc as well as TGF-β1 treatment caused significantly reduced interferon (IFN)-γ secretion in MLC. Combined zinc and TGF-β1 treatment provoked an increased Treg cell induction due to a triggered intracellular zinc signal, which in association with an increased Smad 2/3 activation leads to a boosted Foxp3 expression and resulting in an ameliorated allogeneic reaction in MLC. Thus, zinc can be used as a favorable additive to elevate the induction of Treg cells in adverse immune reactions. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

alpha-Adrenergic-mediated activation of human reconstituted fibrinogen receptor (integrin alphaIIbbeta3) in Chinese hamster ovary cells.

PubMed

Butta, Nora; Larrucea, Susana; Gonzalez-Manchon, Consuelo; Alonso, Sonia; Parrilla, Roberto

2004-12-01

This work reports the functional studies of CHO cells coexpressing alpha-adrenergic (alphaAR) and human fibrinogen (Fg) receptors (integrin alphaIIbbeta3). Stimulation of these cells with alpha-agonists produced a transient rise in the free cytosolic calcium (Ca(++)) accompanied by enhanced binding to soluble Fg, and these effects were prevented by specific alphaAR antagonists. The alpha-adrenergic-induced activation of alphaIIbbeta3 in CHO-alphaIIbbeta3-alphaAR increased the rate of adhesion and extension of cells onto Fg coated plates, and also induced a soluble Fg- and alphaIIbbeta3-dependent formation of cell aggregates, whereas no effects were observed by the stimulation of CHO-alphaIIbbeta3 cells. alpha-Adrenergic antagonists, the ligand mimetic peptide RGDS, pertussis toxin (PTX), or EDTA, they all prevented the alpha-adrenergic stimulation of adhesion and aggregation. However, inhibition of PKC prevented the alpha-adrenergic stimulation of cell adherence, whereas blocking the intracellular Ca(++) mobilization impeded the stimulation of cell aggregation. The alpha-adrenergic activation was associated with phosphorylation of a protein of approximately 100 kDa and proteins of the MAPK family. The former was selectively phosphorylated by alpha-adrenergic stimulation whereas the latter were phosphorylated by the binding of cells to Fg and markedly intensified by alpha-adrenergic stimulation.

Effect of zinc impurity on silicon solar-cell efficiency

NASA Technical Reports Server (NTRS)

Sah, C.-T.; Chan, P. C. H.; Wang, C.-K.; Yamakawa, K. A.; Lutwack, R.; Sah, R. L.-Y.

1981-01-01

Zinc is a major residue impurity in the preparation of solar-grade silicon material by the zinc vapor reduction of silicon tetrachloride. This paper projects that in order to get a 17-percent AM1 cell efficiency for the Block IV module of the Low-Cost Solar Array Project, the concentration of the zinc recombination centers in the base region of silicon solar cells must be less than 4 x 10 to the 11th Zn/cu cm in the p-base n+/p/p+ cell and 7 x 10 to the 11th Zn/cu cm in the n-base p+/n/n+ cell for a base dopant impurity concentration of 5 x 10 to the 14 atoms/cu cm. If the base dopant impurity concentration is increased by a factor of 10 to 5 x 10 to the 15th atoms/cu cm, then the maximum allowable zinc concentration is increased by a factor of about two for a 17-percent AM1 efficiency. The thermal equilibrium electron and hole recombination and generation rates at the double-acceptor zinc centers are obtained from previous high-field measurements as well as new measurements at zero field described in this paper. These rates are used in the exact dc-circuit model to compute the projections.

Zinc suppresses stem cell properties of lung cancer cells through protein kinase C-mediated β-catenin degradation.

PubMed

Ninsontia, Chuanpit; Phiboonchaiyanan, Preeyaporn Plaimee; Kiratipaiboon, Chayanin; Chanvorachote, Pithi

2017-04-01

Highly tumorigenic cancer stem cells (CSCs) residing in most cancers are responsible for cancer progression and treatment failure. Zinc is an element regulator of several cell functions; however, its role in regulation of stem cell program in lung cancer has not been demonstrated. The present study reveals for the first time that zinc can suppress stem cell properties of lung cancer cells. Such findings were proved in different lung cancer cell lines (H460, H23, and H292) and it was found that CSC markers (CD133 and ALDH1A1), stem cell-associated transcription factors (Oct4, Nanog, and Sox-2), and the ability to form tumor spheroid were dramatically suppressed by zinc treatments. Zinc was found to activate protein kinase C-α (PKCα) that further phosphorylated and mediated β-catenin degradation through the ubiquitin-proteasomal pathway. Zinc was found to increase the β-catenin-ubiquitin complex, which can be inhibited by a specific PKC inhibitor, bisindolylmaleimide I. Using specific reactive oxygen species detection and antioxidants, we have demonstrated that superoxide anions generated by zinc are a key upstream mechanism for PKCα activation leading to the subsequent suppression of stem cell features of lung cancer. Zinc increased cellular superoxide anions and the addition of superoxide anion scavenger prevented the activation of PKCα and β-catenin degradation. These findings indicate a novel role for zinc regulation in the PKCα/β-catenin pathway and explain an important mechanism for controlling of stem cell program in lung cancer cells. Copyright © 2017 the American Physiological Society.

Zinc promotes the death of hypoxic astrocytes by upregulating hypoxia-induced hypoxiainducible factor-1alpha expression via Poly(ADP-ribose) polymerase -1

PubMed Central

Pan, Rong; Chen, Chen; Liu, Wenlan; Liu, Ke Jian

2013-01-01

Aim Pathological release of excess zinc ions has been implicated in ischemic brain cell death. However, the underlying mechanisms remain to be elucidated. In stroke, ischemia-induced zinc release and hypoxia-inducible factor-1 (HIF-1) accumulation concurrently occur in the ischemic tissue. The present study testes the hypothesis that the presence of high intracellular zinc concentration is a major cause of modifications to PARP-1 and HIF-1α during hypoxia, which significantly contributes to cell death during ischemia. Methods Primary cortical astrocytes and C8-D1A cells were exposed to different concentrations of zinc chloride. Cell death rate and protein expression of HIF-1 and Poly(ADP-ribose) polymerase (PARP)-1 were examined after 3-hour hypoxic treatment. Results Although 3-hr hypoxia or 100 μM of zinc alone did not induce noticeable cytotoxicity, their combination led to a dramatic increase in astrocytic cell death in a zinc concentration dependent manner. Exposure of astrocytes to hypoxia for 3-hr remarkably increased the levels of intracellular zinc and HIF-1α protein, which was further augmented by added exogenous zinc. Notably HIF-1α knockdown blocked zinc-induced astrocyte death. Moreover, knockdown of PARP-1, another important protein in the response of hypoxia, attenuated the overexpression of HIF-1α and reduced the cell death rate. Conclusions Our studies show that zinc promotes hypoxic cell death through overexpression of the hypoxia response factor HIF-1α via the cell fate determine factor PARP-1 modification, which provides a novel mechanism for zinc-mediated ischemic brain injury. PMID:23582235

Influence of zinc deficiency on cell-membrane fluidity in Jurkat, 3T3 and IMR-32 cells.

PubMed Central

Verstraeten, Sandra V; Zago, M Paola; MacKenzie, Gerardo G; Keen, Carl L; Oteiza, Patricia I

2004-01-01

We investigated whether zinc deficiency can affect plasma membrane rheology. Three cell lines, human leukaemia T-cells (Jurkat), rat fibroblasts (3T3) and human neuroblastoma cells (IMR-32), were cultured for 48 h in control medium, in zinc-deficient medium (1.5 microM zinc; 1.5 Zn), or in the zinc-deficient medium supplemented with 15 microM zinc (15 Zn). The number of viable cells was lower in the 1.5 Zn group than in the control and 15 Zn groups. The frequency of apoptosis was higher in the 1.5 Zn group than in the control and 15 Zn groups. Membrane fluidity was evaluated using the 6-(9-anthroyloxy)stearic acid and 16-(9-anthroyloxy)palmitic acid probes. Membrane fluidity was higher in 1.5 Zn cells than in the control cells; no differences were observed between control cells and 15 Zn cells. The effect of zinc deficiency on membrane fluidity at the water/lipid interface was associated with a higher phosphatidylserine externalization. The higher membrane fluidity in the hydrophobic region of the bilayer was correlated with a lower content of arachidonic acid. We suggest that the increased fluidity of the membrane secondary to zinc deficiency is in part due to a decrease in arachidonic acid content and the apoptosis-related changes in phosphatidylserine distribution. PMID:14629198

Involvement of the Clock Gene Rev-erb alpha in the Regulation of Glucagon Secretion in Pancreatic Alpha-Cells

PubMed Central

Vieira, Elaine; Marroquí, Laura; Figueroa, Ana Lucia C.; Merino, Beatriz; Fernandez-Ruiz, Rebeca; Nadal, Angel; Burris, Thomas P.; Gomis, Ramon; Quesada, Ivan

2013-01-01

Disruption of pancreatic clock genes impairs pancreatic beta-cell function, leading to the onset of diabetes. Despite the importance of pancreatic alpha-cells in the regulation of glucose homeostasis and in diabetes pathophysiology, nothing is known about the role of clock genes in these cells. Here, we identify the clock gene Rev-erb alpha as a new intracellular regulator of glucagon secretion. Rev-erb alpha down-regulation by siRNA (60–70% inhibition) in alphaTC1-9 cells inhibited low-glucose induced glucagon secretion (p<0.05) and led to a decrease in key genes of the exocytotic machinery. The Rev-erb alpha agonist GSK4112 increased glucagon secretion (1.6 fold) and intracellular calcium signals in alphaTC1-9 cells and mouse primary alpha-cells, whereas the Rev-erb alpha antagonist SR8278 produced the opposite effect. At 0.5 mM glucose, alphaTC1-9 cells exhibited intrinsic circadian Rev-erb alpha expression oscillations that were inhibited by 11 mM glucose. In mouse primary alpha-cells, glucose induced similar effects (p<0.001). High glucose inhibited key genes controlled by AMPK such as Nampt, Sirt1 and PGC-1 alpha in alphaTC1-9 cells (p<0.05). AMPK activation by metformin completely reversed the inhibitory effect of glucose on Nampt-Sirt1-PGC-1 alpha and Rev-erb alpha. Nampt inhibition decreased Sirt1, PGC-1 alpha and Rev-erb alpha mRNA expression (p<0.01) and glucagon release (p<0.05). These findings identify Rev-erb alpha as a new intracellular regulator of glucagon secretion via AMPK/Nampt/Sirt1 pathway. PMID:23936124

Zinc Promotes Adipose-Derived Mesenchymal Stem Cell Proliferation and Differentiation towards a Neuronal Fate.

PubMed

Moon, Mi-Young; Kim, Hyun Jung; Choi, Bo Young; Sohn, Min; Chung, Tae Nyoung; Suh, Sang Won

2018-01-01

Zinc is an essential element required for cell division, migration, and proliferation. Under zinc-deficient conditions, proliferation and differentiation of neural progenitors are significantly impaired. Adipose-derived mesenchymal stem cells (AD-MSCs) are multipotent stem cells that can differentiate into neurons. The aim of this study was to evaluate the effect of zinc on AD-MSC proliferation and differentiation. We initially examined the effect of zinc on stem cell proliferation at the undifferentiated stage. AD-MSCs showed high proliferation rates on day 6 in 30  μ M and 100  μ M of ZnCl 2 . Zinc chelation inhibited AD-MSC proliferation via downregulation of ERK1/2 activity. We then assessed whether zinc was involved in cell migration and neurite outgrowth during differentiation. After three days of neuronal differentiation, TUJ-1-positive cells were observed, implying that AD-MSCs had differentiated into early neuron or neuron-like cells. Neurite outgrowth was increased in the zinc-treated group, while the CaEDTA-treated group showed diminished, shrunken neurites. Furthermore, we showed that zinc promoted neurite outgrowth via the inactivation of RhoA and led to the induction of neuronal gene expression (MAP2 and nestin) in differentiated stem cells. Taken together, zinc promoted AD-MSC proliferation and affected neuronal differentiation, mainly by increasing neurite outgrowth.

Zinc Promotes Adipose-Derived Mesenchymal Stem Cell Proliferation and Differentiation towards a Neuronal Fate

PubMed Central

Moon, Mi-Young; Kim, Hyun Jung; Choi, Bo Young; Sohn, Min

2018-01-01

Zinc is an essential element required for cell division, migration, and proliferation. Under zinc-deficient conditions, proliferation and differentiation of neural progenitors are significantly impaired. Adipose-derived mesenchymal stem cells (AD-MSCs) are multipotent stem cells that can differentiate into neurons. The aim of this study was to evaluate the effect of zinc on AD-MSC proliferation and differentiation. We initially examined the effect of zinc on stem cell proliferation at the undifferentiated stage. AD-MSCs showed high proliferation rates on day 6 in 30 μM and 100 μM of ZnCl2. Zinc chelation inhibited AD-MSC proliferation via downregulation of ERK1/2 activity. We then assessed whether zinc was involved in cell migration and neurite outgrowth during differentiation. After three days of neuronal differentiation, TUJ-1-positive cells were observed, implying that AD-MSCs had differentiated into early neuron or neuron-like cells. Neurite outgrowth was increased in the zinc-treated group, while the CaEDTA-treated group showed diminished, shrunken neurites. Furthermore, we showed that zinc promoted neurite outgrowth via the inactivation of RhoA and led to the induction of neuronal gene expression (MAP2 and nestin) in differentiated stem cells. Taken together, zinc promoted AD-MSC proliferation and affected neuronal differentiation, mainly by increasing neurite outgrowth. PMID:29765417

Prevalence of -alpha(3.7) and alpha alpha alpha(anti3.7) alleles in sickle cell trait and beta-thalassemia patients in Mexico.

PubMed

Nava, María Paulina; Ibarra, Bertha; Magaña, María Teresa; de la Luz Chávez, María; Perea, F Javier

2006-01-01

The aim of this study was to determine the frequency of alpha-globin gene mutations in three groups of Mexican unrelated individuals. The first two groups were normal and sickle cell trait individuals from the Costa Chica region, a place with a 12.8% frequency of HbS carriers, and the third group comprised of Mexican mestizo patients with beta-thalassemia. We searched for -alpha(3.7) and -alpha(4.2) alpha(+)-thalassemia deletion alleles, as well as the alpha alpha alpha(anti3.7) triplication through long-gap PCR. The alleles -alpha(3.7) and alpha alpha alpha(anti3.7) were found in the heterozygote state only; 19% of the normal subjects had the -alpha(3.7) allele, and 2% showed the alpha alpha alpha(anti3.7) allele. In individuals with the sickle cell trait, 17% had the -alpha(3.7) deletion, and the alpha alpha alpha(anti3.7) triplication was observed in 3% of these individuals. We revealed that 16% of the subjects with beta-thalassemia showed the -alpha(3.7) deletion and 28% the alpha alpha alpha(anti3.7) triplication. The -alpha(4.2) deletion was not detected in any individual. The frequency of the -alpha(3.7) allele was roughly the same in the three groups studied; this can be explained by the fact that the three groups have common genes from Africa and the Mediterranean, where a high prevalence of alpha(+)-thalassemia has been observed. To our knowledge, the frequency of alpha alpha alpha(anti3.7) triplication observed in the Mexican beta-thalassemia patients is the highest reported. As the -alpha(3.7) and alpha alpha alpha(anti3.7) alleles are very common in our selected populations, we believe that there is a need to investigate systematically the alpha-globin gene mutations in all hemoglobinopathies in the Mexican population.

Effects of TNF-alpha on Endothelial Cell Collective Migration

NASA Astrophysics Data System (ADS)

Chen, Desu; Wu, Di; Helim Aranda-Espinoza, Jose; Losert, Wolfgang

2013-03-01

Tumor necrosis factor (TNF-alpha) is a small cell-signaling protein usually released by monocytes and macrophages during an inflammatory response. Previous work had shown the effects of TNF-alpha on single cell morphology, migration, and biomechanical properties. However, the effect on collective migrations remains unexplored. In this work, we have created scratches on monolayers of human umbilical endothelial cells (HUVECs) treated with 25ng/mL TNF-alpha on glass substrates. The wound healing like processes were imaged with phase contrast microscopy. Quantitative analysis of the collective migration of cells treated with TNF-alpha indicates that these cells maintain their persistent motion and alignment better than untreated cells. In addition, the collective migration was characterized by measuring the amount of non-affine deformations of the wound healing monolayer. We found a lower mean non-affinity and narrower distribution of non-affinities upon TNF-alpha stimulation. These results suggest that TNF-alpha introduces a higher degree of organized cell collective migration.

Stability of zinc stearate under alpha irradiation in the manufacturing process of SFR nuclear fuels

NASA Astrophysics Data System (ADS)

Gracia, J.; Vermeulen, J.; Baux, D.; Sauvage, T.; Venault, L.; Audubert, F.; Colin, X.

2018-03-01

The manufacture of new fuels for sodium-cooled fast reactors (SFRs) will involve powders derived from recycling existing fuels in order to keep on producing electricity while saving natural resources and reducing the amount of waste produced by spent MOX fuels. Using recycled plutonium in this way will significantly increase the amount of 238Pu, a high energy alpha emitter, in the powders. The process of shaping powders by pressing requires the use of a solid lubricant, zinc stearate, to produce pellets with no defects compliant with the standards. The purpose of this study is to determine the impact of alpha radiolysis on this additive and its lubrication properties. Experiments were conducted on samples in contact with PuO2, as well as under external helium ion beam irradiation, in order to define the kinetics of radiolytic gas generation. The yield results relating to the formation of these gases (G0) show that the alpha radiation of plutonium can be simulated using external helium ion beam irradiation. The isotopic composition of plutonium has little impact on the yield. However, an increased yield was globally observed with increasing the mean linear energy transfer (LET). A radiolytic degradation process is proposed.

Synthesis of zinc chlorophyll materials for dye-sensitized solar cell applications

NASA Astrophysics Data System (ADS)

Erten-Ela, Sule; Vakuliuk, Olena; Tarnowska, Anna; Ocakoglu, Kasim; Gryko, Daniel T.

2015-01-01

To design sensitizers for dye sensitized solar cells (DSSCs), a series of zinc chlorins with different substituents were synthesized. Novel zinc methyl 3-devinyl-3-hydroxymethyl-20-phenylacetylenylpyropheophorbide-a (ZnChl-1), zinc methyl 20-bromo-3-devinyl-3-hydroxymethylpyropheophorbide-a (ZnChl-2), zinc methyl 3-devinyl-3-hydroxymethyl-pyropheophorbide-a (ZnChl-3), zinc propyl 3-devinyl-3-hydroxymethyl-pyropheophorbide-a (ZnChl-4) were synthesized and their photovoltaic performances were evaluated in dye-sensitized solar cells. Photoelectrodes with a 7 μm thick nanoporous layer and a 5 μm thick light-scattering layer were used to fabricate dye sensitized solar cells. The best efficiency was obtained with ZnChl-2 sensitizer. ZnChl-2 gave a Jsc of 3.5 mA/cm2, Voc of 412 mV, FF of 0.56 and an overall conversion efficiency of 0.81 at full sun (1000 W m-2).

103. DETAIL OF ZINC CLEANER CELL INTERIOR (EXPOSED AT F/45 ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

103. DETAIL OF ZINC CLEANER CELL INTERIOR (EXPOSED AT F/45 FOR DEPTH OF FIELD PURPOSES). NOTE GALIGHER STYLE BAFFLES AND TENDENCY OF ZINC TO BUILD UP ON CELL COMPONENTS. - Shenandoah-Dives Mill, 135 County Road 2, Silverton, San Juan County, CO

An EXAFS study of zinc coordination in microbial cells.

PubMed

Webb, S M; Gaillard, J F; Jackson, B E; Stahl, D A

2001-03-01

Five microbes were isolated from metal amended enrichment cultures derived from the sediments of a lake contaminated by a zinc smelter. Each of these organisms was grown in pure culture in the presence of zinc. Quick Extended X-ray Absorption Fine Structure (QEXAFS) spectroscopy was used to investigate the average coordination environment of the zinc associated with the microbial biomass. Fitting of the first coordination shell of zinc shows that significant differences exist for each microbial species examined. The coordination environment of zinc varies between sulfurs to six-fold nitrogen/oxygen. with two microbial strains showing mixed coordination shells. Further study is required in order to characterize these sites and their locations within the cell.

Dietary catechins and procyanidins modulate zinc homeostasis in human HepG2 cells.

PubMed

Quesada, Isabel M; Bustos, Mario; Blay, Mayte; Pujadas, Gerard; Ardèvol, Anna; Salvadó, M Josepa; Bladé, Cinta; Arola, Lluís; Fernández-Larrea, Juan

2011-02-01

Catechins and their polymers procyanidins are health-promoting flavonoids found in edible vegetables and fruits. They act as antioxidants by scavenging reactive oxygen species and by chelating the redox-active metals iron and copper. They also behave as signaling molecules, modulating multiple cell signalling pathways and gene expression, including that of antioxidant enzymes. This study aimed at determining whether catechins and procyanidins interact with the redox-inactive metal zinc and at assessing their effect on cellular zinc homeostasis. We found that a grape-seed procyanidin extract (GSPE) and the green tea flavonoid (-)-epigallocatechin-3-gallate (EGCG) bind zinc cations in solution with higher affinity than the zinc-specific chelator Zinquin, and dose-dependently prevent zinc-induced toxicity in the human hepatocarcinoma cell line HepG2, evaluated by the lactate dehydrogenase test. GSPE and EGCG hinder intracellular accumulation of total zinc, measured by atomic flame absorption spectrometry, concomitantly increasing the level of cytoplasmic labile zinc detectable by Zinquin fluorescence. Concurrently, GSPE and EGCG inhibit the expression, evaluated at the mRNA level by quantitative reverse transcriptase-polymerase chain reaction, of zinc-binding metallothioneins and of plasma membrane zinc exporter ZnT1 (SLC30A1), while enhancing the expression of cellular zinc importers ZIP1 (SLC39A1) and ZIP4 (SLC39A4). GSPE and EGCG also produce all these effects when HepG2 cells are stimulated to import zinc by treatment with supplemental zinc or the proinflammatory cytokine interleukin-6. We suggest that extracellular complexation of zinc cations and the elevation of cytoplasmic labile zinc may be relevant mechanisms underlying the modulation of diverse cell signaling and metabolic pathways by catechins and procyanidins. Copyright © 2011 Elsevier Inc. All rights reserved.

Anti-inflammatory effects of zinc in PMA-treated human gingival fibroblast cells

PubMed Central

Kim, Sangwoo; Jeon, Sangmi; Hui, Zheng; Kim, Young; Im, Yeonggwan; Lim, Wonbong; Kim, Changsu; Choi, Hongran; Kim, Okjoon

2015-01-01

Objectives: Abnormal cellular immune response has been considered to be responsible for oral lesions in recurrent aphthous stomatitis. Zinc has been known to be an essential nutrient metal that is necessary for a broad range of biological activities including antioxidant, immune mediator, and anti-inflammatory drugs in oral mucosal disease. The objective of this study was to investigate the effects of zinc in a phorbol-12-myristate-13-acetate (PMA)-treated inflammatory model on human gingival fibroblast cells (hGFs). Study Design: Cells were pre-treated with zinc chloride, followed by PMA in hGFs. The effects were assessed on cell viability, cyclooxygenease-1,2(COX-1/2) protein expression, PGE2 release, ROS production and cytokine release, Results: The effects were assessed on cell viability, COX1/2 protein expression, PGE2 release, ROS production, cytokine release. The results showed that, in the presence of PMA, zinc treatment leads to reduce the production of ROS, which results in decrease of COX-2 expression and PGE2 release. Conclusions: Thus, we suggest that zinc treatment leads to the mitigation of oral inflammation and may prove to be an alternative treatment for recurrent aphthous stomatitis. Key words:Zinc, inflammatory response, cytokines, phorbol-12-myristate-13-acetate, gingival fibroblasts cells. PMID:25662537

Soybean extracts increase cell surface ZIP4 abundance and cellular zinc levels: a potential novel strategy to enhance zinc absorption by ZIP4 targeting.

PubMed

Hashimoto, Ayako; Ohkura, Katsuma; Takahashi, Masakazu; Kizu, Kumiko; Narita, Hiroshi; Enomoto, Shuichi; Miyamae, Yusaku; Masuda, Seiji; Nagao, Masaya; Irie, Kazuhiro; Ohigashi, Hajime; Andrews, Glen K; Kambe, Taiho

2015-12-01

Dietary zinc deficiency puts human health at risk, so we explored strategies for enhancing zinc absorption. In the small intestine, the zinc transporter ZIP4 functions as an essential component of zinc absorption. Overexpression of ZIP4 protein increases zinc uptake and thereby cellular zinc levels, suggesting that food components with the ability to increase ZIP4 could potentially enhance zinc absorption via the intestine. In the present study, we used mouse Hepa cells, which regulate mouse Zip4 (mZip4) in a manner indistinguishable from that in intestinal enterocytes, to screen for suitable food components that can increase the abundance of ZIP4. Using this ZIP4-targeting strategy, two such soybean extracts were identified that were specifically able to decrease mZip4 endocytosis in response to zinc. These soybean extracts also effectively increased the abundance of apically localized mZip4 in transfected polarized Caco2 and Madin-Darby canine kidney cells and, moreover, two apically localized mZip4 acrodermatitis enteropathica mutants. Soybean components were purified from one extract and soyasaponin Bb was identified as an active component that increased both mZip4 protein abundance and zinc levels in Hepa cells. Finally, we confirmed that soyasaponin Bb is capable of enhancing cell surface endogenous human ZIP4 in human cells. Our results suggest that ZIP4 targeting may represent a new strategy to improve zinc absorption in humans. © 2015 Authors; published by Portland Press Limited.

Alpha-keto acid metabolites of organoselenium compounds inhibit histone deacetylase activity in human colon cancer cells.

PubMed

Nian, Hui; Bisson, William H; Dashwood, Wan-Mohaiza; Pinto, John T; Dashwood, Roderick H

2009-08-01

Methylselenocysteine (MSC) and selenomethionine (SM) are two organoselenium compounds receiving interest for their potential anticancer properties. These compounds can be converted to beta-methylselenopyruvate (MSP) and alpha-keto-gamma-methylselenobutyrate (KMSB), alpha-keto acid metabolites that share structural features with the histone deacetylase (HDAC) inhibitor butyrate. We tested the organoselenium compounds in an in vitro assay with human HDAC1 and HDAC8; whereas SM and MSC had little or no activity up to 2 mM, MSP and KMSB caused dose-dependent inhibition of HDAC activity. Subsequent experiments identified MSP as a competitive inhibitor of HDAC8, and computational modeling supported a mechanism involving reversible interaction with the active site zinc atom. In human colon cancer cells, acetylated histone H3 levels were increased during the period 0.5-48 h after treatment with MSP and KMSB, and there was dose-dependent inhibition of HDAC activity. The proportion of cells occupying G(2)/M of the cell cycle was increased at 10-50 microM MSP and KMSB, and apoptosis was induced, as evidenced by morphological changes, Annexin V staining and increased cleaved caspase-3, -6, -7, -9 and poly(adenosine diphosphate-ribose)polymerase. P21WAF1, a well-established target gene of clinically used HDAC inhibitors, was increased in MSP- and KMSB-treated colon cancer cells at both the messenger RNA and protein level, and there was enhanced P21WAF1 promoter activity. These studies confirm that in addition to targeting redox-sensitive signaling molecules, alpha-keto acid metabolites of organoselenium compounds alter HDAC activity and histone acetylation status in colon cancer cells, as recently observed in human prostate cancer cells.

3. Right side of Zinc Plant, from Cell Room midpoint ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

3. Right side of Zinc Plant, from Cell Room midpoint to Plant Office (foreground) and #5 Roaster and Concentrate Handling (background). View is to the east. - Sullivan Electrolytic Zinc Plant, Government Gulch, Kellogg, Shoshone County, ID

Profiling of zinc altered gene expression in human prostate normal versus cancer cells: a time course study

PubMed Central

Lin, Shu-fei; Wei, Hua; Maeder, Dennis; Franklin, Renty B.; Feng, Pei

2010-01-01

We have demonstrated that zinc exposure induces apoptosis in human prostate cancer cells (PC-3) and benign hyperplasia cells (BPH), but not in normal prostate cells (HPR-1). However, the mechanisms underlying the effects of zinc on prostate cancer cell growth and zinc homeostasis remain unclear. To explore the zinc effect on gene expression profiles in normal (HPR-1) and malignant prostate cells (PC-3), we conducted a time course study of Zn treatment with microarray analysis. Microarray data were evaluated and profiled using computational approach for the primary and secondary data analyses. Final analyses were focused on the genes: 1. highly sensitive to zinc, 2. associated with zinc homeostasis, i.e. metallothioneins (MTs), solute zinc carriers (ZIPs) and zinc exporters (ZnTs), 3. relevant to several oncogenic pathways. Zinc-mediated mRNA levels of MT isotypes were further validated by semi-quantitative RT-PCR. Results showed that zinc effect on genome-wide expression patterns was cell type specific, and zinc appeared to have mainly down-regulatory effects on thousands of genes (1,953 in HPR-1; 3,534 in PC-3) with a threshold of ±2.5-fold, while fewer genes were up-regulated (872 in HPR-1; 571 in PC-3). The patterns of zinc effect on functional MT genes’ expression provided evidence for the cell-type dependent zinc accumulation and zinc-induced apoptosis in prostate cells. In PC-3 cells, zinc significantly up-regulated the expression of MT-1 isotypes -J and -M, denoted previously as “non-functional” MT genes, and now a depictive molecular structure of MT-1J was proposed. Examination of genes involved in oncogenic pathways indicated that certain genes, e.g. Fos, Akt1, Jak3 and PI3K were highly regulated by zinc with cell type specificity. This work provided an extensive database on zinc related prostate cancer research. The strategy of data analysis was devoted to find genes highly sensitive to Zn, and the genes associated with zinc accumulation and zinc

Zinc deficiency during growth: influence on renal function and morphology.

PubMed

Tomat, Analía Lorena; Costa, María Angeles; Girgulsky, Luciana Carolina; Veiras, Luciana; Weisstaub, Adriana Ruth; Inserra, Felipe; Balaszczuk, Ana María; Arranz, Cristina Teresa

2007-03-13

This study was designed to investigate the effects of moderate zinc deficiency during growth on renal morphology and function in adult life. Weaned male Wistar rats were divided into two groups and fed either a moderately zinc-deficient diet (zinc: 8 mg/kg, n=12) or a control diet (zinc: 30 mg/kg, n=12) for 60 days. We evaluated: renal parameters, NADPH-diaphorase and nitric oxide synthase activity in kidney, renal morphology and apoptotic cells in renal cortex. Zinc-deficient rats showed a decrease in glomerular filtration rate and no changes in sodium and potassium urinary excretion. Zinc deficiency decreased NADPH diaphorase activity in glomeruli and tubular segment of nephrons, and reduced activity of nitric oxide synthase in the renal medulla and cortex, showing that zinc plays an important role in preservation of the renal nitric oxide system. A reduction in nephron number, glomerular capillary area and number of glomerular nuclei in cortical and juxtamedullary areas was observed in zinc deficient kidneys. Sirius red staining and immunostaining for alpha-smooth muscle-actin and collagen III showed no signs of fibrosis in the renal cortex and medulla. An increase in the number of apoptotic cells in distal tubules and cortical collecting ducts neighboring glomeruli and, to a lesser extent, in the glomeruli was observed in zinc deficient rats. The major finding of our study is the emergence of moderate zinc deficiency during growth as a potential nutritional factor related to abnormalities in renal morphology and function that facilitates the development of cardiovascular and renal diseases in adult life.

Influence of extracellular zinc on M1 microglial activation.

PubMed

Higashi, Youichirou; Aratake, Takaaki; Shimizu, Shogo; Shimizu, Takahiro; Nakamura, Kumiko; Tsuda, Masayuki; Yawata, Toshio; Ueba, Tetuya; Saito, Motoaki

2017-02-27

Extracellular zinc, which is released from hippocampal neurons in response to brain ischaemia, triggers morphological changes in microglia. Under ischaemic conditions, microglia exhibit two opposite activation states (M1 and M2 activation), which may be further regulated by the microenvironment. We examined the role of extracellular zinc on M1 activation of microglia. Pre-treatment of microglia with 30-60 μM ZnCl 2 resulted in dose-dependent increases in interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumour necrosis factor-alpha (TNFα) secretion when M1 activation was induced by lipopolysaccharide administration. In contrast, the cell-permeable zinc chelator TPEN, the radical scavenger Trolox, and the P2X7 receptor antagonist A438079 suppressed the effects of zinc pre-treatment on microglia. Furthermore, endogenous zinc release was induced by cerebral ischaemia-reperfusion, resulting in increased expression of IL-1β, IL-6, TNFα, and the microglial M1 surface marker CD16/32, without hippocampal neuronal cell loss, in addition to impairments in object recognition memory. However, these effects were suppressed by the zinc chelator CaEDTA. These findings suggest that extracellular zinc may prime microglia to enhance production of pro-inflammatory cytokines via P2X7 receptor activation followed by reactive oxygen species generation in response to stimuli that trigger M1 activation, and that these inflammatory processes may result in deficits in object recognition memory.

Influence of extracellular zinc on M1 microglial activation

PubMed Central

Higashi, Youichirou; Aratake, Takaaki; Shimizu, Shogo; Shimizu, Takahiro; Nakamura, Kumiko; Tsuda, Masayuki; Yawata, Toshio; Ueba, Tetuya; Saito, Motoaki

2017-01-01

Extracellular zinc, which is released from hippocampal neurons in response to brain ischaemia, triggers morphological changes in microglia. Under ischaemic conditions, microglia exhibit two opposite activation states (M1 and M2 activation), which may be further regulated by the microenvironment. We examined the role of extracellular zinc on M1 activation of microglia. Pre-treatment of microglia with 30–60 μM ZnCl2 resulted in dose-dependent increases in interleukin-1 beta (IL-1β), interleukin-6 (IL-6), and tumour necrosis factor-alpha (TNFα) secretion when M1 activation was induced by lipopolysaccharide administration. In contrast, the cell-permeable zinc chelator TPEN, the radical scavenger Trolox, and the P2X7 receptor antagonist A438079 suppressed the effects of zinc pre-treatment on microglia. Furthermore, endogenous zinc release was induced by cerebral ischaemia–reperfusion, resulting in increased expression of IL-1β, IL-6, TNFα, and the microglial M1 surface marker CD16/32, without hippocampal neuronal cell loss, in addition to impairments in object recognition memory. However, these effects were suppressed by the zinc chelator CaEDTA. These findings suggest that extracellular zinc may prime microglia to enhance production of pro-inflammatory cytokines via P2X7 receptor activation followed by reactive oxygen species generation in response to stimuli that trigger M1 activation, and that these inflammatory processes may result in deficits in object recognition memory. PMID:28240322

Different susceptibility of rat pancreatic alpha and beta cells to hypoxia.

PubMed

Bloch, Konstantin; Vennäng, Julia; Lazard, Daniel; Vardi, Pnina

2012-06-01

Insulin-producing beta cells are known to be highly susceptible to hypoxia, which is a major factor in their destruction after pancreatic islet transplantation. However, whether the glucagon-producing pancreatic islet alpha cells are sensitive to hypoxia is not known. Our objective was to compare the sensitivity of alpha and beta cells to hypoxia. Isolated rat pancreatic islets were exposed to hypoxia (1% oxygen, 94% N(2), 5% CO(2)) for 3 days. The viability of the alpha and beta cells, as well as the stimulus-specific secretion of glucagon and insulin, was evaluated. A quantitative analysis of the proportion of beta to alpha cells indicated that, under normoxic conditions, islet cells were composed mainly of beta cells (87 ± 3%) with only 13 ± 3% alpha cells. Instead, hypoxia treatment significantly increased the proportion of alpha cells (40 ± 13%) and decreased the proportion of beta cells to 60 ± 13%. Using the fluorescent TUNEL assay we found that only a few percent of beta cells and alpha cells were apoptotic in normoxia. In contrast, hypoxia induced an abundance of apoptotic beta cells (61 ± 22%) and had no effect on the level of apoptosis in alpha cells. In conclusion, this study demonstrates that hypoxia results in severe functional abnormality in both beta and alpha cells while alpha cells display significantly decreased rate of apoptosis compared to intensive apoptotic injury of beta cells. These findings have implications for the understanding of the possible role of hypoxia in the pathophysiology of diabetes.

The Zinc Transporter Zip5 (Slc39a5) Regulates Intestinal Zinc Excretion and Protects the Pancreas against Zinc Toxicity

PubMed Central

Geiser, Jim; De Lisle, Robert C.; Andrews, Glen K.

2013-01-01

Background ZIP5 localizes to the baso-lateral membranes of intestinal enterocytes and pancreatic acinar cells and is internalized and degraded coordinately in these cell-types during periods of dietary zinc deficiency. These cell-types are thought to control zinc excretion from the body. The baso-lateral localization and zinc-regulation of ZIP5 in these cells are unique among the 14 members of the Slc39a family and suggest that ZIP5 plays a role in zinc excretion. Methods/Principal Findings We created mice with floxed Zip5 genes and deleted this gene in the entire mouse or specifically in enterocytes or acinar cells and then examined the effects on zinc homeostasis. We found that ZIP5 is not essential for growth and viability but total knockout of ZIP5 led to increased zinc in the liver in mice fed a zinc-adequate (ZnA) diet but impaired accumulation of pancreatic zinc in mice fed a zinc-excess (ZnE) diet. Loss-of-function of enterocyte ZIP5, in contrast, led to increased pancreatic zinc in mice fed a ZnA diet and increased abundance of intestinal Zip4 mRNA. Finally, loss-of-function of acinar cell ZIP5 modestly reduced pancreatic zinc in mice fed a ZnA diet but did not impair zinc uptake as measured by the rapid accumulation of 67zinc. Retention of pancreatic 67zinc was impaired in these mice but the absence of pancreatic ZIP5 sensitized them to zinc-induced pancreatitis and exacerbated the formation of large cytoplasmic vacuoles containing secretory protein in acinar cells. Conclusions These studies demonstrate that ZIP5 participates in the control of zinc excretion in mice. Specifically, they reveal a paramount function of intestinal ZIP5 in zinc excretion but suggest a role for pancreatic ZIP5 in zinc accumulation/retention in acinar cells. ZIP5 functions in acinar cells to protect against zinc-induced acute pancreatitis and attenuate the process of zymophagy. This suggests that it may play a role in autophagy. PMID:24303081

Early Hematopoietic Zinc Finger Protein Prevents Tumor Cell Recognition by Natural Killer Cells1

PubMed Central

La Rocca, Rosanna; Fulciniti, Mariateresa; Lakshmikanth, Tadepally; Mesuraca, Maria; Ali, Talib Hassan; Mazzei, Valerio; Amodio, Nicola; Catalano, Lucio; Rotoli, Bruno; Ouerfelli, Ouathek; Grieco, Michele; Gulletta, Elio; Bond, Heather M.; Morrone, Giovanni; Ferrone, Soldano; Carbone, Ennio

2009-01-01

Early hematopoietic zinc finger/zinc finger protein 521 (EHZF/ZNF521) is a novel zinc finger protein expressed in hematopoietic stem and progenitor cells and is down-regulated during their differentiation. Its transcript is also abundant in some hematopoietic malignancies. Analysis of the changes in the antigenic profile of cells transfected with EHZF cDNA revealed up-regulation of HLA class I cell surface expression. This phenotypic change was associated with an increased level of HLA class I H chain, in absence of detectable changes in the expression of other Ag-processing machinery components. Enhanced resistance of target cells to NK cell-mediated cytotoxicity was induced by enforced expression of EHZF in the cervical carcinoma cell line HeLa and in the B lymphoblastoid cell line IM9. Preincubation of transfected cells with HLA class I Ag-specific mAb restored target cell susceptibility to NK cell-mediated lysis, indicating a specific role for HLA class I Ag up-regulation in the NK resistance induced by EHZF. A potential clinical significance of these findings is further suggested by the inverse correlation between EHZF and MHC class I expression levels, and autologous NK susceptibility of freshly explanted multiple myeloma cells. PMID:19342626

Mechanically refuelable zinc/air electric vehicle cells

NASA Astrophysics Data System (ADS)

Noring, J.; Gordon, S.; Maimoni, A.; Spragge, M.; Cooper, J. F.

1992-12-01

Refuelable zinc/air batteries have long been considered for motive as well as stationary power because of a combination of high specific energy, low initial cost, and the possibility of mechanical recharge by electrolyte exchange and additions of metallic zinc. In this context, advanced slurry batteries, stationary packed bed cells, and batteries offering replaceable cassettes have been reported recently. The authors are developing self-feeding, particulate-zinc/air batteries for electric vehicle applications. Emissionless vehicle legislation in California motivated efforts to consider a new approach to providing an electric vehicle with long range (400 km), rapid refueling (10 minutes) and highway safe acceleration - factors which define the essential functions of common automobiles. Such an electric vehicle would not compete with emerging secondary battery vehicles in specialized applications (commuting vehicles, delivery trucks). Rather, different markets would be sought where long range or rapid range extension are important. Examples are: taxis, continuous-duty fork-lift trucks and shuttle busses, and general purpose automobiles having modest acceleration capabilities. In the long range, a mature fleet would best use regional plants to efficiently recover zinc from battery reaction products. One option would be to use chemical/thermal reduction to recover the zinc. The work described focuses on development of battery configurations which efficiently and completely consume zinc particles, without clogging or changing discharge characteristics.

TNF-alpha sensitizes HT-29 colonic epithelial cells to intestinal lactobacilli.

PubMed

McCracken, Vance J; Chun, Taehoon; Baldeón, Manuel E; Ahrné, Siv; Molin, Göran; Mackie, Roderick I; Gaskins, H Rex

2002-09-01

The ability of the proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) to influence epithelial interleukin (IL)-8 responses to the intestinal bacterium Lactobacillus plantarum 299v was analyzed in the human HT-29 colonic epithelial cell line. In the absence of TNF-alpha, IL-8 mRNA expression was not detectable by Northern blot analysis in HT-29 cells alone or in HT-29 cells co-cultured with L. plantarum 299v. However, TNF-alpha induced IL-8 mRNA expression, and co-culture of TNF-alpha-treated HT-29 cells with L. plantarum 299v significantly increased IL-8 mRNA expression above levels induced by TNF-alpha alone in an adhesion-dependent manner. The increase in IL-8 mRNA expression was not observed in TNF-alpha-treated HT-29/L. plantarum 299v co-cultures using heat-killed lactobacilli or when L. plantarum adhesion was prevented using mannoside or a trans-well membrane. Paradoxically, IL-8 secretion was decreased in TNF-alpha-treated HT-29 cells with L. plantarum 299v relative to cells treated with TNF-alpha alone. TNF-alpha-mediated responsiveness to L. plantarum 299v was further investigated by analyzing expression of a coreceptor for bacterial cell wall products CD14. HT-29 cells expressed CD14 mRNA and cell-surface CD14; however, TNF-alpha did not alter CD14 mRNA or cell-surface expression, and blockade of CD14 with monoclonal antibody MY4 did not alter the IL-8 response to L. plantarum 299v in TNF-alpha-treated HT-29 cells. These results indicate that although TNF-alpha sensitizes HT-29 epithelial cells to intestinal lactobacilli, the bacteria exert a protective effect by downregulating IL-8 secretion.

Zinc phosphate conversion coatings

DOEpatents

Sugama, Toshifumi

1997-01-01

Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate .alpha.-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal.

Differential regulation of the cell cycle by alpha1-adrenergic receptor subtypes.

PubMed

Gonzalez-Cabrera, Pedro J; Shi, Ting; Yun, June; McCune, Dan F; Rorabaugh, Boyd R; Perez, Dianne M

2004-11-01

Alpha(1)-Adrenergic receptors have been implicated in growth-promoting pathways. A microarray study of individual alpha(1)-adrenergic receptor subtypes (alpha(1A), alpha(1B), and alpha(1D)) expressed in Rat-1 fibroblasts revealed that epinephrine altered the transcription of several cell cycle regulatory genes in a direction consistent with the alpha(1A)- and alpha(1D)-adrenergic receptors mediating G(1)-S cell cycle arrest and the alpha(1B-)mediating cell-cycle progression. A time course indicated that in alpha(1A) cells, epinephrine stimulated a G(1)-S arrest, which began after 8 h of stimulation and maximized at 16 h, at which point was completely blocked with cycloheximide. The alpha(1B)-adrenergic receptor profile also showed unchecked cell cycle progression, even under low serum conditions and induced foci formation. The G(1)-S arrest induced by alpha(1A)- and alpha(1D)-adrenergic receptors was associated with decreased cyclin-dependent kinase-6 and cyclin E-associated kinase activities and increased expression of the cyclin-dependent kinase inhibitor p27(Kip1), all of which were blocked by prazosin. There were no differences in kinase activities and/or expression of p27(Kip1) in epinephrine alpha(1B)-AR fibroblasts, although the microarray did indicate differences in p27(Kip1) RNA levels. Cell counts proved the antimitotic effect of epinephrine in alpha(1A) and alpha(1D) cells and indicated that alpha(1B)-adrenergic receptor subtype expression was sufficient to cause proliferation of Rat-1 fibroblasts independent of agonist stimulation. Analysis in transfected PC12 cells also confirmed the alpha(1A)- and alpha(1B)-adrenergic receptor effect. The alpha(1B)-subtype native to DDT1-MF2 cells, a smooth muscle cell line, caused progression of the cell cycle. These results indicate that the alpha(1A)- and alpha(1D)-adrenergic receptors mediate G(1)-S cell-cycle arrest, whereas alpha(1B)-adrenergic receptor expression causes a cell cycle progression and may induce

Zinc promotes proliferation and activation of myogenic cells via the PI3K/Akt and ERK signaling cascade

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohashi, Kazuya, E-mail: asuno10k@yahoo.co.jp; Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp; Wada, Eiji, E-mail: gacchu1@yahoo.co.jp

2015-05-01

Skeletal muscle stem cells named muscle satellite cells are normally quiescent but are activated in response to various stimuli, such as injury and overload. Activated satellite cells enter the cell cycle and proliferate to produce a large number of myogenic progenitor cells, and these cells then differentiate and fuse to form myofibers. Zinc is one of the essential elements in the human body, and has multiple roles, including cell growth and DNA synthesis. However, the role of zinc in myogenic cells is not well understood, and is the focus of this study. We first examined the effects of zinc onmore » differentiation of murine C2C12 myoblasts and found that zinc promoted proliferation, with an increased number of cells incorporating EdU, but inhibited differentiation with reduced myogenin expression and myotube formation. Furthermore, we used the C2C12 reserve cell model of myogenic quiescence to investigate the role of zinc on activation of myogenic cells. The number of reserve cells incorporating BrdU was increased by zinc in a dose dependent manner, with the number dramatically further increased using a combination of zinc and insulin. Akt and extracellular signal-regulated kinase (ERK) are downstream of insulin signaling, and both were phosphorylated after zinc treatment. The zinc/insulin combination-induced activation involved the phosphoinositide 3-kinase (PI3K)/Akt and ERK cascade. We conclude that zinc promotes activation and proliferation of myogenic cells, and this activation requires phosphorylation of PI3K/Akt and ERK as part of the signaling cascade. - Highlights: • Zinc has roles for promoting proliferation and inhibition differentiation of C2C12. • Zinc promotes activation of reserve cells. • Insulin and zinc synergize activation of reserve cells. • PI3K/Akt and ERK cascade affect zinc/insulin-mediated activation of reserve cells.« less

Effects of zinc and DHA on the epigenetic regulation of human neuronal cells.

PubMed

Sadli, Nadia; Ackland, M Leigh; De Mel, Damitha; Sinclair, Andrew J; Suphioglu, Cenk

2012-01-01

Dietary intake of zinc and omega-3 fatty acids (DHA) have health benefits for a number of human diseases. However, the molecular basis of these health benefits remains unclear. Recently, we reported that zinc and DHA affect expression levels of histones H3 and H4 in human neuronal M17 cells. Here, using immunoblotting and densitometric analysis, we aimed to investigate the effect of zinc and DHA on post-translational modifications of histone H3 in M17 cells. In response to increase in zinc concentration, we observed increase in deacetylation, methylation and phosphorylation of H3 and decrease in acetylation. We also investigated the role of zinc in apoptosis, and found that zinc reduced the levels of the anti-apoptotic marker Bcl-2 while increasing the apoptotic marker caspase-3 levels, correlating with cell viability assays. Conversely, DHA treatment resulted in increase in acetylation of H3 and Bcl-2 levels and decrease in deacetylation, methylation, phosphorylation of H3 and caspase-3 levels, suggesting that DHA promotes gene expression and neuroprotection. Our novel findings show the opposing effects of zinc and DHA on the epigenetic regulation of human neuronal cells and highlight the potential benefit of dietary intake of DHA for management of neurodegenerative diseases. Copyright © 2012 S. Karger AG, Basel.

Effect of zinc supplementation on serum zinc concentration and T cell proliferation in nursing home elderly:A randomized double-blind placebo-controlled trial

USDA-ARS?s Scientific Manuscript database

Background: Zinc is essential for the regulation of immune response. T cell function declines with age. Zinc supplementation has the potential to improve serum zinc concentrations and immunity of nursing home elderly with low serum zinc concentration. Objective: We aimed to determine the effect of ...

Zinc deficiency mediates alcohol-induced apoptotic cell death in the liver of rats through activating ER and mitochondrial cell death pathways

PubMed Central

Sun, Qian; Zhong, Wei; Zhang, Wenliang; Li, Qiong; Sun, Xiuhua; Tan, Xiaobing; Sun, Xinguo; Dong, Daoyin

2015-01-01

Hepatic zinc deficiency has been well documented in alcoholic patients, but the mechanisms by which zinc deficiency mediates cell death have not been well defined. The objectives of this study were to determine whether alcohol perturbs subcellular zinc homeostasis and how organelle zinc depletion may link with cell death pathways. Wistar rats were pair-fed with the Lieber-DeCarli control or ethanol diet for 5 mo. Chronic alcohol exposure significantly reduced zinc level in isolated hepatic endoplasmic reticulum (ER) and mitochondria. Among the detected zinc transporters, ER Zrt/Irt-like protein (ZIP)13 and mitochondrial ZIP8, which transport zinc from ER and mitochondria to cytosol, were significantly increased. Mitochondrial zinc transporter (ZnT) 4, which transports zinc from cytosol to mitochondria, was also increased. ER phosphorylated eukaryotic initiation factor 2α, activating transcription factor 4, and C/EBP homologous protein were significantly upregulated, and mitochondrial cytochrome c release and Bax insertion were detected in association with caspase-3 activation and apoptotic cell death. To define the role of zinc deficiency in ER and mitochondrial stress, H4IIEC3 cells were treated with 3 μM N,N,N′,N′-tetrakis (2-pyridylmethyl) ethylenediamine for 6 h with or without supplementation with zinc or N-acetylcysteine (NAC). The results demonstrated that zinc deprivation induced caspase-3 activation and apoptosis in association with ER and mitochondria dysfunction, which were inhibited by zinc as low as 10 μM but not by 2 mM NAC. These results suggest that chronic ethanol exposure induced in ER and mitochondrial zinc deficiency might activate intrinsic cell death signaling pathway, which could not be effectively rescued by antioxidant treatment. PMID:25767260

Expression of GDNF and GFR alpha 1 in mouse taste bud cells.

PubMed

Takeda, Masako; Suzuki, Yuko; Obara, Nobuko; Uchida, Nobuhiko; Kawakoshi, Kentaro

2004-11-01

GDNF (glial cell line-derived neurotrophic factor) affects the survival and maintenance of central and peripheral neurons. Using an immunocytochemical method, we examined whether the taste bud cells in the circumvallate papillae of normal mice expressed GDNF and its GFR alpha 1 receptor. Using double immunostaining for either of them and NCAM, PGP 9.5, or alpha-gustducin, we additionally sought to determine what type of taste bud cells expressed GDNF or GFR alpha 1, because NCAM is reported to be expressed in type-III cells, PGP 9.5, in type-III and some type-II cells, and alpha-gustducin, in some type-II cells. Normal taste bud cells expressed both GDNF and GFR alpha 1. The percentage of GDNF-immunoreactive cells among all taste bud cells was 31.63%, and that of GFR alpha 1-immunoreactive cells, 83.21%. Confocal laser scanning microscopic observations after double immunostaining showed that almost none of the GDNF-immunoreactive cells in the taste buds were reactive with anti-NCAM or anti-PGP 9.5 antibody, but could be stained with anti-alpha-gustducin antibody. On the other hand, almost all anti-PGP 9.5- or anti-alpha-gustducin-immunoreactive cells were positive for GFR alpha 1. Thus, GDNF-immunoreactive cells did not include type-III cells, but type-II cells, which are alpha-gustducin-immunoreactive; on the other hand, GFR alpha 1-immunoreactive cells included type-II and -III cells, and perhaps type-I cells. We conclude that GDNF in the type-II cells may exert trophic actions on type-I, -II, and -III taste bud cells by binding to their GFR alpha 1 receptors.

Zinc phosphate conversion coatings

DOEpatents

Sugama, T.

1997-02-18

Zinc phosphate conversion coatings for producing metals which exhibit enhanced corrosion prevention characteristics are prepared by the addition of a transition-metal-compound promoter comprising a manganese, iron, cobalt, nickel, or copper compound and an electrolyte such as polyacrylic acid, polymethacrylic acid, polyitaconic acid and poly-L-glutamic acid to a phosphating solution. These coatings are further improved by the incorporation of Fe ions. Thermal treatment of zinc phosphate coatings to generate {alpha}-phase anhydrous zinc phosphate improves the corrosion prevention qualities of the resulting coated metal. 33 figs.

Fishy Business: Effect of Omega-3 Fatty Acids on Zinc Transporters and Free Zinc Availability in Human Neuronal Cells

PubMed Central

De Mel, Damitha; Suphioglu, Cenk

2014-01-01

Omega-3 (ω-3) fatty acids are one of the two main families of long chain polyunsaturated fatty acids (PUFA). The main omega-3 fatty acids in the mammalian body are α-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Central nervous tissues of vertebrates are characterized by a high concentration of omega-3 fatty acids. Moreover, in the human brain, DHA is considered as the main structural omega-3 fatty acid, which comprises about 40% of the PUFAs in total. DHA deficiency may be the cause of many disorders such as depression, inability to concentrate, excessive mood swings, anxiety, cardiovascular disease, type 2 diabetes, dry skin and so on. On the other hand, zinc is the most abundant trace metal in the human brain. There are many scientific studies linking zinc, especially excess amounts of free zinc, to cellular death. Neurodegenerative diseases, such as Alzheimer’s disease, are characterized by altered zinc metabolism. Both animal model studies and human cell culture studies have shown a possible link between omega-3 fatty acids, zinc transporter levels and free zinc availability at cellular levels. Many other studies have also suggested a possible omega-3 and zinc effect on neurodegeneration and cellular death. Therefore, in this review, we will examine the effect of omega-3 fatty acids on zinc transporters and the importance of free zinc for human neuronal cells. Moreover, we will evaluate the collective understanding of mechanism(s) for the interaction of these elements in neuronal research and their significance for the diagnosis and treatment of neurodegeneration. PMID:25195602

Fishy business: effect of omega-3 fatty acids on zinc transporters and free zinc availability in human neuronal cells.

PubMed

De Mel, Damitha; Suphioglu, Cenk

2014-08-15

Omega-3 (ω-3) fatty acids are one of the two main families of long chain polyunsaturated fatty acids (PUFA). The main omega-3 fatty acids in the mammalian body are α-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). Central nervous tissues of vertebrates are characterized by a high concentration of omega-3 fatty acids. Moreover, in the human brain, DHA is considered as the main structural omega-3 fatty acid, which comprises about 40% of the PUFAs in total. DHA deficiency may be the cause of many disorders such as depression, inability to concentrate, excessive mood swings, anxiety, cardiovascular disease, type 2 diabetes, dry skin and so on. On the other hand, zinc is the most abundant trace metal in the human brain. There are many scientific studies linking zinc, especially excess amounts of free zinc, to cellular death. Neurodegenerative diseases, such as Alzheimer's disease, are characterized by altered zinc metabolism. Both animal model studies and human cell culture studies have shown a possible link between omega-3 fatty acids, zinc transporter levels and free zinc availability at cellular levels. Many other studies have also suggested a possible omega-3 and zinc effect on neurodegeneration and cellular death. Therefore, in this review, we will examine the effect of omega-3 fatty acids on zinc transporters and the importance of free zinc for human neuronal cells. Moreover, we will evaluate the collective understanding of mechanism(s) for the interaction of these elements in neuronal research and their significance for the diagnosis and treatment of neurodegeneration.

Impaired Calcium Entry into Cells Is Associated with Pathological Signs of Zinc Deficiency12

PubMed Central

O’Dell, Boyd L.; Browning, Jimmy D.

2013-01-01

Zinc is an essential trace element whose deficiency gives rise to specific pathological signs. These signs occur because an essential metabolic function is impaired as the result of failure to form or maintain a specific metal-ion protein complex. Although zinc is a component of many essential metalloenzymes and transcription factors, few of these have been identified with a specific sign of incipient zinc deficiency. Zinc also functions as a structural component of other essential proteins. Recent research with Swiss murine fibroblasts, 3T3 cells, has shown that zinc deficiency impairs calcium entry into cells, a process essential for many cell functions, including proliferation, maturation, contraction, and immunity. Impairment of calcium entry and the subsequent failure of cell proliferation could explain the growth failure associated with zinc deficiency. Defective calcium uptake is associated with impaired nerve transmission and pathology of the peripheral nervous system, as well as the failure of platelet aggregation and the bleeding tendency of zinc deficiency. There is a strong analogy between the pathology of genetic diseases that result in impaired calcium entry and other signs of zinc deficiency, such as decreased and cyclic food intake, taste abnormalities, abnormal water balance, skin lesions, impaired reproduction, depressed immunity, and teratogenesis. This analogy suggests that failure of calcium entry is involved in these signs of zinc deficiency as well. PMID:23674794

Rising intracellular zinc by membrane depolarization and glucose in insulin-secreting clonal HIT-T15 beta cells.

PubMed

Slepchenko, Kira G; Li, Yang V

2012-01-01

Zinc (Zn(2+)) appears to be intimately involved in insulin metabolism since insulin secretion is correlated with zinc secretion in response to glucose stimulation, but little is known about the regulation of zinc homeostasis in pancreatic beta-cells. This study set out to identify the intracellular zinc transient by imaging free cytosolic zinc in HIT-T15 beta-cells with fluorescent zinc indicators. We observed that membrane depolarization by KCl (30-60 mM) was able to induce a rapid increase in cytosolic concentration of zinc. Multiple zinc transients of similar magnitude were elicited during repeated stimulations. The amplitude of zinc responses was not affected by the removal of extracellular calcium or zinc. However, the half-time of the rising slope was significantly slower after removing extracellular zinc with zinc chelator CaEDTA, suggesting that extracellular zinc affect the initial rising phase of zinc response. Glucose (10 mM) induced substantial and progressive increases in intracellular zinc concentration in a similar way as KCl, with variation in the onset and the duration of zinc mobilization. It is known that the depolarization of beta-cell membrane is coupled with the secretion of insulin. Rising intracellular zinc concentration may act as a critical signaling factor in insulin metabolism of pancreatic beta-cells.

Rising Intracellular Zinc by Membrane Depolarization and Glucose in Insulin-Secreting Clonal HIT-T15 Beta Cells

PubMed Central

Slepchenko, Kira G.; Li, Yang V.

2012-01-01

Zinc (Zn2+) appears to be intimately involved in insulin metabolism since insulin secretion is correlated with zinc secretion in response to glucose stimulation, but little is known about the regulation of zinc homeostasis in pancreatic beta-cells. This study set out to identify the intracellular zinc transient by imaging free cytosolic zinc in HIT-T15 beta-cells with fluorescent zinc indicators. We observed that membrane depolarization by KCl (30–60 mM) was able to induce a rapid increase in cytosolic concentration of zinc. Multiple zinc transients of similar magnitude were elicited during repeated stimulations. The amplitude of zinc responses was not affected by the removal of extracellular calcium or zinc. However, the half-time of the rising slope was significantly slower after removing extracellular zinc with zinc chelator CaEDTA, suggesting that extracellular zinc affect the initial rising phase of zinc response. Glucose (10 mM) induced substantial and progressive increases in intracellular zinc concentration in a similar way as KCl, with variation in the onset and the duration of zinc mobilization. It is known that the depolarization of beta-cell membrane is coupled with the secretion of insulin. Rising intracellular zinc concentration may act as a critical signaling factor in insulin metabolism of pancreatic beta-cells. PMID:22536213

Development and fabrication of large vented nickel--zinc cells. Final report. [300 Ah

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donnel, C.P.I.

1975-12-01

A preliminary cell design for a 300-Ah vented nickel--zinc cell was established based on volume requirements and cell component materials selected by NASA Lewis Research Center. A 100-Ah cell configuration was derived from the 300-Ah cell design utilizing the same size electrodes, separators, and cell terminal hardware. The first cells fabricated were four groups of three cells each in the 100-Ah size. These 100-Ah experimental nickel--zinc cells had as common components the nickel positive electrodes (GFM), flexible inorganic separator (GFM) bags on the negative electrodes, pressed powder zinc oxide electrodes, and cell containers with hardware. The variations introduced were fourmore » differing electrolyte absorber (interseparator) systems used to encase the nickel positive electrodes of each cell group. The four groups of 100-Ah experimental vented nickel--zinc cells were tested to determine, based on cell performance, the best two interseparator systems. Using the two interseparator systems, two groups of experimental 300-AH cells were fabricated. Each group of three cells differed only in the interseparator material used. The six cells were filled, formed and tested to evaluate the interseparator materials and investigate the performance characteristics of the 300-Ah cell configuration and its components. (auth)« less

Zinc deficiency enhanced inflammatory response by increasing immune cell activation and inducing IL6 promoter demethylation

PubMed Central

Wong, Carmen P.; Rinaldi, Nicole A.; Ho, Emily

2015-01-01

Scope Zinc deficiency results in immune dysfunction and promotes systemic inflammation. The objective of this study was to examine the effects of zinc deficiency on cellular immune activation and epigenetic mechanisms that promote inflammation. This work is potentially relevant to the aging population given that age-related immune defects, including chronic inflammation, coincide with declining zinc status. Methods and results An in vitro cell culture system and the aged mouse model were used to characterize immune activation and DNA methylation profiles that may contribute to the enhanced proinflammatory response mediated by zinc deficiency. Zinc deficiency up-regulated cell activation markers ICAM1, MHC class II, and CD86 in THP1 cells, that coincided with increased IL1β and IL6 responses following LPS stimulation. A decreased zinc status in aged mice was similarly associated with increased ICAM1 and IL6 gene expression. Reduced IL6 promoter methylation was observed in zinc deficient THP1 cells, as well as in aged mice and human lymphoblastoid cell lines derived from aged individuals. Conclusion Zinc deficiency induced inflammatory response in part by eliciting aberrant immune cell activation and altered promoter methylation. Our results suggested potential interactions between zinc status, epigenetics, and immune function, and how their dysregulation could contribute to chronic inflammation. PMID:25656040

Metabolism of two Go alpha isoforms in neuronal cells during differentiation.

PubMed

Brabet, P; Pantaloni, C; Bockaert, J; Homburger, V

1991-07-15

We have previously shown that undifferentiated N1E-115 neuroblastoma cells express only one isoform of Go alpha (pI = 5.8), whereas differentiated neuroblastoma cells expressed, in addition to this isoform, another Go alpha with a more acidic pI (5.55). Moreover, primary cultures of cerebellar granule cells, which are extremely well differentiated cells yielding a high density of synapses, expressed only a single Go alpha isoform with a pI of 5.55 (Brabet, P., Pantaloni, C., Rodriguez Martinez, J., Bockaert, J., and Homburger, V. (1990) J. Neurochem. 54, 1310-1320). In this report, using biosynthetic labeling with [35S]methionine and specific quantitative immunoprecipitation with a polyclonal antibody raised against the purified Go alpha protein, we have determined 1) the degradation rate of total Go alpha (sum of the two isoforms) in differentiated as well as in undifferentiated neuroblastoma cells and in cerebellar granule cells, 2) the degradation rates of each isoform in differentiated neuroblastoma cells. The t 1/2 for total Go alpha protein degradation was very different in the three neuronal cell populations and was 28 +/- 5 h (n = 5), 58 +/- 9 h (n = 5), and 154 +/- 22 h (n = 6) in undifferentiated, differentiated neuroblastoma, and granule cells, respectively. Using two-dimensional gel analysis of immunoprecipitates, we have also determined the individual t 1/2 for degradation of each Go alpha isoform in differentiated neuroblastoma cells, in which the two Go alpha isoforms were expressed. Results indicated that the two Go alpha isoforms exhibit similar t1/2 for degradation (49 +/- 5 h, n = 3). Thus, the t1/2 for degradation of the more basic Go alpha isoform is higher in differentiated neuroblastoma cells (49 +/- 5 h, n = 3) than in undifferentiated neuroblastoma cells (28 +/- 5 h, n = 5) which expressed only the more basic Go alpha isoform. It can be concluded that the degradation rate of the more basic Go alpha isoform is not a characteristic of the

Calcium, zinc, and iron bioavailabilities from a commercial human milk fortifier: a comparison study.

PubMed

Etcheverry, P; Wallingford, J C; Miller, D D; Glahn, R P

2004-11-01

Adding human milk fortifiers (HMF) to human milk (HM) is one way of overcoming the nutrient deficits found in the latter. In this study, the bioavailabilities of calcium, zinc, and iron in S-26/SMA HMF added to HM were compared with those in HM fortified with various bovine milk proteins: alpha-lactalbumin, colostrum, caseinate, casein phosphopeptides, and whey protein concentrate. The bioavailability of each mineral was assessed using an in vitro digestion/Caco-2 cell culture model. Calcium and zinc uptake by the cells was traced with radioisotopes; iron uptake was assessed via cell ferritin levels. Samples were prepared on an equal protein content basis and with added calcium, but no zinc or iron was added. Results revealed that calcium uptake from HM + S-26/SMA was not different from any of the HM fortified with the bovine milk proteins, except for unfortified HM and HM + colostrum in which calcium uptake was significantly lower (-89 and -38%, respectively). Uptake of zinc and iron were significantly higher for HM + S-26/SMA than for the other HM + fortifiers.

Zinc regulates iNOS-derived nitric oxide formation in endothelial cells.

PubMed

Cortese-Krott, Miriam M; Kulakov, Larissa; Opländer, Christian; Kolb-Bachofen, Victoria; Kröncke, Klaus-D; Suschek, Christoph V

2014-01-01

Aberrant production of nitric oxide (NO) by inducible NO synthase (iNOS) has been implicated in the pathogenesis of endothelial dysfunction and vascular disease. Mechanisms responsible for the fine-tuning of iNOS activity in inflammation are still not fully understood. Zinc is an important structural element of NOS enzymes and is known to inhibit its catalytical activity. In this study we aimed to investigate the effects of zinc on iNOS activity and expression in endothelial cells. We found that zinc down-regulated the expression of iNOS (mRNA+protein) and decreased cytokine-mediated activation of the iNOS promoter. Zinc-mediated regulation of iNOS expression was due to inhibition of NF-κB transactivation activity, as determined by a decrease in both NF-κB-driven luciferase reporter activity and expression of NF-κB target genes, including cyclooxygenase 2 and IL-1β. However, zinc did not affect NF-κB translocation into the nucleus, as assessed by Western blot analysis of nuclear and cytoplasmic fractions. Taken together our results demonstrate that zinc limits iNOS-derived high output NO production in endothelial cells by inhibiting NF-κB-dependent iNOS expression, pointing to a role of zinc as a regulator of iNOS activity in inflammation.

Zinc regulates iNOS-derived nitric oxide formation in endothelial cells

PubMed Central

Cortese-Krott, Miriam M.; Kulakov, Larissa; Opländer, Christian; Kolb-Bachofen, Victoria; Kröncke, Klaus-D.; Suschek, Christoph V.

2014-01-01

Aberrant production of nitric oxide (NO) by inducible NO synthase (iNOS) has been implicated in the pathogenesis of endothelial dysfunction and vascular disease. Mechanisms responsible for the fine-tuning of iNOS activity in inflammation are still not fully understood. Zinc is an important structural element of NOS enzymes and is known to inhibit its catalytical activity. In this study we aimed to investigate the effects of zinc on iNOS activity and expression in endothelial cells. We found that zinc down-regulated the expression of iNOS (mRNA+protein) and decreased cytokine-mediated activation of the iNOS promoter. Zinc-mediated regulation of iNOS expression was due to inhibition of NF-κB transactivation activity, as determined by a decrease in both NF-κB-driven luciferase reporter activity and expression of NF-κB target genes, including cyclooxygenase 2 and IL-1β. However, zinc did not affect NF-κB translocation into the nucleus, as assessed by Western blot analysis of nuclear and cytoplasmic fractions. Taken together our results demonstrate that zinc limits iNOS-derived high output NO production in endothelial cells by inhibiting NF-κB-dependent iNOS expression, pointing to a role of zinc as a regulator of iNOS activity in inflammation. PMID:25180171

Down-regulation of zinc transporter 8 (SLC30A8) in pancreatic beta-cells promotes cell survival.

USDA-ARS?s Scientific Manuscript database

The pancreatic islet contains high levels of zinc in granular vesicles of ß-cells where insulin is matured, crystallized, and stored before secretion. Zinc is an essential co-factor for insulin crystallization forming dense cores in secretory granules. In insulin-containing secretory granules, zinc ...

Tumor necrosis factor-{alpha} enhances IL-15-induced natural killer cell differentiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jiwon; Lee, Suk Hyung; Korea University of Science and Technology, Yusong, Daejeon 305-333

2009-09-04

The differentiation of natural killer (NK) cells is regulated by various factors including soluble growth factors and transcription factors. Here, we have demonstrated that tumor necrosis factor-{alpha} (TNF-{alpha}) is a positive regulator of NK cell differentiation. TNF-{alpha} augmented the IL-15-induced expression of NK1.1 and CD122 in mature NK cells, and TNF-{alpha} alone also induced NK cell maturation as well as IL-15. TNF-{alpha} also increased IFN-{gamma} production in NK cells in the presence of IL-15. Meanwhile, mRNA expression of several transcription factors, including T-bet and GATA-3, was increased by the addition of TNF-{alpha} and IL-15. In addition, TNF-{alpha} increased nuclear factor-kappamore » B (NF-{kappa}B) activity in NK cells and inhibition of NF-{kappa}B impeded TNF-{alpha}-enhanced NK cell maturation. Overall, these data suggest that TNF-{alpha} significantly increased IL-15-driven NK cell differentiation by increasing the expression of transcription factors that play crucial roles in NK cell maturation and inducing the NF-{kappa}B activity.« less

Automatically activated, 300 ampere-hour silver-zinc cell

NASA Technical Reports Server (NTRS)

Hennigan, T. J.

1972-01-01

A prototype silver zinc cell is reported for which the electrolyte is being stored in a separate tank; the cell is being activated when additional power is required by collapsing the neoprene bellows container and thus forcing the electrolyte into cell through a plastic connection. A solar array is proposed as main power source for the flow actuator.

Zinc Transport Differs in Rat Spermatogenic Cell Types and Is Affected by Treatment with Cyclophosphamide1

PubMed Central

Downey, Anne Marie; Hales, Barbara F.; Robaire, Bernard

2016-01-01

Adequate zinc levels are required for proper cellular functions and for male germ cell development. Zinc transport is accomplished by two families of zinc transporters, the ZIPs and the ZnTs, that increase and decrease cytosolic zinc levels, respectively. However, very little is known about zinc transport in the testis. Furthermore, whether cytotoxic agents such as cyclophosphamide (CPA), a known male germ cell toxicant, can affect zinc transport and homeostasis is unknown. We examined zinc transporter expression and zinc transport in pachytene spermatocytes (PS) and round spermatids (RS) in a normal state and after exposure to CPA. We observed differences in the expression of members of the ZnT and ZIP families in purified populations of PS and RS. We also observed that RS accumulate more zinc over time than PS. The expression of many zinc binding genes was altered after CPA treatment. Interestingly, we found that the expression levels of ZIP5 and ZIP14 were increased in PS from animals treated daily with 6 mg/kg CPA for 4 wk but not in RS. This up-regulation led to an increase in zinc uptake in PS but not in RS from treated animals compared to controls. These data suggest that CPA treatment may alter zinc homeostasis in male germ cells leading to an increased need for zinc. Altered zinc homeostasis may disrupt proper germ cell development and contribute to infertility and effects on progeny. PMID:27281708

Mechanistic studies of the toxicity of zinc gluconate in the olfactory neuronal cell line Odora

PubMed Central

Hsieh, Heidi; Vignesh, Kavitha Subramanian; Deepe, George S.; Choubey, Divaker; Shertzer, Howard G.; Genter, Mary Beth

2016-01-01

Zinc is both an essential and potentially toxic metal. It is widely believed that oral zinc supplementation can reduce the effects of the common cold; however, there is strong clinical evidence that intranasal (IN) zinc gluconate (ZG) gel treatment for this purpose causes anosmia, or the loss of the sense of smell, in humans. Using the rat olfactory neuron cell line, Odora, we investigated the molecular mechanism by which zinc exposure exerts its toxic effects on olfactory neurons. Following treatment of Odora cells with 100 and 200 μM ZG for 0-24 h, RNA-seq and in silico analyses revealed up-regulation of pathways associated with zinc metal response, oxidative stress, and ATP production. We observed that Odora cells recovered from zinc-induced oxidative stress, but ATP depletion persisted with longer exposure to ZG. ZG exposure increased levels of NLRP3 and IL-1β protein levels in a time-dependent manner, suggesting that zinc exposure may cause an inflammasome-mediated cell death, pyroptosis, in olfactory neurons. PMID:27179668

Mechanistic studies of the toxicity of zinc gluconate in the olfactory neuronal cell line Odora.

PubMed

Hsieh, Heidi; Vignesh, Kavitha Subramanian; Deepe, George S; Choubey, Divaker; Shertzer, Howard G; Genter, Mary Beth

2016-09-01

Zinc is both an essential and potentially toxic metal. It is widely believed that oral zinc supplementation can reduce the effects of the common cold; however, there is strong clinical evidence that intranasal (IN) zinc gluconate (ZG) gel treatment for this purpose causes anosmia, or the loss of the sense of smell, in humans. Using the rat olfactory neuron cell line, Odora, we investigated the molecular mechanism by which zinc exposure exerts its toxic effects on olfactory neurons. Following treatment of Odora cells with 100 and 200μM ZG for 0-24h, RNA-seq and in silico analyses revealed up-regulation of pathways associated with zinc metal response, oxidative stress, and ATP production. We observed that Odora cells recovered from zinc-induced oxidative stress, but ATP depletion persisted with longer exposure to ZG. ZG exposure increased levels of NLRP3 and IL-1β protein levels in a time-dependent manner, suggesting that zinc exposure may cause an inflammasome-mediated cell death, pyroptosis, in olfactory neurons. Copyright © 2016 Elsevier Ltd. All rights reserved.

Alpha1B-adrenoceptor signaling and cell motility: GTPase function of Gh/transglutaminase 2 inhibits cell migration through interaction with cytoplasmic tail of integrin alpha subunits.

PubMed

Kang, Sung Koo; Yi, Kye Sook; Kwon, Nyoun Soo; Park, Kwang-Hyun; Kim, Uh-Hyun; Baek, Kwang Jin; Im, Mie-Jae

2004-08-27

A multifunctional enzyme, G(h), is a GTP-binding protein that couples to the alpha(1B)-adrenoreceptor and stimulates phospholipase C-delta1 but also displays transglutaminase 2 (TG2) activity. G(h)/TG2 has been implicated to play a role in cell motility. In this study we have examined which function of G(h)/TG2 is involved in this cellular response and the molecular basis. Treatment of human aortic smooth muscle cell with epinephrine inhibits migration to fibronectin and vitronectin, and the inhibition is blocked by the alpha(1)-adrenoreceptor antagonist prazosin or chloroethylclonidine. Up-regulation or overexpression of G(h)/TG2 in human aortic smooth muscle cells, DDT1-MF2, or human embryonic kidney cells, HEK 293 cells, results in inhibition of the migratory activity, and stimulation of the alpha(1B)-adrenoreceptor with the alpha(1) agonist further augments the inhibition of migration of human aortic smooth muscle cells and DDT1-MF2. G(h)/TG2 is coimmunoprecipitated by an integrin alpha(5) antibody and binds to the cytoplasmic tail peptide of integrins alpha(5), alpha(v), and alpha(IIb) subunits in the presence of guanosine 5'-3-O-(thio)triphosphate (GTPgammaS). Mutation of Lys-Arg residues in the GFFKR motif, present in the alpha(5)-tail, significantly reduces the binding of GTPgammaS-G(h)/TG2. Moreover, the motif-containing integrin alpha(5)-tail peptides block G(h)/TG2 coimmunoprecipitation and reverse the inhibition of the migratory activity of HEK 293 cells caused by overexpression G(h)/TG2. These results provide evidence that G(h) function initiates the modulation of cell motility via association of GTP-bound G(h)/TG2 with the GFFKR motif located in integrin alpha subunits.

Hyperaccumulation of zinc by zinc-depleted Candida utilis grown in chemostat culture.

PubMed

Lawford, H G; Pik, J R; Lawford, G R; Williams, T; Kligerman, A

1980-01-01

The steady-state levels of zinc in Candida utilis yeast grown in continuous culture under conditions of zinc limitations are <1nmol Zn2+/mg dry weight of cells. Unlike carbon-limited cells, zinc-depleted cells from a zinc-limited chemostat possess the capacity to accumulate and store zinc at levels far in excess of the steady-state level of 4 nmol/mg dry biomass observed in carbon-limited chemostat cultures. Zinc uptake is energy-dependent and apparently undirectional since accumulated 65Zn neither exists from preloaded cells nor exchanges with cold Zn2+. The transport system exhibits a high affinity for Zn2+ (Km =.36micrM) with a Vmaxof 2.2 nmol per minute per milligram dry weight of cells. Growth during the period of the uptake assay is responsible for the apparent plateau level of 35 nmol Zn2+/mg dry weight of cells achieved after 20-30 min in the presence of 65Zn at pH 4.5 and 30 degrees C. Inhibition of growth during the uptake assay by cycloheximide results in a biphasic linear pattern of zinc accumulation where the cellular zinc is about 60 nmol/mg dry weight after 1 h. The enhanced level of accumulated zinc is not inhibtory to growth. Zinc-depleted C. utilis contains elevated amounts of polyphosphate and this anionic evidence does not allow discrimination between possible regulation of zinc homestasis either by inhibitions of zinc efflux through control of the membrane carrier or by control of the synthesis of a cytoplasmic zinc-sequestering macromolecule.

Altered Stem Cell Receptor Activity in the Ovarian Surface Epithelium by Exogenous Zinc and/or Progesterone.

PubMed

Oktem, G; Sahin, C; Dilsiz, O Y; Demiray, S B; Goker, E N T; Tavmergen, E

2015-05-01

Ovarian surface epithelium (OSE) has the characteristics of a stem cell and the potential for differentiation. Previous studies on this subject have succeeded in deriving oocytes from OSE stem cells, leading to the belief that OSE could be used for infertility treatment. Each rat (n = 10) was subjected to zinc and/or progesterone injection for 5 days after conception. After a 6-day implantation period, ovarian tissues were removed and comprehensive immunohistochemical analysis of stem cell markers was conducted: Sox2, Klf4, Oct3/4, c-Myc, CD117, CD90, SSEA-1 and Notch pathway analysis; Notch1, Jagged1, and Delta1 in the OSE and ovarian stromal cells were evaluated after treatment with zinc, progesterone, or both. Progesterone moderately affected Sox2 expression (p < 0.001), while zinc application strongly affected Klf4 and Oct3/4 and immunoreactivity (p < 0.001). CD90 immunoreactivity was decreased in the OSE and stroma of the progesterone group (p = 0.006) compared with the zinc (p = 0.244) and zinc/progesterone groups (p = 0.910). On the other hand, SSEA-1 showed moderate staining in the OSE and weak staining in stromal cells in animals treated with zinc (p = 0.727), progesterone (p = 0.626), and zinc/progesterone (p = 0.371), with no differences compared with control. Zinc application affected Notch pathway immunoreactivity, with a significant increase in Notch1 (p = 0.0015) and Jagged1 (p < 0.001). The expression of putative stem cell markers in the OSE was verified and stem cell receptor activity was raised in the OSE and ovarian stromal cells by zinc and progesterone. Thus, this increased expression allows the therapeutic use of zinc and progesterone in ovary-related infertility and brings a different perspective to reproductive medicine. © Georg Thieme Verlag KG Stuttgart · New York.

TNF-alpha induction of GM2 expression on renal cell carcinomas promotes T cell dysfunction.

PubMed

Raval, Gira; Biswas, Soumika; Rayman, Patricia; Biswas, Kaushik; Sa, Gaurisankar; Ghosh, Sankar; Thornton, Mark; Hilston, Cynthia; Das, Tanya; Bukowski, Ronald; Finke, James; Tannenbaum, Charles S

2007-05-15

Previous studies from our laboratory demonstrated the role of tumor-derived gangliosides as important mediators of T cell apoptosis, and hence, as one mechanism by which tumors evade immune destruction. In this study, we report that TNF-alpha secreted by infiltrating inflammatory cells and/or genetically modified tumors augments tumor-associated GM2 levels, which leads to T cell death and immune dysfunction. The conversion of weakly apoptogenic renal cell carcinoma (RCC) clones to lines that can induce T cell death requires 3-5 days of TNF-alpha pretreatment, a time frame paralleling that needed for TNF-alpha to stimulate GM2 accumulation by SK-RC-45, SK-RC-54, and SK-RC-13. RCC tumor cell lines permanently transfected with the TNF-alpha transgene are similarly toxic for T lymphocytes, which correlates with their constitutively elevated levels of GM2. TNF-alpha increases GM2 ganglioside expression by enhancing the mRNA levels encoding its synthetic enzyme, GM2 synthase, as demonstrated by both RT-PCR and Southern analysis. The contribution of GM2 gangliosides to tumor-induced T cell death was supported by the finding that anti-GM2 Abs significantly blocked T cell apoptosis mediated by TNF-alpha-treated tumor cells, and by the observation that small interfering RNA directed against TNF-alpha abrogated GM2 synthase expression by TNF-transfected SK-RC-45, diminished its GM2 accumulation, and inhibited its apoptogenicity for T lymphocytes. Our results indicate that TNF-alpha signaling promotes RCC-induced killing of T cells by stimulating the acquisition of a distinct ganglioside assembly in RCC tumor cells.

Tumor necrosis factor alpha (TNF-alpha)-induced cell adhesion to human endothelial cells is under dominant control of one TNF receptor type, TNF-R55

PubMed Central

1993-01-01

Tumor necrosis factor alpha (TNF-alpha) is a pleiotropic cytokine triggering cell responses through two distinct membrane receptors. Stimulation of leukocyte adhesion to the endothelium is one of the many TNF-alpha activities and is explained by the upregulation of adhesion molecules on the endothelial cell surface. Human umbilical vein endothelial cells (HUVEC) were isolated, cultured, and demonstrated to express both TNF receptor types, TNF-R55 and TNF-R75. Cell adhesion to HUVEC was studied using the HL60, U937, and MOLT-4 cell lines. HUVEC were activated by either TNF-alpha, binding to both TNF-R55 and TNF- R75, and by receptor type-specific agonists, binding exclusively to TNF- R55 or to TNF-R75. The TNF-alpha-induced cell adhesion to HUVEC was found to be controlled almost exclusively by TNF-R55. This finding correlated with the exclusive activity of TNF-R55 in the TNF-alpha- dependent regulation of the expression of the intercellular adhesion molecule type 1 (ICAM-1), E-selectin, and vascular cell adhesion molecule type 1 (VCAM-1). The CD44 adhesion molecule in HUVEC was also found to be upregulated through TNF-R55. However, both TNF-R55 and TNF- R75 upregulate alpha 2 integrin expression in HUVEC. The predominant role of TNF-R55 in TNF-alpha-induced adhesion in HUVEC may correlate with its specific control of NF-kappa B activation, since kappa B elements are known to be present in ICAM-1, E-selectin, and VCAM-1 gene regulatory sequences. PMID:8386742

Improved zinc electrode and rechargeable zinc-air battery

DOEpatents

Ross, P.N. Jr.

1988-06-21

The invention comprises an improved rechargeable zinc-air cell/battery having recirculating alkaline electrolyte and a zinc electrode comprising a porous foam support material which carries the active zinc electrode material. 5 figs.

Effects of exogenous zinc on cell cycle, apoptosis and viability of MDAMB231, HepG2 and 293 T cells.

PubMed

Wang, Yan-hong; Li, Ke-jin; Mao, Li; Hu, Xin; Zhao, Wen-jie; Hu, An; Lian, Hong-zhen; Zheng, Wei-juan

2013-09-01

As a non-toxic metal to humans, zinc is essential for cell proliferation, differentiation, regulation of DNA synthesis, genomic stability and mitosis. Zinc homeostasis in cells, which is crucial for normal cellular functioning, is maintained by various protein families including ZnT (zinc transporter/SLC30A) and ZIP (Zrt-, Irt-like proteins/SLC39A) that decrease and increase cytosolic zinc availability, respectively. In this study, we investigated the influences of a specific concentration range of ZnSO4 on cell cycle and apoptosis by flow cytometry, and cell viability by MTT method in MDAMB231, HepG2 and 293 T cell lines. Fluorescent sensors NBD-TPEA and the counterstain for nuclei Hoechst 33342 were used to stain the treated cells for observing the localisation and amount of Zn(2+) via laser scanning confocal microscope. It was found that the influence manners of ZnSO4 on cell cycle, apoptosis and cell viability in various cell lines were different and corresponding to the changes of Zn(2+) content of the three cell lines, respectively. The significant increase on intracelluar zinc content of MDAMB231 cells resulted in cell death, G1 and G2/M cell cycle arrest and increased apoptotic fraction. Additionally, the mRNA expression levels of ZnT and ZIP families in the three cell lines, when treated with high concentration of ZnSO4, increased and decreased corresponding to their functions, respectively.

Polyphenol-rich beverages enhance zinc uptake and metallothionein expression in Caco-2 cells.

PubMed

Sreenivasulu, Kilari; Raghu, Pullakhandam; Nair, K Madhavan

2010-05-01

The effect of red wine (RW), red grape juice (RGJ), green tea (GT), and representative polyphenols on Caco-2 cell (65)Zn uptake was explored. RW, RGJ, and GT enhanced the uptake of zinc from rice matrix. Fractionation of RW revealed that enhancing activity of zinc uptake was exclusively resided in the polyphenol fraction. Among the polyphenols tested, only tannic acid and quercitin stimulated the uptake of zinc while others did not influence the uptake. In tune with these results, only tannic acid and quercitin competed with zinquin (a zinc selective fluorophore) for zinc in vitro. Although all the polyphenols tested appear to enhance the expression of metallothionein (MT), the induction was higher with tannic acid, quercitin, and RW extract. Furthermore, phytic acid abrogated the tannic acid-induced MT expression. These results suggest that polyphenol-rich beverages, tannic acid, and quercitin bind and stimulate the zinc uptake and MT expression in Caco-2 cells.

Thiazolidinediones inhibit REG I{alpha} gene transcription in gastrointestinal cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamauchi, Akiyo; Laboratory of Molecular Genetics, Tohoku University Graduate School of Pharmaceutical Sciences, Sendai 980-8578; Department of Biochemistry, Nara Medical University, Kashihara 634-8521

2009-02-13

REG (Regenerating gene) I{alpha} protein functions as a growth factor for gastrointestinal cancer cells, and its mRNA expression is strongly associated with a poor prognosis in gastrointestinal cancer patients. We here demonstrated that PPAR{gamma}-agonist thiazolidinediones (TZDs) inhibited cell proliferation and REG I{alpha} protein/mRNA expression in gastrointestinal cancer cells. TZDs inhibited the REG I{alpha} gene promoter activity, via its cis-acting element which lacked PPAR response element and could not bind to PPAR{gamma}, in PPAR{gamma}-expressing gastrointestinal cancer cells. The inhibition was reversed by co-treatment with a specific PPAR{gamma}-antagonist GW9662. Although TZDs did not inhibit the REG I{alpha} gene promoter activity in PPAR{gamma}-non-expressingmore » cells, PPAR{gamma} overexpression in the cells recovered their inhibitory effect. Taken together, TZDs inhibit REG I{alpha} gene transcription through a PPAR{gamma}-dependent pathway. The TZD-induced REG I{alpha} mRNA reduction was abolished by cycloheximide, indicating the necessity of novel protein(s) synthesis. TZDs may therefore be a candidate for novel anti-cancer drugs for patients with gastrointestinal cancer expressing both REG I{alpha} and PPAR{gamma}.« less

Alterations of zinc homeostasis in response to Cryptococcus neoformans in a murine macrophage cell line.

PubMed

Dos Santos, Francine Melise; Piffer, Alícia Corbellini; Schneider, Rafael de Oliveira; Ribeiro, Nicole Sartori; Garcia, Ane Wichine Acosta; Schrank, Augusto; Kmetzsch, Lívia; Vainstein, Marilene Henning; Staats, Charley Christian

2017-05-01

To evaluate alterations of zinc homeostasis in macrophages exposed to Cryptococcus neoformans. Materials & methods: Using a fluorescent zinc probe-based flow cytometry and atomic absorption spectrometry, zinc levels were evaluated in J774.A1 cell lines exposed to C. neoformans H99 cells. The transcription profile of macrophage zinc related homeostasis genes - metallothioneins and zinc transporters (ZnTs) of the SLC30 and SLC39 (Zrt-Irt-protein) families - was analyzed by quantitative PCR. Macrophage intracellular labile zinc levels decreased following exposure to C. neoformans. A significant decrease in transcription levels was detected in specific ZnTs from both the Zrt-Irt-protein and ZnT families, especially 24 h after infection. These findings suggest that macrophages may exhibit zinc depletion in response to C. neoformans infection.

Induction of regulatory T cells in Th1-/Th17-driven experimental autoimmune encephalomyelitis by zinc administration.

PubMed

Rosenkranz, Eva; Maywald, Martina; Hilgers, Ralf-Dieter; Brieger, Anne; Clarner, Tim; Kipp, Markus; Plümäkers, Birgit; Meyer, Sören; Schwerdtle, Tanja; Rink, Lothar

2016-03-01

The essential trace element zinc is indispensable for proper immune function as zinc deficiency accompanies immune defects and dysregulations like allergies, autoimmunity and an increased presence of transplant rejection. This point to the importance of the physiological and dietary control of zinc levels for a functioning immune system. This study investigates the capacity of zinc to induce immune tolerance. The beneficial impact of physiological zinc supplementation of 6 μg/day (0.3mg/kg body weight) or 30 μg/day (1.5mg/kg body weight) on murine experimental autoimmune encephalomyelitis (EAE), an animal model for multiple sclerosis with a Th1/Th17 (Th, T helper) cell-dominated immunopathogenesis, was analyzed. Zinc administration diminished EAE scores in C57BL/6 mice in vivo (P<.05), reduced Th17 RORγT(+) cells (P<.05) and significantly increased inducible iTreg cells (P<.05). While Th17 cells decreased systemically, iTreg cells accumulated in the central nervous system. Cumulatively, zinc supplementation seems to be capable to induce tolerance in unwanted immune reactions by increasing iTreg cells. This makes zinc a promising future tool for treating autoimmune diseases without suppressing the immune system. Copyright © 2015 Elsevier Inc. All rights reserved.

Zinc Signals and Immunity.

PubMed

Maywald, Martina; Wessels, Inga; Rink, Lothar

2017-10-24

Zinc homeostasis is crucial for an adequate function of the immune system. Zinc deficiency as well as zinc excess result in severe disturbances in immune cell numbers and activities, which can result in increased susceptibility to infections and development of especially inflammatory diseases. This review focuses on the role of zinc in regulating intracellular signaling pathways in innate as well as adaptive immune cells. Main underlying molecular mechanisms and targets affected by altered zinc homeostasis, including kinases, caspases, phosphatases, and phosphodiesterases, will be highlighted in this article. In addition, the interplay of zinc homeostasis and the redox metabolism in affecting intracellular signaling will be emphasized. Key signaling pathways will be described in detail for the different cell types of the immune system. In this, effects of fast zinc flux, taking place within a few seconds to minutes will be distinguish from slower types of zinc signals, also designated as "zinc waves", and late homeostatic zinc signals regarding prolonged changes in intracellular zinc.

Zinc Signals and Immunity

PubMed Central

Maywald, Martina; Wessels, Inga; Rink, Lothar

2017-01-01

Zinc homeostasis is crucial for an adequate function of the immune system. Zinc deficiency as well as zinc excess result in severe disturbances in immune cell numbers and activities, which can result in increased susceptibility to infections and development of especially inflammatory diseases. This review focuses on the role of zinc in regulating intracellular signaling pathways in innate as well as adaptive immune cells. Main underlying molecular mechanisms and targets affected by altered zinc homeostasis, including kinases, caspases, phosphatases, and phosphodiesterases, will be highlighted in this article. In addition, the interplay of zinc homeostasis and the redox metabolism in affecting intracellular signaling will be emphasized. Key signaling pathways will be described in detail for the different cell types of the immune system. In this, effects of fast zinc flux, taking place within a few seconds to minutes will be distinguish from slower types of zinc signals, also designated as “zinc waves”, and late homeostatic zinc signals regarding prolonged changes in intracellular zinc. PMID:29064429

Zinc in Cellular Regulation: The Nature and Significance of "Zinc Signals".

PubMed

Maret, Wolfgang

2017-10-31

In the last decade, we witnessed discoveries that established Zn 2+ as a second major signalling metal ion in the transmission of information within cells and in communication between cells. Together with Ca 2+ and Mg 2+ , Zn 2+ covers biological regulation with redox-inert metal ions over many orders of magnitude in concentrations. The regulatory functions of zinc ions, together with their functions as a cofactor in about three thousand zinc metalloproteins, impact virtually all aspects of cell biology. This article attempts to define the regulatory functions of zinc ions, and focuses on the nature of zinc signals and zinc signalling in pathways where zinc ions are either extracellular stimuli or intracellular messengers. These pathways interact with Ca 2+ , redox, and phosphorylation signalling. The regulatory functions of zinc require a complex system of precise homeostatic control for transients, subcellular distribution and traffic, organellar homeostasis, and vesicular storage and exocytosis of zinc ions.

Rapid, efficient charging of lead-acid and nickel-zinc traction cells

NASA Technical Reports Server (NTRS)

Smithrick, J. J.

1978-01-01

Lead-acid and nickel-zinc traction cells were rapidly and efficiently charged using a high rate tapered direct current (HRTDC) charge method which could possibly be used for on-the-road service recharge of electric vehicles. The HRTDC method takes advantage of initial high cell charge acceptance and uses cell gassing rate and temperature as an indicator of charging efficiency. On the average, in these preliminary tests, 300 amp-hour nickel-zinc traction cells were given a HRTDC (initial current 500 amps, final current 100 amps) to 78 percent of rated amp-hour capacity within 53 minutes at an amp-hour efficiency of 92 percent and an energy efficiency of 52 percent. Three hundred amp-hour lead-acid traction cells were charged to 69 percent of rated amp-hour capacity within 46 minutes at an amp-hour efficiency of 91 percent with an energy efficiency of 64 percent. In order to find ways to further decrease the recharge times, the effect of periodically (0 to 400 Hz) pulse discharging cells during a constant current charging process (94% duty cycle) was investigated. Preliminary data indicate no significant effect of this type of pulse discharging during charge on charge acceptance of lead-acid or nickel-zinc cells.

Zinc Chromate Induces Chromosome Instability and DNA Double Strand Breaks in Human Lung Cells

PubMed Central

Xie, Hong; Holmes, Amie L.; Young, Jamie L.; Qin, Qin; Joyce, Kellie; Pelsue, Stephen C.; Peng, Cheng; Wise, Sandra S.; Jeevarajan, Antony S.; Wallace, William T.; Hammond, Dianne; Wise, John Pierce

2014-01-01

Hexavalent chromium Cr(VI) is a respiratory toxicant and carcinogen, with solubility playing an important role in its carcinogenic potential. Zinc chromate, a water insoluble or ‘particulate’ Cr(VI) compound, has been shown to be carcinogenic in epidemiology studies and to induce tumors in experimental animals, but its genotoxicity is poorly understood. Our study shows that zinc chromate induced concentration-dependent increases in cytotoxicity, chromosome damage and DNA double strand breaks in human lung cells. In response to zinc chromate-induced breaks, MRE11 expression was increased and ATM and ATR were phosphorylated, indicating that the DNA double strand break repair system was initiated in the cells. In addition, our data show that zinc chromate-induced double strand breaks were only observed in the G2/M phase population, with no significant amount of double strand breaks observed in G1 and S phase cells. These data will aid in understanding the mechanisms of zinc chromate toxicity and carcinogenesis. PMID:19027772

Evaluation of the Level of Zinc and Malondialdehyde in Basal Cell Carcinoma.

PubMed

Majidi, Ziba; Djalali, Mahmoud; Javanbakht, Mohammad Hasan; Fathi, Mojtaba; Zarei, Mahnaz; Foladsaz, Koorosh

2017-08-01

Basal Cell Carcinoma (BCC) is one of the most common skin cancers in the world and that use to lifestyle, increasing chemical pollutions, environmental factors and poor nutrition. The most important cause of this cancer is oxidative stress and free radicals so antioxidant activities for the body are so important. The aim of this study was to determine the variation of zinc and (Malondialdehyde) MDA in BCC patients. This study has been performed on case and control patients from 2013 to 2014. The samples were collected from cell carcinoma patients at Razi Hospital in Tehran, Iran. We evaluated the level of zinc with the use of Atomic Absorption Spectroscopy (AAS) method. Besides, we evaluated MDA with colorimetric assay. The concentration of MDA was significantly higher in case group in comparison to control group ( P =0.001). In addition, case group had lower concentration of zinc than the control group ( P =0.000). There was no correlation between MDA and body mass index (BMI) and between zinc and BMI. All the patients with BCC showed a significant MDA serum in comparison with control group. However, significant decrease in zinc serum of the patients was seen that is because of consuming zinc during oxidative stress process so topical use of zinc in the form of 2+ ions could be effective on antioxidant protection against the sun UV radiation.

Zinc finger protein 267 is up-regulated in hepatocellular carcinoma and promotes tumor cell proliferation and migration.

PubMed

Schnabl, Bernd; Valletta, Daniela; Kirovski, Georgi; Hellerbrand, Claus

2011-12-01

Zinc finger protein 267 (ZNF267) belongs to the family of Kruppel-like transcription factors, which regulates diverse biological processes that include development, proliferation, and differentiation. We have previously demonstrated that ZNF267 mRNA is up-regulated in liver cirrhosis, which is the main risk factor for hepatocellular carcinoma (HCC). Here, we analyzed the expression of ZNF267 in human HCC cells and tissue specimens and found a significant up-regulation compared to primary human hepatocytes and corresponding non-tumorous liver tissue. Over-expression of the transcription factor Ets-1 further enhanced ZNF267 expression, and reporter gene assays revealed that mutation of the Ets-1 binding site to the ZNF267 promotor markedly inhibited ZNF267 promotor activity. Hypoxic conditions induced Ets-1 in HCC cells via HIF1alpha activation, and hypoxia induced ZNF267 expression while HIF1alpha inhibition significantly reduced both hypoxia-induced as well as basal ZNF267 expression in HCC cells. It is known that hypoxic conditions in tumorous tissues induce the formation of reactive oxygen species (ROS), and ROS have been identified as important factor in the regulation of Ets-1 expression in tumor cells. Here, we found that ROS induction induced and ROS scavenging reduced ZNF267 expression in HCC cells, respectively. Loss and gain of function analysis applying siRNA directed against ZNF267 or transient transfection revealed that ZNF267 promotes proliferation and migration of HCC cells in vitro. These findings indicate Ets-1 and HIF1alpha as critical regulators of basal and hypoxia- or ROS-induced ZNF267 expression in HCC, and further suggest that the pro-tumorigenic effect of these factors is at least in part mediated via increased ZNF267 expression in HCC. Since ZNF267 is already elevated in cirrhosis, ZNF267 appears as promising target for both prevention as well as treatment of HCC in patients with chronic liver disease. Copyright © 2011 Elsevier Inc. All

Zinc finger protein 267 is up-regulated in hepatocellular carcinoma and promotes tumor cell proliferation and migration

PubMed Central

Schnabl, Bernd; Valletta, Daniela; Kirovski, Georgi; Hellerbrand, Claus

2012-01-01

Zinc finger protein 267 (ZNF267) belongs to the family of Kruppel-like transcription factors, which regulates diverse biological processes that include development, proliferation, and differentiation. We have previously demonstrated that ZNF267 mRNA is up-regulated in liver cirrhosis, which is the main risk factor for hepatocellular carcinoma (HCC). Here, we analyzed the expression of ZNF267 in human HCC cells and tissue specimens and found a significant up-regulation compared to primary human hepatocytes and corresponding non-tumorous liver tissue. Over-expression of the transcription factor Ets-1 further enhanced ZNF267 expression, and reporter gene assays revealed that mutation of the Ets-1 binding site to the ZNF267 promotor markedly inhibited ZNF267 promotor activity. Hypoxic conditions induced Ets-1 in HCC cells via HIF1alpha activation, and hypoxia induced ZNF267 expression while HIF1alpha inhibition significantly reduced both hypoxia-induced as well as basal ZNF267 expression in HCC cells. It is known that hypoxic conditions in tumorous tissues induce the formation of reactive oxygen species (ROS), and ROS have been identified as important factor in the regulation of Ets-1 expression in tumor cells. Here, we found that ROS induction induced and ROS scavenging reduced ZNF267 expression in HCC cells, respectively. Loss and gain of function analysis applying siRNA directed against ZNF267 or transient transfection revealed that ZNF267 promotes proliferation and migration of HCC cells in vitro. These findings indicate Ets-1 and HIF1alpha as critical regulators of basal and hypoxia- or ROS-induced ZNF267 expression in HCC, and further suggest that the pro-tumorigenic effect of these factors is at least in part mediated via increased ZNF267 expression in HCC. Since ZNF267 is already elevated in cirrhosis, ZNF267 appears as promising target for both prevention as well as treatment of HCC in patients with chronic liver disease. PMID:21840307

Accumulation of cholesterol and increased demand for zinc in serum-deprived RPE cells

PubMed Central

Mishra, Sanghamitra; Peterson, Katherine; Yin, Lili; Berger, Alan; Fan, Jianguo

2016-01-01

Purpose Having observed that confluent ARPE-19 cells (derived from human RPE) survive well in high-glucose serum-free medium (SFM) without further feeding for several days, we investigated the expression profile of RPE cells under the same conditions. Methods Expression profiles were examined with microarray and quantitative PCR (qPCR) analyses, followed by western blot analysis of key regulated proteins. The effects of low-density lipoprotein (LDL) and zinc supplementation were examined with qPCR. Immunofluorescence was used to localize the LDL receptor and to examine LDL uptake. Cellular cholesterol levels were measured with filipin binding. Expression patterns in primary fetal RPE cells were compared using qPCR. Results Microarray analyses of gene expression in ARPE-19, confirmed with qPCR, showed upregulation of lipid and cholesterol biosynthesis pathways in SFM. At the protein level, the cholesterol synthesis control factor SRBEF2 was activated, and other key lipid synthesis proteins increased. Supplementation of SFM with LDL reversed the upregulation of lipid and cholesterol synthesis genes, but not of cholesterol transport genes. The LDL receptor relocated to the plasma membrane, and LDL uptake was activated by day 5–7 in SFM, suggesting increased demand for cholesterol. Confluent ARPE-19 cells in SFM accumulated intracellular cholesterol, compared with cells supplemented with serum, over 7 days. Over the same time course in SFM, the expression of metallothioneins decreased while the major zinc transporter was upregulated, consistent with a parallel increase in demand for zinc. Supplementation with zinc reversed expression changes for metallothionein genes, but not for other zinc-related genes. Similar patterns of regulation were also seen in primary fetal human RPE cells in SFM. Conclusions ARPE-19 cells respond to serum deprivation and starvation with upregulation of the lipid and cholesterol pathways, accumulation of intracellular cholesterol, and

In vitro and in vivo effects of zinc on cytokine signalling in human T cells.

PubMed

Varin, Audrey; Larbi, Anis; Dedoussis, George V; Kanoni, Stavroula; Jajte, Jolanta; Rink, Lothar; Monti, Daniela; Malavolta, Marco; Marcellini, Fiorella; Mocchegiani, Eugenio; Herbein, Georges; Fulop, Tamas

2008-05-01

Aging is associated with changes in the immune response which are collectively called immunosenescence. The changes mainly affect the adaptive immune response and especially the T cell-mediated cellular immune response. There are a few data indicating that the cytokine signalling in T cells is altered with aging. Zinc has been specifically shown to have potent immunomodulatory effects. The aim of the present work was to study the IL-2 and IL-6 cytokine signalling and activation induced cell death (AICD) in T cells of elderly subjects of various ages and from various European countries. These experiments were performed in the frame of European Community financed project called ZINCAGE "Nutritional zinc, oxidative stress and immunosenescence: biochemical, genetic and lifestyle implications for healthy ageing", assembling 17 laboratories from 8 countries through Europe. The study was carried out in a total of 312 French and a group of 201 (26 from Italy, 63 from France, 57 from Greece, 24 from Poland and 30 from Germany) healthy non-institutionalized men and women older than 60 years of age, with available dietary data. Human peripheral blood mononuclear cells (PBMC) were obtained from heparinized blood and were stimulated in vitro by IL-2 or IL-6 for various periods and the phosphorylation of STAT3 and STAT5 was measured by FACScan. The activation induced cell death (AICD) was measured after anti-CD3 and CD28 restimulation for 48h by using the Annexin:FITC Apoptosis Kit. We found that there is an IL-2 signalling defect with aging up to 90 years of age which cannot be modulated by zinc. In contrast at 90 years and over the zinc could reverse the negative signalling effect of IL-2. There is also a signalling defect for STAT3 and STAT5 activation in T cells under IL-6 stimulation with aging and the zinc supplementation could potentiate only the STAT5 activation in the age-group 90 years and over. Studying signalling in PBL from different countries we detected less

Amino Acid Profiling of Zinc Resistant Prostate Cancer Cell Lines: Associations With Cancer Progression.

PubMed

Kratochvilova, Monika; Raudenska, Martina; Heger, Zbynek; Richtera, Lukas; Cernei, Natalia; Adam, Vojtech; Babula, Petr; Novakova, Marie; Masarik, Michal; Gumulec, Jaromir

2017-05-01

Failure in intracellular zinc accumulation is a key process in prostate carcinogenesis. Nevertheless, epidemiological studies of zinc administration have provided contradicting results. In order to examine the impact of the artificial intracellular increase of zinc(II) ions on prostate cancer metabolism, PNT1A, 22Rv1, and PC-3 prostatic cell lines-depicting different stages of cancer progression-and their zinc-resistant counterparts were used. To determine "benign" and "malignant" metabolic profiles, amino acid patterns, gene expression, and antioxidant capacity of these cell lines were assessed. Amino acid profiles were examined using an ion-exchange liquid chromatography. Intracellular zinc content was measured by atomic absorption spectrometry. Metallothionein was quantified using differential pulse voltammetry. The content of reduced glutathione was determined using high performance liquid chromatography coupled with an electrochemical detector. Cellular antioxidant capacity was determined by the ABTS test and gene expression analysis was performed by qRT-PCR. Long-term zinc treatment was shown to reroute cell metabolism from benign to more malignant type. Long-term application of high concentration of zinc(II) significantly enhanced cisplatin resistance, invasiveness, cellular antioxidant capacity, synthesis of glutathione, and expression of treatment resistance- and stemness-associated genes (SOX2, POU5F1, BIRC5). Tumorous cell lines universally displayed high accumulation of aspartate and sarcosine and depletion of essential amino acids. Increased aspartate/threonine, aspartate/methionine, and sarcosine/serine ratios were associated with cancer phenotype with high levels of sensitivity and specificity. Prostate 77: 604-616, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Hydroxyl-HIF2-alpha is potential therapeutic target for renal cell carcinomas

PubMed Central

Isono, Takahiro; Chano, Tokuhiro; Yoshida, Tetsuya; Kageyama, Susumu; Kawauchi, Akihiro; Suzaki, Masafumi; Yuasa, Takeshi

2016-01-01

Dormant cancer cells are deprivation-resistant, and cause a number of problems for therapeutic approaches for cancers. Renal cell carcinomas (RCCs) include deprivation-resistant cells that are resistant to various treatments. In this study, the specific characteristics of deprivation-resistant cells were transcriptionally identified by next generation sequencing. The hypoxia-inducible factors (HIF) transcription factor network was significantly enhanced in deprivation-resistant RCCs compared to the sensitive RCCs. Deprivation-resistant RCCs, that had lost Von Hippel-Lindau tumor suppressor expression, expressed hydroxyl-HIF2-alpha in the nucleus, but not sensitive-RCCs. Hydroxyl-HIF-alpha was also expressed in nuclei of RCC tissue samples. Knockdown for HIF2-alpha, but not HIF1-alpha, induced cell death related to a reduction in HIF-related gene expression in deprivation-resistant RCC cells. Chetomin, a nuclear HIF-inhibitor, induced marked level of cytotoxicity in deprivation-resistant cells, similar to the knockdown of HIF2-alpha. Therefore, hydroxyl-HIF2-alpha might be a potential therapeutic target for RCCs. PMID:27822416

Electrolyte Loss Tendencies of Primary Silver-Zinc Cells

NASA Technical Reports Server (NTRS)

Thaller, Lawrence H.; Juvinall, Gordon L.

1997-01-01

Since silver zinc cells are not hermetically sealed, care must be taken to prevent the loss of electrolyte which can result in shorting paths within the battery box. Prelaunch battery processing is important in being able to minimize any problems with expelled electrolyte.

UV-A induced oxidative stress is more prominent in naturally pigmented aged human RPE cells compared to non-pigmented human RPE cells independent of zinc treatment.

PubMed

Biesemeier, Antje; Kokkinou, Despina; Julien, Sylvie; Heiduschka, Peter; Berneburg, Mark; Bartz-Schmidt, Karl Ulrich; Schraermeyer, Ulrich

2008-02-27

To investigate the effects of zinc supplementation on human amelanotic (ARPE-19) and native pigmented retinal pigment epithelial cells (hRPE) under normal light conditions and after ultraviolet A light exposure. hRPE cells, containing both melanin and lipofuscin granules, were prepared from human donor eyes of 60-70 year old patients. Cells of the amelanotic ARPE-19 cell line and pigmented hRPE cells were treated with zinc chloride and subjected to oxidative stress by UV-A irradiation. Intracellular H(2)O(2) formation was measured using a fluorescence oxidation assay. Additionally, apoptosis and viability assays were performed. Control cells were treated identically except for irradiation and zinc supplementation. Under normal light conditions, zinc treated hRPE cells produced less H(2)O(2) than unsupplemented hRPE cells. Viability and apoptosis events did not change. After UV-A irradiation, ARPE and hRPE cells were greatly impaired in all tests performed compared to the non-irradiated controls. No differences were found after zinc supplementation. hRPE cells showed a higher apoptosis and mortality rate than non-pigmented cells when stressed by UV-A light. ARPE cells never showed any zinc related effects. In contrast, without irradiation, zinc supplementation reduced H(2)O(2) production in pigmented hRPE cells slightly. We did not find any zinc effect in irradiated hRPE cells. After UV light exposure, pigmented cells showed a higher apoptosis and mortality than cells lacking any pigmentation. We conclude that cells with pigmentation consisting of melanin and lipofuscin granules have more prooxidative than antioxidative capacity when stressed by UV light exposure compared to cells lacking any pigmentation.

The molecular chaperone alphaA-crystallin enhances lens epithelial cell growth and resistance to UVA stress.

PubMed

Andley, U P; Song, Z; Wawrousek, E F; Bassnett, S

1998-11-20

alphaA-Crystallin (alphaA) is a member of the small heat shock protein (sHSP) family and has the ability to prevent denatured proteins from aggregating in vitro. Lens epithelial cells express relatively low levels of alphaA, but in differentiated fiber cells, alphaA is the most abundant soluble protein. The lenses of alphaA-knock-out mice develop opacities at an early age, implying a critical role for alphaA in the maintenance of fiber cell transparency. However, the function of alpha-crystallin in the lens epithelium is unknown. To investigate the physiological function of alphaA in lens epithelial cells, we used the following two systems: alphaA knock-out (alphaA(-/-)) mouse lens epithelial cells and human lens epithelial cells that overexpress alphaA. The growth rate of alphaA(-/-) mouse lens epithelial cells was reduced by 50% compared with wild type cells. Cell cycle kinetics, measured by fluorescence-activated cell sorter analysis of propidium iodide-stained cells, indicated a relative deficiency of alphaA(-/-) cells in the G2/M phases. Exposure of mouse lens epithelial cells to physiological levels of UVA resulted in an increase in the number of apoptotic cells in the cultures. Four hours after irradiation the fraction of apoptotic cells in the alphaA(-/-) cultures was increased 40-fold over wild type. In cells lacking alphaA, UVA exposure modified F-actin, but actin was protected in cells expressing alphaA. Stably transfected cell lines overexpressing human alphaA were generated by transfecting extended life span human lens epithelial cells with the mammalian expression vector construct pCI-neoalphaA. Cells overexpressing alphaA were resistant to UVA stress, as determined by clonogenic survival. alphaA remained cytoplasmic after exposure to either UVA or thermal stress indicating that, unlike other sHSPs, the protective effect of alphaA was not associated with its relocalization to the nucleus. These results indicate that alphaA has important cellular

Down-regulation of zinc transporter 8 (SLC30A8) in pancreatic beta-cells promotes cell survival

USDA-ARS?s Scientific Manuscript database

The pancreatic islet contains high levels of zinc in granular vesicles of beta-cells where insulin is matured, crystallized, and stored before secretion. Zinc is an essential co-factor for insulin crystallization forming dense core in secretory granules. In insulin-containing secretory granules, zin...

Application of catalytic adsorptive stripping voltammetry of the cobalt-alpha-benzil dioxime complex to analysis of cobalt traces in metallic zinc.

PubMed

Bobrowski, A

1994-05-01

The catalytic adsorptive stripping voltammetric method with alpha-benzil dioxime and nitrite affords numerous advantages in cobalt determination. The detailed conditions of the determination of the cobalt traces in metallic zinc by catalytic adsorptive stripping voltammetry have been investigated. Both the linear sweep and the differential pulse stripping modes can be used with similar sensitivity. Possible interferences by Mn, Pb, Cu, Ni and Fe are evaluated. In the presence of 5 x 10(5) fold excess of Zn the linear dependence of the cobalt CASV peak current on concentration ranged from 0.05 mug/l to 3 mug/l. Optimal conditions include the accumulation potential of -0.65 V and the accumulation time of 10 sec. The results of the determination of 10(-5)% level of Co in the metallic zinc showed good reproducibility (relative standard deviation, RSD = 0.07) and reliability.

An antisymmetric cell structure for high-performance zinc bromine flow battery

NASA Astrophysics Data System (ADS)

Kim, Yongbeom; Jeon, Joonhyeon

2017-12-01

Zinc-bromine flow batteries (ZBBs) remain a problem of designing a cell with high coulombic efficiency and stability. This problem is caused intrinsically by different phase transition in each side of the half-cells during charge-discharge process. This paper describes a ZBB with an antisymmetric cell structure, which uses anode and cathode with different surface morphologies, for high-discharge capacity and reliability. The structure of the antisymmetric ZBB cell contains a carbon-surface electrode and a carbon-volume electrode in zinc and bromine half cells, respectively. To demonstrate the effectiveness of this proposed ZBB cell structure, Cyclic Voltammetry measurement is performed on a graphite foil and a carbon felt which are used as the surface and electrodes. Charge and discharge cyclic operations are also carried out with symmetric and antisymmetric ZBB cells combined with the two electrode types. Experimental results show that the arrangement of antisymmetric cell structure in ZBB provides a solution to the high performance and durability.

Zinc stimulates glucose oxidation and glycemic control by modulating the insulin signaling pathway in human and mouse skeletal muscle cell lines.

PubMed

Norouzi, Shaghayegh; Adulcikas, John; Sohal, Sukhwinder Singh; Myers, Stephen

2018-01-01

Zinc is a metal ion that is an essential cell signaling molecule. Highlighting this, zinc is an insulin mimetic, activating cellular pathways that regulate cellular homeostasis and physiological responses. Previous studies have linked dysfunctional zinc signaling with several disease states including cancer, obesity, cardiovascular disease and type 2 diabetes. The present study evaluated the insulin-like effects of zinc on cell signaling molecules including tyrosine, PRSA40, Akt, ERK1/2, SHP-2, GSK-3β and p38, and glucose oxidation in human and mouse skeletal muscle cells. Insulin and zinc independently led to the phosphorylation of these proteins over a 60-minute time course in both mouse and human skeletal muscle cells. Similarly, utilizing a protein array we identified that zinc could active the phosphorylation of p38, ERK1/2 and GSK-3B in human and ERK1/2 and GSK-3B in mouse skeletal muscle cells. Glucose oxidation assays were performed on skeletal muscle cells treated with insulin, zinc, or a combination of both and resulted in a significant induction of glucose consumption in mouse (p<0.01) and human (p<0.05) skeletal muscle cells when treated with zinc alone. Insulin, as expected, increased glucose oxidation in mouse (p<0.001) and human (0.001) skeletal muscle cells, however the combination of zinc and insulin did not augment glucose consumption in these cells. Zinc acts as an insulin mimetic, activating key molecules implicated in cell signaling to maintain glucose homeostasis in mouse and human skeletal muscle cells. Zinc is an important metal ion implicated in several biological processes. The role of zinc as an insulin memetic in activating key signaling molecules involved in glucose homeostasis could provide opportunities to utilize this ion therapeutically in treating disorders associated with dysfunctional zinc signaling.

Inhibition effects of protein-conjugated amorphous zinc sulfide nanoparticles on tumor cells growth

NASA Astrophysics Data System (ADS)

Cao, Ying; Wang, Hua-Jie; Cao, Cui; Sun, Yuan-Yuan; Yang, Lin; Wang, Bao-Qing; Zhou, Jian-Guo

2011-07-01

In this article, a facile and environmentally friendly method was applied to fabricate BSA-conjugated amorphous zinc sulfide (ZnS) nanoparticles using bovine serum albumin (BSA) as the matrix. Transmission electron microscopy analysis indicated that the stable and well-dispersed nanoparticles with the diameter of 15.9 ± 2.1 nm were successfully prepared. The energy dispersive X-ray, X-ray powder diffraction, Fourier transform infrared spectrograph, high resolution transmission electron microscope, and selected area electron diffraction measurements showed that the obtained nanoparticles had the amorphous structure and the coordination occurred between zinc sulfide surfaces and BSA in the nanoparticles. In addition, the inhibition effects of BSA-conjugated amorphous zinc sulfide nanoparticles on tumor cells growth were described in detail by cell viability analysis, optical and electron microscopy methods. The results showed that BSA-conjugated amorphous zinc sulfide nanoparticles could inhibit the metabolism and proliferation of human hepatocellular carcinoma cells, and the inhibition was dose dependent. The half maximal inhibitory concentration (IC50) was 0.36 mg/mL. Overall, this study suggested that BSA-conjugated amorphous zinc sulfide nanoparticles had the application potential as cytostatic agents and BSA in the nanoparticles could provide the modifiable site for the nanoparticles to improve their bioactivity or to endow them with the target function.

Zinc-oxide-based nanostructured materials for heterostructure solar cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bobkov, A. A.; Maximov, A. I.; Moshnikov, V. A., E-mail: vamoshnikov@mail.ru

Results obtained in the deposition of nanostructured zinc-oxide layers by hydrothermal synthesis as the basic method are presented. The possibility of controlling the structure and morphology of the layers is demonstrated. The important role of the procedure employed to form the nucleating layer is noted. The faceted hexagonal nanoprisms obtained are promising for the fabrication of solar cells based on oxide heterostructures, and aluminum-doped zinc-oxide layers with petal morphology, for the deposition of an antireflection layer. The results are compatible and promising for application in flexible electronics.

FcepsilonRI-alpha siRNA inhibits the antigen-induced activation of mast cells.

PubMed

Safaralizadeh, Reza; Soheili, Zahra-Soheila; Deezagi, Abdolkhaleg; Pourpak, Zahra; Samiei, Shahram; Moin, Mostafa

2009-12-01

FcepsilonRI, The high affinity receptor for IgE plays a critical role in triggering the allergic reactions. It is responsible for inducing mast cell degranulation and deliberation of allergy mediators when it is aggregated by allergen and IgE complexes. FcepsilonRI on the mast cells consists of three subunits; alpha chain directly binds IgE, beta chain and dimmer of gamma chains together mediate intracellular signaling. Cross-linking of IgE-bound FcepsilonRI on the surface of mast cells and basophils by the multivalent antigen induces release of chemical mediators. The present in vitro study was designed to investigate the effect of synthetic FcepsilonRI-alpha siRNA on the antigen-induced activation of MC/9 cells. MC/9 cells which are murine mast cells were transfected by FcepsilonRI-alpha siRNA and negative control siRNA. After 6 h, anti-DNP (Dinitrophenyl) IgE was used for the cells sensitization. Then the cells were challenged with Dinitrophenyl-Human Serum Albumin (DNP-HSA) for mast cell degranulation induction before collection of supernatants. The amount of mRNA and protein expression was measured by Real Time PCR and western blot analysis, respectively. Determination of the expression rate of FcepsilonRI-alpha on cell surface was achieved by flow cytometry. ELISA and spectrophotometry methods were used subsequently for measuring the effects of FcepsilonRI-alpha siRNA on antigen-induced histamine and beta-hexosaminidase release. FcepsilonRI-alpha siRNA treated cells showed significant decrease in FcepsilonRI-alpha mRNA and protein expression in comparison to control cells. FcepsilonRI-mediated mast cell release of beta-hexosaminidase and histamine were also inhibited. In this study it was shown that FcepsilonRI-alpha siRNA could suppress FcepsilonRI-alpha expression and inhibited degranulation and histamine release in antigen-stimulated MC/9 cells. In conclusion, knock-down of FcepsilonRI-alpha by siRNA could be a promising method for inhibition of the mast

Development of a transmission alpha particle dosimetry technique using A549 cells and a Ra-223 source for targeted alpha therapy.

PubMed

Al Darwish, R; Staudacher, A H; Li, Y; Brown, M P; Bezak, E

2016-11-01

In targeted radionuclide therapy, regional tumors are targeted with radionuclides delivering therapeutic radiation doses. Targeted alpha therapy (TAT) is of particular interest due to its ability to deliver alpha particles of high linear energy transfer within the confines of the tumor. However, there is a lack of data related to alpha particle distribution in TAT. These data are required to more accurately estimate the absorbed dose on a cellular level. As a result, there is a need for a dosimeter that can estimate, or better yet determine the absorbed dose deposited by alpha particles in cells. In this study, as an initial step, the authors present a transmission dosimetry design for alpha particles using A549 lung carcinoma cells, an external alpha particle emitting source (radium 223; Ra-223) and a Timepix pixelated semiconductor detector. The dose delivery to the A549 lung carcinoma cell line from a Ra-223 source, considered to be an attractive radionuclide for alpha therapy, was investigated in the current work. A549 cells were either unirradiated (control) or irradiated for 12, 1, 2, or 3 h with alpha particles emitted from a Ra-223 source positioned below a monolayer of A549 cells. The Timepix detector was used to determine the number of transmitted alpha particles passing through the A549 cells and DNA double strand breaks (DSBs) in the form of γ-H2AX foci were examined by fluorescence microscopy. The number of transmitted alpha particles was correlated with the observed DNA DSBs and the delivered radiation dose was estimated. Additionally, the dose deposited was calculated using Monte Carlo code SRIM. Approximately 20% of alpha particles were transmitted and detected by Timepix. The frequency and number of γ-H2AX foci increased significantly following alpha particle irradiation as compared to unirradiated controls. The equivalent dose delivered to A549 cells was estimated to be approximately 0.66, 1.32, 2.53, and 3.96 Gy after 12, 1, 2, and 3 h

Interaction Between Yeasts and Zinc

NASA Astrophysics Data System (ADS)

Nicola, Raffaele De; Walker, Graeme

Zinc is an essential trace element in biological systems. For example, it acts as a cellular membrane stabiliser, plays a critical role in gene expression and genome modification and activates nearly 300 enzymes, including alcohol dehydrogenase. The present chapter will be focused on the influence of zinc on cell physiology of industrial yeast strains of Saccharomyces cerevisiae, with special regard to the uptake and subsequent utilisation of this metal. Zinc uptake by yeast is metabolism-dependent, with most of the available zinc translocated very quickly into the vacuole. At cell division, zinc is distributed from mother to daughter cells and this effectively lowers the individual cellular zinc concentration, which may become zinc depleted at the onset of the fermentation. Zinc influences yeast fermentative performance and examples will be provided relating to brewing and wine fermentations. Industrial yeasts are subjected to several stresses that may impair fermentation performance. Such stresses may also impact on yeast cell zinc homeostasis. This chapter will discuss the practical implications for the correct management of zinc bioavailability for yeast-based biotechnologies aimed at improving yeast growth, viability, fermentation performance and resistance to environmental stresses

Tumor necrosis factor-{alpha} enhanced fusions between oral squamous cell carcinoma cells and endothelial cells via VCAM-1/VLA-4 pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Kai; Zhu, Fei; Zhang, Han-zhong

Fusion between cancer cells and host cells, including endothelial cells, may strongly modulate the biological behavior of tumors. However, no one is sure about the driving factors and underlying mechanism involved in such fusion. We hypothesized in this study that inflammation, one of the main characteristics in tumor microenvironment, serves as a prominent catalyst for fusion events. Our results showed that oral cancer cells can fuse spontaneously with endothelial cells in co-culture and inflammatory cytokine tumor necrosis factor-{alpha} (TNF-{alpha}) increased fusion of human umbilical vein endothelium cells and oral cancer cells by up to 3-fold in vitro. Additionally, human oralmore » squamous cell carcinoma cell lines and 35 out of 50 (70%) oral squamous carcinoma specimens express VLA-4, an integrin, previously implicated in fusions between human peripheral blood CD34-positive cells and murine cardiomyocytes. Expression of VCAM-1, a ligand for VLA-4, was evident on vascular endothelium of oral squamous cell carcinoma. Moreover, immunocytochemistry and flow cytometry analysis revealed that expression of VCAM-1 increased obviously in TNF-{alpha}-stimulated endothelial cells. Anti-VLA-4 or anti-VCAM-1 treatment can decrease significantly cancer-endothelial adhesion and block such fusion. Collectively, our results suggested that TNF-{alpha} could enhance cancer-endothelial cell adhesion and fusion through VCAM-1/VLA-4 pathway. This study provides insights into regulatory mechanism of cancer-endothelial cell fusion, and has important implications for the development of novel therapeutic strategies for prevention of metastasis. -- Highlights: Black-Right-Pointing-Pointer Spontaneous oral cancer-endothelial cell fusion. Black-Right-Pointing-Pointer TNF-{alpha} enhanced cell fusions. Black-Right-Pointing-Pointer VCAM-1/VLA-4 expressed in oral cancer. Black-Right-Pointing-Pointer TNF-{alpha} increased expression of VCAM-1 on endothelial cells. Black

hZIP1 zinc uptake transporter down regulation and zinc depletion in prostate cancer

PubMed Central

Franklin, Renty B; Feng, Pei; Milon, B; Desouki, Mohamed M; Singh, Keshav K; Kajdacsy-Balla, André; Bagasra, Omar; Costello, Leslie C

2005-01-01

Background The genetic and molecular mechanisms responsible for and associated with the development and progression of prostate malignancy are largely unidentified. The peripheral zone is the major region of the human prostate gland where malignancy develops. The normal peripheral zone glandular epithelium has the unique function of accumulating high levels of zinc. In contrast, the ability to accumulate zinc is lost in the malignant cells. The lost ability of the neoplastic epithelial cells to accumulate zinc is a consistent factor in their development of malignancy. Recent studies identified ZIP1 (SLC39A1) as an important zinc transporter involved in zinc accumulation in prostate cells. Therefore, we investigated the possibility that down-regulation of hZIP1 gene expression might be involved in the inability of malignant prostate cells to accumulate zinc. To address this issue, the expression of hZIP1 and the depletion of zinc in malignant versus non-malignant prostate glands of prostate cancer tissue sections were analyzed. hZIP1 expression was also determined in malignant prostate cell lines. Results hZIP1 gene expression, ZIP1 transporter protein, and cellular zinc were prominent in normal peripheral zone glandular epithelium and in benign hyperplastic glands (also zinc accumulating glands). In contrast, hZIP1 gene expression and transporter protein were markedly down-regulated and zinc was depleted in adenocarcinomatous glands and in prostate intra-epithelial neoplastic foci (PIN). These changes occur early in malignancy and are sustained during its progression in the peripheral zone. hZIP1 is also expressed in the malignant cell lines LNCaP, PC-3, DU-145; and in the nonmalignant cell lines HPr-1 and BPH-1. Conclusion The studies clearly establish that hZIP1 gene expression is down regulated and zinc is depleted in adenocarcinomatous glands. The fact that all the malignant cell lines express hZIP1 indicates that the down-regulation in adenocarcinomatous

Zinc in innate and adaptive tumor immunity

PubMed Central

2010-01-01

Zinc is important. It is the second most abundant trace metal with 2-4 grams in humans. It is an essential trace element, critical for cell growth, development and differentiation, DNA synthesis, RNA transcription, cell division, and cell activation. Zinc deficiency has adverse consequences during embryogenesis and early childhood development, particularly on immune functioning. It is essential in members of all enzyme classes, including over 300 signaling molecules and transcription factors. Free zinc in immune and tumor cells is regulated by 14 distinct zinc importers (ZIP) and transporters (ZNT1-8). Zinc depletion induces cell death via apoptosis (or necrosis if apoptotic pathways are blocked) while sufficient zinc levels allows maintenance of autophagy. Cancer cells have upregulated zinc importers, and frequently increased zinc levels, which allow them to survive. Based on this novel synthesis, approaches which locally regulate zinc levels to promote survival of immune cells and/or induce tumor apoptosis are in order. PMID:21087493

Urocortin 3 Marks Mature Human Primary and Embryonic Stem Cell-Derived Pancreatic Alpha and Beta Cells

PubMed Central

van der Meulen, Talitha; Xie, Ruiyu; Kelly, Olivia G.; Vale, Wylie W.; Sander, Maike; Huising, Mark O.

2012-01-01

The peptide hormone Urocortin 3 (Ucn 3) is abundantly and exclusively expressed in mouse pancreatic beta cells where it regulates insulin secretion. Here we demonstrate that Ucn 3 first appears at embryonic day (E) 17.5 and, from approximately postnatal day (p) 7 and onwards throughout adult life, becomes a unifying and exclusive feature of mouse beta cells. These observations identify Ucn 3 as a potential beta cell maturation marker. To determine whether Ucn 3 is similarly restricted to beta cells in humans, we conducted comprehensive immunohistochemistry and gene expression experiments on macaque and human pancreas and sorted primary human islet cells. This revealed that Ucn 3 is not restricted to the beta cell lineage in primates, but is also expressed in alpha cells. To substantiate these findings, we analyzed human embryonic stem cell (hESC)-derived pancreatic endoderm that differentiates into mature endocrine cells upon engraftment in mice. Ucn 3 expression in hESC-derived grafts increased robustly upon differentiation into mature endocrine cells and localized to both alpha and beta cells. Collectively, these observations confirm that Ucn 3 is expressed in adult beta cells in both mouse and human and appears late in beta cell differentiation. Expression of Pdx1, Nkx6.1 and PC1/3 in hESC-derived Ucn 3+ beta cells supports this. However, the expression of Ucn 3 in primary and hESC-derived alpha cells demonstrates that human Ucn 3 is not exclusive to the beta cell lineage but is a general marker for both the alpha and beta cell lineages. Ucn 3+ hESC-derived alpha cells do not express Nkx6.1, Pdx1 or PC1/3 in agreement with the presence of a separate population of Ucn 3+ alpha cells. Our study highlights important species differences in Ucn 3 expression, which have implications for its utility as a marker to identify mature beta cells in (re)programming strategies. PMID:23251699

Effect of zinc gluconate, sage oil on inflammatory patterns and hyperglycemia in zinc deficient diabetic rats.

PubMed

Elseweidy, Mohamed M; Ali, Abdel-Moniem A; Elabidine, Nabila Zein; Mursey, Nada M

2017-11-01

The relationship between zinc homeostasis and pancreatic function had been established. In this study we aimed firstly to configure the inflammatory pattern and hyperglycemia in zinc deficient diabetic rats. Secondly to illustrate the effect of two selected agents namely Zinc gluconate and sage oil (Salvia Officinalis, family Lamiaceae). Rats were fed on Zinc deficient diet, deionized water for 28days along with Zinc level check up at intervals to achieve zinc deficient state then rats were rendered diabetic through receiving one dose of alloxan monohydrate (120mg/kg) body weight, classified later into 5 subgroups. Treatment with sage oil (0.042mg/kg IP) and Zinc gluconate orally (150mg/kg) body weight daily for 8 weeks significantly reduced serum glucose, C-reactive protein (CRP), Tumor necrosis factor alpha (TNF- α), interleukins-6 1 β, inflammatory8 (IFN ȣ), pancreatic 1L1-β along with an increase in serum Zinc and pancreatic Zinc transporter 8 (ZNT8). Histopathological results of pancreatic tissues showed a good correlation with the biochemical findings. Both sage oil and zinc gluconate induced an improvement in the glycemic and inflammatory states. This may be of value like the therapeutic agent for diabetes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

TNF-{alpha} promotes cell survival through stimulation of K{sup +} channel and NF{kappa}B activity in corneal epithelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang Ling; Reinach, Peter; Lu, Luo

2005-11-15

Tumor necrosis factor (TNF-{alpha}) in various cell types induces either cell death or mitogenesis through different signaling pathways. In the present study, we determined in human corneal epithelial cells how TNF-{alpha} also promotes cell survival. Human corneal epithelial (HCE) cells were cultured in DMEM/F-12 medium containing 10% FBS. TNF-{alpha} stimulation induced activation of a voltage-gated K{sup +} channel detected by measuring single channel activity using patch clamp techniques. The effect of TNF-{alpha} on downstream events included NF{kappa}B nuclear translocation and increases in DNA binding activities, but did not elicit ERK, JNK, or p38 limb signaling activation. TNF-{alpha} induced increases inmore » p21 expression resulting in partial cell cycle attenuation in the G{sub 1} phase. Cell cycle progression was also mapped by flow cytometer analysis. Blockade of TNF-{alpha}-induced K{sup +} channel activity effectively prevented NF{kappa}B nuclear translocation and binding to DNA, diminishing the cell-survival protective effect of TNF-{alpha}. In conclusion, TNF-{alpha} promotes survival of HCE cells through sequential stimulation of K{sup +} channel and NF{kappa}B activities. This response to TNF-{alpha} is dependent on stimulating K{sup +} channel activity because following suppression of K{sup +} channel activity TNF-{alpha} failed to activate NF{kappa}B nuclear translocation and binding to nuclear DNA.« less

Hepatocyte nuclear factor-4alpha induces transdifferentiation of hematopoietic cells into hepatocytes.

PubMed

Khurana, Satish; Jaiswal, Amit K; Mukhopadhyay, Asok

2010-02-12

Hematopoietic stem cells can directly transdifferentiate into hepatocytes because of cellular plasticity, but the molecular basis of transdifferentiation is not known. Here, we show the molecular basis using lineage-depleted oncostatin M receptor beta-expressing (Lin(-)OSMRbeta(+)) mouse bone marrow cells in a hepatic differentiation culture system. Differentiation of the cells was marked by the expression of albumin. Hepatocyte nuclear factor (HNF)-4alpha was expressed and translocated into the nuclei of the differentiating cells. Suppression of its activation in OSM-neutralized culture medium inhibited cellular differentiation. Ectopic expression of full-length HNF4alpha in 32D myeloid cells resulted in decreased myeloid colony-forming potential and increased expression of hepatocyte-specific genes and proteins. Nevertheless, the neohepatocytes produced in culture expressed active P450 enzyme. The obligatory role of HNF4alpha in hepatic differentiation was confirmed by transfecting Lin(-)OSMRbeta(+) cells with dominant negative HNF4alpha in the differentiation culture because its expression inhibited the transcription of the albumin and tyrosine aminotransferase genes. The loss and gain of functional activities strongly suggested that HNF4alpha plays a central role in the transdifferentiation process. For the first time, this report demonstrates the mechanism of transdifferentiation of hematopoietic cells into hepatocytes, in which HNF4alpha serves as a molecular switch.

Recovery of Metal Values from Spent Zinc-Carbon Dry Cell Batteries

NASA Astrophysics Data System (ADS)

Khan, Majharul Haque; Gulshan, Fahmida; Kurny, A. S. W.

2013-04-01

Spent zinc-carbon dry cell batteries were characterized in the process of recovery of metal values. Zinc, manganese and steel were the major metallic materials constituting 63 % of the weight of spent batteries. Different components of the spent batteries were separately processed to extract the metallic values. A maximum of 92 % of total amount of zinc contained in the anodes could be extracted with a purity of over 99.0 % from the anodes by heating at 600 °C for 10 min in presence of 12 % NH4Cl flux. Spent electrolyte paste containing manganese and zinc as major metallic elements, was leached in sulfuric acid solution in presence of hydrogen peroxide as a reducing agent. The optimum condition for leaching was found to be concentration of sulfuric acid: 2.5 M, concentration of hydrogen peroxide: 10 %, temperature: 60 °C, stirring speed: 600 rpm and solid/liquid ratio 1:12. A maximum of 88 % manganese contained in the paste could be dissolved within 27 min of leaching under the optimized conditions. Dissolution of zinc under the same conditions was 97 %. A maximum of 69.89 % of manganese and 83.29 % of zinc contained in the leach liquor could be precipitated in the form of manganese carbonate and zinc oxalate.

Human Beta Cells Produce and Release Serotonin to Inhibit Glucagon Secretion from Alpha Cells.

PubMed

Almaça, Joana; Molina, Judith; Menegaz, Danusa; Pronin, Alexey N; Tamayo, Alejandro; Slepak, Vladlen; Berggren, Per-Olof; Caicedo, Alejandro

2016-12-20

In the pancreatic islet, serotonin is an autocrine signal increasing beta cell mass during metabolic challenges such as those associated with pregnancy or high-fat diet. It is still unclear whether serotonin is relevant for regular islet physiology and hormone secretion. Here, we show that human beta cells produce and secrete serotonin when stimulated with increases in glucose concentration. Serotonin secretion from beta cells decreases cyclic AMP (cAMP) levels in neighboring alpha cells via 5-HT 1F receptors and inhibits glucagon secretion. Without serotonergic input, alpha cells lose their ability to regulate glucagon secretion in response to changes in glucose concentration, suggesting that diminished serotonergic control of alpha cells can cause glucose blindness and the uncontrolled glucagon secretion associated with diabetes. Supporting this model, pharmacological activation of 5-HT 1F receptors reduces glucagon secretion and has hypoglycemic effects in diabetic mice. Thus, modulation of serotonin signaling in the islet represents a drug intervention opportunity. Published by Elsevier Inc.

Alpha-, gamma- and delta-tocopherols reduce inflammatory angiogenesis in human microvascular endothelial cells.

PubMed

Wells, Shannon R; Jennings, Merilyn H; Rome, Courtney; Hadjivassiliou, Vicky; Papas, Konstantinos A; Alexander, Jonathon S

2010-07-01

Vitamin E, a micronutrient (comprising alpha-, beta-, gamma- and delta-tocopherols, alpha-, beta-, gamma- and delta-tocotrienols), has documented antioxidant and non-antioxidant effects, some of which inhibit inflammation and angiogenesis. We compared the abilities of alpha-, gamma- and delta-tocopherols to regulate human blood cytotoxicity (BEC) and lymphatic endothelial cytotoxicity (LEC), proliferation, invasiveness, permeability, capillary formation and suppression of TNF-alpha-induced VCAM-1 as in vitro models of inflammatory angiogenesis. alpha-, gamma- and delta-tocopherols were not toxic to either cell type up to 40 microM. In BEC, confluent cell density was decreased by all concentrations of delta- and gamma-tocopherol (10-40 microM) but not by alpha-tocopherol. LEC showed no change in cell density in response to tocopherols. delta-Tocopherol (40 microM), but not other isomers, decreased BEC invasiveness. In LEC, all doses of gamma-tocopherol, as well as the highest dose of alpha-tocopherol (40 microM), decreased cell invasiveness. delta-Tocopherol had no effect on LEC invasiveness at any molarity. delta-Tocopherol dose dependently increased cell permeability at 48 h in BEC and LEC; alpha- and gamma-tocopherols showed slight effects. Capillary tube formation was decreased by high dose (40 microM) concentrations of alpha-, gamma- and delta-tocopherol, but showed no effects with smaller doses (10-20 microM) in BEC. gamma-Tocopherol (10-20 microM) and alpha-tocopherol (10 microM), but not delta-tocopherol, increased LEC capillary tube formation. Lastly, in BEC, alpha-, gamma- and delta-tocopherol each dose-dependently reduced TNF-alpha-induced expression of VCAM-1. In LEC, there was no significant change to TNF-alpha-induced VCAM-1 expression with any concentration of alpha-, gamma- or delta-tocopherol. These data demonstrate that physiological levels (0-40 microM) of alpha-, gamma- and delta-tocopherols are nontoxic and dietary tocopherols, especially delta

Induction of autocrine factor inhibiting cell motility from murine B16-BL6 melanoma cells by alpha-melanocyte stimulating hormone.

PubMed

Murata, J; Ayukawa, K; Ogasawara, M; Watanabe, H; Saiki, I

1999-03-15

We have previously reported that neuropeptide alpha-melanocyte stimulating hormone (alpha-MSH) successfully inhibited Matrigel invasion and haptotactic migration of B16-BL6 melanoma cells towards both fibronectin and laminin without affecting their growth. In the present study, we investigated the inhibitory mechanism of tumor cell motility by alpha-MSH. Alpha-MSH significantly blocked the autocrine motility factor (AMF)-enhanced cell motility. However, alpha-MSH did neither prevent the secretion of AMF from B16-BL6 cells nor alter the expression level of AMF receptor (gp78). On the other hand, alpha-MSH induced the secretion of the motility inhibitory factor(s) from B16-BL6 cells in a concentration- and time-dependent manner. The induction of the motility inhibitor(s) was proportional to increasing levels of intracellular cAMP induced by alpha-MSH as well as forskolin, and the activity was abolished by an adenylate cyclase inhibitor, 2',5'-dideoxyadenosine (DDA). The motility-inhibiting activity in conditioned medium (CM) from alpha-MSH-treated B16-BL6 cells was found to have a m.w. below 3 kDa after fractionation. This activity was abolished by boiling but insensitive to trypsin. The treatment of tumor cells with cycloheximide reduced the activity in alpha-MSH-stimulated CM. Our results suggest that alpha-MSH inhibited the motility of B16-BL6 cells through induction of autocrine factor(s).

Cinnamaldehyde inhibits the tumor necrosis factor-{alpha}-induced expression of cell adhesion molecules in endothelial cells by suppressing NF-{kappa}B activation: Effects upon I{kappa}B and Nrf2

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liao, B.-C.; Hsieh, C.-W.; Liu, Y.-C.

The production of adhesion molecules and subsequent attachment of leukocytes to endothelial cells (ECs) are critical early events in atherogenesis. These adhesion molecules thus play an important role in the development of this disease. Recent studies have highlighted the chemoprotective and anti-inflammatory effects of cinnamaldehyde, a Cinnamomum cassia Presl-specific diterpene. In our current study, we have examined the effects of both cinnamaldehyde and extracts of C. cassia on cytokine-induced monocyte/human endothelial cell interactions. We find that these compounds inhibit the adhesion of TNF{alpha}-induced monocytes to endothelial cells and suppress the expression of the cell adhesion molecules, VCAM-1 and ICAM-1, atmore » the transcriptional level. Moreover, in TNF{alpha}-treated ECs, the principal downstream signal of VCAM-1 and ICAM-1, NF-{kappa}B, was also found to be abolished in a time-dependent manner. Interestingly, cinnamaldehyde exerts its anti-inflammatory effects by blocking the degradation of the inhibitory protein I{kappa}B-{alpha}, but only in short term pretreatments, whereas it does so via the induction of Nrf2-related genes, including heme-oxygenase-1 (HO-1), over long term pretreatments. Treating ECs with zinc protoporphyrin, a HO-1 inhibitor, partially blocks the anti-inflammatory effects of cinnamaldehyde. Elevated HO-1 protein levels were associated with the inhibition of TNF{alpha}-induced ICAM-1 expression. In addition to HO-1, we also found that cinnamaldehyde can upregulate Nrf2 in nuclear extracts, and can increase ARE-luciferase activity and upregulate thioredoxin reductase-1, another Nrf2-related gene. Moreover, cinnamaldehyde exposure rapidly reduces the cellular GSH levels in ECs over short term treatments but increases these levels after 9 h exposure. Hence, our present findings indicate that cinnamaldehyde suppresses TNF-induced singling pathways via two distinct mechanisms that are activated by different pretreatment

Bioactive interleukin-1alpha is cytolytically released from Candida albicans-infected oral epithelial cells.

PubMed

Dongari-Bagtzoglou, A; Kashleva, H; Villar, C Cunha

2004-12-01

Oral epithelial cells are primary targets of Candida albicans in the oropharynx and may regulate the inflammatory host response to this pathogen. This investigation studied the mechanisms underlying interleukin-1alpha (IL-1alpha) release by oral epithelial cells and the role of IL-1alpha in regulating the mucosal inflammatory response to C. albicans. Infected oral epithelial cells released processed IL-1alpha protein in culture supernatants. The IL-1alpha generated was stored intracellularly and was released upon cell lysis. This was further supported by the fact that different C. albicans strains induced variable IL-1alpha release, depending on their cytolytic activity. IL-1alpha from C. albicans-infected oral epithelial cells upregulated proinflammatory cytokine secretion (IL-8 and GM-CSF) in uninfected oral epithelial or stromal cells. Our studies suggest that production of IL-1alpha, IL-8 and GM-CSF may take place in the oral mucosa in response to lytic infection of epithelial cells with C. albicans. This process can act as an early innate immune surveillance system and may contribute to the clinicopathologic signs of infection in the oral mucosa.

Long life, rechargeable nickel-zinc battery

NASA Technical Reports Server (NTRS)

Luksha, E.

1974-01-01

A production version of the inorganic separator was evaluated for improving the life of the nickel-zinc system. Nickel-zinc cells (7-10 Ah capacities) of different electrode separator configurations were constructed and tested. The nickel-zinc cells using the inorganic separator encasing the zinc electrode, the nickel electrode, or both electrodes had shorter lives than cells using Visking and cellophane separation. Cells with the inorganic separation all fell below 70% of their theoretical capacity within 30 cycles, but the cells constructed with organic separation required 80 cycles. Failure of the cells using the ceramic separator was irreversible capacity degradation due to zinc loss through cracks developed in the inorganic separator. Zinc loss through the separator was minimized with the use of combinations of the inorganic separator with Visking and cellophane. Cells using the combined separation operated 130 duty cycles before degrading to 70% of their theoretical capacity.

Zinc and Autophagy

PubMed Central

Liuzzi, Juan P.; Guo, Liang; Yoo, Changwon; Stewart, Tiffanie S

2014-01-01

Autophagy is a highly conserved degradative process through which cells overcome stressful conditions. Inasmuch as faulty autophagy has been associated with aging, neuronal degeneration disorders, diabetes, and fatty liver, autophagy is regarded as a potential therapeutic target. This review summarizes the present state of knowledge concerning the role of zinc in the regulation of autophagy, the role of autophagy in zinc metabolism, and the potential role of autophagy as a mediator of the protective effects of zinc. Data from in vitro studies consistently support the notion that zinc is critical for early and late autophagy. Studies have shown inhibition of early and late autophagy in cells cultured in medium treated with zinc chelators. Conversely, excess zinc added to the medium has shown to potentiate the stimulation of autophagy by tamoxifen, H2O2, ethanol and dopamine. The potential role of autophagy in zinc homeostasis has just begun to be investigated.Increasing evidence indicates that autophagy dysregulation causes significant changes in cellular zinc homeostasis. Autophagy may mediate the protective effect of zinc against lipid accumulation, apoptosis and inflammation by promoting degradation of lipid droplets, inflammasomes, p62/SQSTM1 and damaged mitochondria.Studies with humans and animal models are necessary to determine whether autophagy is influenced by zinc intake. PMID:25012760

The p53 inhibitor, pifithrin-{alpha}, suppresses self-renewal of embryonic stem cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdelalim, Essam Mohamed, E-mail: essam_abdelalim@yahoo.com; Department of Cytology and Histology, Faculty of Veterinary Medicine, Suez Canal University, Ismailia 41522; Tooyama, Ikuo

2012-04-13

Highlights: Black-Right-Pointing-Pointer We determine the role of p53 in ES cells under unstressful conditions. Black-Right-Pointing-Pointer PFT-{alpha} suppresses ES cell proliferation. Black-Right-Pointing-Pointer PFT-{alpha} induces ES cell cycle arrest. Black-Right-Pointing-Pointer PFT-{alpha} downregulates Nanog and cyclin D1. -- Abstract: Recent studies have reported the role of p53 in suppressing the pluripotency of embryonic stem (ES) cells after DNA damage and blocking the reprogramming of somatic cells into induced pluripotent stem (iPS) cells. However, to date no evidence has been presented to support the function of p53 in unstressed ES cells. In this study, we investigated the effect of pifithrin (PFT)-{alpha}, an inhibitor ofmore » p53-dependent transcriptional activation, on self-renewal of ES cells. Our results revealed that treatment of ES cells with PFT-{alpha} resulted in the inhibition of ES cell propagation in a dose-dependent manner, as indicated by a marked reduction in the cell number and colony size. Also, PFT-{alpha} caused a cell cycle arrest and significant reduction in DNA synthesis. In addition, inhibition of p53 activity reduced the expression levels of cyclin D1 and Nanog. These findings indicate that p53 pathway in ES cells rather than acting as an inactive gene, is required for ES cell proliferation and self-renewal under unstressful conditions.« less

Roles of zinc and metallothionein-3 in oxidative stress-induced lysosomal dysfunction, cell death, and autophagy in neurons and astrocytes.

PubMed

Lee, Sook-Jeong; Koh, Jae-Young

2010-10-26

Zinc dyshomeostasis has been recognized as an important mechanism for cell death in acute brain injury. An increase in the level of free or histochemically reactive zinc in astrocytes and neurons is considered one of the major causes of death of these cells in ischemia and trauma. Although zinc dyshomeostasis can lead to cell death via diverse routes, the major pathway appears to involve oxidative stress.Recently, we found that a rise of zinc in autophagic vacuoles, including autolysosomes, is a prerequisite for lysosomal membrane permeabilization and cell death in cultured brain cells exposed to oxidative stress conditions. The source of zinc in this process is likely redox-sensitive zinc-binding proteins such as metallothioneins, which release zinc under oxidative conditions. Of the metallothioneins, metallothionein-3 is especially enriched in the central nervous system, but its physiologic role in this tissue is not well established. Like other metallothioneins, metallothionein-3 may function as metal detoxicant, but is also known to inhibit neurite outgrowth and, sometimes, promote neuronal death, likely by serving as a source of toxic zinc release. In addition, metallothionein-3 regulates lysosomal functions. In the absence of metallothionein-3, there are changes in lysosome-associated membrane protein-1 and -2, and reductions in certain lysosomal enzymes that result in decreased autophagic flux. This may have dual effects on cell survival. In acute oxidative injury, zinc dyshomeostasis and lysosomal membrane permeabilization are diminished in metallothionein-3 null cells, resulting in less cell death. But over the longer term, diminished lysosomal function may lead to the accumulation of abnormal proteins and cause cytotoxicity.The roles of zinc and metallothionein-3 in autophagy and/or lysosomal function have just begun to be investigated. In light of evidence that autophagy and lysosomes may play significant roles in the pathogenesis of various neurological

Transforming growth factor-{alpha} enhances corneal epithelial cell migration by promoting EGFR recycling.

PubMed

McClintock, Jennifer L; Ceresa, Brian P

2010-07-01

PURPOSE. The goal of this study was to determine the molecular mechanism by which transforming growth factor-alpha (TGF-alpha) is a more potent activator of epidermal growth factor receptor (EGFR)-mediated corneal wound healing than epidermal growth factor (EGF). METHODS. Telomerase immortalized human corneal epithelial (hTCEpi) cells and primary human corneal epithelial cells were tested for their ability to migrate in response to EGF and TGF-alpha. In parallel, the endocytic trafficking of the EGFR in response to these same ligands was examined using indirect immunofluorescence, immunoblots, and radioligand binding. RESULTS. TGF-alpha, compared with EGF, is a more potent activator of corneal epithelial cell migration. Although both TGF-alpha and EGF were able to induce EGFR internalization and phosphorylation, only those receptors that were stimulated with EGF progressed to lysosomal degradation. EGFRs stimulated with TGF-alpha recycled back to the plasma membrane, where they could be reactivated with ligand. CONCLUSIONS. This study reveals that EGFR-mediated cell migration is limited by ligand-stimulated downregulation of the EGFR. This limitation can be overcome by treating cells with TGF-alpha because TGF-alpha stimulates EGFR endocytosis, but not degradation. After internalization of the TGF-alpha/EGFR complex, EGFR recycles back to the plasma membrane, where it can be restimulated. This sequence of events provides the receptor multiple opportunities for stimulation. Thus, stimulation with TGF-alpha prolongs EGFR signaling compared with EGF.

Serum thymulin in human zinc deficiency.

PubMed Central

Prasad, A S; Meftah, S; Abdallah, J; Kaplan, J; Brewer, G J; Bach, J F; Dardenne, M

1988-01-01

The activity of thymulin (a thymic hormone) is dependent on the presence of zinc in the molecule. We assayed serum thymulin activity in three models of mildly zinc-deficient (ZD) human subjects before and after zinc supplementation: (a) two human volunteers in whom a specific and mild zinc deficiency was induced by dietary means; (b) six mildly ZD adult sickle cell anemia (SCA) subjects; and (c) six mildly ZD adult non-SCA subjects. Their plasma zinc levels were normal and they showed no overt clinical manifestations of zinc deficiency. The diagnosis of mild zinc deficiency was based on the assay of zinc in lymphocytes, granulocytes, and platelets. Serum thymulin activity was decreased as a result of mild zinc deficiency and was corrected by in vivo and in vitro zinc supplementation, suggesting that this parameter was a sensitive indicator of zinc deficiency in humans. An increase in T101-, sIg-cells, decrease in T4+/T8+ ratio, and decreased IL 2 activity were observed in the experimental human model during the zinc depletion phase, all of which were corrected after repletion with zinc. Similar changes in lymphocyte subpopulation, correctable with zinc supplementation, were also observed in mildly ZD SCA subjects. Inasmuch as thymulin is known to induce intra- and extrathymic T cell differentiation, our studies provide a possible mechanism for the role of zinc on T cell functions. Images PMID:3262625

Hydroponics gel as a new electrolyte gelling agent for alkaline zinc-air cells

NASA Astrophysics Data System (ADS)

Othman, R.; Basirun, W. J.; Yahaya, A. H.; Arof, A. K.

The viability of hydroponics gel as a new alkaline electrolyte gelling agent is investigated. Zinc-air cells are fabricated employing 12 wt.% KOH electrolyte immobilised with hydroponics gel. The cells are discharged at constant currents of 5, 50 and 100 mA. XRD and SEM analysis of the anode plates after discharge show that the failure mode is due to the formation of zinc oxide insulating layers and not due to any side reactions between the gel and the plate or the electrolyte.

Cardiac stem cell genetic engineering using the alphaMHC promoter.

PubMed

Bailey, Brandi; Izarra, Alberto; Alvarez, Roberto; Fischer, Kimberlee M; Cottage, Christopher T; Quijada, Pearl; Díez-Juan, Antonio; Sussman, Mark A

2009-11-01

Cardiac stem cells (CSCs) show potential as a cellular therapeutic approach to blunt tissue damage and facilitate reparative and regenerative processes after myocardial infarction. Despite multiple published reports of improvement, functional benefits remain modest using normal stem cells delivered by adoptive transfer into damaged myocardium. The goal of this study is to enhance survival and proliferation of CSCs that have undergone lineage commitment in early phases as evidenced by expression of proteins driven by the alpha-myosin heavy chain (alphaMHC) promoter. The early increased expression of survival kinases augments expansion of the cardiogenic CSC pool and subsequent daughter progeny. Normal CSCs engineered with fluorescent reporter protein constructs under control of the alphaMHC promoter show transgene protein expression, confirming activity of the promoter in CSCs. Cultured CSCs from both nontransgenic and cardiac-specific transgenic mice expressing survival kinases driven by the alphaMHC promoter were analyzed to characterize transgene expression following treatments to promote differentiation in culture. Therapeutic genes controlled by the alphaMHC promoter can be engineered into and expressed in CSCs and cardiomyocyte progeny with the goal of improving the efficacy of cardiac stem cell therapy.

Multiple alpha subunits of integrin are involved in cell-mediated responses of the Manduca immune system.

PubMed

Zhuang, Shufei; Kelo, Lisha; Nardi, James B; Kanost, Michael R

2008-01-01

The cell-mediated responses of the insect innate immune system-phagocytosis, nodulation, encapsulation-involve multiple cell adhesion molecules of hemocyte surfaces. A hemocyte-specific (HS) integrin and a member of the immunoglobulin (Ig) superfamily (neuroglian) are involved in the encapsulation response of hemocytes in Manduca sexta. In addition, two new integrin alpha (alpha) subunits have been found on these hemocytes. The alpha2 subunit is mainly expressed in epidermis and Malphigian tubules, whereas the alpha3 subunit is primarily expressed on hemocytes and fat body cells. Of the three known alpha subunits, the alpha1 subunit found in HS integrin is the predominant subunit of hemocytes. Cell adhesion assays indicate that alpha2 belongs to the integrin family with RGD-binding motifs, confirming the phylogenetic analysis of alpha subunits based on the amino-acid sequence alignment of different alpha subunits. Double-stranded RNAs (dsRNAs) targeting each of these three integrin alpha subunits not only specifically decreased transcript expression of each alpha subunit in hemocytes, but also abolished the cell-mediated encapsulation response of hemocytes to foreign surfaces. The individual alpha subunits of M. sexta integrins, like their integrin counterparts in mammalian immune systems, have critical, individual roles in cell-substrate and cell-cell interactions during immune responses.

Tumor cell alpha-N-acetylgalactosaminidase activity and its involvement in GcMAF-related macrophage activation.

PubMed

Mohamad, Saharuddin B; Nagasawa, Hideko; Uto, Yoshihiro; Hori, Hitoshi

2002-05-01

Alpha-N-acetyl galactosaminidase (alpha-NaGalase) has been reported to accumulate in serum of cancer patients and be responsible for deglycosylation of Gc protein, which is a precursor of GcMAF-mediated macrophage activation cascade, finally leading to immunosuppression in advanced cancer patients. We studied the biochemical characterization of alpha-NaGalase from several human tumor cell lines. We also examined its effect on the potency of GcMAF to activate mouse peritoneal macrophage to produce superoxide in GcMAF-mediated macrophage activation cascade. The specific activity of alpha-NaGalases from human colon tumor cell line HCT116, human hepatoma cell line HepG2, and normal human liver cells (Chang liver cell line) were evaluated using two types of substrates; GalNAc-alpha-PNP (exo-type substrate) and Gal-beta-GalNAc-alpha-PNP (endo-type substrate). Tumor-derived alpha-NaGalase having higher activity than normal alpha-NaGalase, had higher substrate specificity to the exo-type substrate than to the endo-type substrate, and still maintained its activity at pH 7. GcMAF enhance superoxide production in mouse macrophage, and pre-treatment of GcMAF with tumor cell lysate reduce the activity. We conclude that tumor-derived alpha-NaGalase is different in biochemical characterization compared to normal alpha-NaGalase from normal Chang liver cells. In addition, tumor cell-derived alpha-NaGalase decreases the potency of GcMAF on macrophage activation.

Tumor necrosis factor-alpha stimulates the production of squamous cell carcinoma antigen in normal squamous cells.

PubMed

Numa, F; Takeda, O; Nakata, M; Nawata, S; Tsunaga, N; Hirabayashi, K; Suminami, Y; Kato, H; Hamanaka, S

1996-01-01

Squamous cell carcinoma (SCC) antigen, a tumor marker of squamous cell carcinoma, is also increased in several nonmalignant skin lesions, e.g. pemphigus. The aim of the present investigation was to determine if tumor necrosis factor-alpha (TNF-alpha), one of the important environmental factors, stimulated the production of SCC antigen in the normal squamous cells. The exposure of normal human epidermal keratinocytes to TNF-alpha (100 IU/ml) for 72 h greatly increased the SCC antigen production. The stimulatory effect of TNF-alpha (1,000 IU/ml) on the production of SCC antigen was also observed in the normal squamous epithelium tissue. These results would be helpful for understanding the increase of SCC antigen in several nonmalignant skin disorders.

The effects of zinc status on early growth in infants with sickle cell disease

USDA-ARS?s Scientific Manuscript database

Growth failure, maturational delay, and alterations in body composition occur in older children and adults with Sickle Cell Disease (SCD). Poor nutritional status, specifically zinc deficiency, has been widely implicated, although infants with SCD have not been studied. We determined zinc status in ...

A role for the Drosophila zinc transporter Zip88E in protecting against dietary zinc toxicity.

PubMed

Richards, Christopher D; Warr, Coral G; Burke, Richard

2017-01-01

Zinc absorption in animals is thought to be regulated in a local, cell autonomous manner with intestinal cells responding to dietary zinc content. The Drosophila zinc transporter Zip88E shows strong sequence similarity to Zips 42C.1, 42C.2 and 89B as well as mammalian Zips 1, 2 and 3, suggesting that it may act in concert with the apically-localised Drosophila zinc uptake transporters to facilitate dietary zinc absorption by importing ions into the midgut enterocytes. However, the functional characterisation of Zip88E presented here indicates that Zip88E may instead play a role in detecting and responding to zinc toxicity. Larvae homozygous for a null Zip88E allele are viable yet display heightened sensitivity to elevated levels of dietary zinc. This decreased zinc tolerance is accompanied by an overall decrease in Metallothionein B transcription throughout the larval midgut. A Zip88E reporter gene is expressed only in the salivary glands, a handful of enteroendocrine cells at the boundary between the anterior and middle midgut regions, and in two parallel strips of sensory cell projections connecting to the larval ventral ganglion. Zip88E expression solely in this restricted subset of cells is sufficient to rescue the Zip88E mutant phenotype. Together, our data suggest that Zip88E may be functioning in a small subset of cells to detect excessive zinc levels and induce a systemic response to reduce dietary zinc absorption and hence protect against toxicity.

Relative biological effectiveness (RBE) of alpha radiation in cultured porcine aortic endothelial cells.

PubMed

Thomas, Patricia; Tracy, Bliss; Ping, Tilly; Baweja, Anar; Wickstrom, Mark; Sidhu, Narinder; Hiebert, Linda

2007-03-01

Northern peoples can receive elevated radiation doses (1- 10 mSv/y) from transfer of polonium-210 (210Po) through the lichen-caribou-human food chain. Ingested 210Po is primarily blood-borne and thus many of its short range alpha particles irradiate the endothelial cells lining the blood vessels. The relative biological effectiveness (RBE) of alpha particles vs. x-rays was examined in porcine aortic endothelial cells as a surrogate for understanding what might happen to human endothelial cells in northern populations consuming traditional foods. Cultured porcine aortic endothelial cells were exposed to x-ray and 210Po alpha particle radiation. Alpha irradiation was applied to the cell cultures internally via the culture medium and externally, using thin-bottomed culture dishes. The results given here are based on the external irradiation method, which was found to be more reliable. Dose-response curves were compared for four lethal endpoints (cell viability, live cell fraction, release of lactate dehydrogenase [LDH] and clonogenic survival) to determine the relative biological effectiveness (RBE) of alpha radiation. The alpha RBE for porcine cells varied from 1.6-21, depending on the endpoint: 21.2+/-4.5 for cell viability, 12.9+/-2.7 for decrease in live cell number, 5.3+/-0.4 for LDH release to the medium but only 1.6 +/-0.1 for clonogenic survival. The low RBE of 1.6 was due to x-ray hypersensitivity of endothelial cells at low doses.

Zinc

USDA-ARS?s Scientific Manuscript database

Zinc was recognized as an essential trace metal for humans during the studies of Iranian adolescent dwarfs in the early 1960s. Zinc metal existing as Zn2+ is a strong electron acceptor in biological systems without risks of oxidant damage to cells. Zn2+ functions in the structure of proteins and is ...

Prostaglandin production by melanocytic cells and the effect of alpha-melanocyte stimulating hormone.

PubMed

Nicolaou, Anna; Estdale, Sian E; Tsatmali, Marina; Herrero, Daniel Pascual; Thody, Anthony J

2004-07-16

Prostaglandins are potent mediators of the inflammatory response and are also involved in cancer development. In this study, we show that human melanocytes and FM55 melanoma cells express cyclooxygenase-1 and -2 (COX-1 and -2) and thus have the capability to produce prostaglandins. The FM55 cells produced predominantly PGE2 and PGF2alpha, whereas the HaCaT keratinocyte cell line produced mainly PGE2. The anti-inflammatory peptide, alpha-melanocyte stimulating hormone (alpha-MSH), reduced prostaglandin production in FM55 and HaCaT cells and reversed the effect of the pro-inflammatory cytokine TNF-alpha in the former. These results indicate that melanocytes produce prostaglandins and that alpha-MSH, by inhibiting this response, may play an important role in regulating inflammatory responses in the skin.

Lens epithelial cells derived from alphaB-crystallin knockout mice demonstrate hyperproliferation and genomic instability.

PubMed

Andley, U P; Song, Z; Wawrousek, E F; Brady, J P; Bassnett, S; Fleming, T P

2001-01-01

alphaB-crystallin is a member of the small heat shock protein family and can act as a molecular chaperone preventing the in vitro aggregation of other proteins denatured by heat or other stress conditions. Expression of alphaB-crystallin increases in cells exposed to stress and enhanced in tumors of neuroectodermal origin and in many neurodegenerative diseases. In the present study, we examined the properties of lens epithelial cells derived from mice in which the alphaB-crystallin gene had been knocked out. Primary rodent cells immortalize spontaneously in tissue culture with a frequency of 10(-5) to 10(-6). Primary lens epithelial cells derived from alphaB-crystallin-/- mice produced hyperproliferative clones at a frequency of 7.6 x 10(-2), four orders of magnitude greater than predicted by spontaneous immortalization (1). Hyperproliferative alphaB-crystallin-/- cells were shown to be truly immortal since they have been passaged for more than 100 population doublings without any diminution in growth potential. In striking contrast to the wild-type cells, which were diploid, the alphaB-crystallin-/- cultures had a high proportion of tetraploid and higher ploidy cells, indicating that the loss of alphaB-crystallin is associated with an increase in genomic instability. Further evidence of genomic instability of alphaB-crystallin-/- cells was observed when primary cultures were infected with Ad12-SV40 hybrid virus. In striking contrast to wild-type cells, alphaB-crystallin-/- cells expressing SV40 T antigen exhibited a widespread cytocidal response 2 to 3 days after attaining confluence, indicating that SV40 T antigen enhanced the intrinsic genomic instability of alphaB-crystallin-/- lens epithelial cells. These observations suggest that the widely distributed molecular chaperone alphaB-crystallin may play an important nuclear role in maintaining genomic integrity.

Hypoxia preconditioning protection of corneal stromal cells requires HIF1alpha but not VEGF.

PubMed

Xing, Dongmei; Bonanno, Joseph A

2009-05-18

Hypoxia preconditioning protects corneal stromal cells from stress-induced death. This study determined whether the transcription factor HIF-1alpha (Hypoxia Inducible Factor) is responsible and whether this is promulgated by VEGF (Vascular Endothelial Growth Factor). Cultured bovine stromal cells were preconditioned with hypoxia in the presence of cadmium chloride, a chemical inhibitor of HIF-1alpha, and HIF-1alpha siRNA to test if HIF-1alpha activity is needed for hypoxia preconditioning protection from UV-irradiation induced cell death. TUNEL assay was used to detect cell apoptosis after UV-irradiation. RT-PCR and western blot were used to detect the presence of HIF-1alpha and VEGF in transcriptional and translational levels. During hypoxia (0.5% O2), 5 muM cadmium chloride completely inhibited HIF-1alpha expression and reversed the protection by hypoxia preconditioning. HIF-1alpha siRNA (15 nM) reduced HIF-1alpha expression by 90% and produced a complete loss of protection provided by hypoxia preconditioning. Since VEGF is induced by hypoxia, can be HIF-1alpha dependent, and is often protective, we examined the changes in transcription of VEGF and its receptors after 4 h of hypoxia preconditioning. VEGF and its receptors Flt-1 and Flk-1 are up-regulated after hypoxia preconditioning. However, the transcription and translation of VEGF were paradoxically increased by siHIF-1alpha, suggesting that VEGF expression in stromal cells is not down-stream of HIF-1alpha. These findings demonstrate that hypoxia preconditioning protection in corneal stromal cells requires HIF-1alpha, but that VEGF is not a component of the protection.

Zinc and Chlamydia trachomatis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sugarman, B.; Epps, L.R.

1985-07-01

Zinc was noted to have significant effects upon the infection of McCoy cells by each of two strains of Chlamydia trachomatis. With a high or low Chlamydia inoculant, the number of infected cells increased up to 200% utilizing supplemental zinc (up to 1 x 10/sup -4/ M) in the inoculation media compared with standard Chlamydia cultivation media (8 x 10/sup -6/ M zinc). Ferric chloride and calcium chloride did not effect any such changes. Higher concentrations of zinc, after 2 hr of incubation with Chlamydia, significantly decreased the number of inclusions. This direct effect of zinc on the Chlamydia remainedmore » constant after further repassage of the Chlamydia without supplemental zinc, suggesting a lethal effect of the zinc. Supplemental zinc (up to 10/sup -4/ M) may prove to be a useful addition to inoculation media to increase the yield of culturing for Chlamydia trachomatis. Similarly, topical or oral zinc preparations used by people may alter their susceptibility to Chamydia trachomatis infections.« less

Effects of antioxidant components of AREDS vitamins and zinc ions on endothelial cell activation: implications for macular degeneration.

PubMed

Zeng, Shemin; Hernández, Jasmine; Mullins, Robert F

2012-02-01

To investigate whether the benefit of Age-Related Eye Disease Study (AREDS) formula multivitamins and zinc in the progression of age-related macular degeneration (AMD) may occur through inhibiting inflammatory events in the choroid. Mouse C166 endothelial cells (ECs) and, for some experiments, human retinal pigment epithelium (RPE)-choroid organ cultures were treated with AREDS multivitamin solution (MVS) or ZnCl(2). The cytotoxicity of MVS was evaluated using a lactate dehydrogenase colorimetric assay. Cell motility was assessed using a scratch assay. Macrophage adhesion to EC monolayers or ICAM-1 protein was determined after MVS and zinc treatment and with or without lipopolysaccharide (LPS). Quantitative reverse transcription PCR and Western blot analysis were used to determine the effects of MVS on the expression of proinflammatory molecules in treated and untreated cells. AREDS MVS and zinc did not affect C166 EC viability until the 56th hour after treatment. Scratch assays showed partial inhibition of MVS and zinc on EC migration. In cell adhesion assays, MVS and zinc decreased the number of macrophages bound to EC and to ICAM-1 protein. Quantitative PCR showed that LPS increased the expression of ICAM-1 in both C166 and human RPE-choroid cultures, which was partially offset by MVS and zinc. MVS and zinc also mitigated LPS-induced ICAM-1 protein expression on Western blot analysis. Treatment with AREDS MVS and zinc may affect both angiogenesis and endothelial-macrophage interactions. These results suggest that AREDS vitamins and zinc ions may slow the progression of AMD, in part through the attenuation of EC activation.

Physical characterization of plakophilin 1 reconstituted with and without zinc.

PubMed

Hofmann, I; Mücke, N; Reed, J; Herrmann, H; Langowski, J

2000-07-01

Plakophilin 1 (PKP1) belongs to the arm-repeat protein family which is characterized by the presence of a conserved 42-amino-acid motif. Despite individual members of the family containing a similar type of structural domain, they exhibit diverse cellular functions. PKP1 is ubiquitously expressed in human tissues and, depending on the type of cell, found prominently in the karyoplasm and/or in desmosomes. In surface plasmon resonance detection experiments, we noticed that PKP1 specifically bound zinc but not calcium or magnesium. Therefore we have used circular dichroism spectroscopy, limited proteolysis, analytical ultracentrifugation, electron microscopy and dynamic light scattering to establish the physical properties of recombinant PKP1 depending on the presence or absence of zinc. The alpha helix content of PKP1 was considerably higher when reconstituted with zinc than without. By atomic absorption spectroscopy 7.3 atoms zinc were shown to be tightly associated with one molecule of wild-type PKP1. The zinc-reconstituted protein formed globular particles of 21.9 +/- 8.4 nm diameter, as measured by electron microscopy after glycerol spraying/rotary metal shadowing. In parallel, the average sedimentation coefficient (s20, w) for zinc-containing PKP1 was 41S and its diffusion coefficient, as obtained by dynamic light scattering, 1.48 x 10-7 cm2.s-1. The molecular mass of 2.44 x 106 obtained from s and D yields an average stoichiometry of 30 for the PKP1 oligomer. In contrast, PKP1, reconstituted without zinc, contained no significant amount of zinc, sedimented with 4.6S, and was present in monomeric form as determined by sedimentation equilibrium centrifugation.

SLC30A3 Responds to Glucose- and Zinc Variations in ß-Cells and Is Critical for Insulin Production and In Vivo Glucose-Metabolism During ß-Cell Stress

PubMed Central

Smidt, Kamille; Jessen, Niels; Petersen, Andreas Brønden; Larsen, Agnete; Magnusson, Nils; Jeppesen, Johanne Bruun; Stoltenberg, Meredin; Culvenor, Janetta G.; Tsatsanis, Andrew; Brock, Birgitte; Schmitz, Ole; Wogensen, Lise; Bush, Ashley I.; Rungby, Jørgen

2009-01-01

Background Ion transporters of the Slc30A- (ZnT-) family regulate zinc fluxes into sub-cellular compartments. β-cells depend on zinc for both insulin crystallization and regulation of cell mass. Methodology/Principal Findings This study examined: the effect of glucose and zinc chelation on ZnT gene and protein levels and apoptosis in β-cells and pancreatic islets, the effects of ZnT-3 knock-down on insulin secretion in a β-cell line and ZnT-3 knock-out on glucose metabolism in mice during streptozotocin-induced β-cell stress. In INS-1E cells 2 mM glucose down-regulated ZnT-3 and up-regulated ZnT-5 expression relative to 5 mM. 16 mM glucose increased ZnT-3 and decreased ZnT-8 expression. Zinc chelation by DEDTC lowered INS-1E insulin content and insulin expression. Furthermore, zinc depletion increased ZnT-3- and decreased ZnT-8 gene expression whereas the amount of ZnT-3 protein in the cells was decreased. Zinc depletion and high glucose induced apoptosis and necrosis in INS-1E cells. The most responsive zinc transporter, ZnT-3, was investigated further; by immunohistochemistry and western blotting ZnT-3 was demonstrated in INS-1E cells. 44% knock-down of ZnT-3 by siRNA transfection in INS-1E cells decreased insulin expression and secretion. Streptozotocin-treated mice had higher glucose levels after ZnT-3 knock-out, particularly in overt diabetic animals. Conclusion/Significance Zinc transporting proteins in β-cells respond to variations in glucose and zinc levels. ZnT-3, which is pivotal in the development of cellular changes as also seen in type 2 diabetes (e.g. amyloidosis in Alzheimer's disease) but not previously described in β-cells, is present in this cell type, up-regulated by glucose in a concentration dependent manner and up-regulated by zinc depletion which by contrast decreased ZnT-3 protein levels. Knock-down of the ZnT-3 gene lowers insulin secretion in vitro and affects in vivo glucose metabolism after streptozotocin treatment. PMID:19492079

Curcumin inhibits interferon-{alpha} induced NF-{kappa}B and COX-2 in human A549 non-small cell lung cancer cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jeeyun; Im, Young-Hyuck; Jung, Hae Hyun

2005-08-26

The A549 cells, non-small cell lung cancer cell line from human, were resistant to interferon (IFN)-{alpha} treatment. The IFN-{alpha}-treated A549 cells showed increase in protein expression levels of NF-{kappa}B and COX-2. IFN-{alpha} induced NF-{kappa}B binding activity within 30 min and this increased binding activity was markedly suppressed with inclusion of curcumin. Curcumin also inhibited IFN-{alpha}-induced COX-2 expression in A549 cells. Within 10 min, IFN-{alpha} rapidly induced the binding activity of a {gamma}-{sup 32}P-labeled consensus GAS oligonucleotide probe, which was profoundly reversed by curcumin. Taken together, IFN-{alpha}-induced activations of NF-{kappa}B and COX-2 were inhibited by the addition of curcumin in A549more » cells.« less

Requirement for IFN-gamma in IL-12 production induced by collaboration between v(alpha)14(+) NKT cells and antigen-presenting cells.

PubMed

Yang, Y F; Tomura, M; Ono, S; Hamaoka, T; Fujiwara, H

2000-12-01

Two cytokines IL-4 and IL-12 are known to determine the balance between T(h)1 and T(h)2 development. In addition to IL-4 production of V(alpha)14(+) NKT cells, they have recently been demonstrated to have the capacity to stimulate IL-12 production by antigen-presenting cells (APC). This study demonstrates that IFN-gamma is absolutely required for the NKT cell-stimulated IL-12 production. Culture of B cell-depleted spleen cells from C57BL/6 mice with alpha-galactosylceramide (alpha-GalCer) capable of selectively stimulating V(alpha)14/J(alpha)281(+) NKT cells resulted in the production of IL-12 together with IL-4. Whereas IL-4 production occurred in culture of IFN-gamma(-/-) C57BL/6 splenocytes, the same culture failed to generate IL-12 production. While IL-12 production induced during culture of V(alpha)14(+) NKT cells and APC depended on the interaction between CD40 ligand on NKT cells and CD40 on APC, the expression levels of these key molecules were comparable in cells from wild-type and IFN-gamma(-/-) mice. Addition of rIFN-gamma to alpha-GalCer stimulated IFN-gamma(-/-) splenocyte culture, and administration of rIFN-gamma to alpha-GalCer-injected IFN-gamma(-/-) mice resulted in the restoration of IL-12 production in vitro and in vivo. These results illustrate a mandatory role for IFN-gamma in V(alpha)14(+) NKT cell-stimulated IL-12 production by APC.

A defective retroviral vector encoding human interferon-alpha2 can transduce human leukemic cell lines.

PubMed

Austruy, E; Bagnis, C; Carbuccia, N; Maroc, C; Birg, F; Dubreuil, P; Mannoni, P; Chabannon, C

1998-01-01

Using the LXSN backbone, a defective retroviral vector (LISN) was constructed that encodes the human interferon (IFN)-alpha2 (hIFN-alpha2) gene and the neomycin resistance gene; the hIFN-alpha2 gene was cloned from human placental genomic DNA. High titers of the LISN retrovirus were produced by the amphotropic packaging cell line GP+envAM12. LISN is able to infect three human hematopoietic and leukemic cell lines: K562, LAMA-84, and TF-1. G418-resistant cells were detected in a similar proportion after infection with either the LISN retroviral vector or the LnLSN retroviral vector (encoding the nlsLacZ gene instead of hIFN-alpha2), suggesting that hIFN-alpha2 does not inhibit (or only partially inhibits) the production of retroviral particles by the packaging cell line and the infection of human cells. LISN-infected cells express and secrete hIFN-alpha2 as demonstrated by Northern blot analysis of poly(A)+ RNA, detection of the intracellular protein by fluorescence-activated cell sorter analysis, and detection of secreted hIFN-alpha in cell supernatants using an enzyme-linked immunosorbent assay. Retrovirally produced hIFN-alpha2 is biologically active, as demonstrated by the partial inhibition of the growth of K562 and TF-1, the modulation of the expression of cell surface antigens, the induction of the (2'-5') oligoadenylate synthetase, and, for LAMA-84, the down-modulation of the BCR-ABL protein. We conclude that the infection of human leukemic cell lines with a retroviral vector encoding hIFN-alpha2 is feasible and induces the expected biological effects. This experimental model will be useful in investigating the possibility of transducing normal and leukemic cells and hematopoietic progenitors and in determining the consequences of the autocrine production of hIFN-alpha2 on the behavior of these cells.

Fabrication and testing of large size nickel-zinc cells

NASA Technical Reports Server (NTRS)

Klein, M.

1977-01-01

The design and construction of nickel zinc cells, containing sintered nickel electrodes and asbestos coated inorganic separator materials, were outlined. Negative electrodes were prepared by a dry pressing process while various inter-separators were utilized on the positive electrodes, consisting of non-woven nylon, non-woven polypropylene, and asbestos.

Hyperforin changes the zinc-storage capacities of brain cells.

PubMed

Gibon, Julien; Richaud, Pierre; Bouron, Alexandre

2011-12-01

In vitro and in vivo experiments were carried out to investigate the consequences on brain cells of a chronic treatment with hyperforin, a plant extract known to dissipate the mitochondrial membrane potential and to release Zn(2+) and Ca(2+) from these organelles. Dissociated cortical neurons were grown in a culture medium supplemented with 1 μM hyperforin. Live-cell imaging experiments with the fluorescent probes FluoZin-3 and Fluo-4 show that a 3 day-hyperforin treatment diminishes the size of the hyperforin-sensitive pools of Ca(2+) and Zn(2+) whereas it increases the size of the DTDP-sensitive pool of Zn(2+) without affecting the ionomycin-sensitive pool of Ca(2+). When assayed by quantitative PCR the levels of mRNA coding for metallothioneins (MTs) I, II and III were increased in cortical neurons after a 3 day-hyperforin treatment. This was prevented by the zinc chelator TPEN, indicating that the plant extract controls the expression of MTs in a zinc-dependent manner. Brains of adult mice who received a daily injection (i.p.) of hyperforin (4 mg/kg/day) for 4 weeks had a higher sulphur content than control animals. They also exhibited an enhanced expression of the genes coding for MTs. However, the long-term treatment did not affect the brain levels of calcium and zinc. Based on these results showing that hyperforin influences the size of the internal pools of Zn(2+), the expression of MTs and the brain cellular sulphur content, it is proposed that hyperforin changes the Zn-storage capacity of brain cells and interferes with their thiol status. Copyright © 2011 Elsevier Ltd. All rights reserved.

Zinc in Entamoeba invadens.

NASA Technical Reports Server (NTRS)

Morgan, R. S.; Sattilaro, R. F.

1972-01-01

Atomic absorption spectroscopy, electron microprobe analysis, and dithizone staining of trophozoites and cysts of Entamoeba invadens demonstrate that these cells have a high concentration of zinc (approximately one picogram per cell or 1% of their dry weight). In the cysts of this organism, the zinc is confined to the chromatoid bodies, which previous work has shown to contain crystals of ribosomes. The chemical state and function of this zinc are unknown.

Zinc alpha-2 glycoprotein is overproduced in Cushing's syndrome.

PubMed

Escoté, Xavier; Aranda, Gloria B; Mora, Mireia; Casals, Gregori; Enseñat, Joaquim; Vidal, Oscar; Esteban, Yaiza; Halperin, Irene; Hanzu, Felicia A

2017-01-01

Cushing syndrome (CS), an endogenous hypercortisolemic condition with increased cardiometabolic morbidity, leads to development of abdominal obesity, insulin resistance, diabetes and proatherogenic dyslipidemia. Zinc alpha-2 glycoprotein (ZAG) is a recently characterized lipolytic adipokine implicated in regulation of adipose tissue metabolism and fat distribution. In vitro and animal studies suggest that glucocorticoids interact with ZAG secretion and action. To assess the relationship between ZAG and glucocorticoids in a human model of hypercortisolism, circulating ZAG levels were tested in patients with CS and its counterpart controls. An observational, cross-sectional study on 39 women, 13 with active CS and 26 controls matched by age and body mass index. Plasma ZAG levels (μg/ml) were measured by ELISA and correlated with hypercortisolism, metabolic, and phenotypic parameters. Plasma ZAG levels were significantly higher in patients with CS compared to controls (64.3±16.6 vs. 44.0±16.1, p=0.002). In a univariate analysis, ZAG levels positively correlated to 24-h urinary free cortisol (p=0.001), body mass index (p=0.02), non-esterified fatty acids (p=0.05), glucose (p=0.003), LDL-C (p=0.028), and type 2 diabetes mellitus (p=0.016), and were inversely related to total adiponectin levels (p=0.035). In a multivariate analysis, after adjusting for CS, ZAG levels only correlated with body mass index (p=0.012), type 2 diabetes mellitus (p=0.004), and glucose (p<0.001). This study provides initial evidence that plasma ZAG levels are higher in patients with CS as compared to controls. The close relationship of ZAG with metabolic and phenotypic changes in CS suggests that ZAG may play a significant role in adipose tissue changes in hypercortisolism. Copyright © 2017 SEEN. Publicado por Elsevier España, S.L.U. All rights reserved.

Effects of Antioxidant Components of AREDS Vitamins and Zinc Ions on Endothelial Cell Activation: Implications for Macular Degeneration

PubMed Central

Zeng, Shemin; Hernández, Jasmine

2012-01-01

Purpose. To investigate whether the benefit of Age-Related Eye Disease Study (AREDS) formula multivitamins and zinc in the progression of age-related macular degeneration (AMD) may occur through inhibiting inflammatory events in the choroid. Methods. Mouse C166 endothelial cells (ECs) and, for some experiments, human retinal pigment epithelium (RPE)–choroid organ cultures were treated with AREDS multivitamin solution (MVS) or ZnCl2. The cytotoxicity of MVS was evaluated using a lactate dehydrogenase colorimetric assay. Cell motility was assessed using a scratch assay. Macrophage adhesion to EC monolayers or ICAM-1 protein was determined after MVS and zinc treatment and with or without lipopolysaccharide (LPS). Quantitative reverse transcription PCR and Western blot analysis were used to determine the effects of MVS on the expression of proinflammatory molecules in treated and untreated cells. Results. AREDS MVS and zinc did not affect C166 EC viability until the 56th hour after treatment. Scratch assays showed partial inhibition of MVS and zinc on EC migration. In cell adhesion assays, MVS and zinc decreased the number of macrophages bound to EC and to ICAM-1 protein. Quantitative PCR showed that LPS increased the expression of ICAM-1 in both C166 and human RPE-choroid cultures, which was partially offset by MVS and zinc. MVS and zinc also mitigated LPS-induced ICAM-1 protein expression on Western blot analysis. Conclusions. Treatment with AREDS MVS and zinc may affect both angiogenesis and endothelial-macrophage interactions. These results suggest that AREDS vitamins and zinc ions may slow the progression of AMD, in part through the attenuation of EC activation. PMID:22247465

Bimatoprost and prostaglandin F(2 alpha) selectively stimulate intracellular calcium signaling in different cat iris sphincter cells.

PubMed

Spada, Clayton S; Krauss, Achim H-P; Woodward, David F; Chen, June; Protzman, Charles E; Nieves, Amelia L; Wheeler, Larry A; Scott, David F; Sachs, George

2005-01-01

Bimatoprost is a synthetic analog of prostaglandin F(2 alpha) ethanolamide (prostamide F(2 alpha)), and shares a pharmacological profile consistent with that of the prostamides. Like prostaglandin F(2 alpha) carboxylic acid, bimatoprost potently lowers intraocular pressure in dogs, primates and humans. In order to distinguish its mechanism of action from prostaglandin F(2 alpha), fluorescence confocal microscopy was used to examine the effects of bimatoprost, prostaglandin F(2 alpha) and 17-phenyl prostaglandin F(2 alpha) on calcium signaling in resident cells of digested cat iris sphincter, a tissue which exhibits contractile responses to both agonists. Constant superfusion conditions obviated effective conversion of bimatoprost. Serial challenge with 100 nM bimatoprost and prostaglandin F(2 alpha) consistently evoked responses in different cells within the same tissue preparation, whereas prostaglandin F(2 alpha) and 17-phenyl prostaglandin F(2 alpha) elicited signaling responses in the same cells. Bimatoprost-sensitive cells were consistently re-stimulated with bimatoprost only, and prostaglandin F(2 alpha) sensitive cells could only be re-stimulated with prostaglandin F(2 alpha). The selective stimulation of different cells in the same cat iris sphincter preparation by bimatoprost and prostaglandin F(2 alpha), along with the complete absence of observed instances in which the same cells respond to both agonists, strongly suggests the involvement of distinct receptors for prostaglandin F(2 alpha) and bimatoprost. Further, prostaglandin F(2 alpha) but not bimatoprost potently stimulated calcium signaling in isolated human embryonic kidney cells stably transfected with the feline- and human-prostaglandin F(2 alpha) FP-receptor and in human dermal fibroblast cells, and only prostaglandin F(2 alpha) competed with radioligand binding in HEK-feFP cells. These studies provide further evidence for the existence of a bimatoprost-sensitive receptor that is distinct from

Metallothionein provides zinc-mediated protective effects against methamphetamine toxicity in SK-N-SH cells.

PubMed

Ajjimaporn, Amornpan; Swinscoe, John; Shavali, Shaik; Govitrapong, Piyarat; Ebadi, Manuchair

2005-11-30

Methamphetamine (METH) is a drug of abuse and neurotoxin that induces Parkinson's-like pathology after chronic usage by targeting dopaminergic neurons. Elucidation of the intracellular mechanisms that underlie METH-induced dopaminergic neuron toxicity may help in understanding the mechanism by which neurons die in Parkinson's disease. In the present study, we examined the role of reactive oxygen species (ROS) in the METH-induced death of human dopaminergic SK-N-SH cells and further assessed the neuroprotective effects of zinc and metallothionein (MT) against METH-induced toxicity in culture. METH significantly increased the production of reactive oxygen species, decreased intracellular ATP levels and reduced the cell viability. Pre-treatment with zinc markedly prevented the loss of cell viability caused by METH treatment. Zinc pre-treatment mainly increased the expression of metallothionein and prevented the generation of reactive oxygen species and ATP depletion caused by METH. Chelation of zinc by CaEDTA caused a significant decrease in MT expression and loss of protective effects of MT against METH toxicity. These results suggest that zinc-induced MT expression protects dopaminergic neurons via preventing the accumulation of toxic reactive oxygen species and halting the decrease in ATP levels. Furthermore, MT may prevent the loss of mitochondrial functions caused by neurotoxins. In conclusion, our study suggests that MT, a potent scavenger of free radicals is neuroprotective against dopaminergic toxicity in conditions such as drug of abuse and in Parkinson's disease.

Autophagy modulators sensitize prostate epithelial cancer cell lines to TNF-alpha-dependent apoptosis.

PubMed

Giampietri, Claudia; Petrungaro, Simonetta; Padula, Fabrizio; D'Alessio, Alessio; Marini, Elettra Sara; Facchiano, Antonio; Filippini, Antonio; Ziparo, Elio

2012-11-01

TNF-alpha levels in prostate cancer correlate with the extent of disease and are significantly elevated in the metastatic stage. TNF receptor superfamily controls two distinct signalling cascades, leading to opposite effects, i.e. apoptosis and survival; in prostate cancer TNF-alpha-mediated signalling induces cell survival and resistance to therapy. The apoptosis of prostate epithelial cancer cells LNCaP and PC3 was investigated upon treatment with the autophagy inhibitor 3-methyladenine and the autophagy inducer rapamycin, in combination with TNF-alpha. Cells were exposed to these molecules for 18, 24 and 48 h. Autophagy was assessed via LC3 Western blot analysis; propidium iodide and TUNEL stainings followed by flow cytometry or caspase-8 and caspase-3 activation assays were performed to evaluate apoptosis. TNF-alpha-induced apoptosis was potentiated by 3-methyladenine in the androgen-responsive LNCaP cells, whereas no effect was observed in the androgen-insensitive PC3 cells. Interestingly such pro-apoptosis effect in LNCaP cells was associated with reduced c-Flip levels through proteasomal degradation via increased reactive oxygen species production and p38 activation; such c-Flip reduction was reversed in the presence of either the proteasome inhibitor MG132 or the reactive oxygen species scavenger N-acetyl-cysteine. Conversely in PC3 but not in LNCaP cells, rapamycin stimulated TNF-alpha-dependent apoptosis; such effect was associated with reduced c-Flip promoter activity and FoxO3a activation. We conclude that TNF-alpha-induced apoptosis may be potentiated, in prostate cancer epithelial cells, through autophagy modulators. Increased sensitivity to TNF-alpha-dependent apoptosis correlates with reduced c-Flip levels which are consequent to a post-transcriptional and a transcriptional mechanism in LNCaP and PC3 cells respectively.

Pyrrolidine dithiocarbamate-zinc(II) and -copper(II) complexes induce apoptosis in tumor cells by inhibiting the proteasomal activity☆

PubMed Central

Milacic, Vesna; Chen, Di; Giovagnini, Lorena; Diez, Alejandro; Fregona, Dolores; Dou, Q. Ping

2013-01-01

Zinc and copper are trace elements essential for proper folding, stabilization and catalytic activity of many metalloenzymes in living organisms. However, disturbed zinc and copper homeostasis is reported in many types of cancer. We have previously demonstrated that copper complexes induced proteasome inhibition and apoptosis in cultured human cancer cells. In the current study we hypothesized that zinc complexes could also inhibit the proteasomal chymotrypsin-like activity responsible for subsequent apoptosis induction. We first showed that zinc(II) chloride was able to inhibit the chymotrypsin-like activity of a purified 20S proteasome with an IC50 value of 13.8 μM, which was less potent than copper(II) chloride (IC50 5.3 μM). We then compared the potencies of a pyrrolidine dithiocarbamate (PyDT)-zinc(II) complex and a PyDT-copper(II) complex to inhibit cellular proteasomal activity, suppress proliferation and induce apoptosis in various human breast and prostate cancer cell lines. Consistently, zinc complex was less potent than copper complex in inhibiting the proteasome and inducing apoptosis. Additionally, zinc and copper complexes appear to use somewhat different mechanisms to kill tumor cells. Zinc complexes were able to activate calpain-, but not caspase-3-dependent pathway, while copper complexes were able to induce activation of both proteases. Furthermore, the potencies of these PyDT-metal complexes depend on the nature of metals and also on the ratio of PyDT to the metal ion within the complex, which probably affects their stability and availability for interacting with and inhibiting the proteasome in tumor cells. PMID:18501397

Induction of experimental bone metastasis in mice by transfection of integrin alpha 4 beta 1 into tumor cells.

PubMed Central

Matsuura, N.; Puzon-McLaughlin, W.; Irie, A.; Morikawa, Y.; Kakudo, K.; Takada, Y.

1996-01-01

Cell adhesion receptors (eg, integrins and CD44) play an important role in invasion and metastasis during tumor progression. The increase in integrin alpha 4 beta 1 expression on primary melanomas has been reported to significantly correlate with the development of metastases. alpha 4 beta 1 is a cell surface heterodimer that mediates cell-cell and cell-extracellular matrix interactions through adhesion to vascular cell adhesion molecule (VCAM)-1 and to the IIICS region of fibronectin. To test the effects of alpha 4 beta 1 expression on tumor cell metastasis, Chinese hamster ovary cells were transfected with human alpha 4 cDNA. Whereas alpha 4-negative Chinese hamster ovary cells developed only pulmonary metastasis, alpha 4-positive Chinese hamster ovary cells developed bone and pulmonary metastasis in 3 to 4 weeks when injected intravenously into nude mice. Bone metastasis was inhibited by antibody against alpha 4 or VCAM-1. Expression of alpha 3 beta 1, alpha 6 beta 1, or alpha V beta 1 did not induce bone metastasis. Expression of alpha 4 beta 1 also induced bone metastasis in K562 human erythroleukemia cells injected into SCID mice. These results demonstrate that alpha 4 beta 1 can induce tumor cell trafficking to bone, probably via interaction with VCAM-1 that is constitutively expressed on bone marrow stromal cells. Images Figure 1 Figure 3 PMID:8546226

Zinc oxide nanoparticles decrease the expression and activity of plasma membrane calcium ATPase, disrupt the intracellular calcium homeostasis in rat retinal ganglion cells.

PubMed

Guo, Dadong; Bi, Hongsheng; Wang, Daoguang; Wu, Qiuxin

2013-08-01

Zinc oxide nanoparticle is one of the most important materials with diverse applications. However, it has been reported that zinc oxide nanoparticles are toxic to organisms, and that oxidative stress is often hypothesized to be an important factor in cytotoxicity mediated by zinc oxide nanoparticles. Nevertheless, the mechanism of toxicity of zinc oxide nanoparticles has not been completely understood. In this study, we investigated the cytotoxic effect of zinc oxide nanoparticles and the possible molecular mechanism involved in calcium homeostasis mediated by plasma membrane calcium ATPase in rat retinal ganglion cells. Real-time cell electronic sensing assay showed that zinc oxide nanoparticles could exert cytotoxic effect on rat retinal ganglion cells in a concentration-dependent manner; flow cytometric analysis indicated that zinc oxide nanoparticles could lead to cell damage by inducing the overproduction of reactive oxygen species. Furthermore, zinc oxide nanoparticles could also apparently decrease the expression level and their activity of plasma membrane calcium ATPase, which finally disrupt the intracellular calcium homeostasis and result in cell death. Taken together, zinc oxide nanoparticles could apparently decrease the plasma membrane calcium ATPase expression, inhibit their activity, cause the elevated intracellular calcium ion level and disrupt the intracellular calcium homeostasis. Further, the disrupted calcium homeostasis will trigger mitochondrial dysfunction, generate excessive reactive oxygen species, and finally initiate cell death. Thus, the disrupted calcium homeostasis is involved in the zinc oxide nanoparticle-induced rat retinal ganglion cell death. Copyright © 2013 Elsevier Ltd. All rights reserved.

Identification of novel targets for PGC-1{alpha} and histone deacetylase inhibitors in neuroblastoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cowell, Rita M.; Department of Neurology, University of Michigan, Ann Arbor, MI 48109; Talati, Pratik

2009-02-06

Recent evidence suggests that the transcriptional coactivator peroxisome proliferator activated receptor {gamma} coactivator 1{alpha} (PGC-1{alpha}) is involved in the pathology of Huntington's Disease (HD). While animals lacking PGC-1{alpha} express lower levels of genes involved in antioxidant defense and oxidative phosphorylation in the brain, little is known about other targets for PGC-1{alpha} in neuronal cells and whether there are ways to pharmacologically target PGC-1{alpha} in neurons. Here, PGC-1{alpha} overexpression in SH-SY5Y neuroblastoma cells upregulated expression of genes involved in mitochondrial function, glucose transport, fatty acid metabolism, and synaptic function. Overexpression also decreased vulnerability to hydrogen peroxide-induced cell death and caspase 3more » activation. Treatment of cells with the histone deacetylase inhibitors (HDACi's) trichostatin A and valproic acid upregulated PGC-1{alpha} and glucose transporter 4 (GLUT4). These results suggest that PGC-1{alpha} regulates multiple pathways in neurons and that HDACi's may be good candidates to target PGC-1{alpha} and GLUT4 in HD and other neurological disorders.« less

Thalidomide inhibits tumor necrosis factor-alpha production and antigen presentation by Langerhans cells.

PubMed

Deng, Liang; Ding, Wanhong; Granstein, Richard D

2003-11-01

Thalidomide is an effective treatment for several inflammatory and autoimmune disorders including erythema nodosum leprosum, Behcet's syndrome, discoid lupus erythematosus, and Crohn's disease. Thalidomide is believed to exert its anti-inflammatory effects, at least in part, by inhibiting tumor necrosis factor-alpha (TNF-alpha) production by monocytes. We studied the effects of thalidomide on epidermal Langerhans cells (LC). LCs are epidermal antigen-presenting dendritic cells that play important roles in skin immune responses. Using the murine epidermis-derived dendritic cell lines, XS106A from A/J mice and XS52 from BALB/c mice as surrogates for LC, we found that thalidomide inhibited TNF-alpha production in a concentration-dependent manner. Northern blot analysis revealed that thalidomide significantly decreased the peak-induced mRNA level of TNF-alpha in XS106A cells and XS52 cells. We then examined the effect of thalidomide on fresh LC enriched to approximately 98% using positive selection of Ia+ cells with antibodies conjugated to magnetic microspheres. TNF-alpha production was reduced by 67.7% at a thalidomide concentration of 200 microg per mL. Thalidomide also had a profound inhibitory effect on the ability of LC to present antigen to a responsive TH1 clone. Thalidomide inhibits TNF-alpha production and the antigen-presenting ability of epidermal LCs. These mechanisms may contribute to the therapeutic effects observed with this agent.

N-acetylcysteine attenuates TNF-alpha-induced human vascular endothelial cell apoptosis and restores eNOS expression.

PubMed

Xia, Zhengyuan; Liu, Min; Wu, Yong; Sharma, Vijay; Luo, Tao; Ouyang, Jingping; McNeill, John H

2006-11-21

The circulatory inflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) is increased in pathological conditions, such as diabetes, which initiate or exacerbate vascular endothelial injury. Both nitric oxide (NO) and reactive oxygen species may play a dual role (i.e., inhibiting or promoting) in TNF-alpha-induced endothelial cell apoptosis. We investigated the effects of the antioxidant N-acetylcysteine on TNF-alpha-induced apoptosis in human vascular endothelial cell (cell line ECV304) apoptosis, NO production and lipid peroxidation. Cultured vascular endothelial cell (ECV304) were either not treated (control), or treated with TNF-alpha (40 ng/ml) alone or TNF-alpha in the presence of N-acetylcysteine at 30 mmol/l or 1 mmol/l, respectively, for 24 h. Cell viability was measured by MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide) assay. Cell apoptosis was assessed by flow cytometry. TNF-alpha-induced endothelial cell apoptosis was associated with increased inducible NO synthase but reduced endothelial NO synthase (eNOS) protein expression. NO production and the levels of the lipid peroxidation product malondialdehyde were concomitantly increased. Treatment with NAC at 30 mmol/l restored eNOS expression and further increased NO production as compared to TNF-alpha alone, resulting in improved cell viability and reduced apoptosis. This was accompanied by increased superoxide dismutase activity, increased glutathione peroxidase production and reduced malondialdehyde levels. N-acetylcysteine at 1 mmol/l, however, did not have significant effects on TNF-alpha-induced endothelial cell apoptosis and cell viability despite it slightly enhanced glutathione peroxidase production. N-acetylcysteine attenuation of TNF-alpha-induced human vascular endothelial cell apoptosis is associated with the restoration of eNOS expression.

Alpha cells secrete acetylcholine as a non-neuronal paracrine signal priming human beta cell function

PubMed Central

Rodriguez-Diaz, Rayner; Dando, Robin; Jacques-Silva, M. Caroline; Fachado, Alberto; Molina, Judith; Abdulreda, Midhat; Ricordi, Camillo; Roper, Stephen D.; Berggren, Per-Olof; Caicedo, Alejandro

2011-01-01

Acetylcholine is a neurotransmitter that plays a major role in the function of the insulin secreting pancreatic beta cell1,2. Parasympathetic innervation of the endocrine pancreas, the islets of Langerhans, has been shown to provide cholinergic input to the beta cell in several species1,3,4, but the role of autonomic innervation in human beta cell function is at present unclear. Here we show that, in contrast to mouse islets, cholinergic innervation of human islets is sparse. Instead, we find that the alpha cells of the human islet provide paracrine cholinergic input to surrounding endocrine cells. Human alpha cells express the vesicular acetylcholine transporter and release acetylcholine when stimulated with kainate or a lowering in glucose concentration. Acetylcholine secretion by alpha cells in turn sensitizes the beta cell response to increases in glucose concentration. Our results demonstrate that in human islets acetylcholine is a paracrine signal that primes the beta cell to respond optimally to subsequent increases in glucose concentration. We anticipate these results to revise models about neural input and cholinergic signaling in the endocrine pancreas. Cholinergic signaling within the islet represents a potential therapeutic target in diabetes5, highlighting the relevance of this advance to future drug development. PMID:21685896

alpha(4)beta(7) independent pathway for CD8(+) T cell-mediated intestinal immunity to rotavirus.

PubMed

Kuklin, N A; Rott, L; Darling, J; Campbell, J J; Franco, M; Feng, N; Müller, W; Wagner, N; Altman, J; Butcher, E C; Greenberg, H B

2000-12-01

Rotavirus (RV), which replicates exclusively in cells of the small intestine, is the most important cause of severe diarrhea in young children worldwide. Using a mouse model, we show that expression of the intestinal homing integrin alpha(4)ss(7) is not essential for CD8(+) T cells to migrate to the intestine or provide immunity to RV. Mice deficient in ss7 expression (ss7(-/-)) and unable to express alpha(4)ss(7) integrin were found to clear RV as quickly as wild-type (wt) animals. Depletion of CD8(+) T cells in ss7(-/-) animals prolonged viral shedding, and transfer of immune ss7(-/-) CD8(+) T cells into chronically infected Rag-2-deficient mice resolved RV infection as efficiently as wt CD8(+) T cells. Paradoxically, alpha(4)ss(7)(hi) memory CD8(+) T cells purified from wt mice that had been orally immunized cleared RV more efficiently than alpha(4)ss(7)(low) CD8(+) T cells. We explained this apparent contradiction by demonstrating that expression of alpha(4)ss(7) on effector CD8(+) T cells depends upon the site of initial antigen exposure: oral immunization generates RV-specific CD8(+) T cells primarily of an alpha(4)ss(7)(hi) phenotype, but subcutaneous immunization yields both alpha(4)ss(7)(hi) and alpha(4)ss(7)(low) immune CD8(+) T cells with anti-RV effector capabilities. Thus, alpha(4)ss(7) facilitates normal intestinal immune trafficking to the gut, but it is not required for effective CD8(+) T cell immunity.

Zinc starvation induces autophagy in yeast

PubMed Central

Kawamata, Tomoko; Horie, Tetsuro; Matsunami, Miou; Sasaki, Michiko; Ohsumi, Yoshinori

2017-01-01

Zinc is an essential nutrient for all forms of life. Within cells, most zinc is bound to protein. Because zinc serves as a catalytic or structural cofactor for many proteins, cells must maintain zinc homeostasis under severely zinc-deficient conditions. In yeast, the transcription factor Zap1 controls the expression of genes required for uptake and mobilization of zinc, but to date the fate of existing zinc-binding proteins under zinc starvation remains poorly understood. Autophagy is an evolutionarily conserved cellular degradation/recycling process in which cytoplasmic proteins and organelles are sequestered for degradation in the vacuole/lysosome. In this study, we investigated how autophagy functions under zinc starvation. Zinc depletion induced non-selective autophagy, which is important for zinc-limited growth. Induction of autophagy by zinc starvation was not directly related to transcriptional activation of Zap1. Instead, TORC1 inactivation directed zinc starvation-induced autophagy. Abundant zinc proteins, such as Adh1, Fba1, and ribosomal protein Rpl37, were degraded in an autophagy-dependent manner. But the targets of autophagy were not restricted to zinc-binding proteins. When cellular zinc is severely depleted, this non-selective autophagy plays a role in releasing zinc from the degraded proteins and recycling zinc for other essential purposes. PMID:28264932

Effect of positive pulse charge waveforms on cycle life of nickel-zinc cells

NASA Technical Reports Server (NTRS)

Smithrick, J. J.

1980-01-01

Five amp-hour nickel-zinc cells were life cycled to evaluate four different charge methods. Three of the four waveforms investigated were 120 Hz full wave rectified sinusoidal (FWRS), 120 Hz silicon controlled rectified (SCR), and 1 kHz square wave (SW). The fourth, a constant current method, was used as a baseline of comparison. Three sealed Ni-Zn cells connected in series were cycled. Each series string was charged at an average c/20 rate, and discharged at a c/2.5 rate to a 75% rated depth. Results indicate that the relatively inexpensive 120 Hz FWRS charger appears feasible for charging 5 amp-hour nickel-zinc cells with no significant loss in average cycle life when compared to constant current charging. The 1-kHz SW charger could also be used with no significant loss in average cycle life, and suggests the possibility of utilizing the existing electric vehicle chopper controller circuitry for an on-board charger. There was an apparent difference using the 120 Hz SCR charger compared to the others, however, this difference could be due to an inadvertent severe overcharge, which occurred prior to cell failure. The remaining two positive pulse charging waveforms, FWRS and 1 kHz, did not improve the cycle life of 5 amp-hour nickel-zinc cells over that of constant current charging.

Alpha-lactalbumin unfolding is not sufficient to cause apoptosis, but is required for the conversion to HAMLET (human alpha-lactalbumin made lethal to tumor cells).

PubMed

Svensson, Malin; Fast, Jonas; Mossberg, Ann-Kristin; Düringer, Caroline; Gustafsson, Lotta; Hallgren, Oskar; Brooks, Charles L; Berliner, Lawrence; Linse, Sara; Svanborg, Catharina

2003-12-01

HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a complex of human alpha-lactalbumin and oleic acid (C18:1:9 cis) that kills tumor cells by an apoptosis-like mechanism. Previous studies have shown that a conformational change is required to form HAMLET from alpha-lactalbumin, and that a partially unfolded conformation is maintained in the HAMLET complex. This study examined if unfolding of alpha-lactalbumin is sufficient to induce cell death. We used the bovine alpha-lactalbumin Ca(2+) site mutant D87A, which is unable to bind Ca(2+), and thus remains partially unfolded regardless of solvent conditions. The D87A mutant protein was found to be inactive in the apoptosis assay, but could readily be converted to a HAMLET-like complex in the presence of oleic acid. BAMLET (bovine alpha-lactalbumin made lethal to tumor cells) and D87A-BAMLET complexes were both able to kill tumor cells. This activity was independent of the Ca(2+)site, as HAMLET maintained a high affinity for Ca(2+) but D87A-BAMLET was active with no Ca(2+) bound. We conclude that partial unfolding of alpha-lactalbumin is necessary but not sufficient to trigger cell death, and that the activity of HAMLET is defined both by the protein and the lipid cofactor. Furthermore, a functional Ca(2+)-binding site is not required for conversion of alpha-lactalbumin to the active complex or to cause cell death. This suggests that the lipid cofactor stabilizes the altered fold without interfering with the Ca(2+)site.

LPS receptor CD14 participates in release of TNF-alpha in RAW 264.7 and peritoneal cells but not in kupffer cells.

PubMed

Lichtman, S N; Wang, J; Lemasters, J J

1998-07-01

Lipopolysaccharide (LPS) is a bacterial polymer that stimulates macrophages to release tumor necrosis factor-alpha (TNF-alpha). In macrophages (RAW 264.7 and peritoneal cells), LPS binds to the CD14 surface receptor as the first step toward signaling. Liver macrophages, Kupffer cells, are the most numerous fixed-tissue macrophage in the body. The presence of CD14 on Kupffer cells and its role in LPS stimulation of TNF-alpha were examined. TNF-alpha release by Kupffer cells after LPS stimulation was the same in the presence and absence of serum. RAW 264.7 and peritoneal cells, which utilize the CD14 receptor, released significantly less TNF-alpha after LPS stimulation in the absence of serum because of the absence of LPS-binding protein. Phosphatidylinositol-phospholipase C treatment, which cleaves the CD14 receptor, decreased LPS-stimulated TNF-alpha release by RAW 264.7 cells but not by Kupffer cells. Deacylated LPS (dLPS) competes with LPS at the CD14 receptor when incubated in a ratio of 100:1 (dLPS/LPS). Such competition blocked LPS-stimulated TNF-alpha release from RAW 264.7 cells but not from Kupffer cells. Western and fluorescence-activated cell sorter analysis directly demonstrated the presence of CD14 on RAW 264.7 cells and murine peritoneal cells but showed only minimal amounts of CD14 in murine Kupffer cells. LPS stimulation did not increase the amount of CD14 detectable on mouse Kupffer cells. CD14 expression is very low in Kupffer cells, and LPS-stimulated TNF-alpha release is independent of CD14 in these cells.

Alteration of Cell Cycle Mediated by Zinc in Human Bronchial Epithelial Cells In Vitro

EPA Science Inventory

Zinc (Zn2+), a ubiquitous ambient air contaminant, presents an oxidant challenge to the human lung and is linked to adverse human health effects. To further elucidate the adaptive and apoptotic cellular responses of human airway cells to Zn2+, we performed pilot studies to examin...

Zinc enhances intestinal epithelial barrier function through the PI3K/AKT/mTOR signaling pathway in Caco-2 cells.

PubMed

Shao, Yuxin; Wolf, Patricia G; Guo, Shuangshuang; Guo, Yuming; Gaskins, H Rex; Zhang, Bingkun

2017-05-01

Zinc plays an important role in maintaining intestinal barrier function as well as modulating cellular signaling recognition and protein kinase activities. The phosphatidylinositol 3-kinase (PI3K) cascade has been demonstrated to affect intercellular integrity and tight junction (TJ) proteins. The current study investigated the hypothesis that zinc regulates intestinal intercellular junction integrity through the PI3K/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway. A transwell model of Caco-2 cell was incubated with 0, 50 and 100 μM of zinc at various time points. Transepithelial electrical resistance (TEER), paracellular permeability, TJ proteins, cell proliferation, differentiation and cell damage were measured. Compared with controls, 50 and 100 μM of zinc increased cell growth at 6, 12 and 24 h and the expression of proliferating cell nuclear antigen at 24 h. Zinc (100 μM) significantly elevated TEER at 6-24 h and reduced TJ permeability at 24 h, accompanied by the up-regulation of alkaline phosphatase (AP) activity and zonula occludens (ZO)-1 expression. In addition, zinc (100 μM) affected the PI3K/AKT/mTOR pathway by stimulating phosphorylation of AKT and the downstream target mTOR. Inhibition of PI3K signaling by LY294002 counteracted zinc promotion, as shown by a decrease in AP activity, TEER, the abundance of ZO-1 and phosphorylation of AKT and mTOR. Additionally, TJ permeability and the expression of caspase-3 and LC3II (markers of cell damage) were increased by addition of PI3K inhibitor. In conclusion, the activation of PI3K/AKT/mTOR signaling by zinc is involved in improving intestinal barrier function by enhancing cell differentiation and expression of TJ protein ZO-1. Copyright © 2017 Elsevier Inc. All rights reserved.

Nitric oxide interferes with islet cell zinc homeostasis.

PubMed

Tartler, U; Kröncke, K D; Meyer, K L; Suschek, C V; Kolb-Bachofen, V

2000-12-01

Zinc is crucial for the biosynthesis, storage, and secretion of insulin in pancreatic islet cells. We have previously presented evidence that NO interferes with cellular Zn(2+) homeostasis and we therefore investigated the influence of chronic NO exposure on the labile islet cell Zn(2+) content. A strong fluorescence activity in a large islet cell subpopulation was found after staining with the Zn(2+)-specific fluorophore Zinquin. Culture for 24 h in the presence of nontoxic concentrations of the slow-releasing NO donor DETA/NO resulted in a significantly reduced Zn(2+)-dependent fluorescence. This appears to be islet specific as in endothelial cells DETA/NO exposure enhanced the Zn(2+)-dependent fluorescence activity in a concentration-dependent manner. These results suggest that NO interferes with cellular Zn(2+) homeostasis, which in islet cells is crucial for proper hormone delivery and thus special cell function. Copyright 2000 Academic Press.

Dexamethasone protection from TNF-alpha-induced cell death in MCF-7 cells requires NF-kappaB and is independent from AKT.

PubMed

Machuca, Catalina; Mendoza-Milla, Criselda; Córdova, Emilio; Mejía, Salvador; Covarrubias, Luis; Ventura, José; Zentella, Alejandro

2006-02-21

The biochemical bases for hormone dependence in breast cancer have been recognized as an important element in tumor resistance, proliferation and metastasis. On this respect, dexamethasone (Dex) dependent protection against TNF-alpha-mediated cell death in the MCF-7 cell line has been demonstrated to be a useful model for the study of this type of cancer. Recently, cytoplasmic signaling induced by steroid receptors has been described, such as the activation of the PI3K/Akt and NF-kappaB pathways. We evaluated their possible participation in the Dex-dependent protection against TNF-alpha-mediated cell death. Cellular cultures of the MCF-7 cell line were exposed to either, TNF-alpha or TNF-alpha and Dex, and cell viability was evaluated. Next, negative dominants of PI3K and IkappaB-alpha, designed to block the PI3K/Akt and NF-kappaB pathways, respectively, were transfected and selection and evaluation of several clones overexpressing the mutants were examined. Also, correlation with inhibitor of apoptosis proteins (IAPs) expression was examined. Independent inhibition of these two pathways allowed us to test their participation in Dex-dependent protection against TNF-alpha-cytotoxicity in MCF-7 cells. Expression of the PI3K dominant negative mutant did not alter the protection conferred by Dex against TNF-alpha mediated cell death. Contrariwise, clones expressing the IkappaB-alpha dominant negative mutant lost the Dex-conferred protection against TNF-alpha. In these clones degradation of c-IAP was accelerated, while that of XIAP was remained unaffected. NF-kappaB, but not PI3K/Akt activation, is required for the Dex protective effect against TNF-alpha-mediated cell death, and correlates with lack of degradation of the anti-apoptotic protein c-IAP1.

Effects of alpha-particles on survival and chromosomal aberrations in human mammary epithelial cells

NASA Technical Reports Server (NTRS)

Durante, M.; Grossi, G. F.; Gialanella, G.; Pugliese, M.; Nappo, M.; Yang, T. C.

1995-01-01

We have studied the radiation responses of a human mammary epithelial cell line, H184B5 F5-1 M/10. This cell line was derived from primary mammary cells after treatment with chemicals and heavy ions. The F5-1 M/10 cells are immortal, density-inhibited in growth, and non-tumorigenic in athymic nude mice and represent an in vitro model of the human epithelium for radiation studies. Because epithelial cells are the target of alpha-particles emitted from radon daughters, we concentrated our studies on the efficiency of alpha-particles. Confluent cultures of M/10 cells were exposed to accelerated alpha-particles [beam energy incident at the cell monolayer = 3.85 MeV, incident linear energy transfer (LET) in cell = 109 keV/microns] and, for comparison, to 80 kVp x-rays. The following endpoints were studied: (1) survival, (2) chromosome aberrations at the first postirradiation mitosis, and (3) chromosome alterations at later passages following irradiation. The survival curve was exponential for alpha-particles (D0 = 0.73 +/- 0.04 Gy), while a shoulder was observed for x-rays (alpha/beta = 2.9 Gy; D0 = 2.5 Gy, extrapolation number 1.6). The relative biological effectiveness (RBE) of high-LET alpha-particles for human epithelial cell killing was 3.3 at 37% survival. Dose-response curves for the induction of chromosome aberrations were linear for alpha-particles and linearquadratic for x-rays. The RBE for the induction of chromosome aberrations varied with the type of aberration scored and was high (about 5) for chromosome breaks and low (about 2) for chromosome exchanges.(ABSTRACT TRUNCATED AT 250 WORDS).

Effects of alpha-particles on survival and chromosomal aberrations in human mammary epithelial cells.

PubMed

Durante, M; Grossi, G F; Gialanella, G; Pugliese, M; Nappo, M; Yang, T C

1995-08-01

We have studied the radiation responses of a human mammary epithelial cell line, H184B5 F5-1 M/10. This cell line was derived from primary mammary cells after treatment with chemicals and heavy ions. The F5-1 M/10 cells are immortal, density-inhibited in growth, and non-tumorigenic in athymic nude mice and represent an in vitro model of the human epithelium for radiation studies. Because epithelial cells are the target of alpha-particles emitted from radon daughters, we concentrated our studies on the efficiency of alpha-particles. Confluent cultures of M/10 cells were exposed to accelerated alpha-particles [beam energy incident at the cell monolayer = 3.85 MeV, incident linear energy transfer (LET) in cell = 109 keV/microns] and, for comparison, to 80 kVp x-rays. The following endpoints were studied: (1) survival, (2) chromosome aberrations at the first postirradiation mitosis, and (3) chromosome alterations at later passages following irradiation. The survival curve was exponential for alpha-particles (D0 = 0.73 +/- 0.04 Gy), while a shoulder was observed for x-rays (alpha/beta = 2.9 Gy; D0 = 2.5 Gy, extrapolation number 1.6). The relative biological effectiveness (RBE) of high-LET alpha-particles for human epithelial cell killing was 3.3 at 37% survival. Dose-response curves for the induction of chromosome aberrations were linear for alpha-particles and linearquadratic for x-rays. The RBE for the induction of chromosome aberrations varied with the type of aberration scored and was high (about 5) for chromosome breaks and low (about 2) for chromosome exchanges.(ABSTRACT TRUNCATED AT 250 WORDS)

Expression and function of CD8 alpha/beta chains on rat and human mast cells.

PubMed

Kim, Mi-Sun; Kim, Sung-Hoon; Lee, Hye-Jung; Kim, Hyung-Min

2004-03-01

The expression and functional role of CD8 glycoprotein, a marker of cytotoxic/suppressor T lymphocytes and NK cells, were not studied on freshly isolated connective tissue type rat peritoneal mast cells, a rat mucosal type mast cell line (RBL 2H3), or human mast cell line (HMC-1). We used the reverse transcription-polymerase chain reaction (RT-PCR) and Western blot analysis, immunohistochemistry and enzyme-linked immunosorbent assay. RT-PCR and Western blot analysis identified the presence of CD8 alpha/beta chains on the mast cells, and immunohistochemistry confirmed CD8alpha expression on rat or human mast cells. Functional studies demonstrated that stimulation of CD8 alpha/beta chains on rat mast cells induced the secretion of tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), which are regarded as important mediators during infection. However, co-stimulation with stem cell factor had no effect on CD8-induced mediator secretion. Our findings demonstrate novel biological roles of CD8 molecules in mast cells.

Paracrine GABA and insulin regulate pancreatic alpha cell proliferation in a mouse model of type 1 diabetes.

PubMed

Feng, Allen L; Xiang, Yun-Yan; Gui, Le; Kaltsidis, Gesthika; Feng, Qingping; Lu, Wei-Yang

2017-06-01

This study aimed to elucidate the mechanism of increased proliferation of alpha cells in recent-onset type 1 diabetes. Pancreatic beta cells express GAD and produce γ-aminobutyric acid (GABA), which inhibits alpha cell secretion of glucagon. We explored the roles of GABA in alpha cell proliferation in conditions corresponding to type 1 diabetes in a mouse model and in vitro. Type 1 diabetes was induced by injecting the mice with streptozotocin (STZ). Some of the STZ-injected mice were treated with GABA (10 mg/kg daily) for 12 days. Isolated pancreatic islets were treated with STZ or STZ together with GABA for 2 days. The effects of GABA treatment on STZ-induced alpha cell proliferation in vivo and in vitro were assessed. The effect of muscimol, a GABA receptor agonist, on αTC1-6 cell proliferation was also examined. STZ injection substantially decreased levels of GAD, GABA and insulin in pancreatic beta cells 12 h after injection; this was followed by an upsurge of phosphorylated mechanistic target of rapamycin (p-mTOR) in the alpha cells at day 1, and a significant increase in alpha cell mass at day 3. Treating STZ-injected mice with GABA largely restored the immunodetectable levels of insulin and GAD in the beta cells and significantly decreased the number of aldehyde dehydrogenase 1 family, member A3 (ALDH1a3)-positive cells, alpha cell mass and hyperglucagonaemia. STZ treatment also increased alpha cell proliferation in isolated islets, which was reversed by co-treatment with GABA. Muscimol, together with insulin, significantly lowered the level of cytosolic Ca 2+ and p-mTOR, and decreased the proliferation rate of αTC1-6 cells. GABA signalling critically controls the alpha cell population in pancreatic islets. Low intraislet GABA may contribute to alpha cell hyperplasia in early type 1 diabetes.

Determining adaptive and adverse oxidative stress responses in human bronical epithelial cells exposed to zinc

EPA Science Inventory

Determining adaptive and adverse oxidative stress responses in human bronchial epithelial cells exposed to zincJenna M. Currier1,2, Wan-Yun Cheng1, Rory Conolly1, Brian N. Chorley1Zinc is a ubiquitous contaminant of ambient air that presents an oxidant challenge to the human lung...

Trimethyltin-activated cyclooxygenase stimulates tumor necrosis factor-alpha release from glial cells through reactive oxygen species.

PubMed

Viviani, B; Corsini, E; Pesenti, M; Galli, C L; Marinovich, M

2001-04-15

Exposure of a primary culture of glial cells to the classical neurotoxicant trimethyltin (TMT) results in the release of prostaglandin (PG)E(2) and tumor necrosis factor (TNF)-alpha. Prior treatment of glial cells with either the nonspecific inhibitor of cyclooxygenase and lypoxygenase eicosatetraynoic acid (ETYA) or the cyclooxygenase inhibitor indomethacin completely prevented TMT-induced PGE(2) production and TNF-alpha release, suggesting a role for cyclooxygenase metabolites in TMT-induced TNF-alpha release. Exposure of glial cells to increasing concentrations of PGE(2) or other prostanoids did not increase TNF-alpha synthesis, while the presence of exogenous PGE(2) during treatment of glial cells with TMT actually suppressed TNF-alpha release. The activation of arachidonic acid metabolism produces reactive oxygen species (ROS). Scavenging of ROS by means of the antioxidant trolox prevented the TMT-induced release of TNF-alpha from glial cells, while indomethacin was found to suppress ROS formation induced by 1 microM TMT in glial cells. These results suggest that activation of arachidonic acid metabolism causes TNF-alpha release through the production of ROS rather than PGE(2). Indeed, PGE(2) may exert negative feedback on the release of TNF-alpha. Copyright 2001 Academic Press.

Development of single cell protectors for sealed silver-zinc cells, phase 1

NASA Technical Reports Server (NTRS)

Imamura, M. S.; Donovan, R. L.; Lear, J. W.; Murray, B.

1976-01-01

A single cell protector (SCP) assembly capable of protecting a single silver-zinc (Ag Zn) battery cell was designed, fabricated, and tested. The SCP provides cell-level protection against overcharge and overdischarge by a bypass circuit. The bypass circuit consists of a magnetic-latching relay that is controlled by the high and low-voltage limit comparators. Although designed specifically for secondary Ag-Zn cells, the SCP is flexible enough to be adapted to other rechargeable cells. Eighteen SCPs were used in life testing of an 18-cell battery. The cells were sealed Ag-Zn system with inorganic separators. For comparison, another 18-cell battery was subjected to identical life test conditions, but with battery-level protection rather than cell-level. An alternative approach to the SCP design in the form of a microprocessor-based system was conceptually designed. The comparison of SCP and microprocessor approaches is also presented and a preferred approach for Ag-Zn battery protection is discussed.

Effect of thalidomide on the expression of TNF-alpha m-RNA and synthesis of TNF-alpha in cells from leprosy patients with reversal reaction.

PubMed

Tadesse, Azeb; Abebe, Markos; Bizuneh, Elizabeth; Mulugeta, Wondwossen; Aseffa, Abraham; Shannon, E J

2006-01-01

Hypersensitivity reactions called reversal reaction (RR) and erythema nodosum leprosum (ENL) occur in leprosy. They are characterized by an increase in tumor necrosis factor-alpha (TNF-alpha). Thalidomide is an effective treatment for ENL but not RR. Its effectiveness in ENL is attributed to inhibition of TNF-alpha, and this does not explain its failure to treat RR. We assessed thalidomide's effect on TNF-alpha in RR. Mononuclear cells from RR and non-RR patients and healthy individuals were treated with thalidomide and M.leprae (AFB), a cytosol fraction of M. leprae or Dharmendra lepromin. Thalidomide suppressed TNF-alpha, but when some RR patients' cells were stimulated with AFB, it enhanced TNF-alpha.

Zinc starvation induces autophagy in yeast.

PubMed

Kawamata, Tomoko; Horie, Tetsuro; Matsunami, Miou; Sasaki, Michiko; Ohsumi, Yoshinori

2017-05-19

Zinc is an essential nutrient for all forms of life. Within cells, most zinc is bound to protein. Because zinc serves as a catalytic or structural cofactor for many proteins, cells must maintain zinc homeostasis under severely zinc-deficient conditions. In yeast, the transcription factor Zap1 controls the expression of genes required for uptake and mobilization of zinc, but to date the fate of existing zinc-binding proteins under zinc starvation remains poorly understood. Autophagy is an evolutionarily conserved cellular degradation/recycling process in which cytoplasmic proteins and organelles are sequestered for degradation in the vacuole/lysosome. In this study, we investigated how autophagy functions under zinc starvation. Zinc depletion induced non-selective autophagy, which is important for zinc-limited growth. Induction of autophagy by zinc starvation was not directly related to transcriptional activation of Zap1. Instead, TORC1 inactivation directed zinc starvation-induced autophagy. Abundant zinc proteins, such as Adh1, Fba1, and ribosomal protein Rpl37, were degraded in an autophagy-dependent manner. But the targets of autophagy were not restricted to zinc-binding proteins. When cellular zinc is severely depleted, this non-selective autophagy plays a role in releasing zinc from the degraded proteins and recycling zinc for other essential purposes. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

[Experimental study of IFN-alpha and IFN-gamma on reversing ATRA-resistance in MR2 cell line].

PubMed

He, Peng-Cheng; Zhang, Mei; Li, Jing; Cao, Yun-Xin; Cai, Rui-Bo; Liu, Ya-Lin

2007-03-01

To explore the possibility and the possible mechanism of reversing ATRA-resistance in MR2 cells by using IFN-alpha and IFN-gamma in combination with all-trans retinoic acid (ATRA). After MR2 cells(ATRA-resistance cell line) were treated with IFN-alpha, IFN-gamma and ATRA alone or IFN-alpha and IFN-gamma in combination with ATRA respectively, the cell proliferation was tested by MTT colorimetry, the cell differentiation was tested through light microscope, by NBT test and flow cytometry (FCM). The expression of promyelocytic leukemia (PML) protein was observed by indirect immunofluorescence staining. Both IFN-alpha and IFN-gamma could inhibit the proliferation of MR2 cells. The effects were more obviously in both IFN-alpha+ATRA group and IFN-gamma+ATRA group. But there were no significant difference between either IFN-alpha group and IFN-gamma group or IFN-alpha+ATRA group and IFN-gamma+ATRA group (P>0.05). Both IFN could also induce the differentiation of MR2 cells. The effects of IFN-alpha+ATRA group and IFN-gamma+ATRA group were more obvious. However, the differentiation of MR2 cells induced by IFN-gamma+ATRA group was more higher than that by IFN-alpha+ATRA group (P<0.05). Both IFN could induce the expression of PML protein. The reversing effcet of IFN-gamma+ATRA group on ATRA-resistence in MR2 cells are more powerful than that of IFN-alpha+ATRA group, which may be related to the different signal transduction pathway of IFN-alpha and IFN-gamma.

Characterization of synthesis and storage of TGF-alpha in rat parotid acinar and intercalated duct cells.

PubMed

Login, G R; Yang, J; Bryan, K P; Digenis, E C; McBride, J; Elovic, A; Quissell, D O; Dvorak, A M; Wong, D T

1997-03-01

Although the expression and biological role of transforming growth factor-alpha (TGF-alpha) have been explored in a variety of normal cells in mammalian species, little is known about the storage of TGF-alpha in secretory cells of exocrine organs. Parotid glands from four rats were homogenized for RNA isolation followed by reverse transcription-polymerase chain reaction to determine the presence of TGF-alpha message. In situ hybridization using a hamster-specific TGF-alpha riboprobe was done on paraffin sections. Parotid gland and isolated acinar cells were processed for transmission electron microscopy (TEM) and postembedding immunogold labeled for TGF-alpha. Gold particles were counted on approximately 200 granules in 10 acinar cells and in 10 intercalated duct cells. Labeling density was calculated as the number of gold particles per square micrometer +/- SD. Statistical significance was calculated using one-way analysis of variance. Using multiple technologies, we have established that rat parotid acinar and intercalated duct cells synthesize TGF-alpha and store the precursor form of this cytokine in their secretory granules.

Recent Developments in Silver/Zinc Rechargeable Cell Studies

NASA Technical Reports Server (NTRS)

Lewis, Harlan L.

2001-01-01

This viewgraph presentation discusses silver/zinc cell casing configurations and test results examining discharge capacity and silver migration comparisons. The following recommendations were proposed: 1) Use silver-treated cellophane instead of clear cellophane; 2) Use split wrap for cellophane whenever possible; and 3) Strongly consider use of sausage casing with PVA film in the following configuration: 1-mil (tubular) SC/1-mil PVA film/2.3-mil plain or 6-mil fiber-reinforced SC tubular.

Influence of zinc deficiency on AKT-MDM2-P53 signaling axes in normal and malignant human prostate cells

USDA-ARS?s Scientific Manuscript database

With prostate being the highest zinc-accumulating tissue before the onset of cancer, the effects of physiologic levels of zinc on Akt-Mdm2-p53 and Akt-p21 signaling axes in human normal prostate epithelial cells (PrEC) and malignant prostate LNCaP cells were examined. Cells were cultured for 6 d in...

Stabilized nickel-zinc battery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Himy, A.; Wagner, O.C.

An alkaline nickel-zinc cell which has (1) a nickel-nickel hydroxide cathode; (2) a zinc-zinc oxide anode containing (A) a corrosion inhibitor such as PBO, SNO2, Tl2O3, in(OH)3 or mixtures thereof; (B) a slight corrosion accelerator such as cdo, bi2o3, ga2o3, or mixtures thereof; and (C) a zinc active material; (3) a mass-transport separator; (4) an alkaline electrolyte; and (5) means for charging the cell with an interrupted current having a frequency of from more than zero to 16 hertz with a rest period of not less than 60 milliseconds. Another desirable feature is the use of a pressure-cutoff switch tomore » terminate charging when the internal pressure of the cell reaches a selected value in the range of from 5 to 8 psig.« less

Intracellular zinc flux causes reactive oxygen species mediated mitochondrial dysfunction leading to cell death in Leishmania donovani.

PubMed

Kumari, Anjali; Singh, Krishn Pratap; Mandal, Abhishek; Paswan, Ranjeet Kumar; Sinha, Preeti; Das, Pradeep; Ali, Vahab; Bimal, Sanjiva; Lal, Chandra Shekhar

2017-01-01

Leishmaniasis caused by Leishmania parasite is a global threat to public health and one of the most neglected tropical diseases. Therefore, the discovery of novel drug targets and effective drug is a major challenge and an important goal. Leishmania is an obligate intracellular parasite that alternates between sand fly and human host. To survive and establish infections, Leishmania parasites scavenge and internalize nutrients from the host. Nevertheless, host cells presents mechanism like nutrient restriction to inhibit microbial growth and control infection. Zinc is crucial for cellular growth and disruption in its homeostasis hinders growth and survival in many cells. However, little is known about the role of zinc in Leishmania growth and survival. In this study, the effect of zinc on the growth and survival of L.donovani was analyzed by both Zinc-depletion and Zinc-supplementation using Zinc-specific chelator N, N, N', N'-tetrakis (2-pyridylmethyl) ethylenediamine (TPEN) and Zinc Sulfate (ZnSO4). Treatment of parasites with TPEN rather than ZnSO4 had significantly affected the growth in a dose- and time-dependent manner. The pre-treatment of promastigotes with TPEN resulted into reduced host-parasite interaction as indicated by decreased association index. Zn depletion resulted into flux in intracellular labile Zn pool and increased in ROS generation correlated with decreased intracellular total thiol and retention of plasma membrane integrity without phosphatidylserine exposure in TPEN treated promastigotes. We also observed that TPEN-induced Zn depletion resulted into collapse of mitochondrial membrane potential which is associated with increase in cytosolic calcium and cytochrome-c. DNA fragmentation analysis showed increased DNA fragments in Zn-depleted cells. In summary, intracellular Zn depletion in the L. donovani promastigotes led to ROS-mediated caspase-independent mitochondrial dysfunction resulting into apoptosis-like cell death. Therefore, cellular

Overexpression of {alpha}-catenin increases osteoblastic differentiation in mouse mesenchymal C3H10T1/2 cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Dohee; Yang, Jae-Yeon; Shin, Chan Soo, E-mail: csshin@snu.ac.kr

2009-05-15

{alpha}- and {beta}-Catenin link cadherins to the actin-based cytoskeleton at adherens junctions and regulate cell-cell adhesion. Although roles of cadherins and canonical Wnt-/{beta}-catenin-signaling in osteoblastic differentiation have been extensively studied, the role of {alpha}-catenin is not known. Murine embryonic mesenchymal stem cells, C3H10T1/2 cells, were transduced with retrovirus encoding {alpha}-catenin (MSCV-{alpha}-catenin-HA-GFP). In the presence of Wnt-3A conditioned medium or osteogenic medium ({beta}-glycerol phosphate and ascorbic acid), cells overexpressing {alpha}-catenin showed enhanced osteoblastic differentiation as measured by alkaline phosphatase (ALP) staining and ALP activity assay compared to cells transduced with empty virus (MSCV-GFP). In addition, mRNA expression of osteocalcin and Runx2more » was significantly increased compared to control. Cell aggregation assay revealed that {alpha}-catenin overexpression has significantly increased cell-cell aggregation. However, cellular {beta}-catenin levels (total, cytoplasmic-nuclear ratio) and {beta}-catenin-TCF/LEF transcriptional activity did not change by overexpression of {alpha}-catenin. Knock-down of {alpha}-catenin using siRNA decreased osteoblastic differentiation as measured by ALP assay. These results suggest that {alpha}-catenin overexpression increases osteoblastic differentiation by increasing cell-cell adhesion rather than Wnt-/{beta}-catenin-signaling.« less

Radon measurement of natural gas using alpha scintillation cells.

PubMed

Kitto, Michael E; Torres, Miguel A; Haines, Douglas K; Semkow, Thomas M

2014-12-01

Due to their sensitivity and ease of use, alpha-scintillation cells are being increasingly utilized for measurements of radon ((222)Rn) in natural gas. Laboratory studies showed an average increase of 7.3% in the measurement efficiency of alpha-scintillation cells when filled with less-dense natural gas rather than regular air. A theoretical calculation comparing the atomic weight and density of air to that of natural gas suggests a 6-7% increase in the detection efficiency when measuring radon in the cells. A correction is also applicable when the sampling location and measurement laboratory are at different elevations. These corrections to the measurement efficiency need to be considered in order to derive accurate concentrations of radon in natural gas. Copyright © 2014 Elsevier Ltd. All rights reserved.

Role of nutritional zinc in the prevention of osteoporosis.

PubMed

Yamaguchi, Masayoshi

2010-05-01

Zinc is known as an essential nutritional factor in the growth of the human and animals. Bone growth retardation is a common finding in various conditions associated with dietary zinc deficiency. Bone zinc content has been shown to decrease in aging, skeletal unloading, and postmenopausal conditions, suggesting its role in bone disorder. Zinc has been demonstrated to have a stimulatory effect on osteoblastic bone formation and mineralization; the metal directly activates aminoacyl-tRNA synthetase, a rate-limiting enzyme at translational process of protein synthesis, in the cells, and it stimulates cellular protein synthesis. Zinc has been shown to stimulate gene expression of the transcription factors runt-related transcription factor 2 (Runx2) that is related to differentiation into osteoblastic cells. Moreover, zinc has been shown to inhibit osteoclastic bone resorption due to inhibiting osteoclast-like cell formation from bone marrow cells and stimulating apoptotic cell death of mature osteoclasts. Zinc has a suppressive effect on the receptor activator of nuclear factor (NF)-kappaB ligand (RANKL)-induced osteoclastogenesis. Zinc transporter has been shown to express in osteoblastic and osteoclastic cells. Zinc protein is involved in transcription. The intake of dietary zinc causes an increase in bone mass. beta-Alanyl-L: -histidinato zinc (AHZ) is a zinc compound, in which zinc is chelated to beta-alanyl-L: -histidine. The stimulatory effect of AHZ on bone formation is more intensive than that of zinc sulfate. Zinc acexamate has also been shown to have a potent-anabolic effect on bone. The oral administration of AHZ or zinc acexamate has the restorative effect on bone loss under various pathophysiologic conditions including aging, skeletal unloading, aluminum bone toxicity, calcium- and vitamin D-deficiency, adjuvant arthritis, estrogen deficiency, diabetes, and fracture healing. Zinc compounds may be designed as new supplementation factor in the prevention and

Expression of hypoxia-induced factor-1 alpha in early-stage and in metastatic oral squamous cell carcinoma.

PubMed

Ribeiro, Maisa; Teixeira, Sarah R; Azevedo, Monarko N; Fraga, Ailton C; Gontijo, Antônio Pm; Vêncio, Eneida F

2017-04-01

To investigate hypoxia-induced factor-1 alpha expression in distinct oral squamous cell carcinoma subtypes and topographies and correlate with clinicopathological data. Hypoxia-induced factor-1 alpha expression was assessed by immunohistochemistry in 93 cases of OSCC. Clinical and histopathological data were reviewed from medical records. Hypoxia-induced factor-1 alpha status was distinct according to tumor location, subtype and topography affect. In superficial oral squamous cell carcinomas, most tumor cells overexpressed hypoxia-induced factor-1 alpha, whereas hypoxia-induced factor-1 alpha was restricted to the intratumoral region in conventional squamous cell carcinomas. All basaloid squamous cell carcinomas exhibited downregulation of hypoxia-induced factor-1 alpha. Interestingly, metastatic lymph nodes (91.7%, p = 0.001) and the intratumoral regions of corresponding primary tumors (58.3%, p = 0.142) showed hypoxia-induced factor-1 alpha-positive tumor cells. Overall survival was poor in patients with metastatic lymph nodes. Hypoxia-induced factor-1 alpha has distinct expression patterns in different oral squamous cell carcinoma subtypes and topographies, suggesting that low oxygen tension promotes the growth pattern of superficial and conventional squamous cell carcinoma, but not basaloid squamous cell carcinoma. Indeed, a hypoxic environment may facilitate regional metastasis, making it a useful diagnostic and prognostic marker in primary tumors.

Zinc and the modulation of redox homeostasis

PubMed Central

Oteiza, Patricia I.

2012-01-01

Zinc, a redox inactive metal, has been long viewed as a component of the antioxidant network, and growing evidence points to its involvement in redox-regulated signaling. These actions are exerted through several mechanisms based on the unique chemical and functional properties of zinc. Overall, zinc contributes to maintain the cell redox balance through different mechanisms including: i) the regulation of oxidant production and metal-induced oxidative damage; ii) the dynamic association of zinc with sulfur in protein cysteine clusters, from which the metal can be released by nitric oxide, peroxides, oxidized glutathione and other thiol oxidant species; iii) zinc-mediated induction of the zinc-binding protein metallothionein, which releases the metal under oxidative conditions and act per se scavenging oxidants; iv) the involvement of zinc in the regulation of glutathione metabolism and of the overall protein thiol redox status; and v) a direct or indirect regulation of redox signaling. Findings of oxidative stress, altered redox signaling, and associated cell/tissue disfunction in cell and animal models of zinc deficiency, stress the relevant role of zinc in the preservation of cell redox homeostasis. However, while the participation of zinc in antioxidant protection, redox sensing, and redox-regulated signaling is accepted, the involved molecules, targets and mechanisms are still partially known and the subject of active research. PMID:22960578

PDGFBB promotes PDGFR{alpha}-positive cell migration into artificial bone in vivo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yoshida, Shigeyuki; Center for Human Metabolomic Systems Biology, Keio University School of Medicine, 35 Shinano-machi, Shinjuku-ku, Tokyo 160-8582; Iwasaki, Ryotaro

2012-05-18

Highlights: Black-Right-Pointing-Pointer We examined effects of PDGFBB in PDGFR{alpha} positive cell migration in artificial bones. Black-Right-Pointing-Pointer PDGFBB was not expressed in osteoblastic cells but was expressed in peripheral blood cells. Black-Right-Pointing-Pointer PDGFBB promoted PDGFR{alpha} positive cell migration into artificial bones but not osteoblast proliferation. Black-Right-Pointing-Pointer PDGFBB did not inhibit osteoblastogenesis. -- Abstract: Bone defects caused by traumatic bone loss or tumor dissection are now treated with auto- or allo-bone graft, and also occasionally by artificial bone transplantation, particularly in the case of large bone defects. However, artificial bones often exhibit poor affinity to host bones followed by bony union failure.more » Thus therapies combining artificial bones with growth factors have been sought. Here we report that platelet derived growth factor bb (PDGFBB) promotes a significant increase in migration of PDGF receptor {alpha} (PDGFR{alpha})-positive mesenchymal stem cells/pre-osteoblastic cells into artificial bone in vivo. Growth factors such as transforming growth factor beta (TGF{beta}) and hepatocyte growth factor (HGF) reportedly inhibit osteoblast differentiation; however, PDGFBB did not exhibit such inhibitory effects and in fact stimulated osteoblast differentiation in vitro, suggesting that combining artificial bones with PDGFBB treatment could promote host cell migration into artificial bones without inhibiting osteoblastogenesis.« less

Magnesium and zinc borate enhance osteoblastic differentiation of stem cells from human exfoliated deciduous teeth in vitro.

PubMed

Liu, Yao-Jen; Su, Wen-Ta; Chen, Po-Hung

2018-01-01

Various biocompatible and biodegradable scaffolds blended with biochemical signal molecules with adequate osteoinductive and osteoconductive properties have attracted significant interest in hard tissue engineering regeneration. We evaluated the distinct effects of magnesium borate, zinc borate, and boric acid blended into chitosan scaffold for osteogenic differentiation of stem cells from exfoliated deciduous teeth. Stem cells from exfoliated deciduous teeth cells are a potential source of functional osteoblasts for applications in bone tissue engineering, but the efficiency of osteoblastic differentiation is low, thereby significantly limiting their clinical applications. Divalent metal borates have potential function in bone remodeling because they can simulate bone formation and decrease bone resorption. These magnesium, zinc, and B ions can gradually be released into the culture medium from the scaffold and induce advanced osteoblastic differentiation from stem cells from exfoliated deciduous teeth. Stem cells from exfoliated deciduous teeth with magnesium borate or zinc borate as inducer demonstrated more osteoblastic differentiation after 21 days of culture. Differentiated cells exhibited activity of alkaline phosphatase, bone-related gene expression of collagen type I, runt-related transcription factor 2, osteopontin, osteocalcin, vascular endothelial growth factor, and angiopoietin-1, as noted via real-time polymerase chain reaction analysis, as well as significant deposits of calcium minerals. Divalent mental magnesium and zinc and nonmetal boron can be an effective inducer of osteogenesis for stem cells from exfoliated deciduous teeth. This experiment might provide useful inducers for osteoblastic differentiation of stem cells from exfoliated deciduous teeth for tissue engineering and bone repair.

Two novel, putatively cell wall-associated and glycosylphosphatidylinositol-anchored alpha-glucanotransferase enzymes of Aspergillus niger.

PubMed

van der Kaaij, R M; Yuan, X-L; Franken, A; Ram, A F J; Punt, P J; van der Maarel, M J E C; Dijkhuizen, L

2007-07-01

In the genome sequence of Aspergillus niger CBS 513.88, three genes were identified with high similarity to fungal alpha-amylases. The protein sequences derived from these genes were different in two ways from all described fungal alpha-amylases: they were predicted to be glycosylphosphatidylinositol anchored, and some highly conserved amino acids of enzymes in the alpha-amylase family were absent. We expressed two of these enzymes in a suitable A. niger strain and characterized the purified proteins. Both enzymes showed transglycosylation activity on donor substrates with alpha-(1,4)-glycosidic bonds and at least five anhydroglucose units. The enzymes, designated AgtA and AgtB, produced new alpha-(1,4)-glycosidic bonds and therefore belong to the group of the 4-alpha-glucanotransferases (EC 2.4.1.25). Their reaction products reached a degree of polymerization of at least 30. Maltose and larger maltooligosaccharides were the most efficient acceptor substrates, although AgtA also used small nigerooligosaccharides containing alpha-(1,3)-glycosidic bonds as acceptor substrate. An agtA knockout of A. niger showed an increased susceptibility towards the cell wall-disrupting compound calcofluor white, indicating a cell wall integrity defect in this strain. Homologues of AgtA and AgtB are present in other fungal species with alpha-glucans in their cell walls, but not in yeast species lacking cell wall alpha-glucan. Possible roles for these enzymes in the synthesis and/or maintenance of the fungal cell wall are discussed.

Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Que, Emily L.; Bleher, Reiner; Duncan, Francesca E.

2014-12-15

Fertilization of a mammalian egg initiates a series of 'zinc sparks' that are necessary to induce the egg-to-embryo transition. Despite the importance of these zinc-efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches that resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy-dispersive spectroscopy, X-ray fluorescence microscopy and three-dimensional elemental tomography for high-resolution elemental mapping. We show that the zinc spark arises from a system of thousands of zinc-loaded vesicles, each ofmore » which contains, on average, 10(6) zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. The discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes« less

Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks.

PubMed

Que, Emily L; Bleher, Reiner; Duncan, Francesca E; Kong, Betty Y; Gleber, Sophie C; Vogt, Stefan; Chen, Si; Garwin, Seth A; Bayer, Amanda R; Dravid, Vinayak P; Woodruff, Teresa K; O'Halloran, Thomas V

2015-02-01

Fertilization of a mammalian egg initiates a series of 'zinc sparks' that are necessary to induce the egg-to-embryo transition. Despite the importance of these zinc-efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches that resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy-dispersive spectroscopy, X-ray fluorescence microscopy and three-dimensional elemental tomography for high-resolution elemental mapping. We show that the zinc spark arises from a system of thousands of zinc-loaded vesicles, each of which contains, on average, 10(6) zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. The discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes.

Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks

DOE PAGES

Que, Emily L.; Bleher, Reiner; Duncan, Francesca E.; ...

2014-12-15

Fertilization of a mammalian egg induces a series of ‘zinc sparks’ that are necessary for inducing the egg-to-embryo transition. Despite the importance of these zinc efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches to resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy dispersive spectroscopy, X-ray fluorescence microscopy, and 3D elemental tomography for high resolution elemental mapping. Here we show that the zinc spark arises from a system of thousands ofmore » zinc-loaded vesicles, each of which contains, on average, 106 zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. We conclude that the discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes.« less

Quantitative mapping of zinc fluxes in the mammalian egg reveals the origin of fertilization-induced zinc sparks

PubMed Central

Que, Emily L.; Bleher, Reiner; Duncan, Francesca E.; Kong, Betty Y.; Gleber, Sophie C.; Vogt, Stefan; Chen, Si; Garwin, Seth A.; Bayer, Amanda R.; Dravid, Vinayak; Woodruff, Teresa K.; O’Halloran, Thomas V.

2015-01-01

Fertilization of a mammalian egg induces a series of ‘zinc sparks’ that are necessary for inducing the egg-to-embryo transition. Despite the importance of these zinc efflux events little is known about their origin. To understand the molecular mechanism of the zinc spark we combined four physical approaches to resolve zinc distributions in single cells: a chemical probe for dynamic live-cell fluorescence imaging and a combination of scanning transmission electron microscopy with energy dispersive spectroscopy, X-ray fluorescence microscopy, and 3D elemental tomography for high resolution elemental mapping. We show that the zinc spark arises from a system of thousands of zinc-loaded vesicles, each of which contains, on average, 106 zinc atoms. These vesicles undergo dynamic movement during oocyte maturation and exocytosis at the time of fertilization. The discovery of these vesicles and the demonstration that zinc sparks originate from them provides a quantitative framework for understanding how zinc fluxes regulate cellular processes. PMID:25615666

Ex vivo delivered stromal cell-derived factor-1alpha promotes stem cell homing and induces angiomyogenesis in the infarcted myocardium.

PubMed

Elmadbouh, I; Haider, Husnain Kh; Jiang, Shujia; Idris, Niagara Muhammad; Lu, Gang; Ashraf, Muhammad

2007-04-01

We aimed to optimize non-viral transfection of human stromal cell derived factor (SDF-1alpha) gene into skeletal myoblasts (SkM) and, transplant these cells to establish transient SDF-1alpha gradient to favor extra-cardiac stem cell translocation into infarcted heart. Optimized conditions for transfection of SDF-1alpha gene into syngenic SkM were achieved using FuGene6/phSDF-1alpha (3:2v/w, 4 h transfection) with 125 microM ZnCl(2) (p<0.001). After characterization for transgene overexpression by immunostaining, ELISA and PCR, the cells were transplanted in female rat model of myocardial infarction. Thirty-six rats were grouped (n=12/group) to receive 70 microl DMEM without cells (group-1) or containing 1.5 x 10(6) non-transfected (group-2) or SDF-1alpha transfected SkM (group-3). On day 4 post-transplantation (in 4 animals/group), marked expression of SDF-1alpha/sry-gene (p=0.003), total Akt, phospho-Akt and Bcl2 was observed in group-3. The number of CD31(+), C-kit(+) and CD34(+) cells was highest in group-3 hearts (p<0.01). Blood vessel density in group-3 was higher in both scar and peri-scar regions (p<0.001) as compared with other groups. Echocardiography showed improved indices of left ventricle contractile function and remodeling in group-3 (p<0.05) as compared with groups-1 and -2. We conclude that ex vivo SDF-1alpha transgene delivery promotes stem and progenitor cell migration to the heart, activates cell survival signaling and enhances angiomyogenesis in the infarcted heart.

alpha-Lactalbumin species variation, HAMLET formation, and tumor cell death.

PubMed

Pettersson, Jenny; Mossberg, Ann-Kristin; Svanborg, Catharina

2006-06-23

HAMLET (human alpha-lactalbumin made lethal to tumor cells) is a tumoricidal complex of apo alpha-lactalbumin and oleic acid, formed in casein after low pH treatment of human milk. This study examined if HAMLET-like complexes are present in casein from different species and if isolated alpha-lactalbumin from those species can form such complexes with oleic acid. Casein from human, bovine, equine, and porcine milk was separated by ion exchange chromatography and active complexes were only found in human casein. This was not explained by alpha-lactalbumin sequence variation, as purified bovine, equine, porcine, and caprine alpha-lactalbumins formed complexes with oleic acid with biological activity similar to HAMLET. We conclude that structural variation of alpha-lactalbumins does not preclude the formation of HAMLET-like complexes and that natural HAMLET formation in casein was unique to human milk, which also showed the highest oleic acid content.

Stromal cell-derived factor-1{alpha} (SDF-1{alpha}/CXCL12) stimulates ovarian cancer cell growth through the EGF receptor transactivation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Porcile, Carola; Bajetto, Adriana; Barbieri, Federica

2005-08-15

Ovarian cancer (OC) is the leading cause of death in gynecologic diseases in which there is evidence for a complex chemokine network. Chemokines are a family of proteins that play an important role in tumor progression influencing cell proliferation, angiogenic/angiostatic processes, cell migration and metastasis, and, finally, regulating the immune cells recruitment into the tumor mass. We previously demonstrated that astrocytes and glioblastoma cells express both the chemokine receptor CXCR4 and its ligand stromal cell-derived factor-1 (SDF-1), and that SDF-1{alpha} treatment induced cell proliferation, supporting the hypothesis that chemokines may play an important role in tumor cells' growth in vitro.more » In the present study, we report that CXCR4 and SDF-1 are expressed in OC cell lines. We demonstrate that SDF-1{alpha} induces a dose-dependent proliferation in OC cells, by the specific interaction with CXCR4 and a biphasic activation of ERK1/2 and Akt kinases. Our results further indicate that CXCR4 activation induces EGF receptor (EGFR) phosphorylation that in turn was linked to the downstream intracellular kinases activation, ERK1/2 and Akt. In addition, we provide evidence for cytoplasmic tyrosine kinase (c-Src) involvement in the SDF-1/CXCR4-EGFR transactivation. These results suggest a possible important 'cross-talk' between SDF-1/CXCR4 and EGFR intracellular pathways that may link signals of cell proliferation in ovarian cancer.« less

The ectopic expression of Pax4 in the mouse pancreas converts progenitor cells into alpha and subsequently beta cells.

PubMed

Collombat, Patrick; Xu, Xiaobo; Ravassard, Philippe; Sosa-Pineda, Beatriz; Dussaud, Sébastien; Billestrup, Nils; Madsen, Ole D; Serup, Palle; Heimberg, Harry; Mansouri, Ahmed

2009-08-07

We have previously reported that the loss of Arx and/or Pax4 gene activity leads to a shift in the fate of the different endocrine cell subtypes in the mouse pancreas, without affecting the total endocrine cell numbers. Here, we conditionally and ectopically express Pax4 using different cell-specific promoters and demonstrate that Pax4 forces endocrine precursor cells, as well as mature alpha cells, to adopt a beta cell destiny. This results in a glucagon deficiency that provokes a compensatory and continuous glucagon+ cell neogenesis requiring the re-expression of the proendocrine gene Ngn3. However, the newly formed alpha cells fail to correct the hypoglucagonemia since they subsequently acquire a beta cell phenotype upon Pax4 ectopic expression. Notably, this cycle of neogenesis and redifferentiation caused by ectopic expression of Pax4 in alpha cells is capable of restoring a functional beta cell mass and curing diabetes in animals that have been chemically depleted of beta cells.

Zinc finger X-chromosomal protein (ZFX) promotes solid agar colony growth of osteosarcoma cells.

PubMed

Jiang, Rui; Wang, Jin-cheng; Sun, Mei; Zhang, Xing-yi; Wu, Han

2012-01-01

Zinc finger X-chromosomal protein (ZFX) is a member of the zinc finger family of proteins. The importance of ZFX in several cancer types, including prostate cancer, laryngeal squamous cell carcinoma, and glioma, has been addressed. However, the role of ZFX in human osteosarcoma remains unknown. Here we investigated the phenotype of ZFX knockdown on cell proliferation and in vitro tumorigenesis using lentivirus-mediated loss-of-function strategy. The results demonstrated that the proliferation and colony formation ability of human osteosarcoma Saos-2 and MG63 cells was impaired by ZFX small interfering RNA (siRNA)-expressing lentivirus. Moreover, loss of ZFX led to G0/G1 phase cell cycle arrest and a significant increase of cells in the sub-G1 fraction, indicating that ZFX functions as an oncogene in the malignant proliferation process in osteosarcoma. Furthermore, ZFX siRNA may have an antitumorigenic effect on osteosarcoma cells. Our findings hold important significance for RNA interference-mediated cancer gene therapy for human osteosarcoma.

Expression of the transforming growth factor alpha protooncogene in differentiating human promyelocytic leukemia (HL-60) cells.

PubMed

Walz, T M; Malm, C; Wasteson, A

1993-01-01

The process of myeloid differentiation in human promyelocytic leukemia cells (HL-60) is accompanied by the coordinate expression of numerous protooncogenes. To investigate the expression of transforming growth factor alpha (TGF-alpha) in myeloid differentiation, HL-60 cells were induced to differentiate into granulocytes with 1.25% dimethyl sulfoxide, 0.2 microM all-trans retinoic acid, or 500 microM N6,O2-dibutyryladenosine-3'5'-cyclic monophosphate or differentiated along the monocyte/macrophage pathway with 0.1 microM phorbol-12-myristate-13-acetate. Using Northern blot analyses, TGF-alpha transcripts were detected within 24 h of treatment in cells differentiating toward granulocytes; maximal levels of gene expression were reached after 3 days or later and remained essentially constant throughout the observation period. These cells released TGF-alpha protein, as demonstrated by analysis of the incubation medium. In contrast, no TGF-alpha RNA or protein was detectable in HL-60 cell cultures when induced with phorbol-12-myristate-13-acetate. Epidermal growth factor receptor transcripts could not be detected either in undifferentiated or in differentiated HL-60 cells; therefore it appears as if an autocrine loop involving TGF-alpha in HL-60 cells is unlikely. In conclusion, the results demonstrate, for the first time, the expression of TGF-alpha in human granulocyte precursor cells. Our findings may indicate novel regulatory pathways in hematopoiesis.

Analysis of cellular responses of macrophages to zinc ions and zinc oxide nanoparticles: a combined targeted and proteomic approach.

PubMed

Triboulet, Sarah; Aude-Garcia, Catherine; Armand, Lucie; Gerdil, Adèle; Diemer, Hélène; Proamer, Fabienne; Collin-Faure, Véronique; Habert, Aurélie; Strub, Jean-Marc; Hanau, Daniel; Herlin, Nathalie; Carrière, Marie; Van Dorsselaer, Alain; Rabilloud, Thierry

2014-06-07

Two different zinc oxide nanoparticles, as well as zinc ions, are used to study the cellular responses of the RAW 264 macrophage cell line. A proteomic screen is used to provide a wide view of the molecular effects of zinc, and the most prominent results are cross-validated by targeted studies. Furthermore, the alteration of important macrophage functions (e.g. phagocytosis) by zinc is also investigated. The intracellular dissolution/uptake of zinc is also studied to further characterize zinc toxicity. Zinc oxide nanoparticles dissolve readily in the cells, leading to high intracellular zinc concentrations, mostly as protein-bound zinc. The proteomic screen reveals a rather weak response in the oxidative stress response pathway, but a strong response both in the central metabolism and in the proteasomal protein degradation pathway. Targeted experiments confirm that carbohydrate catabolism and proteasome are critical determinants of sensitivity to zinc, which also induces DNA damage. Conversely, glutathione levels and phagocytosis appear unaffected at moderately toxic zinc concentrations.

Silencing alpha-fetoprotein inhibits VEGF and MMP-2/9 production in human hepatocellular carcinoma cell.

PubMed

Meng, Wenbo; Li, Xun; Bai, Zhongtian; Li, Yan; Yuan, Jinqiu; Liu, Tao; Yan, Jun; Zhou, Wence; Zhu, Kexiang; Zhang, Hui; Li, Yumin

2014-01-01

Alpha-fetoprotein not only serves as a diagnostic marker for liver cancer, but also posses a variety of biological functions. However, the role of Alpha-fetoprotein on tumor angiogenesis and cell invasion remains incompletely understood. In this study, we aimed to evaluate if Alpha-fetoprotein can regulate the major angiogenic factors and matrix metalloproteinases in human liver cancer cells. Alpha-fetoprotein silencing was achieved by Stealth RNAi. Expression of Alpha-fetoprotein was examined by a full-automatic electrochemistry luminescence immunity analyzer. Expression of VEGF, VEGFR-2, MMP-9, and MMP-2 was examined by Western blot and immunocytochemistry. Apoptosis was detected by TUNEL assay. Angiogenesis was detected by in vitro angiogenesis assay kit. Silencing of Alpha-fetoprotein led to an increased apoptosis, which was associated with a decreased expression of vascular endothelial growth factor, vascular endothelial growth factor receptor 2, matrix metalloproteinases-2/9. These results suggest that Alpha-fetoprotein may play a regulatory role on angiogenesis and cell invasion during liver cancer development.

[Effect of cultivation in zinc media on the growth of and the degree of zinc in organic form in transgenic metallothionein mushroom].

PubMed

Sheng, Ji-Ping; Shen, Lin; Ru, Bing-Gen

2009-03-01

Metallothioneins (MTs) are a family of low molecular weight, cysteine-rich and metal-binding functional proteins. Transgenic MT mushroom can be used as functional food additives, but its zinc-enriching ability has not been studied systemically until now. The zinc contents in mycelia of transgenic MT mushroom (Pleurotus ostreatus) and wild type mushroom mycelia cultivated in different zinc concentration media were analyzed by ICP-OES. The growth status, zinc-enriching ability and degree of zinc in organic form (DZOF) were also analyzed. Results showed that MT mushroom mycelia grew rapidly, but the growth was inhibited when the zinc content in solid media was higher than 1.6 mmol x L(-1). MT mushroom mycelia could enrich more zinc than that of wild type, and the zinc content in MT mushroom mycelia could be 2.56-27.49 mg x kg(-1) when it was cultivated in a liquid media with 0.6-1.2 mmol x L(-1) zinc. DZOF of MT mushroom mycelia in a liquid media with 0.6 mmol x L(-1) zinc at 7 d was significantly higher (88.7%) than that in the wild type (82.1%, alpha = 0.05), but there was no significant difference in DZOF when the MT mushroom mycelia was cultivated in a liquid media with different zinc content at 7 d.

T1alpha/podoplanin shows raft-associated distribution in mouse lung alveolar epithelial E10 cells.

PubMed

Barth, Kathrin; Bläsche, Robert; Kasper, Michael

2010-01-01

T1alpha/(podoplanin) is abundantly expressed in the alveolar epithelial type I cells (ATI) of rodent and human lungs. Caveolin-1 is a classical primary structural protein of plasmalemal invaginations, so-called caveolae, which represent specialized lipid rafts, and which are particularly abundant in ATI cells. The biological functions of T1alpha in the alveolar epithelium are unknown. Here we report on the characteristics of raft domains in the microplicae/microvillar protrusions of ATI cells, which contain T1alpha. Detergent resistant membranes (DRMs) from cell lysates of the mouse epithelial ATI-like cell line E10 were prepared using different detergents followed by flotation in a sucrose gradient and tested by Western and dot blots with raft markers (caveolin-1, GM1) and nonraft markers (transferrin receptor, PDI and beta-Cop). Immunocytochemistry was employed for the localization of T1alpha in E10 cells and in situ in rat lungs. Our biochemical results showed that the solubility or insolubility of T1alpha and caveolin-1 differs in Triton X-100 and Lubrol WX, two distinct non-ionic detergents. Caveolin-1 was unsoluble in both detergents, whereas T1alpha was Triton X-100 soluble but Lubrol WX insoluble. Immunofluorescence double stainings revealed that both proteins were colocalized with GM1, while caveolin-1 and T1alpha were not colocalized in the plasma membrane. Cholesterol depletion modified the segregation of T1alpha in Lubrol WX DRMs. Cellular processes in ultrathin sections of cultured mouse E10 cells were immunogold positive. Immunoelectron microscopy (postembedding) of rat lung tissue revealed the preferential localization of T1alpha on apical microvillar protrusions of ATI cells. We conclude that T1alpha and caveolin-1 are located in distinct plasma membrane microdomains, which differ in their protein-lipid interactions. The raft-associated distribution of T1alpha may have an impact on a specific, not yet clarified function of this protein in the

Life testing of secondary silver-zinc cells

NASA Technical Reports Server (NTRS)

Brewer, Jeffrey C.; Doreswamy, Rajiv

1991-01-01

Testing on a variety of secondary silver-zinc (Ag-Zn) cells has been in progress at the Marshall Space Flight Center (MSFC) for over six years. The latest test involves a 350-Ah cell design that has been cycled at 10 C for 16 months. This design has achieved over 7200 low-earth-orbit (LEO) cycles as well as 17 deep discharges at an 85 percent depth of discharge. This test not only is a life test on these cells but also addresses different methods of storing these cells between the deep discharges. As the test is approaching completion, some interesting results are being seen. In particular, two of the four packs currently on test have failed to meet the 35-h (295-Ah) deep discharge requirement that was arbitrarily set at the beginning of the test. This capacity loss failure is likely a result of the storage method used on these two packs between deep discharges. The two packs are LEO cycled in such a way as to minimize overcharge in an attempt to prolong life.

Possible Role of Non-Muscle Alpha-Actinins in Muscle Cell Mechanosensitivity

PubMed Central

Ogneva, Irina V.; Biryukov, Nikolay S.; Leinsoo, Toomas A.; Larina, Irina M.

2014-01-01

The main hypothesis suggested that changes in the external mechanical load would lead to different deformations of the submembranous cytoskeleton and, as a result, dissociation of different proteins from its structure (induced by increased/decreased mechanical stress). The study subjects were fibers of the soleus muscle and cardiomyocytes of Wistar rats. Changes in external mechanical conditions were reconstructed by means of antiorthostatic suspension of the animals by their tails for 6, 12, 18, 24 and 72 hours. Transversal stiffness was measured by atomic force microscopy imaging; beta-, gamma-actin, alpha-actinin 1 and alpha-actinin 4 levels in membranous and cytoplasmic fractions were quantified by Western blot analysis; expression rates of the corresponding genes were studied using RT-PCR. Results: In 6 hours, alpha-actinin 1 and alpha-actinin 4 levels decreased in the membranous fraction of proteins of cardiomyocytes and soleus muscle fibers, respectively, but increased in the cytoplasmic fraction of the abovementioned cells. After 6–12 hours of suspension, the expression rates of beta-, gamma-actin, alpha-actinin 1 and alpha-actinin 4 were elevated in the soleus muscle fibers, but the alpha-actinin 1 expression rate returned to the reference level in 72 hours. After 18–24 hours, the expression rates of beta-actin and alpha-actinin 4 increased in cardiomyocytes, while the alpha-actinin 1 expression rate decreased in soleus muscle fibers. After 12 hours, the beta- and gamma-actin content dropped in the membranous fraction and increased in the cytoplasmic protein fractions from both cardiomyocytes and soleus muscle fibers. The stiffness of both cell types decreased after the same period of time. Further, during the unloading period the concentration of nonmuscle actin and different isoforms of alpha-actinins increased in the membranous fraction from cardiomyocytes. At the same time, the concentration of the abovementioned proteins decreased in the soleus

Expression of alpha-AR subtypes in T lymphocytes and role of the alpha-ARs in mediating modulation of T cell function.

PubMed

Bao, Jing-Yin; Huang, Yan; Wang, Feng; Peng, Yu-Ping; Qiu, Yi-Hua

2007-01-01

Previous work in our laboratory has shown that alpha-adrenoreceptors (alpha-ARs) and beta-ARs exist on lymphocytes from functional profile, and that the receptors mediate the regulation of lymphocyte function by catecholamines. In the present study, we directly examined the expression of alpha-AR subtypes, alpha(1)-AR and alpha(2)-AR mRNAs, in T lymphocytes and explored the roles of the alpha-AR subtypes and intracellular signal transduction mechanisms linked to the receptors in mediating the modulation of T lymphocyte function. T lymphocytes from mesenteric lymph nodes of rats were purified by using a nylon wool column. Reverse transcription polymerase chain reaction was used to detect the expression of alpha(1)-AR and alpha(2)-AR mRNAs in the freshly isolated T cells and the mitogen concanavalin A (Con A)-activated lymphocytes. Colorimetric methylthiazoletetrazolium assay was employed to measure lymphocyte proliferation induced by Con A. Interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) levels in the Con A-stimulated lymphocyte culture supernatants were examined by enzyme-linked immunosorbent assay. T cells expressed both alpha(1)-AR and alpha(2)-AR mRNAs. The expression of both alpha(1)-AR and alpha(2)-AR mRNAs was significantly higher in the Con A-activated lymphocytes than in the resting lymphocytes. Phenylephrine, a selective alpha(1)-AR agonist, had no evident effect on lymphocyte proliferation nor on IFN-gamma and IL-4 production induced by Con A. However, the selective alpha(2)-AR agonist clonidine attenuated Con A-induced lymphocyte proliferation as well as IFN-gamma and IL-4 production. The inhibited lymphocyte proliferation and IFN-gamma and IL-4 production by clonidine were blocked by yohimbine, an alpha(2)-AR antagonist. Either phospholipase C inhibitor U-73122 or protein kinase C inhibitor chelerythrine partially prevented the suppressive effect of clonidine on Con A-stimulated lymphocyte proliferation and IL-4 production. T lymphocytes express

Zinc oxyfluoride transparent conductor

DOEpatents

Gordon, Roy G.

1991-02-05

Transparent, electrically conductive and infrared-reflective films of zinc oxyfluoride are produced by chemical vapor deposition from vapor mixtures of zinc, oxygen and fluorine-containing compounds. The substitution of fluorine for some of the oxygen in zinc oxide results in dramatic increases in the electrical conductivity. For example, diethyl zinc, ethyl alcohol and hexafluoropropene vapors are reacted over a glass surface at 400.degree. C. to form a visibly transparent, electrically conductive, infrared reflective and ultraviolet absorptive film of zinc oxyfluoride. Such films are useful in liquid crystal display devices, solar cells, electrochromic absorbers and reflectors, energy-conserving heat mirrors, and antistatic coatings.

AMP-activated protein kinase confers protection against TNF-{alpha}-induced cardiac cell death.

PubMed

Kewalramani, Girish; Puthanveetil, Prasanth; Wang, Fang; Kim, Min Suk; Deppe, Sylvia; Abrahani, Ashraf; Luciani, Dan S; Johnson, James D; Rodrigues, Brian

2009-10-01

Although a substantial role for 5' adenosine monophosphate-activated protein kinase (AMPK) has been established in regulating cardiac metabolism, a less studied action of AMPK is its ability to prevent cardiac cell death. Using established AMPK activators like dexamethasone (DEX) or metformin (MET), the objective of the present study was to determine whether AMPK activation prevents tumour necrosis factor-alpha (TNF-alpha) induced apoptosis in adult rat ventricular cardiomyocytes. Cardiomyocytes were incubated with DEX, MET, or TNF-alpha for varying durations (0-12 h). TNF-alpha-induced cell damage was evaluated by measuring caspase-3 activity and Hoechst staining. Protein and gene estimation techniques were employed to determine the mechanisms mediating the effects of AMPK activators on TNF-alpha-induced cardiomyocyte apoptosis. Incubation of myocytes with TNF-alpha for 8 h has increased caspase-3 activation and apoptotic cell death, an effect that was abrogated by DEX and MET. The beneficial effect of DEX and MET was associated with stimulation of AMPK, which led to a rapid and sustained increase in Bad phosphorylation. This event reduced the interaction between Bad and Bcl-xL, limiting cytochrome c release and caspase-3 activation. Addition of Compound C to inhibit AMPK reduced Bad phosphorylation and prevented the beneficial effects of AMPK against TNF-alpha-induced cytotoxicity. Our data demonstrate that although DEX and MET are used as anti-inflammatory agents or insulin sensitizers, respectively, their common property to phosphorylate AMPK promotes cardiomyocyte cell survival through its regulation of Bad and the mitochondrial apoptotic mechanism.

Impact of Cadmium on Intracellular Zinc Levels in HepG2 Cells: Quantitative Evaluations and Molecular Effects.

PubMed

Urani, Chiara; Melchioretto, Pasquale; Bruschi, Maurizio; Fabbri, Marco; Sacco, Maria Grazia; Gribaldo, Laura

2015-01-01

Cadmium is classified as a human carcinogen, and its disturbance in zinc homeostasis has been well established. However, its extent as well as molecular mechanisms involved in cadmium carcinogenesis has yet to be fully clarified. To this end, we used the zinc specific probe Zinquin to visualize and to quantitatively evaluate changes in the concentration of labile zinc, in an in vitro model of human hepatic cells (HepG2) exposed to cadmium. A very large increase (+93%) of intracellular labile zinc, displaced by cadmium from the zinc proteome, was measured when HepG2 were exposed to 10 µM cadmium for 24 hrs. Microarray expression profiling showed that in cells, featuring an increase of labile zinc after cadmium exposure, one of the top regulated genes is Snail1 (+3.6), which is included in the adherens junction pathway and linked to cancer. In the same pathway MET, TGF-βR, and two members of the Rho-family GTPase, Rac, and cdc42 all implicated in the loss of adherence features and acquisition of migratory and cancer properties were regulated, as well. The microRNAs analysis showed a downregulation of miR-34a and miR-200a, both implicated in the epithelial-mesenchymal transition. These microRNAs results support the role played by zinc in affecting gene expression at the posttranscriptional level.

The thalidomide analogue CC-3052 inhibits HIV-1 and tumour necrosis factor-alpha (TNF-alpha) expression in acutely and chronically infected cells in vitro.

PubMed

La Maestra, L; Zaninoni, A; Marriott, J B; Lazzarin, A; Dalgleish, A G; Barcellini, W

2000-01-01

We investigated the in vitro effect of the water-soluble, highly stable thalidomide analogue CC-3052 on HIV-1 expression and TNF-alpha production in latently infected promonocytic U1 cells, acutely infected T cells and monocyte-derived human macrophages (MDM), and in mitogen-stimulated ex vivo cultures from patients with primary acute HIV-1 infection. HIV-1 expression was assessed by Northern blot analysis of RNAs, and ELISA for p24 antigen release and reverse transcriptase (RT) activity. TNF-alpha expression was evaluated by RT-polymerase chain reaction (PCR)-ELISA for mRNA and ELISA for protein secretion. We demonstrated that CC-3052 is able to inhibit HIV-1 expression, as evaluated by mRNA, p24 release and RT activity, in phorbol myristate acetate (PMA)- and cytokine-stimulated U1 cells. Furthermore, CC-3052 inhibited HIV-1 expression, as evaluated by p24 and RT activity, in acutely infected MDM and T cells. As far as TNF-alpha is concerned, CC-3052 significantly reduced TNF-alpha mRNA and protein secretion in PMA-stimulated U937 and U1 cells, and in PMA-stimulated uninfected and acutely infected MDM. Consistently, the addition of CC-3052 reduced TNF-alpha production in phytohaemagglutinin (PHA) and lipopolysaccharide (LPS)-stimulated whole blood cultures from patients during the primary acute phase of HIV-1 infection. Since TNF-alpha is among the most potent enhancers of HIV-1 expression, the effect of CC-3052 on TNF-alpha may account for its inhibitory activity on HIV-1 expression. Given the well documented immunopathological role of TNF-alpha and its correlation with viral load, advanced disease and poor prognosis, CC-3052 could be an interesting drug for the design of therapeutic strategies in association with anti-retroviral agents.

Identification of potential target genes of ROR-alpha in THP1 and HUVEC cell lines.

PubMed

Gulec, Cagri; Coban, Neslihan; Ozsait-Selcuk, Bilge; Sirma-Ekmekci, Sema; Yildirim, Ozlem; Erginel-Unaltuna, Nihan

2017-04-01

ROR-alpha is a nuclear receptor, activity of which can be modulated by natural or synthetic ligands. Due to its possible involvement in, and potential therapeutic target for atherosclerosis, we aimed to identify ROR-alpha target genes in monocytic and endothelial cell lines. We performed chromatin immunoprecipitation (ChIP) followed by tiling array (ChIP-on-chip) for ROR-alpha in monocytic cell line THP1 and endothelial cell line HUVEC. Following bioinformatic analysis of the array data, we tested four candidate genes in terms of dependence of their expression level on ligand-mediated ROR-alpha activity, and two of them in terms of promoter occupancy by ROR-alpha. Bioinformatic analyses of ChIP-on-chip data suggested that ROR-alpha binds to genomic regions near the transcription start site (TSS) of more than 3000 genes in THP1 and HUVEC. Potential ROR-alpha target genes in both cell types seem to be involved mainly in membrane receptor activity, signal transduction and ion transport. While SPP1 and IKBKA were shown to be direct target genes of ROR-alpha in THP1 monocytes, inflammation related gene HMOX1 and heat shock protein gene HSPA8 were shown to be potential target genes of ROR-alpha. Our results suggest that ROR-alpha may regulate signaling receptor activity, and transmembrane transport activity through its potential target genes. ROR-alpha seems also to play role in cellular sensitivity to environmental substances like arsenite and chloroprene. Although, the expression analyses have shown that synthetic ROR-alpha ligands can modulate some of potential ROR-alpha target genes, functional significance of ligand-dependent modulation of gene expression needs to be confirmed with further analyses. Copyright © 2017 Elsevier Inc. All rights reserved.

Enhanced anti-inflammatory potential of cinnamate-zinc layered hydroxide in lipopolysaccharide-stimulated RAW 264.7 macrophages

PubMed Central

Adewoyin, Malik; Mohsin, Sumaiyah Megat Nabil; Arulselvan, Palanisamy; Hussein, Mohd Zobir; Fakurazi, Sharida

2015-01-01

Background Cinnamic acid (CA) is a phytochemical originally derived from Cinnamomum cassia, a plant with numerous pharmacological properties. The intercalation of CA with a nanocarrier, zinc layered hydroxide, produces cinnamate-zinc layered hydroxide (ZCA), which has been previously characterized. Intercalation is expected to improve the solubility and cell specificity of CA. The nanocarrier will also protect CA from degradation and sustain its release. The aim of this study was to assess the effect of intercalation on the anti-inflammatory capacity of CA. Methods In this study, the anti-inflammatory activity of ZCA was investigated and compared with that of nonintercalated CA. Evaluations were based on the capacity of ZCA and CA to modulate the release of nitric oxide, prostaglandin E2, interleukin (IL)-6, tumor necrosis factor alpha (TNF-α), IL-1β, and IL-10 in lipopolysaccharide-induced RAW 264.7 cells. Additionally, the expression of proinflammatory enzymes, ie, cyclooxygenase-2, inducible nitric oxide synthase, and nuclear factor kappa B (NF-κB), were examined. Results Although both ZCA and CA downregulated nitric oxide, prostaglandin E2, tumor necrosis factor alpha, IL-1β, and IL-6, ZCA clearly displayed better activity. Similarly, expression of cyclooxygenase-2 and inducible nitric oxide synthase were inhibited in samples treated with ZCA and CA. The two compounds effectively inactivated the transcription factor NF-κB, but the anti-inflammatory cytokine, IL-10, was significantly upregulated by ZCA only. Conclusion The present findings suggest that ZCA possesses better anti-inflammatory potential than CA, while zinc layered hydroxide had little or no effect, and these results were comparable with the positive control. PMID:25995619

Reduction of cell viability induced by IFN-alpha generates impaired data on antiviral assay using Hep-2C cells.

PubMed

de Oliveira, Edson R A; Lima, Bruna M M P; de Moura, Wlamir C; Nogueira, Ana Cristina M de A

2013-12-31

Type I interferons (IFNs) exert an array of important biological functions on the innate immune response and has become a useful tool in the treatment of various diseases. An increasing demand in the usage of recombinant IFNs, mainly due to the treatment of chronic hepatitis C infection, augmented the need of quality control for this biopharmaceutical. A traditional bioassay for IFN potency assessment is the cytopathic effect reduction antiviral assay where a given cell line is preserved by IFN from a lytic virus activity using the cell viability as a frequent measure of end point. However, type I IFNs induce other biological effects such as cell-cycle arrest and apoptosis that can influence directly on viability of many cell lines. Here, we standardized a cytopathic effect reduction antiviral assay using Hep-2C cell/mengovirus combination and studied a possible impact of cell viability variations caused by IFN-alpha 2b on responses generated on the antiviral assay. Using the four-parameter logistic model, we observed less correlation and less linearity on antiviral assay when responses from IFN-alpha 2b 1000 IU/ml were considered in the analysis. Cell viability tests with MTT revealed a clear cell growth inhibition of Hep-2C cells under stimulation with IFN-alpha 2b. Flow cytometric cell-cycle analysis and apoptosis assessment showed an increase of S+G2 phase and higher levels of apoptotic cells after treatment with IFN-alpha 2b 1000 IU/ml under our standardized antiviral assay procedure. Considering our studied dose range, we also observed strong STAT1 activation on Hep-2C cells after stimulation with the higher doses of IFN-alpha 2b. Our findings showed that the reduction of cell viability driven by IFN-alpha can cause a negative impact on antiviral assays. We assume that the cell death induction and the cell growth inhibition effect of IFNs should also be considered while employing antiviral assay protocols in a quality control routine and emphasizes the

Zinc protects HepG2 cells against the oxidative damage and DNA damage induced by ochratoxin A

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zheng, Juanjuan; Zhang, Yu; Xu, Wentao, E-mail: xuwentaoboy@sina.com

Oxidative stress and DNA damage are the most studied mechanisms by which ochratoxin A (OTA) induces its toxic effects, which include nephrotoxicity, hepatotoxicity, immunotoxicity and genotoxicity. Zinc, which is an essential trace element, is considered a potential antioxidant. The aim of this paper was to investigate whether zinc supplement could inhibit OTA-induced oxidative damage and DNA damage in HepG2 cells and the mechanism of inhibition. The results indicated that that exposure of OTA decreased the intracellular zinc concentration; zinc supplement significantly reduced the OTA-induced production of reactive oxygen species (ROS) and decrease in superoxide dismutase (SOD) activity but did notmore » affect the OTA-induced decrease in the mitochondrial membrane potential (Δψ{sub m}). Meanwhile, the addition of the zinc chelator N,N,N′,N′-tetrakis(2-pyridylmethyl)ethylenediamine (TPEN) strongly aggravated the OTA-induced oxidative damage. This study also demonstrated that zinc helped to maintain the integrity of DNA through the reduction of OTA-induced DNA strand breaks, 8-hydroxy-2′-deoxyguanosine (8-OHdG) formation and DNA hypomethylation. OTA increased the mRNA expression of metallothionein1-A (MT1A), metallothionein2-A (MT2A) and Cu/Zn superoxide dismutase (SOD1). Zinc supplement further enhanced the mRNA expression of MT1A and MT2A, but it had no effect on the mRNA expression of SOD1 and catalase (CAT). Zinc was for the first time proven to reduce the cytotoxicity of OTA through inhibiting the oxidative damage and DNA damage, and regulating the expression of zinc-associated genes. Thus, the addition of zinc can potentially be used to reduce the OTA toxicity of contaminated feeds. - Highlights: ► OTA decreased the intracellular zinc concentration. ► OTA induced the formation of 8-OHdG in HepG2 cells. ► It was testified for the first time that OTA induced DNA hypomethylation. ► Zinc protects against the oxidative damage and DNA damage

The interaction of zinc oxide-based dental cements with aqueous solutions of potassium fluoride.

PubMed

Pawluk, K; Booth, S E; Coleman, N J; Nicholson, J W

2008-09-01

The ability of zinc oxide-based dental cements (zinc phosphate and zinc polycarboxylate) to take up fluoride from aqueous solution has been studied. Only zinc phosphate cement was found to take up any measurable fluoride after 5 h exposure to the solutions. The zinc oxide filler of the zinc phosphate also failed to take up fluoride from solution. The key interaction for this uptake was thus shown to involve the phosphate groups of the set cement. However, whether this took the form of phosphate/fluoride exchange, or the formation of oxyfluoro-phosphate groups was not clear. Fluoride uptake followed radicaltime kinetics for about 2 h in some cases, but was generally better modelled by the Elovich equation, dq(t)/dt = alpha exp(-betaq(t)). Values for alpha varied from 3.80 to 2.48 x 10(4), and for beta from 7.19 x 10(-3) to 0.1946, though only beta showed any sort of trend, becoming smaller with increasing fluoride concentration. Fluoride was released from the zinc phosphate cements in processes that were diffusion based up to M(t)/M(infinity) of about 0.4. No further release occurred when specimens were placed in fresh volumes of deionised water. Only a fraction of the fluoride taken up was re-released, demonstrating that most of the fluoride taken up becomes irreversibly bound within the cement.

Tumor necrosis factor-alpha (TNF-alpha) concentrations from whole blood cultures correlate with isolated peripheral blood mononuclear cell cultures

USDA-ARS?s Scientific Manuscript database

Many cellular immune assays are impractical because they require labor-intensive isolation of cells from their natural environment. The objectives of this study were to determine the relationship between cell culture supernatant TNF-alpha from isolated peripheral blood mononuclear cells (PBMC) and w...

Isolation of mouse pancreatic alpha, beta, duct and acinar populations with cell surface markers.

PubMed

Dorrell, Craig; Grompe, Maria T; Pan, Fong Cheng; Zhong, Yongping; Canaday, Pamela S; Shultz, Leonard D; Greiner, Dale L; Wright, Chris V; Streeter, Philip R; Grompe, Markus

2011-06-06

Tools permitting the isolation of live pancreatic cell subsets for culture and/or molecular analysis are limited. To address this, we developed a collection of monoclonal antibodies with selective surface labeling of endocrine and exocrine pancreatic cell types. Cell type labeling specificity and cell surface reactivity were validated on mouse pancreatic sections and by gene expression analysis of cells isolated using FACS. Five antibodies which marked populations of particular interest were used to isolate and study viable populations of purified pancreatic ducts, acinar cells, and subsets of acinar cells from whole pancreatic tissue or of alpha or beta cells from isolated mouse islets. Gene expression analysis showed the presence of known endocrine markers in alpha and beta cell populations and revealed that TTR and DPPIV are primarily expressed in alpha cells whereas DGKB and GPM6A have a beta cell specific expression profile. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Alpha-tocopherol and alpha-tocopheryl quinone levels in cervical intraepithelial neoplasia and cervical cancer.

PubMed

Palan, Prabhudas R; Woodall, Angela L; Anderson, Patrick S; Mikhail, Magdy S

2004-05-01

alpha-Tocopherol is a potent antioxidant that protects cell membranes against oxidative damage. Red blood cell alpha-tocopherol levels reflect membrane alpha-tocopherol concentrations, and altered levels may suggest membrane damage. The objective of this study was to determine the levels of alpha-tocopherol and alpha-tocopheryl quinone, the oxidized product of alpha-tocopherol, in plasma and red blood cells that were obtained from control subjects and patients with cervical intraepithelial neoplasia and cervical cancer. In this cross-sectional study, 72 women, (32 African American and 40 Hispanic) were recruited. Among these subjects, 37 women had cervical intraepithelial neoplasia; 14 women had cervical cancer, and 21 women were considered control subjects, who had normal Papanicolaou test results. alpha-Tocopherol and alpha-tocopheryl quinone levels were determined in red blood cell and plasma by high-pressure liquid chromatography. Plasma levels of alpha-tocopherol and alpha-tocopheryl quinone were decreased significantly (P=.012 and=.005, respectively, by Kruskal-Wallis test) in study groups compared with the control group; red blood cell levels of alpha-tocopherol and alpha-tocopheryl quinone were not altered significantly. The lower alpha-tocopherol level that was observed in this study is consistent with our previous reports of decreased antioxidant concentrations and increased oxidative stress in women with cervical intraepithelial neoplasia. Unaltered red blood cell alpha-tocopherol and alpha-tocopheryl quinone levels suggest undamaged cell membrane. Further studies are needed to investigate the potential role of oxidative stress in cervical intraepithelial neoplasia.

CD90-positive cells, an additional cell population, produce laminin {alpha}2 upon transplantation to dy{sup 3k}/dy{sup 3k} mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fukada, So-ichiro; Yamamoto, Yukiko; Segawa, Masashi

2008-01-01

Laminin {alpha}2 is a component of skeletal and cardiac muscle basal lamina. A defect of the laminin {alpha}2 chain leads to severe congenital muscular dystrophy (MDC1A) in humans and dy/dy mice. Myogenic cells including myoblasts, myotubes, and myofibers in skeletal muscle are a possible source of the laminin {alpha}2 chain, and myogenic cells are thus proposed as a cell source for congenital muscular dystrophy therapy. However, we observed production of laminin {alpha}2 in non-myogenic cells of normal mice, and we could enrich these laminin {alpha}2-producing cells in CD90{sup +} cell fractions. Intriguingly, the number of CD90{sup +} cells increased dramaticallymore » during skeletal muscle regeneration in mice. This fraction did not include myogenic cells but exhibited a fibroblast-like phenotype. Moreover, these cells were resident in skeletal muscle, not derived from bone marrow. Finally, the production of laminin {alpha}2 in CD90{sup +} cells was not dependent on fusion with myogenic cells. Thus, CD90{sup +} cells are a newly identified additional cell fraction that increased during skeletal muscle regeneration in vivo and could be another cell source for therapy for lama2-deficient muscular dystrophy.« less

High-density lipoproteins protect endothelial cells from tumor necrosis factor-alpha-induced apoptosis.

PubMed

Sugano, M; Tsuchida, K; Makino, N

2000-06-16

High-density lipoproteins (HDL) levels have been shown to be inversely correlated with coronary heart disease, but the mechanisms of the direct protective effect of HDL on endothelial cells are not fully understood. The apoptosis of endothelial cells induced by cytokines and/or oxidized low-density lipoproteins, etc. may provide a mechanistic clue to the "response-to-injury" hypothesis of atherogenesis. Here we report that HDL prevent the apoptosis of human umbilical venous endothelial cells (HUVECs) induced by tumor necrosis factor-alpha (TNF-alpha) via an inhibition of CPP32-like protease activity. The incubation of HUVECs with TNF-alpha significantly increased the CPP32-like protease activity, and induced apoptosis. Preincubation of HUVECs with HDL before incubation with TNF-alpha significantly suppressed the increase in the CPP32-like protease activity, preventing apoptosis in a concentration-dependent manner. These results suggest that HDL prevent the suicide pathway leading to apoptosis of endothelial cells by decreasing the CPP32-like protease activity and that HDL thus play a protective role against the "response-to-injury" hypothesis of atherogenesis. Copyright 2000 Academic Press.

Alpha-SNAP functions in insulin exocytosis from mature, but not immature secretory granules in pancreatic beta cells.

PubMed

Nakamichi, Y; Nagamatsu, S

1999-06-24

To explore alpha-SNAP function in insulin exocytosis from either immature or mature secretory granules in pancreatic beta cells, we studied the effects of overexpression of adenovirus-mediated wild-type alpha-SNAP and C-terminally deleted alpha-SNAP mutant (1-285) on newly synthesized proinsulin and insulin release by rat islets and MIN6 cells. Rat islets overexpressing alpha-SNAP and mutant alpha-SNAP were pulse-chased. Exocytosis from immature and mature insulin secretory granules was measured as fractional (%) labeled-proinsulin release immediately after the pulse-labeling and percentage labeled-insulin release after a 3-h chase period, respectively. There was no difference in percentage labeled-proinsulin release between the control and alpha-SNAP or mutant alpha-SNAP-overexpressed islets. Although percentage labeled-insulin release after a 3-h chase period was significantly increased in alpha-SNAP-overexpressed islets, it was decreased in mutant alpha-SNAP-overexpressed islets. Thus, the results demonstrated that alpha-SNAP overexpression in rat islets primarily increased exocytosis from mature, but not immature insulin secretory granules. On the other hand, in MIN6 cells, alpha-SNAP overexpression scarcely affected glucose-stimulated insulin release; therefore, we examined the effect of mutant alpha-SNAP overexpression as the dominant-negative inhibitor on the newly synthesized proinsulin/insulin release using the same protocol as in the rat islet experiments. alpha-SNAP mutant (1-285) overexpression in MIN6 cells decreased the percentage labeled insulin release from mature secretory granules, but not percentage labeled proinsulin release from immature secretory granules. Thus, our data demonstrate that alpha-SNAP functions mainly in the mature insulin secretory granules in pancreatic beta cells. Copyright 1999 Academic Press.

Longitudinal changes in zinc transport kinetics, metallothionein, and zinc transporter expression in a blood-brain barrier model in response to a moderately excessive zinc environment$

PubMed Central

Gauthier, Nicole A.; Karki, Shakun; Olley, Bryony J.; Thomas, W. Kelly

2008-01-01

A blood-brain barrier (BBB) model composed of porcine brain capillary endothelial cells (BCEC) was exposed to a moderately excessive zinc environment (50 µmol Zn/L) in cell culture and longitudinal measurements were made of zinc transport kinetics, ZnT-1 (SLC30A1) expression, and changes in the protein concentration of metallothionein (MT), ZnT-1, ZnT-2 (SLC30A2), and Zip1 (SLC39A1). Zinc release by cells of the BBB model was significantly increased after 12–24 h of exposure, but decreased back to control levels after 48–96 h, as indicated by transport across the BBB from both the ablumenal (brain) and lumenal (blood) directions. Expression of ZnT-1, the zinc export protein, increased 169% within 12 h, but was no longer different from controls after 24 h. Likewise, ZnT-1 protein content increased transiently after 12 h of exposure but returned to control levels by 24 h. Capacity for zinc uptake and retention increased from both the lumenal and ablumenal directions within 12–24 h of exposure and remained elevated. MT and ZnT-2 were elevated within 12 h and remained elevated throughout the study. Zip1 was unchanged by the treatment. The BBB’s response to a moderately high zinc environment was dynamic and involved multiple mechanisms. The initial response was to increase the cell’s capacity to sequester zinc with additional MT and increase zinc export with the ZnT-1 protein. But, the longer term strategy involved increasing ZnT-2 transporters, presumably to sequester zinc into intracellular vesicles as a mechanism to protect the brain and maintain brain zinc homeostasis. PMID:18061429

Production of alpha 1,3-galactosyltransferase gene-deficient pigs by somatic cell nuclear transfer: a novel selection method for gal alpha 1,3-Gal antigen-deficient cells.

PubMed

Fujimura, Tatsuya; Takahagi, Yoichi; Shigehisa, Tamotsu; Nagashima, Hiroshi; Miyagawa, Shuji; Shirakura, Ryota; Murakami, Hiroshi

2008-09-01

The objective of the present study was to isolate alpha 1,3-galactosyltransferase (GalGT)-gene double knockout (DKO) cells using a novel simple method of cell selection method. To obtain GalGT-DKO cells, GalGT-gene single knockout (SKO) fetal fibroblast cells were cultured for three to nine passages and GalGT-null cells were separated using a biotin-labeled IB4 lectin attached to streptavidin-coated magnetic beads. After 15-17 days of additional cultivation, seven GalGT-DKO cell colonies were obtained from a total of 2.5 x 10(7) GalGT-SKO cells. A total of 926 somatic nuclear transferred embryos reconstructed with the DKO cells were transferred into eight recipient pigs, producing four farrowed, three liveborns, and six stillborns. Absence of GalGT gene in the cloned pigs was confirmed by PCR and Southern blotting. Flow cytometric analysis revealed that alphaGal antigens were not present in the cells of the cloned DKO pigs.

Characterization of the expression, localization, and secretion of PANDER in alpha-cells.

PubMed

Carnegie, Jason R; Robert-Cooperman, Claudia E; Wu, Jianmei; Young, Robert A; Wolf, Bryan A; Burkhardt, Brant R

2010-08-30

The novel islet-specific protein PANcreatic DERived Factor (PANDER; FAM3B) has been extensively characterized with respect to the beta-cell, and these studies suggest a potential function for PANDER in the regulation of glucose homeostasis. Little is known regarding PANDER in pancreatic -cells, which are critically involved in maintaining euglycemia. Here we present the first report elucidating the expression and regulation of PANDER within the alpha-cell. Pander mRNA and protein are detected in alpha-cells, with primary localization to a glucagon-negative granular cytosolic compartment. PANDER secretion from alpha-cells is nutritionally and hormonally regulated by l-arginine and insulin, demonstrating similarities and differences with glucagon. Signaling via the insulin receptor (IR) through the PI3K and Akt/PKB node is required for insulin-stimulated PANDER release. The separate localization of PANDER and glucagon is consistent with their differential regulation, and the effect of insulin suggests a paracrine/endocrine effect on PANDER release. This provides further insight into the potential glucose-regulatory role of PANDER. Copyright (c) 2010 Elsevier Ireland Ltd. All rights reserved.

Overexpression of IL-7R alpha provides a competitive advantage during early T-cell development.

PubMed

Laouar, Yasmina; Crispe, I Nicholas; Flavell, Richard A

2004-03-15

Critical checkpoints controlling early thymic T-cell development and homeostasis are set by the proper signaling function of the interleukin 7 receptor (IL-7R) and the pre-T-cell antigen receptor. Although alpha beta T-cell development is observed in IL-7- and IL-7R alpha-deficient mice, the number of thymocytes is significantly reduced, implying a role for the IL-7R in controlling the size of the thymic T-cell compartment. Here, we report the overexpression of IL-7R alpha that occurs in the early T-cell compartment from AKR/J mice, animals that are highly susceptible to the spontaneous development of thymoma. Increased IL-7R alpha was revealed by surface staining, and increased IL-7R alpha mRNA was documented by using reverse transcriptase-polymerase chain reaction (RT-PCR). This resulted in increased survival of AKR/J early thymocytes, shown by the decreased frequency of TUNEL(+) (terminal deoxynucleotidyl transferase mediated deoxyuridine triphosphate [dUTP]-fluorescein nick end labeling) cells. In an in vivo thymocyte repopulation model, AKR/J thymocytes had a selective advantage over healthy thymocytes. This advantage occurred at early stages of T-cell development. Our findings support the model that overexpression of growth factor receptors can contribute to proliferation and malignancy.

Zinc in Infection and Inflammation.

PubMed

Gammoh, Nour Zahi; Rink, Lothar

2017-06-17

Micronutrient homeostasis is a key factor in maintaining a healthy immune system. Zinc is an essential micronutrient that is involved in the regulation of the innate and adaptive immune responses. The main cause of zinc deficiency is malnutrition. Zinc deficiency leads to cell-mediated immune dysfunctions among other manifestations. Consequently, such dysfunctions lead to a worse outcome in the response towards bacterial infection and sepsis. For instance, zinc is an essential component of the pathogen-eliminating signal transduction pathways leading to neutrophil extracellular traps (NET) formation, as well as inducing cell-mediated immunity over humoral immunity by regulating specific factors of differentiation. Additionally, zinc deficiency plays a role in inflammation, mainly elevating inflammatory response as well as damage to host tissue. Zinc is involved in the modulation of the proinflammatory response by targeting Nuclear Factor Kappa B (NF-κB), a transcription factor that is the master regulator of proinflammatory responses. It is also involved in controlling oxidative stress and regulating inflammatory cytokines. Zinc plays an intricate function during an immune response and its homeostasis is critical for sustaining proper immune function. This review will summarize the latest findings concerning the role of this micronutrient during the course of infections and inflammatory response and how the immune system modulates zinc depending on different stimuli.

Effects of size and surface of zinc oxide and aluminum-doped zinc oxide nanoparticles on cell viability inferred by proteomic analyses.

PubMed

Pan, Chih-Hong; Liu, Wen-Te; Bien, Mauo-Ying; Lin, I-Chan; Hsiao, Ta-Chih; Ma, Chih-Ming; Lai, Ching-Huang; Chen, Mei-Chieh; Chuang, Kai-Jen; Chuang, Hsiao-Chi

2014-01-01

Although the health effects of zinc oxide nanoparticles (ZnONPs) on the respiratory system have been reported, the fate, potential toxicity, and mechanisms in biological cells of these particles, as related to particle size and surface characteristics, have not been well elucidated. To determine the physicochemical properties of ZnONPs that govern cytotoxicity, we investigated the effects of size, electronic properties, zinc concentration, and pH on cell viability using human alveolar-basal epithelial A549 cells as a model. We observed that a 2-hour or longer exposure to ZnONPs induced changes in cell viability. The alteration in cell viability was associated with the zeta potentials and pH values of the ZnONPs. Proteomic profiling of A549 exposed to ZnONPs for 2 and 4 hours was used to determine the biological mechanisms of ZnONP toxicity. p53-pathway activation was the core mechanism regulating cell viability in response to particle size. Activation of the Wnt and TGFβ signaling pathways was also important in the cellular response to ZnONPs of different sizes. The cadherin and Wnt signaling pathways were important cellular mechanisms triggered by surface differences. These results suggested that the size and surface characteristics of ZnONPs might play an important role in their observed cytotoxicity. This approach facilitates the design of more comprehensive systems for the evaluation of nanoparticles.

Receptor-mediated cytotoxicity of alpha-MSH fragments containing melphalan in a human melanoma cell line.

PubMed

Morandini, R; Süli-Vargha, H; Libert, A; Loir, B; Botyánszki, J; Medzihradszky, K; Ghanem, G

1994-01-02

Four alpha-MSH drug conjugates have been synthesized, 2 C-terminal (Pep 3 and 4) and 2 central fragments (Pep 1 and 2), the latter being the 4-10 sequence known to be the main alpha-MSH-receptor-recognition site. Melphalan was introduced into each sequence at different locations. Their ability to recognize alpha-MSH receptors as well as their cytotoxic effects were compared in 3 cell lines: melanoma, carcinoma and fibroblast cells. Pep 1 and 2 were able to specifically bind to MSH receptors on melanoma cells by displacing labelled alpha-MSH from its binding sites at concentrations similar to the 4-10 heptapeptide sequence known to contain the main receptor-recognition site. They subsequently penetrate the cell, most probably by a receptor internalization mechanism, since about half of their effect could be inhibited by competition at the receptor level. Significant and selective cytotoxic effects to melanoma cells could be observed after only 2 hr exposure to the drug conjugates. Interestingly, these 2 conjugates, differing only in melphalan position, showed completely different cytotoxicity in terms of IC50 values, Pep 1 being 24 times more toxic to all cells; but the 2 were equally specific to melanoma cells. However, they both were less toxic to all cells than melphalan itself. Furthermore, Pep 1 and 2 were able to block the receptor and, unlike Pep 3 and 4, their cytotoxic effect could be significantly inhibited by an alpha-MSH agonist. Pep 3 and 4 were 5 to 10 times less toxic than melphalan to melanoma and carcinoma cells and 50 times less to fibroblast cells, and did not show any cell-type selectivity. They were less toxic than Pep 1 to melanoma and carcinoma cells by a factor of 2, but equally toxic to fibroblasts. In contrast, they were more toxic than Pep 2 to fibroblasts, melanoma and carcinoma by a factor of 3, 10 and 24 respectively. Our data strongly suggest a receptor-mediated cytotoxicity mechanism occurring with alpha-MSH central fragments in human

Increased proliferation of endothelial cells with overexpression of soluble TNF-alpha receptor I gene.

PubMed

Sugano, Masahiro; Tsuchida, Keiko; Tomita, Hideharu; Makino, Naoki

2002-05-01

Vascular endothelial growth factor (VEGF) can overcome a potential anti-angiogenic effect of TNF-alpha by inhibiting endothelial apoptosis induced by this cytokine. Soluble TNF-alpha receptor I (sTNFRI) is an extracellular domain of TNFRI and antagonizes the activity of TNF-alpha. Here we report that sTNFRI is able to stimulate the growth of endothelial cells not by antagonizing TNF-alpha. Exogenously added recombinant human sTNFRI stimulated significantly more cell growth of human umbilical venous endothelial cells (HUVEC) with a low dose (50-200 pg/ml) compared with smooth muscle cells. In contrast, monoclonal antibody against TNF-alpha did not stimulate growth of human HUVEC. The sTNFRI expression plasmid (pcDNA3.1 plasmid) was introduced into the cell culture using OPTI-MEM, lipofectin and transferrin. Growth of HUVEC transfected with sTNFRI vector also increased significantly compared with those transfected with control vector. HUVEC transfected with sTNFRI vector increased the extracellular domain of TNFRI mRNA levels, but did not affect the intracellular domain of TNFRI mRNA levels. Accumulation of sTNFRI significantly increased in conditioned medium from HUVEC transfected with sTNFRI vector compared with those transfected with control vector. HUVEC transfected with sTNFRI vector not only increased sTNFRI but also prevented shedding of sTNFRI from TNFRI. The TNF-alpha -induced internucleosomic fragmentation was also significantly prevented in HUVEC transfected with sTNFRI vector compared with those transfected with control vector. These results suggest that instead of growth factors such as VEGF, local transfection of the sTNFRI gene may have potential therapeutic value in vascular diseases in which TNF-alpha is also usually highly expressed.

Stromal cell derived factor-1alpha protects stem cell derived insulin-producing cells from glucotoxicity under high glucose conditions in-vitro and ameliorates drug induced diabetes in rats

PubMed Central

2013-01-01

Background Diabetes mellitus is affecting more than 300 million people worldwide. Current treatment strategies cannot prevent secondary complications. Stem cells due to their regenerative power have long been the attractive target for the cell-based therapies. Mesenchymal stem cells (MSCs) possess the ability to differentiate into several cell types and to escape immune recognition in vitro. MSCs can be differentiated into insulin-producing cells (IPCs) and could be an exciting therapy for diabetes but problems like poor engraftment and survivability need to be confronted. It was hypothesized that stromal cell derived factor- 1alpha (SDF-1alpha) will enhance therapeutic potential of stem cell derived IPCs by increasing their survival and proliferation rate. Methods Novel culture conditions were developed to differentiate bone marrow derived mesenchymal stem cells (BMSCs) into IPCs by using endocrine differentiation inducers and growth factors via a three stage protocol. In order to enhance their therapeutic potential, we preconditioned IPCs with SDF-1alpha. Results Our results showed that SDF-1alpha increases survival and proliferation of IPCs and protects them from glucotoxicity under high glucose conditions in vitro. SDF-1alpha also enhances the glucose responsive insulin secretion in IPCs in vitro. SDF-1alpha preconditioning reverses hyperglycemia and increase serum insulin in drug induced diabetic rats. Conclusions The differentiation of BMSCs into IPCs and enhancement of their therapeutic potential by SDF-1alpha preconditioning may contribute to cell based therapies for diabetes. PMID:23648189

In situ genetic correction of the sickle cell anemia mutation in human induced pluripotent stem cells using engineered zinc finger nucleases.

PubMed

Sebastiano, Vittorio; Maeder, Morgan L; Angstman, James F; Haddad, Bahareh; Khayter, Cyd; Yeo, Dana T; Goodwin, Mathew J; Hawkins, John S; Ramirez, Cherie L; Batista, Luis F Z; Artandi, Steven E; Wernig, Marius; Joung, J Keith

2011-11-01

The combination of induced pluripotent stem cell (iPSC) technology and targeted gene modification by homologous recombination (HR) represents a promising new approach to generate genetically corrected, patient-derived cells that could be used for autologous transplantation therapies. This strategy has several potential advantages over conventional gene therapy including eliminating the need for immunosuppression, avoiding the risk of insertional mutagenesis by therapeutic vectors, and maintaining expression of the corrected gene by endogenous control elements rather than a constitutive promoter. However, gene targeting in human pluripotent cells has remained challenging and inefficient. Recently, engineered zinc finger nucleases (ZFNs) have been shown to substantially increase HR frequencies in human iPSCs, raising the prospect of using this technology to correct disease causing mutations. Here, we describe the generation of iPSC lines from sickle cell anemia patients and in situ correction of the disease causing mutation using three ZFN pairs made by the publicly available oligomerized pool engineering method (OPEN). Gene-corrected cells retained full pluripotency and a normal karyotype following removal of reprogramming factor and drug-resistance genes. By testing various conditions, we also demonstrated that HR events in human iPSCs can occur as far as 82 bps from a ZFN-induced break. Our approach delineates a roadmap for using ZFNs made by an open-source method to achieve efficient, transgene-free correction of monogenic disease mutations in patient-derived iPSCs. Our results provide an important proof of principle that ZFNs can be used to produce gene-corrected human iPSCs that could be used for therapeutic applications. Copyright © 2011 AlphaMed Press.

Mixed metal oxides for dye-sensitized solar cell using zinc titanium layered double hydroxide as precursor

NASA Astrophysics Data System (ADS)

Liu, Jianqiang; Qin, Yaowei; Zhang, Liangji; Xiao, Hongdi; Song, Jianye; Liu, Dehe; Leng, Mingzhe; Hou, Wanguo; Du, Na

2013-12-01

Mixed metal oxides (MMO) are always obtained from layered double hydroxide (LDH) by thermal decomposition. In the present work, a zinc titanium LDH with the zinc titanium molar ratio of 4.25 was prepared by urea method and ZnO-based mixed oxides were obtained by calcining at or over 500°C. The MMO was used as electrodes for dye sensitized solar cell (DSSC). The cells constructed by films of prepared composite materials using a N719 as dye were prepared. The efficiency values of these cells are 0.691%, 0.572% and 0.302% with MMO prepared at 500, 600 and 700°C, respectively.

alpha-Galactosylceramide-loaded, antigen-expressing B cells prime a wide spectrum of antitumor immunity.

PubMed

Kim, Yeon-Jeong; Ko, Hyun-Jeong; Kim, Yun-Sun; Kim, Dong-Hyeon; Kang, Seock; Kim, Jong-Mook; Chung, Yeonseok; Kang, Chang-Yuil

2008-06-15

Most of the current tumor vaccines successfully elicit strong protection against tumor but offer little therapeutic effect against existing tumors, highlighting the need for a more effective vaccine strategy. Vaccination with tumor antigen-presenting cells can induce antitumor immune responses. We have previously shown that NKT-licensed B cells prime cytotoxic T lymphocytes (CTLs) with epitope peptide and generate prophylactic/therapeutic antitumor effects. To extend our B cell vaccine approach to the whole antigen, and to overcome the MHC restriction, we used a nonreplicating adenovirus to transduce B cells with antigenic gene. Primary B cells transduced with an adenovirus-encoding truncated Her-2/neu (AdHM) efficiently expressed Her-2/neu. Compared with the moderate antitumor activity induced by vaccination with adenovirus-transduced B cells (B/AdHM), vaccination with alpha-galactosylceramide-loaded B/AdHM (B/AdHM/alpha GalCer) induced significantly stronger antitumor immunity, especially in the tumor-bearing mice. The depletion study showed that CD4(+), CD8(+) and NK cells were all necessary for the therapeutic immunity. Confirming the results of the depletion study, B/AdHM/alpha GalCer vaccination induced cytotoxic NK cell responses but B/AdHM did not. Vaccination with B/AdHM/alpha GalCer generated Her-2/neu-specific antibodies more efficiently than B/AdHM immunization. More importantly, B/AdHM/alpha GalCer could prime Her-2/neu-specific cytotoxic T cells more efficiently and durably than B/AdHM. CD4(+) cells appeared to be necessary for the induction of antibody and CTL responses. Our results demonstrate that, with the help of NKT cells, antigen-transduced B cells efficiently induce innate immunity as well as a wide range of adaptive immunity against the tumor, suggesting that they could be used to develop a novel cellular vaccine. (c) 2008 Wiley-Liss, Inc.

The coffee diterpene kahweol inhibits tumor necrosis factor-{alpha}-induced expression of cell adhesion molecules in human endothelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Hyung Gyun; Kim, Ji Young; Hwang, Yong Pil

2006-12-15

Endothelial cells produce adhesion molecules after being stimulated with various inflammatory cytokines. These adhesion molecules play an important role in the development of atherogenesis. Recent studies have highlighted the chemoprotective and anti-inflammatory effects of kahweol, a coffee-specific diterpene. This study examined the effects of kahweol on the cytokine-induced monocyte/human endothelial cell interaction, which is a crucial early event in atherogenesis. Kahweol inhibited the adhesion of TNF{alpha}-induced monocytes to endothelial cells and suppressed the TNF{alpha}-induced protein and mRNA expression of the cell adhesion molecules, VCAM-1 and ICAM-1. Furthermore, kahweol inhibited the TNF{alpha}-induced JAK2-PI3K/Akt-NF-{kappa}B activation pathway in these cells. Overall, kahweol hasmore » anti-inflammatory and anti-atherosclerotic activities, which occurs partly by down-regulating the pathway that affects the expression and interaction of the cell adhesion molecules on endothelial cells.« less

Overexpression of hypoxia-inducible factor 1 alpha improves immunomodulation by dental mesenchymal stem cells.

PubMed

Martinez, Victor G; Ontoria-Oviedo, Imelda; Ricardo, Carolina P; Harding, Sian E; Sacedon, Rosa; Varas, Alberto; Zapata, Agustin; Sepulveda, Pilar; Vicente, Angeles

2017-09-29

Human dental mesenchymal stem cells (MSCs) are considered as highly accessible and attractive MSCs for use in regenerative medicine, yet some of their features are not as well characterized as other MSCs. Hypoxia-preconditioning and hypoxia-inducible factor 1 (HIF-1) alpha overexpression significantly improves MSC therapeutics, but the mechanisms involved are not fully understood. In the present study, we characterize immunomodulatory properties of dental MSCs and determine changes in their ability to modulate adaptive and innate immune populations after HIF-1 alpha overexpression. Human dental MSCs were stably transduced with green fluorescent protein (GFP-MSCs) or GFP-HIF-1 alpha lentivirus vectors (HIF-MSCs). A hypoxic-like metabolic profile was confirmed by mitochondrial and glycolysis stress test. Capacity of HIF-MSCs to modulate T-cell activation, dendritic cell differentiation, monocyte migration, and polarizations towards macrophages and natural killer (NK) cell lytic activity was assessed by a number of functional assays in co-cultures. The expression of relevant factors were determined by polymerase chain reaction (PCR) analysis and enzyme-linked immunosorbent assay (ELISA). While HIF-1 alpha overexpression did not modify the inhibition of T-cell activation by MSCs, HIF-MSCs impaired dendritic cell differentiation more efficiently. In addition, HIF-MSCs showed a tendency to induce higher attraction of monocytes, which differentiate into suppressor macrophages, and exhibited enhanced resistance to NK cell-mediated lysis, which supports the improved therapeutic capacity of HIF-MSCs. HIF-MSCs also displayed a pro-angiogenic profile characterized by increased expression of CXCL12/SDF1 and CCL5/RANTES and complete loss of CXCL10/IP10 transcription. Immunomodulation and expression of trophic factors by dental MSCs make them perfect candidates for cell therapy. Overexpression of HIF-1 alpha enhances these features and increases their resistance to allogenic NK

The regulatory mechanism of Hsp90{alpha} secretion from endothelial cells and its role in angiogenesis during wound healing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Song, Xiaomin; Beijing Key Laboratory for Protein Therapeutics, Tsinghua University, Beijing 100084; Cancer Biology Laboratory, School of Life Sciences, Tsinghua University, Beijing 100084

2010-07-16

Research highlights: {yields} Growth factors such as bFGF, VEGF, PDGF and SDF-1 stimulate Hsp90{alpha} secretion from endothelial cells. {yields} Secreted Hsp90{alpha} localizes on the leading edge of activated endothelial cells. {yields} Secreted Hsp90{alpha} promotes angiogenesis in wound healing. -- Abstract: Heat shock protein 90{alpha} (Hsp90{alpha}) is a ubiquitously expressed molecular chaperone, which is essential for the maintenance of eukaryote homeostasis. Hsp90{alpha} can also be secreted extracellularly and is associated with several physiological and pathological processes including wound healing, cancer, infectious diseases and diabetes. Angiogenesis, defined as the sprouting of new blood vessels from pre-existing capillaries via endothelial cell proliferation andmore » migration, commonly occurs in and contributes to the above mentioned processes. However, the secretion of Hsp90{alpha} from endothelial cells and also its function in angiogenesis are still unclear. Here we investigated the role of extracellular Hsp90{alpha} in angiogenesis using dermal endothelial cells in vitro and a wound healing model in vivo. We find that the secretion of Hsp90{alpha} but not Hsp90{beta} is increased in activated endothelial cells with the induction of angiogenic factors and matrix proteins. Secreted Hsp90{alpha} localizes on the leading edge of endothelial cells and promotes their angiogenic activities, whereas Hsp90{alpha} neutralizing antibodies reverse the effect. Furthermore, using a mouse skin wound healing model in vivo, we demonstrate that extracellular Hsp90{alpha} localizes on blood vessels in granulation tissues of wounded skin and promotes angiogenesis during wound healing. Taken together, our study reveals that Hsp90{alpha} can be secreted by activated endothelial cells and is a positive regulator of angiogenesis, suggesting the potential application of Hsp90{alpha} as a stimulator for wound repair.« less

CPT1{alpha} over-expression increases long-chain fatty acid oxidation and reduces cell viability with incremental palmitic acid concentration in 293T cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jambor de Sousa, Ulrike L.; Koss, Michael D.; Fillies, Marion

2005-12-16

To test the cellular response to an increased fatty acid oxidation, we generated a vector for an inducible expression of the rate-limiting enzyme carnitine palmitoyl-transferase 1{alpha} (CPT1{alpha}). Human embryonic 293T kidney cells were transiently transfected and expression of the CPT1{alpha} transgene in the tet-on vector was activated with doxycycline. Fatty acid oxidation was measured by determining the conversion of supplemented, synthetic cis-10-heptadecenoic acid (C17:1n-7) to C15:ln-7. CPT1{alpha} over-expression increased mitochondrial long-chain fatty acid oxidation about 6-fold. Addition of palmitic acid (PA) decreased viability of CPT1{alpha} over-expressing cells in a concentration-dependent manner. Both, PA and CPT1{alpha} over-expression increased cell death. Interestingly,more » PA reduced total cell number only in cells over-expressing CPT1{alpha}, suggesting an effect on cell proliferation that requires PA translocation across the mitochondrial inner membrane. This inducible expression system should be well suited to study the roles of CPT1 and fatty acid oxidation in lipotoxicity and metabolism in vivo.« less

[Immune diagnostics of disorders in the IFN-alpha/NK-cell system in patients with frequently recurrent herpes simplex].

PubMed

Karsonova, A V; Shulzhenko, A E; Karaulov, A V

2014-01-01

Study of features of NK-cell response to the effect of recombinant IFN-alpha in complex with evaluation of the ability to synthesize inherent IFN-alpha in patients with frequently recurrent herpes simplex (FRHS). 48 patients with genital (n = 31), labial (n = 10) and mixed localization (n = 7) FRHS diagnosis were observed. 31 healthy donors composed the control group. MC were cultivated in the presence of a recombinant human IFN-alpha2b at the concentration of 10, 100 and 1000 U/ml for 24 hours. NK-cell response to the effect of IFN-alpha was evaluated after 24 hours using flow cytometry by degranulation reaction and in the NK-activity test. IFN-alpha synthesis was evaluated in HSV-1, HSV-2 and Newcastle disease virus stimulated cell supernatants by EIA method. Patients with FRHS were established to be a heterogeneous group by parameters in the IFN-alpha/NK-cell cytotoxicity system. 2 types of NK-cell response to the stimulation by recombinant IFN-alpha were identified. Type A is characterized by a decrease of NK-cell response to IFN-alpha in the remission phase and does not have this defect in the exacerbation phase. Synthesis of inherent IFN-alpha in response to viral inductors for type A was comparable with the response in healthy donors in both phases. On the contrary type B having normal sensitivity of NK-cells to IFN-alpha in the remission phase is characterized by a decrease of this parameter in the exacerbation phase for more than 3 times. Synthesis of inherent IFN-alpha in response to viral inductors during type B is increased in the remission phase and decreased in the exacerbation phase. During immune-correcting therapy of FRHS a personalized approach taking into account features of NK-cell response to IFN-alpha is necessary, because types A and B have principal differences by cytotoxicity parameters of NK-cells and their change under the effect of IFN-alpha, as well as by parameters of IFN-alpha synthesis in response to viral inductors at various phases

Vacuolar zinc transporter Zrc1 is required for detoxification of excess intracellular zinc in the human fungal pathogen Cryptococcus neoformans.

PubMed

Cho, Minsu; Hu, Guanggan; Caza, Mélissa; Horianopoulos, Linda C; Kronstad, James W; Jung, Won Hee

2018-01-01

Zinc is an important transition metal in all living organisms and is required for numerous biological processes. However, excess zinc can also be toxic to cells and cause cellular stress. In the model fungus Saccharomyces cerevisiae, a vacuolar zinc transporter, Zrc1, plays important roles in the storage and detoxification of excess intracellular zinc to protect the cell. In this study, we identified an ortholog of the S. cerevisiae ZRC1 gene in the human fungal pathogen Cryptococcus neoformans. Zrc1 was localized in the vacuolar membrane in C. neoformans, and a mutant lacking ZRC1 showed significant growth defects under high-zinc conditions. These results suggested a role for Zrc1 in zinc detoxification. However, contrary to our expectation, the expression of Zrc1 was induced in cells grown in zinc-limited conditions and decreased upon the addition of zinc. These expression patterns were similar to those of Zip1, the high-affinity zinc transporter in the plasma membrane of C. neoformans. Furthermore, we used the zrc1 mutant in a murine model of cryptococcosis to examine whether a mammalian host could inhibit the survival of C. neoformans using zinc toxicity. We found that the mutant showed no difference in virulence compared with the wildtype strain. This result suggests that Zrc1-mediated zinc detoxification is not required for the virulence of C. neoformans, and imply that zinc toxicity may not be an important aspect of the host immune response to the fungus.

Promotive Effect of Zinc Ions on the Vitality, Migration, and Osteogenic Differentiation of Human Dental Pulp Cells.

PubMed

An, Shaofeng; Gong, Qimei; Huang, Yihua

2017-01-01

Zinc is an essential trace element for proper cellular function and bone formation. However, its exact role in the osteogenic differentiation of human dental pulp cells (hDPCs) has not been fully clarified before. Here, we speculated that zinc may be effective to regulate their growth and osteogenic differentiation properties. To test this hypothesis, different concentrations (1 × 10 -5 , 4 × 10 -5 , and 8 × 10 -5  M) of zinc ions (Zn 2+ ) were added to the basic growth culture medium and osteogenic inductive medium. Cell viability and migration were measured by cell counting kit-8 (CCK-8) and transwell migration assay in the basic growth culture medium, respectively. The reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to detect the gene expression levels of selective osteogenic differentiation markers and zinc transporters. Alkaline phosphatase (ALP) activity analysis and alizarin red S staining were used to investigate the mineralization of hDPCs. Exposure of hDPCs to Zn 2+ stimulated their viability and migration capacity in a dose- and time-dependent manner. RT-qPCR assay revealed elevated expression levels of osteogenic differentiation-related genes and zinc transporters genes in various degrees. ALP activity was also increased with elevated Zn 2+ concentrations and extended culture periods, but enhanced matrix nodules formation were observed only in 4 × 10 -5 and 8 × 10 -5  M Zn 2+ groups. These findings suggest that specific concentrations of Zn 2+ could potentiate the vitality, migration, and osteogenic differentiation of hDPCs. We may combine optimum zinc element into pulp capping materials to improve their biological performance.

ttm-1 Encodes CDF Transporters That Excrete Zinc from Intestinal Cells of C. elegans and Act in a Parallel Negative Feedback Circuit That Promotes Homeostasis

PubMed Central

Roh, Hyun Cheol; Collier, Sara; Deshmukh, Krupa; Guthrie, James; Robertson, J. David; Kornfeld, Kerry

2013-01-01

Zinc is an essential metal involved in a wide range of biological processes, and aberrant zinc metabolism is implicated in human diseases. The gastrointestinal tract of animals is a critical site of zinc metabolism that is responsible for dietary zinc uptake and distribution to the body. However, the role of the gastrointestinal tract in zinc excretion remains unclear. Zinc transporters are key regulators of zinc metabolism that mediate the movement of zinc ions across membranes. Here, we identified a comprehensive list of 14 predicted Cation Diffusion Facilitator (CDF) family zinc transporters in Caenorhabditis elegans and demonstrated that zinc is excreted from intestinal cells by one of these CDF proteins, TTM-1B. The ttm-1 locus encodes two transcripts, ttm-1a and ttm-1b, that use different transcription start sites. ttm-1b expression was induced by high levels of zinc specifically in intestinal cells, whereas ttm-1a was not induced by zinc. TTM-1B was localized to the apical plasma membrane of intestinal cells, and analyses of loss-of-function mutant animals indicated that TTM-1B promotes zinc excretion into the intestinal lumen. Zinc excretion mediated by TTM-1B contributes to zinc detoxification. These observations indicate that ttm-1 is a component of a negative feedback circuit, since high levels of cytoplasmic zinc increase ttm-1b transcript levels and TTM-1B protein functions to reduce the level of cytoplasmic zinc. We showed that TTM-1 isoforms function in tandem with CDF-2, which is also induced by high levels of cytoplasmic zinc and reduces cytoplasmic zinc levels by sequestering zinc in lysosome-related organelles. These findings define a parallel negative feedback circuit that promotes zinc homeostasis and advance the understanding of the physiological roles of the gastrointestinal tract in zinc metabolism in animals. PMID:23717214

A kinetic comparison of the processing and secretion of the alpha beta dimer and the uncombined alpha and beta subunits of chorionic gonadotropin synthesized by human choriocarcinoma cells.

PubMed

Peters, B P; Krzesicki, R F; Hartle, R J; Perini, F; Ruddon, R W

1984-12-25

Human choriocarcinoma cells (JAR) synthesize the alpha and beta subunits of the glycoprotein hormone chorionic gonadotropin (hCG) (R.W. Ruddon, C.A. Hanson, A. H. Bryan, G.J. Putterman, E.L. White, F. Perini, K. S. Meade, and P.H. Aldenderfer (1980) J. Biol. Chem. 255, 1000-1007). In addition to the hCG dimer (alpha beta), JAR cells secrete uncombined alpha and beta subunits into the culture medium (L.A. Cole, R.J. Hartle, J.A. Laferla, and R.W. Ruddon (1983) Endocrinology 113, 1176-1178). Pulse-chase studies with [35S]methionine or [3H]mannose were carried out in order to compare free alpha, free beta, and the alpha beta dimer with regard to the kinetics of synthesis, N-linked oligosaccharide processing, and secretion and to determine the kinetics of alpha-beta subunit combination. A panel of three antisera was used to immunoprecipitate directly the free subunits and the alpha beta dimer sequentially from the same cell lysates and culture media. The alpha subunit of hCG was synthesized in a slight molar excess (1.2-1.5-fold) over the beta subunit, and alpha beta dimer was rapidly formed by combination of the intracellular alpha and beta precursors. Dimer formation was already apparent in JAR cells following a 10-min biosynthetic labeling incubation with [35S]methionine. The combination of subunits ceased by 30 min of chase even though 51% of alpha and 44% of beta remained free within the cells. Combination of the alpha and beta precursors had occurred before their N-linked oligosaccharides were processed beyond the Man8GlcNAc2 structure. The initial trimming of glucosyl and mannosyl units from the high-mannose oligosaccharides of the hCG precursors occurred more rapidly for free alpha and CG-alpha than for free beta and CG-beta. JAR cells accumulated alpha precursors bearing mostly Man8GlcNAc2 units and beta precursors bearing Man8GlcNAc2 units that represent the substrates of the rate-limiting step in the secretory pathway. In spite of the fact that their N

Apoptosis induced by tumor necrosis factor-alpha in rat hepatocyte cell lines expressing hepatitis B virus.

PubMed Central

Guilhot, S.; Miller, T.; Cornman, G.; Isom, H. C.

1996-01-01

Three well differentiated SV40-immortalized rat hepatocyte cell lines, CWSV1, CWSV2, and CWSV14, and Hepatitis B Virus (HBV)-producing cell lines derived from them were examined for sensitivity to tumor necrosis factor (TNF)-alpha. CWSV1, CWSV2, and CWSV14 cells were co-transfected with a DNA construct containing a dimer of the HBV genome and the neo gene and selected in G418 to generate stable cell lines. Characterization of these cell lines indicated that they contain integrated HBV DNA, contain low molecular weight HBV DNA compatible with the presence of HBV replication intermediates, express HBV transcripts, and produce HBV proteins. The viability of CWSV1, CWSV2, and CWSV2 cells was not significantly altered when they were treated with TNF-alpha at concentrations as high as 20,000 U/ml. The HBV-expressing CWSV1 cell line, SV1di36, and the HBV-expressing CWSV14 cell line, SV14di208, were also not killed when treated with TNF-alpha. However, the HBV-expressing CWSV2 cell line, SV2di366, was extensively killed when treated with TNF-alpha at concentrations ranging from 200 to 20,000 U/ml. Analysis of several different HBV-producing CWSV2 cell lines indicated that TNF-alpha killing depended upon the level of HBV expression. The TNF-alpha-induced cell killing in high HBV-producing CWSV2 cell lines was accompanied by the presence of an oligonucleosomal DNA ladder characteristic of apoptosis. Images Figure 2 Figure 3 Figure 4 Figure 6 Figure 9 Figure 10 Figure 11 PMID:8774135

Involvement of matrix metalloproteinase-13 in stromal-cell-derived factor 1 alpha-directed invasion of human basal cell carcinoma cells.

PubMed

Chu, C-Y; Cha, S-T; Chang, C-C; Hsiao, C-H; Tan, C-T; Lu, Y-C; Jee, S-H; Kuo, M-L

2007-04-12

Basal cell carcinoma (BCC) is one of the most common skin neoplasms in humans and is usually characterized by local aggressiveness with little metastatic potential, although deep invasion, recurrence, and regional and distant metastases may occur. Here, we studied the mechanism of BCC invasion. We found that human BCC tissues and a BCC cell line had significant expression of CXCR4, which was higher in invasive than non-invasive BCC types. Further, of 19 recurrent tumors among 390 BCCs diagnosed during the past 12 years, 17/19 (89.5%) had high CXCR4 expression. We found that the CXCR4 ligand, stromal-cell-derived factor 1alpha (SDF-1alpha), directed BCC invasion and that this was mediated by time-dependent upregulation of mRNA expression and gelatinase activity of matrix metalloproteinase-13 (MMP-13). The transcriptional regulation of MMP-13 by SDF-1alpha was mediated by phosphorylation of extracellular signal-related kinase 1/2 and activation of the AP-1 component c-Jun. Finally, CXCR4-transfected BCC cells injected into nude mice induced aggressive BCCs that co-expressed CXCR4 and MMP-13. The identification of SDF-1alpha/CXCR4 as an important factor in BCC invasiveness may contribute insight into mechanisms involved in the aggressive potential of human BCC and may improve therapy for invasive BCCs.

In Vivo Biochemistry: Single-Cell Dynamics of Cyclic Di-GMP in Escherichia coli in Response to Zinc Overload.

PubMed

Yeo, Jongchan; Dippel, Andrew B; Wang, Xin C; Hammond, Ming C

2018-01-09

Intracellular signaling enzymes drive critical changes in cellular physiology and gene expression, but their endogenous activities in vivo remain highly challenging to study in real time and for individual cells. Here we show that flow cytometry can be performed in complex media to monitor single-cell population distributions and dynamics of cyclic di-GMP signaling, which controls the bacterial colonization program. These in vivo biochemistry experiments are enabled by our second-generation RNA-based fluorescent (RBF) biosensors, which exhibit high fluorescence turn-on in response to cyclic di-GMP. Specifically, we demonstrate that intracellular levels of cyclic di-GMP in Escherichia coli are repressed with excess zinc, but not with other divalent metals. Furthermore, in both flow cytometry and fluorescence microscopy setups, we monitor the dynamic increase in cellular cyclic di-GMP levels upon zinc depletion and show that this response is due to de-repression of the endogenous diguanylate cyclase DgcZ. In the presence of zinc, cells exhibit enhanced cell motility and increased sensitivity to antibiotics due to inhibited biofilm formation. Taken together, these results showcase the application of RBF biosensors in visualizing single-cell dynamic changes in cyclic di-GMP signaling in direct response to environmental cues such as zinc and highlight our ability to assess whether observed phenotypes are related to specific signaling enzymes and pathways.

IgG1 antimycobacterial antibodies can reverse the inhibitory effect of pentoxifylline on tumour necrosis factor alpha (TNF-alpha) secreted by mycobacterial antigen-stimulated adherent cells.

PubMed

Thakurdas, S M; Hasan, Z; Hussain, R

2004-05-01

Chronic inflammation associated with cachexia, weight loss, fever and arthralgia is the hallmark of advanced mycobacterial diseases. These symptoms are attributed to the chronic stimulation of tumour necrosis factor (TNF)-alpha. Mycobacterial components directly stimulate adherent cells to secrete TNF-alpha. We have shown recently that IgG1 antimycobacterial antibodies play a role in augmenting TNF-alpha in purified protein derivative (PPD)-stimulated adherent cells from non-BCG-vaccinated donors. We now show that IgG1 antibodies can also augment TNF-alpha expression in stimulated adherent cells obtained from BCG-vaccinated donors and this augmentation is not linked to interleukin (IL)-10 secretion. In addition IgG1 antimycobacterial antibodies can reverse the effect of TNF-alpha blockers such as pentoxifylline and thalidomide. These studies therefore have clinical implications for anti-inflammatory drug treatments which are used increasingly to alleviate symptoms associated with chronic inflammation.

Zinc and its transporters, pancreatic beta cells, and insulin metabolism

USDA-ARS?s Scientific Manuscript database

Zinc is an essential trace metal for life. Two families of zinc transporters, SLC30A (ZnT) and SLC39A (ZIP) are required for maintaining cellular zinc homeostasis. ZnTs function to decrease cytoplasmic zinc concentrations whereas ZIPs do the opposite. Expression of zinc transporters can be tissue/ce...

17{alpha}-Estradiol arrests cell cycle progression at G{sub 2}/M and induces apoptotic cell death in human acute leukemia Jurkat T cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jun, Do Youn; Park, Hae Sun; Kim, Jun Seok

2008-09-15

A pharmacological dose (2.5-10 {mu}M) of 17{alpha}-estradiol (17{alpha}-E{sub 2}) exerted a cytotoxic effect on human leukemias Jurkat T and U937 cells, which was not suppressed by the estrogen receptor (ER) antagonist ICI 182,780. Along with cytotoxicity in Jurkat T cells, several apoptotic events including mitochondrial cytochrome c release, activation of caspase-9, -3, and -8, PARP degradation, and DNA fragmentation were induced. The cytotoxicity of 17{alpha}-E{sub 2} was not blocked by the anti-Fas neutralizing antibody ZB-4. While undergoing apoptosis, there was a remarkable accumulation of G{sub 2}/M cells with the upregulatoin of cdc2 kinase activity, which was reflected in the Thr56more » phosphorylation of Bcl-2. Dephosphorylation at Tyr15 and phosphorylation at Thr161 of cdc2, and significant increase in the cyclin B1 level were underlying factors for the cdc2 kinase activation. Whereas the 17{alpha}-E{sub 2}-induced apoptosis was completely abrogated by overexpression of Bcl-2 or by pretreatment with the pan-caspase inhibitor z-VAD-fmk, the accumulation of G{sub 2}/M cells significantly increased. The caspase-8 inhibitor z-IETD-fmk failed to influence 17{alpha}-E{sub 2}-mediated caspase-9 activation, but it markedly reduced caspase-3 activation and PARP degradation with the suppression of apoptosis, indicating the contribution of caspase-8; not as an upstream event of the mitochondrial cytochrome c release, but to caspase-3 activation. In the presence of hydroxyurea, which blocked the cell cycle progression at the G{sub 1}/S boundary, 17{alpha}-E{sub 2} failed to induce the G{sub 2}/M arrest as well as apoptosis. These results demonstrate that the cytotoxicity of 17{alpha}-E{sub 2} toward Jurkat T cells is attributable to apoptosis mainly induced in G{sub 2}/M-arrested cells, in an ER-independent manner, via a mitochondria-dependent caspase pathway regulated by Bcl-2.« less

Zinc in Infection and Inflammation

PubMed Central

Gammoh, Nour Zahi; Rink, Lothar

2017-01-01

Micronutrient homeostasis is a key factor in maintaining a healthy immune system. Zinc is an essential micronutrient that is involved in the regulation of the innate and adaptive immune responses. The main cause of zinc deficiency is malnutrition. Zinc deficiency leads to cell-mediated immune dysfunctions among other manifestations. Consequently, such dysfunctions lead to a worse outcome in the response towards bacterial infection and sepsis. For instance, zinc is an essential component of the pathogen-eliminating signal transduction pathways leading to neutrophil extracellular traps (NET) formation, as well as inducing cell-mediated immunity over humoral immunity by regulating specific factors of differentiation. Additionally, zinc deficiency plays a role in inflammation, mainly elevating inflammatory response as well as damage to host tissue. Zinc is involved in the modulation of the proinflammatory response by targeting Nuclear Factor Kappa B (NF-κB), a transcription factor that is the master regulator of proinflammatory responses. It is also involved in controlling oxidative stress and regulating inflammatory cytokines. Zinc plays an intricate function during an immune response and its homeostasis is critical for sustaining proper immune function. This review will summarize the latest findings concerning the role of this micronutrient during the course of infections and inflammatory response and how the immune system modulates zinc depending on different stimuli. PMID:28629136

Omentin inhibits TNF-{alpha}-induced expression of adhesion molecules in endothelial cells via ERK/NF-{kappa}B pathway

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Xia, E-mail: zhongxia1977@126.com; Li, Xiaonan; Liu, Fuli

2012-08-24

Highlights: Black-Right-Pointing-Pointer Omentin inhibited TNF-{alpha}-induced adhesion of THP-1 cells to HUVECs. Black-Right-Pointing-Pointer Omentin reduces expression of ICAM-1 and VCAM-1 induced by TNF-{alpha} in HUVECs. Black-Right-Pointing-Pointer Omentin inhibits TNF-{alpha}-induced ERK and NF-{kappa}B activation in HUVECs. Black-Right-Pointing-Pointer Omentin supreeses TNF-{alpha}-induced expression of ICAM-1 and VCAM-1 via ERK/NF-{kappa}B pathway. -- Abstract: In the present study, we investigated whether omentin affected the expression of intracellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) in tumor necrosis factor-{alpha} (TNF-{alpha}) induced human umbilical vein endothelial cells (HUVECs). Our data showed that omentin decreased TNF-{alpha}-induced expression of ICAM-1 and VCAM-1 in HUVECs. In addition, omentin inhibitedmore » TNF-{alpha}-induced adhesion of THP-1 cells to HUVECs. Further, we found that omentin inhibited TNF-{alpha}-activated signal pathway of nuclear factor-{kappa}B (NF-{kappa}B) by preventing NF-{kappa}B inhibitory protein (I{kappa}B{alpha}) degradation and NF-{kappa}B/DNA binding activity. Omentin pretreatment significantly inhibited TNF-{alpha}-induced ERK activity and ERK phosphorylation in HUVECs. Pretreatment with PD98059 suppressed TNF-{alpha}-induced NF-{kappa}B activity. Omentin, NF-kB inhibitor (BAY11-7082) and ERK inhibitor (PD98059) reduced the up-regulation of ICAM-1 and VCAM-1 induced by TNF-{alpha}. These results suggest that omentin may inhibit TNF-{alpha}-induced expression of adhesion molecules in endothelial cells via blocking ERK/NF-{kappa}B pathway.« less

Zinc decreases C-reactive protein, lipid peroxidation, and inflammatory cytokines in elderly subjects: a potential implication of zinc as an atheroprotective agent123

PubMed Central

Bao, Bin; Prasad, Ananda S; Beck, Frances WJ; Fitzgerald, James T; Snell, Diane; Bao, Ginny W; Singh, Tapinder; Cardozo, Lavoisier J

2010-01-01

Background: Chronic inflammation and oxidative stress are common risk factors for atherosclerosis. Zinc is an essential micronutrient that can function as an antiinflammatory and antioxidative agent, and as such, it may have atheroprotective properties. Objective: We hypothesized that zinc down-regulates the production of atherosclerosis-related cytokines/molecules in humans. Design: To examine these effects, we conducted a randomized, double-blinded, placebo trial of zinc supplementation in elderly subjects. We recruited 40 healthy elderly subjects (aged 56–83 y) and randomly assigned them to 2 groups. One group was given an oral dose of 45 mg zinc/d as a gluconate for 6 mo. The other group was given a placebo. Cell culture models were conducted to study the mechanism of zinc as an atheroprotective agent. Results: After 6 mo of supplementation, the intake of zinc, compared with intake of placebo, increased the concentrations of plasma zinc and decreased the concentrations of plasma high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, macrophage chemoattractant protein 1 (MCP-1), vascular cell adhesion molecule 1 (VCAM-1), secretory phospholipase A2, and malondialdehyde and hydroxyalkenals (MDA+HAE) in elderly subjects. Regression analysis showed that changes in concentrations of plasma zinc were inversely associated with changes in concentrations of plasma hsCRP, MCP-1, VCAM-1, and MDA+HAE after 6 mo of supplementation. In cell culture studies, we showed that zinc decreased the generation of tumor necrosis factor-α, IL-1β, VCAM-1, and MDA+HAE and the activation of nuclear transcription factor κB and increased antiinflammatory proteins A20 and peroxisome proliferator–activated receptor-α in human monocytic leukemia THP-1 cells and human aortic endothelial cells compared with zinc-deficient cells. Conclusion: These findings suggest that zinc may have a protective effect in atherosclerosis because of its antiinflammatory and antioxidant functions

The influence of inflammation on plasma zinc concentration in apparently healthy, HIV+ Kenyan adults and zinc responses after a multi-micronutrient supplement.

PubMed

Mburu, A S W; Thurnham, D I; Mwaniki, D L; Muniu, E M; Alumasa, F M

2010-05-01

Plasma zinc is an important biomarker of zinc status, but the concentration is depressed by inflammation. Apparently healthy adults, who tested positive twice for human immunodeficiency virus (HIV) but who had not reached stage IV or clinical AIDS, were randomly allocated to receive a food supplement (n=17 and 21) or the food plus a micronutrient capsule (MN; n=10 men and n=33 women) containing 15 mg zinc/day. We used the inflammation biomarkers, C-reactive protein (CRP) and alpha1-acid glycoprotein (AGP), to identify subjects with and without inflammation and determine the effect of inflammation on the response of plasma zinc concentrations to the MN and food supplements. There were no differences between men and women either in plasma zinc or in the responses to the supplements and their data were combined. Plasma zinc was lower in those with inflammation than without. Repeated measures analysis of variance (ANOVA) showed that inflammation blocked increases in plasma zinc, and there was an approximate 10% increase in plasma zinc concentration in response to the MN supplement (P=0.023) in those without inflammation. Subgroup analysis showed mean changes in plasma zinc of 0.95 and -0.83 micromol/l (P=0.031) in response to the MN and food treatments, respectively, in those without inflammation at both time points. Inflammation seems to block any increase in plasma zinc after MN supplement and it is important to identify those without inflammation to determine the effectiveness of a zinc supplementation program.

Efficient inverted polymer solar cells based on conjugated polyelectrolyte and zinc oxide modified ITO electrode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yuan, Tao; Zhu, Xiaoguang; Tu, Guoli, E-mail: tgl@hust.edu.cn

Efficient inverted polymer solar cells (PSCs) were constructed by utilizing a conjugated polyelectrolyte PF{sub EO}SO{sub 3}Na and zinc oxide to modify the indium tin oxide (ITO) electrode. The ITO electrode modified by PF{sub EO}SO{sub 3}Na and zinc oxide possesses high transparency, increased electron mobility, smoothened surface, and lower work function. PTB7:PC{sub 71}BM inverted PSCs containing the modified ITO electrode achieved a high power conversion efficiency (PCE) of 8.49%, exceeding that of the control device containing a ZnO modified ITO electrode (7.48%). Especially, PCE-10:PC{sub 71}BM inverted polymer solar cells achieved a high PCE up to 9.4%. These results demonstrate a usefulmore » approach to improve the performance of inverted polymer solar cells.« less

Membrane androgen receptor characteristics of human ZIP9 (SLC39A) zinc transporter in prostate cancer cells: Androgen-specific activation and involvement of an inhibitory G protein in zinc and MAP kinase signaling.

PubMed

Thomas, Peter; Pang, Yefei; Dong, Jing

2017-05-15

Characteristics of novel human membrane androgen receptor (mAR), ZIP9 (SLC39A9), were investigated in ZIP9-transfected PC-3 cells (PC3-ZIP9). Ligand blot analysis showed plasma membrane [ 3 H]-T binding corresponds to the position of ZIP9 on Western blots which suggests ZIP9 can bind [ 3 H]-T alone, without a protein partner. Progesterone antagonized testosterone actions, blocking increases in zinc, Erk phosphorylation and apoptosis, further evidence that ZIP9 is specifically activated by androgens. Pre-treatment with GTPγS and pertussis toxin decreased plasma membrane [ 3 H]-T binding and blocked testosterone-induced increases in Erk phosphorylation and intracellular zinc, indicating ZIP9 is coupled to an inhibitory G protein (Gi) that mediates both MAP kinase and zinc signaling. Testosterone treatment of nuclei and mitochondria which express ZIP9 decreased their zinc contents, suggesting ZIP9 also regulates free zinc through releasing it from these intracellular organelles. The results show ZIP9 is a specific Gi coupled-mAR mediating testosterone-induced MAP kinase and zinc signaling in PC3-ZIP9 cells. Copyright © 2017 Elsevier B.V. All rights reserved.

alpha-Tocopheryl succinate promotes selective cell death induced by vitamin K3 in combination with ascorbate.

PubMed

Tomasetti, M; Strafella, E; Staffolani, S; Santarelli, L; Neuzil, J; Guerrieri, R

2010-04-13

A strategy to reduce the secondary effects of anti-cancer agents is to potentiate the therapeutic effect by their combination. A combination of vitamin K3 (VK3) and ascorbic acid (AA) exhibited an anti-cancer synergistic effect, associated with extracellular production of H(2)O(2) that promoted cell death. The redox-silent vitamin E analogue alpha-tocopheryl succinate (alpha-TOS) was used in combination with VK3 and AA to evaluate their effect on prostate cancer cells. Prostate cancer cells were sensitive to alpha-TOS and VK3 treatment, but resistant to AA upto 3.2 mM. When combined, a synergistic effect was found for VK3-AA, whereas alpha-TOS-VK3 and alpha-TOS-AA combination showed an antagonist and additive effect, respectively. However, sub-lethal doses of AA-VK3 combination combined with a sub-toxic dose of alpha-TOS showed to induce efficient cell death that resembles autoschizis. Associated with this cell demise, lipid peroxidation, DNA damage, cytoskeleton alteration, lysosomal-mitochondrial perturbation, and release of cytochrome c without caspase activation were observed. Inhibition of lysosomal proteases did not attenuate cell death induced by the combined agents. Furthermore, cell deaths by apoptosis and autoschizis were detected. These finding support the emerging idea that synergistic combinations of some agents can overcome toxicity and other side-effects associated with high doses of single drugs creating the opportunity for therapeutically relevant selectivity.

A new gene deletion in the alpha-like globin gene cluster as the molecular basis for the rare alpha-thalassemia-1(--/alpha alpha) in blacks: HbH disease in sickle cell trait.

PubMed

Steinberg, M H; Coleman, M B; Adams, J G; Hartmann, R C; Saba, H; Anagnou, N P

1986-02-01

A novel deletion of at least 26 kilobase of DNA, including both alpha-globin genes, the psi alpha- and psi zeta-globin genes, but sparing the functional zeta-gene was found in a 10-year-old black boy with HbH disease and sickle cell trait. This particular deletion has not previously been described in blacks. Its existence makes it likely that the absence of Hb Barts hydrops fetalis in blacks is due to the rarity of the chromosome lacking two alpha-globin genes rather than a result of early embryonic death due to the failure to synthesize embryonic hemoglobins because of deletion of functional zeta-globin genes.

Subacute Zinc Administration and L-NAME Caused an Increase of NO, Zinc, Lipoperoxidation, and Caspase-3 during a Cerebral Hypoxia-Ischemia Process in the Rat

PubMed Central

Blanco-Alvarez, Victor Manuel; Lopez-Moreno, Patricia; Soto-Rodriguez, Guadalupe; Martinez-Fong, Daniel; Rubio, Hector; Gonzalez-Barrios, Juan Antonio; Piña-Leyva, Celia; Torres-Soto, Maricela; Gomez-Villalobos, María de Jesus; Hernandez-Baltazar, Daniel; Eguibar, José Ramon; Ugarte, Araceli; Cebada, Jorge

2013-01-01

Zinc or L-NAME administration has been shown to be protector agents, decreasing oxidative stress and cell death. However, the treatment with zinc and L-NAME by intraperitoneal injection has not been studied. The aim of our work was to study the effect of zinc and L-NAME administration on nitrosative stress and cell death. Male Wistar rats were treated with ZnCl2 (2.5 mg/kg each 24 h, for 4 days) and N-ω-nitro-L-arginine-methyl ester (L-NAME, 10 mg/kg) on the day 5 (1 hour before a common carotid-artery occlusion (CCAO)). The temporoparietal cortex and hippocampus were dissected, and zinc, nitrites, and lipoperoxidation were assayed at different times. Cell death was assayed by histopathology using hematoxylin-eosin staining and caspase-3 active by immunostaining. The subacute administration of zinc before CCAO decreases the levels of zinc, nitrites, lipoperoxidation, and cell death in the late phase of the ischemia. L-NAME administration in the rats treated with zinc showed an increase of zinc levels in the early phase and increase of zinc, nitrites, and lipoperoxidation levels, cell death by necrosis, and the apoptosis in the late phase. These results suggest that the use of these two therapeutic strategies increased the injury caused by the CCAO, unlike the alone administration of zinc. PMID:23997853

The Zinc-Schiff Base-Novicidin Complex as a Potential Prostate Cancer Therapy

PubMed Central

Milosavljevic, Vedran; Haddad, Yazan; Merlos Rodrigo, Miguel Angel; Moulick, Amitava; Polanska, Hana; Hynek, David; Heger, Zbynek; Kopel, Pavel; Adam, Vojtech

2016-01-01

Prostate cancer cells control energy metabolism by chelating intracellular zinc. Thus, zinc delivery has been a popular therapeutic approach for prostate cancer. Here, we propose the use of the membrane-penetrating peptide Novicidin connected to zinc-Schiff base as a carrier vehicle for the delivery of zinc to prostate cells. Mass spectrometry, electrochemistry and spectrophotometry confirmed the formation/stability of this complex and provided insight regarding the availability of zinc for complex interactions. This delivery system showed minor toxicity in normal PNT1A cells and high potency towards PC3 tumor cells. The complex preferentially penetrated PC3 tumor cells in contrast to confinement to the membranes of PNT1A. Furthermore, zinc uptake was confirmed in both cell lines. Molecular analysis was used to confirm the activation of zinc stress (e.g., ZnT-1) and apoptosis (e.g., CASP-1). Our results strongly suggest that the zinc-Schiff base-Novicidin complex has great potential as a novel anticancer drug. PMID:27727290

Variability and repertoire size of T-cell receptor V alpha gene segments.

PubMed

Becker, D M; Pattern, P; Chien, Y; Yokota, T; Eshhar, Z; Giedlin, M; Gascoigne, N R; Goodnow, C; Wolf, R; Arai, K

The immune system of higher organisms is composed largely of two distinct cell types, B lymphocytes and T lymphocytes, each of which is independently capable of recognizing an enormous number of distinct entities through their antigen receptors; surface immunoglobulin in the case of the former, and the T-cell receptor (TCR) in the case of the latter. In both cell types, the genes encoding the antigen receptors consist of multiple gene segments which recombine during maturation to produce many possible peptides. One striking difference between B- and T-cell recognition that has not yet been resolved by the structural data is the fact that T cells generally require a major histocompatibility determinant together with an antigen whereas, in most cases, antibodies recognize antigen alone. Recently, we and others have found that a series of TCR V beta gene sequences show conservation of many of the same residues that are conserved between heavy- and light-chain immunoglobulin V regions, and these V beta sequences are predicted to have an immunoglobulin-like secondary structure. To extend these studies, we have isolated and sequenced eight additional alpha-chain complementary cDNA clones and compared them with published sequences. Analyses of these sequences, reported here, indicate that V alpha regions have many of the characteristics of V beta gene segments but differ in that they almost always occur as cross-hybridizing gene families. We conclude that there may be very different selective pressures operating on V alpha and V beta sequences and that the V alpha repertoire may be considerably larger than that of V beta.

Could vitamin C and zinc chloride protect the germ cells against sodium arsenite?

PubMed

Altoé, L S; Reis, I B; Gomes, Mlm; Dolder, H; Pirovani, Jc Monteiro

2017-10-01

Arsenic (As) is commonly associated with natural and human processes such as volcanic emissions, mining and herbicides production, being an important pollutant. Several studies have associated As intake with male fertility reduction, thus the aim of the present study was to evaluate whether vitamin C and/or zinc would counteract As side effects within the testicles. Adult male Wistar rats were divided into six experimental groups: control, sodium arsenite (5 mg/kg/day), vitamin C (100 mg/kg/day), zinc chloride (ZnCl 2 ; 20 mg/kg/day), sodium arsenite + vitamin C and sodium arsenite + ZnCl 2 . Testicles and epididymis were harvested and either frozen or routinely processed to be embedded in glycol methacrylate resin. As reduced the seminiferous epithelium and tubules diameter due to germ cell loss. In addition, both the round spermatids population and the daily sperm production were reduced. However, ZnCl 2 and vitamin C showed to be effective against such side effects, mainly regarding to sperm morphology. Long-term As intake increased the proportions of abnormal sperm, whereas the concomitant intake of As with zinc or vitamin C enhanced the proportions of normal sperm, showing that such compounds could be used to protect this cell type against morphological defects.

Rasagiline protects against alpha-synuclein induced sensitivity to oxidative stress in dopaminergic cells

PubMed Central

Chau, K.Y.; Cooper, J.M.; Schapira, A.H.V.

2010-01-01

Rasagiline is a propargylamine and irreversible monoamine oxidase (MAO) B inhibitor used for the treatment of Parkinson's disease (PD). It has demonstrated neuroprotective properties in laboratory studies. Current concepts of PD aetiopathogenesis include the role of alpha-synuclein, protein aggregation, free radical metabolism and mitochondrial dysfunction in contributing to cell death. We have used a combination of alpha-synuclein and free radical mediated toxicity in a dopaminergic cell line to provide a model of nigral toxicity in order to investigate the potential molecular mechanisms that mediate rasagiline protection. We demonstrate that rasagiline protects against cell death induced by the combination of free radicals generated by paraquat and either wild-type or A53T mutant alpha-synuclein over-expression. This protection was associated with a reduction in caspase 3 activation, a reduction in superoxide generation and a trend to ameliorate the fall in mitochondrial membrane potential. Rasagiline induced an increase in cellular glutathione levels. The results support a role for rasagiline in protecting dopaminergic cells against free radical mediated damage and apoptosis in the presence of alpha-synuclein over-expression. The data are of relevance to the interpretation of the potential mechanisms of action of rasagiline in explaining the results of disease modification trials in PD. PMID:20624440

Involvement of Mst1 in tumor necrosis factor-{alpha}-induced apoptosis of endothelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ohtsubo, Hideki; Ichiki, Toshihiro; Imayama, Ikuyo

2008-03-07

Mammalian sterile 20-kinase 1 (Mst1), a member of the sterile-20 family protein kinase, plays an important role in the induction of apoptosis. However, little is know about the physiological activator of Mst1 and the role of Mst1 in endothelial cells (ECs). We examined whether Mst1 is involved in the tumor necrosis factor (TNF)-{alpha}-induced apoptosis of ECs. Western blot analysis revealed that TNF-{alpha} induced activation of caspase 3 and Mst1 in a time- and dose-dependent manner. TNF-{alpha}-induced Mst1 activation is almost completely prevented by pretreatment with Z-DEVD-FMK, a caspase 3 inhibitor. Nuclear staining with Hoechst 33258 and fluorescence-activated cell sorting ofmore » propidium iodide-stained cells showed that TNF-{alpha} induced apoptosis of EC. Diphenyleneiodonium, an inhibitor of NADPH oxidase, and N-acetylcysteine, a potent antioxidant, also inhibited TNF-{alpha}-induced activation of Mst1 and caspase 3, as well as apoptosis. Knockdown of Mst1 expression by short interfering RNA attenuated TNF-{alpha}-induced apoptosis but not cleavage of caspase 3. These results suggest that Mst1 plays an important role in the induction of TNF-{alpha}-induced apoptosis of EC. However, positive feedback mechanism between Mst1 and caspase 3, which was shown in the previous studies, was not observed. Inhibition of Mst1 function may be beneficial for maintaining the endothelial integrity and inhibition of atherogenesis.« less

Neurotoxicity of dental amalgam is mediated by zinc.

PubMed

Lobner, D; Asrari, M

2003-03-01

The use of dental amalgam is controversial largely because it contains mercury. We tested whether amalgam caused toxicity in neuronal cultures and whether that toxicity was caused by mercury. In this study, we used cortical cell cultures to show for the first time that amalgam causes nerve cell toxicity in culture. However, the toxicity was not blocked by the mercury chelator, 2,3-dimercaptopropane-1-sulphonate (DMPS), but was blocked by the metal chelator, calcium disodium ethylenediaminetetraacetate (CaEDTA). DMPS was an effective mercury chelator in this system, since it blocked mercury toxicity. Of the components that comprise amalgam (mercury, zinc, tin, copper, and silver), only zinc neurotoxicity was blocked by CaEDTA. These results indicate that amalgam is toxic to nerve cells in culture by releasing zinc. While zinc is known to be neurotoxic, ingestion of zinc is not a major concern because zinc levels in the body are tightly regulated.

Zinc Deficiency Induces Apoptosis via Mitochondrial p53- and Caspase-Dependent Pathways in Human Neuronal Precursor Cells

ERIC Educational Resources Information Center

Seth, Rohit; Corniola, Rikki S.; Gower-Winter, Shannon D.; Morgan, Thomas J., Jr.; Bishop, Brian; Levenson, Cathy W.

2015-01-01

Previous studies have shown that zinc deficiency leads to apoptosis of neuronal precursor cells in vivo and in vitro. In addition to the role of p53 as a nuclear transcription factor in zinc deficient cultured human neuronal precursors (NT-2), we have now identified the translocation of phosphorylated p53 to the mitochondria and p53-dependent…

Advancing Stem Cell Models of Alpha-Synuclein Gene Regulation in Neurodegenerative Disease.

PubMed

Piper, Desiree A; Sastre, Danuta; Schüle, Birgitt

2018-01-01

Alpha-synuclein ( non A4 component of amyloid precursor, SNCA, NM_000345.3 ) plays a central role in the pathogenesis of Parkinson's disease (PD) and related Lewy body disorders such as Parkinson's disease dementia, Lewy body dementia, and multiple system atrophy. Since its discovery as a disease-causing gene in 1997, alpha-synuclein has been a central point of scientific interest both at the protein and gene level. Mutations, including copy number variants, missense mutations, short structural variants, and single nucleotide polymorphisms, can be causative for PD and affect conformational changes of the protein, can contribute to changes in expression of alpha-synuclein and its isoforms, and can influence regulation of temporal as well as spatial levels of alpha-synuclein in different tissues and cell types. A lot of progress has been made to understand both the physiological transcriptional and epigenetic regulation of the alpha-synuclein gene and whether changes in transcriptional regulation could lead to disease and neurodegeneration in PD and related alpha-synucleinopathies. Although the histopathological changes in these neurodegenerative disorders are similar, the temporal and spatial presentation and progression distinguishes them which could be in part due to changes or disruption of transcriptional regulation of alpha-synuclein. In this review, we describe different genetic alterations that contribute to PD and neurodegenerative conditions and review aspects of transcriptional regulation of the alpha-synuclein gene in the context of the development of PD. New technologies, advanced gene engineering and stem cell modeling, are on the horizon to shed further light on a better understanding of gene regulatory processes and exploit them for therapeutic developments.

Critical rate of electrolyte circulation for preventing zinc dendrite formation in a zinc-bromine redox flow battery

NASA Astrophysics Data System (ADS)

Yang, Hyeon Sun; Park, Jong Ho; Ra, Ho Won; Jin, Chang-Soo; Yang, Jung Hoon

2016-09-01

In a zinc-bromine redox flow battery, a nonaqueous and dense polybromide phase formed because of bromide oxidation in the positive electrolyte during charging. This formation led to complicated two-phase flow on the electrode surface. The polybromide and aqueous phases led to different kinetics of the Br/Br- redox reaction; poor mixing of the two phases caused uneven redox kinetics on the electrode surface. As the Br/Br- redox reaction was coupled with the zinc deposition reaction, the uneven redox reaction on the positive electrode was accompanied by nonuniform zinc deposition and zinc dendrite formation, which degraded battery stability. A single-flow cell was operated at varying electrolyte circulation rates and current densities. Zinc dendrite formation was observed after cell disassembly following charge-discharge testing. In addition, the flow behavior in the positive compartment was observed by using a transparent version of the cell. At low rate of electrolyte circulation, the polybromide phase clearly separated from the aqueous phase and accumulated at the bottom of the flow frame. In the corresponding area on the negative electrode, a large amount of zinc dendrites was observed after charge-discharge testing. Therefore, a minimum circulation rate should be considered to avoid poor mixing of the positive electrolyte.

Potential Interactions of Calcium-Sensitive Reagents with Zinc Ion in Different Cultured Cells

PubMed Central

Fujikawa, Koichi; Fukumori, Ryo; Nakamura, Saki; Kutsukake, Takaya; Takarada, Takeshi; Yoneda, Yukio

2015-01-01

Background Several chemicals have been widely used to evaluate the involvement of free Ca2+ in mechanisms underlying a variety of biological responses for decades. Here, we report high reactivity to zinc of well-known Ca2+-sensitive reagents in diverse cultured cells. Methodology/Principal Findings In rat astrocytic C6 glioma cells loaded with the fluorescent Ca2+ dye Fluo-3, the addition of ZnCl2 gradually increased the fluorescence intensity in a manner sensitive to the Ca2+ chelator EGTA irrespective of added CaCl2. The addition of the Ca2+ ionophore A23187 drastically increased Fluo-3 fluorescence in the absence of ZnCl2, while the addition of the Zn2+ ionophore pyrithione rapidly and additionally increased the fluorescence in the presence of ZnCl2, but not in its absence. In cells loaded with the zinc dye FluoZin-3 along with Fluo-3, a similarly gradual increase was seen in the fluorescence of Fluo-3, but not of FluoZin-3, in the presence of both CaCl2 and ZnCl2. Further addition of pyrithione drastically increased the fluorescence intensity of both dyes, while the addition of the Zn2+ chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethane-1,2-diamine (TPEN) rapidly and drastically decreased FluoZin-3 fluorescence. In cells loaded with FluoZin-3 alone, the addition of ZnCl2 induced a gradual increase in the fluorescence in a fashion independent of added CaCl2 but sensitive to EGTA. Significant inhibition was found in the vitality to reduce 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide in a manner sensitive to TPEN, EDTA and BAPTA in C6 glioma cells exposed to ZnCl2, with pyrithione accelerating the inhibition. Similar inhibition occurred in an EGTA-sensitive fashion after brief exposure to ZnCl2 in pluripotent P19 cells, neuronal Neuro2A cells and microglial BV2 cells, which all expressed mRNA for particular zinc transporters. Conclusions/Significance Taken together, comprehensive analysis is absolutely required for the demonstration of a

Effects of alpha-galactosylceramides on bone marrow cells in vitro and hematopoiesis in vivo.

PubMed

Motoki, K; Morita, M; Kobayashi, E; Uchida, T; Fukushima, H; Koezuka, Y

1996-07-01

We found that AGL-517, an alpha-galactosylceramide (alpha-GalCer), possesses potent radioprotective activities against mice irradiated with 9 Gy of X-ray in contrast to its having no effect on mice irradiated with 10 Gy of X-ray. The result suggested the possibility that alpha-GalCers protect mice from bone marrow death. To examine this possibility, we examined the effects of two kinds of alpha- and beta-GalCers on counts of platelets (PLT) and white blood cells (WBC) in the peripheral blood of normal mice and mice irradiated in a whole body with 5 Gy of X-ray. alpha-GalCers significantly increased the PLT and WBC counts of both mice in comparison with the vehicle-treated group, and their potencies were stronger than those of their beta-types. Furthermore, we evaluated the in vitro bone marrow cell-proliferation stimulatory activities of four kinds of GalCers, and found that alpha-GalCers show stronger stimulatory effects than beta-types. These results demonstrate that the alpha-configuration of GalCers plays an important role in the manifestation of the above-mentioned activities of GalCers. The results also suggest that alpha-GalCers may be useful as hematopoietic stimulators as well as radioprotective agents.

Induction of a bystander mutagenic effect of alpha particles in mammalian cells

NASA Technical Reports Server (NTRS)

Zhou, H.; Randers-Pehrson, G.; Waldren, C. A.; Vannais, D.; Hall, E. J.; Hei, T. K.; Chatterjee, A. (Principal Investigator)

2000-01-01

Ever since the discovery of X-rays was made by Rontgen more than a hundred years ago, it has always been accepted that the deleterious effects of ionizing radiation such as mutation and carcinogenesis are attributable mainly to direct damage to DNA. Although evidence based on microdosimetric estimation in support of a bystander effect appears to be consistent, direct proof of such extranuclear/extracellular effects are limited. Using a precision charged particle microbeam, we show here that irradiation of 20% of randomly selected A(L) cells with 20 alpha particles each results in a mutant fraction that is 3-fold higher than expected, assuming no bystander modulation effect. Furthermore, analysis by multiplex PCR shows that the types of mutants induced are significantly different from those of spontaneous origin. Pretreatment of cells with the radical scavenger DMSO had no effect on the mutagenic incidence. In contrast, cells pretreated with a 40 microM dose of lindane, which inhibits cell-cell communication, significantly decreased the mutant yield. The doses of DMSO and lindane used in these experiments are nontoxic and nonmutagenic. We further examined the mutagenic yield when 5-10% of randomly selected cells were irradiated with 20 alpha particles each. Results showed, likewise, a higher mutant yield than expected assuming no bystander effects. Our studies provide clear evidence that irradiated cells can induce a bystander mutagenic response in neighboring cells not directly traversed by alpha particles and that cell-cell communication process play a critical role in mediating the bystander phenomenon.

[Expression of integrin alpha5 and actin in the cells of intervertebral disc under cyclic hydrostatic pressure in vitro].

PubMed

Yu, Sheng-ji; Qiu, Gui-xing; Burton, Yang; Sandra, Roth; Cari, Whyne; Albert, Yee

2005-12-15

To investigate the expression of integrin alpha5 and actin in the cells of intervertebral disc under cyclic hydrostatic pressure in vitro. The porcine lumbar intervertebral disc cells were isolated and cultured in vitro, and the cells underwent cyclic hydrostatic loading. After that, the expression of integrin alpha5 and actin in intervertebral disc cells were studied by means of morphology observing, Western blot and immunohistochemistry staining. The morphology of intervertebral disc cells were changed into smaller and flatten shape, and the expression of integrin alpha5 and actin were decreased after loading. The expression of integrin alpha5 decreases under cyclic hydrostatic pressure, and the actin is affected at the same time when signals are transferred into the cells by integrin alpha5. That may be one of the important mechanisms of the mechanotransduction in the cells of intervertebral disc.

Eluted zinc ions stimulate osteoblast differentiation and mineralization in human dental pulp stem cells for bone tissue engineering.

PubMed

Yusa, Kazuyuki; Yamamoto, Osamu; Iino, Mitsuyoshi; Takano, Hiroshi; Fukuda, Masayuki; Qiao, Zhiwei; Sugiyama, Toshihiro

2016-11-01

Zinc is an essential element for proliferation, differentiation and survival in various cell types. In a previous study, we found that zinc ions released from zinc-modified titanium surfaces (eluted zinc ions; EZ) stimulate cell viability, osteoblast marker gene expression and calcium deposition in human bone marrow-derived mesenchymal cells (hBMCs). The aim of the present study was to investigate the effects of EZ on osteoblast differentiation among dental pulp stem cells (DPSCs) in vitro. In this study, we evaluated the effects of EZ on osteogenesis in DPSCs. Osteoblast and osteoclast marker gene expression was evaluated by real-time PCR. We also evaluated alkaline phosphatase (ALP) staining and calcium deposition. We found that EZ stimulated osteoblast marker gene (type I collagen, alkaline phosphatase (ALP), osteocalcin (OCN) and Runx2) expression, vascular endothelial growth factor A (VEGF-A), and TGF-beta signaling pathway-related gene expression after 7days of incubation. Osteoclastogenesis occurs in a receptor for activated nuclear-factor kappa B ligand (RANKL)/osteoprotegerin (OPG)-independent manner. Real-time PCR analysis revealed that EZ did not affect RANKL or OPG mRNA expression. It was also revealed that EZ induced alkaline phosphatase (ALP) staining and calcium deposition in DPSCs. Collectively, these results demonstrate the potential for clinical application to prospective treatment of bone diseases. Copyright © 2016 Elsevier Ltd. All rights reserved.

Metallic Zinc Exhibits Optimal Biocompatibility for Bioabsorbable Endovascular Stents

PubMed Central

Bowen, Patrick K.; Guillory, Roger J.; Shearier, Emily R.; Seitz, Jan-Marten; Drelich, Jaroslaw; Bocks, Martin; Zhao, Feng; Goldman, Jeremy

2015-01-01

Although corrosion resistant bare metal stents are considered generally effective, their permanent presence in a diseased artery is an increasingly recognized limitation due to the potential for long-term complications. We previously reported that metallic zinc exhibited an ideal biocorrosion rate within murine aortas, thus raising the possibility of zinc as a candidate base material for endovascular stenting applications. This study was undertaken to further assess the arterial biocompatibility of metallic zinc. Metallic zinc wires were punctured and advanced into the rat abdominal aorta lumen for up to 6.5 months. This study demonstrated that metallic zinc did not provoke responses that often contribute to restenosis. Low cell densities and neointimal tissue thickness, along with tissue regeneration within the corroding implant, point to optimal biocompatibility of corroding zinc. Furthermore, the lack of progression in neointimal tissue thickness over 6.5 months or the presence of smooth muscle cells near the zinc implant suggest that the products of zinc corrosion may suppress the activities of inflammatory and smooth muscle cells. PMID:26249616

Proliferation of Estrogen Receptor alpha Positive Mammary Epithelial Cells is Restrained by TGFbeta1 in Adult Mice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ewan, Kenneth B.R.; Oketch-Rabah, Hellen A.; Ravani, Shraddha A.

2005-03-03

Transforming growth factor {beta}1 (TGF{beta}1) is a potent inhibitor of mammary epithelial proliferation. In human breast, estrogen receptor {alpha} (ER{alpha}) cells rarely co-localize with markers of proliferation, but their increased frequency correlates with breast cancer risk. To determine whether TGF{beta}1 is necessary for the quiescence of ER{alpha}-positive population, we examined mouse mammary epithelial gland at estrus. Approximately 35% of cells showed TGF{beta}1 activation, which co-localized with nuclear receptor-phosphorylated Smad 2/3, indicating that TGF{beta} signaling is autocrine. Furthermore, nuclear Smad co-localized with nuclear ER{alpha}. To test whether TGF{beta} was functional, we examined genetically engineered mice with different levels of TGF{beta}1. ER{alpha}more » co-localization with markers of proliferation (i.e. Ki-67 or BrdU) at estrus was significantly increased in the mammary glands of Tgf{beta}1 C57/bl/129SV heterozygote mice. This relationship was maintained following pregnancy, but was absent at puberty. Conversely, mammary epithelial expression of constitutively active TGF{beta}1 via the MMTV promoter suppressed proliferation of ER{alpha} positive cells. Thus, TGF{beta}1 activation functionally restrains ER{alpha} positive cells from proliferating in adult mammary gland. Accordingly, we propose that TGF{beta}1 dysregulation may promote proliferation of ER{alpha} positive cells associated with breast cancer risk in humans.« less

Cloning, cell-type specificity, and regulatory function of the mouse alpha(1B)-adrenergic receptor promoter.

PubMed

Zuscik, M J; Piascik, M T; Perez, D M

1999-12-01

The functionality of a 3422-base pair promoter fragment from the mouse alpha(1B)-adrenergic receptor (alpha(1B)AR) gene was examined. This fragment, cloned from a mouse genomic library, was found to have significant sequence homology to the known human and rat alpha(1B)AR promoters. However, the consensus motif of several key cis-acting elements is not conserved among the rat, human, and mouse genes, suggesting species specificity. Confirming fidelity of the murine promoter, robust in vitro expression of a chloramphenicol acetyltransferase (CAT) reporter was detected in known alpha(1B)AR-expressing BC(3)H1, NB41A3, and DDT(1)MF-2 cells transiently transfected with a promoter-CAT construct. Conversely, minimal CAT expression was detected in known alpha(1B)AR-negative RAT-1 and R3T3 cells. These findings were extended by transfecting the same promoter-CAT construct into various primary cell types. In support of the hypothesis that alpha(1)ARs are differentially expressed in the smooth muscle of the vasculature, primary cultures of superior mesenteric and renal artery vascular smooth muscle cells showed significantly stronger CAT expression than did vascular smooth muscle cells derived from pulmonary, femoral, and iliac arteries. Primary osteoblastic bone-forming cells, which are known to be alpha(1B)AR negative, showed minimal CAT expression. Indicating regulatory function through cis-acting elements, RAT-1, R3T3, NB41A3, BC(3)H1, and DDT(1)MF2 cells transfected with the promoter-CAT construct all showed increased CAT production when challenged with forskolin or hypoxic conditions. Additionally, tissue-specific regulation of the promoter was observed when cells were simultaneously challenged with both forskolin and hypoxia. These results collectively demonstrate that a 3.4-kb PvuII fragment of the murine alpha(1B)AR gene promoter can: 1) drive tissue-specific production of a CAT reporter in both clonal and primary cell lines; and 2) confer tissue-specific regulation

Low-Resistivity Zinc Selenide for Heterojunctions

NASA Technical Reports Server (NTRS)

Stirn, R. J.

1986-01-01

Magnetron reactive sputtering enables doping of this semiconductor. Proposed method of reactive sputtering combined with doping shows potential for yielding low-resistivity zinc selenide films. Zinc selenide attractive material for forming heterojunctions with other semiconductor compounds as zinc phosphide, cadmium telluride, and gallium arsenide. Semiconductor junctions promising for future optoelectronic devices, including solar cells and electroluminescent displays. Resistivities of zinc selenide layers deposited by evaporation or chemical vapor deposition too high to form practical heterojunctions.

Distinct expression pattern of IFN-alpha and TNF-alpha in juvenile idiopathic arthritis synovial tissue.

PubMed

Gattorno, M; Chicha, L; Gregorio, A; Ferlito, F; Rossi, F; Jarrossay, D; Lanzavecchia, A; Martini, A; Manz, M G

2007-04-01

Recent laboratory and clinical data suggest that two prototype autoimmune diseases, systemic lupus erythematosus and rheumatoid arthritis are mainly driven by distinct cytokines, interferon (IFN)-alpha and tumour necrosis factor (TNF)-alpha, respectively. We here investigated the presence and characteristics of natural type I IFN-producing cells (IPCs), as well as IFN-alpha and TNF-alpha expression at sites of inflammation in juvenile idiopathic arthritis (JIA). Peripheral blood (PB) and synovial fluid (SF) mononuclear cells (MNCs) (n = 25 each) from JIA patients with active disease were studied. IPCs were identified as BCDA-2(+)CD123(+)HLA-DR(+)CD45RA(+) cells, and dendritic cells (DCs) as CD11c(+)CD14(-/low)lin(-) cells by flow cytometry. IPCs and DCs were analysed for Toll-like receptor-7 and -9 mRNA expression by real-time polymerase chain reaction. IFN-alpha was measured by enzyme-linked immunosorbent assay in serum, SF and in supernatants of influenza virus-infected, cultured IPCs. Synovial tissues of n = 6 additional JIA patients were analysed by immunohistochemistry using mAbs against CD123, IFN-alpha, TNF-alpha, CD3, CD19 and CD138. IPCs were enriched in SF MNCs compared with PB MNCs in all JIA patients. Influenza-induced, but no spontaneous IFN-alpha release was detected from SF IPCs, and serum and SF IFN-alpha levels were not elevated. Nonetheless, in synovial tissue IFN-alpha producing cells accumulated at inflammatory lymph-follicular-like structures, while TNF-alpha producing cells were mostly found at the lining and sublining layers. These data suggest that besides TNF-alpha-expressing cells, IFN-alpha-producing IPCs are involved in initiation, maintenance or regulation of the inflammatory response in JIA.

The effect of red cell and plasma transfusion on serum zinc and copper levels in the neonate.

PubMed

Lockitch, G; Godolphin, W J; Pendray, M R; Quigley, G

1983-11-01

Transfusion of packed red cells (15 to 20 ml/kg) in 11 preterm infants resulted in a slight increase in mean serum zinc levels on the 3rd post transfusion day but no effect was noted on serum copper levels. No significant difference was found between the changes in serum zinc in 141 paired specimens collected a week apart when zero, one, two or three packed cell transfusions were given in the intervening week. A slight decrease in the mean copper level was noted when one transfusion was given. Transfusion of fresh frozen plasma in six newborns with abdominal wall defects resulted in initial serum copper levels two to three times greater than the reference mean for newborns. No effect was noted on zinc levels. Serum copper results should be interpreted with caution in infants who have been transfused with plasma.

Human common acute lymphoblastic leukemia-derived cell lines are competent to recombine their T-cell receptor delta/alpha regions along a hierarchically ordered pathway.

PubMed

Hansen-Hagge, T E; Yokota, S; Reuter, H J; Schwarz, K; Bartram, C R

1992-11-01

Rearrangements of the T-cell receptor (TCR) delta locus are observed in the majority of human B-cell precursor acute lymphoblastic leukemias (ALL) with a striking predominance of V delta 2(D)D delta 3 recombinations in common ALL (cALL) patients. Recently, we and others showed that almost 20% of cALL cases are characterized by further recombination of V delta 2(D)D delta 3 segments to J alpha elements, thereby deleting the TCR delta locus in analogy to the delta Rec/psi J alpha pathway in differentiating alpha/beta-positive T cells. We report here that two human cALL-derived cell lines, REH and Nalm-6, are competent to recombine the TCR delta/alpha locus under standard tissue culture conditions. Analysis of different REH subclones obtained by limiting dilution of the initial culture showed a biased recombination of V delta 2D delta 3 to distinct J alpha elements. During prolonged tissue culture, a subclone acquired growth advantage and displaced parental cells as well as other subclones. Frequently, the DJ junctions of REH subclones contained extended stretches of palindromic sequences derived from modified D delta 3 coding elements. The other cell line, Nalm-6, started the TCR delta/alpha recombination with an unusual signal joint of a cryptic recombinase signal sequence (RSS) upstream of D delta 3 to the 3' RSS of D delta 3. The RSS dimer was subsequently rearranged in all investigated subclones to an identical J alpha element. Both cell lines might become valuable tools to unravel the complex regulation of TCR delta/alpha recombination pathways in malignant and normal lymphopoiesis.

Novel function of STAT1beta in B cells: induction of cell death by a mechanism different from that of STAT1alpha.

PubMed

Najjar, Imen; Schischmanoff, Pierre Olivier; Baran-Marszak, Fanny; Deglesne, Pierre-Antoine; Youlyouz-Marfak, Ibtissam; Pampin, Mathieu; Feuillard, Jean; Bornkamm, Georg W; Chelbi-Alix, Mounira K; Fagard, Remi

2008-12-01

Alternate splicing of STAT1 produces two isoforms: alpha, known as the active form, and beta, previously shown to act as a dominant-negative factor. Most studies have dealt with STAT1alpha, showing its involvement in cell growth control and cell death. To examine the specific function of either isoform in cell death, a naturally STAT1-deficient human B cell line was transfected to express STAT1alpha or STAT1beta. STAT1alpha, expressed alone, enhanced cell death, potentiated the fludarabine-induced apoptosis, and enhanced the nuclear location, the phosphorylation, and the transcriptional activity of p53. Unexpectedly, STAT1beta, expressed alone, induced cell death through a mechanism that was independent of the nuclear function of p53. Indeed, in STAT1beta-expressing B cells, p53 was strictly cytoplasmic where it formed clusters, and there was no induction of the transcriptional activity of p53. These data reveal a novel role of STAT1beta in programmed cell death, which is independent of p53.

Mushroom acidic glycosphingolipid induction of cytokine secretion from murine T cells and proliferation of NK1.1 {alpha}/{beta} TCR-double positive cells in vitro

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nozaki, Hirofumi; Itonori, Saki; Sugita, Mutsumi

2008-08-29

Interferon (IFN)-{gamma} and interleukin (IL)-4 regulate many types of immune responses. Here we report that acidic glycosphingolipids (AGLs) of Hypsizigus marmoreus and Pleurotus eryngii induced secretion of IFN- {gamma} and IL-4 from T cells in a CD11c-positive cell-dependent manner similar to that of {alpha}-galactosylceramide ({alpha}-GalCer) and isoglobotriaosylceramide (iGb3), although activated T cells by AGLs showed less secretion of cytokine than those activated by {alpha}-GalCer. In addition, stimulation of these mushroom AGLs induced proliferation of NK1.1 {alpha}/{beta} TCR-double positive cells in splenocytes. Administration of a mixture of {alpha}-GalCer and AGLs affected the stimulation of {alpha}-GalCer and generally induced a subtle Th1more » bias for splenocytes but induced an extreme Th2 bias for thymocytes. These results suggested that edible mushroom AGLs contribute to immunomodulation.« less

Erythropoietin protects myocardin-expressing cardiac stem cells against cytotoxicity of tumor necrosis factor-{alpha}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Madonna, Rosalinda; Institute of Cardiology, and Center of Excellence on Aging, 'G. d'Annunzio' University, Chieti; Shelat, Harnath

2009-10-15

Cardiac stem cells are vulnerable to inflammation caused by infarction or ischemic injury. The growth factor, erythropoietin (Epo), ameliorates the inflammatory response of the myocardium to ischemic injury. This study was designed to assess the role of Epo in regulation of expression and activation of the cell death-associated intracellular signaling components in cardiac myoblasts stimulated with the proinflammatory cytokine tumor necrosis factor (TNF)-{alpha}. Cardiac myoblasts isolated from canine embryonic hearts characterized by expression of myocardin A, a promyogenic transcription factor for cardiovascular muscle development were pretreated with Epo and then exposed to TNF-{alpha}. Compared to untreated cells, the Epo-treated cardiacmore » myoblasts exhibited better morphology and viability. Immunoblotting revealed lower levels of active caspase-3 and reductions in iNOS expression and NO production in Epo-treated cells. Furthermore, Epo pretreatment reduced nuclear translocation of NF-{kappa}B and inhibited phosphorylation of inhibitor of kappa B (I{kappa}B) in TNF-{alpha}-stimulated cardiac myoblasts. Thus, Epo protects cardiac myocyte progenitors or myoblasts against the cytotoxic effects of TNF-{alpha} by inhibiting NF-{kappa}B-mediated iNOS expression and NO production and by preventing caspase-3 activation.« less

Zinc release contributes to hypoglycemia-induced neuronal death.

PubMed

Suh, Sang Won; Garnier, Philippe; Aoyama, Koji; Chen, Yongmei; Swanson, Raymond A

2004-08-01

Neurons exposed to zinc exhibit activation of poly(ADP-ribose) polymerase-1 (PARP-1), an enzyme that normally participates in DNA repair but promotes cell death when extensively activated. Endogenous, vesicular zinc in brain is released to the extracellular space under conditions causing neuronal depolarization. Here, we used a rat model of insulin-induced hypoglycemia to assess the role of zinc release in PARP-1 activation and neuronal death after severe hypoglycemia. Zinc staining with N-(6-methoxy-8-quinolyl)-para-toluenesulfonamide (TSQ) showed depletion of presynaptic vesicular zinc from hippocampal mossy fiber terminals and accumulation of weakly bound zinc in hippocampal CA1 cell bodies after severe hypoglycemia. Intracerebroventricular injection of the zinc chelator calcium ethylene-diamine tetraacetic acid (CaEDTA) blocked the zinc accumulation and significantly reduced hypoglycemia-induced neuronal death. CaEDTA also attenuated the accumulation of poly(ADP-ribose), the enzymatic product of PARP-1, in hippocampal neurons. These results suggest that zinc translocation is an intermediary step linking hypoglycemia to PARP-1 activation and neuronal death.