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Beta cells AND Tungstate

K M Seemann, M Luysberg, Z Révay, P Kudejova, B Sanz, N Cassinelli, A Loidl, K Ilicic, G Multhoff, T E Schmid
Magnetic nanoparticles are highly desirable for biomedical research and treatment of cancer especially when combined with hyperthermia. The efficacy of nanoparticle-based therapies could be improved by generating radioactive nanoparticles with a convenient decay time and which simultaneously have the capability to be used for locally confined heating. The core-shell morphology of such novel nanoparticles presented in this work involves a polysilico-tungstate molecule of the polyoxometalate family as a precursor coating material, which transforms into an amorphous tungsten oxide coating upon annealing of the FePt core-shell nanoparticles...
January 10, 2015: Journal of Controlled Release: Official Journal of the Controlled Release Society
Ana I Fernández-Mariño, Miguel A Valverde, José M Fernández-Fernández
Tungstate, a compound with antidiabetic, antiobesity, and antihypertensive properties, activates the large-conductance voltage- and Ca(2+)-dependent K(+) (BK) channel containing either β1 or β4 subunits. The BK activation by tungstate is Mg(2+)-dependent and promotes arterial vasodilation, but only in precontracted mouse arteries expressing β1. In this study, we further explored how the β1 subunit participates in tungstate activation of BK channels. Activation of heterologously expressed human BKαβ1 channels in inside-out patches is fully dependent on the Mg(2+) sensitivity of the BK α channel subunit even at high (10 μM) cytosolic Ca(2+) concentration...
July 2014: Pflügers Archiv: European Journal of Physiology
M Milagros Gómez-Gómez, Nuria Rodríguez-Fariñas, Benito Cañas-Montalvo, Jorge Domínguez, Joan Guinovart, Carmen Cámara-Rica
It is known that oral administration of sodium tungstate preserves the pancreatic beta cell function in diabetic rats. Healthy and streptozotocin-induced diabetic rats were treated with sodium tungstate for one, three or six weeks, after which the species of W in serum, were analysed. An increase in serum W with treatment time was observed. After six weeks, the serum W concentration in diabetic rats (70 mg L(-1)) was about 4.6 times higher than in healthy specimens. This different behaviour was also observed for Cu accumulation, while the Zn pattern follows the contrary...
May 30, 2011: Talanta
J Altirriba, R Gasa, S Casas, M J Ramírez-Bajo, S Ros, A Gutierrez-Dalmau, M C Ruiz de Villa, A Barbera, R Gomis
AIMS/HYPOTHESIS: Transmembrane protein 27 (TMEM27) is a membrane protein cleaved and shed by pancreatic beta cells that has been proposed as a beta cell mass biomarker. Despite reports of its possible role in insulin exocytosis and cell proliferation, its function in beta cells remains controversial. We aimed to characterise the function of TMEM27 in islets and its potential use as a beta cell mass biomarker. METHODS: To determine TMEM27 function, we studied TMEM27 gene expression and localisation in human healthy and diabetic islets, the correlation of its expression with cell cycle and insulin secretion genes in human islets, its expression in tungstate-treated rats, and the effects of its overproduction on insulin secretion and proliferation in a beta cell line and islets...
July 2010: Diabetologia
Jordi Altirriba, Albert Barbera, Héctor Del Zotto, Belen Nadal, Sandra Piquer, Alex Sánchez-Pla, Juan J Gagliardino, Ramon Gomis
BACKGROUND: Sodium tungstate is known to be an effective anti-diabetic agent, able to increase beta cell mass in animal models of diabetes, although the molecular mechanisms of this treatment and the genes that control pancreas plasticity are yet to be identified. Using a transcriptomics approach, the aim of the study is to unravel the molecular mechanisms which participate in the recovery of exocrine and endocrine function of streptozotocin (STZ) diabetic rats treated with tungstate, determining the hyperglycemia contribution and the direct effect of tungstate...
2009: BMC Genomics
M C Carmona, M Amigó, S Barceló-Batllori, M Julià, Y Esteban, S Moreno, R Gomis
OBJECTIVE: We have recently shown the in vivo anti-obesity effects of sodium tungstate. In this study, we investigate the in vitro effects of sodium tungstate on adipocyte differentiation and function. METHODS: 3T3-F442A cells were allowed to differentiate in the presence of sodium tungstate, and were analyzed for triglyceride (TG) accumulation, adipocyte differentiation and mitochondrial oxygen consumption. RESULTS: Sodium tungstate treatment of adipose cells decreased TG accumulation and adipocyte differentiation...
May 2009: International Journal of Obesity: Journal of the International Association for the Study of Obesity
Nupur Srivastava, Vijay K Gonugunta, Mallikarjuna R Puli, Agepati S Raghavendra
The effects of chitosan (beta-1,4 linked glucosamine, a fungal elicitor), on the patterns of stomatal movement and signaling components were studied. cPTIO (NO scavenger), sodium tungstate (nitrate reductase inhibitor) or L: -NAME (NO synthase inhibitor) restricted the chitosan induced stomatal closure, demonstrating that NO is an essential factor. Similarly, catalase (H(2)O(2) scavenger) or DPI [NAD(P)H oxidase inhibitor] and BAPTA-AM or BAPTA (calcium chelators) prevented chitosan induced stomatal closure, suggesting that reactive oxygen species (ROS) and calcium were involved during such response...
March 2009: Planta
Zahra Heidari, Mehdi Harati, Hamid Reza Mahmoudzadeh-Sagheb, Bita Moudi
BACKGROUND: Diabetes is a major public health problem. The development of new therapies that are able to improve glycemia management and even to cure diabetes is of great interest. In this study, protective effects of sodium tungstate against STZ-induced beta-cell damages were investigated. METHODS: Sixty rats were divided into six groups: control, diabetic, sodium tungstate treated diabetic rats from one week before STZ injection (TDB), food-restricted diabetic (FRD), tungstate treated control, sodium tungstate treated diabetic rats from one week after STZ administration (TDA)...
2008: Iranian Biomedical Journal
M D Girón, N Sevillano, A M Vargas, J Domínguez, J J Guinovart, R Salto
AIMS/HYPOTHESIS: The aim of this study was to investigate the action of the glucose-lowering compound sodium tungstate on glucose transport in muscle myotubes and to unravel the molecular events underlying the effects observed. METHODS: We studied the effects of tungstate on 2-deoxy-D: -glucose uptake, levels and translocation of the glucose transporters GLUT4 and GLUT1, and Glut4 (also known as Slc2a4) promoter activity. We also measured the modifications of individual components of the signalling pathways involved in the effects observed...
July 2008: Diabetologia
Zahra Heidari, Hamidreza Mahmoudzadeh-Sagheb, Bita Moudi
Diabetes is a major public health problem. Development of new therapies that are able to improve glycemia management, cure diabetes, and can even protect from it, are of great interest. This study investigated the protective effect of sodium tungstate against STZ-induced beta-cell damages by means of stereological methods. Sixty rats were divided into six groups: control (C), tungstate-treated control (TC), STZ-induced diabetic (D), STZ-induced diabetic rats were treated by sodium tungstate from 1 week before STZ injection (TDB), food-restricted diabetic (FRD), and diabetic rats treated with sodium tungstate 1 week after STZ administration (TDA)...
December 2008: Micron: the International Research and Review Journal for Microscopy
Sandra Piquer, Sílvia Barceló-Batllori, Marta Julià, Nuria Marzo, Belen Nadal, Joan J Guinovart, Ramon Gomis
Oral administration of sodium tungstate is an effective treatment for diabetes in animal models. Several lines of evidence indicate the pancreatic beta cell as one of the targets of tungstate action. Here, we examined the molecular mechanism by which this compound exerts its effects on the beta cell line MIN6. Tungstate treatment induced phosphorylation and subsequent activation of p38 and PI3K which in turn are implicated in tungstate PDX-1 nuclear localization and activation. Although no effect was observed in glucose-induced insulin secretion we found that tungstate activates basal insulin release, a process driven, at least in part, by activation of p38...
June 29, 2007: Biochemical and Biophysical Research Communications
Atsunori Negishi, Tadashi Muraoka, Terunobu Maeda, Fumiaki Takeuchi, Tadayoshi Kanao, Kazuo Kamimura, Tsuyoshi Sugio
Growth of five strains of sulfur-oxidizing bacteria Acidithiobacillus thiooxidans, including strain NB1-3, was inhibited completely by 50 microM of sodium tungstate (Na(2)WO(4)). When the cells of NB1-3 were incubated in 0.1 M beta-alanine-SO(4)(2-) buffer (pH 3.0) with 100 microM Na(2)WO(4) for 1 h, the amount of tungsten bound to the cells was 33 microg/mg protein. Approximately 10 times more tungsten was bound to the cells at pH 3.0 than at pH 7.0. The tungsten binding to NB1-3 cells was inhibited by oxyanions such as sodium molybdenum and ammonium vanadate...
November 2005: Bioscience, Biotechnology, and Biochemistry
Satoru Ikeda, Toshiya Hozumi, Kazuhito Hashimoto, Shin-Ichi Ohkoshi
In this paper, we report the crystal structure and magnetic properties of the cyano-bridged gadolinium-tungstate bimetallic assembly, GdIII(DMF)6[WV(CN)8](DMF =N,N-dimethylformamide). X-Ray single crystal analysis shows that this compound crystallizes in the monoclinic system of space group P2(1)/c with cell constants a= 16.40(2)A, b= 11.08(1)A, c= 21.18(2)A, beta= 91.09(8) degrees, and Z= 4. The crystal consists of one-dimensional linear chains, in which [GdIII(DMF)6]3+ and [WV(CN)8]3- ions are linked in an alternating fashion...
June 21, 2005: Dalton Transactions: An International Journal of Inorganic Chemistry
Hui-Kang Liu, Brian D Green, Neville H McClenaghan, Jane T McCluskey, Peter R Flatt
The ultratrace elements vanadate, tungstate, and molybdate exhibit significant antihyperglycemic effects in both type 1 and 2 diabetic animals, but possible effects on the function of pancreatic beta cells are understudied. In the present study, clonal BRIN BD11 cells were cultured for 3 days with each ultratrace element to establish doses lacking detrimental effects on viable beta cell mass. Vanadate treatment (4 micromol/L) had no effect on cellular insulin content but improved glucose-induced insulin secretory responsiveness...
May 2004: Pancreas
J Fernández-Alvarez, A Barberà, B Nadal, S Barceló-Batllori, S Piquer, M Claret, J J Guinovart, R Gomis
AIMS/HYPOTHESIS: Sodium tungstate has recently emerged as an effective oral treatment for diabetes. We examined the effects of tungstate administration in the beta-cell mass of the pancreas as well as its therapeutic potential. METHODS: Sodium tungstate was administered via drinking water to healthy and neonatal streptozotocin (nSTZ)-diabetic rats for one month. The pancreas from each rat was removed and morphometric and immunocytochemical studies were carried out...
March 2004: Diabetologia
Stefan Siemann, Klaus Schneider, Mareke Oley, Achim Müller
In the phototrophic non-sulfur bacterium Rhodobacter capsulatus, the biosynthesis of the conventional Mo-nitrogenase is strictly Mo-regulated. Significant amounts of both dinitrogenase and dinitrogenase reductase were only formed when the growth medium was supplemented with molybdate (1 microM). During cell growth under Mo-deficient conditions, tungstate, at high concentrations (1 mM), was capable of partially (approximately 25%) substituting for molybdate in the induction of nitrogenase synthesis. On the basis of such conditions, a tungsten-substituted nitrogenase was isolated from R...
April 8, 2003: Biochemistry
Vanna Fierabracci, Vincenzo De Tata, Alessandro Pocai, Michela Novelli, Albert Barberà, Pellegrino Masiello
It has been shown that tungstate is an effective hypoglycemic agent in several animal models of diabetes. In this study, we examined the effectiveness of oral tungstate treatment in a new experimental diabetic syndrome, induced by streptozotocin (STZ) and nicotinamide in adult rats, that shares several features with human type 2 diabetes. Sodium tungstate was administered in the drinking water (2 mg/mL) of control and diabetic rats for 15, 30, 60, and 90 d. Glucose metabolism was explored in vivo by intravenous glucose tolerance test...
November 2002: Endocrine
Elena S Stavridi, Yentram Huyen, Ivy R Loreto, Daniel M Scolnick, Thanos D Halazonetis, Nikola P Pavletich, Philip D Jeffrey
The Chfr mitotic checkpoint protein is frequently inactivated in human cancer. We determined the three-dimensional structure of its FHA domain in its native form and in complex with tungstate, an analog of phosphate. The structures revealed a beta sandwich fold similar to the previously determined folds of the Rad53 N- and C-terminal FHA domains, except that the Rad53 domains were monomeric, whereas the Chfr FHA domain crystallized as a segment-swapped dimer. The ability of the Chfr FHA domain to recognize tungstate suggests that it shares the ability with other FHA domains to bind phosphoproteins...
July 2002: Structure
Yutaka Tajima
Previously, a factor (Factor T) was found in aged mixtures of tungstate and phosphate, which greatly sensitizes strains of methicillin-resistant Staphylococcus aureus to beta-lactams. Factor T was purified and identified as undecatungstophosphate([PW11O39]7-). Undecatungstosilicate([SiW11O39]8-), a compound closely related to undecatungstophosphate, showed a similar enhancing effect. Chemically, these compounds are classified as "polyoxotungstates", and it is expected that these tungsten compounds will be useful as a "tool" in laboratory tests: i...
February 2002: Rinsho Byori. the Japanese Journal of Clinical Pathology
T Sugio, H Kuwano, A Negishi, T Maeda, F Takeuchi, K Kamimura
Cell growth of three hundred iron-oxidizing bacteria isolated from natural environments was inhibited strongly by 0.05 mM, and completely by 0.2 mM of sodium tungstate (Na2WO4), respectively. Since no great difference in the level of tungsten inhibition was observed among the 300 strains tested, the mechanism of inhibition by Na2WO4 was studied with Acidithiobacillus ferrooxidans strain AP19-3. When resting cells of AP19-3 were incubated in 0.1 M beta-alanine-SO4(2-) buffer (pH 3.0) with 0.1 mM Na2WO4 for 1 h, the amount of tungsten bound to the cells was 12 microg/mg protein...
March 2001: Bioscience, Biotechnology, and Biochemistry
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