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111.
Role of PLCgamma and Ca(2+) in VEGF- and FGF-induced choroidal endothelial cell proliferation 总被引:2,自引:0,他引:2
Although bothvascular endothelial growth factor (VEGF) and fibroblast growth factor(FGF) receptors have been shown to be important in the regulation ofvascular endothelial cell growth, the roles of phospholipase C (PLC)and Ca2+ in their downstream signaling cascades are stillnot clear. We have examined the effects of VEGF and FGF on PLCphosphorylation and on changes in intracellular Ca2+ levelsin primary endothelial cells. VEGF stimulation leads to PLCactivation and increases in intracellular Ca2+, which arecorrelated with mitogen-activated protein (MAP) kinase (MAPK)activation and cell growth. Inhibition of Ca2+ increases bythe Ca2+ chelator1,2-bis(2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid(BAPTA)-AM resulted in marked inhibition of MAPK activation, which wasshown to be linked to regulation of cell growth in these cells. Incontrast, FGF stimulation did not lead to PLC activation or tochanges in intracellular Ca2+ levels, although MAPKphosphorylation and stimulation of cell proliferation were observed.Neither BAPTA-AM nor the PLC inhibitor U-73122 had an effect on theseFGF-stimulated responses. These data demonstrate a direct role forPLC and Ca2+ in VEGF-regulated endothelial cell growth,whereas this signaling pathway is not linked to FGF-mediated effects inprimary endothelial cells. Thus endothelial cell-specific factorsregulate the ability of VEGF receptors and FGF receptors to couple tothis signaling pathway. 相似文献
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Induction of neuronal apoptosis by thiol oxidation: putative role of intracellular zinc release 总被引:14,自引:0,他引:14
Aizenman E Stout AK Hartnett KA Dineley KE McLaughlin B Reynolds IJ 《Journal of neurochemistry》2000,75(5):1878-1888
The membrane-permeant oxidizing agent 2,2'-dithiodipyridine (DTDP) can induce Zn(2+) release from metalloproteins in cell-free systems. Here, we report that brief exposure to DTDP triggers apoptotic cell death in cultured neurons, detected by the presence of both DNA laddering and asymmetric chromatin formation. Neuronal death was blocked by increased extracellular potassium levels, by tetraethylammonium, and by the broad-spectrum cysteine protease inhibitor butoxy-carbonyl-aspartate-fluoromethylketone. N,N,N', N'-Tetrakis-(2-pyridylmethyl)ethylenediamine (TPEN) and other cell-permeant metal chelators also effectively blocked DTDP-induced toxicity in neurons. Cell death, however, was not abolished by the NMDA receptor blocker MK-801, by the intracellular calcium release antagonist dantrolene, or by high concentrations of ryanodine. DTDP generated increases in fluorescence signals in cultured neurons loaded with the zinc-selective dye Newport Green. The fluorescence signals following DTDP treatment also increased in fura-2- and magfura-2-loaded neurons. These responses were completely reversed by TPEN, consistent with a DTDP-mediated increase in intracellular free Zn(2+) concentrations. Our studies suggest that under conditions of oxidative stress, Zn(2+) released from intracellular stores may contribute to the initiation of neuronal apoptosis. 相似文献
115.
Effects of sulfate on cadmium uptake by Swiss chard: II. Effects due to sulfate addition to soil 总被引:3,自引:0,他引:3
Sulfate complexation of Cd in nutrient solution has been shown to have little impact on Cd uptake by plants. This study examined the effect of sulfate added to soil on Cd concentrations in soil solution and Cd uptake by Swiss chard (Beta vulgaris L. cv. Fordhook Giant). Swiss chard was grown in soil which was wetted with complete nutrient solution containing equivalent salt concentrations of NaNO3 or Na2SO4. Plant growth was reduced by increasing both NO3 and SO4 concentrations in soil solution, with growth reductions similar for both salts. The Cd concentration in soil solution increased P< 0.05) more consistently with increasing concentrations of SO4 compared to NO3 in soil solution. Solution speciation, calculated with GEOCHEM-PC, showed significant increases of Cd2+ activities with increasing salt rates. Shoot Cd content in 19-day-old Swiss chard plants was marginally but significantly P <0.05) increased with increasing SO4 concentration but no effect was observed with increasing NO3 concentration. These results are compared with earlier work on the marked effect of Cl- salinity on Cd availability in Swiss chard. Possible mechanisms explaining the smaller effect of SO4 compared to Cl on Cd availability are proposed. 相似文献
116.
Phytotoxicity of hydrogen fluoride and fluoroborate and their uptake from solution culture by Lycopersicon esculentum and Avena sativa 总被引:6,自引:0,他引:6
The aims of this paper were to determine the phytoavailability and phytotoxicity of hydrogen fluoride (HF) and fluoroborate (BF
4
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) in solution when exposed to the root of the plant. As fluoroborate undergoes a slow hydrolysis to F and borate ions, the stability of BF
4
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under solution culture conditions was determined. Fluoroborate was found to have a zero order rate constant of 0.0136 and took approximately 72 days to hydrolyse completely.Tomato (Lycopersicon esculentum) and oat (Avena sativa) plants were grown in dilute nutrient solutions which contained a range of activities of HF and BF
4
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. Dry matter production of both tomato and oat plants grown in nutrient solutions were found to be restricted by increased activity of HF and BF
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in solution. Tomatoes were more sensitive to HF and BF
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than oats. Limitations to dry matter production coincided with increased uptake of F for F concentrations in tissue of both tomatoes and oats. Fluoride uptake of both HF and BF by tomatoes and oats was orders of magnitude higher compared to similar activities of other ionic species of F reported in previous studies. Possible mechanisms of uptake are discussed. 相似文献
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Lee McMichael Daniel Edson Amanda McLaughlin David Mayer Steven Kopp Joanne Meers Hume Field 《PloS one》2015,10(5)
This paper establishes reference ranges for hematologic and plasma biochemistry values in wild Black flying-foxes (Pteropus alecto) captured in South East Queensland, Australia. Values were found to be consistent with those of other Pteropus species. Four hundred and forty-seven animals were sampled over 12 months and significant differences were found between age, sex, reproductive and body condition cohorts in the sample population. Mean values for each cohort fell within the determined normal adult reference range, with the exception of elevated levels of alkaline phosphatase in juvenile animals. Hematologic and biochemistry parameters of injured animals showed little or no deviation from the normal reference values for minor injuries, while two animals with more severe injury or abscessation showed leucocytosis, anaemia, thrombocytosis, hyperglobulinemia and hypoalbuminemia. 相似文献
119.
Jacqueline Y. Quinn Robert Sidney Cox III Aaron Adler Jacob Beal Swapnil Bhatia Yizhi Cai Joanna Chen Kevin Clancy Michal Galdzicki Nathan J. Hillson Nicolas Le Novère Akshay J. Maheshwari James Alastair McLaughlin Chris J. Myers Umesh P Matthew Pocock Cesar Rodriguez Larisa Soldatova Guy-Bart V. Stan Neil Swainston Anil Wipat Herbert M. Sauro 《PLoS biology》2015,13(12)
Synthetic Biology Open Language (SBOL) Visual is a graphical standard for genetic engineering. It consists of symbols representing DNA subsequences, including regulatory elements and DNA assembly features. These symbols can be used to draw illustrations for communication and instruction, and as image assets for computer-aided design. SBOL Visual is a community standard, freely available for personal, academic, and commercial use (Creative Commons CC0 license). We provide prototypical symbol images that have been used in scientific publications and software tools. We encourage users to use and modify them freely, and to join the SBOL Visual community: http://www.sbolstandard.org/visual. 相似文献
120.
Danxia Yu Jennifer Sonderman Maciej S. Buchowski Joseph K. McLaughlin Xiao-Ou Shu Mark Steinwandel Lisa B. Signorello Xianglan Zhang Margaret K. Hargreaves William J. Blot Wei Zheng 《PLoS medicine》2015,12(5)