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Marie-belle Saab Nicole Bec Marta Martin Elias Estephan Frédéric Cuisinier Christian Larroque Csilla Gergely 《Cell biochemistry and biophysics》2013,65(3):399-411
Though the pharmacological activity of curcumin inhibiting the proliferation of certain cancer cells in culture was demonstrated, its effect on early-stage modifications induced in cell mechanics influencing hereby cell growth and cell adhesion are still questionable. We investigate the morphology and the elastic properties of live cultured, non-malignant human mammalian epithelial cells (HMEC) and cancerous breast epithelial cells (MCF7) by atomic force microscopy. We describe the different behavior of the two similar cell lines under curcumin treatment and we use fluorescence microscopy to identify the microtubules as the cytoskeleton structures responding to curcumin. The first changes in the HMEC cell morphology are observed after already 2 h incubation with curcumin. A 6-h long treatment leaves the MCF7 cells morphology non-affected, but the microtubules of HMEC cells disassemble and form a ring-like organization circumscribing the nuclear area. The observed morphological changes were correlated to modifications in cell’s mechanics via elasticity force mapping measurements. Curcumin treatment modified elasticity of the HMEC cells increasing the cell’s average Young’s modulus two- to threefold, especially in the cytoplasmic area. Contrariwise, a slight decrease in the Young’s modulus was noticed for the MCF7 cells, as they become softer due to the action of curcumin. Chemotherapeutic drugs exert their effect via the perturbation of the dynamic instability of the microtubule, hence the cell-specific perturbation induced by curcumin can help in future understanding of drug induced events on the cell behavior. 相似文献
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Fazakas C Wilhelm I Nagyoszi P Farkas AE Haskó J Molnár J Bauer H Bauer HC Ayaydin F Dung NT Siklós L Krizbai IA 《PloS one》2011,6(6):e20758
Malignant melanoma represents the third common cause of brain metastasis, having the highest propensity to metastasize to the brain of all primary neoplasms in adults. Since the central nervous system lacks a lymphatic system, the only possibility for melanoma cells to reach the brain is via the blood stream and the blood-brain barrier. Despite the great clinical importance, mechanisms of transmigration of melanoma cells through the blood-brain barrier are incompletely understood. In order to investigate this question we have used an in vitro experimental setup based on the culture of cerebral endothelial cells (CECs) and the A2058 and B16/F10 melanoma cell lines, respectively. Melanoma cells were able to adhere to confluent brain endothelial cells, a process followed by elimination of protrusions and transmigration from the luminal to the basolateral side of the endothelial monolayers. The transmigration process of certain cells was accelerated when they were able to use the routes preformed by previously transmigrated melanoma cells. After migrating through the endothelial monolayer several melanoma cells continued their movement beneath the endothelial cell layer. Melanoma cells coming in contact with brain endothelial cells disrupted the tight and adherens junctions of CECs and used (at least partially) the paracellular transmigration pathway. During this process melanoma cells produced and released large amounts of proteolytic enzymes, mainly gelatinolytic serine proteases, including seprase. The serine protease inhibitor Pefabloc® was able to decrease to 44–55% the number of melanoma cells migrating through CECs. Our results suggest that release of serine proteases by melanoma cells and disintegration of the interendothelial junctional complex are main steps in the formation of brain metastases in malignant melanoma. 相似文献
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L. Hudek L. A. Pearson A. Michalczyk B. A. Neilan M. L. Ackland 《Applied microbiology and biotechnology》2013,97(19):8649-8662
The ZIP family of metal transporters is involved in the transport of Zn2+ and other metal cations from the extracellular environment and/or organelles into the cytoplasm of prokaryotes, eukaryotes and archaeotes. In the present study, we identified twin ZIP transporters, Zip11 (Npun_F3111) and Zip63 (Npun_F2202) encoded within the genome of the filamentous cyanobacterium, Nostoc punctiforme PCC73120. Sequence-based analyses and structural predictions confirmed that these cyanobacterial transporters belong to the SLC39 subfamily of metal transporters. Quantitative real-time (QRT)-PCR analyses suggested that the enzymes encoded by zip11 and zip63 have a broad allocrite range that includes zinc as well as cadmium, cobalt, copper, manganese and nickel. Inactivation of either zip11 or zip63 via insertional mutagenesis in N. punctiforme resulted in reduced expression of both genes, highlighting a possible co-regulation mechanism. Uptake experiments using 65Zn demonstrated that both zip mutants had diminished zinc uptake capacity, with the deletion of zip11 resulting in the greatest overall reduction in 65Zn uptake. Over-expression of Zip11 and Zip63 in an E. coli mutant strain (ZupT736::kan) restored divalent metal cation uptake, providing further evidence that these transporters are involved in Zn uptake in N. punctiforme. Our findings show the functional role of these twin metal uptake transporters in N. punctiforme, which are independently expressed in the presence of an array of metals. Both Zip11 and Zip63 are required for the maintenance of homeostatic levels of intracellular zinc N. punctiforme, although Zip11 appears to be the primary zinc transporter in this cyanobacterium, both ZIP’s may be part of a larger metal uptake system with shared regulatory elements. 相似文献
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Stenger-Kovács Csilla Lengyel Edina Sebestyén Viktor Szabó Beáta 《Hydrobiologia》2020,847(13):2933-2946
Hydrobiologia - Agriculture and urbanisation, the two forms of land use, represent serious threats to the ecological status of aquatic ecosystems, especially in the case of small streams at low... 相似文献
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Thierry Cloitre Ivan V. Panayotov Hervé Tassery Csilla Gergely Bernard Levallois Frédéric J. G. Cuisinier 《Journal of biophotonics》2013,6(4):330-337
Multiphoton microscopy has been used to reveal structural details of dentine and enamel at the dentin‐enamel junction (DEJ) based on their 2‐photon excited fluorescence (2PEF) emission and second harmonic generation (SHG). In dentine tubule 2PEF intensity varies due to protein content variation. Intertubular dentin produces both SHG and 2PEF signals. Tubules are surrounded by a thin circular zone with a lower SHG signal than the bulk dentine and the presence of collagen fibers perpendicular to the tubule longitudinal axis is indicated by strong SHG responses. The DEJ appears as a low intensity line on the 2PEF images and this was never previously reported. The SHG signal is completely absent for enamel and aprismatic enamel shows a homogeneous low 2PEF signal contrary to prismatic enamel. The SHG intensity of mantle dentine is increasing from the dentine‐enamel junction in the first 12 μm indicating a progressive presence of fibrillar collagen and corresponding to the more external part of mantle dentine where matrix metallo‐proteases accumulate. The high information content of multiphoton images confirms the huge potential of this method to investigate tooth structures in physiological and pathological conditions. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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Czikora I Kim KM Kása A Bécsi B Verin AD Gergely P Erdodi F Csortos C 《Biochimie》2011,93(7):1139-1145
TIMAP, TGF-β inhibited, membrane-associated protein, is highly abundant in endothelial cells (EC). We have shown earlier the involvement of TIMAP in PKA-mediated ERM (ezrin-radixin-moesin) dephosphorylation as part of EC barrier protection by TIMAP (Csortos et al., 2008). Emerging data demonstrate the regulatory role of TIMAP on protein phosphatase 1 (PP1) activity. We provide here evidence for specific interaction (Ka = 1.80 × 106 M−1) between non-phosphorylated TIMAP and the catalytic subunit of PP1 (PP1c) by surface plasmon resonance based binding studies. Thiophosphorylation of TIMAP by PKA, or sequential thiophosphorylation by PKA and GSK3β slightly modifies the association constant for the interaction of TIMAP with PP1c and decreases the rate of dissociation. However, dephosphorylation of phospho-moesin substrate by PP1cβ is inhibited to different extent in the presence of non- (∼60% inhibition), mono- (∼50% inhibition) or double-thiophosphorylated (<10% inhibition) form of TIMAP. Our data suggest that double-thiophosphorylation of TIMAP has minor effect on its binding ability to PP1c, but considerably attenuates its inhibitory effect on the activity of PP1c. PKA activation by forskolin treatment of EC prevented thrombin evoked barrier dysfunction and ERM phosphorylation at the cell membrane (Csortos et al., 2008). With the employment of specific GSK3β inhibitor it is shown here that PKA activation is followed by GSK3β activation in bovine pulmonary EC and both of these activations are required for the rescuing effect of forskolin in thrombin treated EC. Our results suggest that the forskolin induced PKA/GSK3β activation protects the EC barrier via TIMAP-mediated decreasing of the ERM phosphorylation level. 相似文献
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Fodor-Dunai C Fricke I Potocký M Dorjgotov D Domoki M Jurca ME Otvös K Zárský V Berken A Fehér A 《The Plant journal : for cell and molecular biology》2011,66(4):669-679
Plant ROP (Rho of plants) proteins form a unique subgroup within the family of Rho-type small G-proteins of eukaryotes. In this paper we demonstrate that the phosphomimetic mutation of a serine residue conserved in all Rho proteins affects the signaling properties of plant ROPs. We found that the S74E mutation in Medicago ROP6 and Arabidopsis ROP4 prevented the binding of these proteins to their plant-specific upstream activator the plant-specific ROP nucleotide exchanger (PRONE)-domain-containing RopGEF (guanine nucleotide exchange factor) protein and abolished the PRONE-mediated nucleotide exchange reaction in vitro. Structural modeling supported the hypothesis that potential phosphorylation of the S74 residue interferes with the binding of the PRONE-domain to the adjacent plant-specific R76 residue which plays an important role in functional ROP-PRONE interaction. Moreover, we show that while the binding of constitutively active MsROP6 to the effector protein RIC (ROP-interactive CRIB-motif-containing protein) was not affected by the S74E mutation, the capability of this mutated protein to bind and activate the RRK1 kinase in vitro was reduced. These observations are in agreement with the morphology of tobacco pollen tubes expressing mutant forms of yellow fluorescent protein (YFP):MsROP6. The S74E mutation in MsROP6 had no influence on pollen tube morphology and attenuated the phenotype of a constitutively active form of MsROP6. The presented Medicago and Arabidopsis data support the notion that the phosphorylation of the serine residue in ROPs corresponding to S74 in Medicago ROP6 could be a general principle for regulating ROP activation and signaling in plants. 相似文献
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Littoral diatoms are important contributors of the primary production in shallow aquatic ecosystems and they can be used as
indicators of the trophic status. The aim of the study was to develop an index to assess trophic status of Hungarian lakes
as suggested by the Water Framework Directive. In spring of 2005 and 2006, epiphytic diatom samples were collected from 83
shallow lakes. Weighted average method was used to develop and test the TP model. In the developed TP model correlation between
the observed and diatom inferred TP was high (r
2 = 0.96, n = 67). The optimum and tolerance TP parametrics of 127 species were determined and trophic indicator and sensibility values
were defined for the Trophic Diatom Index for Lakes (TDIL). The TDIL was applicable to assess the ecological status of Hungarian
shallow lakes. According to the TDIL the ecological status of 4 lakes were in excellent, 25 in good, 21 in medium, 21 in tolerable
and 12 in bad status.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.
Handling editor: K. Martens 相似文献