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1.
Malcolm R. Macleod Aaron Lawson McLean Aikaterini Kyriakopoulou Stylianos Serghiou Arno de Wilde Nicki Sherratt Theo Hirst Rachel Hemblade Zsanett Bahor Cristina Nunes-Fonseca Aparna Potluru Andrew Thomson Julija Baginskitae Kieren Egan Hanna Vesterinen Gillian L. Currie Leonid Churilov David W. Howells Emily S. Sena 《PLoS biology》2015,13(10)
2.
Evelin Ramóna Péli Nie Lei Tamás Pócs Zsanett Laufer Stefan Porembski Zoltán Tuba 《Central European Journal of Biology》2011,6(5):838-849
In our present studies, the recovery of photosynthetic activity after rehydration was demonstrated. We measured chlorophyll
fluorescence, CO2 gas exchange and the pigment composition in the previously long-term air-dried cryptogamic inselberg crusts collected from
two tropical areas. The cryptobiotic crusts were collected from different localities on similar ecological and climatic conditions
from extreme habitats of inselbergs (outcrops). These inselbergs are characterized by a dry microclimate and are covered by
scarce soil. We found that the ecophysiological responses of both cryptogamic inselberg crusts showed an extremely high degree
of desiccation-tolerance due to the fast and full recovery during rehydration. The photosynthetic activity of the cryptobiotic
crusts were restored and regained within 15 and 40 min, respectively, after rehydration. Photosynthetic activity of the crusts
was retained at all applied light intensities when enough water was available, however the degree of the recovery was different
between the crusts. Photosynthetic pigment contents were strongly and positively correlated with water content. Our results
indicated that tropical desiccation-tolerant cryptogamic crusts found on inselberg rock surfaces have CO2 fixation ability in the range of cyanobacteria and lichens, suggesting that at a global scale they can assimilate CO2 in a significant amount. 相似文献
3.
Zsanett Laufer Richard P. Beckett Farida V. Minibayeva Sabine Lüthje Michael Bttger 《Mycological Research》2006,110(7):846-853
Following our previous findings of high extracellular redox activity in lichens, the results of the work presented here identify the enzymes involved as laccases. Despite numerous data on laccases in fungi and flowering plants, this is the first report of the occurrence of laccases in lichenized ascomycetes. Extracellular laccase activity was measured in 40 species of lichens from different taxonomic groupings and contrasting habitats. Out of 20 species tested from suborder Peltigerineae, 18 displayed laccase activity, while activity was absent in species tested from other lichen groups. Identification of the enzymes as laccases was confirmed by the ability of lichen leachates to readily metabolize substrates such as 2,2′-azino(bis-3-ethylbenzthiazoline-6-sulfonate) (ABTS), syringaldazine and o-tolidine in the absence of hydrogen peroxide, sensitivity of the enzymes to cyanide and azide, the enzymes having typical laccase pH and temperature optima, and an absorption spectrum with a peak at 614 nm. Desiccation and wounding stimulated laccase activity. Laccase activity was not increased after treatment with normal inducers of laccase synthesis, suggesting that they are constitutively expressed. Electrophoresis showed that the active form of laccase from Peltigera malacea was a tetramer with an unusually high molecular mass of 340 kDa and an isoelectric point (pI) of 4.7. The finding of abundant extracellular redox enzymes known to actively produce reactive oxygen species suggest that their roles may include increasing nutrient supply to lichens by delignification, and deterring pathogens by contributing to the oxidative burst. Furthermore, once released into the environment, they may participate in the carbon cycle by facilitating the breakdown or formation of humic substances. 相似文献
4.
Tamás Juhász Csaba Matta Zoltán Mészár Georgina Nagy Zsolt Szíjgyártó Zsanett Molnár Bernadett Kolozsvári Éva Bakó Róza Zákány 《Central European Journal of Biology》2010,5(5):572-584
We aimed to find a transfection method which provides high efficiency with minimal cytotoxic and/or apoptotic effects for
gene transfer into multilayer primary chondrogenic cell cultures. The pEGFP-C1 plasmid was introduced into the cell culture
and the efficiency of transformation quantified by GFP fluorescence; the resulting nucleofection was effective but resulted
in severe apoptosis. Two liposomal reagents designed to allow transfection into adherent cells did not deliver the plasmids
sufficiently and cartilage formation did not occur. In addition, a third liposomal compound, recommended for transfection
into either adherent or suspension cell cultures, lead to acceptable transfection efficiency but no cartilage formation. When
an amphiphilic reagent was used however, there was acceptable transfection efficiency as well as cartilage formation. The
viability of the cells which were transfected using the amphiphilic reagent remained unaffected but proliferation was severely
diminished, particularly in the presence of GFP. In addition, the amount of cartilage decreased when GFP was expressed, despite
unchanged levels of mRNAs of sox9 and aggrecan core protein, factors reflecting on the efficiency of chondrogenesis. Overexpression of both the constitutively
active delta and gamma isoforms of catalytic subunit of calcineurin, a protein phosphatase described as a positive regulator
of chondrogenesis, decreased protein level of Sox9 and subsequent cartilage formation. In conclusion, we found that amphiphilic
reagent applied prior to the adhesion of cells provides a useful means to transfer plasmids to primary differentiating chondrogenic
cells. 相似文献
5.
Edit Mikó András Vida Tünde Kovács Gyula Ujlaki György Trencsényi Judit Márton Zsanett Sári Patrik Kovács Anita Boratkó Zoltán Hujber Tamás Csonka Péter Antal-Szalmás Mitsuhiro Watanabe Imre Gombos Balazs Csoka Borbála Kiss László Vígh Judit Szabó Péter Bai 《BBA》2018,1859(9):958-974
Our study aimed at finding a mechanistic relationship between the gut microbiome and breast cancer. Breast cancer cells are not in direct contact with these microbes, but disease could be influenced by bacterial metabolites including secondary bile acids that are exclusively synthesized by the microbiome and known to enter the human circulation. In murine and bench experiments, a secondary bile acid, lithocholic acid (LCA) in concentrations corresponding to its tissue reference concentrations (< 1 μM), reduced cancer cell proliferation (by 10–20%) and VEGF production (by 37%), aggressiveness and metastatic potential of primary tumors through inducing mesenchymal-to-epithelial transition, increased antitumor immune response, OXPHOS and the TCA cycle. Part of these effects was due to activation of TGR5 by LCA. Early stage breast cancer patients, versus control women, had reduced serum LCA levels, reduced chenodeoxycholic acid to LCA ratio, and reduced abundance of the baiH (7α/β-hydroxysteroid dehydroxylase, the key enzyme in LCA generation) gene in fecal DNA, all suggesting reduced microbial generation of LCA in early breast cancer. 相似文献
6.
Renáta Zsanett Csoma Edit Tóth-Molnár Anita Varga Hajnalka Szabó Hajnalka Orvos Lajos Kemény Judit Oláh 《PloS one》2016,11(8)
BackgroundThe similar genetic background of a pair of twins, and the similar environmental impacts to which they are exposed allow an exact and objective investigation of various constitutional and environmental factors in naevus development. As far as we are aware, this is the first published survey that simultaneously examines cutaneous and ocular pigmented lesions in an appreciable sample of identical and non-identical twins.Methods172 pairs of twins of Caucasian origin were included in this study. A whole-body skin examination and a detailed ophthalmological examination were performed to determine the density of melanocytic lesions. A standardized questionnaire was used to assess the data relating to constitutional, sun exposure and other variables.ResultsA notably high proportion of the subjects (36.78%) manifested one or more clinically atypical melanocytic naevi (CAMNs), and approximately one-third (31.4%) of them at least one benign uveal pigmented lesion (BUPL). The incidence of iris freckles (IFs), iris naevi (INs) and choroidal naevi (CHNs) proved to be 25.35%, 5.98% and 3.52%, respectively. The interclass correlation coefficients for common melanocytic naevi (CMNs), CAMNs, and INs were 0.77, 0.76 and 0.86 in monozygotic twins, as compared with 0.5, 0.27 and 0.25 in dizygotic twin pairs, respectively. A statistically significant correlation was found between the prevalence of CAMNs and that of INs.ConclusionsThis significant correlation suggests the existence of a subgroup of Caucasian people with an increased susceptibility to both cutaneous and ocular naevus formation. There is accumulating evidence that, besides the presence of cutaneous atypical naevi, INs can serve as a marker of a predisposed phenotype at risk of uveal melanoma. The correlation between cutaneous and ocular pigmented lesions underlines the need for the adequate ophthalmological screening of subjects with CAMNs and INs. 相似文献
7.
Arnab Sen Zsanett Nagy-Zsvér-Vadas Michael P. Krahn 《The Journal of cell biology》2012,199(4):685-698
The assembly and consolidation of the adherens junctions (AJs) are key events in the establishment of an intact epithelium. However, AJs are further modified to obtain flexibility for cell migration and morphogenetic movements. Intact AJs in turn are a prerequisite for the establishment and maintenance of apical–basal polarity in epithelial cells. In this study, we report that the conserved PDZ (PSD95, Discs large, ZO-1) domain–containing protein PATJ (Pals1-associated tight junction protein) was not per se crucial for the maintenance of apical–basal polarity in Drosophila melanogaster epithelial cells but rather regulated Myosin localization and phosphorylation. PATJ directly bound to the Myosin-binding subunit of Myosin phosphatase and decreased Myosin dephosphorylation, resulting in activated Myosin. Thereby, PATJ supports the stability of the Zonula Adherens. Notably, weakening of AJ in a PATJ mutant epithelium led first to a loss of Myosin from the AJ, subsequently to a disassembly of the AJ, and finally, to a loss of apical–basal polarity and disruption of the tissue. 相似文献
8.
Abrahám S Hermesz E Szabó A Ferencz A Jancsó Z Duda E Abrahám M Lázár G Lázár G 《Life sciences》2012,90(3-4):140-146
AimsHeme oxygenase (HO) and metallothionein (MT) genes are rapidly upregulated in the liver by pro-inflammatory cytokines and/or endotoxin as protection against cellular stress and inflammation. Gadolinium chloride (GdCl3)-induced Kupffer cell blockade has beneficial consequences in endotoxemia following bile duct ligation. Herein we further characterized the effects of Kupffer cell inhibition on the activation of the antioxidant defense system (HO and MT gene expressions, and antioxidant enzyme activities) in response to endotoxemia and obstructive jaundice.Main methodsThe isoform-specific expression of MT and HO genes was assessed (RT-PCR) in rat livers following 3-day bile duct ligation, 2-h lipopolysaccharide treatment (1 mg/kg) or their combination, with or without GdCl3 pretreatment (10 mg/kg, 24 h before endotoxin). Lipid peroxidation, DNA damage and hepatic antioxidant enzyme activities were also assessed.Key findingsAll these challenges induced similar extents of DNA damage, whereas the lipid peroxidation increased only when endotoxemia was combined with biliary obstruction. The MT and HO mRNA levels displayed isoform-specific changes: those of MT-1 and HO-2 did not change appreciably, whereas those of MT-2 and HO-1 increased significantly in 2-h endotoxemia, with or without obstructive jaundice. Among the enzymes reflecting the endogenous protective mechanisms, the catalase and copper/zinc-superoxide dismutase levels decreased, while that of Mn-SOD slightly increased. Interestingly, GdCl3 alone induced lipid peroxidation, DNA damage and MT-2 expression. In response to GdCl3, HO-1 induction was significantly lower in each model.SignificanceDespite its moderate hepatocellular toxicity, the ameliorated stress-induced hepatic reactions provided by GdCl3 may contribute to its protective effects. 相似文献
9.
BACKGROUND AND AIMS: Following previous findings of high extracellular redox activity in lichens and the presence of laccases in lichen cell walls, the work presented here additionally demonstrates the presence of tyrosinases. Tests were made for the presence of tyrosinases in 40 species of lichens, and from selected species their cellular location and molecular weights were determined. The effects of stress and inhibitors on enzyme activity were also studied. METHODS: Tyrosinase and laccase activities were assayed spectrophotometrically using a variety of substrates. The molecular mass of the enzymes was estimated using polyacrylamide gel electrophoresis. KEY RESULTS: Extracellular tyrosinase and laccase activity was measured in 40 species of lichens from different taxonomic groupings and contrasting habitats. Out of 20 species tested from the sub-order Peltigerineae, all displayed significant tyrosinase and laccase activity, while activity was low or absent in other species tested. Representatives from both groups of lichens displayed low peroxidase activities. Identification of the enzymes as tyrosinases was confirmed by the ability of lichen thalli or leachates derived by shaking lichens in distilled water to metabolize substrates such as L-dihydroxyphenylalanine (DOPA), tyrosine and epinephrine readily in the absence of hydrogen peroxide, the sensitivity of the enzymes to the inhibitors cyanide, azide and hexylresorcinol, activation by SDS and having typical tyrosinase molecular masses of approx. 60 kDa. Comparing different species within the Peltigerineae showed that the activities of tyrosinases and laccase were correlated to each other. Desiccation and wounding stimulated laccase activity, while only wounding stimulated tyrosinase activity. CONCLUSIONS: Cell walls of lichens in sub-order Peltigerineae have much higher activities and a greater diversity of cell wall redox enzymes compared with other lichens. Possible roles of tyrosinases include melanization, removal of toxic phenols or quinones, and production of herbivore deterrents. 相似文献
10.
Zsanett Miklán Erika Orbán Zoltán Bánóczi Ferenc Hudecz 《Journal of peptide science》2011,17(12):805-811
Pemetrexed (Pem) is a novel antimetabolite type of anticancer drug that demonstrated promising clinical activity in a wide variety of solid tumors, including non‐small cell lung carcinoma and malignant pleural mesothelioma. It inhibits enzymes involved in the folate pathway, for which the presence of its free carboxylic groups is necessary. The heteroaromatic ring system of Pem has a modifiable amino group, which opens a possibility to apply a new strategy to conjugate Pem to carrier molecules. Considering this as well as the necessity of untouched carboxylic groups of Pem in the new conjugates, we developed a new synthesis strategy. Here, we describe the synthesis and the characterization of new Pem‐peptide conjugates in which cell‐penetrating octaarginine or/and lung‐targeting H‐Ile‐Glu‐Leu‐Leu‐Gln‐Ala‐Arg‐NH2 peptide is attached to the drug by thioether bond. The conjugates characterized by RP‐HPLC and MS exhibited cytostatic effect in vitro on non‐small cell lung carcinoma as well as on human leukemia cell lines. The IC50 values of the conjugates were similar, but the conjugates with H‐Ile‐Glu‐Leu‐Leu‐Gln‐Ala‐Arg‐NH2 sequence were slightly more effective. Our data show that the in vitro cytostatic effect of the free Pem was essentially maintained after conjugation with cell‐penetrating or cell‐targeting peptides. Thus, the conjugation strategy reported could lead to the development of a new generation of active Pem conjugates. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd. 相似文献