Knejzlik, Zdenek*
Dotaz
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The benzonitrile herbicides bromoxynil, chloroxynil, dichlobenil, and ioxynil have been used actively worldwide to control weeds in agriculture since 1970s. Even though dichlobenil is prohibited in EU since 2008, studies addressing the fate of benzonitrile herbicides in the environment show that some metabolites of these herbicides are very persistent. We tested the cytotoxic effects of benzonitrile herbicides and their microbial metabolites using two human cell lines, Hep G2 and HEK293T, representing liver and kidneys as potential target organs in humans. The cell viability and proliferation were determined by MTT test and RTCA DP Analyzer system, respectively. The latter allows real-time monitoring of the effect of added substances. As the cytotoxic compounds could compromise cell membrane integrity, the lactate dehydrogenase test was performed as well. We observed high toxic effects of bromoxynil, chloroxynil, and ioxynil on both tested cell lines. In contrast, we determined only low inhibition of cell growth in presence of dichlobenil and microbial metabolites originating from the tested herbicides.
- MeSH
- buněčná membrána účinky léků MeSH
- buňky Hep G2 MeSH
- HEK293 buňky MeSH
- herbicidy toxicita MeSH
- játra účinky léků MeSH
- ledviny účinky léků MeSH
- lidé MeSH
- nitrily toxicita MeSH
- proliferace buněk účinky léků MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Vydání první 133 stran : ilustrace, tabulky ; 28 cm
Vysokoškolská učebnice zaměřená na analýzu DNA, její izolaci, kvantifikaci a tvorbu DNA-profilu.
Small ubiquitin-related modifier-2/3 (SUMO-2/3) is a member of the ubiquitin-like (Ubl) protein family. Conjugation of SUMO-2/3 to target proteins is influenced by various stress conditions and chemical inhibitors. SUMO-2/3 conjugation may serve as a neuroprotective mechanism and may play a role in protein quality control. A method for screening global changes in SUMO-2/3 conjugation would facilitate further research of SUMO-2/3 cellular function. Here we show that dot blot with immunochemical detection allows evaluation of changes in global cellular SUMO-2/3 conjugation and offers an alternative to more laborious Western blot analysis. The method is based on a change of SUMO-2/3 signal intensity upon its conjugation. The dot blot analysis presented here is a time-saving method that enables screening of large numbers of samples and easy statistical evaluation of the results.
- MeSH
- HEK293 buňky MeSH
- imunoblotting metody MeSH
- lidé MeSH
- malé modifikační proteiny související s ubikvitinem * analýza chemie metabolismus MeSH
- ubikvitiny * analýza chemie metabolismus MeSH
- western blotting MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Metabolism of purine bases remains poorly understood in the pathogenic bacterium Mycobacterium tuberculosis and closely related, nonpathogenic Mycobacterium smegmatis (Msm). To gain insight into the purine metabolism in mycobacteria, we tested uptake of purine bases with a ΔpurF Msm mutant with an inactive purine de novo biosynthesis pathway and confirmed that hypoxanthine and guanine, but not xanthine, can serve as nucleotide precursors for recycling in the salvage pathway. Further, we focused on purine catabolism in wild-type (wt) Msm. We found that only xanthine and guanine could serve as a sole nitrogen source for wt Msm. These data confirm that Msm catabolism of purines is directed mainly via oxidative guanine to xanthine interconversion and not through metabolic conversion of hypoxanthine to xanthine. Our data represent the first experimental evidence confirming the use of 8-oxo-purines as a nitrogen source by Msm.
- MeSH
- atypické mykobakteriální infekce metabolismus mikrobiologie MeSH
- guanin metabolismus MeSH
- lidé MeSH
- Mycobacterium smegmatis izolace a purifikace metabolismus MeSH
- puriny metabolismus MeSH
- xanthin metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
UBL5 protein, a structural homologue of ubiquitin, was shown to be involved in pre-mRNA splicing and transcription regulation in yeast and Caenorhabditis elegans, respectively. However, role of the UBL5 human orthologue is still elusive. In our study, we observed that endogenous human UBL5 that was localized in the nucleus, partially associates with Cajal bodies (CBs), nuclear domains where spliceosomal components are assembled. Simultaneous expression of exogenous UBL5 and coilin resulted in their nuclear colocalization in HeLa cells. The ability of UBL5 to interact with coilin was proved by GST pull-down assay using coilin that was either in vitro translated or extracted from HEK293T cells. Further, our results showed that the UBL5-coilin interaction was not influenced by coilin phosphorylation. These results suggest that UBL5 could be targeted to CBs via its interaction with coilin. Relation between human UBL5 protein and CBs is in the agreement with current observations about yeast orthologue Hub1 playing important role in alternative splicing.
- MeSH
- Cajalova tělíska metabolismus MeSH
- fluorescenční mikroskopie MeSH
- glutathiontransferasa genetika metabolismus MeSH
- HEK293 buňky MeSH
- HeLa buňky MeSH
- jaderné proteiny genetika metabolismus MeSH
- lidé MeSH
- oční proteiny genetika metabolismus MeSH
- rekombinantní fúzní proteiny genetika metabolismus MeSH
- transfekce MeSH
- ubikvitiny genetika metabolismus MeSH
- vazba proteinů MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Statins are widely used for the treatment of hypercholesterolemia. However, their inhibitory action on HMG-CoA reductase also results in the depletion of intermediate biosynthetic products, which importantly contribute to cell proliferation. The aim of the present study was to compare the effects of the individual commercially available statins on experimental pancreatic cancer. The in vitro effects of individual statins (pravastatin, atorvastatin, simvastatin, lovastatin, cerivastatin, rosuvastatin and fluvastatin) on the viability of human pancreatic cancer were evaluated in CAPAN-2, BxPc-3 and MiaPaCa-2 cell lines. The in vivo experiments were performed on nude mice xenotransplanted with CAPAN-2 cells. The mice received oral treatments either with a placebo, or with the statins mentioned earlier in a daily dose corresponding to a hypocholesterolemic dose in humans. The effect of these statins on the intracellular Ras protein, trafficking in MiaPaCa-2 transfected cells, was also investigated. Substantial differences in the tumor-suppressive effects of all statins were detected in both in vitro and in vivo experiments. While simvastatin exerted the highest tumor-suppressive effects in vitro, rosuvastatin (p = 0.002), cerivastatin (p = 0.002) and fluvastatin (p = 0.009) were the most potent compounds in an animal model. All statins (except pravastatin) inhibited intracellular Ras protein translocation. In summary, substantial tumor-suppressive effects of various statins on the progression of experimental pancreatic adenocarcinoma were demonstrated, with marked differences among individual statins. These results support greatly the potential of statins for the chemoadjuvant treatment of pancreatic cancer. (c) 2007 Wiley-Liss, Inc.
- MeSH
- adenokarcinom patologie MeSH
- DNA primery MeSH
- financování organizované MeSH
- lidé MeSH
- myši nahé MeSH
- myši MeSH
- nádorové buněčné linie MeSH
- nádory slinivky břišní patologie MeSH
- polymerázová řetězová reakce MeSH
- sekvence nukleotidů MeSH
- statiny farmakologie MeSH
- transplantace nádorů MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
The combination of nanoparticles with the polymerase chain reaction (PCR) can have benefits such as easier sample handling or higher sensitivity, but also drawbacks such as loss of colloidal stability or inhibition of the PCR. The present work systematically investigates the interaction of magnetic iron oxide nanoparticles (MIONs) with the PCR in terms of colloidal stability and potential PCR inhibition due to interaction between the PCR components and the nanoparticle surface. Several types of MIONs with and without surface functionalisation by sodium citrate, dextran and 3-aminopropyl-triethoxysilane (APTES) were prepared and characterised by Transmission Electron Microscopy (TEM), dynamic light scattering (DLS) and Fourier Transform Infrared (FT-IR) spectroscopy. Colloidal stability in the presence of the PCR components was investigated both at room temperature and under PCR thermo-cycling. Dextran-stabilized MIONs show the best colloidal stability in the PCR mix at both room and elevated temperatures. Citrate- and APTES-stabilised as well as uncoated MIONs show a comparable PCR inhibition near the concentration 0.1mgml(-1) while the inhibition of dextran stabilized MIONs became apparent near 0.5mgml(-1). It was demonstrated that the PCR could be effectively carried out even in the presence of elevated concentration of MIONs up to 2mgml(-1) by choosing the right coating approach and supplementing the reaction mix by critical components, Taq DNA polymerase and Mg(2+) ions.
Small ubiquitin-related modifiers 1, 2 and 3 (SUMO-1, -2, -3), members of the ubiquitin-like protein family, can be conjugated to various cellular proteins. Conjugates of SUMO-2 and SUMO-3 (SUMO-2/3) accumulate in cells exposed to various stress stimuli or to MG132 treatment. Although the proteins modified by SUMO-2/3 during heat shock or under MG132 treatment have been identified, the significance of this modification remains unclear. Our data show that the inhibition of translation by puromycin or cycloheximide blocks both the heat shock and MG132 induced accumulation of SUMO-2/3 conjugates in HEK 293T and U2OS cells. However, the heat shock induced accumulation of SUMO-2/3 conjugates was restored by proteasome inhibition, which suggests that the inhibition of translation did not abolish SUMOylation itself. Furthermore, we show that some of the proteins truncated due to the treatment by low concentration of puromycin are SUMOylated in HEK 293T cells. We suggest that the SUMO-2/3 conjugates accumulating under the heat shock or MG132 treatment result largely from new protein synthesis and that portion of them is incorrectly folded.
- MeSH
- benzochinony farmakologie MeSH
- biologické modely MeSH
- cykloheximid farmakologie MeSH
- HEK293 buňky MeSH
- HeLa buňky MeSH
- inhibitory syntézy proteinů farmakologie MeSH
- leupeptiny farmakologie MeSH
- lidé MeSH
- makrocyklické laktamy farmakologie MeSH
- malé modifikační proteiny související s ubikvitinem metabolismus MeSH
- proteasomový endopeptidasový komplex metabolismus MeSH
- proteosyntéza účinky léků MeSH
- puromycin farmakologie MeSH
- reakce na tepelný šok účinky léků MeSH
- sumoylace účinky léků MeSH
- ubikvitiny metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Nicotinamide phosphoribosyltransferase (NAMPT) is located in both the nucleus and cytoplasm and has multiple biological functions including catalyzing the rate-limiting step in NAD synthesis. Moreover, up-regulated NAMPT expression has been observed in many cancers. However, the determinants and regulation of NAMPT's nuclear transport are not known. Here, we constructed a GFP-NAMPT fusion protein to study NAMPT's subcellular trafficking. We observed that in unsynchronized 3T3-L1 preadipocytes, 25% of cells had higher GFP-NAMPT fluorescence in the cytoplasm, and 62% had higher GFP-NAMPT fluorescence in the nucleus. In HepG2 hepatocytes, 6% of cells had higher GFP-NAMPT fluorescence in the cytoplasm, and 84% had higher GFP-NAMPT fluorescence in the nucleus. In both 3T3-L1 and HepG2 cells, GFP-NAMPT was excluded from the nucleus immediately after mitosis and migrated back into it as the cell cycle progressed. In HepG2 cells, endogenous, untagged NAMPT displayed similar changes with the cell cycle, and in nonmitotic cells, GFP-NAMPT accumulated in the nucleus. Similarly, genotoxic, oxidative, or dicarbonyl stress also caused nuclear NAMPT localization. These interventions also increased poly(ADP-ribosyl) polymerase and sirtuin activity, suggesting an increased cellular demand for NAD. We identified a nuclear localization signal in NAMPT and amino acid substitution in this sequence (424RSKK to ASGA), which did not affect its enzymatic activity, blocked nuclear NAMPT transport, slowed cell growth, and increased histone H3 acetylation. These results suggest that NAMPT is transported into the nucleus where it presumably increases NAD synthesis required for cell proliferation. We conclude that specific inhibition of NAMPT transport into the nucleus might be a potential avenue for managing cancer.
- MeSH
- akrylamidy farmakologie MeSH
- aktivní transport - buněčné jádro MeSH
- buněčné jádro metabolismus MeSH
- buňky 3T3-L1 MeSH
- buňky Hep G2 MeSH
- cytoplazma metabolismus MeSH
- histony metabolismus MeSH
- kontrolní body buněčného cyklu MeSH
- lidé MeSH
- mutageneze cílená MeSH
- myši MeSH
- NAD metabolismus MeSH
- nikotinamidfosforibosyltransferasa chemie genetika metabolismus MeSH
- oxidační stres MeSH
- piperidiny farmakologie MeSH
- poly(ADP-ribosa)polymerasy metabolismus MeSH
- proliferace buněk MeSH
- rekombinantní fúzní proteiny chemie genetika metabolismus MeSH
- sirtuiny metabolismus MeSH
- viabilita buněk účinky léků MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
