The design and fabrication of active nanomaterials exhibiting multifunctional properties is a must in the so-called global "Fourth Industrial Revolution". In this sense, molecular engineering is a powerful tool to implant original capabilities on a macroscopic scale. Herein, different bioinspired 2D-MXenes have been developed via a versatile and straightforward synthetic approach. As a proof of concept, Ti3C2Tx MXene has been exploited as a highly sensitive transducing platform for the covalent assembly of active biomolecular architectures (i.e., amino acids). All pivotal properties originated from the anchored targets were proved to be successfully transferred to the resulting bioinspired 2D-MXenes. Appealing applications have been devised for these 2D-MXene prototypes showing (i) chiroptical activity, (ii) fluorescence capabilities, (iii) supramolecular π-π interactions, and (iv) stimuli-responsive molecular switchability. Overall, this work demonstrates the fabrication of programmable 2D-MXenes, taking advantage of the inherent characteristics of the implanted (bio)molecular components. Thus, the current bottleneck in the field of 2D-MXenes can be overcome after the significant findings reported here.

• Klíčová slova
• 2D materials, chiral MXene, electronic devices, fluorescence, molecular switches, supramolecular recognition, surface engineering,
• MeSH
• nanostruktury * MeSH
• titan * MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• titan * MeSH

Liver iron overload can be found in hereditary hemochromatosis, chronic liver diseases such as alcoholic liver disease, and chronic viral hepatitis or secondary to repeated blood transfusions. The excess iron promotes liver damage, including fibrosis, cirrhosis, and hepatocellular carcinoma. Despite significant research effort, we remain largely ignorant of the cellular consequences of liver iron overload and the cellular processes that result in the observed pathological changes. In addition, the variability in outcome and the compensatory response that likely modulates the effect of increased iron levels are not understood. To provide insight into these critical questions, we undertook a study to determine the consequences of iron overload on protein levels in liver using a proteomic approach. Using two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) combined with matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS), we studied hepatic iron overload induced by carbonyl iron-rich diet in mice and identified 30 liver proteins whose quantity changes in condition of excess liver iron. Among the identified proteins were enzymes involved in several important metabolic pathways, namely the urea cycle, fatty acid oxidation, and the methylation cycle. This pattern of changes likely reflects compensatory and pathological changes associated with liver iron overload and provides a window into these processes.

• MeSH
• 2D gelová elektroforéza MeSH
• enzymy metabolismus   MeSH
• játra enzymologie   metabolismus   patologie   MeSH
• mastné kyseliny metabolismus   MeSH
• metylace MeSH
• močovina metabolismus   MeSH
• modely nemocí na zvířatech MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• nemoci jater enzymologie   etiologie   metabolismus   patologie   MeSH
• oxidace-redukce MeSH
• přetížení železem chemicky indukované   komplikace   metabolismus   patologie   MeSH
• proteomika metody   MeSH
• sloučeniny železa MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
• stupeň závažnosti nemoci MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• enzymy MeSH
• iron pentacarbonyl MeSH Prohlížeč
• mastné kyseliny MeSH
• močovina MeSH
• sloučeniny železa MeSH

Retinoic acid (all-trans and 9-cis) isomers represent important therapeutic agents for many types of cancers, including human breast cancer. Changes in protein composition of the MCF-7 human breast cancer cells were induced by all-trans retinoic acid, 9-cis retinoic acid, and their combination and subsequently proteomic strategies based on bottom-up method were applied. Proposed approach was used for the analysis of proteins extracted from MCF-7 human breast cancer cell line utilizing a commercially manufactured kit RIPA and separated on two dimensional (2D) sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) after treatment with both retinoic acid isomers. We found significant differences in occurrence of proteins probably affecting the cell migration process in tumour cells. Heat shock protein 27, ribonucleoprotein SmD3, and cofilin-1 were significantly upregulated after treatment with combination of individual retinoic acid isomers. On the other hand, AP-5 complex subunit beta-1 shows the different response. Thus, the results might help to find the answer to important medical questions on (i) the identification of signaling pathways affected by retinoic acid isomers or (ii) how the observed proteomic pattern might reflect the effectiveness of retinoic acids treatment.

• Klíčová slova
• Biomarker, Breast cancer, MCF-7, Proteomics, Retinoids,
• MeSH
• 2D gelová elektroforéza MeSH
• adaptorové proteiny vezikulární transportní metabolismus   MeSH
• alitretinoin MeSH
• cytoskelet účinky léků   metabolismus   MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• invazivní růst nádoru MeSH
• jádro snRNP - proteiny metabolismus   MeSH
• kofilin 1 metabolismus   MeSH
• lidé MeSH
• nádorové proteiny metabolismus   MeSH
• nádory prsu farmakoterapie   metabolismus   patologie   MeSH
• pohyb buněk účinky léků   MeSH
• proteiny tepelného šoku HSP27 metabolismus   MeSH
• proteomika * metody   MeSH
• protokoly protinádorové kombinované chemoterapie farmakologie   MeSH
• tretinoin farmakologie   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adaptorové proteiny vezikulární transportní MeSH
• alitretinoin MeSH
• AP5B1 protein, human MeSH Prohlížeč
• CFL1 protein, human MeSH Prohlížeč
• jádro snRNP - proteiny MeSH
• kofilin 1 MeSH
• nádorové proteiny MeSH
• proteiny tepelného šoku HSP27 MeSH
• SNRPD3 protein, human MeSH Prohlížeč
• tretinoin MeSH

The effect of valproic acid (VA) on protein expression in human T-lymphocytic leukemia cells MOLT-4 was studied. VA is an inhibitor of histonedeacetylases and has a potential use as antitumor agent in leukemia treatment. The authors in this work prove that 4 h long incubation with 2 mmol/l VA causes phosphorylation of histone H2A.X and its colocalization with 53BP1 in nuclear foci. Their co-localization is typical for DSB signaling machinery. These foci were detected in cells after 4 h exposure without increase of Annexin V positive apoptotic cells. Slight increase in apoptosis (Annexin V positivity) after 24 h is accompanied by more intensive increase in phosphorylation of H2A.X and also by formation of nuclear foci containing gammaH2A.X and 53BP1. Treatment of cells with 2 mmol/l VA resulted in induction of apoptosis affecting about 30% of cells after incubation for 72 h. The changes in protein expression were examined after cell incubation with 2 mmol/l VA for 4 h. Proteins were separated by two-dimensional electrophoresis and quantified using image evaluation system. Those exhibiting significant VA-induced abundance alterations were identified by mass spectrometry. Changes in expression of 22 proteins were detected, of which 15 proteins were down-regulated. Proteomic analysis resulted in successful identification of three proteins involving alfa-tubulin 3, tubulin-specific chaperone and heterogeneous nuclear ribonucloprotein F. Expression of seven proteins was up-regulated, including heterogeneous nuclear ribonucloprotein A/B. Identified proteins are related to microtubular system and hnRNP family. Suppression of microtubular proteins and changes of balance among hnRNPs can contribute to proliferation arrest and apoptosis induction.

• MeSH
• 2D gelová elektroforéza MeSH
• annexin A5 metabolismus   MeSH
• apoptóza účinky léků   MeSH
• heterogenní jaderné ribonukleoproteiny metabolismus   MeSH
• inhibitory enzymů farmakologie   MeSH
• inhibitory histondeacetylas MeSH
• kyselina valproová farmakologie   MeSH
• leukemie T-buněčná farmakoterapie   metabolismus   patologie   MeSH
• lidé MeSH
• nádorové proteiny metabolismus   MeSH
• proteom analýza   MeSH
• průtoková cytometrie MeSH
• signální transdukce MeSH
• spektrometrie hmotnostní - ionizace laserem za účasti matrice MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• annexin A5 MeSH
• heterogenní jaderné ribonukleoproteiny MeSH
• inhibitory enzymů MeSH
• inhibitory histondeacetylas MeSH
• kyselina valproová MeSH
• nádorové proteiny MeSH
• proteom MeSH

Nitrotyrosine formation is caused by presence of reactive oxygen and nitrogen species. Nitration is a very selective process leading to specific modification of only a few tyrosines in protein molecule. 2D electrophoresis and western blotting techniques coupled with mass spectrometry are common methods used in analysis of proteome. Here we describe protocol for analysis of peroxynitrite-induced protein nitration in isolated mitochondria. Mitochondrial proteins are separated by 2D electrophoresis and transferred to nitrocellulose membrane. Membranes are then incubated with antibodies against nitrotyrosine. Positive spots are compared with corresponding Coomassie-stained gels, and protein nitration is confirmed with mass spectrometry techniques.

• Klíčová slova
• 2D electrophoresis, Immunoblotting, Mass spectrometry, Mitochondria, Nitrotyrosine,
• MeSH
• 2D gelová elektroforéza metody   MeSH
• hmotnostní spektrometrie metody   MeSH
• imunoblotting metody   MeSH
• kyselina peroxydusitá chemie   MeSH
• mitochondriální proteiny analýza   metabolismus   MeSH
• skot MeSH
• srdeční mitochondrie chemie   metabolismus   MeSH
• tyrosin analogy a deriváty   analýza   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 3-nitrotyrosine MeSH Prohlížeč
• kyselina peroxydusitá MeSH
• mitochondriální proteiny MeSH
• tyrosin MeSH

Efficient and selective methods for covalent derivatization of graphene are needed because they enable tuning of graphene's surface and electronic properties, thus expanding its application potential. However, existing approaches based mainly on chemistry of graphene and graphene oxide achieve only limited level of functionalization due to chemical inertness of the surface and nonselective simultaneous attachment of different functional groups, respectively. Here we present a conceptually different route based on synthesis of cyanographene via the controllable substitution and defluorination of fluorographene. The highly conductive and hydrophilic cyanographene allows exploiting the complex chemistry of -CN groups toward a broad scale of graphene derivatives with very high functionalization degree. The consequent hydrolysis of cyanographene results in graphene acid, a 2D carboxylic acid with pKa of 5.2, showing excellent biocompatibility, conductivity and dispersibility in water and 3D supramolecular assemblies after drying. Further, the carboxyl groups enable simple, tailored and widely accessible 2D chemistry onto graphene, as demonstrated via the covalent conjugation with a diamine, an aminothiol and an aminoalcohol. The developed methodology represents the most controllable, universal and easy to use approach toward a broad set of 2D materials through consequent chemistries on cyanographene and on the prepared carboxy-, amino-, sulphydryl-, and hydroxy- graphenes.

• Klíčová slova
• 2D acid, fluorographene chemistry, graphene acid, graphene nitrile, nucleophilic substitution,
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The exploitation of two-dimensional (2D) vanadium carbide (V2CTx, denoted as V2C) in electrocatalytic hydrogen evolution reaction (HER) and nitrogen reduction reaction (NRR) is still in the stage of theoretical study with limited experimental exploration. Here, we present the experimental studies of V2C MXene-based materials containing two different bismuth compounds to confirm the possibility of using V2C as a potential electrocatalyst for HER and NRR. In this context, for the first time, we employed two different methods to synthesize 2D/0D and 2D/2D nanostructures. The 2D/2D V2C/BVO consisted of BiVO4 (denoted BVO) nanosheets wrapped in layers of V2C which were synthesized by a facile hydrothermal method, whereas the 2D/0D V2C/Bi consisted of spherical particles of Bi (Bi NPs) anchored on V2C MXenes using the solid-state annealing method. The resultant V2C/BVO catalyst was proven to be beneficial for HER in 0.5 M H2SO4 compared to pristine V2C. We demonstrated that the 2D/2D V2C/BVO structure can favor the higher specific surface area, exposure of more accessible catalytic active sites, and promote electron transfer which can be responsible for optimizing the HER activity. Moreover, V2C/BVO has superior stability in an acidic environment. Whilst we observed that the 2D/0D V2C/Bi could be highly efficient for electrocatalytic NRR purposes. Our results show that the ammonia (NH3) production and faradaic efficiency (FE) of V2C/Bi can reach 88.6 μg h-1 cm-2 and 8% at -0.5 V vs. RHE, respectively. Also V2C/Bi exhibited excellent long-term stability. These achievements present a high performance in terms of the highest generated NH3 compared to recent investigations of MXenes-based electrocatalysts. Such excellent NRR of V2C/Bi activity can be attributed to the effective suppression of HER which is the main competitive reaction of the NRR.

• Publikační typ
• časopisecké články MeSH

The efficient synthesis of 2D polymers (2DPs) with tailorable structures and properties is highly desired but remains a considerable challenge. Here, the first solution synthesis of millimeter-size crystalline covalent triazine frameworks (CTFs) with a clear lamellar structure, which can be exfoliated into micrometer-size few-layer 2DP sheets via both micromechanical cleavage and liquid sonication, is reported. The obtained CTFs or 2DPs show a unique staggered AB stacking with a dominant pore size of ≈0.6 nm, which is different from the common eclipsed AA stacking in various covalent organic frameworks. The preference for AB stacking is due to the specific interaction of triflic acid with CTFs as revealed computationally. When explored as new polymeric anodes for sodium-ion batteries, both crystalline bulk CTF and exfoliated 2DP exhibit very high capacities (225 and 262 mA h g-1 at 0.1 A g-1 , respectively), impressive rate capabilities (67 and 119 mA h g-1 at 5.0 A g-1 , respectively), and excellent cycling stability (95% capacity retention after 1200 cycles) due to their robust conjugated porous structure, outperforming most organic/polymeric sodium-ion battery anodes ever reported.

• Klíčová slova
• 2D polymers, AB stacking, crystalline triazine frameworks, lamellar structures, sodium-ion batteries,
• Publikační typ
• časopisecké články MeSH

Two-dimensional (2D) materials catalysts provide an atomic-scale view on a fascinating arena for understanding the mechanism of electrocatalytic carbon dioxide reduction (CO2 ECR). Here, we successfully exfoliated both layered and nonlayered ultra-thin metal phosphorous trichalcogenides (MPCh3 ) nanosheets via wet grinding exfoliation (WGE), and systematically investigated the mechanism of MPCh3 as catalysts for CO2 ECR. Unlike the layered CoPS3 and NiPS3 nanosheets, the active Sn atoms tend to be exposed on the surfaces of nonlayered SnPS3 nanosheets. Correspondingly, the nonlayered SnPS3 nanosheets exhibit clearly improved catalytic activity, showing formic acid selectivity up to 31.6 % with -7.51 mA cm-2 at -0.65 V vs. RHE. The enhanced catalytic performance can be attributed to the formation of HCOO* via the first proton-electron pair addition on the SnPS3 surface. These results provide a new avenue to understand the novel CO2 ECR mechanism of Sn-based and MPCh3 -based catalysts.

• Klíčová slova
• 2D Materials, CO2 ECR, Exfoliation, MPCh3 Nanosheets, Nonlayered,
• Publikační typ
• časopisecké články MeSH

In young rats, systemic or local administration of kainic acid (KA) elicits scratching as the prevailing automatism whereas in adult rats, wet dog shakes (WDS) are usually recorded. We tested the effects of the alpha 2-adrenergic agonist clonidine (0.25 mg/kg, IP; also acting, however, on imidazoline receptors), which has been reported to block KA-induced WDS in adult rats and the 5-HT2 antagonist ritanserin (20 mg/kg, IP) in rats aged 7, 12, 18, 25, and 90 days treated IP with doses of KA that induce maximum number of automatisms with minimal early lethal effects (i.e., 4, 6, 8, 10, and 14 mg/kg, respectively). Both WDS and scratching were frequently recorded together in one animal. Neither ritanserin nor its solvent had significant effects on the total number of automatisms or on their distribution between WDS and scratching. In contrast, clonidine suppressed automatisms throughout the development studied. In 90-day-old (adult) rats clonidine decreased the incidence of both WDS and scratching, whereas it usually attenuated scratching at younger ages. Kainic acid-induced seizures were also recorded because of reported incompatibility between tonic-clonic seizures and WDS in adult rats. In 18-90-day-old rats, tonic-clonic seizures and WDS were found incompatible. In 7-18-day-old pups, scratching and KA-induced tonic-clonic seizures occurred together. Moreover, in 7-day-old rats, clonidine was anticonvulsant. We have demonstrated that KA-induced automatisms develop from scratching in pups to prevailing WDS in adult rats, whereas the incidence of scratching rather decreases during development.(ABSTRACT TRUNCATED AT 250 WORDS)

• MeSH
• alfa-2-adrenergní receptory účinky léků   fyziologie   MeSH
• clonidin farmakologie   MeSH
• elektroencefalografie účinky léků   MeSH
• krysa rodu Rattus MeSH
• kyselina kainová farmakologie   MeSH
• mozek účinky léků   fyziologie   MeSH
• potkani Wistar MeSH
• receptory serotoninové účinky léků   fyziologie   MeSH
• ritanserin farmakologie   MeSH
• stereotypní chování účinky léků   fyziologie   MeSH
• věkové faktory MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alfa-2-adrenergní receptory MeSH
• clonidin MeSH
• kyselina kainová MeSH
• receptory serotoninové MeSH
• ritanserin MeSH