Ústav experimentální medicíny

Ústav experimentální medicíny Nalezeno 143 záznamů.  předchozí11 - 20dalšíkonec  přejít na záznam: Hledání trvalo 0.02 vteřin. 
WHOLE-GENOME EXPRESSION ANALYSIS IN THP-1 MACROPHAGE-LIKE CELLS EXPOSED TO DIVERSE NANOMATERIALS
Brzicová, Táňa ; Líbalová, Helena ; Vrbová, Kristýna ; Sikorová, Jitka ; Philimonenko, Vlada ; Kléma, J. ; Topinka, Jan ; Rössner ml., Pavel
From the perspective of the immune system, nanomaterials (NMs) represent invading agents. Macrophages are immune cells residing in all organs and tissues as the first line of defense. Interactions of macrophages with NMs can determine the fate of NMs as well as their potential toxic effects. In the present study, we compared toxicity of four different types of NMs [NM-100 (TiO2, 110 nm), NM-110 (ZnO, 20 nm), NM-200 (SiO2, 150 nm) and NM-300K (Ag, 20 nm)], towards THP-1 macrophage-like cells. Cells were incubated with non-cytotoxic concentrations (1-25 mu g/ml) of NMs for 24 hours and microarray technology was used to analyze changes in whole-genome expression. Gene expression profiling revealed a substantially different molecular response following exposure to diverse NMs. While NM-100 did not exert any significant effect on gene expression profile, all other NMs triggered a pro-inflammatory response characterized by an activation of the NF-kappa B transcription factor and induced expression of numerous chemokines and cytokines. NM-110 and NM-300K further modulated processes such as DNA damage response, oxidative and replication stress as well as cell cycle progression and proteasome function. We suppose that genotoxicity of ZnO and Ag NMs leading to DNA damage and alternatively to apoptosis in THP-1 macrophages is probably caused by the extensive intracellular dissolution of these NPs, as confirmed by TEM imaging.
Nanofiber scaffolds for local delivery of stem cells and immunosuppressive drugs for therapeutic purposes
Zajícová, Alena ; Kössl, Jan ; Heřmánková, Barbora ; Boháčová, Pavla ; Holáň, Vladimír
Cell-based therapy of local tissue injuries or damages requires application of stem cells and inhibition of harmful inflammatory reaction which could impede the healing process. To increase the effectiveness of this therapy, a local administration of drugs can avoid their side effects associated with a systemic treatment. A local therapy requires suitable carriers, which can transfer the cells and drugs to the site of injury. As a promising carriers turned out nanofiber scaffolds prepared by electrospinning technology from various types of polymers. The main advantage of this technology is a possibility to define properties of nanofiber scaffolds, optimal for the growth and transfer of stem cells, and which could incorporate various types of immunosuppressive drugs. Here we describe the formation and use of nanofiber scaffolds prepared by needleless electrospinning technology from poly (L-lactic acid) (PLA) which are loaded with immunosuppressive drug Cyclosporine A (CsA). We show that CsA-loaded nanofibers effectively and selectively inhibit proliferation of activated T cells and suppress the production of T cell cytokines in vitro. Simultaneously, these nanofiber scaffolds enable growth of mesenchymal stem cells (MSCs) and thus can serve as stem cell carriers. Moreover, using an experimental mouse model of skin transplantation, we showed that covering skin allografts with MSC-seeded and CsA-loaded nanofibers significantly inhibited the local production of pro-inflammatory cytokines IL-2, IL-17 and IFN-gamma, and supported healing. Thus, nanofiber scaffolds seeded with stem cells and loaded with CsA can serve as carriers of cells and drugs for a local cell therapy and for simultaneous effective immunosuppression.
Effect of iron oxide nanoparticles with ascorbic acid on neural stem cells
Jiráková, Klára ; Moskvin, Maksym ; Horák, Daniel ; Jendelová, Pavla
Cells labelled with iron oxide nanoparticles (ION) can be tracked by magnetic resonance imaging (MRI) in several applications. However, various studies demonstrated toxicity and oxidative stress induction associated with nanoparticles exposure. We analysed biologic effects after the exposure of two types of iron oxide nanoparticles (with and without an antioxidative agent, an ascorbic acid) on human neural stem cells. The labelled cells in gel phantoms were detected in MRI and they showed decreased relaxation rates in comparison with control. ION slightly decreased cell proliferation in comparison with unlabelled cells, which was dependent on concentration and presence of ascorbic acid. None of the nanoparticle type showed negative effect on cell viability and both demonstrated minor effect on reactive oxygen species (ROS) formation. Unfortunately, ascorbic acid bound to nanoparticles did not show any effect on ROS attenuation. Cells exposed to both types of nanoparticles showed increased positivity for a phosphorylated form of H2AX a marker of double strand breaks. We showed that ION in low concentrations do not affect cell viability, but have negative effect on cells on DNA level. Their potential use for oxidative stress reduction is dependent on the concentration of ascorbic acid bound to the nanoparticles and this should be further increased.
Metodika využití nanovlákenných nosičů a kmenových buněk pro léčbu závažných poškození oka
Zajícová, Alena ; Javorková, Eliška ; Holáň, Vladimír
Metodika popisuje nový léčebný postup pro léčbu závažných poškození očního povrchu ve veterinární medicíně. Postup je založen na kultivaci kmenových buněk a na jejich přenosu pomocí nanovlákenných nosičů na poškozený oční povrch. Metoda je využitelná v případech, kde již jiné dostupné formy léčby nejsou úspěšné.
GENE EXPRESSION AND IMMUNOLOGICAL RESPONSE IN MICE EXPOSED TO ZnO NANOPARTICLES
Rössner ml., Pavel ; Vrbová, Kristýna ; Strapáčová, S. ; Rössnerová, Andrea ; Ambrož, Antonín ; Brzicová, Táňa ; Líbalová, Helena ; Javorková, Eliška ; Zajícová, Alena ; Holáň, Vladimír ; Kulich, P. ; Večeřa, Zbyněk ; Mikuška, Pavel ; Coufalík, Pavel ; Křůmal, Kamil ; Čapka, Lukáš ; Dočekal, Bohumil ; Šerý, Omar ; Machala, M. ; Topinka, Jan
We analyzed gene expression changes in the lungs and the immunological response in splenocytes of mice exposed by inhalation of ZnO nanoparticles - NP. Adult female ICR mice were treated for three days and three months, respectively. Analysis of differential expression in genes involved in oxidative stress was conducted using quantitative RT-PCR. The potential immunotoxic and immunomodulatory effects of ZnO NP were analyzed by phenotyping and cytokine production by splenocytes after three months exposure. Three days exposure resulted in down-regulation of GCLC, GSR, HMOX-1, NQO-1, NF-kB2, PTGS2 and TXNRD1 mRNA expression, three months exposure increased the expression of these genes. Three months exposure caused a significant decrease in the percentage of granulocytes in the spleen cells, and affected the production of IL-10 and IL-6 by lipopolysaccharide-stimulated leukocytes. In summary, our study revealed changes in the expression of genes involved in the oxidative stress response following acute ZnO NP exposure. Subchronic ZnO NP exposure induced immunomodulatory effects in the spleen.
L01 DNA damage formation and DNA repair following an intervention of colorectal cell lines with ganoderma lucidum
Vodička, Pavel ; Opattová, Alena ; Čumová, Andrea ; Slíva, D.
Colorectal cancer (CRC) is the third most common malignancy in the world and second most common cause of cancer related deaths in Europe. CRC is complex disease that develops as consequence of environmental and health risk factors with involvement of suboptimal DNA repair, resulting in an accumulation of DNA damage. Reactive oxygen species (ROS) are highly reactive molecules strictly controlled by cellular antioxidant system. Disturbance in the prooxidation–antioxidation homeostasis increases an extent of ROS and consequently an accumulation of DNA damage as well as apoptosis. \nMany natural compounds possess anti-cancer activities tentatively mediated by the generation of ROS. Cancer cells are more sensitive to oxidative DNA damage than non-malignant ones. Modulation of oxidative DNA damage and its repair by natural compounds may lead to selective cancer cell-death and further sensitization of cancer cells to the treatment. Ganoderma Lucidum (GLC) (Reishi, Ling-Zhi), a mushroom used in Chinese medicine for thousands of years, represents an example of a natural compound with empirically recorded anti-cancer as well as anti-proliferative effects. \nThe aim of our study is to define effect of Ganoderma lucidum (GLC) extract on DNA damage and DNA repair system in colorectal cell lines with different genetic backgrounds.\nOur results suggest that GLC extract decreases activity of the cellular antioxidant system which leads to oxidative DNA damage. GLC extract increases genotoxic burden in colorectal cancer cell lines, highlighted by the suppressed base excision repair capacity. These data indicate that specific oxidative DNA damage caused by natural compounds may become a potential tool for the improvement of specific anti-cancer treatment.\n
Vliv přírodních látek na poškození DNA a reparační kapacitu u kolorektálních buněčných linií
Vodenková, Soňa ; Opattová, Alena ; Čumová, Andrea ; Slíva, D. ; Vodička, Pavel
Kolorektální karcinom (CRC) představuje celosvětovou zdravotní zátěž s velmi vysokou incidencí i mortalitou. Problematika CRC se potýká s nedostatkem spolehlivých prediktivních a prognostických biomarkerů, pozdní diagnózou a s poměrně nízkou efektivitou léčby (pouze 50 %). \nCRC je po dlouhá léta konvenčně léčen 5-fluorouracilem (5-FU), který je i v současné době hlavní složkou kombinačních chemoterapeutických režimů. 5-FU, halogenovaný pyrimidin, je buďto přímo inkorporován do DNA nebo způsobuje narušení syntézy thymidinu z uracilu, který je pak chybně inkorporován do DNA. Oprava těchto poškození DNA vyžaduje účast bázově excizní opravy (BER) a systému opravy chybného párování bazí (MMR).\nCílem této studie je sledování účinků 5-FU, GLC a především jejich kombinace na poškození DNA (především oxidační) a na bázově excizní opravu DNA u různých typů buněčných linií kolorektálního karcinomu. \nVýsledky naznačují, že se po přidání jak samotného extraktu z Ganoderma Lucidum, tak jeho kombinace s 5-FU ke kolorektálním liniím, zvyšuje oxidační poškození DNA a nedochází k její reparaci.\nModulace reparační aktivity DNA pomocí přírodních extraktu představuje nový přístup v protinádorové terapii a potenciálně muže pozitivně ovlivňovat rezistenci nádorových buněk k chemoterapeutikům. Použití kombinace GLC a klasické chemoterapie může přispět ke snížení potřebné dávky a následných vedlejších účinků.\n
IL 57 - Sporadic colorectal cancer: From genetic make-up to complex phenotypic measurement, from risk determination to prognostic markers
Vodička, Pavel ; Slyšková, Jana ; Pardini, B. ; Naccarati, A. ; Souček, P. ; Vodičková, Ludmila ; Vymetálková, Veronika ; Svoboda, Miroslav ; Foersti, A. ; Hemminki, K.
Colorectal carcinogenesis (CRC), is a complex process, resulting in both genomic and chromosomal instabilities. The valid theories of carcinogenesis accent either the role of somatic mutation or the surrounding microenvironment, however neither of them explains all features of cancer. Uncontrolled proliferation and genomic instability point to the DNA damage response and repair as to the key players. In the present study, we will overview several biomarkers in mapping heterogeneous complex CRC disease and providing prognostic information.\nVariants in genes involved in important pathways, such as DNA repair, cell cycle control, folate metabolism and methylation, insulin resistance and obesity, ABC transporters, selenoprotein genes, genes involved in inflammatory/immune response have shown various degree of association with CRC risk. We present also the data on mutations in high risk genes involved in colorectal carcinogenesis. Gene expression levels were determined in relevant pathways and complemented with other important parameters (epigenetic regulators of transcription by methylation). Additionally, the role of post-transcriptional regulation via miRNA or lncRNA was investigated in relation to the risk of CRC and the efficacy of chemotherapy. We have discovered several genetic and epigenetic markers affecting independently the prognosis of CRC. Functional DNA repair tests (complex phenotype) have been implemented as markers of individual susceptibility to sporadic CRC and its prognosis.\nAn application of the whole set of various biomarkers is inevitable to define the phenotypic landscape of the disease and to delineate the individual response to the therapy.\n
Natural compounds and their effect on 5-fluorouracil in colorectal cancer cell lines
Čumová, Andrea ; Opattová, Alena ; Vodenková, Soňa ; Horák, Josef ; Slíva, D. ; Vodička, Pavel
Colorectal cancer (CRC) is the second most common type of cancer and the second most common cause of cancer related deaths in Europe. 5-Fluorouracil (5-FU) is widely used in treatment of various cancers including CRC, but apart from the cytotoxic effect on cancer cells may also cause adverse toxic side effects. 5-FU is an anti-metabolite with chemical structure similar to that of the pyrimidine molecules of DNA and RNA. However, response to chemotherapy is often limited by drug resistance. The p53 protein is one of the most widely studied tumour suppressors and mutations in TP53 gene are frequently detected in different types of tumours. \nGanoderma Lucidum (GLC) is a mushroom used in Traditional Eastern Medicine which exhibits anti-cancer and anti-proliferative effects in vitro\nThe aim of our study is to define the role of p53 in the interaction between 5-FU and GLC extract and their simultaneous effect on survival in CRC cell lines.\nOur results suggest that GLC extract significantly increases cytotoxicity and genotoxicity of 5-FU in CRC lines with different p53 status and may potentially modulate the response of p53 knock-out cells which are less sensitive to 5-FU treatment. Interaction of conventional chemotherapeutics with natural compounds introduces a novel aspect in cancer research and therapy.\n\n
Modeling of nucleolar self-assembly
Blažíková, Michaela ; Heřman, P. ; Malínský, Jan
Mammalian cell nucleoli disassemble at the beginning of mitosis and reassemble again during telophase and the early G1. Dynamics of this process was studied using a model based on entropy driven self-assembly of pre-ribosomal particles generated in a single biosynthetic source. Monte Carlo simulations revealed that such model can explain formation of a large aggregate, a nucleolus, in the vicinity of the source. We examined influence of nucleoplasm properties on dynamics of the aggregate formation.

Ústav experimentální medicíny : Nalezeno 143 záznamů.   předchozí11 - 20dalšíkonec  přejít na záznam:
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