|
|
Micronuclei and their connection with intracellular innate immunity and viral infection
Knoblochová, Kateřina ; Bruštíková, Kateřina (advisor) ; Španielová, Hana (referee)
Micronuclei are tiny structures that contain nuclear DNA and a membrane derived from the nucleus. They emerge in cells that have been exposed to severe stress factors, such as viral infections, radiation, or genotoxic substances. While micronuclei have long been used as markers of genotoxic stress, the mechanism of their formation and internal processes are not yet fully understood. DNA enclosed inside micronuclei is restructured in an atypical manner, which may induce mutations and accelerate oncogenic transformation of the cell. Due to these processes micronuclei can also act as reservoirs of immunostimulatory nucleic acids, which may potentially be detected by molecular sensors. Therefore, studying micronuclei is significant in relation to the activation of signaling pathways that are part of the innate intracellular immunity. This work summarizes the current knowledge about micronuclei and their connection to innate intracellular immunity and viral infection. Keywords: micronuclei, innate immunity, molecular sensors, chromotripsis
|
|
|
Males-females differences in the spectrum of chromosomal aberrations in the group of nanocomposites production workers
Rössnerová, Andrea ; Pelcová, D. ; Ždímal, Vladimír ; Elzeinova, Fatima ; Margaryan, Hasmik ; Chvojková, Irena ; Topinka, Jan ; Schwarz, Jaroslav ; Ondráček, Jakub ; Koštejn, Martin ; Komarc, M. ; Vlčková, Š. ; Fenclová, Z. ; Lischková, L. ; Dvořáčková, Š. ; Rössner ml., Pavel
An increase in the use of nanomaterials (NM) has been witnessed in many areas of human life. Therefore, assessment of genotoxicity of NM and nanoparticles (NP) is one of the main objectives of genetic toxicology. Despite this fact, human cytogenetic studies following the exposure to NP are still rare. Moreover, no relevant information on possible differences in sensitivity to NP related to gender is available.\n\nIn this study we periodically (in September 2016, 2017 and 2018; pre-shift and post-shift each year) analyzed a group of workers (both genders), working long time in nanocomposites research, and matched controls. Aerosol exposure monitoring of particulate matter including nano-sized fractions was carried out during working shift. Micronucleus assay using Human Pan Centromeric probes, was applied to distinguish, besides the frequency of total MN in binucleated cells (BNC), also other types of chromosomal damage (losses and breaks). Moreover, whole-chromosome painting (WCP) for autosome #1 and both gonosomes (X and Y) were applied in third sampling period (2018) with the aim to identify the particular structural and numerical chromosomal aberrations.\n\nObtained results showed: (i) differences in the risk of exposure to NP related to individual working processes (welding, smelting and machining); (ii) differences in chemical composition of nano-fraction; (iii) no effect of chronic exposure of NP (total MN) opposite to significant effect of acute exposure; (iv) gender-related DNA damage differences (females seem to be more sensitive to chromosomal losses). Additional data from WCP suggested increased frequency of numerical aberrations in gonosomes.
Plný tet:  PDF
|
|
|
Role of chromosomal aberrations to evaluate genetic risk of exposure to carcinogens.
Rössnerová, Andrea ; Šrám, Radim (advisor) ; Rubeš, Jiří (referee) ; Kuglík, Petr (referee)
(in English) Air pollution is a serious worldwide problem associated with the risk of cancer. The negative effect of carcinogenic polycyclic aromatic hydrocarbons (c-PAHs), including benzo[a]pyrene (B[a]P), on human health is analyzed using specific biomarkers. Among them biomarkers of early effect play an important role. This work summarizes the results of cytogenetic analyses performed by fluorescence in situ hybridization (FISH) (whole chromosome painting of chromosomes #1 and #4) and automated image analysis of micronuclei (MN). During the analyses a total set of 1304 samples was analyzed by the FISH method and 885 samples by the automated image analysis of MN. Studied groups including city policemen, garage men, bus drivers, administrative workers, mothers, newborns, healthy children and children with bronchial asthma and laboratory workers were from Prague, Ostrava and Ceske Budejovice. The locations significantly differed in levels of air pollutants and the type of air pollution. The exposure of participants of the study was assessed by personal and stationary monitoring. The impact of other factors including age, smoking or intake of vitamins was also evaluated in these studies. The results obtained by the FISH method in Prague showed the impact of seasonal variability of concentrations of...
|
|
|
Programmed DNA elimination in animals
Janáková, Šárka ; Reifová, Radka (advisor) ; Choleva, Lukáš (referee)
Programmed DNA elimination (PDE) is a process in which a part of genetic information is eliminated from the organisms genome. It can be found be found in both plants and animals. There is a difference in the genetic inormation eliminated depending on the species. There are some organisms that eliminate only parts of their chromosomes, others that eliminate whole chromosomes and in hybrid organisms one whole parental genome is eliminated. In somatic cells PDE usually takes place during early embryogenesis. If the genome being eliminated comes from the germline cells, PDE takes place during gametogenesis. The function and mechanisms of PDE differs inbetween the species. It is most often connected with soma and germ cell differentiation, sex determination in animals and haploid gamete production in hybrid species. Mechanisms frequently include epigenetic modifications of DNA destined for elimination or production of micronuclei (MN) with the eliminated DNA inside. This work summarizes these functions and mechanisms and provides examples. Key words: programmed DNA elimination, chromatin diminution, chromosomal elimination, hybridogenesis, micronuclei, epigenetic modifications, Germ1, GRC
|
|
|
Role of chromosomal aberrations to evaluate genetic risk of exposure to carcinogens.
Rössnerová, Andrea ; Šrám, Radim (advisor) ; Rubeš, Jiří (referee) ; Kuglík, Petr (referee)
(in English) Air pollution is a serious worldwide problem associated with the risk of cancer. The negative effect of carcinogenic polycyclic aromatic hydrocarbons (c-PAHs), including benzo[a]pyrene (B[a]P), on human health is analyzed using specific biomarkers. Among them biomarkers of early effect play an important role. This work summarizes the results of cytogenetic analyses performed by fluorescence in situ hybridization (FISH) (whole chromosome painting of chromosomes #1 and #4) and automated image analysis of micronuclei (MN). During the analyses a total set of 1304 samples was analyzed by the FISH method and 885 samples by the automated image analysis of MN. Studied groups including city policemen, garage men, bus drivers, administrative workers, mothers, newborns, healthy children and children with bronchial asthma and laboratory workers were from Prague, Ostrava and Ceske Budejovice. The locations significantly differed in levels of air pollutants and the type of air pollution. The exposure of participants of the study was assessed by personal and stationary monitoring. The impact of other factors including age, smoking or intake of vitamins was also evaluated in these studies. The results obtained by the FISH method in Prague showed the impact of seasonal variability of concentrations of...
|
guest ::
